Using range-based for where it makes sense. (#4537)

Amend 82d177c

.github/issue_template.md

@@ -1,6 +1,6 @@
 (Click "Preview" above ^ to turn URL into clickable links)
 
-1. FOR FIRST-TIME USERS PROBLEMS COMPILING/LINKING/RUNNING or LOADING FONTS,  please use [GitHub Discussions](https://github.com/ocornut/imgui/discussions). EVERYTHING ELSE CAN BE POSTED HERE!
+1. FOR FIRST-TIME USERS ISSUES COMPILING/LINKING/RUNNING or LOADING FONTS,  please use [GitHub Discussions](https://github.com/ocornut/imgui/discussions).
 
 2. PLEASE CAREFULLY READ: [FAQ](https://github.com/ocornut/imgui/blob/master/docs/FAQ.md)
 

backends/imgui_impl_allegro5.cpp

@@ -6,17 +6,15 @@
 //  [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 ALLEGRO_KEY_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Clipboard support (from Allegro 5.1.12)
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
-// Issues:
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows)..
 //  [ ] Renderer: The renderer is suboptimal as we need to convert vertices manually.
 //  [ ] Platform: Missing gamepad support.
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
@@ -438,9 +436,9 @@ bool ImGui_ImplAllegro5_Init(ALLEGRO_DISPLAY* display)
     // 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) },
+        { ALLEGRO_PRIM_POSITION, ALLEGRO_PRIM_FLOAT_2, IM_OFFSETOF(ImDrawVertAllegro, pos) },
+        { ALLEGRO_PRIM_TEX_COORD, ALLEGRO_PRIM_FLOAT_2, IM_OFFSETOF(ImDrawVertAllegro, uv) },
+        { ALLEGRO_PRIM_COLOR_ATTR, 0, IM_OFFSETOF(ImDrawVertAllegro, col) },
         { 0, 0, 0 }
     };
     bd->VertexDecl = al_create_vertex_decl(elems, sizeof(ImDrawVertAllegro));

backends/imgui_impl_allegro5.h

@@ -6,17 +6,15 @@
 //  [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 ALLEGRO_KEY_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Clipboard support (from Allegro 5.1.12)
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
-// Issues:
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows)..
 //  [ ] Renderer: The renderer is suboptimal as we need to unindex our buffers and convert vertices manually.
 //  [ ] Platform: Missing gamepad support.
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

backends/imgui_impl_android.cpp

@@ -8,6 +8,7 @@
 //  [ ] Platform: Clipboard support.
 //  [ ] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [ ] Platform: Mouse cursor shape and visibility. 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)
@@ -15,11 +16,8 @@
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)

backends/imgui_impl_android.h

@@ -8,6 +8,7 @@
 //  [ ] Platform: Clipboard support.
 //  [ ] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [ ] Platform: Mouse cursor shape and visibility. 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)
@@ -15,11 +16,8 @@
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

backends/imgui_impl_dx10.cpp

@@ -4,17 +4,16 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'ID3D10ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  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).
 //  2021-05-19: DirectX10: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
@@ -79,6 +78,10 @@ static ImGui_ImplDX10_Data* ImGui_ImplDX10_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX10_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX10_InitPlatformInterface();
+static void ImGui_ImplDX10_ShutdownPlatformInterface();
+
 // Functions
 static void ImGui_ImplDX10_SetupRenderState(ImDrawData* draw_data, ID3D10Device* ctx)
 {
@@ -414,9 +417,9 @@ bool    ImGui_ImplDX10_CreateDeviceObjects()
         // Create the input layout
         D3D10_INPUT_ELEMENT_DESC local_layout[] =
         {
-            { "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)offsetof(ImDrawVert, pos), D3D10_INPUT_PER_VERTEX_DATA, 0 },
-            { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)offsetof(ImDrawVert, uv),  D3D10_INPUT_PER_VERTEX_DATA, 0 },
-            { "COLOR",    0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, (UINT)offsetof(ImDrawVert, col), D3D10_INPUT_PER_VERTEX_DATA, 0 },
+            { "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)IM_OFFSETOF(ImDrawVert, pos), D3D10_INPUT_PER_VERTEX_DATA, 0 },
+            { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)IM_OFFSETOF(ImDrawVert, uv),  D3D10_INPUT_PER_VERTEX_DATA, 0 },
+            { "COLOR",    0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, (UINT)IM_OFFSETOF(ImDrawVert, col), D3D10_INPUT_PER_VERTEX_DATA, 0 },
         };
         if (bd->pd3dDevice->CreateInputLayout(local_layout, 3, vertexShaderBlob->GetBufferPointer(), vertexShaderBlob->GetBufferSize(), &bd->pInputLayout) != S_OK)
         {
@@ -541,6 +544,7 @@ bool    ImGui_ImplDX10_Init(ID3D10Device* device)
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_dx10";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     // Get factory from device
     IDXGIDevice* pDXGIDevice = nullptr;
@@ -557,6 +561,8 @@ bool    ImGui_ImplDX10_Init(ID3D10Device* device)
     if (pDXGIAdapter) pDXGIAdapter->Release();
     bd->pd3dDevice->AddRef();
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplDX10_InitPlatformInterface();
     return true;
 }
 
@@ -566,12 +572,13 @@ void ImGui_ImplDX10_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplDX10_ShutdownPlatformInterface();
     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;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -584,6 +591,129 @@ void ImGui_ImplDX10_NewFrame()
         ImGui_ImplDX10_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..
+//--------------------------------------------------------------------------------------------------------
+
+// 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_Window*).
+    // 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);
+
+    // 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;
+    vd->SwapChain->Present(0, 0); // Present without vsync
+}
+
+void ImGui_ImplDX10_InitPlatformInterface()
+{
+    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_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_dx10.h

@@ -4,14 +4,12 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'ID3D10ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

backends/imgui_impl_dx11.cpp

@@ -4,17 +4,16 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'ID3D11ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  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).
 //  2021-05-19: DirectX11: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
@@ -80,6 +79,10 @@ static ImGui_ImplDX11_Data* ImGui_ImplDX11_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX11_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX11_InitPlatformInterface();
+static void ImGui_ImplDX11_ShutdownPlatformInterface();
+
 // Functions
 static void ImGui_ImplDX11_SetupRenderState(ImDrawData* draw_data, ID3D11DeviceContext* ctx)
 {
@@ -426,9 +429,9 @@ bool    ImGui_ImplDX11_CreateDeviceObjects()
         // Create the input layout
         D3D11_INPUT_ELEMENT_DESC local_layout[] =
         {
-            { "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)offsetof(ImDrawVert, pos), D3D11_INPUT_PER_VERTEX_DATA, 0 },
-            { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)offsetof(ImDrawVert, uv),  D3D11_INPUT_PER_VERTEX_DATA, 0 },
-            { "COLOR",    0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, (UINT)offsetof(ImDrawVert, col), D3D11_INPUT_PER_VERTEX_DATA, 0 },
+            { "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)IM_OFFSETOF(ImDrawVert, pos), D3D11_INPUT_PER_VERTEX_DATA, 0 },
+            { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)IM_OFFSETOF(ImDrawVert, uv),  D3D11_INPUT_PER_VERTEX_DATA, 0 },
+            { "COLOR",    0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, (UINT)IM_OFFSETOF(ImDrawVert, col), D3D11_INPUT_PER_VERTEX_DATA, 0 },
         };
         if (bd->pd3dDevice->CreateInputLayout(local_layout, 3, vertexShaderBlob->GetBufferPointer(), vertexShaderBlob->GetBufferSize(), &bd->pInputLayout) != S_OK)
         {
@@ -553,6 +556,7 @@ bool    ImGui_ImplDX11_Init(ID3D11Device* device, ID3D11DeviceContext* device_co
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_dx11";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     // Get factory from device
     IDXGIDevice* pDXGIDevice = nullptr;
@@ -572,6 +576,9 @@ bool    ImGui_ImplDX11_Init(ID3D11Device* device, ID3D11DeviceContext* device_co
     bd->pd3dDevice->AddRef();
     bd->pd3dDeviceContext->AddRef();
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplDX11_InitPlatformInterface();
+
     return true;
 }
 
@@ -581,13 +588,14 @@ void ImGui_ImplDX11_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplDX11_ShutdownPlatformInterface();
     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;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -600,6 +608,129 @@ void ImGui_ImplDX11_NewFrame()
         ImGui_ImplDX11_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..
+//--------------------------------------------------------------------------------------------------------
+
+// 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); }
+};
+
+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_Window*).
+    // 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);
+
+    // Create the render target
+    if (vd->SwapChain)
+    {
+        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;
+    vd->SwapChain->Present(0, 0); // Present without vsync
+}
+
+static void ImGui_ImplDX11_InitPlatformInterface()
+{
+    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;
+}
+
+static void ImGui_ImplDX11_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_dx11.h

@@ -4,14 +4,12 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'ID3D11ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

backends/imgui_impl_dx12.cpp

@@ -4,6 +4,8 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'D3D12_GPU_DESCRIPTOR_HANDLE' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [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.
 
 // Important: to compile on 32-bit systems, this backend requires code to be compiled with '#define ImTextureID ImU64'.
 // This is because we need ImTextureID to carry a 64-bit value and by default ImTextureID is defined as void*.
@@ -15,14 +17,12 @@
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  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).
 //  2021-05-19: DirectX12: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
@@ -54,7 +54,6 @@
 #endif
 
 // DirectX data
-struct ImGui_ImplDX12_RenderBuffers;
 struct ImGui_ImplDX12_Data
 {
     ID3D12Device*               pd3dDevice;
@@ -67,10 +66,7 @@ struct ImGui_ImplDX12_Data
     ID3D12DescriptorHeap*       pd3dSrvDescHeap;
     UINT                        numFramesInFlight;
 
-    ImGui_ImplDX12_RenderBuffers* pFrameResources;
-    UINT                        frameIndex;
-
-    ImGui_ImplDX12_Data()       { memset((void*)this, 0, sizeof(*this)); frameIndex = UINT_MAX; }
+    ImGui_ImplDX12_Data()       { memset((void*)this, 0, sizeof(*this)); }
 };
 
 // Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
@@ -89,11 +85,88 @@ struct ImGui_ImplDX12_RenderBuffers
     int                 VertexBufferSize;
 };
 
+// Buffers used for secondary viewports created by the multi-viewports systems
+struct ImGui_ImplDX12_FrameContext
+{
+    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;
+    ID3D12Fence*                    Fence;
+    UINT64                          FenceSignaledValue;
+    HANDLE                          FenceEvent;
+    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;
+        Fence = nullptr;
+        FenceSignaledValue = 0;
+        FenceEvent = nullptr;
+        NumFramesInFlight = num_frames_in_flight;
+        FrameCtx = new ImGui_ImplDX12_FrameContext[NumFramesInFlight];
+        FrameIndex = UINT_MAX;
+        FrameRenderBuffers = new ImGui_ImplDX12_RenderBuffers[NumFramesInFlight];
+
+        for (UINT i = 0; i < NumFramesInFlight; ++i)
+        {
+            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(Fence == nullptr);
+        IM_ASSERT(FenceEvent == 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_InitPlatformInterface();
+static void ImGui_ImplDX12_ShutdownPlatformInterface();
+
 // Functions
 static void ImGui_ImplDX12_SetupRenderState(ImDrawData* draw_data, ID3D12GraphicsCommandList* ctx, ImGui_ImplDX12_RenderBuffers* fr)
 {
@@ -167,11 +240,10 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
     if (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f)
         return;
 
-    // FIXME: I'm assuming that this only gets called once per frame!
-    // If not, we can't just re-allocate the IB or VB, we'll have to do a proper allocator.
     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)
@@ -592,9 +664,9 @@ bool    ImGui_ImplDX12_CreateDeviceObjects()
         // Create the input layout
         static D3D12_INPUT_ELEMENT_DESC local_layout[] =
         {
-            { "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)offsetof(ImDrawVert, pos), D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
-            { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)offsetof(ImDrawVert, uv),  D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
-            { "COLOR",    0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, (UINT)offsetof(ImDrawVert, col), D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
+            { "POSITION", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)IM_OFFSETOF(ImDrawVert, pos), D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
+            { "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,   0, (UINT)IM_OFFSETOF(ImDrawVert, uv),  D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
+            { "COLOR",    0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, (UINT)IM_OFFSETOF(ImDrawVert, col), D3D12_INPUT_CLASSIFICATION_PER_VERTEX_DATA, 0 },
         };
         psoDesc.InputLayout = { local_layout, 3 };
     }
@@ -678,6 +750,13 @@ bool    ImGui_ImplDX12_CreateDeviceObjects()
     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();
@@ -689,13 +768,6 @@ void    ImGui_ImplDX12_InvalidateDeviceObjects()
     SafeRelease(bd->pPipelineState);
     SafeRelease(bd->pFontTextureResource);
     io.Fonts->SetTexID(0); // We copied bd->pFontTextureView to io.Fonts->TexID so let's clear that as well.
-
-    for (UINT i = 0; i < bd->numFramesInFlight; i++)
-    {
-        ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[i];
-        SafeRelease(fr->IndexBuffer);
-        SafeRelease(fr->VertexBuffer);
-    }
 }
 
 bool ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FORMAT rtv_format, ID3D12DescriptorHeap* cbv_srv_heap,
@@ -709,25 +781,21 @@ bool ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FO
     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_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplDX12_InitPlatformInterface();
 
     bd->pd3dDevice = device;
     bd->RTVFormat = rtv_format;
     bd->hFontSrvCpuDescHandle = font_srv_cpu_desc_handle;
     bd->hFontSrvGpuDescHandle = font_srv_gpu_desc_handle;
-    bd->pFrameResources = new ImGui_ImplDX12_RenderBuffers[num_frames_in_flight];
     bd->numFramesInFlight = num_frames_in_flight;
     bd->pd3dSrvDescHeap = cbv_srv_heap;
-    bd->frameIndex = UINT_MAX;
 
-    // Create buffers with a default size (they will later be grown as needed)
-    for (int i = 0; i < num_frames_in_flight; i++)
-    {
-        ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[i];
-        fr->IndexBuffer = nullptr;
-        fr->VertexBuffer = nullptr;
-        fr->IndexBufferSize = 10000;
-        fr->VertexBufferSize = 5000;
-    }
+    // 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);
 
     return true;
 }
@@ -738,12 +806,24 @@ void ImGui_ImplDX12_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    // 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;
+    }
+
     // Clean up windows and device objects
+    ImGui_ImplDX12_ShutdownPlatformInterface();
     ImGui_ImplDX12_InvalidateDeviceObjects();
-    delete[] bd->pFrameResources;
+
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -756,6 +836,246 @@ void ImGui_ImplDX12_NewFrame()
         ImGui_ImplDX12_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_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_Window*).
+    // 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);
+
+    vd->FrameIndex = UINT_MAX;
+
+    // Create command queue.
+    D3D12_COMMAND_QUEUE_DESC queue_desc = {};
+    queue_desc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
+    queue_desc.Type = D3D12_COMMAND_LIST_TYPE_DIRECT;
+
+    HRESULT res = S_OK;
+    res = bd->pd3dDevice->CreateCommandQueue(&queue_desc, IID_PPV_ARGS(&vd->CommandQueue));
+    IM_ASSERT(res == S_OK);
+
+    // Create command allocator.
+    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 fence.
+    res = bd->pd3dDevice->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_PPV_ARGS(&vd->Fence));
+    IM_ASSERT(res == S_OK);
+
+    vd->FenceEvent = CreateEvent(nullptr, FALSE, FALSE, nullptr);
+    IM_ASSERT(vd->FenceEvent != nullptr);
+
+    // 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_STRETCH;
+    sd1.Stereo = FALSE;
+
+    IDXGIFactory4* dxgi_factory = nullptr;
+    res = ::CreateDXGIFactory1(IID_PPV_ARGS(&dxgi_factory));
+    IM_ASSERT(res == S_OK);
+
+    IDXGISwapChain1* swap_chain = nullptr;
+    res = dxgi_factory->CreateSwapChainForHwnd(vd->CommandQueue, hwnd, &sd1, nullptr, nullptr, &swap_chain);
+    IM_ASSERT(res == S_OK);
+
+    dxgi_factory->Release();
+
+    // Or swapChain.As(&mSwapChain)
+    IM_ASSERT(vd->SwapChain == nullptr);
+    swap_chain->QueryInterface(IID_PPV_ARGS(&vd->SwapChain));
+    swap_chain->Release();
+
+    // Create the render targets
+    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;
+        }
+    }
+
+    for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        ImGui_ImplDX12_DestroyRenderBuffers(&vd->FrameRenderBuffers[i]);
+}
+
+static void ImGui_WaitForPendingOperations(ImGui_ImplDX12_ViewportData* vd)
+{
+    HRESULT hr = S_FALSE;
+    if (vd && vd->CommandQueue && vd->Fence && vd->FenceEvent)
+    {
+        hr = vd->CommandQueue->Signal(vd->Fence, ++vd->FenceSignaledValue);
+        IM_ASSERT(hr == S_OK);
+        ::WaitForSingleObject(vd->FenceEvent, 0); // Reset any forgotten waits
+        hr = vd->Fence->SetEventOnCompletion(vd->FenceSignaledValue, vd->FenceEvent);
+        IM_ASSERT(hr == S_OK);
+        ::WaitForSingleObject(vd->FenceEvent, INFINITE);
+    }
+}
+
+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);
+
+        SafeRelease(vd->CommandQueue);
+        SafeRelease(vd->CommandList);
+        SafeRelease(vd->SwapChain);
+        SafeRelease(vd->RtvDescHeap);
+        SafeRelease(vd->Fence);
+        ::CloseHandle(vd->FenceEvent);
+        vd->FenceEvent = nullptr;
+
+        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;
+        vd->SwapChain->ResizeBuffers(0, (UINT)size.x, (UINT)size.y, DXGI_FORMAT_UNKNOWN, 0);
+        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 = &vd->FrameCtx[vd->FrameIndex % bd->numFramesInFlight];
+    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, (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->Wait(vd->Fence, vd->FenceSignaledValue);
+    vd->CommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&cmd_list);
+    vd->CommandQueue->Signal(vd->Fence, ++vd->FenceSignaledValue);
+}
+
+static void ImGui_ImplDX12_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData;
+
+    vd->SwapChain->Present(0, 0);
+    while (vd->Fence->GetCompletedValue() < vd->FenceSignaledValue)
+        ::SwitchToThread();
+}
+
+void ImGui_ImplDX12_InitPlatformInterface()
+{
+    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_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_dx12.h

@@ -4,17 +4,15 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'D3D12_GPU_DESCRIPTOR_HANDLE' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // Important: to compile on 32-bit systems, this backend requires code to be compiled with '#define ImTextureID ImU64'.
 // See imgui_impl_dx12.cpp file for details.
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

backends/imgui_impl_dx9.cpp

@@ -4,17 +4,16 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'LPDIRECT3DTEXTURE9' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  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).
 //  2021-06-25: DirectX9: Explicitly disable texture state stages after >= 1.
@@ -75,6 +74,12 @@ static ImGui_ImplDX9_Data* ImGui_ImplDX9_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX9_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX9_InitPlatformInterface();
+static void ImGui_ImplDX9_ShutdownPlatformInterface();
+static void ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows();
+static void ImGui_ImplDX9_InvalidateDeviceObjectsForPlatformWindows();
+
 // Functions
 static void ImGui_ImplDX9_SetupRenderState(ImDrawData* draw_data)
 {
@@ -271,6 +276,11 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
         global_vtx_offset += cmd_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
     bd->pd3dDevice->SetTransform(D3DTS_WORLD, &last_world);
     bd->pd3dDevice->SetTransform(D3DTS_VIEW, &last_view);
@@ -291,10 +301,14 @@ bool ImGui_ImplDX9_Init(IDirect3DDevice9* device)
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_dx9";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     bd->pd3dDevice = device;
     bd->pd3dDevice->AddRef();
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplDX9_InitPlatformInterface();
+
     return true;
 }
 
@@ -304,11 +318,12 @@ void ImGui_ImplDX9_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplDX9_ShutdownPlatformInterface();
     ImGui_ImplDX9_InvalidateDeviceObjects();
     if (bd->pd3dDevice) { bd->pd3dDevice->Release(); }
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -361,6 +376,7 @@ bool ImGui_ImplDX9_CreateDeviceObjects()
         return false;
     if (!ImGui_ImplDX9_CreateFontsTexture())
         return false;
+    ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows();
     return true;
 }
 
@@ -372,6 +388,7 @@ void ImGui_ImplDX9_InvalidateDeviceObjects()
     if (bd->pVB) { bd->pVB->Release(); bd->pVB = nullptr; }
     if (bd->pIB) { bd->pIB->Release(); bd->pIB = nullptr; }
     if (bd->FontTexture) { bd->FontTexture->Release(); bd->FontTexture = nullptr; ImGui::GetIO().Fonts->SetTexID(0); } // We copied bd->pFontTextureView to io.Fonts->TexID so let's clear that as well.
+    ImGui_ImplDX9_InvalidateDeviceObjectsForPlatformWindows();
 }
 
 void ImGui_ImplDX9_NewFrame()
@@ -383,6 +400,148 @@ void ImGui_ImplDX9_NewFrame()
         ImGui_ImplDX9_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..
+//--------------------------------------------------------------------------------------------------------
+
+// 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_Window*).
+    // 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(hr == D3D_OK || hr == D3DERR_DEVICELOST);
+}
+
+static void ImGui_ImplDX9_InitPlatformInterface()
+{
+    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_ShutdownPlatformInterface()
+{
+    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

@@ -4,14 +4,12 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'LPDIRECT3DTEXTURE9' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

backends/imgui_impl_glfw.cpp

@@ -9,24 +9,26 @@
 //  [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 will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+
+// Issues:
+//  [ ] Platform: Multi-viewport support: ParentViewportID not honored, and so io.ConfigViewportsNoDefaultParent has no effect (minor).
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  2023-10-05: Inputs: Added support for extra ImGuiKey values: F13 to F24 function keys.
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2023-07-18: Inputs: Revert ignoring mouse data on GLFW_CURSOR_DISABLED as it can be used differently. User may set ImGuiConfigFLags_NoMouse if desired. (#5625, #6609)
 //  2023-06-12: Accept glfwGetTime() not returning a monotonically increasing value. This seems to happens on some Windows setup when peripherals disconnect, and is likely to also happen on browser + Emscripten. (#6491)
 //  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen/ImGuiMouseSource_Pen on Windows ONLY, using a custom WndProc hook. (#2702)
 //  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)
@@ -99,11 +101,29 @@
 
 // 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()
@@ -124,8 +144,10 @@ struct ImGui_ImplGlfw_Data
     GLFWwindow*             MouseWindow;
     GLFWcursor*             MouseCursors[ImGuiMouseCursor_COUNT];
     ImVec2                  LastValidMousePos;
+    GLFWwindow*             KeyOwnerWindows[GLFW_KEY_LAST];
     bool                    InstalledCallbacks;
     bool                    CallbacksChainForAllWindows;
+    bool                    WantUpdateMonitors;
 
     // Chain GLFW callbacks: our callbacks will call the user's previously installed callbacks, if any.
     GLFWwindowfocusfun      PrevUserCallbackWindowFocus;
@@ -155,6 +177,11 @@ static ImGui_ImplGlfw_Data* ImGui_ImplGlfw_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplGlfw_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplGlfw_UpdateMonitors();
+static void ImGui_ImplGlfw_InitPlatformInterface();
+static void ImGui_ImplGlfw_ShutdownPlatformInterface();
+
 // Functions
 static const char* ImGui_ImplGlfw_GetClipboardText(void* user_data)
 {
@@ -275,18 +302,6 @@ static ImGuiKey ImGui_ImplGlfw_KeyToImGuiKey(int key)
         case GLFW_KEY_F10: return ImGuiKey_F10;
         case GLFW_KEY_F11: return ImGuiKey_F11;
         case GLFW_KEY_F12: return ImGuiKey_F12;
-        case GLFW_KEY_F13: return ImGuiKey_F13;
-        case GLFW_KEY_F14: return ImGuiKey_F14;
-        case GLFW_KEY_F15: return ImGuiKey_F15;
-        case GLFW_KEY_F16: return ImGuiKey_F16;
-        case GLFW_KEY_F17: return ImGuiKey_F17;
-        case GLFW_KEY_F18: return ImGuiKey_F18;
-        case GLFW_KEY_F19: return ImGuiKey_F19;
-        case GLFW_KEY_F20: return ImGuiKey_F20;
-        case GLFW_KEY_F21: return ImGuiKey_F21;
-        case GLFW_KEY_F22: return ImGuiKey_F22;
-        case GLFW_KEY_F23: return ImGuiKey_F23;
-        case GLFW_KEY_F24: return ImGuiKey_F24;
         default: return ImGuiKey_None;
     }
 }
@@ -380,6 +395,9 @@ void ImGui_ImplGlfw_KeyCallback(GLFWwindow* window, int keycode, int scancode, i
 
     ImGui_ImplGlfw_UpdateKeyModifiers(window);
 
+    if (keycode >= 0 && keycode < IM_ARRAYSIZE(bd->KeyOwnerWindows))
+        bd->KeyOwnerWindows[keycode] = (action == GLFW_PRESS) ? window : nullptr;
+
     keycode = ImGui_ImplGlfw_TranslateUntranslatedKey(keycode, scancode);
 
     ImGuiIO& io = ImGui::GetIO();
@@ -405,6 +423,13 @@ void ImGui_ImplGlfw_CursorPosCallback(GLFWwindow* window, double x, double y)
         bd->PrevUserCallbackCursorPos(window, x, y);
 
     ImGuiIO& io = ImGui::GetIO();
+    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);
 }
@@ -443,7 +468,8 @@ 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.
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    bd->WantUpdateMonitors = true;
 }
 
 #ifdef __EMSCRIPTEN__
@@ -488,6 +514,22 @@ static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wPara
     case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK: case WM_XBUTTONUP:
         ImGui::GetIO().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.
+        ImGuiViewport* viewport = (ImGuiViewport*)::GetPropA(hWnd, "IMGUI_VIEWPORT");
+        if (viewport && (viewport->Flags & ImGuiViewportFlags_NoInputs))
+            return HTTRANSPARENT;
+        break;
+    }
+#endif
     }
     return ::CallWindowProc(bd->GlfwWndProc, hWnd, msg, wParam, lParam);
 }
@@ -557,9 +599,16 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     io.BackendPlatformName = "imgui_impl_glfw";
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+#ifndef __EMSCRIPTEN__
+    io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;    // We can create multi-viewports on the Platform side (optional)
+#endif
+#if GLFW_HAS_MOUSE_PASSTHROUGH || (GLFW_HAS_WINDOW_HOVERED && defined(_WIN32))
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
+#endif
 
     bd->Window = window;
     bd->Time = 0.0;
+    bd->WantUpdateMonitors = true;
 
     io.SetClipboardTextFn = ImGui_ImplGlfw_SetClipboardText;
     io.GetClipboardTextFn = ImGui_ImplGlfw_GetClipboardText;
@@ -601,8 +650,13 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     emscripten_set_wheel_callback(EMSCRIPTEN_EVENT_TARGET_DOCUMENT, nullptr, false, ImGui_ImplEmscripten_WheelCallback);
 #endif
 
+    // Update monitors the first time (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;
 #ifdef _WIN32
     main_viewport->PlatformHandleRaw = glfwGetWin32Window(bd->Window);
 #elif defined(__APPLE__)
@@ -610,6 +664,8 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
 #else
     IM_UNUSED(main_viewport);
 #endif
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplGlfw_InitPlatformInterface();
 
     // Windows: register a WndProc hook so we can intercept some messages.
 #ifdef _WIN32
@@ -643,11 +699,10 @@ void ImGui_ImplGlfw_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplGlfw_ShutdownPlatformInterface();
+
     if (bd->InstalledCallbacks)
         ImGui_ImplGlfw_RestoreCallbacks(bd->Window);
-#ifdef __EMSCRIPTEN__
-    emscripten_set_wheel_callback(EMSCRIPTEN_EVENT_TARGET_DOCUMENT, nullptr, false, nullptr);
-#endif
 
     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
         glfwDestroyCursor(bd->MouseCursors[cursor_n]);
@@ -661,7 +716,7 @@ 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);
     IM_DELETE(bd);
 }
 
@@ -669,11 +724,15 @@ 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__
         const bool is_window_focused = true;
@@ -683,19 +742,53 @@ static void ImGui_ImplGlfw_UpdateMouseData()
         if (is_window_focused)
         {
             // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos 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.
+        // - [!] 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 || (GLFW_HAS_WINDOW_HOVERED && defined(_WIN32))
+        const bool window_no_input = (viewport->Flags & ImGuiViewportFlags_NoInputs) != 0;
+#if GLFW_HAS_MOUSE_PASSTHROUGH
+        glfwSetWindowAttrib(window, GLFW_MOUSE_PASSTHROUGH, window_no_input);
+#endif
+        if (glfwGetWindowAttrib(window, GLFW_HOVERED) && !window_no_input)
+            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()
@@ -706,9 +799,10 @@ 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
@@ -777,6 +871,48 @@ static void ImGui_ImplGlfw_UpdateGamepads()
     #undef MAP_ANALOG
 }
 
+static void ImGui_ImplGlfw_UpdateMonitors()
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    bd->WantUpdateMonitors = false;
+
+    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
+#if GLFW_HAS_PER_MONITOR_DPI
+        // 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.
+        float x_scale, y_scale;
+        glfwGetMonitorContentScale(glfw_monitors[n], &x_scale, &y_scale);
+        monitor.DpiScale = x_scale;
+#endif
+        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);
+    }
+}
+
 void ImGui_ImplGlfw_NewFrame()
 {
     ImGuiIO& io = ImGui::GetIO();
@@ -791,6 +927,8 @@ void ImGui_ImplGlfw_NewFrame()
     io.DisplaySize = ImVec2((float)w, (float)h);
     if (w > 0 && h > 0)
         io.DisplayFramebufferScale = ImVec2((float)display_w / (float)w, (float)display_h / (float)h);
+    if (bd->WantUpdateMonitors)
+        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)
@@ -807,6 +945,343 @@ void ImGui_ImplGlfw_NewFrame()
     ImGui_ImplGlfw_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* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplGlfw_ViewportData
+{
+    GLFWwindow* Window;
+    bool        WindowOwned;
+    int         IgnoreWindowPosEventFrame;
+    int         IgnoreWindowSizeEventFrame;
+
+    ImGui_ImplGlfw_ViewportData()  { Window = nullptr; WindowOwned = false; 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;
+    }
+}
+
+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;
+
+    // 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;
+    viewport->PlatformHandle = (void*)vd->Window;
+#ifdef _WIN32
+    viewport->PlatformHandleRaw = glfwGetWin32Window(vd->Window);
+#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.
+
+            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 hook for WM_NCHITTEST message handler
+#if !GLFW_HAS_MOUSE_PASSTHROUGH && GLFW_HAS_WINDOW_HOVERED && defined(_WIN32)
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ::SetPropA(hwnd, "IMGUI_VIEWPORT", viewport);
+    IM_ASSERT(bd->GlfwWndProc == (WNDPROC)::GetWindowLongPtr(hwnd, GWLP_WNDPROC));
+    ::SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR)ImGui_ImplGlfw_WndProc);
+#endif
+
+#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 __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 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_InitPlatformInterface()
+{
+    // 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_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_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_glfw.h

@@ -1,21 +1,23 @@
 // 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.
 //  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen/Pen (Windows only).
 //  [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 will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
-//  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+//  [x] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+
+// Issues:
+//  [ ] Platform: Multi-viewport support: ParentViewportID not honored, and so io.ConfigViewportsNoDefaultParent has no effect (minor).
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

backends/imgui_impl_glut.cpp

@@ -7,7 +7,7 @@
 
 // Implemented features:
 //  [X] Platform: Partial 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 GLUT values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
-// Issues:
+// Missing features:
 //  [ ] Platform: GLUT is unable to distinguish e.g. Backspace from CTRL+H or TAB from CTRL+I
 //  [ ] Platform: Missing horizontal mouse wheel support.
 //  [ ] Platform: Missing mouse cursor shape/visibility support.
@@ -16,11 +16,8 @@
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)

backends/imgui_impl_glut.h

@@ -7,7 +7,7 @@
 
 // Implemented features:
 //  [X] Platform: Partial 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 GLUT values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
-// Issues:
+// Missing features:
 //  [ ] Platform: GLUT is unable to distinguish e.g. Backspace from CTRL+H or TAB from CTRL+I
 //  [ ] Platform: Missing horizontal mouse wheel support.
 //  [ ] Platform: Missing mouse cursor shape/visibility support.
@@ -16,11 +16,8 @@
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #ifndef IMGUI_DISABLE

backends/imgui_impl_metal.h

@@ -4,14 +4,12 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'MTLTexture' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"      // IMGUI_IMPL_API
 #ifndef IMGUI_DISABLE

backends/imgui_impl_metal.mm

@@ -4,17 +4,16 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'MTLTexture' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Metal: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  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.
@@ -38,6 +37,12 @@
 #import <time.h>
 #import <Metal/Metal.h>
 
+// Forward Declarations
+static void ImGui_ImplMetal_InitPlatformInterface();
+static void ImGui_ImplMetal_ShutdownPlatformInterface();
+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
@@ -130,10 +135,14 @@ bool ImGui_ImplMetal_Init(id<MTLDevice> device)
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_metal";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     bd->SharedMetalContext = [[MetalContext alloc] init];
     bd->SharedMetalContext.device = device;
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplMetal_InitPlatformInterface();
+
     return true;
 }
 
@@ -141,13 +150,14 @@ void ImGui_ImplMetal_Shutdown()
 {
     ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
+    ImGui_ImplMetal_ShutdownPlatformInterface();
     ImGui_ImplMetal_DestroyDeviceObjects();
     ImGui_ImplMetal_DestroyBackendData();
 
     ImGuiIO& io = ImGui::GetIO();
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
 }
 
 void ImGui_ImplMetal_NewFrame(MTLRenderPassDescriptor* renderPassDescriptor)
@@ -365,6 +375,7 @@ bool ImGui_ImplMetal_CreateDeviceObjects(id<MTLDevice> device)
     depthStencilDescriptor.depthWriteEnabled = NO;
     depthStencilDescriptor.depthCompareFunction = MTLCompareFunctionAlways;
     bd->SharedMetalContext.depthStencilState = [device newDepthStencilStateWithDescriptor:depthStencilDescriptor];
+    ImGui_ImplMetal_CreateDeviceObjectsForPlatformWindows();
     ImGui_ImplMetal_CreateFontsTexture(device);
 
     return true;
@@ -374,9 +385,155 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
 {
     ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData();
     ImGui_ImplMetal_DestroyFontsTexture();
+    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;
+
+    viewport->DpiScale = (float)window.backingScaleFactor;
+    if (data->MetalLayer.contentsScale != viewport->DpiScale)
+    {
+        data->MetalLayer.contentsScale = viewport->DpiScale;
+        data->MetalLayer.drawableSize = MakeScaledSize(window.frame.size, viewport->DpiScale);
+    }
+    viewport->DrawData->FramebufferScale = ImVec2(viewport->DpiScale, viewport->DpiScale);
+#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_InitPlatformInterface()
+{
+    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_ShutdownPlatformInterface()
+{
+    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
@@ -547,13 +704,13 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
     }
 
     MTLVertexDescriptor* vertexDescriptor = [MTLVertexDescriptor vertexDescriptor];
-    vertexDescriptor.attributes[0].offset = offsetof(ImDrawVert, pos);
+    vertexDescriptor.attributes[0].offset = IM_OFFSETOF(ImDrawVert, pos);
     vertexDescriptor.attributes[0].format = MTLVertexFormatFloat2; // position
     vertexDescriptor.attributes[0].bufferIndex = 0;
-    vertexDescriptor.attributes[1].offset = offsetof(ImDrawVert, uv);
+    vertexDescriptor.attributes[1].offset = IM_OFFSETOF(ImDrawVert, uv);
     vertexDescriptor.attributes[1].format = MTLVertexFormatFloat2; // texCoords
     vertexDescriptor.attributes[1].bufferIndex = 0;
-    vertexDescriptor.attributes[2].offset = offsetof(ImDrawVert, col);
+    vertexDescriptor.attributes[2].offset = IM_OFFSETOF(ImDrawVert, col);
     vertexDescriptor.attributes[2].format = MTLVertexFormatUChar4; // color
     vertexDescriptor.attributes[2].bufferIndex = 0;
     vertexDescriptor.layouts[0].stepRate = 1;

backends/imgui_impl_opengl2.cpp

@@ -3,14 +3,12 @@
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
+//  [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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)**
 // **Prefer using the code in imgui_impl_opengl3.cpp**
@@ -22,6 +20,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2021-12-08: OpenGL: Fixed mishandling of the the ImDrawCmd::IdxOffset field! This is an old bug but it never had an effect until some internal rendering changes in 1.86.
 //  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).
@@ -79,6 +78,10 @@ static ImGui_ImplOpenGL2_Data* ImGui_ImplOpenGL2_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL2_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplOpenGL2_InitPlatformInterface();
+static void ImGui_ImplOpenGL2_ShutdownPlatformInterface();
+
 // Functions
 bool    ImGui_ImplOpenGL2_Init()
 {
@@ -89,6 +92,10 @@ bool    ImGui_ImplOpenGL2_Init()
     ImGui_ImplOpenGL2_Data* bd = IM_NEW(ImGui_ImplOpenGL2_Data)();
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_opengl2";
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;    // We can create multi-viewports on the Renderer side (optional)
+
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplOpenGL2_InitPlatformInterface();
 
     return true;
 }
@@ -99,9 +106,11 @@ void    ImGui_ImplOpenGL2_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplOpenGL2_ShutdownPlatformInterface();
     ImGui_ImplOpenGL2_DestroyDeviceObjects();
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasViewports;
     IM_DELETE(bd);
 }
 
@@ -191,9 +200,9 @@ void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
         const ImDrawList* cmd_list = draw_data->CmdLists[n];
         const ImDrawVert* vtx_buffer = cmd_list->VtxBuffer.Data;
         const ImDrawIdx* idx_buffer = cmd_list->IdxBuffer.Data;
-        glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + offsetof(ImDrawVert, pos)));
-        glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + offsetof(ImDrawVert, uv)));
-        glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + offsetof(ImDrawVert, col)));
+        glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, pos)));
+        glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, uv)));
+        glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, col)));
 
         for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
         {
@@ -293,6 +302,35 @@ void    ImGui_ImplOpenGL2_DestroyDeviceObjects()
     ImGui_ImplOpenGL2_DestroyFontsTexture();
 }
 
