Merge branch 'master' into docking

# Conflicts:
#	imgui.cpp

.github/workflows/build.yml

@@ -24,16 +24,22 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      # The VulkanSDK libs for Windows is manually generated using build_windows_vulkan_libs.ps1 + attached to issue #8925.
+      # (we have a .yml workflow in commit history if it becomes ever useful to create this on CI too)
       - name: Install Dependencies
         shell: powershell
         run: |
-          Invoke-WebRequest -Uri "https://www.libsdl.org/release/SDL2-devel-2.26.3-VC.zip" -OutFile "SDL2-devel-2.26.3-VC.zip"
-          Expand-Archive -Path SDL2-devel-2.26.3-VC.zip
-          echo "SDL2_DIR=$(pwd)\SDL2-devel-2.26.3-VC\SDL2-2.26.3\" >>${env:GITHUB_ENV}
+          Invoke-WebRequest -Uri "https://www.libsdl.org/release/SDL2-devel-2.32.8-VC.zip" -OutFile "SDL2-devel-2.32.8-VC.zip"
+          Expand-Archive -Path SDL2-devel-2.32.8-VC.zip
+          echo "SDL2_DIR=$(pwd)\SDL2-devel-2.32.8-VC\SDL2-2.32.8\" >>${env:GITHUB_ENV}
 
-          Invoke-WebRequest -Uri "https://github.com/ocornut/imgui/files/3789205/vulkan-sdk-1.1.121.2.zip" -OutFile vulkan-sdk-1.1.121.2.zip
-          Expand-Archive -Path vulkan-sdk-1.1.121.2.zip
-          echo "VULKAN_SDK=$(pwd)\vulkan-sdk-1.1.121.2\" >>${env:GITHUB_ENV}
+          Invoke-WebRequest -Uri "https://www.libsdl.org/release/SDL3-devel-3.2.18-VC.zip" -OutFile "SDL3-devel-3.2.18-VC.zip"
+          Expand-Archive -Path SDL3-devel-3.2.18-VC.zip
+          echo "SDL3_DIR=$(pwd)\SDL3-devel-3.2.18-VC\SDL3-3.2.18\" >>${env:GITHUB_ENV}
+
+          Invoke-WebRequest -Uri "https://github.com/user-attachments/files/22464296/vulkan_windows_libs_1.4.326.zip" -OutFile vulkan_windows_libs_1.4.326.zip
+          Expand-Archive -Path vulkan_windows_libs_1.4.326.zip
+          echo "VULKAN_SDK=$(pwd)\vulkan_windows_libs_1.4.326\" >>${env:GITHUB_ENV}
 
       - name: Fix Projects
         shell: powershell
@@ -102,9 +108,12 @@ jobs:
           cl.exe /D_USRDLL /D_WINDLL /I. example_single_file.cpp /LD /FeImGui.dll /link
           cl.exe /DIMGUI_API=__declspec(dllimport) /I. ImGui.lib /Feexample_null.exe examples/example_null/main.cpp
 
+      # Win64 examples are more frequently compilted than the Win32 examples.
+      # More of the Win32 examples requires 'workflow_run' to reduce waste.
       - name: Build Win32 example_glfw_opengl2
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_opengl2/example_glfw_opengl2.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+        if: github.event_name == 'workflow_run'
 
       - name: Build Win32 example_glfw_opengl3
         shell: cmd
@@ -140,72 +149,111 @@ jobs:
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl2_directx11/example_sdl2_directx11.vcxproj /p:Platform=Win32 /p:Configuration=Release'
         if: github.event_name == 'workflow_run'
 
+      - name: Build Win32 example_sdl3_opengl3
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl3_opengl3/example_sdl3_opengl3.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+
+      - name: Build Win32 example_sdl3_sdlgpu3
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl3_sdlgpu3/example_sdl3_sdlgpu3.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+        if: github.event_name == 'workflow_run'
+
+      - name: Build Win32 example_sdl3_sdlrenderer3
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl3_sdlrenderer3/example_sdl3_sdlrenderer3.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+        if: github.event_name == 'workflow_run'
+
+      - name: Build Win32 example_sdl3_vulkan
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl3_vulkan/example_sdl3_vulkan.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+        if: github.event_name == 'workflow_run'
+
       - name: Build Win32 example_win32_directx9
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx9/example_win32_directx9.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+        if: github.event_name == 'workflow_run'
 
       - name: Build Win32 example_win32_directx10
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx10/example_win32_directx10.vcxproj /p:Platform=Win32 /p:Configuration=Release'
+        if: github.event_name == 'workflow_run'
 
       - name: Build Win32 example_win32_directx11
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx11/example_win32_directx11.vcxproj /p:Platform=Win32 /p:Configuration=Release'
         if: github.event_name == 'workflow_run'
 
-      - name: Build x64 example_glfw_opengl2
+      # Windows 64-bits
+      - name: Build Win64 example_glfw_opengl2
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_opengl2/example_glfw_opengl2.vcxproj /p:Platform=x64 /p:Configuration=Release'
         if: github.event_name == 'workflow_run'
 
-      - name: Build x64 example_glfw_opengl3
+      - name: Build Win64 example_glfw_opengl3
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_opengl3/example_glfw_opengl3.vcxproj /p:Platform=x64 /p:Configuration=Release'
 
-      - name: Build x64 example_glfw_vulkan
+      - name: Build Win64 example_glfw_vulkan
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_vulkan/example_glfw_vulkan.vcxproj /p:Platform=x64 /p:Configuration=Release'
 
-      - name: Build x64 example_sdl2_sdlrenderer2
+      - name: Build Win64 example_sdl2_sdlrenderer2
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl2_sdlrenderer2/example_sdl2_sdlrenderer2.vcxproj /p:Platform=x64 /p:Configuration=Release'
         if: github.event_name == 'workflow_run'
 
-      - name: Build x64 example_sdl2_vulkan
+      - name: Build Win64 example_sdl2_vulkan
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl2_vulkan/example_sdl2_vulkan.vcxproj /p:Platform=x64 /p:Configuration=Release'
         if: github.event_name == 'workflow_run'
 
-      - name: Build x64 example_sdl2_opengl2
+      - name: Build Win64 example_sdl2_opengl2
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl2_opengl2/example_sdl2_opengl2.vcxproj /p:Platform=x64 /p:Configuration=Release'
         if: github.event_name == 'workflow_run'
 
-      - name: Build x64 example_sdl2_opengl3
+      - name: Build Win64 example_sdl2_opengl3
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl2_opengl3/example_sdl2_opengl3.vcxproj /p:Platform=x64 /p:Configuration=Release'
         if: github.event_name == 'workflow_run'
 
-      - name: Build x64 example_sdl2_directx11
+      - name: Build Win64 example_sdl2_directx11
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl2_directx11/example_sdl2_directx11.vcxproj /p:Platform=x64 /p:Configuration=Release'
 
-      - name: Build x64 example_win32_directx9
+      - name: Build Win64 example_sdl3_opengl3
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl3_opengl3/example_sdl3_opengl3.vcxproj /p:Platform=x64 /p:Configuration=Release'
+        if: github.event_name == 'workflow_run'
+
+      - name: Build Win64 example_sdl3_sdlgpu3
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl3_sdlgpu3/example_sdl3_sdlgpu3.vcxproj /p:Platform=x64 /p:Configuration=Release'
+
+      - name: Build Win64 example_sdl3_sdlrenderer3
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl3_sdlrenderer3/example_sdl3_sdlrenderer3.vcxproj /p:Platform=x64 /p:Configuration=Release'
+
+      - name: Build Win64 example_sdl3_vulkan
+        shell: cmd
+        run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl3_vulkan/example_sdl3_vulkan.vcxproj /p:Platform=x64 /p:Configuration=Release'
+        if: github.event_name == 'workflow_run'
+
+      - name: Build Win64 example_win32_directx9
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx9/example_win32_directx9.vcxproj /p:Platform=x64 /p:Configuration=Release'
         if: github.event_name == 'workflow_run'
 
-      - name: Build x64 example_win32_directx10
+      - name: Build Win64 example_win32_directx10
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx10/example_win32_directx10.vcxproj /p:Platform=x64 /p:Configuration=Release'
         if: github.event_name == 'workflow_run'
 
-      - name: Build x64 example_win32_directx11
+      - name: Build Win64 example_win32_directx11
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx11/example_win32_directx11.vcxproj /p:Platform=x64 /p:Configuration=Release'
-        if: github.event_name == 'workflow_run'
 
-      - name: Build x64 example_win32_directx12
+      - name: Build Win64 example_win32_directx12
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx12/example_win32_directx12.vcxproj /p:Platform=x64 /p:Configuration=Release'
 
@@ -433,7 +481,7 @@ jobs:
 
     - name: Install Dependencies
       run: |
-        brew install glfw3 sdl2
+        brew install glfw3 sdl2 sdl3
 
     - name: Build example_null (extra warnings, clang 64-bit)
       run: make -C examples/example_null WITH_EXTRA_WARNINGS=1
@@ -491,6 +539,9 @@ jobs:
     - name: Build example_sdl2_opengl3
       run: make -C examples/example_sdl2_opengl3
 
+    - name: Build example_sdl3_opengl3
+      run: make -C examples/example_sdl3_opengl3
+
     - name: Build example_apple_metal
       run: xcodebuild -project examples/example_apple_metal/example_apple_metal.xcodeproj -target example_apple_metal_macos
 
@@ -498,7 +549,7 @@ jobs:
       run: xcodebuild -project examples/example_apple_opengl2/example_apple_opengl2.xcodeproj -target example_osx_opengl2
 
   iOS:
-    runs-on: macos-latest
+    runs-on: macos-14
     steps:
     - uses: actions/checkout@v4
 

.github/workflows/build_windows_vulkan_libs.ps1

@@ -0,0 +1,38 @@
+# This is current meant to be run manually, occasionally:
+# - Run then zip the contents of vulkanArtifact/ into e.g. vulkan_windows_libs_1.4.326
+# - Upload as an attachment to https://github.com/ocornut/imgui/pull/8925 then change filename in build.yml
+# - There is a build_windows_vulkan_libs.yml in commit history that we removed thinking this is run so rarely we don't need to pollute CI UI with it.
+
+# Set default vulkan version if none provided
+if (-not $env:VULKAN_TAG) { $env:VULKAN_TAG = "1.4.326" }
+
+# Create output folder
+mkdir vulkanArtifact
+
+# Download Vulkan Headers
+
+Invoke-WebRequest -Uri "https://github.com/KhronosGroup/Vulkan-Headers/archive/refs/tags/v$($env:VULKAN_TAG).zip" -OutFile Vulkan-Headers-$($env:VULKAN_TAG).zip
+Expand-Archive -Path Vulkan-Headers-$($env:VULKAN_TAG).zip
+
+# Copy Vulkan Headers to artifact folder
+
+cp -R Vulkan-Headers-$($env:VULKAN_TAG)\Vulkan-Headers-$($env:VULKAN_TAG)\include vulkanArtifact\Include
+
+# Download Vulkan Loader
+
+Invoke-WebRequest -Uri "https://github.com/KhronosGroup/Vulkan-Loader/archive/refs/tags/v$($env:VULKAN_TAG).zip" -OutFile Vulkan-Loader-$($env:VULKAN_TAG).zip
+Expand-Archive -Path Vulkan-Loader-$($env:VULKAN_TAG).zip
+
+# Build Vulkan Loader x64
+
+cmake -S Vulkan-Loader-$($env:VULKAN_TAG)\Vulkan-Loader-$($env:VULKAN_TAG) -B VulkanLoader-build64 -D UPDATE_DEPS=On -A x64
+cmake --build VulkanLoader-build64
+mkdir vulkanArtifact\Lib
+copy VulkanLoader-build64\loader\Debug\vulkan-1.lib vulkanArtifact\Lib
+
+# Build Vulkan Loader win32
+
+cmake -S Vulkan-Loader-$($env:VULKAN_TAG)\Vulkan-Loader-$($env:VULKAN_TAG) -B VulkanLoader-build32 -D UPDATE_DEPS=On -A Win32
+cmake --build VulkanLoader-build32
+mkdir vulkanArtifact\Lib32
+copy VulkanLoader-build32\loader\Debug\vulkan-1.lib vulkanArtifact\Lib32

.gitignore

@@ -68,6 +68,7 @@ examples/example_sdl2_opengl2/example_sdl2_opengl2
 examples/example_sdl2_opengl3/example_sdl2_opengl3
 examples/example_sdl2_sdlrenderer2/example_sdl2_sdlrenderer2
 examples/example_sdl2_vulkan/example_sdl2_vulkan
+examples/example_sdl3_metal/example_sdl3_metal
 examples/example_sdl3_opengl3/example_sdl3_opengl3
 examples/example_sdl3_sdlgpu3/example_sdl3_sdlgpu3
 examples/example_sdl3_sdlrenderer3/example_sdl3_sdlrenderer3

backends/imgui_impl_allegro5.cpp

@@ -8,8 +8,9 @@
 //  [X] Platform: Clipboard support (from Allegro 5.1.12).
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 // Missing features or Issues:
-//  [ ] Renderer: The renderer is suboptimal as we need to convert vertices manually.
+//  [ ] Renderer: The renderer is suboptimal as we need to unindex our buffers and convert vertices manually.
 //  [ ] Platform: Missing gamepad support.
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -21,6 +22,9 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-09-18: Call platform_io.ClearRendererHandlers() and platform_io.ClearPlatformHandlers() on shutdown.
+//  2025-08-12: Inputs: fixed missing support for ImGuiKey_PrintScreen under Windows, as raw Allegro 5 does not receive it.
+//  2025-08-12: Added ImGui_ImplAllegro5_SetDisplay() function to change current ALLEGRO_DISPLAY, as Allegro applications often need to do that.
 //  2025-07-07: Fixed texture update broken on some platforms where ALLEGRO_LOCK_WRITEONLY needed all texels to be rewritten.
 //  2025-06-11: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. Removed ImGui_ImplSDLGPU3_CreateFontsTexture() and ImGui_ImplSDLGPU3_DestroyFontsTexture().
 //  2025-02-18: Added ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress mouse cursor support.
@@ -160,10 +164,8 @@ void ImGui_ImplAllegro5_RenderDrawData(ImDrawData* draw_data)
     ImGui_ImplAllegro5_SetupRenderState(draw_data);
 
     // Render command lists
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
-
         ImVector<ImDrawVertAllegro>& vertices = bd->BufVertices;
 #if ALLEGRO_HAS_DRAW_INDEXED_PRIM
         vertices.resize(draw_list->VtxBuffer.Size);
@@ -269,8 +271,6 @@ void ImGui_ImplAllegro5_UpdateTexture(ImTextureData* tex)
         al_set_new_bitmap_flags(ALLEGRO_MEMORY_BITMAP | ALLEGRO_MIN_LINEAR | ALLEGRO_MAG_LINEAR);
         al_set_new_bitmap_format(ALLEGRO_PIXEL_FORMAT_ABGR_8888_LE);
         ALLEGRO_BITMAP* cpu_bitmap = al_create_bitmap(tex->Width, tex->Height);
-        al_set_new_bitmap_flags(new_bitmap_flags);
-        al_set_new_bitmap_format(new_bitmap_format);
         IM_ASSERT(cpu_bitmap != nullptr && "Backend failed to create texture!");
 
         // Upload pixels
@@ -280,10 +280,15 @@ void ImGui_ImplAllegro5_UpdateTexture(ImTextureData* tex)
         al_unlock_bitmap(cpu_bitmap);
 
         // Convert software texture to hardware texture.
+        al_set_new_bitmap_flags(ALLEGRO_VIDEO_BITMAP);
+        al_set_new_bitmap_format(ALLEGRO_PIXEL_FORMAT_ANY_32_WITH_ALPHA);
         ALLEGRO_BITMAP* gpu_bitmap = al_clone_bitmap(cpu_bitmap);
         al_destroy_bitmap(cpu_bitmap);
         IM_ASSERT(gpu_bitmap != nullptr && "Backend failed to create texture!");
 
+        al_set_new_bitmap_flags(new_bitmap_flags);
+        al_set_new_bitmap_format(new_bitmap_format);
+
         // Store identifiers
         tex->SetTexID((ImTextureID)(intptr_t)gpu_bitmap);
         tex->SetStatus(ImTextureStatus_OK);
@@ -478,20 +483,9 @@ bool ImGui_ImplAllegro5_Init(ALLEGRO_DISPLAY* display)
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;       // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;   // We can honor ImGuiPlatformIO::Textures[] requests during render.
 
-    bd->Display = display;
     bd->LastCursor = ALLEGRO_SYSTEM_MOUSE_CURSOR_NONE;
 
-    // Create custom vertex declaration.
-    // Unfortunately Allegro doesn't support 32-bit packed colors so we have to convert them to 4 floats.
-    // We still use a custom declaration to use 'ALLEGRO_PRIM_TEX_COORD' instead of 'ALLEGRO_PRIM_TEX_COORD_PIXEL' else we can't do a reliable conversion.
-    ALLEGRO_VERTEX_ELEMENT elems[] =
-    {
-        { ALLEGRO_PRIM_POSITION, ALLEGRO_PRIM_FLOAT_2, offsetof(ImDrawVertAllegro, pos) },
-        { ALLEGRO_PRIM_TEX_COORD, ALLEGRO_PRIM_FLOAT_2, offsetof(ImDrawVertAllegro, uv) },
-        { ALLEGRO_PRIM_COLOR_ATTR, 0, offsetof(ImDrawVertAllegro, col) },
-        { 0, 0, 0 }
-    };
-    bd->VertexDecl = al_create_vertex_decl(elems, sizeof(ImDrawVertAllegro));
+    ImGui_ImplAllegro5_SetDisplay(display);
 
 #if ALLEGRO_HAS_CLIPBOARD
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
@@ -507,6 +501,7 @@ void ImGui_ImplAllegro5_Shutdown()
     ImGui_ImplAllegro5_Data* bd = ImGui_ImplAllegro5_GetBackendData();
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
     ImGui_ImplAllegro5_InvalidateDeviceObjects();
     if (bd->VertexDecl)
@@ -517,9 +512,38 @@ void ImGui_ImplAllegro5_Shutdown()
     io.BackendPlatformName = io.BackendRendererName = nullptr;
     io.BackendPlatformUserData = nullptr;
     io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_RendererHasTextures);
+    platform_io.ClearRendererHandlers();
+    platform_io.ClearPlatformHandlers();
     IM_DELETE(bd);
 }
 
+void ImGui_ImplAllegro5_SetDisplay(ALLEGRO_DISPLAY* display)
+{
+    ImGui_ImplAllegro5_Data* bd = ImGui_ImplAllegro5_GetBackendData();
+    bd->Display = display;
+
+    if (bd->VertexDecl)
+    {
+        al_destroy_vertex_decl(bd->VertexDecl);
+        bd->VertexDecl = NULL;
+    }
+
+    if (bd->Display && !bd->VertexDecl)
+    {
+        // Create custom vertex declaration.
+        // Unfortunately Allegro doesn't support 32-bits packed colors so we have to convert them to 4 floats.
+        // We still use a custom declaration to use 'ALLEGRO_PRIM_TEX_COORD' instead of 'ALLEGRO_PRIM_TEX_COORD_PIXEL' else we can't do a reliable conversion.
+        ALLEGRO_VERTEX_ELEMENT elems[] =
+        {
+            { ALLEGRO_PRIM_POSITION, ALLEGRO_PRIM_FLOAT_2, offsetof(ImDrawVertAllegro, pos) },
+            { ALLEGRO_PRIM_TEX_COORD, ALLEGRO_PRIM_FLOAT_2, offsetof(ImDrawVertAllegro, uv) },
+            { ALLEGRO_PRIM_COLOR_ATTR, 0, offsetof(ImDrawVertAllegro, col) },
+            { 0, 0, 0 }
+        };
+        bd->VertexDecl = al_create_vertex_decl(elems, sizeof(ImDrawVertAllegro));
+    }
+}
+
 // ev->keyboard.modifiers seems always zero so using that...
 static void ImGui_ImplAllegro5_UpdateKeyModifiers()
 {
@@ -661,6 +685,11 @@ void ImGui_ImplAllegro5_NewFrame()
     io.DeltaTime = bd->Time > 0.0 ? (float)(current_time - bd->Time) : (float)(1.0f / 60.0f);
     bd->Time = current_time;
 
+    // Allegro 5 doesn't receive PrintScreen under Windows
+#ifdef _WIN32
+    io.AddKeyEvent(ImGuiKey_PrintScreen, (::GetAsyncKeyState(VK_SNAPSHOT) & 0x8000) != 0);
+#endif
+
     // Setup mouse cursor shape
     ImGui_ImplAllegro5_UpdateMouseCursor();
 }

backends/imgui_impl_allegro5.h

@@ -10,6 +10,7 @@
 // Missing features or Issues:
 //  [ ] Renderer: The renderer is suboptimal as we need to unindex our buffers and convert vertices manually.
 //  [ ] Platform: Missing gamepad support.
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -32,6 +33,7 @@ IMGUI_IMPL_API void     ImGui_ImplAllegro5_Shutdown();
 IMGUI_IMPL_API void     ImGui_ImplAllegro5_NewFrame();
 IMGUI_IMPL_API void     ImGui_ImplAllegro5_RenderDrawData(ImDrawData* draw_data);
 IMGUI_IMPL_API bool     ImGui_ImplAllegro5_ProcessEvent(ALLEGRO_EVENT* event);
+IMGUI_IMPL_API void     ImGui_ImplAllegro5_SetDisplay(ALLEGRO_DISPLAY* display);
 
 // Use if you want to reset your rendering device without losing Dear ImGui state.
 IMGUI_IMPL_API bool     ImGui_ImplAllegro5_CreateDeviceObjects();

backends/imgui_impl_android.cpp

@@ -8,6 +8,7 @@
 //  [ ] Platform: Clipboard support.
 //  [ ] Platform: Gamepad support.
 //  [ ] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'. FIXME: Check if this is even possible with Android.
+//  [ ] Platform: Multi-viewport support (multiple windows). Not meaningful on Android.
 // Important:
 //  - Consider using SDL or GLFW backend on Android, which will be more full-featured than this.
 //  - FIXME: On-screen keyboard currently needs to be enabled by the application (see examples/ and issue #3446)

backends/imgui_impl_android.h

@@ -8,6 +8,7 @@
 //  [ ] Platform: Clipboard support.
 //  [ ] Platform: Gamepad support.
 //  [ ] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'. FIXME: Check if this is even possible with Android.
+//  [ ] Platform: Multi-viewport support (multiple windows). Not meaningful on Android.
 // Important:
 //  - Consider using SDL or GLFW backend on Android, which will be more full-featured than this.
 //  - FIXME: On-screen keyboard currently needs to be enabled by the application (see examples/ and issue #3446)

backends/imgui_impl_dx10.cpp

@@ -5,6 +5,7 @@
 //  [X] Renderer: User texture binding. Use 'ID3D10ShaderResourceView*' as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -16,6 +17,8 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
 //  2025-06-11: DirectX10: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas.
 //  2025-05-07: DirectX10: Honor draw_data->FramebufferScale to allow for custom backends and experiment using it (consistently with other renderer backends, even though in normal condition it is not set under Windows).
 //  2025-01-06: DirectX10: Expose selected render state in ImGui_ImplDX10_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
@@ -73,7 +76,7 @@ struct ImGui_ImplDX10_Data
     ID3D10InputLayout*          pInputLayout;
     ID3D10Buffer*               pVertexConstantBuffer;
     ID3D10PixelShader*          pPixelShader;
-    ID3D10SamplerState*         pFontSampler;
+    ID3D10SamplerState*         pTexSamplerLinear;
     ID3D10RasterizerState*      pRasterizerState;
     ID3D10BlendState*           pBlendState;
     ID3D10DepthStencilState*    pDepthStencilState;
@@ -95,6 +98,10 @@ static ImGui_ImplDX10_Data* ImGui_ImplDX10_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX10_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX10_InitMultiViewportSupport();
+static void ImGui_ImplDX10_ShutdownMultiViewportSupport();
+
 // Functions
 static void ImGui_ImplDX10_SetupRenderState(ImDrawData* draw_data, ID3D10Device* device)
 {
@@ -140,7 +147,7 @@ static void ImGui_ImplDX10_SetupRenderState(ImDrawData* draw_data, ID3D10Device*
     device->VSSetShader(bd->pVertexShader);
     device->VSSetConstantBuffers(0, 1, &bd->pVertexConstantBuffer);
     device->PSSetShader(bd->pPixelShader);
-    device->PSSetSamplers(0, 1, &bd->pFontSampler);
+    device->PSSetSamplers(0, 1, &bd->pTexSamplerLinear);
     device->GSSetShader(nullptr);
 
     // Setup render state
@@ -200,9 +207,8 @@ void ImGui_ImplDX10_RenderDrawData(ImDrawData* draw_data)
     ImDrawIdx* idx_dst = nullptr;
     bd->pVB->Map(D3D10_MAP_WRITE_DISCARD, 0, (void**)&vtx_dst);
     bd->pIB->Map(D3D10_MAP_WRITE_DISCARD, 0, (void**)&idx_dst);
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         memcpy(vtx_dst, draw_list->VtxBuffer.Data, draw_list->VtxBuffer.Size * sizeof(ImDrawVert));
         memcpy(idx_dst, draw_list->IdxBuffer.Data, draw_list->IdxBuffer.Size * sizeof(ImDrawIdx));
         vtx_dst += draw_list->VtxBuffer.Size;
@@ -258,7 +264,7 @@ void ImGui_ImplDX10_RenderDrawData(ImDrawData* draw_data)
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     ImGui_ImplDX10_RenderState render_state;
     render_state.Device = bd->pd3dDevice;
-    render_state.SamplerDefault = bd->pFontSampler;
+    render_state.SamplerDefault = bd->pTexSamplerLinear;
     render_state.VertexConstantBuffer = bd->pVertexConstantBuffer;
     platform_io.Renderer_RenderState = &render_state;
 
@@ -268,9 +274,8 @@ void ImGui_ImplDX10_RenderDrawData(ImDrawData* draw_data)
     int global_idx_offset = 0;
     ImVec2 clip_off = draw_data->DisplayPos;
     ImVec2 clip_scale = draw_data->FramebufferScale;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         for (int cmd_i = 0; cmd_i < draw_list->CmdBuffer.Size; cmd_i++)
         {
             const ImDrawCmd* pcmd = &draw_list->CmdBuffer[cmd_i];
@@ -326,18 +331,18 @@ void ImGui_ImplDX10_RenderDrawData(ImDrawData* draw_data)
 
 static void ImGui_ImplDX10_DestroyTexture(ImTextureData* tex)
 {
-    ImGui_ImplDX10_Texture* backend_tex = (ImGui_ImplDX10_Texture*)tex->BackendUserData;
-    if (backend_tex == nullptr)
-        return;
-    IM_ASSERT(backend_tex->pTextureView == (ID3D10ShaderResourceView*)(intptr_t)tex->TexID);
-    backend_tex->pTexture->Release();
-    backend_tex->pTextureView->Release();
-    IM_DELETE(backend_tex);
+    if (ImGui_ImplDX10_Texture* backend_tex = (ImGui_ImplDX10_Texture*)tex->BackendUserData)
+    {
+        IM_ASSERT(backend_tex->pTextureView == (ID3D10ShaderResourceView*)(intptr_t)tex->TexID);
+        backend_tex->pTextureView->Release();
+        backend_tex->pTexture->Release();
+        IM_DELETE(backend_tex);
 
-    // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
-    tex->SetTexID(ImTextureID_Invalid);
+        // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
+        tex->SetTexID(ImTextureID_Invalid);
+        tex->BackendUserData = nullptr;
+    }
     tex->SetStatus(ImTextureStatus_Destroyed);
-    tex->BackendUserData = nullptr;
 }
 
 void ImGui_ImplDX10_UpdateTexture(ImTextureData* tex)
@@ -565,7 +570,7 @@ bool    ImGui_ImplDX10_CreateDeviceObjects()
         desc.ComparisonFunc = D3D10_COMPARISON_ALWAYS;
         desc.MinLOD = 0.f;
         desc.MaxLOD = 0.f;
-        bd->pd3dDevice->CreateSamplerState(&desc, &bd->pFontSampler);
+        bd->pd3dDevice->CreateSamplerState(&desc, &bd->pTexSamplerLinear);
     }
 
     return true;
@@ -581,7 +586,7 @@ void    ImGui_ImplDX10_InvalidateDeviceObjects()
     for (ImTextureData* tex : ImGui::GetPlatformIO().Textures)
         if (tex->RefCount == 1)
             ImGui_ImplDX10_DestroyTexture(tex);
-    if (bd->pFontSampler)           { bd->pFontSampler->Release(); bd->pFontSampler = nullptr; }
+    if (bd->pTexSamplerLinear)      { bd->pTexSamplerLinear->Release(); bd->pTexSamplerLinear = nullptr; }
     if (bd->pIB)                    { bd->pIB->Release(); bd->pIB = nullptr; }
     if (bd->pVB)                    { bd->pVB->Release(); bd->pVB = nullptr; }
     if (bd->pBlendState)            { bd->pBlendState->Release(); bd->pBlendState = nullptr; }
@@ -605,6 +610,7 @@ bool    ImGui_ImplDX10_Init(ID3D10Device* device)
     io.BackendRendererName = "imgui_impl_dx10";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
     io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;   // We can honor ImGuiPlatformIO::Textures[] requests during render.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     platform_io.Renderer_TextureMaxWidth = platform_io.Renderer_TextureMaxHeight = D3D10_REQ_TEXTURE2D_U_OR_V_DIMENSION;
@@ -624,6 +630,8 @@ bool    ImGui_ImplDX10_Init(ID3D10Device* device)
     if (pDXGIAdapter) pDXGIAdapter->Release();
     bd->pd3dDevice->AddRef();
 
+    ImGui_ImplDX10_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -632,13 +640,17 @@ void ImGui_ImplDX10_Shutdown()
     ImGui_ImplDX10_Data* bd = ImGui_ImplDX10_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
+    ImGui_ImplDX10_ShutdownMultiViewportSupport();
     ImGui_ImplDX10_InvalidateDeviceObjects();
     if (bd->pFactory) { bd->pFactory->Release(); }
     if (bd->pd3dDevice) { bd->pd3dDevice->Release(); }
+
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
 }
 
@@ -652,6 +664,131 @@ void ImGui_ImplDX10_NewFrame()
             IM_ASSERT(0 && "ImGui_ImplDX10_CreateDeviceObjects() failed!");
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplDX10_ViewportData
+{
+    IDXGISwapChain*         SwapChain;
+    ID3D10RenderTargetView* RTView;
+
+    ImGui_ImplDX10_ViewportData()   { SwapChain = nullptr; RTView = nullptr; }
+    ~ImGui_ImplDX10_ViewportData()  { IM_ASSERT(SwapChain == nullptr && RTView == nullptr); }
+};
+
+static void ImGui_ImplDX10_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplDX10_Data* bd = ImGui_ImplDX10_GetBackendData();
+    ImGui_ImplDX10_ViewportData* vd = IM_NEW(ImGui_ImplDX10_ViewportData)();
+    viewport->RendererUserData = vd;
+
+    // PlatformHandleRaw should always be a HWND, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL's WindowID).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+
+    // Create swap chain
+    DXGI_SWAP_CHAIN_DESC sd;
+    ZeroMemory(&sd, sizeof(sd));
+    sd.BufferDesc.Width = (UINT)viewport->Size.x;
+    sd.BufferDesc.Height = (UINT)viewport->Size.y;
+    sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
+    sd.SampleDesc.Count = 1;
+    sd.SampleDesc.Quality = 0;
+    sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
+    sd.BufferCount = 1;
+    sd.OutputWindow = hwnd;
+    sd.Windowed = TRUE;
+    sd.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
+    sd.Flags = 0;
+
+    IM_ASSERT(vd->SwapChain == nullptr && vd->RTView == nullptr);
+    bd->pFactory->CreateSwapChain(bd->pd3dDevice, &sd, &vd->SwapChain);
+    bd->pFactory->MakeWindowAssociation(hwnd, DXGI_MWA_NO_ALT_ENTER | DXGI_MWA_NO_WINDOW_CHANGES); // Disable e.g. Alt+Enter
+
+    // Create the render target
+    if (vd->SwapChain)
+    {
+        ID3D10Texture2D* pBackBuffer;
+        vd->SwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+        bd->pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &vd->RTView);
+        pBackBuffer->Release();
+    }
+}
+
+static void ImGui_ImplDX10_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 here since we didn't create the data for it.
+    if (ImGui_ImplDX10_ViewportData* vd = (ImGui_ImplDX10_ViewportData*)viewport->RendererUserData)
+    {
+        if (vd->SwapChain)
+            vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        if (vd->RTView)
+            vd->RTView->Release();
+        vd->RTView = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplDX10_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplDX10_Data* bd = ImGui_ImplDX10_GetBackendData();
+    ImGui_ImplDX10_ViewportData* vd = (ImGui_ImplDX10_ViewportData*)viewport->RendererUserData;
+    if (vd->RTView)
+    {
+        vd->RTView->Release();
+        vd->RTView = nullptr;
+    }
+    if (vd->SwapChain)
+    {
+        ID3D10Texture2D* pBackBuffer = nullptr;
+        vd->SwapChain->ResizeBuffers(0, (UINT)size.x, (UINT)size.y, DXGI_FORMAT_UNKNOWN, 0);
+        vd->SwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+        if (pBackBuffer == nullptr) { fprintf(stderr, "ImGui_ImplDX10_SetWindowSize() failed creating buffers.\n"); return; }
+        bd->pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &vd->RTView);
+        pBackBuffer->Release();
+    }
+}
+
+static void ImGui_ImplDX10_RenderViewport(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX10_Data* bd = ImGui_ImplDX10_GetBackendData();
+    ImGui_ImplDX10_ViewportData* vd = (ImGui_ImplDX10_ViewportData*)viewport->RendererUserData;
+    ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+    bd->pd3dDevice->OMSetRenderTargets(1, &vd->RTView, nullptr);
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+        bd->pd3dDevice->ClearRenderTargetView(vd->RTView, (float*)&clear_color);
+    ImGui_ImplDX10_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplDX10_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX10_ViewportData* vd = (ImGui_ImplDX10_ViewportData*)viewport->RendererUserData;
+    if (vd->SwapChain)
+        vd->SwapChain->Present(0, 0); // Present without vsync
+}
+
+void ImGui_ImplDX10_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX10_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX10_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX10_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX10_RenderViewport;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX10_SwapBuffers;
+}
+
+void ImGui_ImplDX10_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_dx10.h

@@ -5,6 +5,7 @@
 //  [X] Renderer: User texture binding. Use 'ID3D10ShaderResourceView*' as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_dx11.cpp

@@ -6,6 +6,7 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -17,8 +18,11 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
 //  2025-06-11: DirectX11: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas.
 //  2025-05-07: DirectX11: Honor draw_data->FramebufferScale to allow for custom backends and experiment using it (consistently with other renderer backends, even though in normal condition it is not set under Windows).
+//  2025-02-24: [Docking] Added undocumented ImGui_ImplDX11_SetSwapChainDescs() to configure swap chain creation for secondary viewports.
 //  2025-01-06: DirectX11: Expose VertexConstantBuffer in ImGui_ImplDX11_RenderState. Reset projection matrix in ImDrawCallback_ResetRenderState handler.
 //  2024-10-07: DirectX11: Changed default texture sampler to Clamp instead of Repeat/Wrap.
 //  2024-10-07: DirectX11: Expose selected render state in ImGui_ImplDX11_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
@@ -76,12 +80,13 @@ struct ImGui_ImplDX11_Data
     ID3D11InputLayout*          pInputLayout;
     ID3D11Buffer*               pVertexConstantBuffer;
     ID3D11PixelShader*          pPixelShader;
-    ID3D11SamplerState*         pFontSampler;
+    ID3D11SamplerState*         pTexSamplerLinear;
     ID3D11RasterizerState*      pRasterizerState;
     ID3D11BlendState*           pBlendState;
     ID3D11DepthStencilState*    pDepthStencilState;
     int                         VertexBufferSize;
     int                         IndexBufferSize;
+    ImVector<DXGI_SWAP_CHAIN_DESC> SwapChainDescsForViewports;
 
     ImGui_ImplDX11_Data()       { memset((void*)this, 0, sizeof(*this)); VertexBufferSize = 5000; IndexBufferSize = 10000; }
 };
@@ -98,8 +103,12 @@ static ImGui_ImplDX11_Data* ImGui_ImplDX11_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX11_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX11_InitMultiViewportSupport();
+static void ImGui_ImplDX11_ShutdownMultiViewportSupport();
+
 // Functions
-static void ImGui_ImplDX11_SetupRenderState(ImDrawData* draw_data, ID3D11DeviceContext* device_ctx)
+static void ImGui_ImplDX11_SetupRenderState(const ImDrawData* draw_data, ID3D11DeviceContext* device_ctx)
 {
     ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
 
@@ -143,7 +152,7 @@ static void ImGui_ImplDX11_SetupRenderState(ImDrawData* draw_data, ID3D11DeviceC
     device_ctx->VSSetShader(bd->pVertexShader, nullptr, 0);
     device_ctx->VSSetConstantBuffers(0, 1, &bd->pVertexConstantBuffer);
     device_ctx->PSSetShader(bd->pPixelShader, nullptr, 0);
-    device_ctx->PSSetSamplers(0, 1, &bd->pFontSampler);
+    device_ctx->PSSetSamplers(0, 1, &bd->pTexSamplerLinear);
     device_ctx->GSSetShader(nullptr, nullptr, 0);
     device_ctx->HSSetShader(nullptr, nullptr, 0); // In theory we should backup and restore this as well.. very infrequently used..
     device_ctx->DSSetShader(nullptr, nullptr, 0); // In theory we should backup and restore this as well.. very infrequently used..
@@ -208,9 +217,8 @@ void ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data)
         return;
     ImDrawVert* vtx_dst = (ImDrawVert*)vtx_resource.pData;
     ImDrawIdx* idx_dst = (ImDrawIdx*)idx_resource.pData;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         memcpy(vtx_dst, draw_list->VtxBuffer.Data, draw_list->VtxBuffer.Size * sizeof(ImDrawVert));
         memcpy(idx_dst, draw_list->IdxBuffer.Data, draw_list->IdxBuffer.Size * sizeof(ImDrawIdx));
         vtx_dst += draw_list->VtxBuffer.Size;
@@ -272,7 +280,7 @@ void ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data)
     ImGui_ImplDX11_RenderState render_state;
     render_state.Device = bd->pd3dDevice;
     render_state.DeviceContext = bd->pd3dDeviceContext;
-    render_state.SamplerDefault = bd->pFontSampler;
+    render_state.SamplerDefault = bd->pTexSamplerLinear;
     render_state.VertexConstantBuffer = bd->pVertexConstantBuffer;
     platform_io.Renderer_RenderState = &render_state;
 
@@ -282,9 +290,8 @@ void ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data)
     int global_vtx_offset = 0;
     ImVec2 clip_off = draw_data->DisplayPos;
     ImVec2 clip_scale = draw_data->FramebufferScale;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         for (int cmd_i = 0; cmd_i < draw_list->CmdBuffer.Size; cmd_i++)
         {
             const ImDrawCmd* pcmd = &draw_list->CmdBuffer[cmd_i];
@@ -342,18 +349,18 @@ void ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data)
 
 static void ImGui_ImplDX11_DestroyTexture(ImTextureData* tex)
 {
-    ImGui_ImplDX11_Texture* backend_tex = (ImGui_ImplDX11_Texture*)tex->BackendUserData;
-    if (backend_tex == nullptr)
-        return;
-    IM_ASSERT(backend_tex->pTextureView == (ID3D11ShaderResourceView*)(intptr_t)tex->TexID);
-    backend_tex->pTextureView->Release();
-    backend_tex->pTexture->Release();
-    IM_DELETE(backend_tex);
+    if (ImGui_ImplDX11_Texture* backend_tex = (ImGui_ImplDX11_Texture*)tex->BackendUserData)
+    {
+        IM_ASSERT(backend_tex->pTextureView == (ID3D11ShaderResourceView*)(intptr_t)tex->TexID);
+        backend_tex->pTextureView->Release();
+        backend_tex->pTexture->Release();
+        IM_DELETE(backend_tex);
 
-    // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
-    tex->SetTexID(ImTextureID_Invalid);
+        // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
+        tex->SetTexID(ImTextureID_Invalid);
+        tex->BackendUserData = nullptr;
+    }
     tex->SetStatus(ImTextureStatus_Destroyed);
-    tex->BackendUserData = nullptr;
 }
 
 void ImGui_ImplDX11_UpdateTexture(ImTextureData* tex)
@@ -580,7 +587,7 @@ bool    ImGui_ImplDX11_CreateDeviceObjects()
         desc.ComparisonFunc = D3D11_COMPARISON_ALWAYS;
         desc.MinLOD = 0.f;
         desc.MaxLOD = 0.f;
-        bd->pd3dDevice->CreateSamplerState(&desc, &bd->pFontSampler);
+        bd->pd3dDevice->CreateSamplerState(&desc, &bd->pTexSamplerLinear);
     }
 
     return true;
@@ -597,7 +604,7 @@ void    ImGui_ImplDX11_InvalidateDeviceObjects()
         if (tex->RefCount == 1)
             ImGui_ImplDX11_DestroyTexture(tex);
 
-    if (bd->pFontSampler)           { bd->pFontSampler->Release(); bd->pFontSampler = nullptr; }
+    if (bd->pTexSamplerLinear)      { bd->pTexSamplerLinear->Release(); bd->pTexSamplerLinear = nullptr; }
     if (bd->pIB)                    { bd->pIB->Release(); bd->pIB = nullptr; }
     if (bd->pVB)                    { bd->pVB->Release(); bd->pVB = nullptr; }
     if (bd->pBlendState)            { bd->pBlendState->Release(); bd->pBlendState = nullptr; }
@@ -621,6 +628,7 @@ bool    ImGui_ImplDX11_Init(ID3D11Device* device, ID3D11DeviceContext* device_co
     io.BackendRendererName = "imgui_impl_dx11";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
     io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;   // We can honor ImGuiPlatformIO::Textures[] requests during render.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     platform_io.Renderer_TextureMaxWidth = platform_io.Renderer_TextureMaxHeight = D3D11_REQ_TEXTURE2D_U_OR_V_DIMENSION;
@@ -643,6 +651,8 @@ bool    ImGui_ImplDX11_Init(ID3D11Device* device, ID3D11DeviceContext* device_co
     bd->pd3dDevice->AddRef();
     bd->pd3dDeviceContext->AddRef();
 
+    ImGui_ImplDX11_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -651,14 +661,18 @@ void ImGui_ImplDX11_Shutdown()
     ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
+    ImGui_ImplDX11_ShutdownMultiViewportSupport();
     ImGui_ImplDX11_InvalidateDeviceObjects();
     if (bd->pFactory)             { bd->pFactory->Release(); }
     if (bd->pd3dDevice)           { bd->pd3dDevice->Release(); }
     if (bd->pd3dDeviceContext)    { bd->pd3dDeviceContext->Release(); }
+
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
 }
 
@@ -672,6 +686,152 @@ void ImGui_ImplDX11_NewFrame()
             IM_ASSERT(0 && "ImGui_ImplDX11_CreateDeviceObjects() failed!");
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplDX11_ViewportData
+{
+    IDXGISwapChain*                 SwapChain;
+    ID3D11RenderTargetView*         RTView;
+
+    ImGui_ImplDX11_ViewportData()   { SwapChain = nullptr; RTView = nullptr; }
+    ~ImGui_ImplDX11_ViewportData()  { IM_ASSERT(SwapChain == nullptr && RTView == nullptr); }
+};
+
+// Multi-Viewports: configure templates used when creating swapchains for secondary viewports. Will try them in order.
+// This is intentionally not declared in the .h file yet, so you will need to copy this declaration:
+void ImGui_ImplDX11_SetSwapChainDescs(const DXGI_SWAP_CHAIN_DESC* desc_templates, int desc_templates_count);
+void ImGui_ImplDX11_SetSwapChainDescs(const DXGI_SWAP_CHAIN_DESC* desc_templates, int desc_templates_count)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    bd->SwapChainDescsForViewports.resize(desc_templates_count);
+    memcpy(bd->SwapChainDescsForViewports.Data, desc_templates, sizeof(DXGI_SWAP_CHAIN_DESC));
+}
+
+static void ImGui_ImplDX11_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    ImGui_ImplDX11_ViewportData* vd = IM_NEW(ImGui_ImplDX11_ViewportData)();
+    viewport->RendererUserData = vd;
+
+    // PlatformHandleRaw should always be a HWND, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL's WindowID).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+    IM_ASSERT(vd->SwapChain == nullptr && vd->RTView == nullptr);
+
+    // Create swap chain
+    HRESULT hr = DXGI_ERROR_UNSUPPORTED;
+    for (const DXGI_SWAP_CHAIN_DESC& sd_template : bd->SwapChainDescsForViewports)
+    {
+        IM_ASSERT(sd_template.BufferDesc.Width == 0 && sd_template.BufferDesc.Height == 0 && sd_template.OutputWindow == nullptr);
+        DXGI_SWAP_CHAIN_DESC sd = sd_template;
+        sd.BufferDesc.Width = (UINT)viewport->Size.x;
+        sd.BufferDesc.Height = (UINT)viewport->Size.y;
+        sd.OutputWindow = hwnd;
+        hr = bd->pFactory->CreateSwapChain(bd->pd3dDevice, &sd, &vd->SwapChain);
+        if (SUCCEEDED(hr))
+            break;
+    }
+    IM_ASSERT(SUCCEEDED(hr));
+    bd->pFactory->MakeWindowAssociation(hwnd, DXGI_MWA_NO_ALT_ENTER | DXGI_MWA_NO_WINDOW_CHANGES); // Disable e.g. Alt+Enter
+
+    // Create the render target
+    if (vd->SwapChain != nullptr)
+    {
+        ID3D11Texture2D* pBackBuffer;
+        vd->SwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+        bd->pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &vd->RTView);
+        pBackBuffer->Release();
+    }
+}
+
+static void ImGui_ImplDX11_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == nullptr since we didn't create the data for it.
+    if (ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData)
+    {
+        if (vd->SwapChain)
+            vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        if (vd->RTView)
+            vd->RTView->Release();
+        vd->RTView = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplDX11_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData;
+    if (vd->RTView)
+    {
+        vd->RTView->Release();
+        vd->RTView = nullptr;
+    }
+    if (vd->SwapChain)
+    {
+        ID3D11Texture2D* pBackBuffer = nullptr;
+        vd->SwapChain->ResizeBuffers(0, (UINT)size.x, (UINT)size.y, DXGI_FORMAT_UNKNOWN, 0);
+        vd->SwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+        if (pBackBuffer == nullptr) { fprintf(stderr, "ImGui_ImplDX11_SetWindowSize() failed creating buffers.\n"); return; }
+        bd->pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &vd->RTView);
+        pBackBuffer->Release();
+    }
+}
+
+static void ImGui_ImplDX11_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData;
+    ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+    bd->pd3dDeviceContext->OMSetRenderTargets(1, &vd->RTView, nullptr);
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+        bd->pd3dDeviceContext->ClearRenderTargetView(vd->RTView, (float*)&clear_color);
+    ImGui_ImplDX11_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplDX11_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData;
+    if (vd->SwapChain)
+        vd->SwapChain->Present(0, 0); // Present without vsync
+}
+
+static void ImGui_ImplDX11_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX11_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX11_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX11_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX11_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX11_SwapBuffers;
+
+    // Default swapchain format
+    DXGI_SWAP_CHAIN_DESC sd;
+    ZeroMemory(&sd, sizeof(sd));
+    sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
+    sd.SampleDesc.Count = 1;
+    sd.SampleDesc.Quality = 0;
+    sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
+    sd.BufferCount = 1;
+    sd.Windowed = TRUE;
+    sd.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
+    sd.Flags = 0;
+    ImGui_ImplDX11_SetSwapChainDescs(&sd, 1);
+}
+
+static void ImGui_ImplDX11_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_dx11.h

@@ -6,6 +6,7 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_dx12.cpp

@@ -6,6 +6,8 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+//      FIXME: The transition from removing a viewport and moving the window in an existing hosted viewport tends to flicker.
 
 // The aim of imgui_impl_dx12.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -20,6 +22,12 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-10-11: DirectX12: Reuse texture upload buffer and grow it only when necessary. (#9002)
+//  2025-09-29: DirectX12: Rework synchronization logic. (#8961)
+//  2025-09-29: DirectX12: Enable swapchain tearing to eliminate viewports framerate throttling. (#8965)
+//  2025-09-29: DirectX12: Reuse a command list and allocator for texture uploads instead of recreating them each time. (#8963)
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
 //  2025-06-19: Fixed build on MinGW. (#8702, #4594)
 //  2025-06-11: DirectX12: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas.
 //  2025-05-07: DirectX12: Honor draw_data->FramebufferScale to allow for custom backends and experiment using it (consistently with other renderer backends, even though in normal condition it is not set under Windows).
@@ -56,7 +64,7 @@
 
 // DirectX
 #include <d3d12.h>
-#include <dxgi1_4.h>
+#include <dxgi1_5.h>
 #include <d3dcompiler.h>
 #ifdef _MSC_VER
 #pragma comment(lib, "d3dcompiler") // Automatically link with d3dcompiler.lib as we are using D3DCompile() below.
@@ -86,6 +94,7 @@ struct ImGui_ImplDX12_Texture
 struct ImGui_ImplDX12_Data
 {
     ImGui_ImplDX12_InitInfo     InitInfo;
+    IDXGIFactory5*              pdxgiFactory;
     ID3D12Device*               pd3dDevice;
     ID3D12RootSignature*        pRootSignature;
     ID3D12PipelineState*        pPipelineState;
@@ -94,15 +103,20 @@ struct ImGui_ImplDX12_Data
     DXGI_FORMAT                 RTVFormat;
     DXGI_FORMAT                 DSVFormat;
     ID3D12DescriptorHeap*       pd3dSrvDescHeap;
+    ID3D12Fence*                Fence;
+    UINT64                      FenceLastSignaledValue;
+    HANDLE                      FenceEvent;
     UINT                        numFramesInFlight;
-
-    ImGui_ImplDX12_RenderBuffers* pFrameResources;
-    UINT                        frameIndex;
-
-    ImGui_ImplDX12_Texture      FontTexture;
+    bool                        tearingSupport;
     bool                        LegacySingleDescriptorUsed;
 
-    ImGui_ImplDX12_Data()       { memset((void*)this, 0, sizeof(*this)); frameIndex = UINT_MAX; }
+    ID3D12CommandAllocator*     pTexCmdAllocator;
+    ID3D12GraphicsCommandList*  pTexCmdList;
+    ID3D12Resource*             pTexUploadBuffer;
+    UINT                        pTexUploadBufferSize;
+    void*                       pTexUploadBufferMapped;
+
+    ImGui_ImplDX12_Data()       { memset((void*)this, 0, sizeof(*this)); }
 };
 
 // Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
@@ -121,11 +135,85 @@ struct ImGui_ImplDX12_RenderBuffers
     int                 VertexBufferSize;
 };
 
+// Buffers used for secondary viewports created by the multi-viewports systems
+struct ImGui_ImplDX12_FrameContext
+{
+    UINT64                          FenceValue;
+    ID3D12CommandAllocator*         CommandAllocator;
+    ID3D12Resource*                 RenderTarget;
+    D3D12_CPU_DESCRIPTOR_HANDLE     RenderTargetCpuDescriptors;
+};
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+// Main viewport created by application will only use the Resources field.
+// Secondary viewports created by this backend will use all the fields (including Window fields),
+struct ImGui_ImplDX12_ViewportData
+{
+    // Window
+    ID3D12CommandQueue*             CommandQueue;
+    ID3D12GraphicsCommandList*      CommandList;
+    ID3D12DescriptorHeap*           RtvDescHeap;
+    IDXGISwapChain3*                SwapChain;
+    HANDLE                          SwapChainWaitableObject;
+    UINT                            NumFramesInFlight;
+    ImGui_ImplDX12_FrameContext*    FrameCtx;
+
+    // Render buffers
+    UINT                            FrameIndex;
+    ImGui_ImplDX12_RenderBuffers*   FrameRenderBuffers;
+
+    ImGui_ImplDX12_ViewportData(UINT num_frames_in_flight)
+    {
+        CommandQueue = nullptr;
+        CommandList = nullptr;
+        RtvDescHeap = nullptr;
+        SwapChain = nullptr;
+        SwapChainWaitableObject = nullptr;
+        NumFramesInFlight = num_frames_in_flight;
+        FrameCtx = new ImGui_ImplDX12_FrameContext[NumFramesInFlight];
+        FrameIndex = 0;
+        FrameRenderBuffers = new ImGui_ImplDX12_RenderBuffers[NumFramesInFlight];
+
+        for (UINT i = 0; i < NumFramesInFlight; ++i)
+        {
+            FrameCtx[i].FenceValue = 0;
+            FrameCtx[i].CommandAllocator = nullptr;
+            FrameCtx[i].RenderTarget = nullptr;
+
+            // Create buffers with a default size (they will later be grown as needed)
+            FrameRenderBuffers[i].IndexBuffer = nullptr;
+            FrameRenderBuffers[i].VertexBuffer = nullptr;
+            FrameRenderBuffers[i].VertexBufferSize = 5000;
+            FrameRenderBuffers[i].IndexBufferSize = 10000;
+        }
+    }
+    ~ImGui_ImplDX12_ViewportData()
+    {
+        IM_ASSERT(CommandQueue == nullptr && CommandList == nullptr);
+        IM_ASSERT(RtvDescHeap == nullptr);
+        IM_ASSERT(SwapChain == nullptr);
+        IM_ASSERT(SwapChainWaitableObject == nullptr);
+
+        for (UINT i = 0; i < NumFramesInFlight; ++i)
+        {
+            IM_ASSERT(FrameCtx[i].CommandAllocator == nullptr && FrameCtx[i].RenderTarget == nullptr);
+            IM_ASSERT(FrameRenderBuffers[i].IndexBuffer == nullptr && FrameRenderBuffers[i].VertexBuffer == nullptr);
+        }
+
+        delete[] FrameCtx; FrameCtx = nullptr;
+        delete[] FrameRenderBuffers; FrameRenderBuffers = nullptr;
+    }
+};
+
 struct VERTEX_CONSTANT_BUFFER_DX12
 {
     float   mvp[4][4];
 };
 
+// Forward Declarations
+static void ImGui_ImplDX12_InitMultiViewportSupport();
+static void ImGui_ImplDX12_ShutdownMultiViewportSupport();
+
 // Functions
 static void ImGui_ImplDX12_SetupRenderState(ImDrawData* draw_data, ID3D12GraphicsCommandList* command_list, ImGui_ImplDX12_RenderBuffers* fr)
 {
@@ -205,8 +293,9 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
 
     // FIXME: We are assuming that this only gets called once per frame!
     ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
-    bd->frameIndex = bd->frameIndex + 1;
-    ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[bd->frameIndex % bd->numFramesInFlight];
+    ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)draw_data->OwnerViewport->RendererUserData;
+    vd->FrameIndex++;
+    ImGui_ImplDX12_RenderBuffers* fr = &vd->FrameRenderBuffers[vd->FrameIndex % bd->numFramesInFlight];
 
     // Create and grow vertex/index buffers if needed
     if (fr->VertexBuffer == nullptr || fr->VertexBufferSize < draw_data->TotalVtxCount)
@@ -262,9 +351,8 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
         return;
     ImDrawVert* vtx_dst = (ImDrawVert*)vtx_resource;
     ImDrawIdx* idx_dst = (ImDrawIdx*)idx_resource;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         memcpy(vtx_dst, draw_list->VtxBuffer.Data, draw_list->VtxBuffer.Size * sizeof(ImDrawVert));
         memcpy(idx_dst, draw_list->IdxBuffer.Data, draw_list->IdxBuffer.Size * sizeof(ImDrawIdx));
         vtx_dst += draw_list->VtxBuffer.Size;
@@ -295,9 +383,8 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
     int global_idx_offset = 0;
     ImVec2 clip_off = draw_data->DisplayPos;
     ImVec2 clip_scale = draw_data->FramebufferScale;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         for (int cmd_i = 0; cmd_i < draw_list->CmdBuffer.Size; cmd_i++)
         {
             const ImDrawCmd* pcmd = &draw_list->CmdBuffer[cmd_i];
@@ -337,21 +424,21 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
 
 static void ImGui_ImplDX12_DestroyTexture(ImTextureData* tex)
 {
-    ImGui_ImplDX12_Texture* backend_tex = (ImGui_ImplDX12_Texture*)tex->BackendUserData;
-    if (backend_tex == nullptr)
-        return;
-    IM_ASSERT(backend_tex->hFontSrvGpuDescHandle.ptr == (UINT64)tex->TexID);
-    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
-    bd->InitInfo.SrvDescriptorFreeFn(&bd->InitInfo, backend_tex->hFontSrvCpuDescHandle, backend_tex->hFontSrvGpuDescHandle);
-    SafeRelease(backend_tex->pTextureResource);
-    backend_tex->hFontSrvCpuDescHandle.ptr = 0;
-    backend_tex->hFontSrvGpuDescHandle.ptr = 0;
-    IM_DELETE(backend_tex);
+    if (ImGui_ImplDX12_Texture* backend_tex = (ImGui_ImplDX12_Texture*)tex->BackendUserData)
+    {
+        IM_ASSERT(backend_tex->hFontSrvGpuDescHandle.ptr == (UINT64)tex->TexID);
+        ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+        bd->InitInfo.SrvDescriptorFreeFn(&bd->InitInfo, backend_tex->hFontSrvCpuDescHandle, backend_tex->hFontSrvGpuDescHandle);
+        SafeRelease(backend_tex->pTextureResource);
+        backend_tex->hFontSrvCpuDescHandle.ptr = 0;
+        backend_tex->hFontSrvGpuDescHandle.ptr = 0;
+        IM_DELETE(backend_tex);
 
-    // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
-    tex->SetTexID(ImTextureID_Invalid);
+        // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
+        tex->SetTexID(ImTextureID_Invalid);
+        tex->BackendUserData = nullptr;
+    }
     tex->SetStatus(ImTextureStatus_Destroyed);
-    tex->BackendUserData = nullptr;
 }
 
 void ImGui_ImplDX12_UpdateTexture(ImTextureData* tex)
@@ -430,58 +517,53 @@ void ImGui_ImplDX12_UpdateTexture(ImTextureData* tex)
         UINT upload_pitch_dst = (upload_pitch_src + D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u) & ~(D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u);
         UINT upload_size = upload_pitch_dst * upload_h;
 
-        D3D12_RESOURCE_DESC desc;
-        ZeroMemory(&desc, sizeof(desc));
-        desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
-        desc.Alignment = 0;
-        desc.Width = upload_size;
-        desc.Height = 1;
-        desc.DepthOrArraySize = 1;
-        desc.MipLevels = 1;
-        desc.Format = DXGI_FORMAT_UNKNOWN;
-        desc.SampleDesc.Count = 1;
-        desc.SampleDesc.Quality = 0;
-        desc.Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
-        desc.Flags = D3D12_RESOURCE_FLAG_NONE;
+        if (bd->pTexUploadBuffer == nullptr || upload_size > bd->pTexUploadBufferSize)
+        {
+            if (bd->pTexUploadBufferMapped)
+            {
+                D3D12_RANGE range = { 0, bd->pTexUploadBufferSize };
+                bd->pTexUploadBuffer->Unmap(0, &range);
+                bd->pTexUploadBufferMapped = nullptr;
+            }
+            SafeRelease(bd->pTexUploadBuffer);
 
-        D3D12_HEAP_PROPERTIES props;
-        memset(&props, 0, sizeof(D3D12_HEAP_PROPERTIES));
-        props.Type = D3D12_HEAP_TYPE_UPLOAD;
-        props.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
-        props.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
+            D3D12_RESOURCE_DESC desc;
+            ZeroMemory(&desc, sizeof(desc));
+            desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
+            desc.Alignment = 0;
+            desc.Width = upload_size;
+            desc.Height = 1;
+            desc.DepthOrArraySize = 1;
+            desc.MipLevels = 1;
+            desc.Format = DXGI_FORMAT_UNKNOWN;
+            desc.SampleDesc.Count = 1;
+            desc.SampleDesc.Quality = 0;
+            desc.Layout = D3D12_TEXTURE_LAYOUT_ROW_MAJOR;
+            desc.Flags = D3D12_RESOURCE_FLAG_NONE;
 
-        // FIXME-OPT: Can upload buffer be reused?
-        ID3D12Resource* uploadBuffer = nullptr;
-        HRESULT hr = bd->pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc,
-            D3D12_RESOURCE_STATE_GENERIC_READ, nullptr, IID_PPV_ARGS(&uploadBuffer));
-        IM_ASSERT(SUCCEEDED(hr));
+            D3D12_HEAP_PROPERTIES props;
+            memset(&props, 0, sizeof(D3D12_HEAP_PROPERTIES));
+            props.Type = D3D12_HEAP_TYPE_UPLOAD;
+            props.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
+            props.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
 
-        // Create temporary command list and execute immediately
-        ID3D12Fence* fence = nullptr;
-        hr = bd->pd3dDevice->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_PPV_ARGS(&fence));
-        IM_ASSERT(SUCCEEDED(hr));
+            HRESULT hr = bd->pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc,
+                D3D12_RESOURCE_STATE_GENERIC_READ, nullptr, IID_PPV_ARGS(&bd->pTexUploadBuffer));
+            IM_ASSERT(SUCCEEDED(hr));
 
-        HANDLE event = ::CreateEvent(0, 0, 0, 0);
-        IM_ASSERT(event != nullptr);
+            D3D12_RANGE range = {0, upload_size};
+            hr = bd->pTexUploadBuffer->Map(0, &range, &bd->pTexUploadBufferMapped);
+            IM_ASSERT(SUCCEEDED(hr));
+            bd->pTexUploadBufferSize = upload_size;
+        }
 
-        // FIXME-OPT: Create once and reuse?
-        ID3D12CommandAllocator* cmdAlloc = nullptr;
-        hr = bd->pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&cmdAlloc));
-        IM_ASSERT(SUCCEEDED(hr));
-
-        // FIXME-OPT: Can be use the one from user? (pass ID3D12GraphicsCommandList* to ImGui_ImplDX12_UpdateTextures)
-        ID3D12GraphicsCommandList* cmdList = nullptr;
-        hr = bd->pd3dDevice->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, cmdAlloc, nullptr, IID_PPV_ARGS(&cmdList));
-        IM_ASSERT(SUCCEEDED(hr));
+        bd->pTexCmdAllocator->Reset();
+        bd->pTexCmdList->Reset(bd->pTexCmdAllocator, nullptr);
+        ID3D12GraphicsCommandList* cmdList = bd->pTexCmdList;
 
         // Copy to upload buffer
-        void* mapped = nullptr;
-        D3D12_RANGE range = { 0, upload_size };
-        hr = uploadBuffer->Map(0, &range, &mapped);
-        IM_ASSERT(SUCCEEDED(hr));
         for (int y = 0; y < upload_h; y++)
-            memcpy((void*)((uintptr_t)mapped + y * upload_pitch_dst), tex->GetPixelsAt(upload_x, upload_y + y), upload_pitch_src);
-        uploadBuffer->Unmap(0, &range);
+            memcpy((void*)((uintptr_t)bd->pTexUploadBufferMapped + y * upload_pitch_dst), tex->GetPixelsAt(upload_x, upload_y + y), upload_pitch_src);
 
         if (need_barrier_before_copy)
         {
@@ -498,7 +580,7 @@ void ImGui_ImplDX12_UpdateTexture(ImTextureData* tex)
         D3D12_TEXTURE_COPY_LOCATION srcLocation = {};
         D3D12_TEXTURE_COPY_LOCATION dstLocation = {};
         {
-            srcLocation.pResource = uploadBuffer;
+            srcLocation.pResource = bd->pTexUploadBuffer;
             srcLocation.Type = D3D12_TEXTURE_COPY_TYPE_PLACED_FOOTPRINT;
             srcLocation.PlacedFootprint.Footprint.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
             srcLocation.PlacedFootprint.Footprint.Width = upload_w;
@@ -522,26 +604,20 @@ void ImGui_ImplDX12_UpdateTexture(ImTextureData* tex)
             cmdList->ResourceBarrier(1, &barrier);
         }
 
-        hr = cmdList->Close();
+        HRESULT hr = cmdList->Close();
         IM_ASSERT(SUCCEEDED(hr));
-
         ID3D12CommandQueue* cmdQueue = bd->pCommandQueue;
         cmdQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&cmdList);
-        hr = cmdQueue->Signal(fence, 1);
+        hr = cmdQueue->Signal(bd->Fence, ++bd->FenceLastSignaledValue);
         IM_ASSERT(SUCCEEDED(hr));
 
         // FIXME-OPT: Suboptimal?
         // - To remove this may need to create NumFramesInFlight x ImGui_ImplDX12_FrameContext in backend data (mimick docking version)
         // - Store per-frame in flight: upload buffer?
         // - Where do cmdList and cmdAlloc fit?
-        fence->SetEventOnCompletion(1, event);
-        ::WaitForSingleObject(event, INFINITE);
+        bd->Fence->SetEventOnCompletion(bd->FenceLastSignaledValue, bd->FenceEvent);
+        ::WaitForSingleObject(bd->FenceEvent, INFINITE);
 
-        cmdList->Release();
-        cmdAlloc->Release();
-        ::CloseHandle(event);
-        fence->Release();
-        uploadBuffer->Release();
         tex->SetStatus(ImTextureStatus_OK);
     }
 
@@ -557,6 +633,13 @@ bool    ImGui_ImplDX12_CreateDeviceObjects()
     if (bd->pPipelineState)
         ImGui_ImplDX12_InvalidateDeviceObjects();
 
+    HRESULT hr = ::CreateDXGIFactory1(IID_PPV_ARGS(&bd->pdxgiFactory));
+    IM_ASSERT(hr == S_OK);
+
+    BOOL allow_tearing = FALSE;
+    bd->pdxgiFactory->CheckFeatureSupport(DXGI_FEATURE_PRESENT_ALLOW_TEARING, &allow_tearing, sizeof(allow_tearing));
+    bd->tearingSupport = (allow_tearing == TRUE);
+
     // Create the root signature
     {
         D3D12_DESCRIPTOR_RANGE descRange = {};
@@ -580,26 +663,26 @@ bool    ImGui_ImplDX12_CreateDeviceObjects()
         param[1].ShaderVisibility = D3D12_SHADER_VISIBILITY_PIXEL;
 
         // Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling.
-        D3D12_STATIC_SAMPLER_DESC staticSampler = {};
-        staticSampler.Filter = D3D12_FILTER_MIN_MAG_MIP_LINEAR;
-        staticSampler.AddressU = D3D12_TEXTURE_ADDRESS_MODE_CLAMP;
-        staticSampler.AddressV = D3D12_TEXTURE_ADDRESS_MODE_CLAMP;
-        staticSampler.AddressW = D3D12_TEXTURE_ADDRESS_MODE_CLAMP;
-        staticSampler.MipLODBias = 0.f;
-        staticSampler.MaxAnisotropy = 0;
-        staticSampler.ComparisonFunc = D3D12_COMPARISON_FUNC_ALWAYS;
-        staticSampler.BorderColor = D3D12_STATIC_BORDER_COLOR_TRANSPARENT_BLACK;
-        staticSampler.MinLOD = 0.f;
-        staticSampler.MaxLOD = D3D12_FLOAT32_MAX;
-        staticSampler.ShaderRegister = 0;
-        staticSampler.RegisterSpace = 0;
-        staticSampler.ShaderVisibility = D3D12_SHADER_VISIBILITY_PIXEL;
+        D3D12_STATIC_SAMPLER_DESC staticSampler[1] = {};
+        staticSampler[0].Filter = D3D12_FILTER_MIN_MAG_MIP_LINEAR;
+        staticSampler[0].AddressU = D3D12_TEXTURE_ADDRESS_MODE_CLAMP;
+        staticSampler[0].AddressV = D3D12_TEXTURE_ADDRESS_MODE_CLAMP;
+        staticSampler[0].AddressW = D3D12_TEXTURE_ADDRESS_MODE_CLAMP;
+        staticSampler[0].MipLODBias = 0.f;
+        staticSampler[0].MaxAnisotropy = 0;
+        staticSampler[0].ComparisonFunc = D3D12_COMPARISON_FUNC_ALWAYS;
+        staticSampler[0].BorderColor = D3D12_STATIC_BORDER_COLOR_TRANSPARENT_BLACK;
+        staticSampler[0].MinLOD = 0.f;
+        staticSampler[0].MaxLOD = D3D12_FLOAT32_MAX;
+        staticSampler[0].ShaderRegister = 0;
+        staticSampler[0].RegisterSpace = 0;
+        staticSampler[0].ShaderVisibility = D3D12_SHADER_VISIBILITY_PIXEL;
 
         D3D12_ROOT_SIGNATURE_DESC desc = {};
         desc.NumParameters = _countof(param);
         desc.pParameters = param;
         desc.NumStaticSamplers = 1;
-        desc.pStaticSamplers = &staticSampler;
+        desc.pStaticSamplers = &staticSampler[0];
         desc.Flags =
             D3D12_ROOT_SIGNATURE_FLAG_ALLOW_INPUT_ASSEMBLER_INPUT_LAYOUT |
             D3D12_ROOT_SIGNATURE_FLAG_DENY_HULL_SHADER_ROOT_ACCESS |
@@ -778,32 +861,59 @@ bool    ImGui_ImplDX12_CreateDeviceObjects()
     if (result_pipeline_state != S_OK)
         return false;
 
+    // Create command allocator and command list for ImGui_ImplDX12_UpdateTexture()
+    hr = bd->pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&bd->pTexCmdAllocator));
+    IM_ASSERT(SUCCEEDED(hr));
+    hr = bd->pd3dDevice->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, bd->pTexCmdAllocator, nullptr, IID_PPV_ARGS(&bd->pTexCmdList));
+    IM_ASSERT(SUCCEEDED(hr));
+    hr = bd->pTexCmdList->Close();
+    IM_ASSERT(SUCCEEDED(hr));
+
+    // Create fence.
+    hr = bd->pd3dDevice->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_PPV_ARGS(&bd->Fence));
+    IM_ASSERT(hr == S_OK);
+    bd->FenceEvent = CreateEvent(nullptr, FALSE, FALSE, nullptr);
+    IM_ASSERT(bd->FenceEvent != nullptr);
+
     return true;
 }
 
+static void ImGui_ImplDX12_DestroyRenderBuffers(ImGui_ImplDX12_RenderBuffers* render_buffers)
+{
+    SafeRelease(render_buffers->IndexBuffer);
+    SafeRelease(render_buffers->VertexBuffer);
+    render_buffers->IndexBufferSize = render_buffers->VertexBufferSize = 0;
+}
+
 void    ImGui_ImplDX12_InvalidateDeviceObjects()
 {
     ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
     if (!bd || !bd->pd3dDevice)
         return;
 
+    SafeRelease(bd->pdxgiFactory);
     if (bd->commandQueueOwned)
         SafeRelease(bd->pCommandQueue);
     bd->commandQueueOwned = false;
     SafeRelease(bd->pRootSignature);
     SafeRelease(bd->pPipelineState);
+    if (bd->pTexUploadBufferMapped)
+    {
+        D3D12_RANGE range = { 0, bd->pTexUploadBufferSize };
+        bd->pTexUploadBuffer->Unmap(0, &range);
+        bd->pTexUploadBufferMapped = nullptr;
+    }
+    SafeRelease(bd->pTexUploadBuffer);
+    SafeRelease(bd->pTexCmdList);
+    SafeRelease(bd->pTexCmdAllocator);
+    SafeRelease(bd->Fence);
+    CloseHandle(bd->FenceEvent);
+    bd->FenceEvent = nullptr;
 
     // Destroy all textures
     for (ImTextureData* tex : ImGui::GetPlatformIO().Textures)
         if (tex->RefCount == 1)
             ImGui_ImplDX12_DestroyTexture(tex);
-
-    for (UINT i = 0; i < bd->numFramesInFlight; i++)
-    {
-        ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[i];
-        SafeRelease(fr->IndexBuffer);
-        SafeRelease(fr->VertexBuffer);
-    }
 }
 
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
@@ -846,11 +956,21 @@ bool ImGui_ImplDX12_Init(ImGui_ImplDX12_InitInfo* init_info)
     bd->DSVFormat = init_info->DSVFormat;
     bd->numFramesInFlight = init_info->NumFramesInFlight;
     bd->pd3dSrvDescHeap = init_info->SrvDescriptorHeap;
+    bd->tearingSupport = false;
 
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_dx12";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
     io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;   // We can honor ImGuiPlatformIO::Textures[] requests during render.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
+
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplDX12_InitMultiViewportSupport();
+
+    // Create a dummy ImGui_ImplDX12_ViewportData holder for the main viewport,
+    // Since this is created and managed by the application, we will only use the ->Resources[] fields.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->RendererUserData = IM_NEW(ImGui_ImplDX12_ViewportData)(bd->numFramesInFlight);
 
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
     if (init_info->SrvDescriptorAllocFn == nullptr)
@@ -858,18 +978,6 @@ bool ImGui_ImplDX12_Init(ImGui_ImplDX12_InitInfo* init_info)
 #endif
     IM_ASSERT(init_info->SrvDescriptorAllocFn != nullptr && init_info->SrvDescriptorFreeFn != nullptr);
 
-    // Create buffers with a default size (they will later be grown as needed)
-    bd->frameIndex = UINT_MAX;
-    bd->pFrameResources = new ImGui_ImplDX12_RenderBuffers[bd->numFramesInFlight];
-    for (int i = 0; i < (int)bd->numFramesInFlight; i++)
-    {
-        ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[i];
-        fr->IndexBuffer = nullptr;
-        fr->VertexBuffer = nullptr;
-        fr->IndexBufferSize = 10000;
-        fr->VertexBufferSize = 5000;
-    }
-
     return true;
 }
 
@@ -908,14 +1016,26 @@ void ImGui_ImplDX12_Shutdown()
     ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
-    // Clean up windows and device objects
+    // Manually delete main viewport render resources in-case we haven't initialized for viewports
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    if (ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)main_viewport->RendererUserData)
+    {
+        // We could just call ImGui_ImplDX12_DestroyWindow(main_viewport) as a convenience but that would be misleading since we only use data->Resources[]
+        for (UINT i = 0; i < bd->numFramesInFlight; i++)
+            ImGui_ImplDX12_DestroyRenderBuffers(&vd->FrameRenderBuffers[i]);
+        IM_DELETE(vd);
+        main_viewport->RendererUserData = nullptr;
+    }
+
+    ImGui_ImplDX12_ShutdownMultiViewportSupport();
     ImGui_ImplDX12_InvalidateDeviceObjects();
-    delete[] bd->pFrameResources;
 
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
 }
 
@@ -929,6 +1049,255 @@ void ImGui_ImplDX12_NewFrame()
             IM_ASSERT(0 && "ImGui_ImplDX12_CreateDeviceObjects() failed!");
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplDX12_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    ImGui_ImplDX12_ViewportData* vd = IM_NEW(ImGui_ImplDX12_ViewportData)(bd->numFramesInFlight);
+    viewport->RendererUserData = vd;
+
+    // PlatformHandleRaw should always be a HWND, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL's WindowID).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+
+    // Use shared command queue from init info
+    vd->FrameIndex = 0;
+    vd->CommandQueue = bd->pCommandQueue;
+
+    // Create command allocator.
+    HRESULT res = S_OK;
+    for (UINT i = 0; i < bd->numFramesInFlight; ++i)
+    {
+        res = bd->pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&vd->FrameCtx[i].CommandAllocator));
+        IM_ASSERT(res == S_OK);
+    }
+
+    // Create command list.
+    res = bd->pd3dDevice->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, vd->FrameCtx[0].CommandAllocator, nullptr, IID_PPV_ARGS(&vd->CommandList));
+    IM_ASSERT(res == S_OK);
+    vd->CommandList->Close();
+
+    // Create swap chain
+    // FIXME-VIEWPORT: May want to copy/inherit swap chain settings from the user/application.
+    DXGI_SWAP_CHAIN_DESC1 sd1;
+    ZeroMemory(&sd1, sizeof(sd1));
+    sd1.BufferCount = bd->numFramesInFlight;
+    sd1.Width = (UINT)viewport->Size.x;
+    sd1.Height = (UINT)viewport->Size.y;
+    sd1.Format = bd->RTVFormat;
+    sd1.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
+    sd1.SampleDesc.Count = 1;
+    sd1.SampleDesc.Quality = 0;
+    sd1.SwapEffect = DXGI_SWAP_EFFECT_FLIP_DISCARD;
+    sd1.AlphaMode = DXGI_ALPHA_MODE_UNSPECIFIED;
+    sd1.Scaling = DXGI_SCALING_NONE;
+    sd1.Stereo = FALSE;
+    sd1.Flags = DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT;
+
+    if (bd->tearingSupport)
+        sd1.Flags |= DXGI_SWAP_CHAIN_FLAG_ALLOW_TEARING;
+
+    IDXGISwapChain1* swap_chain = nullptr;
+    res = bd->pdxgiFactory->CreateSwapChainForHwnd(vd->CommandQueue, hwnd, &sd1, nullptr, nullptr, &swap_chain);
+    IM_ASSERT(res == S_OK);
+    res = bd->pdxgiFactory->MakeWindowAssociation(hwnd, DXGI_MWA_NO_ALT_ENTER | DXGI_MWA_NO_WINDOW_CHANGES); // Disable e.g. Alt+Enter
+    IM_ASSERT(res == S_OK);
+
+    // Or swapChain.As(&mSwapChain)
+    IM_ASSERT(vd->SwapChain == nullptr);
+    swap_chain->QueryInterface(IID_PPV_ARGS(&vd->SwapChain));
+    swap_chain->Release();
+
+    // Create the render targets and waitable object
+    if (vd->SwapChain)
+    {
+        D3D12_DESCRIPTOR_HEAP_DESC desc = {};
+        desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_RTV;
+        desc.NumDescriptors = bd->numFramesInFlight;
+        desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
+        desc.NodeMask = 1;
+
+        HRESULT hr = bd->pd3dDevice->CreateDescriptorHeap(&desc, IID_PPV_ARGS(&vd->RtvDescHeap));
+        IM_ASSERT(hr == S_OK);
+
+        SIZE_T rtv_descriptor_size = bd->pd3dDevice->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_RTV);
+        D3D12_CPU_DESCRIPTOR_HANDLE rtv_handle = vd->RtvDescHeap->GetCPUDescriptorHandleForHeapStart();
+        for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        {
+            vd->FrameCtx[i].RenderTargetCpuDescriptors = rtv_handle;
+            rtv_handle.ptr += rtv_descriptor_size;
+        }
+
+        ID3D12Resource* back_buffer;
+        for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        {
+            IM_ASSERT(vd->FrameCtx[i].RenderTarget == nullptr);
+            vd->SwapChain->GetBuffer(i, IID_PPV_ARGS(&back_buffer));
+            bd->pd3dDevice->CreateRenderTargetView(back_buffer, nullptr, vd->FrameCtx[i].RenderTargetCpuDescriptors);
+            vd->FrameCtx[i].RenderTarget = back_buffer;
+        }
+
+        hr = vd->SwapChain->SetMaximumFrameLatency(bd->numFramesInFlight);
+        IM_ASSERT(hr == S_OK);
+        vd->SwapChainWaitableObject = vd->SwapChain->GetFrameLatencyWaitableObject();
+    }
+
+    for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        ImGui_ImplDX12_DestroyRenderBuffers(&vd->FrameRenderBuffers[i]);
+}
+
+static void ImGui_WaitForPendingOperations(ImGui_ImplDX12_ViewportData* vd)
+{
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    HRESULT hr = vd->CommandQueue->Signal(bd->Fence, ++bd->FenceLastSignaledValue);
+    IM_ASSERT(hr == S_OK);
+
+    hr = bd->Fence->SetEventOnCompletion(bd->FenceLastSignaledValue, bd->FenceEvent);
+    IM_ASSERT(hr == S_OK);
+    ::WaitForSingleObject(bd->FenceEvent, INFINITE);
+}
+
+static ImGui_ImplDX12_FrameContext* ImGui_WaitForNextFrameContext(ImGui_ImplDX12_ViewportData* vd)
+{
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    ImGui_ImplDX12_FrameContext* frame_context = &vd->FrameCtx[vd->FrameIndex % vd->NumFramesInFlight];
+    if (bd->Fence->GetCompletedValue() < frame_context->FenceValue)
+    {
+        HRESULT hr = bd->Fence->SetEventOnCompletion(frame_context->FenceValue, bd->FenceEvent);
+        IM_ASSERT(hr == S_OK);
+        HANDLE waitableObjects[] = { vd->SwapChainWaitableObject, bd->FenceEvent };
+        ::WaitForMultipleObjects(2, waitableObjects, TRUE, INFINITE);
+    }
+    else
+    {
+        ::WaitForSingleObject(vd->SwapChainWaitableObject, INFINITE);
+    }
+    return frame_context;
+}
+
+static void ImGui_ImplDX12_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    if (ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData)
+    {
+        ImGui_WaitForPendingOperations(vd);
+
+        vd->CommandQueue = nullptr;
+        ::CloseHandle(vd->SwapChainWaitableObject);
+        vd->SwapChainWaitableObject = nullptr;
+        SafeRelease(vd->CommandList);
+        SafeRelease(vd->SwapChain);
+        SafeRelease(vd->RtvDescHeap);
+
+        for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        {
+            SafeRelease(vd->FrameCtx[i].RenderTarget);
+            SafeRelease(vd->FrameCtx[i].CommandAllocator);
+            ImGui_ImplDX12_DestroyRenderBuffers(&vd->FrameRenderBuffers[i]);
+        }
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplDX12_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData;
+
+    ImGui_WaitForPendingOperations(vd);
+
+    for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        SafeRelease(vd->FrameCtx[i].RenderTarget);
+
+    if (vd->SwapChain)
+    {
+        ID3D12Resource* back_buffer = nullptr;
+        DXGI_SWAP_CHAIN_DESC1 desc = {};
+        vd->SwapChain->GetDesc1(&desc);
+        vd->SwapChain->ResizeBuffers(0, (UINT)size.x, (UINT)size.y, desc.Format, desc.Flags);
+        for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        {
+            vd->SwapChain->GetBuffer(i, IID_PPV_ARGS(&back_buffer));
+            bd->pd3dDevice->CreateRenderTargetView(back_buffer, nullptr, vd->FrameCtx[i].RenderTargetCpuDescriptors);
+            vd->FrameCtx[i].RenderTarget = back_buffer;
+        }
+    }
+}
+
+static void ImGui_ImplDX12_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData;
+
+    ImGui_ImplDX12_FrameContext* frame_context = ImGui_WaitForNextFrameContext(vd);
+    UINT back_buffer_idx = vd->SwapChain->GetCurrentBackBufferIndex();
+
+    const ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+    D3D12_RESOURCE_BARRIER barrier = {};
+    barrier.Type = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
+    barrier.Flags = D3D12_RESOURCE_BARRIER_FLAG_NONE;
+    barrier.Transition.pResource = vd->FrameCtx[back_buffer_idx].RenderTarget;
+    barrier.Transition.Subresource = D3D12_RESOURCE_BARRIER_ALL_SUBRESOURCES;
+    barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_PRESENT;
+    barrier.Transition.StateAfter = D3D12_RESOURCE_STATE_RENDER_TARGET;
+
+    // Draw
+    ID3D12GraphicsCommandList* cmd_list = vd->CommandList;
+
+    frame_context->CommandAllocator->Reset();
+    cmd_list->Reset(frame_context->CommandAllocator, nullptr);
+    cmd_list->ResourceBarrier(1, &barrier);
+    cmd_list->OMSetRenderTargets(1, &vd->FrameCtx[back_buffer_idx].RenderTargetCpuDescriptors, FALSE, nullptr);
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+        cmd_list->ClearRenderTargetView(vd->FrameCtx[back_buffer_idx].RenderTargetCpuDescriptors, (const float*)&clear_color, 0, nullptr);
+    cmd_list->SetDescriptorHeaps(1, &bd->pd3dSrvDescHeap);
+
+    ImGui_ImplDX12_RenderDrawData(viewport->DrawData, cmd_list);
+
+    barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_RENDER_TARGET;
+    barrier.Transition.StateAfter = D3D12_RESOURCE_STATE_PRESENT;
+    cmd_list->ResourceBarrier(1, &barrier);
+    cmd_list->Close();
+
+    vd->CommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&cmd_list);
+
+    HRESULT hr = vd->CommandQueue->Signal(bd->Fence, ++bd->FenceLastSignaledValue);
+    IM_ASSERT(hr == S_OK);
+    frame_context->FenceValue = bd->FenceLastSignaledValue;
+}
+
+static void ImGui_ImplDX12_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData;
+
+    vd->SwapChain->Present(0, bd->tearingSupport ? DXGI_PRESENT_ALLOW_TEARING : 0);
+    vd->FrameIndex++;
+}
+
+void ImGui_ImplDX12_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX12_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX12_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX12_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX12_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX12_SwapBuffers;
+}
+
+void ImGui_ImplDX12_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_dx12.h

@@ -6,6 +6,7 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // The aim of imgui_impl_dx12.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/

backends/imgui_impl_dx9.cpp

@@ -6,6 +6,7 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: IMGUI_USE_BGRA_PACKED_COLOR support, as this is the optimal color encoding for DirectX9.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -17,6 +18,8 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
 //  2025-06-11: DirectX9: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas.
 //  2024-10-07: DirectX9: Changed default texture sampler to Clamp instead of Repeat/Wrap.
 //  2024-02-12: DirectX9: Using RGBA format when supported by the driver to avoid CPU side conversion. (#6575)
@@ -86,6 +89,12 @@ static ImGui_ImplDX9_Data* ImGui_ImplDX9_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX9_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX9_InitMultiViewportSupport();
+static void ImGui_ImplDX9_ShutdownMultiViewportSupport();
+static void ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows();
+static void ImGui_ImplDX9_InvalidateDeviceObjectsForPlatformWindows();
+
 // Functions
 static void ImGui_ImplDX9_SetupRenderState(ImDrawData* draw_data)
 {
@@ -228,9 +237,8 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
     // FIXME-OPT: This is a minor waste of resource, the ideal is to use imconfig.h and
     //  1) to avoid repacking colors:   #define IMGUI_USE_BGRA_PACKED_COLOR
     //  2) to avoid repacking vertices: #define IMGUI_OVERRIDE_DRAWVERT_STRUCT_LAYOUT struct ImDrawVert { ImVec2 pos; float z; ImU32 col; ImVec2 uv; }
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         const ImDrawVert* vtx_src = draw_list->VtxBuffer.Data;
         for (int i = 0; i < draw_list->VtxBuffer.Size; i++)
         {
@@ -260,9 +268,8 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
     int global_vtx_offset = 0;
     int global_idx_offset = 0;
     ImVec2 clip_off = draw_data->DisplayPos;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         for (int cmd_i = 0; cmd_i < draw_list->CmdBuffer.Size; cmd_i++)
         {
             const ImDrawCmd* pcmd = &draw_list->CmdBuffer[cmd_i];
@@ -297,6 +304,11 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
         global_vtx_offset += draw_list->VtxBuffer.Size;
     }
 
+    // When using multi-viewports, it appears that there's an odd logic in DirectX9 which prevent subsequent windows
+    // from rendering until the first window submits at least one draw call, even once. That's our workaround. (see #2560)
+    if (global_vtx_offset == 0)
+        bd->pd3dDevice->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, 0, 0, 0);
+
     // Restore the DX9 transform
     device->SetTransform(D3DTS_WORLD, &last_world);
     device->SetTransform(D3DTS_VIEW, &last_view);
@@ -337,6 +349,7 @@ bool ImGui_ImplDX9_Init(IDirect3DDevice9* device)
     io.BackendRendererName = "imgui_impl_dx9";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
     io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;   // We can honor ImGuiPlatformIO::Textures[] requests during render.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     platform_io.Renderer_TextureMaxWidth = platform_io.Renderer_TextureMaxHeight = 4096;
@@ -345,6 +358,8 @@ bool ImGui_ImplDX9_Init(IDirect3DDevice9* device)
     bd->pd3dDevice->AddRef();
     bd->HasRgbaSupport = ImGui_ImplDX9_CheckFormatSupport(bd->pd3dDevice, D3DFMT_A8B8G8R8);
 
+    ImGui_ImplDX9_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -353,12 +368,16 @@ void ImGui_ImplDX9_Shutdown()
     ImGui_ImplDX9_Data* bd = ImGui_ImplDX9_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
+    ImGui_ImplDX9_ShutdownMultiViewportSupport();
     ImGui_ImplDX9_InvalidateDeviceObjects();
     if (bd->pd3dDevice) { bd->pd3dDevice->Release(); }
+
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
 }
 
@@ -429,14 +448,14 @@ void ImGui_ImplDX9_UpdateTexture(ImTextureData* tex)
     }
     else if (tex->Status == ImTextureStatus_WantDestroy)
     {
-        LPDIRECT3DTEXTURE9 backend_tex = (LPDIRECT3DTEXTURE9)tex->TexID;
-        if (backend_tex == nullptr)
-            return;
-        IM_ASSERT(tex->TexID == (ImTextureID)(intptr_t)backend_tex);
-        backend_tex->Release();
+        if (LPDIRECT3DTEXTURE9 backend_tex = (LPDIRECT3DTEXTURE9)tex->TexID)
+        {
+            IM_ASSERT(tex->TexID == (ImTextureID)(intptr_t)backend_tex);
+            backend_tex->Release();
 
-        // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
-        tex->SetTexID(ImTextureID_Invalid);
+            // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
+            tex->SetTexID(ImTextureID_Invalid);
+        }
         tex->SetStatus(ImTextureStatus_Destroyed);
     }
 }
@@ -446,6 +465,7 @@ bool ImGui_ImplDX9_CreateDeviceObjects()
     ImGui_ImplDX9_Data* bd = ImGui_ImplDX9_GetBackendData();
     if (!bd || !bd->pd3dDevice)
         return false;
+    ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows();
     return true;
 }
 
