Merge branch 'master' into docking

# Conflicts:
#	imgui_internal.h

.github/ISSUE_TEMPLATE/issue_template.yml

@@ -8,7 +8,7 @@ body:
         For anything else: **we are happy to use 'GitHub Issues' for many types of open-ended questions**. We are encouraging 'Issues' becoming a large, centralized, tagged, cross-referenced database of Dear ImGui contents.
 
         Be mindful that messages are being sent to the e-mail box of "Watching" users. Try to proof-read your messages before sending them. Edits are not seen by those users.
-        
+
         **If you are using Dear ImGui as part of a job that you are being well-paid for** and your company is not a sponsor. Please be mindful that this is a Free Software and you might be about to ask volunteers to help you doing your job. Please put extra effort describing your issue or question properly. If your company is wealthy, please read [Funding](https://github.com/ocornut/imgui/wiki/Funding) and consider getting in touch.
   - type: markdown
     attributes:

.gitignore

@@ -49,6 +49,9 @@ examples/example_sdl2_opengl3/web/*
 .idea
 cmake-build-*
 
+## VS code artifacts
+.vscode
+
 ## Unix executables from our example Makefiles
 examples/example_glfw_metal/example_glfw_metal
 examples/example_glfw_opengl2/example_glfw_opengl2

backends/imgui_impl_allegro5.cpp

@@ -7,8 +7,9 @@
 //  [X] Platform: Clipboard support (from Allegro 5.1.12).
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 // Missing features or Issues:
-//  [ ] Renderer: The renderer is suboptimal as we need to convert vertices manually.
+//  [ ] Renderer: The renderer is suboptimal as we need to unindex our buffers and convert vertices manually.
 //  [ ] Platform: Missing gamepad support.
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -20,6 +21,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-02-18: Added ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress mouse cursor support.
 //  2025-01-06: Avoid calling al_set_mouse_cursor() repeatedly since it appears to leak on on X11 (#8256).
 //  2024-08-22: moved some OS/backend related function pointers from ImGuiIO to ImGuiPlatformIO:
 //               - io.GetClipboardTextFn    -> platform_io.Platform_GetClipboardTextFn
@@ -594,6 +596,8 @@ static void ImGui_ImplAllegro5_UpdateMouseCursor()
         case ImGuiMouseCursor_ResizeEW:     cursor_id = ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_E; break;
         case ImGuiMouseCursor_ResizeNESW:   cursor_id = ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_NE; break;
         case ImGuiMouseCursor_ResizeNWSE:   cursor_id = ALLEGRO_SYSTEM_MOUSE_CURSOR_RESIZE_NW; break;
+        case ImGuiMouseCursor_Wait:         cursor_id = ALLEGRO_SYSTEM_MOUSE_CURSOR_BUSY; break;
+        case ImGuiMouseCursor_Progress:     cursor_id = ALLEGRO_SYSTEM_MOUSE_CURSOR_PROGRESS; break;
         case ImGuiMouseCursor_NotAllowed:   cursor_id = ALLEGRO_SYSTEM_MOUSE_CURSOR_UNAVAILABLE; break;
         }
         al_set_system_mouse_cursor(bd->Display, cursor_id);

backends/imgui_impl_allegro5.h

@@ -9,6 +9,7 @@
 // Missing features or Issues:
 //  [ ] Renderer: The renderer is suboptimal as we need to unindex our buffers and convert vertices manually.
 //  [ ] Platform: Missing gamepad support.
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

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

backends/imgui_impl_android.h

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

backends/imgui_impl_dx10.cpp

@@ -4,6 +4,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'ID3D10ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
+//  [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.
@@ -15,6 +16,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2025-01-06: DirectX10: Expose selected render state in ImGui_ImplDX10_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
 //  2024-10-07: DirectX10: Changed default texture sampler to Clamp instead of Repeat/Wrap.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
@@ -47,7 +49,7 @@
 #pragma comment(lib, "d3dcompiler") // Automatically link with d3dcompiler.lib as we are using D3DCompile() below.
 #endif
 
-// DirectX data
+// DirectX10 data
 struct ImGui_ImplDX10_Data
 {
     ID3D10Device*               pd3dDevice;
@@ -81,14 +83,17 @@ static ImGui_ImplDX10_Data* ImGui_ImplDX10_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX10_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX10_InitMultiViewportSupport();
+static void ImGui_ImplDX10_ShutdownMultiViewportSupport();
+
 // Functions
 static void ImGui_ImplDX10_SetupRenderState(ImDrawData* draw_data, ID3D10Device* device)
 {
     ImGui_ImplDX10_Data* bd = ImGui_ImplDX10_GetBackendData();
 
     // Setup viewport
-    D3D10_VIEWPORT vp;
-    memset(&vp, 0, sizeof(D3D10_VIEWPORT));
+    D3D10_VIEWPORT vp = {};
     vp.Width = (UINT)draw_data->DisplaySize.x;
     vp.Height = (UINT)draw_data->DisplaySize.y;
     vp.MinDepth = 0.0f;
@@ -152,8 +157,7 @@ void ImGui_ImplDX10_RenderDrawData(ImDrawData* draw_data)
     {
         if (bd->pVB) { bd->pVB->Release(); bd->pVB = nullptr; }
         bd->VertexBufferSize = draw_data->TotalVtxCount + 5000;
-        D3D10_BUFFER_DESC desc;
-        memset(&desc, 0, sizeof(D3D10_BUFFER_DESC));
+        D3D10_BUFFER_DESC desc = {};
         desc.Usage = D3D10_USAGE_DYNAMIC;
         desc.ByteWidth = bd->VertexBufferSize * sizeof(ImDrawVert);
         desc.BindFlags = D3D10_BIND_VERTEX_BUFFER;
@@ -167,8 +171,7 @@ void ImGui_ImplDX10_RenderDrawData(ImDrawData* draw_data)
     {
         if (bd->pIB) { bd->pIB->Release(); bd->pIB = nullptr; }
         bd->IndexBufferSize = draw_data->TotalIdxCount + 10000;
-        D3D10_BUFFER_DESC desc;
-        memset(&desc, 0, sizeof(D3D10_BUFFER_DESC));
+        D3D10_BUFFER_DESC desc = {};
         desc.Usage = D3D10_USAGE_DYNAMIC;
         desc.ByteWidth = bd->IndexBufferSize * sizeof(ImDrawIdx);
         desc.BindFlags = D3D10_BIND_INDEX_BUFFER;
@@ -431,7 +434,7 @@ bool    ImGui_ImplDX10_CreateDeviceObjects()
 
         // Create the constant buffer
         {
-            D3D10_BUFFER_DESC desc;
+            D3D10_BUFFER_DESC desc = {};
             desc.ByteWidth = sizeof(VERTEX_CONSTANT_BUFFER_DX10);
             desc.Usage = D3D10_USAGE_DYNAMIC;
             desc.BindFlags = D3D10_BIND_CONSTANT_BUFFER;
@@ -563,6 +566,7 @@ 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;
@@ -579,6 +583,8 @@ bool    ImGui_ImplDX10_Init(ID3D10Device* device)
     if (pDXGIAdapter) pDXGIAdapter->Release();
     bd->pd3dDevice->AddRef();
 
+    ImGui_ImplDX10_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -588,12 +594,13 @@ void ImGui_ImplDX10_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplDX10_ShutdownMultiViewportSupport();
     ImGui_ImplDX10_InvalidateDeviceObjects();
     if (bd->pFactory) { bd->pFactory->Release(); }
     if (bd->pd3dDevice) { bd->pd3dDevice->Release(); }
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -606,6 +613,129 @@ 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's WindowID).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+
+    // Create swap chain
+    DXGI_SWAP_CHAIN_DESC sd;
+    ZeroMemory(&sd, sizeof(sd));
+    sd.BufferDesc.Width = (UINT)viewport->Size.x;
+    sd.BufferDesc.Height = (UINT)viewport->Size.y;
+    sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
+    sd.SampleDesc.Count = 1;
+    sd.SampleDesc.Quality = 0;
+    sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
+    sd.BufferCount = 1;
+    sd.OutputWindow = hwnd;
+    sd.Windowed = TRUE;
+    sd.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
+    sd.Flags = 0;
+
+    IM_ASSERT(vd->SwapChain == nullptr && vd->RTView == nullptr);
+    bd->pFactory->CreateSwapChain(bd->pd3dDevice, &sd, &vd->SwapChain);
+
+    // 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_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX10_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX10_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX10_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX10_RenderViewport;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX10_SwapBuffers;
+}
+
+void ImGui_ImplDX10_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_dx10.h

@@ -4,6 +4,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'ID3D10ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_dx11.cpp

@@ -5,6 +5,7 @@
 //  [X] Renderer: User texture binding. Use 'ID3D11ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -16,6 +17,8 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-02-24: [Docking] Added undocumented ImGui_ImplDX11_SetSwapChainDescs() to configure swap chain creation for secondary viewports.
 //  2025-01-06: DirectX11: Expose VertexConstantBuffer in ImGui_ImplDX11_RenderState. Reset projection matrix in ImDrawCallback_ResetRenderState handler.
 //  2024-10-07: DirectX11: Changed default texture sampler to Clamp instead of Repeat/Wrap.
 //  2024-10-07: DirectX11: Expose selected render state in ImGui_ImplDX11_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
@@ -68,6 +71,7 @@ struct ImGui_ImplDX11_Data
     ID3D11DepthStencilState*    pDepthStencilState;
     int                         VertexBufferSize;
     int                         IndexBufferSize;
+    ImVector<DXGI_SWAP_CHAIN_DESC> SwapChainDescsForViewports;
 
     ImGui_ImplDX11_Data()       { memset((void*)this, 0, sizeof(*this)); VertexBufferSize = 5000; IndexBufferSize = 10000; }
 };
@@ -84,14 +88,17 @@ static ImGui_ImplDX11_Data* ImGui_ImplDX11_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX11_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX11_InitMultiViewportSupport();
+static void ImGui_ImplDX11_ShutdownMultiViewportSupport();
+
 // Functions
 static void ImGui_ImplDX11_SetupRenderState(ImDrawData* draw_data, ID3D11DeviceContext* device_ctx)
 {
     ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
 
     // Setup viewport
-    D3D11_VIEWPORT vp;
-    memset(&vp, 0, sizeof(D3D11_VIEWPORT));
+    D3D11_VIEWPORT vp = {};
     vp.Width = draw_data->DisplaySize.x;
     vp.Height = draw_data->DisplaySize.y;
     vp.MinDepth = 0.0f;
@@ -158,8 +165,7 @@ void ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data)
     {
         if (bd->pVB) { bd->pVB->Release(); bd->pVB = nullptr; }
         bd->VertexBufferSize = draw_data->TotalVtxCount + 5000;
-        D3D11_BUFFER_DESC desc;
-        memset(&desc, 0, sizeof(D3D11_BUFFER_DESC));
+        D3D11_BUFFER_DESC desc = {};
         desc.Usage = D3D11_USAGE_DYNAMIC;
         desc.ByteWidth = bd->VertexBufferSize * sizeof(ImDrawVert);
         desc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
@@ -172,8 +178,7 @@ void ImGui_ImplDX11_RenderDrawData(ImDrawData* draw_data)
     {
         if (bd->pIB) { bd->pIB->Release(); bd->pIB = nullptr; }
         bd->IndexBufferSize = draw_data->TotalIdxCount + 10000;
-        D3D11_BUFFER_DESC desc;
-        memset(&desc, 0, sizeof(D3D11_BUFFER_DESC));
+        D3D11_BUFFER_DESC desc = {};
         desc.Usage = D3D11_USAGE_DYNAMIC;
         desc.ByteWidth = bd->IndexBufferSize * sizeof(ImDrawIdx);
         desc.BindFlags = D3D11_BIND_INDEX_BUFFER;
@@ -447,7 +452,7 @@ bool    ImGui_ImplDX11_CreateDeviceObjects()
 
         // Create the constant buffer
         {
-            D3D11_BUFFER_DESC desc;
+            D3D11_BUFFER_DESC desc = {};
             desc.ByteWidth = sizeof(VERTEX_CONSTANT_BUFFER_DX11);
             desc.Usage = D3D11_USAGE_DYNAMIC;
             desc.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
@@ -579,6 +584,7 @@ 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;
@@ -598,6 +604,8 @@ bool    ImGui_ImplDX11_Init(ID3D11Device* device, ID3D11DeviceContext* device_co
     bd->pd3dDevice->AddRef();
     bd->pd3dDeviceContext->AddRef();
 
+    ImGui_ImplDX11_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -607,13 +615,14 @@ void ImGui_ImplDX11_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplDX11_ShutdownMultiViewportSupport();
     ImGui_ImplDX11_InvalidateDeviceObjects();
     if (bd->pFactory)             { bd->pFactory->Release(); }
     if (bd->pd3dDevice)           { bd->pd3dDevice->Release(); }
     if (bd->pd3dDeviceContext)    { bd->pd3dDeviceContext->Release(); }
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -626,6 +635,150 @@ 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); }
+};
+
+// Multi-Viewports: configure templates used when creating swapchains for secondary viewports. Will try them in order.
+// This is intentionally not declared in the .h file yet, so you will need to copy this declaration:
+void ImGui_ImplDX11_SetSwapChainDescs(const DXGI_SWAP_CHAIN_DESC* desc_templates, int desc_templates_count);
+void ImGui_ImplDX11_SetSwapChainDescs(const DXGI_SWAP_CHAIN_DESC* desc_templates, int desc_templates_count)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    bd->SwapChainDescsForViewports.resize(desc_templates_count);
+    memcpy(bd->SwapChainDescsForViewports.Data, desc_templates, sizeof(DXGI_SWAP_CHAIN_DESC));
+}
+
+static void ImGui_ImplDX11_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    ImGui_ImplDX11_ViewportData* vd = IM_NEW(ImGui_ImplDX11_ViewportData)();
+    viewport->RendererUserData = vd;
+
+    // PlatformHandleRaw should always be a HWND, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL's WindowID).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+    IM_ASSERT(vd->SwapChain == nullptr && vd->RTView == nullptr);
+
+    // Create swap chain
+    HRESULT hr = DXGI_ERROR_UNSUPPORTED;
+    for (const DXGI_SWAP_CHAIN_DESC& sd_template : bd->SwapChainDescsForViewports)
+    {
+        IM_ASSERT(sd_template.BufferDesc.Width == 0 && sd_template.BufferDesc.Height == 0 && sd_template.OutputWindow == nullptr);
+        DXGI_SWAP_CHAIN_DESC sd = sd_template;
+        sd.BufferDesc.Width = (UINT)viewport->Size.x;
+        sd.BufferDesc.Height = (UINT)viewport->Size.y;
+        sd.OutputWindow = hwnd;
+        hr = bd->pFactory->CreateSwapChain(bd->pd3dDevice, &sd, &vd->SwapChain);
+        if (SUCCEEDED(hr))
+            break;
+    }
+    IM_ASSERT(SUCCEEDED(hr));
+
+    // Create the render target
+    if (vd->SwapChain != nullptr)
+    {
+        ID3D11Texture2D* pBackBuffer;
+        vd->SwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+        bd->pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &vd->RTView);
+        pBackBuffer->Release();
+    }
+}
+
+static void ImGui_ImplDX11_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == nullptr since we didn't create the data for it.
+    if (ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData)
+    {
+        if (vd->SwapChain)
+            vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        if (vd->RTView)
+            vd->RTView->Release();
+        vd->RTView = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplDX11_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData;
+    if (vd->RTView)
+    {
+        vd->RTView->Release();
+        vd->RTView = nullptr;
+    }
+    if (vd->SwapChain)
+    {
+        ID3D11Texture2D* pBackBuffer = nullptr;
+        vd->SwapChain->ResizeBuffers(0, (UINT)size.x, (UINT)size.y, DXGI_FORMAT_UNKNOWN, 0);
+        vd->SwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+        if (pBackBuffer == nullptr) { fprintf(stderr, "ImGui_ImplDX11_SetWindowSize() failed creating buffers.\n"); return; }
+        bd->pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &vd->RTView);
+        pBackBuffer->Release();
+    }
+}
+
+static void ImGui_ImplDX11_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData;
+    ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+    bd->pd3dDeviceContext->OMSetRenderTargets(1, &vd->RTView, nullptr);
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+        bd->pd3dDeviceContext->ClearRenderTargetView(vd->RTView, (float*)&clear_color);
+    ImGui_ImplDX11_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplDX11_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData;
+    vd->SwapChain->Present(0, 0); // Present without vsync
+}
+
+static void ImGui_ImplDX11_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX11_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX11_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX11_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX11_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX11_SwapBuffers;
+
+    // Default swapchain format
+    DXGI_SWAP_CHAIN_DESC sd;
+    ZeroMemory(&sd, sizeof(sd));
+    sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
+    sd.SampleDesc.Count = 1;
+    sd.SampleDesc.Quality = 0;
+    sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
+    sd.BufferCount = 1;
+    sd.Windowed = TRUE;
+    sd.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
+    sd.Flags = 0;
+    ImGui_ImplDX11_SetSwapChainDescs(&sd, 1);
+}
+
+static void ImGui_ImplDX11_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_dx11.h

@@ -5,6 +5,7 @@
 //  [X] Renderer: User texture binding. Use 'ID3D11ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_dx12.cpp

@@ -5,6 +5,8 @@
 //  [X] Renderer: User texture binding. Use 'D3D12_GPU_DESCRIPTOR_HANDLE' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+//      FIXME: The transition from removing a viewport and moving the window in an existing hosted viewport tends to flicker.
 