+
+//--------------------------------------------------------------------------------------------------------
+// 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_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL2_RenderWindow;
+}
+
+static void ImGui_ImplOpenGL2_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_opengl2.h

@@ -3,14 +3,12 @@
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
+//  [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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)**
 // **Prefer using the code in imgui_impl_opengl3.cpp**

backends/imgui_impl_opengl3.cpp

@@ -5,7 +5,8 @@
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
-//  [x] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+//  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+//  [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.
@@ -14,16 +15,12 @@
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  2023-11-08: OpenGL: Update GL3W based imgui_impl_opengl3_loader.h to load "libGL.so" instead of "libGL.so.1", accomodating for NetBSD systems having only "libGL.so.3" available. (#6983)
-//  2023-10-05: OpenGL: Rename symbols in our internal loader so that LTO compilation with another copy of gl3w is possible. (#6875, #6668, #4445)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2023-06-20: OpenGL: Fixed erroneous use glGetIntegerv(GL_CONTEXT_PROFILE_MASK) on contexts lower than 3.2. (#6539, #6333)
 //  2023-05-09: OpenGL: Support for glBindSampler() backup/restore on ES3. (#6375)
 //  2023-04-18: OpenGL: Restore front and back polygon mode separately when supported by context. (#6333)
@@ -241,6 +238,10 @@ static ImGui_ImplOpenGL3_Data* ImGui_ImplOpenGL3_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL3_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplOpenGL3_InitPlatformInterface();
+static void ImGui_ImplOpenGL3_ShutdownPlatformInterface();
+
 // OpenGL vertex attribute state (for ES 1.0 and ES 2.0 only)
 #ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
 struct ImGui_ImplOpenGL3_VtxAttribState
@@ -332,6 +333,7 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     if (bd->GlVersion >= 320)
         io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
 #endif
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     // Store GLSL version string so we can refer to it later in case we recreate shaders.
     // Note: GLSL version is NOT the same as GL version. Leave this to nullptr if unsure.
@@ -369,6 +371,9 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     }
 #endif
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplOpenGL3_InitPlatformInterface();
+
     return true;
 }
 
@@ -378,10 +383,11 @@ void    ImGui_ImplOpenGL3_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplOpenGL3_ShutdownPlatformInterface();
     ImGui_ImplOpenGL3_DestroyDeviceObjects();
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -462,9 +468,9 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid
     GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxPos));
     GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxUV));
     GL_CALL(glEnableVertexAttribArray(bd->AttribLocationVtxColor));
-    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxPos,   2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)offsetof(ImDrawVert, pos)));
-    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxUV,    2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)offsetof(ImDrawVert, uv)));
-    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)offsetof(ImDrawVert, col)));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxPos,   2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, pos)));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxUV,    2, GL_FLOAT,         GL_FALSE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, uv)));
+    GL_CALL(glVertexAttribPointer(bd->AttribLocationVtxColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)IM_OFFSETOF(ImDrawVert, col)));
 }
 
 // OpenGL3 Render function.
@@ -935,6 +941,34 @@ void    ImGui_ImplOpenGL3_DestroyDeviceObjects()
     ImGui_ImplOpenGL3_DestroyFontsTexture();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// 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_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL3_RenderWindow;
+}
+
+static void ImGui_ImplOpenGL3_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__GNUC__)

backends/imgui_impl_opengl3.h

@@ -5,7 +5,8 @@
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
-//  [x] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+//  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+//  [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.
@@ -14,11 +15,8 @@
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // About GLSL version:
 //  The 'glsl_version' initialization parameter should be nullptr (default) or a "#version XXX" string.

backends/imgui_impl_opengl3_loader.h

@@ -118,7 +118,7 @@ extern "C" {
 ** included as <GL/glcorearb.h>.
 **
 ** glcorearb.h includes only APIs in the latest OpenGL core profile
-** implementation together with APIs in newer ARB extensions which
+** implementation together with APIs in newer ARB extensions which 
 ** can be supported by the core profile. It does not, and never will
 ** include functionality removed from the core profile, such as
 ** fixed-function vertex and fragment processing.
@@ -467,7 +467,7 @@ GL3W_API int imgl3wIsSupported(int major, int minor);
 GL3W_API GL3WglProc imgl3wGetProcAddress(const char *proc);
 
 /* gl3w internal state */
-union ImGL3WProcs {
+union GL3WProcs {
     GL3WglProc ptr[59];
     struct {
         PFNGLACTIVETEXTUREPROC            ActiveTexture;
@@ -532,7 +532,7 @@ union ImGL3WProcs {
     } gl;
 };
 
-GL3W_API extern union ImGL3WProcs imgl3wProcs;
+GL3W_API extern union GL3WProcs imgl3wProcs;
 
 /* OpenGL functions */
 #define glActiveTexture                   imgl3wProcs.gl.ActiveTexture
@@ -666,8 +666,7 @@ static GL3WglProc (*glx_get_proc_address)(const GLubyte *);
 
 static int open_libgl(void)
 {
-    // While most systems use libGL.so.1, NetBSD seems to use that libGL.so.3. See https://github.com/ocornut/imgui/issues/6983
-    libgl = dlopen("libGL.so", RTLD_LAZY | RTLD_LOCAL);
+    libgl = dlopen("libGL.so.1", RTLD_LAZY | RTLD_LOCAL);
     if (!libgl)
         return GL3W_ERROR_LIBRARY_OPEN;
     *(void **)(&glx_get_proc_address) = dlsym(libgl, "glXGetProcAddressARB");
@@ -795,7 +794,7 @@ static const char *proc_names[] = {
     "glViewport",
 };
 
-GL3W_API union ImGL3WProcs imgl3wProcs;
+GL3W_API union GL3WProcs imgl3wProcs;
 
 static void load_procs(GL3WGetProcAddressProc proc)
 {

backends/imgui_impl_osx.h

@@ -10,14 +10,12 @@
 //  [X] Platform: OSX clipboard is supported within core Dear ImGui (no specific code in this backend).
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: IME support.
+//  [X] Platform: Multi-viewport / platform 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"      // IMGUI_IMPL_API
 #ifndef IMGUI_DISABLE

backends/imgui_impl_osx.mm

@@ -10,14 +10,12 @@
 //  [X] Platform: OSX clipboard is supported within core Dear ImGui (no specific code in this backend).
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: IME support.
+//  [X] Platform: Multi-viewport / platform 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #import "imgui.h"
 #ifndef IMGUI_DISABLE
@@ -29,7 +27,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  2023-10-05: Inputs: Added support for extra ImGuiKey values: F13 to F20 function keys. Stopped mapping F13 into PrintScreen.
+//  2023-XX-XX: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2023-04-09: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_Pen.
 //  2023-02-01: Fixed scroll wheel scaling for devices emitting events with hasPreciseScrollingDeltas==false (e.g. non-Apple mices).
 //  2022-11-02: Fixed mouse coordinates before clicking the host window.
@@ -80,6 +78,7 @@ struct ImGui_ImplOSX_Data
     KeyEventResponder*          KeyEventResponder;
     NSTextInputContext*         InputContext;
     id                          Monitor;
+    NSWindow*                   Window;
 
     ImGui_ImplOSX_Data()        { memset(this, 0, sizeof(*this)); }
 };
@@ -91,6 +90,9 @@ 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_InitPlatformInterface();
+static void ImGui_ImplOSX_ShutdownPlatformInterface();
+static void ImGui_ImplOSX_UpdateMonitors();
 static void ImGui_ImplOSX_AddTrackingArea(NSView* _Nonnull view);
 static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
 
@@ -234,6 +236,7 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
 
 - (void)onApplicationBecomeActive:(NSNotification*)aNotification;
 - (void)onApplicationBecomeInactive:(NSNotification*)aNotification;
+- (void)displaysDidChange:(NSNotification*)aNotification;
 
 @end
 
@@ -251,6 +254,11 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
     io.AddFocusEvent(false);
 }
 
+- (void)displaysDidChange:(NSNotification*)aNotification
+{
+    ImGui_ImplOSX_UpdateMonitors();
+}
+
 @end
 
 // Functions
@@ -338,36 +346,36 @@ static ImGuiKey ImGui_ImplOSX_KeyCodeToImGuiKey(int key_code)
         case kVK_RightOption: return ImGuiKey_RightAlt;
         case kVK_RightCommand: return ImGuiKey_RightSuper;
 //      case kVK_Function: return ImGuiKey_;
+//      case kVK_F17: return ImGuiKey_;
 //      case kVK_VolumeUp: return ImGuiKey_;
 //      case kVK_VolumeDown: return ImGuiKey_;
 //      case kVK_Mute: return ImGuiKey_;
-        case kVK_F1: return ImGuiKey_F1;
-        case kVK_F2: return ImGuiKey_F2;
-        case kVK_F3: return ImGuiKey_F3;
-        case kVK_F4: return ImGuiKey_F4;
+//      case kVK_F18: return ImGuiKey_;
+//      case kVK_F19: return ImGuiKey_;
+//      case kVK_F20: return ImGuiKey_;
         case kVK_F5: return ImGuiKey_F5;
         case kVK_F6: return ImGuiKey_F6;
         case kVK_F7: return ImGuiKey_F7;
+        case kVK_F3: return ImGuiKey_F3;
         case kVK_F8: return ImGuiKey_F8;
         case kVK_F9: return ImGuiKey_F9;
-        case kVK_F10: return ImGuiKey_F10;
         case kVK_F11: return ImGuiKey_F11;
-        case kVK_F12: return ImGuiKey_F12;
-        case kVK_F13: return ImGuiKey_F13;
-        case kVK_F14: return ImGuiKey_F14;
-        case kVK_F15: return ImGuiKey_F15;
-        case kVK_F16: return ImGuiKey_F16;
-        case kVK_F17: return ImGuiKey_F17;
-        case kVK_F18: return ImGuiKey_F18;
-        case kVK_F19: return ImGuiKey_F19;
-        case kVK_F20: return ImGuiKey_F20;
+        case kVK_F13: return ImGuiKey_PrintScreen;
+//      case kVK_F16: return ImGuiKey_;
+//      case kVK_F14: return ImGuiKey_;
+        case kVK_F10: return ImGuiKey_F10;
         case 0x6E: return ImGuiKey_Menu;
+        case kVK_F12: return ImGuiKey_F12;
+//      case kVK_F15: return ImGuiKey_;
         case kVK_Help: return ImGuiKey_Insert;
         case kVK_Home: return ImGuiKey_Home;
         case kVK_PageUp: return ImGuiKey_PageUp;
         case kVK_ForwardDelete: return ImGuiKey_Delete;
+        case kVK_F4: return ImGuiKey_F4;
         case kVK_End: return ImGuiKey_End;
+        case kVK_F2: return ImGuiKey_F2;
         case kVK_PageDown: return ImGuiKey_PageDown;
+        case kVK_F1: return ImGuiKey_F1;
         case kVK_LeftArrow: return ImGuiKey_LeftArrow;
         case kVK_RightArrow: return ImGuiKey_RightArrow;
         case kVK_DownArrow: return ImGuiKey_DownArrow;
@@ -398,9 +406,16 @@ bool ImGui_ImplOSX_Init(NSView* view)
     // Setup backend capabilities flags
     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.BackendPlatformName = "imgui_impl_osx";
 
     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;
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplOSX_InitPlatformInterface();
 
     // Load cursors. Some of them are undocumented.
     bd->MouseCursorHidden = false;
@@ -490,12 +505,12 @@ void ImGui_ImplOSX_Shutdown()
         bd->Monitor = nullptr;
     }
 
+    ImGui_ImplOSX_ShutdownPlatformInterface();
     ImGui_ImplOSX_DestroyBackendData();
-
     ImGuiIO& io = ImGui::GetIO();
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
-    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasGamepad);
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasGamepad | ImGuiBackendFlags_PlatformHasViewports);
 }
 
 static void ImGui_ImplOSX_UpdateMouseCursor()
@@ -672,14 +687,23 @@ 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;
@@ -807,6 +831,286 @@ 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 ImGuiViewportDataOSX
+{
+    NSWindow*               Window;
+    bool                    WindowOwned;
+
+    ImGuiViewportDataOSX()  { WindowOwned = false; }
+    ~ImGuiViewportDataOSX() { IM_ASSERT(Window == nil); }
+};
+
+@interface ImGui_ImplOSX_Window: NSWindow
+@end
+
+@implementation ImGui_ImplOSX_Window
+
+- (BOOL)canBecomeKeyWindow
+{
+    return YES;
+}
+
+@end
+
+static void ConvertNSRect(NSScreen* screen, NSRect* r)
+{
+    r->origin.y = screen.frame.size.height - r->origin.y - r->size.height;
+}
+
+static void ImGui_ImplOSX_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGuiViewportDataOSX* data = IM_NEW(ImGuiViewportDataOSX)();
+    viewport->PlatformUserData = data;
+
+    NSScreen* screen = bd->Window.screen;
+    NSRect rect = NSMakeRect(viewport->Pos.x, viewport->Pos.y, viewport->Size.x, viewport->Size.y);
+    ConvertNSRect(screen, &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)
+        [view setWantsBestResolutionOpenGLSurface:YES];
+
+    window.contentView = view;
+
+    data->Window = window;
+    data->WindowOwned = true;
+    viewport->PlatformRequestResize = false;
+    viewport->PlatformHandle = viewport->PlatformHandleRaw = (__bridge_retained void*)window;
+}
+
+static void ImGui_ImplOSX_DestroyWindow(ImGuiViewport* viewport)
+{
+    NSWindow* window = (__bridge_transfer NSWindow*)viewport->PlatformHandleRaw;
+    window = nil;
+
+    if (ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData)
+    {
+        NSWindow* window = data->Window;
+        if (window != nil && data->WindowOwned)
+        {
+            window.contentView = nil;
+            window.contentViewController = nil;
+            [window orderOut:nil];
+        }
+        data->Window = nil;
+        IM_DELETE(data);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = viewport->PlatformHandleRaw = nullptr;
+}
+
+static void ImGui_ImplOSX_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+        [data->Window orderFront:nil];
+    else
+        [data->Window makeKeyAndOrderFront:nil];
+
+    [data->Window setIsVisible:YES];
+}
+
+static ImVec2 ImGui_ImplOSX_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    NSWindow* window = data->Window;
+    NSScreen* screen = window.screen;
+    NSSize size = screen.frame.size;
+    NSRect frame = window.frame;
+    NSRect rect = window.contentLayoutRect;
+    return ImVec2(frame.origin.x, size.height - frame.origin.y - rect.size.height);
+}
+
+static void ImGui_ImplOSX_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    NSWindow* window = data->Window;
+    NSSize size = window.frame.size;
+
+    NSRect r = NSMakeRect(pos.x, pos.y, size.width, size.height);
+    ConvertNSRect(window.screen, &r);
+    [window setFrameOrigin:r.origin];
+}
+
+static ImVec2 ImGui_ImplOSX_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    NSWindow* window = data->Window;
+    NSSize size = window.contentLayoutRect.size;
+    return ImVec2(size.width, size.height);
+}
+
+static void ImGui_ImplOSX_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    NSWindow* window = data->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 void ImGui_ImplOSX_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+    [data->Window makeKeyAndOrderFront:bd->Window];
+}
+
+static bool ImGui_ImplOSX_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    return data->Window.isKeyWindow;
+}
+
+static bool ImGui_ImplOSX_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    return data->Window.isMiniaturized;
+}
+
+static void ImGui_ImplOSX_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    data->Window.title = [NSString stringWithUTF8String:title];
+}
+
+static void ImGui_ImplOSX_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+    IM_ASSERT(alpha >= 0.0f && alpha <= 1.0f);
+
+    data->Window.alphaValue = alpha;
+}
+
+static float ImGui_ImplOSX_GetWindowDpiScale(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    return data->Window.backingScaleFactor;
+}
+
+static void ImGui_ImplOSX_UpdateMonitors()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Monitors.resize(0);
+
+    for (NSScreen* screen in NSScreen.screens)
+    {
+        NSRect frame = screen.frame;
+        NSRect visibleFrame = screen.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_InitPlatformInterface()
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGui_ImplOSX_UpdateMonitors();
+
+    // 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_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();
+    ImGuiViewportDataOSX* data = IM_NEW(ImGuiViewportDataOSX)();
+    data->Window = bd->Window;
+    data->WindowOwned = false;
+    main_viewport->PlatformUserData = data;
+    main_viewport->PlatformHandle = (__bridge void*)bd->Window;
+
+    [NSNotificationCenter.defaultCenter addObserver:bd->Observer
+                                           selector:@selector(displaysDidChange:)
+                                               name:NSApplicationDidChangeScreenParametersNotification
+                                             object:nil];
+}
+
+static void ImGui_ImplOSX_ShutdownPlatformInterface()
+{
+    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();
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)main_viewport->PlatformUserData;
+    IM_DELETE(data);
+    main_viewport->PlatformUserData = nullptr;
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_sdl2.cpp

@@ -9,19 +9,19 @@
 //  [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 will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. 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:
+//  [ ] Platform: Multi-viewport + Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [x] Platform: Basic IME support. 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  2023-10-05: Inputs: Added support for extra ImGuiKey values: F13 to F24 function keys, app back/forward keys.
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2023-04-06: Inputs: Avoid calling SDL_StartTextInput()/SDL_StopTextInput() as they don't only pertain to IME. It's unclear exactly what their relation is to IME. (#6306)
 //  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen. (#2702)
 //  2023-02-23: Accept SDL_GetPerformanceCounter() not returning a monotonically increasing value. (#6189, #6114, #3644)
@@ -46,7 +46,7 @@
 //  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.
@@ -87,6 +87,7 @@
 #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>
 #if defined(__APPLE__)
@@ -98,7 +99,15 @@
 #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)
+#if !SDL_HAS_VULKAN
+static const Uint32 SDL_WINDOW_VULKAN = 0x10000000;
+#endif
 
 // SDL Data
 struct ImGui_ImplSDL2_Data
@@ -113,6 +122,9 @@ struct ImGui_ImplSDL2_Data
     int             PendingMouseLeaveFrame;
     char*           ClipboardTextData;
     bool            MouseCanUseGlobalState;
+    bool            MouseCanReportHoveredViewport;  // This is hard to use/unreliable on SDL so we'll set ImGuiBackendFlags_HasMouseHoveredViewport dynamically based on state.
+    bool            UseVulkan;
+    bool            WantUpdateMonitors;
 
     ImGui_ImplSDL2_Data()   { memset((void*)this, 0, sizeof(*this)); }
 };
@@ -126,6 +138,11 @@ 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_InitPlatformInterface(SDL_Window* window, void* sdl_gl_context);
+static void ImGui_ImplSDL2_ShutdownPlatformInterface();
+
 // Functions
 static const char* ImGui_ImplSDL2_GetClipboardText(void*)
 {
@@ -142,13 +159,13 @@ static void ImGui_ImplSDL2_SetClipboardText(void*, 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_SetPlatformImeData(ImGuiViewport*, ImGuiPlatformImeData* data)
+static void ImGui_ImplSDL2_SetPlatformImeData(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);
@@ -264,20 +281,6 @@ static ImGuiKey ImGui_ImplSDL2_KeycodeToImGuiKey(int keycode)
         case SDLK_F10: return ImGuiKey_F10;
         case SDLK_F11: return ImGuiKey_F11;
         case SDLK_F12: return ImGuiKey_F12;
-        case SDLK_F13: return ImGuiKey_F13;
-        case SDLK_F14: return ImGuiKey_F14;
-        case SDLK_F15: return ImGuiKey_F15;
-        case SDLK_F16: return ImGuiKey_F16;
-        case SDLK_F17: return ImGuiKey_F17;
-        case SDLK_F18: return ImGuiKey_F18;
-        case SDLK_F19: return ImGuiKey_F19;
-        case SDLK_F20: return ImGuiKey_F20;
-        case SDLK_F21: return ImGuiKey_F21;
-        case SDLK_F22: return ImGuiKey_F22;
-        case SDLK_F23: return ImGuiKey_F23;
-        case SDLK_F24: return ImGuiKey_F24;
-        case SDLK_AC_BACK: return ImGuiKey_AppBack;
-        case SDLK_AC_FORWARD: return ImGuiKey_AppForward;
     }
     return ImGuiKey_None;
 }
@@ -306,6 +309,13 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
         case SDL_MOUSEMOTION:
         {
             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;
@@ -357,6 +367,15 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
             io.SetKeyEventNativeData(key, event->key.keysym.sym, event->key.keysym.scancode, 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:
         {
             // - 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.
@@ -374,15 +393,26 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
                 bd->PendingMouseLeaveFrame = ImGui::GetFrameCount() + 1;
             if (window_event == SDL_WINDOWEVENT_FOCUS_GAINED)
                 io.AddFocusEvent(true);
-            else if (event->window.event == SDL_WINDOWEVENT_FOCUS_LOST)
+            else if (window_event == SDL_WINDOWEVENT_FOCUS_LOST)
                 io.AddFocusEvent(false);
+            if (window_event == SDL_WINDOWEVENT_CLOSE || window_event == SDL_WINDOWEVENT_MOVED || window_event == SDL_WINDOWEVENT_RESIZED)
+                if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)SDL_GetWindowFromID(event->window.windowID)))
+                {
+                    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;
+                }
             return true;
         }
     }
     return false;
 }
 
-static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer)
+static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void* sdl_gl_context)
 {
     ImGuiIO& io = ImGui::GetIO();
     IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
@@ -402,12 +432,23 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer)
     ImGui_ImplSDL2_Data* bd = IM_NEW(ImGui_ImplSDL2_Data)();
     io.BackendPlatformUserData = (void*)bd;
     io.BackendPlatformName = "imgui_impl_sdl2";
-    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_HasMouseCursors;           // We can honor GetMouseCursor() values (optional)
+    io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;            // We can honor io.WantSetMousePos requests (optional, rarely used)
+    if (mouse_can_use_global_state)
+        io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;  // We can create multi-viewports on the Platform side (optional)
 
     bd->Window = 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.
     bd->MouseCanUseGlobalState = mouse_can_use_global_state;
+#ifndef __APPLE__
+    bd->MouseCanReportHoveredViewport = bd->MouseCanUseGlobalState;
+#else
+    bd->MouseCanReportHoveredViewport = false;
+#endif
+    bd->WantUpdateMonitors = true;
 
     io.SetClipboardTextFn = ImGui_ImplSDL2_SetClipboardText;
     io.GetClipboardTextFn = ImGui_ImplSDL2_GetClipboardText;
@@ -428,6 +469,7 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer)
     // Set platform dependent data in viewport
     // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->PlatformHandle = (void*)window;
     main_viewport->PlatformHandleRaw = nullptr;
     SDL_SysWMinfo info;
     SDL_VERSION(&info.version);
@@ -461,13 +503,17 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer)
     SDL_SetHint(SDL_HINT_MOUSE_AUTO_CAPTURE, "0");
 #endif
 
+    // We need SDL_CaptureMouse(), SDL_GetGlobalMouseState() from SDL 2.0.4+ to support multiple viewports.
+    // We left the call to ImGui_ImplSDL2_InitPlatformInterface() outside of #ifdef to avoid unused-function warnings.
+    if ((io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) && (io.BackendFlags & ImGuiBackendFlags_PlatformHasViewports))
+        ImGui_ImplSDL2_InitPlatformInterface(window, sdl_gl_context);
+
     return true;
 }
 
 bool ImGui_ImplSDL2_InitForOpenGL(SDL_Window* window, void* sdl_gl_context)
 {
-    IM_UNUSED(sdl_gl_context); // Viewport branch will need this.
-    return ImGui_ImplSDL2_Init(window, nullptr);
+    return ImGui_ImplSDL2_Init(window, nullptr, sdl_gl_context);
 }
 
 bool ImGui_ImplSDL2_InitForVulkan(SDL_Window* window)
@@ -475,7 +521,11 @@ bool ImGui_ImplSDL2_InitForVulkan(SDL_Window* window)
 #if !SDL_HAS_VULKAN
     IM_ASSERT(0 && "Unsupported");
 #endif
-    return ImGui_ImplSDL2_Init(window, 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)
@@ -483,22 +533,22 @@ bool ImGui_ImplSDL2_InitForD3D(SDL_Window* window)
 #if !defined(_WIN32)
     IM_ASSERT(0 && "Unsupported");
 #endif
-    return ImGui_ImplSDL2_Init(window, nullptr);
+    return ImGui_ImplSDL2_Init(window, nullptr, nullptr);
 }
 
 bool ImGui_ImplSDL2_InitForMetal(SDL_Window* window)
 {
-    return ImGui_ImplSDL2_Init(window, nullptr);
+    return ImGui_ImplSDL2_Init(window, nullptr, nullptr);
 }
 
 bool ImGui_ImplSDL2_InitForSDLRenderer(SDL_Window* window, SDL_Renderer* renderer)
 {
-    return ImGui_ImplSDL2_Init(window, renderer);
+    return ImGui_ImplSDL2_Init(window, renderer, nullptr);
 }
 
 bool ImGui_ImplSDL2_InitForOther(SDL_Window* window)
 {
-    return ImGui_ImplSDL2_Init(window, nullptr);
+    return ImGui_ImplSDL2_Init(window, nullptr, nullptr);
 }
 
 void ImGui_ImplSDL2_Shutdown()
@@ -507,6 +557,8 @@ void ImGui_ImplSDL2_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplSDL2_ShutdownPlatformInterface();
+
     if (bd->ClipboardTextData)
         SDL_free(bd->ClipboardTextData);
     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
@@ -515,10 +567,11 @@ 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);
     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();
@@ -529,25 +582,57 @@ static void ImGui_ImplSDL2_UpdateMouseData()
     // SDL_CaptureMouse() let the OS know e.g. that our imgui drag outside the SDL window boundaries shouldn't e.g. trigger other operations outside
     SDL_CaptureMouse((bd->MouseButtonsDown != 0) ? SDL_TRUE : SDL_FALSE);
     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::FindViewportByPlatformHandle((void*)focused_window)));
 #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 ImGuiConfigFlags_NavEnableSetMousePos 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)
         if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0)
         {
-            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));
+            // 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 mouse_x, mouse_y, 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 (SDL_Window* sdl_mouse_window = SDL_GetWindowFromID(bd->MouseWindowID))
+            if (ImGuiViewport* mouse_viewport = ImGui::FindViewportByPlatformHandle((void*)sdl_mouse_window))
+                mouse_viewport_id = mouse_viewport->ID;
+        io.AddMouseViewportEvent(mouse_viewport_id);
+    }
 }
 
 static void ImGui_ImplSDL2_UpdateMouseCursor()
@@ -622,6 +707,39 @@ static void ImGui_ImplSDL2_UpdateGamepads()
     #undef MAP_ANALOG
 }
 
+// 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
+        SDL_GetDisplayUsableBounds(n, &r);
+        monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+#endif
+#if SDL_HAS_PER_MONITOR_DPI
+        // FIXME-VIEWPORT: On MacOS SDL reports actual monitor DPI scale, ignoring OS configuration. We may want to set
+        //  DpiScale to cocoa_window.backingScaleFactor here.
+        float dpi = 0.0f;
+        if (!SDL_GetDisplayDPI(n, &dpi, nullptr, nullptr))
+            monitor.DpiScale = dpi / 96.0f;
+#endif
+        monitor.PlatformHandle = (void*)(intptr_t)n;
+        platform_io.Monitors.push_back(monitor);
+    }
+}
+
 void ImGui_ImplSDL2_NewFrame()
 {
     ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
@@ -642,6 +760,10 @@ void ImGui_ImplSDL2_NewFrame()
     if (w > 0 && h > 0)
         io.DisplayFramebufferScale = ImVec2((float)display_w / w, (float)display_h / h);
 
+    // Update monitors
+    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();
@@ -658,6 +780,13 @@ 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 rygorous, 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();
 
@@ -665,6 +794,253 @@ 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* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplSDL2_ViewportData
+{
+    SDL_Window*     Window;
+    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*)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)
+    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);
+    }
+
+    // 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 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_InitPlatformInterface(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_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 = vd->Window;
+}
+
+static void ImGui_ImplSDL2_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_sdl2.h

@@ -8,15 +8,15 @@
 //  [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 will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. 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:
+//  [ ] Platform: Multi-viewport + Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [x] Platform: Basic IME support. 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

backends/imgui_impl_sdl3.cpp

@@ -9,21 +9,19 @@
 //  [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 will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [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:
+//  [ ] Platform: Multi-viewport + Minimized windows seems to break mouse wheel events (at least under Windows).
 //  [x] Platform: Basic 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  2023-11-13: Updated for recent SDL3 API changes.
-//  2023-10-05: Inputs: Added support for extra ImGuiKey values: F13 to F24 function keys, app back/forward keys.
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2023-05-04: Fixed build on Emscripten/iOS/Android. (#6391)
 //  2023-04-06: Inputs: Avoid calling SDL_StartTextInput()/SDL_StopTextInput() as they don't only pertain to IME. It's unclear exactly what their relation is to IME. (#6306)
 //  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen. (#2702)
@@ -42,15 +40,10 @@
 
 // SDL
 #include <SDL3/SDL.h>
+#include <SDL3/SDL_syswm.h>
 #if defined(__APPLE__)
 #include <TargetConditionals.h>
 #endif
-#ifdef _WIN32
-#ifndef WIN32_LEAN_AND_MEAN
-#define WIN32_LEAN_AND_MEAN
-#endif
-#include <windows.h>
-#endif
 
 #if !defined(__EMSCRIPTEN__) && !defined(__ANDROID__) && !(defined(__APPLE__) && TARGET_OS_IOS) && !defined(__amigaos4__)
 #define SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE    1
@@ -71,6 +64,9 @@ struct ImGui_ImplSDL3_Data
     int             PendingMouseLeaveFrame;
     char*           ClipboardTextData;
     bool            MouseCanUseGlobalState;
+    bool            MouseCanReportHoveredViewport;  // This is hard to use/unreliable on SDL so we'll set ImGuiBackendFlags_HasMouseHoveredViewport dynamically based on state.
+    bool            UseVulkan;
+    bool            WantUpdateMonitors;
 
     ImGui_ImplSDL3_Data()   { memset((void*)this, 0, sizeof(*this)); }
 };
@@ -84,6 +80,11 @@ 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_InitPlatformInterface(SDL_Window* window, void* sdl_gl_context);
+static void ImGui_ImplSDL3_ShutdownPlatformInterface();
+
 // Functions
 static const char* ImGui_ImplSDL3_GetClipboardText(void*)
 {
@@ -99,13 +100,13 @@ static void ImGui_ImplSDL3_SetClipboardText(void*, const char* text)
     SDL_SetClipboardText(text);
 }
 
-static void ImGui_ImplSDL3_SetPlatformImeData(ImGuiViewport*, ImGuiPlatformImeData* data)
+static void ImGui_ImplSDL3_SetPlatformImeData(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);
@@ -221,20 +222,6 @@ static ImGuiKey ImGui_ImplSDL3_KeycodeToImGuiKey(int keycode)
         case SDLK_F10: return ImGuiKey_F10;
         case SDLK_F11: return ImGuiKey_F11;
         case SDLK_F12: return ImGuiKey_F12;
-        case SDLK_F13: return ImGuiKey_F13;
-        case SDLK_F14: return ImGuiKey_F14;
-        case SDLK_F15: return ImGuiKey_F15;
-        case SDLK_F16: return ImGuiKey_F16;
-        case SDLK_F17: return ImGuiKey_F17;
-        case SDLK_F18: return ImGuiKey_F18;
-        case SDLK_F19: return ImGuiKey_F19;
-        case SDLK_F20: return ImGuiKey_F20;
-        case SDLK_F21: return ImGuiKey_F21;
-        case SDLK_F22: return ImGuiKey_F22;
-        case SDLK_F23: return ImGuiKey_F23;
-        case SDLK_F24: return ImGuiKey_F24;
-        case SDLK_AC_BACK: return ImGuiKey_AppBack;
-        case SDLK_AC_FORWARD: return ImGuiKey_AppForward;
     }
     return ImGuiKey_None;
 }
@@ -263,6 +250,13 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
         case SDL_EVENT_MOUSE_MOTION:
         {
             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;
@@ -309,6 +303,15 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
             io.SetKeyEventNativeData(key, event->key.keysym.sym, event->key.keysym.scancode, event->key.keysym.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_CONNECTED:
+        case SDL_EVENT_DISPLAY_DISCONNECTED:
+        case SDL_EVENT_DISPLAY_MOVED:
+        case SDL_EVENT_DISPLAY_CONTENT_SCALE_CHANGED:
+        {
+            bd->WantUpdateMonitors = true;
+            return true;
+        }
         case SDL_EVENT_WINDOW_MOUSE_ENTER:
         {
             bd->MouseWindowID = event->window.windowID;
@@ -330,25 +333,28 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
         case SDL_EVENT_WINDOW_FOCUS_LOST:
             io.AddFocusEvent(false);
             return true;
+        case SDL_EVENT_WINDOW_CLOSE_REQUESTED:
+        case SDL_EVENT_WINDOW_MOVED:
+        case SDL_EVENT_WINDOW_RESIZED:
+            if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)SDL_GetWindowFromID(event->window.windowID)))
+            {
+                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;
+            }
+            return true;
     }
     return false;
 }
 
-static void ImGui_ImplSDL3_SetupPlatformHandles(ImGuiViewport* viewport, SDL_Window* window)
-{
-    viewport->PlatformHandleRaw = nullptr;
-#if defined(__WIN32__) && !defined(__WINRT__)
-    viewport->PlatformHandleRaw = (HWND)SDL_GetProperty(SDL_GetWindowProperties(window), "SDL.window.win32.hwnd", NULL);
-#elif defined(__APPLE__) && defined(SDL_VIDEO_DRIVER_COCOA)
-    viewport->PlatformHandleRaw = (void*)SDL_GetProperty(SDL_GetWindowProperties(window), "SDL.window.cocoa.window", NULL);
-#endif
-}
-
 static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void* sdl_gl_context)
 {
     ImGuiIO& io = ImGui::GetIO();
     IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
-    IM_UNUSED(sdl_gl_context); // Unused in this branch
 
     // Check and store if we are on a SDL backend that supports global mouse position
     // ("wayland" and "rpi" don't support it, but we chose to use a white-list instead of a black-list)
@@ -367,10 +373,21 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void
     io.BackendPlatformName = "imgui_impl_sdl3";
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;           // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;            // We can honor io.WantSetMousePos requests (optional, rarely used)
+    if (mouse_can_use_global_state)
+        io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;  // We can create multi-viewports on the Platform side (optional)
 
     bd->Window = 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.
     bd->MouseCanUseGlobalState = mouse_can_use_global_state;
+#ifndef __APPLE__
+    bd->MouseCanReportHoveredViewport = bd->MouseCanUseGlobalState;
+#else
+    bd->MouseCanReportHoveredViewport = false;
+#endif
+    bd->WantUpdateMonitors = true;
 
     io.SetClipboardTextFn = ImGui_ImplSDL3_SetClipboardText;
     io.GetClipboardTextFn = ImGui_ImplSDL3_GetClipboardText;
@@ -391,34 +408,51 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void
     // Set platform dependent data in viewport
     // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
-    ImGui_ImplSDL3_SetupPlatformHandles(main_viewport, window);
+    main_viewport->PlatformHandle = (void*)window;
+    main_viewport->PlatformHandleRaw = nullptr;
+    SDL_SysWMinfo info;
+    if (SDL_GetWindowWMInfo(window, &info, SDL_SYSWM_CURRENT_VERSION) == 0)
+    {
+#if defined(SDL_ENABLE_SYSWM_WINDOWS)
+        main_viewport->PlatformHandleRaw = (void*)info.info.win.window;
+#elif defined(__APPLE__) && defined(SDL_ENABLE_SYSWM_COCOA)
+        main_viewport->PlatformHandleRaw = (void*)info.info.cocoa.window;
+#endif
+    }
 
     // From 2.0.5: Set SDL hint to receive mouse click events on window focus, otherwise SDL doesn't emit the event.
     // 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
     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.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) && (io.BackendFlags & ImGuiBackendFlags_PlatformHasViewports))
+        ImGui_ImplSDL3_InitPlatformInterface(window, sdl_gl_context);
 
     return true;
 }
 
 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)
@@ -450,6 +484,8 @@ void ImGui_ImplSDL3_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplSDL3_ShutdownPlatformInterface();
+
     if (bd->ClipboardTextData)
         SDL_free(bd->ClipboardTextData);
     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
@@ -458,10 +494,11 @@ 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);
     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();
@@ -472,7 +509,7 @@ static void ImGui_ImplSDL3_UpdateMouseData()
     // SDL_CaptureMouse() let the OS know e.g. that our imgui drag outside the SDL window boundaries shouldn't e.g. trigger other operations outside
     SDL_CaptureMouse((bd->MouseButtonsDown != 0) ? SDL_TRUE : SDL_FALSE);
     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::FindViewportByPlatformHandle((void*)focused_window)));
 #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
@@ -481,19 +518,48 @@ static void ImGui_ImplSDL3_UpdateMouseData()
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos 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)
         if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0)
         {
             // 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((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 (SDL_Window* sdl_mouse_window = SDL_GetWindowFromID(bd->MouseWindowID))
+            if (ImGuiViewport* mouse_viewport = ImGui::FindViewportByPlatformHandle((void*)sdl_mouse_window))
+                mouse_viewport_id = mouse_viewport->ID;
+        io.AddMouseViewportEvent(mouse_viewport_id);
+    }
 }
 
 static void ImGui_ImplSDL3_UpdateMouseCursor()
@@ -542,10 +608,10 @@ static void ImGui_ImplSDL3_UpdateGamepads()
     const int thumb_dead_zone = 8000;           // SDL_gamecontroller.h suggests using this value.
     MAP_BUTTON(ImGuiKey_GamepadStart,           SDL_GAMEPAD_BUTTON_START);
     MAP_BUTTON(ImGuiKey_GamepadBack,            SDL_GAMEPAD_BUTTON_BACK);
-    MAP_BUTTON(ImGuiKey_GamepadFaceLeft,        SDL_GAMEPAD_BUTTON_WEST);           // Xbox X, PS Square
-    MAP_BUTTON(ImGuiKey_GamepadFaceRight,       SDL_GAMEPAD_BUTTON_EAST);           // Xbox B, PS Circle
-    MAP_BUTTON(ImGuiKey_GamepadFaceUp,          SDL_GAMEPAD_BUTTON_NORTH);          // Xbox Y, PS Triangle
-    MAP_BUTTON(ImGuiKey_GamepadFaceDown,        SDL_GAMEPAD_BUTTON_SOUTH);          // Xbox A, PS Cross
+    MAP_BUTTON(ImGuiKey_GamepadFaceLeft,        SDL_GAMEPAD_BUTTON_X);              // Xbox X, PS Square
+    MAP_BUTTON(ImGuiKey_GamepadFaceRight,       SDL_GAMEPAD_BUTTON_B);              // Xbox B, PS Circle
+    MAP_BUTTON(ImGuiKey_GamepadFaceUp,          SDL_GAMEPAD_BUTTON_Y);              // Xbox Y, PS Triangle
+    MAP_BUTTON(ImGuiKey_GamepadFaceDown,        SDL_GAMEPAD_BUTTON_A);              // Xbox A, PS Cross
     MAP_BUTTON(ImGuiKey_GamepadDpadLeft,        SDL_GAMEPAD_BUTTON_DPAD_LEFT);
     MAP_BUTTON(ImGuiKey_GamepadDpadRight,       SDL_GAMEPAD_BUTTON_DPAD_RIGHT);
     MAP_BUTTON(ImGuiKey_GamepadDpadUp,          SDL_GAMEPAD_BUTTON_DPAD_UP);
@@ -568,6 +634,35 @@ static void ImGui_ImplSDL3_UpdateGamepads()
     #undef MAP_ANALOG
 }
 