@@ -464,6 +484,7 @@ void ImGui_ImplDX9_InvalidateDeviceObjects()
         }
     if (bd->pVB) { bd->pVB->Release(); bd->pVB = nullptr; }
     if (bd->pIB) { bd->pIB->Release(); bd->pIB = nullptr; }
+    ImGui_ImplDX9_InvalidateDeviceObjectsForPlatformWindows();
 }
 
 void ImGui_ImplDX9_NewFrame()
@@ -473,6 +494,148 @@ void ImGui_ImplDX9_NewFrame()
     IM_UNUSED(bd);
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplDX9_ViewportData
+{
+    IDirect3DSwapChain9*    SwapChain;
+    D3DPRESENT_PARAMETERS   d3dpp;
+
+    ImGui_ImplDX9_ViewportData()  { SwapChain = nullptr; ZeroMemory(&d3dpp, sizeof(D3DPRESENT_PARAMETERS)); }
+    ~ImGui_ImplDX9_ViewportData() { IM_ASSERT(SwapChain == nullptr); }
+};
+
+static void ImGui_ImplDX9_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplDX9_Data* bd = ImGui_ImplDX9_GetBackendData();
+    ImGui_ImplDX9_ViewportData* vd = IM_NEW(ImGui_ImplDX9_ViewportData)();
+    viewport->RendererUserData = vd;
+
+    // PlatformHandleRaw should always be a HWND, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL's WindowID).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+
+    ZeroMemory(&vd->d3dpp, sizeof(D3DPRESENT_PARAMETERS));
+    vd->d3dpp.Windowed = TRUE;
+    vd->d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
+    vd->d3dpp.BackBufferWidth = (UINT)viewport->Size.x;
+    vd->d3dpp.BackBufferHeight = (UINT)viewport->Size.y;
+    vd->d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
+    vd->d3dpp.hDeviceWindow = hwnd;
+    vd->d3dpp.EnableAutoDepthStencil = FALSE;
+    vd->d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
+    vd->d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;   // Present without vsync
+
+    HRESULT hr = bd->pd3dDevice->CreateAdditionalSwapChain(&vd->d3dpp, &vd->SwapChain); IM_UNUSED(hr);
+    IM_ASSERT(hr == D3D_OK);
+    IM_ASSERT(vd->SwapChain != nullptr);
+}
+
+static void ImGui_ImplDX9_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
+    if (ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData)
+    {
+        if (vd->SwapChain)
+            vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        ZeroMemory(&vd->d3dpp, sizeof(D3DPRESENT_PARAMETERS));
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplDX9_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplDX9_Data* bd = ImGui_ImplDX9_GetBackendData();
+    ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData;
+    if (vd->SwapChain)
+    {
+        vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        vd->d3dpp.BackBufferWidth = (UINT)size.x;
+        vd->d3dpp.BackBufferHeight = (UINT)size.y;
+        HRESULT hr = bd->pd3dDevice->CreateAdditionalSwapChain(&vd->d3dpp, &vd->SwapChain); IM_UNUSED(hr);
+        IM_ASSERT(hr == D3D_OK);
+    }
+}
+
+static void ImGui_ImplDX9_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX9_Data* bd = ImGui_ImplDX9_GetBackendData();
+    ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData;
+    ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+
+    LPDIRECT3DSURFACE9 render_target = nullptr;
+    LPDIRECT3DSURFACE9 last_render_target = nullptr;
+    LPDIRECT3DSURFACE9 last_depth_stencil = nullptr;
+    vd->SwapChain->GetBackBuffer(0, D3DBACKBUFFER_TYPE_MONO, &render_target);
+    bd->pd3dDevice->GetRenderTarget(0, &last_render_target);
+    bd->pd3dDevice->GetDepthStencilSurface(&last_depth_stencil);
+    bd->pd3dDevice->SetRenderTarget(0, render_target);
+    bd->pd3dDevice->SetDepthStencilSurface(nullptr);
+
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+    {
+        D3DCOLOR clear_col_dx = D3DCOLOR_RGBA((int)(clear_color.x*255.0f), (int)(clear_color.y*255.0f), (int)(clear_color.z*255.0f), (int)(clear_color.w*255.0f));
+        bd->pd3dDevice->Clear(0, nullptr, D3DCLEAR_TARGET, clear_col_dx, 1.0f, 0);
+    }
+
+    ImGui_ImplDX9_RenderDrawData(viewport->DrawData);
+
+    // Restore render target
+    bd->pd3dDevice->SetRenderTarget(0, last_render_target);
+    bd->pd3dDevice->SetDepthStencilSurface(last_depth_stencil);
+    render_target->Release();
+    last_render_target->Release();
+    if (last_depth_stencil) last_depth_stencil->Release();
+}
+
+static void ImGui_ImplDX9_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData;
+    HRESULT hr = vd->SwapChain->Present(nullptr, nullptr, vd->d3dpp.hDeviceWindow, nullptr, 0);
+    // Let main application handle D3DERR_DEVICELOST by resetting the device.
+    IM_ASSERT(SUCCEEDED(hr) || hr == D3DERR_DEVICELOST);
+}
+
+static void ImGui_ImplDX9_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX9_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX9_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX9_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX9_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX9_SwapBuffers;
+}
+
+static void ImGui_ImplDX9_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
+static void ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (!platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplDX9_CreateWindow(platform_io.Viewports[i]);
+}
+
+static void ImGui_ImplDX9_InvalidateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplDX9_DestroyWindow(platform_io.Viewports[i]);
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_dx9.h

@@ -6,6 +6,7 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: IMGUI_USE_BGRA_PACKED_COLOR support, as this is the optimal color encoding for DirectX9.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_glfw.cpp

@@ -9,10 +9,12 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLFW_KEY_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Resizing cursors requires GLFW 3.4+! Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 //  [X] Multiple Dear ImGui contexts support.
 // Missing features or Issues:
-//  [ ] Touch events are only correctly identified as Touch on Windows. This create issues with some interactions. GLFW doesn't provide a way to identify touch inputs from mouse inputs, we cannot call io.AddMouseSourceEvent() to identify the source. We provide a Windows-specific workaround.
-//  [ ] Missing ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress cursors.
+//  [ ] Platform: Touch events are only correctly identified as Touch on Windows. This create issues with some interactions. GLFW doesn't provide a way to identify touch inputs from mouse inputs, we cannot call io.AddMouseSourceEvent() to identify the source. We provide a Windows-specific workaround.
+//  [ ] Platform: Missing ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress cursors.
+//  [ ] Platform: Multi-viewport: Missing ImGuiBackendFlags_HasParentViewport support. The viewport->ParentViewportID field is ignored, and therefore io.ConfigViewportsNoDefaultParent has no effect either.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -29,11 +31,19 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-18: Call platform_io.ClearPlatformHandlers() on shutdown.
+//  2025-09-15: Content Scales are always reported as 1.0 on Wayland. FramebufferScale are always reported as 1.0 on X11. (#8920, #8921)
+//  2025-09-10: [Docking] Improve multi-viewport behavior in tiling WMs on X11 via the ImGui_ImplGlfw_SetWindowFloating() function. Note: using GLFW backend on Linux/BSD etc. requires linking with -lX11. (#8884, #8474, #8289)
 //  2025-07-08: Made ImGui_ImplGlfw_GetContentScaleForWindow(), ImGui_ImplGlfw_GetContentScaleForMonitor() helpers return 1.0f on Emscripten and Android platforms, matching macOS logic. (#8742, #8733)
 //  2025-06-18: Added support for multiple Dear ImGui contexts. (#8676, #8239, #8069)
 //  2025-06-11: Added ImGui_ImplGlfw_GetContentScaleForWindow(GLFWwindow* window) and ImGui_ImplGlfw_GetContentScaleForMonitor(GLFWmonitor* monitor) helper to facilitate making DPI-aware apps.
+//  2025-05-15: [Docking] Add Platform_GetWindowFramebufferScale() handler, to allow varying Retina display density on multiple monitors.
+//  2025-04-26: [Docking] Disable multi-viewports under Wayland. (#8587)
 //  2025-03-10: Map GLFW_KEY_WORLD_1 and GLFW_KEY_WORLD_2 into ImGuiKey_Oem102.
 //  2025-03-03: Fixed clipboard handler assertion when using GLFW <= 3.2.1 compiled with asserts enabled.
+//  2025-02-21: [Docking] Update monitors and work areas information every frame, as the later may change regardless of monitor changes. (#8415)
+//  2024-11-05: [Docking] Added Linux workaround for spurious mouse up events emitted while dragging and creating new viewport. (#3158, #7733, #7922)
 //  2024-08-22: Moved some OS/backend related function pointers from ImGuiIO to ImGuiPlatformIO:
 //               - io.GetClipboardTextFn    -> platform_io.Platform_GetClipboardTextFn
 //               - io.SetClipboardTextFn    -> platform_io.Platform_SetClipboardTextFn
@@ -50,6 +60,7 @@
 //  2023-03-16: Inputs: Fixed key modifiers handling on secondary viewports (docking branch). Broken on 2023/01/04. (#6248, #6034)
 //  2023-03-14: Emscripten: Avoid using glfwGetError() and glfwGetGamepadState() which are not correctly implemented in Emscripten emulation. (#6240)
 //  2023-02-03: Emscripten: Registering custom low-level mouse wheel handler to get more accurate scrolling impulses on Emscripten. (#4019, #6096)
+//  2023-01-18: Handle unsupported glfwGetVideoMode() call on e.g. Emscripten.
 //  2023-01-04: Inputs: Fixed mods state on Linux when using Alt-GR text input (e.g. German keyboard layout), could lead to broken text input. Revert a 2022/01/17 change were we resumed using mods provided by GLFW, turns out they were faulty.
 //  2022-11-22: Perform a dummy glfwGetError() read to cancel missing names with glfwGetKeyName(). (#5908)
 //  2022-10-18: Perform a dummy glfwGetError() read to cancel missing mouse cursors errors. Using GLFW_VERSION_COMBINED directly. (#5785)
@@ -100,24 +111,40 @@
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wold-style-cast"     // warning: use of old-style cast
 #pragma clang diagnostic ignored "-Wsign-conversion"    // warning: implicit conversion changes signedness
+#elif defined(__GNUC__)
+#pragma GCC diagnostic ignored "-Wfloat-equal"          // warning: comparing floating-point with '==' or '!=' is unsafe
 #endif
 
 // GLFW
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || defined(__DragonFly__)
+#define GLFW_HAS_X11_OR_WAYLAND     1
+#else
+#define GLFW_HAS_X11_OR_WAYLAND     0
+#endif
 #include <GLFW/glfw3.h>
-
 #ifdef _WIN32
 #undef APIENTRY
-#ifndef GLFW_EXPOSE_NATIVE_WIN32
+#ifndef GLFW_EXPOSE_NATIVE_WIN32    // for glfwGetWin32Window()
 #define GLFW_EXPOSE_NATIVE_WIN32
 #endif
-#include <GLFW/glfw3native.h>   // for glfwGetWin32Window()
-#endif
-#ifdef __APPLE__
-#ifndef GLFW_EXPOSE_NATIVE_COCOA
+#include <GLFW/glfw3native.h>
+#elif defined(__APPLE__)
+#ifndef GLFW_EXPOSE_NATIVE_COCOA    // for glfwGetCocoaWindow()
 #define GLFW_EXPOSE_NATIVE_COCOA
 #endif
-#include <GLFW/glfw3native.h>   // for glfwGetCocoaWindow()
+#include <GLFW/glfw3native.h>
+#elif GLFW_HAS_X11_OR_WAYLAND
+#ifndef GLFW_EXPOSE_NATIVE_X11      // for glfwGetX11Display(), glfwGetX11Window() on Freedesktop (Linux, BSD, etc.)
+#define GLFW_EXPOSE_NATIVE_X11
+#include <X11/Xatom.h>
 #endif
+#ifndef GLFW_EXPOSE_NATIVE_WAYLAND
+#define GLFW_EXPOSE_NATIVE_WAYLAND
+#endif
+#include <GLFW/glfw3native.h>
+#undef Status                   // X11 headers are leaking this.
+#endif
+
 #ifndef _WIN32
 #include <unistd.h>             // for usleep()
 #endif
@@ -135,17 +162,35 @@
 
 // We gather version tests as define in order to easily see which features are version-dependent.
 #define GLFW_VERSION_COMBINED           (GLFW_VERSION_MAJOR * 1000 + GLFW_VERSION_MINOR * 100 + GLFW_VERSION_REVISION)
+#define GLFW_HAS_WINDOW_TOPMOST         (GLFW_VERSION_COMBINED >= 3200) // 3.2+ GLFW_FLOATING
+#define GLFW_HAS_WINDOW_HOVERED         (GLFW_VERSION_COMBINED >= 3300) // 3.3+ GLFW_HOVERED
+#define GLFW_HAS_WINDOW_ALPHA           (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwSetWindowOpacity
 #define GLFW_HAS_PER_MONITOR_DPI        (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetMonitorContentScale
+#if defined(__EMSCRIPTEN__) || defined(__SWITCH__)                      // no Vulkan support in GLFW for Emscripten or homebrew Nintendo Switch
+#define GLFW_HAS_VULKAN                 (0)
+#else
+#define GLFW_HAS_VULKAN                 (GLFW_VERSION_COMBINED >= 3200) // 3.2+ glfwCreateWindowSurface
+#endif
+#define GLFW_HAS_FOCUS_WINDOW           (GLFW_VERSION_COMBINED >= 3200) // 3.2+ glfwFocusWindow
+#define GLFW_HAS_FOCUS_ON_SHOW          (GLFW_VERSION_COMBINED >= 3300) // 3.3+ GLFW_FOCUS_ON_SHOW
+#define GLFW_HAS_MONITOR_WORK_AREA      (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetMonitorWorkarea
+#define GLFW_HAS_OSX_WINDOW_POS_FIX     (GLFW_VERSION_COMBINED >= 3301) // 3.3.1+ Fixed: Resizing window repositions it on MacOS #1553
 #ifdef GLFW_RESIZE_NESW_CURSOR          // Let's be nice to people who pulled GLFW between 2019-04-16 (3.4 define) and 2019-11-29 (cursors defines) // FIXME: Remove when GLFW 3.4 is released?
 #define GLFW_HAS_NEW_CURSORS            (GLFW_VERSION_COMBINED >= 3400) // 3.4+ GLFW_RESIZE_ALL_CURSOR, GLFW_RESIZE_NESW_CURSOR, GLFW_RESIZE_NWSE_CURSOR, GLFW_NOT_ALLOWED_CURSOR
 #else
 #define GLFW_HAS_NEW_CURSORS            (0)
 #endif
+#ifdef GLFW_MOUSE_PASSTHROUGH           // Let's be nice to people who pulled GLFW between 2019-04-16 (3.4 define) and 2020-07-17 (passthrough)
+#define GLFW_HAS_MOUSE_PASSTHROUGH      (GLFW_VERSION_COMBINED >= 3400) // 3.4+ GLFW_MOUSE_PASSTHROUGH
+#else
+#define GLFW_HAS_MOUSE_PASSTHROUGH      (0)
+#endif
 #define GLFW_HAS_GAMEPAD_API            (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetGamepadState() new api
 #define GLFW_HAS_GETKEYNAME             (GLFW_VERSION_COMBINED >= 3200) // 3.2+ glfwGetKeyName()
 #define GLFW_HAS_GETERROR               (GLFW_VERSION_COMBINED >= 3300) // 3.3+ glfwGetError()
+#define GLFW_HAS_GETPLATFORM            (GLFW_VERSION_COMBINED >= 3400) // 3.4+ glfwGetPlatform()
 
-// Map GLFWWindow* to ImGuiContext*. 
+// Map GLFWWindow* to ImGuiContext*.
 // - Would be simpler if we could use glfwSetWindowUserPointer()/glfwGetWindowUserPointer(), but this is a single and shared resource.
 // - Would be simpler if we could use e.g. std::map<> as well. But we don't.
 // - This is not particularly optimized as we expect size to be small and queries to be rare.
@@ -155,14 +200,14 @@ static void ImGui_ImplGlfw_ContextMap_Add(GLFWwindow* window, ImGuiContext* ctx)
 static void ImGui_ImplGlfw_ContextMap_Remove(GLFWwindow* window)                 { for (ImGui_ImplGlfw_WindowToContext& entry : g_ContextMap) if (entry.Window == window) { g_ContextMap.erase_unsorted(&entry); return; } }
 static ImGuiContext* ImGui_ImplGlfw_ContextMap_Get(GLFWwindow* window)           { for (ImGui_ImplGlfw_WindowToContext& entry : g_ContextMap) if (entry.Window == window) return entry.Context; return nullptr; }
 
-// GLFW data
 enum GlfwClientApi
 {
-    GlfwClientApi_Unknown,
     GlfwClientApi_OpenGL,
     GlfwClientApi_Vulkan,
+    GlfwClientApi_Unknown,  // Anything else fits here.
 };
 
+// GLFW data
 struct ImGui_ImplGlfw_Data
 {
     ImGuiContext*           Context;
@@ -171,7 +216,11 @@ struct ImGui_ImplGlfw_Data
     double                  Time;
     GLFWwindow*             MouseWindow;
     GLFWcursor*             MouseCursors[ImGuiMouseCursor_COUNT];
+    bool                    MouseIgnoreButtonUpWaitForFocusLoss;
+    bool                    MouseIgnoreButtonUp;
     ImVec2                  LastValidMousePos;
+    GLFWwindow*             KeyOwnerWindows[GLFW_KEY_LAST];
+    bool                    IsWayland;
     bool                    InstalledCallbacks;
     bool                    CallbacksChainForAllWindows;
     char                    BackendPlatformName[32];
@@ -215,7 +264,29 @@ static ImGui_ImplGlfw_Data* ImGui_ImplGlfw_GetBackendData(GLFWwindow* window)
     return (ImGui_ImplGlfw_Data*)ImGui::GetIO(ctx).BackendPlatformUserData;
 }
 
+// Forward Declarations
+static void ImGui_ImplGlfw_UpdateMonitors();
+static void ImGui_ImplGlfw_InitMultiViewportSupport();
+static void ImGui_ImplGlfw_ShutdownMultiViewportSupport();
+
 // Functions
+static bool ImGui_ImplGlfw_IsWayland()
+{
+#if !GLFW_HAS_X11_OR_WAYLAND
+    return false;
+#elif GLFW_HAS_GETPLATFORM
+    return glfwGetPlatform() == GLFW_PLATFORM_WAYLAND;
+#else
+    const char* version = glfwGetVersionString();
+    if (strstr(version, "Wayland") == NULL) // e.g. Ubuntu 22.04 ships with GLFW 3.3.6 compiled without Wayland
+        return false;
+#ifdef GLFW_EXPOSE_NATIVE_X11
+    if (glfwGetX11Display() != NULL)
+        return false;
+#endif
+    return true;
+#endif
+}
 
 // Not static to allow third-party code to use that if they want to (but undocumented)
 ImGuiKey ImGui_ImplGlfw_KeyToImGuiKey(int keycode, int scancode);
@@ -365,10 +436,13 @@ static bool ImGui_ImplGlfw_ShouldChainCallback(ImGui_ImplGlfw_Data* bd, GLFWwind
 void ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow* window, int button, int action, int mods)
 {
     ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData(window);
-
     if (bd->PrevUserCallbackMousebutton != nullptr && ImGui_ImplGlfw_ShouldChainCallback(bd, window))
         bd->PrevUserCallbackMousebutton(window, button, action, mods);
 
+    // Workaround for Linux: ignore mouse up events which are following an focus loss following a viewport creation
+    if (bd->MouseIgnoreButtonUp && action == GLFW_RELEASE)
+        return;
+
     ImGuiIO& io = ImGui::GetIO(bd->Context);
     ImGui_ImplGlfw_UpdateKeyModifiers(io, window);
     if (button >= 0 && button < ImGuiMouseButton_COUNT)
@@ -436,6 +510,9 @@ void ImGui_ImplGlfw_KeyCallback(GLFWwindow* window, int keycode, int scancode, i
     ImGuiIO& io = ImGui::GetIO(bd->Context);
     ImGui_ImplGlfw_UpdateKeyModifiers(io, window);
 
+    if (keycode >= 0 && keycode < IM_ARRAYSIZE(bd->KeyOwnerWindows))
+        bd->KeyOwnerWindows[keycode] = (action == GLFW_PRESS) ? window : nullptr;
+
     keycode = ImGui_ImplGlfw_TranslateUntranslatedKey(keycode, scancode);
 
     ImGuiKey imgui_key = ImGui_ImplGlfw_KeyToImGuiKey(keycode, scancode);
@@ -449,6 +526,10 @@ void ImGui_ImplGlfw_WindowFocusCallback(GLFWwindow* window, int focused)
     if (bd->PrevUserCallbackWindowFocus != nullptr && ImGui_ImplGlfw_ShouldChainCallback(bd, window))
         bd->PrevUserCallbackWindowFocus(window, focused);
 
+    // Workaround for Linux: when losing focus with MouseIgnoreButtonUpWaitForFocusLoss set, we will temporarily ignore subsequent Mouse Up events
+    bd->MouseIgnoreButtonUp = (bd->MouseIgnoreButtonUpWaitForFocusLoss && focused == 0);
+    bd->MouseIgnoreButtonUpWaitForFocusLoss = false;
+
     ImGuiIO& io = ImGui::GetIO(bd->Context);
     io.AddFocusEvent(focused != 0);
 }
@@ -460,6 +541,13 @@ void ImGui_ImplGlfw_CursorPosCallback(GLFWwindow* window, double x, double y)
         bd->PrevUserCallbackCursorPos(window, x, y);
 
     ImGuiIO& io = ImGui::GetIO(bd->Context);
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        int window_x, window_y;
+        glfwGetWindowPos(window, &window_x, &window_y);
+        x += window_x;
+        y += window_y;
+    }
     io.AddMousePosEvent((float)x, (float)y);
     bd->LastValidMousePos = ImVec2((float)x, (float)y);
 }
@@ -498,7 +586,7 @@ void ImGui_ImplGlfw_CharCallback(GLFWwindow* window, unsigned int c)
 
 void ImGui_ImplGlfw_MonitorCallback(GLFWmonitor*, int)
 {
-    // Unused in 'master' branch but 'docking' branch will use this, so we declare it ahead of it so if you have to install callbacks you can install this one too.
+    // This function is technically part of the API even if we stopped using the callback, so leaving it around.
 }
 
 #ifdef EMSCRIPTEN_USE_EMBEDDED_GLFW3
@@ -521,35 +609,7 @@ static EM_BOOL ImGui_ImplEmscripten_WheelCallback(int, const EmscriptenWheelEven
 #endif
 
 #ifdef _WIN32
-// GLFW doesn't allow to distinguish Mouse vs TouchScreen vs Pen.
-// Add support for Win32 (based on imgui_impl_win32), because we rely on _TouchScreen info to trickle inputs differently.
-static ImGuiMouseSource GetMouseSourceFromMessageExtraInfo()
-{
-    LPARAM extra_info = ::GetMessageExtraInfo();
-    if ((extra_info & 0xFFFFFF80) == 0xFF515700)
-        return ImGuiMouseSource_Pen;
-    if ((extra_info & 0xFFFFFF80) == 0xFF515780)
-        return ImGuiMouseSource_TouchScreen;
-    return ImGuiMouseSource_Mouse;
-}
-static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
-{
-    ImGui_ImplGlfw_Data* bd = (ImGui_ImplGlfw_Data*)::GetPropA(hWnd, "IMGUI_BACKEND_DATA");
-    ImGuiIO& io = ImGui::GetIO(bd->Context);
-
-    switch (msg)
-    {
-    case WM_MOUSEMOVE: case WM_NCMOUSEMOVE:
-    case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK: case WM_LBUTTONUP:
-    case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK: case WM_RBUTTONUP:
-    case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK: case WM_MBUTTONUP:
-    case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK: case WM_XBUTTONUP:
-        io.AddMouseSourceEvent(GetMouseSourceFromMessageExtraInfo());
-        break;
-    default: break;
-    }
-    return ::CallWindowProcW(bd->PrevWndProc, hWnd, msg, wParam, lParam);
-}
+static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 #endif
 
 void ImGui_ImplGlfw_InstallCallbacks(GLFWwindow* window)
@@ -594,7 +654,7 @@ void ImGui_ImplGlfw_RestoreCallbacks(GLFWwindow* window)
     bd->PrevUserCallbackMonitor = nullptr;
 }
 
-// Set to 'true' to enable chaining installed callbacks for all windows (including secondary viewports created by backends or by user.
+// Set to 'true' to enable chaining installed callbacks for all windows (including secondary viewports created by backends or by user).
 // This is 'false' by default meaning we only chain callbacks for the main viewport.
 // We cannot set this to 'true' by default because user callbacks code may be not testing the 'window' parameter of their callback.
 // If you set this to 'true' your user callback code will need to make sure you are testing the 'window' parameter.
@@ -627,9 +687,24 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
 
+    bool has_viewports = false;
+#ifndef __EMSCRIPTEN__
+    has_viewports = true;
+#if GLFW_HAS_GETPLATFORM
+    if (glfwGetPlatform() == GLFW_PLATFORM_WAYLAND)
+        has_viewports = false;
+#endif
+    if (has_viewports)
+        io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;  // We can create multi-viewports on the Platform side (optional)
+#endif
+#if GLFW_HAS_MOUSE_PASSTHROUGH || GLFW_HAS_WINDOW_HOVERED
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
+#endif
+
     bd->Context = ImGui::GetCurrentContext();
     bd->Window = window;
     bd->Time = 0.0;
+    bd->IsWayland = ImGui_ImplGlfw_IsWayland();
     ImGui_ImplGlfw_ContextMap_Add(window, bd->Context);
 
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
@@ -675,6 +750,11 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     if (install_callbacks)
         ImGui_ImplGlfw_InstallCallbacks(window);
 
+    // Update monitor a first time during init
+    // (note: monitor callback are broken in GLFW 3.2 and earlier, see github.com/glfw/glfw/issues/784)
+    ImGui_ImplGlfw_UpdateMonitors();
+    glfwSetMonitorCallback(ImGui_ImplGlfw_MonitorCallback);
+
     // Set platform dependent data in viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = (void*)bd->Window;
@@ -685,6 +765,8 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
 #else
     IM_UNUSED(main_viewport);
 #endif
+    if (has_viewports)
+        ImGui_ImplGlfw_InitMultiViewportSupport();
 
     // Windows: register a WndProc hook so we can intercept some messages.
 #ifdef _WIN32
@@ -735,8 +817,11 @@ void ImGui_ImplGlfw_Shutdown()
 {
     ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
-    ImGuiIO& io = ImGui::GetIO();
 
+    ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+
+    ImGui_ImplGlfw_ShutdownMultiViewportSupport();
     if (bd->InstalledCallbacks)
         ImGui_ImplGlfw_RestoreCallbacks(bd->Window);
 #ifdef EMSCRIPTEN_USE_EMBEDDED_GLFW3
@@ -757,7 +842,8 @@ void ImGui_ImplGlfw_Shutdown()
 
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad);
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad | ImGuiBackendFlags_PlatformHasViewports | ImGuiBackendFlags_HasMouseHoveredViewport);
+    platform_io.ClearPlatformHandlers();
     ImGui_ImplGlfw_ContextMap_Remove(bd->Window);
     IM_DELETE(bd);
 }
@@ -766,10 +852,15 @@ static void ImGui_ImplGlfw_UpdateMouseData()
 {
     ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
-    // (those braces are here to reduce diff with multi-viewports support in 'docking' branch)
+    ImGuiID mouse_viewport_id = 0;
+    const ImVec2 mouse_pos_prev = io.MousePos;
+    for (int n = 0; n < platform_io.Viewports.Size; n++)
     {
-        GLFWwindow* window = bd->Window;
+        ImGuiViewport* viewport = platform_io.Viewports[n];
+        GLFWwindow* window = (GLFWwindow*)viewport->PlatformHandle;
+
 #ifdef EMSCRIPTEN_USE_EMBEDDED_GLFW3
         const bool is_window_focused = true;
 #else
@@ -778,19 +869,54 @@ static void ImGui_ImplGlfw_UpdateMouseData()
         if (is_window_focused)
         {
             // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when io.ConfigNavMoveSetMousePos is enabled by user)
+            // When multi-viewports are enabled, all Dear ImGui positions are same as OS positions.
             if (io.WantSetMousePos)
-                glfwSetCursorPos(window, (double)io.MousePos.x, (double)io.MousePos.y);
+                glfwSetCursorPos(window, (double)(mouse_pos_prev.x - viewport->Pos.x), (double)(mouse_pos_prev.y - viewport->Pos.y));
 
             // (Optional) Fallback to provide mouse position when focused (ImGui_ImplGlfw_CursorPosCallback already provides this when hovered or captured)
             if (bd->MouseWindow == nullptr)
             {
                 double mouse_x, mouse_y;
                 glfwGetCursorPos(window, &mouse_x, &mouse_y);
+                if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+                {
+                    // Single viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
+                    // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+                    int window_x, window_y;
+                    glfwGetWindowPos(window, &window_x, &window_y);
+                    mouse_x += window_x;
+                    mouse_y += window_y;
+                }
                 bd->LastValidMousePos = ImVec2((float)mouse_x, (float)mouse_y);
                 io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
             }
         }
+
+        // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+        // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+        // - [X] GLFW >= 3.3 backend ON WINDOWS ONLY does correctly ignore viewports with the _NoInputs flag (since we implement hit via our WndProc hook)
+        //       On other platforms we rely on the library fallbacking to its own search when reporting a viewport with _NoInputs flag.
+        // - [!] GLFW <= 3.2 backend CANNOT correctly ignore viewports with the _NoInputs flag, and CANNOT reported Hovered Viewport because of mouse capture.
+        //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+        //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+        //       by the backend, and use its flawed heuristic to guess the viewport behind.
+        // - [X] GLFW backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+        // FIXME: This is currently only correct on Win32. See what we do below with the WM_NCHITTEST, missing an equivalent for other systems.
+        // See https://github.com/glfw/glfw/issues/1236 if you want to help in making this a GLFW feature.
+#if GLFW_HAS_MOUSE_PASSTHROUGH
+        const bool window_no_input = (viewport->Flags & ImGuiViewportFlags_NoInputs) != 0;
+        glfwSetWindowAttrib(window, GLFW_MOUSE_PASSTHROUGH, window_no_input);
+#endif
+#if GLFW_HAS_MOUSE_PASSTHROUGH || GLFW_HAS_WINDOW_HOVERED
+        if (glfwGetWindowAttrib(window, GLFW_HOVERED))
+            mouse_viewport_id = viewport->ID;
+#else
+        // We cannot use bd->MouseWindow maintained from CursorEnter/Leave callbacks, because it is locked to the window capturing mouse.
+#endif
     }
+
+    if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)
+        io.AddMouseViewportEvent(mouse_viewport_id);
 }
 
 static void ImGui_ImplGlfw_UpdateMouseCursor()
@@ -801,9 +927,10 @@ static void ImGui_ImplGlfw_UpdateMouseCursor()
         return;
 
     ImGuiMouseCursor imgui_cursor = ImGui::GetMouseCursor();
-    // (those braces are here to reduce diff with multi-viewports support in 'docking' branch)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int n = 0; n < platform_io.Viewports.Size; n++)
     {
-        GLFWwindow* window = bd->Window;
+        GLFWwindow* window = (GLFWwindow*)platform_io.Viewports[n]->PlatformHandle;
         if (imgui_cursor == ImGuiMouseCursor_None || io.MouseDrawCursor)
         {
             // Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
@@ -872,11 +999,54 @@ static void ImGui_ImplGlfw_UpdateGamepads()
     #undef MAP_ANALOG
 }
 
+static void ImGui_ImplGlfw_UpdateMonitors()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+
+    int monitors_count = 0;
+    GLFWmonitor** glfw_monitors = glfwGetMonitors(&monitors_count);
+    if (monitors_count == 0) // Preserve existing monitor list if there are none. Happens on macOS sleeping (#5683)
+        return;
+
+    platform_io.Monitors.resize(0);
+    for (int n = 0; n < monitors_count; n++)
+    {
+        ImGuiPlatformMonitor monitor;
+        int x, y;
+        glfwGetMonitorPos(glfw_monitors[n], &x, &y);
+        const GLFWvidmode* vid_mode = glfwGetVideoMode(glfw_monitors[n]);
+        if (vid_mode == nullptr)
+            continue; // Failed to get Video mode (e.g. Emscripten does not support this function)
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)x, (float)y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)vid_mode->width, (float)vid_mode->height);
+#if GLFW_HAS_MONITOR_WORK_AREA
+        int w, h;
+        glfwGetMonitorWorkarea(glfw_monitors[n], &x, &y, &w, &h);
+        if (w > 0 && h > 0) // Workaround a small GLFW issue reporting zero on monitor changes: https://github.com/glfw/glfw/pull/1761
+        {
+            monitor.WorkPos = ImVec2((float)x, (float)y);
+            monitor.WorkSize = ImVec2((float)w, (float)h);
+        }
+#endif
+        float scale = ImGui_ImplGlfw_GetContentScaleForMonitor(glfw_monitors[n]);
+        if (scale == 0.0f)
+            continue; // Some accessibility applications are declaring virtual monitors with a DPI of 0, see #7902.
+        monitor.DpiScale = scale;
+        monitor.PlatformHandle = (void*)glfw_monitors[n]; // [...] GLFW doc states: "guaranteed to be valid only until the monitor configuration changes"
+        platform_io.Monitors.push_back(monitor);
+    }
+}
+
 // - On Windows the process needs to be marked DPI-aware!! SDL2 doesn't do it by default. You can call ::SetProcessDPIAware() or call ImGui_ImplWin32_EnableDpiAwareness() from Win32 backend.
 // - Apple platforms use FramebufferScale so we always return 1.0f.
 // - Some accessibility applications are declaring virtual monitors with a DPI of 0.0f, see #7902. We preserve this value for caller to handle.
 float ImGui_ImplGlfw_GetContentScaleForWindow(GLFWwindow* window)
 {
+#if GLFW_HAS_X11_OR_WAYLAND
+    if (ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData(window))
+        if (bd->IsWayland)
+            return 1.0f;
+#endif
 #if GLFW_HAS_PER_MONITOR_DPI && !(defined(__APPLE__) || defined(__EMSCRIPTEN__) || defined(__ANDROID__))
     float x_scale, y_scale;
     glfwGetWindowContentScale(window, &x_scale, &y_scale);
@@ -889,6 +1059,10 @@ float ImGui_ImplGlfw_GetContentScaleForWindow(GLFWwindow* window)
 
 float ImGui_ImplGlfw_GetContentScaleForMonitor(GLFWmonitor* monitor)
 {
+#if GLFW_HAS_X11_OR_WAYLAND
+    if (ImGui_ImplGlfw_IsWayland()) // We can't access our bd->IsWayland cache for a monitor.
+        return 1.0f;
+#endif
 #if GLFW_HAS_PER_MONITOR_DPI && !(defined(__APPLE__) || defined(__EMSCRIPTEN__) || defined(__ANDROID__))
     float x_scale, y_scale;
     glfwGetMonitorContentScale(monitor, &x_scale, &y_scale);
@@ -905,10 +1079,17 @@ static void ImGui_ImplGlfw_GetWindowSizeAndFramebufferScale(GLFWwindow* window,
     int display_w, display_h;
     glfwGetWindowSize(window, &w, &h);
     glfwGetFramebufferSize(window, &display_w, &display_h);
+    float fb_scale_x = (w > 0) ? (float)display_w / w : 1.0f;
+    float fb_scale_y = (h > 0) ? (float)display_h / h : 1.0f;
+#if GLFW_HAS_X11_OR_WAYLAND
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData(window);
+    if (!bd->IsWayland)
+        fb_scale_x = fb_scale_y = 1.0f;
+#endif
     if (out_size != nullptr)
         *out_size = ImVec2((float)w, (float)h);
     if (out_framebuffer_scale != nullptr)
-        *out_framebuffer_scale = (w > 0 && h > 0) ? ImVec2((float)display_w / (float)w, (float)display_h / (float)h) : ImVec2(1.0f, 1.0f);
+        *out_framebuffer_scale = ImVec2(fb_scale_x, fb_scale_y);
 }
 
 void ImGui_ImplGlfw_NewFrame()
@@ -919,6 +1100,7 @@ void ImGui_ImplGlfw_NewFrame()
 
     // Setup main viewport size (every frame to accommodate for window resizing)
     ImGui_ImplGlfw_GetWindowSizeAndFramebufferScale(bd->Window, &io.DisplaySize, &io.DisplayFramebufferScale);
+    ImGui_ImplGlfw_UpdateMonitors();
 
     // Setup time step
     // (Accept glfwGetTime() not returning a monotonically increasing value. Seems to happens on disconnecting peripherals and probably on VMs and Emscripten, see #6491, #6189, #6114, #3644)
@@ -928,6 +1110,7 @@ void ImGui_ImplGlfw_NewFrame()
     io.DeltaTime = bd->Time > 0.0 ? (float)(current_time - bd->Time) : (float)(1.0f / 60.0f);
     bd->Time = current_time;
 
+    bd->MouseIgnoreButtonUp = false;
     ImGui_ImplGlfw_UpdateMouseData();
     ImGui_ImplGlfw_UpdateMouseCursor();
 
@@ -997,6 +1180,444 @@ void ImGui_ImplGlfw_InstallEmscriptenCallbacks(GLFWwindow* window, const char* c
 }
 #endif // #ifdef EMSCRIPTEN_USE_PORT_CONTRIB_GLFW3
 
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* PlatformUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplGlfw_ViewportData
+{
+    GLFWwindow* Window;             // Stored in ImGuiViewport::PlatformHandle
+    bool        WindowOwned;
+    int         IgnoreWindowPosEventFrame;
+    int         IgnoreWindowSizeEventFrame;
+#ifdef _WIN32
+    WNDPROC     PrevWndProc;
+#endif
+
+    ImGui_ImplGlfw_ViewportData()  { memset((void*)this, 0, sizeof(*this)); IgnoreWindowSizeEventFrame = IgnoreWindowPosEventFrame = -1; }
+    ~ImGui_ImplGlfw_ViewportData() { IM_ASSERT(Window == nullptr); }
+};
+
+static void ImGui_ImplGlfw_WindowCloseCallback(GLFWwindow* window)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+        viewport->PlatformRequestClose = true;
+}
+
+// GLFW may dispatch window pos/size events after calling glfwSetWindowPos()/glfwSetWindowSize().
+// However: depending on the platform the callback may be invoked at different time:
+// - on Windows it appears to be called within the glfwSetWindowPos()/glfwSetWindowSize() call
+// - on Linux it is queued and invoked during glfwPollEvents()
+// Because the event doesn't always fire on glfwSetWindowXXX() we use a frame counter tag to only
+// ignore recent glfwSetWindowXXX() calls.
+static void ImGui_ImplGlfw_WindowPosCallback(GLFWwindow* window, int, int)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+    {
+        if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+        {
+            bool ignore_event = (ImGui::GetFrameCount() <= vd->IgnoreWindowPosEventFrame + 1);
+            //data->IgnoreWindowPosEventFrame = -1;
+            if (ignore_event)
+                return;
+        }
+        viewport->PlatformRequestMove = true;
+    }
+}
+
+static void ImGui_ImplGlfw_WindowSizeCallback(GLFWwindow* window, int, int)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+    {
+        if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+        {
+            bool ignore_event = (ImGui::GetFrameCount() <= vd->IgnoreWindowSizeEventFrame + 1);
+            //data->IgnoreWindowSizeEventFrame = -1;
+            if (ignore_event)
+                return;
+        }
+        viewport->PlatformRequestResize = true;
+    }
+}
+
+#if !defined(__APPLE__) && !defined(_WIN32) && !defined(__EMSCRIPTEN__) && GLFW_HAS_GETPLATFORM
+#define IMGUI_GLFW_HAS_SETWINDOWFLOATING
+static void ImGui_ImplGlfw_SetWindowFloating(GLFWwindow* window)
+{
+#ifdef GLFW_EXPOSE_NATIVE_X11
+    if (glfwGetPlatform() == GLFW_PLATFORM_X11)
+    {
+        Display* display = glfwGetX11Display();
+        Window xwindow = glfwGetX11Window(window);
+        Atom wm_type = XInternAtom(display, "_NET_WM_WINDOW_TYPE", False);
+        Atom wm_type_dialog = XInternAtom(display, "_NET_WM_WINDOW_TYPE_DIALOG", False);
+        XChangeProperty(display, xwindow, wm_type, XA_ATOM, 32, PropModeReplace, (unsigned char*)&wm_type_dialog, 1);
+        XSetWindowAttributes attrs;
+        attrs.override_redirect = False;
+        XChangeWindowAttributes(display, xwindow, CWOverrideRedirect, &attrs);
+        XFlush(display);
+    }
+#endif // GLFW_EXPOSE_NATIVE_X11
+#ifdef GLFW_EXPOSE_NATIVE_WAYLAND
+    // FIXME: Help needed, see #8884, #8474 for discussions about this.
+#endif // GLFW_EXPOSE_NATIVE_X11
+}
+#endif // IMGUI_GLFW_HAS_SETWINDOWFLOATING
+
+static void ImGui_ImplGlfw_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = IM_NEW(ImGui_ImplGlfw_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    // Workaround for Linux: ignore mouse up events corresponding to losing focus of the previously focused window (#7733, #3158, #7922)
+#ifdef __linux__
+    bd->MouseIgnoreButtonUpWaitForFocusLoss = true;
+#endif
+
+    // GLFW 3.2 unfortunately always set focus on glfwCreateWindow() if GLFW_VISIBLE is set, regardless of GLFW_FOCUSED
+    // With GLFW 3.3, the hint GLFW_FOCUS_ON_SHOW fixes this problem
+    glfwWindowHint(GLFW_VISIBLE, false);
+    glfwWindowHint(GLFW_FOCUSED, false);
+#if GLFW_HAS_FOCUS_ON_SHOW
+    glfwWindowHint(GLFW_FOCUS_ON_SHOW, false);
+#endif
+    glfwWindowHint(GLFW_DECORATED, (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? false : true);
+#if GLFW_HAS_WINDOW_TOPMOST
+    glfwWindowHint(GLFW_FLOATING, (viewport->Flags & ImGuiViewportFlags_TopMost) ? true : false);
+#endif
+    GLFWwindow* share_window = (bd->ClientApi == GlfwClientApi_OpenGL) ? bd->Window : nullptr;
+    vd->Window = glfwCreateWindow((int)viewport->Size.x, (int)viewport->Size.y, "No Title Yet", nullptr, share_window);
+    vd->WindowOwned = true;
+    ImGui_ImplGlfw_ContextMap_Add(vd->Window, bd->Context);
+    viewport->PlatformHandle = (void*)vd->Window;
+#ifdef IMGUI_GLFW_HAS_SETWINDOWFLOATING
+    ImGui_ImplGlfw_SetWindowFloating(vd->Window);
+#endif
+#ifdef _WIN32
+    viewport->PlatformHandleRaw = glfwGetWin32Window(vd->Window);
+    ::SetPropA((HWND)viewport->PlatformHandleRaw, "IMGUI_BACKEND_DATA", bd);
+#elif defined(__APPLE__)
+    viewport->PlatformHandleRaw = (void*)glfwGetCocoaWindow(vd->Window);
+#endif
+    glfwSetWindowPos(vd->Window, (int)viewport->Pos.x, (int)viewport->Pos.y);
+
+    // Install GLFW callbacks for secondary viewports
+    glfwSetWindowFocusCallback(vd->Window, ImGui_ImplGlfw_WindowFocusCallback);
+    glfwSetCursorEnterCallback(vd->Window, ImGui_ImplGlfw_CursorEnterCallback);
+    glfwSetCursorPosCallback(vd->Window, ImGui_ImplGlfw_CursorPosCallback);
+    glfwSetMouseButtonCallback(vd->Window, ImGui_ImplGlfw_MouseButtonCallback);
+    glfwSetScrollCallback(vd->Window, ImGui_ImplGlfw_ScrollCallback);
+    glfwSetKeyCallback(vd->Window, ImGui_ImplGlfw_KeyCallback);
+    glfwSetCharCallback(vd->Window, ImGui_ImplGlfw_CharCallback);
+    glfwSetWindowCloseCallback(vd->Window, ImGui_ImplGlfw_WindowCloseCallback);
+    glfwSetWindowPosCallback(vd->Window, ImGui_ImplGlfw_WindowPosCallback);
+    glfwSetWindowSizeCallback(vd->Window, ImGui_ImplGlfw_WindowSizeCallback);
+    if (bd->ClientApi == GlfwClientApi_OpenGL)
+    {
+        glfwMakeContextCurrent(vd->Window);
+        glfwSwapInterval(0);
+    }
+}
+
+static void ImGui_ImplGlfw_DestroyWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+    {
+        if (vd->WindowOwned)
+        {
+#if !GLFW_HAS_MOUSE_PASSTHROUGH && GLFW_HAS_WINDOW_HOVERED && defined(_WIN32)
+            HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+            ::RemovePropA(hwnd, "IMGUI_VIEWPORT");
+#endif
+
+            // Release any keys that were pressed in the window being destroyed and are still held down,
+            // because we will not receive any release events after window is destroyed.
+            for (int i = 0; i < IM_ARRAYSIZE(bd->KeyOwnerWindows); i++)
+                if (bd->KeyOwnerWindows[i] == vd->Window)
+                    ImGui_ImplGlfw_KeyCallback(vd->Window, i, 0, GLFW_RELEASE, 0); // Later params are only used for main viewport, on which this function is never called.
+
+            ImGui_ImplGlfw_ContextMap_Remove(vd->Window);
+            glfwDestroyWindow(vd->Window);
+        }
+        vd->Window = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplGlfw_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+
+#if defined(_WIN32)
+    // GLFW hack: Hide icon from task bar
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+    if (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon)
+    {
+        LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
+        ex_style &= ~WS_EX_APPWINDOW;
+        ex_style |= WS_EX_TOOLWINDOW;
+        ::SetWindowLong(hwnd, GWL_EXSTYLE, ex_style);
+    }
+
+    // GLFW hack: install WndProc for mouse source event and WM_NCHITTEST message handler.
+    ::SetPropA(hwnd, "IMGUI_VIEWPORT", viewport);
+    vd->PrevWndProc = (WNDPROC)::GetWindowLongPtrW(hwnd, GWLP_WNDPROC);
+    ::SetWindowLongPtrW(hwnd, GWLP_WNDPROC, (LONG_PTR)ImGui_ImplGlfw_WndProc);
+
+#if !GLFW_HAS_FOCUS_ON_SHOW
+    // GLFW hack: GLFW 3.2 has a bug where glfwShowWindow() also activates/focus the window.
+    // The fix was pushed to GLFW repository on 2018/01/09 and should be included in GLFW 3.3 via a GLFW_FOCUS_ON_SHOW window attribute.
+    // See https://github.com/glfw/glfw/issues/1189
+    // FIXME-VIEWPORT: Implement same work-around for Linux/OSX in the meanwhile.
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+    {
+        ::ShowWindow(hwnd, SW_SHOWNA);
+        return;
+    }
+#endif
+#endif
+
+    glfwShowWindow(vd->Window);
+}
+
+static ImVec2 ImGui_ImplGlfw_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    int x = 0, y = 0;
+    glfwGetWindowPos(vd->Window, &x, &y);
+    return ImVec2((float)x, (float)y);
+}
+
+static void ImGui_ImplGlfw_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    vd->IgnoreWindowPosEventFrame = ImGui::GetFrameCount();
+    glfwSetWindowPos(vd->Window, (int)pos.x, (int)pos.y);
+}
+
+static ImVec2 ImGui_ImplGlfw_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    int w = 0, h = 0;
+    glfwGetWindowSize(vd->Window, &w, &h);
+    return ImVec2((float)w, (float)h);
+}
+
+static void ImGui_ImplGlfw_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+#if defined(__APPLE__) && !GLFW_HAS_OSX_WINDOW_POS_FIX
+    // Native OS windows are positioned from the bottom-left corner on macOS, whereas on other platforms they are
+    // positioned from the upper-left corner. GLFW makes an effort to convert macOS style coordinates, however it
+    // doesn't handle it when changing size. We are manually moving the window in order for changes of size to be based
+    // on the upper-left corner.
+    int x, y, width, height;
+    glfwGetWindowPos(vd->Window, &x, &y);
+    glfwGetWindowSize(vd->Window, &width, &height);
+    glfwSetWindowPos(vd->Window, x, y - height + size.y);
+#endif
+    vd->IgnoreWindowSizeEventFrame = ImGui::GetFrameCount();
+    glfwSetWindowSize(vd->Window, (int)size.x, (int)size.y);
+}
+
+static ImVec2 ImGui_ImplGlfw_GetWindowFramebufferScale(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    ImVec2 framebuffer_scale;
+    ImGui_ImplGlfw_GetWindowSizeAndFramebufferScale(vd->Window, nullptr, &framebuffer_scale);
+    return framebuffer_scale;
+}
+
+static void ImGui_ImplGlfw_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    glfwSetWindowTitle(vd->Window, title);
+}
+
+static void ImGui_ImplGlfw_SetWindowFocus(ImGuiViewport* viewport)
+{
+#if GLFW_HAS_FOCUS_WINDOW
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    glfwFocusWindow(vd->Window);
+#else
+    // FIXME: What are the effect of not having this function? At the moment imgui doesn't actually call SetWindowFocus - we set that up ahead, will answer that question later.
+    (void)viewport;
+#endif
+}
+
+static bool ImGui_ImplGlfw_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    return glfwGetWindowAttrib(vd->Window, GLFW_FOCUSED) != 0;
+}
+
+static bool ImGui_ImplGlfw_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    return glfwGetWindowAttrib(vd->Window, GLFW_ICONIFIED) != 0;
+}
+
+#if GLFW_HAS_WINDOW_ALPHA
+static void ImGui_ImplGlfw_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    glfwSetWindowOpacity(vd->Window, alpha);
+}
+#endif
+
+static void ImGui_ImplGlfw_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    if (bd->ClientApi == GlfwClientApi_OpenGL)
+        glfwMakeContextCurrent(vd->Window);
+}
+
+static void ImGui_ImplGlfw_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    if (bd->ClientApi == GlfwClientApi_OpenGL)
+    {
+        glfwMakeContextCurrent(vd->Window);
+        glfwSwapBuffers(vd->Window);
+    }
+}
+
+//--------------------------------------------------------------------------------------------------------
+// Vulkan support (the Vulkan renderer needs to call a platform-side support function to create the surface)
+//--------------------------------------------------------------------------------------------------------
+
+// Avoid including <vulkan.h> so we can build without it
+#if GLFW_HAS_VULKAN
+#ifndef VULKAN_H_
+#define VK_DEFINE_HANDLE(object) typedef struct object##_T* object;
+#if defined(__LP64__) || defined(_WIN64) || defined(__x86_64__) || defined(_M_X64) || defined(__ia64) || defined (_M_IA64) || defined(__aarch64__) || defined(__powerpc64__)
+#define VK_DEFINE_NON_DISPATCHABLE_HANDLE(object) typedef struct object##_T *object;
+#else
+#define VK_DEFINE_NON_DISPATCHABLE_HANDLE(object) typedef uint64_t object;
+#endif
+VK_DEFINE_HANDLE(VkInstance)
+VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkSurfaceKHR)
+struct VkAllocationCallbacks;
+enum VkResult { VK_RESULT_MAX_ENUM = 0x7FFFFFFF };
+#endif // VULKAN_H_
+extern "C" { extern GLFWAPI VkResult glfwCreateWindowSurface(VkInstance instance, GLFWwindow* window, const VkAllocationCallbacks* allocator, VkSurfaceKHR* surface); }
+static int ImGui_ImplGlfw_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_instance, const void* vk_allocator, ImU64* out_vk_surface)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    IM_UNUSED(bd);
+    IM_ASSERT(bd->ClientApi == GlfwClientApi_Vulkan);
+    VkResult err = glfwCreateWindowSurface((VkInstance)vk_instance, vd->Window, (const VkAllocationCallbacks*)vk_allocator, (VkSurfaceKHR*)out_vk_surface);
+    return (int)err;
+}
+#endif // GLFW_HAS_VULKAN
+
+static void ImGui_ImplGlfw_InitMultiViewportSupport()
+{
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplGlfw_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplGlfw_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplGlfw_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplGlfw_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplGlfw_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplGlfw_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplGlfw_GetWindowSize;
+    platform_io.Platform_GetWindowFramebufferScale = ImGui_ImplGlfw_GetWindowFramebufferScale;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplGlfw_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplGlfw_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplGlfw_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplGlfw_SetWindowTitle;
+    platform_io.Platform_RenderWindow = ImGui_ImplGlfw_RenderWindow;
+    platform_io.Platform_SwapBuffers = ImGui_ImplGlfw_SwapBuffers;
+#if GLFW_HAS_WINDOW_ALPHA
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplGlfw_SetWindowAlpha;
+#endif
+#if GLFW_HAS_VULKAN
+    platform_io.Platform_CreateVkSurface = ImGui_ImplGlfw_CreateVkSurface;
+#endif
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplGlfw_ViewportData* vd = IM_NEW(ImGui_ImplGlfw_ViewportData)();
+    vd->Window = bd->Window;
+    vd->WindowOwned = false;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = (void*)bd->Window;
+}
+
+static void ImGui_ImplGlfw_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
+//-----------------------------------------------------------------------------
+
+// WndProc hook (declared here because we will need access to ImGui_ImplGlfw_ViewportData)
+#ifdef _WIN32
+static ImGuiMouseSource GetMouseSourceFromMessageExtraInfo()
+{
+    LPARAM extra_info = ::GetMessageExtraInfo();
+    if ((extra_info & 0xFFFFFF80) == 0xFF515700)
+        return ImGuiMouseSource_Pen;
+    if ((extra_info & 0xFFFFFF80) == 0xFF515780)
+        return ImGuiMouseSource_TouchScreen;
+    return ImGuiMouseSource_Mouse;
+}
+static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    ImGui_ImplGlfw_Data* bd = (ImGui_ImplGlfw_Data*)::GetPropA(hWnd, "IMGUI_BACKEND_DATA");
+    ImGuiIO& io = ImGui::GetIO(bd->Context);
+
+    WNDPROC prev_wndproc = bd->PrevWndProc;
+    ImGuiViewport* viewport = (ImGuiViewport*)::GetPropA(hWnd, "IMGUI_VIEWPORT");
+    if (viewport != NULL)
+        if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+            prev_wndproc = vd->PrevWndProc;
+
+    switch (msg)
+    {
+        // GLFW doesn't allow to distinguish Mouse vs TouchScreen vs Pen.
+        // Add support for Win32 (based on imgui_impl_win32), because we rely on _TouchScreen info to trickle inputs differently.
+    case WM_MOUSEMOVE: case WM_NCMOUSEMOVE:
+    case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK: case WM_LBUTTONUP:
+    case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK: case WM_RBUTTONUP:
+    case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK: case WM_MBUTTONUP:
+    case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK: case WM_XBUTTONUP:
+        io.AddMouseSourceEvent(GetMouseSourceFromMessageExtraInfo());
+        break;
+
+        // We have submitted https://github.com/glfw/glfw/pull/1568 to allow GLFW to support "transparent inputs".
+        // In the meanwhile we implement custom per-platform workarounds here (FIXME-VIEWPORT: Implement same work-around for Linux/OSX!)
+#if !GLFW_HAS_MOUSE_PASSTHROUGH && GLFW_HAS_WINDOW_HOVERED
+    case WM_NCHITTEST:
+    {
+        // Let mouse pass-through the window. This will allow the backend to call io.AddMouseViewportEvent() properly (which is OPTIONAL).
+        // The ImGuiViewportFlags_NoInputs flag is set while dragging a viewport, as want to detect the window behind the one we are dragging.
+        // If you cannot easily access those viewport flags from your windowing/event code: you may manually synchronize its state e.g. in
+        // your main loop after calling UpdatePlatformWindows(). Iterate all viewports/platform windows and pass the flag to your windowing system.
+        if (viewport && (viewport->Flags & ImGuiViewportFlags_NoInputs))
+            return HTTRANSPARENT;
+        break;
+    }
+#endif
+    default: break;
+    }
+    return ::CallWindowProcW(prev_wndproc, hWnd, msg, wParam, lParam);
+}
+#endif // #ifdef _WIN32
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_glfw.h

@@ -1,6 +1,7 @@
 // dear imgui: Platform Backend for GLFW
 // This needs to be used along with a Renderer (e.g. OpenGL3, Vulkan, WebGPU..)
 // (Info: GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
+// (Requires: GLFW 3.1+. Prefer GLFW 3.3+ for full feature support.)
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
@@ -8,10 +9,12 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLFW_KEY_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Resizing cursors requires GLFW 3.4+! Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 //  [X] Multiple Dear ImGui contexts support.
 // Missing features or Issues:
-//  [ ] Touch events are only correctly identified as Touch on Windows. This create issues with some interactions. GLFW doesn't provide a way to identify touch inputs from mouse inputs, we cannot call io.AddMouseSourceEvent() to identify the source. We provide a Windows-specific workaround.
-//  [ ] Missing ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress cursors.
+//  [ ] Platform: Touch events are only correctly identified as Touch on Windows. This create issues with some interactions. GLFW doesn't provide a way to identify touch inputs from mouse inputs, we cannot call io.AddMouseSourceEvent() to identify the source. We provide a Windows-specific workaround.
+//  [ ] Platform: Missing ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress cursors.
+//  [ ] Platform: Multi-viewport: Missing ImGuiBackendFlags_HasParentViewport support. The viewport->ParentViewportID field is ignored, and therefore io.ConfigViewportsNoDefaultParent has no effect either.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_glut.cpp

@@ -13,6 +13,7 @@
 //  [ ] Platform: Missing mouse cursor shape/visibility support.
 //  [ ] Platform: Missing clipboard support (not supported by Glut).
 //  [ ] Platform: Missing gamepad support.
+//  [ ] Platform: Missing multi-viewport support (multiple windows).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_glut.h

@@ -13,6 +13,7 @@
 //  [ ] Platform: Missing mouse cursor shape/visibility support.
 //  [ ] Platform: Missing clipboard support (not supported by Glut).
 //  [ ] Platform: Missing gamepad support.
+//  [ ] Platform: Missing multi-viewport support (multiple windows).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_metal.h

@@ -5,6 +5,7 @@
 //  [X] Renderer: User texture binding. Use 'MTLTexture' as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_metal.mm

@@ -5,6 +5,7 @@
 //  [X] Renderer: User texture binding. Use 'MTLTexture' as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -16,9 +17,11 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Metal: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
 //  2025-06-11: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. Removed ImGui_ImplMetal_CreateFontsTexture() and ImGui_ImplMetal_DestroyFontsTexture().
 //  2025-02-03: Metal: Crash fix. (#8367)
-//  2024-01-08: Metal: Fixed memory leaks when using metal-cpp (#8276, #8166) or when using multiple contexts (#7419).
+//  2025-01-08: Metal: Fixed memory leaks when using metal-cpp (#8276, #8166) or when using multiple contexts (#7419).
 //  2022-08-23: Metal: Update deprecated property 'sampleCount'->'rasterSampleCount'.
 //  2022-07-05: Metal: Add dispatch synchronization.
 //  2022-06-30: Metal: Use __bridge for ARC based systems.
@@ -42,6 +45,12 @@
 #import <time.h>
 #import <Metal/Metal.h>
 
+// Forward Declarations
+static void ImGui_ImplMetal_InitMultiViewportSupport();
+static void ImGui_ImplMetal_ShutdownMultiViewportSupport();
+static void ImGui_ImplMetal_CreateDeviceObjectsForPlatformWindows();
+static void ImGui_ImplMetal_InvalidateDeviceObjectsForPlatformWindows();
+
 #pragma mark - Support classes
 
 // A wrapper around a MTLBuffer object that knows the last time it was reused
@@ -136,10 +145,13 @@ bool ImGui_ImplMetal_Init(id<MTLDevice> device)
     io.BackendRendererName = "imgui_impl_metal";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
     io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;   // We can honor ImGuiPlatformIO::Textures[] requests during render.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     bd->SharedMetalContext = [[MetalContext alloc] init];
     bd->SharedMetalContext.device = device;
 
+    ImGui_ImplMetal_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -148,13 +160,17 @@ void ImGui_ImplMetal_Shutdown()
     ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData();
     IM_UNUSED(bd);
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
+    ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+
+    ImGui_ImplMetal_ShutdownMultiViewportSupport();
     ImGui_ImplMetal_DestroyDeviceObjects();
     ImGui_ImplMetal_DestroyBackendData();
 
-    ImGuiIO& io = ImGui::GetIO();
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
+    platform_io.ClearRendererHandlers();
 }
 
 void ImGui_ImplMetal_NewFrame(MTLRenderPassDescriptor* renderPassDescriptor)
@@ -223,7 +239,7 @@ void ImGui_ImplMetal_RenderDrawData(ImDrawData* draw_data, id<MTLCommandBuffer>
     // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
     int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
     int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
-    if (fb_width <= 0 || fb_height <= 0 || draw_data->CmdListsCount == 0)
+    if (fb_width <= 0 || fb_height <= 0 || draw_data->CmdLists.Size == 0)
         return;
 
     // Catch up with texture updates. Most of the times, the list will have 1 element with an OK status, aka nothing to do.
@@ -259,10 +275,8 @@ void ImGui_ImplMetal_RenderDrawData(ImDrawData* draw_data, id<MTLCommandBuffer>
     // Render command lists
     size_t vertexBufferOffset = 0;
     size_t indexBufferOffset = 0;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
-
         memcpy((char*)vertexBuffer.buffer.contents + vertexBufferOffset, draw_list->VtxBuffer.Data, (size_t)draw_list->VtxBuffer.Size * sizeof(ImDrawVert));
         memcpy((char*)indexBuffer.buffer.contents + indexBufferOffset, draw_list->IdxBuffer.Data, (size_t)draw_list->IdxBuffer.Size * sizeof(ImDrawIdx));
 
@@ -336,16 +350,16 @@ void ImGui_ImplMetal_RenderDrawData(ImDrawData* draw_data, id<MTLCommandBuffer>
 
 static void ImGui_ImplMetal_DestroyTexture(ImTextureData* tex)
 {
-    MetalTexture* backend_tex = (__bridge_transfer MetalTexture*)(tex->BackendUserData);
-    if (backend_tex == nullptr)
-        return;
-    IM_ASSERT(backend_tex.metalTexture == (__bridge id<MTLTexture>)(void*)(intptr_t)tex->TexID);
-    backend_tex.metalTexture = nil;
+    if (MetalTexture* backend_tex = (__bridge_transfer MetalTexture*)(tex->BackendUserData))
+    {
+        IM_ASSERT(backend_tex.metalTexture == (__bridge id<MTLTexture>)(void*)(intptr_t)tex->TexID);
+        backend_tex.metalTexture = nil;
 
-    // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
-    tex->SetTexID(ImTextureID_Invalid);
+        // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
+        tex->SetTexID(ImTextureID_Invalid);
+        tex->BackendUserData = nullptr;
+    }
     tex->SetStatus(ImTextureStatus_Destroyed);
-    tex->BackendUserData = nullptr;
 }
 
 void ImGui_ImplMetal_UpdateTexture(ImTextureData* tex)
@@ -408,6 +422,7 @@ bool ImGui_ImplMetal_CreateDeviceObjects(id<MTLDevice> device)
     depthStencilDescriptor.depthWriteEnabled = NO;
     depthStencilDescriptor.depthCompareFunction = MTLCompareFunctionAlways;
     bd->SharedMetalContext.depthStencilState = [device newDepthStencilStateWithDescriptor:depthStencilDescriptor];
+    ImGui_ImplMetal_CreateDeviceObjectsForPlatformWindows();
 #ifdef IMGUI_IMPL_METAL_CPP
     [depthStencilDescriptor release];
 #endif
@@ -424,9 +439,154 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
         if (tex->RefCount == 1)
             ImGui_ImplMetal_DestroyTexture(tex);
 
+    ImGui_ImplMetal_InvalidateDeviceObjectsForPlatformWindows();
     [bd->SharedMetalContext.renderPipelineStateCache removeAllObjects];
 }
 
+#pragma mark - Multi-viewport support
+
+#import <QuartzCore/CAMetalLayer.h>
+
+#if TARGET_OS_OSX
+#import <Cocoa/Cocoa.h>
+#endif
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the back-end to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+struct ImGuiViewportDataMetal
+{
+    CAMetalLayer*               MetalLayer;
+    id<MTLCommandQueue>         CommandQueue;
+    MTLRenderPassDescriptor*    RenderPassDescriptor;
+    void*                       Handle = nullptr;
+    bool                        FirstFrame = true;
+};
+
+static void ImGui_ImplMetal_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData();
+    ImGuiViewportDataMetal* data = IM_NEW(ImGuiViewportDataMetal)();
+    viewport->RendererUserData = data;
+
+    // PlatformHandleRaw should always be a NSWindow*, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL_Window*).
+    // Some back-ends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the NSWindow*.
+    void* handle = viewport->PlatformHandleRaw ? viewport->PlatformHandleRaw : viewport->PlatformHandle;
+    IM_ASSERT(handle != nullptr);
+
+    id<MTLDevice> device = bd->SharedMetalContext.device;
+    CAMetalLayer* layer = [CAMetalLayer layer];
+    layer.device = device;
+    layer.framebufferOnly = YES;
+    layer.pixelFormat = bd->SharedMetalContext.framebufferDescriptor.colorPixelFormat;
+#if TARGET_OS_OSX
+    NSWindow* window = (__bridge NSWindow*)handle;
+    NSView* view = window.contentView;
+    view.layer = layer;
+    view.wantsLayer = YES;
+#endif
+    data->MetalLayer = layer;
+    data->CommandQueue = [device newCommandQueue];
+    data->RenderPassDescriptor = [[MTLRenderPassDescriptor alloc] init];
+    data->Handle = handle;
+}
+
+static void ImGui_ImplMetal_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
+    if (ImGuiViewportDataMetal* data = (ImGuiViewportDataMetal*)viewport->RendererUserData)
+        IM_DELETE(data);
+    viewport->RendererUserData = nullptr;
+}
+
+inline static CGSize MakeScaledSize(CGSize size, CGFloat scale)
+{
+    return CGSizeMake(size.width * scale, size.height * scale);
+}
+
+static void ImGui_ImplMetal_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGuiViewportDataMetal* data = (ImGuiViewportDataMetal*)viewport->RendererUserData;
+    data->MetalLayer.drawableSize = MakeScaledSize(CGSizeMake(size.x, size.y), viewport->DpiScale);
+}
+
+static void ImGui_ImplMetal_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGuiViewportDataMetal* data = (ImGuiViewportDataMetal*)viewport->RendererUserData;
+
+#if TARGET_OS_OSX
+    void* handle = viewport->PlatformHandleRaw ? viewport->PlatformHandleRaw : viewport->PlatformHandle;
+    NSWindow* window = (__bridge NSWindow*)handle;
+
+    // Always render the first frame, regardless of occlusionState, to avoid an initial flicker
+    if ((window.occlusionState & NSWindowOcclusionStateVisible) == 0 && !data->FirstFrame)
+    {
+        // Do not render windows which are completely occluded. Calling -[CAMetalLayer nextDrawable] will hang for
+        // approximately 1 second if the Metal layer is completely occluded.
+        return;
+    }
+    data->FirstFrame = false;
+
+    float fb_scale = (float)window.backingScaleFactor;
+    if (data->MetalLayer.contentsScale != fb_scale)
+    {
+        data->MetalLayer.contentsScale = fb_scale;
+        data->MetalLayer.drawableSize = MakeScaledSize(window.frame.size, fb_scale);
+    }
+#endif
+
+    id <CAMetalDrawable> drawable = [data->MetalLayer nextDrawable];
+    if (drawable == nil)
+        return;
+
+    MTLRenderPassDescriptor* renderPassDescriptor = data->RenderPassDescriptor;
+    renderPassDescriptor.colorAttachments[0].texture = drawable.texture;
+    renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(0, 0, 0, 0);
+    if ((viewport->Flags & ImGuiViewportFlags_NoRendererClear) == 0)
+        renderPassDescriptor.colorAttachments[0].loadAction = MTLLoadActionClear;
+
+    id <MTLCommandBuffer> commandBuffer = [data->CommandQueue commandBuffer];
+    id <MTLRenderCommandEncoder> renderEncoder = [commandBuffer renderCommandEncoderWithDescriptor:renderPassDescriptor];
+    ImGui_ImplMetal_RenderDrawData(viewport->DrawData, commandBuffer, renderEncoder);
+    [renderEncoder endEncoding];
+
+    [commandBuffer presentDrawable:drawable];
+    [commandBuffer commit];
+}
+
+static void ImGui_ImplMetal_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplMetal_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplMetal_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplMetal_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplMetal_RenderWindow;
+}
+
+static void ImGui_ImplMetal_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
+static void ImGui_ImplMetal_CreateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (!platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplMetal_CreateWindow(platform_io.Viewports[i]);
+}
+
+static void ImGui_ImplMetal_InvalidateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplMetal_DestroyWindow(platform_io.Viewports[i]);
+}
+
 #pragma mark - MetalBuffer implementation
 
 @implementation MetalBuffer

backends/imgui_impl_opengl2.cpp

@@ -4,6 +4,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 // Missing features or Issues:
 //  [ ] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 
@@ -25,6 +26,9 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
+//  2025-07-15: OpenGL: Set GL_UNPACK_ALIGNMENT to 1 before updating textures. (#8802)
 //  2025-06-11: OpenGL: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. Removed ImGui_ImplOpenGL2_CreateFontsTexture() and ImGui_ImplOpenGL2_DestroyFontsTexture().
 //  2024-10-07: OpenGL: Changed default texture sampler to Clamp instead of Repeat/Wrap.
 //  2024-06-28: OpenGL: ImGui_ImplOpenGL2_NewFrame() recreates font texture if it has been destroyed by ImGui_ImplOpenGL2_DestroyFontsTexture(). (#7748)
@@ -93,6 +97,10 @@ static ImGui_ImplOpenGL2_Data* ImGui_ImplOpenGL2_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL2_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplOpenGL2_InitMultiViewportSupport();
+static void ImGui_ImplOpenGL2_ShutdownMultiViewportSupport();
+
 // Functions
 bool    ImGui_ImplOpenGL2_Init()
 {
@@ -105,6 +113,9 @@ bool    ImGui_ImplOpenGL2_Init()
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_opengl2";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;       // We can honor ImGuiPlatformIO::Textures[] requests during render.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;      // We can create multi-viewports on the Renderer side (optional)
+
+    ImGui_ImplOpenGL2_InitMultiViewportSupport();
 
     return true;
 }
@@ -114,11 +125,15 @@ void    ImGui_ImplOpenGL2_Shutdown()
     ImGui_ImplOpenGL2_Data* bd = ImGui_ImplOpenGL2_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
+    ImGui_ImplOpenGL2_ShutdownMultiViewportSupport();
     ImGui_ImplOpenGL2_DestroyDeviceObjects();
+
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasTextures);
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
 }
 
@@ -208,9 +223,8 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
     ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
 
     // Render command lists
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         const ImDrawVert* vtx_buffer = draw_list->VtxBuffer.Data;
         const ImDrawIdx* idx_buffer = draw_list->IdxBuffer.Data;
         glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + offsetof(ImDrawVert, pos)));
@@ -286,6 +300,7 @@ void ImGui_ImplOpenGL2_UpdateTexture(ImTextureData* tex)
         GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP));
         GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP));
         GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
+        GL_CALL(glPixelStorei(GL_UNPACK_ALIGNMENT, 1));
         GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tex->Width, tex->Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels));
 
         // Store identifiers
@@ -305,6 +320,7 @@ void ImGui_ImplOpenGL2_UpdateTexture(ImTextureData* tex)
         GLuint gl_tex_id = (GLuint)(intptr_t)tex->TexID;
         GL_CALL(glBindTexture(GL_TEXTURE_2D, gl_tex_id));
         GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, tex->Width));
+        GL_CALL(glPixelStorei(GL_UNPACK_ALIGNMENT, 1));
         for (ImTextureRect& r : tex->Updates)
             GL_CALL(glTexSubImage2D(GL_TEXTURE_2D, 0, r.x, r.y, r.w, r.h, GL_RGBA, GL_UNSIGNED_BYTE, tex->GetPixelsAt(r.x, r.y)));
         GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
@@ -337,6 +353,35 @@ void    ImGui_ImplOpenGL2_DestroyDeviceObjects()
         }
 }
 
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplOpenGL2_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+    {
+        ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+        glClear(GL_COLOR_BUFFER_BIT);
+    }
+    ImGui_ImplOpenGL2_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplOpenGL2_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL2_RenderWindow;
+}
+
+static void ImGui_ImplOpenGL2_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_opengl2.h

@@ -4,6 +4,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 // Missing features or Issues:
 //  [ ] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 

backends/imgui_impl_opengl3.cpp

@@ -7,6 +7,7 @@
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
 //  [x] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset) [Desktop OpenGL only!]
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // About WebGL/ES:
 // - You need to '#define IMGUI_IMPL_OPENGL_ES2' or '#define IMGUI_IMPL_OPENGL_ES3' to use WebGL or OpenGL ES.
@@ -23,6 +24,10 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
+//  2025-07-22: OpenGL: Add and call embedded loader shutdown during ImGui_ImplOpenGL3_Shutdown() to facilitate multiple init/shutdown cycles in same process. (#8792)
+//  2025-07-15: OpenGL: Set GL_UNPACK_ALIGNMENT to 1 before updating textures (#8802) + restore non-WebGL/ES update path that doesn't require a CPU-side copy.
 //  2025-06-11: OpenGL: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. Removed ImGui_ImplOpenGL3_CreateFontsTexture() and ImGui_ImplOpenGL3_DestroyFontsTexture().
 //  2025-06-04: OpenGL: Made GLES 3.20 contexts not access GL_CONTEXT_PROFILE_MASK nor GL_PRIMITIVE_RESTART. (#8664)
 //  2025-02-18: OpenGL: Lazily reinitialize embedded GL loader for when calling backend from e.g. other DLL boundaries. (#8406)
@@ -244,6 +249,7 @@ struct ImGui_ImplOpenGL3_Data
     GLsizeiptr      VertexBufferSize;
     GLsizeiptr      IndexBufferSize;
     bool            HasPolygonMode;
+    bool            HasBindSampler;
     bool            HasClipOrigin;
     bool            UseBufferSubData;
     ImVector<char>  TempBuffer;
@@ -258,6 +264,10 @@ static ImGui_ImplOpenGL3_Data* ImGui_ImplOpenGL3_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL3_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplOpenGL3_InitMultiViewportSupport();
+static void ImGui_ImplOpenGL3_ShutdownMultiViewportSupport();
+
 // OpenGL vertex attribute state (for ES 1.0 and ES 2.0 only)
 #ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
 struct ImGui_ImplOpenGL3_VtxAttribState
@@ -364,6 +374,7 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
         io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
 #endif
     io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;       // We can honor ImGuiPlatformIO::Textures[] requests during render.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;      // We can create multi-viewports on the Renderer side (optional)
 
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     platform_io.Renderer_TextureMaxWidth = platform_io.Renderer_TextureMaxHeight = (int)bd->MaxTextureSize;
@@ -394,6 +405,9 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     // Detect extensions we support
 #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_POLYGON_MODE
     bd->HasPolygonMode = (!bd->GlProfileIsES2 && !bd->GlProfileIsES3);
+#endif
+#ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
+    bd->HasBindSampler = (bd->GlVersion >= 330 || bd->GlProfileIsES3);
 #endif
     bd->HasClipOrigin = (bd->GlVersion >= 450);
 #ifdef IMGUI_IMPL_OPENGL_HAS_EXTENSIONS
@@ -407,6 +421,8 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     }
 #endif
 
+    ImGui_ImplOpenGL3_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -415,12 +431,20 @@ void    ImGui_ImplOpenGL3_Shutdown()
     ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
+    ImGui_ImplOpenGL3_ShutdownMultiViewportSupport();
     ImGui_ImplOpenGL3_DestroyDeviceObjects();
+
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
+
+#ifdef IMGUI_IMPL_OPENGL_LOADER_IMGL3W
+    imgl3wShutdown();
+#endif
 }
 
 void    ImGui_ImplOpenGL3_NewFrame()
@@ -489,7 +513,7 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid
     glUniformMatrix4fv(bd->AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
 
 #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
-    if (bd->GlVersion >= 330 || bd->GlProfileIsES3)
+    if (bd->HasBindSampler)
         glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 and GL ES 3.0 may set that otherwise.
 #endif
 
@@ -537,7 +561,7 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
     GLuint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&last_program);
     GLuint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, (GLint*)&last_texture);
 #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
-    GLuint last_sampler; if (bd->GlVersion >= 330 || bd->GlProfileIsES3) { glGetIntegerv(GL_SAMPLER_BINDING, (GLint*)&last_sampler); } else { last_sampler = 0; }
+    GLuint last_sampler; if (bd->HasBindSampler) { glGetIntegerv(GL_SAMPLER_BINDING, (GLint*)&last_sampler); } else { last_sampler = 0; }
 #endif
     GLuint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, (GLint*)&last_array_buffer);
 #ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
@@ -584,10 +608,8 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
     ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
 
     // Render command lists
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
-
         // Upload vertex/index buffers
         // - OpenGL drivers are in a very sorry state nowadays....
         //   During 2021 we attempted to switch from glBufferData() to orphaning+glBufferSubData() following reports
@@ -664,7 +686,7 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
     if (last_program == 0 || glIsProgram(last_program)) glUseProgram(last_program);
     glBindTexture(GL_TEXTURE_2D, last_texture);
 #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
-    if (bd->GlVersion >= 330 || bd->GlProfileIsES3)
+    if (bd->HasBindSampler)
         glBindSampler(0, last_sampler);
 #endif
     glActiveTexture(last_active_texture);
@@ -711,6 +733,17 @@ static void ImGui_ImplOpenGL3_DestroyTexture(ImTextureData* tex)
 
 void ImGui_ImplOpenGL3_UpdateTexture(ImTextureData* tex)
 {
+    // FIXME: Consider backing up and restoring
+    if (tex->Status == ImTextureStatus_WantCreate || tex->Status == ImTextureStatus_WantUpdates)
+    {
+#ifdef GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
+        GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
+#endif
+#ifdef GL_UNPACK_ALIGNMENT
+        GL_CALL(glPixelStorei(GL_UNPACK_ALIGNMENT, 1));
+#endif
+    }
+
     if (tex->Status == ImTextureStatus_WantCreate)
     {
         // Create and upload new texture to graphics system
@@ -730,9 +763,6 @@ void ImGui_ImplOpenGL3_UpdateTexture(ImTextureData* tex)
         GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
         GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
         GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
-#ifdef GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
-        GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, 0));
-#endif
         GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tex->Width, tex->Height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels));
 
         // Store identifiers
@@ -751,7 +781,7 @@ void ImGui_ImplOpenGL3_UpdateTexture(ImTextureData* tex)
 
         GLuint gl_tex_id = (GLuint)(intptr_t)tex->TexID;
         GL_CALL(glBindTexture(GL_TEXTURE_2D, gl_tex_id));
-#if 0// GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
+#if GL_UNPACK_ROW_LENGTH // Not on WebGL/ES
         GL_CALL(glPixelStorei(GL_UNPACK_ROW_LENGTH, tex->Width));
         for (ImTextureRect& r : tex->Updates)
             GL_CALL(glTexSubImage2D(GL_TEXTURE_2D, 0, r.x, r.y, r.w, r.h, GL_RGBA, GL_UNSIGNED_BYTE, tex->GetPixelsAt(r.x, r.y)));
@@ -1026,6 +1056,34 @@ void    ImGui_ImplOpenGL3_DestroyDeviceObjects()
             ImGui_ImplOpenGL3_DestroyTexture(tex);
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplOpenGL3_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+    {
+        ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+        glClear(GL_COLOR_BUFFER_BIT);
+    }
+    ImGui_ImplOpenGL3_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplOpenGL3_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL3_RenderWindow;
+}
+
+static void ImGui_ImplOpenGL3_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__GNUC__)

backends/imgui_impl_opengl3.h

@@ -7,6 +7,7 @@
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture as texture identifier. Read the FAQ about ImTextureID/ImTextureRef!
 //  [x] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset) [Desktop OpenGL only!]
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // About WebGL/ES:
 // - You need to '#define IMGUI_IMPL_OPENGL_ES2' or '#define IMGUI_IMPL_OPENGL_ES3' to use WebGL or OpenGL ES.

backends/imgui_impl_opengl3_loader.h

@@ -166,6 +166,7 @@ typedef khronos_uint8_t GLubyte;
 #define GL_SCISSOR_BOX                    0x0C10
 #define GL_SCISSOR_TEST                   0x0C11
 #define GL_UNPACK_ROW_LENGTH              0x0CF2
+#define GL_UNPACK_ALIGNMENT               0x0CF5
 #define GL_PACK_ALIGNMENT                 0x0D05
 #define GL_MAX_TEXTURE_SIZE               0x0D33
 #define GL_TEXTURE_2D                     0x0DE1
@@ -179,6 +180,7 @@ typedef khronos_uint8_t GLubyte;
 #define GL_RENDERER                       0x1F01
 #define GL_VERSION                        0x1F02
 #define GL_EXTENSIONS                     0x1F03
+#define GL_NEAREST                        0x2600
 #define GL_LINEAR                         0x2601
 #define GL_TEXTURE_MAG_FILTER             0x2800
 #define GL_TEXTURE_MIN_FILTER             0x2801
@@ -399,9 +401,15 @@ GLAPI void APIENTRY glDrawElementsBaseVertex (GLenum mode, GLsizei count, GLenum
 #ifndef GL_VERSION_3_3
 #define GL_VERSION_3_3 1
 #define GL_SAMPLER_BINDING                0x8919
+typedef void (APIENTRYP PFNGLGENSAMPLERSPROC) (GLsizei count, GLuint *samplers);
+typedef void (APIENTRYP PFNGLDELETESAMPLERSPROC) (GLsizei count, const GLuint *samplers);
 typedef void (APIENTRYP PFNGLBINDSAMPLERPROC) (GLuint unit, GLuint sampler);
+typedef void (APIENTRYP PFNGLSAMPLERPARAMETERIPROC) (GLuint sampler, GLenum pname, GLint param);
 #ifdef GL_GLEXT_PROTOTYPES
+GLAPI void APIENTRY glGenSamplers (GLsizei count, GLuint *samplers);
+GLAPI void APIENTRY glDeleteSamplers (GLsizei count, const GLuint *samplers);
 GLAPI void APIENTRY glBindSampler (GLuint unit, GLuint sampler);
+GLAPI void APIENTRY glSamplerParameteri (GLuint sampler, GLenum pname, GLint param);
 #endif
 #endif /* GL_VERSION_3_3 */
 #ifndef GL_VERSION_4_1
@@ -476,12 +484,13 @@ typedef GL3WglProc (*GL3WGetProcAddressProc)(const char *proc);
 /* gl3w api */
 GL3W_API int imgl3wInit(void);
 GL3W_API int imgl3wInit2(GL3WGetProcAddressProc proc);
+GL3W_API void imgl3wShutdown(void);
 GL3W_API int imgl3wIsSupported(int major, int minor);
 GL3W_API GL3WglProc imgl3wGetProcAddress(const char *proc);
 
 /* gl3w internal state */
 union ImGL3WProcs {
-    GL3WglProc ptr[60];
+    GL3WglProc ptr[63];
     struct {
         PFNGLACTIVETEXTUREPROC            ActiveTexture;
         PFNGLATTACHSHADERPROC             AttachShader;
@@ -501,6 +510,7 @@ union ImGL3WProcs {
         PFNGLCREATESHADERPROC             CreateShader;
         PFNGLDELETEBUFFERSPROC            DeleteBuffers;
         PFNGLDELETEPROGRAMPROC            DeleteProgram;
+        PFNGLDELETESAMPLERSPROC           DeleteSamplers;
         PFNGLDELETESHADERPROC             DeleteShader;
         PFNGLDELETETEXTURESPROC           DeleteTextures;
         PFNGLDELETEVERTEXARRAYSPROC       DeleteVertexArrays;
@@ -513,6 +523,7 @@ union ImGL3WProcs {
         PFNGLENABLEVERTEXATTRIBARRAYPROC  EnableVertexAttribArray;
         PFNGLFLUSHPROC                    Flush;
         PFNGLGENBUFFERSPROC               GenBuffers;
+        PFNGLGENSAMPLERSPROC              GenSamplers;
         PFNGLGENTEXTURESPROC              GenTextures;
         PFNGLGENVERTEXARRAYSPROC          GenVertexArrays;
         PFNGLGETATTRIBLOCATIONPROC        GetAttribLocation;
@@ -533,6 +544,7 @@ union ImGL3WProcs {
         PFNGLPIXELSTOREIPROC              PixelStorei;
         PFNGLPOLYGONMODEPROC              PolygonMode;
         PFNGLREADPIXELSPROC               ReadPixels;
+        PFNGLSAMPLERPARAMETERIPROC        SamplerParameteri;
         PFNGLSCISSORPROC                  Scissor;
         PFNGLSHADERSOURCEPROC             ShaderSource;
         PFNGLTEXIMAGE2DPROC               TexImage2D;
@@ -567,6 +579,7 @@ GL3W_API extern union ImGL3WProcs imgl3wProcs;
 #define glCreateShader                    imgl3wProcs.gl.CreateShader
 #define glDeleteBuffers                   imgl3wProcs.gl.DeleteBuffers
 #define glDeleteProgram                   imgl3wProcs.gl.DeleteProgram
+#define glDeleteSamplers                  imgl3wProcs.gl.DeleteSamplers
 #define glDeleteShader                    imgl3wProcs.gl.DeleteShader
 #define glDeleteTextures                  imgl3wProcs.gl.DeleteTextures
 #define glDeleteVertexArrays              imgl3wProcs.gl.DeleteVertexArrays
@@ -579,6 +592,7 @@ GL3W_API extern union ImGL3WProcs imgl3wProcs;
 #define glEnableVertexAttribArray         imgl3wProcs.gl.EnableVertexAttribArray
 #define glFlush                           imgl3wProcs.gl.Flush
 #define glGenBuffers                      imgl3wProcs.gl.GenBuffers
+#define glGenSamplers                     imgl3wProcs.gl.GenSamplers
 #define glGenTextures                     imgl3wProcs.gl.GenTextures
 #define glGenVertexArrays                 imgl3wProcs.gl.GenVertexArrays
 #define glGetAttribLocation               imgl3wProcs.gl.GetAttribLocation
@@ -599,6 +613,7 @@ GL3W_API extern union ImGL3WProcs imgl3wProcs;
 #define glPixelStorei                     imgl3wProcs.gl.PixelStorei
 #define glPolygonMode                     imgl3wProcs.gl.PolygonMode
 #define glReadPixels                      imgl3wProcs.gl.ReadPixels
+#define glSamplerParameteri               imgl3wProcs.gl.SamplerParameteri
 #define glScissor                         imgl3wProcs.gl.Scissor
 #define glShaderSource                    imgl3wProcs.gl.ShaderSource
 #define glTexImage2D                      imgl3wProcs.gl.TexImage2D
@@ -631,7 +646,7 @@ extern "C" {
 #endif
 #include <windows.h>
 
-static HMODULE libgl;
+static HMODULE libgl = NULL;
 typedef PROC(__stdcall* GL3WglGetProcAddr)(LPCSTR);
 static GL3WglGetProcAddr wgl_get_proc_address;
 
@@ -644,7 +659,7 @@ static int open_libgl(void)
     return GL3W_OK;
 }
 
-static void close_libgl(void) { FreeLibrary(libgl); }
+static void close_libgl(void) { FreeLibrary(libgl); libgl = NULL; }
 static GL3WglProc get_proc(const char *proc)
 {
     GL3WglProc res;
@@ -656,7 +671,7 @@ static GL3WglProc get_proc(const char *proc)
 #elif defined(__APPLE__)
 #include <dlfcn.h>
 
-static void *libgl;
+static void *libgl = NULL;
 static int open_libgl(void)
 {
     libgl = dlopen("/System/Library/Frameworks/OpenGL.framework/OpenGL", RTLD_LAZY | RTLD_LOCAL);
@@ -665,7 +680,7 @@ static int open_libgl(void)
     return GL3W_OK;
 }
 
-static void close_libgl(void) { dlclose(libgl); }
+static void close_libgl(void) { dlclose(libgl); libgl = NULL; }
 
 static GL3WglProc get_proc(const char *proc)
 {
@@ -699,7 +714,11 @@ static void close_libgl(void)
 
 static int is_library_loaded(const char* name, void** lib)
 {
+#if defined(__HAIKU__)
+    *lib = NULL; // no support for RTLD_NOLOAD on Haiku.
+#else
     *lib = dlopen(name, RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD);
+#endif
     return *lib != NULL;
 }
 
@@ -833,6 +852,11 @@ int imgl3wInit2(GL3WGetProcAddressProc proc)
     return parse_version();
 }
 
+void imgl3wShutdown(void)
+{
+    close_libgl();
+}
+
 int imgl3wIsSupported(int major, int minor)
 {
     if (major < 2)
@@ -863,6 +887,7 @@ static const char *proc_names[] = {
     "glCreateShader",
     "glDeleteBuffers",
     "glDeleteProgram",
+    "glDeleteSamplers",
     "glDeleteShader",
     "glDeleteTextures",
     "glDeleteVertexArrays",
@@ -875,6 +900,7 @@ static const char *proc_names[] = {
     "glEnableVertexAttribArray",
     "glFlush",
     "glGenBuffers",
+    "glGenSamplers",
     "glGenTextures",
     "glGenVertexArrays",
     "glGetAttribLocation",
@@ -895,6 +921,7 @@ static const char *proc_names[] = {
     "glPixelStorei",
     "glPolygonMode",
     "glReadPixels",
+    "glSamplerParameteri",
     "glScissor",
     "glShaderSource",
     "glTexImage2D",

backends/imgui_impl_osx.h

@@ -10,6 +10,10 @@
 //  [X] Platform: Gamepad support.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: IME support.
+//  [x] Platform: Multi-viewport / platform windows.
+// Missing features or Issues:
+//  [ ] Platform: Multi-viewport: Window size not correctly reported when enabling io.ConfigViewportsNoDecoration
+//  [ ] Platform: Multi-viewport: Missing ImGuiBackendFlags_HasParentViewport support. The viewport->ParentViewportID field is ignored, and therefore io.ConfigViewportsNoDefaultParent has no effect either.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_osx.mm