 // The aim of imgui_impl_dx12.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -19,6 +21,9 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-02-24: DirectX12: Fixed an issue where ImGui_ImplDX12_Init() signature change from 2024-11-15 combined with change from 2025-01-15 made legacy ImGui_ImplDX12_Init() crash. (#8429)
+//  2025-01-15: DirectX12: Texture upload use the command queue provided in ImGui_ImplDX12_InitInfo instead of creating its own.
 //  2024-12-09: DirectX12: Let user specifies the DepthStencilView format by setting ImGui_ImplDX12_InitInfo::DSVFormat.
 //  2024-11-15: DirectX12: *BREAKING CHANGE* Changed ImGui_ImplDX12_Init() signature to take a ImGui_ImplDX12_InitInfo struct. Legacy ImGui_ImplDX12_Init() signature is still supported (will obsolete).
 //  2024-11-15: DirectX12: *BREAKING CHANGE* User is now required to pass function pointers to allocate/free SRV Descriptors. We provide convenience legacy fields to pass a single descriptor, matching the old API, but upcoming features will want multiple.
@@ -64,6 +69,8 @@ struct ImGui_ImplDX12_Texture
     ID3D12Resource*             pTextureResource;
     D3D12_CPU_DESCRIPTOR_HANDLE hFontSrvCpuDescHandle;
     D3D12_GPU_DESCRIPTOR_HANDLE hFontSrvGpuDescHandle;
+
+    ImGui_ImplDX12_Texture()    { memset((void*)this, 0, sizeof(*this)); }
 };
 
 struct ImGui_ImplDX12_Data
@@ -72,18 +79,16 @@ struct ImGui_ImplDX12_Data
     ID3D12Device*               pd3dDevice;
     ID3D12RootSignature*        pRootSignature;
     ID3D12PipelineState*        pPipelineState;
+    ID3D12CommandQueue*         pCommandQueue;
+    bool                        commandQueueOwned;
     DXGI_FORMAT                 RTVFormat;
     DXGI_FORMAT                 DSVFormat;
     ID3D12DescriptorHeap*       pd3dSrvDescHeap;
     UINT                        numFramesInFlight;
-
-    ImGui_ImplDX12_RenderBuffers* pFrameResources;
-    UINT                        frameIndex;
-
     ImGui_ImplDX12_Texture      FontTexture;
     bool                        LegacySingleDescriptorUsed;
 
-    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
@@ -102,11 +107,88 @@ 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* command_list, ImGui_ImplDX12_RenderBuffers* fr)
 {
@@ -131,8 +213,7 @@ static void ImGui_ImplDX12_SetupRenderState(ImDrawData* draw_data, ID3D12Graphic
     }
 
     // Setup viewport
-    D3D12_VIEWPORT vp;
-    memset(&vp, 0, sizeof(D3D12_VIEWPORT));
+    D3D12_VIEWPORT vp = {};
     vp.Width = draw_data->DisplaySize.x;
     vp.Height = draw_data->DisplaySize.y;
     vp.MinDepth = 0.0f;
@@ -143,14 +224,12 @@ static void ImGui_ImplDX12_SetupRenderState(ImDrawData* draw_data, ID3D12Graphic
     // Bind shader and vertex buffers
     unsigned int stride = sizeof(ImDrawVert);
     unsigned int offset = 0;
-    D3D12_VERTEX_BUFFER_VIEW vbv;
-    memset(&vbv, 0, sizeof(D3D12_VERTEX_BUFFER_VIEW));
+    D3D12_VERTEX_BUFFER_VIEW vbv = {};
     vbv.BufferLocation = fr->VertexBuffer->GetGPUVirtualAddress() + offset;
     vbv.SizeInBytes = fr->VertexBufferSize * stride;
     vbv.StrideInBytes = stride;
     command_list->IASetVertexBuffers(0, 1, &vbv);
-    D3D12_INDEX_BUFFER_VIEW ibv;
-    memset(&ibv, 0, sizeof(D3D12_INDEX_BUFFER_VIEW));
+    D3D12_INDEX_BUFFER_VIEW ibv = {};
     ibv.BufferLocation = fr->IndexBuffer->GetGPUVirtualAddress();
     ibv.SizeInBytes = fr->IndexBufferSize * sizeof(ImDrawIdx);
     ibv.Format = sizeof(ImDrawIdx) == 2 ? DXGI_FORMAT_R16_UINT : DXGI_FORMAT_R32_UINT;
@@ -180,24 +259,22 @@ 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.
+    // FIXME: We are assuming that this only gets called once per frame!
     ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
-    bd->frameIndex = bd->frameIndex + 1;
-    ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[bd->frameIndex % bd->numFramesInFlight];
+    ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)draw_data->OwnerViewport->RendererUserData;
+    vd->FrameIndex++;
+    ImGui_ImplDX12_RenderBuffers* fr = &vd->FrameRenderBuffers[vd->FrameIndex % bd->numFramesInFlight];
 
     // Create and grow vertex/index buffers if needed
     if (fr->VertexBuffer == nullptr || fr->VertexBufferSize < draw_data->TotalVtxCount)
     {
         SafeRelease(fr->VertexBuffer);
         fr->VertexBufferSize = draw_data->TotalVtxCount + 5000;
-        D3D12_HEAP_PROPERTIES props;
-        memset(&props, 0, sizeof(D3D12_HEAP_PROPERTIES));
+        D3D12_HEAP_PROPERTIES props = {};
         props.Type = D3D12_HEAP_TYPE_UPLOAD;
         props.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
         props.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
-        D3D12_RESOURCE_DESC desc;
-        memset(&desc, 0, sizeof(D3D12_RESOURCE_DESC));
+        D3D12_RESOURCE_DESC desc = {};
         desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
         desc.Width = fr->VertexBufferSize * sizeof(ImDrawVert);
         desc.Height = 1;
@@ -214,13 +291,11 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
     {
         SafeRelease(fr->IndexBuffer);
         fr->IndexBufferSize = draw_data->TotalIdxCount + 10000;
-        D3D12_HEAP_PROPERTIES props;
-        memset(&props, 0, sizeof(D3D12_HEAP_PROPERTIES));
+        D3D12_HEAP_PROPERTIES props = {};
         props.Type = D3D12_HEAP_TYPE_UPLOAD;
         props.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
         props.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
-        D3D12_RESOURCE_DESC desc;
-        memset(&desc, 0, sizeof(D3D12_RESOURCE_DESC));
+        D3D12_RESOURCE_DESC desc = {};
         desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
         desc.Width = fr->IndexBufferSize * sizeof(ImDrawIdx);
         desc.Height = 1;
@@ -328,8 +403,7 @@ static void ImGui_ImplDX12_CreateFontsTexture()
     // Upload texture to graphics system
     ImGui_ImplDX12_Texture* font_tex = &bd->FontTexture;
     {
-        D3D12_HEAP_PROPERTIES props;
-        memset(&props, 0, sizeof(D3D12_HEAP_PROPERTIES));
+        D3D12_HEAP_PROPERTIES props = {};
         props.Type = D3D12_HEAP_TYPE_DEFAULT;
         props.CPUPageProperty = D3D12_CPU_PAGE_PROPERTY_UNKNOWN;
         props.MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN;
@@ -352,11 +426,11 @@ static void ImGui_ImplDX12_CreateFontsTexture()
         bd->pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc,
             D3D12_RESOURCE_STATE_COPY_DEST, nullptr, IID_PPV_ARGS(&pTexture));
 
-        UINT uploadPitch = (width * 4 + D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u) & ~(D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u);
-        UINT uploadSize = height * uploadPitch;
+        UINT upload_pitch = (width * 4 + D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u) & ~(D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u);
+        UINT upload_size = height * upload_pitch;
         desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
         desc.Alignment = 0;
-        desc.Width = uploadSize;
+        desc.Width = upload_size;
         desc.Height = 1;
         desc.DepthOrArraySize = 1;
         desc.MipLevels = 1;
@@ -376,26 +450,28 @@ static void ImGui_ImplDX12_CreateFontsTexture()
         IM_ASSERT(SUCCEEDED(hr));
 
         void* mapped = nullptr;
-        D3D12_RANGE range = { 0, uploadSize };
+        D3D12_RANGE range = { 0, upload_size };
         hr = uploadBuffer->Map(0, &range, &mapped);
         IM_ASSERT(SUCCEEDED(hr));
         for (int y = 0; y < height; y++)
-            memcpy((void*) ((uintptr_t) mapped + y * uploadPitch), pixels + y * width * 4, width * 4);
+            memcpy((void*) ((uintptr_t) mapped + y * upload_pitch), pixels + y * width * 4, width * 4);
         uploadBuffer->Unmap(0, &range);
 
         D3D12_TEXTURE_COPY_LOCATION srcLocation = {};
-        srcLocation.pResource = uploadBuffer;
-        srcLocation.Type = D3D12_TEXTURE_COPY_TYPE_PLACED_FOOTPRINT;
-        srcLocation.PlacedFootprint.Footprint.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
-        srcLocation.PlacedFootprint.Footprint.Width = width;
-        srcLocation.PlacedFootprint.Footprint.Height = height;
-        srcLocation.PlacedFootprint.Footprint.Depth = 1;
-        srcLocation.PlacedFootprint.Footprint.RowPitch = uploadPitch;
-
         D3D12_TEXTURE_COPY_LOCATION dstLocation = {};
-        dstLocation.pResource = pTexture;
-        dstLocation.Type = D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX;
-        dstLocation.SubresourceIndex = 0;
+        {
+            srcLocation.pResource = uploadBuffer;
+            srcLocation.Type = D3D12_TEXTURE_COPY_TYPE_PLACED_FOOTPRINT;
+            srcLocation.PlacedFootprint.Footprint.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
+            srcLocation.PlacedFootprint.Footprint.Width = width;
+            srcLocation.PlacedFootprint.Footprint.Height = height;
+            srcLocation.PlacedFootprint.Footprint.Depth = 1;
+            srcLocation.PlacedFootprint.Footprint.RowPitch = upload_pitch;
+
+            dstLocation.pResource = pTexture;
+            dstLocation.Type = D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX;
+            dstLocation.SubresourceIndex = 0;
+        }
 
         D3D12_RESOURCE_BARRIER barrier = {};
         barrier.Type = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
@@ -412,15 +488,6 @@ static void ImGui_ImplDX12_CreateFontsTexture()
         HANDLE event = ::CreateEvent(0, 0, 0, 0);
         IM_ASSERT(event != nullptr);
 
-        D3D12_COMMAND_QUEUE_DESC queueDesc = {};
-        queueDesc.Type     = D3D12_COMMAND_LIST_TYPE_DIRECT;
-        queueDesc.Flags    = D3D12_COMMAND_QUEUE_FLAG_NONE;
-        queueDesc.NodeMask = 1;
-
-        ID3D12CommandQueue* cmdQueue = nullptr;
-        hr = bd->pd3dDevice->CreateCommandQueue(&queueDesc, IID_PPV_ARGS(&cmdQueue));
-        IM_ASSERT(SUCCEEDED(hr));
-
         ID3D12CommandAllocator* cmdAlloc = nullptr;
         hr = bd->pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&cmdAlloc));
         IM_ASSERT(SUCCEEDED(hr));
@@ -435,6 +502,7 @@ static void ImGui_ImplDX12_CreateFontsTexture()
         hr = cmdList->Close();
         IM_ASSERT(SUCCEEDED(hr));
 
+        ID3D12CommandQueue* cmdQueue = bd->pCommandQueue;
         cmdQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&cmdList);
         hr = cmdQueue->Signal(fence, 1);
         IM_ASSERT(SUCCEEDED(hr));
@@ -444,7 +512,6 @@ static void ImGui_ImplDX12_CreateFontsTexture()
 
         cmdList->Release();
         cmdAlloc->Release();
-        cmdQueue->Release();
         ::CloseHandle(event);
         fence->Release();
         uploadBuffer->Release();
@@ -563,8 +630,7 @@ bool    ImGui_ImplDX12_CreateDeviceObjects()
     //  2) use code to detect any version of the DLL and grab a pointer to D3DCompile from the DLL.
     // See https://github.com/ocornut/imgui/pull/638 for sources and details.
 
-    D3D12_GRAPHICS_PIPELINE_STATE_DESC psoDesc;
-    memset(&psoDesc, 0, sizeof(D3D12_GRAPHICS_PIPELINE_STATE_DESC));
+    D3D12_GRAPHICS_PIPELINE_STATE_DESC psoDesc = {};
     psoDesc.NodeMask = 1;
     psoDesc.PrimitiveTopologyType = D3D12_PRIMITIVE_TOPOLOGY_TYPE_TRIANGLE;
     psoDesc.pRootSignature = bd->pRootSignature;
@@ -701,28 +767,31 @@ 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();
     if (!bd || !bd->pd3dDevice)
         return;
 
-    ImGuiIO& io = ImGui::GetIO();
+    if (bd->commandQueueOwned)
+        SafeRelease(bd->pCommandQueue);
+    bd->commandQueueOwned = false;
     SafeRelease(bd->pRootSignature);
     SafeRelease(bd->pPipelineState);
 
     // Free SRV descriptor used by texture
+    ImGuiIO& io = ImGui::GetIO();
     ImGui_ImplDX12_Texture* font_tex = &bd->FontTexture;
     bd->InitInfo.SrvDescriptorFreeFn(&bd->InitInfo, font_tex->hFontSrvCpuDescHandle, font_tex->hFontSrvGpuDescHandle);
     SafeRelease(font_tex->pTextureResource);
     io.Fonts->SetTexID(0); // We copied bd->hFontSrvGpuDescHandle 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(ImGui_ImplDX12_InitInfo* init_info)
@@ -737,6 +806,8 @@ bool ImGui_ImplDX12_Init(ImGui_ImplDX12_InitInfo* init_info)
     init_info = &bd->InitInfo;
 
     bd->pd3dDevice = init_info->Device;
+    IM_ASSERT(init_info->CommandQueue != NULL);
+    bd->pCommandQueue = init_info->CommandQueue;
     bd->RTVFormat = init_info->RTVFormat;
     bd->DSVFormat = init_info->DSVFormat;
     bd->numFramesInFlight = init_info->NumFramesInFlight;
@@ -745,6 +816,14 @@ bool ImGui_ImplDX12_Init(ImGui_ImplDX12_InitInfo* init_info)
     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();
+
+    // Create a dummy ImGui_ImplDX12_ViewportData holder for the main viewport,
+    // Since this is created and managed by the application, we will only use the ->Resources[] fields.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->RendererUserData = IM_NEW(ImGui_ImplDX12_ViewportData)(bd->numFramesInFlight);
 
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
     if (init_info->SrvDescriptorAllocFn == nullptr)
@@ -754,7 +833,7 @@ bool ImGui_ImplDX12_Init(ImGui_ImplDX12_InitInfo* init_info)
         init_info->SrvDescriptorAllocFn = [](ImGui_ImplDX12_InitInfo*, D3D12_CPU_DESCRIPTOR_HANDLE* out_cpu_handle, D3D12_GPU_DESCRIPTOR_HANDLE* out_gpu_handle)
         {
             ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
-            IM_ASSERT(bd->LegacySingleDescriptorUsed == false);
+            IM_ASSERT(bd->LegacySingleDescriptorUsed == false && "Only 1 simultaneous texture allowed with legacy ImGui_ImplDX12_Init() signature!");
             *out_cpu_handle = bd->InitInfo.LegacySingleSrvCpuDescriptor;
             *out_gpu_handle = bd->InitInfo.LegacySingleSrvGpuDescriptor;
             bd->LegacySingleDescriptorUsed = true;
@@ -772,18 +851,6 @@ bool ImGui_ImplDX12_Init(ImGui_ImplDX12_InitInfo* init_info)
     IM_ASSERT(init_info->SrvDescriptorAllocFn != nullptr && init_info->SrvDescriptorFreeFn != nullptr);
     init_info->SrvDescriptorAllocFn(&bd->InitInfo, &bd->FontTexture.hFontSrvCpuDescHandle, &bd->FontTexture.hFontSrvGpuDescHandle);
 
-    // Create buffers with a default size (they will later be grown as needed)
-    bd->frameIndex = UINT_MAX;
-    bd->pFrameResources = new ImGui_ImplDX12_RenderBuffers[bd->numFramesInFlight];
-    for (int i = 0; i < (int)bd->numFramesInFlight; i++)
-    {
-        ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[i];
-        fr->IndexBuffer = nullptr;
-        fr->VertexBuffer = nullptr;
-        fr->IndexBufferSize = 10000;
-        fr->VertexBufferSize = 5000;
-    }
-
     return true;
 }
 
@@ -798,8 +865,19 @@ bool ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FO
     init_info.RTVFormat = rtv_format;
     init_info.SrvDescriptorHeap = srv_descriptor_heap;
     init_info.LegacySingleSrvCpuDescriptor = font_srv_cpu_desc_handle;
-    init_info.LegacySingleSrvGpuDescriptor = font_srv_gpu_desc_handle;;
-    return ImGui_ImplDX12_Init(&init_info);
+    init_info.LegacySingleSrvGpuDescriptor = font_srv_gpu_desc_handle;
+
+    D3D12_COMMAND_QUEUE_DESC queueDesc = {};
+    queueDesc.Type = D3D12_COMMAND_LIST_TYPE_DIRECT;
+    queueDesc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
+    queueDesc.NodeMask = 1;
+    HRESULT hr = device->CreateCommandQueue(&queueDesc, IID_PPV_ARGS(&init_info.CommandQueue));
+    IM_ASSERT(SUCCEEDED(hr));
+
+    bool ret = ImGui_ImplDX12_Init(&init_info);
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    bd->commandQueueOwned = true;
+    return ret;
 }
 #endif
 
@@ -809,13 +887,24 @@ 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);
 }
 
@@ -828,6 +917,246 @@ 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's WindowID).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+
+    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_NONE;
+    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

@@ -5,6 +5,7 @@
 //  [X] Renderer: User texture binding. Use 'D3D12_GPU_DESCRIPTOR_HANDLE' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // The aim of imgui_impl_dx12.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -27,14 +28,14 @@
 struct ImGui_ImplDX12_InitInfo
 {
     ID3D12Device*               Device;
-    ID3D12CommandQueue*         CommandQueue;
+    ID3D12CommandQueue*         CommandQueue;       // Command queue used for queuing texture uploads.
     int                         NumFramesInFlight;
     DXGI_FORMAT                 RTVFormat;          // RenderTarget format.
     DXGI_FORMAT                 DSVFormat;          // DepthStencilView format.
     void*                       UserData;
 
     // Allocating SRV descriptors for textures is up to the application, so we provide callbacks.
-    // (current version of the backend will only allocate one descriptor, future versions will need to allocate more)
+    // (current version of the backend will only allocate one descriptor, from 1.92 the backend will need to allocate more)
     ID3D12DescriptorHeap*       SrvDescriptorHeap;
     void                        (*SrvDescriptorAllocFn)(ImGui_ImplDX12_InitInfo* info, D3D12_CPU_DESCRIPTOR_HANDLE* out_cpu_desc_handle, D3D12_GPU_DESCRIPTOR_HANDLE* out_gpu_desc_handle);
     void                        (*SrvDescriptorFreeFn)(ImGui_ImplDX12_InitInfo* info, D3D12_CPU_DESCRIPTOR_HANDLE cpu_desc_handle, D3D12_GPU_DESCRIPTOR_HANDLE gpu_desc_handle);
@@ -54,7 +55,8 @@ IMGUI_IMPL_API void     ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3
 