+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);
+        SDL_GetDisplayUsableBounds(display_id, &r);
+        monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+        // FIXME-VIEWPORT: On MacOS SDL reports actual monitor DPI scale, ignoring OS configuration. We may want to set
+        //  DpiScale to cocoa_window.backingScaleFactor here.
+        monitor.DpiScale = SDL_GetDisplayContentScale(display_id);
+        monitor.PlatformHandle = (void*)(intptr_t)n;
+        platform_io.Monitors.push_back(monitor);
+    }
+}
+
 void ImGui_ImplSDL3_NewFrame()
 {
     ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
@@ -585,6 +680,10 @@ void ImGui_ImplSDL3_NewFrame()
     if (w > 0 && h > 0)
         io.DisplayFramebufferScale = ImVec2((float)display_w / w, (float)display_h / h);
 
+    // Update monitors
+    if (bd->WantUpdateMonitors)
+        ImGui_ImplSDL3_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();
@@ -601,6 +700,13 @@ 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 rygorous, 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();
 
@@ -608,6 +714,242 @@ 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* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplSDL3_ViewportData
+{
+    SDL_Window*     Window;
+    Uint32          WindowID;
+    bool            WindowOwned;
+    SDL_GLContext   GLContext;
+
+    ImGui_ImplSDL3_ViewportData() { Window = nullptr; WindowID = 0; WindowOwned = false; GLContext = nullptr; }
+    ~ImGui_ImplSDL3_ViewportData() { IM_ASSERT(Window == nullptr && GLContext == 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;
+
+    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);
+    }
+
+    Uint32 sdl_flags = 0;
+    sdl_flags |= use_opengl ? SDL_WINDOW_OPENGL : (bd->UseVulkan ? SDL_WINDOW_VULKAN : 0);
+    sdl_flags |= SDL_GetWindowFlags(bd->Window);
+    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_ImplSDL3_ShowWindow().
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon) ? SDL_WINDOW_UTILITY : 0;
+#endif
+    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);
+    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);
+
+    viewport->PlatformHandle = (void*)vd->Window;
+    viewport->PlatformHandleRaw = nullptr;
+    SDL_SysWMinfo info;
+    if (SDL_GetWindowWMInfo(vd->Window, &info, SDL_SYSWM_CURRENT_VERSION))
+    {
+#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_ImplSDL3_DestroyWindow(ImGuiViewport* viewport)
+{
+    if (ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_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_ImplSDL3_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+#if defined(_WIN32)
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+
+    // SDL hack: Hide icon from task bar
+    // Note: SDL 3.0.0+ has a SDL_WINDOW_UTILITY 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);
+    }
+
+    // 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_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 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;
+    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
+}
+
+static void ImGui_ImplSDL3_InitPlatformInterface(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_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_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_gl_context;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = vd->Window;
+}
+
+static void ImGui_ImplSDL3_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_sdl3.h

@@ -9,16 +9,15 @@
 //  [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 will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [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:
+//  [ ] Platform: Multi-viewport + Minimized windows seems to break mouse wheel events (at least under Windows).
 //  [x] Platform: Basic 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

backends/imgui_impl_sdlrenderer2.cpp

@@ -10,14 +10,12 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+// 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 //  2023-05-30: Renamed imgui_impl_sdlrenderer.h/.cpp to imgui_impl_sdlrenderer2.h/.cpp to accommodate for upcoming SDL3.
@@ -181,12 +179,12 @@ void ImGui_ImplSDLRenderer2_RenderDrawData(ImDrawData* draw_data)
                 SDL_Rect r = { (int)(clip_min.x), (int)(clip_min.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y) };
                 SDL_RenderSetClipRect(bd->SDLRenderer, &r);
 
-                const float* xy = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, pos));
-                const float* uv = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, uv));
+                const float* xy = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, pos));
+                const float* uv = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, uv));
 #if SDL_VERSION_ATLEAST(2,0,19)
-                const SDL_Color* color = (const SDL_Color*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, col)); // SDL 2.0.19+
+                const SDL_Color* color = (const SDL_Color*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, col)); // SDL 2.0.19+
 #else
-                const int* color = (const int*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, col)); // SDL 2.0.17 and 2.0.18
+                const int* color = (const int*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, col)); // SDL 2.0.17 and 2.0.18
 #endif
 
                 // Bind texture, Draw

backends/imgui_impl_sdlrenderer2.h

@@ -10,14 +10,8 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
-
-// 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.
-// 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
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 #pragma once
 #ifndef IMGUI_DISABLE

backends/imgui_impl_sdlrenderer3.cpp

@@ -10,14 +10,12 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+// 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 //  2023-05-30: Initial version.
@@ -176,12 +174,12 @@ void ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_data)
                 SDL_Rect r = { (int)(clip_min.x), (int)(clip_min.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y) };
                 SDL_SetRenderClipRect(bd->SDLRenderer, &r);
 
-                const float* xy = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, pos));
-                const float* uv = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, uv));
+                const float* xy = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, pos));
+                const float* uv = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, uv));
 #if SDL_VERSION_ATLEAST(2,0,19)
-                const SDL_Color* color = (const SDL_Color*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, col)); // SDL 2.0.19+
+                const SDL_Color* color = (const SDL_Color*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, col)); // SDL 2.0.19+
 #else
-                const int* color = (const int*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, col)); // SDL 2.0.17 and 2.0.18
+                const int* color = (const int*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, col)); // SDL 2.0.17 and 2.0.18
 #endif
 
                 // Bind texture, Draw

backends/imgui_impl_sdlrenderer3.h

@@ -10,14 +10,8 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
-
-// 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.
-// 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
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

backends/imgui_impl_vulkan.cpp

@@ -2,8 +2,9 @@
 // This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
 
 // Implemented features:
-//  [!] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
+//  [x] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [x] Renderer: Multi-viewport / platform windows. With issues (flickering when creating a new viewport).
 
 // Important: on 32-bit systems, user texture binding is only supported if your imconfig file has '#define ImTextureID ImU64'.
 // This is because we need ImTextureID to carry a 64-bit value and by default ImTextureID is defined as void*.
@@ -13,16 +14,13 @@
 // - [Solution 3] IDE/msbuild: edit imconfig.h and add '#define ImTextureID ImU64' (prefer solution 2 to create your own config file!)
 // - [Solution 4] command-line: add '/D ImTextureID=ImU64' to your cl.exe command-line (this is what we do in our batch files)
 
-// 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/
-
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// 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/
 
 // Important note to the reader who wish to integrate imgui_impl_vulkan.cpp/.h in their own engine/app.
 // - Common ImGui_ImplVulkan_XXX functions and structures are used to interface with imgui_impl_vulkan.cpp/.h.
@@ -33,11 +31,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  2023-11-10: *BREAKING CHANGE*: Removed parameter from ImGui_ImplVulkan_CreateFontsTexture(): backend now creates its own command-buffer to upload fonts.
-//              *BREAKING CHANGE*: Removed ImGui_ImplVulkan_DestroyFontUploadObjects() which is now unecessary as we create and destroy those objects in the backend.
-//              ImGui_ImplVulkan_CreateFontsTexture() is automatically called by NewFrame() the first time.
-//              You can call ImGui_ImplVulkan_CreateFontsTexture() again to recreate the font atlas texture.
-//              Added ImGui_ImplVulkan_DestroyFontsTexture() but you probably never need to call this.
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2023-07-04: Vulkan: Added optional support for VK_KHR_dynamic_rendering. User needs to set init_info->UseDynamicRendering = true and init_info->ColorAttachmentFormat.
 //  2023-01-02: Vulkan: Fixed sampler passed to ImGui_ImplVulkan_AddTexture() not being honored + removed a bunch of duplicate code.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
@@ -105,6 +99,18 @@ struct ImGui_ImplVulkanH_WindowRenderBuffers
     ImGui_ImplVulkanH_FrameRenderBuffers*   FrameRenderBuffers;
 };
 
+// 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
+{
+    bool                                    WindowOwned;
+    ImGui_ImplVulkanH_Window                Window;             // Used by secondary viewports only
+    ImGui_ImplVulkanH_WindowRenderBuffers   RenderBuffers;      // Used by all viewports
+
+    ImGui_ImplVulkan_ViewportData()         { WindowOwned = false; memset(&RenderBuffers, 0, sizeof(RenderBuffers)); }
+    ~ImGui_ImplVulkan_ViewportData()        { }
+};
+
 // Vulkan data
 struct ImGui_ImplVulkan_Data
 {
@@ -125,8 +131,8 @@ struct ImGui_ImplVulkan_Data
     VkImage                     FontImage;
     VkImageView                 FontView;
     VkDescriptorSet             FontDescriptorSet;
-    VkCommandPool               FontCommandPool;
-    VkCommandBuffer             FontCommandBuffer;
+    VkDeviceMemory              UploadBufferMemory;
+    VkBuffer                    UploadBuffer;
 
     // Render buffers for main window
     ImGui_ImplVulkanH_WindowRenderBuffers MainWindowRenderBuffers;
@@ -145,6 +151,7 @@ void ImGui_ImplVulkanH_DestroyFrame(VkDevice device, ImGui_ImplVulkanH_Frame* fd
 void ImGui_ImplVulkanH_DestroyFrameSemaphores(VkDevice device, ImGui_ImplVulkanH_FrameSemaphores* fsd, const VkAllocationCallbacks* allocator);
 void ImGui_ImplVulkanH_DestroyFrameRenderBuffers(VkDevice device, ImGui_ImplVulkanH_FrameRenderBuffers* buffers, const VkAllocationCallbacks* allocator);
 void ImGui_ImplVulkanH_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVulkanH_WindowRenderBuffers* buffers, const VkAllocationCallbacks* allocator);
+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);
 void ImGui_ImplVulkanH_CreateWindowCommandBuffers(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, uint32_t queue_family, const VkAllocationCallbacks* allocator);
 
@@ -160,7 +167,6 @@ 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(vkBeginCommandBuffer) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkBindBufferMemory) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkBindImageMemory) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindDescriptorSets) \
@@ -203,7 +209,6 @@ static bool g_FunctionsLoaded = true;
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroySurfaceKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroySwapchainKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkDeviceWaitIdle) \
-    IMGUI_VULKAN_FUNC_MAP_MACRO(vkEndCommandBuffer) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkFlushMappedMemoryRanges) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkFreeCommandBuffers) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkFreeDescriptorSets) \
@@ -216,11 +221,19 @@ static bool g_FunctionsLoaded = true;
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfacePresentModesKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetSwapchainImagesKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkMapMemory) \
-    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueueSubmit) \
-    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueueWaitIdle) \
-    IMGUI_VULKAN_FUNC_MAP_MACRO(vkResetCommandPool) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkUnmapMemory) \
-    IMGUI_VULKAN_FUNC_MAP_MACRO(vkUpdateDescriptorSets)
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkUpdateDescriptorSets) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceSupportKHR) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkWaitForFences) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBeginRenderPass) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdEndRenderPass) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueuePresentKHR) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkBeginCommandBuffer) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkEndCommandBuffer) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkResetFences) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueueSubmit) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkResetCommandPool) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkAcquireNextImageKHR)
 
 // Define function pointers
 #define IMGUI_VULKAN_FUNC_DEF(func) static PFN_##func func;
@@ -238,6 +251,10 @@ static PFN_vkCmdEndRenderingKHR     ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR;
 // SHADERS
 //-----------------------------------------------------------------------------
 
+// Forward Declarations
+static void ImGui_ImplVulkan_InitPlatformInterface();
+static void ImGui_ImplVulkan_ShutdownPlatformInterface();
+
 // glsl_shader.vert, compiled with:
 // # glslangValidator -V -x -o glsl_shader.vert.u32 glsl_shader.vert
 /*
@@ -469,8 +486,10 @@ 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_ImplVulkanH_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_ImplVulkanH_WindowRenderBuffers* wrb = &viewport_renderer_data->RenderBuffers;
     if (wrb->FrameRenderBuffers == nullptr)
     {
         wrb->Index = 0;
@@ -597,55 +616,19 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
     vkCmdSetScissor(command_buffer, 0, 1, &scissor);
 }
 
-bool ImGui_ImplVulkan_CreateFontsTexture()
+bool ImGui_ImplVulkan_CreateFontsTexture(VkCommandBuffer command_buffer)
 {
     ImGuiIO& io = ImGui::GetIO();
     ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
     ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
-    VkResult err;
-
-    // Destroy existing texture (if any)
-    if (bd->FontView || bd->FontImage || bd->FontMemory || bd->FontDescriptorSet)
-    {
-        vkQueueWaitIdle(v->Queue);
-        ImGui_ImplVulkan_DestroyFontsTexture();
-    }
-
-    // Create command pool/buffer
-    if (bd->FontCommandPool == VK_NULL_HANDLE)
-    {
-        VkCommandPoolCreateInfo info = {};
-        info.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
-        info.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT;
-        info.queueFamilyIndex = v->QueueFamily;
-        vkCreateCommandPool(v->Device, &info, nullptr, &bd->FontCommandPool);
-    }
-    if (bd->FontCommandBuffer == VK_NULL_HANDLE)
-    {
-        VkCommandBufferAllocateInfo info = {};
-        info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
-        info.commandPool = bd->FontCommandPool;
-        info.commandBufferCount = 1;
-        err = vkAllocateCommandBuffers(v->Device, &info, &bd->FontCommandBuffer);
-        check_vk_result(err);
-    }
-
-    // Start command buffer
-    {
-        err = vkResetCommandPool(v->Device, bd->FontCommandPool, 0);
-        check_vk_result(err);
-        VkCommandBufferBeginInfo begin_info = {};
-        begin_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
-        begin_info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
-        err = vkBeginCommandBuffer(bd->FontCommandBuffer, &begin_info);
-        check_vk_result(err);
-    }
 
     unsigned char* pixels;
     int width, height;
     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
     size_t upload_size = width * height * 4 * sizeof(char);
 
+    VkResult err;
+
     // Create the Image:
     {
         VkImageCreateInfo info = {};
@@ -694,42 +677,40 @@ bool ImGui_ImplVulkan_CreateFontsTexture()
     bd->FontDescriptorSet = (VkDescriptorSet)ImGui_ImplVulkan_AddTexture(bd->FontSampler, bd->FontView, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);
 
     // Create the Upload Buffer:
-    VkDeviceMemory upload_buffer_memory;
-    VkBuffer upload_buffer;
     {
         VkBufferCreateInfo buffer_info = {};
         buffer_info.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
         buffer_info.size = upload_size;
         buffer_info.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
         buffer_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
-        err = vkCreateBuffer(v->Device, &buffer_info, v->Allocator, &upload_buffer);
+        err = vkCreateBuffer(v->Device, &buffer_info, v->Allocator, &bd->UploadBuffer);
         check_vk_result(err);
         VkMemoryRequirements req;
-        vkGetBufferMemoryRequirements(v->Device, upload_buffer, &req);
+        vkGetBufferMemoryRequirements(v->Device, bd->UploadBuffer, &req);
         bd->BufferMemoryAlignment = (bd->BufferMemoryAlignment > req.alignment) ? bd->BufferMemoryAlignment : req.alignment;
         VkMemoryAllocateInfo alloc_info = {};
         alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
         alloc_info.allocationSize = req.size;
         alloc_info.memoryTypeIndex = ImGui_ImplVulkan_MemoryType(VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT, req.memoryTypeBits);
-        err = vkAllocateMemory(v->Device, &alloc_info, v->Allocator, &upload_buffer_memory);
+        err = vkAllocateMemory(v->Device, &alloc_info, v->Allocator, &bd->UploadBufferMemory);
         check_vk_result(err);
-        err = vkBindBufferMemory(v->Device, upload_buffer, upload_buffer_memory, 0);
+        err = vkBindBufferMemory(v->Device, bd->UploadBuffer, bd->UploadBufferMemory, 0);
         check_vk_result(err);
     }
 
     // Upload to Buffer:
     {
         char* map = nullptr;
-        err = vkMapMemory(v->Device, upload_buffer_memory, 0, upload_size, 0, (void**)(&map));
+        err = vkMapMemory(v->Device, bd->UploadBufferMemory, 0, upload_size, 0, (void**)(&map));
         check_vk_result(err);
         memcpy(map, pixels, upload_size);
         VkMappedMemoryRange range[1] = {};
         range[0].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
-        range[0].memory = upload_buffer_memory;
+        range[0].memory = bd->UploadBufferMemory;
         range[0].size = upload_size;
         err = vkFlushMappedMemoryRanges(v->Device, 1, range);
         check_vk_result(err);
-        vkUnmapMemory(v->Device, upload_buffer_memory);
+        vkUnmapMemory(v->Device, bd->UploadBufferMemory);
     }
 
     // Copy to Image:
@@ -745,7 +726,7 @@ bool ImGui_ImplVulkan_CreateFontsTexture()
         copy_barrier[0].subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
         copy_barrier[0].subresourceRange.levelCount = 1;
         copy_barrier[0].subresourceRange.layerCount = 1;
-        vkCmdPipelineBarrier(bd->FontCommandBuffer, VK_PIPELINE_STAGE_HOST_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT, 0, 0, nullptr, 0, nullptr, 1, copy_barrier);
+        vkCmdPipelineBarrier(command_buffer, VK_PIPELINE_STAGE_HOST_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT, 0, 0, nullptr, 0, nullptr, 1, copy_barrier);
 
         VkBufferImageCopy region = {};
         region.imageSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
@@ -753,7 +734,7 @@ bool ImGui_ImplVulkan_CreateFontsTexture()
         region.imageExtent.width = width;
         region.imageExtent.height = height;
         region.imageExtent.depth = 1;
-        vkCmdCopyBufferToImage(bd->FontCommandBuffer, upload_buffer, bd->FontImage, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1, &region);
+        vkCmdCopyBufferToImage(command_buffer, bd->UploadBuffer, bd->FontImage, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1, &region);
 
         VkImageMemoryBarrier use_barrier[1] = {};
         use_barrier[0].sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
@@ -767,50 +748,15 @@ bool ImGui_ImplVulkan_CreateFontsTexture()
         use_barrier[0].subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
         use_barrier[0].subresourceRange.levelCount = 1;
         use_barrier[0].subresourceRange.layerCount = 1;
-        vkCmdPipelineBarrier(bd->FontCommandBuffer, VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, 0, 0, nullptr, 0, nullptr, 1, use_barrier);
+        vkCmdPipelineBarrier(command_buffer, VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, 0, 0, nullptr, 0, nullptr, 1, use_barrier);
     }
 
     // Store our identifier
     io.Fonts->SetTexID((ImTextureID)bd->FontDescriptorSet);
 
-    // End command buffer
-    VkSubmitInfo end_info = {};
-    end_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
-    end_info.commandBufferCount = 1;
-    end_info.pCommandBuffers = &bd->FontCommandBuffer;
-    err = vkEndCommandBuffer(bd->FontCommandBuffer);
-    check_vk_result(err);
-    err = vkQueueSubmit(v->Queue, 1, &end_info, VK_NULL_HANDLE);
-    check_vk_result(err);
-
-    err = vkDeviceWaitIdle(v->Device);
-    check_vk_result(err);
-
-    vkDestroyBuffer(v->Device, upload_buffer, v->Allocator);
-    vkFreeMemory(v->Device, upload_buffer_memory, v->Allocator);
-
     return true;
 }
 
-// You probably never need to call this, as it is called by ImGui_ImplVulkan_CreateFontsTexture() and ImGui_ImplVulkan_Shutdown().
-void ImGui_ImplVulkan_DestroyFontsTexture()
-{
-    ImGuiIO& io = ImGui::GetIO();
-    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
-    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
-
-    if (bd->FontDescriptorSet)
-    {
-        ImGui_ImplVulkan_RemoveTexture(bd->FontDescriptorSet);
-        bd->FontDescriptorSet = VK_NULL_HANDLE;
-        io.Fonts->SetTexID(0);
-    }
-
-    if (bd->FontView)   { vkDestroyImageView(v->Device, bd->FontView, v->Allocator); bd->FontView = VK_NULL_HANDLE; }
-    if (bd->FontImage)  { vkDestroyImage(v->Device, bd->FontImage, v->Allocator); bd->FontImage = VK_NULL_HANDLE; }
-    if (bd->FontMemory) { vkFreeMemory(v->Device, bd->FontMemory, v->Allocator); bd->FontMemory = VK_NULL_HANDLE; }
-}
-
 static void ImGui_ImplVulkan_CreateShaderModules(VkDevice device, const VkAllocationCallbacks* allocator)
 {
     // Create the shader modules
@@ -858,15 +804,15 @@ static void ImGui_ImplVulkan_CreatePipeline(VkDevice device, const VkAllocationC
     attribute_desc[0].location = 0;
     attribute_desc[0].binding = binding_desc[0].binding;
     attribute_desc[0].format = VK_FORMAT_R32G32_SFLOAT;
-    attribute_desc[0].offset = offsetof(ImDrawVert, pos);
+    attribute_desc[0].offset = IM_OFFSETOF(ImDrawVert, pos);
     attribute_desc[1].location = 1;
     attribute_desc[1].binding = binding_desc[0].binding;
     attribute_desc[1].format = VK_FORMAT_R32G32_SFLOAT;
-    attribute_desc[1].offset = offsetof(ImDrawVert, uv);
+    attribute_desc[1].offset = IM_OFFSETOF(ImDrawVert, uv);
     attribute_desc[2].location = 2;
     attribute_desc[2].binding = binding_desc[0].binding;
     attribute_desc[2].format = VK_FORMAT_R8G8B8A8_UNORM;
-    attribute_desc[2].offset = offsetof(ImDrawVert, col);
+    attribute_desc[2].offset = IM_OFFSETOF(ImDrawVert, col);
 
     VkPipelineVertexInputStateCreateInfo vertex_info = {};
     vertex_info.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
@@ -1013,16 +959,34 @@ bool ImGui_ImplVulkan_CreateDeviceObjects()
     return true;
 }
 
+void    ImGui_ImplVulkan_DestroyFontUploadObjects()
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+    if (bd->UploadBuffer)
+    {
+        vkDestroyBuffer(v->Device, bd->UploadBuffer, v->Allocator);
+        bd->UploadBuffer = VK_NULL_HANDLE;
+    }
+    if (bd->UploadBufferMemory)
+    {
+        vkFreeMemory(v->Device, bd->UploadBufferMemory, v->Allocator);
+        bd->UploadBufferMemory = VK_NULL_HANDLE;
+    }
+}
+
 void    ImGui_ImplVulkan_DestroyDeviceObjects()
 {
     ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
     ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
-    ImGui_ImplVulkanH_DestroyWindowRenderBuffers(v->Device, &bd->MainWindowRenderBuffers, v->Allocator);
-    ImGui_ImplVulkan_DestroyFontsTexture();
+    ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(v->Device, v->Allocator);
+    ImGui_ImplVulkan_DestroyFontUploadObjects();
 
-    if (bd->FontCommandPool)      { vkDestroyCommandPool(v->Device, bd->FontCommandPool, v->Allocator); bd->FontCommandPool = 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->FontView)             { vkDestroyImageView(v->Device, bd->FontView, v->Allocator); bd->FontView = VK_NULL_HANDLE; }
+    if (bd->FontImage)            { vkDestroyImage(v->Device, bd->FontImage, v->Allocator); bd->FontImage = VK_NULL_HANDLE; }
+    if (bd->FontMemory)           { vkFreeMemory(v->Device, bd->FontMemory, v->Allocator); bd->FontMemory = VK_NULL_HANDLE; }
     if (bd->FontSampler)          { vkDestroySampler(v->Device, bd->FontSampler, v->Allocator); bd->FontSampler = 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; }
@@ -1083,6 +1047,7 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass rend
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_vulkan";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     IM_ASSERT(info->Instance != VK_NULL_HANDLE);
     IM_ASSERT(info->PhysicalDevice != VK_NULL_HANDLE);
@@ -1100,6 +1065,13 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass rend
 
     ImGui_ImplVulkan_CreateDeviceObjects();
 
+    // 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)();
+
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplVulkan_InitPlatformInterface();
+
     return true;
 }
 
@@ -1109,10 +1081,21 @@ void ImGui_ImplVulkan_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    // First destroy objects in all viewports
     ImGui_ImplVulkan_DestroyDeviceObjects();
+
+    // 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_ShutdownPlatformInterface();
+
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -1120,9 +1103,7 @@ void ImGui_ImplVulkan_NewFrame()
 {
     ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
     IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplVulkan_Init()?");
-
-    if (!bd->FontDescriptorSet)
-        ImGui_ImplVulkan_CreateFontsTexture();
+    IM_UNUSED(bd);
 }
 
 void ImGui_ImplVulkan_SetMinImageCount(uint32_t min_image_count)
@@ -1132,10 +1113,12 @@ 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_ImplVulkanH_DestroyWindowRenderBuffers(v->Device, &bd->MainWindowRenderBuffers, v->Allocator);
+    ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(v->Device, v->Allocator);
+
     bd->VulkanInitInfo.MinImageCount = min_image_count;
 }
 
@@ -1501,6 +1484,7 @@ void ImGui_ImplVulkanH_CreateOrResizeWindow(VkInstance instance, VkPhysicalDevic
     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_ImplVulkan_CreatePipeline(device, allocator, VK_NULL_HANDLE, wd->RenderPass, VK_SAMPLE_COUNT_1_BIT, &wd->Pipeline, g_VulkanInitInfo.Subpass);
     ImGui_ImplVulkanH_CreateWindowCommandBuffers(physical_device, device, wd, queue_family, allocator);
 }
 
@@ -1566,6 +1550,264 @@ void ImGui_ImplVulkanH_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVul
     buffers->Count = 0;
 }
 
+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_ImplVulkanH_DestroyWindowRenderBuffers(device, &vd->RenderBuffers, allocator);
+}
+
+//--------------------------------------------------------------------------------------------------------
+// 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
+    const VkFormat requestSurfaceImageFormat[] = { VK_FORMAT_B8G8R8A8_UNORM, VK_FORMAT_R8G8B8A8_UNORM, VK_FORMAT_B8G8R8_UNORM, VK_FORMAT_R8G8B8_UNORM };
+    const VkColorSpaceKHR requestSurfaceColorSpace = VK_COLORSPACE_SRGB_NONLINEAR_KHR;
+    wd->SurfaceFormat = ImGui_ImplVulkanH_SelectSurfaceFormat(v->PhysicalDevice, wd->Surface, requestSurfaceImageFormat, (size_t)IM_ARRAYSIZE(requestSurfaceImageFormat), 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);
+    vd->WindowOwned = true;
+}
+
+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_ImplVulkanH_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);
+}
+
+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;
+
+    ImGui_ImplVulkanH_Frame* fd = &wd->Frames[wd->FrameIndex];
+    ImGui_ImplVulkanH_FrameSemaphores* fsd = &wd->FrameSemaphores[wd->SemaphoreIndex];
+    {
+        {
+          err = vkAcquireNextImageKHR(v->Device, wd->Swapchain, UINT64_MAX, fsd->ImageAcquiredSemaphore, VK_NULL_HANDLE, &wd->FrameIndex);
+          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_UNDEFINED;
+            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_TOP_OF_PIPE_BIT, 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, wd->Pipeline);
+
+    {
+#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;
+
+    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 || err == VK_SUBOPTIMAL_KHR)
+        ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, &vd->Window, v->QueueFamily, v->Allocator, (int)viewport->Size.x, (int)viewport->Size.y, v->MinImageCount);
+    else
+        check_vk_result(err);
+
+    wd->FrameIndex = (wd->FrameIndex + 1) % wd->ImageCount;         // This is for the next vkWaitForFences()
+    wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->ImageCount; // Now we can use the next set of semaphores
+}
+
+void ImGui_ImplVulkan_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        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_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_vulkan.h

@@ -2,22 +2,20 @@
 // This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
 
 // Implemented features:
-//  [!] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
+//  [x] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [x] Renderer: Multi-viewport / platform windows. With issues (flickering when creating a new viewport).
 
 // Important: on 32-bit systems, user texture binding is only supported if your imconfig file has '#define ImTextureID ImU64'.
 // See imgui_impl_vulkan.cpp file for details.
 
-// 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/
-
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// 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/
 
 // Important note to the reader who wish to integrate imgui_impl_vulkan.cpp/.h in their own engine/app.
 // - Common ImGui_ImplVulkan_XXX functions and structures are used to interface with imgui_impl_vulkan.cpp/.h.
@@ -78,8 +76,8 @@ IMGUI_IMPL_API bool         ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* inf
 IMGUI_IMPL_API void         ImGui_ImplVulkan_Shutdown();
 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 bool         ImGui_ImplVulkan_CreateFontsTexture();
-IMGUI_IMPL_API void         ImGui_ImplVulkan_DestroyFontsTexture();
+IMGUI_IMPL_API bool         ImGui_ImplVulkan_CreateFontsTexture(VkCommandBuffer command_buffer);
+IMGUI_IMPL_API void         ImGui_ImplVulkan_DestroyFontUploadObjects();
 IMGUI_IMPL_API void         ImGui_ImplVulkan_SetMinImageCount(uint32_t min_image_count); // To override MinImageCount after initialization (e.g. if swap chain is recreated)
 
 // Register a texture (VkDescriptorSet == ImTextureID)

backends/imgui_impl_wgpu.cpp

@@ -5,14 +5,13 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'WGPUTextureView' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows). Not meaningful on the web.
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
@@ -601,9 +600,9 @@ bool ImGui_ImplWGPU_CreateDeviceObjects()
     // Vertex input configuration
     WGPUVertexAttribute attribute_desc[] =
     {
-        { WGPUVertexFormat_Float32x2, (uint64_t)offsetof(ImDrawVert, pos), 0 },
-        { WGPUVertexFormat_Float32x2, (uint64_t)offsetof(ImDrawVert, uv),  1 },
-        { WGPUVertexFormat_Unorm8x4,  (uint64_t)offsetof(ImDrawVert, col), 2 },
+        { WGPUVertexFormat_Float32x2, (uint64_t)IM_OFFSETOF(ImDrawVert, pos), 0 },
+        { WGPUVertexFormat_Float32x2, (uint64_t)IM_OFFSETOF(ImDrawVert, uv),  1 },
+        { WGPUVertexFormat_Unorm8x4,  (uint64_t)IM_OFFSETOF(ImDrawVert, col), 2 },
     };
 
     WGPUVertexBufferLayout buffer_layouts[1];

backends/imgui_impl_wgpu.h

@@ -5,14 +5,13 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'WGPUTextureView' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows). Not meaningful on the web.
 
 // 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"          // IMGUI_IMPL_API

backends/imgui_impl_win32.cpp

@@ -7,14 +7,12 @@
 //  [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 VK_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #ifndef IMGUI_DISABLE
@@ -39,9 +37,7 @@ typedef DWORD (WINAPI *PFN_XInputGetState)(DWORD, XINPUT_STATE*);
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  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).
-//  2023-09-07: Inputs: Added support for keyboard codepage conversion for when application is compiled in MBCS mode and using a non-Unicode window.
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2023-04-19: Added ImGui_ImplWin32_InitForOpenGL() to facilitate combining raw Win32/Winapi with OpenGL. (#3218)
 //  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen/ImGuiMouseSource_Pen. (#2702)
 //  2023-02-15: Inputs: Use WM_NCMOUSEMOVE / WM_NCMOUSELEAVE to track mouse position over non-client area (e.g. OS decorations) when app is not focused. (#6045, #6162)
@@ -91,6 +87,11 @@ typedef DWORD (WINAPI *PFN_XInputGetState)(DWORD, XINPUT_STATE*);
 //  2017-10-23: Inputs: Using Win32 ::SetCapture/::GetCapture() to retrieve mouse positions outside the client area when dragging.
 //  2016-11-12: Inputs: Only call Win32 ::SetCursor(nullptr) when io.MouseDrawCursor is set.
 