@@ -10,6 +10,10 @@
 //  [X] Platform: Gamepad support.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: IME support.
+//  [x] Platform: Multi-viewport / platform windows.
+// Missing features or Issues:
+//  [ ] Platform: Multi-viewport: Window size not correctly reported when enabling io.ConfigViewportsNoDecoration
+//  [ ] Platform: Multi-viewport: Missing ImGuiBackendFlags_HasParentViewport support. The viewport->ParentViewportID field is ignored, and therefore io.ConfigViewportsNoDefaultParent has no effect either.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -29,8 +33,12 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-18: Call platform_io.ClearPlatformHandlers() on shutdown.
+//  2025-07-08: [Docking] Fixed multi-viewport handling broken on 2025-06-02. (#8644, #8777)
 //  2025-06-27: Added ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress mouse cursor support.
 //  2025-06-12: ImGui_ImplOSX_HandleEvent() only process event for window containing our view. (#8644)
+//  2025-05-15: [Docking] Add Platform_GetWindowFramebufferScale() handler, to allow varying Retina display density on multiple monitors.
 //  2025-03-21: Fill gamepad inputs and set ImGuiBackendFlags_HasGamepad regardless of ImGuiConfigFlags_NavEnableGamepad being set.
 //  2025-01-20: Removed notification observer when shutting down. (#8331)
 //  2024-08-22: moved some OS/backend related function pointers from ImGuiIO to ImGuiPlatformIO:
@@ -100,6 +108,9 @@ static void                     ImGui_ImplOSX_DestroyBackendData()  { IM_DELETE(
 static inline CFTimeInterval    GetMachAbsoluteTimeInSeconds()      { return (CFTimeInterval)(double)(clock_gettime_nsec_np(CLOCK_UPTIME_RAW) / 1e9); }
 
 // Forward Declarations
+static void ImGui_ImplOSX_InitMultiViewportSupport();
+static void ImGui_ImplOSX_ShutdownMultiViewportSupport();
+static void ImGui_ImplOSX_UpdateMonitors();
 static void ImGui_ImplOSX_AddTrackingArea(NSView* _Nonnull view);
 static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
 
@@ -147,9 +158,25 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
     NSWindow* window = view.window;
     if (!window)
         return;
-    NSRect contentRect = [window contentRectForFrameRect:window.frame];
-    NSRect rect = NSMakeRect(_posX, contentRect.size.height - _posY, 0, 0);
-    _imeRect = [window convertRectToScreen:rect];
+
+    ImGuiIO& io = ImGui::GetIO();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        NSRect frame = window.frame;
+        NSRect contentRect = window.contentLayoutRect;
+        if (window.styleMask & NSWindowStyleMaskFullSizeContentView) // No title bar windows should be considered.
+            contentRect = frame;
+
+        NSRect firstScreenFrame = NSScreen.screens[0].frame;
+        _imeRect = NSMakeRect(_posX, _posY, 0, 0);
+        _imeRect.origin.y = firstScreenFrame.size.height - _imeRect.size.height - _imeRect.origin.y; // Opposite of ConvertNSRect()
+    }
+    else
+    {
+        NSRect contentRect = [window contentRectForFrameRect:window.frame];
+        NSRect rect = NSMakeRect(_posX, contentRect.size.height - _posY, 0, 0);
+        _imeRect = [window convertRectToScreen:rect];
+    }
 }
 
 - (void)viewDidMoveToWindow
@@ -244,6 +271,7 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
 
 - (void)onApplicationBecomeActive:(NSNotification*)aNotification;
 - (void)onApplicationBecomeInactive:(NSNotification*)aNotification;
+- (void)displaysDidChange:(NSNotification*)aNotification;
 
 @end
 
@@ -261,6 +289,11 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
     io.AddFocusEvent(false);
 }
 
+- (void)displaysDidChange:(NSNotification*)aNotification
+{
+    ImGui_ImplOSX_UpdateMonitors();
+}
+
 @end
 
 // Functions
@@ -415,11 +448,15 @@ bool ImGui_ImplOSX_Init(NSView* view)
     io.BackendPlatformName = "imgui_impl_osx";
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;           // We can honor GetMouseCursor() values (optional)
     //io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+    io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;      // We can create multi-viewports on the Platform side (optional)
+    //io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
 
     bd->Observer = [ImGuiObserver new];
     bd->Window = view.window ?: NSApp.orderedWindows.firstObject;
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = main_viewport->PlatformHandleRaw = (__bridge_retained void*)bd->Window;
+    ImGui_ImplOSX_UpdateMonitors();
+    ImGui_ImplOSX_InitMultiViewportSupport();
 
     // Load cursors. Some of them are undocumented.
     bd->MouseCursorHidden = false;
@@ -511,12 +548,15 @@ void ImGui_ImplOSX_Shutdown()
         bd->Monitor = nullptr;
     }
 
+    ImGui_ImplOSX_ShutdownMultiViewportSupport();
     ImGui_ImplOSX_DestroyBackendData();
-
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasGamepad);
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasGamepad | ImGuiBackendFlags_PlatformHasViewports);
+    platform_io.ClearPlatformHandlers();
 }
 
 static void ImGui_ImplOSX_UpdateMouseCursor()
@@ -625,9 +665,9 @@ void ImGui_ImplOSX_NewFrame(NSView* view)
     // Setup display size
     if (view)
     {
-        const float dpi = (float)[view.window backingScaleFactor];
+        const float fb_scale = (float)[view.window backingScaleFactor];
         io.DisplaySize = ImVec2((float)view.bounds.size.width, (float)view.bounds.size.height);
-        io.DisplayFramebufferScale = ImVec2(dpi, dpi);
+        io.DisplayFramebufferScale = ImVec2(fb_scale, fb_scale);
     }
 
     // Setup time step
@@ -666,10 +706,10 @@ static ImGuiMouseSource GetMouseSource(NSEvent* event)
 static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view)
 {
     // Only process events from the window containing ImGui view
-    if (event.window != view.window)
+    if (!ImGui::FindViewportByPlatformHandle((__bridge void*)event.window))
         return false;
-    ImGuiIO& io = ImGui::GetIO();
 
+    ImGuiIO& io = ImGui::GetIO();
     if (event.type == NSEventTypeLeftMouseDown || event.type == NSEventTypeRightMouseDown || event.type == NSEventTypeOtherMouseDown)
     {
         int button = (int)[event buttonNumber];
@@ -694,14 +734,23 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view)
 
     if (event.type == NSEventTypeMouseMoved || event.type == NSEventTypeLeftMouseDragged || event.type == NSEventTypeRightMouseDragged || event.type == NSEventTypeOtherMouseDragged)
     {
-        NSPoint mousePoint = event.locationInWindow;
-        if (event.window == nil)
-            mousePoint = [[view window] convertPointFromScreen:mousePoint];
-        mousePoint = [view convertPoint:mousePoint fromView:nil];
-        if ([view isFlipped])
-            mousePoint = NSMakePoint(mousePoint.x, mousePoint.y);
+        NSPoint mousePoint;
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            mousePoint = NSEvent.mouseLocation;
+            mousePoint.y = CGDisplayPixelsHigh(kCGDirectMainDisplay) - mousePoint.y; // Normalize y coordinate to top-left of main display.
+        }
         else
-            mousePoint = NSMakePoint(mousePoint.x, view.bounds.size.height - mousePoint.y);
+        {
+            mousePoint = event.locationInWindow;
+            if (event.window == nil)
+                mousePoint = [[view window] convertPointFromScreen:mousePoint];
+            mousePoint = [view convertPoint:mousePoint fromView:nil]; // Convert to local coordinates of view
+            if ([view isFlipped])
+                mousePoint = NSMakePoint(mousePoint.x, mousePoint.y);
+            else
+                mousePoint = NSMakePoint(mousePoint.x, view.bounds.size.height - mousePoint.y);
+        }
         io.AddMouseSourceEvent(GetMouseSource(event));
         io.AddMousePosEvent((float)mousePoint.x, (float)mousePoint.y);
         return io.WantCaptureMouse;
@@ -827,6 +876,300 @@ static void ImGui_ImplOSX_AddTrackingArea(NSView* _Nonnull view)
     }];
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the back-end to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+struct ImGui_ImplOSX_ViewportData
+{
+    NSWindow*        Window;
+    bool             WindowOwned;
+
+    ImGui_ImplOSX_ViewportData()  { WindowOwned = false; }
+    ~ImGui_ImplOSX_ViewportData() { IM_ASSERT(Window == nil); }
+};
+
+@interface ImGui_ImplOSX_Window: NSWindow
+@end
+
+@implementation ImGui_ImplOSX_Window
+
+- (BOOL)canBecomeKeyWindow
+{
+    return YES;
+}
+
+@end
+
+static void ConvertNSRect(NSRect* r)
+{
+    NSRect firstScreenFrame = NSScreen.screens[0].frame;
+    IM_ASSERT(firstScreenFrame.origin.x == 0 && firstScreenFrame.origin.y == 0);
+    r->origin.y = firstScreenFrame.size.height - r->origin.y - r->size.height;
+}
+
+static void ImGui_ImplOSX_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGui_ImplOSX_ViewportData* vd = IM_NEW(ImGui_ImplOSX_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    NSScreen* screen = bd->Window.screen;
+    NSRect rect = NSMakeRect(viewport->Pos.x, viewport->Pos.y, viewport->Size.x, viewport->Size.y);
+    ConvertNSRect(&rect);
+
+    NSWindowStyleMask styleMask = 0;
+    if (viewport->Flags & ImGuiViewportFlags_NoDecoration)
+        styleMask |= NSWindowStyleMaskBorderless;
+    else
+        styleMask |= NSWindowStyleMaskTitled | NSWindowStyleMaskResizable | NSWindowStyleMaskClosable | NSWindowStyleMaskMiniaturizable;
+
+    NSWindow* window = [[ImGui_ImplOSX_Window alloc] initWithContentRect:rect
+                                                               styleMask:styleMask
+                                                                 backing:NSBackingStoreBuffered
+                                                                   defer:YES
+                                                                  screen:screen];
+    if (viewport->Flags & ImGuiViewportFlags_TopMost)
+        [window setLevel:NSFloatingWindowLevel];
+
+    window.title = @"Untitled";
+    window.opaque = YES;
+
+    KeyEventResponder* view = [[KeyEventResponder alloc] initWithFrame:rect];
+    if (floor(NSAppKitVersionNumber) > NSAppKitVersionNumber10_6 && ceil(NSAppKitVersionNumber) < NSAppKitVersionNumber10_15)
+        [view setWantsBestResolutionOpenGLSurface:YES];
+
+    window.contentView = view;
+
+    vd->Window = window;
+    vd->WindowOwned = true;
+    viewport->PlatformRequestResize = false;
+    viewport->PlatformHandle = viewport->PlatformHandleRaw = (__bridge_retained void*)window;
+}
+
+static void ImGui_ImplOSX_DestroyWindow(ImGuiViewport* viewport)
+{
+    if (ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData)
+    {
+        NSWindow* window = vd->Window;
+        if (window != nil && vd->WindowOwned)
+        {
+            window.contentView = nil;
+            window.contentViewController = nil;
+            [window orderOut:nil];
+        }
+        vd->Window = nil;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = viewport->PlatformHandleRaw = nullptr;
+}
+
+static void ImGui_ImplOSX_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+        [vd->Window orderFront:nil];
+    else
+        [vd->Window makeKeyAndOrderFront:nil];
+
+    [vd->Window setIsVisible:YES];
+}
+
+static ImVec2 ImGui_ImplOSX_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+
+    NSWindow* window = vd->Window;
+    NSRect frame = window.frame;
+    NSRect contentRect = window.contentLayoutRect;
+    if (window.styleMask & NSWindowStyleMaskFullSizeContentView) // No title bar windows should be considered.
+        contentRect = frame;
+
+    NSRect firstScreenFrame = NSScreen.screens[0].frame;
+    return ImVec2(frame.origin.x, firstScreenFrame.size.height - frame.origin.y - contentRect.size.height);
+}
+
+static void ImGui_ImplOSX_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+
+    NSWindow* window = vd->Window;
+    NSSize size = window.frame.size;
+
+    NSRect r = NSMakeRect(pos.x, pos.y, size.width, size.height);
+    ConvertNSRect(&r);
+    [window setFrameOrigin:r.origin];
+}
+
+static ImVec2 ImGui_ImplOSX_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+
+    NSWindow* window = vd->Window;
+    NSSize size = window.contentLayoutRect.size;
+    return ImVec2(size.width, size.height);
+}
+
+static void ImGui_ImplOSX_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+
+    NSWindow* window = vd->Window;
+    NSRect rect = window.frame;
+    rect.origin.y -= (size.y - rect.size.height);
+    rect.size.width = size.x;
+    rect.size.height = size.y;
+    [window setFrame:rect display:YES];
+}
+
+static ImVec2 ImGui_ImplOSX_GetWindowFramebufferScale(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    NSWindow* window = vd->Window;
+    const float fb_scale = (float)[window backingScaleFactor];
+    return ImVec2(fb_scale, fb_scale);
+}
+
+static void ImGui_ImplOSX_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+    [vd->Window makeKeyAndOrderFront:bd->Window];
+}
+
+static bool ImGui_ImplOSX_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+
+    return vd->Window.isKeyWindow;
+}
+
+static bool ImGui_ImplOSX_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+
+    return vd->Window.isMiniaturized;
+}
+
+static void ImGui_ImplOSX_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+
+    vd->Window.title = [NSString stringWithUTF8String:title];
+}
+
+static void ImGui_ImplOSX_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+    IM_ASSERT(alpha >= 0.0f && alpha <= 1.0f);
+
+    vd->Window.alphaValue = alpha;
+}
+
+static float ImGui_ImplOSX_GetWindowDpiScale(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Window != 0);
+
+    return vd->Window.backingScaleFactor;
+}
+
+static void ImGui_ImplOSX_UpdateMonitors()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Monitors.resize(0);
+
+    NSRect firstScreenFrame = NSScreen.screens[0].frame;
+    IM_ASSERT(firstScreenFrame.origin.x == 0 && firstScreenFrame.origin.y == 0);
+
+    for (NSScreen* screen in NSScreen.screens)
+    {
+        NSRect frame = screen.frame;
+        NSRect visibleFrame = screen.visibleFrame;
+        ConvertNSRect(&frame);
+        ConvertNSRect(&visibleFrame);
+
+        ImGuiPlatformMonitor imgui_monitor;
+        imgui_monitor.MainPos = ImVec2(frame.origin.x, frame.origin.y);
+        imgui_monitor.MainSize = ImVec2(frame.size.width, frame.size.height);
+        imgui_monitor.WorkPos = ImVec2(visibleFrame.origin.x, visibleFrame.origin.y);
+        imgui_monitor.WorkSize = ImVec2(visibleFrame.size.width, visibleFrame.size.height);
+        imgui_monitor.DpiScale = screen.backingScaleFactor;
+        imgui_monitor.PlatformHandle = (__bridge_retained void*)screen;
+
+        platform_io.Monitors.push_back(imgui_monitor);
+    }
+}
+
+static void ImGui_ImplOSX_InitMultiViewportSupport()
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplOSX_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplOSX_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplOSX_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplOSX_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplOSX_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplOSX_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplOSX_GetWindowSize;
+    platform_io.Platform_GetWindowFramebufferScale = ImGui_ImplOSX_GetWindowFramebufferScale;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplOSX_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplOSX_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplOSX_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplOSX_SetWindowTitle;
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplOSX_SetWindowAlpha;
+    platform_io.Platform_GetWindowDpiScale = ImGui_ImplOSX_GetWindowDpiScale; // FIXME-DPI
+
+    // Register main window handle (which is owned by the main application, not by us)
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplOSX_ViewportData* vd = IM_NEW(ImGui_ImplOSX_ViewportData)();
+    vd->Window = bd->Window;
+    vd->WindowOwned = false;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = (__bridge void*)bd->Window;
+
+    [NSNotificationCenter.defaultCenter addObserver:bd->Observer
+                                           selector:@selector(displaysDidChange:)
+                                               name:NSApplicationDidChangeScreenParametersNotification
+                                             object:nil];
+}
+
+static void ImGui_ImplOSX_ShutdownMultiViewportSupport()
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    [NSNotificationCenter.defaultCenter removeObserver:bd->Observer
+                                                  name:NSApplicationDidChangeScreenParametersNotification
+                                                object:nil];
+    bd->Observer = nullptr;
+    bd->Window = nullptr;
+    if (bd->Monitor != nullptr)
+    {
+        [NSEvent removeMonitor:bd->Monitor];
+        bd->Monitor = nullptr;
+    }
+
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplOSX_ViewportData* vd = (ImGui_ImplOSX_ViewportData*)main_viewport->PlatformUserData;
+    IM_DELETE(vd);
+    main_viewport->PlatformUserData = nullptr;
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_sdl2.cpp

@@ -10,6 +10,10 @@
 //  [X] Platform: Gamepad support.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: Basic IME support. App needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// Missing features or Issues:
+//  [ ] Platform: Multi-viewport: Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [ ] Platform: Multi-viewport: Missing ImGuiBackendFlags_HasParentViewport support. The viewport->ParentViewportID field is ignored, and therefore io.ConfigViewportsNoDefaultParent has no effect either.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -21,13 +25,21 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-24: Skip using the SDL_GetGlobalMouseState() state when one of our window is hovered, as the SDL_MOUSEMOTION data is reliable. Fix macOS notch mouse coordinates issue in fullscreen mode + better perf on X11. (#7919, #7786)
+//  2025-09-18: Call platform_io.ClearPlatformHandlers() on shutdown.
+//  2025-09-15: Content Scales are always reported as 1.0 on Wayland. (#8921)
 //  2025-07-08: Made ImGui_ImplSDL2_GetContentScaleForWindow(), ImGui_ImplSDL2_GetContentScaleForDisplay() helpers return 1.0f on Emscripten and Android platforms, matching macOS logic. (#8742, #8733)
 //  2025-06-11: Added ImGui_ImplSDL2_GetContentScaleForWindow(SDL_Window* window) and ImGui_ImplSDL2_GetContentScaleForDisplay(int display_index) helper to facilitate making DPI-aware apps.
+//  2025-05-15: [Docking] Add Platform_GetWindowFramebufferScale() handler, to allow varying Retina display density on multiple monitors.
+//  2025-04-09: [Docking] Revert update monitors and work areas information every frame. Only do it on Windows. (#8415, #8558)
 //  2025-04-09: Don't attempt to call SDL_CaptureMouse() on drivers where we don't call SDL_GetGlobalMouseState(). (#8561)
 //  2025-03-21: Fill gamepad inputs and set ImGuiBackendFlags_HasGamepad regardless of ImGuiConfigFlags_NavEnableGamepad being set.
 //  2025-03-10: When dealing with OEM keys, use scancodes instead of translated keycodes to choose ImGuiKey values. (#7136, #7201, #7206, #7306, #7670, #7672, #8468)
 //  2025-02-26: Only start SDL_CaptureMouse() when mouse is being dragged, to mitigate issues with e.g.Linux debuggers not claiming capture back. (#6410, #3650)
+//  2025-02-25: [Docking] Revert to use SDL_GetDisplayBounds() for WorkPos/WorkRect if SDL_GetDisplayUsableBounds() failed.
 //  2025-02-24: Avoid calling SDL_GetGlobalMouseState() when mouse is in relative mode.
+//  2025-02-21: [Docking] Update monitors and work areas information every frame, as the later may change regardless of monitor changes. (#8415)
 //  2025-02-18: Added ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress mouse cursor support.
 //  2025-02-10: Using SDL_OpenURL() in platform_io.Platform_OpenInShellFn handler.
 //  2025-01-20: Made ImGui_ImplSDL2_SetGamepadMode(ImGui_ImplSDL2_GamepadMode_Manual) accept an empty array.
@@ -68,7 +80,7 @@
 //  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
 //  2021-08-17: Calling io.AddFocusEvent() on SDL_WINDOWEVENT_FOCUS_GAINED/SDL_WINDOWEVENT_FOCUS_LOST.
 //  2021-07-29: Inputs: MousePos is correctly reported when the host platform window is hovered but not focused (using SDL_GetMouseFocus() + SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH, requires SDL 2.0.5+)
-//  2021-06-29: *BREAKING CHANGE* Removed 'SDL_Window* window' parameter to ImGui_ImplSDL2_NewFrame() which was unnecessary.
+//  2021-06:29: *BREAKING CHANGE* Removed 'SDL_Window* window' parameter to ImGui_ImplSDL2_NewFrame() which was unnecessary.
 //  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
 //  2021-03-22: Rework global mouse pos availability check listing supported platforms explicitly, effectively fixing mouse access on Raspberry Pi. (#2837, #3950)
 //  2020-05-25: Misc: Report a zero display-size when window is minimized, to be consistent with other backends.
@@ -110,6 +122,7 @@
 #endif
 
 // SDL
+// (the multi-viewports feature requires SDL features supported from SDL 2.0.4+. SDL 2.0.5+ is highly recommended)
 #include <SDL.h>
 #include <SDL_syswm.h>
 #include <stdio.h>              // for snprintf()
@@ -126,22 +139,31 @@
 #else
 #define SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE    0
 #endif
+#define SDL_HAS_WINDOW_ALPHA                SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_ALWAYS_ON_TOP               SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_USABLE_DISPLAY_BOUNDS       SDL_VERSION_ATLEAST(2,0,5)
 #define SDL_HAS_PER_MONITOR_DPI             SDL_VERSION_ATLEAST(2,0,4)
 #define SDL_HAS_VULKAN                      SDL_VERSION_ATLEAST(2,0,6)
+#define SDL_HAS_DISPLAY_EVENT               SDL_VERSION_ATLEAST(2,0,9)
 #define SDL_HAS_OPEN_URL                    SDL_VERSION_ATLEAST(2,0,14)
+#define SDL_HAS_SHOW_WINDOW_ACTIVATION_HINT SDL_VERSION_ATLEAST(2,0,18)
 #if SDL_HAS_VULKAN
 #include <SDL_vulkan.h>
+#else
+static const Uint32 SDL_WINDOW_VULKAN = 0x10000000;
 #endif
 
 // SDL Data
 struct ImGui_ImplSDL2_Data
 {
     SDL_Window*             Window;
-    Uint32                  WindowID;
+    Uint32                  WindowID;       // Stored in ImGuiViewport::PlatformHandle. Use SDL_GetWindowFromID() to get SDL_Window* from Uint32 WindowID.
     SDL_Renderer*           Renderer;
     Uint64                  Time;
     char*                   ClipboardTextData;
     char                    BackendPlatformName[48];
+    bool                    UseVulkan;
+    bool                    WantUpdateMonitors;
 
     // Mouse handling
     Uint32                  MouseWindowID;
@@ -151,6 +173,7 @@ struct ImGui_ImplSDL2_Data
     int                     MouseLastLeaveFrame;
     bool                    MouseCanUseGlobalState;
     bool                    MouseCanUseCapture;
+    bool                    MouseCanReportHoveredViewport;  // This is hard to use/unreliable on SDL so we'll set ImGuiBackendFlags_HasMouseHoveredViewport dynamically based on state.
 
     // Gamepad handling
     ImVector<SDL_GameController*> Gamepads;
@@ -169,6 +192,11 @@ static ImGui_ImplSDL2_Data* ImGui_ImplSDL2_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplSDL2_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplSDL2_UpdateMonitors();
+static void ImGui_ImplSDL2_InitMultiViewportSupport(SDL_Window* window, void* sdl_gl_context);
+static void ImGui_ImplSDL2_ShutdownMultiViewportSupport();
+
 // Functions
 static const char* ImGui_ImplSDL2_GetClipboardText(ImGuiContext*)
 {
@@ -185,13 +213,13 @@ static void ImGui_ImplSDL2_SetClipboardText(ImGuiContext*, const char* text)
 }
 
 // Note: native IME will only display if user calls SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1") _before_ SDL_CreateWindow().
-static void ImGui_ImplSDL2_PlatformSetImeData(ImGuiContext*, ImGuiViewport*, ImGuiPlatformImeData* data)
+static void ImGui_ImplSDL2_PlatformSetImeData(ImGuiContext*, ImGuiViewport* viewport, ImGuiPlatformImeData* data)
 {
     if (data->WantVisible)
     {
         SDL_Rect r;
-        r.x = (int)data->InputPos.x;
-        r.y = (int)data->InputPos.y;
+        r.x = (int)(data->InputPos.x - viewport->Pos.x);
+        r.y = (int)(data->InputPos.y - viewport->Pos.y + data->InputLineHeight);
         r.w = 1;
         r.h = (int)data->InputLineHeight;
         SDL_SetTextInputRect(&r);
@@ -357,15 +385,13 @@ static void ImGui_ImplSDL2_UpdateKeyModifiers(SDL_Keymod sdl_key_mods)
 
 static ImGuiViewport* ImGui_ImplSDL2_GetViewportForWindowID(Uint32 window_id)
 {
-    ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
-    return (window_id == bd->WindowID) ? ImGui::GetMainViewport() : nullptr;
+    return ImGui::FindViewportByPlatformHandle((void*)(intptr_t)window_id);
 }
 
 // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
 // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-// If you have multiple SDL events and some of them are not meant to be used by dear imgui, you may need to filter events based on their windowID field.
 bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
 {
     ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
@@ -379,6 +405,13 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
             if (ImGui_ImplSDL2_GetViewportForWindowID(event->motion.windowID) == nullptr)
                 return false;
             ImVec2 mouse_pos((float)event->motion.x, (float)event->motion.y);
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                int window_x, window_y;
+                SDL_GetWindowPosition(SDL_GetWindowFromID(event->motion.windowID), &window_x, &window_y);
+                mouse_pos.x += window_x;
+                mouse_pos.y += window_y;
+            }
             io.AddMouseSourceEvent(event->motion.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMousePosEvent(mouse_pos.x, mouse_pos.y);
             return true;
@@ -430,20 +463,32 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
         case SDL_KEYDOWN:
         case SDL_KEYUP:
         {
-            if (ImGui_ImplSDL2_GetViewportForWindowID(event->key.windowID) == nullptr)
+            ImGuiViewport* viewport = ImGui_ImplSDL2_GetViewportForWindowID(event->key.windowID);
+            if (viewport == nullptr)
                 return false;
+            //IMGUI_DEBUG_LOG("SDL_KEY%s : key=0x%08X ('%s'), scancode=%d ('%s'), mod=%X, windowID=%d, viewport=%08X\n",
+            //    (event->type == SDL_KEYDOWN) ? "DOWN" : "UP  ", event->key.keysym.sym, SDL_GetKeyName(event->key.keysym.sym), event->key.keysym.scancode, SDL_GetScancodeName(event->key.keysym.scancode), event->key.keysym.mod, event->key.windowID, viewport ? viewport->ID : 0);
             ImGui_ImplSDL2_UpdateKeyModifiers((SDL_Keymod)event->key.keysym.mod);
-            //IMGUI_DEBUG_LOG("SDL_KEY_%s : key=%d ('%s'), scancode=%d ('%s'), mod=%X\n",
-            //    (event->type == SDL_KEYDOWN) ? "DOWN" : "UP  ", event->key.keysym.sym, SDL_GetKeyName(event->key.keysym.sym), event->key.keysym.scancode, SDL_GetScancodeName(event->key.keysym.scancode), event->key.keysym.mod);
             ImGuiKey key = ImGui_ImplSDL2_KeyEventToImGuiKey(event->key.keysym.sym, event->key.keysym.scancode);
             io.AddKeyEvent(key, (event->type == SDL_KEYDOWN));
             io.SetKeyEventNativeData(key, (int)event->key.keysym.sym, (int)event->key.keysym.scancode, (int)event->key.keysym.scancode); // To support legacy indexing (<1.87 user code). Legacy backend uses SDLK_*** as indices to IsKeyXXX() functions.
             return true;
         }
+#if SDL_HAS_DISPLAY_EVENT
+        case SDL_DISPLAYEVENT:
+        {
+            // 2.0.26 has SDL_DISPLAYEVENT_CONNECTED/SDL_DISPLAYEVENT_DISCONNECTED/SDL_DISPLAYEVENT_ORIENTATION,
+            // so change of DPI/Scaling are not reflected in this event. (SDL3 has it)
+            bd->WantUpdateMonitors = true;
+            return true;
+        }
+#endif
         case SDL_WINDOWEVENT:
         {
-            if (ImGui_ImplSDL2_GetViewportForWindowID(event->window.windowID) == nullptr)
+            ImGuiViewport* viewport = ImGui_ImplSDL2_GetViewportForWindowID(event->window.windowID);
+            if (viewport == NULL)
                 return false;
+
             // - When capturing mouse, SDL will send a bunch of conflicting LEAVE/ENTER event on every mouse move, but the final ENTER tends to be right.
             // - However we won't get a correct LEAVE event for a captured window.
             // - In some cases, when detaching a window from main viewport SDL may send SDL_WINDOWEVENT_ENTER one frame too late,
@@ -457,10 +502,18 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
             }
             if (window_event == SDL_WINDOWEVENT_LEAVE)
                 bd->MouseLastLeaveFrame = ImGui::GetFrameCount() + 1;
+            //if (window_event == SDL_WINDOWEVENT_FOCUS_GAINED) { IMGUI_DEBUG_LOG("SDL_WINDOWEVENT_FOCUS_GAINED: windowId %d, viewport: %08X\n", event->window.windowID, viewport ? viewport->ID : 0); }
+            //if (window_event == SDL_WINDOWEVENT_FOCUS_LOST) { IMGUI_DEBUG_LOG("SDL_WINDOWEVENT_FOCUS_LOST: windowId %d, viewport: %08X\n", event->window.windowID, viewport ? viewport->ID : 0); }
             if (window_event == SDL_WINDOWEVENT_FOCUS_GAINED)
                 io.AddFocusEvent(true);
-            else if (event->window.event == SDL_WINDOWEVENT_FOCUS_LOST)
+            if (window_event == SDL_WINDOWEVENT_FOCUS_LOST)
                 io.AddFocusEvent(false);
+            if (window_event == SDL_WINDOWEVENT_CLOSE)
+                viewport->PlatformRequestClose = true;
+            if (window_event == SDL_WINDOWEVENT_MOVED)
+                viewport->PlatformRequestMove = true;
+            if (window_event == SDL_WINDOWEVENT_RESIZED)
+                viewport->PlatformRequestResize = true;
             return true;
         }
         case SDL_CONTROLLERDEVICEADDED:
@@ -484,6 +537,7 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
     ImGuiIO& io = ImGui::GetIO();
     IMGUI_CHECKVERSION();
     IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
+    //SDL_SetHint(SDL_HINT_EVENT_LOGGING, "2");
 
     // Obtain compiled and runtime versions
     SDL_version ver_compiled;
@@ -499,11 +553,20 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
     io.BackendPlatformName = bd->BackendPlatformName;
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;           // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;            // We can honor io.WantSetMousePos requests (optional, rarely used)
+    // (ImGuiBackendFlags_PlatformHasViewports may be set just below)
 
     bd->Window = window;
     bd->WindowID = SDL_GetWindowID(window);
     bd->Renderer = renderer;
 
+    // SDL on Linux/OSX doesn't report events for unfocused windows (see https://github.com/ocornut/imgui/issues/4960)
+    // We will use 'MouseCanReportHoveredViewport' to set 'ImGuiBackendFlags_HasMouseHoveredViewport' dynamically each frame.
+#ifndef __APPLE__
+    bd->MouseCanReportHoveredViewport = bd->MouseCanUseGlobalState;
+#else
+    bd->MouseCanReportHoveredViewport = false;
+#endif
+
     // Check and store if we are on a SDL backend that supports SDL_GetGlobalMouseState() and SDL_CaptureMouse()
     // ("wayland" and "rpi" don't support it, but we chose to use a white-list instead of a black-list)
     bd->MouseCanUseGlobalState = false;
@@ -515,6 +578,8 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
         if (strncmp(sdl_backend, item, strlen(item)) == 0)
             bd->MouseCanUseGlobalState = bd->MouseCanUseCapture = true;
 #endif
+    if (bd->MouseCanUseGlobalState)
+        io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;  // We can create multi-viewports on the Platform side (optional)
 
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     platform_io.Platform_SetClipboardTextFn = ImGui_ImplSDL2_SetClipboardText;
@@ -527,6 +592,9 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
     platform_io.Platform_OpenInShellFn = [](ImGuiContext*, const char* url) { return SDL_OpenURL(url) == 0; };
 #endif
 
+    // Update monitor a first time during init
+    ImGui_ImplSDL2_UpdateMonitors();
+
     // Gamepad handling
     bd->GamepadMode = ImGui_ImplSDL2_GamepadMode_AutoFirst;
     bd->WantUpdateGamepadsList = true;
@@ -581,7 +649,11 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
     SDL_SetHint(SDL_HINT_MOUSE_AUTO_CAPTURE, "0");
 #endif
 
-    (void)sdl_gl_context; // Unused in 'master' branch.
+    // We need SDL_CaptureMouse(), SDL_GetGlobalMouseState() from SDL 2.0.4+ to support multiple viewports.
+    // We left the call to ImGui_ImplSDL2_InitMultiViewportSupport() outside of #ifdef to avoid unused-function warnings.
+    if (io.BackendFlags & ImGuiBackendFlags_PlatformHasViewports)
+        ImGui_ImplSDL2_InitMultiViewportSupport(window, sdl_gl_context);
+
     return true;
 }
 
@@ -595,7 +667,11 @@ bool ImGui_ImplSDL2_InitForVulkan(SDL_Window* window)
 #if !SDL_HAS_VULKAN
     IM_ASSERT(0 && "Unsupported");
 #endif
-    return ImGui_ImplSDL2_Init(window, nullptr, nullptr);
+    if (!ImGui_ImplSDL2_Init(window, nullptr, nullptr))
+        return false;
+    ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
+    bd->UseVulkan = true;
+    return true;
 }
 
 bool ImGui_ImplSDL2_InitForD3D(SDL_Window* window)
@@ -628,7 +704,9 @@ void ImGui_ImplSDL2_Shutdown()
     ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
+    ImGui_ImplSDL2_ShutdownMultiViewportSupport();
     if (bd->ClipboardTextData)
         SDL_free(bd->ClipboardTextData);
     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
@@ -637,10 +715,12 @@ void ImGui_ImplSDL2_Shutdown()
 
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad);
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad | ImGuiBackendFlags_PlatformHasViewports | ImGuiBackendFlags_HasMouseHoveredViewport);
+    platform_io.ClearPlatformHandlers();
     IM_DELETE(bd);
 }
 
+// This code is incredibly messy because some of the functions we need for full viewport support are not available in SDL < 2.0.4.
 static void ImGui_ImplSDL2_UpdateMouseData()
 {
     ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
@@ -660,27 +740,60 @@ static void ImGui_ImplSDL2_UpdateMouseData()
     }
 
     SDL_Window* focused_window = SDL_GetKeyboardFocus();
-    const bool is_app_focused = (bd->Window == focused_window);
+    const bool is_app_focused = (focused_window && (bd->Window == focused_window || ImGui_ImplSDL2_GetViewportForWindowID(SDL_GetWindowID(focused_window)) != NULL));
 #else
+    SDL_Window* focused_window = bd->Window;
     const bool is_app_focused = (SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0; // SDL 2.0.3 and non-windowed systems: single-viewport only
 #endif
+
     if (is_app_focused)
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when io.ConfigNavMoveSetMousePos is enabled by user)
         if (io.WantSetMousePos)
-            SDL_WarpMouseInWindow(bd->Window, (int)io.MousePos.x, (int)io.MousePos.y);
+        {
+#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+                SDL_WarpMouseGlobal((int)io.MousePos.x, (int)io.MousePos.y);
+            else
+#endif
+                SDL_WarpMouseInWindow(bd->Window, (int)io.MousePos.x, (int)io.MousePos.y);
+        }
 
-        // (Optional) Fallback to provide mouse position when focused (SDL_MOUSEMOTION already provides this when hovered or captured)
+        // (Optional) Fallback to provide unclamped mouse position when focused but not hovered (SDL_MOUSEMOTION already provides this when hovered or captured)
+        // Note that SDL_GetGlobalMouseState() is in theory slow on X11, but this only runs on rather specific cases. If a problem we may provide a way to opt-out this feature.
+        SDL_Window* hovered_window = SDL_GetMouseFocus();
         const bool is_relative_mouse_mode = SDL_GetRelativeMouseMode() != 0;
-        if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0 && !is_relative_mouse_mode)
+        if (hovered_window == NULL && bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0 && !is_relative_mouse_mode)
         {
             // Single-viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
-            int window_x, window_y, mouse_x_global, mouse_y_global;
-            SDL_GetGlobalMouseState(&mouse_x_global, &mouse_y_global);
-            SDL_GetWindowPosition(bd->Window, &window_x, &window_y);
-            io.AddMousePosEvent((float)(mouse_x_global - window_x), (float)(mouse_y_global - window_y));
+            // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+            int mouse_x, mouse_y;
+            int window_x, window_y;
+            SDL_GetGlobalMouseState(&mouse_x, &mouse_y);
+            if (!(io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable))
+            {
+                SDL_GetWindowPosition(focused_window, &window_x, &window_y);
+                mouse_x -= window_x;
+                mouse_y -= window_y;
+            }
+            io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
         }
     }
+
+    // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+    // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+    // - [!] SDL backend does NOT correctly ignore viewports with the _NoInputs flag.
+    //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+    //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+    //       by the backend, and use its flawed heuristic to guess the viewport behind.
+    // - [X] SDL backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+    if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)
+    {
+        ImGuiID mouse_viewport_id = 0;
+        if (ImGuiViewport* mouse_viewport = ImGui_ImplSDL2_GetViewportForWindowID(bd->MouseWindowID))
+            mouse_viewport_id = mouse_viewport->ID;
+        io.AddMouseViewportEvent(mouse_viewport_id);
+    }
 }
 
 static void ImGui_ImplSDL2_UpdateMouseCursor()
@@ -719,6 +832,9 @@ float ImGui_ImplSDL2_GetContentScaleForWindow(SDL_Window* window)
 
 float ImGui_ImplSDL2_GetContentScaleForDisplay(int display_index)
 {
+    const char* sdl_driver = SDL_GetCurrentVideoDriver();
+    if (sdl_driver && strcmp(sdl_driver, "wayland") == 0)
+        return 1.0f;
 #if SDL_HAS_PER_MONITOR_DPI
 #if !defined(__APPLE__) && !defined(__EMSCRIPTEN__) && !defined(__ANDROID__)
     float dpi = 0.0f;
@@ -832,6 +948,38 @@ static void ImGui_ImplSDL2_UpdateGamepads()
     ImGui_ImplSDL2_UpdateGamepadAnalog(bd, io, ImGuiKey_GamepadRStickDown,  SDL_CONTROLLER_AXIS_RIGHTY, +thumb_dead_zone, +32767);
 }
 
+// FIXME: Note that doesn't update with DPI/Scaling change only as SDL2 doesn't have an event for it (SDL3 has).
+static void ImGui_ImplSDL2_UpdateMonitors()
+{
+    ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Monitors.resize(0);
+    bd->WantUpdateMonitors = false;
+    int display_count = SDL_GetNumVideoDisplays();
+    for (int n = 0; n < display_count; n++)
+    {
+        // Warning: the validity of monitor DPI information on Windows depends on the application DPI awareness settings, which generally needs to be set in the manifest or at runtime.
+        ImGuiPlatformMonitor monitor;
+        SDL_Rect r;
+        SDL_GetDisplayBounds(n, &r);
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+#if SDL_HAS_USABLE_DISPLAY_BOUNDS
+        if (SDL_GetDisplayUsableBounds(n, &r) == 0 && r.w > 0 && r.h > 0)
+        {
+            monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+            monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+        }
+#endif
+        float dpi_scale = ImGui_ImplSDL2_GetContentScaleForDisplay(n);
+        if (dpi_scale <= 0.0f)
+            continue; // Some accessibility applications are declaring virtual monitors with a DPI of 0, see #7902.
+        monitor.DpiScale = dpi_scale;
+        monitor.PlatformHandle = (void*)(intptr_t)n;
+        platform_io.Monitors.push_back(monitor);
+    }
+}
+
 static void ImGui_ImplSDL2_GetWindowSizeAndFramebufferScale(SDL_Window* window, SDL_Renderer* renderer, ImVec2* out_size, ImVec2* out_framebuffer_scale)
 {
     int w, h;
@@ -862,6 +1010,13 @@ void ImGui_ImplSDL2_NewFrame()
     // Setup main viewport size (every frame to accommodate for window resizing)
     ImGui_ImplSDL2_GetWindowSizeAndFramebufferScale(bd->Window, bd->Renderer, &io.DisplaySize, &io.DisplayFramebufferScale);
 
+    // Update monitors
+#ifdef WIN32
+    bd->WantUpdateMonitors = true; // Keep polling under Windows to handle changes of work area when resizing task-bar (#8415)
+#endif
+    if (bd->WantUpdateMonitors)
+        ImGui_ImplSDL2_UpdateMonitors();
+
     // Setup time step (we don't use SDL_GetTicks() because it is using millisecond resolution)
     // (Accept SDL_GetPerformanceCounter() not returning a monotonically increasing value. Happens in VMs and Emscripten, see #6189, #6114, #3644)
     static Uint64 frequency = SDL_GetPerformanceFrequency();
@@ -878,6 +1033,13 @@ void ImGui_ImplSDL2_NewFrame()
         io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
     }
 
+    // Our io.AddMouseViewportEvent() calls will only be valid when not capturing.
+    // Technically speaking testing for 'bd->MouseButtonsDown == 0' would be more rigorous, but testing for payload reduces noise and potential side-effects.
+    if (bd->MouseCanReportHoveredViewport && ImGui::GetDragDropPayload() == nullptr)
+        io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport;
+    else
+        io.BackendFlags &= ~ImGuiBackendFlags_HasMouseHoveredViewport;
+
     ImGui_ImplSDL2_UpdateMouseData();
     ImGui_ImplSDL2_UpdateMouseCursor();
 
@@ -885,6 +1047,266 @@ void ImGui_ImplSDL2_NewFrame()
     ImGui_ImplSDL2_UpdateGamepads();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* PlatformUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplSDL2_ViewportData
+{
+    SDL_Window*     Window;
+    Uint32          WindowID;       // Stored in ImGuiViewport::PlatformHandle. Use SDL_GetWindowFromID() to get SDL_Window* from Uint32 WindowID.
+    bool            WindowOwned;
+    SDL_GLContext   GLContext;
+
+    ImGui_ImplSDL2_ViewportData()   { Window = nullptr; WindowID = 0; WindowOwned = false; GLContext = nullptr; }
+    ~ImGui_ImplSDL2_ViewportData()  { IM_ASSERT(Window == nullptr && GLContext == nullptr); }
+};
+
+static void ImGui_ImplSDL2_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
+    ImGui_ImplSDL2_ViewportData* vd = IM_NEW(ImGui_ImplSDL2_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL2_ViewportData* main_viewport_data = (ImGui_ImplSDL2_ViewportData*)main_viewport->PlatformUserData;
+
+    // Share GL resources with main context
+    bool use_opengl = (main_viewport_data->GLContext != nullptr);
+    SDL_GLContext backup_context = nullptr;
+    if (use_opengl)
+    {
+        backup_context = SDL_GL_GetCurrentContext();
+        SDL_GL_SetAttribute(SDL_GL_SHARE_WITH_CURRENT_CONTEXT, 1);
+        SDL_GL_MakeCurrent(main_viewport_data->Window, main_viewport_data->GLContext);
+    }
+
+    Uint32 sdl_flags = 0;
+    sdl_flags |= use_opengl ? SDL_WINDOW_OPENGL : (bd->UseVulkan ? SDL_WINDOW_VULKAN : 0);
+    sdl_flags |= SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_ALLOW_HIGHDPI;
+    sdl_flags |= SDL_WINDOW_HIDDEN;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? SDL_WINDOW_BORDERLESS : 0;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? 0 : SDL_WINDOW_RESIZABLE;
+#if !defined(_WIN32)
+    // See SDL hack in ImGui_ImplSDL2_ShowWindow().
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon) ? SDL_WINDOW_SKIP_TASKBAR : 0;
+#endif
+#if SDL_HAS_ALWAYS_ON_TOP
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_TopMost) ? SDL_WINDOW_ALWAYS_ON_TOP : 0;
+#endif
+    vd->Window = SDL_CreateWindow("No Title Yet", (int)viewport->Pos.x, (int)viewport->Pos.y, (int)viewport->Size.x, (int)viewport->Size.y, sdl_flags);
+    vd->WindowOwned = true;
+    if (use_opengl)
+    {
+        vd->GLContext = SDL_GL_CreateContext(vd->Window);
+        SDL_GL_SetSwapInterval(0);
+    }
+    if (use_opengl && backup_context)
+        SDL_GL_MakeCurrent(vd->Window, backup_context);
+
+    viewport->PlatformHandle = (void*)(intptr_t)SDL_GetWindowID(vd->Window);
+    viewport->PlatformHandleRaw = nullptr;
+    SDL_SysWMinfo info;
+    SDL_VERSION(&info.version);
+    if (SDL_GetWindowWMInfo(vd->Window, &info))
+    {
+#if defined(SDL_VIDEO_DRIVER_WINDOWS)
+        viewport->PlatformHandleRaw = info.info.win.window;
+#elif defined(__APPLE__) && defined(SDL_VIDEO_DRIVER_COCOA)
+        viewport->PlatformHandleRaw = (void*)info.info.cocoa.window;
+#endif
+    }
+}
+
+static void ImGui_ImplSDL2_DestroyWindow(ImGuiViewport* viewport)
+{
+    if (ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData)
+    {
+        if (vd->GLContext && vd->WindowOwned)
+            SDL_GL_DeleteContext(vd->GLContext);
+        if (vd->Window && vd->WindowOwned)
+            SDL_DestroyWindow(vd->Window);
+        vd->GLContext = nullptr;
+        vd->Window = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplSDL2_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+#if defined(_WIN32) && !(defined(WINAPI_FAMILY) && ((defined(WINAPI_FAMILY_APP) && WINAPI_FAMILY == WINAPI_FAMILY_APP) || (defined(WINAPI_FAMILY_GAMES) && WINAPI_FAMILY == WINAPI_FAMILY_GAMES)))
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+
+    // SDL hack: Hide icon from task bar
+    // Note: SDL 2.0.6+ has a SDL_WINDOW_SKIP_TASKBAR flag which is supported under Windows but the way it create the window breaks our seamless transition.
+    if (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon)
+    {
+        LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
+        ex_style &= ~WS_EX_APPWINDOW;
+        ex_style |= WS_EX_TOOLWINDOW;
+        ::SetWindowLong(hwnd, GWL_EXSTYLE, ex_style);
+    }
+#endif
+
+#if SDL_HAS_SHOW_WINDOW_ACTIVATION_HINT
+    SDL_SetHint(SDL_HINT_WINDOW_NO_ACTIVATION_WHEN_SHOWN, (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing) ? "1" : "0");
+#elif defined(_WIN32)
+    // SDL hack: SDL always activate/focus windows :/
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+    {
+        ::ShowWindow(hwnd, SW_SHOWNA);
+        return;
+    }
+#endif
+    SDL_ShowWindow(vd->Window);
+}
+
+static ImVec2 ImGui_ImplSDL2_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    int x = 0, y = 0;
+    SDL_GetWindowPosition(vd->Window, &x, &y);
+    return ImVec2((float)x, (float)y);
+}
+
+static void ImGui_ImplSDL2_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowPosition(vd->Window, (int)pos.x, (int)pos.y);
+}
+
+static ImVec2 ImGui_ImplSDL2_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    int w = 0, h = 0;
+    SDL_GetWindowSize(vd->Window, &w, &h);
+    return ImVec2((float)w, (float)h);
+}
+
+static void ImGui_ImplSDL2_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowSize(vd->Window, (int)size.x, (int)size.y);
+}
+
+static ImVec2 ImGui_ImplSDL2_GetWindowFramebufferScale(ImGuiViewport* viewport)
+{
+    // FIXME: SDL_Renderer does not support multi-viewport.
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    ImVec2 framebuffer_scale;
+    ImGui_ImplSDL2_GetWindowSizeAndFramebufferScale(vd->Window, nullptr, nullptr, &framebuffer_scale);
+    return framebuffer_scale;
+}
+
+static void ImGui_ImplSDL2_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowTitle(vd->Window, title);
+}
+
+#if SDL_HAS_WINDOW_ALPHA
+static void ImGui_ImplSDL2_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowOpacity(vd->Window, alpha);
+}
+#endif
+
+static void ImGui_ImplSDL2_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_RaiseWindow(vd->Window);
+}
+
+static bool ImGui_ImplSDL2_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    return (SDL_GetWindowFlags(vd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0;
+}
+
+static bool ImGui_ImplSDL2_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    return (SDL_GetWindowFlags(vd->Window) & SDL_WINDOW_MINIMIZED) != 0;
+}
+
+static void ImGui_ImplSDL2_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    if (vd->GLContext)
+        SDL_GL_MakeCurrent(vd->Window, vd->GLContext);
+}
+
+static void ImGui_ImplSDL2_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    if (vd->GLContext)
+    {
+        SDL_GL_MakeCurrent(vd->Window, vd->GLContext);
+        SDL_GL_SwapWindow(vd->Window);
+    }
+}
+
+// Vulkan support (the Vulkan renderer needs to call a platform-side support function to create the surface)
+// SDL is graceful enough to _not_ need <vulkan/vulkan.h> so we can safely include this.
+#if SDL_HAS_VULKAN
+#include <SDL_vulkan.h>
+static int ImGui_ImplSDL2_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_instance, const void* vk_allocator, ImU64* out_vk_surface)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    (void)vk_allocator;
+    SDL_bool ret = SDL_Vulkan_CreateSurface(vd->Window, (VkInstance)vk_instance, (VkSurfaceKHR*)out_vk_surface);
+    return ret ? 0 : 1; // ret ? VK_SUCCESS : VK_NOT_READY
+}
+#endif // SDL_HAS_VULKAN
+
+static void ImGui_ImplSDL2_InitMultiViewportSupport(SDL_Window* window, void* sdl_gl_context)
+{
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplSDL2_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplSDL2_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplSDL2_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplSDL2_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplSDL2_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplSDL2_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplSDL2_GetWindowSize;
+    platform_io.Platform_GetWindowFramebufferScale = ImGui_ImplSDL2_GetWindowFramebufferScale;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplSDL2_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplSDL2_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplSDL2_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplSDL2_SetWindowTitle;
+    platform_io.Platform_RenderWindow = ImGui_ImplSDL2_RenderWindow;
+    platform_io.Platform_SwapBuffers = ImGui_ImplSDL2_SwapBuffers;
+#if SDL_HAS_WINDOW_ALPHA
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplSDL2_SetWindowAlpha;
+#endif
+#if SDL_HAS_VULKAN
+    platform_io.Platform_CreateVkSurface = ImGui_ImplSDL2_CreateVkSurface;
+#endif
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL2_ViewportData* vd = IM_NEW(ImGui_ImplSDL2_ViewportData)();
+    vd->Window = window;
+    vd->WindowID = SDL_GetWindowID(window);
+    vd->WindowOwned = false;
+    vd->GLContext = sdl_gl_context;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = (void*)(intptr_t)vd->WindowID;
+}
+
+static void ImGui_ImplSDL2_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_sdl2.h

@@ -9,6 +9,10 @@
 //  [X] Platform: Gamepad support.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: Basic IME support. App needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// Missing features or Issues:
+//  [ ] Platform: Multi-viewport: Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [ ] Platform: Multi-viewport: Missing ImGuiBackendFlags_HasParentViewport support. The viewport->ParentViewportID field is ignored, and therefore io.ConfigViewportsNoDefaultParent has no effect either.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_sdl3.cpp

@@ -8,7 +8,10 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy SDL_SCANCODE_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
-//  [X] Platform: IME support.
+//  [x] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable' -> the OS animation effect when window gets created/destroyed is problematic. SDL2 backend doesn't have issue.
+// Missing features or Issues:
+//  [ ] Platform: Multi-viewport: Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [x] Platform: IME support. Position somehow broken in SDL3 + app needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -20,18 +23,28 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-24: Skip using the SDL_GetGlobalMouseState() state when one of our window is hovered, as the SDL_EVENT_MOUSE_MOTION data is reliable. Fix macOS notch mouse coordinates issue in fullscreen mode + better perf on X11. (#7919, #7786)
+//  2025-09-18: Call platform_io.ClearPlatformHandlers() on shutdown.
+//  2025-09-15: Use SDL_GetWindowDisplayScale() on Mac to output DisplayFrameBufferScale. The function is more reliable during resolution changes e.g. going fullscreen. (#8703, #4414)
 //  2025-06-27: IME: avoid calling SDL_StartTextInput() again if already active. (#8727)
+//  2025-05-15: [Docking] Add Platform_GetWindowFramebufferScale() handler, to allow varying Retina display density on multiple monitors.
+//  2025-05-06: [Docking] macOS: fixed secondary viewports not appearing on other monitors before of parenting.
+//  2025-04-09: [Docking] Revert update monitors and work areas information every frame. Only do it on Windows. (#8415, #8558)
 //  2025-04-22: IME: honor ImGuiPlatformImeData->WantTextInput as an alternative way to call SDL_StartTextInput(), without IME being necessarily visible.
 //  2025-04-09: Don't attempt to call SDL_CaptureMouse() on drivers where we don't call SDL_GetGlobalMouseState(). (#8561)
 //  2025-03-30: Update for SDL3 api changes: Revert SDL_GetClipboardText() memory ownership change. (#8530, #7801)
 //  2025-03-21: Fill gamepad inputs and set ImGuiBackendFlags_HasGamepad regardless of ImGuiConfigFlags_NavEnableGamepad being set.
 //  2025-03-10: When dealing with OEM keys, use scancodes instead of translated keycodes to choose ImGuiKey values. (#7136, #7201, #7206, #7306, #7670, #7672, #8468)
 //  2025-02-26: Only start SDL_CaptureMouse() when mouse is being dragged, to mitigate issues with e.g.Linux debuggers not claiming capture back. (#6410, #3650)
+//  2025-02-25: [Docking] Revert to use SDL_GetDisplayBounds() for WorkPos/WorkRect if SDL_GetDisplayUsableBounds() failed.
 //  2025-02-24: Avoid calling SDL_GetGlobalMouseState() when mouse is in relative mode.
+//  2025-02-21: [Docking] Update monitors and work areas information every frame, as the later may change regardless of monitor changes. (#8415)
 //  2025-02-18: Added ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress mouse cursor support.
 //  2025-02-10: Using SDL_OpenURL() in platform_io.Platform_OpenInShellFn handler.
 //  2025-01-20: Made ImGui_ImplSDL3_SetGamepadMode(ImGui_ImplSDL3_GamepadMode_Manual) accept an empty array.
 //  2024-10-24: Emscripten: SDL_EVENT_MOUSE_WHEEL event doesn't require dividing by 100.0f on Emscripten.
+//  2024-09-11: (Docking) Added support for viewport->ParentViewportId field to support parenting at OS level. (#7973)
 //  2024-09-03: Update for SDL3 api changes: SDL_GetGamepads() memory ownership revert. (#7918, #7898, #7807)
 //  2024-08-22: moved some OS/backend related function pointers from ImGuiIO to ImGuiPlatformIO:
 //               - io.GetClipboardTextFn    -> platform_io.Platform_GetClipboardTextFn
@@ -105,6 +118,8 @@ struct ImGui_ImplSDL3_Data
     Uint64                  Time;
     char*                   ClipboardTextData;
     char                    BackendPlatformName[48];
+    bool                    UseVulkan;
+    bool                    WantUpdateMonitors;
 
     // IME handling
     SDL_Window*             ImeWindow;
@@ -117,11 +132,12 @@ struct ImGui_ImplSDL3_Data
     int                     MousePendingLeaveFrame;
     bool                    MouseCanUseGlobalState;
     bool                    MouseCanUseCapture;
+    bool                    MouseCanReportHoveredViewport;  // This is hard to use/unreliable on SDL so we'll set ImGuiBackendFlags_HasMouseHoveredViewport dynamically based on state.
 
     // Gamepad handling
-    ImVector<SDL_Gamepad*>      Gamepads;
+    ImVector<SDL_Gamepad*>  Gamepads;
     ImGui_ImplSDL3_GamepadMode  GamepadMode;
-    bool                        WantUpdateGamepadsList;
+    bool                    WantUpdateGamepadsList;
 
     ImGui_ImplSDL3_Data()   { memset((void*)this, 0, sizeof(*this)); }
 };
@@ -135,6 +151,11 @@ static ImGui_ImplSDL3_Data* ImGui_ImplSDL3_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplSDL3_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplSDL3_UpdateMonitors();
+static void ImGui_ImplSDL3_InitMultiViewportSupport(SDL_Window* window, void* sdl_gl_context);
+static void ImGui_ImplSDL3_ShutdownMultiViewportSupport();
+
 // Functions
 static const char* ImGui_ImplSDL3_GetClipboardText(ImGuiContext*)
 {
@@ -163,8 +184,8 @@ static void ImGui_ImplSDL3_PlatformSetImeData(ImGuiContext*, ImGuiViewport* view
     if (data->WantVisible)
     {
         SDL_Rect r;
-        r.x = (int)data->InputPos.x;
-        r.y = (int)data->InputPos.y;
+        r.x = (int)(data->InputPos.x - viewport->Pos.x);
+        r.y = (int)(data->InputPos.y - viewport->Pos.y + data->InputLineHeight);
         r.w = 1;
         r.h = (int)data->InputLineHeight;
         SDL_SetTextInputArea(window, &r, 0);
@@ -336,18 +357,15 @@ static void ImGui_ImplSDL3_UpdateKeyModifiers(SDL_Keymod sdl_key_mods)
     io.AddKeyEvent(ImGuiMod_Super, (sdl_key_mods & SDL_KMOD_GUI) != 0);
 }
 
-
 static ImGuiViewport* ImGui_ImplSDL3_GetViewportForWindowID(SDL_WindowID window_id)
 {
-    ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
-    return (window_id == bd->WindowID) ? ImGui::GetMainViewport() : nullptr;
+    return ImGui::FindViewportByPlatformHandle((void*)(intptr_t)window_id);
 }
 
 // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
 // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-// If you have multiple SDL events and some of them are not meant to be used by dear imgui, you may need to filter events based on their windowID field.
 bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
 {
     ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
@@ -361,6 +379,13 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
             if (ImGui_ImplSDL3_GetViewportForWindowID(event->motion.windowID) == nullptr)
                 return false;
             ImVec2 mouse_pos((float)event->motion.x, (float)event->motion.y);
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                int window_x, window_y;
+                SDL_GetWindowPosition(SDL_GetWindowFromID(event->motion.windowID), &window_x, &window_y);
+                mouse_pos.x += window_x;
+                mouse_pos.y += window_y;
+            }
             io.AddMouseSourceEvent(event->motion.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMousePosEvent(mouse_pos.x, mouse_pos.y);
             return true;
@@ -404,16 +429,26 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
         case SDL_EVENT_KEY_DOWN:
         case SDL_EVENT_KEY_UP:
         {
-            if (ImGui_ImplSDL3_GetViewportForWindowID(event->key.windowID) == nullptr)
+            ImGuiViewport* viewport = ImGui_ImplSDL3_GetViewportForWindowID(event->key.windowID);
+            if (viewport == nullptr)
                 return false;
+            //IMGUI_DEBUG_LOG("SDL_EVENT_KEY_%s : key=0x%08X ('%s'), scancode=%d ('%s'), mod=%X, windowID=%d, viewport=%08X\n",
+            //    (event->type == SDL_EVENT_KEY_DOWN) ? "DOWN" : "UP  ", event->key.key, SDL_GetKeyName(event->key.key), event->key.scancode, SDL_GetScancodeName(event->key.scancode), event->key.mod, event->key.windowID, viewport ? viewport->ID : 0);
             ImGui_ImplSDL3_UpdateKeyModifiers((SDL_Keymod)event->key.mod);
-            //IMGUI_DEBUG_LOG("SDL_EVENT_KEY_%s : key=%d ('%s'), scancode=%d ('%s'), mod=%X\n",
-            //    (event->type == SDL_EVENT_KEY_DOWN) ? "DOWN" : "UP  ", event->key.key, SDL_GetKeyName(event->key.key), event->key.scancode, SDL_GetScancodeName(event->key.scancode), event->key.mod);
             ImGuiKey key = ImGui_ImplSDL3_KeyEventToImGuiKey(event->key.key, event->key.scancode);
             io.AddKeyEvent(key, (event->type == SDL_EVENT_KEY_DOWN));
             io.SetKeyEventNativeData(key, (int)event->key.key, (int)event->key.scancode, (int)event->key.scancode); // To support legacy indexing (<1.87 user code). Legacy backend uses SDLK_*** as indices to IsKeyXXX() functions.
             return true;
         }
+        case SDL_EVENT_DISPLAY_ORIENTATION:
+        case SDL_EVENT_DISPLAY_ADDED:
+        case SDL_EVENT_DISPLAY_REMOVED:
+        case SDL_EVENT_DISPLAY_MOVED:
+        case SDL_EVENT_DISPLAY_CONTENT_SCALE_CHANGED:
+        {
+            bd->WantUpdateMonitors = true;
+            return true;
+        }
         case SDL_EVENT_WINDOW_MOUSE_ENTER:
         {
             if (ImGui_ImplSDL3_GetViewportForWindowID(event->window.windowID) == nullptr)
@@ -436,11 +471,28 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
         case SDL_EVENT_WINDOW_FOCUS_GAINED:
         case SDL_EVENT_WINDOW_FOCUS_LOST:
         {
-            if (ImGui_ImplSDL3_GetViewportForWindowID(event->window.windowID) == nullptr)
+            ImGuiViewport* viewport = ImGui_ImplSDL3_GetViewportForWindowID(event->window.windowID);
+            if (viewport == nullptr)
                 return false;
+            //IMGUI_DEBUG_LOG("%s: windowId %d, viewport: %08X\n", (event->type == SDL_EVENT_WINDOW_FOCUS_GAINED) ? "SDL_EVENT_WINDOW_FOCUS_GAINED" : "SDL_WINDOWEVENT_FOCUS_LOST", event->window.windowID, viewport ? viewport->ID : 0);
             io.AddFocusEvent(event->type == SDL_EVENT_WINDOW_FOCUS_GAINED);
             return true;
         }
+        case SDL_EVENT_WINDOW_CLOSE_REQUESTED:
+        case SDL_EVENT_WINDOW_MOVED:
+        case SDL_EVENT_WINDOW_RESIZED:
+        {
+            ImGuiViewport* viewport = ImGui_ImplSDL3_GetViewportForWindowID(event->window.windowID);
+            if (viewport == NULL)
+                return false;
+            if (event->type == SDL_EVENT_WINDOW_CLOSE_REQUESTED)
+                viewport->PlatformRequestClose = true;
+            if (event->type == SDL_EVENT_WINDOW_MOVED)
+                viewport->PlatformRequestMove = true;
+            if (event->type == SDL_EVENT_WINDOW_RESIZED)
+                viewport->PlatformRequestResize = true;
+            return true;
+        }
         case SDL_EVENT_GAMEPAD_ADDED:
         case SDL_EVENT_GAMEPAD_REMOVED:
         {
@@ -470,6 +522,7 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void
     IMGUI_CHECKVERSION();
     IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
     IM_UNUSED(sdl_gl_context); // Unused in this branch
+    //SDL_SetHint(SDL_HINT_EVENT_LOGGING, "2");
 
     const int ver_linked = SDL_GetVersion();
 
@@ -481,11 +534,21 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void
     io.BackendPlatformName = bd->BackendPlatformName;
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;           // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;            // We can honor io.WantSetMousePos requests (optional, rarely used)
+    // (ImGuiBackendFlags_PlatformHasViewports and ImGuiBackendFlags_HasParentViewport may be set just below)
+    // (ImGuiBackendFlags_HasMouseHoveredViewport is set dynamically in our _NewFrame function)
 
     bd->Window = window;
     bd->WindowID = SDL_GetWindowID(window);
     bd->Renderer = renderer;
 
+    // SDL on Linux/OSX doesn't report events for unfocused windows (see https://github.com/ocornut/imgui/issues/4960)
+    // We will use 'MouseCanReportHoveredViewport' to set 'ImGuiBackendFlags_HasMouseHoveredViewport' dynamically each frame.
+#ifndef __APPLE__
+    bd->MouseCanReportHoveredViewport = bd->MouseCanUseGlobalState;
+#else
+    bd->MouseCanReportHoveredViewport = false;
+#endif
+
     // Check and store if we are on a SDL backend that supports SDL_GetGlobalMouseState() and SDL_CaptureMouse()
     // ("wayland" and "rpi" don't support it, but we chose to use a white-list instead of a black-list)
     bd->MouseCanUseGlobalState = false;
@@ -497,6 +560,11 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void
         if (strncmp(sdl_backend, item, strlen(item)) == 0)
             bd->MouseCanUseGlobalState = bd->MouseCanUseCapture = true;
 #endif
+    if (bd->MouseCanUseGlobalState)
+    {
+        io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;  // We can create multi-viewports on the Platform side (optional)
+        io.BackendFlags |= ImGuiBackendFlags_HasParentViewport;     // We can honor viewport->ParentViewportId by applying the corresponding parent/child relationship at platform level (optional)
+    }
 
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     platform_io.Platform_SetClipboardTextFn = ImGui_ImplSDL3_SetClipboardText;
@@ -504,6 +572,9 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void
     platform_io.Platform_SetImeDataFn = ImGui_ImplSDL3_PlatformSetImeData;
     platform_io.Platform_OpenInShellFn = [](ImGuiContext*, const char* url) { return SDL_OpenURL(url) == 0; };
 
+    // Update monitor a first time during init
+    ImGui_ImplSDL3_UpdateMonitors();
+
     // Gamepad handling
     bd->GamepadMode = ImGui_ImplSDL3_GamepadMode_AutoFirst;
     bd->WantUpdateGamepadsList = true;
@@ -530,28 +601,36 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void
     // Without this, when clicking to gain focus, our widgets wouldn't activate even though they showed as hovered.
     // (This is unfortunately a global SDL setting, so enabling it might have a side-effect on your application.
     // It is unlikely to make a difference, but if your app absolutely needs to ignore the initial on-focus click:
-    // you can ignore SDL_EVENT_MOUSE_BUTTON_DOWN events coming right after a SDL_WINDOWEVENT_FOCUS_GAINED)
-#ifdef SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH
+    // you can ignore SDL_EVENT_MOUSE_BUTTON_DOWN events coming right after a SDL_EVENT_WINDOW_FOCUS_GAINED)
     SDL_SetHint(SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH, "1");
-#endif
 
     // From 2.0.22: Disable auto-capture, this is preventing drag and drop across multiple windows (see #5710)
-#ifdef SDL_HINT_MOUSE_AUTO_CAPTURE
     SDL_SetHint(SDL_HINT_MOUSE_AUTO_CAPTURE, "0");
-#endif
+
+    // SDL 3.x : see https://github.com/libsdl-org/SDL/issues/6659
+    SDL_SetHint("SDL_BORDERLESS_WINDOWED_STYLE", "0");
+
+    // We need SDL_CaptureMouse(), SDL_GetGlobalMouseState() from SDL 2.0.4+ to support multiple viewports.
+    // We left the call to ImGui_ImplSDL3_InitPlatformInterface() outside of #ifdef to avoid unused-function warnings.
+    if (io.BackendFlags & ImGuiBackendFlags_PlatformHasViewports)
+        ImGui_ImplSDL3_InitMultiViewportSupport(window, sdl_gl_context);
 
     return true;
 }
 
+// Should technically be a SDL_GLContext but due to typedef it is sane to keep it void* in public interface.
 bool ImGui_ImplSDL3_InitForOpenGL(SDL_Window* window, void* sdl_gl_context)
 {
-    IM_UNUSED(sdl_gl_context); // Viewport branch will need this.
     return ImGui_ImplSDL3_Init(window, nullptr, sdl_gl_context);
 }
 
 bool ImGui_ImplSDL3_InitForVulkan(SDL_Window* window)
 {
-    return ImGui_ImplSDL3_Init(window, nullptr, nullptr);
+    if (!ImGui_ImplSDL3_Init(window, nullptr, nullptr))
+        return false;
+    ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
+    bd->UseVulkan = true;
+    return true;
 }
 
 bool ImGui_ImplSDL3_InitForD3D(SDL_Window* window)
@@ -589,7 +668,9 @@ void ImGui_ImplSDL3_Shutdown()
     ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
+    ImGui_ImplSDL3_ShutdownMultiViewportSupport();
     if (bd->ClipboardTextData)
         SDL_free(bd->ClipboardTextData);
     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
@@ -598,10 +679,12 @@ void ImGui_ImplSDL3_Shutdown()
 
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad);
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad | ImGuiBackendFlags_PlatformHasViewports | ImGuiBackendFlags_HasMouseHoveredViewport | ImGuiBackendFlags_HasParentViewport);
+    platform_io.ClearPlatformHandlers();
     IM_DELETE(bd);
 }
 
+// This code is incredibly messy because some of the functions we need for full viewport support are not available in SDL < 2.0.4.
 static void ImGui_ImplSDL3_UpdateMouseData()
 {
     ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
@@ -621,7 +704,7 @@ static void ImGui_ImplSDL3_UpdateMouseData()
     }
 
     SDL_Window* focused_window = SDL_GetKeyboardFocus();
-    const bool is_app_focused = (bd->Window == focused_window);
+    const bool is_app_focused = (focused_window && (bd->Window == focused_window || ImGui_ImplSDL3_GetViewportForWindowID(SDL_GetWindowID(focused_window)) != NULL));
 #else
     SDL_Window* focused_window = bd->Window;
     const bool is_app_focused = (SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0; // SDL 2.0.3 and non-windowed systems: single-viewport only
@@ -630,20 +713,50 @@ static void ImGui_ImplSDL3_UpdateMouseData()
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when io.ConfigNavMoveSetMousePos is enabled by user)
         if (io.WantSetMousePos)
-            SDL_WarpMouseInWindow(bd->Window, io.MousePos.x, io.MousePos.y);
+        {
+#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+                SDL_WarpMouseGlobal(io.MousePos.x, io.MousePos.y);
+            else
+#endif
+                SDL_WarpMouseInWindow(bd->Window, io.MousePos.x, io.MousePos.y);
+        }
 
-        // (Optional) Fallback to provide mouse position when focused (SDL_EVENT_MOUSE_MOTION already provides this when hovered or captured)
+        // (Optional) Fallback to provide unclamped mouse position when focused but not hovered (SDL_EVENT_MOUSE_MOTION already provides this when hovered or captured)
+        // Note that SDL_GetGlobalMouseState() is in theory slow on X11, but this only runs on rather specific cases. If a problem we may provide a way to opt-out this feature.
+        SDL_Window* hovered_window = SDL_GetMouseFocus();
         const bool is_relative_mouse_mode = SDL_GetWindowRelativeMouseMode(bd->Window);
-        if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0 && !is_relative_mouse_mode)
+        if (hovered_window == NULL && bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0 && !is_relative_mouse_mode)
         {
             // Single-viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
-            float mouse_x_global, mouse_y_global;
+            // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+            float mouse_x, mouse_y;
             int window_x, window_y;
-            SDL_GetGlobalMouseState(&mouse_x_global, &mouse_y_global);
-            SDL_GetWindowPosition(focused_window, &window_x, &window_y);
-            io.AddMousePosEvent(mouse_x_global - window_x, mouse_y_global - window_y);
+            SDL_GetGlobalMouseState(&mouse_x, &mouse_y);
+            if (!(io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable))
+            {
+                SDL_GetWindowPosition(focused_window, &window_x, &window_y);
+                mouse_x -= window_x;
+                mouse_y -= window_y;
+            }
+            io.AddMousePosEvent(mouse_x, mouse_y);
         }
     }
+
+    // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+    // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+    // - [!] SDL backend does NOT correctly ignore viewports with the _NoInputs flag.
+    //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+    //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+    //       by the backend, and use its flawed heuristic to guess the viewport behind.
+    // - [X] SDL backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+    if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)
+    {
+        ImGuiID mouse_viewport_id = 0;
+        if (ImGuiViewport* mouse_viewport = ImGui_ImplSDL3_GetViewportForWindowID(bd->MouseWindowID))
+            mouse_viewport_id = mouse_viewport->ID;
+        io.AddMouseViewportEvent(mouse_viewport_id);
+    }
 }
 
 static void ImGui_ImplSDL3_UpdateMouseCursor()
@@ -775,18 +888,59 @@ static void ImGui_ImplSDL3_UpdateGamepads()
     ImGui_ImplSDL3_UpdateGamepadAnalog(bd, io, ImGuiKey_GamepadRStickDown,  SDL_GAMEPAD_AXIS_RIGHTY, +thumb_dead_zone, +32767);
 }
 
+static void ImGui_ImplSDL3_UpdateMonitors()
+{
+    ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Monitors.resize(0);
+    bd->WantUpdateMonitors = false;
+
+    int display_count;
+    SDL_DisplayID* displays = SDL_GetDisplays(&display_count);
+    for (int n = 0; n < display_count; n++)
+    {
+        // Warning: the validity of monitor DPI information on Windows depends on the application DPI awareness settings, which generally needs to be set in the manifest or at runtime.
+        SDL_DisplayID display_id = displays[n];
+        ImGuiPlatformMonitor monitor;
+        SDL_Rect r;
+        SDL_GetDisplayBounds(display_id, &r);
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+        if (SDL_GetDisplayUsableBounds(display_id, &r) && r.w > 0 && r.h > 0)
+        {
+            monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+            monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+        }
+        monitor.DpiScale = SDL_GetDisplayContentScale(display_id); // See https://wiki.libsdl.org/SDL3/README-highdpi for details.
+        monitor.PlatformHandle = (void*)(intptr_t)n;
+        if (monitor.DpiScale <= 0.0f)
+            continue; // Some accessibility applications are declaring virtual monitors with a DPI of 0, see #7902.
+        platform_io.Monitors.push_back(monitor);
+    }
+    SDL_free(displays);
+}
+
 static void ImGui_ImplSDL3_GetWindowSizeAndFramebufferScale(SDL_Window* window, ImVec2* out_size, ImVec2* out_framebuffer_scale)
 {
     int w, h;
-    int display_w, display_h;
     SDL_GetWindowSize(window, &w, &h);
     if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED)
         w = h = 0;
+
+#if defined(__APPLE__)
+    float fb_scale_x = SDL_GetWindowDisplayScale(window); // Seems more reliable during resolution change (#8703)
+    float fb_scale_y = fb_scale_x;
+#else
+    int display_w, display_h;
     SDL_GetWindowSizeInPixels(window, &display_w, &display_h);
+    float fb_scale_x = (w > 0) ? (float)display_w / w : 1.0f;
+    float fb_scale_y = (h > 0) ? (float)display_h / h : 1.0f;
+#endif
+
     if (out_size != nullptr)
         *out_size = ImVec2((float)w, (float)h);
     if (out_framebuffer_scale != nullptr)
-        *out_framebuffer_scale = (w > 0 && h > 0) ? ImVec2((float)display_w / w, (float)display_h / h) : ImVec2(1.0f, 1.0f);
+        *out_framebuffer_scale = ImVec2(fb_scale_x, fb_scale_y);
 }
 
 void ImGui_ImplSDL3_NewFrame()
@@ -798,6 +952,13 @@ void ImGui_ImplSDL3_NewFrame()
     // Setup main viewport size (every frame to accommodate for window resizing)
     ImGui_ImplSDL3_GetWindowSizeAndFramebufferScale(bd->Window, &io.DisplaySize, &io.DisplayFramebufferScale);
 
+    // Update monitors
+#ifdef WIN32
+    bd->WantUpdateMonitors = true; // Keep polling under Windows to handle changes of work area when resizing task-bar (#8415)
+#endif
+    if (bd->WantUpdateMonitors)
+        ImGui_ImplSDL3_UpdateMonitors();
+
     // Setup time step (we could also use SDL_GetTicksNS() available since SDL3)
     // (Accept SDL_GetPerformanceCounter() not returning a monotonically increasing value. Happens in VMs and Emscripten, see #6189, #6114, #3644)
     static Uint64 frequency = SDL_GetPerformanceFrequency();
@@ -814,6 +975,13 @@ void ImGui_ImplSDL3_NewFrame()
         io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
     }
 
+    // Our io.AddMouseViewportEvent() calls will only be valid when not capturing.
+    // Technically speaking testing for 'bd->MouseButtonsDown == 0' would be more rigorous, but testing for payload reduces noise and potential side-effects.
+    if (bd->MouseCanReportHoveredViewport && ImGui::GetDragDropPayload() == nullptr)
+        io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport;
+    else
+        io.BackendFlags &= ~ImGuiBackendFlags_HasMouseHoveredViewport;
+
     ImGui_ImplSDL3_UpdateMouseData();
     ImGui_ImplSDL3_UpdateMouseCursor();
 
@@ -821,6 +989,272 @@ void ImGui_ImplSDL3_NewFrame()
     ImGui_ImplSDL3_UpdateGamepads();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* PlatformUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplSDL3_ViewportData
+{
+    SDL_Window*     Window;
+    SDL_Window*     ParentWindow;
+    Uint32          WindowID;       // Stored in ImGuiViewport::PlatformHandle. Use SDL_GetWindowFromID() to get SDL_Window* from Uint32 WindowID.
+    bool            WindowOwned;
+    SDL_GLContext   GLContext;
+
+    ImGui_ImplSDL3_ViewportData()   { Window = ParentWindow = nullptr; WindowID = 0; WindowOwned = false; GLContext = nullptr; }
+    ~ImGui_ImplSDL3_ViewportData()  { IM_ASSERT(Window == nullptr && GLContext == nullptr); }
+};
+
+static SDL_Window* ImGui_ImplSDL3_GetSDLWindowFromViewport(ImGuiViewport* viewport)
+{
+    if (viewport != nullptr)
+    {
+        SDL_WindowID window_id = (SDL_WindowID)(intptr_t)viewport->PlatformHandle;
+        return SDL_GetWindowFromID(window_id);
+    }
+    return nullptr;
+}
+
+static void ImGui_ImplSDL3_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
+    ImGui_ImplSDL3_ViewportData* vd = IM_NEW(ImGui_ImplSDL3_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    vd->ParentWindow = ImGui_ImplSDL3_GetSDLWindowFromViewport(viewport->ParentViewport);
+
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL3_ViewportData* main_viewport_data = (ImGui_ImplSDL3_ViewportData*)main_viewport->PlatformUserData;
+
+    // Share GL resources with main context
+    bool use_opengl = (main_viewport_data->GLContext != nullptr);
+    SDL_GLContext backup_context = nullptr;
+    if (use_opengl)
+    {
+        backup_context = SDL_GL_GetCurrentContext();
+        SDL_GL_SetAttribute(SDL_GL_SHARE_WITH_CURRENT_CONTEXT, 1);
+        SDL_GL_MakeCurrent(main_viewport_data->Window, main_viewport_data->GLContext);
+    }
+
+    SDL_WindowFlags sdl_flags = 0;
+    sdl_flags |= SDL_WINDOW_HIDDEN;
+    sdl_flags |= use_opengl ? SDL_WINDOW_OPENGL : (bd->UseVulkan ? SDL_WINDOW_VULKAN : 0);
+    sdl_flags |= SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_HIGH_PIXEL_DENSITY;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? SDL_WINDOW_BORDERLESS : 0;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? 0 : SDL_WINDOW_RESIZABLE;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon) ? SDL_WINDOW_UTILITY : 0;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_TopMost) ? SDL_WINDOW_ALWAYS_ON_TOP : 0;
+    vd->Window = SDL_CreateWindow("No Title Yet", (int)viewport->Size.x, (int)viewport->Size.y, sdl_flags);
+#ifndef __APPLE__ // On Mac, SDL3 Parenting appears to prevent viewport from appearing in another monitor
+    SDL_SetWindowParent(vd->Window, vd->ParentWindow);
+#endif
+    SDL_SetWindowPosition(vd->Window, (int)viewport->Pos.x, (int)viewport->Pos.y);
+    vd->WindowOwned = true;
+    if (use_opengl)
+    {
+        vd->GLContext = SDL_GL_CreateContext(vd->Window);
+        SDL_GL_SetSwapInterval(0);
+    }
+    if (use_opengl && backup_context)
+        SDL_GL_MakeCurrent(vd->Window, backup_context);
+
+    ImGui_ImplSDL3_SetupPlatformHandles(viewport, vd->Window);
+}
+
+static void ImGui_ImplSDL3_DestroyWindow(ImGuiViewport* viewport)
+{
+    if (ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData)
+    {
+        if (vd->GLContext && vd->WindowOwned)
+            SDL_GL_DestroyContext(vd->GLContext);
+        if (vd->Window && vd->WindowOwned)
+            SDL_DestroyWindow(vd->Window);
+        vd->GLContext = nullptr;
+        vd->Window = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplSDL3_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+#if defined(_WIN32) && !(defined(WINAPI_FAMILY) && ((defined(WINAPI_FAMILY_APP) && WINAPI_FAMILY == WINAPI_FAMILY_APP) || (defined(WINAPI_FAMILY_GAMES) && WINAPI_FAMILY == WINAPI_FAMILY_GAMES)))
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+
+    // SDL hack: Show icon in task bar (#7989)
+    // Note: SDL_WINDOW_UTILITY can be used to control task bar visibility, but on Windows, it does not affect child windows.
+    if (!(viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon))
+    {
+        LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
+        ex_style |= WS_EX_APPWINDOW;
+        ex_style &= ~WS_EX_TOOLWINDOW;
+        ::ShowWindow(hwnd, SW_HIDE);
+        ::SetWindowLong(hwnd, GWL_EXSTYLE, ex_style);
+    }
+#endif
+
+#ifdef __APPLE__
+    SDL_SetHint(SDL_HINT_WINDOW_ACTIVATE_WHEN_SHOWN, "1"); // Otherwise new window appear under
+#else
+    SDL_SetHint(SDL_HINT_WINDOW_ACTIVATE_WHEN_SHOWN, (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing) ? "0" : "1");
+#endif
+    SDL_ShowWindow(vd->Window);
+}
+
+static void ImGui_ImplSDL3_UpdateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    IM_UNUSED(vd);
+
+#ifndef __APPLE__ // On Mac, SDL3 Parenting appears to prevent viewport from appearing in another monitor
+    // Update SDL3 parent if it changed _after_ creation.
+    // This is for advanced apps that are manipulating ParentViewportID manually.
+    SDL_Window* new_parent = ImGui_ImplSDL3_GetSDLWindowFromViewport(viewport->ParentViewport);
+    if (new_parent != vd->ParentWindow)
+    {
+        vd->ParentWindow = new_parent;
+        SDL_SetWindowParent(vd->Window, vd->ParentWindow);
+    }
+#endif
+}
+
+static ImVec2 ImGui_ImplSDL3_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    int x = 0, y = 0;
+    SDL_GetWindowPosition(vd->Window, &x, &y);
+    return ImVec2((float)x, (float)y);
+}
+
+static void ImGui_ImplSDL3_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowPosition(vd->Window, (int)pos.x, (int)pos.y);
+}
+
+static ImVec2 ImGui_ImplSDL3_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    int w = 0, h = 0;
+    SDL_GetWindowSize(vd->Window, &w, &h);
+    return ImVec2((float)w, (float)h);
+}
+
+static void ImGui_ImplSDL3_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowSize(vd->Window, (int)size.x, (int)size.y);
+}
+
+static ImVec2 ImGui_ImplSDL3_GetWindowFramebufferScale(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    ImVec2 framebuffer_scale;
+    ImGui_ImplSDL3_GetWindowSizeAndFramebufferScale(vd->Window, nullptr, &framebuffer_scale);
+    return framebuffer_scale;
+}
+
+static void ImGui_ImplSDL3_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowTitle(vd->Window, title);
+}
+
+static void ImGui_ImplSDL3_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowOpacity(vd->Window, alpha);
+}
+
+static void ImGui_ImplSDL3_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    SDL_RaiseWindow(vd->Window);
+}
+
+static bool ImGui_ImplSDL3_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    return (SDL_GetWindowFlags(vd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0;
+}
+
+static bool ImGui_ImplSDL3_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    return (SDL_GetWindowFlags(vd->Window) & SDL_WINDOW_MINIMIZED) != 0;
+}
+
+static void ImGui_ImplSDL3_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    if (vd->GLContext)
+        SDL_GL_MakeCurrent(vd->Window, vd->GLContext);
+}
+
+static void ImGui_ImplSDL3_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    if (vd->GLContext)
+    {
+        SDL_GL_MakeCurrent(vd->Window, vd->GLContext);
+        SDL_GL_SwapWindow(vd->Window);
+    }
+}
+
+// Vulkan support (the Vulkan renderer needs to call a platform-side support function to create the surface)
+// SDL is graceful enough to _not_ need <vulkan/vulkan.h> so we can safely include this.
+#include <SDL3/SDL_vulkan.h>
+static int ImGui_ImplSDL3_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_instance, const void* vk_allocator, ImU64* out_vk_surface)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    (void)vk_allocator;
+    bool ret = SDL_Vulkan_CreateSurface(vd->Window, (VkInstance)vk_instance, (const VkAllocationCallbacks*)vk_allocator, (VkSurfaceKHR*)out_vk_surface);
+    return ret ? 0 : 1; // ret ? VK_SUCCESS : VK_NOT_READY
+}
+
+static void ImGui_ImplSDL3_InitMultiViewportSupport(SDL_Window* window, void* sdl_gl_context)
+{
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplSDL3_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplSDL3_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplSDL3_ShowWindow;
+    platform_io.Platform_UpdateWindow = ImGui_ImplSDL3_UpdateWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplSDL3_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplSDL3_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplSDL3_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplSDL3_GetWindowSize;
+    platform_io.Platform_GetWindowFramebufferScale = ImGui_ImplSDL3_GetWindowFramebufferScale;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplSDL3_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplSDL3_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplSDL3_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplSDL3_SetWindowTitle;
+    platform_io.Platform_RenderWindow = ImGui_ImplSDL3_RenderWindow;
+    platform_io.Platform_SwapBuffers = ImGui_ImplSDL3_SwapBuffers;
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplSDL3_SetWindowAlpha;
+    platform_io.Platform_CreateVkSurface = ImGui_ImplSDL3_CreateVkSurface;
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL3_ViewportData* vd = IM_NEW(ImGui_ImplSDL3_ViewportData)();
+    vd->Window = window;
+    vd->WindowID = SDL_GetWindowID(window);
+    vd->WindowOwned = false;
+    vd->GLContext = (SDL_GLContext)sdl_gl_context;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = (void*)(intptr_t)vd->WindowID;
+}
+
+static void ImGui_ImplSDL3_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_sdl3.h

@@ -8,7 +8,10 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy SDL_SCANCODE_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
-//  [X] Platform: IME support.
+//  [x] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable' -> the OS animation effect when window gets created/destroyed is problematic. SDL2 backend doesn't have issue.
+// Missing features or Issues:
+//  [ ] Platform: Multi-viewport: Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [x] Platform: IME support. Position somehow broken in SDL3 + app needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_sdlgpu3.cpp

@@ -2,9 +2,10 @@
 // This needs to be used along with the SDL3 Platform Backend
 
 // Implemented features:
-//  [X] Renderer: User texture binding. Use simply cast a reference to your SDL_GPUTextureSamplerBinding to ImTextureID.
+//  [X] Renderer: User texture binding. Use 'SDL_GPUTexture*' as texture identifier. Read the FAQ about ImTextureID/ImTextureRef! **IMPORTANT** Before 2025/08/08, ImTextureID was a reference to a SDL_GPUTextureSamplerBinding struct.
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // The aim of imgui_impl_sdlgpu3.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -22,6 +23,11 @@
 //   Calling the function is MANDATORY, otherwise the ImGui will not upload neither the vertex nor the index buffer for the GPU. See imgui_impl_sdlgpu3.cpp for more info.
 