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
 // Legacy initialization API Obsoleted in 1.91.5
-// font_srv_cpu_desc_handle and font_srv_gpu_desc_handle are handles to a single SRV descriptor to use for the internal font texture, they must be in 'srv_descriptor_heap'
+// - font_srv_cpu_desc_handle and font_srv_gpu_desc_handle are handles to a single SRV descriptor to use for the internal font texture, they must be in 'srv_descriptor_heap'
+// - When we introduced the ImGui_ImplDX12_InitInfo struct we also added a 'ID3D12CommandQueue* CommandQueue' field.
 IMGUI_IMPL_API bool     ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FORMAT rtv_format, ID3D12DescriptorHeap* srv_descriptor_heap, D3D12_CPU_DESCRIPTOR_HANDLE font_srv_cpu_desc_handle, D3D12_GPU_DESCRIPTOR_HANDLE font_srv_gpu_desc_handle);
 #endif
 

backends/imgui_impl_dx9.cpp

@@ -5,6 +5,7 @@
 //  [X] Renderer: User texture binding. Use 'LPDIRECT3DTEXTURE9' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: IMGUI_USE_BGRA_PACKED_COLOR support, as this is the optimal color encoding for DirectX9.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -16,6 +17,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2024-10-07: DirectX9: Changed default texture sampler to Clamp instead of Repeat/Wrap.
 //  2024-02-12: DirectX9: Using RGBA format when supported by the driver to avoid CPU side conversion. (#6575)
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
@@ -79,6 +81,12 @@ static ImGui_ImplDX9_Data* ImGui_ImplDX9_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX9_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX9_InitMultiViewportSupport();
+static void ImGui_ImplDX9_ShutdownMultiViewportSupport();
+static void ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows();
+static void ImGui_ImplDX9_InvalidateDeviceObjectsForPlatformWindows();
+
 // Functions
 static void ImGui_ImplDX9_SetupRenderState(ImDrawData* draw_data)
 {
@@ -283,6 +291,11 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
         global_vtx_offset += draw_list->VtxBuffer.Size;
     }
 
+    // When using multi-viewports, it appears that there's an odd logic in DirectX9 which prevent subsequent windows
+    // from rendering until the first window submits at least one draw call, even once. That's our workaround. (see #2560)
+    if (global_vtx_offset == 0)
+        bd->pd3dDevice->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, 0, 0, 0);
+
     // Restore the DX9 transform
     device->SetTransform(D3DTS_WORLD, &last_world);
     device->SetTransform(D3DTS_VIEW, &last_view);
@@ -322,11 +335,14 @@ 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();
     bd->HasRgbaSupport = ImGui_ImplDX9_CheckFormatSupport(bd->pd3dDevice, D3DFMT_A8B8G8R8);
 
+    ImGui_ImplDX9_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -336,11 +352,12 @@ void ImGui_ImplDX9_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplDX9_ShutdownMultiViewportSupport();
     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);
 }
 
@@ -397,6 +414,7 @@ bool ImGui_ImplDX9_CreateDeviceObjects()
         return false;
     if (!ImGui_ImplDX9_CreateFontsTexture())
         return false;
+    ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows();
     return true;
 }
 
@@ -408,6 +426,7 @@ 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()
@@ -419,6 +438,148 @@ 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's WindowID).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+
+    ZeroMemory(&vd->d3dpp, sizeof(D3DPRESENT_PARAMETERS));
+    vd->d3dpp.Windowed = TRUE;
+    vd->d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
+    vd->d3dpp.BackBufferWidth = (UINT)viewport->Size.x;
+    vd->d3dpp.BackBufferHeight = (UINT)viewport->Size.y;
+    vd->d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
+    vd->d3dpp.hDeviceWindow = hwnd;
+    vd->d3dpp.EnableAutoDepthStencil = FALSE;
+    vd->d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
+    vd->d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;   // Present without vsync
+
+    HRESULT hr = bd->pd3dDevice->CreateAdditionalSwapChain(&vd->d3dpp, &vd->SwapChain); IM_UNUSED(hr);
+    IM_ASSERT(hr == D3D_OK);
+    IM_ASSERT(vd->SwapChain != nullptr);
+}
+
+static void ImGui_ImplDX9_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
+    if (ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData)
+    {
+        if (vd->SwapChain)
+            vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        ZeroMemory(&vd->d3dpp, sizeof(D3DPRESENT_PARAMETERS));
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplDX9_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplDX9_Data* bd = ImGui_ImplDX9_GetBackendData();
+    ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData;
+    if (vd->SwapChain)
+    {
+        vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        vd->d3dpp.BackBufferWidth = (UINT)size.x;
+        vd->d3dpp.BackBufferHeight = (UINT)size.y;
+        HRESULT hr = bd->pd3dDevice->CreateAdditionalSwapChain(&vd->d3dpp, &vd->SwapChain); IM_UNUSED(hr);
+        IM_ASSERT(hr == D3D_OK);
+    }
+}
+
+static void ImGui_ImplDX9_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX9_Data* bd = ImGui_ImplDX9_GetBackendData();
+    ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData;
+    ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+
+    LPDIRECT3DSURFACE9 render_target = nullptr;
+    LPDIRECT3DSURFACE9 last_render_target = nullptr;
+    LPDIRECT3DSURFACE9 last_depth_stencil = nullptr;
+    vd->SwapChain->GetBackBuffer(0, D3DBACKBUFFER_TYPE_MONO, &render_target);
+    bd->pd3dDevice->GetRenderTarget(0, &last_render_target);
+    bd->pd3dDevice->GetDepthStencilSurface(&last_depth_stencil);
+    bd->pd3dDevice->SetRenderTarget(0, render_target);
+    bd->pd3dDevice->SetDepthStencilSurface(nullptr);
+
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+    {
+        D3DCOLOR clear_col_dx = D3DCOLOR_RGBA((int)(clear_color.x*255.0f), (int)(clear_color.y*255.0f), (int)(clear_color.z*255.0f), (int)(clear_color.w*255.0f));
+        bd->pd3dDevice->Clear(0, nullptr, D3DCLEAR_TARGET, clear_col_dx, 1.0f, 0);
+    }
+
+    ImGui_ImplDX9_RenderDrawData(viewport->DrawData);
+
+    // Restore render target
+    bd->pd3dDevice->SetRenderTarget(0, last_render_target);
+    bd->pd3dDevice->SetDepthStencilSurface(last_depth_stencil);
+    render_target->Release();
+    last_render_target->Release();
+    if (last_depth_stencil) last_depth_stencil->Release();
+}
+
+static void ImGui_ImplDX9_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData;
+    HRESULT hr = vd->SwapChain->Present(nullptr, nullptr, vd->d3dpp.hDeviceWindow, nullptr, 0);
+    // Let main application handle D3DERR_DEVICELOST by resetting the device.
+    IM_ASSERT(SUCCEEDED(hr) || hr == D3DERR_DEVICELOST);
+}
+
+static void ImGui_ImplDX9_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX9_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX9_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX9_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX9_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX9_SwapBuffers;
+}
+
+static void ImGui_ImplDX9_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
+static void ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (!platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplDX9_CreateWindow(platform_io.Viewports[i]);
+}
+
+static void ImGui_ImplDX9_InvalidateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplDX9_DestroyWindow(platform_io.Viewports[i]);
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_dx9.h

@@ -5,6 +5,7 @@
 //  [X] Renderer: User texture binding. Use 'LPDIRECT3DTEXTURE9' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: IMGUI_USE_BGRA_PACKED_COLOR support, as this is the optimal color encoding for DirectX9.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_glfw.cpp

@@ -9,6 +9,11 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLFW_KEY_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Resizing cursors requires GLFW 3.4+! Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// Missing features or Issues:
+//  [ ] Touch events are only correctly identified as Touch on Windows. This create issues with some interactions. GLFW doesn't provide a way to identify touch inputs from mouse inputs, we cannot call io.AddMouseSourceEvent() to identify the source. We provide a Windows-specific workaround.
+//  [ ] Missing ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress cursors.
+//  [ ] Multi-viewport: 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.
@@ -25,7 +30,12 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  2024-08-22: moved some OS/backend related function pointers from ImGuiIO to ImGuiPlatformIO:
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-03-10: Map GLFW_KEY_WORLD_1 and GLFW_KEY_WORLD_2 into ImGuiKey_Oem102.
+//  2025-03-03: Fixed clipboard handler assertion when using GLFW <= 3.2.1 compiled with asserts enabled.
+//  2025-02-21: [Docking] Update monitors and work areas information every frame, as the later may change regardless of monitor changes. (#8415)
+//  2024-11-05: [Docking] Added Linux workaround for spurious mouse up events emitted while dragging and creating new viewport. (#3158, #7733, #7922)
+//  2024-08-22: Moved some OS/backend related function pointers from ImGuiIO to ImGuiPlatformIO:
 //               - io.GetClipboardTextFn    -> platform_io.Platform_GetClipboardTextFn
 //               - io.SetClipboardTextFn    -> platform_io.Platform_SetClipboardTextFn
 //               - io.PlatformOpenInShellFn -> platform_io.Platform_OpenInShellFn
@@ -41,6 +51,7 @@
 //  2023-03-16: Inputs: Fixed key modifiers handling on secondary viewports (docking branch). Broken on 2023/01/04. (#6248, #6034)
 //  2023-03-14: Emscripten: Avoid using glfwGetError() and glfwGetGamepadState() which are not correctly implemented in Emscripten emulation. (#6240)
 //  2023-02-03: Emscripten: Registering custom low-level mouse wheel handler to get more accurate scrolling impulses on Emscripten. (#4019, #6096)
+//  2023-01-18: Handle unsupported glfwGetVideoMode() call on e.g. Emscripten.
 //  2023-01-04: Inputs: Fixed mods state on Linux when using Alt-GR text input (e.g. German keyboard layout), could lead to broken text input. Revert a 2022/01/17 change were we resumed using mods provided by GLFW, turns out they were faulty.
 //  2022-11-22: Perform a dummy glfwGetError() read to cancel missing names with glfwGetKeyName(). (#5908)
 //  2022-10-18: Perform a dummy glfwGetError() read to cancel missing mouse cursors errors. Using GLFW_VERSION_COMBINED directly. (#5785)
@@ -125,11 +136,29 @@
 
 // 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()
@@ -149,7 +178,10 @@ struct ImGui_ImplGlfw_Data
     double                  Time;
     GLFWwindow*             MouseWindow;
     GLFWcursor*             MouseCursors[ImGuiMouseCursor_COUNT];
+    bool                    MouseIgnoreButtonUpWaitForFocusLoss;
+    bool                    MouseIgnoreButtonUp;
     ImVec2                  LastValidMousePos;
+    GLFWwindow*             KeyOwnerWindows[GLFW_KEY_LAST];
     bool                    InstalledCallbacks;
     bool                    CallbacksChainForAllWindows;
 #ifdef EMSCRIPTEN_USE_EMBEDDED_GLFW3
@@ -184,6 +216,11 @@ 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_InitMultiViewportSupport();
+static void ImGui_ImplGlfw_ShutdownMultiViewportSupport();
+
 // Functions
 
 // Not static to allow third-party code to use that if they want to (but undocumented)
@@ -217,6 +254,8 @@ ImGuiKey ImGui_ImplGlfw_KeyToImGuiKey(int keycode, int scancode)
         case GLFW_KEY_EQUAL: return ImGuiKey_Equal;
         case GLFW_KEY_LEFT_BRACKET: return ImGuiKey_LeftBracket;
         case GLFW_KEY_BACKSLASH: return ImGuiKey_Backslash;
+        case GLFW_KEY_WORLD_1: return ImGuiKey_Oem102;
+        case GLFW_KEY_WORLD_2: return ImGuiKey_Oem102;
         case GLFW_KEY_RIGHT_BRACKET: return ImGuiKey_RightBracket;
         case GLFW_KEY_GRAVE_ACCENT: return ImGuiKey_GraveAccent;
         case GLFW_KEY_CAPS_LOCK: return ImGuiKey_CapsLock;
@@ -337,6 +376,10 @@ void ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow* window, int button, int acti
     if (bd->PrevUserCallbackMousebutton != nullptr && ImGui_ImplGlfw_ShouldChainCallback(window))
         bd->PrevUserCallbackMousebutton(window, button, action, mods);
 
+    // Workaround for Linux: ignore mouse up events which are following an focus loss following a viewport creation
+    if (bd->MouseIgnoreButtonUp && action == GLFW_RELEASE)
+        return;
+
     ImGui_ImplGlfw_UpdateKeyModifiers(window);
 
     ImGuiIO& io = ImGui::GetIO();
@@ -404,6 +447,9 @@ 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();
@@ -418,6 +464,10 @@ void ImGui_ImplGlfw_WindowFocusCallback(GLFWwindow* window, int focused)
     if (bd->PrevUserCallbackWindowFocus != nullptr && ImGui_ImplGlfw_ShouldChainCallback(window))
         bd->PrevUserCallbackWindowFocus(window, focused);
 
+    // Workaround for Linux: when losing focus with MouseIgnoreButtonUpWaitForFocusLoss set, we will temporarily ignore subsequent Mouse Up events
+    bd->MouseIgnoreButtonUp = (bd->MouseIgnoreButtonUpWaitForFocusLoss && focused == 0);
+    bd->MouseIgnoreButtonUpWaitForFocusLoss = false;
+
     ImGuiIO& io = ImGui::GetIO();
     io.AddFocusEvent(focused != 0);
 }
@@ -429,6 +479,13 @@ 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);
 }
@@ -467,7 +524,7 @@ void ImGui_ImplGlfw_CharCallback(GLFWwindow* window, unsigned int c)
 
 void ImGui_ImplGlfw_MonitorCallback(GLFWmonitor*, int)
 {
-	// Unused in 'master' branch but 'docking' branch will use this, so we declare it ahead of it so if you have to install callbacks you can install this one too.
+    // This function is technically part of the API even if we stopped using the callback, so leaving it around.
 }
 
 #ifdef EMSCRIPTEN_USE_EMBEDDED_GLFW3
@@ -489,32 +546,7 @@ static EM_BOOL ImGui_ImplEmscripten_WheelCallback(int, const EmscriptenWheelEven
 #endif
 
 #ifdef _WIN32
-// GLFW doesn't allow to distinguish Mouse vs TouchScreen vs Pen.
-// Add support for Win32 (based on imgui_impl_win32), because we rely on _TouchScreen info to trickle inputs differently.
-static ImGuiMouseSource GetMouseSourceFromMessageExtraInfo()
-{
-    LPARAM extra_info = ::GetMessageExtraInfo();
-    if ((extra_info & 0xFFFFFF80) == 0xFF515700)
-        return ImGuiMouseSource_Pen;
-    if ((extra_info & 0xFFFFFF80) == 0xFF515780)
-        return ImGuiMouseSource_TouchScreen;
-    return ImGuiMouseSource_Mouse;
-}
-static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
-{
-    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
-    switch (msg)
-    {
-    case WM_MOUSEMOVE: case WM_NCMOUSEMOVE:
-    case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK: case WM_LBUTTONUP:
-    case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK: case WM_RBUTTONUP:
-    case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK: case WM_MBUTTONUP:
-    case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK: case WM_XBUTTONUP:
-        ImGui::GetIO().AddMouseSourceEvent(GetMouseSourceFromMessageExtraInfo());
-        break;
-    }
-    return ::CallWindowProcW(bd->PrevWndProc, hWnd, msg, wParam, lParam);
-}
+static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 #endif
 
 void ImGui_ImplGlfw_InstallCallbacks(GLFWwindow* window)
@@ -590,13 +622,25 @@ 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
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
+#endif
 
     bd->Window = window;
     bd->Time = 0.0;
 
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+#if GLFW_VERSION_COMBINED < 3300
+    platform_io.Platform_SetClipboardTextFn = [](ImGuiContext*, const char* text) { glfwSetClipboardString(ImGui_ImplGlfw_GetBackendData()->Window, text); };
+    platform_io.Platform_GetClipboardTextFn = [](ImGuiContext*) { return glfwGetClipboardString(ImGui_ImplGlfw_GetBackendData()->Window); };
+#else
     platform_io.Platform_SetClipboardTextFn = [](ImGuiContext*, const char* text) { glfwSetClipboardString(nullptr, text); };
     platform_io.Platform_GetClipboardTextFn = [](ImGuiContext*) { return glfwGetClipboardString(nullptr); };
+#endif
+
 #ifdef __EMSCRIPTEN__
     platform_io.Platform_OpenInShellFn = [](ImGuiContext*, const char* url) { ImGui_ImplGlfw_EmscriptenOpenURL(url); return true; };
 #endif
@@ -631,6 +675,11 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     if (install_callbacks)
         ImGui_ImplGlfw_InstallCallbacks(window);
 
+    // Update monitor a first time during init
+    // (note: monitor callback are broken in GLFW 3.2 and earlier, see github.com/glfw/glfw/issues/784)
+    ImGui_ImplGlfw_UpdateMonitors();
+    glfwSetMonitorCallback(ImGui_ImplGlfw_MonitorCallback);
+
     // Set platform dependent data in viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = (void*)bd->Window;
@@ -641,6 +690,7 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
 #else
     IM_UNUSED(main_viewport);
 #endif
+    ImGui_ImplGlfw_InitMultiViewportSupport();
 
     // Windows: register a WndProc hook so we can intercept some messages.
 #ifdef _WIN32
@@ -691,6 +741,8 @@ void ImGui_ImplGlfw_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplGlfw_ShutdownMultiViewportSupport();
+
     if (bd->InstalledCallbacks)
         ImGui_ImplGlfw_RestoreCallbacks(bd->Window);
 #ifdef EMSCRIPTEN_USE_EMBEDDED_GLFW3
@@ -710,7 +762,7 @@ 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);
 }
 
@@ -718,10 +770,15 @@ static void ImGui_ImplGlfw_UpdateMouseData()
 {
     ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
-    // (those braces are here to reduce diff with multi-viewports support in 'docking' branch)
+    ImGuiID mouse_viewport_id = 0;
+    const ImVec2 mouse_pos_prev = io.MousePos;
+    for (int n = 0; n < platform_io.Viewports.Size; n++)
     {
-        GLFWwindow* window = bd->Window;
+        ImGuiViewport* viewport = platform_io.Viewports[n];
+        GLFWwindow* window = (GLFWwindow*)viewport->PlatformHandle;
+
 #ifdef EMSCRIPTEN_USE_EMBEDDED_GLFW3
         const bool is_window_focused = true;
 #else
@@ -730,19 +787,54 @@ static void ImGui_ImplGlfw_UpdateMouseData()
         if (is_window_focused)
         {
             // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when io.ConfigNavMoveSetMousePos is enabled by user)
+            // When multi-viewports are enabled, all Dear ImGui positions are same as OS positions.
             if (io.WantSetMousePos)
-                glfwSetCursorPos(window, (double)io.MousePos.x, (double)io.MousePos.y);
+                glfwSetCursorPos(window, (double)(mouse_pos_prev.x - viewport->Pos.x), (double)(mouse_pos_prev.y - viewport->Pos.y));
 