+// Forward Declarations
+static void ImGui_ImplWin32_InitPlatformInterface(bool platformHasOwnDC);
+static void ImGui_ImplWin32_ShutdownPlatformInterface();
+static void ImGui_ImplWin32_UpdateMonitors();
+
 struct ImGui_ImplWin32_Data
 {
     HWND                        hWnd;
@@ -100,7 +101,7 @@ struct ImGui_ImplWin32_Data
     INT64                       Time;
     INT64                       TicksPerSecond;
     ImGuiMouseCursor            LastMouseCursor;
-    UINT32                      KeyboardCodePage;
+    bool                        WantUpdateMonitors;
 
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
     bool                        HasGamepad;
@@ -123,16 +124,6 @@ static ImGui_ImplWin32_Data* ImGui_ImplWin32_GetBackendData()
 }
 
 // Functions
-static void ImGui_ImplWin32_UpdateKeyboardCodePage()
-{
-    // Retrieve keyboard code page, required for handling of non-Unicode Windows.
-    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
-    HKL keyboard_layout = ::GetKeyboardLayout(0);
-    LCID keyboard_lcid = MAKELCID(HIWORD(keyboard_layout), SORT_DEFAULT);
-    if (::GetLocaleInfoA(keyboard_lcid, (LOCALE_RETURN_NUMBER | LOCALE_IDEFAULTANSICODEPAGE), (LPSTR)&bd->KeyboardCodePage, sizeof(bd->KeyboardCodePage)) == 0)
-        bd->KeyboardCodePage = CP_ACP; // Fallback to default ANSI code page when fails.
-}
-
 static bool ImGui_ImplWin32_InitEx(void* hwnd, bool platform_has_own_dc)
 {
     ImGuiIO& io = ImGui::GetIO();
@@ -150,16 +141,20 @@ 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)
 
     bd->hWnd = (HWND)hwnd;
+    bd->WantUpdateMonitors = true;
     bd->TicksPerSecond = perf_frequency;
     bd->Time = perf_counter;
     bd->LastMouseCursor = ImGuiMouseCursor_COUNT;
-    ImGui_ImplWin32_UpdateKeyboardCodePage();
 
-    // Set platform dependent data in viewport
-    ImGui::GetMainViewport()->PlatformHandleRaw = (void*)hwnd;
-    IM_UNUSED(platform_has_own_dc); // Used in 'docking' branch
+    // 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;
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplWin32_InitPlatformInterface(platform_has_own_dc);
 
     // Dynamically load XInput library
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
@@ -202,6 +197,8 @@ void    ImGui_ImplWin32_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplWin32_ShutdownPlatformInterface();
+
     // Unload XInput library
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
     if (bd->XInputDLL)
@@ -210,7 +207,7 @@ 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);
     IM_DELETE(bd);
 }
 
@@ -284,33 +281,59 @@ static void ImGui_ImplWin32_UpdateKeyModifiers()
     io.AddKeyEvent(ImGuiMod_Super, IsVkDown(VK_APPS));
 }
 
+// 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()
 {
     ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
     ImGuiIO& io = ImGui::GetIO();
     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::FindViewportByPlatformHandle((void*)focused_window)));
     if (is_app_focused)
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos 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::FindViewportByPlatformHandle((void*)hovered_hwnd))
+                mouse_viewport_id = viewport->ID;
+    io.AddMouseViewportEvent(mouse_viewport_id);
 }
 
 // Gamepad navigation mapping
@@ -370,6 +393,35 @@ static void ImGui_ImplWin32_UpdateGamepads()
 #endif // #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
 }
 
+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;
+    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()
 {
     ImGuiIO& io = ImGui::GetIO();
@@ -380,6 +432,8 @@ void    ImGui_ImplWin32_NewFrame()
     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;
@@ -517,20 +571,6 @@ static ImGuiKey ImGui_ImplWin32_VirtualKeyToImGuiKey(WPARAM wParam)
         case VK_F10: return ImGuiKey_F10;
         case VK_F11: return ImGuiKey_F11;
         case VK_F12: return ImGuiKey_F12;
-        case VK_F13: return ImGuiKey_F13;
-        case VK_F14: return ImGuiKey_F14;
-        case VK_F15: return ImGuiKey_F15;
-        case VK_F16: return ImGuiKey_F16;
-        case VK_F17: return ImGuiKey_F17;
-        case VK_F18: return ImGuiKey_F18;
-        case VK_F19: return ImGuiKey_F19;
-        case VK_F20: return ImGuiKey_F20;
-        case VK_F21: return ImGuiKey_F21;
-        case VK_F22: return ImGuiKey_F22;
-        case VK_F23: return ImGuiKey_F23;
-        case VK_F24: return ImGuiKey_F24;
-        case VK_BROWSER_BACK: return ImGuiKey_AppBack;
-        case VK_BROWSER_FORWARD: return ImGuiKey_AppForward;
         default: return ImGuiKey_None;
     }
 }
@@ -595,8 +635,11 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
             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.
-            break;
+        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);
         break;
@@ -672,14 +715,10 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
             int vk = (int)wParam;
             if ((wParam == VK_RETURN) && (HIWORD(lParam) & KF_EXTENDED))
                 vk = IM_VK_KEYPAD_ENTER;
-            const ImGuiKey key = ImGui_ImplWin32_VirtualKeyToImGuiKey(vk);
-            const int scancode = (int)LOBYTE(HIWORD(lParam));
-
-            // Special behavior for VK_SNAPSHOT / ImGuiKey_PrintScreen as Windows doesn't emit the key down event.
-            if (key == ImGuiKey_PrintScreen && !is_key_down)
-                ImGui_ImplWin32_AddKeyEvent(key, true, vk, scancode);
 
             // Submit key event
+            const ImGuiKey key = ImGui_ImplWin32_VirtualKeyToImGuiKey(vk);
+            const int scancode = (int)LOBYTE(HIWORD(lParam));
             if (key != ImGuiKey_None)
                 ImGui_ImplWin32_AddKeyEvent(key, is_key_down, vk, scancode);
 
@@ -707,9 +746,6 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
     case WM_KILLFOCUS:
         io.AddFocusEvent(msg == WM_SETFOCUS);
         return 0;
-    case WM_INPUTLANGCHANGE:
-        ImGui_ImplWin32_UpdateKeyboardCodePage();
-        return 0;
     case WM_CHAR:
         if (::IsWindowUnicode(hwnd))
         {
@@ -720,7 +756,7 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
         else
         {
             wchar_t wch = 0;
-            ::MultiByteToWideChar(bd->KeyboardCodePage, MB_PRECOMPOSED, (char*)&wParam, 1, &wch, 1);
+            ::MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, (char*)&wParam, 1, &wch, 1);
             io.AddInputCharacter(wch);
         }
         return 0;
@@ -735,6 +771,9 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
             bd->WantUpdateHasGamepad = true;
 #endif
         return 0;
+    case WM_DISPLAYCHANGE:
+        bd->WantUpdateMonitors = true;
+        return 0;
     }
     return 0;
 }
@@ -799,6 +838,10 @@ 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
@@ -898,6 +941,348 @@ 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* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplWin32_ViewportData
+{
+    HWND    Hwnd;
+    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_GetHwndFromViewportID(ImGuiID viewport_id)
+{
+    if (viewport_id != 0)
+        if (ImGuiViewport* viewport = ImGui::FindViewportByID(viewport_id))
+            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_GetHwndFromViewportID(viewport->ParentViewportId);
+
+    // 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 = ::CreateWindowEx(
+        vd->DwExStyle, _T("ImGui Platform"), _T("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;
+}
+
+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);
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+        ::ShowWindow(vd->Hwnd, SW_SHOWNA);
+    else
+        ::ShowWindow(vd->Hwnd, SW_SHOW);
+}
+
+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_GetHwndFromViewportID(viewport->ParentViewportId);
+    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_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 };
+    ::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 };
+    ::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);
+    ::SetWindowTextW(vd->Hwnd, 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 style = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE) | WS_EX_LAYERED;
+        ::SetWindowLongW(vd->Hwnd, GWL_EXSTYLE, style);
+        ::SetLayeredWindowAttributes(vd->Hwnd, 0, (BYTE)(255 * alpha), LWA_ALPHA);
+    }
+    else
+    {
+        DWORD style = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE) & ~WS_EX_LAYERED;
+        ::SetWindowLongW(vd->Hwnd, GWL_EXSTYLE, 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
+}
+
+static LRESULT CALLBACK ImGui_ImplWin32_WndProcHandler_PlatformWindow(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
+        return true;
+
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)hWnd))
+    {
+        switch (msg)
+        {
+        case WM_CLOSE:
+            viewport->PlatformRequestClose = true;
+            return 0;
+        case WM_MOVE:
+            viewport->PlatformRequestMove = true;
+            break;
+        case WM_SIZE:
+            viewport->PlatformRequestResize = true;
+            break;
+        case WM_MOUSEACTIVATE:
+            if (viewport->Flags & ImGuiViewportFlags_NoFocusOnClick)
+                return 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)
+                return HTTRANSPARENT;
+            break;
+        }
+    }
+
+    return DefWindowProc(hWnd, msg, wParam, lParam);
+}
+
+static void ImGui_ImplWin32_InitPlatformInterface(bool platform_has_own_dc)
+{
+    WNDCLASSEX wcex;
+    wcex.cbSize = sizeof(WNDCLASSEX);
+    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 = _T("ImGui Platform");
+    wcex.hIconSm = nullptr;
+    ::RegisterClassEx(&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;
+    main_viewport->PlatformHandle = (void*)bd->hWnd;
+}
+
+static void ImGui_ImplWin32_ShutdownPlatformInterface()
+{
+    ::UnregisterClass(_T("ImGui Platform"), ::GetModuleHandle(nullptr));
+    ImGui::DestroyPlatformWindows();
+}
+
 //---------------------------------------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_win32.h

@@ -7,14 +7,12 @@
 //  [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 VK_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. 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.
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #pragma once
 #include "imgui.h"      // IMGUI_IMPL_API

docs/CHANGELOG.txt

@@ -37,218 +37,9 @@ HOW TO UPDATE?
 
 
 -----------------------------------------------------------------------
- VERSION 1.90.0 (Released 2023-11-15)
+ VERSION 1.89.9 WIP (In Progress)
 -----------------------------------------------------------------------
 
-Breaking changes:
-
- - BeginChild(): Upgraded 'bool border = false' parameter to 'ImGuiChildFlags flags = 0'.
-   Added ImGuiChildFlags_Border value. As with our prior "bool-to-flags" API updates,
-   the ImGuiChildFlags_Border value is guaranteed to be == true forever to ensure a
-   smoother transition, meaning all existing calls will still work.
-   If you want to neatly transition your call sites:
-      Before:  BeginChild("Name", size, true)
-      After:   BeginChild("Name", size, ImGuiChildFlags_Border)
-      Before:  BeginChild("Name", size, false)
-      After:   BeginChild("Name", size) or BeginChild("Name", 0) or BeginChild("Name", size, ImGuiChildFlags_None)
-   Existing code will still work as 'ImGuiChildFlags_Border == true', but you are encouraged to update call sites.
- - BeginChild(): Added child-flag ImGuiChildFlags_AlwaysUseWindowPadding as a replacement for
-   the window-flag ImGuiWindowFlags_AlwaysUseWindowPadding: the feature only ever made sense
-   for use with BeginChild() anyhow, passing it to Begin() had no effect. Now that we accept
-   child-flags we are moving it there. (#462)
-      Before:  BeginChild("Name", size, 0, ImGuiWindowFlags_AlwaysUseWindowPadding);
-      After:   BeginChild("Name", size, ImGuiChildFlags_AlwaysUseWindowPadding, 0);
-   Kept inline redirection enum (will obsolete later) so existing code will work.
- - BeginChildFrame()/EndChildFrame(): removed functions in favor of using BeginChild() with
-   the ImGuiChildFlags_FrameStyle flag. Kept inline redirection function (will obsolete).
-   Those functions were merely PushStyle/PopStyle helpers and custom versions are easy to create.
-   (The removal isn't so much motivated by needing to add the feature in BeginChild(), but by the
-   necessity to avoid BeginChildFrame() signature mismatching BeginChild() signature and features.)
- - Debug Tools: Renamed ShowStackToolWindow() ("Stack Tool") to ShowIDStackToolWindow() ("ID Stack Tool"),
-   as earlier name was misleading. Kept inline redirection function. (#4631)
- - IO: Removed io.MetricsActiveAllocations introduced in 1.63, was displayed in Metrics and unlikely to
-   be accessed by end-user. Value still visible in the UI and easily to recompute from a delta.
- - Defining IMGUI_DISABLE_OBSOLETE_FUNCTIONS now automatically defines IMGUI_DISABLE_OBSOLETE_KEYIO. (#4921)
- - Removed IM_OFFSETOF() macro in favor of using offsetof() available in C++11. Kept redirection define. (#4537)
- - ListBox, Combo: Changed signature of "name getter" callback in old one-liner ListBox()/Combo() apis.
-   Before:
-      getter type:   bool (*getter)(void* user_data, int idx, const char** out_text)
-      function:      bool Combo(const char* label, int* current_item, bool (*getter)(void* user_data, int idx, const char** out_text), ...);
-      function:      bool ListBox(const char* label, int* current_item, bool (*getting)(void* user_data, int idx, const char** out_text), ...);
-   After:
-      getter type:   const char* (*getter)(void* user_data, int idx)
-      function:      bool Combo(const char* label, int* current_item, const char* (*getter)(void* user_data, int idx), ...);
-      function:      bool ListBox(const char* label, int* current_item, const char* (*getter)(void* user_data, int idx), ...);
-   Old type was unnecessarily complex and harder to wrap in e.g. a lambda. Kept inline redirection function (will obsolete).
- - Commented out obsolete redirecting enums/functions that were marked obsolete two years ago:
-   - GetWindowContentRegionWidth() -> use GetWindowContentRegionMax().x - GetWindowContentRegionMin().x.
-     Consider that generally 'GetContentRegionAvail().x' is often more correct and more useful.
-   - ImDrawCornerFlags_XXX         -> use ImDrawFlags_RoundCornersXXX names.
-     Read 1.82 changelog for details + grep commented names in sources.
-   - Commented out runtime support for hardcoded ~0 or 0x01..0x0F rounding flags values for
-     AddRect()/AddRectFilled()/PathRect()/AddImageRounded(). -> Use ImDrawFlags_RoundCornersXXX flags.
-     Read 1.82 changelog for details.
- - Backends: Vulkan: Removed parameter from ImGui_ImplVulkan_CreateFontsTexture(): backend now creates its own
-   command-buffer to upload fonts. Removed ImGui_ImplVulkan_DestroyFontUploadObjects() which is now unnecessary.
-   No need to call ImGui_ImplVulkan_CreateFontsTexture() as it is done automatically in ImGui_ImplVulkan_NewFrame().
-   You can call ImGui_ImplVulkan_CreateFontsTexture() manually if you need to reload the font atlas texture.
-   (#6943, #6715, #6327, #3743, #4618)
-
-Other changes:
-
-- Windows:
-  - BeginChild(): Added ImGuiChildFlags_ResizeX and ImGuiChildFlags_ResizeY to allow resizing
-    child windows from the bottom/right border (toward layout direction). Resized child windows
-    settings are saved and persistent in .ini file. (#1710)
-  - BeginChild(): Added ImGuiChildFlags_Border as a replacement for 'bool border = true' parameter.
-  - BeginChild(): Added ImGuiChildFlags_AutoResizeX and ImGuiChildFlags_AutoResizeY to auto-resize
-    on one axis, while generally providing a size on the other axis. (#1666, #1395, #1496, #1710)
-    e.g. BeginChild("name", {-FLT_MIN, 0.0f}, ImGuiChildFlags_AutoResizeY);
-    - Size is only reevaluated if the child window is within visible boundaries or just appearing.
-      This allows coarse clipping to be performed and auto-resizing childs to return false when
-      hidden because of being scrolled out.
-    - Combining this with also specifying ImGuiChildFlags_AlwaysAutoResize disables
-      this optimization, meaning child contents will never be clipped (not recommended).
-    - Please be considerate that child are full windows and carry significant overhead:
-      combining auto-resizing for both axises to create a non-scrolling child to merely draw
-      a border would be better more optimally using BeginGroup(). (see #1496)
-      (until we come up with new helpers for framed groups and work-rect adjustments).
-  - BeginChild(): made it possible to use SetNextWindowSizeConstraints() rectangle, often
-    useful when ImGuiChildFlags_AutoResizeX or ImGuiChildFlags_AutoResizeY. (#1666, #1395, #1496)
-    Custom constraint callback are not supported with child window.
-  - BeginChild(): Added ImGuiChildFlags_FrameStyle as a replacement for BeginChildFrame(),
-    use it to make child window use FrameBg, FrameRounding, FrameBorderSize, FramePadding
-    instead of ChildBg, ChildRounding, ChildBorderSize, WindowPadding.
-  - Popups: clarified meaning of 'p_open != NULL' in BeginPopupModal() + set back user value
-    to false when popup is closed in ways other than clicking the close button. (#6900)
-  - Double-clicking lower-left resize grip auto-resize (like lower-right one).
-  - Double-clicking bottom or right window border auto-resize on a singles axis.
-  - Use relative mouse movement for border resize when the border geometry has moved
-    (e.g. resizing a child window triggering parent scroll) in order to avoid resizing
-    feedback loops. Unless manually mouse-wheeling while border resizing. (#1710)
-- Separators:
-  - Altered end-points to use more standard boundaries. (#205, #4787, #1643)
-    Left position is always current cursor X position, right position is always work-rect
-    rightmost edge. It effectively means that:
-    - A separator in the root of a window will end up a little more distant from edges
-      than previously (essentially following WindowPadding instead of clipping edges).
-    - A separator inside a table cell end up a little distance from edges instead of
-      touching them (essentially following CellPadding instead of clipping edges).
-    - Matches tree indentation (was not the case before).
-    - Matches SeparatorText(). (#1643)
-    - Makes things correct inside groups without specific/hard-coded handling. (#205)
-  - Support legacy behavior when used inside old Columns(), as we favored that idiom back then,
-    only different is left position follows indentation level, to match calling a Separator()
-    inside or outside Columns().
-- Tooltips:
-  - Made using SetItemTooltip()/IsItemHovered(ImGuiHoveredFlags_ForTooltip) defaults to
-    activate tooltips on disabled items. This is done by adding ImGuiHoveredFlags_AllowWhenDisabled
-    to the default value of style.HoverFlagsForTooltipMouse/HoverFlagsForTooltipNav. (#1485)
-  - Made is possible to combine ImGuiHoveredFlags_ForTooltip with a ImGuiHoveredFlags_DelayXXX
-    override. (#1485)
-- Drag and Drop:
-  - Reworked drop target highlight: reduce rectangle to its visible portion, and then expand
-    slightly. A full rectangle is always visible and it may protrude slightly. (#4281, #3272)
-  - Fixed submitting a tooltip from drop target location when using AcceptDragDropPayload()
-    with ImGuiDragDropFlags_AcceptNoPreviewTooltip and submitting a tooltip manually.
-- Tables:
-  - Added angled headers support. You need to set ImGuiTableColumnFlags_AngledHeader on selected
-    columns and call TableAngledHeadersRow(). Added style.TableAngledHeadersAngle style option.
-  - Added ImGuiTableFlags_HighlightHoveredColumn flag, currently highlighting column header.
-  - Fixed an edge-case when no columns are visible + table scrollbar is visible + user
-    code is always testing return value of TableSetColumnIndex() to coarse clip. With an active
-    clipper it would have asserted. Without a clipper, the scrollbar range would be wrong.
-  - Request user to submit contents when outer host-window is requesting auto-resize,
-    so a scrolling table can contribute to initial window size. (#6510)
-  - Fixed subtle drawing overlap between borders in some situations.
-  - Fixed bottom-most and right-most outer border offset by one. (#6765, #3752) [@v-ein]
-  - Fixed top-most and left-most outer border overlapping inner clip-rect when scrolling. (#6765)
-  - Fixed top-most outer border being drawn with both TableBorderLight and TableBorderStrong
-    in some situations, causing the earlier to be visible underneath when alpha is not 1.0f.
-  - Fixed right-clicking right-most section (past right-most column) from highlighting a column.
-  - Fixed an issue with ScrollX enabled where an extraneous draw command would be created.
-- Menus:
-  - Menus: Fixed a bug where activating an item in a child-menu and dragging mouse over the
-    parent-menu would erroneously close the child-menu. (Regression from 1.88). (#6869)
-  - MenuBar: Fixed an issue where layouting an item in the menu-bar would erroneously
-    register contents size in a way that would affect the scrolling layer.
-    Was most often noticeable when using an horizontal scrollbar. (#6789)
-- InputText:
-  - InputTextMultiline: Fixed a crash pressing Down on last empty line of a multi-line buffer.
-    (regression from 1.89.2, only happened in some states). (#6783, #6000)
-  - InputTextMultiline: Fixed Tabbing cycle leading to a situation where Enter key wouldn't
-    be accepted by the widget when navigation highlight is visible. (#6802, #3092, #5759, #787)
-- Nav: Tabbing always enable nav highlight when ImGuiConfigFlags_NavEnableKeyboard is set.
-  Previously was inconsistent and only enabled when stepping through a non-input item.
-  (#6802, #3092, #5759, #787)
-- TreeNode: Added ImGuiTreeNodeFlags_SpanAllColumns for use in tables. (#3151, #3565, #2451, #2438)
-- TabBar: Fixed position of unsaved document marker (ImGuiTabItemFlags_UnsavedDocument) which was
-  accidentally offset in 1.89.9. (#6862) [@alektron]
-- ColorPicker4(): Fixed ImGuiColorEditFlags_NoTooltip not being forwarded to individual DragFloat3
-  sub-widgets which have a visible color preview when ImGuiColorEditFlags_NoSidePreview is also set. (#6957)
-- BeginGroup(): Fixed a bug pushing line lower extent too far down when called after a call
-  to SameLine() followed by manual cursor manipulation.
-- BeginCombo(): Added ImGuiComboFlags_WidthFitPreview flag. (#6881) [@mpv-enjoyer]
-- BeginListBox(): Fixed not consuming SetNextWindowXXX() data when returning false.
-- Fonts:
-  - Argument 'float size_pixels' passed to AddFontXXX() functions is now rounded to lowest integer.
-    This is because our layout/font system currently doesn't fully support non-integer sizes. Until
-    it does, this has been a common pitfall leading to more or less subtle issues. (#3164, #3309, #6800)
-  - Better assert during load when passing truncated font data or wrong data size. (#6822)
-  - Ensure calling AddFontXXX function doesn't invalidates ImFont's ConfigData pointers
-    prior to building again. (#6825)
-  - Added ImFontConfig::RasterizerDensity field to increase texture size of rendered glyphs
-    without altering other metrics. Among other things, this makes it easier to have zooming code
-    swapping between 2 fonts (e.g. a 100% and a 400% fonts) depending on current scale. (#6925) [@thedmd]
-    Important: if you increase this it is expected that you would render the font with a scale of
-    similar value or magnitude. Merely increasing this without increasing scale may lower quality.
-  - imgui_freetype: Added support for RasterizerDensity. (#6925) [@thedmd]
-  - imgui_freetype: Fixed a warning and leak in IMGUI_ENABLE_FREETYPE_LUNASVG support. (#6842, #6591)
-- Inputs: Added IsKeyChordPressed() helper function e.g. IsKeyChordPressed(ImGuiMod_Ctrl | ImGuiKey_S).
-  (note that ImGuiMod_Shortcut may be used as an alias for Cmd on OSX and Ctrl on other systems).
-- Misc: Most text functions also treat "%.*s" (along with "%s") specially to bypass formatting. (#3466, #6846)
-- IO: Add extra keys to ImGuiKey enum: ImGuiKey_F13 to ImGuiKey_F24. (#6891, #4921)
-- IO: Add extra keys to ImGuiKey enum: ImGuiKey_AppBack, ImGuiKey_AppForward. (#4921)
-- IO: Setting io.WantSetMousePos ignores incoming MousePos events. (#6837, #228) [@bertaye]
-- Debug Tools: Metrics: Added log of recent alloc/free calls.
-- Debug Tools: Metrics: Added "Show groups rectangles" in tools.
-- ImDrawList: Added AddEllipse(), AddEllipseFilled(), PathEllipticalArcTo(). (#2743) [@Doohl]
-- ImVector: Added find_index() helper.
-- Demo: Added "Drag and Drop -> Tooltip at target location" demo.
-- Demo: Added "Layout -> Child Windows -> Manual-resize" demo. (#1710)
-- Demo: Added "Layout -> Child Windows -> Auto-resize with constraints" demo. (#1666, #1395, #1496, #1710)
-- Demo: Partly fixed "Examples -> Constrained-resizing window" custom constrains demo. (#6210) [@cfillion]
-- Backends: Vulkan: Removed parameter from ImGui_ImplVulkan_CreateFontsTexture(): backend now creates its own
-  command-buffer to upload fonts. Removed ImGui_ImplVulkan_DestroyFontUploadObjects() which is now unnecessary.
-  No need to call ImGui_ImplVulkan_CreateFontsTexture() as it is done automatically in ImGui_ImplVulkan_NewFrame().
-  You can call ImGui_ImplVulkan_CreateFontsTexture() manually if you need to reload font atlas texture.
-  Fixed leaks, and added ImGui_ImplVulkan_DestroyFontsTexture() (probably no need to call this directly).
-  (#6943, #6715, #6327, #3743, #4618)
-  [@helynranta, @thomasherzog, @guybrush77, @albin-johansson, @MiroKaku, @benbatya-fb, @ocornut]
-- Backends: GLFW: Clear emscripten's MouseWheel callback before shutdown. (#6790, #6096, #4019) [@halx99]
-- Backends: GLFW: Added support for F13 to F24 function keys. (#6891)
-- Backends: SDL2, SDL3: Added support for F13 to F24 function keys, AppBack, AppForward. (#6891)
-- Backends: SDL3: Updates for recent API changes. (#7000, #6974)
-- Backends: Win32: Added support for F13 to F24 function keys, AppBack, AppForward. (#6891)
-- Backends: Win32: Added support for keyboard codepage conversion for when application
-  is compiled in MBCS mode and using a non-Unicode window. (#6785, #6782, #5725, #5961) [@sneakyevil]
-- Backends: Win32: Synthesize key-down event on key-up for VK_SNAPSHOT / ImGuiKey_PrintScreen as Windows
-  doesn't emit it (same behavior as GLFW/SDL). (#6859) [@thedmd, @SuperWangKai]
-- Backends: OpenGL3: rename symbols in our internal loader so that LTO compilation with another
-  copy of gl3w becomes possible. (#6875, #6668, #4445) [@nicolasnoble]
-- Backends: OpenGL3: Update GL3W based imgui_impl_opengl3_loader.h to load "libGL.so" instead
-  of "libGL.so.1", accommodating for NetBSD systems having only "libGL.so.3" available. (#6983)
-- Backends: OSX: Added support for F13 to F20 function keys. Support mapping F13 to PrintScreen. (#6891)
-- Examples: GLFW+Vulkan, SDL+Vulkan: Simplified and removed code due to backend improvements.
-- Internals: Renamed ImFloor() to ImTrunc(). Renamed ImFloorSigned() to ImFloor(). (#6861)
-
-
------------------------------------------------------------------------
- VERSION 1.89.9 (Released 2023-09-04)
------------------------------------------------------------------------
-
-Decorated log and release notes: https://github.com/ocornut/imgui/releases/tag/v1.89.9
-
 Breaking changes:
 
 - Clipper: Renamed IncludeRangeByIndices(), also called ForceDisplayRangeByIndices()
@@ -266,8 +57,6 @@ Other changes:
 - Windows: Layout of Close/Collapse buttons uses style.ItemInnerSpacing.x between items,
   stopped incorrectly using FramePadding in a way where hit-boxes could overlap when
   setting large values. (#6749)
-- TabBar, Style: added style.TabBarBorderSize and associated ImGuiStyleVar_TabBarBorderSize.
-  Tweaked rendering of that separator to allow thicker values. (#6820, #4859, #5022, #5239)
 - InputFloat, SliderFloat, DragFloat: always turn both '.' and ',' into the current decimal
   point character when using Decimal/Scientific character filter. (#6719, #2278) [@adamsepp]
 - ColorEdit, ColorPicker: Manipulating options popup don't mark item as edited. (#6722)
@@ -299,6 +88,11 @@ Other changes:
 - Examples: Emscripten+WebGPU: Fixed WGPUInstance creation process + use preferred
   framebuffer format. (#6640, #6748) [@smileorigin]
 
+Docking+Viewports Branch:
+
+- Docking: when io.ConfigDockingWithShift is enabled, staying stationary while moving
+  a window displays an help tooltip to increase affordance. (#6709, #4643)
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.8 (Released 2023-08-01)
@@ -367,6 +161,16 @@ Other changes:
 - Examples: Vulkan: Creating minimal descriptor pools to fit only what is needed by
   example. (#6642) [@SaschaWillem]
 
+Docking+Viewports Branch:
+
+- Docking, Style: resizing separators use same colors as window borders (ImGuiCol_Border)
+  for consistency. With default styles it doesn't make a big difference. (#2522) [@rmitton]
+  In the future if we promote using thick value for inner/outer docking padding we may
+  need to introduce new colors for it.
+- Docking: added style.DockingSeparatorSize, ImGuiStyleVar_DockingSeparatorSize. Now
+  also scaled by style.ScaleAllSizes(). (#3481, #4721, #2522) [@PossiblyAShrub, @wobbier]
+- Docking: fixed rendering of docked-window scrollbar above outer border. (#2522)
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.7 (Released 2023-07-04)
@@ -462,6 +266,23 @@ Other changes:
 - Examples: Win32+OpenGL3: Changed DefWindowProc() to DefWindowProcW() to match other examples
   and support the example app being compiled without UNICODE. (#6516, #5725, #5961, #5975) [@yenixing]
 
+Docking+Viewports Branch:
+
+- Viewports+Docking: Fixed extraneous viewport+platform-window recreation in various
+  combination of showing or hiding windows, docking with/without split, undocking.
+  While with some backends and without OS decorations, some extraneous window recreation
+  were visibly not noticeable, they would typically become noticeable when enabling
+  OS decorations on those windows (e.g. Windows title bar fade-in/animation).
+- Viewports: Closing a viewport via OS/platform means (e.g. OS close button or task-bar menu),
+  mark all windows in this viewport as closed.
+- Docking: Fixed one-frame flickering on reappearing windows binding to a dock node
+  where a later-submitted window was already bound.
+- Docking: Fixed dragging from title-bar empty space (regression from 1.88 related to
+  keeping ID alive when calling low-level ButtonBehavior() directly). (#5181, #2645)
+- Docking: [Internal] DockBuilderDockWindow() API calls don't clear docking order
+  if the target node is same as existing one.
+- Backends: Win32: Added support for changing ParentViewportID after viewport creation.
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.6 (Released 2023-05-31)
@@ -531,6 +352,23 @@ Other changes:
 - Examples: Added SDL3+SDL_Renderer example. (#6286)
 - Examples: Updated all Visual Studio projects and batches to use /utf-8 argument.
 
+Docking+Viewports Branch:
+
+- Viewports: Fixed platform-side focus (e.g. Alt+Tab) from leading to accidental
+  closure of Modal windows. Regression from 1.89.5. (#6357, #6299)
+- Viewports: Fixed loss of imgui-side focus when dragging a secondary viewport back in
+  main viewport, due to platform-side handling changes. Regression from 1.89.5 (#6299)
+- Viewports: Avoid applying imgui-side focus when focus change is due to a viewport
+  destruction. Fixes erroneous popup closure on closing a previous popup. (#6462, #6299)
+- Viewports: Added void* ImGuiPlatformMonitor::PlatformHandle field (backend-dependant),
+  for usage by user code.
+- Backends: GLFW: Preserve monitor list when there are no monitor, may briefly
+  happen when recovering from macOS sleeping mode. (#5683) [@Guistac]
+- Backends: SDL2: Update monitor list when receiving a display event. (#6348)
+  Note however that SDL2 currently doesn't have an event for a DPI/Scaling change,
+  so monitor data won't be updated in this situation.
+- Backends: SDL3: Update monitor list when receiving a display event. (#6348)
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.5 (Released 2023-04-13)
@@ -588,7 +426,6 @@ Other changes:
   is to other IME function such as SDL_SetTextInputRect(). (#6306, #6071, #1953)
 - Backends: GLFW: Added support on Win32 only for io.AddMouseSourceEvent() to discriminate
   Mouse/TouchScreen/Pen. (#2334, #2702)
-- Backends: GLFW: Fixed key modifiers handling on secondary viewports. (#6248, #6034) [@aiekick]
 - Backends: Android: Added support for io.AddMouseSourceEvent() to discriminate Mouse/TouchScreen/Pen.
   (#6315) [@PathogenDavid]
 - Backends: OSX: Added support for io.AddMouseSourceEvent() to discriminate Mouse/Pen.
@@ -604,6 +441,16 @@ Other changes:
 - TestSuite: Added variety of new regression tests and improved/amended existing ones
   in imgui_test_engine/ repo. [@PathogenDavid, @ocornut]
 
+Docking+Viewports Branch:
+
+- Viewports: Setting focus from Platform/OS (e.g. via decoration, or Alt-Tab) sets corresponding
+  focus at Dear ImGui level (generally last focused window in the viewport). (#6299)
+- Docking: Fixed using GetItemXXX() or IsItemXXX() functions after a DockSpace(). (#6217)
+- Backends: GLFW: Fixed key modifiers handling on secondary viewports. (#6248, #6034) [@aiekick]
+- Backends: GLFW: Fixed Emscripten erroneously enabling multi-viewport support, leading to assert. (#5683)
+- Backends: SDL2/SDL3: Fixed IME text input rectangle position with viewports. (#6071, #1953)
+- Backends: SDL3: Fixed for compilation with multi-viewports. (#6255) [@P3RK4N]
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.4 (Released 2023-03-14)
@@ -678,7 +525,6 @@ Other changes:
   and ImGuiConfigFlags_NavEnableGamepad by default. (#787)
 - Internals: Misc tweaks to facilitate applying an explicit-context patch. (#5856) [@Dragnalith]
 
-
 -----------------------------------------------------------------------
  VERSION 1.89.3 (Released 2023-02-14)
 -----------------------------------------------------------------------
@@ -779,6 +625,10 @@ Other changes:
 - Examples: SDL2+SDL_Renderer: Added call to SDL_RenderSetScale() to fix display on a
   Retina display (albeit lower-res as our other unmodified examples). (#6121, #6065, #5931).
 
+Docking+Viewports Branch:
+
+- Backends: GLFW: Handle unsupported glfwGetVideoMode() for Emscripten. (#6096)
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.2 (Released 2023-01-05)
@@ -829,6 +679,17 @@ All changes:
 - Backends: Vulkan: Fixed sampler passed to ImGui_ImplVulkan_AddTexture() not being honored as we were using
   an immutable sampler. (#5502, #6001, #914) [@martin-ejdestig, @rytisss]
 
+Docking+Viewports Branch:
+
+- Docking: Internals: fixed DockBuilderCopyDockSpace() crashing when windows not in the
+  remapping list are docked on the left or top side of a split. (#6035)
+- Docking: fixed DockSpace() with ImGuiDockNodeFlags_KeepAliveOnly marking current window
+  as written to, even if it doesn't technically submit an item. This allow using KeepAliveOnly
+  from any window location. (#6037)
+- Backends: OSX: fixed typo in ImGui_ImplOSX_GetWindowSize that would cause issues when resiing
+  from OS decorations, if they are enabled on secondary viewports. (#6009) [@sivu]
+- Backends: Metal: fixed secondary viewport rendering. (#6015) [@dmirty-kuzmenko]
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.1 (Released 2022-11-24)
@@ -855,6 +716,13 @@ Other changes:
 - Backends: GLFW: cancel out errors emitted by glfwGetKeyName() when a name is missing. (#5908)
 - Backends: WebGPU: fixed validation error with default depth buffer settings. (#5869, #5914) [@kdchambers]
 
+Docking+Viewports Branch:
+
+- Viewports: Fixed collapsed windows setting ImGuiViewportFlags_NoRendererClear without
+  making title bar color opaque, leading to potential texture/fb garbage being visible.
+  Right now as we don't fully support transparent viewports (#2766), so we turn that
+  'TitleBgCollapsed' color opaque just lke we do for 'WindowBG' on uncollapsed windows.
+
 
 -----------------------------------------------------------------------
  VERSION 1.89 (Released 2022-11-15)
@@ -1046,6 +914,23 @@ Other Changes:
 - Backends: Vulkan: Added experimental ImGui_ImplVulkan_RemoveTexture() for api symetry. (#914, #5738).
 - Backends: WebGPU: fixed rendering when a depth buffer is enabled. (#5869) [@brainlag]
 
+Docking+Viewports Branch:
+
+- Docking: Fixed incorrect focus highlight on docking node when focusing a menu. (#5702)
+- Docking, Nav: Fixed using gamepad/keyboard navigation not being able enter menu layer when
+  it only contained the standard Collapse/Close buttons and no actual menu. (#5463, #4792)
+- Docking: Fixed regression introduced in v1.87 when docked window content not rendered
+  while switching between with CTRL+Tab. [@rokups]
+- Docking: Fixed amending into an existing tab bar from rendering invisible items. (#5515)
+- Docking: Made spacing between dock nodes not a dropping gap. When hovering it only
+  outer-docking drop markers are visible.
+- Docking+Viewports: Fixed undocking window node causing parent viewports to become unresponsive
+  in certain situation (e.g. hidden tab bar). (#5503) [@rokups]
+- Backends: SDL: Fixed building backend under non-OSX Apple targets (e.g. iPhone). (#5665)
+- Backends: SDL: Fixed drag'n drop crossing a viewport border losing mouse coordinates. (#5710, #5012)
+- Backends: GLFW: Fixed leftover static variable preventing from changing or
+  reinitializing backend while application is running. (#4616, #5434) [@rtoumazet]
+
 
 -----------------------------------------------------------------------
  VERSION 1.88 (Released 2022-06-21)
@@ -1180,6 +1065,26 @@ Other Changes:
 - Examples: Emscripten+WebGPU: Fix building for latest WebGPU specs. (#3632)
 - Examples: OSX+Metal, OSX+OpenGL: Removed now-unnecessary calls to ImGui_ImplOSX_HandleEvent(). (#4821)
 
+Docking+Viewports Branch:
+
+- Docking: Fixed floating docked nodes not being clamped into viewport workrect to stay reachable
+  when io.ConfigWindowsMoveFromTitleBarOnly is true and multi-viewports are disabled. (#5044)
+- Docking: Fixed a regression where moving window would be interrupted after undocking a tab
+  when io.ConfigDockingAlwaysTabBar is true. (#5324) [@rokups]
+- Docking: Fixed incorrect focus highlight on docking node when focusing empty central node
+  or a child window which was manually injected into a dockspace window.
+- Docking, Modal: Fixed a crash when opening popup from a parent which is being docked on the same frame. (#5401)
+- Viewports: Fixed an issue where MouseViewport was lagging by a frame when using 1.87 Input Queue.
+  A common side-effect would be that when releasing a window drag the underlying window would highlight
+  for a frame. (#5837, #4921) [@cfillion]
+- Viewports: Fixed translating a host viewport from briefly altering the size of AlwaysAutoResize windows. (#5057)
+- Viewports: Fixed main viewport size not matching ImDrawData::DisplaySize for one frame during resize
+  when multi-viewports are disabled. (#4900)
+- Backends: SDL: Fixed dragging out main viewport broken on some SDL setups. (#5012) [@rokups]
+- Backends: OSX: Added support for multi-viewports. [@stuartcarnie, @metarutaiga] (#4821, #2778)
+- Backends: Metal: Added support for multi-viewports. [@stuartcarnie, @metarutaiga] (#4821, #2778)
+- Examples: OSX+Metal, SDL+Metal, GLFW+Metal: Added support for multi-viewports. [@rokups]
+
 
 -----------------------------------------------------------------------
  VERSION 1.87 (Released 2022-02-07)
@@ -1322,6 +1227,29 @@ Other Changes:
 - Backends: WebGPU: Fixed incorrect size parameters in wgpuRenderPassEncoderSetIndexBuffer() and
   wgpuRenderPassEncoderSetVertexBuffer() calls. (#4891) [@FeepsDev]
 
+Docking+Viewports Branch:
+
+- Docking: Fixed a CTRL+TAB crash when aiming at an empty docked window. (#4792)
+- Docking: Tabs use their own identifier instead of the Window identifier.
+  (This will invalidate some stored .ini data such as last selected tab, sorry!)
+- Docking: Fixed size constraints not working on single window holding on a dock id (still doesn't work on docked windows).
+- Docking: Fixed CTRL+TAB back into a docked window not selecting menu layer when no item are on main layer.
+- Viewports, IO: Added io.AddMouseViewportEvent() function to queue hovered viewport change (when known by backend).
+- Viewports: Relaxed specs for backend supporting ImGuiBackendFlags_HasMouseHoveredViewport: it is now _optional_
+  for the backend to have to ignore viewports with the _NoInputs flag when call io.AddMouseViewportEvent(). It is
+  much better if they can (Win32 and GLFW 3.3+ backends can, SDL and GLFW 3.2 backends cannot, they are lacking data).
+  A concrete example is: when dragging a viewport for docking, the viewport is marked with _NoInputs to allow us
+  to pick the target viewports for docking. If the backend reports a viewport with _NoInputs when calling the
+  io.AddMouseViewportEvent() function, then Dear ImGui will revert to its flawed heuristic to find the viewport under.
+  By lowering those specs, we allow the SDL and more backend to support this, only relying on the heuristic in a few
+  drag and drop situations rather that relying on it everywhere.
+- Viewports: Fixed a CTRL+TAB crash with viewports enabled when the window list needs to appears in
+  its own viewport (regression from 1.86). (#4023, #787)
+- Viewports: Fixed active InputText() from preventing viewports to merge. (#4212)
+- Backends: SDL: Added support for ImGuiBackendFlags_HasMouseHoveredViewport now that its specs have been lowered.
+- (Breaking) Removed ImGuiPlatformIO::Platform_SetImeInputPos() in favor of newly standardized
+  io.SetPlatformImeDataFn() function. Should not affect more than default backends.
+
 
 -----------------------------------------------------------------------
  VERSION 1.86 (Released 2021-12-22)
@@ -1420,6 +1348,24 @@ Other Changes:
   wgpuRenderPassEncoderSetIndexBuffer() functions as validation layers appears to not do what the
   in-flux specs says. (#4766) [@meshula]
 
+Docking+Viewports Branch:
+
+- Docking: Revert removal of io.ConfigDockingWithShift config option (removed in 1.83). (#4643)
+- Docking: Fixed a bug undocking windows docked into a non-visible or _KeepAliveOnly dockspace
+  when unrelated windows submitted before the dockspace have dynamic visibility. (#4757)
+- Docking, Style: Docked windows honor ImGuiCol_WindowBg. (#2700, #2539)
+- Docking, Style: Docked windows honor display their border properly. (#2522)
+- Docking: Fixed incorrectly rounded tab bars for dock node that are not at the top of their dock tree.
+- Docking: Fixed single-frame node pos/size inconsistencies when window stop or start being submitted.
+- Docking: Prevent docking any window created above a popup/modal. (#4317)
+- Viewports: Made it possible to explicitly assign ImGuiWindowClass::ParentViewportId to 0 in order
+  to ensure a window is not parented. Previously this would use the global default (which might be 0,
+  but not always as it would depend on io.ConfigViewportsNoDefaultParent). (#3152, #2871)
+- Viewports: Fixed tooltip in own viewport over modal from being incorrectly dimmed. (#4729)
+- Viewports: Fixed CTRL+TAB highlight outline on docked windows not always fitting in host viewport.
+- Backends: Made it possible to shutdown default Platform Backends before the Renderer backends. (#4656)
+- Disabled: Fixed nested BeginDisabled()/EndDisabled() bug in Docking branch due to bad merge. (#4655, #4452, #4453, #4462)
+
 
 -----------------------------------------------------------------------
  VERSION 1.85 (Released 2021-10-12)
@@ -1438,6 +1384,10 @@ Breaking Changes:
   Can use 'GetWindowContentRegionMax().x - GetWindowContentRegionMin().x' instead but it's not
   very useful in practice, and the only use of it in the demo was illfit.
   Using 'GetContentRegionAvail().x' is generally a better choice.
+- (Docking branch) IsWindowFocused() and IsWindowHovered() with only the _ChildWindows flag
+  and without the _RootWindow flag used to leak docking hierarchy, so a docked window would
+  return as the child of the window hosting the dockspace. This was inconsistent and incorrect
+  with other behaviors so we fixed it. Added a new _DockHierarchy flag to opt-in this behavior.
 