 // CHANGELOG
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
+//  2025-08-20: Added ImGui_ImplSDLGPU3_InitInfo::SwapchainComposition and ImGui_ImplSDLGPU3_InitInfo::PresentMode to configure how secondary viewports are created.
+//  2025-08-08: *BREAKING* Changed ImTextureID type from SDL_GPUTextureSamplerBinding* to SDL_GPUTexture*, which is more natural and easier for user to manage. If you need to change the current sampler, you can access the ImGui_ImplSDLGPU3_RenderState struct. (#8866, #8163, #7998, #7988)
+//  2025-08-08: Expose SamplerDefault and SamplerCurrent in ImGui_ImplSDLGPU3_RenderState. Allow callback to change sampler.
 //  2025-06-25: Mapping transfer buffer for texture update use cycle=true. Fixes artifacts e.g. on Metal backend.
 //  2025-06-11: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. Removed ImGui_ImplSDLGPU3_CreateFontsTexture() and ImGui_ImplSDLGPU3_DestroyFontsTexture().
 //  2025-04-28: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
@@ -36,11 +42,6 @@
 #include "imgui_impl_sdlgpu3_shaders.h"
 
 // SDL_GPU Data
-struct ImGui_ImplSDLGPU3_Texture
-{
-    SDL_GPUTexture*              Texture = nullptr;
-    SDL_GPUTextureSamplerBinding TextureSamplerBinding = { nullptr, nullptr };
-};
 
 // Reusable buffers used for rendering 1 current in-flight frame, for ImGui_ImplSDLGPU3_RenderDrawData()
 struct ImGui_ImplSDLGPU3_FrameData
@@ -61,7 +62,7 @@ struct ImGui_ImplSDLGPU3_Data
     SDL_GPUShader*               VertexShader           = nullptr;
     SDL_GPUShader*               FragmentShader         = nullptr;
     SDL_GPUGraphicsPipeline*     Pipeline               = nullptr;
-    SDL_GPUSampler*              TexSampler             = nullptr;
+    SDL_GPUSampler*              TexSamplerLinear       = nullptr;
     SDL_GPUTransferBuffer*       TexTransferBuffer      = nullptr;
     uint32_t                     TexTransferBufferSize  = 0;
 
@@ -84,12 +85,13 @@ static ImGui_ImplSDLGPU3_Data* ImGui_ImplSDLGPU3_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplSDLGPU3_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
-static void ImGui_ImplSDLGPU3_SetupRenderState(ImDrawData* draw_data, SDL_GPUGraphicsPipeline* pipeline, SDL_GPUCommandBuffer* command_buffer, SDL_GPURenderPass * render_pass, ImGui_ImplSDLGPU3_FrameData* fd, uint32_t fb_width, uint32_t fb_height)
+static void ImGui_ImplSDLGPU3_SetupRenderState(ImDrawData* draw_data, ImGui_ImplSDLGPU3_RenderState* render_state, SDL_GPUGraphicsPipeline* pipeline, SDL_GPUCommandBuffer* command_buffer, SDL_GPURenderPass* render_pass, ImGui_ImplSDLGPU3_FrameData* fd, uint32_t fb_width, uint32_t fb_height)
 {
-    //ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
+    ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
+    render_state->SamplerCurrent = bd->TexSamplerLinear;
 
     // Bind graphics pipeline
-    SDL_BindGPUGraphicsPipeline(render_pass,pipeline);
+    SDL_BindGPUGraphicsPipeline(render_pass, pipeline);
 
     // Bind Vertex And Index Buffers
     if (draw_data->TotalVtxCount > 0)
@@ -180,9 +182,8 @@ void ImGui_ImplSDLGPU3_PrepareDrawData(ImDrawData* draw_data, SDL_GPUCommandBuff
 
     ImDrawVert* vtx_dst = (ImDrawVert*)SDL_MapGPUTransferBuffer(v->Device, fd->VertexTransferBuffer, true);
     ImDrawIdx* idx_dst = (ImDrawIdx*)SDL_MapGPUTransferBuffer(v->Device, fd->IndexTransferBuffer, true);
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         memcpy(vtx_dst, draw_list->VtxBuffer.Data, draw_list->VtxBuffer.Size * sizeof(ImDrawVert));
         memcpy(idx_dst, draw_list->IdxBuffer.Data, draw_list->IdxBuffer.Size * sizeof(ImDrawIdx));
         vtx_dst += draw_list->VtxBuffer.Size;
@@ -228,19 +229,25 @@ void ImGui_ImplSDLGPU3_RenderDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffe
     if (pipeline == nullptr)
         pipeline = bd->Pipeline;
 
-    ImGui_ImplSDLGPU3_SetupRenderState(draw_data, pipeline, command_buffer, render_pass, fd, fb_width, fb_height);
-
     // Will project scissor/clipping rectangles into framebuffer space
     ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
     ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
 
+    // Setup render state structure (for callbacks and custom texture bindings)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    ImGui_ImplSDLGPU3_RenderState render_state;
+    render_state.Device = bd->InitInfo.Device;
+    render_state.SamplerDefault = render_state.SamplerCurrent = bd->TexSamplerLinear;
+    platform_io.Renderer_RenderState = &render_state;
+
+    ImGui_ImplSDLGPU3_SetupRenderState(draw_data, &render_state, pipeline, command_buffer, render_pass, fd, fb_width, fb_height);
+
     // Render command lists
     // (Because we merged all buffers into a single one, we maintain our own offset into them)
     int global_vtx_offset = 0;
     int global_idx_offset = 0;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         for (int cmd_i = 0; cmd_i < draw_list->CmdBuffer.Size; cmd_i++)
         {
             const ImDrawCmd* pcmd = &draw_list->CmdBuffer[cmd_i];
@@ -249,7 +256,7 @@ void ImGui_ImplSDLGPU3_RenderDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffe
                 // User callback, registered via ImDrawList::AddCallback()
                 // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
                 if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
-                    ImGui_ImplSDLGPU3_SetupRenderState(draw_data, pipeline, command_buffer, render_pass, fd, fb_width, fb_height);
+                    ImGui_ImplSDLGPU3_SetupRenderState(draw_data, &render_state, pipeline, command_buffer, render_pass, fd, fb_width, fb_height);
                 else
                     pcmd->UserCallback(draw_list, pcmd);
             }
@@ -276,9 +283,14 @@ void ImGui_ImplSDLGPU3_RenderDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffe
                 SDL_SetGPUScissor(render_pass,&scissor_rect);
 
                 // Bind DescriptorSet with font or user texture
-                SDL_BindGPUFragmentSamplers(render_pass, 0, (SDL_GPUTextureSamplerBinding*)pcmd->GetTexID(), 1);
+                SDL_GPUTextureSamplerBinding texture_sampler_binding;
+                texture_sampler_binding.texture = (SDL_GPUTexture*)(intptr_t)pcmd->GetTexID();
+                texture_sampler_binding.sampler = render_state.SamplerCurrent;
+                SDL_BindGPUFragmentSamplers(render_pass, 0, &texture_sampler_binding, 1);
 
                 // Draw
+                // **IF YOU GET A CRASH HERE** In 1.92.2 on 2025/08/08 we have changed ImTextureID to store 'SDL_GPUTexture*' instead of storing 'SDL_GPUTextureSamplerBinding'.
+                // Any code loading custom texture using this backend needs to be updated.
                 SDL_DrawGPUIndexedPrimitives(render_pass, pcmd->ElemCount, 1, pcmd->IdxOffset + global_idx_offset, pcmd->VtxOffset + global_vtx_offset, 0);
             }
         }
@@ -297,18 +309,12 @@ void ImGui_ImplSDLGPU3_RenderDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffe
 static void ImGui_ImplSDLGPU3_DestroyTexture(ImTextureData* tex)
 {
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
-    ImGui_ImplSDLGPU3_Texture* backend_tex = (ImGui_ImplSDLGPU3_Texture*)tex->BackendUserData;
-    if (backend_tex == nullptr)
-        return;
-    SDL_GPUTextureSamplerBinding* binding = (SDL_GPUTextureSamplerBinding*)(intptr_t)tex->BackendUserData;
-    IM_ASSERT(backend_tex->Texture == binding->texture);
-    SDL_ReleaseGPUTexture(bd->InitInfo.Device, backend_tex->Texture);
-    IM_DELETE(backend_tex);
+    if (SDL_GPUTexture* raw_tex = (SDL_GPUTexture*)(intptr_t)tex->GetTexID())
+        SDL_ReleaseGPUTexture(bd->InitInfo.Device, raw_tex);
 
     // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
     tex->SetTexID(ImTextureID_Invalid);
     tex->SetStatus(ImTextureStatus_Destroyed);
-    tex->BackendUserData = nullptr;
 }
 
 void ImGui_ImplSDLGPU3_UpdateTexture(ImTextureData* tex)
@@ -322,7 +328,6 @@ void ImGui_ImplSDLGPU3_UpdateTexture(ImTextureData* tex)
         //IMGUI_DEBUG_LOG("UpdateTexture #%03d: WantCreate %dx%d\n", tex->UniqueID, tex->Width, tex->Height);
         IM_ASSERT(tex->TexID == ImTextureID_Invalid && tex->BackendUserData == nullptr);
         IM_ASSERT(tex->Format == ImTextureFormat_RGBA32);
-        ImGui_ImplSDLGPU3_Texture* backend_tex = IM_NEW(ImGui_ImplSDLGPU3_Texture)();
 
         // Create texture
         SDL_GPUTextureCreateInfo texture_info = {};
@@ -335,19 +340,16 @@ void ImGui_ImplSDLGPU3_UpdateTexture(ImTextureData* tex)
         texture_info.num_levels = 1;
         texture_info.sample_count = SDL_GPU_SAMPLECOUNT_1;
 
-        backend_tex->Texture = SDL_CreateGPUTexture(v->Device, &texture_info);
-        backend_tex->TextureSamplerBinding.texture = backend_tex->Texture;
-        backend_tex->TextureSamplerBinding.sampler = bd->TexSampler;
-        IM_ASSERT(backend_tex->Texture && "Failed to create font texture, call SDL_GetError() for more info");
+        SDL_GPUTexture* raw_tex = SDL_CreateGPUTexture(v->Device, &texture_info);
+        IM_ASSERT(raw_tex != nullptr && "Failed to create texture, call SDL_GetError() for more info");
 
         // Store identifiers
-        tex->SetTexID((ImTextureID)(intptr_t)&backend_tex->TextureSamplerBinding);
-        tex->BackendUserData = backend_tex;
+        tex->SetTexID((ImTextureID)(intptr_t)raw_tex);
     }
 
     if (tex->Status == ImTextureStatus_WantCreate || tex->Status == ImTextureStatus_WantUpdates)
     {
-        ImGui_ImplSDLGPU3_Texture* backend_tex = (ImGui_ImplSDLGPU3_Texture*)tex->BackendUserData;
+        SDL_GPUTexture* raw_tex = (SDL_GPUTexture*)(intptr_t)tex->GetTexID();
         IM_ASSERT(tex->Format == ImTextureFormat_RGBA32);
 
         // Update full texture or selected blocks. We only ever write to textures regions which have never been used before!
@@ -369,7 +371,7 @@ void ImGui_ImplSDLGPU3_UpdateTexture(ImTextureData* tex)
             transferbuffer_info.size = upload_size + 1024;
             bd->TexTransferBufferSize = upload_size + 1024;
             bd->TexTransferBuffer = SDL_CreateGPUTransferBuffer(v->Device, &transferbuffer_info);
-            IM_ASSERT(bd->TexTransferBuffer != nullptr && "Failed to create font transfer buffer, call SDL_GetError() for more information");
+            IM_ASSERT(bd->TexTransferBuffer != nullptr && "Failed to create transfer buffer, call SDL_GetError() for more information");
         }
 
         // Copy to transfer buffer
@@ -385,7 +387,7 @@ void ImGui_ImplSDLGPU3_UpdateTexture(ImTextureData* tex)
         transfer_info.transfer_buffer = bd->TexTransferBuffer;
 
         SDL_GPUTextureRegion texture_region = {};
-        texture_region.texture = backend_tex->Texture;
+        texture_region.texture = raw_tex;
         texture_region.x = (Uint32)upload_x;
         texture_region.y = (Uint32)upload_y;
         texture_region.w = (Uint32)upload_w;
@@ -558,7 +560,7 @@ void ImGui_ImplSDLGPU3_CreateDeviceObjects()
 
     ImGui_ImplSDLGPU3_DestroyDeviceObjects();
 
-    if (bd->TexSampler == nullptr)
+    if (bd->TexSamplerLinear == nullptr)
     {
         // Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling.
         SDL_GPUSamplerCreateInfo sampler_info = {};
@@ -575,8 +577,8 @@ void ImGui_ImplSDLGPU3_CreateDeviceObjects()
         sampler_info.max_anisotropy = 1.0f;
         sampler_info.enable_compare = false;
 
-        bd->TexSampler = SDL_CreateGPUSampler(v->Device, &sampler_info);
-        IM_ASSERT(bd->TexSampler != nullptr && "Failed to create font sampler, call SDL_GetError() for more information");
+        bd->TexSamplerLinear = SDL_CreateGPUSampler(v->Device, &sampler_info);
+        IM_ASSERT(bd->TexSamplerLinear != nullptr && "Failed to create sampler, call SDL_GetError() for more information");
     }
 
     ImGui_ImplSDLGPU3_CreateGraphicsPipeline();
@@ -611,10 +613,13 @@ void ImGui_ImplSDLGPU3_DestroyDeviceObjects()
     if (bd->TexTransferBuffer)  { SDL_ReleaseGPUTransferBuffer(v->Device, bd->TexTransferBuffer); bd->TexTransferBuffer = nullptr; }
     if (bd->VertexShader)       { SDL_ReleaseGPUShader(v->Device, bd->VertexShader); bd->VertexShader = nullptr; }
     if (bd->FragmentShader)     { SDL_ReleaseGPUShader(v->Device, bd->FragmentShader); bd->FragmentShader = nullptr; }
-    if (bd->TexSampler)         { SDL_ReleaseGPUSampler(v->Device, bd->TexSampler); bd->TexSampler = nullptr; }
+    if (bd->TexSamplerLinear)   { SDL_ReleaseGPUSampler(v->Device, bd->TexSamplerLinear); bd->TexSamplerLinear = nullptr; }
     if (bd->Pipeline)           { SDL_ReleaseGPUGraphicsPipeline(v->Device, bd->Pipeline); bd->Pipeline = nullptr; }
 }
 
+static void ImGui_ImplSDLGPU3_InitMultiViewportSupport();
+static void ImGui_ImplSDLGPU3_ShutdownMultiViewportSupport();
+
 bool ImGui_ImplSDLGPU3_Init(ImGui_ImplSDLGPU3_InitInfo* info)
 {
     ImGuiIO& io = ImGui::GetIO();
@@ -627,12 +632,15 @@ bool ImGui_ImplSDLGPU3_Init(ImGui_ImplSDLGPU3_InitInfo* info)
     io.BackendRendererName = "imgui_impl_sdlgpu3";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
     io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;   // We can honor ImGuiPlatformIO::Textures[] requests during render.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     IM_ASSERT(info->Device != nullptr);
     IM_ASSERT(info->ColorTargetFormat != SDL_GPU_TEXTUREFORMAT_INVALID);
 
     bd->InitInfo = *info;
 
+    ImGui_ImplSDLGPU3_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -641,11 +649,15 @@ void ImGui_ImplSDLGPU3_Shutdown()
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
+    ImGui_ImplSDLGPU3_ShutdownMultiViewportSupport();
     ImGui_ImplSDLGPU3_DestroyDeviceObjects();
+
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
 }
 
@@ -654,8 +666,80 @@ void ImGui_ImplSDLGPU3_NewFrame()
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
     IM_ASSERT(bd != nullptr && "Context or backend not initialized! Did you call ImGui_ImplSDLGPU3_Init()?");
 
-    if (!bd->TexSampler)
+    if (!bd->TexSamplerLinear)
         ImGui_ImplSDLGPU3_CreateDeviceObjects();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplSDLGPU3_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDLGPU3_Data* data = ImGui_ImplSDLGPU3_GetBackendData();
+    SDL_Window* window = SDL_GetWindowFromID((SDL_WindowID)(intptr_t)viewport->PlatformHandle);
+    SDL_ClaimWindowForGPUDevice(data->InitInfo.Device, window);
+    SDL_SetGPUSwapchainParameters(data->InitInfo.Device, window, data->InitInfo.SwapchainComposition, data->InitInfo.PresentMode);
+    viewport->RendererUserData = (void*)1;
+}
+
+static void ImGui_ImplSDLGPU3_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDLGPU3_Data* data = ImGui_ImplSDLGPU3_GetBackendData();
+    SDL_Window* window = SDL_GetWindowFromID((SDL_WindowID)(intptr_t)viewport->PlatformHandle);
+
+    ImDrawData* draw_data = viewport->DrawData;
+
+    SDL_GPUCommandBuffer* command_buffer = SDL_AcquireGPUCommandBuffer(data->InitInfo.Device);
+
+    SDL_GPUTexture* swapchain_texture;
+    SDL_AcquireGPUSwapchainTexture(command_buffer, window, &swapchain_texture, nullptr, nullptr);
+
+    if (swapchain_texture != nullptr)
+    {
+        ImGui_ImplSDLGPU3_PrepareDrawData(draw_data, command_buffer); // FIXME-OPT: Not optimal, may this be done earlier?
+        SDL_GPUColorTargetInfo target_info = {};
+        target_info.texture = swapchain_texture;
+        target_info.clear_color = SDL_FColor{ 0.0f,0.0f,0.0f,1.0f };
+        target_info.load_op = SDL_GPU_LOADOP_CLEAR;
+        target_info.store_op = SDL_GPU_STOREOP_STORE;
+        target_info.mip_level = 0;
+        target_info.layer_or_depth_plane = 0;
+        target_info.cycle = false;
+        SDL_GPURenderPass* render_pass = SDL_BeginGPURenderPass(command_buffer, &target_info, 1, nullptr);
+        ImGui_ImplSDLGPU3_RenderDrawData(draw_data, command_buffer, render_pass);
+        SDL_EndGPURenderPass(render_pass);
+    }
+
+    SDL_SubmitGPUCommandBuffer(command_buffer);
+}
+
+static void ImGui_ImplSDLGPU3_DestroyWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDLGPU3_Data* data = ImGui_ImplSDLGPU3_GetBackendData();
+    if (viewport->RendererUserData)
+    {
+        SDL_Window* window = SDL_GetWindowFromID((SDL_WindowID)(intptr_t)viewport->PlatformHandle);
+        SDL_ReleaseWindowFromGPUDevice(data->InitInfo.Device, window);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplSDLGPU3_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplSDLGPU3_RenderWindow;
+    platform_io.Renderer_CreateWindow = ImGui_ImplSDLGPU3_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplSDLGPU3_DestroyWindow;
+}
+
+static void ImGui_ImplSDLGPU3_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
+//-----------------------------------------------------------------------------
+
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_sdlgpu3.h

@@ -2,9 +2,10 @@
 // This needs to be used along with the SDL3 Platform Backend
 
 // Implemented features:
-//  [X] Renderer: User texture binding. Use simply cast a reference to your SDL_GPUTextureSamplerBinding to ImTextureID.
+//  [X] Renderer: User texture binding. Use 'SDL_GPUTexture*' as texture identifier. Read the FAQ about ImTextureID/ImTextureRef! **IMPORTANT** Before 2025/08/08, ImTextureID was a reference to a SDL_GPUTextureSamplerBinding struct.
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // The aim of imgui_impl_sdlgpu3.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -27,12 +28,14 @@
 #include <SDL3/SDL_gpu.h>
 
 // Initialization data, for ImGui_ImplSDLGPU_Init()
-// - Remember to set ColorTargetFormat to the correct format. If you're rendering to the swapchain, call SDL_GetGPUSwapchainTextureFormat to query the right value
+// - Remember to set ColorTargetFormat to the correct format. If you're rendering to the swapchain, call SDL_GetGPUSwapchainTextureFormat() to query the right value
 struct ImGui_ImplSDLGPU3_InitInfo
 {
-    SDL_GPUDevice*       Device             = nullptr;
-    SDL_GPUTextureFormat ColorTargetFormat  = SDL_GPU_TEXTUREFORMAT_INVALID;
-    SDL_GPUSampleCount   MSAASamples        = SDL_GPU_SAMPLECOUNT_1;
+    SDL_GPUDevice*              Device                  = nullptr;
+    SDL_GPUTextureFormat        ColorTargetFormat       = SDL_GPU_TEXTUREFORMAT_INVALID;
+    SDL_GPUSampleCount          MSAASamples             = SDL_GPU_SAMPLECOUNT_1;
+    SDL_GPUSwapchainComposition SwapchainComposition    = SDL_GPU_SWAPCHAINCOMPOSITION_SDR;     // Only used in multi-viewports mode.
+    SDL_GPUPresentMode          PresentMode             = SDL_GPU_PRESENTMODE_VSYNC;            // Only used in multi-viewports mode.
 };
 
 // Follow "Getting Started" link and check examples/ folder to learn about using backends!
@@ -49,4 +52,14 @@ IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_DestroyDeviceObjects();
 // (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
 IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_UpdateTexture(ImTextureData* tex);
 
+// [BETA] Selected render state data shared with callbacks.
+// This is temporarily stored in GetPlatformIO().Renderer_RenderState during the ImGui_ImplSDLGPU3_RenderDrawData() call.
+// (Please open an issue if you feel you need access to more data)
+struct ImGui_ImplSDLGPU3_RenderState
+{
+    SDL_GPUDevice*      Device;
+    SDL_GPUSampler*     SamplerDefault;     // Default sampler (bilinear filtering)
+    SDL_GPUSampler*     SamplerCurrent;     // Current sampler (may be changed by callback)
+};
+
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_sdlrenderer2.cpp

@@ -14,6 +14,8 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -24,6 +26,7 @@
 // - Introduction, links and more at the top of imgui.cpp
 
 // CHANGELOG
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
 //  2025-06-11: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. Removed ImGui_ImplSDLRenderer2_CreateFontsTexture() and ImGui_ImplSDLRenderer2_DestroyFontsTexture().
 //  2025-01-18: Use endian-dependent RGBA32 texture format, to match SDL_Color.
 //  2024-10-09: Expose selected render state in ImGui_ImplSDLRenderer2_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
@@ -94,12 +97,14 @@ void ImGui_ImplSDLRenderer2_Shutdown()
     ImGui_ImplSDLRenderer2_Data* bd = ImGui_ImplSDLRenderer2_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
     ImGui_ImplSDLRenderer2_DestroyDeviceObjects();
 
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
     io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
 }
 
@@ -169,9 +174,8 @@ void ImGui_ImplSDLRenderer2_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
     ImVec2 clip_scale = render_scale;
 
     // Render command lists
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         const ImDrawVert* vtx_buffer = draw_list->VtxBuffer.Data;
         const ImDrawIdx* idx_buffer = draw_list->IdxBuffer.Data;
 
@@ -265,10 +269,8 @@ void ImGui_ImplSDLRenderer2_UpdateTexture(ImTextureData* tex)
     }
     else if (tex->Status == ImTextureStatus_WantDestroy)
     {
-        SDL_Texture* sdl_texture = (SDL_Texture*)(intptr_t)tex->TexID;
-        if (sdl_texture == nullptr)
-            return;
-        SDL_DestroyTexture(sdl_texture);
+        if (SDL_Texture* sdl_texture = (SDL_Texture*)(intptr_t)tex->TexID)
+            SDL_DestroyTexture(sdl_texture);
 
         // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
         tex->SetTexID(ImTextureID_Invalid);

backends/imgui_impl_sdlrenderer2.h

@@ -14,6 +14,8 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_sdlrenderer3.cpp

@@ -14,6 +14,8 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -24,6 +26,7 @@
 // - Introduction, links and more at the top of imgui.cpp
 
 // CHANGELOG
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
 //  2025-06-11: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. Removed ImGui_ImplSDLRenderer3_CreateFontsTexture() and ImGui_ImplSDLRenderer3_DestroyFontsTexture().
 //  2025-01-18: Use endian-dependent RGBA32 texture format, to match SDL_Color.
 //  2024-10-09: Expose selected render state in ImGui_ImplSDLRenderer3_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
@@ -92,12 +95,14 @@ void ImGui_ImplSDLRenderer3_Shutdown()
     ImGui_ImplSDLRenderer3_Data* bd = ImGui_ImplSDLRenderer3_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
     ImGui_ImplSDLRenderer3_DestroyDeviceObjects();
 
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
     io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
 }
 
@@ -189,9 +194,8 @@ void ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
     ImVec2 clip_scale = render_scale;
 
     // Render command lists
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         const ImDrawVert* vtx_buffer = draw_list->VtxBuffer.Data;
         const ImDrawIdx* idx_buffer = draw_list->IdxBuffer.Data;
 
@@ -281,10 +285,8 @@ void ImGui_ImplSDLRenderer3_UpdateTexture(ImTextureData* tex)
     }
     else if (tex->Status == ImTextureStatus_WantDestroy)
     {
-        SDL_Texture* sdl_texture = (SDL_Texture*)(intptr_t)tex->TexID;
-        if (sdl_texture == nullptr)
-            return;
-        SDL_DestroyTexture(sdl_texture);
+        if (SDL_Texture* sdl_texture = (SDL_Texture*)(intptr_t)tex->TexID)
+            SDL_DestroyTexture(sdl_texture);
 
         // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
         tex->SetTexID(ImTextureID_Invalid);

backends/imgui_impl_sdlrenderer3.h

@@ -14,6 +14,8 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_vulkan.cpp

@@ -6,6 +6,7 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [x] Renderer: Multi-viewport / platform windows. With issues (flickering when creating a new viewport).
 
 // The aim of imgui_impl_vulkan.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -27,6 +28,15 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-26: *BREAKING CHANGE*: moved some fields in ImGui_ImplVulkan_InitInfo: init_info.RenderPass --> init_info.PipelineInfoMain.RenderPass, init_info.Subpass --> init_info.PipelineInfoMain.Subpass, init_info.MSAASamples --> init_info.PipelineInfoMain.MSAASamples, init_info.PipelineRenderingCreateInfo --> init_info.PipelineInfoMain.PipelineRenderingCreateInfo.
+//  2025-09-26: *BREAKING CHANGE*: renamed ImGui_ImplVulkan_MainPipelineCreateInfo to ImGui_ImplVulkan_PipelineInfo. Introduced very recently so shouldn't affect many users.
+//  2025-09-26: *BREAKING CHANGE*: helper ImGui_ImplVulkanH_CreateOrResizeWindow() added a VkImageUsageFlags image_usage` argument, default to VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT if 0.
+//  2025-09-26: Vulkan: Added a way to customize shaders by filling ImGui_ImplVulkan_InitInfo::CustomShaderVertCreateInfo/CustomShaderFragCreateInfo. (#8585)
+//  2025-09-22: [Docking] Added ImGui_ImplVulkanH_GetWindowDataFromViewport() accessor/helper. (#8946, #8940)
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
+//  2025-09-04: Vulkan: Added ImGui_ImplVulkan_CreateMainPipeline(). (#8110, #8111)
+//  2025-07-27: Vulkan: Fixed texture update corruption introduced on 2025-06-11. (#8801, #8755, #8840)
 //  2025-07-07: Vulkan: Fixed texture synchronization issue introduced on 2025-06-11. (#8772)
 //  2025-06-27: Vulkan: Fixed validation errors during texture upload/update by aligning upload size to 'nonCoherentAtomSize'. (#8743, #8744)
 //  2025-06-11: Vulkan: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. Removed ImGui_ImplVulkan_CreateFontsTexture() and ImGui_ImplVulkan_DestroyFontsTexture().
@@ -114,11 +124,12 @@ void ImGui_ImplVulkan_DestroyFrameRenderBuffers(VkDevice device, ImGui_ImplVulka
 void ImGui_ImplVulkan_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVulkan_WindowRenderBuffers* buffers, const VkAllocationCallbacks* allocator);
 void ImGui_ImplVulkanH_DestroyFrame(VkDevice device, ImGui_ImplVulkanH_Frame* fd, const VkAllocationCallbacks* allocator);
 void ImGui_ImplVulkanH_DestroyFrameSemaphores(VkDevice device, ImGui_ImplVulkanH_FrameSemaphores* fsd, const VkAllocationCallbacks* allocator);
-void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count);
+void ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(VkDevice device, const VkAllocationCallbacks* allocator);
+void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count, VkImageUsageFlags image_usage);
 void ImGui_ImplVulkanH_CreateWindowCommandBuffers(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, uint32_t queue_family, const VkAllocationCallbacks* allocator);
 
 // Vulkan prototypes for use with custom loaders
-// (see description of IMGUI_IMPL_VULKAN_NO_PROTOTYPES in imgui_impl_vulkan.h
+// (see description of IMGUI_IMPL_VULKAN_NO_PROTOTYPES in imgui_impl_vulkan.h)
 #if defined(VK_NO_PROTOTYPES) && !defined(VOLK_H_)
 #define IMGUI_IMPL_VULKAN_USE_LOADER
 static bool g_FunctionsLoaded = false;
@@ -130,15 +141,18 @@ static bool g_FunctionsLoaded = true;
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkAllocateCommandBuffers) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkAllocateDescriptorSets) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkAllocateMemory) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkAcquireNextImageKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkBeginCommandBuffer) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkBindBufferMemory) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkBindImageMemory) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBeginRenderPass) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindDescriptorSets) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindIndexBuffer) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindPipeline) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindVertexBuffers) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdCopyBufferToImage) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdDrawIndexed) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdEndRenderPass) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdPipelineBarrier) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdPushConstants) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdSetScissor) \
@@ -190,8 +204,10 @@ static bool g_FunctionsLoaded = true;
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceCapabilitiesKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceFormatsKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfacePresentModesKHR) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceSupportKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetSwapchainImagesKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkMapMemory) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueuePresentKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueueSubmit) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueueWaitIdle) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkResetCommandPool) \
@@ -242,6 +258,20 @@ struct ImGui_ImplVulkan_Texture
     ImGui_ImplVulkan_Texture() { memset((void*)this, 0, sizeof(*this)); }
 };
 
+// For multi-viewport support:
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplVulkan_ViewportData
+{
+    ImGui_ImplVulkanH_Window                Window;                 // Used by secondary viewports only
+    ImGui_ImplVulkan_WindowRenderBuffers    RenderBuffers;          // Used by all viewports
+    bool                                    WindowOwned;
+    bool                                    SwapChainNeedRebuild;   // Flag when viewport swapchain resized in the middle of processing a frame
+    bool                                    SwapChainSuboptimal;    // Flag when VK_SUBOPTIMAL_KHR was returned.
+
+    ImGui_ImplVulkan_ViewportData() { WindowOwned = SwapChainNeedRebuild = SwapChainSuboptimal = false; memset((void*)&RenderBuffers, 0, sizeof(RenderBuffers)); }
+    ~ImGui_ImplVulkan_ViewportData() { }
+};
+
 // Vulkan data
 struct ImGui_ImplVulkan_Data
 {
@@ -251,13 +281,15 @@ struct ImGui_ImplVulkan_Data
     VkPipelineCreateFlags       PipelineCreateFlags;
     VkDescriptorSetLayout       DescriptorSetLayout;
     VkPipelineLayout            PipelineLayout;
-    VkPipeline                  Pipeline;
+    VkPipeline                  Pipeline;               // pipeline for main render pass (created by app)
+    VkPipeline                  PipelineForViewports;   // pipeline for secondary viewports (created by backend)
     VkShaderModule              ShaderModuleVert;
     VkShaderModule              ShaderModuleFrag;
     VkDescriptorPool            DescriptorPool;
+    ImVector<VkFormat>          PipelineRenderingCreateInfoColorAttachmentFormats; // Deep copy of format array
 
     // Texture management
-    VkSampler                   TexSampler;
+    VkSampler                   TexSamplerLinear;
     VkCommandPool               TexCommandPool;
     VkCommandBuffer             TexCommandBuffer;
 
@@ -276,6 +308,10 @@ struct ImGui_ImplVulkan_Data
 // SHADERS
 //-----------------------------------------------------------------------------
 
+// Forward Declarations
+static void ImGui_ImplVulkan_InitMultiViewportSupport();
+static void ImGui_ImplVulkan_ShutdownMultiViewportSupport();
+
 // backends/vulkan/glsl_shader.vert, compiled with:
 // # glslangValidator -V -x -o glsl_shader.vert.u32 glsl_shader.vert
 /*
@@ -520,8 +556,10 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
     if (pipeline == VK_NULL_HANDLE)
         pipeline = bd->Pipeline;
 
-    // Allocate array to store enough vertex/index buffers
-    ImGui_ImplVulkan_WindowRenderBuffers* wrb = &bd->MainWindowRenderBuffers;
+    // Allocate array to store enough vertex/index buffers. Each unique viewport gets its own storage.
+    ImGui_ImplVulkan_ViewportData* viewport_renderer_data = (ImGui_ImplVulkan_ViewportData*)draw_data->OwnerViewport->RendererUserData;
+    IM_ASSERT(viewport_renderer_data != nullptr);
+    ImGui_ImplVulkan_WindowRenderBuffers* wrb = &viewport_renderer_data->RenderBuffers;
     if (wrb->FrameRenderBuffers.Size == 0)
     {
         wrb->Index = 0;
@@ -550,9 +588,8 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
         check_vk_result(err);
         err = vkMapMemory(v->Device, rb->IndexBufferMemory, 0, index_size, 0, (void**)&idx_dst);
         check_vk_result(err);
-        for (int n = 0; n < draw_data->CmdListsCount; n++)
+        for (const ImDrawList* draw_list : draw_data->CmdLists)
         {
-            const ImDrawList* draw_list = draw_data->CmdLists[n];
             memcpy(vtx_dst, draw_list->VtxBuffer.Data, draw_list->VtxBuffer.Size * sizeof(ImDrawVert));
             memcpy(idx_dst, draw_list->IdxBuffer.Data, draw_list->IdxBuffer.Size * sizeof(ImDrawIdx));
             vtx_dst += draw_list->VtxBuffer.Size;
@@ -588,11 +625,11 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
 
     // Render command lists
     // (Because we merged all buffers into a single one, we maintain our own offset into them)
+    VkDescriptorSet last_desc_set = VK_NULL_HANDLE;
     int global_vtx_offset = 0;
     int global_idx_offset = 0;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         for (int cmd_i = 0; cmd_i < draw_list->CmdBuffer.Size; cmd_i++)
         {
             const ImDrawCmd* pcmd = &draw_list->CmdBuffer[cmd_i];
@@ -604,6 +641,7 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
                     ImGui_ImplVulkan_SetupRenderState(draw_data, pipeline, command_buffer, rb, fb_width, fb_height);
                 else
                     pcmd->UserCallback(draw_list, pcmd);
+                last_desc_set = VK_NULL_HANDLE;
             }
             else
             {
@@ -629,7 +667,9 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
 
                 // Bind DescriptorSet with font or user texture
                 VkDescriptorSet desc_set = (VkDescriptorSet)pcmd->GetTexID();
-                vkCmdBindDescriptorSets(command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS, bd->PipelineLayout, 0, 1, &desc_set, 0, nullptr);
+                if (desc_set != last_desc_set)
+                    vkCmdBindDescriptorSets(command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS, bd->PipelineLayout, 0, 1, &desc_set, 0, nullptr);
+                last_desc_set = desc_set;
 
                 // Draw
                 vkCmdDrawIndexed(command_buffer, pcmd->ElemCount, 1, pcmd->IdxOffset + global_idx_offset, pcmd->VtxOffset + global_vtx_offset, 0);
@@ -653,22 +693,22 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
 
 static void ImGui_ImplVulkan_DestroyTexture(ImTextureData* tex)
 {
-    ImGui_ImplVulkan_Texture* backend_tex = (ImGui_ImplVulkan_Texture*)tex->BackendUserData;
-    if (backend_tex == nullptr)
-        return;
-    IM_ASSERT(backend_tex->DescriptorSet == (VkDescriptorSet)tex->TexID);
-    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
-    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
-    ImGui_ImplVulkan_RemoveTexture(backend_tex->DescriptorSet);
-    vkDestroyImageView(v->Device, backend_tex->ImageView, v->Allocator);
-    vkDestroyImage(v->Device, backend_tex->Image, v->Allocator);
-    vkFreeMemory(v->Device, backend_tex->Memory, v->Allocator);
-    IM_DELETE(backend_tex);
+    if (ImGui_ImplVulkan_Texture* backend_tex = (ImGui_ImplVulkan_Texture*)tex->BackendUserData)
+    {
+        IM_ASSERT(backend_tex->DescriptorSet == (VkDescriptorSet)tex->TexID);
+        ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+        ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+        ImGui_ImplVulkan_RemoveTexture(backend_tex->DescriptorSet);
+        vkDestroyImageView(v->Device, backend_tex->ImageView, v->Allocator);
+        vkDestroyImage(v->Device, backend_tex->Image, v->Allocator);
+        vkFreeMemory(v->Device, backend_tex->Memory, v->Allocator);
+        IM_DELETE(backend_tex);
 
-    // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
-    tex->SetTexID(ImTextureID_Invalid);
+        // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
+        tex->SetTexID(ImTextureID_Invalid);
+        tex->BackendUserData = nullptr;
+    }
     tex->SetStatus(ImTextureStatus_Destroyed);
-    tex->BackendUserData = nullptr;
 }
 
 void ImGui_ImplVulkan_UpdateTexture(ImTextureData* tex)
@@ -732,7 +772,7 @@ void ImGui_ImplVulkan_UpdateTexture(ImTextureData* tex)
         }
 
         // Create the Descriptor Set
-        backend_tex->DescriptorSet = ImGui_ImplVulkan_AddTexture(bd->TexSampler, backend_tex->ImageView, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);
+        backend_tex->DescriptorSet = ImGui_ImplVulkan_AddTexture(bd->TexSamplerLinear, backend_tex->ImageView, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);
 
         // Store identifiers
         tex->SetTexID((ImTextureID)backend_tex->DescriptorSet);
@@ -820,7 +860,7 @@ void ImGui_ImplVulkan_UpdateTexture(ImTextureData* tex)
             VkImageMemoryBarrier copy_barrier[1] = {};
             copy_barrier[0].sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
             copy_barrier[0].dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
-            copy_barrier[0].oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
+            copy_barrier[0].oldLayout = (tex->Status == ImTextureStatus_WantCreate) ? VK_IMAGE_LAYOUT_UNDEFINED : VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
             copy_barrier[0].newLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
             copy_barrier[0].srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
             copy_barrier[0].dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
@@ -881,29 +921,35 @@ void ImGui_ImplVulkan_UpdateTexture(ImTextureData* tex)
 
 static void ImGui_ImplVulkan_CreateShaderModules(VkDevice device, const VkAllocationCallbacks* allocator)
 {
-    // Create the shader modules
     ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
     if (bd->ShaderModuleVert == VK_NULL_HANDLE)
     {
-        VkShaderModuleCreateInfo vert_info = {};
-        vert_info.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
-        vert_info.codeSize = sizeof(__glsl_shader_vert_spv);
-        vert_info.pCode = (uint32_t*)__glsl_shader_vert_spv;
-        VkResult err = vkCreateShaderModule(device, &vert_info, allocator, &bd->ShaderModuleVert);
+        VkShaderModuleCreateInfo default_vert_info = {};
+        default_vert_info.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
+        default_vert_info.codeSize = sizeof(__glsl_shader_vert_spv);
+        default_vert_info.pCode = (uint32_t*)__glsl_shader_vert_spv;
+        VkShaderModuleCreateInfo* p_vert_info = (v->CustomShaderVertCreateInfo.sType == VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO) ? &v->CustomShaderVertCreateInfo : &default_vert_info;
+        VkResult err = vkCreateShaderModule(device, p_vert_info, allocator, &bd->ShaderModuleVert);
         check_vk_result(err);
     }
     if (bd->ShaderModuleFrag == VK_NULL_HANDLE)
     {
-        VkShaderModuleCreateInfo frag_info = {};
-        frag_info.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
-        frag_info.codeSize = sizeof(__glsl_shader_frag_spv);
-        frag_info.pCode = (uint32_t*)__glsl_shader_frag_spv;
-        VkResult err = vkCreateShaderModule(device, &frag_info, allocator, &bd->ShaderModuleFrag);
+        VkShaderModuleCreateInfo default_frag_info = {};
+        default_frag_info.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
+        default_frag_info.codeSize = sizeof(__glsl_shader_frag_spv);
+        default_frag_info.pCode = (uint32_t*)__glsl_shader_frag_spv;
+        VkShaderModuleCreateInfo* p_frag_info = (v->CustomShaderFragCreateInfo.sType == VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO) ? &v->CustomShaderFragCreateInfo : &default_frag_info;
+        VkResult err = vkCreateShaderModule(device, p_frag_info, allocator, &bd->ShaderModuleFrag);
         check_vk_result(err);
     }
 }
 
-static void ImGui_ImplVulkan_CreatePipeline(VkDevice device, const VkAllocationCallbacks* allocator, VkPipelineCache pipelineCache, VkRenderPass renderPass, VkSampleCountFlagBits MSAASamples, VkPipeline* pipeline, uint32_t subpass)
+#if !defined(IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING) && !(defined(VK_VERSION_1_3) || defined(VK_KHR_dynamic_rendering))
+typedef void VkPipelineRenderingCreateInfoKHR;
+#endif
+
+static VkPipeline ImGui_ImplVulkan_CreatePipeline(VkDevice device, const VkAllocationCallbacks* allocator, VkPipelineCache pipelineCache, const ImGui_ImplVulkan_PipelineInfo* info)
 {
     ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
     ImGui_ImplVulkan_CreateShaderModules(device, allocator);
@@ -961,7 +1007,7 @@ static void ImGui_ImplVulkan_CreatePipeline(VkDevice device, const VkAllocationC
 
     VkPipelineMultisampleStateCreateInfo ms_info = {};
     ms_info.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
-    ms_info.rasterizationSamples = (MSAASamples != 0) ? MSAASamples : VK_SAMPLE_COUNT_1_BIT;
+    ms_info.rasterizationSamples = (info->MSAASamples != 0) ? info->MSAASamples : VK_SAMPLE_COUNT_1_BIT;
 
     VkPipelineColorBlendAttachmentState color_attachment[1] = {};
     color_attachment[0].blendEnable = VK_TRUE;
@@ -987,35 +1033,36 @@ static void ImGui_ImplVulkan_CreatePipeline(VkDevice device, const VkAllocationC
     dynamic_state.dynamicStateCount = (uint32_t)IM_ARRAYSIZE(dynamic_states);
     dynamic_state.pDynamicStates = dynamic_states;
 
-    VkGraphicsPipelineCreateInfo info = {};
-    info.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
-    info.flags = bd->PipelineCreateFlags;
-    info.stageCount = 2;
-    info.pStages = stage;
-    info.pVertexInputState = &vertex_info;
-    info.pInputAssemblyState = &ia_info;
-    info.pViewportState = &viewport_info;
-    info.pRasterizationState = &raster_info;
-    info.pMultisampleState = &ms_info;
-    info.pDepthStencilState = &depth_info;
-    info.pColorBlendState = &blend_info;
-    info.pDynamicState = &dynamic_state;
-    info.layout = bd->PipelineLayout;
-    info.renderPass = renderPass;
-    info.subpass = subpass;
+    VkGraphicsPipelineCreateInfo create_info = {};
+    create_info.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
+    create_info.flags = bd->PipelineCreateFlags;
+    create_info.stageCount = 2;
+    create_info.pStages = stage;
+    create_info.pVertexInputState = &vertex_info;
+    create_info.pInputAssemblyState = &ia_info;
+    create_info.pViewportState = &viewport_info;
+    create_info.pRasterizationState = &raster_info;
+    create_info.pMultisampleState = &ms_info;
+    create_info.pDepthStencilState = &depth_info;
+    create_info.pColorBlendState = &blend_info;
+    create_info.pDynamicState = &dynamic_state;
+    create_info.layout = bd->PipelineLayout;
+    create_info.renderPass = info->RenderPass;
+    create_info.subpass = info->Subpass;
 
 #ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
     if (bd->VulkanInitInfo.UseDynamicRendering)
     {
-        IM_ASSERT(bd->VulkanInitInfo.PipelineRenderingCreateInfo.sType == VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR && "PipelineRenderingCreateInfo sType must be VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR");
-        IM_ASSERT(bd->VulkanInitInfo.PipelineRenderingCreateInfo.pNext == nullptr && "PipelineRenderingCreateInfo pNext must be nullptr");
-        info.pNext = &bd->VulkanInitInfo.PipelineRenderingCreateInfo;
-        info.renderPass = VK_NULL_HANDLE; // Just make sure it's actually nullptr.
+        IM_ASSERT(info->PipelineRenderingCreateInfo.sType == VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR && "PipelineRenderingCreateInfo::sType must be VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR");
+        IM_ASSERT(info->PipelineRenderingCreateInfo.pNext == nullptr && "PipelineRenderingCreateInfo::pNext must be nullptr");
+        create_info.pNext = &info->PipelineRenderingCreateInfo;
+        create_info.renderPass = VK_NULL_HANDLE; // Just make sure it's actually nullptr.
     }
 #endif
-
-    VkResult err = vkCreateGraphicsPipelines(device, pipelineCache, 1, &info, allocator, pipeline);
+    VkPipeline pipeline;
+    VkResult err = vkCreateGraphicsPipelines(device, pipelineCache, 1, &create_info, allocator, &pipeline);
     check_vk_result(err);
+    return pipeline;
 }
 
 bool ImGui_ImplVulkan_CreateDeviceObjects()
@@ -1024,7 +1071,7 @@ bool ImGui_ImplVulkan_CreateDeviceObjects()
     ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
     VkResult err;
 
-    if (!bd->TexSampler)
+    if (!bd->TexSamplerLinear)
     {
         // Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling.
         VkSamplerCreateInfo info = {};
@@ -1038,7 +1085,7 @@ bool ImGui_ImplVulkan_CreateDeviceObjects()
         info.minLod = -1000;
         info.maxLod = 1000;
         info.maxAnisotropy = 1.0f;
-        err = vkCreateSampler(v->Device, &info, v->Allocator, &bd->TexSampler);
+        err = vkCreateSampler(v->Device, &info, v->Allocator, &bd->TexSamplerLinear);
         check_vk_result(err);
     }
 
@@ -1089,7 +1136,13 @@ bool ImGui_ImplVulkan_CreateDeviceObjects()
         check_vk_result(err);
     }
 
-    ImGui_ImplVulkan_CreatePipeline(v->Device, v->Allocator, v->PipelineCache, v->RenderPass, v->MSAASamples, &bd->Pipeline, v->Subpass);
+    // Create pipeline
+    bool create_main_pipeline = (v->PipelineInfoMain.RenderPass != VK_NULL_HANDLE);
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+    create_main_pipeline |= (v->UseDynamicRendering && v->PipelineInfoMain.PipelineRenderingCreateInfo.sType == VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR);
+#endif
+    if (create_main_pipeline)
+        ImGui_ImplVulkan_CreateMainPipeline(&v->PipelineInfoMain);
 
     // Create command pool/buffer for texture upload
     if (!bd->TexCommandPool)
@@ -1114,11 +1167,39 @@ bool ImGui_ImplVulkan_CreateDeviceObjects()
     return true;
 }
 
+void ImGui_ImplVulkan_CreateMainPipeline(const ImGui_ImplVulkan_PipelineInfo* pipeline_info_in)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+    if (bd->Pipeline)
+    {
+        vkDestroyPipeline(v->Device, bd->Pipeline, v->Allocator);
+        bd->Pipeline = VK_NULL_HANDLE;
+    }
+    ImGui_ImplVulkan_PipelineInfo* pipeline_info = &v->PipelineInfoMain;
+    if (pipeline_info != pipeline_info_in)
+        *pipeline_info = *pipeline_info_in;
+
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+    VkPipelineRenderingCreateInfoKHR* pipeline_rendering_create_info = &pipeline_info->PipelineRenderingCreateInfo;
+    if (v->UseDynamicRendering && pipeline_rendering_create_info->pColorAttachmentFormats != NULL)
+    {
+        // Deep copy buffer to reduce error-rate for end user (#8282)
+        ImVector<VkFormat> formats;
+        formats.resize((int)pipeline_rendering_create_info->colorAttachmentCount);
+        memcpy(formats.Data, pipeline_rendering_create_info->pColorAttachmentFormats, (size_t)formats.size_in_bytes());
+        formats.swap(bd->PipelineRenderingCreateInfoColorAttachmentFormats);
+        pipeline_rendering_create_info->pColorAttachmentFormats = bd->PipelineRenderingCreateInfoColorAttachmentFormats.Data;
+    }
+#endif
+    bd->Pipeline = ImGui_ImplVulkan_CreatePipeline(v->Device, v->Allocator, v->PipelineCache, pipeline_info);
+}
+
 void    ImGui_ImplVulkan_DestroyDeviceObjects()
 {
     ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
     ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
-    ImGui_ImplVulkan_DestroyWindowRenderBuffers(v->Device, &bd->MainWindowRenderBuffers, v->Allocator);
+    ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(v->Device, v->Allocator);
 
     // Destroy all textures
     for (ImTextureData* tex : ImGui::GetPlatformIO().Textures)
@@ -1127,12 +1208,13 @@ void    ImGui_ImplVulkan_DestroyDeviceObjects()
 
     if (bd->TexCommandBuffer)     { vkFreeCommandBuffers(v->Device, bd->TexCommandPool, 1, &bd->TexCommandBuffer); bd->TexCommandBuffer = VK_NULL_HANDLE; }
     if (bd->TexCommandPool)       { vkDestroyCommandPool(v->Device, bd->TexCommandPool, v->Allocator); bd->TexCommandPool = VK_NULL_HANDLE; }
-    if (bd->TexSampler)           { vkDestroySampler(v->Device, bd->TexSampler, v->Allocator); bd->TexSampler = VK_NULL_HANDLE; }
+    if (bd->TexSamplerLinear)     { vkDestroySampler(v->Device, bd->TexSamplerLinear, v->Allocator); bd->TexSamplerLinear = VK_NULL_HANDLE; }
     if (bd->ShaderModuleVert)     { vkDestroyShaderModule(v->Device, bd->ShaderModuleVert, v->Allocator); bd->ShaderModuleVert = VK_NULL_HANDLE; }
     if (bd->ShaderModuleFrag)     { vkDestroyShaderModule(v->Device, bd->ShaderModuleFrag, v->Allocator); bd->ShaderModuleFrag = VK_NULL_HANDLE; }
     if (bd->DescriptorSetLayout)  { vkDestroyDescriptorSetLayout(v->Device, bd->DescriptorSetLayout, v->Allocator); bd->DescriptorSetLayout = VK_NULL_HANDLE; }
     if (bd->PipelineLayout)       { vkDestroyPipelineLayout(v->Device, bd->PipelineLayout, v->Allocator); bd->PipelineLayout = VK_NULL_HANDLE; }
     if (bd->Pipeline)             { vkDestroyPipeline(v->Device, bd->Pipeline, v->Allocator); bd->Pipeline = VK_NULL_HANDLE; }
+    if (bd->PipelineForViewports) { vkDestroyPipeline(v->Device, bd->PipelineForViewports, v->Allocator); bd->PipelineForViewports = VK_NULL_HANDLE; }
     if (bd->DescriptorPool)       { vkDestroyDescriptorPool(v->Device, bd->DescriptorPool, v->Allocator); bd->DescriptorPool = VK_NULL_HANDLE; }
 }
 
@@ -1225,19 +1307,21 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info)
     io.BackendRendererName = "imgui_impl_vulkan";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
     io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;   // We can honor ImGuiPlatformIO::Textures[] requests during render.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
+    // Sanity checks
     IM_ASSERT(info->Instance != VK_NULL_HANDLE);
     IM_ASSERT(info->PhysicalDevice != VK_NULL_HANDLE);
     IM_ASSERT(info->Device != VK_NULL_HANDLE);
     IM_ASSERT(info->Queue != VK_NULL_HANDLE);
+    IM_ASSERT(info->MinImageCount >= 2);
+    IM_ASSERT(info->ImageCount >= info->MinImageCount);
     if (info->DescriptorPool != VK_NULL_HANDLE) // Either DescriptorPool or DescriptorPoolSize must be set, not both!
         IM_ASSERT(info->DescriptorPoolSize == 0);
     else
         IM_ASSERT(info->DescriptorPoolSize > 0);
-    IM_ASSERT(info->MinImageCount >= 2);
-    IM_ASSERT(info->ImageCount >= info->MinImageCount);
-    if (info->UseDynamicRendering == false)
-        IM_ASSERT(info->RenderPass != VK_NULL_HANDLE);
+    if (info->UseDynamicRendering)
+        IM_ASSERT(info->PipelineInfoMain.RenderPass == VK_NULL_HANDLE && info->PipelineInfoForViewports.RenderPass == VK_NULL_HANDLE);
 
     bd->VulkanInitInfo = *info;
 
@@ -1245,20 +1329,15 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info)
     vkGetPhysicalDeviceProperties(info->PhysicalDevice, &properties);
     bd->NonCoherentAtomSize = properties.limits.nonCoherentAtomSize;
 
-#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
-    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
-    if (v->PipelineRenderingCreateInfo.pColorAttachmentFormats != NULL)
-    {
-        // Deep copy buffer to reduce error-rate for end user (#8282)
-        VkFormat* formats_copy = (VkFormat*)IM_ALLOC(sizeof(VkFormat) * v->PipelineRenderingCreateInfo.colorAttachmentCount);
-        memcpy(formats_copy, v->PipelineRenderingCreateInfo.pColorAttachmentFormats, sizeof(VkFormat) * v->PipelineRenderingCreateInfo.colorAttachmentCount);
-        v->PipelineRenderingCreateInfo.pColorAttachmentFormats = formats_copy;
-    }
-#endif
-
     if (!ImGui_ImplVulkan_CreateDeviceObjects())
         IM_ASSERT(0 && "ImGui_ImplVulkan_CreateDeviceObjects() failed!"); // <- Can't be hit yet.
 
+    // Our render function expect RendererUserData to be storing the window render buffer we need (for the main viewport we won't use ->Window)
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->RendererUserData = IM_NEW(ImGui_ImplVulkan_ViewportData)();
+
+    ImGui_ImplVulkan_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -1267,15 +1346,24 @@ void ImGui_ImplVulkan_Shutdown()
     ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
+    // First destroy objects in all viewports
     ImGui_ImplVulkan_DestroyDeviceObjects();
-#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
-    IM_FREE((void*)const_cast<VkFormat*>(bd->VulkanInitInfo.PipelineRenderingCreateInfo.pColorAttachmentFormats));
-#endif
+
+    // Manually delete main viewport render data in-case we haven't initialized for viewports
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)main_viewport->RendererUserData)
+        IM_DELETE(vd);
+    main_viewport->RendererUserData = nullptr;
+
+    // Clean up windows
+    ImGui_ImplVulkan_ShutdownMultiViewportSupport();
 
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
 }
 
@@ -1293,10 +1381,12 @@ void ImGui_ImplVulkan_SetMinImageCount(uint32_t min_image_count)
     if (bd->VulkanInitInfo.MinImageCount == min_image_count)
         return;
 
+    IM_ASSERT(0); // FIXME-VIEWPORT: Unsupported. Need to recreate all swap chains!
     ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
     VkResult err = vkDeviceWaitIdle(v->Device);
     check_vk_result(err);
-    ImGui_ImplVulkan_DestroyWindowRenderBuffers(v->Device, &bd->MainWindowRenderBuffers, v->Allocator);
+    ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(v->Device, v->Allocator);
+
     bd->VulkanInitInfo.MinImageCount = min_image_count;
 }
 
@@ -1366,7 +1456,7 @@ void ImGui_ImplVulkan_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVulk
 
 //-------------------------------------------------------------------------
 // Internal / Miscellaneous Vulkan Helpers
-// (Used by example's main.cpp. Used by multi-viewport features. PROBABLY NOT used by your own app.)
+// (Used by example's main.cpp. Used by multi-viewport features. PROBABLY NOT used by your own engine/app.)
 //-------------------------------------------------------------------------
 // You probably do NOT need to use or care about those functions.
 // Those functions only exist because:
@@ -1376,7 +1466,7 @@ void ImGui_ImplVulkan_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVulk
 // but it is too much code to duplicate everywhere so we exceptionally expose them.
 //
 // Your engine/app will likely _already_ have code to setup all that stuff (swap chain, render pass, frame buffers, etc.).
-// You may read this code to learn about Vulkan, but it is recommended you use you own custom tailored code to do equivalent work.
+// You may read this code to learn about Vulkan, but it is recommended you use your own custom tailored code to do equivalent work.
 // (The ImGui_ImplVulkanH_XXX functions do not interact with any of the state used by the regular ImGui_ImplVulkan_XXX functions)
 //-------------------------------------------------------------------------
 
@@ -1554,7 +1644,7 @@ int ImGui_ImplVulkanH_GetMinImageCountFromPresentMode(VkPresentModeKHR present_m
 }
 
 // Also destroy old swap chain and in-flight frames data, if any.
-void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count)
+void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count, VkImageUsageFlags image_usage)
 {
     VkResult err;
     VkSwapchainKHR old_swapchain = wd->Swapchain;
@@ -1573,8 +1663,6 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
     wd->ImageCount = 0;
     if (wd->RenderPass)
         vkDestroyRenderPass(device, wd->RenderPass, allocator);
-    if (wd->Pipeline)
-        vkDestroyPipeline(device, wd->Pipeline, allocator);
 
     // If min image count was not specified, request different count of images dependent on selected present mode
     if (min_image_count == 0)
@@ -1593,7 +1681,7 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
         info.imageFormat = wd->SurfaceFormat.format;
         info.imageColorSpace = wd->SurfaceFormat.colorSpace;
         info.imageArrayLayers = 1;
-        info.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
+        info.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | image_usage;
         info.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;           // Assume that graphics family == present family
         info.preTransform = (cap.supportedTransforms & VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR) ? VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR : cap.currentTransform;
         info.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
@@ -1721,11 +1809,12 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
 }
 
 // Create or resize window
-void ImGui_ImplVulkanH_CreateOrResizeWindow(VkInstance instance, VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, uint32_t queue_family, const VkAllocationCallbacks* allocator, int width, int height, uint32_t min_image_count)
+// - 2025/09/26: v1.92.4 added a trailing 'VkImageUsageFlags image_usage' parameter which is usually VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT.
+void ImGui_ImplVulkanH_CreateOrResizeWindow(VkInstance instance, VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, uint32_t queue_family, const VkAllocationCallbacks* allocator, int width, int height, uint32_t min_image_count, VkImageUsageFlags image_usage)
 {
     IM_ASSERT(g_FunctionsLoaded && "Need to call ImGui_ImplVulkan_LoadFunctions() if IMGUI_IMPL_VULKAN_NO_PROTOTYPES or VK_NO_PROTOTYPES are set!");
     (void)instance;
-    ImGui_ImplVulkanH_CreateWindowSwapChain(physical_device, device, wd, allocator, width, height, min_image_count);
+    ImGui_ImplVulkanH_CreateWindowSwapChain(physical_device, device, wd, allocator, width, height, min_image_count, image_usage);
     ImGui_ImplVulkanH_CreateWindowCommandBuffers(physical_device, device, wd, queue_family, allocator);
 
     // FIXME: to submit the command buffer, we need a queue. In the examples folder, the ImGui_ImplVulkanH_CreateOrResizeWindow function is called
@@ -1816,7 +1905,6 @@ void ImGui_ImplVulkanH_DestroyWindow(VkInstance instance, VkDevice device, ImGui
         ImGui_ImplVulkanH_DestroyFrameSemaphores(device, &wd->FrameSemaphores[i], allocator);
     wd->Frames.clear();
     wd->FrameSemaphores.clear();
-    vkDestroyPipeline(device, wd->Pipeline, allocator);
     vkDestroyRenderPass(device, wd->RenderPass, allocator);
     vkDestroySwapchainKHR(device, wd->Swapchain, allocator);
     vkDestroySurfaceKHR(instance, wd->Surface, allocator);
@@ -1844,6 +1932,317 @@ void ImGui_ImplVulkanH_DestroyFrameSemaphores(VkDevice device, ImGui_ImplVulkanH
     fsd->ImageAcquiredSemaphore = fsd->RenderCompleteSemaphore = VK_NULL_HANDLE;
 }
 
+void ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(VkDevice device, const VkAllocationCallbacks* allocator)
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int n = 0; n < platform_io.Viewports.Size; n++)
+        if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)platform_io.Viewports[n]->RendererUserData)
+            ImGui_ImplVulkan_DestroyWindowRenderBuffers(device, &vd->RenderBuffers, allocator);
+}
+
+ImGui_ImplVulkanH_Window* ImGui_ImplVulkanH_GetWindowDataFromViewport(ImGuiViewport* viewport)
+{
+    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
+    return vd ? &vd->Window : nullptr;
+}
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplVulkan_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = IM_NEW(ImGui_ImplVulkan_ViewportData)();
+    viewport->RendererUserData = vd;
+    ImGui_ImplVulkanH_Window* wd = &vd->Window;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+
+    // Create surface
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    VkResult err = (VkResult)platform_io.Platform_CreateVkSurface(viewport, (ImU64)v->Instance, (const void*)v->Allocator, (ImU64*)&wd->Surface);
+    check_vk_result(err);
+
+    // Check for WSI support
+    VkBool32 res;
+    vkGetPhysicalDeviceSurfaceSupportKHR(v->PhysicalDevice, v->QueueFamily, wd->Surface, &res);
+    if (res != VK_TRUE)
+    {
+        IM_ASSERT(0); // Error: no WSI support on physical device
+        return;
+    }
+
+    // Select Surface Format
+    ImGui_ImplVulkan_PipelineInfo* pipeline_info = &v->PipelineInfoForViewports;
+    ImVector<VkFormat> requestSurfaceImageFormats;
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+    for (uint32_t n = 0; n < pipeline_info->PipelineRenderingCreateInfo.colorAttachmentCount; n++)
+        requestSurfaceImageFormats.push_back(pipeline_info->PipelineRenderingCreateInfo.pColorAttachmentFormats[n]);
+#endif
+    const VkFormat defaultFormats[] = { VK_FORMAT_B8G8R8A8_UNORM, VK_FORMAT_R8G8B8A8_UNORM, VK_FORMAT_B8G8R8_UNORM, VK_FORMAT_R8G8B8_UNORM };
+    for (VkFormat format : defaultFormats)
+        requestSurfaceImageFormats.push_back(format);
+
+    const VkColorSpaceKHR requestSurfaceColorSpace = VK_COLORSPACE_SRGB_NONLINEAR_KHR;
+    wd->SurfaceFormat = ImGui_ImplVulkanH_SelectSurfaceFormat(v->PhysicalDevice, wd->Surface, requestSurfaceImageFormats.Data, (size_t)requestSurfaceImageFormats.Size, requestSurfaceColorSpace);
+
+    // Select Present Mode
+    // FIXME-VULKAN: Even thought mailbox seems to get us maximum framerate with a single window, it halves framerate with a second window etc. (w/ Nvidia and SDK 1.82.1)
+    VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_MAILBOX_KHR, VK_PRESENT_MODE_IMMEDIATE_KHR, VK_PRESENT_MODE_FIFO_KHR };
+    wd->PresentMode = ImGui_ImplVulkanH_SelectPresentMode(v->PhysicalDevice, wd->Surface, &present_modes[0], IM_ARRAYSIZE(present_modes));
+    //printf("[vulkan] Secondary window selected PresentMode = %d\n", wd->PresentMode);
+
+    // Create SwapChain, RenderPass, Framebuffer, etc.
+    wd->ClearEnable = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? false : true;
+    wd->UseDynamicRendering = v->UseDynamicRendering;
+    ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, wd, v->QueueFamily, v->Allocator, (int)viewport->Size.x, (int)viewport->Size.y, v->MinImageCount, pipeline_info->SwapChainImageUsage);
+    vd->WindowOwned = true;
+
+    // Create pipeline (shared by all secondary viewports)
+    if (bd->PipelineForViewports == VK_NULL_HANDLE)
+    {
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+        if (wd->UseDynamicRendering)
+        {
+            pipeline_info->PipelineRenderingCreateInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO;
+            pipeline_info->PipelineRenderingCreateInfo.colorAttachmentCount = 1;
+            pipeline_info->PipelineRenderingCreateInfo.pColorAttachmentFormats = &wd->SurfaceFormat.format;
+        }
+        else
+        {
+            pipeline_info->RenderPass = wd->RenderPass;
+        }
+#endif
+        bd->PipelineForViewports = ImGui_ImplVulkan_CreatePipeline(v->Device, v->Allocator, VK_NULL_HANDLE, &v->PipelineInfoForViewports);
+    }
+}
+
+static void ImGui_ImplVulkan_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData)
+    {
+        ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+        if (vd->WindowOwned)
+            ImGui_ImplVulkanH_DestroyWindow(v->Instance, v->Device, &vd->Window, v->Allocator);
+        ImGui_ImplVulkan_DestroyWindowRenderBuffers(v->Device, &vd->RenderBuffers, v->Allocator);
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplVulkan_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
+    if (vd == nullptr) // This is nullptr for the main viewport (which is left to the user/app to handle)
+        return;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+    vd->Window.ClearEnable = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? false : true;
+    ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, &vd->Window, v->QueueFamily, v->Allocator, (int)size.x, (int)size.y, v->MinImageCount, v->PipelineInfoForViewports.SwapChainImageUsage);
+}
+
+static void ImGui_ImplVulkan_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
+    ImGui_ImplVulkanH_Window* wd = &vd->Window;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+    VkResult err;
+
+    if (vd->SwapChainNeedRebuild || vd->SwapChainSuboptimal)
+    {
+        ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, wd, v->QueueFamily, v->Allocator, (int)viewport->Size.x, (int)viewport->Size.y, v->MinImageCount, v->PipelineInfoForViewports.SwapChainImageUsage);
+        vd->SwapChainNeedRebuild = vd->SwapChainSuboptimal = false;
+    }
+
+    ImGui_ImplVulkanH_Frame* fd = nullptr;
+    ImGui_ImplVulkanH_FrameSemaphores* fsd = &wd->FrameSemaphores[wd->SemaphoreIndex];
+    {
+        {
+            err = vkAcquireNextImageKHR(v->Device, wd->Swapchain, UINT64_MAX, fsd->ImageAcquiredSemaphore, VK_NULL_HANDLE, &wd->FrameIndex);
+            if (err == VK_ERROR_OUT_OF_DATE_KHR)
+            {
+                vd->SwapChainNeedRebuild = true; // Since we are not going to swap this frame anyway, it's ok that recreation happens on next frame.
+                return;
+            }
+            if (err == VK_SUBOPTIMAL_KHR)
+                vd->SwapChainSuboptimal = true;
+            else
+                check_vk_result(err);
+            fd = &wd->Frames[wd->FrameIndex];
+        }
+        for (;;)
+        {
+            err = vkWaitForFences(v->Device, 1, &fd->Fence, VK_TRUE, 100);
+            if (err == VK_SUCCESS) break;
+            if (err == VK_TIMEOUT) continue;
+            check_vk_result(err);
+        }
+        {
+            err = vkResetCommandPool(v->Device, fd->CommandPool, 0);
+            check_vk_result(err);
+            VkCommandBufferBeginInfo info = {};
+            info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
+            info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
+            err = vkBeginCommandBuffer(fd->CommandBuffer, &info);
+            check_vk_result(err);
+        }
+        {
+            ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+            memcpy(&wd->ClearValue.color.float32[0], &clear_color, 4 * sizeof(float));
+        }
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+        if (v->UseDynamicRendering)
+        {
+            // Transition swapchain image to a layout suitable for drawing.
+            VkImageMemoryBarrier barrier = {};
+            barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
+            barrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
+            barrier.oldLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
+            barrier.newLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+            barrier.image = fd->Backbuffer;
+            barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+            barrier.subresourceRange.levelCount = 1;
+            barrier.subresourceRange.layerCount = 1;
+            vkCmdPipelineBarrier(fd->CommandBuffer, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT | VK_PIPELINE_STAGE_NONE, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT, 0, 0, nullptr, 0, nullptr, 1, &barrier);
+
+            VkRenderingAttachmentInfo attachmentInfo = {};
+            attachmentInfo.sType = VK_STRUCTURE_TYPE_RENDERING_ATTACHMENT_INFO_KHR;
+            attachmentInfo.imageView = fd->BackbufferView;
+            attachmentInfo.imageLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+            attachmentInfo.resolveMode = VK_RESOLVE_MODE_NONE;
+            attachmentInfo.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
+            attachmentInfo.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
+            attachmentInfo.clearValue = wd->ClearValue;
+
+            VkRenderingInfo renderingInfo = {};
+            renderingInfo.sType = VK_STRUCTURE_TYPE_RENDERING_INFO_KHR;
+            renderingInfo.renderArea.extent.width = wd->Width;
+            renderingInfo.renderArea.extent.height = wd->Height;
+            renderingInfo.layerCount = 1;
+            renderingInfo.viewMask = 0;
+            renderingInfo.colorAttachmentCount = 1;
+            renderingInfo.pColorAttachments = &attachmentInfo;
+
+            ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR(fd->CommandBuffer, &renderingInfo);
+        }
+        else
+#endif
+        {
+            VkRenderPassBeginInfo info = {};
+            info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
+            info.renderPass = wd->RenderPass;
+            info.framebuffer = fd->Framebuffer;
+            info.renderArea.extent.width = wd->Width;
+            info.renderArea.extent.height = wd->Height;
+            info.clearValueCount = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? 0 : 1;
+            info.pClearValues = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? nullptr : &wd->ClearValue;
+            vkCmdBeginRenderPass(fd->CommandBuffer, &info, VK_SUBPASS_CONTENTS_INLINE);
+        }
+    }
+
+    ImGui_ImplVulkan_RenderDrawData(viewport->DrawData, fd->CommandBuffer, bd->PipelineForViewports);
+
+    {
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+        if (v->UseDynamicRendering)
+        {
+            ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR(fd->CommandBuffer);
+
+            // Transition image to a layout suitable for presentation
+            VkImageMemoryBarrier barrier = {};
+            barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
+            barrier.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
+            barrier.oldLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+            barrier.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
+            barrier.image = fd->Backbuffer;
+            barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+            barrier.subresourceRange.levelCount = 1;
+            barrier.subresourceRange.layerCount = 1;
+            vkCmdPipelineBarrier(fd->CommandBuffer, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT, VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT, 0, 0, nullptr, 0, nullptr, 1, &barrier);
+        }
+        else
+#endif
+        {
+            vkCmdEndRenderPass(fd->CommandBuffer);
+        }
+        {
+            VkPipelineStageFlags wait_stage = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
+            VkSubmitInfo info = {};
+            info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
+            info.waitSemaphoreCount = 1;
+            info.pWaitSemaphores = &fsd->ImageAcquiredSemaphore;
+            info.pWaitDstStageMask = &wait_stage;
+            info.commandBufferCount = 1;
+            info.pCommandBuffers = &fd->CommandBuffer;
+            info.signalSemaphoreCount = 1;
+            info.pSignalSemaphores = &fsd->RenderCompleteSemaphore;
+
+            err = vkEndCommandBuffer(fd->CommandBuffer);
+            check_vk_result(err);
+            err = vkResetFences(v->Device, 1, &fd->Fence);
+            check_vk_result(err);
+            err = vkQueueSubmit(v->Queue, 1, &info, fd->Fence);
+            check_vk_result(err);
+        }
+    }
+}
+
+static void ImGui_ImplVulkan_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
+    ImGui_ImplVulkanH_Window* wd = &vd->Window;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+
+    if (vd->SwapChainNeedRebuild) // Frame data became invalid in the middle of rendering
+        return;
+
+    VkResult err;
+    uint32_t present_index = wd->FrameIndex;
+
+    ImGui_ImplVulkanH_FrameSemaphores* fsd = &wd->FrameSemaphores[wd->SemaphoreIndex];
+    VkPresentInfoKHR info = {};
+    info.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
+    info.waitSemaphoreCount = 1;
+    info.pWaitSemaphores = &fsd->RenderCompleteSemaphore;
+    info.swapchainCount = 1;
+    info.pSwapchains = &wd->Swapchain;
+    info.pImageIndices = &present_index;
+    err = vkQueuePresentKHR(v->Queue, &info);
+    if (err == VK_ERROR_OUT_OF_DATE_KHR)
+    {
+        vd->SwapChainNeedRebuild = true;
+        return;
+    }
+    if (err == VK_SUBOPTIMAL_KHR)
+        vd->SwapChainSuboptimal = true;
+    else
+        check_vk_result(err);
+    wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->SemaphoreCount; // Now we can use the next set of semaphores
+}
+
+void ImGui_ImplVulkan_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    if (ImGui::GetIO().BackendFlags & ImGuiBackendFlags_PlatformHasViewports)
+        IM_ASSERT(platform_io.Platform_CreateVkSurface != nullptr && "Platform needs to setup the CreateVkSurface handler.");
+    platform_io.Renderer_CreateWindow = ImGui_ImplVulkan_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplVulkan_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplVulkan_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplVulkan_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplVulkan_SwapBuffers;
+}
+
+void ImGui_ImplVulkan_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_vulkan.h

@@ -6,6 +6,7 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [x] Renderer: Multi-viewport / platform windows. With issues (flickering when creating a new viewport).
 
 // The aim of imgui_impl_vulkan.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -65,6 +66,23 @@
 // Backend uses a small number of descriptors per font atlas + as many as additional calls done to ImGui_ImplVulkan_AddTexture().
 #define IMGUI_IMPL_VULKAN_MINIMUM_IMAGE_SAMPLER_POOL_SIZE   (8)     // Minimum per atlas
 
+// Specify settings to create pipeline and swapchain
+struct ImGui_ImplVulkan_PipelineInfo
+{
+    // For Main viewport only
+    VkRenderPass                    RenderPass;                     // Ignored if using dynamic rendering
+
+    // For Main and Secondary viewports
+    uint32_t                        Subpass;                        //
+    VkSampleCountFlagBits           MSAASamples = {};               // 0 defaults to VK_SAMPLE_COUNT_1_BIT
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+    VkPipelineRenderingCreateInfoKHR PipelineRenderingCreateInfo;   // Optional, valid if .sType == VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR
+#endif
+
+    // For Secondary viewports only (created/managed by backend)
+    VkImageUsageFlags               SwapChainImageUsage;            // Extra flags for vkCreateSwapchainKHR() calls for secondary viewports. We automatically add VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT. You can add e.g. VK_IMAGE_USAGE_TRANSFER_SRC_BIT if you need to capture from viewports.
+};
+
 // Initialization data, for ImGui_ImplVulkan_Init()
 // [Please zero-clear before use!]
 // - About descriptor pool:
@@ -82,29 +100,33 @@ struct ImGui_ImplVulkan_InitInfo
     uint32_t                        QueueFamily;
     VkQueue                         Queue;
     VkDescriptorPool                DescriptorPool;             // See requirements in note above; ignored if using DescriptorPoolSize > 0
-    VkRenderPass                    RenderPass;                 // Ignored if using dynamic rendering
+    uint32_t                        DescriptorPoolSize;         // Optional: set to create internal descriptor pool automatically instead of using DescriptorPool.
     uint32_t                        MinImageCount;              // >= 2
     uint32_t                        ImageCount;                 // >= MinImageCount
-    VkSampleCountFlagBits           MSAASamples;                // 0 defaults to VK_SAMPLE_COUNT_1_BIT
+    VkPipelineCache                 PipelineCache;              // Optional
 
-    // (Optional)
-    VkPipelineCache                 PipelineCache;
-    uint32_t                        Subpass;
-
-    // (Optional) Set to create internal descriptor pool instead of using DescriptorPool
-    uint32_t                        DescriptorPoolSize;
+    // Pipeline
+    ImGui_ImplVulkan_PipelineInfo   PipelineInfoMain;           // Infos for Main Viewport (created by app/user)
+    ImGui_ImplVulkan_PipelineInfo   PipelineInfoForViewports;   // Infos for Secondary Viewports (created by backend)
+    //VkRenderPass                  RenderPass;                 // --> Since 2025/09/26: set 'PipelineInfoMain.RenderPass' instead
+    //uint32_t                      Subpass;                    // --> Since 2025/09/26: set 'PipelineInfoMain.Subpass' instead
+    //VkSampleCountFlagBits         MSAASamples;                // --> Since 2025/09/26: set 'PipelineInfoMain.MSAASamples' instead
+    //VkPipelineRenderingCreateInfoKHR PipelineRenderingCreateInfo; // Since 2025/09/26: set 'PipelineInfoMain.PipelineRenderingCreateInfo' instead
 
     // (Optional) Dynamic Rendering
-    // Need to explicitly enable VK_KHR_dynamic_rendering extension to use this, even for Vulkan 1.3.
+    // Need to explicitly enable VK_KHR_dynamic_rendering extension to use this, even for Vulkan 1.3 + setup PipelineInfoMain.PipelineRenderingCreateInfo and PipelineInfoViewports.PipelineRenderingCreateInfo.
     bool                            UseDynamicRendering;
-#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
-    VkPipelineRenderingCreateInfoKHR PipelineRenderingCreateInfo;
-#endif
 
     // (Optional) Allocation, Debugging
     const VkAllocationCallbacks*    Allocator;
     void                            (*CheckVkResultFn)(VkResult err);
     VkDeviceSize                    MinAllocationSize;          // Minimum allocation size. Set to 1024*1024 to satisfy zealous best practices validation layer and waste a little memory.
+
+    // (Optional) Customize default vertex/fragment shaders.
+    // - if .sType == VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO we use specified structs, otherwise we use defaults.
+    // - Shader inputs/outputs need to match ours. Code/data pointed to by the structure needs to survive for whole during of backend usage.
+    VkShaderModuleCreateInfo        CustomShaderVertCreateInfo;
+    VkShaderModuleCreateInfo        CustomShaderFragCreateInfo;
 };
 
 // Follow "Getting Started" link and check examples/ folder to learn about using backends!
@@ -114,6 +136,11 @@ IMGUI_IMPL_API void             ImGui_ImplVulkan_NewFrame();
 IMGUI_IMPL_API void             ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer command_buffer, VkPipeline pipeline = VK_NULL_HANDLE);
 IMGUI_IMPL_API void             ImGui_ImplVulkan_SetMinImageCount(uint32_t min_image_count); // To override MinImageCount after initialization (e.g. if swap chain is recreated)
 
+// (Advanced) Use e.g. if you need to recreate pipeline without reinitializing the backend (see #8110, #8111)
+// The main window pipeline will be created by ImGui_ImplVulkan_Init() if possible (== RenderPass xor (UseDynamicRendering && PipelineRenderingCreateInfo->sType == VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR))
+// Else, the pipeline can be created, or re-created, using ImGui_ImplVulkan_CreateMainPipeline() before rendering.
+IMGUI_IMPL_API void             ImGui_ImplVulkan_CreateMainPipeline(const ImGui_ImplVulkan_PipelineInfo* info);
+
 // (Advanced) Use e.g. if you need to precisely control the timing of texture updates (e.g. for staged rendering), by setting ImDrawData::Textures = NULL to handle this manually.
 IMGUI_IMPL_API void             ImGui_ImplVulkan_UpdateTexture(ImTextureData* tex);
 
@@ -151,25 +178,26 @@ struct ImGui_ImplVulkan_RenderState
 //
 // Your engine/app will likely _already_ have code to setup all that stuff (swap chain,
 // render pass, frame buffers, etc.). You may read this code if you are curious, but
-// it is recommended you use you own custom tailored code to do equivalent work.
+// it is recommended you use your own custom tailored code to do equivalent work.
 //
 // We don't provide a strong guarantee that we won't change those functions API.
 //
 // The ImGui_ImplVulkanH_XXX functions should NOT interact with any of the state used
-// by the regular ImGui_ImplVulkan_XXX functions).
+// by the regular ImGui_ImplVulkan_XXX functions.
 //-------------------------------------------------------------------------
 
 struct ImGui_ImplVulkanH_Frame;
 struct ImGui_ImplVulkanH_Window;
 
 // Helpers
-IMGUI_IMPL_API void                 ImGui_ImplVulkanH_CreateOrResizeWindow(VkInstance instance, VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wnd, uint32_t queue_family, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count);
-IMGUI_IMPL_API void                 ImGui_ImplVulkanH_DestroyWindow(VkInstance instance, VkDevice device, ImGui_ImplVulkanH_Window* wnd, const VkAllocationCallbacks* allocator);
+IMGUI_IMPL_API void                 ImGui_ImplVulkanH_CreateOrResizeWindow(VkInstance instance, VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, uint32_t queue_family, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count, VkImageUsageFlags image_usage);
+IMGUI_IMPL_API void                 ImGui_ImplVulkanH_DestroyWindow(VkInstance instance, VkDevice device, ImGui_ImplVulkanH_Window* wd, const VkAllocationCallbacks* allocator);
 IMGUI_IMPL_API VkSurfaceFormatKHR   ImGui_ImplVulkanH_SelectSurfaceFormat(VkPhysicalDevice physical_device, VkSurfaceKHR surface, const VkFormat* request_formats, int request_formats_count, VkColorSpaceKHR request_color_space);
 IMGUI_IMPL_API VkPresentModeKHR     ImGui_ImplVulkanH_SelectPresentMode(VkPhysicalDevice physical_device, VkSurfaceKHR surface, const VkPresentModeKHR* request_modes, int request_modes_count);
 IMGUI_IMPL_API VkPhysicalDevice     ImGui_ImplVulkanH_SelectPhysicalDevice(VkInstance instance);
 IMGUI_IMPL_API uint32_t             ImGui_ImplVulkanH_SelectQueueFamilyIndex(VkPhysicalDevice physical_device);
 IMGUI_IMPL_API int                  ImGui_ImplVulkanH_GetMinImageCountFromPresentMode(VkPresentModeKHR present_mode);
+IMGUI_IMPL_API ImGui_ImplVulkanH_Window* ImGui_ImplVulkanH_GetWindowDataFromViewport(ImGuiViewport* viewport); // Access to Vulkan objects associated with a viewport (e.g to export a screenshot)
 
 // Helper structure to hold the data needed by one rendering frame
 // (Used by example's main.cpp. Used by multi-viewport features. Probably NOT used by your own engine/app.)
@@ -201,7 +229,6 @@ struct ImGui_ImplVulkanH_Window
     VkSurfaceFormatKHR  SurfaceFormat;
     VkPresentModeKHR    PresentMode;
     VkRenderPass        RenderPass;
-    VkPipeline          Pipeline;               // The window pipeline may uses a different VkRenderPass than the one passed in ImGui_ImplVulkan_InitInfo
     bool                UseDynamicRendering;
     bool                ClearEnable;
     VkClearValue        ClearValue;

backends/imgui_impl_wgpu.cpp

@@ -7,6 +7,8 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
 //  [X] Renderer: Texture updates support for dynamic font system (ImGuiBackendFlags_RendererHasTextures).
+// Missing features or Issues:
+//  [ ] Renderer: Multi-viewport support (multiple windows), useful for desktop.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -18,6 +20,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-09-18: Call platform_io.ClearRendererHandlers() on shutdown.
 //  2025-06-12: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. (#8465)
 //  2025-02-26: Recreate image bind groups during render. (#8426, #8046, #7765, #8027) + Update for latest webgpu-native changes.
 //  2024-10-14: Update Dawn support for change of string usages. (#8082, #8083)
@@ -45,7 +48,7 @@
 
 #include "imgui.h"
 
-// When targeting native platforms (i.e. NOT emscripten), one of IMGUI_IMPL_WEBGPU_BACKEND_DAWN
+// When targeting native platforms (i.e. NOT Emscripten), one of IMGUI_IMPL_WEBGPU_BACKEND_DAWN
 // or IMGUI_IMPL_WEBGPU_BACKEND_WGPU must be provided. See imgui_impl_wgpu.h for more details.
 #ifndef __EMSCRIPTEN__
     #if defined(IMGUI_IMPL_WEBGPU_BACKEND_DAWN) == defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
@@ -367,7 +370,7 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder
     // Avoid rendering when minimized
     int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
     int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
-    if (fb_width <= 0 || fb_height <= 0 || draw_data->CmdListsCount == 0)
+    if (fb_width <= 0 || fb_height <= 0 || draw_data->CmdLists.Size == 0)
         return;
 
     // Catch up with texture updates. Most of the times, the list will have 1 element with an OK status, aka nothing to do.
@@ -442,9 +445,8 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder
     // Upload vertex/index data into a single contiguous GPU buffer
     ImDrawVert* vtx_dst = (ImDrawVert*)fr->VertexBufferHost;
     ImDrawIdx* idx_dst = (ImDrawIdx*)fr->IndexBufferHost;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         memcpy(vtx_dst, draw_list->VtxBuffer.Data, draw_list->VtxBuffer.Size * sizeof(ImDrawVert));
         memcpy(idx_dst, draw_list->IdxBuffer.Data, draw_list->IdxBuffer.Size * sizeof(ImDrawIdx));
         vtx_dst += draw_list->VtxBuffer.Size;
@@ -471,9 +473,8 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder
     int global_idx_offset = 0;
     ImVec2 clip_scale = draw_data->FramebufferScale;
     ImVec2 clip_off = draw_data->DisplayPos;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* draw_list = draw_data->CmdLists[n];
         for (int cmd_i = 0; cmd_i < draw_list->CmdBuffer.Size; cmd_i++)
         {
             const ImDrawCmd* pcmd = &draw_list->CmdBuffer[cmd_i];
@@ -534,19 +535,18 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder
 
 static void ImGui_ImplWGPU_DestroyTexture(ImTextureData* tex)
 {
-    ImGui_ImplWGPU_Texture* backend_tex = (ImGui_ImplWGPU_Texture*)tex->BackendUserData;
-    if (backend_tex == nullptr)
-        return;
+    if (ImGui_ImplWGPU_Texture* backend_tex = (ImGui_ImplWGPU_Texture*)tex->BackendUserData)
+    {
+        IM_ASSERT(backend_tex->TextureView == (WGPUTextureView)(intptr_t)tex->TexID);
+        wgpuTextureViewRelease(backend_tex->TextureView);
+        wgpuTextureRelease(backend_tex->Texture);
+        IM_DELETE(backend_tex);
 
-    IM_ASSERT(backend_tex->TextureView == (WGPUTextureView)(intptr_t)tex->TexID);
-    wgpuTextureViewRelease(backend_tex->TextureView);
-    wgpuTextureRelease(backend_tex->Texture);
-    IM_DELETE(backend_tex);
-
-    // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
-    tex->SetTexID(ImTextureID_Invalid);
+        // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
+        tex->SetTexID(ImTextureID_Invalid);
+        tex->BackendUserData = nullptr;
+    }
     tex->SetStatus(ImTextureStatus_Destroyed);
-    tex->BackendUserData = nullptr;
 }
 
 void ImGui_ImplWGPU_UpdateTexture(ImTextureData* tex)
@@ -882,6 +882,7 @@ void ImGui_ImplWGPU_Shutdown()
     ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
     ImGui_ImplWGPU_InvalidateDeviceObjects();
     delete[] bd->pFrameResources;
@@ -894,6 +895,7 @@ void ImGui_ImplWGPU_Shutdown()
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
     io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures);
+    platform_io.ClearRendererHandlers();
     IM_DELETE(bd);
 }
 

backends/imgui_impl_wgpu.h

@@ -14,6 +14,8 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
 //  [X] Renderer: Texture updates support for dynamic font system (ImGuiBackendFlags_RendererHasTextures).
+// Missing features or Issues:
+//  [ ] Renderer: Multi-viewport support (multiple windows), useful for desktop.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -32,7 +34,7 @@
 // Initialization data, for ImGui_ImplWGPU_Init()
 struct ImGui_ImplWGPU_InitInfo
 {
-    WGPUDevice              Device;
+    WGPUDevice              Device = nullptr;
     int                     NumFramesInFlight = 3;
     WGPUTextureFormat       RenderTargetFormat = WGPUTextureFormat_Undefined;
     WGPUTextureFormat       DepthStencilFormat = WGPUTextureFormat_Undefined;

backends/imgui_impl_win32.cpp

@@ -7,6 +7,7 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy VK_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -21,9 +22,18 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-09-23: Inputs: Minor optimization not submitting gamepad input if packet number has not changed.
+//  2025-09-18: Call platform_io.ClearPlatformHandlers() on shutdown.
+//  2025-06-02: [Docking] WM_DPICHANGED also apply io.ConfigDpiScaleViewports for main viewport instead of letting it be done by application code.
 //  2025-04-30: Inputs: Fixed an issue where externally losing mouse capture (due to e.g. focus loss) would fail to claim it again the next subsequent click. (#8594)
+//  2025-03-26: [Docking] Viewports: fixed an issue when closing a window from the OS close button (with io.ConfigViewportsNoDecoration = false) while user code was discarding the 'bool* p_open = false' output from Begin(). Because we allowed the Win32 window to close early, Windows destroyed it and our imgui window became not visible even though user code was still submitting it.
 //  2025-03-10: When dealing with OEM keys, use scancodes instead of translated keycodes to choose ImGuiKey values. (#7136, #7201, #7206, #7306, #7670, #7672, #8468)
+//  2025-02-21: [Docking] WM_SETTINGCHANGE's SPI_SETWORKAREA message also triggers a refresh of monitor list. (#8415)
 //  2025-02-18: Added ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress mouse cursor support.
+//  2024-11-21: [Docking] Fixed a crash when multiple processes are running with multi-viewports, caused by misusage of GetProp(). (#8162, #8069)
+//  2024-10-28: [Docking] Rely on property stored inside HWND to retrieve context/viewport, should facilitate attempt to use this for parallel contexts. (#8069)
+//  2024-09-16: [Docking] Inputs: fixed an issue where a viewport destroyed while clicking would hog mouse tracking and temporary lead to incorrect update of HoveredWindow. (#7971)
 //  2024-07-08: Inputs: Fixed ImGuiMod_Super being mapped to VK_APPS instead of VK_LWIN||VK_RWIN. (#7768)
 //  2023-10-05: Inputs: Added support for extra ImGuiKey values: F13 to F24 function keys, app back/forward keys.
 //  2023-09-25: Inputs: Synthesize key-down event on key-up for VK_SNAPSHOT / ImGuiKey_PrintScreen as Windows doesn't emit it (same behavior as GLFW/SDL).
@@ -106,6 +116,11 @@ typedef DWORD(WINAPI* PFN_XInputGetState)(DWORD, XINPUT_STATE*);
 #pragma GCC diagnostic ignored "-Wcast-function-type"       // warning: cast between incompatible function types (for loader)
 #endif
 
+// Forward Declarations
+static void ImGui_ImplWin32_InitMultiViewportSupport(bool platform_has_own_dc);
+static void ImGui_ImplWin32_ShutdownMultiViewportSupport();
+static void ImGui_ImplWin32_UpdateMonitors();
+
 struct ImGui_ImplWin32_Data
 {
     HWND                        hWnd;
@@ -116,6 +131,7 @@ struct ImGui_ImplWin32_Data
     INT64                       TicksPerSecond;
     ImGuiMouseCursor            LastMouseCursor;
     UINT32                      KeyboardCodePage;
+    bool                        WantUpdateMonitors;
 
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
     bool                        HasGamepad;
@@ -123,6 +139,7 @@ struct ImGui_ImplWin32_Data
     HMODULE                     XInputDLL;
     PFN_XInputGetCapabilities   XInputGetCapabilities;
     PFN_XInputGetState          XInputGetState;
+    DWORD                       XInputPacketNumber;
 #endif
 
     ImGui_ImplWin32_Data()      { memset((void*)this, 0, sizeof(*this)); }
@@ -170,6 +187,9 @@ static bool ImGui_ImplWin32_InitEx(void* hwnd, bool platform_has_own_dc)
     io.BackendPlatformName = "imgui_impl_win32";
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+    io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;    // We can create multi-viewports on the Platform side (optional)
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
+    io.BackendFlags |= ImGuiBackendFlags_HasParentViewport;       // We can honor viewport->ParentViewportId by applying the corresponding parent/child relationship at platform levle (optional)
 
     bd->hWnd = (HWND)hwnd;
     bd->TicksPerSecond = perf_frequency;
@@ -177,10 +197,17 @@ static bool ImGui_ImplWin32_InitEx(void* hwnd, bool platform_has_own_dc)
     bd->LastMouseCursor = ImGuiMouseCursor_COUNT;
     ImGui_ImplWin32_UpdateKeyboardCodePage(io);
 
-    // Set platform dependent data in viewport
+    // Update monitor a first time during init
+    ImGui_ImplWin32_UpdateMonitors();
+
+    // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = main_viewport->PlatformHandleRaw = (void*)bd->hWnd;
-    IM_UNUSED(platform_has_own_dc); // Used in 'docking' branch
+
+    // Be aware that GetPropA()/SetPropA() may be accessed from other processes.
+    // So as we store a pointer in IMGUI_CONTEXT we need to make sure we only call GetPropA() on windows owned by our process.
+    ::SetPropA(bd->hWnd, "IMGUI_CONTEXT", ImGui::GetCurrentContext());
+    ImGui_ImplWin32_InitMultiViewportSupport(platform_has_own_dc);
 
     // Dynamically load XInput library
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
@@ -222,6 +249,10 @@ void    ImGui_ImplWin32_Shutdown()
     ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+
+    ::SetPropA(bd->hWnd, "IMGUI_CONTEXT", nullptr);
+    ImGui_ImplWin32_ShutdownMultiViewportSupport();
 
     // Unload XInput library
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
@@ -231,7 +262,8 @@ void    ImGui_ImplWin32_Shutdown()
 
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad);
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad | ImGuiBackendFlags_PlatformHasViewports | ImGuiBackendFlags_HasMouseHoveredViewport | ImGuiBackendFlags_HasParentViewport);
+    platform_io.ClearPlatformHandlers();
     IM_DELETE(bd);
 }
 
@@ -303,32 +335,69 @@ static void ImGui_ImplWin32_UpdateKeyModifiers(ImGuiIO& io)
     io.AddKeyEvent(ImGuiMod_Super, IsVkDown(VK_LWIN) || IsVkDown(VK_RWIN));
 }
 