             // (Optional) Fallback to provide mouse position when focused (ImGui_ImplGlfw_CursorPosCallback already provides this when hovered or captured)
             if (bd->MouseWindow == nullptr)
             {
                 double mouse_x, mouse_y;
                 glfwGetCursorPos(window, &mouse_x, &mouse_y);
+                if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+                {
+                    // Single viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
+                    // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+                    int window_x, window_y;
+                    glfwGetWindowPos(window, &window_x, &window_y);
+                    mouse_x += window_x;
+                    mouse_y += window_y;
+                }
                 bd->LastValidMousePos = ImVec2((float)mouse_x, (float)mouse_y);
                 io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
             }
         }
+
+        // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+        // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+        // - [X] GLFW >= 3.3 backend ON WINDOWS ONLY does correctly ignore viewports with the _NoInputs flag (since we implement hit via our WndProc hook)
+        //       On other platforms we rely on the library fallbacking to its own search when reporting a viewport with _NoInputs flag.
+        // - [!] GLFW <= 3.2 backend CANNOT correctly ignore viewports with the _NoInputs flag, and CANNOT reported Hovered Viewport because of mouse capture.
+        //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+        //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+        //       by the backend, and use its flawed heuristic to guess the viewport behind.
+        // - [X] GLFW backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+        // FIXME: This is currently only correct on Win32. See what we do below with the WM_NCHITTEST, missing an equivalent for other systems.
+        // See https://github.com/glfw/glfw/issues/1236 if you want to help in making this a GLFW feature.
+#if GLFW_HAS_MOUSE_PASSTHROUGH
+        const bool window_no_input = (viewport->Flags & ImGuiViewportFlags_NoInputs) != 0;
+        glfwSetWindowAttrib(window, GLFW_MOUSE_PASSTHROUGH, window_no_input);
+#endif
+#if GLFW_HAS_MOUSE_PASSTHROUGH || GLFW_HAS_WINDOW_HOVERED
+        if (glfwGetWindowAttrib(window, GLFW_HOVERED))
+            mouse_viewport_id = viewport->ID;
+#else
+        // We cannot use bd->MouseWindow maintained from CursorEnter/Leave callbacks, because it is locked to the window capturing mouse.
+#endif
     }
+
+    if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)
+        io.AddMouseViewportEvent(mouse_viewport_id);
 }
 
 static void ImGui_ImplGlfw_UpdateMouseCursor()
@@ -753,9 +845,10 @@ 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
@@ -824,6 +917,48 @@ static void ImGui_ImplGlfw_UpdateGamepads()
     #undef MAP_ANALOG
 }
 
+static void ImGui_ImplGlfw_UpdateMonitors()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+
+    int monitors_count = 0;
+    GLFWmonitor** glfw_monitors = glfwGetMonitors(&monitors_count);
+    if (monitors_count == 0) // Preserve existing monitor list if there are none. Happens on macOS sleeping (#5683)
+        return;
+
+    platform_io.Monitors.resize(0);
+    for (int n = 0; n < monitors_count; n++)
+    {
+        ImGuiPlatformMonitor monitor;
+        int x, y;
+        glfwGetMonitorPos(glfw_monitors[n], &x, &y);
+        const GLFWvidmode* vid_mode = glfwGetVideoMode(glfw_monitors[n]);
+        if (vid_mode == nullptr)
+            continue; // Failed to get Video mode (e.g. Emscripten does not support this function)
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)x, (float)y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)vid_mode->width, (float)vid_mode->height);
+#if GLFW_HAS_MONITOR_WORK_AREA
+        int w, h;
+        glfwGetMonitorWorkarea(glfw_monitors[n], &x, &y, &w, &h);
+        if (w > 0 && h > 0) // Workaround a small GLFW issue reporting zero on monitor changes: https://github.com/glfw/glfw/pull/1761
+        {
+            monitor.WorkPos = ImVec2((float)x, (float)y);
+            monitor.WorkSize = ImVec2((float)w, (float)h);
+        }
+#endif
+#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);
+        if (x_scale == 0.0f)
+            continue; // Some accessibility applications are declaring virtual monitors with a DPI of 0, see #7902.
+        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();
@@ -838,6 +973,7 @@ 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);
+    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)
@@ -847,6 +983,7 @@ void ImGui_ImplGlfw_NewFrame()
     io.DeltaTime = bd->Time > 0.0 ? (float)(current_time - bd->Time) : (float)(1.0f / 60.0f);
     bd->Time = current_time;
 
+    bd->MouseIgnoreButtonUp = false;
     ImGui_ImplGlfw_UpdateMouseData();
     ImGui_ImplGlfw_UpdateMouseCursor();
 
@@ -916,6 +1053,404 @@ void ImGui_ImplGlfw_InstallEmscriptenCallbacks(GLFWwindow* window, const char* c
 }
 #endif // #ifdef EMSCRIPTEN_USE_PORT_CONTRIB_GLFW3
 
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* PlatformUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplGlfw_ViewportData
+{
+    GLFWwindow* Window;             // Stored in ImGuiViewport::PlatformHandle
+    bool        WindowOwned;
+    int         IgnoreWindowPosEventFrame;
+    int         IgnoreWindowSizeEventFrame;
+#ifdef _WIN32
+    WNDPROC     PrevWndProc;
+#endif
+
+    ImGui_ImplGlfw_ViewportData()  { memset((void*)this, 0, sizeof(*this)); IgnoreWindowSizeEventFrame = IgnoreWindowPosEventFrame = -1; }
+    ~ImGui_ImplGlfw_ViewportData() { IM_ASSERT(Window == nullptr); }
+};
+
+static void ImGui_ImplGlfw_WindowCloseCallback(GLFWwindow* window)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+        viewport->PlatformRequestClose = true;
+}
+
+// GLFW may dispatch window pos/size events after calling glfwSetWindowPos()/glfwSetWindowSize().
+// However: depending on the platform the callback may be invoked at different time:
+// - on Windows it appears to be called within the glfwSetWindowPos()/glfwSetWindowSize() call
+// - on Linux it is queued and invoked during glfwPollEvents()
+// Because the event doesn't always fire on glfwSetWindowXXX() we use a frame counter tag to only
+// ignore recent glfwSetWindowXXX() calls.
+static void ImGui_ImplGlfw_WindowPosCallback(GLFWwindow* window, int, int)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+    {
+        if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+        {
+            bool ignore_event = (ImGui::GetFrameCount() <= vd->IgnoreWindowPosEventFrame + 1);
+            //data->IgnoreWindowPosEventFrame = -1;
+            if (ignore_event)
+                return;
+        }
+        viewport->PlatformRequestMove = true;
+    }
+}
+
+static void ImGui_ImplGlfw_WindowSizeCallback(GLFWwindow* window, int, int)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+    {
+        if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+        {
+            bool ignore_event = (ImGui::GetFrameCount() <= vd->IgnoreWindowSizeEventFrame + 1);
+            //data->IgnoreWindowSizeEventFrame = -1;
+            if (ignore_event)
+                return;
+        }
+        viewport->PlatformRequestResize = true;
+    }
+}
+
+static void ImGui_ImplGlfw_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = IM_NEW(ImGui_ImplGlfw_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    // Workaround for Linux: ignore mouse up events corresponding to losing focus of the previously focused window (#7733, #3158, #7922)
+#ifdef __linux__
+    bd->MouseIgnoreButtonUpWaitForFocusLoss = true;
+#endif
+
+    // GLFW 3.2 unfortunately always set focus on glfwCreateWindow() if GLFW_VISIBLE is set, regardless of GLFW_FOCUSED
+    // With GLFW 3.3, the hint GLFW_FOCUS_ON_SHOW fixes this problem
+    glfwWindowHint(GLFW_VISIBLE, false);
+    glfwWindowHint(GLFW_FOCUSED, false);
+#if GLFW_HAS_FOCUS_ON_SHOW
+    glfwWindowHint(GLFW_FOCUS_ON_SHOW, false);
+ #endif
+    glfwWindowHint(GLFW_DECORATED, (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? false : true);
+#if GLFW_HAS_WINDOW_TOPMOST
+    glfwWindowHint(GLFW_FLOATING, (viewport->Flags & ImGuiViewportFlags_TopMost) ? true : false);
+#endif
+    GLFWwindow* share_window = (bd->ClientApi == GlfwClientApi_OpenGL) ? bd->Window : nullptr;
+    vd->Window = glfwCreateWindow((int)viewport->Size.x, (int)viewport->Size.y, "No Title Yet", nullptr, share_window);
+    vd->WindowOwned = true;
+    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)
+    ::SetPropA(hwnd, "IMGUI_VIEWPORT", viewport);
+    vd->PrevWndProc = (WNDPROC)::GetWindowLongPtrW(hwnd, GWLP_WNDPROC);
+    ::SetWindowLongPtrW(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_InitMultiViewportSupport()
+{
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplGlfw_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplGlfw_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplGlfw_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplGlfw_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplGlfw_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplGlfw_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplGlfw_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplGlfw_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplGlfw_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplGlfw_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplGlfw_SetWindowTitle;
+    platform_io.Platform_RenderWindow = ImGui_ImplGlfw_RenderWindow;
+    platform_io.Platform_SwapBuffers = ImGui_ImplGlfw_SwapBuffers;
+#if GLFW_HAS_WINDOW_ALPHA
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplGlfw_SetWindowAlpha;
+#endif
+#if GLFW_HAS_VULKAN
+    platform_io.Platform_CreateVkSurface = ImGui_ImplGlfw_CreateVkSurface;
+#endif
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplGlfw_ViewportData* vd = IM_NEW(ImGui_ImplGlfw_ViewportData)();
+    vd->Window = bd->Window;
+    vd->WindowOwned = false;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = (void*)bd->Window;
+}
+
+static void ImGui_ImplGlfw_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
+//-----------------------------------------------------------------------------
+
+// WndProc hook (declared here because we will need access to ImGui_ImplGlfw_ViewportData)
+#ifdef _WIN32
+static ImGuiMouseSource GetMouseSourceFromMessageExtraInfo()
+{
+    LPARAM extra_info = ::GetMessageExtraInfo();
+    if ((extra_info & 0xFFFFFF80) == 0xFF515700)
+        return ImGuiMouseSource_Pen;
+    if ((extra_info & 0xFFFFFF80) == 0xFF515780)
+        return ImGuiMouseSource_TouchScreen;
+    return ImGuiMouseSource_Mouse;
+}
+static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    WNDPROC prev_wndproc = bd->PrevWndProc;
+    ImGuiViewport* viewport = (ImGuiViewport*)::GetPropA(hWnd, "IMGUI_VIEWPORT");
+    if (viewport != NULL)
+        if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+            prev_wndproc = vd->PrevWndProc;
+
+    switch (msg)
+    {
+        // GLFW doesn't allow to distinguish Mouse vs TouchScreen vs Pen.
+        // Add support for Win32 (based on imgui_impl_win32), because we rely on _TouchScreen info to trickle inputs differently.
+    case WM_MOUSEMOVE: case WM_NCMOUSEMOVE:
+    case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK: case WM_LBUTTONUP:
+    case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK: case WM_RBUTTONUP:
+    case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK: case WM_MBUTTONUP:
+    case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK: case WM_XBUTTONUP:
+        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.
+        if (viewport && (viewport->Flags & ImGuiViewportFlags_NoInputs))
+            return HTTRANSPARENT;
+        break;
+    }
+#endif
+    }
+    return ::CallWindowProcW(prev_wndproc, hWnd, msg, wParam, lParam);
+}
+#endif // #ifdef _WIN32
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_glfw.h

@@ -1,6 +1,7 @@
 // dear imgui: Platform Backend for GLFW
 // This needs to be used along with a Renderer (e.g. OpenGL3, Vulkan, WebGPU..)
 // (Info: GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
+// (Requires: GLFW 3.1+. Prefer GLFW 3.3+ for full feature support.)
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
@@ -8,6 +9,11 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLFW_KEY_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Resizing cursors requires GLFW 3.4+! Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// Missing features or Issues:
+//  [ ] Touch events are only correctly identified as Touch on Windows. This create issues with some interactions. GLFW doesn't provide a way to identify touch inputs from mouse inputs, we cannot call io.AddMouseSourceEvent() to identify the source. We provide a Windows-specific workaround.
+//  [ ] Missing ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress cursors.
+//  [ ] Multi-viewport: 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.

backends/imgui_impl_glut.cpp

@@ -13,6 +13,7 @@
 //  [ ] Platform: Missing mouse cursor shape/visibility support.
 //  [ ] Platform: Missing clipboard support (not supported by Glut).
 //  [ ] Platform: Missing gamepad support.
+//  [ ] Platform: Missing multi-viewport support (multiple windows).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -50,7 +51,7 @@
 
 static int g_Time = 0;          // Current time, in milliseconds
 
-// Glut has 1 function for characters and one for "special keys". We map the characters in the 0..255 range and the keys above.
+// Glut has one function for characters and one for "special keys". We map the characters in the 0..255 range and the keys above.
 static ImGuiKey ImGui_ImplGLUT_KeyToImGuiKey(int key)
 {
     switch (key)

backends/imgui_impl_glut.h

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

backends/imgui_impl_metal.h

@@ -4,6 +4,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'MTLTexture' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
+//  [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.
@@ -13,6 +14,7 @@
 // - Documentation        https://dearimgui.com/docs (same as your local docs/ folder).
 // - Introduction, links and more at the top of imgui.cpp
 
+#pragma once
 #include "imgui.h"      // IMGUI_IMPL_API
 #ifndef IMGUI_DISABLE
 

backends/imgui_impl_metal.mm

@@ -4,6 +4,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'MTLTexture' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
+//  [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.
@@ -15,7 +16,9 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  2024-01-08: Metal: Fixed memory leaks when using metal-cpp (#8276, #8166) or when using multiple contexts (#7419).
+//  2025-XX-XX: Metal: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-02-03: Metal: Crash fix. (#8367)
+//  2025-01-08: Metal: Fixed memory leaks when using metal-cpp (#8276, #8166) or when using multiple contexts (#7419).
 //  2022-08-23: Metal: Update deprecated property 'sampleCount'->'rasterSampleCount'.
 //  2022-07-05: Metal: Add dispatch synchronization.
 //  2022-06-30: Metal: Use __bridge for ARC based systems.
@@ -39,6 +42,12 @@
 #import <time.h>
 #import <Metal/Metal.h>
 
+// Forward Declarations
+static void ImGui_ImplMetal_InitMultiViewportSupport();
+static void ImGui_ImplMetal_ShutdownMultiViewportSupport();
+static void ImGui_ImplMetal_CreateDeviceObjectsForPlatformWindows();
+static void ImGui_ImplMetal_InvalidateDeviceObjectsForPlatformWindows();
+
 #pragma mark - Support classes
 
 // A wrapper around a MTLBuffer object that knows the last time it was reused
@@ -133,10 +142,13 @@ 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;
 
+    ImGui_ImplMetal_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -145,13 +157,14 @@ void ImGui_ImplMetal_Shutdown()
     ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData();
     IM_UNUSED(bd);
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
+    ImGui_ImplMetal_ShutdownMultiViewportSupport();
     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)
@@ -311,11 +324,11 @@ void ImGui_ImplMetal_RenderDrawData(ImDrawData* drawData, id<MTLCommandBuffer> c
         indexBufferOffset += (size_t)draw_list->IdxBuffer.Size * sizeof(ImDrawIdx);
     }
 
-    __block MetalContext* sharedMetalContext = bd->SharedMetalContext;
+    MetalContext* sharedMetalContext = bd->SharedMetalContext;
     [commandBuffer addCompletedHandler:^(id<MTLCommandBuffer>)
     {
         dispatch_async(dispatch_get_main_queue(), ^{
-            @synchronized(bd->SharedMetalContext.bufferCache)
+            @synchronized(sharedMetalContext.bufferCache)
             {
                 [sharedMetalContext.bufferCache addObject:vertexBuffer];
                 [sharedMetalContext.bufferCache addObject:indexBuffer];
@@ -369,6 +382,7 @@ bool ImGui_ImplMetal_CreateDeviceObjects(id<MTLDevice> device)
     depthStencilDescriptor.depthWriteEnabled = NO;
     depthStencilDescriptor.depthCompareFunction = MTLCompareFunctionAlways;
     bd->SharedMetalContext.depthStencilState = [device newDepthStencilStateWithDescriptor:depthStencilDescriptor];
+    ImGui_ImplMetal_CreateDeviceObjectsForPlatformWindows();
 #ifdef IMGUI_IMPL_METAL_CPP
     [depthStencilDescriptor release];
 #endif
@@ -380,9 +394,155 @@ 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_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplMetal_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplMetal_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplMetal_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplMetal_RenderWindow;
+}
+
+static void ImGui_ImplMetal_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
+static void ImGui_ImplMetal_CreateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (!platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplMetal_CreateWindow(platform_io.Viewports[i]);
+}
+
+static void ImGui_ImplMetal_InvalidateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplMetal_DestroyWindow(platform_io.Viewports[i]);
+}
+
 #pragma mark - MetalBuffer implementation
 
 @implementation MetalBuffer

backends/imgui_impl_opengl2.cpp

@@ -3,6 +3,7 @@
 
 // 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'.
 // Missing features or Issues:
 //  [ ] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 
@@ -24,6 +25,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2024-10-07: OpenGL: Changed default texture sampler to Clamp instead of Repeat/Wrap.
 //  2024-06-28: OpenGL: ImGui_ImplOpenGL2_NewFrame() recreates font texture if it has been destroyed by ImGui_ImplOpenGL2_DestroyFontsTexture(). (#7748)
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
@@ -69,6 +71,16 @@
 #include <GL/gl.h>
 #endif
 
+// [Debugging]
+//#define IMGUI_IMPL_OPENGL_DEBUG
+#ifdef IMGUI_IMPL_OPENGL_DEBUG
+#include <stdio.h>
+#define GL_CALL(_CALL)      do { _CALL; GLenum gl_err = glGetError(); if (gl_err != 0) fprintf(stderr, "GL error 0x%x returned from '%s'.\n", gl_err, #_CALL); } while (0)  // Call with error check
+#else
+#define GL_CALL(_CALL)      _CALL   // Call without error check
+#endif
+
+// OpenGL data
 struct ImGui_ImplOpenGL2_Data
 {
     GLuint       FontTexture;
@@ -83,6 +95,10 @@ static ImGui_ImplOpenGL2_Data* ImGui_ImplOpenGL2_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL2_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplOpenGL2_InitMultiViewportSupport();
+static void ImGui_ImplOpenGL2_ShutdownMultiViewportSupport();
+
 // Functions
 bool    ImGui_ImplOpenGL2_Init()
 {
@@ -94,6 +110,9 @@ 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)
+
+    ImGui_ImplOpenGL2_InitMultiViewportSupport();
 
     return true;
 }
@@ -104,9 +123,11 @@ void    ImGui_ImplOpenGL2_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplOpenGL2_ShutdownMultiViewportSupport();
     ImGui_ImplOpenGL2_DestroyDeviceObjects();
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasViewports;
     IM_DELETE(bd);
 }
 
@@ -155,7 +176,7 @@ static void ImGui_ImplOpenGL2_SetupRenderState(ImDrawData* draw_data, int fb_wid
 
     // Setup viewport, orthographic projection matrix
     // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayPos is (0,0) for single viewport apps.
-    glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height);
+    GL_CALL(glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height));
     glMatrixMode(GL_PROJECTION);
     glPushMatrix();
     glLoadIdentity();
@@ -302,6 +323,35 @@ 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_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL2_RenderWindow;
+}
+
+static void ImGui_ImplOpenGL2_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_opengl2.h