 Other Changes:
 
@@ -1511,6 +1461,29 @@ Other Changes:
 - Backends: All renderers: Normalize clipping rect handling across backends. (#4464)
 - Examples: Added SDL + SDL_Renderer example in "examples/example_sdl_sdlrenderer/" folder. (#3926) [@1bsyl]
 
+Docking+Viewports Branch:
+
+- IsWindowFocused: Fixed using ImGuiFocusedFlags_ChildWindows (without _RootWindow) from leaking the
+  docking hierarchy. Added ImGuiFocusedFlags_DockHierarchy flag to consider docking hierarchy in the test.
+- IsWindowHovered: Fixed using ImGuiHoveredFlags_ChildWindows (without _RootWindow) from leaking the
+  docking hierarchy. Added ImGuiHoveredFlags_DockHierarchy flag to consider docking hierarchy in the test.
+- Nav: Fixed an issue with losing focus on docked windows when pressing Alt while keyboard navigation
+  is disabled. (#4547, #4439) [@PathogenDavid]
+- Docking: Fixed IsItemHovered() and functions depending on it (e.g. BeginPopupContextItem()) when
+  called after Begin() on a docked window (broken 2021/03/04). (#3851)
+- Docking: Improved resizing system so that non-central zone are better at keeping their fixed size.
+  The algorithm is still not handling the allocation of size ideally for nested sibling, but it got better.
+- Docking: Fixed settings load issue when mouse wheeling. (#4310)
+- Docking: Fixed manually created floating node with a central node from not hiding when windows are gone.
+- Docking + Drag and Drop: Fixed using BeginDragDropSource() or BeginDragDropTarget() inside a Begin()
+  that returned false because the window is docked. (#4515)
+- Viewports: Fixed a crash while a window owning its viewport disappear while being dragged.
+  It would manifest when e.g. reconfiguring dock nodes while dragging.
+- Viewports: Fixed unnecessary creation of temporary viewports when multiple docked windows
+  got reassigned to a new node (created mid-frame) which already has a HostWindow.
+- Viewports: Fixed window with viewport ini data immediately merged into a host viewport from
+  leaving a temporary viewport alive for a frame (would leak into backend).
+
 
 -----------------------------------------------------------------------
  VERSION 1.84.2 (Released 2021-08-23)
@@ -1543,7 +1516,7 @@ Breaking Changes:
 - Commented out redirecting functions/enums names that were marked obsolete in 1.67 and 1.69 (March 2019):
   - ImGui::GetOverlayDrawList() -> use ImGui::GetForegroundDrawList()
   - ImFont::GlyphRangesBuilder  -> use ImFontGlyphRangesBuilder
-- Backends: OpenGL3: added a third source file "imgui_impl_opengl3_loader.h". (#4445) [@rokups]
+- Backends: OpenGL3: added a third source file "imgui_impl_opengl3_loader.h". [@rokups]
 - Backends: GLFW: backend now uses glfwSetCursorEnterCallback(). (#3751, #4377, #2445)
 - Backends: GLFW: backend now uses glfwSetWindowFocusCallback(). (#4388) [@thedmd]
   - If calling ImGui_ImplGlfw_InitXXX with install_callbacks=true: this is already done for you.
@@ -1632,7 +1605,7 @@ Other Changes:
   about building on 32-bit systems. (#4225) [@kingofthebongo2008]
 - Backends: OpenGL3: Embed our own minimal GL headers/loader (imgui_impl_opengl3_loader.h) based on gl3w.
   Reduces the frequent issues and confusion coming from having to support multiple loaders and requiring users to use and
-  initialize the same loader as the backend. (#4445) [@rokups]
+  initialize the same loader as the backend. [@rokups]
   Removed support for gl3w, glew, glad, glad2, glbinding2, glbinding3 (all now unnecessary).
 - Backends: OpenGL3: Handle GL_CLIP_ORIGIN on <4.5 contexts if "GL_ARB_clip_control" extension is detected. (#4170, #3998)
 - Backends: OpenGL3: Destroy vertex/fragment shader objects right after they are linked into main shader. (#4244) [@Crowbarous]
@@ -1647,6 +1620,25 @@ Other Changes:
 - Examples: Updated all .vcxproj to VS2015 (toolset v140) to facilitate usage with vcpkg.
 - Examples: SDL2: Accommodate  for vcpkg install having headers in SDL2/SDL.h vs SDL.h.
 
+Docking+Viewports Branch:
+
+- Docking: Clicking on the right-most close button of a docking node closes all windows. (#4186)
+- Docking: Fix IsWindowAppearing() and ImGuiCond_Appearing on docked windows. (#4177, #3982, #1497, #1061)
+- Docking: Fix crash using DockBuilderRemoveNode() in some situations. (#3111, #3179, #3203, #4295) [@hsimyu]
+- Docking: Fix crash when a dock node gets re-qualified as dockspace>floating>dockspace, which tends to happen
+  when incorrectly calling DockBuilderAddNode() without ImGuiDockNodeFlags_Dockspace and using it as a Dockspace
+  on the next frame after the floating window hosting the node has been automatically created. (#3203, #4295)
+- Docking: Reworked node flags saving/inheritance so that flags enforced by docked windows via the
+  DockNodeFlagsOverrideSet mechanism are are not left in empty dockspace nodes once the windows gets undocked.
+  (#4292, #3834, #3633, #3521, #3492, #3335, #2999, #2648)
+- Docking: (Internal/Experimental) Removed DockNodeFlagsOverrideClear flags from ImGuiWindowClass as
+  it is ambiguous how to apply them and we haven't got a use out of them yet.
+- Docking: Fixed ImGuiWindowFlags_UnsavedDocument clipping label in docked windows when there are
+  no close button. (#5745)
+- Viewports: Fix popup/tooltip created without a parent window from being given a ParentViewportId value
+  from the implicit/fallback window. (#4236, #2409)
+- Backends: Vulkan: Fix the use of the incorrect fence for secondary viewports. (#4208) [@FunMiles]
+
 
 -----------------------------------------------------------------------
  VERSION 1.83 (Released 2021-05-24)
@@ -1731,6 +1723,22 @@ Other Changes:
 - Docs: Improvements to description of using colored glyphs/emojis. (#4169, #3369)
 - Docs: Improvements to minor mistakes in documentation comments (#3923) [@ANF-Studios]
 
+Docking+Viewports Branch:
+
+- [Breaking] Removed io.ConfigDockingWithShift config option. Behavior always equivalent to having the
+  option set to false (dock/undock by default, hold shift to avoid docking). (#2109)
+- Docking: DockSpace() returns its node ID.
+- Docking: Dockspace() never draws a background. (#3924)
+- Docking: Undocking nodes/windows covering most of the monitor max their size down to 90% to ease manipulations.
+- Docking: Docking node tab bar honors ItemInnerSpacing.x before first tab. (#4130)
+- Docking: Tweak rendering and alignment of dock node menu marker. (#4130)
+- Docking: Fixed restoring of tab order within a dockspace or a split node.
+- Docking: Fixed reappearing docked windows with no close button showing a tab with extraneous space for one frame.
+- Docking: Fixed multiple simultaneously reappearing window from appearing undocked for one frame.
+- Viewports: Hotfix for crash in monitor array access, caused by 4b9bc4902. (#3967)
+- Backends, Viewports: GLFW: Add a workaround for stuck keys after closing a GLFW window (#3837).
+- Backends, Viewports: Vulkan: Rebuild swapchain on VK_SUBOPTIMAL_KHR. (#3881)
+
 
 -----------------------------------------------------------------------
  VERSION 1.82 (Released 2021-02-15)
@@ -1826,6 +1834,13 @@ Other Changes:
   scheduled builds builds are not required. [@rokups]
 - Log/Capture: Added LogTextV, a va_list variant of LogText. [@PathogenDavid]
 
+Docking+Viewports Branch:
+
+- Viewports: Fix setting of ImGuiViewportFlags_NoRendererClear. (#3213)
+- Viewports: Added GetViewportPlatformMonitor() with a safety net to keep code portable.
+- Viewports, Backends: SDL: Fix missing ImGuiBackendFlags_HasSetMousePos flag in docking branch.
+- Viewports, Backends: GLFW: Fix application of WantSetMousePos. (#1542, #787)
+
 
 -----------------------------------------------------------------------
  VERSION 1.81 (Released 2021-02-10)
@@ -1907,6 +1922,17 @@ Other Changes:
 - Examples: WebGPU: Added Emscripten+WebGPU example. (#3632) [@bfierz]
 - Backends: GLFW: Added ImGui_ImplGlfw_InitForOther() initialization call to use with non OpenGL API. (#3632)
 
+Docking+Viewports Branch:
+
+- Docking: Fix losing docking information on closed windows for which the hosting node was split. (#3716) [@GamingMinds-DanielC]
+- Docking: Fix gap in hit test hole when using ImGuiDockNodeFlags_PassthruCentralNode touching the edge of a viewport. (#3733)
+- Viewports: (Breaking) removed ImGuiPlatformIO::MainViewport which is now pretty much unused and duplicate
+  (and misleading as we will evolve the concept).
+- Viewports: (Breaking) turned ImGuiViewport::GetWorkPos(), ImGuiViewport::GetWorkSize() into regular fields
+  (WorkPos, WorkSize) before exposing in master branch.
+- Viewports: Fix issue inferring viewport z-order when new popups gets created. (#3734) + Metrics updates.
+- Viewports, Backends: Vulkan: handle VK_ERROR_OUT_OF_DATE_KHR when resizing secondary viewport (#3766, #3758)
+
 
 -----------------------------------------------------------------------
  VERSION 1.80 (Released 2021-01-21)
@@ -2026,6 +2052,14 @@ Other Changes:
 - Docs: Split examples/README.txt into docs/BACKENDS.md and docs/EXAMPLES.md, and improved them.
 - Docs: Consistently renamed all occurrences of "binding" and "back-end" to "backend" in comments and docs.
 
+Docking+Viewports Branch:
+
+- Docking: Docked windows honor change of tab and text colors. (#2771)
+- Docking: Support for appending into existing tab-bar made to work with Docking + internal helper DockNodeBeginAmendTabBar().
+- Docking: Added experimental TabItemFlagsOverrideSet to ImGuiWindowClass.
+- Viewports: Fixed incorrect whitening of popups above a modal if both use their own viewport.
+- Viewports: Backends: Vulkan: Fixed build, removed extraneous pipeline creation. (#3459, #3579)
+
 
 -----------------------------------------------------------------------
  VERSION 1.79 (Released 2020-10-08)
@@ -2120,6 +2154,21 @@ Other Changes:
 - Examples: DX12: Added '#define ImTextureID ImU64' in project and build files to also allow building
   on 32-bit systems. Added project to default Visual Studio solution file. (#301)
 
+Docking+Viewports Branch:
+
+- Docking: DockSpace() emits ItemSize() properly (useful when not filling all space).
+- Docking: Fixed docking while hovering a child window. (#3420) broken by 85a661d. Improve metrics debugging.
+- Docking: Fix honoring payload filter with overlapping nodes (we incorrectly over-relied on g.HoveredDockNode
+  when making change for #3398).
+- Docking: Fix handling of WindowMenuButtonPosition == ImGuiDir_None in Docking Nodes. (#3499)
+- Viewports: Fixed a rare edge-case if the window targeted by CTRL+Tab stops being rendered.
+- Viewports, Backends: DX12: Make secondary viewport format match main viewport one (#3462) {@BeastLe9enD]
+- Viewports: Backends: Vulkan: Removed unused shader code. Fix leaks. Avoid unnecessary pipeline creation for main
+  viewport. (#3459) + Add ImGui_ImplVulkanH_CreateWindowSwapChain in ImGui_ImplVulkanH_CreateOrResizeWindow().
+- Viewports: Backends: DirectX9: Recover from D3DERR_DEVICELOST on secondary viewports. (#3424)
+- Viewports, Backends: Win32: Fix toggling of ImGuiViewportFlags_TopMost (#3477) [@Kodokuna]
+- Viewports: Backends: GLFW: Workaround for cases where glfwGetMonitorWorkarea fails (#3457) [@dougbinks]
+
 
 -----------------------------------------------------------------------
  VERSION 1.78 (Released 2020-08-18)
@@ -2221,6 +2270,23 @@ Other Changes:
 - Examples: Vulkan: Fixed GLFW+Vulkan and SDL+Vulkan clear color not being set. (#3390) [@RoryO]
 - CI: Emscripten has stopped their support for their fastcomp backend, switching to latest sdk [@Xipiryon]
 
+Docking+Viewports Branch:
+
+- Docking: Made DockBuilderAddNode() automatically call DockBuilderRemoveNode(). (#3399, #2109)
+- Docking: Storing HoveredDockNode in context which can be useful for easily detecting e.g. hovering an
+  empty node. (#3398)
+- Docking: Fixed docking overlay bits appearing at (0,0), because of 43bd80a. Most typically noticeable
+  when disabling multi-viewport.
+- Docking: Workaround recovery for node created without the _DockSpace flags later becoming a DockSpace. (#3340)
+- Docking: Rework size allocations to recover when there's no enough room for nodes + do not hold on
+  _WantLockSizeOnce forever. (#3328)
+- Docking: Rework size allocation to allow user code to override node sizes. Not all edge cases will be
+  properly handled but this is a step toward toolbar emitting size constraints.
+- Docking: Added experimental flags to perform more docking filtering and disable resize per axis.
+  Designed for toolbar patterns.
+- Viewports, Backends, GLFW: Use GLFW_MOUSE_PASSTHROUGH when available.
+- Viewports, Backends: DX12: Fixed issue on shutdown when viewports are disabled. (#3347)
+
 
 -----------------------------------------------------------------------
  VERSION 1.77 (Released 2020-06-29)
@@ -2312,6 +2378,17 @@ Other Changes:
 - Examples: Apple: Fixed example_apple_metal and example_apple_opengl2 using imgui_impl_osx.mm
   not forwarding right and center mouse clicks. (#3260) [@nburrus]
 
+Docking+Viewports Branch:
+
+- Viewports: Don't set ImGuiViewportFlags_NoRendererClear when ImGuiWindowFlags_NoBackground is set. (#3213)
+- Viewports: Report minimized viewports as zero DisplaySize to be consistent with main branch. (#1542)
+- Docking, Settings: Allow reload of settings data at runtime. (#2573)
+- Backends, GLFW: Fix windows resizing incorrectly on Linux due to GLFW firing window positioning
+  callbacks on next frame after window is resized manually. (#2117)
+- Backends: DX12: Fix OBJECT_DELETED_WHILE_STILL_IN_USE on viewport resizing. (#3210)
+- Backends: DX12: Fix for crash caused by early resource release. (#3121)
+- Backends, Win32: Request monitor update when DPI awareness is enabled to make sure they have the correct DPI settings.
+
 
 -----------------------------------------------------------------------
  VERSION 1.76 (Released 2020-04-12)
@@ -2384,6 +2461,20 @@ Other Changes:
 - Examples: SDL+DX11: Fixed resizing main window. (#3057) [@joeslay]
 - Examples: Added SDL+Metal example application. (#3017) [@coding-jackalope]
 
+Docking+Viewports Branch:
+
+- Docking: Fixed assert preventing dockspace from being created instead a hidden tab. (#3101)
+- Viewports: Fixed secondary viewports accidentally merging into a minimized host viewport. (#3118)
+- Viewports, Docking: Added per-viewport work area system for e.g. menu-bars. Fixed DockspaceOverViewport()
+  and demo code (overlay etc) accordingly. (#3035, #2889, #2474, #1542, #2109)
+- Viewports: Improve menu positioning in multi-monitor setups. [@rokups]
+- Viewports: Software mouse cursor is also scaled by current DpiScale. (amend #939)
+- Viewports: Avoid manually clipping resize grips and borders, which messes up with automation ability
+  to locate those items. Also simpler and more standard.
+- Viewports: Fix for UWP in the imgui_impl_win32.cpp IME handler. (#2895, #2892).
+- Viewports: Bunch of extra of comments to facilitate setting up multi-viewports.
+- Viewports, GLFW: Avoid using window positioning workaround for GLFW 3.3+ versions that have it fixed.
+
 
 -----------------------------------------------------------------------
  VERSION 1.75 (Released 2020-02-10)
@@ -2482,6 +2573,21 @@ Other Changes:
 - Examples: Metal: Wrapped main loop in @autoreleasepool block to ensure allocations get freed
   even if underlying system event loop gets paused due to app nap. (#2910, #2917) [@bear24rw]
 
+Docking+Viewports Branch:
+
+- Docking + Nav: Fixed messed up Ctrl+Tab order with docked windows.
+- Docking + Nav: Fixed failing to restore NavId when refocusing a child within a docked window.
+- Docking + Nav: Fixed failing to restore NavId when refocusing due to missing nav window (when
+  it stops being submitted).
+- Docking: Fixed a bug where the tab bar of a hidden dockspace would keep requesting focus. (#2960)
+- Docking: Added experimental DockNodeFlagsOverrideSet/DockNodeFlagsOverrideClear flags in ImGuiWindowClass
+  (currently experimenting with toolbar idioms).
+- Viewports: Fix resizing viewport-owning windows when mouse pos is outside the InnerClipRect
+  (can happen with OS decoration enabled).
+- Viewports: Preserve last known size for minimized main viewport to be consistent with secondary viewports.
+- Backends: SDL: Honor NoTaskBarIcon flag under non Win32 OS. (#2117)
+- Backends: GLFW, SDL: Platform monitors declared properly even if multi-viewport is not enabled.
+
 
 -----------------------------------------------------------------------
  VERSION 1.74 (Released 2019-11-25)
@@ -2561,6 +2667,14 @@ Other Changes:
 - CI: Set up a bunch of continuous-integration tests using GitHub Actions. We now compile many of the example
   applications on Windows, Linux, MacOS, iOS, Emscripten. Removed Travis integration. (#2865) [@rokups]
 
+Docking+Viewports Branch:
+
+- Docking: Can undock from the small triangle button. (#2109,. #2645)
+- Docking: Fixed node->HasCloseButton not honoring ImGuiDockNodeFlags_NoCloseButton in a floating node,
+  leading to empty space at the right of tab-bars with those flags. (#2109)
+- Docking: Made docked windows not use style.ChildRounding.
+- Multi-viewports: Added multi-viewport support in the DX12 back-end. (#2851) [@obfuscate]
+
 
 -----------------------------------------------------------------------
  VERSION 1.73 (Released 2019-09-24)
@@ -2623,6 +2737,28 @@ Other Changes:
 - Misc: Updated stb_rect_pack.h from 0.99 to 1.00 (fixes by @rygorous: off-by-1 bug in best-fit heuristic,
   fix handling of rectangles too large to fit inside texture). (#2762) [@tido64]
 
+Docking+Viewports Branch:
+
+- Docking: Fix BeginDocked() path that creates node so that SetNextWindowDockID() doesn't immediately discard the node. (#2109)
+- Docking: Fix for node created at the same time as windows that are still resizing (typically with
+  io.ConfigDockingAlwaysTabBar) to not be zero/min sized. (#2109). The fix delays their visibility by one frame,
+  which is not ideal but not very problematic as the .ini data gets populated after that.
+- Docking: Fix a crash that could occur with a malformed ini file (DockNode Parent value pointing to a missing node).
+- Viewport: Fix modal/popup window being stuck in unowned hidden viewport associated to fallback window without stealing
+  it back. Fix modal reference viewport when opened outside of another window. (#1542)
+- Viewport: Modals don't need to set ImGuiViewportFlags_NoFocusOnClick, this also mitigate the issue described by #2445,
+  which becomes particularly bad with unfocused modal. (#1542)
+- Viewport: better case case where host window gets moved and resized simultaneous (toggling maximized state).
+  There's no perfect solution there, than using io.ConfigViewportsNoAutoMerge = false. (#1542)
+- Viewport, Docking: Fixed incorrect assignment of IsFallbackWindow which would tag dock node host windows created
+  in NewFrame() as such, messing with popup viewport inheritance.
+- Viewport: Fixed issue where resize grip would display as hovered while mouse is still off the OS bounds so a click
+  would miss it and focus the OS window behind expected one. (#1542)
+- Viewport: Fix to allow multiple shutdown / calls to DestroyPlatformWindows(). (#2769)
+- Viewport: Backends: GLFW: Fix setting window size on macOS (#2767, #2117) [@rokups]
+- Viewport: Backends: GLFW+Linux: Fix window having incorrect size after uncollapse. (#2756, #2117) [@rokups]
+- Viewport: Backends: DirectX9: Workaround for windows not refreshing when main viewport has no draw call. (#2560)
+
 
 -----------------------------------------------------------------------
  VERSION 1.72b (Released 2019-07-31)
@@ -2725,6 +2861,25 @@ Other Changes:
   (#2482, #2632) [@josiahmanson]
 - Examples: Added SDL2+DirectX11 example application. (#2632, #2612, #2482) [@vincenthamm]
 
+Docking+Viewports Branch:
+
+- Docking: Making it possible to undock a node by clicking on the tab bar / title bar for the node. (#2645).
+- Docking: Explicitly inhibit constraint when docked for now. Fix clipping issue related to constraints. (#2690).
+- Docking: Fixed dragging/resizing from OS decoration not marking settings as dirty.
+- Docking: Renamed io.ConfigDockingTabBarOnSingleWindows to io.ConfigDockingAlwaysTabBar.
+  Added ImGuiWindowClass::DockingAlwaysTabBar to set on individual windows.
+- Docking: Perform simple check: assert if Docking or Viewport are enabled exactly on frame 1 (instead of frame 0
+  or later), which is a common user error leading to loss of .ini data on load.
+- Docking: Fix so that an appearing window making a dock node reappear won't have a zero-size on its first frame.
+- Docking: Fixed using ImGuiDockNodeFlags_AutoHideTabBar with io.ConfigDockingTabBarOnSingleWindows.
+- Docking: Added ImGuiDockNode to .natvis file.
+- Docking: Fixed support for large meshes in GetBackgroundDrawList(), GetForegroundDrawList(). (#2638)
+- Viewport: Fix monitor dpi info not being copied to main viewport when multi-viewports are not enabled. (#2621, #1676)
+- Viewport: Refactored ImGuiWindowClass's ViewportFlagsOverrideMask + ViewportFlagsOverrideValue into
+  ViewportFlagsOverrideSet + ViewportFlagsOverrideClear which appears easier to grasp. (#1542)
+- Viewport: Added ImGuiViewportFlags_NoAutoMerge to prevent merging into host viewport in a per-window basis
+  via the ImGuiWindowClass override mechanism. (#1542)
+
 
 -----------------------------------------------------------------------
  VERSION 1.71 (Released 2019-06-12)
@@ -3064,6 +3219,7 @@ Breaking Changes:
 - Renamed ImFontAtlas::GlyphRangesBuilder to ImFontGlyphRangesBuilder. Kept redirection typedef (will obsolete).
 
 Other Changes:
+
 - Added BETA api for Tab Bar/Tabs widgets: (#261, #351)
   - Added BeginTabBar(), EndTabBar(), BeginTabItem(), EndTabItem(), SetTabItemClosed() API.
   - Added ImGuiTabBarFlags flags for BeginTabBar().

docs/EXAMPLES.md

@@ -10,7 +10,7 @@ integrating Dear ImGui in your own application/game/engine.
 **Once Dear ImGui is setup and running, run and refer to `ImGui::ShowDemoWindow()` in imgui_demo.cpp for usage of the end-user API.**
 
 You can find Windows binaries for some of those example applications at:
-  https://www.dearimgui.com/binaries
+  http://www.dearimgui.com/binaries
 
 
 ### Getting Started
@@ -74,7 +74,7 @@ ImGui::DestroyContext();
 
 Please read 'PROGRAMMER GUIDE' in imgui.cpp for notes on how to setup Dear ImGui in your codebase.
 Please read the comments and instruction at the top of each file.
-Please read FAQ at https://www.dearimgui.com/faq
+Please read FAQ at http://www.dearimgui.com/faq
 
 If you are using any of the backends provided here, you can add the backends/imgui_impl_xxxx(.cpp,.h)
 files to your project and use as-in. Each imgui_impl_xxxx.cpp file comes with its own individual

docs/FAQ.md

@@ -125,8 +125,13 @@ void MyLowLevelMouseButtonHandler(int button, bool down)
 }
 ```
 
+
 **Note:** The `io.WantCaptureMouse` is more correct that any manual attempt to "check if the mouse is hovering a window" (don't do that!). It handles mouse dragging correctly (both dragging that started over your application or over a Dear ImGui window) and handle e.g. popup and modal windows blocking inputs.
 
+**Note:** Those flags are updated by `ImGui::NewFrame()`. However it is generally more correct and easier that you poll flags from the previous frame, then submit your inputs, then call `NewFrame()`. If you attempt to do the opposite (which is generally harder) you are likely going to submit your inputs after `NewFrame()`, and therefore too late.
+
+**Note:** If you are using a touch device, you may find use for an early call to `UpdateHoveredWindowAndCaptureFlags()` to correctly dispatch your initial touch. We will work on better out-of-the-box touch support in the future.
+
 **Note:** Text input widget releases focus on the "KeyDown" event of the Return key, so the subsequent "KeyUp" event that your application receive will typically have `io.WantCaptureKeyboard == false`. Depending on your application logic it may or not be inconvenient to receive that KeyUp event. You might want to track which key-downs were targeted for Dear ImGui, e.g. with an array of bool, and filter out the corresponding key-ups.)
 
 ##### [Return to Index](#index)
@@ -137,7 +142,7 @@ void MyLowLevelMouseButtonHandler(int button, bool down)
 - The gamepad/keyboard navigation is fairly functional and keeps being improved. The initial focus was to support game controllers, but keyboard is becoming increasingly and decently usable. Gamepad support is particularly useful to use Dear ImGui on a game console (e.g. PS4, Switch, XB1) without a mouse connected!
 - Keyboard: set `io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard` to enable.
 - Gamepad: set `io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad` to enable (with a supporting backend).
-- See [Control Sheets for Gamepads](https://www.dearimgui.com/controls_sheets) (reference PNG/PSD for PS4, XB1, Switch gamepads).
+- See [Control Sheets for Gamepads](http://www.dearimgui.com/controls_sheets) (reference PNG/PSD for PS4, XB1, Switch gamepads).
 - See `USING GAMEPAD/KEYBOARD NAVIGATION CONTROLS` section of [imgui.cpp](https://github.com/ocornut/imgui/blob/master/imgui.cpp) for more details.
 
 ##### [Return to Index](#index)
@@ -212,7 +217,7 @@ Interactive widgets (such as calls to Button buttons) need a unique ID.
 **Unique IDs are used internally to track active widgets and occasionally associate state to widgets.<BR>
 Unique IDs are implicitly built from the hash of multiple elements that identify the "path" to the UI element.**
 
-Since Dear ImGui 1.85, you can use `Demo>Tools>ID Stack Tool` or call `ImGui::ShowIDStackToolWindow()`. The tool display intermediate values leading to the creation of a unique ID, making things easier to debug and understand.
+Since Dear ImGui 1.85, you can use `Demo>Tools>Stack Tool` or call `ImGui::ShowStackToolWindow()`. The tool display intermediate values leading to the creation of a unique ID, making things easier to debug and understand.
 
 ![Stack tool](https://user-images.githubusercontent.com/8225057/136235657-a0ea5665-dcd1-423f-9be6-dc3f8ced8f12.png)
 
@@ -622,7 +627,7 @@ You may take a look at:
 - [Quotes](https://github.com/ocornut/imgui/wiki/Quotes)
 - [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui)
 - [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors)
-- [Gallery](https://github.com/ocornut/imgui/issues/6897)
+- [Gallery](https://github.com/ocornut/imgui/issues/6478)
 
 ##### [Return to Index](#index)
 
@@ -664,11 +669,11 @@ There is an auto-generated [c-api for Dear ImGui (cimgui)](https://github.com/ci
 # Q&A: Community
 
 ### Q: How can I help?
-- Businesses: please reach out to `omar AT dearimgui.com` if you work in a place using Dear ImGui! We can discuss ways for your company to fund development via invoiced technical support, maintenance, or sponsoring contacts. This is among the most useful thing you can do for Dear ImGui. With increased funding, we can hire more people to work on this project.
+- Businesses: please reach out to `contact AT dearimgui.com` if you work in a place using Dear ImGui! We can discuss ways for your company to fund development via invoiced technical support, maintenance, or sponsoring contacts. This is among the most useful thing you can do for Dear ImGui. With increased funding, we can hire more people to work on this project.
 - Individuals: you can support continued maintenance and development via PayPal donations. See [README](https://github.com/ocornut/imgui/blob/master/docs/README.md).
 - If you are experienced with Dear ImGui and C++, look at [GitHub Issues](https://github.com/ocornut/imgui/issues), [GitHub Discussions](https://github.com/ocornut/imgui/discussions), the [Wiki](https://github.com/ocornut/imgui/wiki), read [docs/TODO.txt](https://github.com/ocornut/imgui/blob/master/docs/TODO.txt), and see how you want to help and can help!
 - Disclose your usage of Dear ImGui via a dev blog post, a tweet, a screenshot, a mention somewhere, etc.
-You may post screenshots or links in the [gallery threads](https://github.com/ocornut/imgui/issues/6897). Visuals are ideal as they inspire other programmers. Disclosing your use of Dear ImGui helps the library grow credibility, and helps other teams and programmers with taking decisions.
+You may post screenshots or links in the [gallery threads](https://github.com/ocornut/imgui/issues/6478). Visuals are ideal as they inspire other programmers. Disclosing your use of Dear ImGui helps the library grow credibility, and helps other teams and programmers with taking decisions.
 - If you have issues or if you need to hack into the library, even if you don't expect any support it is useful that you share your issues or sometimes incomplete PR.
 
 ##### [Return to Index](#index)

docs/FONTS.md

@@ -14,13 +14,12 @@ In the [misc/fonts/](https://github.com/ocornut/imgui/tree/master/misc/fonts) fo
 - [Troubleshooting](#troubleshooting)
 - [How should I handle DPI in my application?](#how-should-i-handle-dpi-in-my-application)
 - [Fonts Loading Instructions](#fonts-loading-instructions)
-- [Loading Font Data from Memory](#loading-font-data-from-memory)
-- [Loading Font Data Embedded In Source Code](#loading-font-data-embedded-in-source-code)
 - [Using Icon Fonts](#using-icon-fonts)
 - [Using FreeType Rasterizer (imgui_freetype)](#using-freetype-rasterizer-imgui_freetype)
 - [Using Colorful Glyphs/Emojis](#using-colorful-glyphsemojis)
 - [Using Custom Glyph Ranges](#using-custom-glyph-ranges)
 - [Using Custom Colorful Icons](#using-custom-colorful-icons)
+- [Using Font Data Embedded In Source Code](#using-font-data-embedded-in-source-code)
 - [About Filenames](#about-filenames)
 - [About UTF-8 Encoding](#about-utf-8-encoding)
 - [Debug Tools](#debug-tools)
@@ -62,7 +61,6 @@ Some solutions:
 
 ##### [Return to Index](#index)
 
----------------------------------------
 
 ## How should I handle DPI in my application?
 
@@ -70,7 +68,6 @@ See [FAQ entry](https://github.com/ocornut/imgui/blob/master/docs/FAQ.md#q-how-s
 
 ##### [Return to Index](#index)
 
----------------------------------------
 
 ## Fonts Loading Instructions
 
@@ -142,6 +139,7 @@ io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, nullptr, io.Fonts->GetGlyp
 ```
 See [Using Custom Glyph Ranges](#using-custom-glyph-ranges) section to create your own ranges.
 