-static void ImGui_ImplWin32_UpdateMouseData(ImGuiIO& io)
+static ImGuiViewport* ImGui_ImplWin32_FindViewportByPlatformHandle(ImGuiPlatformIO& platform_io, HWND hwnd)
+{
+    // We cannot use ImGui::FindViewportByPlatformHandle() because it doesn't take a context.
+    // When called from ImGui_ImplWin32_WndProcHandler_PlatformWindow() we don't assume that context is bound.
+    //return ImGui::FindViewportByPlatformHandle((void*)hwnd);
+    for (ImGuiViewport* viewport : platform_io.Viewports)
+        if (viewport->PlatformHandle == hwnd)
+            return viewport;
+    return nullptr;
+}
+
+// This code supports multi-viewports (multiple OS Windows mapped into different Dear ImGui viewports)
+// Because of that, it is a little more complicated than your typical single-viewport binding code!
+static void ImGui_ImplWin32_UpdateMouseData(ImGuiIO& io, ImGuiPlatformIO& platform_io)
 {
     ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData(io);
     IM_ASSERT(bd->hWnd != 0);
 
+    POINT mouse_screen_pos;
+    bool has_mouse_screen_pos = ::GetCursorPos(&mouse_screen_pos) != 0;
+
     HWND focused_window = ::GetForegroundWindow();
-    const bool is_app_focused = (focused_window == bd->hWnd);
+    const bool is_app_focused = (focused_window && (focused_window == bd->hWnd || ::IsChild(focused_window, bd->hWnd) || ImGui_ImplWin32_FindViewportByPlatformHandle(platform_io, focused_window)));
     if (is_app_focused)
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when io.ConfigNavMoveSetMousePos is enabled by user)
+        // When multi-viewports are enabled, all Dear ImGui positions are same as OS positions.
         if (io.WantSetMousePos)
         {
             POINT pos = { (int)io.MousePos.x, (int)io.MousePos.y };
-            if (::ClientToScreen(bd->hWnd, &pos))
-                ::SetCursorPos(pos.x, pos.y);
+            if ((io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) == 0)
+                ::ClientToScreen(focused_window, &pos);
+            ::SetCursorPos(pos.x, pos.y);
         }
 
         // (Optional) Fallback to provide mouse position when focused (WM_MOUSEMOVE already provides this when hovered or captured)
         // This also fills a short gap when clicking non-client area: WM_NCMOUSELEAVE -> modal OS move -> gap -> WM_NCMOUSEMOVE
-        if (!io.WantSetMousePos && bd->MouseTrackedArea == 0)
+        if (!io.WantSetMousePos && bd->MouseTrackedArea == 0 && has_mouse_screen_pos)
         {
-            POINT pos;
-            if (::GetCursorPos(&pos) && ::ScreenToClient(bd->hWnd, &pos))
-                io.AddMousePosEvent((float)pos.x, (float)pos.y);
+            // Single viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
+            // (This is the position you can get with ::GetCursorPos() + ::ScreenToClient() or WM_MOUSEMOVE.)
+            // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+            // (This is the position you can get with ::GetCursorPos() or WM_MOUSEMOVE + ::ClientToScreen(). In theory adding viewport->Pos to a client position would also be the same.)
+            POINT mouse_pos = mouse_screen_pos;
+            if (!(io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable))
+                ::ScreenToClient(bd->hWnd, &mouse_pos);
+            io.AddMousePosEvent((float)mouse_pos.x, (float)mouse_pos.y);
         }
     }
+
+    // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+    // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+    // - [X] Win32 backend correctly ignore viewports with the _NoInputs flag (here using ::WindowFromPoint with WM_NCHITTEST + HTTRANSPARENT in WndProc does that)
+    //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+    //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+    //       by the backend, and use its flawed heuristic to guess the viewport behind.
+    // - [X] Win32 backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+    ImGuiID mouse_viewport_id = 0;
+    if (has_mouse_screen_pos)
+        if (HWND hovered_hwnd = ::WindowFromPoint(mouse_screen_pos))
+            if (ImGuiViewport* viewport = ImGui_ImplWin32_FindViewportByPlatformHandle(platform_io, hovered_hwnd))
+                mouse_viewport_id = viewport->ID;
+    io.AddMouseViewportEvent(mouse_viewport_id);
 }
 
 // Gamepad navigation mapping
@@ -352,6 +421,9 @@ static void ImGui_ImplWin32_UpdateGamepads(ImGuiIO& io)
     if (!bd->HasGamepad || bd->XInputGetState == nullptr || bd->XInputGetState(0, &xinput_state) != ERROR_SUCCESS)
         return;
     io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
+    if (bd->XInputPacketNumber != 0 && bd->XInputPacketNumber == xinput_state.dwPacketNumber)
+        return;
+    bd->XInputPacketNumber = xinput_state.dwPacketNumber;
 
     #define IM_SATURATE(V)                      (V < 0.0f ? 0.0f : V > 1.0f ? 1.0f : V)
     #define MAP_BUTTON(KEY_NO, BUTTON_ENUM)     { io.AddKeyEvent(KEY_NO, (gamepad.wButtons & BUTTON_ENUM) != 0); }
@@ -387,16 +459,50 @@ static void ImGui_ImplWin32_UpdateGamepads(ImGuiIO& io)
 #endif
 }
 
+static BOOL CALLBACK ImGui_ImplWin32_UpdateMonitors_EnumFunc(HMONITOR monitor, HDC, LPRECT, LPARAM)
+{
+    MONITORINFO info = {};
+    info.cbSize = sizeof(MONITORINFO);
+    if (!::GetMonitorInfo(monitor, &info))
+        return TRUE;
+    ImGuiPlatformMonitor imgui_monitor;
+    imgui_monitor.MainPos = ImVec2((float)info.rcMonitor.left, (float)info.rcMonitor.top);
+    imgui_monitor.MainSize = ImVec2((float)(info.rcMonitor.right - info.rcMonitor.left), (float)(info.rcMonitor.bottom - info.rcMonitor.top));
+    imgui_monitor.WorkPos = ImVec2((float)info.rcWork.left, (float)info.rcWork.top);
+    imgui_monitor.WorkSize = ImVec2((float)(info.rcWork.right - info.rcWork.left), (float)(info.rcWork.bottom - info.rcWork.top));
+    imgui_monitor.DpiScale = ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
+    imgui_monitor.PlatformHandle = (void*)monitor;
+    if (imgui_monitor.DpiScale <= 0.0f)
+        return TRUE; // Some accessibility applications are declaring virtual monitors with a DPI of 0, see #7902.
+    ImGuiPlatformIO& io = ImGui::GetPlatformIO();
+    if (info.dwFlags & MONITORINFOF_PRIMARY)
+        io.Monitors.push_front(imgui_monitor);
+    else
+        io.Monitors.push_back(imgui_monitor);
+    return TRUE;
+}
+
+static void ImGui_ImplWin32_UpdateMonitors()
+{
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    ImGui::GetPlatformIO().Monitors.resize(0);
+    ::EnumDisplayMonitors(nullptr, nullptr, ImGui_ImplWin32_UpdateMonitors_EnumFunc, 0);
+    bd->WantUpdateMonitors = false;
+}
+
 void    ImGui_ImplWin32_NewFrame()
 {
     ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
     IM_ASSERT(bd != nullptr && "Context or backend not initialized? Did you call ImGui_ImplWin32_Init()?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
     // Setup display size (every frame to accommodate for window resizing)
     RECT rect = { 0, 0, 0, 0 };
     ::GetClientRect(bd->hWnd, &rect);
     io.DisplaySize = ImVec2((float)(rect.right - rect.left), (float)(rect.bottom - rect.top));
+    if (bd->WantUpdateMonitors)
+        ImGui_ImplWin32_UpdateMonitors();
 
     // Setup time step
     INT64 current_time = 0;
@@ -405,7 +511,7 @@ void    ImGui_ImplWin32_NewFrame()
     bd->Time = current_time;
 
     // Update OS mouse position
-    ImGui_ImplWin32_UpdateMouseData(io);
+    ImGui_ImplWin32_UpdateMouseData(io, platform_io);
 
     // Process workarounds for known Windows key handling issues
     ImGui_ImplWin32_ProcessKeyEventsWorkarounds(io);
@@ -610,6 +716,10 @@ static ImGuiMouseSource ImGui_ImplWin32_GetMouseSourceFromMessageExtraInfo()
 extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);                // Use ImGui::GetCurrentContext()
 extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandlerEx(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam, ImGuiIO& io); // Doesn't use ImGui::GetCurrentContext()
 
+#ifndef WM_DPICHANGED
+#define WM_DPICHANGED 0x02E0 // From Windows SDK 8.1+ headers
+#endif
+
 IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
 {
     // Most backends don't have silent checks like this one, but we need it because WndProc are called early in CreateWindow().
@@ -644,8 +754,11 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandlerEx(HWND hwnd, UINT msg, WPA
             bd->MouseTrackedArea = area;
         }
         POINT mouse_pos = { (LONG)GET_X_LPARAM(lParam), (LONG)GET_Y_LPARAM(lParam) };
-        if (msg == WM_NCMOUSEMOVE && ::ScreenToClient(hwnd, &mouse_pos) == FALSE) // WM_NCMOUSEMOVE are provided in absolute coordinates.
-            return 0;
+        bool want_absolute_pos = (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) != 0;
+        if (msg == WM_MOUSEMOVE && want_absolute_pos)    // WM_MOUSEMOVE are client-relative coordinates.
+            ::ClientToScreen(hwnd, &mouse_pos);
+        if (msg == WM_NCMOUSEMOVE && !want_absolute_pos) // WM_NCMOUSEMOVE are absolute coordinates.
+            ::ScreenToClient(hwnd, &mouse_pos);
         io.AddMouseSourceEvent(mouse_source);
         io.AddMousePosEvent((float)mouse_pos.x, (float)mouse_pos.y);
         return 0;
@@ -794,6 +907,20 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandlerEx(HWND hwnd, UINT msg, WPA
             bd->WantUpdateHasGamepad = true;
 #endif
         return 0;
+    case WM_DISPLAYCHANGE:
+        bd->WantUpdateMonitors = true;
+        return 0;
+    case WM_SETTINGCHANGE:
+        if (wParam == SPI_SETWORKAREA)
+            bd->WantUpdateMonitors = true;
+        return 0;
+    case WM_DPICHANGED:
+    {
+        const RECT* suggested_rect = (RECT*)lParam;
+        if (io.ConfigDpiScaleViewports)
+            ::SetWindowPos(hwnd, nullptr, suggested_rect->left, suggested_rect->top, suggested_rect->right - suggested_rect->left, suggested_rect->bottom - suggested_rect->top, SWP_NOZORDER | SWP_NOACTIVATE);
+        return 0;
+    }
     }
     return 0;
 }
@@ -858,6 +985,10 @@ typedef DPI_AWARENESS_CONTEXT(WINAPI* PFN_SetThreadDpiAwarenessContext)(DPI_AWAR
 // Helper function to enable DPI awareness without setting up a manifest
 void ImGui_ImplWin32_EnableDpiAwareness()
 {
+    // Make sure monitors will be updated with latest correct scaling
+    if (ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData())
+        bd->WantUpdateMonitors = true;
+
     if (_IsWindows10OrGreater())
     {
         static HINSTANCE user32_dll = ::LoadLibraryA("user32.dll"); // Reference counted per-process
@@ -957,6 +1088,385 @@ void ImGui_ImplWin32_EnableAlphaCompositing(void* hwnd)
     }
 }
 
+//---------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* PlatformUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplWin32_ViewportData
+{
+    HWND    Hwnd;               // Stored in ImGuiViewport::PlatformHandle + PlatformHandleRaw
+    HWND    HwndParent;
+    bool    HwndOwned;
+    DWORD   DwStyle;
+    DWORD   DwExStyle;
+
+    ImGui_ImplWin32_ViewportData() { Hwnd = HwndParent = nullptr; HwndOwned = false;  DwStyle = DwExStyle = 0; }
+    ~ImGui_ImplWin32_ViewportData() { IM_ASSERT(Hwnd == nullptr); }
+};
+
+static void ImGui_ImplWin32_GetWin32StyleFromViewportFlags(ImGuiViewportFlags flags, DWORD* out_style, DWORD* out_ex_style)
+{
+    if (flags & ImGuiViewportFlags_NoDecoration)
+        *out_style = WS_POPUP;
+    else
+        *out_style = WS_OVERLAPPEDWINDOW;
+
+    if (flags & ImGuiViewportFlags_NoTaskBarIcon)
+        *out_ex_style = WS_EX_TOOLWINDOW;
+    else
+        *out_ex_style = WS_EX_APPWINDOW;
+
+    if (flags & ImGuiViewportFlags_TopMost)
+        *out_ex_style |= WS_EX_TOPMOST;
+}
+
+static HWND ImGui_ImplWin32_GetHwndFromViewport(ImGuiViewport* viewport)
+{
+    if (viewport != nullptr)
+        return (HWND)viewport->PlatformHandle;
+    return nullptr;
+}
+
+static void ImGui_ImplWin32_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = IM_NEW(ImGui_ImplWin32_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    // Select style and parent window
+    ImGui_ImplWin32_GetWin32StyleFromViewportFlags(viewport->Flags, &vd->DwStyle, &vd->DwExStyle);
+    vd->HwndParent = ImGui_ImplWin32_GetHwndFromViewport(viewport->ParentViewport);
+
+    // Create window
+    RECT rect = { (LONG)viewport->Pos.x, (LONG)viewport->Pos.y, (LONG)(viewport->Pos.x + viewport->Size.x), (LONG)(viewport->Pos.y + viewport->Size.y) };
+    ::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle);
+    vd->Hwnd = ::CreateWindowExW(
+        vd->DwExStyle, L"ImGui Platform", L"Untitled", vd->DwStyle,       // Style, class name, window name
+        rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top,    // Window area
+        vd->HwndParent, nullptr, ::GetModuleHandle(nullptr), nullptr);          // Owner window, Menu, Instance, Param
+    vd->HwndOwned = true;
+    viewport->PlatformRequestResize = false;
+    viewport->PlatformHandle = viewport->PlatformHandleRaw = vd->Hwnd;
+
+    // Secondary viewports store their imgui context
+    ::SetPropA(vd->Hwnd, "IMGUI_CONTEXT", ImGui::GetCurrentContext());
+}
+
+static void ImGui_ImplWin32_DestroyWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    if (ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData)
+    {
+        if (::GetCapture() == vd->Hwnd)
+        {
+            // Transfer capture so if we started dragging from a window that later disappears, we'll still receive the MOUSEUP event.
+            ::ReleaseCapture();
+            ::SetCapture(bd->hWnd);
+        }
+        if (vd->Hwnd && vd->HwndOwned)
+            ::DestroyWindow(vd->Hwnd);
+        vd->Hwnd = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplWin32_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+
+    // ShowParent() also brings parent to front, which is not always desirable,
+    // so we temporarily disable parenting. (#7354)
+    if (vd->HwndParent != NULL)
+        ::SetWindowLongPtr(vd->Hwnd, GWLP_HWNDPARENT, (LONG_PTR)nullptr);
+
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+        ::ShowWindow(vd->Hwnd, SW_SHOWNA);
+    else
+        ::ShowWindow(vd->Hwnd, SW_SHOW);
+
+    // Restore
+    if (vd->HwndParent != NULL)
+        ::SetWindowLongPtr(vd->Hwnd, GWLP_HWNDPARENT, (LONG_PTR)vd->HwndParent);
+}
+
+static void ImGui_ImplWin32_UpdateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+
+    // Update Win32 parent if it changed _after_ creation
+    // Unlike style settings derived from configuration flags, this is more likely to change for advanced apps that are manipulating ParentViewportID manually.
+    HWND new_parent = ImGui_ImplWin32_GetHwndFromViewport(viewport->ParentViewport);
+    if (new_parent != vd->HwndParent)
+    {
+        // Win32 windows can either have a "Parent" (for WS_CHILD window) or an "Owner" (which among other thing keeps window above its owner).
+        // Our Dear Imgui-side concept of parenting only mostly care about what Win32 call "Owner".
+        // The parent parameter of CreateWindowEx() sets up Parent OR Owner depending on WS_CHILD flag. In our case an Owner as we never use WS_CHILD.
+        // Calling ::SetParent() here would be incorrect: it will create a full child relation, alter coordinate system and clipping.
+        // Calling ::SetWindowLongPtr() with GWLP_HWNDPARENT seems correct although poorly documented.
+        // https://devblogs.microsoft.com/oldnewthing/20100315-00/?p=14613
+        vd->HwndParent = new_parent;
+        ::SetWindowLongPtr(vd->Hwnd, GWLP_HWNDPARENT, (LONG_PTR)vd->HwndParent);
+    }
+
+    // (Optional) Update Win32 style if it changed _after_ creation.
+    // Generally they won't change unless configuration flags are changed, but advanced uses (such as manually rewriting viewport flags) make this useful.
+    DWORD new_style;
+    DWORD new_ex_style;
+    ImGui_ImplWin32_GetWin32StyleFromViewportFlags(viewport->Flags, &new_style, &new_ex_style);
+
+    // Only reapply the flags that have been changed from our point of view (as other flags are being modified by Windows)
+    if (vd->DwStyle != new_style || vd->DwExStyle != new_ex_style)
+    {
+        // (Optional) Update TopMost state if it changed _after_ creation
+        bool top_most_changed = (vd->DwExStyle & WS_EX_TOPMOST) != (new_ex_style & WS_EX_TOPMOST);
+        HWND insert_after = top_most_changed ? ((viewport->Flags & ImGuiViewportFlags_TopMost) ? HWND_TOPMOST : HWND_NOTOPMOST) : 0;
+        UINT swp_flag = top_most_changed ? 0 : SWP_NOZORDER;
+
+        // Apply flags and position (since it is affected by flags)
+        vd->DwStyle = new_style;
+        vd->DwExStyle = new_ex_style;
+        ::SetWindowLong(vd->Hwnd, GWL_STYLE, vd->DwStyle);
+        ::SetWindowLong(vd->Hwnd, GWL_EXSTYLE, vd->DwExStyle);
+        RECT rect = { (LONG)viewport->Pos.x, (LONG)viewport->Pos.y, (LONG)(viewport->Pos.x + viewport->Size.x), (LONG)(viewport->Pos.y + viewport->Size.y) };
+        ::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle); // Client to Screen
+        ::SetWindowPos(vd->Hwnd, insert_after, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, swp_flag | SWP_NOACTIVATE | SWP_FRAMECHANGED);
+        ::ShowWindow(vd->Hwnd, SW_SHOWNA); // This is necessary when we alter the style
+        viewport->PlatformRequestMove = viewport->PlatformRequestResize = true;
+    }
+}
+
+static ImVec2 ImGui_ImplWin32_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    POINT pos = { 0, 0 };
+    ::ClientToScreen(vd->Hwnd, &pos);
+    return ImVec2((float)pos.x, (float)pos.y);
+}
+
+static void ImGui_ImplWin32_UpdateWin32StyleFromWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    vd->DwStyle = ::GetWindowLongW(vd->Hwnd, GWL_STYLE);
+    vd->DwExStyle = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE);
+}
+
+static void ImGui_ImplWin32_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    RECT rect = { (LONG)pos.x, (LONG)pos.y, (LONG)pos.x, (LONG)pos.y };
+    if (viewport->Flags & ImGuiViewportFlags_OwnedByApp)
+        ImGui_ImplWin32_UpdateWin32StyleFromWindow(viewport); // Not our window, poll style before using
+    ::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle);
+    ::SetWindowPos(vd->Hwnd, nullptr, rect.left, rect.top, 0, 0, SWP_NOZORDER | SWP_NOSIZE | SWP_NOACTIVATE);
+}
+
+static ImVec2 ImGui_ImplWin32_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    RECT rect;
+    ::GetClientRect(vd->Hwnd, &rect);
+    return ImVec2(float(rect.right - rect.left), float(rect.bottom - rect.top));
+}
+
+static void ImGui_ImplWin32_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    RECT rect = { 0, 0, (LONG)size.x, (LONG)size.y };
+    if (viewport->Flags & ImGuiViewportFlags_OwnedByApp)
+        ImGui_ImplWin32_UpdateWin32StyleFromWindow(viewport); // Not our window, poll style before using
+    ::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle); // Client to Screen
+    ::SetWindowPos(vd->Hwnd, nullptr, 0, 0, rect.right - rect.left, rect.bottom - rect.top, SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE);
+}
+
+static void ImGui_ImplWin32_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    ::BringWindowToTop(vd->Hwnd);
+    ::SetForegroundWindow(vd->Hwnd);
+    ::SetFocus(vd->Hwnd);
+}
+
+static bool ImGui_ImplWin32_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    return ::GetForegroundWindow() == vd->Hwnd;
+}
+
+static bool ImGui_ImplWin32_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    return ::IsIconic(vd->Hwnd) != 0;
+}
+
+static void ImGui_ImplWin32_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    // ::SetWindowTextA() doesn't properly handle UTF-8 so we explicitely convert our string.
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    int n = ::MultiByteToWideChar(CP_UTF8, 0, title, -1, nullptr, 0);
+    ImVector<wchar_t> title_w;
+    title_w.resize(n);
+    ::MultiByteToWideChar(CP_UTF8, 0, title, -1, title_w.Data, n);
+
+    // Calling SetWindowTextW() in a project where UNICODE is not set doesn't work but there's a trick
+    // which is to pass it directly to the DefWindowProcW() handler.
+    // See: https://stackoverflow.com/questions/9410681/setwindowtextw-in-an-ansi-project
+    //::SetWindowTextW(vd->Hwnd, title_w.Data);
+    ::DefWindowProcW(vd->Hwnd, WM_SETTEXT, 0, (LPARAM)title_w.Data);
+}
+
+static void ImGui_ImplWin32_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    IM_ASSERT(alpha >= 0.0f && alpha <= 1.0f);
+    if (alpha < 1.0f)
+    {
+        DWORD ex_style = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE) | WS_EX_LAYERED;
+        ::SetWindowLongW(vd->Hwnd, GWL_EXSTYLE, ex_style);
+        ::SetLayeredWindowAttributes(vd->Hwnd, 0, (BYTE)(255 * alpha), LWA_ALPHA);
+    }
+    else
+    {
+        DWORD ex_style = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE) & ~WS_EX_LAYERED;
+        ::SetWindowLongW(vd->Hwnd, GWL_EXSTYLE, ex_style);
+    }
+}
+
+static float ImGui_ImplWin32_GetWindowDpiScale(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    return ImGui_ImplWin32_GetDpiScaleForHwnd(vd->Hwnd);
+}
+
+// FIXME-DPI: Testing DPI related ideas
+static void ImGui_ImplWin32_OnChangedViewport(ImGuiViewport* viewport)
+{
+    (void)viewport;
+#if 0
+    ImGuiStyle default_style;
+    //default_style.WindowPadding = ImVec2(0, 0);
+    //default_style.WindowBorderSize = 0.0f;
+    //default_style.ItemSpacing.y = 3.0f;
+    //default_style.FramePadding = ImVec2(0, 0);
+    default_style.ScaleAllSizes(viewport->DpiScale);
+    ImGuiStyle& style = ImGui::GetStyle();
+    style = default_style;
+#endif
+}
+
+namespace ImGui { extern ImGuiIO& GetIO(ImGuiContext*); extern ImGuiPlatformIO& GetPlatformIO(ImGuiContext*); }
+
+static LRESULT CALLBACK ImGui_ImplWin32_WndProcHandler_PlatformWindow(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    // Allow secondary viewport WndProc to be called regardless of current context
+    ImGuiContext* ctx = (ImGuiContext*)::GetPropA(hWnd, "IMGUI_CONTEXT");
+    if (ctx == NULL)
+        return DefWindowProc(hWnd, msg, wParam, lParam); // unlike ImGui_ImplWin32_WndProcHandler() we are called directly by Windows, we can't just return 0.
+
+    ImGuiIO& io = ImGui::GetIO(ctx);
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO(ctx);
+    LRESULT result = 0;
+    if (ImGui_ImplWin32_WndProcHandlerEx(hWnd, msg, wParam, lParam, io))
+        result = 1;
+    else if (ImGuiViewport* viewport = ImGui_ImplWin32_FindViewportByPlatformHandle(platform_io, hWnd))
+    {
+        switch (msg)
+        {
+        case WM_CLOSE:
+            viewport->PlatformRequestClose = true;
+            return 0; // 0 = Operating system will ignore the message and not destroy the window. We close ourselves.
+        case WM_MOVE:
+            viewport->PlatformRequestMove = true;
+            break;
+        case WM_SIZE:
+            viewport->PlatformRequestResize = true;
+            break;
+        case WM_MOUSEACTIVATE:
+            if (viewport->Flags & ImGuiViewportFlags_NoFocusOnClick)
+                result = MA_NOACTIVATE;
+            break;
+        case WM_NCHITTEST:
+            // Let mouse pass-through the window. This will allow the backend to call io.AddMouseViewportEvent() correctly. (which is optional).
+            // The ImGuiViewportFlags_NoInputs flag is set while dragging a viewport, as want to detect the window behind the one we are dragging.
+            // If you cannot easily access those viewport flags from your windowing/event code: you may manually synchronize its state e.g. in
+            // your main loop after calling UpdatePlatformWindows(). Iterate all viewports/platform windows and pass the flag to your windowing system.
+            if (viewport->Flags & ImGuiViewportFlags_NoInputs)
+                result = HTTRANSPARENT;
+            break;
+        }
+    }
+    if (result == 0)
+        result = DefWindowProc(hWnd, msg, wParam, lParam);
+    return result;
+}
+
+static void ImGui_ImplWin32_InitMultiViewportSupport(bool platform_has_own_dc)
+{
+    WNDCLASSEXW wcex;
+    wcex.cbSize = sizeof(WNDCLASSEXW);
+    wcex.style = CS_HREDRAW | CS_VREDRAW | (platform_has_own_dc ? CS_OWNDC : 0);
+    wcex.lpfnWndProc = ImGui_ImplWin32_WndProcHandler_PlatformWindow;
+    wcex.cbClsExtra = 0;
+    wcex.cbWndExtra = 0;
+    wcex.hInstance = ::GetModuleHandle(nullptr);
+    wcex.hIcon = nullptr;
+    wcex.hCursor = nullptr;
+    wcex.hbrBackground = (HBRUSH)(COLOR_BACKGROUND + 1);
+    wcex.lpszMenuName = nullptr;
+    wcex.lpszClassName = L"ImGui Platform";
+    wcex.hIconSm = nullptr;
+    ::RegisterClassExW(&wcex);
+
+    ImGui_ImplWin32_UpdateMonitors();
+
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplWin32_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplWin32_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplWin32_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplWin32_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplWin32_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplWin32_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplWin32_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplWin32_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplWin32_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplWin32_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplWin32_SetWindowTitle;
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplWin32_SetWindowAlpha;
+    platform_io.Platform_UpdateWindow = ImGui_ImplWin32_UpdateWindow;
+    platform_io.Platform_GetWindowDpiScale = ImGui_ImplWin32_GetWindowDpiScale; // FIXME-DPI
+    platform_io.Platform_OnChangedViewport = ImGui_ImplWin32_OnChangedViewport; // FIXME-DPI
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    ImGui_ImplWin32_ViewportData* vd = IM_NEW(ImGui_ImplWin32_ViewportData)();
+    vd->Hwnd = bd->hWnd;
+    vd->HwndOwned = false;
+    main_viewport->PlatformUserData = vd;
+}
+
+static void ImGui_ImplWin32_ShutdownMultiViewportSupport()
+{
+    ::UnregisterClassW(L"ImGui Platform", ::GetModuleHandle(nullptr));
+    ImGui::DestroyPlatformWindows();
+}
+
 //---------------------------------------------------------------------------------------------------------
 
 #if defined(__GNUC__)

backends/imgui_impl_win32.h

@@ -7,6 +7,7 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy VK_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

docs/BACKENDS.md

@@ -182,6 +182,7 @@ The Platform backends in impl_impl_XXX.cpp files contain many implementations.
   - `ImGuiBackendFlags_HasSetMousePos`: supports io.WantSetMousePos requests to reposition the OS mouse position (only used if io.ConfigNavMoveSetMousePos is set).
   - `ImGuiBackendFlags_PlatformHasViewports` supports multiple viewports. (multi-viewports only)
   - `ImGuiBackendFlags_HasMouseHoveredViewport` supports calling io.AddMouseViewportEvent() with the viewport under the mouse. IF POSSIBLE, ignore viewports with the ImGuiViewportFlags_NoInputs flag. If this cannot be done, Dear ImGui needs to use a flawed heuristic to find the viewport under mouse position, as it doesn't know about foreign windows. (multi-viewports only)
+  - `ImGuiBackendFlags_HasParentViewport` supports honoring viewport->ParentViewportId value, by applying the corresponding parent/child relation at the Platform level.
 
 **In your `ImGui_ImplXXX_NewFrame()` function:**
 - Set `io.DeltaTime` to the time elapsed (in seconds) since last frame.
@@ -245,9 +246,8 @@ void MyImGuiBackend_RenderDrawData(ImDrawData* draw_data)
     // Render command lists
     ImVec2 clip_off = draw_data->DisplayPos;
     ImVec2 clip_scale = draw_data->FramebufferScale;
-    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    for (const ImDrawList* draw_list : draw_data->CmdLists)
     {
-        const ImDrawList* cmd_list = draw_data->CmdLists[n];
         const ImDrawVert* vtx_buffer = cmd_list->VtxBuffer.Data;  // vertex buffer generated by Dear ImGui
         const ImDrawIdx* idx_buffer = cmd_list->IdxBuffer.Data;   // index buffer generated by Dear ImGui
         for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)

docs/EXAMPLES.md

@@ -149,6 +149,14 @@ SDL2 (Win32, Mac, Linux, etc.) + Vulkan example. <BR>
 This is quite long and tedious, because: Vulkan. <BR>
 For this example, the main.cpp file exceptionally use helpers function from imgui_impl_vulkan.h/cpp.
 
+[example_sdl3_directx11/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl3_directx11/) <BR>
+SDL3 + DirectX11 examples, Windows only. <BR>
+= main.cpp + imgui_impl_sdl3.cpp + imgui_impl_dx11.cpp <BR>
+
+[example_sdl3_metal/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl3_metal/) <BR>
+SDL3 + Metal example, Mac only. <BR>
+= main.cpp + imgui_impl_sdl3.cpp + imgui_impl_metal.mm <BR>
+
 [example_sdl3_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl3_opengl3/) <BR>
 SDL3 (Win32, Mac, Linux, etc.) + OpenGL3+/ES2/ES3 example. <BR>
 = main.cpp + imgui_impl_sdl3.cpp + imgui_impl_opengl3.cpp <BR>

docs/FAQ.md

@@ -13,13 +13,14 @@ or view this file with any Markdown viewer.
 :---------------------------------------------------------- |
 | [Where is the documentation?](#q-where-is-the-documentation) |
 | [What is this library called?](#q-what-is-this-library-called) |
+| [What is the difference between Dear ImGui and traditional UI toolkits?](#q-what-is-the-difference-between-dear-imgui-and-traditional-ui-toolkits) |
 | [Which version should I get?](#q-which-version-should-i-get) |
 | **Q&A: Integration** |
 | **[How to get started?](#q-how-to-get-started)** |
 | **[How can I tell whether to dispatch mouse/keyboard to Dear ImGui or my application?](#q-how-can-i-tell-whether-to-dispatch-mousekeyboard-to-dear-imgui-or-my-application)** |
 | [How can I enable keyboard or gamepad controls?](#q-how-can-i-enable-keyboard-or-gamepad-controls) |
 | [How can I use this on a machine without mouse, keyboard or screen? (input share, remote display)](#q-how-can-i-use-this-on-a-machine-without-mouse-keyboard-or-screen-input-share-remote-display) |
-| [How can I create my own backend?](q-how-can-i-create-my-own-backend)
+| [How can I create my own backend?](#q-how-can-i-create-my-own-backend)
 | [I integrated Dear ImGui in my engine and little squares are showing instead of text...](#q-i-integrated-dear-imgui-in-my-engine-and-little-squares-are-showing-instead-of-text) |
 | [I integrated Dear ImGui in my engine and some elements are clipping or disappearing when I move windows around...](#q-i-integrated-dear-imgui-in-my-engine-and-some-elements-are-clipping-or-disappearing-when-i-move-windows-around) |
 | [I integrated Dear ImGui in my engine and some elements are displaying outside their expected windows boundaries...](#q-i-integrated-dear-imgui-in-my-engine-and-some-elements-are-displaying-outside-their-expected-windows-boundaries) |
@@ -75,6 +76,60 @@ or view this file with any Markdown viewer.
 
 ---
 
+### Q: What is the difference between Dear ImGui and traditional UI toolkits?
+
+Here's a very simplified comparison between the approach taken by Dear ImGui vs traditional toolkits:
+
+| Dear ImGui | Qt/GTK/WPF... |
+|--------------------------|--------------------------|
+| UI fully issued on every update. | UI issued once then later modified. |
+| UI layout is fully dynamic and can change at any time.<BR>UI is generally emitted programmatically, which empowers reflecting a dynamic set of data. | UI layout is mostly static.<BR>UI may be emitted programmatically or from data created by offline tools. UI need extra code to evolve, which is often tedious and error-prone if it needs to be reflecting dynamic data and systems. |
+| Application can submit UI based on arbitrary logic and then forget about it. | Application needs more bookkeeping of UI elements. |
+| UI library stores minimal amounts of data. At one point in time, it typically doesn't know or remember which other widgets are displayed and which widgets are coming next. As a result, certain layout features (alignment, resizing) are not as easy to implement or require ad-hoc code. | UI library stores entire widgets tree and state. UI library can use this retained data to easily layout things. |
+| UI code may be added anywhere.<BR>You can even create UI to edit a local variable! | UI code needs to be added in dedicated spots. |
+| UI layout/logic/action/data bindings are all nearby in the code. | UI layout/logic/action/data bindings in distinct functions, files or formats. |
+| Data is naturally always synchronized. | Use callback/signal/slot for synchronizing data (error-prone). |
+| API is simple and easy to learn. In particular, doing basic things is very easy. | API is more complex and specialized. |
+| API is low-level (raw language types). | API are higher-level (more abstractions, advanced language features). |
+| Less fancy look and feel. | Standard look and feel. |
+| Compile yourself. Easy to debug, hack, modify, study. | Mostly use precompiled libraries. Compiling, modifying or studying is daunting if not impossible. |
+| Run on every platform. | Run on limited desktop platforms. |
+
+Idiomatic Dear ImGui code:
+```cpp
+if (ImGui::Button("Save"))
+    MySaveFunction();
+
+ImGui::SliderFloat("Slider", &m_MyValue, 0.0f, 1.0f);
+```
+Idiomatic code with traditional toolkit:
+```cpp
+UiButton* button = new UiButton("Save");
+button->OnClick = &MySaveFunction;
+parent->Add(button);
+
+UiSlider* slider = new UiSlider("Slider");
+slider->SetRange(0.0f, 1.0f);
+slider->BindData<float>(&m_MyValue);
+parent->Add(slider);
+```
+This is only meant to give you a intuitive feeling of the main differences, but pros & cons go deeper than that.
+
+Some of those properties are typically associated to the umbrella term "IMGUI", but the term has no simple and well-agreed definition. There are many erroneous statements and misunderstandings with what IMGUI means. It is partly caused by the fact that most popular IMGUI implementations (including Dear ImGui) have originated from game industry needs and have targeted specific use cases, causing people to conflate IMGUI properties with what a specific library does. However, it is perfectly possible to implement an IMGUI library that would have very different properties than e.g. Dear ImGui. My take on defining what an IMGUI is:
+
+**IMGUI refers to the API: literally the interface between the application and the UI system.**
+- An IMGUI API favors the application code owning its data and being the single source of truth for it.
+- An IMGUI API tries to minimize the application having to retain/manage data related to the UI system.
+- An IMGUI API tries to minimize the UI system having to retain/manage data related to the application.
+- Synchronization between application data and UI data is natural and less error-prone.
+
+**IMGUI does NOT refer to the implementation. Whatever happens inside the UI library code doesn't matter.**
+<BR>Also see: [Links to many articles about the IMGUI paradigm](https://github.com/ocornut/imgui/wiki/#about-the-imgui-paradigm).
+
+##### [Return to Index](#index)
+
+---
+
 ### Q: Which version should I get?
 I occasionally tag [Releases](https://github.com/ocornut/imgui/releases) but it is generally safe and recommended to sync to master/latest. The library is fairly stable and regressions tend to be fixed fast when reported.
 
@@ -389,8 +444,8 @@ node open/closed state differently. See what makes more sense in your situation!
 ### Q: What are ImTextureID/ImTextureRef?
 
 **Short explanation:**
-- Refer to [Image Loading and Displaying Examples](https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples) on the [Wiki](https://github.com/ocornut/imgui/wiki).
 - You may use functions such as `ImGui::Image()`, `ImGui::ImageButton()` or lower-level `ImDrawList::AddImage()` to emit draw calls that will use your own textures.
+- To load and display your own textures, refer to [Image Loading and Displaying Examples](https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples) on the [Wiki](https://github.com/ocornut/imgui/wiki).
 - Actual textures are identified in a way that is up to the user/engine. Those identifiers are stored and passed as an opaque ImTextureID value.
 - By default ImTextureID can store up to 64-bits. You may `#define` it to a custom type/structure if you need.
 - Loading image files from the disk and turning them into a texture is not within the scope of Dear ImGui (for a good reason), but the examples linked above may be useful references.
@@ -398,12 +453,20 @@ node open/closed state differently. See what makes more sense in your situation!
 **Details:**
 
 1.92 introduced `ImTextureRef` in June 2025.
-- Most drawing functions using ImTextureID were changed to use ImTextureRef.
-- We intentionally do not provide an implicit ImTextureRef -> ImTextureID cast operator because it is technically lossy to convert ImTextureRef to ImTextureID before rendering.
+- All drawing functions using `ImTextureID` were changed to use `ImTextureRef`.
+- You can trivially create a `ImTextureRef` from a `ImTextureID`.
+- **If you use Image functions with textures that you have loaded/created yourself, you will mostly likely only ever store/manipulate `ImTextureID` and then pass them as `ImTextureRef`.**
+- You only NEED to manipulate `ImTextureRef` when dealing with textures managed by the backend itself, aka mainly the atlas texture for now.
+- We intentionally do not provide an implicit `ImTextureRef` -> `ImTextureID` cast operator because it is technically lossy to convert ImTextureRef to ImTextureID before rendering.
 
 **ImTextureID = backend specific, low-level identifier for a texture uploaded in GPU/graphics system.**
+```cpp
+#ifndef ImTextureID
+typedef ImU64 ImTextureID;  // Default: store up to 64-bits (any pointer or integer). A majority of backends are ok with that.
+#endif
+```
 - When a Rendered Backend creates a texture, it store its native identifier into a ImTextureID value (e.g. Used by DX11 backend to a `ID3D11ShaderResourceView*`; Used by OpenGL backends to store `GLuint`; Used by SDLGPU backend to store a `SDL_GPUTextureSamplerBinding*`, etc.).
-- User may submit their own textures to e.g. ImGui::Image() function by passing the same type.
+- User may submit their own textures to e.g. `ImGui::Image()` function by passing this value.
 - During the rendering loop, the Renderer Backend retrieve the ImTextureID, which stored inside a ImTextureRef, which is stored inside ImDrawCmd.
 - Compile-time type configuration:
   - To use something other than a 64-bit value: add '#define ImTextureID MyTextureType*' in your imconfig.h file.
@@ -411,13 +474,29 @@ node open/closed state differently. See what makes more sense in your situation!
   - You may decide to store a higher-level structure containing texture, sampler, shader etc. with various constructors if you like. You will need to implement ==/!= operators.
 
 **ImTextureRef = higher-level identifier for a texture.**
+```cpp
+// Store a ImTextureID _or_ a ImTextureData*.
+struct ImTextureRef
+{
+    ImTextureRef()                          { _TexData = NULL; _TexID = ImTextureID_Invalid; }
+    ImTextureRef(ImTextureID tex_id)        { _TexData = NULL; _TexID = tex_id; }
+    inline ImTextureID  GetTexID() const    { return _TexData ? _TexData->TexID : _TexID; }
+
+    // Members (either are set, never both!)
+    ImTextureData*      _TexData;           //      A texture, generally owned by a ImFontAtlas. Will convert to ImTextureID during render loop, after texture has been uploaded.
+    ImTextureID         _TexID;             // _OR_ Low-level backend texture identifier, if already uploaded or created by user/app. Generally provided to e.g. ImGui::Image() calls.
+};
+```
 - The identifier is valid even before the texture has been uploaded to the GPU/graphics system.
 - This is what gets passed to functions such as `ImGui::Image()`, `ImDrawList::AddImage()`.
 - This is what gets stored in draw commands (`ImDrawCmd`) to identify a texture during rendering.
- - When a texture is created by user code (e.g. custom images), we directly stores the low-level `ImTextureID`.
- - When a texture is created by the backend, we stores a `ImTextureData*` which becomes an indirection to extract the `ImTextureID` value during rendering, after texture upload has happened.
- - There is no constructor to create a `ImTextureID` from a `ImTextureData*` as we don't expect this to be useful to the end-user, and it would be erroneously called by many legacy code.
- - If you want to bind the current atlas when using custom rectangle, you can use `io.Fonts->TexRef`.
+ - When a texture is created by user code (e.g. custom images), we directly store the low-level `ImTextureID`.
+   - Because of this, when displaying your own texture you are likely to ever only manage ImTextureID values on your side.
+ - When a texture is created by the backend, we store a `ImTextureData*` which becomes an indirection to extract the `ImTextureID` value during rendering, after texture upload has happened.
+ - To create a `ImTextureRef` from a `ImTextureData*` you can use `ImTextureData::GetTexRef()`.
+   We intentionally do not provide an `ImTextureRef` constructor for this: we don't expect this to be frequently useful to the end-user, and it would be erroneously called by many legacy code.
+ - There is no constructor to create a `ImTextureRef` from a `ImTextureData*` as we don't expect this to be useful to the end-user, and it would be erroneously called by many legacy code.
+ - If you want to bind the current atlas when using custom rectangles, you can use `io.Fonts->TexRef`.
  - Binding generators for languages such as C (which don't have constructors), should provide a helper, e.g. `inline ImTextureRef ImTextureRefFromID(ImTextureID tex_id) { ImTextureRef tex_ref = { ._TexData = NULL, .TexID = tex_id }; return tex_ref; }`
 
 **Please read documentations or tutorials on your graphics API to understand how to display textures on the screen before moving onward.**

docs/FONTS.md

@@ -150,7 +150,6 @@ ImFontConfig config;
 config.MergeMode = true;
 io.Fonts->AddFontFromFileTTF("DroidSans.ttf", 0.0f, &config);           // Merge into first font to add e.g. Asian characters
 io.Fonts->AddFontFromFileTTF("fontawesome-webfont.ttf", 0.0f, &config); // Merge into first font to add Icons
-io.Fonts->Build();
 ```
 :rewind: **Before 1.92, or without an up to date backend:**
 ```cpp
@@ -588,15 +587,18 @@ Some fonts files are available in the `misc/fonts/` folder:
 
 #### MONOSPACE FONTS
 
+<img width="1172" height="715" alt="image" src="https://github.com/user-attachments/assets/c9702534-4877-41c9-ae0d-252933c26ced" />
+
 Pixel Perfect:
 - Proggy Fonts, by Tristan Grimmer http://www.proggyfonts.net or http://upperboundsinteractive.com/fonts.php
 - Sweet16, Sweet16 Mono, by Martin Sedlak (Latin + Supplemental + Extended A) https://github.com/kmar/Sweet16Font (also include an .inl file to use directly in dear imgui.)
 
 Regular:
-- Google Noto Mono Fonts https://www.google.com/get/noto/
-- Typefaces for source code beautification https://github.com/chrissimpkins/codeface
-- Programmation fonts http://s9w.github.io/font_compare/
-- Inconsolata http://www.levien.com/type/myfonts/inconsolata.html
+- ProggyVector if you want the old school Dear ImGui font to scale: https://github.com/bluescan/proggyfonts
+- Google Noto Mono Fonts: https://www.google.com/get/noto/
+- Typefaces for source code beautification: https://github.com/chrissimpkins/codeface
+- Programmation fonts: http://s9w.github.io/font_compare/
+- Inconsolata: http://www.levien.com/type/myfonts/inconsolata.html
 - Adobe Source Code Pro: Monospaced font family for ui & coding environments https://github.com/adobe-fonts/source-code-pro
 - Monospace/Fixed Width Programmer's Fonts http://www.lowing.org/fonts/
 

docs/README.md

@@ -16,7 +16,7 @@ Businesses: support continued development and maintenance via invoiced sponsorin
 | [The Pitch](#the-pitch) - [Usage](#usage) - [How it works](#how-it-works) - [Releases & Changelogs](#releases--changelogs) - [Demo](#demo) - [Getting Started & Integration](#getting-started--integration) |
 :----------------------------------------------------------: |
 | [Gallery](#gallery) - [Support, FAQ](#support-frequently-asked-questions-faq) -  [How to help](#how-to-help) - **[Funding & Sponsors](https://github.com/ocornut/imgui/wiki/Funding)** - [Credits](#credits) - [License](#license) |
-| [Wiki](https://github.com/ocornut/imgui/wiki) - [Extensions](https://github.com/ocornut/imgui/wiki/Useful-Extensions) - [Languages bindings & frameworks backends](https://github.com/ocornut/imgui/wiki/Bindings) - [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui) - [User quotes](https://github.com/ocornut/imgui/wiki/Quotes) |
+| [Wiki](https://github.com/ocornut/imgui/wiki) - [Extensions](https://github.com/ocornut/imgui/wiki/Useful-Extensions) - [Language bindings & framework backends](https://github.com/ocornut/imgui/wiki/Bindings) - [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui) - [User quotes](https://github.com/ocornut/imgui/wiki/Quotes) |
 
 ### The Pitch
 
@@ -107,22 +107,26 @@ Reading the changelogs is a good way to keep up to date with the things Dear ImG
 
 ### Demo
 
-Calling the `ImGui::ShowDemoWindow()` function will create a demo window showcasing a variety of features and examples. The code is always available for reference in `imgui_demo.cpp`. [Here's how the demo looks](https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v167/v167-misc.png).
+Calling the `ImGui::ShowDemoWindow()` function will create a demo window showcasing a variety of features and examples. The code is always available for reference in `imgui_demo.cpp`. 
+- [Web version of the demo](https://pthom.github.io/imgui_manual_online/manual/imgui_manual.html) courtesy of [@pthom](https://github.com/pthom).
+- [Screenshot of the demo](https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v167/v167-misc.png).
 
 You should be able to build the examples from sources. If you don't, let us know! If you want to have a quick look at some Dear ImGui features, you can download Windows binaries of the demo app here:
 - [imgui-demo-binaries-20250625.zip](https://www.dearimgui.com/binaries/imgui-demo-binaries-20250625.zip) (Windows, 1.92.0, built 2025/06/25, master) or [older binaries](https://www.dearimgui.com/binaries).
 
-The demo applications are not DPI aware so expect some blurriness on a 4K screen. For DPI awareness in your application, you can load/reload your font at a different scale and scale your style with `style.ScaleAllSizes()` (see [FAQ](https://www.dearimgui.com/faq)).
-
 ### Getting Started & Integration
 
 See the [Getting Started](https://github.com/ocornut/imgui/wiki/Getting-Started) guide for details.
 
 On most platforms and when using C++, **you should be able to use a combination of the [imgui_impl_xxxx](https://github.com/ocornut/imgui/tree/master/backends) backends without modification** (e.g. `imgui_impl_win32.cpp` + `imgui_impl_dx11.cpp`). If your engine supports multiple platforms, consider using more imgui_impl_xxxx files instead of rewriting them: this will be less work for you, and you can get Dear ImGui running immediately. You can _later_ decide to rewrite a custom backend using your custom engine functions if you wish so.
 
-Integrating Dear ImGui within your custom engine is a matter of 1) wiring mouse/keyboard/gamepad inputs 2) uploading a texture to your GPU/render engine 3) providing a render function that can bind textures and render textured triangles, which is essentially what Backends are doing. The [examples/](https://github.com/ocornut/imgui/tree/master/examples) folder is populated with applications doing just that: setting up a window and using backends. If you follow the [Getting Started](https://github.com/ocornut/imgui/wiki/Getting-Started) guide it should in theory take you less than an hour to integrate Dear ImGui.  **Make sure to spend time reading the [FAQ](https://www.dearimgui.com/faq), comments, and the examples applications!**
+Integrating Dear ImGui within your custom engine is a matter of mainly 1) wiring mouse/keyboard/gamepad inputs 2) uploading a texture to your GPU/render engine 3) providing a render function that can create/update textures and render textured triangles. This is exactly what backends are doing.
+- The [examples/](https://github.com/ocornut/imgui/tree/master/examples) folder is populated with applications setting up a window and using standard backends.
+- The [Getting Started](https://github.com/ocornut/imgui/wiki/Getting-Started) guide has instructions to integrate imgui into an existing application using standard backends. It should in theory take you less than an hour to integrate Dear ImGui into your existing codebase where support libraries are linked. Less if you read carefully.
+- The [Backends](https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md) guide explains what backends are doing, and has instructions to implement a custom backend. You can also refer to the source code of our ~20 backends to understand how they work.
+- Generally, **make sure to spend time reading the [FAQ](https://www.dearimgui.com/faq), comments, and the examples applications!**
 
-Officially maintained backends/bindings (in repository):
+Officially maintained backends (in repository):
 - Renderers: DirectX9, DirectX10, DirectX11, DirectX12, Metal, OpenGL/ES/ES2, SDL_GPU, SDL_Renderer2/3, Vulkan, WebGPU.
 - Platforms: GLFW, SDL2/SDL3, Win32, Glut, OSX, Android.
 - Frameworks: Allegro5, Emscripten.
@@ -130,7 +134,7 @@ Officially maintained backends/bindings (in repository):
 [Third-party backends/bindings](https://github.com/ocornut/imgui/wiki/Bindings) wiki page:
 - Languages: C, C# and: Beef, ChaiScript, CovScript, Crystal, D, Go, Haskell, Haxe/hxcpp, Java, JavaScript, Julia, Kotlin, Lobster, Lua, Nim, Odin, Pascal, PureBasic, Python, ReaScript, Ruby, Rust, Swift, Zig...
 - Frameworks: AGS/Adventure Game Studio, Amethyst, Blender, bsf, Cinder, Cocos2d-x, Defold, Diligent Engine, Ebiten, Flexium, GML/Game Maker Studio, GLEQ, Godot, GTK3, Irrlicht Engine, JUCE, LÖVE+LUA, Mach Engine, Magnum, Marmalade, Monogame, NanoRT, nCine, Nim Game Lib, Nintendo 3DS/Switch/WiiU (homebrew), Ogre, openFrameworks, OSG/OpenSceneGraph, Orx, Photoshop, px_render, Qt/QtDirect3D, raylib, SFML, Sokol, Unity, Unreal Engine 4/5, UWP, vtk, VulkanHpp, VulkanSceneGraph, Win32 GDI, WxWidgets.
-- Many bindings are auto-generated (by good old [cimgui](https://github.com/cimgui/cimgui) or newer/experimental [dear_bindings](https://github.com/dearimgui/dear_bindings)), you can use their metadata output to generate bindings for other languages.
+- Many bindings are auto-generated (by good old [cimgui](https://github.com/cimgui/cimgui) or our newer [dear_bindings](https://github.com/dearimgui/dear_bindings)), you can use their metadata output to generate bindings for other languages.
 
 [Useful Extensions/Widgets](https://github.com/ocornut/imgui/wiki/Useful-Extensions) wiki page:
 - Automation/testing, Text editors, node editors, timeline editors, plotting, software renderers, remote network access, memory editors, gizmos, etc. Notable and well supported extensions include [ImPlot](https://github.com/epezent/implot) and [Dear ImGui Test Engine](https://github.com/ocornut/imgui_test_engine).
@@ -184,7 +188,7 @@ How to help
 - See [GitHub Forum/Issues](https://github.com/ocornut/imgui/issues).
 - You may help with development and submit pull requests! Please understand that by submitting a PR you are also submitting a request for the maintainer to review your code and then take over its maintenance forever. PR should be crafted both in the interest of the end-users and also to ease the maintainer into understanding and accepting it.
 - See [Help wanted](https://github.com/ocornut/imgui/wiki/Help-Wanted) on the [Wiki](https://github.com/ocornut/imgui/wiki/) for some more ideas.
-- Be a [Funding Supporter](https://github.com/ocornut/imgui/wiki/Funding)! Have your company financially support this project via invoiced sponsors/maintenance or by buying a license for [Dear ImGui Test Engine](https://github.com/ocornut/imgui_test_engine) (please reach out: omar AT dearimgui DOT com).
+- Be a [Funding Supporter](https://github.com/ocornut/imgui/wiki/Funding)! Have your company financially support this project via invoiced sponsors/maintenance or by buying a license for [Dear ImGui Test Engine](https://github.com/ocornut/imgui_test_engine) (please reach out: contact AT dearimgui DOT com).
 
 Sponsors
 --------
@@ -214,7 +218,7 @@ Omar: "I first discovered the IMGUI paradigm at [Q-Games](https://www.q-games.co
 Embeds [ProggyClean.ttf](https://www.proggyfonts.net) font by Tristan Grimmer (MIT license).
 <br>Embeds [stb_textedit.h, stb_truetype.h, stb_rect_pack.h](https://github.com/nothings/stb/) by Sean Barrett (public domain).
 
-Inspiration, feedback, and testing for early versions: Casey Muratori, Atman Binstock, Mikko Mononen, Emmanuel Briney, Stefan Kamoda, Anton Mikhailov, Matt Willis. Also thank you to everyone posting feedback, questions and patches on GitHub.
+Inspiration, feedback, and testing for early versions: Casey Muratori, Atman Binstock, Mikko Mononen, Emmanuel Briney, Stefan Kamoda, Anton Mikhailov, Matt Willis. Special thanks to Alex Evans, Patrick Doane, Marco Koegler for kindly helping. Also thank you to everyone posting feedback, questions and patches on GitHub.
 
 License
 -------

docs/TODO.txt

@@ -87,7 +87,6 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - input text multi-line: line numbers? status bar? (follow up on #200)
  - input text multi-line: behave better when user changes input buffer while editing is active (even though it is illegal behavior). namely, the change of buffer can create a scrollbar glitch (#725)
  - input text multi-line: better horizontal scrolling support (#383, #1224)
- - input text multi-line: single call to AddText() should be coarse clipped on InputTextEx() end.
  - input number: optional range min/max for Input*() functions
  - input number: holding [-]/[+] buttons could increase the step speed non-linearly (or user-controlled)
  - input number: use mouse wheel to step up/down
@@ -124,7 +123,35 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - separator: width, thickness, centering (#1643, #2657)
  - splitter: formalize the splitter idiom into an official api (we want to handle n-way split) (#319)
 
- - docking: merge docking branch (#2109)
+ - docking: B: ordering currently held in tab bar should be implicitly held by windows themselves (also see #2304)
+ - docking: B- tab bar: the order/focus restoring code could be part of TabBar and not DockNode? (#8)
+ - docking: B~ rework code to be able to lazily create tab bar instance in a single place. The _Unsorted tab flag could be replacing a trailing-counter in DockNode?
+ - docking: B~ fully track windows/settings reference in dock nodes. perhaps find a representation that allows facilitate use of dock builder functions.
+ - docking: B~ Unreal style document system (requires low-level controls of dockspace serialization fork/copy/delete). this is mostly working but the DockBuilderXXX api are not exposed/finished.
+ - docking: B: when docking outer, perform size locking on neighbors nodes the same way we do it with splitters, so other nodes are not resized.
+ - docking: B~ central node resizing behavior incorrect.
+ - docking: B: changing title font/style per-window is not supported as dock nodes are created in NewFrame.
+ - docking: B- dock node inside its own viewports creates 1 temporary viewport per window on startup before ditching them (doesn't affect the user nor request platform windows to be created, but unnecessary)
+ - docking: B- resize sibling locking behavior may be less desirable if we merged same-axis sibling in a same node level?
+ - docking: B- single visible node part of a hidden split hierarchy (OnlyNodeWithWindows != NULL) should show a normal title bar (not a tab bar)
+ - docking: B~ SetNextWindowDock() calls (with conditional) -> defer everything to DockContextUpdate (repro: Documents->[X]Windows->Dock 1 elsewhere->Click Redock All
+ - docking: B~ tidy up tab list popup buttons features (available with manual tab-bar, see ImGuiTabBarFlags_NoTabListPopupButton code, not used by docking nodes)
+ - docking: B- SetNextWindowDockId(0) with a second Begin() in the frame will asserts
+ - docking: B: resize grip drawn in host window typically appears under scrollbar.
+ - docking: B: resize grip auto-resize on multiple node hierarchy doesn't make much sense or should be improved?
+ - docking: B- SetNextWindowFocus() doesn't seem to apply if the window is hidden this frame, need repro (#4)
+ - docking: B- resizing a dock tree small currently has glitches (overlapping collapse and close button, etc.)
+ - docking: B- dpi: look at interaction with the hi-dpi and multi-dpi stuff.
+ - docking: B- tab bar: appearing on first frame with a dumb layout would do less harm that not appearing? (when behind dynamic branch) or store titles + render in EndTabBar()
+ - docking: B- tab bar: make selected tab always shows its full title?
+ - docking: B- hide close button on single tab bar?
+ - docking: B- nav: design interactions so nav controls can dock/undock
+ - docking: B- dockspace: flag to lock the dock tree and/or sizes (ImGuiDockNodeFlags_Locked?)
+ - docking: B- reintroduce collapsing a floating dock node. also collapsing a docked dock node!
+ - docking: B- allow dragging a non-floating dock node by clicking on the title-bar-looking section (not just the collapse/menu button)
+ - docking: B- option to remember undocked window size? (instead of keeping their docked size) (relate to #2104)
+ - docking: C- nav: CTRL+TAB highlighting tabs shows the mismatch between focus-stack and tab-order (not visible in VS because it doesn't highlight the tabs)
+ - docking: C- after a dock/undock, the Scrollbar Status update in Begin() should use an updated e.g. size_y_for_scrollbars to avoid a 1 frame scrollbar flicker.
 
  - tabs: "there is currently a problem because TabItem() will try to submit their own tooltip after 0.50 second, and this will have the effect of making your tooltip flicker once." -> tooltip priority work (WIP branch)
  - tabs: make EndTabBar fail if users doesn't respect BeginTabBar return value, for consistency/future-proofing.
@@ -287,6 +314,21 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - nav/windowing: Resizing window will currently fail with certain types of resizing constraints/callback applied
  - focus: preserve ActiveId/focus stack state, e.g. when opening a menu and close it, previously selected InputText() focus gets restored (#622)
 
+ - viewport: make it possible to have no main/hosting viewport (see #8268)
+ - viewport: We set ImGuiViewportFlags_NoFocusOnAppearing in a way that is required for GLFW/SDL binding, but could be handled better without
+   on a custom e.g. Win32 bindings. It prevents newly dragged-out viewports from taking the focus, which makes ALT+F4 more ambiguous.
+ - viewport: not focusing newly undocked viewport means clicking back on previous one doesn't bring OS window to front.
+ - viewport: with platform decoration enabled, platform may force constraint (e.g. minimum size)
+ - viewport: use getfocus/setfocus api to synchronize imgui<>platform focus better (e.g imgui-side ctrl-tab can focus os window, OS initial setup and alt-tab can focus imgui window etc.)
+ - viewport: store per-viewport/monitor DPI in .ini file so an application reload or main window changing DPI on reload can be properly patched for.
+ - viewport: implicit/fallback Debug window can hog a zombie viewport (harmless, noisy?) > could at least clear out the reference on a per session basis?
+ - viewport: need to clarify how to use GetMousePos() from a user point of view.
+ - viewport: could apply monitor boundaries to cliprect to coarse clip things out of monitor? (#8698)
+ - platform: glfw: no support for ImGuiBackendFlags_HasMouseHoveredViewport.
+ - platform: sdl: no support for ImGuiBackendFlags_HasMouseHoveredViewport. maybe we could use SDL_GetMouseFocus() / SDL_WINDOW_MOUSE_FOCUS if imgui could fallback on its heuristic when NoInputs is set
+ - platform: sdl: no refresh of monitor/display (SDL doesn't seem to have an event for it).
+ - platform: sdl: multi-viewport + minimized window seems to break mouse wheel events (at least under Win32).
+
  - inputs: support track pad style scrolling & slider edit.
  - inputs/io: backspace and arrows in the context of a text input could use system repeat rate.
  - inputs/io: clarify/standardize/expose repeat rate and repeat delays (#1808)

examples/example_allegro5/main.cpp

@@ -28,7 +28,7 @@ int main(int, char**)
     al_install_mouse();
     al_init_primitives_addon();
     al_set_new_display_flags(ALLEGRO_RESIZABLE);
-    ALLEGRO_DISPLAY* display = al_create_display(1280, 720);
+    ALLEGRO_DISPLAY* display = al_create_display(1280, 800);
     al_set_window_title(display, "Dear ImGui Allegro 5 example");
     ALLEGRO_EVENT_QUEUE* queue = al_create_event_queue();
     al_register_event_source(queue, al_get_display_event_source(display));
@@ -40,6 +40,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;      // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -53,7 +54,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();

examples/example_android_opengl3/android/.gitignore

@@ -1,12 +1,14 @@
-.cxx
-.externalNativeBuild
 build/
 *.iml
-
-.idea
 .gradle
+.idea
+.DS_Store
+/captures
+.externalNativeBuild
+.cxx
 local.properties
 
 # Android Studio puts a Gradle wrapper here, that we don't want:
 gradle/
+!gradle/libs.versions.toml
 gradlew*

examples/example_android_opengl3/android/app/build.gradle

@@ -1,16 +1,16 @@
-apply plugin: 'com.android.application'
-apply plugin: 'kotlin-android'
+plugins {
+    alias(libs.plugins.android.application)
+    alias(libs.plugins.kotlin.android)
+}
 
 android {
-    compileSdkVersion 33
-    buildToolsVersion "33.0.2"
-    ndkVersion "25.2.9519653"
+    namespace 'imgui.example.android'
+    compileSdk 36
 
     defaultConfig {
         applicationId "imgui.example.android"
-        namespace "imgui.example.android"
-        minSdkVersion 24
-        targetSdkVersion 33
+        minSdk 24
+        targetSdk 36
         versionCode 1
         versionName "1.0"
     }
@@ -21,26 +21,17 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android-optimize.txt')
         }
     }
-
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_11
         targetCompatibility JavaVersion.VERSION_11
     }
-
     kotlinOptions {
-        jvmTarget="11"
+        jvmTarget = '11'
     }
-
     externalNativeBuild {
         cmake {
-            path "../../CMakeLists.txt"
+            path file('../../CMakeLists.txt')
             version '3.22.1'
         }
     }
 }
-repositories {
-    mavenCentral()
-}
-dependencies {
-    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
-}

examples/example_android_opengl3/android/app/src/main/AndroidManifest.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools">
 
     <application
         android:label="ImGuiExample"

examples/example_android_opengl3/android/build.gradle

@@ -1,24 +1,5 @@
-buildscript {
-    ext.kotlin_version = '1.8.0'
-    repositories {
-        google()
-        mavenCentral()
-
-    }
-    dependencies {
-        classpath 'com.android.tools.build:gradle:7.4.1'
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-
-    }
-}
-
-allprojects {
-    repositories {
-        google()
-        mavenCentral()
-    }
-}
-
-task clean(type: Delete) {
-    delete rootProject.buildDir
+// Top-level build file where you can add configuration options common to all sub-projects/modules.
+plugins {
+    alias(libs.plugins.android.application) apply false
+    alias(libs.plugins.kotlin.android) apply false
 }

examples/example_android_opengl3/android/gradle/libs.versions.toml

@@ -0,0 +1,8 @@
+[versions]
+agp = "8.12.0"
+kotlin = "2.0.21"
+
+[plugins]
+android-application = { id = "com.android.application", version.ref = "agp" }
+kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
+

examples/example_android_opengl3/android/settings.gradle

@@ -1 +1,22 @@
+pluginManagement {
+    repositories {
+        google {
+            content {
+                includeGroupByRegex("com\\.android.*")
+                includeGroupByRegex("com\\.google.*")
+                includeGroupByRegex("androidx.*")
+            }
+        }
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
 include ':app'

examples/example_android_opengl3/main.cpp

@@ -154,7 +154,7 @@ void Init(struct android_app* app)
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     // - Android: The TTF files have to be placed into the assets/ directory (android/app/src/main/assets), we use our GetAssetData() helper to retrieve them.
 

examples/example_apple_metal/example_apple_metal.xcodeproj/project.pbxproj

@@ -7,7 +7,10 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		050450AB2768052600AB6805 /* imgui_tables.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 5079822D257677DB0038A28D /* imgui_tables.cpp */; };
+		050450AD276863B000AB6805 /* QuartzCore.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 050450AC276863B000AB6805 /* QuartzCore.framework */; };
 		05318E0F274C397200A8DE2E /* GameController.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 05318E0E274C397200A8DE2E /* GameController.framework */; };
+		05A275442773BEA20084EF39 /* QuartzCore.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 05A275432773BEA20084EF39 /* QuartzCore.framework */; };
 		07A82ED82139413D0078D120 /* imgui_widgets.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 07A82ED72139413C0078D120 /* imgui_widgets.cpp */; };
 		07A82ED92139418F0078D120 /* imgui_widgets.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 07A82ED72139413C0078D120 /* imgui_widgets.cpp */; };
 		5079822E257677DB0038A28D /* imgui_tables.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 5079822D257677DB0038A28D /* imgui_tables.cpp */; };
@@ -33,7 +36,11 @@
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
+		050450AC276863B000AB6805 /* QuartzCore.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = QuartzCore.framework; path = System/Library/Frameworks/QuartzCore.framework; sourceTree = SDKROOT; };
 		05318E0E274C397200A8DE2E /* GameController.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = GameController.framework; path = System/Library/Frameworks/GameController.framework; sourceTree = SDKROOT; };
+		05A2754027728F5B0084EF39 /* imgui_impl_metal.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = imgui_impl_metal.h; path = ../../backends/imgui_impl_metal.h; sourceTree = "<group>"; };
+		05A2754127728F5B0084EF39 /* imgui_impl_osx.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = imgui_impl_osx.h; path = ../../backends/imgui_impl_osx.h; sourceTree = "<group>"; };
+		05A275432773BEA20084EF39 /* QuartzCore.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = QuartzCore.framework; path = Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS15.2.sdk/System/Library/Frameworks/QuartzCore.framework; sourceTree = DEVELOPER_DIR; };
 		07A82ED62139413C0078D120 /* imgui_internal.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = imgui_internal.h; path = ../../imgui_internal.h; sourceTree = "<group>"; };
 		07A82ED72139413C0078D120 /* imgui_widgets.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = imgui_widgets.cpp; path = ../../imgui_widgets.cpp; sourceTree = "<group>"; };
 		5079822D257677DB0038A28D /* imgui_tables.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = imgui_tables.cpp; path = ../../imgui_tables.cpp; sourceTree = "<group>"; };
@@ -66,6 +73,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				05A275442773BEA20084EF39 /* QuartzCore.framework in Frameworks */,
 				8309BD8F253CCAAA0045E2A1 /* UIKit.framework in Frameworks */,
 				83BBE9E720EB46BD00295997 /* MetalKit.framework in Frameworks */,
 				83BBE9E520EB46B900295997 /* Metal.framework in Frameworks */,
@@ -76,6 +84,7 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				050450AD276863B000AB6805 /* QuartzCore.framework in Frameworks */,
 				8309BDC6253CCCFE0045E2A1 /* AppKit.framework in Frameworks */,
 				83BBE9EC20EB471700295997 /* MetalKit.framework in Frameworks */,
 				05318E0F274C397200A8DE2E /* GameController.framework in Frameworks */,
@@ -136,6 +145,8 @@
 		83BBE9E320EB46B800295997 /* Frameworks */ = {
 			isa = PBXGroup;
 			children = (
+				050450AC276863B000AB6805 /* QuartzCore.framework */,
+				05A275432773BEA20084EF39 /* QuartzCore.framework */,
 				05318E0E274C397200A8DE2E /* GameController.framework */,
 				8309BDC5253CCCFE0045E2A1 /* AppKit.framework */,
 				8309BD8E253CCAAA0045E2A1 /* UIKit.framework */,
@@ -153,7 +164,9 @@
 			isa = PBXGroup;
 			children = (
 				5079822D257677DB0038A28D /* imgui_tables.cpp */,
+				05A2754027728F5B0084EF39 /* imgui_impl_metal.h */,
 				8309BDB5253CCC9D0045E2A1 /* imgui_impl_metal.mm */,
+				05A2754127728F5B0084EF39 /* imgui_impl_osx.h */,
 				8309BDB6253CCC9D0045E2A1 /* imgui_impl_osx.mm */,
 				83BBEA0420EB54E700295997 /* imconfig.h */,
 				83BBEA0320EB54E700295997 /* imgui.cpp */,
@@ -285,7 +298,7 @@
 				83BBEA0A20EB54E700295997 /* imgui.cpp in Sources */,
 				83BBEA0820EB54E700295997 /* imgui_demo.cpp in Sources */,
 				83BBEA0620EB54E700295997 /* imgui_draw.cpp in Sources */,
-				5079822E257677DB0038A28D /* imgui_tables.cpp in Sources */,
+				050450AB2768052600AB6805 /* imgui_tables.cpp in Sources */,
 				07A82ED92139418F0078D120 /* imgui_widgets.cpp in Sources */,
 				8309BDA8253CCC080045E2A1 /* main.mm in Sources */,
 			);

examples/example_apple_metal/main.mm

@@ -60,11 +60,21 @@
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Renderer backend
     ImGui_ImplMetal_Init(_device);
 
@@ -73,7 +83,7 @@
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -94,7 +104,7 @@
 
 -(void)loadView
 {
-    self.view = [[MTKView alloc] initWithFrame:CGRectMake(0, 0, 1200, 720)];
+    self.view = [[MTKView alloc] initWithFrame:CGRectMake(0, 0, 1200, 800)];
 }
 
 -(void)viewDidLoad
@@ -195,6 +205,13 @@
     // Present
     [commandBuffer presentDrawable:view.currentDrawable];
     [commandBuffer commit];
+
+    // Update and Render additional Platform Windows
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
 }
 
 -(void)mtkView:(MTKView*)view drawableSizeWillChange:(CGSize)size

examples/example_apple_opengl2/main.mm

@@ -6,6 +6,8 @@
 // - Documentation        https://dearimgui.com/docs (same as your local docs/ folder).
 // - Introduction, links and more at the top of imgui.cpp
 
+// FIXME: Multi-viewports is not yet functional in this example. May need backend rework/coordination.
+
 #import <Cocoa/Cocoa.h>
 #import <OpenGL/gl.h>
 #import <OpenGL/glu.h>
@@ -47,11 +49,21 @@
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplOSX_Init(self);
     ImGui_ImplOpenGL2_Init();
@@ -61,7 +73,7 @@
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -136,6 +148,13 @@
 
     ImGui_ImplOpenGL2_RenderDrawData(draw_data);
 
+    // Update and Render additional Platform Windows
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
+
     // Present
     [[self openGLContext] flushBuffer];
 
@@ -171,7 +190,7 @@
     if (_window != nil)
         return (_window);
 
-    NSRect viewRect = NSMakeRect(100.0, 100.0, 100.0 + 1280.0, 100 + 720.0);
+    NSRect viewRect = NSMakeRect(100.0, 100.0, 100.0 + 1280.0, 100 + 800.0);
 
     _window = [[NSWindow alloc] initWithContentRect:viewRect styleMask:NSWindowStyleMaskTitled|NSWindowStyleMaskMiniaturizable|NSWindowStyleMaskResizable|NSWindowStyleMaskClosable backing:NSBackingStoreBuffered defer:YES];
     [_window setTitle:@"Dear ImGui OSX+OpenGL2 Example"];

examples/example_glfw_metal/main.mm

@@ -27,23 +27,57 @@ static void glfw_error_callback(int error, const char* description)
 
 int main(int, char**)
 {
+    glfwSetErrorCallback(glfw_error_callback);
+    if (!glfwInit())
+        return 1;
+
+    // Create window with graphics context
+    float main_scale = ImGui_ImplGlfw_GetContentScaleForMonitor(glfwGetPrimaryMonitor()); // Valid on GLFW 3.3+ only
+    glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
+    GLFWwindow* window = glfwCreateWindow((int)(1280 * main_scale), (int)(800 * main_scale), "Dear ImGui GLFW+Metal example", nullptr, nullptr);
+    if (window == nullptr)
+        return 1;
+
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
-    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
-    io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
 
-    // Setup style
+    // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
+    id <MTLDevice> device = MTLCreateSystemDefaultDevice();
+    id <MTLCommandQueue> commandQueue = [device newCommandQueue];
+
+    // Setup Platform/Renderer backends
+    ImGui_ImplGlfw_InitForOpenGL(window, true);
+    ImGui_ImplMetal_Init(device);
+
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -54,24 +88,6 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf");
     //IM_ASSERT(font != nullptr);
 
-    // Setup window
-    glfwSetErrorCallback(glfw_error_callback);
-    if (!glfwInit())
-        return 1;
-
-    // Create window with graphics context
-    glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
-    GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+Metal example", nullptr, nullptr);
-    if (window == nullptr)
-        return 1;
-
-    id <MTLDevice> device = MTLCreateSystemDefaultDevice();
-    id <MTLCommandQueue> commandQueue = [device newCommandQueue];
-
-    // Setup Platform/Renderer backends
-    ImGui_ImplGlfw_InitForOpenGL(window, true);
-    ImGui_ImplMetal_Init(device);
-
     NSWindow *nswin = glfwGetCocoaWindow(window);
     CAMetalLayer *layer = [CAMetalLayer layer];
     layer.device = device;
@@ -157,6 +173,13 @@ int main(int, char**)
             ImGui::Render();
             ImGui_ImplMetal_RenderDrawData(ImGui::GetDrawData(), commandBuffer, renderEncoder);
 
+            // Update and Render additional Platform Windows
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                ImGui::UpdatePlatformWindows();
+                ImGui::RenderPlatformWindowsDefault();
+            }
+
             [renderEncoder popDebugGroup];
             [renderEncoder endEncoding];
 

examples/example_glfw_opengl2/Makefile

@@ -21,6 +21,7 @@ SOURCES += $(IMGUI_DIR)/imgui.cpp $(IMGUI_DIR)/imgui_demo.cpp $(IMGUI_DIR)/imgui
 SOURCES += $(IMGUI_DIR)/backends/imgui_impl_glfw.cpp $(IMGUI_DIR)/backends/imgui_impl_opengl2.cpp
 OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES))))
 UNAME_S := $(shell uname -s)
+LINUX_GL_LIBS = -lGL
 
 CXXFLAGS = -std=c++11 -I$(IMGUI_DIR) -I$(IMGUI_DIR)/backends
 CXXFLAGS += -g -Wall -Wformat
@@ -32,7 +33,7 @@ LIBS =
 
 ifeq ($(UNAME_S), Linux) #LINUX
 	ECHO_MESSAGE = "Linux"
-	LIBS += -lGL `pkg-config --static --libs glfw3`
+	LIBS += $(LINUX_GL_LIBS) -lX11 `pkg-config --static --libs glfw3`
 
 	CXXFLAGS += `pkg-config --cflags glfw3`
 	CFLAGS = $(CXXFLAGS)

examples/example_glfw_opengl2/main.cpp

@@ -40,7 +40,8 @@ int main(int, char**)
         return 1;
 
     // Create window with graphics context
-    GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+OpenGL2 example", nullptr, nullptr);
+    float main_scale = ImGui_ImplGlfw_GetContentScaleForMonitor(glfwGetPrimaryMonitor()); // Valid on GLFW 3.3+ only
+    GLFWwindow* window = glfwCreateWindow((int)(1280 * main_scale), (int)(800 * main_scale), "Dear ImGui GLFW+OpenGL2 example", nullptr, nullptr);
     if (window == nullptr)
         return 1;
     glfwMakeContextCurrent(window);
@@ -52,11 +53,29 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplGlfw_InitForOpenGL(window, true);
     ImGui_ImplOpenGL2_Init();
@@ -66,7 +85,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -155,6 +174,17 @@ int main(int, char**)
         ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
         //glUseProgram(last_program);
 
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            GLFWwindow* backup_current_context = glfwGetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            glfwMakeContextCurrent(backup_current_context);
+        }
+
         glfwMakeContextCurrent(window);
         glfwSwapBuffers(window);
     }

examples/example_glfw_opengl3/Makefile

@@ -41,7 +41,7 @@ LIBS =
 
 ifeq ($(UNAME_S), Linux) #LINUX
 	ECHO_MESSAGE = "Linux"
-	LIBS += $(LINUX_GL_LIBS) `pkg-config --static --libs glfw3`
+	LIBS += $(LINUX_GL_LIBS) -lX11 `pkg-config --static --libs glfw3`
 
 	CXXFLAGS += `pkg-config --cflags glfw3`
 	CFLAGS = $(CXXFLAGS)

examples/example_glfw_opengl3/main.cpp

@@ -84,6 +84,10 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -93,6 +97,17 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+#if GLFW_VERSION_MAJOR >= 3 && GLFW_VERSION_MINOR >= 3
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+#endif
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplGlfw_InitForOpenGL(window, true);
@@ -106,7 +121,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     // - Our Emscripten build process allows embedding fonts to be accessible at runtime from the "fonts/" folder. See Makefile.emscripten for details.
     //style.FontSizeBase = 20.0f;
@@ -196,6 +211,17 @@ int main(int, char**)
         glClear(GL_COLOR_BUFFER_BIT);
         ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            GLFWwindow* backup_current_context = glfwGetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            glfwMakeContextCurrent(backup_current_context);
+        }
+
         glfwSwapBuffers(window);
     }
 #ifdef __EMSCRIPTEN__

examples/example_glfw_vulkan/CMakeLists.txt

@@ -36,6 +36,7 @@ find_package(Vulkan REQUIRED)
   #NAMES vulkan vulkan-1)
 #set(LIBRARIES "glfw;${VULKAN_LIBRARY}")
 set(LIBRARIES "glfw;Vulkan::Vulkan")
+# FIXME: Linux needs linking with "X11" as well?
 
 # Use vulkan headers from glfw:
 include_directories(${GLFW_DIR}/deps)

examples/example_glfw_vulkan/Makefile

@@ -33,7 +33,7 @@ LIBS =
 
 ifeq ($(UNAME_S), Linux) #LINUX
 	ECHO_MESSAGE = "Linux"
-	LIBS += $(LINUX_GL_LIBS) `pkg-config --static --libs glfw3 vulkan`
+	LIBS += $(LINUX_GL_LIBS) -lX11 `pkg-config --static --libs glfw3 vulkan`
 
 	CXXFLAGS += `pkg-config --cflags glfw3 vulkan`
 	CFLAGS = $(CXXFLAGS)

examples/example_glfw_vulkan/main.cpp

@@ -239,7 +239,7 @@ static void SetupVulkanWindow(ImGui_ImplVulkanH_Window* wd, VkSurfaceKHR surface
 
     // Create SwapChain, RenderPass, Framebuffer, etc.
     IM_ASSERT(g_MinImageCount >= 2);
-    ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
+    ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, width, height, g_MinImageCount, 0);
 }
 
 static void CleanupVulkan()
@@ -357,7 +357,8 @@ int main(int, char**)
 
     // Create window with Vulkan context
     glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
-    GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+Vulkan example", nullptr, nullptr);
+    float main_scale = ImGui_ImplGlfw_GetContentScaleForMonitor(glfwGetPrimaryMonitor()); // Valid on GLFW 3.3+ only
+    GLFWwindow* window = glfwCreateWindow((int)(1280 * main_scale), (int)(800 * main_scale), "Dear ImGui GLFW+Vulkan example", nullptr, nullptr);
     if (!glfwVulkanSupported())
     {
         printf("GLFW: Vulkan Not Supported\n");
@@ -388,11 +389,29 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplGlfw_InitForVulkan(window, true);
     ImGui_ImplVulkan_InitInfo init_info = {};
@@ -404,12 +423,12 @@ int main(int, char**)
     init_info.Queue = g_Queue;
     init_info.PipelineCache = g_PipelineCache;
     init_info.DescriptorPool = g_DescriptorPool;
-    init_info.RenderPass = wd->RenderPass;
-    init_info.Subpass = 0;
     init_info.MinImageCount = g_MinImageCount;
     init_info.ImageCount = wd->ImageCount;
-    init_info.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
     init_info.Allocator = g_Allocator;
+    init_info.PipelineInfoMain.RenderPass = wd->RenderPass;
+    init_info.PipelineInfoMain.Subpass = 0;
+    init_info.PipelineInfoMain.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
     init_info.CheckVkResultFn = check_vk_result;
     ImGui_ImplVulkan_Init(&init_info);
 
@@ -418,7 +437,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -450,7 +469,7 @@ int main(int, char**)
         if (fb_width > 0 && fb_height > 0 && (g_SwapChainRebuild || g_MainWindowData.Width != fb_width || g_MainWindowData.Height != fb_height))
         {
             ImGui_ImplVulkan_SetMinImageCount(g_MinImageCount);
-            ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, fb_width, fb_height, g_MinImageCount);
+            ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, fb_width, fb_height, g_MinImageCount, 0);
             g_MainWindowData.FrameIndex = 0;
             g_SwapChainRebuild = false;
         }
@@ -504,17 +523,25 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
-        ImDrawData* draw_data = ImGui::GetDrawData();
-        const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
-        if (!is_minimized)
+        ImDrawData* main_draw_data = ImGui::GetDrawData();
+        const bool main_is_minimized = (main_draw_data->DisplaySize.x <= 0.0f || main_draw_data->DisplaySize.y <= 0.0f);
+        wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
+        wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
+        wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
+        wd->ClearValue.color.float32[3] = clear_color.w;
+        if (!main_is_minimized)
+            FrameRender(wd, main_draw_data);
+
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
         {
-            wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
-            wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
-            wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
-            wd->ClearValue.color.float32[3] = clear_color.w;
-            FrameRender(wd, draw_data);
-            FramePresent(wd);
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
         }
+
+        // Present Main Platform Window
+        if (!main_is_minimized)
+            FramePresent(wd);
     }
 
     // Cleanup

examples/example_glfw_wgpu/main.cpp

@@ -1,4 +1,4 @@
-// Dear ImGui: standalone example application for using GLFW + WebGPU
+// Dear ImGui: standalone example application for GLFW + WebGPU
 // - Emscripten is supported for publishing on web. See https://emscripten.org.
 // - Dawn is used as a WebGPU implementation on desktop.
 