@@ -3,6 +3,7 @@
 
 // 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'.
 // Missing features or Issues:
 //  [ ] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 

backends/imgui_impl_opengl3.cpp

@@ -6,6 +6,7 @@
 // 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) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset) [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.
@@ -22,6 +23,8 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-02-18: OpenGL: Lazily reinitialize embedded GL loader for when calling backend from e.g. other DLL boundaries. (#8406)
 //  2024-10-07: OpenGL: Changed default texture sampler to Clamp instead of Repeat/Wrap.
 //  2024-06-28: OpenGL: ImGui_ImplOpenGL3_NewFrame() recreates font texture if it has been destroyed by ImGui_ImplOpenGL3_DestroyFontsTexture(). (#7748)
 //  2024-05-07: OpenGL: Update loader for Linux to support EGL/GLVND. (#7562)
@@ -53,7 +56,7 @@
 //  2021-01-03: OpenGL: Backup, setup and restore GL_STENCIL_TEST state.
 //  2020-10-23: OpenGL: Backup, setup and restore GL_PRIMITIVE_RESTART state.
 //  2020-10-15: OpenGL: Use glGetString(GL_VERSION) instead of glGetIntegerv(GL_MAJOR_VERSION, ...) when the later returns zero (e.g. Desktop GL 2.x)
-//  2020-09-17: OpenGL: Fix to avoid compiling/calling glBindSampler() on ES or pre 3.3 context which have the defines set by a loader.
+//  2020-09-17: OpenGL: Fix to avoid compiling/calling glBindSampler() on ES or pre-3.3 context which have the defines set by a loader.
 //  2020-07-10: OpenGL: Added support for glad2 OpenGL loader.
 //  2020-05-08: OpenGL: Made default GLSL version 150 (instead of 130) on OSX.
 //  2020-04-21: OpenGL: Fixed handling of glClipControl(GL_UPPER_LEFT) by inverting projection matrix.
@@ -169,6 +172,7 @@
 // - You can temporarily use an unstripped version. See https://github.com/dearimgui/gl3w_stripped/releases
 // Changes to this backend using new APIs should be accompanied by a regenerated stripped loader version.
 #define IMGL3W_IMPL
+#define IMGUI_IMPL_OPENGL_LOADER_IMGL3W
 #include "imgui_impl_opengl3_loader.h"
 #endif
 
@@ -252,6 +256,10 @@ static ImGui_ImplOpenGL3_Data* ImGui_ImplOpenGL3_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL3_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplOpenGL3_InitMultiViewportSupport();
+static void ImGui_ImplOpenGL3_ShutdownMultiViewportSupport();
+
 // OpenGL vertex attribute state (for ES 1.0 and ES 2.0 only)
 #ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
 struct ImGui_ImplOpenGL3_VtxAttribState
@@ -276,6 +284,21 @@ struct ImGui_ImplOpenGL3_VtxAttribState
 };
 #endif
 
+// Not static to allow third-party code to use that if they want to (but undocumented)
+bool ImGui_ImplOpenGL3_InitLoader();
+bool ImGui_ImplOpenGL3_InitLoader()
+{
+    // Initialize our loader
+#ifdef IMGUI_IMPL_OPENGL_LOADER_IMGL3W
+    if (glGetIntegerv == nullptr && imgl3wInit() != 0)
+    {
+        fprintf(stderr, "Failed to initialize OpenGL loader!\n");
+        return false;
+    }
+#endif
+    return true;
+}
+
 // Functions
 bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
 {
@@ -283,14 +306,9 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     IMGUI_CHECKVERSION();
     IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
 
-    // Initialize our loader
-#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
-    if (imgl3wInit() != 0)
-    {
-        fprintf(stderr, "Failed to initialize OpenGL loader!\n");
+    // Initialize loader
+    if (!ImGui_ImplOpenGL3_InitLoader())
         return false;
-    }
-#endif
 
     // Setup backend capabilities flags
     ImGui_ImplOpenGL3_Data* bd = IM_NEW(ImGui_ImplOpenGL3_Data)();
@@ -303,6 +321,7 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     // GLES 2
     bd->GlVersion = 200;
     bd->GlProfileIsES2 = true;
+    IM_UNUSED(gl_version_str);
 #else
     // Desktop or GLES 3
     GLint major = 0;
@@ -344,6 +363,7 @@ 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.
@@ -384,6 +404,8 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     }
 #endif
 
+    ImGui_ImplOpenGL3_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -393,10 +415,11 @@ void    ImGui_ImplOpenGL3_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplOpenGL3_ShutdownMultiViewportSupport();
     ImGui_ImplOpenGL3_DestroyDeviceObjects();
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -405,6 +428,8 @@ void    ImGui_ImplOpenGL3_NewFrame()
     ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
     IM_ASSERT(bd != nullptr && "Context or backend not initialized! Did you call ImGui_ImplOpenGL3_Init()?");
 
+    ImGui_ImplOpenGL3_InitLoader(); // Lazily init loader if not already done for e.g. DLL boundaries.
+
     if (!bd->ShaderHandle)
         ImGui_ImplOpenGL3_CreateDeviceObjects();
     if (!bd->FontTexture)
@@ -496,6 +521,8 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
     if (fb_width <= 0 || fb_height <= 0)
         return;
 
+    ImGui_ImplOpenGL3_InitLoader(); // Lazily init loader if not already done for e.g. DLL boundaries.
+
     ImGui_ImplOpenGL3_Data* bd = ImGui_ImplOpenGL3_GetBackendData();
 
     // Backup GL state
@@ -956,6 +983,34 @@ 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_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL3_RenderWindow;
+}
+
+static void ImGui_ImplOpenGL3_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__GNUC__)

backends/imgui_impl_opengl3.h

@@ -6,6 +6,7 @@
 // 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) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset) [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.

backends/imgui_impl_osx.h

@@ -10,6 +10,11 @@
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: IME support.
+//  [x] Platform: Multi-viewport / platform windows.
+// Missing features or Issues:
+//  [ ] Missing ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress cursors.
+//  [ ] Multi-viewport: Window size not correctly reported when enabling io.ConfigViewportsNoDecoration
+//  [ ] Multi-viewport: 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.
@@ -19,6 +24,7 @@
 // - Documentation        https://dearimgui.com/docs (same as your local docs/ folder).
 // - Introduction, links and more at the top of imgui.cpp
 
+#pragma once
 #include "imgui.h"      // IMGUI_IMPL_API
 #ifndef IMGUI_DISABLE
 

backends/imgui_impl_osx.mm

@@ -10,6 +10,11 @@
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: IME support.
+//  [x] Platform: Multi-viewport / platform windows.
+// Missing features or Issues:
+//  [ ] Missing ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress cursors.
+//  [ ] Multi-viewport: Window size not correctly reported when enabling io.ConfigViewportsNoDecoration
+//  [ ] Multi-viewport: 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.
@@ -29,6 +34,8 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-01-20: Removed notification observer when shutting down. (#8331)
 //  2024-08-22: moved some OS/backend related function pointers from ImGuiIO to ImGuiPlatformIO:
 //               - io.GetClipboardTextFn    -> platform_io.Platform_GetClipboardTextFn
 //               - io.SetClipboardTextFn    -> platform_io.Platform_SetClipboardTextFn
@@ -36,7 +43,7 @@
 //  2024-07-02: Update for io.SetPlatformImeDataFn() -> io.PlatformSetImeDataFn() renaming in main library.
 //  2023-10-05: Inputs: Added support for extra ImGuiKey values: F13 to F20 function keys. Stopped mapping F13 into PrintScreen.
 //  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).
+//  2023-02-01: Fixed scroll wheel scaling for devices emitting events with hasPreciseScrollingDeltas==false (e.g. non-Apple mice).
 //  2022-11-02: Fixed mouse coordinates before clicking the host window.
 //  2022-10-06: Fixed mouse inputs on flipped views.
 //  2022-09-26: Inputs: Renamed ImGuiKey_ModXXX introduced in 1.87 to ImGuiMod_XXX (old names still supported).
@@ -96,6 +103,9 @@ static void                     ImGui_ImplOSX_DestroyBackendData()  { IM_DELETE(
 static inline CFTimeInterval    GetMachAbsoluteTimeInSeconds()      { return (CFTimeInterval)(double)(clock_gettime_nsec_np(CLOCK_UPTIME_RAW) / 1e9); }
 
 // Forward Declarations
+static void ImGui_ImplOSX_InitMultiViewportSupport();
+static void ImGui_ImplOSX_ShutdownMultiViewportSupport();
+static void ImGui_ImplOSX_UpdateMonitors();
 static void ImGui_ImplOSX_AddTrackingArea(NSView* _Nonnull view);
 static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
 
@@ -142,9 +152,25 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
     NSWindow* window = view.window;
     if (!window)
         return;
-    NSRect contentRect = [window contentRectForFrameRect:window.frame];
-    NSRect rect = NSMakeRect(_posX, contentRect.size.height - _posY, 0, 0);
-    _imeRect = [window convertRectToScreen:rect];
+
+    ImGuiIO& io = ImGui::GetIO();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        NSRect frame = window.frame;
+        NSRect contentRect = window.contentLayoutRect;
+        if (window.styleMask & NSWindowStyleMaskFullSizeContentView) // No title bar windows should be considered.
+            contentRect = frame;
+
+        NSRect firstScreenFrame = NSScreen.screens[0].frame;
+        _imeRect = NSMakeRect(_posX, _posY, 0, 0);
+        _imeRect.origin.y = firstScreenFrame.size.height - _imeRect.size.height - _imeRect.origin.y; // Opposite of ConvertNSRect()
+    }
+    else
+    {
+        NSRect contentRect = [window contentRectForFrameRect:window.frame];
+        NSRect rect = NSMakeRect(_posX, contentRect.size.height - _posY, 0, 0);
+        _imeRect = [window convertRectToScreen:rect];
+    }
 }
 
 - (void)viewDidMoveToWindow
@@ -239,6 +265,7 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
 
 - (void)onApplicationBecomeActive:(NSNotification*)aNotification;
 - (void)onApplicationBecomeInactive:(NSNotification*)aNotification;
+- (void)displaysDidChange:(NSNotification*)aNotification;
 
 @end
 
@@ -256,6 +283,11 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
     io.AddFocusEvent(false);
 }
 
+- (void)displaysDidChange:(NSNotification*)aNotification
+{
+    ImGui_ImplOSX_UpdateMonitors();
+}
+
 @end
 
 // Functions
@@ -410,23 +442,27 @@ bool ImGui_ImplOSX_Init(NSView* view)
     io.BackendPlatformName = "imgui_impl_osx";
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;           // We can honor GetMouseCursor() values (optional)
     //io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+    io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;      // We can create multi-viewports on the Platform side (optional)
+    //io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
 
     bd->Observer = [ImGuiObserver new];
     bd->Window = view.window ?: NSApp.orderedWindows.firstObject;
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = main_viewport->PlatformHandleRaw = (__bridge_retained void*)bd->Window;
+    ImGui_ImplOSX_UpdateMonitors();
+    ImGui_ImplOSX_InitMultiViewportSupport();
 
     // Load cursors. Some of them are undocumented.
     bd->MouseCursorHidden = false;
     bd->MouseCursors[ImGuiMouseCursor_Arrow] = [NSCursor arrowCursor];
     bd->MouseCursors[ImGuiMouseCursor_TextInput] = [NSCursor IBeamCursor];
     bd->MouseCursors[ImGuiMouseCursor_ResizeAll] = [NSCursor closedHandCursor];
-    bd->MouseCursors[ImGuiMouseCursor_Hand] = [NSCursor pointingHandCursor];
-    bd->MouseCursors[ImGuiMouseCursor_NotAllowed] = [NSCursor operationNotAllowedCursor];
     bd->MouseCursors[ImGuiMouseCursor_ResizeNS] = [NSCursor respondsToSelector:@selector(_windowResizeNorthSouthCursor)] ? [NSCursor _windowResizeNorthSouthCursor] : [NSCursor resizeUpDownCursor];
     bd->MouseCursors[ImGuiMouseCursor_ResizeEW] = [NSCursor respondsToSelector:@selector(_windowResizeEastWestCursor)] ? [NSCursor _windowResizeEastWestCursor] : [NSCursor resizeLeftRightCursor];
     bd->MouseCursors[ImGuiMouseCursor_ResizeNESW] = [NSCursor respondsToSelector:@selector(_windowResizeNorthEastSouthWestCursor)] ? [NSCursor _windowResizeNorthEastSouthWestCursor] : [NSCursor closedHandCursor];
     bd->MouseCursors[ImGuiMouseCursor_ResizeNWSE] = [NSCursor respondsToSelector:@selector(_windowResizeNorthWestSouthEastCursor)] ? [NSCursor _windowResizeNorthWestSouthEastCursor] : [NSCursor closedHandCursor];
+    bd->MouseCursors[ImGuiMouseCursor_Hand] = [NSCursor pointingHandCursor];
+    bd->MouseCursors[ImGuiMouseCursor_NotAllowed] = [NSCursor operationNotAllowedCursor];
 
     // Note that imgui.cpp also include default OSX clipboard handlers which can be enabled
     // by adding '#define IMGUI_ENABLE_OSX_DEFAULT_CLIPBOARD_FUNCTIONS' in imconfig.h and adding '-framework ApplicationServices' to your linker command-line.
@@ -497,6 +533,7 @@ void ImGui_ImplOSX_Shutdown()
     ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
 
+    [[NSNotificationCenter defaultCenter] removeObserver:bd->Observer];
     bd->Observer = nullptr;
     if (bd->Monitor != nullptr)
     {
@@ -504,12 +541,12 @@ void ImGui_ImplOSX_Shutdown()
         bd->Monitor = nullptr;
     }
 
+    ImGui_ImplOSX_ShutdownMultiViewportSupport();
     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()
@@ -686,14 +723,23 @@ 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;
@@ -821,6 +867,294 @@ 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(NSRect* r)
+{
+    NSRect firstScreenFrame = NSScreen.screens[0].frame;
+    IM_ASSERT(firstScreenFrame.origin.x == 0 && firstScreenFrame.origin.y == 0);
+    r->origin.y = firstScreenFrame.size.height - r->origin.y - r->size.height;
+}
+
+static void ImGui_ImplOSX_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    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(&rect);
+
+    NSWindowStyleMask styleMask = 0;
+    if (viewport->Flags & ImGuiViewportFlags_NoDecoration)
+        styleMask |= NSWindowStyleMaskBorderless;
+    else
+        styleMask |= NSWindowStyleMaskTitled | NSWindowStyleMaskResizable | NSWindowStyleMaskClosable | NSWindowStyleMaskMiniaturizable;
+
+    NSWindow* window = [[ImGui_ImplOSX_Window alloc] initWithContentRect:rect
+                                                               styleMask:styleMask
+                                                                 backing:NSBackingStoreBuffered
+                                                                   defer:YES
+                                                                  screen:screen];
+    if (viewport->Flags & ImGuiViewportFlags_TopMost)
+        [window setLevel:NSFloatingWindowLevel];
+
+    window.title = @"Untitled";
+    window.opaque = YES;
+
+    KeyEventResponder* view = [[KeyEventResponder alloc] initWithFrame:rect];
+    if (floor(NSAppKitVersionNumber) > NSAppKitVersionNumber10_6 && ceil(NSAppKitVersionNumber) < NSAppKitVersionNumber10_15)
+        [view setWantsBestResolutionOpenGLSurface:YES];
+
+    window.contentView = view;
+
+    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;
+    NSRect frame = window.frame;
+    NSRect contentRect = window.contentLayoutRect;
+    if (window.styleMask & NSWindowStyleMaskFullSizeContentView) // No title bar windows should be considered.
+        contentRect = frame;
+
+    NSRect firstScreenFrame = NSScreen.screens[0].frame;
+    return ImVec2(frame.origin.x, firstScreenFrame.size.height - frame.origin.y - contentRect.size.height);
+}
+
+static void ImGui_ImplOSX_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    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(&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);
+
+    NSRect firstScreenFrame = NSScreen.screens[0].frame;
+    IM_ASSERT(firstScreenFrame.origin.x == 0 && firstScreenFrame.origin.y == 0);
+
+    for (NSScreen* screen in NSScreen.screens)
+    {
+        NSRect frame = screen.frame;
+        NSRect visibleFrame = screen.visibleFrame;
+        ConvertNSRect(&frame);
+        ConvertNSRect(&visibleFrame);
+
+        ImGuiPlatformMonitor imgui_monitor;
+        imgui_monitor.MainPos = ImVec2(frame.origin.x, frame.origin.y);
+        imgui_monitor.MainSize = ImVec2(frame.size.width, frame.size.height);
+        imgui_monitor.WorkPos = ImVec2(visibleFrame.origin.x, visibleFrame.origin.y);
+        imgui_monitor.WorkSize = ImVec2(visibleFrame.size.width, visibleFrame.size.height);
+        imgui_monitor.DpiScale = screen.backingScaleFactor;
+        imgui_monitor.PlatformHandle = (__bridge_retained void*)screen;
+
+        platform_io.Monitors.push_back(imgui_monitor);
+    }
+}
+
+static void ImGui_ImplOSX_InitMultiViewportSupport()
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplOSX_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplOSX_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplOSX_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplOSX_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplOSX_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplOSX_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplOSX_GetWindowSize;
+    platform_io.Platform_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_ShutdownMultiViewportSupport()
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    [NSNotificationCenter.defaultCenter removeObserver:bd->Observer
+                                                  name:NSApplicationDidChangeScreenParametersNotification
+                                                object:nil];
+    bd->Observer = nullptr;
+    bd->Window = nullptr;
+    if (bd->Monitor != nullptr)
+    {
+        [NSEvent removeMonitor:bd->Monitor];
+        bd->Monitor = nullptr;
+    }
+
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)main_viewport->PlatformUserData;
+    IM_DELETE(data);
+    main_viewport->PlatformUserData = nullptr;
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_sdl2.cpp