+
 **Example loading and using a Japanese font:**
 
 ```cpp
@@ -163,48 +161,6 @@ ImGui::SliderFloat("float", &f, 0.0f, 1.0f);
 
 ##### [Return to Index](#index)
 
----------------------------------------
-
-## Loading Font Data from Memory
-
-```cpp
-ImFont* font = io.Fonts->AddFontFromMemoryTTF(data, data_size, size_pixels, ...);
-```
-
-IMPORTANT: `AddFontFromMemoryTTF()` by default transfer ownership of the data buffer to the font atlas, which will attempt to free it on destruction.
-This was to avoid an unnecessary copy, and is perhaps not a good API (a future version will redesign it).
-If you want to keep ownership of the data and free it yourself, you need to clear the `FontDataOwnedByAtlas` field:
-
-```cpp
-ImFontConfig font_cfg;
-font_cfg.FontDataOwnedByAtlas = false;
-ImFont* font = io.Fonts->AddFontFromMemoryTTF(data, data_size, size_pixels, &font_cfg);
-```
-
-##### [Return to Index](#index)
-
----------------------------------------
-
-## Loading Font Data Embedded In Source Code
-
-- Compile and use [binary_to_compressed_c.cpp](https://github.com/ocornut/imgui/blob/master/misc/fonts/binary_to_compressed_c.cpp) to create a compressed C style array that you can embed in source code.
-- See the documentation in [binary_to_compressed_c.cpp](https://github.com/ocornut/imgui/blob/master/misc/fonts/binary_to_compressed_c.cpp) for instructions on how to use the tool.
-- You may find a precompiled version binary_to_compressed_c.exe for Windows inside the demo binaries package (see [README](https://github.com/ocornut/imgui/blob/master/docs/README.md)).
-- The tool can optionally output Base85 encoding to reduce the size of _source code_ but the read-only arrays in the actual binary will be about 20% bigger.
-
-Then load the font with:
-```cpp
-ImFont* font = io.Fonts->AddFontFromMemoryCompressedTTF(compressed_data, compressed_data_size, size_pixels, ...);
-```
-or
-```cpp
-ImFont* font = io.Fonts->AddFontFromMemoryCompressedBase85TTF(compressed_data_base85, size_pixels, ...);
-```
-
-##### [Return to Index](#index)
-
----------------------------------------
-
 ## Using Icon Fonts
 
 Using an icon font (such as [FontAwesome](http://fontawesome.io) or [OpenFontIcons](https://github.com/traverseda/OpenFontIcons)) is an easy and practical way to use icons in your Dear ImGui application.
@@ -248,8 +204,6 @@ Here's an application using icons ("Avoyd", https://www.avoyd.com):
 
 ##### [Return to Index](#index)
 
----------------------------------------
-
 ## Using FreeType Rasterizer (imgui_freetype)
 
 - Dear ImGui uses imstb\_truetype.h to rasterize fonts (with optional oversampling). This technique and its implementation are not ideal for fonts rendered at small sizes, which may appear a little blurry or hard to read.
@@ -260,8 +214,6 @@ Here's an application using icons ("Avoyd", https://www.avoyd.com):
 
 ##### [Return to Index](#index)
 
----------------------------------------
-
 ## Using Colorful Glyphs/Emojis
 
 - Rendering of colored emojis is supported by imgui_freetype with FreeType 2.10+.
@@ -284,8 +236,6 @@ io.Fonts->AddFontFromFileTTF("C:\\Windows\\Fonts\\seguiemj.ttf", 16.0f, &cfg, ra
 
 ##### [Return to Index](#index)
 
----------------------------------------
-
 ## Using Custom Glyph Ranges
 
 You can use the `ImFontGlyphRangesBuilder` helper to create glyph ranges based on text input. For example: for a game where your script is known, if you can feed your entire script to it and only build the characters the game needs.
@@ -303,8 +253,6 @@ io.Fonts->Build();                                     // Build the atlas while
 
 ##### [Return to Index](#index)
 
----------------------------------------
-
 ## Using Custom Colorful Icons
 
 As an alternative to rendering colorful glyphs using imgui_freetype with `ImGuiFreeTypeBuilderFlags_LoadColor`, you may allocate your own space in the texture atlas and write yourself into it. **(This is a BETA api, use if you are familiar with dear imgui and with your rendering backend)**
@@ -347,7 +295,25 @@ for (int rect_n = 0; rect_n < IM_ARRAYSIZE(rect_ids); rect_n++)
 
 ##### [Return to Index](#index)
 
----------------------------------------
+## Using Font Data Embedded In Source Code
+
+- Compile and use [binary_to_compressed_c.cpp](https://github.com/ocornut/imgui/blob/master/misc/fonts/binary_to_compressed_c.cpp) to create a compressed C style array that you can embed in source code.
+- See the documentation in [binary_to_compressed_c.cpp](https://github.com/ocornut/imgui/blob/master/misc/fonts/binary_to_compressed_c.cpp) for instructions on how to use the tool.
+- You may find a precompiled version binary_to_compressed_c.exe for Windows inside the demo binaries package (see [README](https://github.com/ocornut/imgui/blob/master/docs/README.md)).
+- The tool can optionally output Base85 encoding to reduce the size of _source code_ but the read-only arrays in the actual binary will be about 20% bigger.
+
+Then load the font with:
+```cpp
+ImFont* font = io.Fonts->AddFontFromMemoryCompressedTTF(compressed_data, compressed_data_size, size_pixels, ...);
+```
+or
+```cpp
+ImFont* font = io.Fonts->AddFontFromMemoryCompressedBase85TTF(compressed_data_base85, size_pixels, ...);
+```
+
+##### [Return to Index](#index)
+
+--
 
 ## About Filenames
 
@@ -369,7 +335,7 @@ io.Fonts->AddFontFromFileTTF("../MyImage01.jpg", ...);    // Load from the paren
 ```
 ##### [Return to Index](#index)
 