@@ -12,36 +12,32 @@
 #include "imgui_impl_glfw.h"
 #include "imgui_impl_wgpu.h"
 #include <stdio.h>
+#include <GLFW/glfw3.h>
 
+// This example can also compile and run with Emscripten! See 'Makefile.emscripten' for details.
 #ifdef __EMSCRIPTEN__
 #include <emscripten.h>
 #include <emscripten/html5.h>
 #include <emscripten/html5_webgpu.h>
+#include "../libs/emscripten/emscripten_mainloop_stub.h"
 #else
 #include <webgpu/webgpu_glfw.h>
 #endif
-
-#include <GLFW/glfw3.h>
 #include <webgpu/webgpu.h>
 #include <webgpu/webgpu_cpp.h>
 
-// This example can also compile and run with Emscripten! See 'Makefile.emscripten' for details.
-#ifdef __EMSCRIPTEN__
-#include "../libs/emscripten/emscripten_mainloop_stub.h"
-#endif
-
-// Global WebGPU required states
+// Data
 static WGPUInstance      wgpu_instance = nullptr;
 static WGPUDevice        wgpu_device = nullptr;
 static WGPUSurface       wgpu_surface = nullptr;
 static WGPUTextureFormat wgpu_preferred_fmt = WGPUTextureFormat_RGBA8Unorm;
 static WGPUSwapChain     wgpu_swap_chain = nullptr;
-static int               wgpu_swap_chain_width = 1280;
-static int               wgpu_swap_chain_height = 720;
+static int               wgpu_surface_width = 1280;
+static int               wgpu_surface_height = 800;
 
 // Forward declarations
 static bool InitWGPU(GLFWwindow* window);
-static void CreateSwapChain(int width, int height);
+static void ResizeSurface(int width, int height);
 
 static void glfw_error_callback(int error, const char* description)
 {
@@ -72,19 +68,23 @@ int main(int, char**)
     // Make sure GLFW does not initialize any graphics context.
     // This needs to be done explicitly later.
     glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
-    GLFWwindow* window = glfwCreateWindow(wgpu_swap_chain_width, wgpu_swap_chain_height, "Dear ImGui GLFW+WebGPU example", nullptr, nullptr);
+
+    // Create window
+    float main_scale = ImGui_ImplGlfw_GetContentScaleForMonitor(glfwGetPrimaryMonitor()); // Valid on GLFW 3.3+ only
+    wgpu_surface_width *= main_scale;
+    wgpu_surface_height *= main_scale;
+    GLFWwindow* window = glfwCreateWindow(wgpu_surface_width, wgpu_surface_height, "Dear ImGui GLFW+WebGPU example", nullptr, nullptr);
     if (window == nullptr)
         return 1;
 
     // Initialize the WebGPU environment
     if (!InitWGPU(window))
     {
-        if (window)
-            glfwDestroyWindow(window);
+        glfwDestroyWindow(window);
         glfwTerminate();
         return 1;
     }
-    CreateSwapChain(wgpu_swap_chain_width, wgpu_swap_chain_height);
+    ResizeSurface(wgpu_surface_width, wgpu_surface_height);
     glfwShowWindow(window);
 
     // Setup Dear ImGui context
@@ -93,11 +93,17 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+
     // Setup Platform/Renderer backends
     ImGui_ImplGlfw_InitForOther(window, true);
 #ifdef __EMSCRIPTEN__
@@ -115,17 +121,16 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
-    // - Emscripten allows preloading a file or folder to be accessible at runtime. See Makefile for details.
-    //io.Fonts->AddFontDefault();
+    // - Our Emscripten build process allows embedding fonts to be accessible at runtime from the "fonts/" folder. See Makefile.emscripten for details.
     //style.FontSizeBase = 20.0f;
+    //io.Fonts->AddFontDefault();
 #ifndef IMGUI_DISABLE_FILE_FUNCTIONS
     //io.Fonts->AddFontFromFileTTF("fonts/segoeui.ttf");
     //io.Fonts->AddFontFromFileTTF("fonts/DroidSans.ttf");
     //io.Fonts->AddFontFromFileTTF("fonts/Roboto-Medium.ttf");
     //io.Fonts->AddFontFromFileTTF("fonts/Cousine-Regular.ttf");
-    //io.Fonts->AddFontFromFileTTF("fonts/ProggyTiny.ttf");
     //ImFont* font = io.Fonts->AddFontFromFileTTF("fonts/ArialUni.ttf");
     //IM_ASSERT(font != nullptr);
 #endif
@@ -160,10 +165,10 @@ int main(int, char**)
         // React to changes in screen size
         int width, height;
         glfwGetFramebufferSize((GLFWwindow*)window, &width, &height);
-        if (width != wgpu_swap_chain_width || height != wgpu_swap_chain_height)
+        if (width != wgpu_surface_width || height != wgpu_surface_height)
         {
             ImGui_ImplWGPU_InvalidateDeviceObjects();
-            CreateSwapChain(width, height);
+            ResizeSurface(width, height);
             ImGui_ImplWGPU_CreateDeviceObjects();
         }
 
@@ -238,8 +243,8 @@ int main(int, char**)
 
         WGPUCommandBufferDescriptor cmd_buffer_desc = {};
         WGPUCommandBuffer cmd_buffer = wgpuCommandEncoderFinish(encoder, &cmd_buffer_desc);
-        WGPUQueue queue = wgpuDeviceGetQueue(wgpu_device);
-        wgpuQueueSubmit(queue, 1, &cmd_buffer);
+        WGPUQueue wgpu_queue = wgpuDeviceGetQueue(wgpu_device);
+        wgpuQueueSubmit(wgpu_queue, 1, &cmd_buffer);
 
 #ifndef __EMSCRIPTEN__
         wgpuSwapChainPresent(wgpu_swap_chain);
@@ -311,10 +316,10 @@ static bool InitWGPU(GLFWwindow* window)
 #endif
 
 #ifdef __EMSCRIPTEN__
-    wgpu::SurfaceDescriptorFromCanvasHTMLSelector html_surface_desc = {};
-    html_surface_desc.selector = "#canvas";
+    wgpu::SurfaceDescriptorFromCanvasHTMLSelector canvas_desc = {};
+    canvas_desc.selector = "#canvas";
     wgpu::SurfaceDescriptor surface_desc = {};
-    surface_desc.nextInChain = &html_surface_desc;
+    surface_desc.nextInChain = &canvas_desc;
     wgpu::Surface surface = instance.CreateSurface(&surface_desc);
 
     wgpu::Adapter adapter = {};
@@ -326,6 +331,7 @@ static bool InitWGPU(GLFWwindow* window)
     wgpu_preferred_fmt = WGPUTextureFormat_BGRA8Unorm;
 #endif
 
+    // Moving Dawn objects into WGPU handles
     wgpu_instance = instance.MoveToCHandle();
     wgpu_surface = surface.MoveToCHandle();
 
@@ -334,12 +340,12 @@ static bool InitWGPU(GLFWwindow* window)
     return true;
 }
 
-static void CreateSwapChain(int width, int height)
+static void ResizeSurface(int width, int height)
 {
     if (wgpu_swap_chain)
         wgpuSwapChainRelease(wgpu_swap_chain);
-    wgpu_swap_chain_width = width;
-    wgpu_swap_chain_height = height;
+    wgpu_surface_width = width;
+    wgpu_surface_height = height;
     WGPUSwapChainDescriptor swap_chain_desc = {};
     swap_chain_desc.usage = WGPUTextureUsage_RenderAttachment;
     swap_chain_desc.format = wgpu_preferred_fmt;

examples/example_glut_opengl2/main.cpp

@@ -48,7 +48,7 @@ int main(int argc, char** argv)
     glutSetOption(GLUT_ACTION_ON_WINDOW_CLOSE, GLUT_ACTION_GLUTMAINLOOP_RETURNS);
 #endif
     glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_MULTISAMPLE);
-    glutInitWindowSize(1280, 720);
+    glutInitWindowSize(1280, 800);
     glutCreateWindow("Dear ImGui GLUT+OpenGL2 Example");
 
     // Setup GLUT display function
@@ -61,6 +61,7 @@ int main(int argc, char** argv)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -78,13 +79,12 @@ int main(int argc, char** argv)
     // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
     ImGui_ImplGLUT_InstallFuncs();
 
-
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();

examples/example_sdl2_directx11/main.cpp

@@ -39,7 +39,7 @@ int main(int, char**)
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // From 2.0.18: Enable native IME.
@@ -50,11 +50,11 @@ int main(int, char**)
     // Setup window
     float main_scale = ImGui_ImplSDL2_GetContentScaleForDisplay(0);
     SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+DirectX11 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(720 * main_scale), window_flags);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+DirectX11 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
     if (window == nullptr)
     {
         printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     SDL_SysWMinfo wmInfo;
@@ -75,6 +75,10 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -84,6 +88,15 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForD3D(window);
@@ -94,7 +107,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -190,6 +203,13 @@ int main(int, char**)
         g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         g_pSwapChain->Present(1, 0); // Present with vsync
         //g_pSwapChain->Present(0, 0); // Present without vsync
     }
@@ -230,9 +250,19 @@ bool CreateDeviceD3D(HWND hWnd)
     //createDeviceFlags |= D3D11_CREATE_DEVICE_DEBUG;
     D3D_FEATURE_LEVEL featureLevel;
     const D3D_FEATURE_LEVEL featureLevelArray[2] = { D3D_FEATURE_LEVEL_11_0, D3D_FEATURE_LEVEL_10_0, };
-    if (D3D11CreateDeviceAndSwapChain(nullptr, D3D_DRIVER_TYPE_HARDWARE, nullptr, createDeviceFlags, featureLevelArray, 2, D3D11_SDK_VERSION, &sd, &g_pSwapChain, &g_pd3dDevice, &featureLevel, &g_pd3dDeviceContext) != S_OK)
+    HRESULT res = D3D11CreateDeviceAndSwapChain(nullptr, D3D_DRIVER_TYPE_HARDWARE, nullptr, createDeviceFlags, featureLevelArray, 2, D3D11_SDK_VERSION, &sd, &g_pSwapChain, &g_pd3dDevice, &featureLevel, &g_pd3dDeviceContext);
+    if (res == DXGI_ERROR_UNSUPPORTED) // Try high-performance WARP software driver if hardware is not available.
+        res = D3D11CreateDeviceAndSwapChain(nullptr, D3D_DRIVER_TYPE_WARP, nullptr, createDeviceFlags, featureLevelArray, 2, D3D11_SDK_VERSION, &sd, &g_pSwapChain, &g_pd3dDevice, &featureLevel, &g_pd3dDeviceContext);
+    if (res != S_OK)
         return false;
 
+    // Disable DXGI's default Alt+Enter fullscreen behavior.
+    // - You are free to leave this enabled, but it will not work properly with multiple viewports.
+    // - This must be done for all windows associated to the device. Our DX11 backend does this automatically for secondary viewports that it creates.
+    IDXGIFactory* pSwapChainFactory;
+    if (SUCCEEDED(g_pSwapChain->GetParent(IID_PPV_ARGS(&pSwapChainFactory))))
+        pSwapChainFactory->MakeWindowAssociation(hWnd, DXGI_MWA_NO_ALT_ENTER);
+
     CreateRenderTarget();
     return true;
 }

examples/example_sdl2_metal/main.mm

@@ -24,17 +24,27 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;      // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;    // Enable Multi-Viewport / Platform Windows
 
     // Setup style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -51,7 +61,7 @@ int main(int, char**)
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // Inform SDL that we will be using metal for rendering. Without this hint initialization of metal renderer may fail.
@@ -60,7 +70,7 @@ int main(int, char**)
     // Enable native IME.
     SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
 
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL+Metal example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL+Metal example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 800, SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
     if (window == nullptr)
     {
         printf("Error creating window: %s\n", SDL_GetError());
@@ -168,6 +178,13 @@ int main(int, char**)
             ImGui::Render();
             ImGui_ImplMetal_RenderDrawData(ImGui::GetDrawData(), commandBuffer, renderEncoder);
 
+            // Update and Render additional Platform Windows
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                ImGui::UpdatePlatformWindows();
+                ImGui::RenderPlatformWindowsDefault();
+            }
+
             [renderEncoder popDebugGroup];
             [renderEncoder endEncoding];
 

examples/example_sdl2_opengl2/main.cpp

@@ -31,7 +31,7 @@ int main(int, char**)
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // From 2.0.18: Enable native IME.
@@ -47,11 +47,11 @@ int main(int, char**)
     SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
     float main_scale = ImGui_ImplSDL2_GetContentScaleForDisplay(0);
     SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(720 * main_scale), window_flags);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
     if (window == nullptr)
     {
         printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     SDL_GLContext gl_context = SDL_GL_CreateContext(window);
@@ -64,6 +64,10 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -73,6 +77,15 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
@@ -83,7 +96,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -172,6 +185,19 @@ int main(int, char**)
         glClear(GL_COLOR_BUFFER_BIT);
         //glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context where shaders may be bound
         ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
+
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
+            SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
+        }
+
         SDL_GL_SwapWindow(window);
     }
 

examples/example_sdl2_opengl3/main.cpp

@@ -36,7 +36,7 @@ int main(int, char**)
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // Decide GL+GLSL versions
@@ -81,18 +81,18 @@ int main(int, char**)
     SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
     float main_scale = ImGui_ImplSDL2_GetContentScaleForDisplay(0);
     SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(720 * main_scale), window_flags);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
     if (window == nullptr)
     {
         printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     SDL_GLContext gl_context = SDL_GL_CreateContext(window);
     if (gl_context == nullptr)
     {
         printf("Error: SDL_GL_CreateContext(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     SDL_GL_MakeCurrent(window, gl_context);
@@ -104,6 +104,10 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -113,6 +117,15 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
@@ -123,7 +136,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     // - Our Emscripten build process allows embedding fonts to be accessible at runtime from the "fonts/" folder. See Makefile.emscripten for details.
     //style.FontSizeBase = 20.0f;
@@ -219,6 +232,19 @@ int main(int, char**)
         glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
         glClear(GL_COLOR_BUFFER_BIT);
         ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
+            SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
+        }
+
         SDL_GL_SwapWindow(window);
     }
 #ifdef __EMSCRIPTEN__

examples/example_sdl2_sdlrenderer2/main.cpp

@@ -33,7 +33,7 @@ int main(int, char**)
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // From 2.0.18: Enable native IME.
@@ -44,17 +44,17 @@ int main(int, char**)
     // Create window with SDL_Renderer graphics context
     float main_scale = ImGui_ImplSDL2_GetContentScaleForDisplay(0);
     SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+SDL_Renderer example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(720 * main_scale), window_flags);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+SDL_Renderer example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
     if (window == nullptr)
     {
         printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
     SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);
     if (renderer == nullptr)
     {
         SDL_Log("Error creating SDL_Renderer!");
-        return -1;
+        return 1;
     }
     //SDL_RendererInfo info;
     //SDL_GetRendererInfo(renderer, &info);
@@ -66,6 +66,7 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -75,6 +76,8 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForSDLRenderer(window, renderer);
@@ -85,7 +88,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();

examples/example_sdl2_vulkan/main.cpp

@@ -230,7 +230,7 @@ static void SetupVulkanWindow(ImGui_ImplVulkanH_Window* wd, VkSurfaceKHR surface
 
     // Create SwapChain, RenderPass, Framebuffer, etc.
     IM_ASSERT(g_MinImageCount >= 2);
-    ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
+    ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, width, height, g_MinImageCount, 0);
 }
 
 static void CleanupVulkan()
@@ -349,7 +349,7 @@ int main(int, char**)
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // From 2.0.18: Enable native IME.
@@ -360,11 +360,11 @@ int main(int, char**)
     // Create window with Vulkan graphics context
     float main_scale = ImGui_ImplSDL2_GetContentScaleForDisplay(0);
     SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_VULKAN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+Vulkan example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(720 * main_scale), window_flags);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+Vulkan example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
     if (window == nullptr)
     {
         printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     ImVector<const char*> extensions;
@@ -395,6 +395,10 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
+    //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -404,6 +408,15 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForVulkan(window);
@@ -416,12 +429,12 @@ int main(int, char**)
     init_info.Queue = g_Queue;
     init_info.PipelineCache = g_PipelineCache;
     init_info.DescriptorPool = g_DescriptorPool;
-    init_info.RenderPass = wd->RenderPass;
-    init_info.Subpass = 0;
     init_info.MinImageCount = g_MinImageCount;
     init_info.ImageCount = wd->ImageCount;
-    init_info.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
     init_info.Allocator = g_Allocator;
+    init_info.PipelineInfoMain.RenderPass = wd->RenderPass;
+    init_info.PipelineInfoMain.Subpass = 0;
+    init_info.PipelineInfoMain.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
     init_info.CheckVkResultFn = check_vk_result;
     ImGui_ImplVulkan_Init(&init_info);
 
@@ -430,7 +443,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -476,7 +489,7 @@ int main(int, char**)
         if (fb_width > 0 && fb_height > 0 && (g_SwapChainRebuild || g_MainWindowData.Width != fb_width || g_MainWindowData.Height != fb_height))
         {
             ImGui_ImplVulkan_SetMinImageCount(g_MinImageCount);
-            ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, fb_width, fb_height, g_MinImageCount);
+            ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, fb_width, fb_height, g_MinImageCount, 0);
             g_MainWindowData.FrameIndex = 0;
             g_SwapChainRebuild = false;
         }
@@ -525,17 +538,25 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
-        ImDrawData* draw_data = ImGui::GetDrawData();
-        const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
-        if (!is_minimized)
+        ImDrawData* main_draw_data = ImGui::GetDrawData();
+        const bool main_is_minimized = (main_draw_data->DisplaySize.x <= 0.0f || main_draw_data->DisplaySize.y <= 0.0f);
+        wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
+        wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
+        wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
+        wd->ClearValue.color.float32[3] = clear_color.w;
+        if (!main_is_minimized)
+            FrameRender(wd, main_draw_data);
+
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
         {
-            wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
-            wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
-            wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
-            wd->ClearValue.color.float32[3] = clear_color.w;
-            FrameRender(wd, draw_data);
-            FramePresent(wd);
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
         }
+
+        // Present Main Platform Window
+        if (!main_is_minimized)
+            FramePresent(wd);
     }
 
     // Cleanup

examples/example_sdl3_directx11/build_win32.bat

@@ -0,0 +1,8 @@
+@REM Build for Visual Studio compiler. Run your copy of vcvars32.bat or vcvarsall.bat to setup command-line compiler.
+@set OUT_DIR=Debug
+@set OUT_EXE=example_sdl3_directx11
+@set INCLUDES=/I..\.. /I..\..\backends /I%SDL3_DIR%\include /I "%WindowsSdkDir%Include\um" /I "%WindowsSdkDir%Include\shared" /I "%DXSDK_DIR%Include"
+@set SOURCES=main.cpp ..\..\backends\imgui_impl_sdl3.cpp ..\..\backends\imgui_impl_dx11.cpp ..\..\imgui*.cpp
+@set LIBS=/LIBPATH:%SDL3_DIR%\lib\x86 SDL3.lib /LIBPATH:"%DXSDK_DIR%/Lib/x86" d3d11.lib d3dcompiler.lib shell32.lib
+mkdir %OUT_DIR%
+cl /nologo /Zi /MD /utf-8 %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console

examples/example_sdl3_directx11/example_sdl3_directx11.vcxproj

@@ -0,0 +1,187 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{009DAC16-1A9C-47BE-9770-A30A046E8090}</ProjectGuid>
+    <RootNamespace>example_sdl3_directx11</RootNamespace>
+    <WindowsTargetPlatformVersion>8.1</WindowsTargetPlatformVersion>
+    <ProjectName>example_sdl3_directx11</ProjectName>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <OutDir>$(ProjectDir)$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)$(Configuration)\</IntDir>
+    <IncludePath>$(IncludePath)</IncludePath>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <OutDir>$(ProjectDir)$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)$(Configuration)\</IntDir>
+    <IncludePath>$(IncludePath)</IncludePath>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <OutDir>$(ProjectDir)$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)$(Configuration)\</IntDir>
+    <IncludePath>$(IncludePath)</IncludePath>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <OutDir>$(ProjectDir)$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)$(Configuration)\</IntDir>
+    <IncludePath>$(IncludePath)</IncludePath>
+  </PropertyGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+    <Link>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>%SDL3_DIR%\lib\x86;$(DXSDK_DIR)/Lib/x86;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>SDL3.lib;d3d11.lib;d3dcompiler.lib;dxgi.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <SubSystem>Console</SubSystem>
+      <IgnoreSpecificDefaultLibraries>msvcrt.lib</IgnoreSpecificDefaultLibraries>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+    <Link>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>%SDL3_DIR%\lib\x64;$(DXSDK_DIR)/Lib/x64;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>SDL3.lib;d3d11.lib;d3dcompiler.lib;dxgi.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <SubSystem>Console</SubSystem>
+      <IgnoreSpecificDefaultLibraries>msvcrt.lib</IgnoreSpecificDefaultLibraries>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+    <Link>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalLibraryDirectories>%SDL3_DIR%\lib\x86;$(DXSDK_DIR)/Lib/x86;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>SDL3.lib;d3d11.lib;d3dcompiler.lib;dxgi.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <SubSystem>Console</SubSystem>
+      <IgnoreSpecificDefaultLibraries>
+      </IgnoreSpecificDefaultLibraries>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+    <Link>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalLibraryDirectories>%SDL3_DIR%\lib\x64;$(DXSDK_DIR)/Lib/x64;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>SDL3.lib;d3d11.lib;d3dcompiler.lib;dxgi.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <SubSystem>Console</SubSystem>
+      <IgnoreSpecificDefaultLibraries>
+      </IgnoreSpecificDefaultLibraries>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\imgui.cpp" />
+    <ClCompile Include="..\..\imgui_demo.cpp" />
+    <ClCompile Include="..\..\imgui_draw.cpp" />
+    <ClCompile Include="..\..\imgui_tables.cpp" />
+    <ClCompile Include="..\..\imgui_widgets.cpp" />
+    <ClCompile Include="..\..\backends\imgui_impl_sdl3.cpp" />
+    <ClCompile Include="..\..\backends\imgui_impl_dx11.cpp" />
+    <ClCompile Include="main.cpp" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\..\imconfig.h" />
+    <ClInclude Include="..\..\imgui.h" />
+    <ClInclude Include="..\..\imgui_internal.h" />
+    <ClInclude Include="..\..\backends\imgui_impl_sdl3.h" />
+    <ClInclude Include="..\..\backends\imgui_impl_dx11.h" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="..\..\misc\debuggers\imgui.natstepfilter" />
+    <None Include="..\..\misc\debuggers\imgui.natvis" />
+    <None Include="..\README.txt" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>

examples/example_sdl3_directx11/example_sdl3_directx11.vcxproj.filters

@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Filter Include="imgui">
+      <UniqueIdentifier>{0587d7a3-f2ce-4d56-b84f-a0005d3bfce6}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="sources">
+      <UniqueIdentifier>{08e36723-ce4f-4cff-9662-c40801cf1acf}</UniqueIdentifier>
+    </Filter>
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\..\imconfig.h">
+      <Filter>imgui</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\imgui.h">
+      <Filter>imgui</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\imgui_internal.h">
+      <Filter>imgui</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\backends\imgui_impl_sdl3.h">
+      <Filter>sources</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\backends\imgui_impl_dx11.h">
+      <Filter>sources</Filter>
+    </ClInclude>
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\imgui.cpp">
+      <Filter>imgui</Filter>
+    </ClCompile>
+    <ClCompile Include="main.cpp">
+      <Filter>sources</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\imgui_demo.cpp">
+      <Filter>imgui</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\imgui_draw.cpp">
+      <Filter>imgui</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\imgui_tables.cpp">
+      <Filter>imgui</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\imgui_widgets.cpp">
+      <Filter>imgui</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\backends\imgui_impl_sdl3.cpp">
+      <Filter>sources</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\backends\imgui_impl_dx11.cpp">
+      <Filter>sources</Filter>
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="..\README.txt" />
+    <None Include="..\..\misc\debuggers\imgui.natvis">
+      <Filter>imgui</Filter>
+    </None>
+    <None Include="..\..\misc\debuggers\imgui.natstepfilter">
+      <Filter>imgui</Filter>
+    </None>
+  </ItemGroup>
+</Project>

examples/example_sdl3_directx11/main.cpp

@@ -0,0 +1,284 @@
+// Dear ImGui: standalone example application for SDL3 + DirectX 11
+// (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)
+
+// Learn about Dear ImGui:
+// - FAQ                  https://dearimgui.com/faq
+// - Getting Started      https://dearimgui.com/getting-started
+// - Documentation        https://dearimgui.com/docs (same as your local docs/ folder).
+// - Introduction, links and more at the top of imgui.cpp
+
+#include "imgui.h"
+#include "imgui_impl_sdl3.h"
+#include "imgui_impl_dx11.h"
+#include <d3d11.h>
+#include <stdio.h>              // printf
+#include <SDL3/SDL.h>
+
+// Data
+static ID3D11Device*            g_pd3dDevice = nullptr;
+static ID3D11DeviceContext*     g_pd3dDeviceContext = nullptr;
+static IDXGISwapChain*          g_pSwapChain = nullptr;
+static ID3D11RenderTargetView*  g_mainRenderTargetView = nullptr;
+
+// Forward declarations of helper functions
+bool CreateDeviceD3D(HWND hWnd);
+void CleanupDeviceD3D();
+void CreateRenderTarget();
+void CleanupRenderTarget();
+
+// Main code
+int main(int, char**)
+{
+    // Setup SDL
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below until the main loop starts would likely be your SDL_AppInit() function]
+    if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
+    {
+        printf("Error: SDL_Init(): %s\n", SDL_GetError());
+        return 1;
+    }
+
+    // Setup window
+    float main_scale = SDL_GetDisplayContentScale(SDL_GetPrimaryDisplay());
+    SDL_WindowFlags window_flags = SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN | SDL_WINDOW_HIGH_PIXEL_DENSITY;
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+DirectX11 example", (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
+    if (window == nullptr)
+    {
+        printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
+        return 1;
+    }
+
+    SDL_PropertiesID props = SDL_GetWindowProperties(window);
+    HWND hwnd = (HWND)SDL_GetPointerProperty(props, SDL_PROP_WINDOW_WIN32_HWND_POINTER, NULL);
+
+    // Initialize Direct3D
+    if (!CreateDeviceD3D(hwnd))
+    {
+        CleanupDeviceD3D();
+        return 1;
+    }
+
+    SDL_SetWindowPosition(window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
+    SDL_ShowWindow(window);
+
+    // Setup Dear ImGui context
+    IMGUI_CHECKVERSION();
+    ImGui::CreateContext();
+    ImGuiIO& io = ImGui::GetIO(); (void)io;
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
+
+    // Setup Dear ImGui style
+    ImGui::StyleColorsDark();
+    //ImGui::StyleColorsLight();
+
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
+    // Setup Platform/Renderer backends
+    ImGui_ImplSDL3_InitForD3D(window);
+    ImGui_ImplDX11_Init(g_pd3dDevice, g_pd3dDeviceContext);
+
+    // Load Fonts
+    // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
+    // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
+    // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
+    // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
+    // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
+    //style.FontSizeBase = 20.0f;
+    //io.Fonts->AddFontDefault();
+    //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf");
+    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf");
+    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf");
+    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf");
+    //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf");
+    //IM_ASSERT(font != nullptr);
+
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+
+    // Main loop
+    bool done = false;
+    while (!done)
+    {
+        // Poll and handle events (inputs, window resize, etc.)
+        // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
+        // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
+        // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
+        // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
+        // [If using SDL_MAIN_USE_CALLBACKS: call ImGui_ImplSDL3_ProcessEvent() from your SDL_AppEvent() function]
+        SDL_Event event;
+        while (SDL_PollEvent(&event))
+        {
+            ImGui_ImplSDL3_ProcessEvent(&event);
+            if (event.type == SDL_EVENT_QUIT)
+                done = true;
+            if (event.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED && event.window.windowID == SDL_GetWindowID(window))
+                done = true;
+            if (event.type == SDL_EVENT_WINDOW_RESIZED && event.window.windowID == SDL_GetWindowID(window))
+            {
+                // Release all outstanding references to the swap chain's buffers before resizing.
+                CleanupRenderTarget();
+                g_pSwapChain->ResizeBuffers(0, 0, 0, DXGI_FORMAT_UNKNOWN, 0);
+                CreateRenderTarget();
+            }
+        }
+
+        // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppIterate() function]
+        if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED)
+        {
+            SDL_Delay(10);
+            continue;
+        }
+
+        // Start the Dear ImGui frame
+        ImGui_ImplDX11_NewFrame();
+        ImGui_ImplSDL3_NewFrame();
+        ImGui::NewFrame();
+
+        // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
+        if (show_demo_window)
+            ImGui::ShowDemoWindow(&show_demo_window);
+
+        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+        {
+            static float f = 0.0f;
+            static int counter = 0;
+
+            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+
+            ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
+            ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
+            ImGui::Checkbox("Another Window", &show_another_window);
+
+            ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
+            ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
+
+            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+                counter++;
+            ImGui::SameLine();
+            ImGui::Text("counter = %d", counter);
+
+            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
+            ImGui::End();
+        }
+
+        // 3. Show another simple window.
+        if (show_another_window)
+        {
+            ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
+            ImGui::Text("Hello from another window!");
+            if (ImGui::Button("Close Me"))
+                show_another_window = false;
+            ImGui::End();
+        }
+
+        // Rendering
+        ImGui::Render();
+        const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
+        g_pd3dDeviceContext->OMSetRenderTargets(1, &g_mainRenderTargetView, nullptr);
+        g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
+        ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
+
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
+        g_pSwapChain->Present(1, 0); // Present with vsync
+        //g_pSwapChain->Present(0, 0); // Present without vsync
+    }
+
+    // Cleanup
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppQuit() function]
+    ImGui_ImplDX11_Shutdown();
+    ImGui_ImplSDL3_Shutdown();
+    ImGui::DestroyContext();
+
+    CleanupDeviceD3D();
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+
+    return 0;
+}
+
+// Helper functions to use DirectX11
+bool CreateDeviceD3D(HWND hWnd)
+{
+    // Setup swap chain
+    DXGI_SWAP_CHAIN_DESC sd;
+    ZeroMemory(&sd, sizeof(sd));
+    sd.BufferCount = 2;
+    sd.BufferDesc.Width = 0;
+    sd.BufferDesc.Height = 0;
+    sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
+    sd.BufferDesc.RefreshRate.Numerator = 60;
+    sd.BufferDesc.RefreshRate.Denominator = 1;
+    sd.Flags = DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH;
+    sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
+    sd.OutputWindow = hWnd;
+    sd.SampleDesc.Count = 1;
+    sd.SampleDesc.Quality = 0;
+    sd.Windowed = TRUE;
+    sd.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
+
+    UINT createDeviceFlags = 0;
+    //createDeviceFlags |= D3D11_CREATE_DEVICE_DEBUG;
+    D3D_FEATURE_LEVEL featureLevel;
+    const D3D_FEATURE_LEVEL featureLevelArray[2] = { D3D_FEATURE_LEVEL_11_0, D3D_FEATURE_LEVEL_10_0, };
+    HRESULT res = D3D11CreateDeviceAndSwapChain(nullptr, D3D_DRIVER_TYPE_HARDWARE, nullptr, createDeviceFlags, featureLevelArray, 2, D3D11_SDK_VERSION, &sd, &g_pSwapChain, &g_pd3dDevice, &featureLevel, &g_pd3dDeviceContext);
+    if (res == DXGI_ERROR_UNSUPPORTED) // Try high-performance WARP software driver if hardware is not available.
+        res = D3D11CreateDeviceAndSwapChain(nullptr, D3D_DRIVER_TYPE_WARP, nullptr, createDeviceFlags, featureLevelArray, 2, D3D11_SDK_VERSION, &sd, &g_pSwapChain, &g_pd3dDevice, &featureLevel, &g_pd3dDeviceContext);
+    if (res != S_OK)
+        return false;
+
+    // Disable DXGI's default Alt+Enter fullscreen behavior.
+    // - You are free to leave this enabled, but it will not work properly with multiple viewports.
+    // - This must be done for all windows associated to the device. Our DX11 backend does this automatically for secondary viewports that it creates.
+    IDXGIFactory* pSwapChainFactory;
+    if (SUCCEEDED(g_pSwapChain->GetParent(IID_PPV_ARGS(&pSwapChainFactory))))
+        pSwapChainFactory->MakeWindowAssociation(hWnd, DXGI_MWA_NO_ALT_ENTER);
+
+    CreateRenderTarget();
+    return true;
+}
+
+void CleanupDeviceD3D()
+{
+    CleanupRenderTarget();
+    if (g_pSwapChain) { g_pSwapChain->Release(); g_pSwapChain = nullptr; }
+    if (g_pd3dDeviceContext) { g_pd3dDeviceContext->Release(); g_pd3dDeviceContext = nullptr; }
+    if (g_pd3dDevice) { g_pd3dDevice->Release(); g_pd3dDevice = nullptr; }
+}
+
+void CreateRenderTarget()
+{
+    ID3D11Texture2D* pBackBuffer;
+    g_pSwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+    g_pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &g_mainRenderTargetView);
+    pBackBuffer->Release();
+}
+
+void CleanupRenderTarget()
+{
+    if (g_mainRenderTargetView) { g_mainRenderTargetView->Release(); g_mainRenderTargetView = nullptr; }
+}

examples/example_sdl3_metal/Makefile

@@ -0,0 +1,48 @@
+#
+# You will need SDL3 (http://www.libsdl.org):
+#   brew install sdl3
+#
+
+#CXX = g++
+#CXX = clang++
+
+EXE = example_sdl3_metal
+IMGUI_DIR = ../..
+SOURCES = main.mm
+SOURCES += $(IMGUI_DIR)/imgui.cpp $(IMGUI_DIR)/imgui_demo.cpp $(IMGUI_DIR)/imgui_draw.cpp $(IMGUI_DIR)/imgui_tables.cpp $(IMGUI_DIR)/imgui_widgets.cpp
+SOURCES += $(IMGUI_DIR)/backends/imgui_impl_sdl3.cpp $(IMGUI_DIR)/backends/imgui_impl_metal.mm
+OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES))))
+
+LIBS = -framework Metal -framework MetalKit -framework Cocoa -framework IOKit -framework CoreVideo -framework QuartzCore
+LIBS += `pkg-config --libs sdl3`
+LIBS += -L/usr/local/lib -L/opt/local/lib
+
+CXXFLAGS += `pkg-config --cflags sdl3`
+CXXFLAGS += -I/usr/local/include -I/opt/local/include
+CXXFLAGS += -std=c++11 -I$(IMGUI_DIR) -I$(IMGUI_DIR)/backends
+CXXFLAGS += -Wall -Wformat
+CFLAGS = $(CXXFLAGS)
+
+%.o:%.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+%.o:$(IMGUI_DIR)/%.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+%.o:$(IMGUI_DIR)/backends/%.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+%.o:%.mm
+	$(CXX) $(CXXFLAGS) -ObjC++ -fobjc-weak -fobjc-arc -c -o $@ $<
+
+%.o:$(IMGUI_DIR)/backends/%.mm
+	$(CXX) $(CXXFLAGS) -ObjC++ -fobjc-weak -fobjc-arc -c -o $@ $<
+
+all: $(EXE)
+	@echo Build complete
+
+$(EXE): $(OBJS)
+	$(CXX) -o $@ $^ $(CXXFLAGS) $(LIBS)
+
+clean:
+	rm -f $(EXE) $(OBJS)

examples/example_sdl3_metal/main.mm

@@ -0,0 +1,208 @@
+// Dear ImGui: standalone example application for SDL3 + Metal
+// (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)
+
+// Learn about Dear ImGui:
+// - FAQ                  https://dearimgui.com/faq
+// - Getting Started      https://dearimgui.com/getting-started
+// - Documentation        https://dearimgui.com/docs (same as your local docs/ folder).
+// - Introduction, links and more at the top of imgui.cpp
+
+#include "imgui.h"
+#include "imgui_impl_sdl3.h"
+#include "imgui_impl_metal.h"
+#include <stdio.h>          // printf, fprintf
+#include <SDL3/SDL.h>
+
+#import <Metal/Metal.h>
+#import <QuartzCore/QuartzCore.h>
+
+// Main code
+int main(int, char**)
+{
+    // Setup SDL
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below until the main loop starts would likely be your SDL_AppInit() function]
+    if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
+    {
+        printf("Error: SDL_Init(): %s\n", SDL_GetError());
+        return 1;
+    }
+
+    // Create SDL window graphics context
+    float main_scale = SDL_GetDisplayContentScale(SDL_GetPrimaryDisplay());
+    SDL_WindowFlags window_flags = SDL_WINDOW_METAL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN | SDL_WINDOW_HIGH_PIXEL_DENSITY;
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+Metal example", (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
+    if (window == nullptr)
+    {
+        printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
+        return 1;
+    }
+    SDL_SetWindowPosition(window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
+    SDL_ShowWindow(window);
+
+    // Create Metal device _before_ creating the view/layer
+    id<MTLDevice> metalDevice = MTLCreateSystemDefaultDevice();
+    if (!metalDevice)
+    {
+        printf("Error: failed to create Metal device.\n");
+        SDL_DestroyWindow(window);
+        SDL_Quit();
+        return 1;
+    }
+    SDL_MetalView view = SDL_Metal_CreateView(window);
+    CAMetalLayer* layer = (__bridge CAMetalLayer*)SDL_Metal_GetLayer(view);
+    layer.device = metalDevice;
+    layer.pixelFormat = MTLPixelFormatBGRA8Unorm;
+
+    id<MTLCommandQueue> commandQueue = [layer.device newCommandQueue];
+    MTLRenderPassDescriptor* renderPassDescriptor = [MTLRenderPassDescriptor new];
+
+    // Setup Dear ImGui context
+    IMGUI_CHECKVERSION();
+    ImGui::CreateContext();
+    ImGuiIO& io = ImGui::GetIO(); (void)io;
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+
+    // Setup Dear ImGui style
+    ImGui::StyleColorsDark();
+    //ImGui::StyleColorsLight();
+
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+
+    // Setup Platform/Renderer backends
+    ImGui_ImplMetal_Init(layer.device);
+    ImGui_ImplSDL3_InitForMetal(window);
+
+    // Load Fonts
+    // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
+    // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
+    // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
+    // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
+    // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
+    //style.FontSizeBase = 20.0f;
+    //io.Fonts->AddFontDefault();
+    //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf");
+    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf");
+    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf");
+    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf");
+    //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf");
+    //IM_ASSERT(font != nullptr);
+
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    float clear_color[4] = { 0.45f, 0.55f, 0.60f, 1.00f };
+
+    // Main loop
+    bool done = false;
+    while (!done)
+    {
+        @autoreleasepool
+        {
+            // Poll and handle events (inputs, window resize, etc.)
+            // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
+            // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
+            // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
+            // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
+            // [If using SDL_MAIN_USE_CALLBACKS: call ImGui_ImplSDL3_ProcessEvent() from your SDL_AppEvent() function]
+            SDL_Event event;
+            while (SDL_PollEvent(&event))
+            {
+                ImGui_ImplSDL3_ProcessEvent(&event);
+                if (event.type == SDL_EVENT_QUIT)
+                    done = true;
+                if (event.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED && event.window.windowID == SDL_GetWindowID(window))
+                    done = true;
+            }
+
+            // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppIterate() function]
+            if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED)
+            {
+                SDL_Delay(10);
+                continue;
+            }
+
+            int width, height;
+            SDL_GetWindowSizeInPixels(window, &width, &height);
+
+            layer.drawableSize = CGSizeMake(width, height);
+            id<CAMetalDrawable> drawable = [layer nextDrawable];
+
+            id<MTLCommandBuffer> commandBuffer = [commandQueue commandBuffer];
+            renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(clear_color[0] * clear_color[3], clear_color[1] * clear_color[3], clear_color[2] * clear_color[3], clear_color[3]);
+            renderPassDescriptor.colorAttachments[0].texture = drawable.texture;
+            renderPassDescriptor.colorAttachments[0].loadAction = MTLLoadActionClear;
+            renderPassDescriptor.colorAttachments[0].storeAction = MTLStoreActionStore;
+            id <MTLRenderCommandEncoder> renderEncoder = [commandBuffer renderCommandEncoderWithDescriptor:renderPassDescriptor];
+            [renderEncoder pushDebugGroup:@"ImGui demo"];
+
+            // Start the Dear ImGui frame
+            ImGui_ImplMetal_NewFrame(renderPassDescriptor);
+            ImGui_ImplSDL3_NewFrame();
+            ImGui::NewFrame();
+
+            // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
+            if (show_demo_window)
+                ImGui::ShowDemoWindow(&show_demo_window);
+
+            // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+            {
+                static float f = 0.0f;
+                static int counter = 0;
+
+                ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+
+                ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
+                ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
+                ImGui::Checkbox("Another Window", &show_another_window);
+
+                ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
+                ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
+
+                if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+                    counter++;
+                ImGui::SameLine();
+                ImGui::Text("counter = %d", counter);
+
+                ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
+                ImGui::End();
+            }
+
+            // 3. Show another simple window.
+            if (show_another_window)
+            {
+                ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
+                ImGui::Text("Hello from another window!");
+                if (ImGui::Button("Close Me"))
+                    show_another_window = false;
+                ImGui::End();
+            }
+
+            // Rendering
+            ImGui::Render();
+            ImDrawData* draw_data = ImGui::GetDrawData();
+            ImGui_ImplMetal_RenderDrawData(draw_data, commandBuffer, renderEncoder);
+
+            [renderEncoder popDebugGroup];
+            [renderEncoder endEncoding];
+
+            [commandBuffer presentDrawable:drawable];
+            [commandBuffer commit];
+        }
+    }
+
+    // Cleanup
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppQuit() function]
+    ImGui_ImplMetal_Shutdown();
+    ImGui_ImplSDL3_Shutdown();
+    ImGui::DestroyContext();
+
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+
+    return 0;
+}

examples/example_sdl3_opengl3/main.cpp

@@ -30,7 +30,7 @@ int main(int, char**)
     if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
     {
         printf("Error: SDL_Init(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // Decide GL+GLSL versions
@@ -70,17 +70,17 @@ int main(int, char**)
     SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
     float main_scale = SDL_GetDisplayContentScale(SDL_GetPrimaryDisplay());
     SDL_WindowFlags window_flags = SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN | SDL_WINDOW_HIGH_PIXEL_DENSITY;
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+OpenGL3 example", (int)(1280 * main_scale), (int)(720 * main_scale), window_flags);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+OpenGL3 example", (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
     if (window == nullptr)
     {
         printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
     SDL_GLContext gl_context = SDL_GL_CreateContext(window);
     if (gl_context == nullptr)
     {
         printf("Error: SDL_GL_CreateContext(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     SDL_GL_MakeCurrent(window, gl_context);
@@ -94,6 +94,10 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -103,6 +107,15 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL3_InitForOpenGL(window, gl_context);
@@ -113,7 +126,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     // - Our Emscripten build process allows embedding fonts to be accessible at runtime from the "fonts/" folder. See Makefile.emscripten for details.
     //style.FontSizeBase = 20.0f;
@@ -212,6 +225,19 @@ int main(int, char**)
         glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
         glClear(GL_COLOR_BUFFER_BIT);
         ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
+            SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
+        }
+
         SDL_GL_SwapWindow(window);
     }
 #ifdef __EMSCRIPTEN__

examples/example_sdl3_sdlgpu3/main.cpp

@@ -1,4 +1,5 @@
 // Dear ImGui: standalone example application for SDL3 + SDL_GPU
+// (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)
 
 // Learn about Dear ImGui:
 // - FAQ                  https://dearimgui.com/faq
@@ -30,17 +31,17 @@ int main(int, char**)
     if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
     {
         printf("Error: SDL_Init(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // Create SDL window graphics context
     float main_scale = SDL_GetDisplayContentScale(SDL_GetPrimaryDisplay());
     SDL_WindowFlags window_flags = SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN | SDL_WINDOW_HIGH_PIXEL_DENSITY;
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+SDL_GPU example", (int)(1280 * main_scale), (int)(720 * main_scale), window_flags);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+SDL_GPU example", (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
     if (window == nullptr)
     {
         printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
     SDL_SetWindowPosition(window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
     SDL_ShowWindow(window);
@@ -50,16 +51,16 @@ int main(int, char**)
     if (gpu_device == nullptr)
     {
         printf("Error: SDL_CreateGPUDevice(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // Claim window for GPU Device
     if (!SDL_ClaimWindowForGPUDevice(gpu_device, window))
     {
         printf("Error: SDL_ClaimWindowForGPUDevice(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
-    SDL_SetGPUSwapchainParameters(gpu_device, window, SDL_GPU_SWAPCHAINCOMPOSITION_SDR, SDL_GPU_PRESENTMODE_MAILBOX);
+    SDL_SetGPUSwapchainParameters(gpu_device, window, SDL_GPU_SWAPCHAINCOMPOSITION_SDR, SDL_GPU_PRESENTMODE_VSYNC);
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
@@ -67,6 +68,8 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -76,13 +79,24 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL3_InitForSDLGPU(window);
     ImGui_ImplSDLGPU3_InitInfo init_info = {};
     init_info.Device = gpu_device;
     init_info.ColorTargetFormat = SDL_GetGPUSwapchainTextureFormat(gpu_device, window);
-    init_info.MSAASamples = SDL_GPU_SAMPLECOUNT_1;
+    init_info.MSAASamples = SDL_GPU_SAMPLECOUNT_1;                      // Only used in multi-viewports mode.
+    init_info.SwapchainComposition = SDL_GPU_SWAPCHAINCOMPOSITION_SDR;  // Only used in multi-viewports mode.
+    init_info.PresentMode = SDL_GPU_PRESENTMODE_VSYNC;
     ImGui_ImplSDLGPU3_Init(&init_info);
 
     // Load Fonts
@@ -90,7 +104,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -154,7 +168,7 @@ int main(int, char**)
             ImGui::Checkbox("Another Window", &show_another_window);
 
             ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
-            ImGui::ColorEdit4("clear color", (float*)&clear_color); // Edit 3 floats representing a color
+            ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
 
             if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
                 counter++;
@@ -183,7 +197,7 @@ int main(int, char**)
         SDL_GPUCommandBuffer* command_buffer = SDL_AcquireGPUCommandBuffer(gpu_device); // Acquire a GPU command buffer
 
         SDL_GPUTexture* swapchain_texture;
-        SDL_AcquireGPUSwapchainTexture(command_buffer, window, &swapchain_texture, nullptr, nullptr); // Acquire a swapchain texture
+        SDL_WaitAndAcquireGPUSwapchainTexture(command_buffer, window, &swapchain_texture, nullptr, nullptr); // Acquire a swapchain texture
 
         if (swapchain_texture != nullptr && !is_minimized)
         {
@@ -207,6 +221,13 @@ int main(int, char**)
             SDL_EndGPURenderPass(render_pass);
         }
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         // Submit the command buffer
         SDL_SubmitGPUCommandBuffer(command_buffer);
     }

examples/example_sdl3_sdlrenderer3/main.cpp

@@ -28,24 +28,24 @@ int main(int, char**)
     if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
     {
         printf("Error: SDL_Init(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // Create window with SDL_Renderer graphics context
     float main_scale = SDL_GetDisplayContentScale(SDL_GetPrimaryDisplay());
     SDL_WindowFlags window_flags = SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN | SDL_WINDOW_HIGH_PIXEL_DENSITY;
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+SDL_Renderer example", (int)(1280 * main_scale), (int)(720 * main_scale), window_flags);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+SDL_Renderer example", (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
     if (window == nullptr)
     {
         printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
     SDL_Renderer* renderer = SDL_CreateRenderer(window, nullptr);
     SDL_SetRenderVSync(renderer, 1);
     if (renderer == nullptr)
     {
         SDL_Log("Error: SDL_CreateRenderer(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
     SDL_SetWindowPosition(window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
     SDL_ShowWindow(window);
@@ -56,6 +56,7 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -65,6 +66,8 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    //io.ConfigDpiScaleFonts = true;        // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    //io.ConfigDpiScaleViewports = true;    // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL3_InitForSDLRenderer(window, renderer);
@@ -75,7 +78,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     // - Our Emscripten build process allows embedding fonts to be accessible at runtime from the "fonts/" folder. See Makefile.emscripten for details.
     //style.FontSizeBase = 20.0f;

examples/example_sdl3_vulkan/main.cpp

@@ -232,7 +232,7 @@ static void SetupVulkanWindow(ImGui_ImplVulkanH_Window* wd, VkSurfaceKHR surface
 
     // Create SwapChain, RenderPass, Framebuffer, etc.
     IM_ASSERT(g_MinImageCount >= 2);
-    ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
+    ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, width, height, g_MinImageCount, 0);
 }
 
 static void CleanupVulkan()
@@ -349,17 +349,17 @@ int main(int, char**)
     if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
     {
         printf("Error: SDL_Init(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     // Create window with Vulkan graphics context
     float main_scale = SDL_GetDisplayContentScale(SDL_GetPrimaryDisplay());
     SDL_WindowFlags window_flags = SDL_WINDOW_VULKAN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN | SDL_WINDOW_HIGH_PIXEL_DENSITY;
-    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+Vulkan example", (int)(1280 * main_scale), (int)(720 * main_scale), window_flags);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+Vulkan example", (int)(1280 * main_scale), (int)(800 * main_scale), window_flags);
     if (window == nullptr)
     {
         printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
-        return -1;
+        return 1;
     }
 
     ImVector<const char*> extensions;
@@ -394,6 +394,10 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
+    //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -403,6 +407,15 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL3_InitForVulkan(window);
@@ -415,12 +428,12 @@ int main(int, char**)
     init_info.Queue = g_Queue;
     init_info.PipelineCache = g_PipelineCache;
     init_info.DescriptorPool = g_DescriptorPool;
-    init_info.RenderPass = wd->RenderPass;
-    init_info.Subpass = 0;
     init_info.MinImageCount = g_MinImageCount;
     init_info.ImageCount = wd->ImageCount;
-    init_info.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
     init_info.Allocator = g_Allocator;
+    init_info.PipelineInfoMain.RenderPass = wd->RenderPass;
+    init_info.PipelineInfoMain.Subpass = 0;
+    init_info.PipelineInfoMain.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
     init_info.CheckVkResultFn = check_vk_result;
     ImGui_ImplVulkan_Init(&init_info);
 
@@ -429,7 +442,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -478,7 +491,7 @@ int main(int, char**)
         if (fb_width > 0 && fb_height > 0 && (g_SwapChainRebuild || g_MainWindowData.Width != fb_width || g_MainWindowData.Height != fb_height))
         {
             ImGui_ImplVulkan_SetMinImageCount(g_MinImageCount);
-            ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, fb_width, fb_height, g_MinImageCount);
+            ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, fb_height, fb_height, g_MinImageCount, 0);
             g_MainWindowData.FrameIndex = 0;
             g_SwapChainRebuild = false;
         }
@@ -527,17 +540,25 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
-        ImDrawData* draw_data = ImGui::GetDrawData();
-        const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
-        if (!is_minimized)
+        ImDrawData* main_draw_data = ImGui::GetDrawData();
+        const bool main_is_minimized = (main_draw_data->DisplaySize.x <= 0.0f || main_draw_data->DisplaySize.y <= 0.0f);
+        wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
+        wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
+        wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
+        wd->ClearValue.color.float32[3] = clear_color.w;
+        if (!main_is_minimized)
+            FrameRender(wd, main_draw_data);
+
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
         {
-            wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
-            wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
-            wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
-            wd->ClearValue.color.float32[3] = clear_color.w;
-            FrameRender(wd, draw_data);
-            FramePresent(wd);
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
         }
+
+        // Present Main Platform Window
+        if (!main_is_minimized)
+            FramePresent(wd);
     }
 
     // Cleanup

examples/example_win32_directx10/main.cpp

@@ -1,4 +1,4 @@
-// Dear ImGui: standalone example application for DirectX 10
+// Dear ImGui: standalone example application for Windows API + DirectX 10
 
 // Learn about Dear ImGui:
 // - FAQ                  https://dearimgui.com/faq
@@ -57,6 +57,10 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -66,6 +70,15 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplWin32_Init(hwnd);
@@ -76,7 +89,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -175,6 +188,13 @@ int main(int, char**)
         g_pd3dDevice->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX10_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         // Present
         HRESULT hr = g_pSwapChain->Present(1, 0);   // Present with vsync
         //HRESULT hr = g_pSwapChain->Present(0, 0); // Present without vsync
@@ -194,7 +214,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain
@@ -222,6 +241,13 @@ bool CreateDeviceD3D(HWND hWnd)
     if (res != S_OK)
         return false;
 
+    // Disable DXGI's default Alt+Enter fullscreen behavior.
+    // - You are free to leave this enabled, but it will not work properly with multiple viewports.
+    // - This must be done for all windows associated to the device. Our DX11 backend does this automatically for secondary viewports that it creates.
+    IDXGIFactory* pSwapChainFactory;
+    if (SUCCEEDED(g_pSwapChain->GetParent(IID_PPV_ARGS(&pSwapChainFactory))))
+        pSwapChainFactory->MakeWindowAssociation(hWnd, DXGI_MWA_NO_ALT_ENTER);
+
     CreateRenderTarget();
     return true;
 }

examples/example_win32_directx11/main.cpp

@@ -1,4 +1,4 @@
-// Dear ImGui: standalone example application for DirectX 11
+// Dear ImGui: standalone example application for Windows API + DirectX 11
 
 // Learn about Dear ImGui:
 // - FAQ                  https://dearimgui.com/faq
@@ -57,6 +57,12 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
+    //io.ConfigDockingAlwaysTabBar = true;
+    //io.ConfigDockingTransparentPayload = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -66,6 +72,15 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplWin32_Init(hwnd);
@@ -76,7 +91,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -175,6 +190,13 @@ int main(int, char**)
         g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         // Present
         HRESULT hr = g_pSwapChain->Present(1, 0);   // Present with vsync
         //HRESULT hr = g_pSwapChain->Present(0, 0); // Present without vsync
@@ -194,7 +216,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain
@@ -224,6 +245,13 @@ bool CreateDeviceD3D(HWND hWnd)
     if (res != S_OK)
         return false;
 
+    // Disable DXGI's default Alt+Enter fullscreen behavior.
+    // - You are free to leave this enabled, but it will not work properly with multiple viewports.
+    // - This must be done for all windows associated to the device. Our DX11 backend does this automatically for secondary viewports that it creates.
+    IDXGIFactory* pSwapChainFactory;
+    if (SUCCEEDED(g_pSwapChain->GetParent(IID_PPV_ARGS(&pSwapChainFactory))))
+        pSwapChainFactory->MakeWindowAssociation(hWnd, DXGI_MWA_NO_ALT_ENTER);
+
     CreateRenderTarget();
     return true;
 }

examples/example_win32_directx12/main.cpp

@@ -1,4 +1,4 @@
-// Dear ImGui: standalone example application for DirectX 12
+// Dear ImGui: standalone example application for Windows API + DirectX 12
 
 // Learn about Dear ImGui:
 // - FAQ                  https://dearimgui.com/faq
@@ -10,7 +10,7 @@
 #include "imgui_impl_win32.h"
 #include "imgui_impl_dx12.h"
 #include <d3d12.h>
-#include <dxgi1_4.h>
+#include <dxgi1_5.h>
 #include <tchar.h>
 
 #ifdef _DEBUG
@@ -92,6 +92,7 @@ static ID3D12Fence*                 g_fence = nullptr;
 static HANDLE                       g_fenceEvent = nullptr;
 static UINT64                       g_fenceLastSignaledValue = 0;
 static IDXGISwapChain3*             g_pSwapChain = nullptr;
+static bool                         g_SwapChainTearingSupport = false;
 static bool                         g_SwapChainOccluded = false;
 static HANDLE                       g_hSwapChainWaitableObject = nullptr;
 static ID3D12Resource*              g_mainRenderTargetResource[APP_NUM_BACK_BUFFERS] = {};
@@ -102,8 +103,8 @@ bool CreateDeviceD3D(HWND hWnd);
 void CleanupDeviceD3D();
 void CreateRenderTarget();
 void CleanupRenderTarget();
-void WaitForLastSubmittedFrame();
-FrameContext* WaitForNextFrameResources();
+void WaitForPendingOperations();
+FrameContext* WaitForNextFrameContext();
 LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 
 // Main code
@@ -136,6 +137,10 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -145,6 +150,15 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplWin32_Init(hwnd);
@@ -170,7 +184,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -256,7 +270,7 @@ int main(int, char**)
         // Rendering
         ImGui::Render();
 
-        FrameContext* frameCtx = WaitForNextFrameResources();
+        FrameContext* frameCtx = WaitForNextFrameContext();
         UINT backBufferIdx = g_pSwapChain->GetCurrentBackBufferIndex();
         frameCtx->CommandAllocator->Reset();
 
@@ -283,18 +297,24 @@ int main(int, char**)
 
         g_pd3dCommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&g_pd3dCommandList);
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
+        g_pd3dCommandQueue->Signal(g_fence, ++g_fenceLastSignaledValue);
+        frameCtx->FenceValue = g_fenceLastSignaledValue;
+
         // Present
         HRESULT hr = g_pSwapChain->Present(1, 0);   // Present with vsync
-        //HRESULT hr = g_pSwapChain->Present(0, 0); // Present without vsync
+        //HRESULT hr = g_pSwapChain->Present(0, g_SwapChainTearingSupport ? DXGI_PRESENT_ALLOW_TEARING : 0); // Present without vsync
         g_SwapChainOccluded = (hr == DXGI_STATUS_OCCLUDED);
-
-        UINT64 fenceValue = g_fenceLastSignaledValue + 1;
-        g_pd3dCommandQueue->Signal(g_fence, fenceValue);
-        g_fenceLastSignaledValue = fenceValue;
-        frameCtx->FenceValue = fenceValue;
+        g_frameIndex++;
     }
 
-    WaitForLastSubmittedFrame();
+    WaitForPendingOperations();
 
     // Cleanup
     ImGui_ImplDX12_Shutdown();
@@ -309,7 +329,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain
@@ -409,14 +428,24 @@ bool CreateDeviceD3D(HWND hWnd)
         return false;
 
     {
-        IDXGIFactory4* dxgiFactory = nullptr;
+        IDXGIFactory5* dxgiFactory = nullptr;
         IDXGISwapChain1* swapChain1 = nullptr;
         if (CreateDXGIFactory1(IID_PPV_ARGS(&dxgiFactory)) != S_OK)
             return false;
+
+        BOOL allow_tearing = FALSE;
+        dxgiFactory->CheckFeatureSupport(DXGI_FEATURE_PRESENT_ALLOW_TEARING, &allow_tearing, sizeof(allow_tearing));
+        g_SwapChainTearingSupport = (allow_tearing == TRUE);
+        if (g_SwapChainTearingSupport)
+            sd.Flags |= DXGI_SWAP_CHAIN_FLAG_ALLOW_TEARING;
+
         if (dxgiFactory->CreateSwapChainForHwnd(g_pd3dCommandQueue, hWnd, &sd, nullptr, nullptr, &swapChain1) != S_OK)
             return false;
         if (swapChain1->QueryInterface(IID_PPV_ARGS(&g_pSwapChain)) != S_OK)
             return false;
+        if (g_SwapChainTearingSupport)
+            dxgiFactory->MakeWindowAssociation(hWnd, DXGI_MWA_NO_ALT_ENTER);
+
         swapChain1->Release();
         dxgiFactory->Release();
         g_pSwapChain->SetMaximumFrameLatency(APP_NUM_BACK_BUFFERS);
@@ -465,49 +494,33 @@ void CreateRenderTarget()
 
 void CleanupRenderTarget()
 {
-    WaitForLastSubmittedFrame();
+    WaitForPendingOperations();
 
     for (UINT i = 0; i < APP_NUM_BACK_BUFFERS; i++)
         if (g_mainRenderTargetResource[i]) { g_mainRenderTargetResource[i]->Release(); g_mainRenderTargetResource[i] = nullptr; }
 }
 
-void WaitForLastSubmittedFrame()
+void WaitForPendingOperations()
 {
-    FrameContext* frameCtx = &g_frameContext[g_frameIndex % APP_NUM_FRAMES_IN_FLIGHT];
+    g_pd3dCommandQueue->Signal(g_fence, ++g_fenceLastSignaledValue);
 
-    UINT64 fenceValue = frameCtx->FenceValue;
-    if (fenceValue == 0)
-        return; // No fence was signaled
-
-    frameCtx->FenceValue = 0;
-    if (g_fence->GetCompletedValue() >= fenceValue)
-        return;
-
-    g_fence->SetEventOnCompletion(fenceValue, g_fenceEvent);
-    WaitForSingleObject(g_fenceEvent, INFINITE);
+    g_fence->SetEventOnCompletion(g_fenceLastSignaledValue, g_fenceEvent);
+    ::WaitForSingleObject(g_fenceEvent, INFINITE);
 }
 
-FrameContext* WaitForNextFrameResources()
+FrameContext* WaitForNextFrameContext()
 {
-    UINT nextFrameIndex = g_frameIndex + 1;
-    g_frameIndex = nextFrameIndex;
-
-    HANDLE waitableObjects[] = { g_hSwapChainWaitableObject, nullptr };
-    DWORD numWaitableObjects = 1;
-
-    FrameContext* frameCtx = &g_frameContext[nextFrameIndex % APP_NUM_FRAMES_IN_FLIGHT];
-    UINT64 fenceValue = frameCtx->FenceValue;
-    if (fenceValue != 0) // means no fence was signaled
+    FrameContext* frame_context = &g_frameContext[g_frameIndex % APP_NUM_FRAMES_IN_FLIGHT];
+    if (g_fence->GetCompletedValue() < frame_context->FenceValue)
     {
-        frameCtx->FenceValue = 0;
-        g_fence->SetEventOnCompletion(fenceValue, g_fenceEvent);
-        waitableObjects[1] = g_fenceEvent;
-        numWaitableObjects = 2;
+        g_fence->SetEventOnCompletion(frame_context->FenceValue, g_fenceEvent);
+        HANDLE waitableObjects[] = { g_hSwapChainWaitableObject, g_fenceEvent };
+        ::WaitForMultipleObjects(2, waitableObjects, TRUE, INFINITE);
     }
+    else
+        ::WaitForSingleObject(g_hSwapChainWaitableObject, INFINITE);
 
-    WaitForMultipleObjects(numWaitableObjects, waitableObjects, TRUE, INFINITE);
-
-    return frameCtx;
+    return frame_context;
 }
 
 // Forward declare message handler from imgui_impl_win32.cpp
@@ -528,9 +541,10 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
     case WM_SIZE:
         if (g_pd3dDevice != nullptr && wParam != SIZE_MINIMIZED)
         {
-            WaitForLastSubmittedFrame();
             CleanupRenderTarget();
-            HRESULT result = g_pSwapChain->ResizeBuffers(0, (UINT)LOWORD(lParam), (UINT)HIWORD(lParam), DXGI_FORMAT_UNKNOWN, DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT);
+            DXGI_SWAP_CHAIN_DESC1 desc = {};
+            g_pSwapChain->GetDesc1(&desc);
+            HRESULT result = g_pSwapChain->ResizeBuffers(0, (UINT)LOWORD(lParam), (UINT)HIWORD(lParam), desc.Format, desc.Flags);
             assert(SUCCEEDED(result) && "Failed to resize swapchain.");
             CreateRenderTarget();
         }

examples/example_win32_directx9/main.cpp

@@ -1,4 +1,4 @@
-// Dear ImGui: standalone example application for DirectX 9
+// Dear ImGui: standalone example application for Windows API + DirectX 9
 
 // Learn about Dear ImGui:
 // - FAQ                  https://dearimgui.com/faq
@@ -55,6 +55,10 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -64,6 +68,15 @@ int main(int, char**)
     ImGuiStyle& style = ImGui::GetStyle();
     style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
     style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
 
     // Setup Platform/Renderer backends
     ImGui_ImplWin32_Init(hwnd);
@@ -74,7 +87,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -185,6 +198,14 @@ int main(int, char**)
             ImGui_ImplDX9_RenderDrawData(ImGui::GetDrawData());
             g_pd3dDevice->EndScene();
         }
+
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         HRESULT result = g_pd3dDevice->Present(nullptr, nullptr, nullptr, nullptr);
         if (result == D3DERR_DEVICELOST)
             g_DeviceLost = true;
@@ -203,7 +224,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     if ((g_pD3D = Direct3DCreate9(D3D_SDK_VERSION)) == nullptr)

examples/example_win32_opengl3/main.cpp

@@ -1,4 +1,4 @@
-// Dear ImGui: standalone example application for Win32 + OpenGL 3
+// Dear ImGui: standalone example application for Windows API + OpenGL
 
 // Learn about Dear ImGui:
 // - FAQ                  https://dearimgui.com/faq
@@ -15,7 +15,7 @@
 #define WIN32_LEAN_AND_MEAN
 #endif
 #include <windows.h>
-#include <GL/GL.h>
+#include <GL/gl.h>
 #include <tchar.h>
 
 // Data stored per platform window
@@ -33,14 +33,53 @@ void CleanupDeviceWGL(HWND hWnd, WGL_WindowData* data);
 void ResetDeviceWGL();
 LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 
+// Support function for multi-viewports
+// Unlike most other backend combination, we need specific hooks to combine Win32+OpenGL.
+// We could in theory decide to support Win32-specific code in OpenGL backend via e.g. an hypothetical ImGui_ImplOpenGL3_InitForRawWin32().
+static void Hook_Renderer_CreateWindow(ImGuiViewport* viewport)
+{
+    assert(viewport->RendererUserData == NULL);
+
+    WGL_WindowData* data = IM_NEW(WGL_WindowData);
+    CreateDeviceWGL((HWND)viewport->PlatformHandle, data);
+    viewport->RendererUserData = data;
+}
+
+static void Hook_Renderer_DestroyWindow(ImGuiViewport* viewport)
+{
+    if (viewport->RendererUserData != NULL)
+    {
+        WGL_WindowData* data = (WGL_WindowData*)viewport->RendererUserData;
+        CleanupDeviceWGL((HWND)viewport->PlatformHandle, data);
+        IM_DELETE(data);
+        viewport->RendererUserData = NULL;
+    }
+}
+
+static void Hook_Platform_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    // Activate the platform window DC in the OpenGL rendering context
+    if (WGL_WindowData* data = (WGL_WindowData*)viewport->RendererUserData)
+        wglMakeCurrent(data->hDC, g_hRC);
+}
+
+static void Hook_Renderer_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    if (WGL_WindowData* data = (WGL_WindowData*)viewport->RendererUserData)
+        ::SwapBuffers(data->hDC);
+}
+
 // Main code
 int main(int, char**)
 {
+    // Make process DPI aware and obtain main monitor scale
+    //ImGui_ImplWin32_EnableDpiAwareness(); // FIXME: This somehow doesn't work in the Win32+OpenGL example. Why?
+    float main_scale = ImGui_ImplWin32_GetDpiScaleForMonitor(::MonitorFromPoint(POINT{ 0, 0 }, MONITOR_DEFAULTTOPRIMARY));
+
     // Create application window
-    //ImGui_ImplWin32_EnableDpiAwareness();
     WNDCLASSEXW wc = { sizeof(wc), CS_OWNDC, WndProc, 0L, 0L, GetModuleHandle(nullptr), nullptr, nullptr, nullptr, nullptr, L"ImGui Example", nullptr };
     ::RegisterClassExW(&wc);
-    HWND hwnd = ::CreateWindowW(wc.lpszClassName, L"Dear ImGui Win32+OpenGL3 Example", WS_OVERLAPPEDWINDOW, 100, 100, 1280, 800, nullptr, nullptr, wc.hInstance, nullptr);
+    HWND hwnd = ::CreateWindowW(wc.lpszClassName, L"Dear ImGui Win32+OpenGL3 Example", WS_OVERLAPPEDWINDOW, 100, 100, (int)(1280 * main_scale), (int)(800 * main_scale), nullptr, nullptr, wc.hInstance, nullptr);
 
     // Initialize OpenGL
     if (!CreateDeviceWGL(hwnd, &g_MainWindow))
@@ -62,21 +101,51 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;   // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;    // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;       // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;     // Enable Multi-Viewport / Platform Windows
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplWin32_InitForOpenGL(hwnd);
     ImGui_ImplOpenGL3_Init();
 
+    // Win32+GL needs specific hooks for viewport, as there are specific things needed to tie Win32 and GL api.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+        IM_ASSERT(platform_io.Renderer_CreateWindow == NULL);
+        IM_ASSERT(platform_io.Renderer_DestroyWindow == NULL);
+        IM_ASSERT(platform_io.Renderer_SwapBuffers == NULL);
+        IM_ASSERT(platform_io.Platform_RenderWindow == NULL);
+        platform_io.Renderer_CreateWindow = Hook_Renderer_CreateWindow;
+        platform_io.Renderer_DestroyWindow = Hook_Renderer_DestroyWindow;
+        platform_io.Renderer_SwapBuffers = Hook_Renderer_SwapBuffers;
+        platform_io.Platform_RenderWindow = Hook_Platform_RenderWindow;
+    }
+
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -163,6 +232,16 @@ int main(int, char**)
         glClear(GL_COLOR_BUFFER_BIT);
         ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+
+            // Restore the OpenGL rendering context to the main window DC, since platform windows might have changed it.
+            wglMakeCurrent(g_MainWindow.hDC, g_hRC);
+        }
+
         // Present
         ::SwapBuffers(g_MainWindow.hDC);
     }

examples/example_win32_vulkan/main.cpp

@@ -1,4 +1,4 @@
-// Dear ImGui: standalone example application for Win32 + Vulkan
+// Dear ImGui: standalone example application for Windows API + Vulkan
 
 // Learn about Dear ImGui:
 // - FAQ                  https://dearimgui.com/faq
@@ -228,7 +228,7 @@ static void SetupVulkanWindow(ImGui_ImplVulkanH_Window* wd, VkSurfaceKHR surface
 
     // Create SwapChain, RenderPass, Framebuffer, etc.
     IM_ASSERT(g_MinImageCount >= 2);
-    ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
+    ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, width, height, g_MinImageCount, 0);
 }
 
 static void CleanupVulkan()
@@ -339,14 +339,27 @@ static void FramePresent(ImGui_ImplVulkanH_Window* wd)
 
 LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 
+// FIXME: This code would ideally be inside imgui_impl_win32.cpp, it would create a dependency on Vulkan headers in imgui_impl_win32.cpp
+static int ImGui_ImplWin32_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_instance, const void* vk_allocator, ImU64* out_vk_surface)
+{
+    VkWin32SurfaceCreateInfoKHR createInfo = {};
+    createInfo.sType = VK_STRUCTURE_TYPE_WIN32_SURFACE_CREATE_INFO_KHR;
+    createInfo.hwnd = (HWND)viewport->PlatformHandleRaw;
+    createInfo.hinstance = ::GetModuleHandle(nullptr);
+    return (int)vkCreateWin32SurfaceKHR((VkInstance)vk_instance, &createInfo, (VkAllocationCallbacks*)vk_allocator, (VkSurfaceKHR*)out_vk_surface);
+}
+
 // Main code
 int main(int, char**)
 {
+    // Make process DPI aware and obtain main monitor scale
+    ImGui_ImplWin32_EnableDpiAwareness();
+    float main_scale = ImGui_ImplWin32_GetDpiScaleForMonitor(::MonitorFromPoint(POINT{ 0, 0 }, MONITOR_DEFAULTTOPRIMARY));
+
     // Create application window
-    //ImGui_ImplWin32_EnableDpiAwareness();
     WNDCLASSEXW wc = { sizeof(wc), CS_CLASSDC, WndProc, 0L, 0L, GetModuleHandle(nullptr), nullptr, nullptr, nullptr, nullptr, L"ImGui Example", nullptr };
     ::RegisterClassExW(&wc);
-    HWND hwnd = ::CreateWindowW(wc.lpszClassName, L"Dear ImGui Win32+Vulkan Example", WS_OVERLAPPEDWINDOW, 100, 100, 1280, 800, nullptr, nullptr, wc.hInstance, nullptr);
+    HWND hwnd = ::CreateWindowW(wc.lpszClassName, L"Dear ImGui Win32+Vulkan Example", WS_OVERLAPPEDWINDOW, 100, 100, (int)(1280 * main_scale), (int)(800 * main_scale), nullptr, nullptr, wc.hInstance, nullptr);
 
     ImVector<const char*> extensions;
     extensions.push_back("VK_KHR_surface");
@@ -369,7 +382,7 @@ int main(int, char**)
     // Show the window
     // FIXME: Retrieve client size from window itself.
     ImGui_ImplVulkanH_Window* wd = &g_MainWindowData;
-    SetupVulkanWindow(wd, surface, 1280, 800);
+    SetupVulkanWindow(wd, surface, (int)(1280 * main_scale), (int)(800 * main_scale));
     ::ShowWindow(hwnd, SW_SHOWDEFAULT);
     ::UpdateWindow(hwnd);
 
@@ -379,13 +392,33 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
+    //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // Setup scaling
+    ImGuiStyle& style = ImGui::GetStyle();
+    style.ScaleAllSizes(main_scale);        // Bake a fixed style scale. (until we have a solution for dynamic style scaling, changing this requires resetting Style + calling this again)
+    style.FontScaleDpi = main_scale;        // Set initial font scale. (using io.ConfigDpiScaleFonts=true makes this unnecessary. We leave both here for documentation purpose)
+    io.ConfigDpiScaleFonts = true;          // [Experimental] Automatically overwrite style.FontScaleDpi in Begin() when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    io.ConfigDpiScaleViewports = true;      // [Experimental] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplWin32_Init(hwnd);
+    ImGui::GetPlatformIO().Platform_CreateVkSurface = ImGui_ImplWin32_CreateVkSurface;
+
     ImGui_ImplVulkan_InitInfo init_info = {};
     //init_info.ApiVersion = VK_API_VERSION_1_3;              // Pass in your value of VkApplicationInfo::apiVersion, otherwise will default to header version.
     init_info.Instance = g_Instance;
@@ -395,12 +428,12 @@ int main(int, char**)
     init_info.Queue = g_Queue;
     init_info.PipelineCache = g_PipelineCache;
     init_info.DescriptorPool = g_DescriptorPool;
-    init_info.RenderPass = wd->RenderPass;
-    init_info.Subpass = 0;
     init_info.MinImageCount = g_MinImageCount;
     init_info.ImageCount = wd->ImageCount;
-    init_info.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
     init_info.Allocator = g_Allocator;
+    init_info.PipelineInfoMain.RenderPass = wd->RenderPass;
+    init_info.PipelineInfoMain.Subpass = 0;
+    init_info.PipelineInfoMain.MSAASamples = VK_SAMPLE_COUNT_1_BIT;
     init_info.CheckVkResultFn = check_vk_result;
     ImGui_ImplVulkan_Init(&init_info);
 
@@ -409,7 +442,7 @@ int main(int, char**)
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
-    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Read 'docs/FONTS.md' for more instructions and details. If you like the default font but want it to scale better, consider using the 'ProggyVector' from the same author!
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //style.FontSizeBase = 20.0f;
     //io.Fonts->AddFontDefault();
@@ -486,17 +519,25 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
-        ImDrawData* draw_data = ImGui::GetDrawData();
-        const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
-        if (!is_minimized)
+        ImDrawData* main_draw_data = ImGui::GetDrawData();
+        const bool main_is_minimized = (main_draw_data->DisplaySize.x <= 0.0f || main_draw_data->DisplaySize.y <= 0.0f);
+        wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
+        wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
+        wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
+        wd->ClearValue.color.float32[3] = clear_color.w;
+        if (!main_is_minimized)
+            FrameRender(wd, main_draw_data);
+
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
         {
-            wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
-            wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
-            wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
-            wd->ClearValue.color.float32[3] = clear_color.w;
-            FrameRender(wd, draw_data);
-            FramePresent(wd);
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
         }
+
+        // Present Main Platform Window
+        if (!main_is_minimized)
+            FramePresent(wd);
     }
 
     // Cleanup
@@ -541,7 +582,7 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
             if (fb_width > 0 && fb_height > 0 && (g_SwapChainRebuild || g_MainWindowData.Width != fb_width || g_MainWindowData.Height != fb_height))
             {
                 ImGui_ImplVulkan_SetMinImageCount(g_MinImageCount);
-                ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, fb_width, fb_height, g_MinImageCount);
+                ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, fb_width, fb_height, g_MinImageCount, 0);
                 g_MainWindowData.FrameIndex = 0;
                 g_SwapChainRebuild = false;
             }

examples/imgui_examples.sln

@@ -39,6 +39,8 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "example_win32_vulkan", "exa
 EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "example_sdl3_sdlgpu3", "example_sdl3_sdlgpu3\example_sdl3_sdlgpu3.vcxproj", "{C22CB6F8-39A5-4DDA-90ED-4ACA4E81E1E5}"
 EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "example_sdl3_directx11", "example_sdl3_directx11\example_sdl3_directx11.vcxproj", "{009DAC16-1A9C-47BE-9770-A30A046E8090}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Win32 = Debug|Win32
@@ -191,6 +193,14 @@ Global
 		{C22CB6F8-39A5-4DDA-90ED-4ACA4E81E1E5}.Release|Win32.Build.0 = Release|Win32
 		{C22CB6F8-39A5-4DDA-90ED-4ACA4E81E1E5}.Release|x64.ActiveCfg = Release|x64
 		{C22CB6F8-39A5-4DDA-90ED-4ACA4E81E1E5}.Release|x64.Build.0 = Release|x64
+		{009DAC16-1A9C-47BE-9770-A30A046E8090}.Debug|Win32.ActiveCfg = Debug|Win32
+		{009DAC16-1A9C-47BE-9770-A30A046E8090}.Debug|Win32.Build.0 = Debug|Win32
+		{009DAC16-1A9C-47BE-9770-A30A046E8090}.Debug|x64.ActiveCfg = Debug|x64
+		{009DAC16-1A9C-47BE-9770-A30A046E8090}.Debug|x64.Build.0 = Debug|x64
+		{009DAC16-1A9C-47BE-9770-A30A046E8090}.Release|Win32.ActiveCfg = Release|Win32
+		{009DAC16-1A9C-47BE-9770-A30A046E8090}.Release|Win32.Build.0 = Release|Win32
+		{009DAC16-1A9C-47BE-9770-A30A046E8090}.Release|x64.ActiveCfg = Release|x64
+		{009DAC16-1A9C-47BE-9770-A30A046E8090}.Release|x64.Build.0 = Release|x64
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

imconfig.h

@@ -83,6 +83,7 @@
 
 //---- Use FreeType to build and rasterize the font atlas (instead of stb_truetype which is embedded by default in Dear ImGui)
 // Requires FreeType headers to be available in the include path. Requires program to be compiled with 'misc/freetype/imgui_freetype.cpp' (in this repository) + the FreeType library (not provided).
+// Note that imgui_freetype.cpp may be used _without_ this define, if you manually call ImFontAtlas::SetFontLoader(). The define is simply a convenience.
 // On Windows you may use vcpkg with 'vcpkg install freetype --triplet=x64-windows' + 'vcpkg integrate install'.
 //#define IMGUI_ENABLE_FREETYPE
 

imgui.h

@@ -1,4 +1,4 @@
-// dear imgui, v1.92.1
+// dear imgui, v1.92.4
 // (headers)
 
 // Help:
@@ -28,10 +28,12 @@
 
 // Library Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM >= 12345')
-#define IMGUI_VERSION       "1.92.1"
-#define IMGUI_VERSION_NUM   19210
+#define IMGUI_VERSION       "1.92.4"
+#define IMGUI_VERSION_NUM   19240
 #define IMGUI_HAS_TABLE             // Added BeginTable() - from IMGUI_VERSION_NUM >= 18000
 #define IMGUI_HAS_TEXTURES          // Added ImGuiBackendFlags_RendererHasTextures - from IMGUI_VERSION_NUM >= 19198
+#define IMGUI_HAS_VIEWPORT          // In 'docking' WIP branch.
+#define IMGUI_HAS_DOCK              // In 'docking' WIP branch.
 
 /*
 
@@ -45,14 +47,14 @@ Index of this file:
 // [SECTION] Helpers: Debug log, Memory allocations macros, ImVector<>
 // [SECTION] ImGuiStyle
 // [SECTION] ImGuiIO
-// [SECTION] Misc data structures (ImGuiInputTextCallbackData, ImGuiSizeCallbackData, ImGuiPayload)
+// [SECTION] Misc data structures (ImGuiInputTextCallbackData, ImGuiSizeCallbackData, ImGuiWindowClass, ImGuiPayload)
 // [SECTION] Helpers (ImGuiOnceUponAFrame, ImGuiTextFilter, ImGuiTextBuffer, ImGuiStorage, ImGuiListClipper, Math Operators, ImColor)
 // [SECTION] Multi-Select API flags and structures (ImGuiMultiSelectFlags, ImGuiMultiSelectIO, ImGuiSelectionRequest, ImGuiSelectionBasicStorage, ImGuiSelectionExternalStorage)
 // [SECTION] Drawing API (ImDrawCallback, ImDrawCmd, ImDrawIdx, ImDrawVert, ImDrawChannel, ImDrawListSplitter, ImDrawFlags, ImDrawListFlags, ImDrawList, ImDrawData)
 // [SECTION] Texture API (ImTextureFormat, ImTextureStatus, ImTextureRect, ImTextureData)
 // [SECTION] Font API (ImFontConfig, ImFontGlyph, ImFontGlyphRangesBuilder, ImFontAtlasFlags, ImFontAtlas, ImFontBaked, ImFont)
 // [SECTION] Viewports (ImGuiViewportFlags, ImGuiViewport)
-// [SECTION] ImGuiPlatformIO + other Platform Dependent Interfaces (ImGuiPlatformImeData)
+// [SECTION] ImGuiPlatformIO + other Platform Dependent Interfaces (ImGuiPlatformMonitor, ImGuiPlatformImeData)
 // [SECTION] Obsolete functions and types
 
 */
@@ -100,8 +102,10 @@ Index of this file:
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 
 // Helper Macros - IM_FMTARGS, IM_FMTLIST: Apply printf-style warnings to our formatting functions.
-// (MSVC provides an equivalent mechanism via SAL Annotations but it would require the macros in a different
-//  location. e.g. #include <sal.h> + void myprintf(_Printf_format_string_ const char* format, ...))
+// (MSVC provides an equivalent mechanism via SAL Annotations but it requires the macros in a different
+//  location. e.g. #include <sal.h> + void myprintf(_Printf_format_string_ const char* format, ...),
+//  and only works when using Code Analysis, rather than just normal compiling).
+// (see https://github.com/ocornut/imgui/issues/8871 for a patch to enable this for MSVC's Code Analysis)
 #if !defined(IMGUI_USE_STB_SPRINTF) && defined(__MINGW32__) && !defined(__clang__)
 #define IM_FMTARGS(FMT)             __attribute__((format(gnu_printf, FMT, FMT+1)))
 #define IM_FMTLIST(FMT)             __attribute__((format(gnu_printf, FMT, 0)))
@@ -191,8 +195,9 @@ struct ImGuiListClipper;            // Helper to manually clip large list of ite
 struct ImGuiMultiSelectIO;          // Structure to interact with a BeginMultiSelect()/EndMultiSelect() block
 struct ImGuiOnceUponAFrame;         // Helper for running a block of code not more than once a frame
 struct ImGuiPayload;                // User data payload for drag and drop operations
-struct ImGuiPlatformIO;             // Interface between platform/renderer backends and ImGui (e.g. Clipboard, IME hooks). Extends ImGuiIO. In docking branch, this gets extended to support multi-viewports.
+struct ImGuiPlatformIO;             // Interface between platform/renderer backends and ImGui (e.g. Clipboard, IME, Multi-Viewport support). Extends ImGuiIO.
 struct ImGuiPlatformImeData;        // Platform IME data for io.PlatformSetImeDataFn() function.
+struct ImGuiPlatformMonitor;        // Multi-viewport support: user-provided bounds for each connected monitor/display. Used when positioning popups and tooltips to avoid them straddling monitors
 struct ImGuiSelectionBasicStorage;  // Optional helper to store multi-selection state + apply multi-selection requests.
 struct ImGuiSelectionExternalStorage;//Optional helper to apply multi-selection requests to existing randomly accessible storage.
 struct ImGuiSelectionRequest;       // A selection request (stored in ImGuiMultiSelectIO)
@@ -204,7 +209,8 @@ struct ImGuiTableSortSpecs;         // Sorting specifications for a table (often
 struct ImGuiTableColumnSortSpecs;   // Sorting specification for one column of a table
 struct ImGuiTextBuffer;             // Helper to hold and append into a text buffer (~string builder)
 struct ImGuiTextFilter;             // Helper to parse and apply text filters (e.g. "aaaaa[,bbbbb][,ccccc]")
-struct ImGuiViewport;               // A Platform Window (always only one in 'master' branch), in the future may represent Platform Monitor
+struct ImGuiViewport;               // A Platform Window (always 1 unless multi-viewport are enabled. One per platform window to output to). In the future may represent Platform Monitor
+struct ImGuiWindowClass;            // Window class (rare/advanced uses: provide hints to the platform backend via altered viewport flags and parent/child info)
 
 // Enumerations
 // - We don't use strongly typed enums much because they add constraints (can't extend in private code, can't store typed in bit fields, extra casting on iteration)
@@ -231,6 +237,7 @@ typedef int ImGuiTableBgTarget;     // -> enum ImGuiTableBgTarget_   // Enum: A
 //   - In VS Code, CLion, etc.: CTRL+click can follow symbols inside comments.
 typedef int ImDrawFlags;            // -> enum ImDrawFlags_          // Flags: for ImDrawList functions
 typedef int ImDrawListFlags;        // -> enum ImDrawListFlags_      // Flags: for ImDrawList instance
+typedef int ImDrawTextFlags;        // -> enum ImDrawTextFlags_      // Internal, do not use!
 typedef int ImFontFlags;            // -> enum ImFontFlags_          // Flags: for ImFont
 typedef int ImFontAtlasFlags;       // -> enum ImFontAtlasFlags_     // Flags: for ImFontAtlas
 typedef int ImGuiBackendFlags;      // -> enum ImGuiBackendFlags_    // Flags: for io.BackendFlags
@@ -239,6 +246,7 @@ typedef int ImGuiChildFlags;        // -> enum ImGuiChildFlags_      // Flags: f
 typedef int ImGuiColorEditFlags;    // -> enum ImGuiColorEditFlags_  // Flags: for ColorEdit4(), ColorPicker4() etc.
 typedef int ImGuiConfigFlags;       // -> enum ImGuiConfigFlags_     // Flags: for io.ConfigFlags
 typedef int ImGuiComboFlags;        // -> enum ImGuiComboFlags_      // Flags: for BeginCombo()
+typedef int ImGuiDockNodeFlags;     // -> enum ImGuiDockNodeFlags_   // Flags: for DockSpace()
 typedef int ImGuiDragDropFlags;     // -> enum ImGuiDragDropFlags_   // Flags: for BeginDragDropSource(), AcceptDragDropPayload()
 typedef int ImGuiFocusedFlags;      // -> enum ImGuiFocusedFlags_    // Flags: for IsWindowFocused()
 typedef int ImGuiHoveredFlags;      // -> enum ImGuiHoveredFlags_    // Flags: for IsItemHovered(), IsWindowHovered() etc.
@@ -246,6 +254,7 @@ typedef int ImGuiInputFlags;        // -> enum ImGuiInputFlags_      // Flags: f
 typedef int ImGuiInputTextFlags;    // -> enum ImGuiInputTextFlags_  // Flags: for InputText(), InputTextMultiline()
 typedef int ImGuiItemFlags;         // -> enum ImGuiItemFlags_       // Flags: for PushItemFlag(), shared by all items
 typedef int ImGuiKeyChord;          // -> ImGuiKey | ImGuiMod_XXX    // Flags: for IsKeyChordPressed(), Shortcut() etc. an ImGuiKey optionally OR-ed with one or more ImGuiMod_XXX values.
+typedef int ImGuiListClipperFlags;  // -> enum ImGuiListClipperFlags_// Flags: for ImGuiListClipper
 typedef int ImGuiPopupFlags;        // -> enum ImGuiPopupFlags_      // Flags: for OpenPopup*(), BeginPopupContext*(), IsPopupOpen()
 typedef int ImGuiMultiSelectFlags;  // -> enum ImGuiMultiSelectFlags_// Flags: for BeginMultiSelect()
 typedef int ImGuiSelectableFlags;   // -> enum ImGuiSelectableFlags_ // Flags: for Selectable()
@@ -317,7 +326,7 @@ IM_MSVC_RUNTIME_CHECKS_RESTORE
 // - When a Rendered Backend creates a texture, it store its native identifier into a ImTextureID value.
 //   (e.g. Used by DX11 backend to a `ID3D11ShaderResourceView*`; Used by OpenGL backends to store `GLuint`;
 //         Used by SDLGPU backend to store a `SDL_GPUTextureSamplerBinding*`, etc.).
-// - User may submit their own textures to e.g. ImGui::Image() function by passing the same type.
+// - User may submit their own textures to e.g. ImGui::Image() function by passing this value.
 // - During the rendering loop, the Renderer Backend retrieve the ImTextureID, which stored inside a
 //   ImTextureRef, which is stored inside a ImDrawCmd.
 // - Compile-time type configuration:
@@ -337,15 +346,17 @@ typedef ImU64 ImTextureID;      // Default: store up to 64-bits (any pointer or
 #define ImTextureID_Invalid     ((ImTextureID)0)
 #endif
 
-// ImTextureRef = higher-level identifier for a texture.
+// ImTextureRef = higher-level identifier for a texture. Store a ImTextureID _or_ a ImTextureData*.
 // The identifier is valid even before the texture has been uploaded to the GPU/graphics system.
 // This is what gets passed to functions such as `ImGui::Image()`, `ImDrawList::AddImage()`.
 // This is what gets stored in draw commands (`ImDrawCmd`) to identify a texture during rendering.
 // - When a texture is created by user code (e.g. custom images), we directly stores the low-level ImTextureID.
+//   Because of this, when displaying your own texture you are likely to ever only manage ImTextureID values on your side.
 // - When a texture is created by the backend, we stores a ImTextureData* which becomes an indirection
 //   to extract the ImTextureID value during rendering, after texture upload has happened.
-// - There is no constructor to create a ImTextureID from a ImTextureData* as we don't expect this
-//   to be useful to the end-user, and it would be erroneously called by many legacy code.
+// - To create a ImTextureRef from a ImTextureData you can use ImTextureData::GetTexRef().
+//   We intentionally do not provide an ImTextureRef constructor for this: we don't expect this
+//   to be frequently useful to the end-user, and it would be erroneously called by many legacy code.
 // - If you want to bind the current atlas when using custom rectangle, you can use io.Fonts->TexRef.
 // - Binding generators for languages such as C (which don't have constructors), should provide a helper, e.g.
 //      inline ImTextureRef ImTextureRefFromID(ImTextureID tex_id) { ImTextureRef tex_ref = { ._TexData = NULL, .TexID = tex_id }; return tex_ref; }
@@ -454,10 +465,12 @@ namespace ImGui
     IMGUI_API bool          IsWindowFocused(ImGuiFocusedFlags flags=0); // is current window focused? or its root/child, depending on flags. see flags for options.
     IMGUI_API bool          IsWindowHovered(ImGuiHoveredFlags flags=0); // is current window hovered and hoverable (e.g. not blocked by a popup/modal)? See ImGuiHoveredFlags_ for options. IMPORTANT: If you are trying to check whether your mouse should be dispatched to Dear ImGui or to your underlying app, you should not use this function! Use the 'io.WantCaptureMouse' boolean for that! Refer to FAQ entry "How can I tell whether to dispatch mouse/keyboard to Dear ImGui or my application?" for details.
     IMGUI_API ImDrawList*   GetWindowDrawList();                        // get draw list associated to the current window, to append your own drawing primitives
+    IMGUI_API float         GetWindowDpiScale();                        // get DPI scale currently associated to the current window's viewport.
     IMGUI_API ImVec2        GetWindowPos();                             // get current window position in screen space (IT IS UNLIKELY YOU EVER NEED TO USE THIS. Consider always using GetCursorScreenPos() and GetContentRegionAvail() instead)
     IMGUI_API ImVec2        GetWindowSize();                            // get current window size (IT IS UNLIKELY YOU EVER NEED TO USE THIS. Consider always using GetCursorScreenPos() and GetContentRegionAvail() instead)
     IMGUI_API float         GetWindowWidth();                           // get current window width (IT IS UNLIKELY YOU EVER NEED TO USE THIS). Shortcut for GetWindowSize().x.
     IMGUI_API float         GetWindowHeight();                          // get current window height (IT IS UNLIKELY YOU EVER NEED TO USE THIS). Shortcut for GetWindowSize().y.
+    IMGUI_API ImGuiViewport*GetWindowViewport();                        // get viewport currently associated to the current window.
 
     // Window manipulation
     // - Prefer using SetNextXXX functions (before Begin) rather that SetXXX functions (after Begin).
@@ -469,6 +482,7 @@ namespace ImGui
     IMGUI_API void          SetNextWindowFocus();                                                       // set next window to be focused / top-most. call before Begin()
     IMGUI_API void          SetNextWindowScroll(const ImVec2& scroll);                                  // set next window scrolling value (use < 0.0f to not affect a given axis).
     IMGUI_API void          SetNextWindowBgAlpha(float alpha);                                          // set next window background color alpha. helper to easily override the Alpha component of ImGuiCol_WindowBg/ChildBg/PopupBg. you may also use ImGuiWindowFlags_NoBackground.
+    IMGUI_API void          SetNextWindowViewport(ImGuiID viewport_id);                                 // set next window viewport
     IMGUI_API void          SetWindowPos(const ImVec2& pos, ImGuiCond cond = 0);                        // (not recommended) set current window position - call within Begin()/End(). prefer using SetNextWindowPos(), as this may incur tearing and side-effects.
     IMGUI_API void          SetWindowSize(const ImVec2& size, ImGuiCond cond = 0);                      // (not recommended) set current window size - call within Begin()/End(). set to ImVec2(0, 0) to force an auto-fit. prefer using SetNextWindowSize(), as this may incur tearing and minor side-effects.
     IMGUI_API void          SetWindowCollapsed(bool collapsed, ImGuiCond cond = 0);                     // (not recommended) set current window collapsed state. prefer using SetNextWindowCollapsed().
@@ -914,7 +928,7 @@ namespace ImGui
     IMGUI_API ImGuiTableSortSpecs*  TableGetSortSpecs();                        // get latest sort specs for the table (NULL if not sorting).  Lifetime: don't hold on this pointer over multiple frames or past any subsequent call to BeginTable().
     IMGUI_API int                   TableGetColumnCount();                      // return number of columns (value passed to BeginTable)
     IMGUI_API int                   TableGetColumnIndex();                      // return current column index.
-    IMGUI_API int                   TableGetRowIndex();                         // return current row index.
+    IMGUI_API int                   TableGetRowIndex();                         // return current row index (header rows are accounted for)
     IMGUI_API const char*           TableGetColumnName(int column_n = -1);      // return "" if column didn't have a name declared by TableSetupColumn(). Pass -1 to use current column.
     IMGUI_API ImGuiTableColumnFlags TableGetColumnFlags(int column_n = -1);     // return column flags so you can query their Enabled/Visible/Sorted/Hovered status flags. Pass -1 to use current column.
     IMGUI_API void                  TableSetColumnEnabled(int column_n, bool v);// change user accessible enabled/disabled state of a column. Set to false to hide the column. User can use the context menu to change this themselves (right-click in headers, or right-click in columns body with ImGuiTableFlags_ContextMenuInBody)
@@ -941,6 +955,32 @@ namespace ImGui
     IMGUI_API bool          TabItemButton(const char* label, ImGuiTabItemFlags flags = 0);      // create a Tab behaving like a button. return true when clicked. cannot be selected in the tab bar.
     IMGUI_API void          SetTabItemClosed(const char* tab_or_docked_window_label);           // notify TabBar or Docking system of a closed tab/window ahead (useful to reduce visual flicker on reorderable tab bars). For tab-bar: call after BeginTabBar() and before Tab submissions. Otherwise call with a window name.
 
+    // Docking
+    // - Read https://github.com/ocornut/imgui/wiki/Docking for details.
+    // - Enable with io.ConfigFlags |= ImGuiConfigFlags_DockingEnable.
+    // - You can use most Docking facilities without calling any API. You don't necessarily need to call a DockSpaceXXX function to use Docking!
+    //   - Drag from window title bar or their tab to dock/undock. Hold SHIFT to disable docking.
+    //   - Drag from window menu button (upper-left button) to undock an entire node (all windows).
+    //   - When io.ConfigDockingWithShift == true, you instead need to hold SHIFT to enable docking.
+    // - Dockspaces:
+    //   - If you want to dock windows into the edge of your screen, most application can simply call DockSpaceOverViewport():
+    //     e.g. ImGui::NewFrame(); then ImGui::DockSpaceOverViewport();  // Create a dockspace in main viewport.
+    //      or: ImGui::NewFrame(); then ImGui::DockSpaceOverViewport(0, nullptr, ImGuiDockNodeFlags_PassthruCentralNode);  // Create a dockspace in main viewport, where central node is transparent.
+    //   - A dockspace is an explicit dock node within an existing window.
+    //   - DockSpaceOverViewport() basically creates an invisible window covering a viewport, and submit a DockSpace() into it.
+    //   - IMPORTANT: Dockspaces need to be submitted _before_ any window they can host. Submit them early in your frame!
+    //   - IMPORTANT: Dockspaces need to be kept alive if hidden, otherwise windows docked into it will be undocked.
+    //     If you have e.g. multiple tabs with a dockspace inside each tab: submit the non-visible dockspaces with ImGuiDockNodeFlags_KeepAliveOnly.
+    // - Programmatic docking:
+    //   - There is no public API yet other than the very limited SetNextWindowDockID() function. Sorry for that!
+    //   - Read https://github.com/ocornut/imgui/wiki/Docking for examples of how to use current internal API.
+    IMGUI_API ImGuiID       DockSpace(ImGuiID dockspace_id, const ImVec2& size = ImVec2(0, 0), ImGuiDockNodeFlags flags = 0, const ImGuiWindowClass* window_class = NULL);
+    IMGUI_API ImGuiID       DockSpaceOverViewport(ImGuiID dockspace_id = 0, const ImGuiViewport* viewport = NULL, ImGuiDockNodeFlags flags = 0, const ImGuiWindowClass* window_class = NULL);
+    IMGUI_API void          SetNextWindowDockID(ImGuiID dock_id, ImGuiCond cond = 0);           // set next window dock id
+    IMGUI_API void          SetNextWindowClass(const ImGuiWindowClass* window_class);           // set next window class (control docking compatibility + provide hints to platform backend via custom viewport flags and platform parent/child relationship)
+    IMGUI_API ImGuiID       GetWindowDockID();
+    IMGUI_API bool          IsWindowDocked();                                                   // is current window docked into another window?
+
     // Logging/Capture
     // - All text output from the interface can be captured into tty/file/clipboard. By default, tree nodes are automatically opened during logging.
     IMGUI_API void          LogToTTY(int auto_open_depth = -1);                                 // start logging to tty (stdout)
@@ -1015,8 +1055,8 @@ namespace ImGui
     IMGUI_API ImGuiViewport* GetMainViewport();                                                 // return primary/default viewport. This can never be NULL.
 