@@ -10,6 +10,10 @@
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: Basic IME support. App needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// Missing features or Issues:
+//  [ ] Platform: Multi-viewport: Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [ ] Platform: Multi-viewport: 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.
@@ -21,6 +25,15 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-03-10: When dealing with OEM keys, use scancodes instead of translated keycodes to choose ImGuiKey values. (#7136, #7201, #7206, #7306, #7670, #7672, #8468)
+//  2025-02-26: Only start SDL_CaptureMouse() when mouse is being dragged, to mitigate issues with e.g.Linux debuggers not claiming capture back. (#6410, #3650)
+//  2025-02-25: [Docking] Revert to use SDL_GetDisplayBounds() for WorkPos/WorkRect if SDL_GetDisplayUsableBounds() failed.
+//  2025-02-24: Avoid calling SDL_GetGlobalMouseState() when mouse is in relative mode.
+//  2025-02-21: [Docking] Update monitors and work areas information every frame, as the later may change regardless of monitor changes. (#8415)
+//  2025-02-18: Added ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress mouse cursor support.
+//  2025-02-10: Using SDL_OpenURL() in platform_io.Platform_OpenInShellFn handler.
+//  2025-01-20: Made ImGui_ImplSDL2_SetGamepadMode(ImGui_ImplSDL2_GamepadMode_Manual) accept an empty array.
 //  2024-10-24: Emscripten: from SDL 2.30.9, SDL_EVENT_MOUSE_WHEEL event doesn't require dividing by 100.0f.
 //  2024-09-09: use SDL_Vulkan_GetDrawableSize() when available. (#7967, #3190)
 //  2024-08-22: moved some OS/backend related function pointers from ImGuiIO to ImGuiPlatformIO:
@@ -58,7 +71,7 @@
 //  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.
@@ -99,6 +112,7 @@
 #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>
 #ifdef __APPLE__
@@ -113,19 +127,29 @@
 #else
 #define SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE    0
 #endif
+#define SDL_HAS_WINDOW_ALPHA                SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_ALWAYS_ON_TOP               SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_USABLE_DISPLAY_BOUNDS       SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_PER_MONITOR_DPI             SDL_VERSION_ATLEAST(2,0,4)
 #define SDL_HAS_VULKAN                      SDL_VERSION_ATLEAST(2,0,6)
+#define SDL_HAS_DISPLAY_EVENT               SDL_VERSION_ATLEAST(2,0,9)
+#define SDL_HAS_OPEN_URL                    SDL_VERSION_ATLEAST(2,0,14)
+#define SDL_HAS_SHOW_WINDOW_ACTIVATION_HINT SDL_VERSION_ATLEAST(2,0,18)
 #if SDL_HAS_VULKAN
 #include <SDL_vulkan.h>
+#else
+static const Uint32 SDL_WINDOW_VULKAN = 0x10000000;
 #endif
 
 // SDL Data
 struct ImGui_ImplSDL2_Data
 {
     SDL_Window*             Window;
-    Uint32                  WindowID;
+    Uint32                  WindowID;       // Stored in ImGuiViewport::PlatformHandle. Use SDL_GetWindowFromID() to get SDL_Window* from Uint32 WindowID.
     SDL_Renderer*           Renderer;
     Uint64                  Time;
     char*                   ClipboardTextData;
+    bool                    UseVulkan;
 
     // Mouse handling
     Uint32                  MouseWindowID;
@@ -134,6 +158,7 @@ struct ImGui_ImplSDL2_Data
     SDL_Cursor*             MouseLastCursor;
     int                     MouseLastLeaveFrame;
     bool                    MouseCanUseGlobalState;
+    bool                    MouseCanReportHoveredViewport;  // This is hard to use/unreliable on SDL so we'll set ImGuiBackendFlags_HasMouseHoveredViewport dynamically based on state.
 
     // Gamepad handling
     ImVector<SDL_GameController*> Gamepads;
@@ -152,6 +177,11 @@ static ImGui_ImplSDL2_Data* ImGui_ImplSDL2_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplSDL2_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplSDL2_UpdateMonitors();
+static void ImGui_ImplSDL2_InitMultiViewportSupport(SDL_Window* window, void* sdl_gl_context);
+static void ImGui_ImplSDL2_ShutdownMultiViewportSupport();
+
 // Functions
 static const char* ImGui_ImplSDL2_GetClipboardText(ImGuiContext*)
 {
@@ -168,13 +198,13 @@ static void ImGui_ImplSDL2_SetClipboardText(ImGuiContext*, const char* text)
 }
 
 // Note: native IME will only display if user calls SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1") _before_ SDL_CreateWindow().
-static void ImGui_ImplSDL2_PlatformSetImeData(ImGuiContext*, ImGuiViewport*, ImGuiPlatformImeData* data)
+static void ImGui_ImplSDL2_PlatformSetImeData(ImGuiContext*, ImGuiViewport* viewport, ImGuiPlatformImeData* data)
 {
     if (data->WantVisible)
     {
         SDL_Rect r;
-        r.x = (int)data->InputPos.x;
-        r.y = (int)data->InputPos.y;
+        r.x = (int)(data->InputPos.x - viewport->Pos.x);
+        r.y = (int)(data->InputPos.y - viewport->Pos.y + data->InputLineHeight);
         r.w = 1;
         r.h = (int)data->InputLineHeight;
         SDL_SetTextInputRect(&r);
@@ -185,7 +215,6 @@ static void ImGui_ImplSDL2_PlatformSetImeData(ImGuiContext*, ImGuiViewport*, ImG
 ImGuiKey ImGui_ImplSDL2_KeyEventToImGuiKey(SDL_Keycode keycode, SDL_Scancode scancode);
 ImGuiKey ImGui_ImplSDL2_KeyEventToImGuiKey(SDL_Keycode keycode, SDL_Scancode scancode)
 {
-    IM_UNUSED(scancode);
     switch (keycode)
     {
         case SDLK_TAB: return ImGuiKey_Tab;
@@ -203,17 +232,17 @@ ImGuiKey ImGui_ImplSDL2_KeyEventToImGuiKey(SDL_Keycode keycode, SDL_Scancode sca
         case SDLK_SPACE: return ImGuiKey_Space;
         case SDLK_RETURN: return ImGuiKey_Enter;
         case SDLK_ESCAPE: return ImGuiKey_Escape;
-        case SDLK_QUOTE: return ImGuiKey_Apostrophe;
+        //case SDLK_QUOTE: return ImGuiKey_Apostrophe;
         case SDLK_COMMA: return ImGuiKey_Comma;
-        case SDLK_MINUS: return ImGuiKey_Minus;
+        //case SDLK_MINUS: return ImGuiKey_Minus;
         case SDLK_PERIOD: return ImGuiKey_Period;
-        case SDLK_SLASH: return ImGuiKey_Slash;
+        //case SDLK_SLASH: return ImGuiKey_Slash;
         case SDLK_SEMICOLON: return ImGuiKey_Semicolon;
-        case SDLK_EQUALS: return ImGuiKey_Equal;
-        case SDLK_LEFTBRACKET: return ImGuiKey_LeftBracket;
-        case SDLK_BACKSLASH: return ImGuiKey_Backslash;
-        case SDLK_RIGHTBRACKET: return ImGuiKey_RightBracket;
-        case SDLK_BACKQUOTE: return ImGuiKey_GraveAccent;
+        //case SDLK_EQUALS: return ImGuiKey_Equal;
+        //case SDLK_LEFTBRACKET: return ImGuiKey_LeftBracket;
+        //case SDLK_BACKSLASH: return ImGuiKey_Backslash;
+        //case SDLK_RIGHTBRACKET: return ImGuiKey_RightBracket;
+        //case SDLK_BACKQUOTE: return ImGuiKey_GraveAccent;
         case SDLK_CAPSLOCK: return ImGuiKey_CapsLock;
         case SDLK_SCROLLLOCK: return ImGuiKey_ScrollLock;
         case SDLK_NUMLOCKCLEAR: return ImGuiKey_NumLock;
@@ -309,6 +338,24 @@ ImGuiKey ImGui_ImplSDL2_KeyEventToImGuiKey(SDL_Keycode keycode, SDL_Scancode sca
         case SDLK_AC_FORWARD: return ImGuiKey_AppForward;
         default: break;
     }
+
+    // Fallback to scancode
+    switch (scancode)
+    {
+    case SDL_SCANCODE_GRAVE: return ImGuiKey_GraveAccent;
+    case SDL_SCANCODE_MINUS: return ImGuiKey_Minus;
+    case SDL_SCANCODE_EQUALS: return ImGuiKey_Equal;
+    case SDL_SCANCODE_LEFTBRACKET: return ImGuiKey_LeftBracket;
+    case SDL_SCANCODE_RIGHTBRACKET: return ImGuiKey_RightBracket;
+    case SDL_SCANCODE_NONUSBACKSLASH: return ImGuiKey_Oem102;
+    case SDL_SCANCODE_BACKSLASH: return ImGuiKey_Backslash;
+    case SDL_SCANCODE_SEMICOLON: return ImGuiKey_Semicolon;
+    case SDL_SCANCODE_APOSTROPHE: return ImGuiKey_Apostrophe;
+    case SDL_SCANCODE_COMMA: return ImGuiKey_Comma;
+    case SDL_SCANCODE_PERIOD: return ImGuiKey_Period;
+    case SDL_SCANCODE_SLASH: return ImGuiKey_Slash;
+    default: break;
+    }
     return ImGuiKey_None;
 }
 
@@ -323,15 +370,13 @@ static void ImGui_ImplSDL2_UpdateKeyModifiers(SDL_Keymod sdl_key_mods)
 
 static ImGuiViewport* ImGui_ImplSDL2_GetViewportForWindowID(Uint32 window_id)
 {
-    ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
-    return (window_id == bd->WindowID) ? ImGui::GetMainViewport() : nullptr;
+    return ImGui::FindViewportByPlatformHandle((void*)(intptr_t)window_id);
 }
 
 // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
 // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-// If you have multiple SDL events and some of them are not meant to be used by dear imgui, you may need to filter events based on their windowID field.
 bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
 {
     ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
@@ -345,6 +390,13 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
             if (ImGui_ImplSDL2_GetViewportForWindowID(event->motion.windowID) == nullptr)
                 return false;
             ImVec2 mouse_pos((float)event->motion.x, (float)event->motion.y);
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                int window_x, window_y;
+                SDL_GetWindowPosition(SDL_GetWindowFromID(event->motion.windowID), &window_x, &window_y);
+                mouse_pos.x += window_x;
+                mouse_pos.y += window_y;
+            }
             io.AddMouseSourceEvent(event->motion.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMousePosEvent(mouse_pos.x, mouse_pos.y);
             return true;
@@ -408,8 +460,10 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
         }
         case SDL_WINDOWEVENT:
         {
-            if (ImGui_ImplSDL2_GetViewportForWindowID(event->window.windowID) == nullptr)
+            ImGuiViewport* viewport = ImGui_ImplSDL2_GetViewportForWindowID(event->window.windowID);
+            if (viewport == NULL)
                 return false;
+
             // - When capturing mouse, SDL will send a bunch of conflicting LEAVE/ENTER event on every mouse move, but the final ENTER tends to be right.
             // - However we won't get a correct LEAVE event for a captured window.
             // - In some cases, when detaching a window from main viewport SDL may send SDL_WINDOWEVENT_ENTER one frame too late,
@@ -425,8 +479,14 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
                 bd->MouseLastLeaveFrame = 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);
+            else if (window_event == SDL_WINDOWEVENT_CLOSE)
+                viewport->PlatformRequestClose = true;
+            else if (window_event == SDL_WINDOWEVENT_MOVED)
+                viewport->PlatformRequestMove = true;
+            else if (window_event == SDL_WINDOWEVENT_RESIZED)
+                viewport->PlatformRequestResize = true;
             return true;
         }
         case SDL_CONTROLLERDEVICEADDED:
@@ -464,13 +524,23 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
     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->WindowID = SDL_GetWindowID(window);
     bd->Renderer = renderer;
+
+    // SDL on Linux/OSX doesn't report events for unfocused windows (see https://github.com/ocornut/imgui/issues/4960)
+    // We will use 'MouseCanReportHoveredViewport' to set 'ImGuiBackendFlags_HasMouseHoveredViewport' dynamically each frame.
     bd->MouseCanUseGlobalState = mouse_can_use_global_state;
+#ifndef __APPLE__
+    bd->MouseCanReportHoveredViewport = bd->MouseCanUseGlobalState;
+#else
+    bd->MouseCanReportHoveredViewport = false;
+#endif
 
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     platform_io.Platform_SetClipboardTextFn = ImGui_ImplSDL2_SetClipboardText;
@@ -479,8 +549,13 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
     platform_io.Platform_SetImeDataFn = ImGui_ImplSDL2_PlatformSetImeData;
 #ifdef __EMSCRIPTEN__
     platform_io.Platform_OpenInShellFn = [](ImGuiContext*, const char* url) { ImGui_ImplSDL2_EmscriptenOpenURL(url); return true; };
+#elif SDL_HAS_OPEN_URL
+    platform_io.Platform_OpenInShellFn = [](ImGuiContext*, const char* url) { return SDL_OpenURL(url) == 0; };
 #endif
 
+    // Update monitor a first time during init
+    ImGui_ImplSDL2_UpdateMonitors();
+
     // Gamepad handling
     bd->GamepadMode = ImGui_ImplSDL2_GamepadMode_AutoFirst;
     bd->WantUpdateGamepadsList = true;
@@ -494,6 +569,8 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
     bd->MouseCursors[ImGuiMouseCursor_ResizeNESW] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZENESW);
     bd->MouseCursors[ImGuiMouseCursor_ResizeNWSE] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_SIZENWSE);
     bd->MouseCursors[ImGuiMouseCursor_Hand] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_HAND);
+    bd->MouseCursors[ImGuiMouseCursor_Wait] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_WAIT);
+    bd->MouseCursors[ImGuiMouseCursor_Progress] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_WAITARROW);
     bd->MouseCursors[ImGuiMouseCursor_NotAllowed] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_NO);
 
     // Set platform dependent data in viewport
@@ -533,7 +610,11 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void
     SDL_SetHint(SDL_HINT_MOUSE_AUTO_CAPTURE, "0");
 #endif
 
-    (void)sdl_gl_context; // Unused in 'master' branch.
+    // We need SDL_CaptureMouse(), SDL_GetGlobalMouseState() from SDL 2.0.4+ to support multiple viewports.
+    // We left the call to ImGui_ImplSDL2_InitMultiViewportSupport() outside of #ifdef to avoid unused-function warnings.
+    if (io.BackendFlags & ImGuiBackendFlags_PlatformHasViewports)
+        ImGui_ImplSDL2_InitMultiViewportSupport(window, sdl_gl_context);
+
     return true;
 }
 
@@ -547,7 +628,11 @@ bool ImGui_ImplSDL2_InitForVulkan(SDL_Window* window)
 #if !SDL_HAS_VULKAN
     IM_ASSERT(0 && "Unsupported");
 #endif
-    return ImGui_ImplSDL2_Init(window, nullptr, nullptr);
+    if (!ImGui_ImplSDL2_Init(window, nullptr, nullptr))
+        return false;
+    ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
+    bd->UseVulkan = true;
+    return true;
 }
 
 bool ImGui_ImplSDL2_InitForD3D(SDL_Window* window)
@@ -581,6 +666,8 @@ void ImGui_ImplSDL2_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplSDL2_ShutdownMultiViewportSupport();
+
     if (bd->ClipboardTextData)
         SDL_free(bd->ClipboardTextData);
     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
@@ -589,10 +676,11 @@ 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();
@@ -600,28 +688,66 @@ static void ImGui_ImplSDL2_UpdateMouseData()
 
     // We forward mouse input when hovered or captured (via SDL_MOUSEMOTION) or when focused (below)
 #if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
-    // 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_CaptureMouse() let the OS know e.g. that our drags can extend outside of parent boundaries (we want updated position) and shouldn't trigger other operations outside.
+    // - Debuggers under Linux tends to leave captured mouse on break, which may be very inconvenient, so to migitate the issue we wait until mouse has moved to begin capture.
+    bool want_capture = false;
+    for (int button_n = 0; button_n < ImGuiMouseButton_COUNT && !want_capture; button_n++)
+        if (ImGui::IsMouseDragging(button_n, 1.0f))
+            want_capture = true;
+    SDL_CaptureMouse(want_capture ? 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_ImplSDL2_GetViewportForWindowID(SDL_GetWindowID(focused_window)) != NULL));
 #else
+    SDL_Window* focused_window = bd->Window;
     const bool is_app_focused = (SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0; // SDL 2.0.3 and non-windowed systems: single-viewport only
 #endif
+
     if (is_app_focused)
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when io.ConfigNavMoveSetMousePos is enabled by user)
         if (io.WantSetMousePos)
-            SDL_WarpMouseInWindow(bd->Window, (int)io.MousePos.x, (int)io.MousePos.y);
+        {
+#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+                SDL_WarpMouseGlobal((int)io.MousePos.x, (int)io.MousePos.y);
+            else
+#endif
+                SDL_WarpMouseInWindow(bd->Window, (int)io.MousePos.x, (int)io.MousePos.y);
+        }
 
         // (Optional) Fallback to provide mouse position when focused (SDL_MOUSEMOTION already provides this when hovered or captured)
-        if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0)
+        const bool is_relative_mouse_mode = SDL_GetRelativeMouseMode() != 0;
+        if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0 && !is_relative_mouse_mode)
         {
-            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 (ImGuiViewport* mouse_viewport = ImGui_ImplSDL2_GetViewportForWindowID(bd->MouseWindowID))
+            mouse_viewport_id = mouse_viewport->ID;
+        io.AddMouseViewportEvent(mouse_viewport_id);
+    }
 }
 
 static void ImGui_ImplSDL2_UpdateMouseCursor()
@@ -665,7 +791,7 @@ void ImGui_ImplSDL2_SetGamepadMode(ImGui_ImplSDL2_GamepadMode mode, struct _SDL_
     ImGui_ImplSDL2_CloseGamepads();
     if (mode == ImGui_ImplSDL2_GamepadMode_Manual)
     {
-        IM_ASSERT(manual_gamepads_array != nullptr && manual_gamepads_count > 0);
+        IM_ASSERT(manual_gamepads_array != nullptr || manual_gamepads_count <= 0);
         for (int n = 0; n < manual_gamepads_count; n++)
             bd->Gamepads.push_back(manual_gamepads_array[n]);
     }
@@ -755,6 +881,43 @@ static void ImGui_ImplSDL2_UpdateGamepads()
     ImGui_ImplSDL2_UpdateGamepadAnalog(bd, io, ImGuiKey_GamepadRStickDown,  SDL_CONTROLLER_AXIS_RIGHTY, +thumb_dead_zone, +32767);
 }
 
+// FIXME: Note that doesn't update with DPI/Scaling change only as SDL2 doesn't have an event for it (SDL3 has).
+static void ImGui_ImplSDL2_UpdateMonitors()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Monitors.resize(0);
+    int display_count = SDL_GetNumVideoDisplays();
+    for (int n = 0; n < display_count; n++)
+    {
+        // Warning: the validity of monitor DPI information on Windows depends on the application DPI awareness settings, which generally needs to be set in the manifest or at runtime.
+        ImGuiPlatformMonitor monitor;
+        SDL_Rect r;
+        SDL_GetDisplayBounds(n, &r);
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+#if SDL_HAS_USABLE_DISPLAY_BOUNDS
+        if (SDL_GetDisplayUsableBounds(n, &r) == 0 && r.w > 0 && r.h > 0)
+        {
+            monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+            monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+        }
+#endif
+#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))
+        {
+            if (dpi <= 0.0f)
+                continue; // Some accessibility applications are declaring virtual monitors with a DPI of 0, see #7902.
+            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();
@@ -779,6 +942,9 @@ void ImGui_ImplSDL2_NewFrame()
     if (w > 0 && h > 0)
         io.DisplayFramebufferScale = ImVec2((float)display_w / w, (float)display_h / h);
 