----------------------------------------
+--
 
 ## About UTF-8 Encoding
 
@@ -416,7 +382,7 @@ ImGui::Text(U8("こんにちは"));
 ```
 ##### [Return to Index](#index)
 
----------------------------------------
+--
 
 ## Debug Tools
 
@@ -432,7 +398,7 @@ You can use the `UTF-8 Encoding viewer` in `Metrics/Debugger` to verify the cont
 
 ##### [Return to Index](#index)
 
----------------------------------------
+--
 
 ## Credits/Licenses For Fonts Included In Repository
 

docs/README.md

@@ -27,7 +27,7 @@ Dear ImGui is designed to **enable fast iterations** and to **empower programmer
 Dear ImGui is particularly suited to integration in game engines (for tooling), real-time 3D applications, fullscreen applications, embedded applications, or any applications on console platforms where operating system features are non-standard.
 
  - Minimize state synchronization.
- - Minimize UI-related state storage on user side.
+ - Minimize state storage on user side.
  - Minimize setup and maintenance.
  - Easy to use to create dynamic UI which are the reflection of a dynamic data set.
  - Easy to use to create code-driven and data-driven tools.
@@ -128,18 +128,18 @@ Officially maintained backends/bindings (in repository):
 - Frameworks: Allegro5, Emscripten.
 
 [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.
+- Languages: C, C# and: Beef, ChaiScript, Crystal, D, Go, Haskell, Haxe/hxcpp, Java, JavaScript, Julia, Kotlin, Lobster, Lua, Odin, Pascal, PureBasic, Python, Ruby, Rust, Swift...
+- Frameworks: AGS/Adventure Game Studio, Amethyst, Blender, bsf, Cinder, Cocos2d-x, Diligent Engine, Flexium, GML/Game Maker Studio2, GLEQ, Godot, GTK3+OpenGL3, Irrlicht Engine, LÖVE+LUA, Magnum, Monogame, NanoRT, nCine, Nim Game Lib, Nintendo 3DS & Switch (homebrew), Ogre, openFrameworks, OSG/OpenSceneGraph, Orx, Photoshop, px_render, Qt/QtDirect3D, SDL_Renderer, SFML, Sokol, Unity, Unreal Engine 4, 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.
 
 [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).
+- Automation/testing, Text editors, node editors, timeline editors, plotting, software renderers, remote network access, memory editors, gizmos, etc. One of the most notable and well supported extension is [ImPlot](https://github.com/epezent/implot).
 
 Also see [Wiki](https://github.com/ocornut/imgui/wiki) for more links and ideas.
 
 ### Gallery
 
-For more user-submitted screenshots of projects using Dear ImGui, check out the [Gallery Threads](https://github.com/ocornut/imgui/issues/6897)!
+For more user-submitted screenshots of projects using Dear ImGui, check out the [Gallery Threads](https://github.com/ocornut/imgui/issues/6478)!
 
 For a list of third-party widgets and extensions, check out the [Useful Extensions/Widgets](https://github.com/ocornut/imgui/wiki/Useful-Extensions) wiki page.
 
@@ -160,7 +160,7 @@ See: [Upcoming Changes](https://github.com/ocornut/imgui/wiki/Upcoming-Changes).
 
 See: [Dear ImGui Test Engine + Test Suite](https://github.com/ocornut/imgui_test_engine) for Automation & Testing.
 
-Getting started? For first-time users having issues compiling/linking/running or issues loading fonts, please use [GitHub Discussions](https://github.com/ocornut/imgui/discussions). For ANY other questions, bug reports, requests, feedback, please post on [GitHub Issues](https://github.com/ocornut/imgui/issues). Please read and fill the New Issue template carefully.
+Getting started? For first-time users having issues compiling/linking/running or issues loading fonts, please use [GitHub Discussions](https://github.com/ocornut/imgui/discussions). For other questions, bug reports, requests, feedback, you may post on [GitHub Issues](https://github.com/ocornut/imgui/issues). Please read and fill the New Issue template carefully.
 
 Private support is available for paying business customers (E-mail: _contact @ dearimgui dot com_).
 
@@ -170,17 +170,17 @@ We occasionally tag [Releases](https://github.com/ocornut/imgui/releases) (with
 
 **Who uses Dear ImGui?**
 
-See the [Quotes](https://github.com/ocornut/imgui/wiki/Quotes), [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors), and [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui) Wiki pages for an idea of who is using Dear ImGui. Please add your game/software if you can! Also, see the [Gallery Threads](https://github.com/ocornut/imgui/issues/6897)!
+See the [Quotes](https://github.com/ocornut/imgui/wiki/Quotes), [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors), and [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui) Wiki pages for an idea of who is using Dear ImGui. Please add your game/software if you can! Also, see the [Gallery Threads](https://github.com/ocornut/imgui/issues/6478)!
 
 How to help
 -----------
 
 **How can I help?**
 
-- See [GitHub Forum/Issues](https://github.com/ocornut/imgui/issues).
+- See [GitHub Forum/Issues](https://github.com/ocornut/imgui/issues) and [GitHub Discussions](https://github.com/ocornut/imgui/discussions).
 - 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 [sponsor](https://github.com/ocornut/imgui/wiki/Sponsors)! 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).
+- Have your company financially support this project with invoiced sponsoring/support contracts 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
 --------
@@ -201,9 +201,9 @@ Credits
 
 Developed by [Omar Cornut](https://www.miracleworld.net) and every direct or indirect [contributors](https://github.com/ocornut/imgui/graphs/contributors) to the GitHub. The early version of this library was developed with the support of [Media Molecule](https://www.mediamolecule.com) and first used internally on the game [Tearaway](https://tearaway.mediamolecule.com) (PS Vita).
 
-Recurring contributors include Rokas Kupstys [@rokups](https://github.com/rokups) (2020-2022): a good portion of work on automation system and regression tests now available in [Dear ImGui Test Engine](https://github.com/ocornut/imgui_test_engine).
+Recurring contributors (2022): Omar Cornut [@ocornut](https://github.com/ocornut), Rokas Kupstys [@rokups](https://github.com/rokups) (a good portion of work on automation system and regression tests now available in [Dear ImGui Test Engine](https://github.com/ocornut/imgui_test_engine)).
 
-Sponsoring, maintenance/support contracts and other B2B transactions are hosted and handled by [Disco Hello](https://www.discohello.com).
+Sponsoring, support contracts and other B2B transactions are hosted and handled by [Disco Hello](https://www.discohello.com).
 
 Omar: "I first discovered the IMGUI paradigm at [Q-Games](https://www.q-games.com) where Atman Binstock had dropped his own simple implementation in the codebase, which I spent quite some time improving and thinking about. It turned out that Atman was exposed to the concept directly by working with Casey. When I moved to Media Molecule I rewrote a new library trying to overcome the flaws and limitations of the first one I've worked with. It became this library and since then I have spent an unreasonable amount of time iterating and improving it."
 

docs/TODO.txt

@@ -126,10 +126,38 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
 
  - separator: expose flags (#759)
  - separator: take indent into consideration (optional)
- - separator: width, thickness, centering (#1643, #2657)
+ - separator: width, thickness, centering (#1643)
  - 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.
@@ -187,6 +215,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - tree node / selectable render mismatch which is visible if you use them both next to each other (e.g. cf. property viewer)
  - tree node: tweak color scheme to distinguish headers from selected tree node (#581)
  - tree node: leaf/non-leaf highlight mismatch.
+ - tree node: flag to disable formatting and/or detect "%s"
  - tree node/opt: could avoid formatting when clipped (flag assuming we don't care about width/height, assume single line height? format only %s/%c to be able to count height?)
 
  - settings: write more decent code to allow saving/loading new fields: columns, selected tree nodes?
@@ -303,6 +332,20 @@ 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
+ - 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.
+ - 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

@@ -1,10 +1,6 @@
 // Dear ImGui: standalone example application for Allegro 5
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // On Windows, you can install Allegro5 using vcpkg:
 //   git clone https://github.com/Microsoft/vcpkg
@@ -40,6 +36,7 @@ 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();

examples/example_android_opengl3/main.cpp

@@ -1,10 +1,5 @@
 // dear imgui: standalone example application for Android + OpenGL ES 3
-
-// 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
+// If you are new to dear imgui, see examples/README.txt and documentation at the top of imgui.cpp.
 
 #include "imgui.h"
 #include "imgui_impl_android.h"

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 */,
@@ -268,9 +281,9 @@
 				8309BDBB253CCCAD0045E2A1 /* imgui_impl_metal.mm in Sources */,
 				83BBEA0920EB54E700295997 /* imgui.cpp in Sources */,
 				83BBEA0720EB54E700295997 /* imgui_demo.cpp in Sources */,
-                83BBEA0520EB54E700295997 /* imgui_draw.cpp in Sources */,
+				83BBEA0520EB54E700295997 /* imgui_draw.cpp in Sources */,
 				5079822E257677DB0038A28D /* imgui_tables.cpp in Sources */,
-                07A82ED82139413D0078D120 /* imgui_widgets.cpp in Sources */,
+				07A82ED82139413D0078D120 /* imgui_widgets.cpp in Sources */,
 				8309BDA5253CCC070045E2A1 /* main.mm in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -281,10 +294,10 @@
 			files = (
 				8309BDBE253CCCB60045E2A1 /* imgui_impl_metal.mm in Sources */,
 				8309BDBF253CCCB60045E2A1 /* imgui_impl_osx.mm in Sources */,
-                83BBEA0A20EB54E700295997 /* imgui.cpp in Sources */,
-                83BBEA0820EB54E700295997 /* imgui_demo.cpp in Sources */,
-                83BBEA0620EB54E700295997 /* imgui_draw.cpp in Sources */,
-                5079822E257677DB0038A28D /* imgui_tables.cpp in Sources */,
+				83BBEA0A20EB54E700295997 /* imgui.cpp in Sources */,
+				83BBEA0820EB54E700295997 /* imgui_demo.cpp in Sources */,
+				83BBEA0620EB54E700295997 /* imgui_draw.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

@@ -1,10 +1,6 @@
 // Dear ImGui: standalone example application for OSX + Metal.
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #import <Foundation/Foundation.h>
 
@@ -60,11 +56,21 @@
     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);
 
@@ -195,6 +201,13 @@
 	// 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

@@ -1,10 +1,6 @@
 // Dear ImGui: standalone example application for OSX + OpenGL2, using legacy fixed pipeline
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #import <Cocoa/Cocoa.h>
 #import <OpenGL/gl.h>
@@ -47,11 +43,21 @@
     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();
@@ -136,6 +142,13 @@
 
     ImGui_ImplOpenGL2_RenderDrawData(draw_data);
 
+    // Update and Render additional Platform Windows
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
+
     // Present
     [[self openGLContext] flushBuffer];
 

examples/example_emscripten_wgpu/main.cpp

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for Emscripten, using GLFW + WebGPU
 // (Emscripten is a C++-to-javascript compiler, used to publish executables for the web. See https://emscripten.org/)
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #include "imgui_impl_glfw.h"

examples/example_glfw_metal/main.mm

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for GLFW + Metal, using programmable pipeline
 // (GLFW 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #include "imgui_impl_glfw.h"
@@ -33,11 +29,21 @@ 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.
@@ -69,7 +75,7 @@ int main(int, char**)
     id <MTLCommandQueue> commandQueue = [device newCommandQueue];
 
     // Setup Platform/Renderer backends
-    ImGui_ImplGlfw_InitForOpenGL(window, true);
+    ImGui_ImplGlfw_InitForOther(window, true);
     ImGui_ImplMetal_Init(device);
 
     NSWindow *nswin = glfwGetCocoaWindow(window);
@@ -157,6 +163,13 @@ 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/main.cpp

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for GLFW + OpenGL2, using legacy fixed pipeline
 // (GLFW 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)**
 // **Prefer using the code in the example_glfw_opengl2/ folder**
@@ -52,11 +48,23 @@ 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();
 
+    // 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_ImplGlfw_InitForOpenGL(window, true);
     ImGui_ImplOpenGL2_Init();
@@ -150,6 +158,17 @@ 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/main.cpp

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for GLFW + OpenGL 3, using programmable pipeline
 // (GLFW 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #include "imgui_impl_glfw.h"
@@ -77,11 +73,23 @@ 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();
 
+    // 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_ImplGlfw_InitForOpenGL(window, true);
     ImGui_ImplOpenGL3_Init(glsl_version);
@@ -176,6 +184,17 @@ 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/main.cpp

@@ -1,10 +1,6 @@
 // Dear ImGui: standalone example application for Glfw + Vulkan
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // Important note to the reader who wish to integrate imgui_impl_vulkan.cpp/.h in their own engine/app.
 // - Common ImGui_ImplVulkan_XXX functions and structures are used to interface with imgui_impl_vulkan.cpp/.h.
@@ -419,11 +415,23 @@ 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();
 
+    // 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_ImplGlfw_InitForVulkan(window, true);
     ImGui_ImplVulkan_InitInfo init_info = {};
@@ -458,6 +466,36 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != nullptr);
 
+    // Upload Fonts
+    {
+        // Use any command queue
+        VkCommandPool command_pool = wd->Frames[wd->FrameIndex].CommandPool;
+        VkCommandBuffer command_buffer = wd->Frames[wd->FrameIndex].CommandBuffer;
+
+        err = vkResetCommandPool(g_Device, command_pool, 0);
+        check_vk_result(err);
+        VkCommandBufferBeginInfo begin_info = {};
+        begin_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
+        begin_info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
+        err = vkBeginCommandBuffer(command_buffer, &begin_info);
+        check_vk_result(err);
+
+        ImGui_ImplVulkan_CreateFontsTexture(command_buffer);
+
+        VkSubmitInfo end_info = {};
+        end_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
+        end_info.commandBufferCount = 1;
+        end_info.pCommandBuffers = &command_buffer;
+        err = vkEndCommandBuffer(command_buffer);
+        check_vk_result(err);
+        err = vkQueueSubmit(g_Queue, 1, &end_info, VK_NULL_HANDLE);
+        check_vk_result(err);
+
+        err = vkDeviceWaitIdle(g_Device);
+        check_vk_result(err);
+        ImGui_ImplVulkan_DestroyFontUploadObjects();
+    }
+
     // Our state
     bool show_demo_window = true;
     bool show_another_window = false;
@@ -531,17 +569,25 @@ 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_glut_opengl2/main.cpp

@@ -1,10 +1,6 @@
 // Dear ImGui: standalone example application for GLUT/FreeGLUT + OpenGL2, using legacy fixed pipeline
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // !!! GLUT/FreeGLUT IS OBSOLETE PREHISTORIC SOFTWARE. Using GLUT is not recommended unless you really miss the 90's. !!!
 // !!! If someone or something is teaching you GLUT today, you are being abused. Please show some resistance. !!!
@@ -61,6 +57,7 @@ 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();
@@ -78,7 +75,6 @@ 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.

examples/example_sdl2_directx11/main.cpp

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for SDL2 + 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #include "imgui_impl_sdl2.h"
@@ -65,11 +61,23 @@ 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();
 
+    // 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_ImplSDL2_InitForD3D(window);
     ImGui_ImplDX11_Init(g_pd3dDevice, g_pd3dDeviceContext);
@@ -170,6 +178,13 @@ 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
     }

examples/example_sdl2_metal/main.mm

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for SDL2 + 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #include "imgui_impl_sdl2.h"
@@ -24,11 +20,21 @@ 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.
@@ -168,6 +174,13 @@ 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

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for SDL2 + OpenGL
 // (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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)**
 // **Prefer using the code in the example_sdl2_opengl3/ folder**
@@ -51,11 +47,23 @@ 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();
 
+    // 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_ImplSDL2_InitForOpenGL(window, gl_context);
     ImGui_ImplOpenGL2_Init();
@@ -149,6 +157,19 @@ 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

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for SDL2 + OpenGL
 // (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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #include "imgui_impl_sdl2.h"
@@ -78,11 +74,23 @@ 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();
 
+    // 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_ImplSDL2_InitForOpenGL(window, gl_context);
     ImGui_ImplOpenGL3_Init(glsl_version);
@@ -183,6 +191,19 @@ 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

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for SDL2 + SDL_Renderer
 // (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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // Important to understand: SDL_Renderer is an _optional_ component of SDL2.
 // For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.

examples/example_sdl2_vulkan/main.cpp

@@ -1,10 +1,6 @@
 // Dear ImGui: standalone example application for SDL2 + Vulkan
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // Important note to the reader who wish to integrate imgui_impl_vulkan.cpp/.h in their own engine/app.
 // - Common ImGui_ImplVulkan_XXX functions and structures are used to interface with imgui_impl_vulkan.cpp/.h.
@@ -414,11 +410,23 @@ 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();
 
+    // 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_ImplSDL2_InitForVulkan(window);
     ImGui_ImplVulkan_InitInfo init_info = {};
@@ -453,6 +461,36 @@ int main(int, char**)
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != nullptr);
 
+    // Upload Fonts
+    {
+        // Use any command queue
+        VkCommandPool command_pool = wd->Frames[wd->FrameIndex].CommandPool;
+        VkCommandBuffer command_buffer = wd->Frames[wd->FrameIndex].CommandBuffer;
+
+        err = vkResetCommandPool(g_Device, command_pool, 0);
+        check_vk_result(err);
+        VkCommandBufferBeginInfo begin_info = {};
+        begin_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
+        begin_info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
+        err = vkBeginCommandBuffer(command_buffer, &begin_info);
+        check_vk_result(err);
+
+        ImGui_ImplVulkan_CreateFontsTexture(command_buffer);
+
+        VkSubmitInfo end_info = {};
+        end_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
+        end_info.commandBufferCount = 1;
+        end_info.pCommandBuffers = &command_buffer;
+        err = vkEndCommandBuffer(command_buffer);
+        check_vk_result(err);
+        err = vkQueueSubmit(g_Queue, 1, &end_info, VK_NULL_HANDLE);
+        check_vk_result(err);
+
+        err = vkDeviceWaitIdle(g_Device);
+        check_vk_result(err);
+        ImGui_ImplVulkan_DestroyFontUploadObjects();
+    }
+
     // Our state
     bool show_demo_window = true;
     bool show_another_window = false;
@@ -535,17 +573,25 @@ 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_opengl3/main.cpp

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for SDL3 + OpenGL
 // (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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #include "imgui_impl_sdl3.h"
@@ -83,11 +79,23 @@ 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();
 
+    // 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_ImplSDL3_InitForOpenGL(window, gl_context);
     ImGui_ImplOpenGL3_Init(glsl_version);
@@ -188,6 +196,19 @@ 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_sdlrenderer3/main.cpp

@@ -1,11 +1,7 @@
 // Dear ImGui: standalone example application for SDL3 + SDL_Renderer
 // (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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // Important to understand: SDL_Renderer is an _optional_ component of SDL3.
 // For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.

examples/example_win32_directx10/main.cpp

@@ -1,10 +1,6 @@
 // Dear ImGui: standalone example application for DirectX 10
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #include "imgui_impl_win32.h"
@@ -53,11 +49,23 @@ 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();
 
+    // 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_ImplWin32_Init(hwnd);
     ImGui_ImplDX10_Init(g_pd3dDevice);
@@ -158,6 +166,13 @@ 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();
+        }
+
         g_pSwapChain->Present(1, 0); // Present with vsync
         //g_pSwapChain->Present(0, 0); // Present without vsync
     }
@@ -174,7 +189,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain

examples/example_win32_directx11/main.cpp

@@ -1,10 +1,6 @@
 // Dear ImGui: standalone example application for DirectX 11
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #include "imgui_impl_win32.h"
@@ -53,11 +49,28 @@ 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.ConfigViewportsNoDefaultParent = true;
+    //io.ConfigDockingAlwaysTabBar = true;
+    //io.ConfigDockingTransparentPayload = true;
+    //io.ConfigFlags |= ImGuiConfigFlags_DpiEnableScaleFonts;     // FIXME-DPI: Experimental. THIS CURRENTLY DOESN'T WORK AS EXPECTED. DON'T USE IN USER APP!
+    //io.ConfigFlags |= ImGuiConfigFlags_DpiEnableScaleViewports; // FIXME-DPI: Experimental.
 
     // 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_ImplWin32_Init(hwnd);
     ImGui_ImplDX11_Init(g_pd3dDevice, g_pd3dDeviceContext);
@@ -158,6 +171,13 @@ 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
     }
@@ -175,7 +195,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain
@@ -230,6 +249,10 @@ void CleanupRenderTarget()
     if (g_mainRenderTargetView) { g_mainRenderTargetView->Release(); g_mainRenderTargetView = nullptr; }
 }
 
+#ifndef WM_DPICHANGED
+#define WM_DPICHANGED 0x02E0 // From Windows SDK 8.1+ headers
+#endif
+
 // Forward declare message handler from imgui_impl_win32.cpp
 extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 
@@ -258,6 +281,15 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
     case WM_DESTROY:
         ::PostQuitMessage(0);
         return 0;
+    case WM_DPICHANGED:
+        if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_DpiEnableScaleViewports)
+        {
+            //const int dpi = HIWORD(wParam);
+            //printf("WM_DPICHANGED to %d (%.0f%%)\n", dpi, (float)dpi / 96.0f * 100.0f);
+            const RECT* suggested_rect = (RECT*)lParam;
+            ::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);
+        }
+        break;
     }
     return ::DefWindowProcW(hWnd, msg, wParam, lParam);
 }

examples/example_win32_directx12/main.cpp

@@ -1,10 +1,6 @@
 // Dear ImGui: standalone example application for DirectX 12
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // Important: to compile on 32-bit systems, the DirectX12 backend requires code to be compiled with '#define ImTextureID ImU64'.
 // This is because we need ImTextureID to carry a 64-bit value and by default ImTextureID is defined as void*.
@@ -87,11 +83,23 @@ 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();
 
+    // 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_ImplWin32_Init(hwnd);
     ImGui_ImplDX12_Init(g_pd3dDevice, NUM_FRAMES_IN_FLIGHT,
@@ -209,6 +217,13 @@ 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(nullptr, (void*)g_pd3dCommandList);
+        }
+
         g_pSwapChain->Present(1, 0); // Present with vsync
         //g_pSwapChain->Present(0, 0); // Present without vsync
 
@@ -233,7 +248,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain

examples/example_win32_directx9/main.cpp

@@ -1,10 +1,6 @@
 // Dear ImGui: standalone example application for DirectX 9
-
-// 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
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 #include "imgui.h"
 #include "imgui_impl_dx9.h"
@@ -51,11 +47,23 @@ 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();
 
+    // 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_ImplWin32_Init(hwnd);
     ImGui_ImplDX9_Init(g_pd3dDevice);
@@ -162,6 +170,14 @@ 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);
 
         // Handle loss of D3D9 device
@@ -181,7 +197,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     if ((g_pD3D = Direct3DCreate9(D3D_SDK_VERSION)) == nullptr)
@@ -217,6 +232,10 @@ void ResetDevice()
     ImGui_ImplDX9_CreateDeviceObjects();
 }
 
+#ifndef WM_DPICHANGED
+#define WM_DPICHANGED 0x02E0 // From Windows SDK 8.1+ headers
+#endif
+
 // Forward declare message handler from imgui_impl_win32.cpp
 extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 
@@ -245,6 +264,15 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
     case WM_DESTROY:
         ::PostQuitMessage(0);
         return 0;
+    case WM_DPICHANGED:
+        if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_DpiEnableScaleViewports)
+        {
+            //const int dpi = HIWORD(wParam);
+            //printf("WM_DPICHANGED to %d (%.0f%%)\n", dpi, (float)dpi / 96.0f * 100.0f);
+            const RECT* suggested_rect = (RECT*)lParam;
+            ::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);
+        }
+        break;
     }
     return ::DefWindowProcW(hWnd, msg, wParam, lParam);
 }

examples/example_win32_opengl3/main.cpp

@@ -1,12 +1,8 @@
 // Dear ImGui: standalone example application for Win32 + OpenGL 3
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
 
-// 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
-
-// This is provided for completeness, however it is strongly recommended you use OpenGL with SDL or GLFW.
+// This is provided for completeness, however it is strogly recommended you use OpenGL with SDL or GLFW.
 
 #include "imgui.h"
 #include "imgui_impl_opengl3.h"
@@ -33,6 +29,42 @@ 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**)
 {
@@ -62,15 +94,39 @@ 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();
 
+    // 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_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.
@@ -158,6 +214,16 @@ 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);
     }

imconfig.h

@@ -28,13 +28,13 @@
 
 //---- Don't define obsolete functions/enums/behaviors. Consider enabling from time to time after updating to clean your code of obsolete function/names.
 //#define IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-//#define IMGUI_DISABLE_OBSOLETE_KEYIO                      // 1.87+ disable legacy io.KeyMap[]+io.KeysDown[] in favor io.AddKeyEvent(). This is automatically done by IMGUI_DISABLE_OBSOLETE_FUNCTIONS.
+//#define IMGUI_DISABLE_OBSOLETE_KEYIO                      // 1.87: disable legacy io.KeyMap[]+io.KeysDown[] in favor io.AddKeyEvent(). This will be folded into IMGUI_DISABLE_OBSOLETE_FUNCTIONS in a few versions.
 
 //---- Disable all of Dear ImGui or don't implement standard windows/tools.
 // It is very strongly recommended to NOT disable the demo windows and debug tool during development. They are extremely useful in day to day work. Please read comments in imgui_demo.cpp.
 //#define IMGUI_DISABLE                                     // Disable everything: all headers and source files will be empty.
 //#define IMGUI_DISABLE_DEMO_WINDOWS                        // Disable demo windows: ShowDemoWindow()/ShowStyleEditor() will be empty.
-//#define IMGUI_DISABLE_DEBUG_TOOLS                         // Disable metrics/debugger and other debug tools: ShowMetricsWindow(), ShowDebugLogWindow() and ShowIDStackToolWindow() will be empty.
+//#define IMGUI_DISABLE_DEBUG_TOOLS                         // Disable metrics/debugger and other debug tools: ShowMetricsWindow(), ShowDebugLogWindow() and ShowStackToolWindow() will be empty (this was called IMGUI_DISABLE_METRICS_WINDOW before 1.88).
 
 //---- Don't implement some functions to reduce linkage requirements.
 //#define IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS   // [Win32] Don't implement default clipboard handler. Won't use and link with OpenClipboard/GetClipboardData/CloseClipboard etc. (user32.lib/.a, kernel32.lib/.a)

imgui_draw.cpp

@@ -1,4 +1,4 @@
-// dear imgui, v1.90.0
+// dear imgui, v1.89.9
 // (drawing and font code)
 
 /*
@@ -135,7 +135,7 @@ namespace IMGUI_STB_NAMESPACE
 #define STBTT_sqrt(x)       ImSqrt(x)
 #define STBTT_pow(x,y)      ImPow(x,y)
 #define STBTT_fabs(x)       ImFabs(x)
-#define STBTT_ifloor(x)     ((int)ImFloor(x))
+#define STBTT_ifloor(x)     ((int)ImFloorSigned(x))
 #define STBTT_iceil(x)      ((int)ImCeil(x))
 #define STBTT_STATIC
 #define STB_TRUETYPE_IMPLEMENTATION
@@ -214,6 +214,8 @@ void ImGui::StyleColorsDark(ImGuiStyle* dst)
     colors[ImGuiCol_TabActive]              = ImLerp(colors[ImGuiCol_HeaderActive], colors[ImGuiCol_TitleBgActive], 0.60f);
     colors[ImGuiCol_TabUnfocused]           = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabUnfocusedActive]     = ImLerp(colors[ImGuiCol_TabActive],    colors[ImGuiCol_TitleBg], 0.40f);
+    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);
@@ -274,6 +276,8 @@ void ImGui::StyleColorsClassic(ImGuiStyle* dst)
     colors[ImGuiCol_TabActive]              = ImLerp(colors[ImGuiCol_HeaderActive], colors[ImGuiCol_TitleBgActive], 0.60f);
     colors[ImGuiCol_TabUnfocused]           = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabUnfocusedActive]     = ImLerp(colors[ImGuiCol_TabActive],    colors[ImGuiCol_TitleBg], 0.40f);
+    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);
@@ -335,6 +339,8 @@ void ImGui::StyleColorsLight(ImGuiStyle* dst)
     colors[ImGuiCol_TabActive]              = ImLerp(colors[ImGuiCol_HeaderActive], colors[ImGuiCol_TitleBgActive], 0.60f);
     colors[ImGuiCol_TabUnfocused]           = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabUnfocusedActive]     = ImLerp(colors[ImGuiCol_TabActive],    colors[ImGuiCol_TitleBg], 0.40f);
+    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);
@@ -386,9 +392,9 @@ void ImDrawListSharedData::SetCircleTessellationMaxError(float max_error)
 void ImDrawList::_ResetForNewFrame()
 {
     // Verify that the ImDrawCmd fields we want to memcmp() are contiguous in memory.
-    IM_STATIC_ASSERT(offsetof(ImDrawCmd, ClipRect) == 0);
-    IM_STATIC_ASSERT(offsetof(ImDrawCmd, TextureId) == sizeof(ImVec4));
-    IM_STATIC_ASSERT(offsetof(ImDrawCmd, VtxOffset) == sizeof(ImVec4) + sizeof(ImTextureID));
+    IM_STATIC_ASSERT(IM_OFFSETOF(ImDrawCmd, ClipRect) == 0);
+    IM_STATIC_ASSERT(IM_OFFSETOF(ImDrawCmd, TextureId) == sizeof(ImVec4));
+    IM_STATIC_ASSERT(IM_OFFSETOF(ImDrawCmd, VtxOffset) == sizeof(ImVec4) + sizeof(ImTextureID));
     if (_Splitter._Count > 1)
         _Splitter.Merge(this);
 
@@ -475,7 +481,7 @@ void ImDrawList::AddCallback(ImDrawCallback callback, void* callback_data)
 }
 
 // Compare ClipRect, TextureId and VtxOffset with a single memcmp()
-#define ImDrawCmd_HeaderSize                            (offsetof(ImDrawCmd, VtxOffset) + sizeof(unsigned int))
+#define ImDrawCmd_HeaderSize                            (IM_OFFSETOF(ImDrawCmd, VtxOffset) + sizeof(unsigned int))
 #define ImDrawCmd_HeaderCompare(CMD_LHS, CMD_RHS)       (memcmp(CMD_LHS, CMD_RHS, ImDrawCmd_HeaderSize))    // Compare ClipRect, TextureId, VtxOffset
 #define ImDrawCmd_HeaderCopy(CMD_DST, CMD_SRC)          (memcpy(CMD_DST, CMD_SRC, ImDrawCmd_HeaderSize))    // Copy ClipRect, TextureId, VtxOffset
 #define ImDrawCmd_AreSequentialIdxOffset(CMD_0, CMD_1)  (CMD_0->IdxOffset + CMD_0->ElemCount == CMD_1->IdxOffset)
@@ -1191,8 +1197,8 @@ void ImDrawList::PathArcTo(const ImVec2& center, float radius, float a_min, floa
         const float a_min_sample_f = IM_DRAWLIST_ARCFAST_SAMPLE_MAX * a_min / (IM_PI * 2.0f);
         const float a_max_sample_f = IM_DRAWLIST_ARCFAST_SAMPLE_MAX * a_max / (IM_PI * 2.0f);
 
-        const int a_min_sample = a_is_reverse ? (int)ImFloor(a_min_sample_f) : (int)ImCeil(a_min_sample_f);
-        const int a_max_sample = a_is_reverse ? (int)ImCeil(a_max_sample_f) : (int)ImFloor(a_max_sample_f);
+        const int a_min_sample = a_is_reverse ? (int)ImFloorSigned(a_min_sample_f) : (int)ImCeil(a_min_sample_f);
+        const int a_max_sample = a_is_reverse ? (int)ImCeil(a_max_sample_f) : (int)ImFloorSigned(a_max_sample_f);
         const int a_mid_samples = a_is_reverse ? ImMax(a_min_sample - a_max_sample, 0) : ImMax(a_max_sample - a_min_sample, 0);
 
         const float a_min_segment_angle = a_min_sample * IM_PI * 2.0f / IM_DRAWLIST_ARCFAST_SAMPLE_MAX;
@@ -1217,27 +1223,6 @@ void ImDrawList::PathArcTo(const ImVec2& center, float radius, float a_min, floa
     }
 }
 
-void ImDrawList::PathEllipticalArcTo(const ImVec2& center, float radius_x, float radius_y, float rot, float a_min, float a_max, int num_segments)
-{
-    if (num_segments <= 0)
-        num_segments = _CalcCircleAutoSegmentCount(ImMax(radius_x, radius_y)); // A bit pessimistic, maybe there's a better computation to do here.
-
-    _Path.reserve(_Path.Size + (num_segments + 1));
-
-    const float cos_rot = ImCos(rot);
-    const float sin_rot = ImSin(rot);
-    for (int i = 0; i <= num_segments; i++)
-    {
-        const float a = a_min + ((float)i / (float)num_segments) * (a_max - a_min);
-        ImVec2 point(ImCos(a) * radius_x, ImSin(a) * radius_y);
-        const float rel_x = (point.x * cos_rot) - (point.y * sin_rot);
-        const float rel_y = (point.x * sin_rot) + (point.y * cos_rot);
-        point.x = rel_x + center.x;
-        point.y = rel_y + center.y;
-        _Path.push_back(point);
-    }
-}
-
 ImVec2 ImBezierCubicCalc(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, float t)
 {
     float u = 1.0f - t;
@@ -1333,22 +1318,33 @@ void ImDrawList::PathBezierQuadraticCurveTo(const ImVec2& p2, const ImVec2& p3,
     }
 }
 
+IM_STATIC_ASSERT(ImDrawFlags_RoundCornersTopLeft == (1 << 4));
 static inline ImDrawFlags FixRectCornerFlags(ImDrawFlags flags)
 {
-    /*
-    IM_STATIC_ASSERT(ImDrawFlags_RoundCornersTopLeft == (1 << 4));
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-    // Obsoleted in 1.82 (from February 2021). This code was stripped/simplified and mostly commented in 1.90 (from September 2023)
-    // - Legacy Support for hard coded ~0 (used to be a suggested equivalent to ImDrawCornerFlags_All)
-    if (flags == ~0)                    { return ImDrawFlags_RoundCornersAll; }
-    // - Legacy Support for hard coded 0x01 to 0x0F (matching 15 out of 16 old flags combinations). Read details in older version of this code.
-    if (flags >= 0x01 && flags <= 0x0F) { return (flags << 4); }
+    // Obsoleted in 1.82 (from February 2021)
+    // Legacy Support for hard coded ~0 (used to be a suggested equivalent to ImDrawCornerFlags_All)
+    //   ~0   --> ImDrawFlags_RoundCornersAll or 0
+    if (flags == ~0)
+        return ImDrawFlags_RoundCornersAll;
+
+    // Legacy Support for hard coded 0x01 to 0x0F (matching 15 out of 16 old flags combinations)
+    //   0x01 --> ImDrawFlags_RoundCornersTopLeft (VALUE 0x01 OVERLAPS ImDrawFlags_Closed but ImDrawFlags_Closed is never valid in this path!)
+    //   0x02 --> ImDrawFlags_RoundCornersTopRight
+    //   0x03 --> ImDrawFlags_RoundCornersTopLeft | ImDrawFlags_RoundCornersTopRight
+    //   0x04 --> ImDrawFlags_RoundCornersBotLeft
+    //   0x05 --> ImDrawFlags_RoundCornersTopLeft | ImDrawFlags_RoundCornersBotLeft
+    //   ...
+    //   0x0F --> ImDrawFlags_RoundCornersAll or 0
+    // (See all values in ImDrawCornerFlags_)
+    if (flags >= 0x01 && flags <= 0x0F)
+        return (flags << 4);
+
     // We cannot support hard coded 0x00 with 'float rounding > 0.0f' --> replace with ImDrawFlags_RoundCornersNone or use 'float rounding = 0.0f'
 #endif
-    */
-    // If this assert triggers, please update your code replacing hardcoded values with new ImDrawFlags_RoundCorners* values.
-    // Note that ImDrawFlags_Closed (== 0x01) is an invalid flag for AddRect(), AddRectFilled(), PathRect() etc. anyway.
-    // See details in 1.82 Changelog as well as 2021/03/12 and 2023/09/08 entries in "API BREAKING CHANGES" section.
+
+    // If this triggers, please update your code replacing hardcoded values with new ImDrawFlags_RoundCorners* values.
+    // Note that ImDrawFlags_Closed (== 0x01) is an invalid flag for AddRect(), AddRectFilled(), PathRect() etc...
     IM_ASSERT((flags & 0x0F) == 0 && "Misuse of legacy hardcoded ImDrawCornerFlags values!");
 
     if ((flags & ImDrawFlags_RoundCornersMask_) == 0)
@@ -1557,35 +1553,6 @@ void ImDrawList::AddNgonFilled(const ImVec2& center, float radius, ImU32 col, in
     PathFillConvex(col);
 }
 
-// Ellipse
-void ImDrawList::AddEllipse(const ImVec2& center, float radius_x, float radius_y, ImU32 col, float rot, int num_segments, float thickness)
-{
-    if ((col & IM_COL32_A_MASK) == 0)
-        return;
-
-    if (num_segments <= 0)
-        num_segments = _CalcCircleAutoSegmentCount(ImMax(radius_x, radius_y)); // A bit pessimistic, maybe there's a better computation to do here.
-
-    // Because we are filling a closed shape we remove 1 from the count of segments/points
-    const float a_max = IM_PI * 2.0f * ((float)num_segments - 1.0f) / (float)num_segments;
-    PathEllipticalArcTo(center, radius_x, radius_y, rot, 0.0f, a_max, num_segments - 1);
-    PathStroke(col, true, thickness);
-}
-
-void ImDrawList::AddEllipseFilled(const ImVec2& center, float radius_x, float radius_y, ImU32 col, float rot, int num_segments)
-{
-    if ((col & IM_COL32_A_MASK) == 0)
-        return;
-
-    if (num_segments <= 0)
-        num_segments = _CalcCircleAutoSegmentCount(ImMax(radius_x, radius_y)); // A bit pessimistic, maybe there's a better computation to do here.
-
-    // Because we are filling a closed shape we remove 1 from the count of segments/points
-    const float a_max = IM_PI * 2.0f * ((float)num_segments - 1.0f) / (float)num_segments;
-    PathEllipticalArcTo(center, radius_x, radius_y, rot, 0.0f, a_max, num_segments - 1);
-    PathFillConvex(col);
-}
-
 // Cubic Bezier takes 4 controls points
 void ImDrawList::AddBezierCubic(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, ImU32 col, float thickness, int num_segments)
 {
@@ -1989,14 +1956,6 @@ void ImGui::ShadeVertsLinearUV(ImDrawList* draw_list, int vert_start_idx, int ve
     }
 }
 
-void ImGui::ShadeVertsTransformPos(ImDrawList* draw_list, int vert_start_idx, int vert_end_idx, const ImVec2& pivot_in, float cos_a, float sin_a, const ImVec2& pivot_out)
-{
-    ImDrawVert* vert_start = draw_list->VtxBuffer.Data + vert_start_idx;
-    ImDrawVert* vert_end = draw_list->VtxBuffer.Data + vert_end_idx;
-    for (ImDrawVert* vertex = vert_start; vertex < vert_end; ++vertex)
-        vertex->pos = ImRotate(vertex->pos- pivot_in, cos_a, sin_a) + pivot_out;
-}
-
 //-----------------------------------------------------------------------------
 // [SECTION] ImFontConfig
 //-----------------------------------------------------------------------------
@@ -2009,7 +1968,6 @@ ImFontConfig::ImFontConfig()
     OversampleV = 1;
     GlyphMaxAdvanceX = FLT_MAX;
     RasterizerMultiply = 1.0f;
-    RasterizerDensity = 1.0f;
     EllipsisChar = (ImWchar)-1;
 }
 
@@ -2192,8 +2150,6 @@ ImFont* ImFontAtlas::AddFont(const ImFontConfig* font_cfg)
     if (new_font_cfg.DstFont->EllipsisChar == (ImWchar)-1)
         new_font_cfg.DstFont->EllipsisChar = font_cfg->EllipsisChar;
 
-    ImFontAtlasUpdateConfigDataPointers(this);
-
     // Invalidate texture
     TexReady = false;
     ClearTexData();
@@ -2230,7 +2186,7 @@ ImFont* ImFontAtlas::AddFontDefault(const ImFontConfig* font_cfg_template)
     if (font_cfg.Name[0] == '\0')
         ImFormatString(font_cfg.Name, IM_ARRAYSIZE(font_cfg.Name), "ProggyClean.ttf, %dpx", (int)font_cfg.SizePixels);
     font_cfg.EllipsisChar = (ImWchar)0x0085;
-    font_cfg.GlyphOffset.y = 1.0f * IM_TRUNC(font_cfg.SizePixels / 13.0f);  // Add +1 offset per 13 units
+    font_cfg.GlyphOffset.y = 1.0f * IM_FLOOR(font_cfg.SizePixels / 13.0f);  // Add +1 offset per 13 units
 
     const char* ttf_compressed_base85 = GetDefaultCompressedFontDataTTFBase85();
     const ImWchar* glyph_ranges = font_cfg.GlyphRanges != NULL ? font_cfg.GlyphRanges : GetGlyphRangesDefault();
@@ -2260,14 +2216,13 @@ ImFont* ImFontAtlas::AddFontFromFileTTF(const char* filename, float size_pixels,
 }
 
 // NB: Transfer ownership of 'ttf_data' to ImFontAtlas, unless font_cfg_template->FontDataOwnedByAtlas == false. Owned TTF buffer will be deleted after Build().
-ImFont* ImFontAtlas::AddFontFromMemoryTTF(void* font_data, int font_data_size, float size_pixels, const ImFontConfig* font_cfg_template, const ImWchar* glyph_ranges)
+ImFont* ImFontAtlas::AddFontFromMemoryTTF(void* ttf_data, int ttf_size, float size_pixels, const ImFontConfig* font_cfg_template, const ImWchar* glyph_ranges)
 {
     IM_ASSERT(!Locked && "Cannot modify a locked ImFontAtlas between NewFrame() and EndFrame/Render()!");
     ImFontConfig font_cfg = font_cfg_template ? *font_cfg_template : ImFontConfig();
     IM_ASSERT(font_cfg.FontData == NULL);
-    IM_ASSERT(font_data_size > 100 && "Incorrect value for font_data_size!"); // Heuristic to prevent accidentally passing a wrong value to font_data_size.
-    font_cfg.FontData = font_data;
-    font_cfg.FontDataSize = font_data_size;
+    font_cfg.FontData = ttf_data;
+    font_cfg.FontDataSize = ttf_size;
     font_cfg.SizePixels = size_pixels > 0.0f ? size_pixels : font_cfg.SizePixels;
     if (glyph_ranges)
         font_cfg.GlyphRanges = glyph_ranges;
@@ -2482,10 +2437,7 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
         const int font_offset = stbtt_GetFontOffsetForIndex((unsigned char*)cfg.FontData, cfg.FontNo);
         IM_ASSERT(font_offset >= 0 && "FontData is incorrect, or FontNo cannot be found.");
         if (!stbtt_InitFont(&src_tmp.FontInfo, (unsigned char*)cfg.FontData, font_offset))
-        {
-            IM_ASSERT(0 && "stbtt_InitFont(): failed to parse FontData. It is correct and complete? Check FontDataSize.");
             return false;
-        }
 
         // Measure highest codepoints
         ImFontBuildDstData& dst_tmp = dst_tmp_array[src_tmp.DstIndex];
@@ -2567,7 +2519,7 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
 
         // Convert our ranges in the format stb_truetype wants
         ImFontConfig& cfg = atlas->ConfigData[src_i];
-        src_tmp.PackRange.font_size = cfg.SizePixels * cfg.RasterizerDensity;
+        src_tmp.PackRange.font_size = cfg.SizePixels;
         src_tmp.PackRange.first_unicode_codepoint_in_range = 0;
         src_tmp.PackRange.array_of_unicode_codepoints = src_tmp.GlyphsList.Data;
         src_tmp.PackRange.num_chars = src_tmp.GlyphsList.Size;
@@ -2576,7 +2528,7 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
         src_tmp.PackRange.v_oversample = (unsigned char)cfg.OversampleV;
 
         // Gather the sizes of all rectangles we will need to pack (this loop is based on stbtt_PackFontRangesGatherRects)
-        const float scale = (cfg.SizePixels > 0.0f) ? stbtt_ScaleForPixelHeight(&src_tmp.FontInfo, cfg.SizePixels * cfg.RasterizerDensity) : stbtt_ScaleForMappingEmToPixels(&src_tmp.FontInfo, -cfg.SizePixels * cfg.RasterizerDensity);
+        const float scale = (cfg.SizePixels > 0) ? stbtt_ScaleForPixelHeight(&src_tmp.FontInfo, cfg.SizePixels) : stbtt_ScaleForMappingEmToPixels(&src_tmp.FontInfo, -cfg.SizePixels);
         const int padding = atlas->TexGlyphPadding;
         for (int glyph_i = 0; glyph_i < src_tmp.GlyphsList.Size; glyph_i++)
         {
@@ -2672,14 +2624,12 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
         int unscaled_ascent, unscaled_descent, unscaled_line_gap;
         stbtt_GetFontVMetrics(&src_tmp.FontInfo, &unscaled_ascent, &unscaled_descent, &unscaled_line_gap);
 
-        const float ascent = ImTrunc(unscaled_ascent * font_scale + ((unscaled_ascent > 0.0f) ? +1 : -1));
-        const float descent = ImTrunc(unscaled_descent * font_scale + ((unscaled_descent > 0.0f) ? +1 : -1));
+        const float ascent = ImFloor(unscaled_ascent * font_scale + ((unscaled_ascent > 0.0f) ? +1 : -1));
+        const float descent = ImFloor(unscaled_descent * font_scale + ((unscaled_descent > 0.0f) ? +1 : -1));
         ImFontAtlasBuildSetupFont(atlas, dst_font, &cfg, ascent, descent);
         const float font_off_x = cfg.GlyphOffset.x;
         const float font_off_y = cfg.GlyphOffset.y + IM_ROUND(dst_font->Ascent);
 
-        const float inv_rasterization_scale = 1.0f / cfg.RasterizerDensity;
-
         for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++)
         {
             // Register glyph
@@ -2688,11 +2638,7 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
             stbtt_aligned_quad q;
             float unused_x = 0.0f, unused_y = 0.0f;
             stbtt_GetPackedQuad(src_tmp.PackedChars, atlas->TexWidth, atlas->TexHeight, glyph_i, &unused_x, &unused_y, &q, 0);
-            float x0 = q.x0 * inv_rasterization_scale + font_off_x;
-            float y0 = q.y0 * inv_rasterization_scale + font_off_y;
-            float x1 = q.x1 * inv_rasterization_scale + font_off_x;
-            float y1 = q.y1 * inv_rasterization_scale + font_off_y;
-            dst_font->AddGlyph(&cfg, (ImWchar)codepoint, x0, y0, x1, y1, q.s0, q.t0, q.s1, q.t1, pc.xadvance * inv_rasterization_scale);
+            dst_font->AddGlyph(&cfg, (ImWchar)codepoint, q.x0 + font_off_x, q.y0 + font_off_y, q.x1 + font_off_x, q.y1 + font_off_y, q.s0, q.t0, q.s1, q.t1, pc.xadvance);
         }
     }
 
@@ -2712,31 +2658,19 @@ const ImFontBuilderIO* ImFontAtlasGetBuilderForStbTruetype()
 
 #endif // IMGUI_ENABLE_STB_TRUETYPE
 
-void ImFontAtlasUpdateConfigDataPointers(ImFontAtlas* atlas)
-{
-    for (ImFontConfig& font_cfg : atlas->ConfigData)
-    {
-        ImFont* font = font_cfg.DstFont;
-        if (!font_cfg.MergeMode)
-        {
-            font->ConfigData = &font_cfg;
-            font->ConfigDataCount = 0;
-        }
-        font->ConfigDataCount++;
-    }
-}
-
 void ImFontAtlasBuildSetupFont(ImFontAtlas* atlas, ImFont* font, ImFontConfig* font_config, float ascent, float descent)
 {
     if (!font_config->MergeMode)
     {
         font->ClearOutputData();
         font->FontSize = font_config->SizePixels;
-        IM_ASSERT(font->ConfigData == font_config);
+        font->ConfigData = font_config;
+        font->ConfigDataCount = 0;
         font->ContainerAtlas = atlas;
         font->Ascent = ascent;
         font->Descent = descent;
     }
+    font->ConfigDataCount++;
 }
 
 void ImFontAtlasBuildPackCustomRects(ImFontAtlas* atlas, void* stbrp_context_opaque)
@@ -2883,13 +2817,6 @@ static void ImFontAtlasBuildRenderLinesTexData(ImFontAtlas* atlas)
 // Note: this is called / shared by both the stb_truetype and the FreeType builder
 void ImFontAtlasBuildInit(ImFontAtlas* atlas)
 {
-    // Round font size
-    // - We started rounding in 1.90 WIP (18991) as our layout system currently doesn't support non-rounded font size well yet.
-    // - Note that using io.FontGlobalScale or SetWindowFontScale(), with are legacy-ish, partially supported features, can still lead to unrounded sizes.
-    // - We may support it better later and remove this rounding.
-    for (ImFontConfig& cfg : atlas->ConfigData)
-       cfg.SizePixels = ImTrunc(cfg.SizePixels);
-
     // Register texture region for mouse cursors or standard white pixels
     if (atlas->PackIdMouseCursors < 0)
     {
@@ -3298,7 +3225,6 @@ void ImFont::BuildLookupTable()
         max_codepoint = ImMax(max_codepoint, (int)Glyphs[i].Codepoint);
 
     // Build lookup table
-    IM_ASSERT(Glyphs.Size > 0 && "Font has not loaded glyph!");
     IM_ASSERT(Glyphs.Size < 0xFFFF); // -1 is reserved
     IndexAdvanceX.clear();
     IndexLookup.clear();
@@ -3415,7 +3341,7 @@ void ImFont::AddGlyph(const ImFontConfig* cfg, ImWchar codepoint, float x0, floa
         advance_x = ImClamp(advance_x, cfg->GlyphMinAdvanceX, cfg->GlyphMaxAdvanceX);
         if (advance_x != advance_x_original)
         {
-            float char_off_x = cfg->PixelSnapH ? ImTrunc((advance_x - advance_x_original) * 0.5f) : (advance_x - advance_x_original) * 0.5f;
+            float char_off_x = cfg->PixelSnapH ? ImFloor((advance_x - advance_x_original) * 0.5f) : (advance_x - advance_x_original) * 0.5f;
             x0 += char_off_x;
             x1 += char_off_x;
         }
@@ -3683,8 +3609,8 @@ void ImFont::RenderChar(ImDrawList* draw_list, float size, const ImVec2& pos, Im
     if (glyph->Colored)
         col |= ~IM_COL32_A_MASK;
     float scale = (size >= 0.0f) ? (size / FontSize) : 1.0f;
-    float x = IM_TRUNC(pos.x);
-    float y = IM_TRUNC(pos.y);
+    float x = IM_FLOOR(pos.x);
+    float y = IM_FLOOR(pos.y);
     draw_list->PrimReserve(6, 4);
     draw_list->PrimRectUV(ImVec2(x + glyph->X0 * scale, y + glyph->Y0 * scale), ImVec2(x + glyph->X1 * scale, y + glyph->Y1 * scale), ImVec2(glyph->U0, glyph->V0), ImVec2(glyph->U1, glyph->V1), col);
 }
@@ -3696,8 +3622,8 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, Im
         text_end = text_begin + strlen(text_begin); // ImGui:: functions generally already provides a valid text_end, so this is merely to handle direct calls.
 
     // Align to be pixel perfect
-    float x = IM_TRUNC(pos.x);
-    float y = IM_TRUNC(pos.y);
+    float x = IM_FLOOR(pos.x);
+    float y = IM_FLOOR(pos.y);
     if (y > clip_rect.w)
         return;
 
@@ -3881,6 +3807,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, Im
 // - RenderArrow()
 // - RenderBullet()
 // - RenderCheckMark()
+// - RenderArrowDockMenu()
 // - RenderArrowPointingAt()
 // - RenderRectFilledRangeH()
 // - RenderRectFilledWithHole()
@@ -3955,6 +3882,14 @@ 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;
@@ -4040,6 +3975,17 @@ 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.

imgui_tables.cpp

@@ -1,4 +1,4 @@
-// dear imgui, v1.90.0
+// dear imgui, v1.89.9
 // (tables and columns code)
 
 /*
@@ -48,8 +48,7 @@ Index of this file:
 // - TableUpdateLayout() [Internal]             followup to BeginTable(): setup everything: widths, columns positions, clipping rectangles. Automatically called by the FIRST call to TableNextRow() or TableHeadersRow().
 //    | TableSetupDrawChannels()                - setup ImDrawList channels
 //    | TableUpdateBorders()                    - detect hovering columns for resize, ahead of contents submission
-//    | TableBeginContextMenuPopup()
-//    | - TableDrawDefaultContextMenu()         - draw right-click context menu contents
+//    | TableDrawContextMenu()                  - draw right-click context menu
 //-----------------------------------------------------------------------------
 // - TableHeadersRow() or TableHeader()         user submit a headers row (optional)
 //    | TableSortSpecsClickColumn()             - when left-clicked: alter sort order and sort direction
@@ -320,10 +319,9 @@ bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImG
     // If an outer size is specified ahead we will be able to early out when not visible. Exact clipping criteria may evolve.
     const bool use_child_window = (flags & (ImGuiTableFlags_ScrollX | ImGuiTableFlags_ScrollY)) != 0;
     const ImVec2 avail_size = GetContentRegionAvail();
-    const ImVec2 actual_outer_size = CalcItemSize(outer_size, ImMax(avail_size.x, 1.0f), use_child_window ? ImMax(avail_size.y, 1.0f) : 0.0f);
-    const ImRect outer_rect(outer_window->DC.CursorPos, outer_window->DC.CursorPos + actual_outer_size);
-    const bool outer_window_is_measuring_size = (outer_window->AutoFitFramesX > 0) || (outer_window->AutoFitFramesY > 0); // Doesn't apply to AlwaysAutoResize windows!
-    if (use_child_window && IsClippedEx(outer_rect, 0) && !outer_window_is_measuring_size)
+    ImVec2 actual_outer_size = CalcItemSize(outer_size, ImMax(avail_size.x, 1.0f), use_child_window ? ImMax(avail_size.y, 1.0f) : 0.0f);
+    ImRect outer_rect(outer_window->DC.CursorPos, outer_window->DC.CursorPos + actual_outer_size);
+    if (use_child_window && IsClippedEx(outer_rect, 0))