     // Background/Foreground Draw Lists
-    IMGUI_API ImDrawList*   GetBackgroundDrawList();                                            // this draw list will be the first rendered one. Useful to quickly draw shapes/text behind dear imgui contents.
-    IMGUI_API ImDrawList*   GetForegroundDrawList();                                            // this draw list will be the last rendered one. Useful to quickly draw shapes/text over dear imgui contents.
+    IMGUI_API ImDrawList*   GetBackgroundDrawList(ImGuiViewport* viewport = NULL);              // get background draw list for the given viewport or viewport associated to the current window. this draw list will be the first rendering one. Useful to quickly draw shapes/text behind dear imgui contents.
+    IMGUI_API ImDrawList*   GetForegroundDrawList(ImGuiViewport* viewport = NULL);              // get foreground draw list for the given viewport or viewport associated to the current window. this draw list will be the top-most rendered one. Useful to quickly draw shapes/text over dear imgui contents.
 
     // Miscellaneous Utilities
     IMGUI_API bool          IsRectVisible(const ImVec2& size);                                  // test if rectangle (of given size, starting from cursor position) is visible / not clipped.
@@ -1051,8 +1091,8 @@ namespace ImGui
 
     // Inputs Utilities: Shortcut Testing & Routing [BETA]
     // - ImGuiKeyChord = a ImGuiKey + optional ImGuiMod_Alt/ImGuiMod_Ctrl/ImGuiMod_Shift/ImGuiMod_Super.
-    //       ImGuiKey_C                          // Accepted by functions taking ImGuiKey or ImGuiKeyChord arguments)
-    //       ImGuiMod_Ctrl | ImGuiKey_C          // Accepted by functions taking ImGuiKeyChord arguments)
+    //       ImGuiKey_C                          // Accepted by functions taking ImGuiKey or ImGuiKeyChord arguments
+    //       ImGuiMod_Ctrl | ImGuiKey_C          // Accepted by functions taking ImGuiKeyChord arguments
     //   only ImGuiMod_XXX values are legal to combine with an ImGuiKey. You CANNOT combine two ImGuiKey values.
     // - The general idea is that several callers may register interest in a shortcut, and only one owner gets it.
     //      Parent   -> call Shortcut(Ctrl+S)    // When Parent is focused, Parent gets the shortcut.
@@ -1131,6 +1171,15 @@ namespace ImGui
     IMGUI_API void*         MemAlloc(size_t size);
     IMGUI_API void          MemFree(void* ptr);
 
+    // (Optional) Platform/OS interface for multi-viewport support
+    // Read comments around the ImGuiPlatformIO structure for more details.
+    // Note: You may use GetWindowViewport() to get the current viewport of the current window.
+    IMGUI_API void          UpdatePlatformWindows();                                // call in main loop. will call CreateWindow/ResizeWindow/etc. platform functions for each secondary viewport, and DestroyWindow for each inactive viewport.
+    IMGUI_API void          RenderPlatformWindowsDefault(void* platform_render_arg = NULL, void* renderer_render_arg = NULL); // call in main loop. will call RenderWindow/SwapBuffers platform functions for each secondary viewport which doesn't have the ImGuiViewportFlags_Minimized flag set. May be reimplemented by user for custom rendering needs.
+    IMGUI_API void          DestroyPlatformWindows();                               // call DestroyWindow platform functions for all viewports. call from backend Shutdown() if you need to close platform windows before imgui shutdown. otherwise will be called by DestroyContext().
+    IMGUI_API ImGuiViewport* FindViewportByID(ImGuiID id);                          // this is a helper for backends.
+    IMGUI_API ImGuiViewport* FindViewportByPlatformHandle(void* platform_handle);   // this is a helper for backends. the type platform_handle is decided by the backend (e.g. HWND, MyWindow*, GLFWwindow* etc.)
+
 } // namespace ImGui
 
 //-----------------------------------------------------------------------------
@@ -1161,11 +1210,13 @@ enum ImGuiWindowFlags_
     ImGuiWindowFlags_NoNavInputs            = 1 << 16,  // No keyboard/gamepad navigation within the window
     ImGuiWindowFlags_NoNavFocus             = 1 << 17,  // No focusing toward this window with keyboard/gamepad navigation (e.g. skipped by CTRL+TAB)
     ImGuiWindowFlags_UnsavedDocument        = 1 << 18,  // Display a dot next to the title. When used in a tab/docking context, tab is selected when clicking the X + closure is not assumed (will wait for user to stop submitting the tab). Otherwise closure is assumed when pressing the X, so if you keep submitting the tab may reappear at end of tab bar.
+    ImGuiWindowFlags_NoDocking              = 1 << 19,  // Disable docking of this window
     ImGuiWindowFlags_NoNav                  = ImGuiWindowFlags_NoNavInputs | ImGuiWindowFlags_NoNavFocus,
     ImGuiWindowFlags_NoDecoration           = ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoCollapse,
     ImGuiWindowFlags_NoInputs               = ImGuiWindowFlags_NoMouseInputs | ImGuiWindowFlags_NoNavInputs | ImGuiWindowFlags_NoNavFocus,
 
     // [Internal]
+    ImGuiWindowFlags_DockNodeHost           = 1 << 23,  // Don't use! For internal use by Begin()/NewFrame()
     ImGuiWindowFlags_ChildWindow            = 1 << 24,  // Don't use! For internal use by BeginChild()
     ImGuiWindowFlags_Tooltip                = 1 << 25,  // Don't use! For internal use by BeginTooltip()
     ImGuiWindowFlags_Popup                  = 1 << 26,  // Don't use! For internal use by BeginPopup()
@@ -1180,7 +1231,7 @@ enum ImGuiWindowFlags_
 };
 
 // Flags for ImGui::BeginChild()
-// (Legacy: bit 0 must always correspond to ImGuiChildFlags_Borders to be backward compatible with old API using 'bool border = false'.
+// (Legacy: bit 0 must always correspond to ImGuiChildFlags_Borders to be backward compatible with old API using 'bool border = false'.)
 // About using AutoResizeX/AutoResizeY flags:
 // - May be combined with SetNextWindowSizeConstraints() to set a min/max size for each axis (see "Demo->Child->Auto-resize with Constraints").
 // - Size measurement for a given axis is only performed when the child window is within visible boundaries, or is just appearing.
@@ -1259,6 +1310,15 @@ enum ImGuiInputTextFlags_
     ImGuiInputTextFlags_CallbackResize      = 1 << 22,  // Callback on buffer capacity changes request (beyond 'buf_size' parameter value), allowing the string to grow. Notify when the string wants to be resized (for string types which hold a cache of their Size). You will be provided a new BufSize in the callback and NEED to honor it. (see misc/cpp/imgui_stdlib.h for an example of using this)
     ImGuiInputTextFlags_CallbackEdit        = 1 << 23,  // Callback on any edit. Note that InputText() already returns true on edit + you can always use IsItemEdited(). The callback is useful to manipulate the underlying buffer while focus is active.
 
+    // Multi-line Word-Wrapping [BETA]
+    // - Not well tested yet. Please report any incorrect cursor movement, selection behavior etc. bug to https://github.com/ocornut/imgui/issues/3237.
+    // - Wrapping style is not ideal. Wrapping of long words/sections (e.g. words larger than total available width) may be particularly unpleasing.
+    // - Wrapping width needs to always account for the possibility of a vertical scrollbar.
+    // - It is much slower than regular text fields.
+    //   Ballpark estimate of cost on my 2019 desktop PC: for a 100 KB text buffer: +~0.3 ms (Optimized) / +~1.0 ms (Debug build).
+    //   The CPU cost is very roughly proportional to text length, so a 10 KB buffer should cost about ten times less.
+    ImGuiInputTextFlags_WordWrap            = 1 << 24,  // InputTextMultine(): word-wrap lines that are too long.
+
     // Obsolete names
     //ImGuiInputTextFlags_AlwaysInsertMode  = ImGuiInputTextFlags_AlwaysOverwrite   // [renamed in 1.82] name was not matching behavior
 };
@@ -1296,7 +1356,7 @@ enum ImGuiTreeNodeFlags_
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
     ImGuiTreeNodeFlags_NavLeftJumpsBackHere = ImGuiTreeNodeFlags_NavLeftJumpsToParent,  // Renamed in 1.92.0
     ImGuiTreeNodeFlags_SpanTextWidth        = ImGuiTreeNodeFlags_SpanLabelWidth,        // Renamed in 1.90.7
-    ImGuiTreeNodeFlags_AllowItemOverlap     = ImGuiTreeNodeFlags_AllowOverlap,          // Renamed in 1.89.7
+    //ImGuiTreeNodeFlags_AllowItemOverlap   = ImGuiTreeNodeFlags_AllowOverlap,          // Renamed in 1.89.7
 #endif
 };
 
@@ -1335,10 +1395,11 @@ enum ImGuiSelectableFlags_
     ImGuiSelectableFlags_Disabled           = 1 << 3,   // Cannot be selected, display grayed out text
     ImGuiSelectableFlags_AllowOverlap       = 1 << 4,   // (WIP) Hit testing to allow subsequent widgets to overlap this one
     ImGuiSelectableFlags_Highlight          = 1 << 5,   // Make the item be displayed as if it is hovered
+    ImGuiSelectableFlags_SelectOnNav        = 1 << 6,   // Auto-select when moved into, unless Ctrl is held. Automatic when in a BeginMultiSelect() block.
 
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
     ImGuiSelectableFlags_DontClosePopups    = ImGuiSelectableFlags_NoAutoClosePopups,   // Renamed in 1.91.0
-    ImGuiSelectableFlags_AllowItemOverlap   = ImGuiSelectableFlags_AllowOverlap,        // Renamed in 1.89.7
+    //ImGuiSelectableFlags_AllowItemOverlap = ImGuiSelectableFlags_AllowOverlap,        // Renamed in 1.89.7
 #endif
 };
 
@@ -1368,10 +1429,17 @@ enum ImGuiTabBarFlags_
     ImGuiTabBarFlags_NoTabListScrollingButtons      = 1 << 4,   // Disable scrolling buttons (apply when fitting policy is ImGuiTabBarFlags_FittingPolicyScroll)
     ImGuiTabBarFlags_NoTooltip                      = 1 << 5,   // Disable tooltips when hovering a tab
     ImGuiTabBarFlags_DrawSelectedOverline           = 1 << 6,   // Draw selected overline markers over selected tab
-    ImGuiTabBarFlags_FittingPolicyResizeDown        = 1 << 7,   // Resize tabs when they don't fit
-    ImGuiTabBarFlags_FittingPolicyScroll            = 1 << 8,   // Add scroll buttons when tabs don't fit
-    ImGuiTabBarFlags_FittingPolicyMask_             = ImGuiTabBarFlags_FittingPolicyResizeDown | ImGuiTabBarFlags_FittingPolicyScroll,
-    ImGuiTabBarFlags_FittingPolicyDefault_          = ImGuiTabBarFlags_FittingPolicyResizeDown,
+
+    // Fitting/Resize policy
+    ImGuiTabBarFlags_FittingPolicyMixed             = 1 << 7,   // Shrink down tabs when they don't fit, until width is style.TabMinWidthShrink, then enable scrolling buttons.
+    ImGuiTabBarFlags_FittingPolicyShrink            = 1 << 8,   // Shrink down tabs when they don't fit
+    ImGuiTabBarFlags_FittingPolicyScroll            = 1 << 9,   // Enable scrolling buttons when tabs don't fit
+    ImGuiTabBarFlags_FittingPolicyMask_             = ImGuiTabBarFlags_FittingPolicyMixed | ImGuiTabBarFlags_FittingPolicyShrink | ImGuiTabBarFlags_FittingPolicyScroll,
+    ImGuiTabBarFlags_FittingPolicyDefault_          = ImGuiTabBarFlags_FittingPolicyMixed,
+
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+    ImGuiTabBarFlags_FittingPolicyResizeDown        = ImGuiTabBarFlags_FittingPolicyShrink, // Renamed in 1.92.2
+#endif
 };
 
 // Flags for ImGui::BeginTabItem()
@@ -1397,7 +1465,7 @@ enum ImGuiFocusedFlags_
     ImGuiFocusedFlags_RootWindow                    = 1 << 1,   // Test from root window (top most parent of the current hierarchy)
     ImGuiFocusedFlags_AnyWindow                     = 1 << 2,   // Return true if any window is focused. Important: If you are trying to tell how to dispatch your low-level inputs, do NOT use this. Use 'io.WantCaptureMouse' instead! Please read the FAQ!
     ImGuiFocusedFlags_NoPopupHierarchy              = 1 << 3,   // Do not consider popup hierarchy (do not treat popup emitter as parent of popup) (when used with _ChildWindows or _RootWindow)
-    //ImGuiFocusedFlags_DockHierarchy               = 1 << 4,   // Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
+    ImGuiFocusedFlags_DockHierarchy                 = 1 << 4,   // Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
     ImGuiFocusedFlags_RootAndChildWindows           = ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_ChildWindows,
 };
 
@@ -1411,7 +1479,7 @@ enum ImGuiHoveredFlags_
     ImGuiHoveredFlags_RootWindow                    = 1 << 1,   // IsWindowHovered() only: Test from root window (top most parent of the current hierarchy)
     ImGuiHoveredFlags_AnyWindow                     = 1 << 2,   // IsWindowHovered() only: Return true if any window is hovered
     ImGuiHoveredFlags_NoPopupHierarchy              = 1 << 3,   // IsWindowHovered() only: Do not consider popup hierarchy (do not treat popup emitter as parent of popup) (when used with _ChildWindows or _RootWindow)
-    //ImGuiHoveredFlags_DockHierarchy               = 1 << 4,   // IsWindowHovered() only: Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
+    ImGuiHoveredFlags_DockHierarchy                 = 1 << 4,   // IsWindowHovered() only: Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
     ImGuiHoveredFlags_AllowWhenBlockedByPopup       = 1 << 5,   // Return true even if a popup window is normally blocking access to this item/window
     //ImGuiHoveredFlags_AllowWhenBlockedByModal     = 1 << 6,   // Return true even if a modal popup window is normally blocking access to this item/window. FIXME-TODO: Unavailable yet.
     ImGuiHoveredFlags_AllowWhenBlockedByActiveItem  = 1 << 7,   // Return true even if an active item is blocking access to this item/window. Useful for Drag and Drop patterns.
@@ -1441,6 +1509,27 @@ enum ImGuiHoveredFlags_
     ImGuiHoveredFlags_NoSharedDelay                 = 1 << 17,  // IsItemHovered() only: Disable shared delay system where moving from one item to the next keeps the previous timer for a short time (standard for tooltips with long delays)
 };
 
+// Flags for ImGui::DockSpace(), shared/inherited by child nodes.
+// (Some flags can be applied to individual nodes directly)
+// FIXME-DOCK: Also see ImGuiDockNodeFlagsPrivate_ which may involve using the WIP and internal DockBuilder api.
+enum ImGuiDockNodeFlags_
+{
+    ImGuiDockNodeFlags_None                         = 0,
+    ImGuiDockNodeFlags_KeepAliveOnly                = 1 << 0,   //       // Don't display the dockspace node but keep it alive. Windows docked into this dockspace node won't be undocked.
+    //ImGuiDockNodeFlags_NoCentralNode              = 1 << 1,   //       // Disable Central Node (the node which can stay empty)
+    ImGuiDockNodeFlags_NoDockingOverCentralNode     = 1 << 2,   //       // Disable docking over the Central Node, which will be always kept empty.
+    ImGuiDockNodeFlags_PassthruCentralNode          = 1 << 3,   //       // Enable passthru dockspace: 1) DockSpace() will render a ImGuiCol_WindowBg background covering everything excepted the Central Node when empty. Meaning the host window should probably use SetNextWindowBgAlpha(0.0f) prior to Begin() when using this. 2) When Central Node is empty: let inputs pass-through + won't display a DockingEmptyBg background. See demo for details.
+    ImGuiDockNodeFlags_NoDockingSplit               = 1 << 4,   //       // Disable other windows/nodes from splitting this node.
+    ImGuiDockNodeFlags_NoResize                     = 1 << 5,   // Saved // Disable resizing node using the splitter/separators. Useful with programmatically setup dockspaces.
+    ImGuiDockNodeFlags_AutoHideTabBar               = 1 << 6,   //       // Tab bar will automatically hide when there is a single window in the dock node.
+    ImGuiDockNodeFlags_NoUndocking                  = 1 << 7,   //       // Disable undocking this node.
+
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+    ImGuiDockNodeFlags_NoSplit                      = ImGuiDockNodeFlags_NoDockingSplit, // Renamed in 1.90
+    ImGuiDockNodeFlags_NoDockingInCentralNode       = ImGuiDockNodeFlags_NoDockingOverCentralNode, // Renamed in 1.90
+#endif
+};
+
 // Flags for ImGui::BeginDragDropSource(), ImGui::AcceptDragDropPayload()
 enum ImGuiDragDropFlags_
 {
@@ -1673,6 +1762,13 @@ enum ImGuiConfigFlags_
     ImGuiConfigFlags_NoMouseCursorChange    = 1 << 5,   // Instruct backend to not alter mouse cursor shape and visibility. Use if the backend cursor changes are interfering with yours and you don't want to use SetMouseCursor() to change mouse cursor. You may want to honor requests from imgui by reading GetMouseCursor() yourself instead.
     ImGuiConfigFlags_NoKeyboard             = 1 << 6,   // Instruct dear imgui to disable keyboard inputs and interactions. This is done by ignoring keyboard events and clearing existing states.
 
+    // [BETA] Docking
+    ImGuiConfigFlags_DockingEnable          = 1 << 7,   // Docking enable flags.
+
+    // [BETA] Viewports
+    // When using viewports it is recommended that your default value for ImGuiCol_WindowBg is opaque (Alpha=1.0) so transition to a viewport won't be noticeable.
+    ImGuiConfigFlags_ViewportsEnable        = 1 << 10,  // Viewport enable flags (require both ImGuiBackendFlags_PlatformHasViewports + ImGuiBackendFlags_RendererHasViewports set by the respective backends)
+
     // User storage (to allow your backend/engine to communicate to code that may be shared between multiple projects. Those flags are NOT used by core Dear ImGui)
     ImGuiConfigFlags_IsSRGB                 = 1 << 20,  // Application is SRGB-aware.
     ImGuiConfigFlags_IsTouchScreen          = 1 << 21,  // Application is using a touch screen instead of a mouse.
@@ -1680,6 +1776,8 @@ enum ImGuiConfigFlags_
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
     ImGuiConfigFlags_NavEnableSetMousePos   = 1 << 2,   // [moved/renamed in 1.91.4] -> use bool io.ConfigNavMoveSetMousePos
     ImGuiConfigFlags_NavNoCaptureKeyboard   = 1 << 3,   // [moved/renamed in 1.91.4] -> use bool io.ConfigNavCaptureKeyboard
+    ImGuiConfigFlags_DpiEnableScaleFonts    = 1 << 14,  // [moved/renamed in 1.92.0] -> use bool io.ConfigDpiScaleFonts
+    ImGuiConfigFlags_DpiEnableScaleViewports= 1 << 15,  // [moved/renamed in 1.92.0] -> use bool io.ConfigDpiScaleViewports
 #endif
 };
 
@@ -1692,6 +1790,12 @@ enum ImGuiBackendFlags_
     ImGuiBackendFlags_HasSetMousePos        = 1 << 2,   // Backend Platform supports io.WantSetMousePos requests to reposition the OS mouse position (only used if io.ConfigNavMoveSetMousePos is set).
     ImGuiBackendFlags_RendererHasVtxOffset  = 1 << 3,   // Backend Renderer supports ImDrawCmd::VtxOffset. This enables output of large meshes (64K+ vertices) while still using 16-bit indices.
     ImGuiBackendFlags_RendererHasTextures   = 1 << 4,   // Backend Renderer supports ImTextureData requests to create/update/destroy textures. This enables incremental texture updates and texture reloads. See https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md for instructions on how to upgrade your custom backend.
+
+    // [BETA] Multi-Viewports
+    ImGuiBackendFlags_RendererHasViewports  = 1 << 10,  // Backend Renderer supports multiple viewports.
+    ImGuiBackendFlags_PlatformHasViewports  = 1 << 11,  // Backend Platform supports multiple viewports.
+    ImGuiBackendFlags_HasMouseHoveredViewport=1 << 12,  // Backend Platform supports calling io.AddMouseViewportEvent() with the viewport under the mouse. IF POSSIBLE, ignore viewports with the ImGuiViewportFlags_NoInputs flag (Win32 backend, GLFW 3.30+ backend can do this, SDL backend cannot). If this cannot be done, Dear ImGui needs to use a flawed heuristic to find the viewport under.
+    ImGuiBackendFlags_HasParentViewport     = 1 << 13,  // Backend Platform supports honoring viewport->ParentViewport/ParentViewportId value, by applying the corresponding parent/child relation at the Platform level.
 };
 
 // Enumeration for PushStyleColor() / PopStyleColor()
@@ -1738,6 +1842,8 @@ enum ImGuiCol_
     ImGuiCol_TabDimmed,             // Tab background, when tab-bar is unfocused & tab is unselected
     ImGuiCol_TabDimmedSelected,     // Tab background, when tab-bar is unfocused & tab is selected
     ImGuiCol_TabDimmedSelectedOverline,//..horizontal overline, when tab-bar is unfocused & tab is selected
+    ImGuiCol_DockingPreview,        // Preview overlay color when about to docking something
+    ImGuiCol_DockingEmptyBg,        // Background color for empty node (e.g. CentralNode with no window docked into it)
     ImGuiCol_PlotLines,
     ImGuiCol_PlotLinesHovered,
     ImGuiCol_PlotHistogram,
@@ -1751,6 +1857,7 @@ enum ImGuiCol_
     ImGuiCol_TextSelectedBg,        // Selected text inside an InputText
     ImGuiCol_TreeLines,             // Tree node hierarchy outlines when using ImGuiTreeNodeFlags_DrawLines
     ImGuiCol_DragDropTarget,        // Rectangle highlighting a drop target
+    ImGuiCol_UnsavedMarker,         // Unsaved Document marker (in window title and tabs)
     ImGuiCol_NavCursor,             // Color of keyboard/gamepad navigation cursor/rectangle, when visible
     ImGuiCol_NavWindowingHighlight, // Highlight window when using CTRL+TAB
     ImGuiCol_NavWindowingDimBg,     // Darken/colorize entire screen behind the CTRL+TAB window list, when active
@@ -1796,11 +1903,14 @@ enum ImGuiStyleVar_
     ImGuiStyleVar_CellPadding,              // ImVec2    CellPadding
     ImGuiStyleVar_ScrollbarSize,            // float     ScrollbarSize
     ImGuiStyleVar_ScrollbarRounding,        // float     ScrollbarRounding
+    ImGuiStyleVar_ScrollbarPadding,         // float     ScrollbarPadding
     ImGuiStyleVar_GrabMinSize,              // float     GrabMinSize
     ImGuiStyleVar_GrabRounding,             // float     GrabRounding
     ImGuiStyleVar_ImageBorderSize,          // float     ImageBorderSize
     ImGuiStyleVar_TabRounding,              // float     TabRounding
     ImGuiStyleVar_TabBorderSize,            // float     TabBorderSize
+    ImGuiStyleVar_TabMinWidthBase,          // float     TabMinWidthBase
+    ImGuiStyleVar_TabMinWidthShrink,        // float     TabMinWidthShrink
     ImGuiStyleVar_TabBarBorderSize,         // float     TabBarBorderSize
     ImGuiStyleVar_TabBarOverlineSize,       // float     TabBarOverlineSize
     ImGuiStyleVar_TableAngledHeadersAngle,  // float     TableAngledHeadersAngle
@@ -1812,6 +1922,7 @@ enum ImGuiStyleVar_
     ImGuiStyleVar_SeparatorTextBorderSize,  // float     SeparatorTextBorderSize
     ImGuiStyleVar_SeparatorTextAlign,       // ImVec2    SeparatorTextAlign
     ImGuiStyleVar_SeparatorTextPadding,     // ImVec2    SeparatorTextPadding
+    ImGuiStyleVar_DockingSeparatorSize,     // float     DockingSeparatorSize
     ImGuiStyleVar_COUNT
 };
 
@@ -2170,7 +2281,7 @@ struct ImVector
     // Constructors, destructor
     inline ImVector()                                       { Size = Capacity = 0; Data = NULL; }
     inline ImVector(const ImVector<T>& src)                 { Size = Capacity = 0; Data = NULL; operator=(src); }
-    inline ImVector<T>& operator=(const ImVector<T>& src)   { clear(); resize(src.Size); if (src.Data) memcpy(Data, src.Data, (size_t)Size * sizeof(T)); return *this; }
+    inline ImVector<T>& operator=(const ImVector<T>& src)   { clear(); resize(src.Size); if (Data && src.Data) memcpy(Data, src.Data, (size_t)Size * sizeof(T)); return *this; }
     inline ~ImVector()                                      { if (Data) IM_FREE(Data); } // Important: does not destruct anything
 
     inline void         clear()                             { if (Data) { Size = Capacity = 0; IM_FREE(Data); Data = NULL; } }  // Important: does not destruct anything
@@ -2260,12 +2371,15 @@ struct ImGuiStyle
     float       ColumnsMinSpacing;          // Minimum horizontal spacing between two columns. Preferably > (FramePadding.x + 1).
     float       ScrollbarSize;              // Width of the vertical scrollbar, Height of the horizontal scrollbar.
     float       ScrollbarRounding;          // Radius of grab corners for scrollbar.
+    float       ScrollbarPadding;           // Padding of scrollbar grab within its frame (same for both axises).
     float       GrabMinSize;                // Minimum width/height of a grab box for slider/scrollbar.
     float       GrabRounding;               // Radius of grabs corners rounding. Set to 0.0f to have rectangular slider grabs.
     float       LogSliderDeadzone;          // The size in pixels of the dead-zone around zero on logarithmic sliders that cross zero.
     float       ImageBorderSize;            // Thickness of border around Image() calls.
     float       TabRounding;                // Radius of upper corners of a tab. Set to 0.0f to have rectangular tabs.
     float       TabBorderSize;              // Thickness of border around tabs.
+    float       TabMinWidthBase;            // Minimum tab width, to make tabs larger than their contents. TabBar buttons are not affected.
+    float       TabMinWidthShrink;          // Minimum tab width after shrinking, when using ImGuiTabBarFlags_FittingPolicyMixed policy.
     float       TabCloseButtonMinWidthSelected;     // -1: always visible. 0.0f: visible when hovered. >0.0f: visible when hovered if minimum width.
     float       TabCloseButtonMinWidthUnselected;   // -1: always visible. 0.0f: visible when hovered. >0.0f: visible when hovered if minimum width. FLT_MAX: never show close button when unselected.
     float       TabBarBorderSize;           // Thickness of tab-bar separator, which takes on the tab active color to denote focus.
@@ -2283,6 +2397,8 @@ struct ImGuiStyle
     ImVec2      SeparatorTextPadding;       // Horizontal offset of text from each edge of the separator + spacing on other axis. Generally small values. .y is recommended to be == FramePadding.y.
     ImVec2      DisplayWindowPadding;       // Apply to regular windows: amount which we enforce to keep visible when moving near edges of your screen.
     ImVec2      DisplaySafeAreaPadding;     // Apply to every windows, menus, popups, tooltips: amount where we avoid displaying contents. Adjust if you cannot see the edges of your screen (e.g. on a TV where scaling has not been configured).
+    bool        DockingNodeHasCloseButton;  // Docking node has their own CloseButton() to close all docked windows.
+    float       DockingSeparatorSize;       // Thickness of resizing border between docked windows
     float       MouseCursorScale;           // Scale software rendered mouse cursor (when io.MouseDrawCursor is enabled). We apply per-monitor DPI scaling over this scale. May be removed later.
     bool        AntiAliasedLines;           // Enable anti-aliased lines/borders. Disable if you are really tight on CPU/GPU. Latched at the beginning of the frame (copied to ImDrawList).
     bool        AntiAliasedLinesUseTex;     // Enable anti-aliased lines/borders using textures where possible. Require backend to render with bilinear filtering (NOT point/nearest filtering). Latched at the beginning of the frame (copied to ImDrawList).
@@ -2367,6 +2483,24 @@ struct ImGuiIO
     bool        ConfigNavCursorVisibleAuto;     // = true           // Using directional navigation key makes the cursor visible. Mouse click hides the cursor.
     bool        ConfigNavCursorVisibleAlways;   // = false          // Navigation cursor is always visible.
 
+    // Docking options (when ImGuiConfigFlags_DockingEnable is set)
+    bool        ConfigDockingNoSplit;           // = false          // Simplified docking mode: disable window splitting, so docking is limited to merging multiple windows together into tab-bars.
+    bool        ConfigDockingWithShift;         // = false          // Enable docking with holding Shift key (reduce visual noise, allows dropping in wider space)
+    bool        ConfigDockingAlwaysTabBar;      // = false          // [BETA] [FIXME: This currently creates regression with auto-sizing and general overhead] Make every single floating window display within a docking node.
+    bool        ConfigDockingTransparentPayload;// = false          // [BETA] Make window or viewport transparent when docking and only display docking boxes on the target viewport. Useful if rendering of multiple viewport cannot be synced. Best used with ConfigViewportsNoAutoMerge.
+
+    // Viewport options (when ImGuiConfigFlags_ViewportsEnable is set)
+    bool        ConfigViewportsNoAutoMerge;     // = false;         // Set to make all floating imgui windows always create their own viewport. Otherwise, they are merged into the main host viewports when overlapping it. May also set ImGuiViewportFlags_NoAutoMerge on individual viewport.
+    bool        ConfigViewportsNoTaskBarIcon;   // = false          // Disable default OS task bar icon flag for secondary viewports. When a viewport doesn't want a task bar icon, ImGuiViewportFlags_NoTaskBarIcon will be set on it.
+    bool        ConfigViewportsNoDecoration;    // = true           // Disable default OS window decoration flag for secondary viewports. When a viewport doesn't want window decorations, ImGuiViewportFlags_NoDecoration will be set on it. Enabling decoration can create subsequent issues at OS levels (e.g. minimum window size).
+    bool        ConfigViewportsNoDefaultParent; // = true           // When false: set secondary viewports' ParentViewportId to main viewport ID by default. Expects the platform backend to setup a parent/child relationship between the OS windows based on this value. Some backend may ignore this. Set to true if you want viewports to automatically be parent of main viewport, otherwise all viewports will be top-level OS windows.
+    bool        ConfigViewportsPlatformFocusSetsImGuiFocus;//= true // When a platform window is focused (e.g. using Alt+Tab, clicking Platform Title Bar), apply corresponding focus on imgui windows (may clear focus/active id from imgui windows location in other platform windows). In principle this is better enabled but we provide an opt-out, because some Linux window managers tend to eagerly focus windows (e.g. on mouse hover, or even a simple window pos/size change).
+
+    // DPI/Scaling options
+    // This may keep evolving during 1.92.x releases. Expect some turbulence.
+    bool        ConfigDpiScaleFonts;            // = false          // [EXPERIMENTAL] Automatically overwrite style.FontScaleDpi when Monitor DPI changes. This will scale fonts but _NOT_ scale sizes/padding for now.
+    bool        ConfigDpiScaleViewports;        // = false          // [EXPERIMENTAL] Scale Dear ImGui and Platform Windows when Monitor DPI changes.
+
     // Miscellaneous options
     // (you can visualize and interact with all options in 'Demo->Configuration')
     bool        MouseDrawCursor;                // = false          // Request ImGui to draw a mouse cursor for you (if you are on a platform without a mouse cursor). Cannot be easily renamed to 'io.ConfigXXX' because this is frequently used by backend implementations.
@@ -2415,7 +2549,7 @@ struct ImGuiIO
     // Option to enable various debug tools showing buttons that will call the IM_DEBUG_BREAK() macro.
     // - The Item Picker tool will be available regardless of this being enabled, in order to maximize its discoverability.
     // - Requires a debugger being attached, otherwise IM_DEBUG_BREAK() options will appear to crash your application.
-    //   e.g. io.ConfigDebugIsDebuggerPresent = ::IsDebuggerPresent() on Win32, or refer to ImOsIsDebuggerPresent() imgui_test_engine/imgui_te_utils.cpp for a Unix compatible version).
+    //   e.g. io.ConfigDebugIsDebuggerPresent = ::IsDebuggerPresent() on Win32, or refer to ImOsIsDebuggerPresent() imgui_test_engine/imgui_te_utils.cpp for a Unix compatible version.
     bool        ConfigDebugIsDebuggerPresent;   // = false          // Enable various tools calling IM_DEBUG_BREAK().
 
     // Tools to detect code submitting items with conflicting/duplicate IDs
@@ -2464,6 +2598,7 @@ struct ImGuiIO
     IMGUI_API void  AddMouseButtonEvent(int button, bool down);             // Queue a mouse button change
     IMGUI_API void  AddMouseWheelEvent(float wheel_x, float wheel_y);       // Queue a mouse wheel update. wheel_y<0: scroll down, wheel_y>0: scroll up, wheel_x<0: scroll right, wheel_x>0: scroll left.
     IMGUI_API void  AddMouseSourceEvent(ImGuiMouseSource source);           // Queue a mouse source change (Mouse/TouchScreen/Pen)
+    IMGUI_API void  AddMouseViewportEvent(ImGuiID id);                      // Queue a mouse hovered viewport. Requires backend to set ImGuiBackendFlags_HasMouseHoveredViewport to call this (for multi-viewport support).
     IMGUI_API void  AddFocusEvent(bool focused);                            // Queue a gain/loss of focus for the application (generally based on OS/platform focus of your window)
     IMGUI_API void  AddInputCharacter(unsigned int c);                      // Queue a new character input
     IMGUI_API void  AddInputCharacterUTF16(ImWchar16 c);                    // Queue a new character input from a UTF-16 character, it can be a surrogate
@@ -2512,13 +2647,14 @@ struct ImGuiIO
     float       MouseWheel;                         // Mouse wheel Vertical: 1 unit scrolls about 5 lines text. >0 scrolls Up, <0 scrolls Down. Hold SHIFT to turn vertical scroll into horizontal scroll.
     float       MouseWheelH;                        // Mouse wheel Horizontal. >0 scrolls Left, <0 scrolls Right. Most users don't have a mouse with a horizontal wheel, may not be filled by all backends.
     ImGuiMouseSource MouseSource;                   // Mouse actual input peripheral (Mouse/TouchScreen/Pen).
-    bool        KeyCtrl;                            // Keyboard modifier down: Control
+    ImGuiID     MouseHoveredViewport;               // (Optional) Modify using io.AddMouseViewportEvent(). With multi-viewports: viewport the OS mouse is hovering. If possible _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag is much better (few backends can handle that). Set io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport if you can provide this info. If you don't imgui will infer the value using the rectangles and last focused time of the viewports it knows about (ignoring other OS windows).
+    bool        KeyCtrl;                            // Keyboard modifier down: Ctrl (non-macOS), Cmd (macOS)
     bool        KeyShift;                           // Keyboard modifier down: Shift
     bool        KeyAlt;                             // Keyboard modifier down: Alt
-    bool        KeySuper;                           // Keyboard modifier down: Cmd/Super/Windows
+    bool        KeySuper;                           // Keyboard modifier down: Windows/Super (non-macOS), Ctrl (macOS)
 
     // Other state maintained from data above + IO function calls
-    ImGuiKeyChord KeyMods;                          // Key mods flags (any of ImGuiMod_Ctrl/ImGuiMod_Shift/ImGuiMod_Alt/ImGuiMod_Super flags, same as io.KeyCtrl/KeyShift/KeyAlt/KeySuper but merged into flags. Read-only, updated by NewFrame()
+    ImGuiKeyChord KeyMods;                          // Key mods flags (any of ImGuiMod_Ctrl/ImGuiMod_Shift/ImGuiMod_Alt/ImGuiMod_Super flags, same as io.KeyCtrl/KeyShift/KeyAlt/KeySuper but merged into flags). Read-only, updated by NewFrame()
     ImGuiKeyData  KeysData[ImGuiKey_NamedKey_COUNT];// Key state for all known keys. MUST use 'key - ImGuiKey_NamedKey_BEGIN' as index. Use IsKeyXXX() functions to access this.
     bool        WantCaptureMouseUnlessPopupClose;   // Alternative to WantCaptureMouse: (WantCaptureMouse == true && WantCaptureMouseUnlessPopupClose == false) when a click over void is expected to close a popup.
     ImVec2      MousePosPrev;                       // Previous mouse position (note that MouseDelta is not necessary == MousePos-MousePosPrev, in case either position is invalid)
@@ -2536,6 +2672,7 @@ struct ImGuiIO
     bool        MouseCtrlLeftAsRightClick;          // (OSX) Set to true when the current click was a Ctrl+click that spawned a simulated right click
     float       MouseDownDuration[5];               // Duration the mouse button has been down (0.0f == just clicked)
     float       MouseDownDurationPrev[5];           // Previous time the mouse button has been down
+    ImVec2      MouseDragMaxDistanceAbs[5];         // Maximum distance, absolute, on each axis, of how much mouse has traveled from the clicking point
     float       MouseDragMaxDistanceSqr[5];         // Squared maximum distance of how much mouse has traveled from the clicking point (used for moving thresholds)
     float       PenPressure;                        // Touch/Pen pressure (0.0f to 1.0f, should be >0.0f only when MouseDown[0] == true). Helper storage currently unused by Dear ImGui.
     bool        AppFocusLost;                       // Only modify via AddFocusEvent()
@@ -2595,10 +2732,10 @@ struct ImGuiInputTextCallbackData
     ImGuiKey            EventKey;       // Key pressed (Up/Down/TAB)            // Read-only    // [Completion,History]
     char*               Buf;            // Text buffer                          // Read-write   // [Resize] Can replace pointer / [Completion,History,Always] Only write to pointed data, don't replace the actual pointer!
     int                 BufTextLen;     // Text length (in bytes)               // Read-write   // [Resize,Completion,History,Always] Exclude zero-terminator storage. In C land: == strlen(some_text), in C++ land: string.length()
-    int                 BufSize;        // Buffer size (in bytes) = capacity+1  // Read-only    // [Resize,Completion,History,Always] Include zero-terminator storage. In C land == ARRAYSIZE(my_char_array), in C++ land: string.capacity()+1
+    int                 BufSize;        // Buffer size (in bytes) = capacity+1  // Read-only    // [Resize,Completion,History,Always] Include zero-terminator storage. In C land: == ARRAYSIZE(my_char_array), in C++ land: string.capacity()+1
     bool                BufDirty;       // Set if you modify Buf/BufTextLen!    // Write        // [Completion,History,Always]
     int                 CursorPos;      //                                      // Read-write   // [Completion,History,Always]
-    int                 SelectionStart; //                                      // Read-write   // [Completion,History,Always] == to SelectionEnd when no selection)
+    int                 SelectionStart; //                                      // Read-write   // [Completion,History,Always] == to SelectionEnd when no selection
     int                 SelectionEnd;   //                                      // Read-write   // [Completion,History,Always]
 
     // Helper functions for text manipulation.
@@ -2621,6 +2758,28 @@ struct ImGuiSizeCallbackData
     ImVec2  DesiredSize;    // Read-write.  Desired size, based on user's mouse position. Write to this field to restrain resizing.
 };
 
+// [ALPHA] Rarely used / very advanced uses only. Use with SetNextWindowClass() and DockSpace() functions.
+// Important: the content of this class is still highly WIP and likely to change and be refactored
+// before we stabilize Docking features. Please be mindful if using this.
+// Provide hints:
+// - To the platform backend via altered viewport flags (enable/disable OS decoration, OS task bar icons, etc.)
+// - To the platform backend for OS level parent/child relationships of viewport.
+// - To the docking system for various options and filtering.
+struct ImGuiWindowClass
+{
+    ImGuiID             ClassId;                    // User data. 0 = Default class (unclassed). Windows of different classes cannot be docked with each others.
+    ImGuiID             ParentViewportId;           // Hint for the platform backend. -1: use default. 0: request platform backend to not parent the platform. != 0: request platform backend to create a parent<>child relationship between the platform windows. Not conforming backends are free to e.g. parent every viewport to the main viewport or not.
+    ImGuiID             FocusRouteParentWindowId;   // ID of parent window for shortcut focus route evaluation, e.g. Shortcut() call from Parent Window will succeed when this window is focused.
+    ImGuiViewportFlags  ViewportFlagsOverrideSet;   // Viewport flags to set when a window of this class owns a viewport. This allows you to enforce OS decoration or task bar icon, override the defaults on a per-window basis.
+    ImGuiViewportFlags  ViewportFlagsOverrideClear; // Viewport flags to clear when a window of this class owns a viewport. This allows you to enforce OS decoration or task bar icon, override the defaults on a per-window basis.
+    ImGuiTabItemFlags   TabItemFlagsOverrideSet;    // [EXPERIMENTAL] TabItem flags to set when a window of this class gets submitted into a dock node tab bar. May use with ImGuiTabItemFlags_Leading or ImGuiTabItemFlags_Trailing.
+    ImGuiDockNodeFlags  DockNodeFlagsOverrideSet;   // [EXPERIMENTAL] Dock node flags to set when a window of this class is hosted by a dock node (it doesn't have to be selected!)
+    bool                DockingAlwaysTabBar;        // Set to true to enforce single floating windows of this class always having their own docking node (equivalent of setting the global io.ConfigDockingAlwaysTabBar)
+    bool                DockingAllowUnclassed;      // Set to true to allow windows of this class to be docked/merged with an unclassed window. // FIXME-DOCK: Move to DockNodeFlags override?
+
+    ImGuiWindowClass() { memset(this, 0, sizeof(*this)); ParentViewportId = (ImGuiID)-1; DockingAllowUnclassed = true; }
+};
+
 // Data payload for Drag and Drop operations: AcceptDragDropPayload(), GetDragDropPayload()
 struct ImGuiPayload
 {
@@ -2767,6 +2926,13 @@ struct ImGuiStorage
 #endif
 };
 
+// Flags for ImGuiListClipper (currently not fully exposed in function calls: a future refactor will likely add this to ImGuiListClipper::Begin function equivalent)
+enum ImGuiListClipperFlags_
+{
+    ImGuiListClipperFlags_None                  = 0,
+    ImGuiListClipperFlags_NoSetTableRowCounters = 1 << 0,   // [Internal] Disabled modifying table row counters. Avoid assumption that 1 clipper item == 1 table row.
+};
+
 // Helper: Manually clip large list of items.
 // If you have lots evenly spaced items and you have random access to the list, you can perform coarse
 // clipping based on visibility to only submit items that are in view.
@@ -2797,6 +2963,7 @@ struct ImGuiListClipper
     double          StartPosY;          // [Internal] Cursor position at the time of Begin() or after table frozen rows are all processed
     double          StartSeekOffsetY;   // [Internal] Account for frozen rows in a table and initial loss of precision in very large windows.
     void*           TempData;           // [Internal] Internal data
+    ImGuiListClipperFlags Flags;        // [Internal] Flags, currently not yet well exposed.
 
     // items_count: Use INT_MAX if you don't know how many items you have (in which case the cursor won't be advanced in the final step, and you can call SeekCursorForItem() manually if you need)
     // items_height: Use -1.0f to be calculated automatically on first step. Otherwise pass in the distance between your items, typically GetTextLineHeightWithSpacing() or GetFrameHeightWithSpacing().
@@ -2817,7 +2984,7 @@ struct ImGuiListClipper
     IMGUI_API void  SeekCursorForItem(int item_index);
 
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-    inline void IncludeRangeByIndices(int item_begin, int item_end)      { IncludeItemsByIndex(item_begin, item_end); } // [renamed in 1.89.9]
+    //inline void IncludeRangeByIndices(int item_begin, int item_end)      { IncludeItemsByIndex(item_begin, item_end); } // [renamed in 1.89.9]
     //inline void ForceDisplayRangeByIndices(int item_begin, int item_end) { IncludeItemsByIndex(item_begin, item_end); } // [renamed in 1.89.6]
     //inline ImGuiListClipper(int items_count, float items_height = -1.0f) { memset(this, 0, sizeof(*this)); ItemsCount = -1; Begin(items_count, items_height); } // [removed in 1.79]
 #endif
@@ -3107,7 +3274,7 @@ struct ImDrawCmd
 
     // Since 1.83: returns ImTextureID associated with this draw call. Warning: DO NOT assume this is always same as 'TextureId' (we will change this function for an upcoming feature)
     // Since 1.92: removed ImDrawCmd::TextureId field, the getter function must be used!
-    inline ImTextureID GetTexID() const;    // == (TexRef._TexData ? TexRef._TexData->TexID : TexRef._TexID
+    inline ImTextureID GetTexID() const;    // == (TexRef._TexData ? TexRef._TexData->TexID : TexRef._TexID)
 };
 
 // Vertex layout
@@ -3303,7 +3470,7 @@ struct ImDrawList
 
     // Advanced: Miscellaneous
     IMGUI_API void  AddDrawCmd();                                               // This is useful if you need to forcefully create a new draw call (to allow for dependent rendering / blending). Otherwise primitives are merged into the same draw-call as much as possible
-    IMGUI_API ImDrawList* CloneOutput() const;                                  // Create a clone of the CmdBuffer/IdxBuffer/VtxBuffer.
+    IMGUI_API ImDrawList* CloneOutput() const;                                  // Create a clone of the CmdBuffer/IdxBuffer/VtxBuffer. For multi-threaded rendering, consider using `imgui_threaded_rendering` from https://github.com/ocornut/imgui_club instead.
 
     // Advanced: Channels
     // - Use to split render into layers. By switching channels to can render out-of-order (e.g. submit FG primitives before BG primitives)
@@ -3359,7 +3526,7 @@ struct ImDrawList
 struct ImDrawData
 {
     bool                Valid;              // Only valid after Render() is called and before the next NewFrame() is called.
-    int                 CmdListsCount;      // Number of ImDrawList* to render. (== CmdLists.Size). Exists for legacy reason.
+    int                 CmdListsCount;      // == CmdLists.Size. (OBSOLETE: exists for legacy reasons). Number of ImDrawList* to render.
     int                 TotalIdxCount;      // For convenience, sum of all ImDrawList's IdxBuffer.Size
     int                 TotalVtxCount;      // For convenience, sum of all ImDrawList's VtxBuffer.Size
     ImVector<ImDrawList*> CmdLists;         // Array of ImDrawList* to render. The ImDrawLists are owned by ImGuiContext and only pointed to from here.
@@ -3424,7 +3591,7 @@ struct ImTextureRect
 struct ImTextureData
 {
     //------------------------------------------ core / backend ---------------------------------------
-    int                 UniqueID;               // w    -   // Sequential index to facilitate identifying a texture when debugging/printing. Unique per atlas.
+    int                 UniqueID;               // w    -   // [DEBUG] Sequential index to facilitate identifying a texture when debugging/printing. Unique per atlas.
     ImTextureStatus     Status;                 // rw   rw  // ImTextureStatus_OK/_WantCreate/_WantUpdates/_WantDestroy. Always use SetStatus() to modify!
     void*               BackendUserData;        // -    rw  // Convenience storage for backend. Some backends may have enough with TexID.
     ImTextureID         TexID;                  // r    w   // Backend-specific texture identifier. Always use SetTexID() to modify! The identifier will stored in ImDrawCmd::GetTexID() and passed to backend's RenderDrawData function.
@@ -3442,7 +3609,7 @@ struct ImTextureData
     bool                WantDestroyNextFrame;   // rw   -   // [Internal] Queued to set ImTextureStatus_WantDestroy next frame. May still be used in the current frame.
 
     // Functions
-    ImTextureData()     { memset(this, 0, sizeof(*this)); TexID = ImTextureID_Invalid; }
+    ImTextureData()     { memset(this, 0, sizeof(*this)); Status = ImTextureStatus_Destroyed; TexID = ImTextureID_Invalid; }
     ~ImTextureData()    { DestroyPixels(); }
     IMGUI_API void      Create(ImTextureFormat format, int w, int h);
     IMGUI_API void      DestroyPixels();
@@ -3454,8 +3621,10 @@ struct ImTextureData
     ImTextureID         GetTexID() const            { return TexID; }
 
     // Called by Renderer backend
-    void                SetTexID(ImTextureID tex_id)      { TexID = tex_id; }   // Call after creating or destroying the texture. Never modify TexID directly!
-    void                SetStatus(ImTextureStatus status) { Status = status; }  // Call after honoring a request. Never modify Status directly!
+    // - Call SetTexID() and SetStatus() after honoring texture requests. Never modify TexID and Status directly!
+    // - A backend may decide to destroy a texture that we did not request to destroy, which is fine (e.g. freeing resources), but we immediately set the texture back in _WantCreate mode.
+    void    SetTexID(ImTextureID tex_id)            { TexID = tex_id; }
+    void    SetStatus(ImTextureStatus status)       { Status = status; if (status == ImTextureStatus_Destroyed && !WantDestroyNextFrame) Status = ImTextureStatus_WantCreate; }
 };
 
 //-----------------------------------------------------------------------------
@@ -3604,7 +3773,7 @@ struct ImFontAtlas
     // - User is in charge of copying the pixels into graphics memory (e.g. create a texture with your engine). Then store your texture handle with SetTexID().
     // - The pitch is always = Width * BytesPerPixels (1 or 4)
     // - Building in RGBA32 format is provided for convenience and compatibility, but note that unless you manually manipulate or copy color data into
-    //   the texture (e.g. when using the AddCustomRect*** api), then the RGB pixels emitted will always be white (~75% of memory/bandwidth waste.
+    //   the texture (e.g. when using the AddCustomRect*** api), then the RGB pixels emitted will always be white (~75% of memory/bandwidth waste).
     // - From 1.92 with backends supporting ImGuiBackendFlags_RendererHasTextures:
     //   - Calling Build(), GetTexDataAsAlpha8(), GetTexDataAsRGBA32() is not needed.
     //   - In backend: replace calls to ImFontAtlas::SetTexID() with calls to ImTextureData::SetTexID() after honoring texture creation.
@@ -3719,7 +3888,7 @@ struct ImFontAtlas
     IMGUI_API ImFontAtlasRectId AddCustomRectFontGlyphForSize(ImFont* font, float font_size, ImWchar codepoint, int w, int h, float advance_x, const ImVec2& offset = ImVec2(0, 0));    // ADDED AND OBSOLETED in 1.92.X
 #endif
     //unsigned int                      FontBuilderFlags;        // OBSOLETED in 1.92.X: Renamed to FontLoaderFlags.
-    //int                               TexDesiredWidth;         // OBSOLETED in 1.92.X: Force texture width before calling Build(). Must be a power-of-two. If have many glyphs your graphics API have texture size restrictions you may want to increase texture width to decrease height)
+    //int                               TexDesiredWidth;         // OBSOLETED in 1.92.X: Force texture width before calling Build(). Must be a power-of-two. If have many glyphs your graphics API have texture size restrictions you may want to increase texture width to decrease height.
     //typedef ImFontAtlasRect           ImFontAtlasCustomRect;   // OBSOLETED in 1.92.X
     //typedef ImFontAtlasCustomRect     CustomRect;              // OBSOLETED in 1.72+
     //typedef ImFontGlyphRangesBuilder  GlyphRangesBuilder;      // OBSOLETED in 1.67+
@@ -3744,9 +3913,10 @@ struct ImFontBaked
     float                       Ascent, Descent;    // 4+4   // out // Ascent: distance from top to bottom of e.g. 'A' [0..FontSize] (unscaled)
     unsigned int                MetricsTotalSurface:26;// 3  // out // Total surface in pixels to get an idea of the font rasterization/texture cost (not exact, we approximate the cost of padding between glyphs)
     unsigned int                WantDestroy:1;         // 0  //     // Queued for destroy
-    unsigned int                LockLoadingFallback:1; // 0  //     //
-    int                         LastUsedFrame;      // 4     //     // Record of that time this was bounds
-    ImGuiID                     BakedId;            // 4     //
+    unsigned int                LoadNoFallback:1;      // 0  //     // Disable loading fallback in lower-level calls.
+    unsigned int                LoadNoRenderOnLayout:1;// 0  //     // Enable a two-steps mode where CalcTextSize() calls will load AdvanceX *without* rendering/packing glyphs. Only advantagous if you know that the glyph is unlikely to actually be rendered, otherwise it is slower because we'd do one query on the first CalcTextSize and one query on the first Draw.
+    int                         LastUsedFrame;         // 4  //     // Record of that time this was bounds
+    ImGuiID                     BakedId;            // 4     //     // Unique ID for this baked storage
     ImFont*                     ContainerFont;      // 4-8   // in  // Parent font
     void*                       FontLoaderDatas;    // 4-8   //     // Font loader opaque storage (per baked font * sources): single contiguous buffer allocated by imgui, passed to loader.
 
@@ -3807,10 +3977,10 @@ struct ImFont
     // 'max_width' stops rendering after a certain width (could be turned into a 2d size). FLT_MAX to disable.
     // 'wrap_width' enable automatic word-wrapping across multiple lines to fit into given width. 0.0f to disable.
     IMGUI_API ImFontBaked*      GetFontBaked(float font_size, float density = -1.0f);  // Get or create baked data for given size
-    IMGUI_API ImVec2            CalcTextSizeA(float size, float max_width, float wrap_width, const char* text_begin, const char* text_end = NULL, const char** remaining = NULL); // utf8
+    IMGUI_API ImVec2            CalcTextSizeA(float size, float max_width, float wrap_width, const char* text_begin, const char* text_end = NULL, const char** out_remaining = NULL);
     IMGUI_API const char*       CalcWordWrapPosition(float size, const char* text, const char* text_end, float wrap_width);
     IMGUI_API void              RenderChar(ImDrawList* draw_list, float size, const ImVec2& pos, ImU32 col, ImWchar c, const ImVec4* cpu_fine_clip = NULL);
-    IMGUI_API void              RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, ImU32 col, const ImVec4& clip_rect, const char* text_begin, const char* text_end, float wrap_width = 0.0f, bool cpu_fine_clip = false);
+    IMGUI_API void              RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, ImU32 col, const ImVec4& clip_rect, const char* text_begin, const char* text_end, float wrap_width = 0.0f, ImDrawTextFlags flags = 0);
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
     inline const char*          CalcWordWrapPositionA(float scale, const char* text, const char* text_end, float wrap_width) { return CalcWordWrapPosition(LegacySize * scale, text, text_end, wrap_width); }
 #endif
@@ -3849,11 +4019,24 @@ enum ImGuiViewportFlags_
     ImGuiViewportFlags_None                     = 0,
     ImGuiViewportFlags_IsPlatformWindow         = 1 << 0,   // Represent a Platform Window
     ImGuiViewportFlags_IsPlatformMonitor        = 1 << 1,   // Represent a Platform Monitor (unused yet)
-    ImGuiViewportFlags_OwnedByApp               = 1 << 2,   // Platform Window: Is created/managed by the application (rather than a dear imgui backend)
+    ImGuiViewportFlags_OwnedByApp               = 1 << 2,   // Platform Window: Is created/managed by the user application? (rather than our backend)
+    ImGuiViewportFlags_NoDecoration             = 1 << 3,   // Platform Window: Disable platform decorations: title bar, borders, etc. (generally set all windows, but if ImGuiConfigFlags_ViewportsDecoration is set we only set this on popups/tooltips)
+    ImGuiViewportFlags_NoTaskBarIcon            = 1 << 4,   // Platform Window: Disable platform task bar icon (generally set on popups/tooltips, or all windows if ImGuiConfigFlags_ViewportsNoTaskBarIcon is set)
+    ImGuiViewportFlags_NoFocusOnAppearing       = 1 << 5,   // Platform Window: Don't take focus when created.
+    ImGuiViewportFlags_NoFocusOnClick           = 1 << 6,   // Platform Window: Don't take focus when clicked on.
+    ImGuiViewportFlags_NoInputs                 = 1 << 7,   // Platform Window: Make mouse pass through so we can drag this window while peaking behind it.
+    ImGuiViewportFlags_NoRendererClear          = 1 << 8,   // Platform Window: Renderer doesn't need to clear the framebuffer ahead (because we will fill it entirely).
+    ImGuiViewportFlags_NoAutoMerge              = 1 << 9,   // Platform Window: Avoid merging this window into another host window. This can only be set via ImGuiWindowClass viewport flags override (because we need to now ahead if we are going to create a viewport in the first place!).
+    ImGuiViewportFlags_TopMost                  = 1 << 10,  // Platform Window: Display on top (for tooltips only).
+    ImGuiViewportFlags_CanHostOtherWindows      = 1 << 11,  // Viewport can host multiple imgui windows (secondary viewports are associated to a single window). // FIXME: In practice there's still probably code making the assumption that this is always and only on the MainViewport. Will fix once we add support for "no main viewport".
+
+    // Output status flags (from Platform)
+    ImGuiViewportFlags_IsMinimized              = 1 << 12,  // Platform Window: Window is minimized, can skip render. When minimized we tend to avoid using the viewport pos/size for clipping window or testing if they are contained in the viewport.
+    ImGuiViewportFlags_IsFocused                = 1 << 13,  // Platform Window: Window is focused (last call to Platform_GetWindowFocus() returned true)
 };
 
 // - Currently represents the Platform Window created by the application which is hosting our Dear ImGui windows.
-// - In 'docking' branch with multi-viewport enabled, we extend this concept to have multiple active viewports.
+// - With multi-viewport enabled, we extend this concept to have multiple active viewports.
 // - In the future we will extend this concept further to also represent Platform Monitor and support a "no main platform window" operation mode.
 // - About Main Area vs Work Area:
 //   - Main Area = entire viewport.
@@ -3868,12 +4051,27 @@ struct ImGuiViewport
     ImVec2              FramebufferScale;       // Density of the viewport for Retina display (always 1,1 on Windows, may be 2,2 etc on macOS/iOS). This will affect font rasterizer density.
     ImVec2              WorkPos;                // Work Area: Position of the viewport minus task bars, menus bars, status bars (>= Pos)
     ImVec2              WorkSize;               // Work Area: Size of the viewport minus task bars, menu bars, status bars (<= Size)
+    float               DpiScale;               // 1.0f = 96 DPI = No extra scale.
+    ImGuiID             ParentViewportId;       // (Advanced) 0: no parent. Instruct the platform backend to setup a parent/child relationship between platform windows.
+    ImGuiViewport*      ParentViewport;         // (Advanced) Direct shortcut to ImGui::FindViewportByID(ParentViewportId). NULL: no parent.
+    ImDrawData*         DrawData;               // The ImDrawData corresponding to this viewport. Valid after Render() and until the next call to NewFrame().
 
     // Platform/Backend Dependent Data
-    void*               PlatformHandle;         // void* to hold higher-level, platform window handle (e.g. HWND, GLFWWindow*, SDL_Window*)
-    void*               PlatformHandleRaw;      // void* to hold lower-level, platform-native window handle (under Win32 this is expected to be a HWND, unused for other platforms)
+    // Our design separate the Renderer and Platform backends to facilitate combining default backends with each others.
+    // When our create your own backend for a custom engine, it is possible that both Renderer and Platform will be handled
+    // by the same system and you may not need to use all the UserData/Handle fields.
+    // The library never uses those fields, they are merely storage to facilitate backend implementation.
+    void*               RendererUserData;       // void* to hold custom data structure for the renderer (e.g. swap chain, framebuffers etc.). generally set by your Renderer_CreateWindow function.
+    void*               PlatformUserData;       // void* to hold custom data structure for the OS / platform (e.g. windowing info, render context). generally set by your Platform_CreateWindow function.
+    void*               PlatformHandle;         // void* to hold higher-level, platform window handle (e.g. HWND for Win32 backend, Uint32 WindowID for SDL, GLFWWindow* for GLFW), for FindViewportByPlatformHandle().
+    void*               PlatformHandleRaw;      // void* to hold lower-level, platform-native window handle (always HWND on Win32 platform, unused for other platforms).
+    bool                PlatformWindowCreated;  // Platform window has been created (Platform_CreateWindow() has been called). This is false during the first frame where a viewport is being created.
+    bool                PlatformRequestMove;    // Platform window requested move (e.g. window was moved by the OS / host window manager, authoritative position will be OS window position)
+    bool                PlatformRequestResize;  // Platform window requested resize (e.g. window was resized by the OS / host window manager, authoritative size will be OS window size)
+    bool                PlatformRequestClose;   // Platform window requested closure (e.g. window was moved by the OS / host window manager, e.g. pressing ALT-F4)
 
     ImGuiViewport()     { memset(this, 0, sizeof(*this)); }
+    ~ImGuiViewport()    { IM_ASSERT(PlatformUserData == NULL && RendererUserData == NULL); }
 
     // Helpers
     ImVec2              GetCenter() const       { return ImVec2(Pos.x + Size.x * 0.5f, Pos.y + Size.y * 0.5f); }
@@ -3881,7 +4079,53 @@ struct ImGuiViewport
 };
 
 //-----------------------------------------------------------------------------
-// [SECTION] Platform Dependent Interfaces
+// [SECTION] ImGuiPlatformIO + other Platform Dependent Interfaces (ImGuiPlatformMonitor, ImGuiPlatformImeData)
+//-----------------------------------------------------------------------------
+
+// [BETA] (Optional) Multi-Viewport Support!
+// If you are new to Dear ImGui and trying to integrate it into your engine, you can probably ignore this for now.
+//
+// This feature allows you to seamlessly drag Dear ImGui windows outside of your application viewport.
+// This is achieved by creating new Platform/OS windows on the fly, and rendering into them.
+// Dear ImGui manages the viewport structures, and the backend create and maintain one Platform/OS window for each of those viewports.
+//
+// See Recap:   https://github.com/ocornut/imgui/wiki/Multi-Viewports
+// See Glossary https://github.com/ocornut/imgui/wiki/Glossary for details about some of the terminology.
+//
+// About the coordinates system:
+// - When multi-viewports are enabled, all Dear ImGui coordinates become absolute coordinates (same as OS coordinates!)
+// - So e.g. ImGui::SetNextWindowPos(ImVec2(0,0)) will position a window relative to your primary monitor!
+// - If you want to position windows relative to your main application viewport, use ImGui::GetMainViewport()->Pos as a base position.
+//
+// Steps to use multi-viewports in your application, when using a default backend from the examples/ folder:
+// - Application:  Enable feature with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// - Backend:      The backend initialization will setup all necessary ImGuiPlatformIO's functions and update monitors info every frame.
+// - Application:  In your main loop, call ImGui::UpdatePlatformWindows(), ImGui::RenderPlatformWindowsDefault() after EndFrame() or Render().
+// - Application:  Fix absolute coordinates used in ImGui::SetWindowPos() or ImGui::SetNextWindowPos() calls.
+//
+// Steps to use multi-viewports in your application, when using a custom backend:
+// - Important:    THIS IS NOT EASY TO DO and comes with many subtleties not described here!
+//                 It's also an experimental feature, so some of the requirements may evolve.
+//                 Consider using default backends if you can. Either way, carefully follow and refer to examples/ backends for details.
+// - Application:  Enable feature with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// - Backend:      Hook ImGuiPlatformIO's Platform_* and Renderer_* callbacks (see below).
+//                 Set 'io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports' and 'io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports'.
+//                 Update ImGuiPlatformIO's Monitors list every frame.
+//                 Update MousePos every frame, in absolute coordinates.
+// - Application:  In your main loop, call ImGui::UpdatePlatformWindows(), ImGui::RenderPlatformWindowsDefault() after EndFrame() or Render().
+//                 You may skip calling RenderPlatformWindowsDefault() if its API is not convenient for your needs. Read comments below.
+// - Application:  Fix absolute coordinates used in ImGui::SetWindowPos() or ImGui::SetNextWindowPos() calls.
+//
+// About ImGui::RenderPlatformWindowsDefault():
+// - This function is a mostly a _helper_ for the common-most cases, and to facilitate using default backends.
+// - You can check its simple source code to understand what it does.
+//   It basically iterates secondary viewports and call 4 functions that are setup in ImGuiPlatformIO, if available:
+//     Platform_RenderWindow(), Renderer_RenderWindow(), Platform_SwapBuffers(), Renderer_SwapBuffers()
+//   Those functions pointers exists only for the benefit of RenderPlatformWindowsDefault().
+// - If you have very specific rendering needs (e.g. flipping multiple swap-chain simultaneously, unusual sync/threading issues, etc.),
+//   you may be tempted to ignore RenderPlatformWindowsDefault() and write customized code to perform your renderingg.
+//   You may decide to setup the platform_io's *RenderWindow and *SwapBuffers pointers and call your functions through those pointers,
+//   or you may decide to never setup those pointers and call your code directly. They are a convenience, not an obligatory interface.
 //-----------------------------------------------------------------------------
 
 // Access via ImGui::GetPlatformIO()
@@ -3925,6 +4169,56 @@ struct ImGuiPlatformIO
     // Written by some backends during ImGui_ImplXXXX_RenderDrawData() call to point backend_specific ImGui_ImplXXXX_RenderState* structure.
     void*       Renderer_RenderState;
 
+    //------------------------------------------------------------------
+    // Input - Interface with Platform & Renderer backends for Multi-Viewport support
+    //------------------------------------------------------------------
+
+    // For reference, the second column shows which function are generally calling the Platform Functions:
+    //   N = ImGui::NewFrame()                        ~ beginning of the dear imgui frame: read info from platform/OS windows (latest size/position)
+    //   F = ImGui::Begin(), ImGui::EndFrame()        ~ during the dear imgui frame
+    //   U = ImGui::UpdatePlatformWindows()           ~ after the dear imgui frame: create and update all platform/OS windows
+    //   R = ImGui::RenderPlatformWindowsDefault()    ~ render
+    //   D = ImGui::DestroyPlatformWindows()          ~ shutdown
+    // The general idea is that NewFrame() we will read the current Platform/OS state, and UpdatePlatformWindows() will write to it.
+
+    // The handlers are designed so we can mix and match two imgui_impl_xxxx files, one Platform backend and one Renderer backend.
+    // Custom engine backends will often provide both Platform and Renderer interfaces together and so may not need to use all functions.
+    // Platform functions are typically called _before_ their Renderer counterpart, apart from Destroy which are called the other way.
+
+    // Platform Backend functions (e.g. Win32, GLFW, SDL) ------------------- Called by -----
+    void    (*Platform_CreateWindow)(ImGuiViewport* vp);                    // . . U . .  // Create a new platform window for the given viewport
+    void    (*Platform_DestroyWindow)(ImGuiViewport* vp);                   // N . U . D  //
+    void    (*Platform_ShowWindow)(ImGuiViewport* vp);                      // . . U . .  // Newly created windows are initially hidden so SetWindowPos/Size/Title can be called on them before showing the window
+    void    (*Platform_SetWindowPos)(ImGuiViewport* vp, ImVec2 pos);        // . . U . .  // Set platform window position (given the upper-left corner of client area)
+    ImVec2  (*Platform_GetWindowPos)(ImGuiViewport* vp);                    // N . . . .  //
+    void    (*Platform_SetWindowSize)(ImGuiViewport* vp, ImVec2 size);      // . . U . .  // Set platform window client area size (ignoring OS decorations such as OS title bar etc.)
+    ImVec2  (*Platform_GetWindowSize)(ImGuiViewport* vp);                   // N . . . .  // Get platform window client area size
+    ImVec2  (*Platform_GetWindowFramebufferScale)(ImGuiViewport* vp);       // N . . . .  // Return viewport density. Always 1,1 on Windows, often 2,2 on Retina display on macOS/iOS. MUST BE INTEGER VALUES.
+    void    (*Platform_SetWindowFocus)(ImGuiViewport* vp);                  // N . . . .  // Move window to front and set input focus
+    bool    (*Platform_GetWindowFocus)(ImGuiViewport* vp);                  // . . U . .  //
+    bool    (*Platform_GetWindowMinimized)(ImGuiViewport* vp);              // N . . . .  // Get platform window minimized state. When minimized, we generally won't attempt to get/set size and contents will be culled more easily
+    void    (*Platform_SetWindowTitle)(ImGuiViewport* vp, const char* str); // . . U . .  // Set platform window title (given an UTF-8 string)
+    void    (*Platform_SetWindowAlpha)(ImGuiViewport* vp, float alpha);     // . . U . .  // (Optional) Setup global transparency (not per-pixel transparency)
+    void    (*Platform_UpdateWindow)(ImGuiViewport* vp);                    // . . U . .  // (Optional) Called by UpdatePlatformWindows(). Optional hook to allow the platform backend from doing general book-keeping every frame.
+    void    (*Platform_RenderWindow)(ImGuiViewport* vp, void* render_arg);  // . . . R .  // (Optional) Main rendering (platform side! This is often unused, or just setting a "current" context for OpenGL bindings). 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+    void    (*Platform_SwapBuffers)(ImGuiViewport* vp, void* render_arg);   // . . . R .  // (Optional) Call Present/SwapBuffers (platform side! This is often unused!). 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+    float   (*Platform_GetWindowDpiScale)(ImGuiViewport* vp);               // N . . . .  // (Optional) [BETA] FIXME-DPI: DPI handling: Return DPI scale for this viewport. 1.0f = 96 DPI.
+    void    (*Platform_OnChangedViewport)(ImGuiViewport* vp);               // . F . . .  // (Optional) [BETA] FIXME-DPI: DPI handling: Called during Begin() every time the viewport we are outputting into changes, so backend has a chance to swap fonts to adjust style.
+    ImVec4  (*Platform_GetWindowWorkAreaInsets)(ImGuiViewport* vp);         // N . . . .  // (Optional) [BETA] Get initial work area inset for the viewport (won't be covered by main menu bar, dockspace over viewport etc.). Default to (0,0),(0,0). 'safeAreaInsets' in iOS land, 'DisplayCutout' in Android land.
+    int     (*Platform_CreateVkSurface)(ImGuiViewport* vp, ImU64 vk_inst, const void* vk_allocators, ImU64* out_vk_surface); // (Optional) For a Vulkan Renderer to call into Platform code (since the surface creation needs to tie them both).
+
+    // Renderer Backend functions (e.g. DirectX, OpenGL, Vulkan) ------------ Called by -----
+    void    (*Renderer_CreateWindow)(ImGuiViewport* vp);                    // . . U . .  // Create swap chain, frame buffers etc. (called after Platform_CreateWindow)
+    void    (*Renderer_DestroyWindow)(ImGuiViewport* vp);                   // N . U . D  // Destroy swap chain, frame buffers etc. (called before Platform_DestroyWindow)
+    void    (*Renderer_SetWindowSize)(ImGuiViewport* vp, ImVec2 size);      // . . U . .  // Resize swap chain, frame buffers etc. (called after Platform_SetWindowSize)
+    void    (*Renderer_RenderWindow)(ImGuiViewport* vp, void* render_arg);  // . . . R .  // (Optional) Clear framebuffer, setup render target, then render the viewport->DrawData. 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+    void    (*Renderer_SwapBuffers)(ImGuiViewport* vp, void* render_arg);   // . . . R .  // (Optional) Call Present/SwapBuffers. 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+
+    // (Optional) Monitor list
+    // - Updated by: app/backend. Update every frame to dynamically support changing monitor or DPI configuration.
+    // - Used by: dear imgui to query DPI info, clamp popups/tooltips within same monitor and not have them straddle monitors.
+    ImVector<ImGuiPlatformMonitor>  Monitors;
+
     //------------------------------------------------------------------
     // Output
     //------------------------------------------------------------------
@@ -3932,6 +4226,28 @@ struct ImGuiPlatformIO
     // Textures list (the list is updated by calling ImGui::EndFrame or ImGui::Render)
     // The ImGui_ImplXXXX_RenderDrawData() function of each backend generally access this via ImDrawData::Textures which points to this. The array is available here mostly because backends will want to destroy textures on shutdown.
     ImVector<ImTextureData*>        Textures;           // List of textures used by Dear ImGui (most often 1) + contents of external texture list is automatically appended into this.
+
+    // Viewports list (the list is updated by calling ImGui::EndFrame or ImGui::Render)
+    // (in the future we will attempt to organize this feature to remove the need for a "main viewport")
+    ImVector<ImGuiViewport*>        Viewports;          // Main viewports, followed by all secondary viewports.
+
+    //------------------------------------------------------------------
+    // Functions
+    //------------------------------------------------------------------
+
+    void    ClearPlatformHandlers();    // Clear all Platform_XXX fields. Typically called on Platform Backend shutdown.
+    void    ClearRendererHandlers();    // Clear all Renderer_XXX fields. Typically called on Renderer Backend shutdown.
+};
+
+// (Optional) This is required when enabling multi-viewport. Represent the bounds of each connected monitor/display and their DPI.
+// We use this information for multiple DPI support + clamping the position of popups and tooltips so they don't straddle multiple monitors.
+struct ImGuiPlatformMonitor
+{
+    ImVec2  MainPos, MainSize;      // Coordinates of the area displayed on this monitor (Min = upper left, Max = bottom right)
+    ImVec2  WorkPos, WorkSize;      // Coordinates without task bars / side bars / menu bars. Used to avoid positioning popups/tooltips inside this region. If you don't have this info, please copy the value for MainPos/MainSize.
+    float   DpiScale;               // 1.0f = 96 DPI
+    void*   PlatformHandle;         // Backend dependant data (e.g. HMONITOR, GLFWmonitor*, SDL Display Index, NSScreen*)
+    ImGuiPlatformMonitor()          { MainPos = MainSize = WorkPos = WorkSize = ImVec2(0, 0); DpiScale = 1.0f; PlatformHandle = NULL; }
 };
 
 // (Optional) Support for IME (Input Method Editor) via the platform_io.Platform_SetImeDataFn() function. Handler is called during EndFrame().
@@ -3956,24 +4272,24 @@ struct ImGuiPlatformImeData
 namespace ImGui
 {
     // OBSOLETED in 1.92.0 (from June 2025)
-    static inline void  PushFont(ImFont* font)                                  { PushFont(font, font ? font->LegacySize : 0.0f); }
+    inline void         PushFont(ImFont* font)                                  { PushFont(font, font ? font->LegacySize : 0.0f); }
     IMGUI_API void      SetWindowFontScale(float scale);                        // Set font scale factor for current window. Prefer using PushFont(NULL, style.FontSizeBase * factor) or use style.FontScaleMain to scale all windows.
     // OBSOLETED in 1.91.9 (from February 2025)
     IMGUI_API void      Image(ImTextureRef tex_ref, const ImVec2& image_size, const ImVec2& uv0, const ImVec2& uv1, const ImVec4& tint_col, const ImVec4& border_col); // <-- 'border_col' was removed in favor of ImGuiCol_ImageBorder. If you use 'tint_col', use ImageWithBg() instead.
     // OBSOLETED in 1.91.0 (from July 2024)
-    static inline void  PushButtonRepeat(bool repeat)                           { PushItemFlag(ImGuiItemFlags_ButtonRepeat, repeat); }
-    static inline void  PopButtonRepeat()                                       { PopItemFlag(); }
-    static inline void  PushTabStop(bool tab_stop)                              { PushItemFlag(ImGuiItemFlags_NoTabStop, !tab_stop); }
-    static inline void  PopTabStop()                                            { PopItemFlag(); }
+    inline void         PushButtonRepeat(bool repeat)                           { PushItemFlag(ImGuiItemFlags_ButtonRepeat, repeat); }
+    inline void         PopButtonRepeat()                                       { PopItemFlag(); }
+    inline void         PushTabStop(bool tab_stop)                              { PushItemFlag(ImGuiItemFlags_NoTabStop, !tab_stop); }
+    inline void         PopTabStop()                                            { PopItemFlag(); }
     IMGUI_API ImVec2    GetContentRegionMax();                                  // Content boundaries max (e.g. window boundaries including scrolling, or current column boundaries). You should never need this. Always use GetCursorScreenPos() and GetContentRegionAvail()!
     IMGUI_API ImVec2    GetWindowContentRegionMin();                            // Content boundaries min for the window (roughly (0,0)-Scroll), in window-local coordinates. You should never need this. Always use GetCursorScreenPos() and GetContentRegionAvail()!
     IMGUI_API ImVec2    GetWindowContentRegionMax();                            // Content boundaries max for the window (roughly (0,0)+Size-Scroll), in window-local coordinates. You should never need this. Always use GetCursorScreenPos() and GetContentRegionAvail()!
     // OBSOLETED in 1.90.0 (from September 2023)
-    static inline bool  BeginChildFrame(ImGuiID id, const ImVec2& size, ImGuiWindowFlags window_flags = 0)  { return BeginChild(id, size, ImGuiChildFlags_FrameStyle, window_flags); }
-    static inline void  EndChildFrame()                                                                     { EndChild(); }
-    //static inline bool BeginChild(const char* str_id, const ImVec2& size_arg, bool borders, ImGuiWindowFlags window_flags){ return BeginChild(str_id, size_arg, borders ? ImGuiChildFlags_Borders : ImGuiChildFlags_None, window_flags); } // Unnecessary as true == ImGuiChildFlags_Borders
-    //static inline bool BeginChild(ImGuiID id, const ImVec2& size_arg, bool borders, ImGuiWindowFlags window_flags)        { return BeginChild(id, size_arg, borders ? ImGuiChildFlags_Borders : ImGuiChildFlags_None, window_flags);     } // Unnecessary as true == ImGuiChildFlags_Borders
-    static inline void  ShowStackToolWindow(bool* p_open = NULL)                { ShowIDStackToolWindow(p_open); }
+    inline bool         BeginChildFrame(ImGuiID id, const ImVec2& size, ImGuiWindowFlags window_flags = 0)  { return BeginChild(id, size, ImGuiChildFlags_FrameStyle, window_flags); }
+    inline void         EndChildFrame()                                                                     { EndChild(); }
+    //inline bool       BeginChild(const char* str_id, const ImVec2& size_arg, bool borders, ImGuiWindowFlags window_flags){ return BeginChild(str_id, size_arg, borders ? ImGuiChildFlags_Borders : ImGuiChildFlags_None, window_flags); } // Unnecessary as true == ImGuiChildFlags_Borders
+    //inline bool       BeginChild(ImGuiID id, const ImVec2& size_arg, bool borders, ImGuiWindowFlags window_flags)        { return BeginChild(id, size_arg, borders ? ImGuiChildFlags_Borders : ImGuiChildFlags_None, window_flags);     } // Unnecessary as true == ImGuiChildFlags_Borders
+    inline void         ShowStackToolWindow(bool* p_open = NULL)                { ShowIDStackToolWindow(p_open); }
     IMGUI_API bool      Combo(const char* label, int* current_item, bool (*old_callback)(void* user_data, int idx, const char** out_text), void* user_data, int items_count, int popup_max_height_in_items = -1);
     IMGUI_API bool      ListBox(const char* label, int* current_item, bool (*old_callback)(void* user_data, int idx, const char** out_text), void* user_data, int items_count, int height_in_items = -1);
     // OBSOLETED in 1.89.7 (from June 2023)

imgui_demo.cpp

@@ -1,4 +1,4 @@
-// dear imgui, v1.92.1
+// dear imgui, v1.92.4
 // (demo code)
 
 // Help:
@@ -118,6 +118,7 @@ Index of this file:
 // [SECTION] Example App: Fullscreen window / ShowExampleAppFullscreen()
 // [SECTION] Example App: Manipulating window titles / ShowExampleAppWindowTitles()
 // [SECTION] Example App: Custom Rendering using ImDrawList API / ShowExampleAppCustomRendering()
+// [SECTION] Example App: Docking, DockSpace / ShowExampleAppDockSpace()
 // [SECTION] Example App: Documents Handling / ShowExampleAppDocuments()
 // [SECTION] Example App: Assets Browser / ShowExampleAppAssetsBrowser()
 
@@ -237,6 +238,7 @@ static void ShowExampleAppMainMenuBar();
 static void ShowExampleAppAssetsBrowser(bool* p_open);
 static void ShowExampleAppConsole(bool* p_open);
 static void ShowExampleAppCustomRendering(bool* p_open);
+static void ShowExampleAppDockSpace(bool* p_open);
 static void ShowExampleAppDocuments(bool* p_open);
 static void ShowExampleAppLog(bool* p_open);
 static void ShowExampleAppLayout(bool* p_open);
@@ -282,6 +284,16 @@ static void HelpMarker(const char* desc)
     }
 }
 
+static void ShowDockingDisabledMessage()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui::Text("ERROR: Docking is not enabled! See Demo > Configuration.");
+    ImGui::Text("Set io.ConfigFlags |= ImGuiConfigFlags_DockingEnable in your code, or ");
+    ImGui::SameLine(0.0f, 0.0f);
+    if (ImGui::SmallButton("click here"))
+        io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;
+}
+
 // Helper to wire demo markers located in code to an interactive browser
 typedef void (*ImGuiDemoMarkerCallback)(const char* file, int line, const char* section, void* user_data);
 extern ImGuiDemoMarkerCallback      GImGuiDemoMarkerCallback;
@@ -303,6 +315,7 @@ struct ImGuiDemoWindowData
     bool ShowAppConsole = false;
     bool ShowAppCustomRendering = false;
     bool ShowAppDocuments = false;
+    bool ShowAppDockSpace = false;
     bool ShowAppLog = false;
     bool ShowAppLayout = false;
     bool ShowAppPropertyEditor = false;
@@ -344,7 +357,8 @@ void ImGui::ShowDemoWindow(bool* p_open)
 
     // Examples Apps (accessible from the "Examples" menu)
     if (demo_data.ShowMainMenuBar)          { ShowExampleAppMainMenuBar(); }
-    if (demo_data.ShowAppDocuments)         { ShowExampleAppDocuments(&demo_data.ShowAppDocuments); }
+    if (demo_data.ShowAppDockSpace)         { ShowExampleAppDockSpace(&demo_data.ShowAppDockSpace); } // Important: Process the Docking app first, as explicit DockSpace() nodes needs to be submitted early (read comments near the DockSpace function)
+    if (demo_data.ShowAppDocuments)         { ShowExampleAppDocuments(&demo_data.ShowAppDocuments); } // ...process the Document app next, as it may also use a DockSpace()
     if (demo_data.ShowAppAssetsBrowser)     { ShowExampleAppAssetsBrowser(&demo_data.ShowAppAssetsBrowser); }
     if (demo_data.ShowAppConsole)           { ShowExampleAppConsole(&demo_data.ShowAppConsole); }
     if (demo_data.ShowAppCustomRendering)   { ShowExampleAppCustomRendering(&demo_data.ShowAppCustomRendering); }
@@ -381,6 +395,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
     static bool no_nav = false;
     static bool no_background = false;
     static bool no_bring_to_front = false;
+    static bool no_docking = false;
     static bool unsaved_document = false;
 
     ImGuiWindowFlags window_flags = 0;
@@ -393,6 +408,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
     if (no_nav)             window_flags |= ImGuiWindowFlags_NoNav;
     if (no_background)      window_flags |= ImGuiWindowFlags_NoBackground;
     if (no_bring_to_front)  window_flags |= ImGuiWindowFlags_NoBringToFrontOnFocus;
+    if (no_docking)         window_flags |= ImGuiWindowFlags_NoDocking;
     if (unsaved_document)   window_flags |= ImGuiWindowFlags_UnsavedDocument;
     if (no_close)           p_open = NULL; // Don't pass our bool* to Begin
 
@@ -505,6 +521,52 @@ void ImGui::ShowDemoWindow(bool* p_open)
             ImGui::Checkbox("io.ConfigNavCursorVisibleAlways", &io.ConfigNavCursorVisibleAlways);
             ImGui::SameLine(); HelpMarker("Navigation cursor is always visible.");
 
+            ImGui::SeparatorText("Docking");
+            ImGui::CheckboxFlags("io.ConfigFlags: DockingEnable", &io.ConfigFlags, ImGuiConfigFlags_DockingEnable);
+            ImGui::SameLine();
+            if (io.ConfigDockingWithShift)
+                HelpMarker("Drag from window title bar or their tab to dock/undock. Hold SHIFT to enable docking.\n\nDrag from window menu button (upper-left button) to undock an entire node (all windows).");
+            else
+                HelpMarker("Drag from window title bar or their tab to dock/undock. Hold SHIFT to disable docking.\n\nDrag from window menu button (upper-left button) to undock an entire node (all windows).");
+            if (io.ConfigFlags & ImGuiConfigFlags_DockingEnable)
+            {
+                ImGui::Indent();
+                ImGui::Checkbox("io.ConfigDockingNoSplit", &io.ConfigDockingNoSplit);
+                ImGui::SameLine(); HelpMarker("Simplified docking mode: disable window splitting, so docking is limited to merging multiple windows together into tab-bars.");
+                ImGui::Checkbox("io.ConfigDockingWithShift", &io.ConfigDockingWithShift);
+                ImGui::SameLine(); HelpMarker("Enable docking when holding Shift only (allow to drop in wider space, reduce visual noise)");
+                ImGui::Checkbox("io.ConfigDockingAlwaysTabBar", &io.ConfigDockingAlwaysTabBar);
+                ImGui::SameLine(); HelpMarker("Create a docking node and tab-bar on single floating windows.");
+                ImGui::Checkbox("io.ConfigDockingTransparentPayload", &io.ConfigDockingTransparentPayload);
+                ImGui::SameLine(); HelpMarker("Make window or viewport transparent when docking and only display docking boxes on the target viewport. Useful if rendering of multiple viewport cannot be synced. Best used with ConfigViewportsNoAutoMerge.");
+                ImGui::Unindent();
+            }
+
+            ImGui::SeparatorText("Multi-viewports");
+            ImGui::CheckboxFlags("io.ConfigFlags: ViewportsEnable", &io.ConfigFlags, ImGuiConfigFlags_ViewportsEnable);
+            ImGui::SameLine(); HelpMarker("[beta] Enable beta multi-viewports support. See ImGuiPlatformIO for details.");
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                ImGui::Indent();
+                ImGui::Checkbox("io.ConfigViewportsNoAutoMerge", &io.ConfigViewportsNoAutoMerge);
+                ImGui::SameLine(); HelpMarker("Set to make all floating imgui windows always create their own viewport. Otherwise, they are merged into the main host viewports when overlapping it.");
+                ImGui::Checkbox("io.ConfigViewportsNoTaskBarIcon", &io.ConfigViewportsNoTaskBarIcon);
+                ImGui::SameLine(); HelpMarker("(note: some platform backends may not reflect a change of this value for existing viewports, and may need the viewport to be recreated)");
+                ImGui::Checkbox("io.ConfigViewportsNoDecoration", &io.ConfigViewportsNoDecoration);
+                ImGui::SameLine(); HelpMarker("(note: some platform backends may not reflect a change of this value for existing viewports, and may need the viewport to be recreated)");
+                ImGui::Checkbox("io.ConfigViewportsNoDefaultParent", &io.ConfigViewportsNoDefaultParent);
+                ImGui::SameLine(); HelpMarker("(note: some platform backends may not reflect a change of this value for existing viewports, and may need the viewport to be recreated)");
+                ImGui::Checkbox("io.ConfigViewportsPlatformFocusSetsImGuiFocus", &io.ConfigViewportsPlatformFocusSetsImGuiFocus);
+                ImGui::SameLine(); HelpMarker("When a platform window is focused (e.g. using Alt+Tab, clicking Platform Title Bar), apply corresponding focus on imgui windows (may clear focus/active id from imgui windows location in other platform windows). In principle this is better enabled but we provide an opt-out, because some Linux window managers tend to eagerly focus windows (e.g. on mouse hover, or even a simple window pos/size change).");
+                ImGui::Unindent();
+            }
+
+            //ImGui::SeparatorText("DPI/Scaling");
+            //ImGui::Checkbox("io.ConfigDpiScaleFonts", &io.ConfigDpiScaleFonts);
+            //ImGui::SameLine(); HelpMarker("Experimental: Automatically update style.FontScaleDpi when Monitor DPI changes. This will scale fonts but NOT style sizes/padding for now.");
+            //ImGui::Checkbox("io.ConfigDpiScaleViewports", &io.ConfigDpiScaleViewports);
+            //ImGui::SameLine(); HelpMarker("Experimental: Scale Dear ImGui and Platform Windows when Monitor DPI changes.");
+
             ImGui::SeparatorText("Windows");
             ImGui::Checkbox("io.ConfigWindowsResizeFromEdges", &io.ConfigWindowsResizeFromEdges);
             ImGui::SameLine(); HelpMarker("Enable resizing of windows from their edges and from the lower-left corner.\nThis requires ImGuiBackendFlags_HasMouseCursors for better mouse cursor feedback.");
@@ -570,13 +632,18 @@ void ImGui::ShowDemoWindow(bool* p_open)
                 "Those flags are set by the backends (imgui_impl_xxx files) to specify their capabilities.\n"
                 "Here we expose them as read-only fields to avoid breaking interactions with your backend.");
 
+            // Make a local copy to avoid modifying actual backend flags.
             // FIXME: Maybe we need a BeginReadonly() equivalent to keep label bright?
             ImGui::BeginDisabled();
-            ImGui::CheckboxFlags("io.BackendFlags: HasGamepad",           &io.BackendFlags, ImGuiBackendFlags_HasGamepad);
-            ImGui::CheckboxFlags("io.BackendFlags: HasMouseCursors",      &io.BackendFlags, ImGuiBackendFlags_HasMouseCursors);
-            ImGui::CheckboxFlags("io.BackendFlags: HasSetMousePos",       &io.BackendFlags, ImGuiBackendFlags_HasSetMousePos);
-            ImGui::CheckboxFlags("io.BackendFlags: RendererHasVtxOffset", &io.BackendFlags, ImGuiBackendFlags_RendererHasVtxOffset);
-            ImGui::CheckboxFlags("io.BackendFlags: RendererHasTextures",  &io.BackendFlags, ImGuiBackendFlags_RendererHasTextures);
+            ImGui::CheckboxFlags("io.BackendFlags: HasGamepad",             &io.BackendFlags, ImGuiBackendFlags_HasGamepad);
+            ImGui::CheckboxFlags("io.BackendFlags: HasMouseCursors",        &io.BackendFlags, ImGuiBackendFlags_HasMouseCursors);
+            ImGui::CheckboxFlags("io.BackendFlags: HasSetMousePos",         &io.BackendFlags, ImGuiBackendFlags_HasSetMousePos);
+            ImGui::CheckboxFlags("io.BackendFlags: PlatformHasViewports",   &io.BackendFlags, ImGuiBackendFlags_PlatformHasViewports);
+            ImGui::CheckboxFlags("io.BackendFlags: HasMouseHoveredViewport",&io.BackendFlags, ImGuiBackendFlags_HasMouseHoveredViewport);
+            ImGui::CheckboxFlags("io.BackendFlags: HasParentViewport",      &io.BackendFlags, ImGuiBackendFlags_HasParentViewport);
+            ImGui::CheckboxFlags("io.BackendFlags: RendererHasVtxOffset",   &io.BackendFlags, ImGuiBackendFlags_RendererHasVtxOffset);
+            ImGui::CheckboxFlags("io.BackendFlags: RendererHasTextures",    &io.BackendFlags, ImGuiBackendFlags_RendererHasTextures);
+            ImGui::CheckboxFlags("io.BackendFlags: RendererHasViewports",   &io.BackendFlags, ImGuiBackendFlags_RendererHasViewports);
             ImGui::EndDisabled();
 