+    // Update monitors
+    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();
@@ -795,6 +961,13 @@ void ImGui_ImplSDL2_NewFrame()
         io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
     }
 
+    // Our io.AddMouseViewportEvent() calls will only be valid when not capturing.
+    // Technically speaking testing for 'bd->MouseButtonsDown == 0' would be more rigorous, but testing for payload reduces noise and potential side-effects.
+    if (bd->MouseCanReportHoveredViewport && ImGui::GetDragDropPayload() == nullptr)
+        io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport;
+    else
+        io.BackendFlags &= ~ImGuiBackendFlags_HasMouseHoveredViewport;
+
     ImGui_ImplSDL2_UpdateMouseData();
     ImGui_ImplSDL2_UpdateMouseCursor();
 
@@ -802,6 +975,256 @@ void ImGui_ImplSDL2_NewFrame()
     ImGui_ImplSDL2_UpdateGamepads();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* PlatformUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplSDL2_ViewportData
+{
+    SDL_Window*     Window;
+    Uint32          WindowID;       // Stored in ImGuiViewport::PlatformHandle. Use SDL_GetWindowFromID() to get SDL_Window* from Uint32 WindowID.
+    bool            WindowOwned;
+    SDL_GLContext   GLContext;
+
+    ImGui_ImplSDL2_ViewportData()   { Window = nullptr; WindowID = 0; WindowOwned = false; GLContext = nullptr; }
+    ~ImGui_ImplSDL2_ViewportData()  { IM_ASSERT(Window == nullptr && GLContext == nullptr); }
+};
+
+static void ImGui_ImplSDL2_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
+    ImGui_ImplSDL2_ViewportData* vd = IM_NEW(ImGui_ImplSDL2_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL2_ViewportData* main_viewport_data = (ImGui_ImplSDL2_ViewportData*)main_viewport->PlatformUserData;
+
+    // Share GL resources with main context
+    bool use_opengl = (main_viewport_data->GLContext != nullptr);
+    SDL_GLContext backup_context = nullptr;
+    if (use_opengl)
+    {
+        backup_context = SDL_GL_GetCurrentContext();
+        SDL_GL_SetAttribute(SDL_GL_SHARE_WITH_CURRENT_CONTEXT, 1);
+        SDL_GL_MakeCurrent(main_viewport_data->Window, main_viewport_data->GLContext);
+    }
+
+    Uint32 sdl_flags = 0;
+    sdl_flags |= use_opengl ? SDL_WINDOW_OPENGL : (bd->UseVulkan ? SDL_WINDOW_VULKAN : 0);
+    sdl_flags |= SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_ALLOW_HIGHDPI;
+    sdl_flags |= SDL_WINDOW_HIDDEN;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? SDL_WINDOW_BORDERLESS : 0;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? 0 : SDL_WINDOW_RESIZABLE;
+#if !defined(_WIN32)
+    // See SDL hack in ImGui_ImplSDL2_ShowWindow().
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon) ? SDL_WINDOW_SKIP_TASKBAR : 0;
+#endif
+#if SDL_HAS_ALWAYS_ON_TOP
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_TopMost) ? SDL_WINDOW_ALWAYS_ON_TOP : 0;
+#endif
+    vd->Window = SDL_CreateWindow("No Title Yet", (int)viewport->Pos.x, (int)viewport->Pos.y, (int)viewport->Size.x, (int)viewport->Size.y, sdl_flags);
+    vd->WindowOwned = true;
+    if (use_opengl)
+    {
+        vd->GLContext = SDL_GL_CreateContext(vd->Window);
+        SDL_GL_SetSwapInterval(0);
+    }
+    if (use_opengl && backup_context)
+        SDL_GL_MakeCurrent(vd->Window, backup_context);
+
+    viewport->PlatformHandle = (void*)(intptr_t)SDL_GetWindowID(vd->Window);
+    viewport->PlatformHandleRaw = nullptr;
+    SDL_SysWMinfo info;
+    SDL_VERSION(&info.version);
+    if (SDL_GetWindowWMInfo(vd->Window, &info))
+    {
+#if defined(SDL_VIDEO_DRIVER_WINDOWS)
+        viewport->PlatformHandleRaw = info.info.win.window;
+#elif defined(__APPLE__) && defined(SDL_VIDEO_DRIVER_COCOA)
+        viewport->PlatformHandleRaw = (void*)info.info.cocoa.window;
+#endif
+    }
+}
+
+static void ImGui_ImplSDL2_DestroyWindow(ImGuiViewport* viewport)
+{
+    if (ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData)
+    {
+        if (vd->GLContext && vd->WindowOwned)
+            SDL_GL_DeleteContext(vd->GLContext);
+        if (vd->Window && vd->WindowOwned)
+            SDL_DestroyWindow(vd->Window);
+        vd->GLContext = nullptr;
+        vd->Window = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplSDL2_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+#if defined(_WIN32) && !(defined(WINAPI_FAMILY) && (WINAPI_FAMILY == WINAPI_FAMILY_APP || WINAPI_FAMILY == WINAPI_FAMILY_GAMES))
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+
+    // SDL hack: Hide icon from task bar
+    // Note: SDL 2.0.6+ has a SDL_WINDOW_SKIP_TASKBAR flag which is supported under Windows but the way it create the window breaks our seamless transition.
+    if (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon)
+    {
+        LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
+        ex_style &= ~WS_EX_APPWINDOW;
+        ex_style |= WS_EX_TOOLWINDOW;
+        ::SetWindowLong(hwnd, GWL_EXSTYLE, ex_style);
+    }
+#endif
+
+#if SDL_HAS_SHOW_WINDOW_ACTIVATION_HINT
+    SDL_SetHint(SDL_HINT_WINDOW_NO_ACTIVATION_WHEN_SHOWN, (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing) ? "1" : "0");
+#elif defined(_WIN32)
+    // SDL hack: SDL always activate/focus windows :/
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+    {
+        ::ShowWindow(hwnd, SW_SHOWNA);
+        return;
+    }
+#endif
+    SDL_ShowWindow(vd->Window);
+}
+
+static ImVec2 ImGui_ImplSDL2_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    int x = 0, y = 0;
+    SDL_GetWindowPosition(vd->Window, &x, &y);
+    return ImVec2((float)x, (float)y);
+}
+
+static void ImGui_ImplSDL2_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowPosition(vd->Window, (int)pos.x, (int)pos.y);
+}
+
+static ImVec2 ImGui_ImplSDL2_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    int w = 0, h = 0;
+    SDL_GetWindowSize(vd->Window, &w, &h);
+    return ImVec2((float)w, (float)h);
+}
+
+static void ImGui_ImplSDL2_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowSize(vd->Window, (int)size.x, (int)size.y);
+}
+
+static void ImGui_ImplSDL2_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowTitle(vd->Window, title);
+}
+
+#if SDL_HAS_WINDOW_ALPHA
+static void ImGui_ImplSDL2_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowOpacity(vd->Window, alpha);
+}
+#endif
+
+static void ImGui_ImplSDL2_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_RaiseWindow(vd->Window);
+}
+
+static bool ImGui_ImplSDL2_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    return (SDL_GetWindowFlags(vd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0;
+}
+
+static bool ImGui_ImplSDL2_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    return (SDL_GetWindowFlags(vd->Window) & SDL_WINDOW_MINIMIZED) != 0;
+}
+
+static void ImGui_ImplSDL2_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    if (vd->GLContext)
+        SDL_GL_MakeCurrent(vd->Window, vd->GLContext);
+}
+
+static void ImGui_ImplSDL2_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    if (vd->GLContext)
+    {
+        SDL_GL_MakeCurrent(vd->Window, vd->GLContext);
+        SDL_GL_SwapWindow(vd->Window);
+    }
+}
+
+// Vulkan support (the Vulkan renderer needs to call a platform-side support function to create the surface)
+// SDL is graceful enough to _not_ need <vulkan/vulkan.h> so we can safely include this.
+#if SDL_HAS_VULKAN
+#include <SDL_vulkan.h>
+static int ImGui_ImplSDL2_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_instance, const void* vk_allocator, ImU64* out_vk_surface)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    (void)vk_allocator;
+    SDL_bool ret = SDL_Vulkan_CreateSurface(vd->Window, (VkInstance)vk_instance, (VkSurfaceKHR*)out_vk_surface);
+    return ret ? 0 : 1; // ret ? VK_SUCCESS : VK_NOT_READY
+}
+#endif // SDL_HAS_VULKAN
+
+static void ImGui_ImplSDL2_InitMultiViewportSupport(SDL_Window* window, void* sdl_gl_context)
+{
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplSDL2_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplSDL2_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplSDL2_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplSDL2_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplSDL2_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplSDL2_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplSDL2_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplSDL2_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplSDL2_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplSDL2_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplSDL2_SetWindowTitle;
+    platform_io.Platform_RenderWindow = ImGui_ImplSDL2_RenderWindow;
+    platform_io.Platform_SwapBuffers = ImGui_ImplSDL2_SwapBuffers;
+#if SDL_HAS_WINDOW_ALPHA
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplSDL2_SetWindowAlpha;
+#endif
+#if SDL_HAS_VULKAN
+    platform_io.Platform_CreateVkSurface = ImGui_ImplSDL2_CreateVkSurface;
+#endif
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL2_ViewportData* vd = IM_NEW(ImGui_ImplSDL2_ViewportData)();
+    vd->Window = window;
+    vd->WindowID = SDL_GetWindowID(window);
+    vd->WindowOwned = false;
+    vd->GLContext = sdl_gl_context;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = (void*)(intptr_t)vd->WindowID;
+}
+
+static void ImGui_ImplSDL2_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_sdl2.h

@@ -9,6 +9,10 @@
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
 //  [X] Platform: Basic IME support. App needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// Missing features or Issues:
+//  [ ] Platform: Multi-viewport: Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [ ] Platform: Multi-viewport: 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.

backends/imgui_impl_sdl3.cpp

@@ -1,16 +1,17 @@
-// dear imgui: Platform Backend for SDL3 (*EXPERIMENTAL*)
-// This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)
+// dear imgui: Platform Backend for SDL3
+// This needs to be used along with a Renderer (e.g. SDL_GPU, DirectX11, OpenGL3, Vulkan..)
 // (Info: SDL3 is a cross-platform general purpose library for handling windows, inputs, graphics context creation, etc.)
 
-// (**IMPORTANT: SDL 3.0.0 is NOT YET RELEASED AND CURRENTLY HAS A FAST CHANGING API. THIS CODE BREAKS OFTEN AS SDL3 CHANGES.**)
-
 // Implemented features:
 //  [X] Platform: Clipboard support.
 //  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen.
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy SDL_SCANCODE_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
-//  [X] Platform: IME support.
+//  [x] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable' -> the OS animation effect when window gets created/destroyed is problematic. SDL2 backend doesn't have issue.
+// Missing features or Issues:
+//  [ ] Platform: Multi-viewport: Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [x] Platform: IME support. Position somehow broken in SDL3 + app needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -22,7 +23,17 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-03-10: When dealing with OEM keys, use scancodes instead of translated keycodes to choose ImGuiKey values. (#7136, #7201, #7206, #7306, #7670, #7672, #8468)
+//  2025-02-26: Only start SDL_CaptureMouse() when mouse is being dragged, to mitigate issues with e.g.Linux debuggers not claiming capture back. (#6410, #3650)
+//  2025-02-25: [Docking] Revert to use SDL_GetDisplayBounds() for WorkPos/WorkRect if SDL_GetDisplayUsableBounds() failed.
+//  2025-02-24: Avoid calling SDL_GetGlobalMouseState() when mouse is in relative mode.
+//  2025-02-21: [Docking] Update monitors and work areas information every frame, as the later may change regardless of monitor changes. (#8415)
+//  2025-02-18: Added ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress mouse cursor support.
+//  2025-02-10: Using SDL_OpenURL() in platform_io.Platform_OpenInShellFn handler.
+//  2025-01-20: Made ImGui_ImplSDL3_SetGamepadMode(ImGui_ImplSDL3_GamepadMode_Manual) accept an empty array.
 //  2024-10-24: Emscripten: SDL_EVENT_MOUSE_WHEEL event doesn't require dividing by 100.0f on Emscripten.
+//  2024-09-11: (Docking) Added support for viewport->ParentViewportId field to support parenting at OS level. (#7973)
 //  2024-09-03: Update for SDL3 api changes: SDL_GetGamepads() memory ownership revert. (#7918, #7898, #7807)
 //  2024-08-22: moved some OS/backend related function pointers from ImGuiIO to ImGuiPlatformIO:
 //               - io.GetClipboardTextFn    -> platform_io.Platform_GetClipboardTextFn
@@ -93,6 +104,7 @@ struct ImGui_ImplSDL3_Data
     SDL_Renderer*           Renderer;
     Uint64                  Time;
     char*                   ClipboardTextData;
+    bool                    UseVulkan;
 
     // IME handling
     SDL_Window*             ImeWindow;
@@ -104,11 +116,12 @@ struct ImGui_ImplSDL3_Data
     SDL_Cursor*             MouseLastCursor;
     int                     MousePendingLeaveFrame;
     bool                    MouseCanUseGlobalState;
+    bool                    MouseCanReportHoveredViewport;  // This is hard to use/unreliable on SDL so we'll set ImGuiBackendFlags_HasMouseHoveredViewport dynamically based on state.
 
     // Gamepad handling
-    ImVector<SDL_Gamepad*>      Gamepads;
+    ImVector<SDL_Gamepad*>  Gamepads;
     ImGui_ImplSDL3_GamepadMode  GamepadMode;
-    bool                        WantUpdateGamepadsList;
+    bool                    WantUpdateGamepadsList;
 
     ImGui_ImplSDL3_Data()   { memset((void*)this, 0, sizeof(*this)); }
 };
@@ -122,6 +135,11 @@ static ImGui_ImplSDL3_Data* ImGui_ImplSDL3_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplSDL3_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplSDL3_UpdateMonitors();
+static void ImGui_ImplSDL3_InitMultiViewportSupport(SDL_Window* window, void* sdl_gl_context);
+static void ImGui_ImplSDL3_ShutdownMultiViewportSupport();
+
 // Functions
 static const char* ImGui_ImplSDL3_GetClipboardText(ImGuiContext*)
 {
@@ -151,8 +169,8 @@ static void ImGui_ImplSDL3_PlatformSetImeData(ImGuiContext*, ImGuiViewport* view
     if (data->WantVisible)
     {
         SDL_Rect r;
-        r.x = (int)data->InputPos.x;
-        r.y = (int)data->InputPos.y;
+        r.x = (int)(data->InputPos.x - viewport->Pos.x);
+        r.y = (int)(data->InputPos.y - viewport->Pos.y + data->InputLineHeight);
         r.w = 1;
         r.h = (int)data->InputLineHeight;
         SDL_SetTextInputArea(window, &r, 0);
@@ -204,17 +222,17 @@ ImGuiKey ImGui_ImplSDL3_KeyEventToImGuiKey(SDL_Keycode keycode, SDL_Scancode sca
         case SDLK_SPACE: return ImGuiKey_Space;
         case SDLK_RETURN: return ImGuiKey_Enter;
         case SDLK_ESCAPE: return ImGuiKey_Escape;
-        case SDLK_APOSTROPHE: return ImGuiKey_Apostrophe;
+        //case SDLK_APOSTROPHE: return ImGuiKey_Apostrophe;
         case SDLK_COMMA: return ImGuiKey_Comma;
-        case SDLK_MINUS: return ImGuiKey_Minus;
+        //case SDLK_MINUS: return ImGuiKey_Minus;
         case SDLK_PERIOD: return ImGuiKey_Period;
-        case SDLK_SLASH: return ImGuiKey_Slash;
+        //case SDLK_SLASH: return ImGuiKey_Slash;
         case SDLK_SEMICOLON: return ImGuiKey_Semicolon;
-        case SDLK_EQUALS: return ImGuiKey_Equal;
-        case SDLK_LEFTBRACKET: return ImGuiKey_LeftBracket;
-        case SDLK_BACKSLASH: return ImGuiKey_Backslash;
-        case SDLK_RIGHTBRACKET: return ImGuiKey_RightBracket;
-        case SDLK_GRAVE: return ImGuiKey_GraveAccent;
+        //case SDLK_EQUALS: return ImGuiKey_Equal;
+        //case SDLK_LEFTBRACKET: return ImGuiKey_LeftBracket;
+        //case SDLK_BACKSLASH: return ImGuiKey_Backslash;
+        //case SDLK_RIGHTBRACKET: return ImGuiKey_RightBracket;
+        //case SDLK_GRAVE: return ImGuiKey_GraveAccent;
         case SDLK_CAPSLOCK: return ImGuiKey_CapsLock;
         case SDLK_SCROLLLOCK: return ImGuiKey_ScrollLock;
         case SDLK_NUMLOCKCLEAR: return ImGuiKey_NumLock;
@@ -293,6 +311,24 @@ ImGuiKey ImGui_ImplSDL3_KeyEventToImGuiKey(SDL_Keycode keycode, SDL_Scancode sca
         case SDLK_AC_FORWARD: return ImGuiKey_AppForward;
         default: break;
     }
+
+    // Fallback to scancode
+    switch (scancode)
+    {
+    case SDL_SCANCODE_GRAVE: return ImGuiKey_GraveAccent;
+    case SDL_SCANCODE_MINUS: return ImGuiKey_Minus;
+    case SDL_SCANCODE_EQUALS: return ImGuiKey_Equal;
+    case SDL_SCANCODE_LEFTBRACKET: return ImGuiKey_LeftBracket;
+    case SDL_SCANCODE_RIGHTBRACKET: return ImGuiKey_RightBracket;
+    case SDL_SCANCODE_NONUSBACKSLASH: return ImGuiKey_Oem102;
+    case SDL_SCANCODE_BACKSLASH: return ImGuiKey_Backslash;
+    case SDL_SCANCODE_SEMICOLON: return ImGuiKey_Semicolon;
+    case SDL_SCANCODE_APOSTROPHE: return ImGuiKey_Apostrophe;
+    case SDL_SCANCODE_COMMA: return ImGuiKey_Comma;
+    case SDL_SCANCODE_PERIOD: return ImGuiKey_Period;
+    case SDL_SCANCODE_SLASH: return ImGuiKey_Slash;
+    default: break;
+    }
     return ImGuiKey_None;
 }
 
@@ -305,18 +341,15 @@ static void ImGui_ImplSDL3_UpdateKeyModifiers(SDL_Keymod sdl_key_mods)
     io.AddKeyEvent(ImGuiMod_Super, (sdl_key_mods & SDL_KMOD_GUI) != 0);
 }
 