     {
         ItemSize(outer_rect);
         return false;
@@ -347,8 +345,7 @@ bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImG
     flags = TableFixFlags(flags, outer_window);
 
     // Initialize
-    const int previous_frame_active = table->LastFrameActive;
-    const int instance_no = (previous_frame_active != g.FrameCount) ? 0 : table->InstanceCurrent + 1;
+    const int instance_no = (table->LastFrameActive != g.FrameCount) ? 0 : table->InstanceCurrent + 1;
     table->ID = id;
     table->Flags = flags;
     table->LastFrameActive = g.FrameCount;
@@ -407,10 +404,6 @@ bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImG
         table->InnerRect = table->InnerWindow->InnerRect;
         IM_ASSERT(table->InnerWindow->WindowPadding.x == 0.0f && table->InnerWindow->WindowPadding.y == 0.0f && table->InnerWindow->WindowBorderSize == 0.0f);
 
-        // Allow submitting when host is measuring
-        if (table->InnerWindow->SkipItems && outer_window_is_measuring_size)
-            table->InnerWindow->SkipItems = false;
-
         // When using multiple instances, ensure they have the same amount of horizontal decorations (aka vertical scrollbar) so stretched columns can be aligned)
         if (instance_no == 0)
         {
@@ -446,18 +439,6 @@ bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImG
     temp_data->HostBackupItemWidthStackSize = outer_window->DC.ItemWidthStack.Size;
     inner_window->DC.PrevLineSize = inner_window->DC.CurrLineSize = ImVec2(0.0f, 0.0f);
 
-    // Make left and top borders not overlap our contents by offsetting HostClipRect (#6765)
-    // (we normally shouldn't alter HostClipRect as we rely on TableMergeDrawChannels() expanding non-clipped column toward the
-    // limits of that rectangle, in order for ImDrawListSplitter::Merge() to merge the draw commands. However since the overlap
-    // problem only affect scrolling tables in this case we can get away with doing it without extra cost).
-    if (inner_window != outer_window)
-    {
-        if (flags & ImGuiTableFlags_BordersOuterV)
-            table->HostClipRect.Min.x = ImMin(table->HostClipRect.Min.x + TABLE_BORDER_SIZE, table->HostClipRect.Max.x);
-        if (flags & ImGuiTableFlags_BordersOuterH)
-            table->HostClipRect.Min.y = ImMin(table->HostClipRect.Min.y + TABLE_BORDER_SIZE, table->HostClipRect.Max.y);
-    }
-
     // Padding and Spacing
     // - None               ........Content..... Pad .....Content........
     // - PadOuter           | Pad ..Content..... Pad .....Content.. Pad |
@@ -491,10 +472,7 @@ bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImG
     table->FreezeRowsRequest = table->FreezeRowsCount = 0; // This will be setup by TableSetupScrollFreeze(), if any
     table->FreezeColumnsRequest = table->FreezeColumnsCount = 0;
     table->IsUnfrozenRows = true;
-    table->DeclColumnsCount = table->AngledHeadersCount = 0;
-    if (previous_frame_active + 1 < g.FrameCount)
-        table->IsActiveIdInTable = false;
-    temp_data->AngledheadersExtraWidth = 0.0f;
+    table->DeclColumnsCount = 0;
 
     // Using opaque colors facilitate overlapping lines of the grid, otherwise we'd need to improve TableDrawBorders()
     table->BorderColorStrong = GetColorU32(ImGuiCol_TableBorderStrong);
@@ -868,8 +846,8 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
     table->RightMostEnabledColumn = (ImGuiTableColumnIdx)prev_visible_column_idx;
     IM_ASSERT(table->LeftMostEnabledColumn >= 0 && table->RightMostEnabledColumn >= 0);
 
-    // [Part 2] Disable child window clipping while fitting columns. This is not strictly necessary but makes it possible to avoid
-    // the column fitting having to wait until the first visible frame of the child container (may or not be a good thing). Also see #6510.
+    // [Part 2] Disable child window clipping while fitting columns. This is not strictly necessary but makes it possible
+    // to avoid the column fitting having to wait until the first visible frame of the child container (may or not be a good thing).
     // FIXME-TABLE: for always auto-resizing columns may not want to do that all the time.
     if (has_auto_fit_request && table->OuterWindow != table->InnerWindow)
         table->InnerWindow->SkipItems = false;
@@ -954,7 +932,7 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
         if (column->Flags & ImGuiTableColumnFlags_WidthStretch)
         {
             float weight_ratio = column->StretchWeight / stretch_sum_weights;
-            column->WidthRequest = IM_TRUNC(ImMax(width_avail_for_stretched_columns * weight_ratio, table->MinColumnWidth) + 0.01f);
+            column->WidthRequest = IM_FLOOR(ImMax(width_avail_for_stretched_columns * weight_ratio, table->MinColumnWidth) + 0.01f);
             width_remaining_for_stretched_columns -= column->WidthRequest;
         }
 
@@ -964,7 +942,7 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
             column->Flags |= ImGuiTableColumnFlags_NoDirectResize_;
 
         // Assign final width, record width in case we will need to shrink
-        column->WidthGiven = ImTrunc(ImMax(column->WidthRequest, table->MinColumnWidth));
+        column->WidthGiven = ImFloor(ImMax(column->WidthRequest, table->MinColumnWidth));
         table->ColumnsGivenWidth += column->WidthGiven;
     }
 
@@ -991,23 +969,17 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
     ImGuiTableInstanceData* table_instance = TableGetInstanceData(table, table->InstanceCurrent);
     table_instance->HoveredRowLast = table_instance->HoveredRowNext;
     table_instance->HoveredRowNext = -1;
-    table->HoveredColumnBody = table->HoveredColumnBorder = -1;
+    table->HoveredColumnBody = -1;
+    table->HoveredColumnBorder = -1;
     const ImRect mouse_hit_rect(table->OuterRect.Min.x, table->OuterRect.Min.y, table->OuterRect.Max.x, ImMax(table->OuterRect.Max.y, table->OuterRect.Min.y + table_instance->LastOuterHeight));
     const ImGuiID backup_active_id = g.ActiveId;
     g.ActiveId = 0;
     const bool is_hovering_table = ItemHoverable(mouse_hit_rect, 0, ImGuiItemFlags_None);
     g.ActiveId = backup_active_id;
 
-    // Determine skewed MousePos.x to support angled headers.
-    float mouse_skewed_x = g.IO.MousePos.x;
-    if (table->AngledHeadersHeight > 0.0f)
-        if (g.IO.MousePos.y >= table->OuterRect.Min.y && g.IO.MousePos.y <= table->OuterRect.Min.y + table->AngledHeadersHeight)
-            mouse_skewed_x += ImTrunc((table->OuterRect.Min.y + table->AngledHeadersHeight - g.IO.MousePos.y) * table->AngledHeadersSlope);
-
     // [Part 6] Setup final position, offset, skip/clip states and clipping rectangles, detect hovered column
     // Process columns in their visible orders as we are comparing the visible order and adjusting host_clip_rect while looping.
     int visible_n = 0;
-    bool has_at_least_one_column_requesting_output = false;
     bool offset_x_frozen = (table->FreezeColumnsCount > 0);
     float offset_x = ((table->FreezeColumnsCount > 0) ? table->OuterRect.Min.x : work_rect.Min.x) + table->OuterPaddingX - table->CellSpacingX1;
     ImRect host_clip_rect = table->InnerClipRect;
@@ -1045,7 +1017,7 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
         }
 
         // Detect hovered column
-        if (is_hovering_table && mouse_skewed_x >= column->ClipRect.Min.x && mouse_skewed_x < column->ClipRect.Max.x)
+        if (is_hovering_table && g.IO.MousePos.x >= column->ClipRect.Min.x && g.IO.MousePos.x < column->ClipRect.Max.x)
             table->HoveredColumnBody = (ImGuiTableColumnIdx)column_n;
 
         // Lock start position
@@ -1064,7 +1036,7 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
         // - FIXME-TABLE: We want equal width columns to have equal (ClipRect.Max.x - WorkMinX) width, which means ClipRect.max.x cannot stray off host_clip_rect.Max.x else right-most column may appear shorter.
         column->WorkMinX = column->MinX + table->CellPaddingX + table->CellSpacingX1;
         column->WorkMaxX = column->MaxX - table->CellPaddingX - table->CellSpacingX2; // Expected max
-        column->ItemWidth = ImTrunc(column->WidthGiven * 0.65f);
+        column->ItemWidth = ImFloor(column->WidthGiven * 0.65f);
         column->ClipRect.Min.x = column->MinX;
         column->ClipRect.Min.y = work_rect.Min.y;
         column->ClipRect.Max.x = column->MaxX; //column->WorkMaxX;
@@ -1088,12 +1060,9 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
         column->IsRequestOutput = is_visible || column->AutoFitQueue != 0 || column->CannotSkipItemsQueue != 0;
 
         // Mark column as SkipItems (ignoring all items/layout)
-        // (table->HostSkipItems is a copy of inner_window->SkipItems before we cleared it above in Part 2)
         column->IsSkipItems = !column->IsEnabled || table->HostSkipItems;
         if (column->IsSkipItems)
             IM_ASSERT(!is_visible);
-        if (column->IsRequestOutput && !column->IsSkipItems)
-            has_at_least_one_column_requesting_output = true;
 
         // Update status flags
         column->Flags |= ImGuiTableColumnFlags_IsEnabled;
@@ -1131,26 +1100,18 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
         visible_n++;
     }
 
-    // In case the table is visible (e.g. decorations) but all columns clipped, we keep a column visible.
-    // Else if give no chance to a clipper-savy user to submit rows and therefore total contents height used by scrollbar.
-    if (has_at_least_one_column_requesting_output == false)
-    {
-        table->Columns[table->LeftMostEnabledColumn].IsRequestOutput = true;
-        table->Columns[table->LeftMostEnabledColumn].IsSkipItems = false;
-    }
-
     // [Part 7] Detect/store when we are hovering the unused space after the right-most column (so e.g. context menus can react on it)
     // Clear Resizable flag if none of our column are actually resizable (either via an explicit _NoResize flag, either
     // because of using _WidthAuto/_WidthStretch). This will hide the resizing option from the context menu.
     const float unused_x1 = ImMax(table->WorkRect.Min.x, table->Columns[table->RightMostEnabledColumn].ClipRect.Max.x);
     if (is_hovering_table && table->HoveredColumnBody == -1)
-        if (mouse_skewed_x >= unused_x1)
+    {
+        if (g.IO.MousePos.x >= unused_x1)
             table->HoveredColumnBody = (ImGuiTableColumnIdx)table->ColumnsCount;
+    }
     if (has_resizable == false && (table->Flags & ImGuiTableFlags_Resizable))
         table->Flags &= ~ImGuiTableFlags_Resizable;
 
-    table->IsActiveIdAliveBeforeTable = (g.ActiveIdIsAlive != 0);
-
     // [Part 8] Lock actual OuterRect/WorkRect right-most position.
     // This is done late to handle the case of fixed-columns tables not claiming more widths that they need.
     // Because of this we are careful with uses of WorkRect and InnerClipRect before this point.
@@ -1162,8 +1123,8 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
         table->InnerClipRect.Max.x = ImMin(table->InnerClipRect.Max.x, unused_x1);
     }
     table->InnerWindow->ParentWorkRect = table->WorkRect;
-    table->BorderX1 = table->InnerClipRect.Min.x;
-    table->BorderX2 = table->InnerClipRect.Max.x;
+    table->BorderX1 = table->InnerClipRect.Min.x;// +((table->Flags & ImGuiTableFlags_BordersOuter) ? 0.0f : -1.0f);
+    table->BorderX2 = table->InnerClipRect.Max.x;// +((table->Flags & ImGuiTableFlags_BordersOuter) ? 0.0f : +1.0f);
 
     // Setup window's WorkRect.Max.y for GetContentRegionAvail(). Other values will be updated in each TableBeginCell() call.
     float window_content_max_y;
@@ -1179,26 +1140,14 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
     // [Part 10] Hit testing on borders
     if (table->Flags & ImGuiTableFlags_Resizable)
         TableUpdateBorders(table);
-    table_instance->LastTopHeadersRowHeight = 0.0f;
+    table_instance->LastFirstRowHeight = 0.0f;
     table->IsLayoutLocked = true;
     table->IsUsingHeaders = false;
 
-    // Highlight header
-    table->HighlightColumnHeader = -1;
-    if (table->IsContextPopupOpen && table->ContextPopupColumn != -1 && table->InstanceInteracted == table->InstanceCurrent)
-        table->HighlightColumnHeader = table->ContextPopupColumn;
-    else if ((table->Flags & ImGuiTableFlags_HighlightHoveredColumn) && table->HoveredColumnBody != -1 && table->HoveredColumnBody != table->ColumnsCount && table->HoveredColumnBorder == -1)
-        if (g.ActiveId == 0 || (table->IsActiveIdInTable || g.DragDropActive))
-            table->HighlightColumnHeader = table->HoveredColumnBody;
-
-    // [Part 11] Default context menu
-    // - To append to this menu: you can call TableBeginContextMenuPopup()/.../EndPopup().
-    // - To modify or replace this: set table->IsContextPopupNoDefaultContents = true, then call TableBeginContextMenuPopup()/.../EndPopup().
-    // - You may call TableDrawDefaultContextMenu() with selected flags to display specific sections of the default menu,
-    //   e.g. TableDrawDefaultContextMenu(table, table->Flags & ~ImGuiTableFlags_Hideable) will display everything EXCEPT columns visibility options.
-    if (table->DisableDefaultContextMenu == false && TableBeginContextMenuPopup(table))
+    // [Part 11] Context menu
+    if (TableBeginContextMenuPopup(table))
     {
-        TableDrawDefaultContextMenu(table, table->Flags);
+        TableDrawContextMenu(table);
         EndPopup();
     }
 
@@ -1235,9 +1184,9 @@ void ImGui::TableUpdateBorders(ImGuiTable* table)
     // Actual columns highlight/render will be performed in EndTable() and not be affected.
     ImGuiTableInstanceData* table_instance = TableGetInstanceData(table, table->InstanceCurrent);
     const float hit_half_width = TABLE_RESIZE_SEPARATOR_HALF_THICKNESS;
-    const float hit_y1 = (table->FreezeRowsCount >= 1 ? table->OuterRect.Min.y : table->WorkRect.Min.y) + table->AngledHeadersHeight;
+    const float hit_y1 = table->OuterRect.Min.y;
     const float hit_y2_body = ImMax(table->OuterRect.Max.y, hit_y1 + table_instance->LastOuterHeight);
-    const float hit_y2_head = hit_y1 + table_instance->LastTopHeadersRowHeight;
+    const float hit_y2_head = hit_y1 + table_instance->LastFirstRowHeight;
 
     for (int order_n = 0; order_n < table->ColumnsCount; order_n++)
     {
@@ -1268,7 +1217,7 @@ void ImGui::TableUpdateBorders(ImGuiTable* table)
         {
             TableSetColumnWidthAutoSingle(table, column_n);
             ClearActiveID();
-            held = false;
+            held = hovered = false;
         }
         if (held)
         {
@@ -1340,7 +1289,7 @@ void    ImGui::EndTable()
             max_pos_x = ImMax(max_pos_x, table->Columns[table->RightMostEnabledColumn].WorkMaxX + table->CellPaddingX + table->OuterPaddingX - outer_padding_for_border);
         if (table->ResizedColumn != -1)
             max_pos_x = ImMax(max_pos_x, table->ResizeLockMinContentsX2);
-        table->InnerWindow->DC.CursorMaxPos.x = max_pos_x + table->TempData->AngledheadersExtraWidth;
+        table->InnerWindow->DC.CursorMaxPos.x = max_pos_x;
     }
 
     // Pop clipping rect
@@ -1412,12 +1361,10 @@ void    ImGui::EndTable()
     {
         ImGuiTableColumn* column = &table->Columns[table->ResizedColumn];
         const float new_x2 = (g.IO.MousePos.x - g.ActiveIdClickOffset.x + TABLE_RESIZE_SEPARATOR_HALF_THICKNESS);
-        const float new_width = ImTrunc(new_x2 - column->MinX - table->CellSpacingX1 - table->CellPaddingX * 2.0f);
+        const float new_width = ImFloor(new_x2 - column->MinX - table->CellSpacingX1 - table->CellPaddingX * 2.0f);
         table->ResizedColumnNextWidth = new_width;
     }
 
-    table->IsActiveIdInTable = (g.ActiveIdIsAlive != 0 && table->IsActiveIdAliveBeforeTable == false);
-
     // Pop from id stack
     IM_ASSERT_USER_ERROR(inner_window->IDStack.back() == table_instance->TableInstanceID, "Mismatching PushID/PopID!");
     IM_ASSERT_USER_ERROR(outer_window->DC.ItemWidthStack.Size >= temp_data->HostBackupItemWidthStackSize, "Too many PopItemWidth!");
@@ -1458,7 +1405,7 @@ void    ImGui::EndTable()
     }
     else if (temp_data->UserOuterSize.x <= 0.0f)
     {
-        const float decoration_size = table->TempData->AngledheadersExtraWidth + ((table->Flags & ImGuiTableFlags_ScrollX) ? inner_window->ScrollbarSizes.x : 0.0f);
+        const float decoration_size = (table->Flags & ImGuiTableFlags_ScrollX) ? inner_window->ScrollbarSizes.x : 0.0f;
         outer_window->DC.IdealMaxPos.x = ImMax(outer_window->DC.IdealMaxPos.x, table->OuterRect.Min.x + table->ColumnsAutoFitWidth + decoration_size - temp_data->UserOuterSize.x);
         outer_window->DC.CursorMaxPos.x = ImMax(backup_outer_max_pos.x, ImMin(table->OuterRect.Max.x, table->OuterRect.Min.x + table->ColumnsAutoFitWidth));
     }
@@ -1497,7 +1444,7 @@ void    ImGui::EndTable()
     NavUpdateCurrentWindowIsScrollPushableX();
 }
 
-// See "COLUMNS SIZING POLICIES" comments at the top of this file
+// See "COLUMN SIZING POLICIES" comments at the top of this file
 // If (init_width_or_weight <= 0.0f) it is ignored
 void ImGui::TableSetupColumn(const char* label, ImGuiTableColumnFlags flags, float init_width_or_weight, ImGuiID user_id)
 {
@@ -1525,11 +1472,6 @@ void ImGui::TableSetupColumn(const char* label, ImGuiTableColumnFlags flags, flo
     if ((flags & ImGuiTableColumnFlags_WidthMask_) == 0 && init_width_or_weight > 0.0f)
         if ((table->Flags & ImGuiTableFlags_SizingMask_) == ImGuiTableFlags_SizingFixedFit || (table->Flags & ImGuiTableFlags_SizingMask_) == ImGuiTableFlags_SizingFixedSame)
             flags |= ImGuiTableColumnFlags_WidthFixed;
-    if (flags & ImGuiTableColumnFlags_AngledHeader)
-    {
-        flags |= ImGuiTableColumnFlags_NoHeaderLabel;
-        table->AngledHeadersCount++;
-    }
 
     TableSetupColumnFlags(table, column, flags);
     column->UserID = user_id;
@@ -1877,16 +1819,15 @@ void ImGui::TableEndRow(ImGuiTable* table)
     const float bg_y2 = table->RowPosY2;
     const bool unfreeze_rows_actual = (table->CurrentRow + 1 == table->FreezeRowsCount);
     const bool unfreeze_rows_request = (table->CurrentRow + 1 == table->FreezeRowsRequest);
-    ImGuiTableInstanceData* table_instance = TableGetInstanceData(table, table->InstanceCurrent);
-    if ((table->RowFlags & ImGuiTableRowFlags_Headers) && (table->CurrentRow == 0 || (table->LastRowFlags & ImGuiTableRowFlags_Headers)))
-        table_instance->LastTopHeadersRowHeight += bg_y2 - bg_y1;
+    if (table->CurrentRow == 0)
+        TableGetInstanceData(table, table->InstanceCurrent)->LastFirstRowHeight = bg_y2 - bg_y1;
 
     const bool is_visible = (bg_y2 >= table->InnerClipRect.Min.y && bg_y1 <= table->InnerClipRect.Max.y);
     if (is_visible)
     {
         // Update data for TableGetHoveredRow()
         if (table->HoveredColumnBody != -1 && g.IO.MousePos.y >= bg_y1 && g.IO.MousePos.y < bg_y2)
-            table_instance->HoveredRowNext = table->CurrentRow;
+            TableGetInstanceData(table, table->InstanceCurrent)->HoveredRowNext = table->CurrentRow;
 
         // Decide of background color for the row
         ImU32 bg_col0 = 0;
@@ -1899,14 +1840,15 @@ void ImGui::TableEndRow(ImGuiTable* table)
             bg_col1 = table->RowBgColor[1];
 
         // Decide of top border color
-        ImU32 top_border_col = 0;
+        ImU32 border_col = 0;
         const float border_size = TABLE_BORDER_SIZE;
-        if (table->CurrentRow > 0 && (table->Flags & ImGuiTableFlags_BordersInnerH))
-            top_border_col = (table->LastRowFlags & ImGuiTableRowFlags_Headers) ? table->BorderColorStrong : table->BorderColorLight;
+        if (table->CurrentRow > 0 || table->InnerWindow == table->OuterWindow)
+            if (table->Flags & ImGuiTableFlags_BordersInnerH)
+                border_col = (table->LastRowFlags & ImGuiTableRowFlags_Headers) ? table->BorderColorStrong : table->BorderColorLight;
 
         const bool draw_cell_bg_color = table->RowCellDataCurrent >= 0;
         const bool draw_strong_bottom_border = unfreeze_rows_actual;
-        if ((bg_col0 | bg_col1 | top_border_col) != 0 || draw_strong_bottom_border || draw_cell_bg_color)
+        if ((bg_col0 | bg_col1 | border_col) != 0 || draw_strong_bottom_border || draw_cell_bg_color)
         {
             // In theory we could call SetWindowClipRectBeforeSetChannel() but since we know TableEndRow() is
             // always followed by a change of clipping rectangle we perform the smallest overwrite possible here.
@@ -1945,8 +1887,8 @@ void ImGui::TableEndRow(ImGuiTable* table)
         }
 
         // Draw top border
-        if (top_border_col && bg_y1 >= table->BgClipRect.Min.y && bg_y1 < table->BgClipRect.Max.y)
-            window->DrawList->AddLine(ImVec2(table->BorderX1, bg_y1), ImVec2(table->BorderX2, bg_y1), top_border_col, border_size);
+        if (border_col && bg_y1 >= table->BgClipRect.Min.y && bg_y1 < table->BgClipRect.Max.y)
+            window->DrawList->AddLine(ImVec2(table->BorderX1, bg_y1), ImVec2(table->BorderX2, bg_y1), border_col, border_size);
 
         // Draw bottom border at the row unfreezing mark (always strong)
         if (draw_strong_bottom_border && bg_y2 >= table->BgClipRect.Min.y && bg_y2 < table->BgClipRect.Max.y)
@@ -1964,7 +1906,7 @@ void ImGui::TableEndRow(ImGuiTable* table)
         IM_ASSERT(table->IsUnfrozenRows == false);
         const float y0 = ImMax(table->RowPosY2 + 1, window->InnerClipRect.Min.y);
         table->IsUnfrozenRows = true;
-        table_instance->LastFrozenHeight = y0 - table->OuterRect.Min.y;
+        TableGetInstanceData(table, table->InstanceCurrent)->LastFrozenHeight = y0 - table->OuterRect.Min.y;
 
         // BgClipRect starts as table->InnerClipRect, reduce it now and make BgClipRectForDrawCmd == BgClipRect
         table->BgClipRect.Min.y = table->Bg2ClipRectForDrawCmd.Min.y = ImMin(y0, window->InnerClipRect.Max.y);
@@ -2342,7 +2284,6 @@ void ImGui::TableUpdateColumnsWeightFromWidth(ImGuiTable* table)
 // - TablePopBackgroundChannel() [Internal]
 // - TableSetupDrawChannels() [Internal]
 // - TableMergeDrawChannels() [Internal]
-// - TableGetColumnBorderCol() [Internal]
 // - TableDrawBorders() [Internal]
 //-------------------------------------------------------------------------
 
@@ -2626,18 +2567,6 @@ void ImGui::TableMergeDrawChannels(ImGuiTable* table)
     }
 }
 
-static ImU32 TableGetColumnBorderCol(ImGuiTable* table, int order_n, int column_n)
-{
-    const bool is_hovered = (table->HoveredColumnBorder == column_n);
-    const bool is_resized = (table->ResizedColumn == column_n) && (table->InstanceInteracted == table->InstanceCurrent);
-    const bool is_frozen_separator = (table->FreezeColumnsCount == order_n + 1);
-    if (is_resized || is_hovered)
-        return ImGui::GetColorU32(is_resized ? ImGuiCol_SeparatorActive : ImGuiCol_SeparatorHovered);
-    if (is_frozen_separator || (table->Flags & (ImGuiTableFlags_NoBordersInBody | ImGuiTableFlags_NoBordersInBodyUntilResize)))
-        return table->BorderColorStrong;
-    return table->BorderColorLight;
-}
-
 // FIXME-TABLE: This is a mess, need to redesign how we render borders (as some are also done in TableEndRow)
 void ImGui::TableDrawBorders(ImGuiTable* table)
 {
@@ -2652,9 +2581,9 @@ void ImGui::TableDrawBorders(ImGuiTable* table)
     // Draw inner border and resizing feedback
     ImGuiTableInstanceData* table_instance = TableGetInstanceData(table, table->InstanceCurrent);
     const float border_size = TABLE_BORDER_SIZE;
-    const float draw_y1 = ImMax(table->InnerRect.Min.y, (table->FreezeRowsCount >= 1 ? table->InnerRect.Min.y : table->WorkRect.Min.y) + table->AngledHeadersHeight) + ((table->Flags & ImGuiTableFlags_BordersOuterH) ? 1.0f : 0.0f);
+    const float draw_y1 = table->InnerRect.Min.y;
     const float draw_y2_body = table->InnerRect.Max.y;
-    const float draw_y2_head = table->IsUsingHeaders ? ImMin(table->InnerRect.Max.y, (table->FreezeRowsCount >= 1 ? table->InnerRect.Min.y : table->WorkRect.Min.y) + table_instance->LastTopHeadersRowHeight) : draw_y1;
+    const float draw_y2_head = table->IsUsingHeaders ? ImMin(table->InnerRect.Max.y, (table->FreezeRowsCount >= 1 ? table->InnerRect.Min.y : table->WorkRect.Min.y) + table_instance->LastFirstRowHeight) : draw_y1;
     if (table->Flags & ImGuiTableFlags_BordersInnerV)
     {
         for (int order_n = 0; order_n < table->ColumnsCount; order_n++)
@@ -2680,9 +2609,21 @@ void ImGui::TableDrawBorders(ImGuiTable* table)
 
             // Draw in outer window so right-most column won't be clipped
             // Always draw full height border when being resized/hovered, or on the delimitation of frozen column scrolling.
-            float draw_y2 = (is_hovered || is_resized || is_frozen_separator || (table->Flags & (ImGuiTableFlags_NoBordersInBody | ImGuiTableFlags_NoBordersInBodyUntilResize)) == 0) ? draw_y2_body : draw_y2_head;
+            ImU32 col;
+            float draw_y2;
+            if (is_hovered || is_resized || is_frozen_separator)
+            {
+                draw_y2 = draw_y2_body;
+                col = is_resized ? GetColorU32(ImGuiCol_SeparatorActive) : is_hovered ? GetColorU32(ImGuiCol_SeparatorHovered) : table->BorderColorStrong;
+            }
+            else
+            {
+                draw_y2 = (table->Flags & (ImGuiTableFlags_NoBordersInBody | ImGuiTableFlags_NoBordersInBodyUntilResize)) ? draw_y2_head : draw_y2_body;
+                col = (table->Flags & (ImGuiTableFlags_NoBordersInBody | ImGuiTableFlags_NoBordersInBodyUntilResize)) ? table->BorderColorStrong : table->BorderColorLight;
+            }
+
             if (draw_y2 > draw_y1)
-                inner_drawlist->AddLine(ImVec2(column->MaxX, draw_y1), ImVec2(column->MaxX, draw_y2), TableGetColumnBorderCol(table, order_n, column_n), border_size);
+                inner_drawlist->AddLine(ImVec2(column->MaxX, draw_y1), ImVec2(column->MaxX, draw_y2), col, border_size);
         }
     }
 
@@ -2699,7 +2640,7 @@ void ImGui::TableDrawBorders(ImGuiTable* table)
         const ImU32 outer_col = table->BorderColorStrong;
         if ((table->Flags & ImGuiTableFlags_BordersOuter) == ImGuiTableFlags_BordersOuter)
         {
-            inner_drawlist->AddRect(outer_border.Min, outer_border.Max + ImVec2(1, 1), outer_col, 0.0f, 0, border_size);
+            inner_drawlist->AddRect(outer_border.Min, outer_border.Max, outer_col, 0.0f, 0, border_size);
         }
         else if (table->Flags & ImGuiTableFlags_BordersOuterV)
         {
@@ -2714,7 +2655,7 @@ void ImGui::TableDrawBorders(ImGuiTable* table)
     }
     if ((table->Flags & ImGuiTableFlags_BordersInnerH) && table->RowPosY2 < table->OuterRect.Max.y)
     {
-        // Draw bottom-most row border between it is above outer border.
+        // Draw bottom-most row border
         const float border_y = table->RowPosY2;
         if (border_y >= table->BgClipRect.Min.y && border_y < table->BgClipRect.Max.y)
             inner_drawlist->AddLine(ImVec2(table->BorderX1, border_y), ImVec2(table->BorderX2, border_y), table->BorderColorLight, border_size);
@@ -2925,8 +2866,6 @@ void ImGui::TableSortSpecsBuild(ImGuiTable* table)
 // - TableGetHeaderRowHeight() [Internal]
 // - TableHeadersRow()
 // - TableHeader()
-// - TableAngledHeadersRow()
-// - TableAngledHeadersRowEx() [Internal]
 //-------------------------------------------------------------------------
 
 float ImGui::TableGetHeaderRowHeight()
@@ -2935,26 +2874,16 @@ float ImGui::TableGetHeaderRowHeight()
     // Calculate row height, for the unlikely case that some labels may be taller than others.
     // If we didn't do that, uneven header height would highlight but smaller one before the tallest wouldn't catch input for all height.
     // In your custom header row you may omit this all together and just call TableNextRow() without a height...
-    ImGuiContext& g = *GImGui;
-    ImGuiTable* table = g.CurrentTable;
-    float row_height = g.FontSize;
-    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
-        if (IM_BITARRAY_TESTBIT(table->EnabledMaskByIndex, column_n))
-            if ((table->Columns[column_n].Flags & ImGuiTableColumnFlags_NoHeaderLabel) == 0)
-                row_height = ImMax(row_height, CalcTextSize(TableGetColumnName(table, column_n)).y);
-    return row_height + g.Style.CellPadding.y * 2.0f;
-}
-
-float ImGui::TableGetHeaderAngledMaxLabelWidth()
-{
-    ImGuiContext& g = *GImGui;
-    ImGuiTable* table = g.CurrentTable;
-    float width = 0.0f;
-    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
-        if (IM_BITARRAY_TESTBIT(table->EnabledMaskByIndex, column_n))
-            if (table->Columns[column_n].Flags & ImGuiTableColumnFlags_AngledHeader)
-                width = ImMax(width, CalcTextSize(TableGetColumnName(table, column_n), NULL, true).x);
-    return width + g.Style.CellPadding.x * 2.0f;
+    float row_height = GetTextLineHeight();
+    int columns_count = TableGetColumnCount();
+    for (int column_n = 0; column_n < columns_count; column_n++)
+    {
+        ImGuiTableColumnFlags flags = TableGetColumnFlags(column_n);
+        if ((flags & ImGuiTableColumnFlags_IsEnabled) && !(flags & ImGuiTableColumnFlags_NoHeaderLabel))
+            row_height = ImMax(row_height, CalcTextSize(TableGetColumnName(column_n)).y);
+    }
+    row_height += GetStyle().CellPadding.y * 2.0f;
+    return row_height;
 }
 
 // [Public] This is a helper to output TableHeader() calls based on the column names declared in TableSetupColumn().
@@ -2974,9 +2903,9 @@ void ImGui::TableHeadersRow()
         TableUpdateLayout(table);
 
     // Open row
+    const float row_y1 = GetCursorScreenPos().y;
     const float row_height = TableGetHeaderRowHeight();
     TableNextRow(ImGuiTableRowFlags_Headers, row_height);
-    const float row_y1 = GetCursorScreenPos().y;
     if (table->HostSkipItems) // Merely an optimization, you may skip in your own code.
         return;
 
@@ -2998,7 +2927,7 @@ void ImGui::TableHeadersRow()
     ImVec2 mouse_pos = ImGui::GetMousePos();
     if (IsMouseReleased(1) && TableGetHoveredColumn() == columns_count)
         if (mouse_pos.y >= row_y1 && mouse_pos.y < row_y1 + row_height)
-            TableOpenContextMenu(columns_count); // Will open a non-column-specific popup.
+            TableOpenContextMenu(-1); // Will open a non-column-specific popup.
 }
 
 // Emit a column header (text + optional sort order)
@@ -3032,14 +2961,11 @@ void ImGui::TableHeader(const char* label)
     // Calculate ideal size for sort order arrow
     float w_arrow = 0.0f;
     float w_sort_text = 0.0f;
-    bool sort_arrow = false;
     char sort_order_suf[4] = "";
     const float ARROW_SCALE = 0.65f;
     if ((table->Flags & ImGuiTableFlags_Sortable) && !(column->Flags & ImGuiTableColumnFlags_NoSort))
     {
-        w_arrow = ImTrunc(g.FontSize * ARROW_SCALE + g.Style.FramePadding.x);
-        if (column->SortOrder != -1)
-            sort_arrow = true;
+        w_arrow = ImFloor(g.FontSize * ARROW_SCALE + g.Style.FramePadding.x);
         if (column->SortOrder > 0)
         {
             ImFormatString(sort_order_suf, IM_ARRAYSIZE(sort_order_suf), "%d", column->SortOrder + 1);
@@ -3047,12 +2973,13 @@ void ImGui::TableHeader(const char* label)
         }
     }
 
-    // We feed our unclipped width to the column without writing on CursorMaxPos, so that column is still considered for merging.
+    // We feed our unclipped width to the column without writing on CursorMaxPos, so that column is still considering for merging.
     float max_pos_x = label_pos.x + label_size.x + w_sort_text + w_arrow;
-    column->ContentMaxXHeadersUsed = ImMax(column->ContentMaxXHeadersUsed, sort_arrow ? cell_r.Max.x : ImMin(max_pos_x, cell_r.Max.x));
+    column->ContentMaxXHeadersUsed = ImMax(column->ContentMaxXHeadersUsed, column->WorkMaxX);
     column->ContentMaxXHeadersIdeal = ImMax(column->ContentMaxXHeadersIdeal, max_pos_x);
 
     // Keep header highlighted when context menu is open.
+    const bool selected = (table->IsContextPopupOpen && table->ContextPopupColumn == column_n && table->InstanceInteracted == table->InstanceCurrent);
     ImGuiID id = window->GetID(label);
     ImRect bb(cell_r.Min.x, cell_r.Min.y, cell_r.Max.x, ImMax(cell_r.Max.y, cell_r.Min.y + label_height + g.Style.CellPadding.y * 2.0f));
     ItemSize(ImVec2(0.0f, label_height)); // Don't declare unclipped width, it'll be fed ContentMaxPosHeadersIdeal
@@ -3063,10 +2990,9 @@ void ImGui::TableHeader(const char* label)
     //GetForegroundDrawList()->AddRect(bb.Min, bb.Max, IM_COL32(255, 0, 0, 255)); // [DEBUG]
 
     // Using AllowOverlap mode because we cover the whole cell, and we want user to be able to submit subsequent items.
-    const bool highlight = (table->HighlightColumnHeader == column_n);
     bool hovered, held;
     bool pressed = ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags_AllowOverlap);
-    if (held || hovered || highlight)
+    if (held || hovered || selected)
     {
         const ImU32 col = GetColorU32(held ? ImGuiCol_HeaderActive : hovered ? ImGuiCol_HeaderHovered : ImGuiCol_Header);
         //RenderFrame(bb.Min, bb.Max, col, false, 0.0f);
@@ -3144,126 +3070,11 @@ void ImGui::TableHeader(const char* label)
         TableOpenContextMenu(column_n);
 }
 
-// Unlike TableHeadersRow() it is not expected that you can reimplement or customize this with custom widgets.
-// FIXME: highlight without ImGuiTableFlags_HighlightHoveredColumn
-// FIXME: No hit-testing/button on the angled header.
-void ImGui::TableAngledHeadersRow()
-{
-    ImGuiContext& g = *GImGui;
-    TableAngledHeadersRowEx(g.Style.TableAngledHeadersAngle, 0.0f);
-}
-
-void ImGui::TableAngledHeadersRowEx(float angle, float max_label_width)
-{
-    ImGuiContext& g = *GImGui;
-    ImGuiTable* table = g.CurrentTable;
-    ImGuiWindow* window = g.CurrentWindow;
-    ImDrawList* draw_list = window->DrawList;
-    IM_ASSERT(table != NULL && "Need to call TableHeadersRow() after BeginTable()!");
-    IM_ASSERT(table->CurrentRow == -1 && "Must be first row");
-
-    if (max_label_width == 0.0f)
-        max_label_width = TableGetHeaderAngledMaxLabelWidth();
-
-    // Angle argument expressed in (-IM_PI/2 .. +IM_PI/2) as it is easier to think about for user.
-    const bool flip_label = (angle < 0.0f);
-    angle -= IM_PI * 0.5f;
-    const float cos_a = ImCos(angle);
-    const float sin_a = ImSin(angle);
-    const float label_cos_a = flip_label ? ImCos(angle + IM_PI) : cos_a;
-    const float label_sin_a = flip_label ? ImSin(angle + IM_PI) : sin_a;
-    const ImVec2 unit_right = ImVec2(cos_a, sin_a);
-
-    // Calculate our base metrics and set angled headers data _before_ the first call to TableNextRow()
-    // FIXME-STYLE: Would it be better for user to submit 'max_label_width' or 'row_height' ? One can be derived from the other.
-    const float header_height = table->RowCellPaddingY * 2.0f + g.FontSize;
-    const float row_height = ImFabs(ImRotate(ImVec2(max_label_width, flip_label ? +header_height : -header_height), cos_a, sin_a).y);
-    const ImVec2 header_angled_vector = unit_right * (row_height / -sin_a);
-    table->AngledHeadersHeight = row_height;
-    table->AngledHeadersSlope = (sin_a != 0.0f) ? (cos_a / sin_a) : 0.0f;
-
-    // Declare row, override and draw our own background
-    TableNextRow(ImGuiTableRowFlags_Headers, row_height);
-    TableNextColumn();
-    table->DrawSplitter->SetCurrentChannel(draw_list, TABLE_DRAW_CHANNEL_BG0);
-    float clip_rect_min_x = table->BgClipRect.Min.x;
-    if (table->FreezeColumnsCount > 0)
-        clip_rect_min_x = ImMax(clip_rect_min_x, table->Columns[table->FreezeColumnsCount - 1].MaxX);
-    TableSetBgColor(ImGuiTableBgTarget_RowBg0, 0); // Cancel
-    PushClipRect(table->BgClipRect.Min, table->BgClipRect.Max, false); // Span all columns
-    draw_list->AddRectFilled(table->BgClipRect.Min, table->BgClipRect.Max, GetColorU32(ImGuiCol_TableHeaderBg, 0.25f)); // FIXME-STYLE: Change row background with an arbitrary color.
-    PushClipRect(ImVec2(clip_rect_min_x, table->BgClipRect.Min.y), table->BgClipRect.Max, true); // Span all columns
-
-    const ImRect row_r(table->WorkRect.Min.x, table->BgClipRect.Min.y, table->WorkRect.Max.x, window->DC.CursorPos.y + row_height);
-    const ImGuiID row_id = GetID("##AngledHeaders");
-    ButtonBehavior(row_r, row_id, NULL, NULL);
-    KeepAliveID(row_id);
-
-    ImGuiTableInstanceData* table_instance = TableGetInstanceData(table, table->InstanceCurrent);
-    int highlight_column_n = table->HighlightColumnHeader;
-    if (highlight_column_n == -1 && table->HoveredColumnBody != -1)
-        if (table_instance->HoveredRowLast == 0 && table->HoveredColumnBorder == -1 && (g.ActiveId == 0 || g.ActiveId == row_id || (table->IsActiveIdInTable || g.DragDropActive)))
-            highlight_column_n = table->HoveredColumnBody;
-
-    float max_x = 0.0f;
-    for (int pass = 0; pass < 2; pass++)
-        for (int order_n = 0; order_n < table->ColumnsCount; order_n++)
-        {
-            if (!IM_BITARRAY_TESTBIT(table->EnabledMaskByDisplayOrder, order_n))
-                continue;
-            const int column_n = table->DisplayOrderToIndex[order_n];
-            ImGuiTableColumn* column = &table->Columns[column_n];
-            if ((column->Flags & ImGuiTableColumnFlags_AngledHeader) == 0) // Note: can't rely on ImGuiTableColumnFlags_IsVisible test here.
-                continue;
-
-            ImVec2 bg_shape[4];
-            bg_shape[0] = ImVec2(column->MaxX, row_r.Max.y);
-            bg_shape[1] = ImVec2(column->MinX, row_r.Max.y);
-            bg_shape[2] = bg_shape[1] + header_angled_vector;
-            bg_shape[3] = bg_shape[0] + header_angled_vector;
-            if (pass == 0)
-            {
-                // Draw shape
-                draw_list->AddQuadFilled(bg_shape[0], bg_shape[1], bg_shape[2], bg_shape[3], GetColorU32(ImGuiCol_TableHeaderBg));
-                if (column_n == highlight_column_n)
-                    draw_list->AddQuadFilled(bg_shape[0], bg_shape[1], bg_shape[2], bg_shape[3], GetColorU32(ImGuiCol_Header)); // Highlight on hover
-                //draw_list->AddQuad(bg_shape[0], bg_shape[1], bg_shape[2], bg_shape[3], GetColorU32(ImGuiCol_TableBorderLight), 1.0f);
-                max_x = ImMax(max_x, bg_shape[3].x);
-
-                // Draw label (first draw at an offset where RenderTextXXX() function won't meddle with applying current ClipRect, then transform to final offset)
-                // FIXME: May be worth tidying up all those operations to make them easier to understand.
-                const char* label_name = TableGetColumnName(table, column_n);
-                const float clip_width = max_label_width - (sin_a * table->RowCellPaddingY);
-                ImRect label_r(window->ClipRect.Min, window->ClipRect.Min + ImVec2(clip_width + (flip_label ? 0.0f : table->CellPaddingX), header_height + table->RowCellPaddingY));
-                ImVec2 label_size = CalcTextSize(label_name, NULL, true);
-                ImVec2 label_off = ImVec2(flip_label ? ImMax(0.0f, max_label_width - label_size.x - table->CellPaddingX) : table->CellPaddingX, table->RowCellPaddingY);
-                int vtx_idx_begin = draw_list->_VtxCurrentIdx;
-                RenderTextEllipsis(draw_list, label_r.Min + label_off, label_r.Max, label_r.Max.x, label_r.Max.x, label_name, NULL, &label_size);
-                //if (g.IO.KeyShift) { draw_list->AddRect(label_r.Min, label_r.Max, IM_COL32(0, 255, 0, 255), 0.0f, 0, 2.0f); }
-                int vtx_idx_end = draw_list->_VtxCurrentIdx;
-
-                // Rotate and offset label
-                ImVec2 pivot_in = label_r.GetBL();
-                ImVec2 pivot_out = ImVec2(column->WorkMinX, row_r.Max.y) + (flip_label ? (unit_right * clip_width) : ImVec2(header_height, 0.0f));
-                ShadeVertsTransformPos(draw_list, vtx_idx_begin, vtx_idx_end, pivot_in, label_cos_a, label_sin_a, pivot_out); // Rotate and offset
-            }
-            if (pass == 1)
-            {
-                // Draw border
-                draw_list->AddLine(bg_shape[0], bg_shape[3], TableGetColumnBorderCol(table, order_n, column_n));
-            }
-        }
-    PopClipRect();
-    PopClipRect();
-    table->TempData->AngledheadersExtraWidth = ImMax(0.0f, max_x - table->Columns[table->RightMostEnabledColumn].MaxX);
-}
-
 //-------------------------------------------------------------------------
 // [SECTION] Tables: Context Menu
 //-------------------------------------------------------------------------
 // - TableOpenContextMenu() [Internal]
-// - TableBeginContextMenuPopup() [Internal]
-// - TableDrawDefaultContextMenu() [Internal]
+// - TableDrawContextMenu() [Internal]
 //-------------------------------------------------------------------------
 
 // Use -1 to open menu not specific to a given column.
@@ -3299,13 +3110,7 @@ bool ImGui::TableBeginContextMenuPopup(ImGuiTable* table)
 
 // Output context menu into current window (generally a popup)
 // FIXME-TABLE: Ideally this should be writable by the user. Full programmatic access to that data?
-// Sections to display are pulled from 'flags_for_section_to_display', which is typically == table->Flags.
-// - ImGuiTableFlags_Resizable   -> display Sizing menu items
-// - ImGuiTableFlags_Reorderable -> display "Reset Order"
-////- ImGuiTableFlags_Sortable   -> display sorting options (disabled)
-// - ImGuiTableFlags_Hideable    -> display columns visibility menu items
-// It means if you have a custom context menus you can call this section and omit some sections, and add your own.
-void ImGui::TableDrawDefaultContextMenu(ImGuiTable* table, ImGuiTableFlags flags_for_section_to_display)
+void ImGui::TableDrawContextMenu(ImGuiTable* table)
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
@@ -3317,7 +3122,7 @@ void ImGui::TableDrawDefaultContextMenu(ImGuiTable* table, ImGuiTableFlags flags
     ImGuiTableColumn* column = (column_n != -1) ? &table->Columns[column_n] : NULL;
 
     // Sizing
-    if (flags_for_section_to_display & ImGuiTableFlags_Resizable)
+    if (table->Flags & ImGuiTableFlags_Resizable)
     {
         if (column != NULL)
         {
@@ -3337,7 +3142,7 @@ void ImGui::TableDrawDefaultContextMenu(ImGuiTable* table, ImGuiTableFlags flags
     }
 
     // Ordering
-    if (flags_for_section_to_display & ImGuiTableFlags_Reorderable)
+    if (table->Flags & ImGuiTableFlags_Reorderable)
     {
         if (MenuItem(LocalizeGetMsg(ImGuiLocKey_TableResetOrder), NULL, false, !table->IsDefaultDisplayOrder))
             table->IsResetDisplayOrderRequest = true;
@@ -3351,7 +3156,7 @@ void ImGui::TableDrawDefaultContextMenu(ImGuiTable* table, ImGuiTableFlags flags
     // Sorting
     // (modify TableOpenContextMenu() to add _Sortable flag if enabling this)
 #if 0
-    if ((flags_for_section_to_display & ImGuiTableFlags_Sortable) && column != NULL && (column->Flags & ImGuiTableColumnFlags_NoSort) == 0)
+    if ((table->Flags & ImGuiTableFlags_Sortable) && column != NULL && (column->Flags & ImGuiTableColumnFlags_NoSort) == 0)
     {
         if (want_separator)
             Separator();
@@ -3366,7 +3171,7 @@ void ImGui::TableDrawDefaultContextMenu(ImGuiTable* table, ImGuiTableFlags flags
 #endif
 
     // Hiding / Visibility
-    if (flags_for_section_to_display & ImGuiTableFlags_Hideable)
+    if (table->Flags & ImGuiTableFlags_Hideable)
     {
         if (want_separator)
             Separator();
@@ -4134,7 +3939,7 @@ void ImGui::BeginColumns(const char* str_id, int columns_count, ImGuiOldColumnFl
     // Set state for first column
     // We aim so that the right-most column will have the same clipping width as other after being clipped by parent ClipRect
     const float column_padding = g.Style.ItemSpacing.x;
-    const float half_clip_extend_x = ImTrunc(ImMax(window->WindowPadding.x * 0.5f, window->WindowBorderSize));
+    const float half_clip_extend_x = ImFloor(ImMax(window->WindowPadding.x * 0.5f, window->WindowBorderSize));
     const float max_1 = window->WorkRect.Max.x + column_padding - ImMax(column_padding - window->WindowPadding.x, 0.0f);
     const float max_2 = window->WorkRect.Max.x + half_clip_extend_x;
     columns->OffMinX = window->DC.Indent.x - column_padding + ImMax(column_padding - window->WindowPadding.x, 0.0f);
@@ -4181,7 +3986,7 @@ void ImGui::BeginColumns(const char* str_id, int columns_count, ImGuiOldColumnFl
     float width = offset_1 - offset_0;
     PushItemWidth(width * 0.65f);
     window->DC.ColumnsOffset.x = ImMax(column_padding - window->WindowPadding.x, 0.0f);
-    window->DC.CursorPos.x = IM_TRUNC(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
+    window->DC.CursorPos.x = IM_FLOOR(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
     window->WorkRect.Max.x = window->Pos.x + offset_1 - column_padding;
     window->WorkRect.Max.y = window->ContentRegionRect.Max.y;
 }
@@ -4197,7 +4002,7 @@ void ImGui::NextColumn()
 
     if (columns->Count == 1)
     {
-        window->DC.CursorPos.x = IM_TRUNC(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
+        window->DC.CursorPos.x = IM_FLOOR(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
         IM_ASSERT(columns->Current == 0);
         return;
     }
@@ -4229,7 +4034,7 @@ void ImGui::NextColumn()
         window->DC.IsSameLine = false;
         columns->LineMinY = columns->LineMaxY;
     }
-    window->DC.CursorPos.x = IM_TRUNC(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
+    window->DC.CursorPos.x = IM_FLOOR(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
     window->DC.CursorPos.y = columns->LineMinY;
     window->DC.CurrLineSize = ImVec2(0.0f, 0.0f);
     window->DC.CurrLineTextBaseOffset = 0.0f;
@@ -4293,7 +4098,7 @@ void ImGui::EndColumns()
 
             // Draw column
             const ImU32 col = GetColorU32(held ? ImGuiCol_SeparatorActive : hovered ? ImGuiCol_SeparatorHovered : ImGuiCol_Separator);
-            const float xi = IM_TRUNC(x);
+            const float xi = IM_FLOOR(x);
             window->DrawList->AddLine(ImVec2(xi, y1 + 1.0f), ImVec2(xi, y2), col);
         }
 
@@ -4314,7 +4119,7 @@ void ImGui::EndColumns()
     window->ParentWorkRect = columns->HostBackupParentWorkRect;
     window->DC.CurrentColumns = NULL;
     window->DC.ColumnsOffset.x = 0.0f;
-    window->DC.CursorPos.x = IM_TRUNC(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
+    window->DC.CursorPos.x = IM_FLOOR(window->Pos.x + window->DC.Indent.x + window->DC.ColumnsOffset.x);
     NavUpdateCurrentWindowIsScrollPushableX();
 }
 

imstb_textedit.h

@@ -2,7 +2,7 @@
 // This is a slightly modified version of stb_textedit.h 1.14.
 // Those changes would need to be pushed into nothings/stb:
 // - Fix in stb_textedit_discard_redo (see https://github.com/nothings/stb/issues/321)
-// - Fix in stb_textedit_find_charpos to handle last line (see https://github.com/ocornut/imgui/issues/6000 + #6783)
+// - Fix in stb_textedit_find_charpos to handle last line (see https://github.com/ocornut/imgui/issues/6000)
 // Grep for [DEAR IMGUI] to find the changes.
 
 // stb_textedit.h - v1.14  - public domain - Sean Barrett
@@ -549,10 +549,7 @@ static void stb_textedit_find_charpos(StbFindState *find, STB_TEXTEDIT_STRING *s
       i += r.num_chars;
       find->y += r.baseline_y_delta;
       if (i == z) // [DEAR IMGUI]
-      {
-         r.num_chars = 0; // [DEAR IMGUI]
          break;   // [DEAR IMGUI]
-      }
    }
 
    find->first_char = first = i;

misc/debuggers/imgui.natvis

@@ -55,4 +55,8 @@ More information at: https://docs.microsoft.com/en-us/visualstudio/debugger/crea
   <DisplayString>{{Name {Name,s} Active {(Active||WasActive)?1:0,d} Child {(Flags &amp; 0x01000000)?1:0,d} Popup {(Flags &amp; 0x04000000)?1:0,d} Hidden {(Hidden)?1:0,d}}</DisplayString>
 </Type>
 
+<Type Name="ImGuiDockNode">
+  <DisplayString>{{ID {ID,x} Pos=({Pos.x,g} {Pos.y,g}) Size=({Size.x,g} {Size.y,g}) Parent {(ParentNode==0)?0:ParentNode->ID,x} Childs {(ChildNodes[0] != 0)+(ChildNodes[1] != 0)} Windows {Windows.Size}  }</DisplayString>
+</Type>
+
 </AutoVisualizer>

misc/freetype/imgui_freetype.cpp

@@ -6,7 +6,6 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  2023/11/13: added support for ImFontConfig::RasterizationDensity field for scaling render density without scaling metrics.
 //  2023/08/01: added support for SVG fonts, enable by using '#define IMGUI_ENABLE_FREETYPE_LUNASVG' (#6591)
 //  2023/01/04: fixed a packing issue which in some occurrences would prevent large amount of glyphs from being packed correctly.
 //  2021/08/23: fixed crash when FT_Render_Glyph() fails to render a glyph and returns NULL.
@@ -64,10 +63,8 @@
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wpragmas"                  // warning: unknown option after '#pragma GCC diagnostic' kind
 #pragma GCC diagnostic ignored "-Wunused-function"          // warning: 'xxxx' defined but not used
-#ifndef __clang__
 #pragma GCC diagnostic ignored "-Wsubobject-linkage"        // warning: 'xxxx' has a field 'xxxx' whose type uses the anonymous namespace
 #endif
-#endif
 
 //-------------------------------------------------------------------------
 // Data
@@ -167,8 +164,6 @@ namespace
         unsigned int    UserFlags;          // = ImFontConfig::RasterizerFlags
         FT_Int32        LoadFlags;
         FT_Render_Mode  RenderMode;
-        float           RasterizationDensity;
-        float           InvRasterizationDensity;
     };
 
     // From SDL_ttf: Handy routines for converting from fixed point
@@ -211,9 +206,6 @@ namespace
         if (UserFlags & ImGuiFreeTypeBuilderFlags_LoadColor)
             LoadFlags |= FT_LOAD_COLOR;
 
-        RasterizationDensity = cfg.RasterizerDensity;
-        InvRasterizationDensity = 1.0f / RasterizationDensity;
-
         memset(&Info, 0, sizeof(Info));
         SetPixelHeight((uint32_t)cfg.SizePixels);
 
@@ -237,19 +229,19 @@ namespace
         FT_Size_RequestRec req;
         req.type = (UserFlags & ImGuiFreeTypeBuilderFlags_Bitmap) ? FT_SIZE_REQUEST_TYPE_NOMINAL : FT_SIZE_REQUEST_TYPE_REAL_DIM;
         req.width = 0;
-        req.height = (uint32_t)(pixel_height * 64 * RasterizationDensity);
+        req.height = (uint32_t)pixel_height * 64;
         req.horiResolution = 0;
         req.vertResolution = 0;
         FT_Request_Size(Face, &req);
 
         // Update font info
         FT_Size_Metrics metrics = Face->size->metrics;
-        Info.PixelHeight = (uint32_t)(pixel_height * InvRasterizationDensity);
-        Info.Ascender = (float)FT_CEIL(metrics.ascender) * InvRasterizationDensity;
-        Info.Descender = (float)FT_CEIL(metrics.descender) * InvRasterizationDensity;
-        Info.LineSpacing = (float)FT_CEIL(metrics.height) * InvRasterizationDensity;
-        Info.LineGap = (float)FT_CEIL(metrics.height - metrics.ascender + metrics.descender) * InvRasterizationDensity;
-        Info.MaxAdvanceWidth = (float)FT_CEIL(metrics.max_advance) * InvRasterizationDensity;
+        Info.PixelHeight = (uint32_t)pixel_height;
+        Info.Ascender = (float)FT_CEIL(metrics.ascender);
+        Info.Descender = (float)FT_CEIL(metrics.descender);
+        Info.LineSpacing = (float)FT_CEIL(metrics.height);
+        Info.LineGap = (float)FT_CEIL(metrics.height - metrics.ascender + metrics.descender);
+        Info.MaxAdvanceWidth = (float)FT_CEIL(metrics.max_advance);
     }
 
     const FT_Glyph_Metrics* FreeTypeFont::LoadGlyph(uint32_t codepoint)
@@ -701,15 +693,15 @@ bool ImFontAtlasBuildWithFreeTypeEx(FT_Library ft_library, ImFontAtlas* atlas, u
             const int ty = pack_rect.y + padding;
 
             // Register glyph
-            float x0 = info.OffsetX * src_tmp.Font.InvRasterizationDensity + font_off_x;
-            float y0 = info.OffsetY * src_tmp.Font.InvRasterizationDensity + font_off_y;
-            float x1 = x0 + info.Width * src_tmp.Font.InvRasterizationDensity;
-            float y1 = y0 + info.Height * src_tmp.Font.InvRasterizationDensity;
+            float x0 = info.OffsetX + font_off_x;
+            float y0 = info.OffsetY + font_off_y;
+            float x1 = x0 + info.Width;
+            float y1 = y0 + info.Height;
             float u0 = (tx) / (float)atlas->TexWidth;
             float v0 = (ty) / (float)atlas->TexHeight;
             float u1 = (tx + info.Width) / (float)atlas->TexWidth;
             float v1 = (ty + info.Height) / (float)atlas->TexHeight;
-            dst_font->AddGlyph(&cfg, (ImWchar)src_glyph.Codepoint, x0, y0, x1, y1, u0, v0, u1, v1, info.AdvanceX * src_tmp.Font.InvRasterizationDensity);
+            dst_font->AddGlyph(&cfg, (ImWchar)src_glyph.Codepoint, x0, y0, x1, y1, u0, v0, u1, v1, info.AdvanceX);
 
             ImFontGlyph* dst_glyph = &dst_font->Glyphs.back();
             IM_ASSERT(dst_glyph->Codepoint == src_glyph.Codepoint);
@@ -848,7 +840,7 @@ static FT_Error ImGuiLunasvgPortInit(FT_Pointer* _state)
 
 static void ImGuiLunasvgPortFree(FT_Pointer* _state)
 {
-    IM_DELETE(*(LunasvgPortState**)_state);
+    IM_DELETE(*_state);
 }
 
 static FT_Error ImGuiLunasvgPortRender(FT_GlyphSlot slot, FT_Pointer* _state)