             ImGui::TreePop();
@@ -628,6 +695,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
             ImGui::TableNextColumn(); ImGui::Checkbox("No nav", &no_nav);
             ImGui::TableNextColumn(); ImGui::Checkbox("No background", &no_background);
             ImGui::TableNextColumn(); ImGui::Checkbox("No bring to front", &no_bring_to_front);
+            ImGui::TableNextColumn(); ImGui::Checkbox("No docking", &no_docking);
             ImGui::TableNextColumn(); ImGui::Checkbox("Unsaved document", &unsaved_document);
             ImGui::EndTable();
         }
@@ -670,6 +738,7 @@ static void DemoWindowMenuBar(ImGuiDemoWindowData* demo_data)
             ImGui::MenuItem("Console", NULL, &demo_data->ShowAppConsole);
             ImGui::MenuItem("Custom rendering", NULL, &demo_data->ShowAppCustomRendering);
             ImGui::MenuItem("Documents", NULL, &demo_data->ShowAppDocuments);
+            ImGui::MenuItem("Dockspace", NULL, &demo_data->ShowAppDockSpace);
             ImGui::MenuItem("Log", NULL, &demo_data->ShowAppLog);
             ImGui::MenuItem("Property editor", NULL, &demo_data->ShowAppPropertyEditor);
             ImGui::MenuItem("Simple layout", NULL, &demo_data->ShowAppLayout);
@@ -2170,7 +2239,7 @@ static void DemoWindowWidgetsQueryingStatuses()
         );
         ImGui::BulletText(
             "with Hovering Delay or Stationary test:\n"
-            "IsItemHovered() = = %d\n"
+            "IsItemHovered() = %d\n"
             "IsItemHovered(_Stationary) = %d\n"
             "IsItemHovered(_DelayShort) = %d\n"
             "IsItemHovered(_DelayNormal) = %d\n"
@@ -2201,18 +2270,24 @@ static void DemoWindowWidgetsQueryingStatuses()
             "IsWindowFocused() = %d\n"
             "IsWindowFocused(_ChildWindows) = %d\n"
             "IsWindowFocused(_ChildWindows|_NoPopupHierarchy) = %d\n"
+            "IsWindowFocused(_ChildWindows|_DockHierarchy) = %d\n"
             "IsWindowFocused(_ChildWindows|_RootWindow) = %d\n"
             "IsWindowFocused(_ChildWindows|_RootWindow|_NoPopupHierarchy) = %d\n"
+            "IsWindowFocused(_ChildWindows|_RootWindow|_DockHierarchy) = %d\n"
             "IsWindowFocused(_RootWindow) = %d\n"
             "IsWindowFocused(_RootWindow|_NoPopupHierarchy) = %d\n"
+            "IsWindowFocused(_RootWindow|_DockHierarchy) = %d\n"
             "IsWindowFocused(_AnyWindow) = %d\n",
             ImGui::IsWindowFocused(),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows | ImGuiFocusedFlags_NoPopupHierarchy),
+            ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows | ImGuiFocusedFlags_DockHierarchy),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows | ImGuiFocusedFlags_RootWindow),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows | ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_NoPopupHierarchy),
+            ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows | ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_DockHierarchy),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_RootWindow),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_NoPopupHierarchy),
+            ImGui::IsWindowFocused(ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_DockHierarchy),
             ImGui::IsWindowFocused(ImGuiFocusedFlags_AnyWindow));
 
         // Testing IsWindowHovered() function with its various flags.
@@ -2222,10 +2297,13 @@ static void DemoWindowWidgetsQueryingStatuses()
             "IsWindowHovered(_AllowWhenBlockedByActiveItem) = %d\n"
             "IsWindowHovered(_ChildWindows) = %d\n"
             "IsWindowHovered(_ChildWindows|_NoPopupHierarchy) = %d\n"
+            "IsWindowHovered(_ChildWindows|_DockHierarchy) = %d\n"
             "IsWindowHovered(_ChildWindows|_RootWindow) = %d\n"
             "IsWindowHovered(_ChildWindows|_RootWindow|_NoPopupHierarchy) = %d\n"
+            "IsWindowHovered(_ChildWindows|_RootWindow|_DockHierarchy) = %d\n"
             "IsWindowHovered(_RootWindow) = %d\n"
             "IsWindowHovered(_RootWindow|_NoPopupHierarchy) = %d\n"
+            "IsWindowHovered(_RootWindow|_DockHierarchy) = %d\n"
             "IsWindowHovered(_ChildWindows|_AllowWhenBlockedByPopup) = %d\n"
             "IsWindowHovered(_AnyWindow) = %d\n"
             "IsWindowHovered(_Stationary) = %d\n",
@@ -2234,10 +2312,13 @@ static void DemoWindowWidgetsQueryingStatuses()
             ImGui::IsWindowHovered(ImGuiHoveredFlags_AllowWhenBlockedByActiveItem),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_NoPopupHierarchy),
+            ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_DockHierarchy),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_RootWindow),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_NoPopupHierarchy),
+            ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_DockHierarchy),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_RootWindow),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_NoPopupHierarchy),
+            ImGui::IsWindowHovered(ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_DockHierarchy),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_AllowWhenBlockedByPopup),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_AnyWindow),
             ImGui::IsWindowHovered(ImGuiHoveredFlags_Stationary));
@@ -2250,10 +2331,13 @@ static void DemoWindowWidgetsQueryingStatuses()
 
         // Calling IsItemHovered() after begin returns the hovered status of the title bar.
         // This is useful in particular if you want to create a context menu associated to the title bar of a window.
+        // This will also work when docked into a Tab (the Tab replace the Title Bar and guarantee the same properties).
         static bool test_window = false;
         ImGui::Checkbox("Hovered/Active tests after Begin() for title bar testing", &test_window);
         if (test_window)
         {
+            // FIXME-DOCK: This window cannot be docked within the ImGui Demo window, this will cause a feedback loop and get them stuck.
+            // Could we fix this through an ImGuiWindowClass feature? Or an API call to tag our parent as "don't skip items"?
             ImGui::Begin("Title bar Hovered/Active tests", &test_window);
             if (ImGui::BeginPopupContextItem()) // <-- This is using IsItemHovered()
             {
@@ -3229,7 +3313,7 @@ static void DemoWindowWidgetsSelectionAndMultiSelect(ImGuiDemoWindowData* demo_d
                     ImGui::BeginTable("##Split", 2, ImGuiTableFlags_Resizable | ImGuiTableFlags_NoSavedSettings | ImGuiTableFlags_NoPadOuterX);
                     ImGui::TableSetupColumn("", ImGuiTableColumnFlags_WidthStretch, 0.70f);
                     ImGui::TableSetupColumn("", ImGuiTableColumnFlags_WidthStretch, 0.30f);
-                    //ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacingY, 0.0f);
+                    //ImGui::PushStyleVarY(ImGuiStyleVar_ItemSpacing, 0.0f);
                 }
 
                 ImGuiListClipper clipper;
@@ -3379,6 +3463,18 @@ static void DemoWindowWidgetsSelectionAndMultiSelect(ImGuiDemoWindowData* demo_d
 // [SECTION] DemoWindowWidgetsTabs()
 //-----------------------------------------------------------------------------
 
+static void EditTabBarFittingPolicyFlags(ImGuiTabBarFlags* p_flags)
+{
+    if ((*p_flags & ImGuiTabBarFlags_FittingPolicyMask_) == 0)
+        *p_flags |= ImGuiTabBarFlags_FittingPolicyDefault_;
+    if (ImGui::CheckboxFlags("ImGuiTabBarFlags_FittingPolicyMixed", p_flags, ImGuiTabBarFlags_FittingPolicyMixed))
+        *p_flags &= ~(ImGuiTabBarFlags_FittingPolicyMask_ ^ ImGuiTabBarFlags_FittingPolicyMixed);
+    if (ImGui::CheckboxFlags("ImGuiTabBarFlags_FittingPolicyShrink", p_flags, ImGuiTabBarFlags_FittingPolicyShrink))
+        *p_flags &= ~(ImGuiTabBarFlags_FittingPolicyMask_ ^ ImGuiTabBarFlags_FittingPolicyShrink);
+    if (ImGui::CheckboxFlags("ImGuiTabBarFlags_FittingPolicyScroll", p_flags, ImGuiTabBarFlags_FittingPolicyScroll))
+        *p_flags &= ~(ImGuiTabBarFlags_FittingPolicyMask_ ^ ImGuiTabBarFlags_FittingPolicyScroll);
+}
+
 static void DemoWindowWidgetsTabs()
 {
     IMGUI_DEMO_MARKER("Widgets/Tabs");
@@ -3421,12 +3517,7 @@ static void DemoWindowWidgetsTabs()
             ImGui::CheckboxFlags("ImGuiTabBarFlags_TabListPopupButton", &tab_bar_flags, ImGuiTabBarFlags_TabListPopupButton);
             ImGui::CheckboxFlags("ImGuiTabBarFlags_NoCloseWithMiddleMouseButton", &tab_bar_flags, ImGuiTabBarFlags_NoCloseWithMiddleMouseButton);
             ImGui::CheckboxFlags("ImGuiTabBarFlags_DrawSelectedOverline", &tab_bar_flags, ImGuiTabBarFlags_DrawSelectedOverline);
-            if ((tab_bar_flags & ImGuiTabBarFlags_FittingPolicyMask_) == 0)
-                tab_bar_flags |= ImGuiTabBarFlags_FittingPolicyDefault_;
-            if (ImGui::CheckboxFlags("ImGuiTabBarFlags_FittingPolicyResizeDown", &tab_bar_flags, ImGuiTabBarFlags_FittingPolicyResizeDown))
-                tab_bar_flags &= ~(ImGuiTabBarFlags_FittingPolicyMask_ ^ ImGuiTabBarFlags_FittingPolicyResizeDown);
-            if (ImGui::CheckboxFlags("ImGuiTabBarFlags_FittingPolicyScroll", &tab_bar_flags, ImGuiTabBarFlags_FittingPolicyScroll))
-                tab_bar_flags &= ~(ImGuiTabBarFlags_FittingPolicyMask_ ^ ImGuiTabBarFlags_FittingPolicyScroll);
+            EditTabBarFittingPolicyFlags(&tab_bar_flags);
 
             // Tab Bar
             ImGui::AlignTextToFramePadding();
@@ -3475,12 +3566,8 @@ static void DemoWindowWidgetsTabs()
             ImGui::Checkbox("Show Trailing TabItemButton()", &show_trailing_button);
 
             // Expose some other flags which are useful to showcase how they interact with Leading/Trailing tabs
-            static ImGuiTabBarFlags tab_bar_flags = ImGuiTabBarFlags_AutoSelectNewTabs | ImGuiTabBarFlags_Reorderable | ImGuiTabBarFlags_FittingPolicyResizeDown;
-            ImGui::CheckboxFlags("ImGuiTabBarFlags_TabListPopupButton", &tab_bar_flags, ImGuiTabBarFlags_TabListPopupButton);
-            if (ImGui::CheckboxFlags("ImGuiTabBarFlags_FittingPolicyResizeDown", &tab_bar_flags, ImGuiTabBarFlags_FittingPolicyResizeDown))
-                tab_bar_flags &= ~(ImGuiTabBarFlags_FittingPolicyMask_ ^ ImGuiTabBarFlags_FittingPolicyResizeDown);
-            if (ImGui::CheckboxFlags("ImGuiTabBarFlags_FittingPolicyScroll", &tab_bar_flags, ImGuiTabBarFlags_FittingPolicyScroll))
-                tab_bar_flags &= ~(ImGuiTabBarFlags_FittingPolicyMask_ ^ ImGuiTabBarFlags_FittingPolicyScroll);
+            static ImGuiTabBarFlags tab_bar_flags = ImGuiTabBarFlags_AutoSelectNewTabs | ImGuiTabBarFlags_Reorderable | ImGuiTabBarFlags_FittingPolicyShrink;
+            EditTabBarFittingPolicyFlags(&tab_bar_flags);
 
             if (ImGui::BeginTabBar("MyTabBar", tab_bar_flags))
             {
@@ -3705,6 +3792,8 @@ static void DemoWindowWidgetsTextInput()
             static ImGuiInputTextFlags flags = ImGuiInputTextFlags_AllowTabInput;
             HelpMarker("You can use the ImGuiInputTextFlags_CallbackResize facility if you need to wire InputTextMultiline() to a dynamic string type. See misc/cpp/imgui_stdlib.h for an example. (This is not demonstrated in imgui_demo.cpp because we don't want to include <string> in here)");
             ImGui::CheckboxFlags("ImGuiInputTextFlags_ReadOnly", &flags, ImGuiInputTextFlags_ReadOnly);
+            ImGui::CheckboxFlags("ImGuiInputTextFlags_WordWrap", &flags, ImGuiInputTextFlags_WordWrap);
+            ImGui::SameLine(); HelpMarker("Feature is currently in Beta. Please read comments in imgui.h");
             ImGui::CheckboxFlags("ImGuiInputTextFlags_AllowTabInput", &flags, ImGuiInputTextFlags_AllowTabInput);
             ImGui::SameLine(); HelpMarker("When _AllowTabInput is set, passing through the widget with Tabbing doesn't automatically activate it, in order to also cycling through subsequent widgets.");
             ImGui::CheckboxFlags("ImGuiInputTextFlags_CtrlEnterForNewLine", &flags, ImGuiInputTextFlags_CtrlEnterForNewLine);
@@ -3852,10 +3941,13 @@ static void DemoWindowWidgetsTextInput()
             // For this demo we are using ImVector as a string container.
             // Note that because we need to store a terminating zero character, our size/capacity are 1 more
             // than usually reported by a typical string class.
+            static ImGuiInputTextFlags flags = ImGuiInputTextFlags_None;
+            ImGui::CheckboxFlags("ImGuiInputTextFlags_WordWrap", &flags, ImGuiInputTextFlags_WordWrap);
+
             static ImVector<char> my_str;
             if (my_str.empty())
                 my_str.push_back(0);
-            Funcs::MyInputTextMultiline("##MyStr", &my_str, ImVec2(-FLT_MIN, ImGui::GetTextLineHeight() * 16));
+            Funcs::MyInputTextMultiline("##MyStr", &my_str, ImVec2(-FLT_MIN, ImGui::GetTextLineHeight() * 16), flags);
             ImGui::Text("Data: %p\nSize: %d\nCapacity: %d", (void*)my_str.begin(), my_str.size(), my_str.capacity());
             ImGui::TreePop();
         }
@@ -4787,15 +4879,18 @@ static void DemoWindowLayout()
 
         ImGui::Checkbox("Decoration", &enable_extra_decorations);
 
+        ImGui::PushItemWidth(ImGui::GetFontSize() * 10);
+        enable_track |= ImGui::DragInt("##item", &track_item, 0.25f, 0, 99, "Item = %d");
+        ImGui::SameLine();
         ImGui::Checkbox("Track", &enable_track);
-        ImGui::PushItemWidth(100);
-        ImGui::SameLine(140); enable_track |= ImGui::DragInt("##item", &track_item, 0.25f, 0, 99, "Item = %d");
 
-        bool scroll_to_off = ImGui::Button("Scroll Offset");
-        ImGui::SameLine(140); scroll_to_off |= ImGui::DragFloat("##off", &scroll_to_off_px, 1.00f, 0, FLT_MAX, "+%.0f px");
+        bool scroll_to_off = ImGui::DragFloat("##off", &scroll_to_off_px, 1.00f, 0, FLT_MAX, "+%.0f px");
+        ImGui::SameLine();
+        scroll_to_off |= ImGui::Button("Scroll Offset");
 
-        bool scroll_to_pos = ImGui::Button("Scroll To Pos");
-        ImGui::SameLine(140); scroll_to_pos |= ImGui::DragFloat("##pos", &scroll_to_pos_px, 1.00f, -10, FLT_MAX, "X/Y = %.0f px");
+        bool scroll_to_pos = ImGui::DragFloat("##pos", &scroll_to_pos_px, 1.00f, -10, FLT_MAX, "X/Y = %.0f px");
+        ImGui::SameLine();
+        scroll_to_pos |= ImGui::Button("Scroll To Pos");
         ImGui::PopItemWidth();
 
         if (scroll_to_off || scroll_to_pos)
@@ -5179,7 +5274,7 @@ static void DemoWindowPopups()
     // Typical use for regular windows:
     //   bool my_tool_is_active = false; if (ImGui::Button("Open")) my_tool_is_active = true; [...] if (my_tool_is_active) Begin("My Tool", &my_tool_is_active) { [...] } End();
     // Typical use for popups:
-    //   if (ImGui::Button("Open")) ImGui::OpenPopup("MyPopup"); if (ImGui::BeginPopup("MyPopup") { [...] EndPopup(); }
+    //   if (ImGui::Button("Open")) ImGui::OpenPopup("MyPopup"); if (ImGui::BeginPopup("MyPopup")) { [...] EndPopup(); }
 
     // With popups we have to go through a library call (here OpenPopup) to manipulate the visibility state.
     // This may be a bit confusing at first but it should quickly make sense. Follow on the examples below.
@@ -5765,7 +5860,7 @@ static void DemoWindowTables()
         ImGui::SameLine(); ImGui::RadioButton("Text", &contents_type, CT_Text);
         ImGui::SameLine(); ImGui::RadioButton("FillButton", &contents_type, CT_FillButton);
         ImGui::Checkbox("Display headers", &display_headers);
-        ImGui::CheckboxFlags("ImGuiTableFlags_NoBordersInBody", &flags, ImGuiTableFlags_NoBordersInBody); ImGui::SameLine(); HelpMarker("Disable vertical borders in columns Body (borders will always appear in Headers");
+        ImGui::CheckboxFlags("ImGuiTableFlags_NoBordersInBody", &flags, ImGuiTableFlags_NoBordersInBody); ImGui::SameLine(); HelpMarker("Disable vertical borders in columns Body (borders will always appear in Headers)");
         PopStyleCompact();
 
         if (ImGui::BeginTable("table1", 3, flags))
@@ -7258,7 +7353,7 @@ static void DemoWindowTables()
                 ImGui::CheckboxFlags("ImGuiTableFlags_BordersH", &flags, ImGuiTableFlags_BordersH);
                 ImGui::CheckboxFlags("ImGuiTableFlags_BordersOuterH", &flags, ImGuiTableFlags_BordersOuterH);
                 ImGui::CheckboxFlags("ImGuiTableFlags_BordersInnerH", &flags, ImGuiTableFlags_BordersInnerH);
-                ImGui::CheckboxFlags("ImGuiTableFlags_NoBordersInBody", &flags, ImGuiTableFlags_NoBordersInBody); ImGui::SameLine(); HelpMarker("Disable vertical borders in columns Body (borders will always appear in Headers");
+                ImGui::CheckboxFlags("ImGuiTableFlags_NoBordersInBody", &flags, ImGuiTableFlags_NoBordersInBody); ImGui::SameLine(); HelpMarker("Disable vertical borders in columns Body (borders will always appear in Headers)");
                 ImGui::CheckboxFlags("ImGuiTableFlags_NoBordersInBodyUntilResize", &flags, ImGuiTableFlags_NoBordersInBodyUntilResize); ImGui::SameLine(); HelpMarker("Disable vertical borders in columns Body until hovered for resize (borders will always appear in Headers)");
                 ImGui::TreePop();
             }
@@ -8096,6 +8191,9 @@ void ImGui::ShowAboutWindow(bool* p_open)
         ImGui::Separator();
         ImGui::Text("sizeof(size_t): %d, sizeof(ImDrawIdx): %d, sizeof(ImDrawVert): %d", (int)sizeof(size_t), (int)sizeof(ImDrawIdx), (int)sizeof(ImDrawVert));
         ImGui::Text("define: __cplusplus=%d", (int)__cplusplus);
+#ifdef IMGUI_ENABLE_TEST_ENGINE
+        ImGui::Text("define: IMGUI_ENABLE_TEST_ENGINE");
+#endif
 #ifdef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
         ImGui::Text("define: IMGUI_DISABLE_OBSOLETE_FUNCTIONS");
 #endif
@@ -8162,6 +8260,12 @@ void ImGui::ShowAboutWindow(bool* p_open)
 #ifdef __EMSCRIPTEN__
         ImGui::Text("define: __EMSCRIPTEN__");
         ImGui::Text("Emscripten: %d.%d.%d", __EMSCRIPTEN_major__, __EMSCRIPTEN_minor__, __EMSCRIPTEN_tiny__);
+#endif
+#ifdef IMGUI_HAS_VIEWPORT
+        ImGui::Text("define: IMGUI_HAS_VIEWPORT");
+#endif
+#ifdef IMGUI_HAS_DOCK
+        ImGui::Text("define: IMGUI_HAS_DOCK");
 #endif
         ImGui::Separator();
         ImGui::Text("io.BackendPlatformName: %s", io.BackendPlatformName ? io.BackendPlatformName : "NULL");
@@ -8172,7 +8276,19 @@ void ImGui::ShowAboutWindow(bool* p_open)
         if (io.ConfigFlags & ImGuiConfigFlags_NoMouse)                  ImGui::Text(" NoMouse");
         if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)      ImGui::Text(" NoMouseCursorChange");
         if (io.ConfigFlags & ImGuiConfigFlags_NoKeyboard)               ImGui::Text(" NoKeyboard");
+        if (io.ConfigFlags & ImGuiConfigFlags_DockingEnable)            ImGui::Text(" DockingEnable");
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)          ImGui::Text(" ViewportsEnable");
         if (io.MouseDrawCursor)                                         ImGui::Text("io.MouseDrawCursor");
+        if (io.ConfigDpiScaleFonts)                                     ImGui::Text("io.ConfigDpiScaleFonts");
+        if (io.ConfigDpiScaleViewports)                                 ImGui::Text("io.ConfigDpiScaleViewports");
+        if (io.ConfigViewportsNoAutoMerge)                              ImGui::Text("io.ConfigViewportsNoAutoMerge");
+        if (io.ConfigViewportsNoTaskBarIcon)                            ImGui::Text("io.ConfigViewportsNoTaskBarIcon");
+        if (io.ConfigViewportsNoDecoration)                             ImGui::Text("io.ConfigViewportsNoDecoration");
+        if (io.ConfigViewportsNoDefaultParent)                          ImGui::Text("io.ConfigViewportsNoDefaultParent");
+        if (io.ConfigDockingNoSplit)                                    ImGui::Text("io.ConfigDockingNoSplit");
+        if (io.ConfigDockingWithShift)                                  ImGui::Text("io.ConfigDockingWithShift");
+        if (io.ConfigDockingAlwaysTabBar)                               ImGui::Text("io.ConfigDockingAlwaysTabBar");
+        if (io.ConfigDockingTransparentPayload)                         ImGui::Text("io.ConfigDockingTransparentPayload");
         if (io.ConfigMacOSXBehaviors)                                   ImGui::Text("io.ConfigMacOSXBehaviors");
         if (io.ConfigNavMoveSetMousePos)                                ImGui::Text("io.ConfigNavMoveSetMousePos");
         if (io.ConfigNavCaptureKeyboard)                                ImGui::Text("io.ConfigNavCaptureKeyboard");
@@ -8184,8 +8300,12 @@ void ImGui::ShowAboutWindow(bool* p_open)
         if (io.BackendFlags & ImGuiBackendFlags_HasGamepad)             ImGui::Text(" HasGamepad");
         if (io.BackendFlags & ImGuiBackendFlags_HasMouseCursors)        ImGui::Text(" HasMouseCursors");
         if (io.BackendFlags & ImGuiBackendFlags_HasSetMousePos)         ImGui::Text(" HasSetMousePos");
+        if (io.BackendFlags & ImGuiBackendFlags_PlatformHasViewports)   ImGui::Text(" PlatformHasViewports");
+        if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)ImGui::Text(" HasMouseHoveredViewport");
+        if (io.BackendFlags & ImGuiBackendFlags_HasParentViewport)      ImGui::Text(" HasParentViewport");
         if (io.BackendFlags & ImGuiBackendFlags_RendererHasVtxOffset)   ImGui::Text(" RendererHasVtxOffset");
         if (io.BackendFlags & ImGuiBackendFlags_RendererHasTextures)    ImGui::Text(" RendererHasTextures");
+        if (io.BackendFlags & ImGuiBackendFlags_RendererHasViewports)   ImGui::Text(" RendererHasViewports");
         ImGui::Separator();
         ImGui::Text("io.Fonts: %d fonts, Flags: 0x%08X, TexSize: %d,%d", io.Fonts->Fonts.Size, io.Fonts->Flags, io.Fonts->TexData->Width, io.Fonts->TexData->Height);
         ImGui::Text("io.Fonts->FontLoaderName: %s", io.Fonts->FontLoaderName ? io.Fonts->FontLoaderName : "NULL");
@@ -8218,22 +8338,34 @@ void ImGui::ShowAboutWindow(bool* p_open)
 //-----------------------------------------------------------------------------
 
 // Demo helper function to select among default colors. See ShowStyleEditor() for more advanced options.
-// Here we use the simplified Combo() api that packs items into a single literal string.
-// Useful for quick combo boxes where the choices are known locally.
 bool ImGui::ShowStyleSelector(const char* label)
 {
+    // FIXME: This is a bit tricky to get right as style are functions, they don't register a name nor the fact that one is active.
+    // So we keep track of last active one among our limited selection.
     static int style_idx = -1;
-    if (ImGui::Combo(label, &style_idx, "Dark\0Light\0Classic\0"))
+    const char* style_names[] = { "Dark", "Light", "Classic" };
+    bool ret = false;
+    if (ImGui::BeginCombo(label, (style_idx >= 0 && style_idx < IM_ARRAYSIZE(style_names)) ? style_names[style_idx] : ""))
     {
-        switch (style_idx)
+        for (int n = 0; n < IM_ARRAYSIZE(style_names); n++)
         {
-        case 0: ImGui::StyleColorsDark(); break;
-        case 1: ImGui::StyleColorsLight(); break;
-        case 2: ImGui::StyleColorsClassic(); break;
+            if (ImGui::Selectable(style_names[n], style_idx == n, ImGuiSelectableFlags_SelectOnNav))
+            {
+                style_idx = n;
+                ret = true;
+                switch (style_idx)
+                {
+                case 0: ImGui::StyleColorsDark(); break;
+                case 1: ImGui::StyleColorsLight(); break;
+                case 2: ImGui::StyleColorsClassic(); break;
+                }
+            }
+            else if (style_idx == n)
+                ImGui::SetItemDefaultFocus();
         }
-        return true;
+        ImGui::EndCombo();
     }
-    return false;
+    return ret;
 }
 
 static const char* GetTreeLinesFlagsName(ImGuiTreeNodeFlags flags)
@@ -8319,7 +8451,6 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             SliderFloat2("ItemInnerSpacing", (float*)&style.ItemInnerSpacing, 0.0f, 20.0f, "%.0f");
             SliderFloat2("TouchExtraPadding", (float*)&style.TouchExtraPadding, 0.0f, 10.0f, "%.0f");
             SliderFloat("IndentSpacing", &style.IndentSpacing, 0.0f, 30.0f, "%.0f");
-            SliderFloat("ScrollbarSize", &style.ScrollbarSize, 1.0f, 20.0f, "%.0f");
             SliderFloat("GrabMinSize", &style.GrabMinSize, 1.0f, 20.0f, "%.0f");
 
             SeparatorText("Borders");
@@ -8333,16 +8464,22 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             SliderFloat("ChildRounding", &style.ChildRounding, 0.0f, 12.0f, "%.0f");
             SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 12.0f, "%.0f");
             SliderFloat("PopupRounding", &style.PopupRounding, 0.0f, 12.0f, "%.0f");
-            SliderFloat("ScrollbarRounding", &style.ScrollbarRounding, 0.0f, 12.0f, "%.0f");
             SliderFloat("GrabRounding", &style.GrabRounding, 0.0f, 12.0f, "%.0f");
 
+            SeparatorText("Scrollbar");
+            SliderFloat("ScrollbarSize", &style.ScrollbarSize, 1.0f, 20.0f, "%.0f");
+            SliderFloat("ScrollbarRounding", &style.ScrollbarRounding, 0.0f, 12.0f, "%.0f");
+            SliderFloat("ScrollbarPadding", &style.ScrollbarPadding, 0.0f, 10.0f, "%.0f");
+
             SeparatorText("Tabs");
             SliderFloat("TabBorderSize", &style.TabBorderSize, 0.0f, 1.0f, "%.0f");
             SliderFloat("TabBarBorderSize", &style.TabBarBorderSize, 0.0f, 2.0f, "%.0f");
             SliderFloat("TabBarOverlineSize", &style.TabBarOverlineSize, 0.0f, 3.0f, "%.0f");
             SameLine(); HelpMarker("Overline is only drawn over the selected tab when ImGuiTabBarFlags_DrawSelectedOverline is set.");
-            DragFloat("TabCloseButtonMinWidthSelected", &style.TabCloseButtonMinWidthSelected, 0.1f, -1.0f, 100.0f, (style.TabCloseButtonMinWidthSelected < 0.0f) ? "%.0f (Always)" : "%.0f");
-            DragFloat("TabCloseButtonMinWidthUnselected", &style.TabCloseButtonMinWidthUnselected, 0.1f, -1.0f, 100.0f, (style.TabCloseButtonMinWidthUnselected < 0.0f) ? "%.0f (Always)" : "%.0f");
+            DragFloat("TabMinWidthBase", &style.TabMinWidthBase, 0.5f, 1.0f, 500.0f, "%.0f");
+            DragFloat("TabMinWidthShrink", &style.TabMinWidthShrink, 0.5f, 1.0f, 500.0f, "%0.f");
+            DragFloat("TabCloseButtonMinWidthSelected", &style.TabCloseButtonMinWidthSelected, 0.5f, -1.0f, 100.0f, (style.TabCloseButtonMinWidthSelected < 0.0f) ? "%.0f (Always)" : "%.0f");
+            DragFloat("TabCloseButtonMinWidthUnselected", &style.TabCloseButtonMinWidthUnselected, 0.5f, -1.0f, 100.0f, (style.TabCloseButtonMinWidthUnselected < 0.0f) ? "%.0f (Always)" : "%.0f");
             SliderFloat("TabRounding", &style.TabRounding, 0.0f, 12.0f, "%.0f");
 
             SeparatorText("Tables");
@@ -8384,6 +8521,11 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             SliderFloat("LogSliderDeadzone", &style.LogSliderDeadzone, 0.0f, 12.0f, "%.0f");
             SliderFloat("ImageBorderSize", &style.ImageBorderSize, 0.0f, 1.0f, "%.0f");
 
+            SeparatorText("Docking");
+            //SetCursorPosX(GetCursorPosX() + CalcItemWidth() - GetFrameHeight());
+            Checkbox("DockingNodeHasCloseButton", &style.DockingNodeHasCloseButton);
+            SliderFloat("DockingSeparatorSize", &style.DockingSeparatorSize, 0.0f, 12.0f, "%.0f");
+
             SeparatorText("Tooltips");
             for (int n = 0; n < 2; n++)
                 if (TreeNodeEx(n == 0 ? "HoverFlagsForTooltipMouse" : "HoverFlagsForTooltipNav"))
@@ -9277,10 +9419,9 @@ static void ShowExampleAppLayout(bool* p_open)
             ImGui::BeginChild("left pane", ImVec2(150, 0), ImGuiChildFlags_Borders | ImGuiChildFlags_ResizeX);
             for (int i = 0; i < 100; i++)
             {
-                // FIXME: Good candidate to use ImGuiSelectableFlags_SelectOnNav
                 char label[128];
                 sprintf(label, "MyObject %d", i);
-                if (ImGui::Selectable(label, selected == i))
+                if (ImGui::Selectable(label, selected == i, ImGuiSelectableFlags_SelectOnNav))
                     selected = i;
             }
             ImGui::EndChild();
@@ -9632,7 +9773,7 @@ static void ShowExampleAppConstrainedResize(bool* p_open)
         IMGUI_DEMO_MARKER("Examples/Constrained Resizing window");
         if (ImGui::GetIO().KeyShift)
         {
-            // Display a dummy viewport (in your real app you would likely use ImageButton() to display a texture.
+            // Display a dummy viewport (in your real app you would likely use ImageButton() to display a texture)
             ImVec2 avail_size = ImGui::GetContentRegionAvail();
             ImVec2 pos = ImGui::GetCursorScreenPos();
             ImGui::ColorButton("viewport", ImVec4(0.5f, 0.2f, 0.5f, 1.0f), ImGuiColorEditFlags_NoTooltip | ImGuiColorEditFlags_NoDragDrop, avail_size);
@@ -9642,6 +9783,8 @@ static void ShowExampleAppConstrainedResize(bool* p_open)
         else
         {
             ImGui::Text("(Hold SHIFT to display a dummy viewport)");
+            if (ImGui::IsWindowDocked())
+                ImGui::Text("Warning: Sizing Constraints won't work if the window is docked!");
             if (ImGui::Button("Set 200x200")) { ImGui::SetWindowSize(ImVec2(200, 200)); } ImGui::SameLine();
             if (ImGui::Button("Set 500x500")) { ImGui::SetWindowSize(ImVec2(500, 500)); } ImGui::SameLine();
             if (ImGui::Button("Set 800x200")) { ImGui::SetWindowSize(ImVec2(800, 200)); }
@@ -9668,7 +9811,7 @@ static void ShowExampleAppSimpleOverlay(bool* p_open)
 {
     static int location = 0;
     ImGuiIO& io = ImGui::GetIO();
-    ImGuiWindowFlags window_flags = ImGuiWindowFlags_NoDecoration | ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_NoFocusOnAppearing | ImGuiWindowFlags_NoNav;
+    ImGuiWindowFlags window_flags = ImGuiWindowFlags_NoDecoration | ImGuiWindowFlags_NoDocking | ImGuiWindowFlags_AlwaysAutoResize | ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_NoFocusOnAppearing | ImGuiWindowFlags_NoNav;
     if (location >= 0)
     {
         const float PAD = 10.0f;
@@ -9681,6 +9824,7 @@ static void ShowExampleAppSimpleOverlay(bool* p_open)
         window_pos_pivot.x = (location & 1) ? 1.0f : 0.0f;
         window_pos_pivot.y = (location & 2) ? 1.0f : 0.0f;
         ImGui::SetNextWindowPos(window_pos, ImGuiCond_Always, window_pos_pivot);
+        ImGui::SetNextWindowViewport(viewport->ID);
         window_flags |= ImGuiWindowFlags_NoMove;
     }
     else if (location == -2)
@@ -10100,6 +10244,134 @@ static void ShowExampleAppCustomRendering(bool* p_open)
     ImGui::End();
 }
 
+//-----------------------------------------------------------------------------
+// [SECTION] Example App: Docking, DockSpace / ShowExampleAppDockSpace()
+//-----------------------------------------------------------------------------
+
+// Demonstrate using DockSpace() to create an explicit docking node within an existing window, with various options.
+// THIS IS A DEMO FOR ADVANCED USAGE OF DockSpace().
+// MOST REGULAR APPLICATIONS WHO WANT TO ALLOW DOCKING WINDOWS ON THE EDGE OF YOUR SCREEN CAN SIMPLY USE:
+//    ImGui::NewFrame();
+//    ImGui::DockSpaceOverViewport(); // Create a dockspace in main viewport
+// OR:
+//    ImGui::NewFrame();
+//    ImGui::DockSpaceOverViewport(0, nullptr, ImGuiDockNodeFlags_PassthruCentralNode); // Create a dockspace in main viewport, where central node is transparent.
+// Read https://github.com/ocornut/imgui/wiki/Docking for details.
+// The reasons we do not use DockSpaceOverViewport() in this demo is because:
+// - (1) we allow the host window to be floating/moveable instead of filling the viewport (when opt_fullscreen == false)
+//       which is mostly to showcase the idea that DockSpace() may be submitted anywhere.
+// - (2) we allow the host window to have padding (when opt_padding == true)
+// - (3) we expose many flags and need a way to have them visible.
+// - (4) we have a local menu bar in the host window (vs. you could use BeginMainMenuBar() + DockSpaceOverViewport()
+//       in your code, but we don't here because we allow the window to be floating)
+void ShowExampleAppDockSpace(bool* p_open)
+{
+    // TL;DR; this demo is more complicated than what most users you would normally use.
+    // If we remove all options we are showcasing, this demo would become a simple call to ImGui::DockSpaceOverViewport() !!
+    // In this specific demo, we are not using DockSpaceOverViewport() because:
+
+    static bool opt_fullscreen = true;
+    static bool opt_padding = false;
+    static ImGuiDockNodeFlags dockspace_flags = ImGuiDockNodeFlags_None;
+
+    // We are using the ImGuiWindowFlags_NoDocking flag to make the parent window not dockable into,
+    // because it would be confusing to have two docking targets within each others.
+    ImGuiWindowFlags window_flags = ImGuiWindowFlags_MenuBar | ImGuiWindowFlags_NoDocking;
+    if (opt_fullscreen)
+    {
+        const ImGuiViewport* viewport = ImGui::GetMainViewport();
+        ImGui::SetNextWindowPos(viewport->WorkPos);
+        ImGui::SetNextWindowSize(viewport->WorkSize);
+        ImGui::SetNextWindowViewport(viewport->ID);
+        ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
+        ImGui::PushStyleVar(ImGuiStyleVar_WindowBorderSize, 0.0f);
+        window_flags |= ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove;
+        window_flags |= ImGuiWindowFlags_NoBringToFrontOnFocus | ImGuiWindowFlags_NoNavFocus;
+    }
+    else
+    {
+        dockspace_flags &= ~ImGuiDockNodeFlags_PassthruCentralNode;
+    }
+
+    // When using ImGuiDockNodeFlags_PassthruCentralNode, DockSpace() will render our background
+    // and handle the pass-thru hole, so we ask Begin() to not render a background.
+    if (dockspace_flags & ImGuiDockNodeFlags_PassthruCentralNode)
+        window_flags |= ImGuiWindowFlags_NoBackground;
+
+    // Important: note that we proceed even if Begin() returns false (aka window is collapsed).
+    // This is because we want to keep our DockSpace() active. If a DockSpace() is inactive,
+    // all active windows docked into it will lose their parent and become undocked.
+    // We cannot preserve the docking relationship between an active window and an inactive docking, otherwise
+    // any change of dockspace/settings would lead to windows being stuck in limbo and never being visible.
+    if (!opt_padding)
+        ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0.0f, 0.0f));
+    ImGui::Begin("DockSpace Demo", p_open, window_flags);
+    if (!opt_padding)
+        ImGui::PopStyleVar();
+
+    if (opt_fullscreen)
+        ImGui::PopStyleVar(2);
+
+    // Submit the DockSpace
+    // REMINDER: THIS IS A DEMO FOR ADVANCED USAGE OF DockSpace()!
+    // MOST REGULAR APPLICATIONS WILL SIMPLY WANT TO CALL DockSpaceOverViewport(). READ COMMENTS ABOVE.
+    ImGuiIO& io = ImGui::GetIO();
+    if (io.ConfigFlags & ImGuiConfigFlags_DockingEnable)
+    {
+        ImGuiID dockspace_id = ImGui::GetID("MyDockSpace");
+        ImGui::DockSpace(dockspace_id, ImVec2(0.0f, 0.0f), dockspace_flags);
+    }
+    else
+    {
+        ShowDockingDisabledMessage();
+    }
+
+    // Show demo options and help
+    if (ImGui::BeginMenuBar())
+    {
+        if (ImGui::BeginMenu("Options"))
+        {
+            // Disabling fullscreen would allow the window to be moved to the front of other windows,
+            // which we can't undo at the moment without finer window depth/z control.
+            ImGui::MenuItem("Fullscreen", NULL, &opt_fullscreen);
+            ImGui::MenuItem("Padding", NULL, &opt_padding);
+            ImGui::Separator();
+
+            if (ImGui::MenuItem("Flag: NoDockingOverCentralNode", "", (dockspace_flags & ImGuiDockNodeFlags_NoDockingOverCentralNode) != 0)) { dockspace_flags ^= ImGuiDockNodeFlags_NoDockingOverCentralNode; }
+            if (ImGui::MenuItem("Flag: NoDockingSplit",         "", (dockspace_flags & ImGuiDockNodeFlags_NoDockingSplit) != 0))             { dockspace_flags ^= ImGuiDockNodeFlags_NoDockingSplit; }
+            if (ImGui::MenuItem("Flag: NoUndocking",            "", (dockspace_flags & ImGuiDockNodeFlags_NoUndocking) != 0))                { dockspace_flags ^= ImGuiDockNodeFlags_NoUndocking; }
+            if (ImGui::MenuItem("Flag: NoResize",               "", (dockspace_flags & ImGuiDockNodeFlags_NoResize) != 0))                   { dockspace_flags ^= ImGuiDockNodeFlags_NoResize; }
+            if (ImGui::MenuItem("Flag: AutoHideTabBar",         "", (dockspace_flags & ImGuiDockNodeFlags_AutoHideTabBar) != 0))             { dockspace_flags ^= ImGuiDockNodeFlags_AutoHideTabBar; }
+            if (ImGui::MenuItem("Flag: PassthruCentralNode",    "", (dockspace_flags & ImGuiDockNodeFlags_PassthruCentralNode) != 0, opt_fullscreen)) { dockspace_flags ^= ImGuiDockNodeFlags_PassthruCentralNode; }
+            ImGui::Separator();
+
+            if (ImGui::MenuItem("Close", NULL, false, p_open != NULL))
+                *p_open = false;
+            ImGui::EndMenu();
+        }
+        if (ImGui::BeginMenu("Help"))
+        {
+            ImGui::TextUnformatted(
+                "This demo has nothing to do with enabling docking!" "\n"
+                "This demo only demonstrate the use of ImGui::DockSpace() which allows you to manually\ncreate a docking node _within_ another window." "\n"
+                "Most application can simply call ImGui::DockSpaceOverViewport() and be done with it.");
+            ImGui::Separator();
+            ImGui::TextUnformatted("When docking is enabled, you can ALWAYS dock MOST window into another! Try it now!" "\n"
+                "- Drag from window title bar or their tab to dock/undock." "\n"
+                "- Drag from window menu button (upper-left button) to undock an entire node (all windows)." "\n"
+                "- Hold SHIFT to disable docking (if io.ConfigDockingWithShift == false, default)" "\n"
+                "- Hold SHIFT to enable docking (if io.ConfigDockingWithShift == true)");
+            ImGui::Separator();
+            ImGui::TextUnformatted("More details:"); ImGui::Bullet(); ImGui::SameLine(); ImGui::TextLinkOpenURL("Docking Wiki page", "https://github.com/ocornut/imgui/wiki/Docking");
+            ImGui::BulletText("Read comments in ShowExampleAppDockSpace()");
+            ImGui::EndMenu();
+        }
+        ImGui::EndMenuBar();
+    }
+
+    ImGui::End();
+}
+
 //-----------------------------------------------------------------------------
 // [SECTION] Example App: Documents Handling / ShowExampleAppDocuments()
 //-----------------------------------------------------------------------------
@@ -10225,11 +10497,25 @@ void ShowExampleAppDocuments(bool* p_open)
     static ExampleAppDocuments app;
 
     // Options
+    enum Target
+    {
+        Target_None,
+        Target_Tab,                 // Create documents as local tab into a local tab bar
+        Target_DockSpaceAndWindow   // Create documents as regular windows, and create an embedded dockspace
+    };
+    static Target opt_target = Target_Tab;
     static bool opt_reorderable = true;
     static ImGuiTabBarFlags opt_fitting_flags = ImGuiTabBarFlags_FittingPolicyDefault_;
 
+    // When (opt_target == Target_DockSpaceAndWindow) there is the possibily that one of our child Document window (e.g. "Eggplant")
+    // that we emit gets docked into the same spot as the parent window ("Example: Documents").
+    // This would create a problematic feedback loop because selecting the "Eggplant" tab would make the "Example: Documents" tab
+    // not visible, which in turn would stop submitting the "Eggplant" window.
+    // We avoid this problem by submitting our documents window even if our parent window is not currently visible.
+    // Another solution may be to make the "Example: Documents" window use the ImGuiWindowFlags_NoDocking.
+
     bool window_contents_visible = ImGui::Begin("Example: Documents", p_open, ImGuiWindowFlags_MenuBar);
-    if (!window_contents_visible)
+    if (!window_contents_visible && opt_target != Target_DockSpaceAndWindow)
     {
         ImGui::End();
         return;
@@ -10273,6 +10559,12 @@ void ShowExampleAppDocuments(bool* p_open)
                 doc.DoForceClose();
         ImGui::PopID();
     }
+    ImGui::PushItemWidth(ImGui::GetFontSize() * 12);
+    ImGui::Combo("Output", (int*)&opt_target, "None\0TabBar+Tabs\0DockSpace+Window\0");
+    ImGui::PopItemWidth();
+    bool redock_all = false;
+    if (opt_target == Target_Tab)                { ImGui::SameLine(); ImGui::Checkbox("Reorderable Tabs", &opt_reorderable); }
+    if (opt_target == Target_DockSpaceAndWindow) { ImGui::SameLine(); redock_all = ImGui::Button("Redock all"); }
 
     ImGui::Separator();
 
@@ -10286,7 +10578,8 @@ void ShowExampleAppDocuments(bool* p_open)
     //   hole for one-frame, both in the tab-bar and in tab-contents when closing a tab/window.
     //   The rarely used SetTabItemClosed() function is a way to notify of programmatic closure to avoid the one-frame hole.
 
-    // Submit Tab Bar and Tabs
+    // Tabs
+    if (opt_target == Target_Tab)
     {
         ImGuiTabBarFlags tab_bar_flags = (opt_fitting_flags) | (opt_reorderable ? ImGuiTabBarFlags_Reorderable : 0);
         tab_bar_flags |= ImGuiTabBarFlags_DrawSelectedOverline;
@@ -10329,6 +10622,53 @@ void ShowExampleAppDocuments(bool* p_open)
             ImGui::EndTabBar();
         }
     }
+    else if (opt_target == Target_DockSpaceAndWindow)
+    {
+        if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_DockingEnable)
+        {
+            app.NotifyOfDocumentsClosedElsewhere();
+
+            // Create a DockSpace node where any window can be docked
+            ImGuiID dockspace_id = ImGui::GetID("MyDockSpace");
+            ImGui::DockSpace(dockspace_id);
+
+            // Create Windows
+            for (int doc_n = 0; doc_n < app.Documents.Size; doc_n++)
+            {
+                MyDocument* doc = &app.Documents[doc_n];
+                if (!doc->Open)
+                    continue;
+
+                ImGui::SetNextWindowDockID(dockspace_id, redock_all ? ImGuiCond_Always : ImGuiCond_FirstUseEver);
+                ImGuiWindowFlags window_flags = (doc->Dirty ? ImGuiWindowFlags_UnsavedDocument : 0);
+                bool visible = ImGui::Begin(doc->Name, &doc->Open, window_flags);
+
+                // Cancel attempt to close when unsaved add to save queue so we can display a popup.
+                if (!doc->Open && doc->Dirty)
+                {
+                    doc->Open = true;
+                    app.CloseQueue.push_back(doc);
+                }
+
+                app.DisplayDocContextMenu(doc);
+                if (visible)
+                    app.DisplayDocContents(doc);
+
+                ImGui::End();
+            }
+        }
+        else
+        {
+            ShowDockingDisabledMessage();
+        }
+    }
+
+    // Early out other contents
+    if (!window_contents_visible)
+    {
+        ImGui::End();
+        return;
+    }
 
     // Display renaming UI
     if (app.RenamingDoc != NULL)

imgui_draw.cpp

@@ -1,4 +1,4 @@
-// dear imgui, v1.92.1
+// dear imgui, v1.92.4
 // (drawing and font code)
 
 /*
@@ -48,7 +48,7 @@ Index of this file:
 #pragma warning (disable: 4505)     // unreferenced local function has been removed (stb stuff)
 #pragma warning (disable: 4996)     // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen
 #pragma warning (disable: 26451)    // [Static Analyzer] Arithmetic overflow : Using operator 'xxx' on a 4 byte value and then casting the result to a 8 byte value. Cast the value to the wider type before calling operator 'xxx' to avoid overflow(io.2).
-#pragma warning (disable: 26812)    // [Static Analyzer] The enum type 'xxx' is unscoped. Prefer 'enum class' over 'enum' (Enum.3). [MSVC Static Analyzer)
+#pragma warning (disable: 26812)    // [Static Analyzer] The enum type 'xxx' is unscoped. Prefer 'enum class' over 'enum' (Enum.3).
 #endif
 
 // Clang/GCC warnings with -Weverything
@@ -227,6 +227,8 @@ void ImGui::StyleColorsDark(ImGuiStyle* dst)
     colors[ImGuiCol_TabDimmed]              = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabDimmedSelected]      = ImLerp(colors[ImGuiCol_TabSelected],  colors[ImGuiCol_TitleBg], 0.40f);
     colors[ImGuiCol_TabDimmedSelectedOverline] = ImVec4(0.50f, 0.50f, 0.50f, 0.00f);
+    colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_HeaderActive] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(0.61f, 0.61f, 0.61f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(1.00f, 0.43f, 0.35f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -240,6 +242,7 @@ void ImGui::StyleColorsDark(ImGuiStyle* dst)
     colors[ImGuiCol_TextSelectedBg]         = ImVec4(0.26f, 0.59f, 0.98f, 0.35f);
     colors[ImGuiCol_TreeLines]              = colors[ImGuiCol_Border];
     colors[ImGuiCol_DragDropTarget]         = ImVec4(1.00f, 1.00f, 0.00f, 0.90f);
+    colors[ImGuiCol_UnsavedMarker]          = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
     colors[ImGuiCol_NavCursor]              = ImVec4(0.26f, 0.59f, 0.98f, 1.00f);
     colors[ImGuiCol_NavWindowingHighlight]  = ImVec4(1.00f, 1.00f, 1.00f, 0.70f);
     colors[ImGuiCol_NavWindowingDimBg]      = ImVec4(0.80f, 0.80f, 0.80f, 0.20f);
@@ -292,6 +295,8 @@ void ImGui::StyleColorsClassic(ImGuiStyle* dst)
     colors[ImGuiCol_TabDimmed]              = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabDimmedSelected]      = ImLerp(colors[ImGuiCol_TabSelected],  colors[ImGuiCol_TitleBg], 0.40f);
     colors[ImGuiCol_TabDimmedSelectedOverline] = ImVec4(0.53f, 0.53f, 0.87f, 0.00f);
+    colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_Header] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -305,6 +310,7 @@ void ImGui::StyleColorsClassic(ImGuiStyle* dst)
     colors[ImGuiCol_TextSelectedBg]         = ImVec4(0.00f, 0.00f, 1.00f, 0.35f);
     colors[ImGuiCol_TreeLines]              = colors[ImGuiCol_Border];
     colors[ImGuiCol_DragDropTarget]         = ImVec4(1.00f, 1.00f, 0.00f, 0.90f);
+    colors[ImGuiCol_UnsavedMarker]          = ImVec4(0.90f, 0.90f, 0.90f, 1.00f);
     colors[ImGuiCol_NavCursor]              = colors[ImGuiCol_HeaderHovered];
     colors[ImGuiCol_NavWindowingHighlight]  = ImVec4(1.00f, 1.00f, 1.00f, 0.70f);
     colors[ImGuiCol_NavWindowingDimBg]      = ImVec4(0.80f, 0.80f, 0.80f, 0.20f);
@@ -358,6 +364,8 @@ void ImGui::StyleColorsLight(ImGuiStyle* dst)
     colors[ImGuiCol_TabDimmed]              = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabDimmedSelected]      = ImLerp(colors[ImGuiCol_TabSelected],  colors[ImGuiCol_TitleBg], 0.40f);
     colors[ImGuiCol_TabDimmedSelectedOverline] = ImVec4(0.26f, 0.59f, 1.00f, 0.00f);
+    colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_Header] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(0.39f, 0.39f, 0.39f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(1.00f, 0.43f, 0.35f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -371,6 +379,7 @@ void ImGui::StyleColorsLight(ImGuiStyle* dst)
     colors[ImGuiCol_TextSelectedBg]         = ImVec4(0.26f, 0.59f, 0.98f, 0.35f);
     colors[ImGuiCol_TreeLines]              = colors[ImGuiCol_Border];
     colors[ImGuiCol_DragDropTarget]         = ImVec4(0.26f, 0.59f, 0.98f, 0.95f);
+    colors[ImGuiCol_UnsavedMarker]          = ImVec4(0.00f, 0.00f, 0.00f, 1.00f);
     colors[ImGuiCol_NavCursor]              = colors[ImGuiCol_HeaderHovered];
     colors[ImGuiCol_NavWindowingHighlight]  = ImVec4(0.70f, 0.70f, 0.70f, 0.70f);
     colors[ImGuiCol_NavWindowingDimBg]      = ImVec4(0.20f, 0.20f, 0.20f, 0.20f);
@@ -478,9 +487,10 @@ void ImDrawList::_ClearFreeMemory()
     _Splitter.ClearFreeMemory();
 }
 
+// Note: For multi-threaded rendering, consider using `imgui_threaded_rendering` from https://github.com/ocornut/imgui_club
 ImDrawList* ImDrawList::CloneOutput() const
 {
-    ImDrawList* dst = IM_NEW(ImDrawList(_Data));
+    ImDrawList* dst = IM_NEW(ImDrawList(NULL));
     dst->CmdBuffer = CmdBuffer;
     dst->IdxBuffer = IdxBuffer;
     dst->VtxBuffer = VtxBuffer;
@@ -517,6 +527,7 @@ void ImDrawList::AddCallback(ImDrawCallback callback, void* userdata, size_t use
 {
     IM_ASSERT_PARANOID(CmdBuffer.Size > 0);
     ImDrawCmd* curr_cmd = &CmdBuffer.Data[CmdBuffer.Size - 1];
+    IM_ASSERT(callback != NULL);
     IM_ASSERT(curr_cmd->UserCallback == NULL);
     if (curr_cmd->ElemCount != 0)
     {
@@ -1717,7 +1728,7 @@ void ImDrawList::AddText(ImFont* font, float font_size, const ImVec2& pos, ImU32
         clip_rect.z = ImMin(clip_rect.z, cpu_fine_clip_rect->z);
         clip_rect.w = ImMin(clip_rect.w, cpu_fine_clip_rect->w);
     }
-    font->RenderText(this, font_size, pos, col, clip_rect, text_begin, text_end, wrap_width, cpu_fine_clip_rect != NULL);
+    font->RenderText(this, font_size, pos, col, clip_rect, text_begin, text_end, wrap_width, (cpu_fine_clip_rect != NULL) ? ImDrawTextFlags_CpuFineClip : ImDrawTextFlags_None);
 }
 
 void ImDrawList::AddText(const ImVec2& pos, ImU32 col, const char* text_begin, const char* text_end)
@@ -2312,17 +2323,16 @@ void ImDrawData::DeIndexAllBuffers()
 {
     ImVector<ImDrawVert> new_vtx_buffer;
     TotalVtxCount = TotalIdxCount = 0;
-    for (int i = 0; i < CmdListsCount; i++)
+    for (ImDrawList* draw_list : CmdLists)
     {
-        ImDrawList* cmd_list = CmdLists[i];
-        if (cmd_list->IdxBuffer.empty())
+        if (draw_list->IdxBuffer.empty())
             continue;
-        new_vtx_buffer.resize(cmd_list->IdxBuffer.Size);
-        for (int j = 0; j < cmd_list->IdxBuffer.Size; j++)
-            new_vtx_buffer[j] = cmd_list->VtxBuffer[cmd_list->IdxBuffer[j]];
-        cmd_list->VtxBuffer.swap(new_vtx_buffer);
-        cmd_list->IdxBuffer.resize(0);
-        TotalVtxCount += cmd_list->VtxBuffer.Size;
+        new_vtx_buffer.resize(draw_list->IdxBuffer.Size);
+        for (int j = 0; j < draw_list->IdxBuffer.Size; j++)
+            new_vtx_buffer[j] = draw_list->VtxBuffer[draw_list->IdxBuffer[j]];
+        draw_list->VtxBuffer.swap(new_vtx_buffer);
+        draw_list->IdxBuffer.resize(0);
+        TotalVtxCount += draw_list->VtxBuffer.Size;
     }
 }
 
@@ -2457,8 +2467,10 @@ const char* ImTextureDataGetFormatName(ImTextureFormat format)
 
 void ImTextureData::Create(ImTextureFormat format, int w, int h)
 {
+    IM_ASSERT(Status == ImTextureStatus_Destroyed);
     DestroyPixels();
     Format = format;
+    Status = ImTextureStatus_WantCreate;
     Width = w;
     Height = h;
     BytesPerPixel = ImTextureDataGetFormatBytesPerPixel(format);
@@ -2630,6 +2642,7 @@ ImFontAtlas::ImFontAtlas()
     TexMinHeight = 128;
     TexMaxWidth = 8192;
     TexMaxHeight = 8192;
+    TexRef._TexID = ImTextureID_Invalid;
     RendererHasTextures = false; // Assumed false by default, as apps can call e.g Atlas::Build() after backend init and before ImGui can update.
     TexNextUniqueID = 1;
     FontNextUniqueID = 1;
@@ -2739,10 +2752,9 @@ void ImFontAtlasUpdateNewFrame(ImFontAtlas* atlas, int frame_count, bool rendere
         if (atlas->Builder == NULL) // This will only happen if fonts were not already loaded.
             ImFontAtlasBuildMain(atlas);
     }
-    else // Legacy backend
-    {
+    // Legacy backend
+    if (!atlas->RendererHasTextures)
         IM_ASSERT_USER_ERROR(atlas->TexIsBuilt, "Backend does not support ImGuiBackendFlags_RendererHasTextures, and font atlas is not built! Update backend OR make sure you called ImGui_ImplXXXX_NewFrame() function for renderer backend, which should call io.Fonts->GetTexDataAsRGBA32() / GetTexDataAsAlpha8().");
-    }
     if (atlas->TexIsBuilt && atlas->Builder->PreloadedAllGlyphsRanges)
         IM_ASSERT_USER_ERROR(atlas->RendererHasTextures == false, "Called ImFontAtlas::Build() before ImGuiBackendFlags_RendererHasTextures got set! With new backends: you don't need to call Build().");
 
@@ -2787,20 +2799,29 @@ void ImFontAtlasUpdateNewFrame(ImFontAtlas* atlas, int frame_count, bool rendere
         if (tex->Status == ImTextureStatus_WantCreate && atlas->RendererHasTextures)
             IM_ASSERT(tex->TexID == ImTextureID_Invalid && tex->BackendUserData == NULL && "Backend set texture's TexID/BackendUserData but did not update Status to OK.");
 
+        // Request destroy
+        // - Keep bool to true in order to differentiate a planned destroy vs a destroy decided by the backend.
+        // - We don't destroy pixels right away, as backend may have an in-flight copy from RAM.
+        if (tex->WantDestroyNextFrame && tex->Status != ImTextureStatus_Destroyed && tex->Status != ImTextureStatus_WantDestroy)
+        {
+            IM_ASSERT(tex->Status == ImTextureStatus_OK || tex->Status == ImTextureStatus_WantCreate || tex->Status == ImTextureStatus_WantUpdates);
+            tex->Status = ImTextureStatus_WantDestroy;
+        }
+
+        // If a texture has never reached the backend, they don't need to know about it.
+        // (note: backends between 1.92.0 and 1.92.4 could set an already destroyed texture to ImTextureStatus_WantDestroy
+        //  when invalidating graphics objects twice, which would previously remove it from the list and crash.)
+        if (tex->Status == ImTextureStatus_WantDestroy && tex->TexID == ImTextureID_Invalid && tex->BackendUserData == NULL)
+            tex->Status = ImTextureStatus_Destroyed;
+
+        // Process texture being destroyed
         if (tex->Status == ImTextureStatus_Destroyed)
         {
             IM_ASSERT(tex->TexID == ImTextureID_Invalid && tex->BackendUserData == NULL && "Backend set texture Status to Destroyed but did not clear TexID/BackendUserData!");
             if (tex->WantDestroyNextFrame)
                 remove_from_list = true; // Destroy was scheduled by us
             else
-                tex->Status = ImTextureStatus_WantCreate; // Destroy was done was backend (e.g. freed resources mid-run)
-        }
-        else if (tex->WantDestroyNextFrame && tex->Status != ImTextureStatus_WantDestroy)
-        {
-            // Request destroy. Keep bool as it allows us to keep track of things.
-            // We don't destroy pixels right away, as backend may have an in-flight copy from RAM.
-            IM_ASSERT(tex->Status == ImTextureStatus_OK || tex->Status == ImTextureStatus_WantCreate || tex->Status == ImTextureStatus_WantUpdates);
-            tex->Status = ImTextureStatus_WantDestroy;
+                tex->Status = ImTextureStatus_WantCreate; // Destroy was done was backend: recreate it (e.g. freed resources mid-run)
         }
 
         // The backend may need defer destroying by a few frames, to handle texture used by previous in-flight rendering.
@@ -2808,13 +2829,10 @@ void ImFontAtlasUpdateNewFrame(ImFontAtlas* atlas, int frame_count, bool rendere
         if (tex->Status == ImTextureStatus_WantDestroy)
             tex->UnusedFrames++;
 
-        // If a texture has never reached the backend, they don't need to know about it.
-        if (tex->Status == ImTextureStatus_WantDestroy && tex->TexID == ImTextureID_Invalid && tex->BackendUserData == NULL)
-            remove_from_list = true;
-
         // Destroy and remove
         if (remove_from_list)
         {
+            IM_ASSERT(atlas->TexData != tex);
             tex->DestroyPixels();
             IM_DELETE(tex);
             atlas->TexList.erase(atlas->TexList.begin() + tex_n);
@@ -2954,7 +2972,7 @@ void ImFontAtlasTextureBlockQueueUpload(ImFontAtlas* atlas, ImTextureData* tex,
     tex->UsedRect.h = (unsigned short)(ImMax(tex->UsedRect.y + tex->UsedRect.h, req.y + req.h) - tex->UsedRect.y);
     atlas->TexIsBuilt = false;
 
-    // No need to queue if status is _WantCreate
+    // No need to queue if status is == ImTextureStatus_WantCreate
     if (tex->Status == ImTextureStatus_OK || tex->Status == ImTextureStatus_WantUpdates)
     {
         tex->Status = ImTextureStatus_WantUpdates;
@@ -3023,7 +3041,7 @@ ImFont* ImFontAtlas::AddFont(const ImFontConfig* font_cfg_in)
     else
     {
         IM_ASSERT(Fonts.Size > 0 && "Cannot use MergeMode for the first font"); // When using MergeMode make sure that a font has already been added before. You can use ImGui::GetIO().Fonts->AddFontDefault() to add the default imgui font.
-        font = Fonts.back();
+        font = font_cfg_in->DstFont ? font_cfg_in->DstFont : Fonts.back();
     }
 
     // Add to list
@@ -3094,6 +3112,7 @@ static const char* GetDefaultCompressedFontDataTTF(int* out_size);
 #endif
 
 // Load embedded ProggyClean.ttf at size 13, disable oversampling
+// If you want a similar font which may be better scaled, consider using ProggyVector from the same author!
 ImFont* ImFontAtlas::AddFontDefault(const ImFontConfig* font_cfg_template)
 {
 #ifndef IMGUI_DISABLE_DEFAULT_FONT
@@ -3112,9 +3131,7 @@ ImFont* ImFontAtlas::AddFontDefault(const ImFontConfig* font_cfg_template)
 
     int ttf_compressed_size = 0;
     const char* ttf_compressed = GetDefaultCompressedFontDataTTF(&ttf_compressed_size);
-    const ImWchar* glyph_ranges = font_cfg.GlyphRanges != NULL ? font_cfg.GlyphRanges : GetGlyphRangesDefault();
-    ImFont* font = AddFontFromMemoryCompressedTTF(ttf_compressed, ttf_compressed_size, font_cfg.SizePixels, &font_cfg, glyph_ranges);
-    return font;
+    return AddFontFromMemoryCompressedTTF(ttf_compressed, ttf_compressed_size, font_cfg.SizePixels, &font_cfg);
 #else
     IM_ASSERT(0 && "AddFontDefault() disabled in this build.");
     IM_UNUSED(font_cfg_template);
@@ -3361,11 +3378,7 @@ void ImFontAtlasBuildMain(ImFontAtlas* atlas)
 {
     IM_ASSERT(!atlas->Locked && "Cannot modify a locked ImFontAtlas!");
     if (atlas->TexData && atlas->TexData->Format != atlas->TexDesiredFormat)
-    {
-        ImVec2i new_tex_size = ImFontAtlasTextureGetSizeEstimate(atlas);
-        ImFontAtlasBuildDestroy(atlas);
-        ImFontAtlasTextureAdd(atlas, new_tex_size.x, new_tex_size.y);
-    }
+        ImFontAtlasBuildClear(atlas);
 
     if (atlas->Builder == NULL)
         ImFontAtlasBuildInit(atlas);
@@ -3971,7 +3984,6 @@ ImTextureData* ImFontAtlasTextureAdd(ImFontAtlas* atlas, int w, int h)
     }
 
     new_tex->Create(atlas->TexDesiredFormat, w, h);
-    new_tex->Status = ImTextureStatus_WantCreate;
     atlas->TexIsBuilt = false;
 
     ImFontAtlasBuildSetTexture(atlas, new_tex);
@@ -4296,6 +4308,8 @@ void ImFontAtlasPackDiscardRect(ImFontAtlas* atlas, ImFontAtlasRectId id)
     index_entry->IsUsed = false;
     index_entry->TargetIndex = builder->RectsIndexFreeListStart;
     index_entry->Generation++;
+    if (index_entry->Generation == 0)
+        index_entry->Generation++; // Keep non-zero on overflow
 
     const int pack_padding = atlas->TexGlyphPadding;
     builder->RectsIndexFreeListStart = index_idx;
@@ -4375,6 +4389,7 @@ ImTextureRect* ImFontAtlasPackGetRectSafe(ImFontAtlas* atlas, ImFontAtlasRectId
     if (atlas->Builder == NULL)
         ImFontAtlasBuildInit(atlas);
     ImFontAtlasBuilder* builder = (ImFontAtlasBuilder*)atlas->Builder;
+    IM_MSVC_WARNING_SUPPRESS(28182); // Static Analysis false positive "warning C28182: Dereferencing NULL pointer 'builder'"
     if (index_idx >= builder->RectsIndex.Size)
         return NULL;
     ImFontAtlasRectEntry* index_entry = &builder->RectsIndex[index_idx];
@@ -4417,7 +4432,7 @@ static ImFontGlyph* ImFontBaked_BuildLoadGlyph(ImFontBaked* baked, ImWchar codep
     if (atlas->Locked || (font->Flags & ImFontFlags_NoLoadGlyphs))
     {
         // Lazily load fallback glyph
-        if (baked->FallbackGlyphIndex == -1 && baked->LockLoadingFallback == 0)
+        if (baked->FallbackGlyphIndex == -1 && baked->LoadNoFallback == 0)
             ImFontAtlasBuildSetupFontBakedFallback(baked);
         return NULL;
     }
@@ -4469,7 +4484,7 @@ static ImFontGlyph* ImFontBaked_BuildLoadGlyph(ImFontBaked* baked, ImWchar codep
     }
 
     // Lazily load fallback glyph
-    if (baked->LockLoadingFallback)
+    if (baked->LoadNoFallback)
         return NULL;
     if (baked->FallbackGlyphIndex == -1)
         ImFontAtlasBuildSetupFontBakedFallback(baked);
@@ -4483,7 +4498,7 @@ static ImFontGlyph* ImFontBaked_BuildLoadGlyph(ImFontBaked* baked, ImWchar codep
 
 static float ImFontBaked_BuildLoadGlyphAdvanceX(ImFontBaked* baked, ImWchar codepoint)
 {
-    if (baked->Size >= IMGUI_FONT_SIZE_THRESHOLD_FOR_LOADADVANCEXONLYMODE)
+    if (baked->Size >= IMGUI_FONT_SIZE_THRESHOLD_FOR_LOADADVANCEXONLYMODE || baked->LoadNoRenderOnLayout)
     {
         // First load AdvanceX value used by CalcTextSize() API then load the rest when loaded by drawing API.
         float only_advance_x = 0.0f;
@@ -4518,16 +4533,16 @@ void ImFontAtlasDebugLogTextureRequests(ImFontAtlas* atlas)
         if (tex->Status == ImTextureStatus_WantCreate)
             IMGUI_DEBUG_LOG_FONT("[font] Texture #%03d: create %dx%d\n", tex->UniqueID, tex->Width, tex->Height);
         else if (tex->Status == ImTextureStatus_WantDestroy)
-            IMGUI_DEBUG_LOG_FONT("[font] Texture #%03d: destroy %dx%d, texid=0x%" IM_PRIX64 ", backend_data=%p\n", tex->UniqueID, tex->Width, tex->Height, tex->TexID, tex->BackendUserData);
+            IMGUI_DEBUG_LOG_FONT("[font] Texture #%03d: destroy %dx%d, texid=0x%" IM_PRIX64 ", backend_data=%p\n", tex->UniqueID, tex->Width, tex->Height, IM_TEXTUREID_TO_U64(tex->TexID), tex->BackendUserData);
         else if (tex->Status == ImTextureStatus_WantUpdates)
         {
-            IMGUI_DEBUG_LOG_FONT("[font] Texture #%03d: update %d regions, texid=0x%" IM_PRIX64 ", backend_data=0x%" IM_PRIX64 "\n", tex->UniqueID, tex->Updates.Size, tex->TexID, (ImU64)(intptr_t)tex->BackendUserData);
+            IMGUI_DEBUG_LOG_FONT("[font] Texture #%03d: update %d regions, texid=0x%" IM_PRIX64 ", backend_data=0x%" IM_PRIX64 "\n", tex->UniqueID, tex->Updates.Size, IM_TEXTUREID_TO_U64(tex->TexID), (ImU64)(intptr_t)tex->BackendUserData);
             for (const ImTextureRect& r : tex->Updates)
             {
                 IM_UNUSED(r);
                 IM_ASSERT(r.x >= 0 && r.y >= 0);
                 IM_ASSERT(r.x + r.w <= tex->Width && r.y + r.h <= tex->Height); // In theory should subtract PackPadding but it's currently part of atlas and mid-frame change would wreck assert.
-                //IMGUI_DEBUG_LOG_FONT("[font] Texture #%03d: update (% 4d..%-4d)->(% 4d..%-4d), texid=0x%" IM_PRIX64 ", backend_data=0x%" IM_PRIX64 "\n", tex->UniqueID, r.x, r.y, r.x + r.w, r.y + r.h, tex->TexID, (ImU64)(intptr_t)tex->BackendUserData);
+                //IMGUI_DEBUG_LOG_FONT("[font] Texture #%03d: update (% 4d..%-4d)->(% 4d..%-4d), texid=0x%" IM_PRIX64 ", backend_data=0x%" IM_PRIX64 "\n", tex->UniqueID, r.x, r.y, r.x + r.w, r.y + r.h, IM_TEXTUREID_TO_U64(tex->TexID), (ImU64)(intptr_t)tex->BackendUserData);
             }
         }
     }
@@ -4572,15 +4587,16 @@ static bool ImGui_ImplStbTrueType_FontSrcInit(ImFontAtlas* atlas, ImFontConfig*
     }
     src->FontLoaderData = bd_font_data;
 
+    const float ref_size = src->DstFont->Sources[0]->SizePixels;
     if (src->MergeMode && src->SizePixels == 0.0f)
-        src->SizePixels = src->DstFont->Sources[0]->SizePixels;
+        src->SizePixels = ref_size;
 
     if (src->SizePixels >= 0.0f)
         bd_font_data->ScaleFactor = stbtt_ScaleForPixelHeight(&bd_font_data->FontInfo, 1.0f);
     else
         bd_font_data->ScaleFactor = stbtt_ScaleForMappingEmToPixels(&bd_font_data->FontInfo, 1.0f);
-    if (src->MergeMode && src->SizePixels != 0.0f)
-        bd_font_data->ScaleFactor *= src->SizePixels / src->DstFont->Sources[0]->SizePixels; // FIXME-NEWATLAS: Should tidy up that a bit
+    if (src->MergeMode && src->SizePixels != 0.0f && ref_size != 0.0f)
+        bd_font_data->ScaleFactor *= src->SizePixels / ref_size; // FIXME-NEWATLAS: Should tidy up that a bit
 
     return true;
 }
@@ -4679,15 +4695,12 @@ static bool ImGui_ImplStbTrueType_FontBakedLoadGlyph(ImFontAtlas* atlas, ImFontC
         builder->TempBuffer.resize(w * h * 1);
         unsigned char* bitmap_pixels = builder->TempBuffer.Data;
         memset(bitmap_pixels, 0, w * h * 1);
-        stbtt_MakeGlyphBitmapSubpixel(&bd_font_data->FontInfo, bitmap_pixels, r->w - oversample_h + 1, r->h - oversample_v + 1, w,
-            scale_for_raster_x, scale_for_raster_y, 0, 0, glyph_index);
 
-        // Oversampling
+        // Render with oversampling
         // (those functions conveniently assert if pixels are not cleared, which is another safety layer)
-        if (oversample_h > 1)
-            stbtt__h_prefilter(bitmap_pixels, r->w, r->h, r->w, oversample_h);
-        if (oversample_v > 1)
-            stbtt__v_prefilter(bitmap_pixels, r->w, r->h, r->w, oversample_v);
+        float sub_x, sub_y;
+        stbtt_MakeGlyphBitmapSubpixelPrefilter(&bd_font_data->FontInfo, bitmap_pixels, w, h, w,
+            scale_for_raster_x, scale_for_raster_y, 0, 0, oversample_h, oversample_v, &sub_x, &sub_y, glyph_index);
 
         const float ref_size = baked->ContainerFont->Sources[0]->SizePixels;
         const float offsets_scale = (ref_size != 0.0f) ? (baked->Size / ref_size) : 1.0f;
@@ -4697,8 +4710,8 @@ static bool ImGui_ImplStbTrueType_FontBakedLoadGlyph(ImFontAtlas* atlas, ImFontC
             font_off_x = IM_ROUND(font_off_x);
         if (src->PixelSnapV)
             font_off_y = IM_ROUND(font_off_y);
-        font_off_x += stbtt__oversample_shift(oversample_h);
-        font_off_y += stbtt__oversample_shift(oversample_v) + IM_ROUND(baked->Ascent);
+        font_off_x += sub_x;
+        font_off_y += sub_y + IM_ROUND(baked->Ascent);
         float recip_h = 1.0f / (oversample_h * rasterizer_density);
         float recip_v = 1.0f / (oversample_v * rasterizer_density);
 
@@ -5225,9 +5238,9 @@ ImFontGlyph* ImFontBaked::FindGlyphNoFallback(ImWchar c)
         if (i != IM_FONTGLYPH_INDEX_UNUSED)
             return &Glyphs.Data[i];
     }
-    LockLoadingFallback = true; // This is actually a rare call, not done in hot-loop, so we prioritize not adding extra cruft to ImFontBaked_BuildLoadGlyph() call sites.
+    LoadNoFallback = true; // This is actually a rare call, not done in hot-loop, so we prioritize not adding extra cruft to ImFontBaked_BuildLoadGlyph() call sites.
     ImFontGlyph* glyph = ImFontBaked_BuildLoadGlyph(this, c, NULL);
-    LockLoadingFallback = false;
+    LoadNoFallback = false;
     return glyph;
 }
 
@@ -5342,10 +5355,11 @@ ImFontBaked* ImFontAtlasBakedGetOrAdd(ImFontAtlas* atlas, ImFont* font, float fo
 }
 
 // Trim trailing space and find beginning of next line
-static inline const char* CalcWordWrapNextLineStartA(const char* text, const char* text_end)
+const char* ImTextCalcWordWrapNextLineStart(const char* text, const char* text_end, ImDrawTextFlags flags)
 {
-    while (text < text_end && ImCharIsBlankA(*text))
-        text++;
+    if ((flags & ImDrawTextFlags_WrapKeepBlanks) == 0)
+        while (text < text_end && ImCharIsBlankA(*text))
+            text++;
     if (*text == '\n')
         text++;
     return text;
@@ -5354,7 +5368,7 @@ static inline const char* CalcWordWrapNextLineStartA(const char* text, const cha
 // Simple word-wrapping for English, not full-featured. Please submit failing cases!
 // This will return the next location to wrap from. If no wrapping if necessary, this will fast-forward to e.g. text_end.
 // FIXME: Much possible improvements (don't cut things like "word !", "word!!!" but cut within "word,,,,", more sensible support for punctuations, support for Unicode punctuations, etc.)
-const char* ImFont::CalcWordWrapPosition(float size, const char* text, const char* text_end, float wrap_width)
+const char* ImFontCalcWordWrapPositionEx(ImFont* font, float size, const char* text, const char* text_end, float wrap_width, ImDrawTextFlags flags)
 {
     // For references, possible wrap point marked with ^
     //  "aaa bbb, ccc,ddd. eee   fff. ggg!"
@@ -5368,7 +5382,7 @@ const char* ImFont::CalcWordWrapPosition(float size, const char* text, const cha
     // Cut words that cannot possibly fit within one line.
     // e.g.: "The tropical fish" with ~5 characters worth of width --> "The tr" "opical" "fish"
 
-    ImFontBaked* baked = GetFontBaked(size);
+    ImFontBaked* baked = font->GetFontBaked(size);
     const float scale = size / baked->Size;
 
     float line_width = 0.0f;
@@ -5394,12 +5408,7 @@ const char* ImFont::CalcWordWrapPosition(float size, const char* text, const cha
         if (c < 32)
         {
             if (c == '\n')
-            {
-                line_width = word_width = blank_width = 0.0f;
-                inside_word = true;
-                s = next_s;
-                continue;
-            }
+                return s; // Direct return, skip "Wrap_width is too small to fit anything" path.
             if (c == '\r')
             {
                 s = next_s;
@@ -5434,6 +5443,8 @@ const char* ImFont::CalcWordWrapPosition(float size, const char* text, const cha
             {
                 prev_word_end = word_end;
                 line_width += word_width + blank_width;
+                if ((flags & ImDrawTextFlags_WrapKeepBlanks) && line_width <= wrap_width)
+                    prev_word_end = s;
                 word_width = blank_width = 0.0f;
             }
 
@@ -5460,14 +5471,21 @@ const char* ImFont::CalcWordWrapPosition(float size, const char* text, const cha
     return s;
 }
 
-ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, const char* text_begin, const char* text_end, const char** remaining)
+const char* ImFont::CalcWordWrapPosition(float size, const char* text, const char* text_end, float wrap_width)
+{
+    return ImFontCalcWordWrapPositionEx(this, size, text, text_end, wrap_width, ImDrawTextFlags_None);
+}
+
+ImVec2 ImFontCalcTextSizeEx(ImFont* font, float size, float max_width, float wrap_width, const char* text_begin, const char* text_end_display, const char* text_end, const char** out_remaining, ImVec2* out_offset, ImDrawTextFlags flags)
 {
     if (!text_end)
         text_end = text_begin + ImStrlen(text_begin); // FIXME-OPT: Need to avoid this.
+    if (!text_end_display)
+        text_end_display = text_end;
 
+    ImFontBaked* baked = font->GetFontBaked(size);
     const float line_height = size;
-    ImFontBaked* baked = GetFontBaked(size);
-    const float scale = size / baked->Size;
+    const float scale = line_height / baked->Size;
 
     ImVec2 text_size = ImVec2(0, 0);
     float line_width = 0.0f;
@@ -5476,13 +5494,14 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, cons
     const char* word_wrap_eol = NULL;
 
     const char* s = text_begin;
-    while (s < text_end)
+    while (s < text_end_display)
     {
+        // Word-wrapping
         if (word_wrap_enabled)
         {
             // Calculate how far we can render. Requires two passes on the string data but keeps the code simple and not intrusive for what's essentially an uncommon feature.
             if (!word_wrap_eol)
-                word_wrap_eol = CalcWordWrapPosition(size, s, text_end, wrap_width - line_width);
+                word_wrap_eol = ImFontCalcWordWrapPositionEx(font, size, s, text_end, wrap_width - line_width, flags);
 
             if (s >= word_wrap_eol)
             {
@@ -5490,8 +5509,10 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, cons
                     text_size.x = line_width;
                 text_size.y += line_height;
                 line_width = 0.0f;
+                s = ImTextCalcWordWrapNextLineStart(s, text_end, flags); // Wrapping skips upcoming blanks
+                if (flags & ImDrawTextFlags_StopOnNewLine)
+                    break;
                 word_wrap_eol = NULL;
-                s = CalcWordWrapNextLineStartA(s, text_end); // Wrapping skips upcoming blanks
                 continue;
             }
         }
@@ -5504,18 +5525,17 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, cons
         else
             s += ImTextCharFromUtf8(&c, s, text_end);
 
-        if (c < 32)
+        if (c == '\n')
         {
-            if (c == '\n')
-            {
-                text_size.x = ImMax(text_size.x, line_width);
-                text_size.y += line_height;
-                line_width = 0.0f;
-                continue;
-            }
-            if (c == '\r')
-                continue;
+            text_size.x = ImMax(text_size.x, line_width);
+            text_size.y += line_height;
+            line_width = 0.0f;
+            if (flags & ImDrawTextFlags_StopOnNewLine)
+                break;
+            continue;
         }
+        if (c == '\r')
+            continue;
 
         // Optimized inline version of 'float char_width = GetCharAdvance((ImWchar)c);'
         float char_width = (c < (unsigned int)baked->IndexAdvanceX.Size) ? baked->IndexAdvanceX.Data[c] : -1.0f;
@@ -5535,15 +5555,23 @@ ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, cons
     if (text_size.x < line_width)
         text_size.x = line_width;
 
-    if (line_width > 0 || text_size.y == 0.0f)
+    if (out_offset != NULL)
+        *out_offset = ImVec2(line_width, text_size.y + line_height);  // offset allow for the possibility of sitting after a trailing \n
+
+    if (line_width > 0 || text_size.y == 0.0f)                        // whereas size.y will ignore the trailing \n
         text_size.y += line_height;
 
-    if (remaining)
-        *remaining = s;
+    if (out_remaining != NULL)
+        *out_remaining = s;
 
     return text_size;
 }
 
+ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, const char* text_begin, const char* text_end, const char** out_remaining)
+{
+    return ImFontCalcTextSizeEx(this, size, max_width, wrap_width, text_begin, text_end, text_end, out_remaining, NULL, ImDrawTextFlags_None);
+}
+
 // Note: as with every ImDrawList drawing function, this expects that the font atlas texture is bound.
 void ImFont::RenderChar(ImDrawList* draw_list, float size, const ImVec2& pos, ImU32 col, ImWchar c, const ImVec4* cpu_fine_clip)
 {
@@ -5584,7 +5612,8 @@ void ImFont::RenderChar(ImDrawList* draw_list, float size, const ImVec2& pos, Im
 }
 
 // Note: as with every ImDrawList drawing function, this expects that the font atlas texture is bound.
-void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, ImU32 col, const ImVec4& clip_rect, const char* text_begin, const char* text_end, float wrap_width, bool cpu_fine_clip)
+// DO NOT CALL DIRECTLY THIS WILL CHANGE WILDLY IN 2025-2025. Use ImDrawList::AddText().
+void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, ImU32 col, const ImVec4& clip_rect, const char* text_begin, const char* text_end, float wrap_width, ImDrawTextFlags flags)
 {
     // Align to be pixel perfect
 begin:
@@ -5614,8 +5643,8 @@ begin:
                 // FIXME-OPT: This is not optimal as do first do a search for \n before calling CalcWordWrapPosition().
                 // If the specs for CalcWordWrapPosition() were reworked to optionally return on \n we could combine both.
                 // However it is still better than nothing performing the fast-forward!
-                s = CalcWordWrapPosition(size, s, line_end ? line_end : text_end, wrap_width);
-                s = CalcWordWrapNextLineStartA(s, text_end);
+                s = ImFontCalcWordWrapPositionEx(this, size, s, line_end ? line_end : text_end, wrap_width, flags);
+                s = ImTextCalcWordWrapNextLineStart(s, text_end, flags);
             }
             else
             {
@@ -5650,6 +5679,7 @@ begin:
     ImDrawIdx*   idx_write = draw_list->_IdxWritePtr;
     unsigned int vtx_index = draw_list->_VtxCurrentIdx;
     const int cmd_count = draw_list->CmdBuffer.Size;
+    const bool cpu_fine_clip = (flags & ImDrawTextFlags_CpuFineClip) != 0;
 
     const ImU32 col_untinted = col | ~IM_COL32_A_MASK;
     const char* word_wrap_eol = NULL;
@@ -5660,7 +5690,7 @@ begin:
         {
             // Calculate how far we can render. Requires two passes on the string data but keeps the code simple and not intrusive for what's essentially an uncommon feature.
             if (!word_wrap_eol)
-                word_wrap_eol = CalcWordWrapPosition(size, s, text_end, wrap_width - (x - origin_x));
+                word_wrap_eol = ImFontCalcWordWrapPositionEx(this, size, s, text_end, wrap_width - (x - origin_x), flags);
 
             if (s >= word_wrap_eol)
             {
@@ -5669,7 +5699,7 @@ begin:
                 if (y > clip_rect.w)
                     break; // break out of main loop
                 word_wrap_eol = NULL;
-                s = CalcWordWrapNextLineStartA(s, text_end); // Wrapping skips upcoming blanks
+                s = ImTextCalcWordWrapNextLineStart(s, text_end, flags); // Wrapping skips upcoming blanks
                 continue;
             }
         }
@@ -5795,6 +5825,7 @@ begin:
 // - RenderArrow()
 // - RenderBullet()
 // - RenderCheckMark()
+// - RenderArrowDockMenu()
 // - RenderArrowPointingAt()
 // - RenderRectFilledRangeH()
 // - RenderRectFilledWithHole()
@@ -5837,8 +5868,9 @@ void ImGui::RenderArrow(ImDrawList* draw_list, ImVec2 pos, ImU32 col, ImGuiDir d
 
 void ImGui::RenderBullet(ImDrawList* draw_list, ImVec2 pos, ImU32 col)
 {
-    // FIXME-OPT: This should be baked in font.
-    draw_list->AddCircleFilled(pos, draw_list->_Data->FontSize * 0.20f, col, 8);
+    // FIXME-OPT: This should be baked in font now that it's easier.
+    float font_size = draw_list->_Data->FontSize;
+    draw_list->AddCircleFilled(pos, font_size * 0.20f, col, (font_size < 22) ? 8 : (font_size < 40) ? 12 : 0); // Hardcode optimal/nice tessellation threshold
 }
 
 void ImGui::RenderCheckMark(ImDrawList* draw_list, ImVec2 pos, ImU32 col, float sz)
@@ -5869,6 +5901,14 @@ void ImGui::RenderArrowPointingAt(ImDrawList* draw_list, ImVec2 pos, ImVec2 half
     }
 }
 
+// This is less wide than RenderArrow() and we use in dock nodes instead of the regular RenderArrow() to denote a change of functionality,
+// and because the saved space means that the left-most tab label can stay at exactly the same position as the label of a loose window.
+void ImGui::RenderArrowDockMenu(ImDrawList* draw_list, ImVec2 p_min, float sz, ImU32 col)
+{
+    draw_list->AddRectFilled(p_min + ImVec2(sz * 0.20f, sz * 0.15f), p_min + ImVec2(sz * 0.80f, sz * 0.30f), col);
+    RenderArrowPointingAt(draw_list, p_min + ImVec2(sz * 0.50f, sz * 0.85f), ImVec2(sz * 0.30f, sz * 0.40f), ImGuiDir_Down, col);
+}
+
 static inline float ImAcos01(float x)
 {
     if (x <= 0.0f) return IM_PI * 0.5f;
@@ -5954,6 +5994,17 @@ void ImGui::RenderRectFilledWithHole(ImDrawList* draw_list, const ImRect& outer,
     if (fill_R && fill_D) draw_list->AddRectFilled(ImVec2(inner.Max.x, inner.Max.y), ImVec2(outer.Max.x, outer.Max.y), col, rounding, ImDrawFlags_RoundCornersBottomRight);
 }
 
+ImDrawFlags ImGui::CalcRoundingFlagsForRectInRect(const ImRect& r_in, const ImRect& r_outer, float threshold)
+{
+    bool round_l = r_in.Min.x <= r_outer.Min.x + threshold;
+    bool round_r = r_in.Max.x >= r_outer.Max.x - threshold;
+    bool round_t = r_in.Min.y <= r_outer.Min.y + threshold;
+    bool round_b = r_in.Max.y >= r_outer.Max.y - threshold;
+    return ImDrawFlags_RoundCornersNone
+        | ((round_t && round_l) ? ImDrawFlags_RoundCornersTopLeft : 0) | ((round_t && round_r) ? ImDrawFlags_RoundCornersTopRight : 0)
+        | ((round_b && round_l) ? ImDrawFlags_RoundCornersBottomLeft : 0) | ((round_b && round_r) ? ImDrawFlags_RoundCornersBottomRight : 0);
+}
+
 // Helper for ColorPicker4()
 // NB: This is rather brittle and will show artifact when rounding this enabled if rounded corners overlap multiple cells. Caller currently responsible for avoiding that.
 // Spent a non reasonable amount of time trying to getting this right for ColorButton with rounding+anti-aliasing+ImGuiColorEditFlags_HalfAlphaPreview flag + various grid sizes and offsets, and eventually gave up... probably more reasonable to disable rounding altogether.
@@ -6121,6 +6172,7 @@ static unsigned int stb_decompress(unsigned char *output, const unsigned char *i
 // Copyright (c) 2004, 2005 Tristan Grimmer
 // MIT license (see License.txt in http://www.proggyfonts.net/index.php?menu=download)
 // Download and more information at http://www.proggyfonts.net or http://upperboundsinteractive.com/fonts.php
+// If you want a similar font which may be better scaled, consider using ProggyVector from the same author!
 //-----------------------------------------------------------------------------
 
 #ifndef IMGUI_DISABLE_DEFAULT_FONT