-
 static ImGuiViewport* ImGui_ImplSDL3_GetViewportForWindowID(SDL_WindowID window_id)
 {
-    ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
-    return (window_id == bd->WindowID) ? ImGui::GetMainViewport() : nullptr;
+    return ImGui::FindViewportByPlatformHandle((void*)(intptr_t)window_id);
 }
 
 // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
 // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
-// If you have multiple SDL events and some of them are not meant to be used by dear imgui, you may need to filter events based on their windowID field.
 bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
 {
     ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
@@ -330,6 +363,13 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
             if (ImGui_ImplSDL3_GetViewportForWindowID(event->motion.windowID) == nullptr)
                 return false;
             ImVec2 mouse_pos((float)event->motion.x, (float)event->motion.y);
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                int window_x, window_y;
+                SDL_GetWindowPosition(SDL_GetWindowFromID(event->motion.windowID), &window_x, &window_y);
+                mouse_pos.x += window_x;
+                mouse_pos.y += window_y;
+            }
             io.AddMouseSourceEvent(event->motion.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMousePosEvent(mouse_pos.x, mouse_pos.y);
             return true;
@@ -410,6 +450,21 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
             io.AddFocusEvent(event->type == SDL_EVENT_WINDOW_FOCUS_GAINED);
             return true;
         }
+        case SDL_EVENT_WINDOW_CLOSE_REQUESTED:
+        case SDL_EVENT_WINDOW_MOVED:
+        case SDL_EVENT_WINDOW_RESIZED:
+        {
+            ImGuiViewport* viewport = ImGui_ImplSDL3_GetViewportForWindowID(event->window.windowID);
+            if (viewport == NULL)
+                return false;
+            if (event->type == SDL_EVENT_WINDOW_CLOSE_REQUESTED)
+                viewport->PlatformRequestClose = true;
+            if (event->type == SDL_EVENT_WINDOW_MOVED)
+                viewport->PlatformRequestMove = true;
+            if (event->type == SDL_EVENT_WINDOW_RESIZED)
+                viewport->PlatformRequestResize = true;
+            return true;
+        }
         case SDL_EVENT_GAMEPAD_ADDED:
         case SDL_EVENT_GAMEPAD_REMOVED:
         {
@@ -455,16 +510,30 @@ 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->WindowID = SDL_GetWindowID(window);
     bd->Renderer = renderer;
+
+    // SDL on Linux/OSX doesn't report events for unfocused windows (see https://github.com/ocornut/imgui/issues/4960)
+    // We will use 'MouseCanReportHoveredViewport' to set 'ImGuiBackendFlags_HasMouseHoveredViewport' dynamically each frame.
     bd->MouseCanUseGlobalState = mouse_can_use_global_state;
+#ifndef __APPLE__
+    bd->MouseCanReportHoveredViewport = bd->MouseCanUseGlobalState;
+#else
+    bd->MouseCanReportHoveredViewport = false;
+#endif
 
     ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
     platform_io.Platform_SetClipboardTextFn = ImGui_ImplSDL3_SetClipboardText;
     platform_io.Platform_GetClipboardTextFn = ImGui_ImplSDL3_GetClipboardText;
     platform_io.Platform_SetImeDataFn = ImGui_ImplSDL3_PlatformSetImeData;
+    platform_io.Platform_OpenInShellFn = [](ImGuiContext*, const char* url) { return SDL_OpenURL(url) == 0; };
+
+    // Update monitor a first time during init
+    ImGui_ImplSDL3_UpdateMonitors();
 
     // Gamepad handling
     bd->GamepadMode = ImGui_ImplSDL3_GamepadMode_AutoFirst;
@@ -479,6 +548,8 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void
     bd->MouseCursors[ImGuiMouseCursor_ResizeNESW] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_NESW_RESIZE);
     bd->MouseCursors[ImGuiMouseCursor_ResizeNWSE] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_NWSE_RESIZE);
     bd->MouseCursors[ImGuiMouseCursor_Hand] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_POINTER);
+    bd->MouseCursors[ImGuiMouseCursor_Wait] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_WAIT);
+    bd->MouseCursors[ImGuiMouseCursor_Progress] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_PROGRESS);
     bd->MouseCursors[ImGuiMouseCursor_NotAllowed] = SDL_CreateSystemCursor(SDL_SYSTEM_CURSOR_NOT_ALLOWED);
 
     // Set platform dependent data in viewport
@@ -491,27 +562,35 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void
     // (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.BackendFlags & ImGuiBackendFlags_PlatformHasViewports)
+        ImGui_ImplSDL3_InitMultiViewportSupport(window, sdl_gl_context);
 
     return true;
 }
 
+// Should technically be a SDL_GLContext but due to typedef it is sane to keep it void* in public interface.
 bool ImGui_ImplSDL3_InitForOpenGL(SDL_Window* window, void* sdl_gl_context)
 {
-    IM_UNUSED(sdl_gl_context); // Viewport branch will need this.
     return ImGui_ImplSDL3_Init(window, nullptr, sdl_gl_context);
 }
 
 bool ImGui_ImplSDL3_InitForVulkan(SDL_Window* window)
 {
-    return ImGui_ImplSDL3_Init(window, nullptr, nullptr);
+    if (!ImGui_ImplSDL3_Init(window, nullptr, nullptr))
+        return false;
+    ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
+    bd->UseVulkan = true;
+    return true;
 }
 
 bool ImGui_ImplSDL3_InitForD3D(SDL_Window* window)
@@ -550,6 +629,8 @@ void ImGui_ImplSDL3_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplSDL3_ShutdownMultiViewportSupport();
+
     if (bd->ClipboardTextData)
         SDL_free(bd->ClipboardTextData);
     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
@@ -558,10 +639,11 @@ 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();
@@ -569,10 +651,16 @@ static void ImGui_ImplSDL3_UpdateMouseData()
 
     // We forward mouse input when hovered or captured (via SDL_EVENT_MOUSE_MOTION) or when focused (below)
 #if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
-    // 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_CaptureMouse() let the OS know e.g. that our drags can extend outside of parent boundaries (we want updated position) and shouldn't trigger other operations outside.
+    // - Debuggers under Linux tends to leave captured mouse on break, which may be very inconvenient, so to migitate the issue we wait until mouse has moved to begin capture.
+    bool want_capture = false;
+    for (int button_n = 0; button_n < ImGuiMouseButton_COUNT && !want_capture; button_n++)
+        if (ImGui::IsMouseDragging(button_n, 1.0f))
+            want_capture = true;
+    SDL_CaptureMouse(want_capture);
+
     SDL_Window* focused_window = SDL_GetKeyboardFocus();
-    const bool is_app_focused = (bd->Window == focused_window);
+    const bool is_app_focused = (focused_window && (bd->Window == focused_window || ImGui_ImplSDL3_GetViewportForWindowID(SDL_GetWindowID(focused_window)) != NULL));
 #else
     SDL_Window* focused_window = bd->Window;
     const bool is_app_focused = (SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0; // SDL 2.0.3 and non-windowed systems: single-viewport only
@@ -581,19 +669,48 @@ static void ImGui_ImplSDL3_UpdateMouseData()
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when io.ConfigNavMoveSetMousePos is enabled by user)
         if (io.WantSetMousePos)
-            SDL_WarpMouseInWindow(bd->Window, io.MousePos.x, io.MousePos.y);
+        {
+#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+                SDL_WarpMouseGlobal(io.MousePos.x, io.MousePos.y);
+            else
+#endif
+                SDL_WarpMouseInWindow(bd->Window, io.MousePos.x, io.MousePos.y);
+        }
 
         // (Optional) Fallback to provide mouse position when focused (SDL_EVENT_MOUSE_MOTION already provides this when hovered or captured)
-        if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0)
+        const bool is_relative_mouse_mode = SDL_GetWindowRelativeMouseMode(bd->Window);
+        if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0 && !is_relative_mouse_mode)
         {
             // Single-viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
-            float mouse_x_global, mouse_y_global;
+            // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+            float mouse_x, mouse_y;
             int window_x, window_y;
-            SDL_GetGlobalMouseState(&mouse_x_global, &mouse_y_global);
-            SDL_GetWindowPosition(focused_window, &window_x, &window_y);
-            io.AddMousePosEvent(mouse_x_global - window_x, mouse_y_global - window_y);
+            SDL_GetGlobalMouseState(&mouse_x, &mouse_y);
+            if (!(io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable))
+            {
+                SDL_GetWindowPosition(focused_window, &window_x, &window_y);
+                mouse_x -= window_x;
+                mouse_y -= window_y;
+            }
+            io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
         }
     }
+
+    // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+    // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+    // - [!] SDL backend does NOT correctly ignore viewports with the _NoInputs flag.
+    //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+    //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+    //       by the backend, and use its flawed heuristic to guess the viewport behind.
+    // - [X] SDL backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+    if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)
+    {
+        ImGuiID mouse_viewport_id = 0;
+        if (ImGuiViewport* mouse_viewport = ImGui_ImplSDL3_GetViewportForWindowID(bd->MouseWindowID))
+            mouse_viewport_id = mouse_viewport->ID;
+        io.AddMouseViewportEvent(mouse_viewport_id);
+    }
 }
 
 static void ImGui_ImplSDL3_UpdateMouseCursor()
@@ -637,7 +754,7 @@ void ImGui_ImplSDL3_SetGamepadMode(ImGui_ImplSDL3_GamepadMode mode, SDL_Gamepad*
     ImGui_ImplSDL3_CloseGamepads();
     if (mode == ImGui_ImplSDL3_GamepadMode_Manual)
     {
-        IM_ASSERT(manual_gamepads_array != nullptr && manual_gamepads_count > 0);
+        IM_ASSERT(manual_gamepads_array != nullptr || manual_gamepads_count <= 0);
         for (int n = 0; n < manual_gamepads_count; n++)
             bd->Gamepads.push_back(manual_gamepads_array[n]);
     }
@@ -728,6 +845,38 @@ static void ImGui_ImplSDL3_UpdateGamepads()
     ImGui_ImplSDL3_UpdateGamepadAnalog(bd, io, ImGuiKey_GamepadRStickDown,  SDL_GAMEPAD_AXIS_RIGHTY, +thumb_dead_zone, +32767);
 }
 
+static void ImGui_ImplSDL3_UpdateMonitors()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Monitors.resize(0);
+
+    int display_count;
+    SDL_DisplayID* displays = SDL_GetDisplays(&display_count);
+    for (int n = 0; n < display_count; n++)
+    {
+        // Warning: the validity of monitor DPI information on Windows depends on the application DPI awareness settings, which generally needs to be set in the manifest or at runtime.
+        SDL_DisplayID display_id = displays[n];
+        ImGuiPlatformMonitor monitor;
+        SDL_Rect r;
+        SDL_GetDisplayBounds(display_id, &r);
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+        if (SDL_GetDisplayUsableBounds(display_id, &r) && r.w > 0 && r.h > 0)
+        {
+            monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+            monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+        }
+        // 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;
+        if (monitor.DpiScale <= 0.0f)
+            continue; // Some accessibility applications are declaring virtual monitors with a DPI of 0, see #7902.
+        platform_io.Monitors.push_back(monitor);
+    }
+    SDL_free(displays);
+}
+
 void ImGui_ImplSDL3_NewFrame()
 {
     ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
@@ -745,6 +894,9 @@ void ImGui_ImplSDL3_NewFrame()
     if (w > 0 && h > 0)
         io.DisplayFramebufferScale = ImVec2((float)display_w / w, (float)display_h / h);
 
+    // Update monitors
+    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();
@@ -761,6 +913,13 @@ void ImGui_ImplSDL3_NewFrame()
         io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
     }
 
+    // Our io.AddMouseViewportEvent() calls will only be valid when not capturing.
+    // Technically speaking testing for 'bd->MouseButtonsDown == 0' would be more rigorous, but testing for payload reduces noise and potential side-effects.
+    if (bd->MouseCanReportHoveredViewport && ImGui::GetDragDropPayload() == nullptr)
+        io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport;
+    else
+        io.BackendFlags &= ~ImGuiBackendFlags_HasMouseHoveredViewport;
+
     ImGui_ImplSDL3_UpdateMouseData();
     ImGui_ImplSDL3_UpdateMouseCursor();
 
@@ -768,6 +927,255 @@ void ImGui_ImplSDL3_NewFrame()
     ImGui_ImplSDL3_UpdateGamepads();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* PlatformUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplSDL3_ViewportData
+{
+    SDL_Window*     Window;
+    SDL_Window*     ParentWindow;
+    Uint32          WindowID;       // Stored in ImGuiViewport::PlatformHandle. Use SDL_GetWindowFromID() to get SDL_Window* from Uint32 WindowID.
+    bool            WindowOwned;
+    SDL_GLContext   GLContext;
+
+    ImGui_ImplSDL3_ViewportData()   { Window = ParentWindow = nullptr; WindowID = 0; WindowOwned = false; GLContext = nullptr; }
+    ~ImGui_ImplSDL3_ViewportData()  { IM_ASSERT(Window == nullptr && GLContext == nullptr); }
+};
+
+static SDL_Window* ImGui_ImplSDL3_GetSDLWindowFromViewportID(ImGuiID viewport_id)
+{
+    if (viewport_id != 0)
+        if (ImGuiViewport* viewport = ImGui::FindViewportByID(viewport_id))
+        {
+            SDL_WindowID window_id = (SDL_WindowID)(intptr_t)viewport->PlatformHandle;
+            return SDL_GetWindowFromID(window_id);
+        }
+    return nullptr;
+}
+
+static void ImGui_ImplSDL3_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
+    ImGui_ImplSDL3_ViewportData* vd = IM_NEW(ImGui_ImplSDL3_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    vd->ParentWindow = ImGui_ImplSDL3_GetSDLWindowFromViewportID(viewport->ParentViewportId);
+
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL3_ViewportData* main_viewport_data = (ImGui_ImplSDL3_ViewportData*)main_viewport->PlatformUserData;
+
+    // Share GL resources with main context
+    bool use_opengl = (main_viewport_data->GLContext != nullptr);
+    SDL_GLContext backup_context = nullptr;
+    if (use_opengl)
+    {
+        backup_context = SDL_GL_GetCurrentContext();
+        SDL_GL_SetAttribute(SDL_GL_SHARE_WITH_CURRENT_CONTEXT, 1);
+        SDL_GL_MakeCurrent(main_viewport_data->Window, main_viewport_data->GLContext);
+    }
+
+    SDL_WindowFlags sdl_flags = 0;
+    sdl_flags |= SDL_WINDOW_HIDDEN;
+    sdl_flags |= use_opengl ? SDL_WINDOW_OPENGL : (bd->UseVulkan ? SDL_WINDOW_VULKAN : 0);
+    sdl_flags |= SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_HIGH_PIXEL_DENSITY;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? SDL_WINDOW_BORDERLESS : 0;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? 0 : SDL_WINDOW_RESIZABLE;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon) ? SDL_WINDOW_UTILITY : 0;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_TopMost) ? SDL_WINDOW_ALWAYS_ON_TOP : 0;
+    vd->Window = SDL_CreateWindow("No Title Yet", (int)viewport->Size.x, (int)viewport->Size.y, sdl_flags);
+    SDL_SetWindowParent(vd->Window, vd->ParentWindow);
+    SDL_SetWindowPosition(vd->Window, (int)viewport->Pos.x, (int)viewport->Pos.y);
+    vd->WindowOwned = true;
+    if (use_opengl)
+    {
+        vd->GLContext = SDL_GL_CreateContext(vd->Window);
+        SDL_GL_SetSwapInterval(0);
+    }
+    if (use_opengl && backup_context)
+        SDL_GL_MakeCurrent(vd->Window, backup_context);
+
+    ImGui_ImplSDL3_SetupPlatformHandles(viewport, vd->Window);
+}
+
+static void ImGui_ImplSDL3_DestroyWindow(ImGuiViewport* viewport)
+{
+    if (ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData)
+    {
+        if (vd->GLContext && vd->WindowOwned)
+            SDL_GL_DestroyContext(vd->GLContext);
+        if (vd->Window && vd->WindowOwned)
+            SDL_DestroyWindow(vd->Window);
+        vd->GLContext = nullptr;
+        vd->Window = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplSDL3_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+#if defined(_WIN32) && !(defined(WINAPI_FAMILY) && (WINAPI_FAMILY == WINAPI_FAMILY_APP || WINAPI_FAMILY == WINAPI_FAMILY_GAMES))
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+
+    // SDL hack: Show icon in task bar (#7989)
+    // Note: SDL_WINDOW_UTILITY can be used to control task bar visibility, but on Windows, it does not affect child windows.
+    if (!(viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon))
+    {
+        LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
+        ex_style |= WS_EX_APPWINDOW;
+        ex_style &= ~WS_EX_TOOLWINDOW;
+        ::ShowWindow(hwnd, SW_HIDE);
+        ::SetWindowLong(hwnd, GWL_EXSTYLE, ex_style);
+    }
+#endif
+
+    SDL_SetHint(SDL_HINT_WINDOW_ACTIVATE_WHEN_SHOWN, (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing) ? "0" : "1");
+    SDL_ShowWindow(vd->Window);
+}
+
+static void ImGui_ImplSDL3_UpdateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+
+    // Update SDL3 parent if it changed _after_ creation.
+    // This is for advanced apps that are manipulating ParentViewportID manually.
+    SDL_Window* new_parent = ImGui_ImplSDL3_GetSDLWindowFromViewportID(viewport->ParentViewportId);
+    if (new_parent != vd->ParentWindow)
+    {
+        vd->ParentWindow = new_parent;
+        SDL_SetWindowParent(vd->Window, vd->ParentWindow);
+    }
+}
+
+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;
+    bool ret = SDL_Vulkan_CreateSurface(vd->Window, (VkInstance)vk_instance, (VkAllocationCallbacks*)vk_allocator, (VkSurfaceKHR*)out_vk_surface);
+    return ret ? 0 : 1; // ret ? VK_SUCCESS : VK_NOT_READY
+}
+
+static void ImGui_ImplSDL3_InitMultiViewportSupport(SDL_Window* window, void* sdl_gl_context)
+{
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplSDL3_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplSDL3_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplSDL3_ShowWindow;
+    platform_io.Platform_UpdateWindow = ImGui_ImplSDL3_UpdateWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplSDL3_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplSDL3_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplSDL3_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplSDL3_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplSDL3_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplSDL3_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplSDL3_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplSDL3_SetWindowTitle;
+    platform_io.Platform_RenderWindow = ImGui_ImplSDL3_RenderWindow;
+    platform_io.Platform_SwapBuffers = ImGui_ImplSDL3_SwapBuffers;
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplSDL3_SetWindowAlpha;
+    platform_io.Platform_CreateVkSurface = ImGui_ImplSDL3_CreateVkSurface;
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL3_ViewportData* vd = IM_NEW(ImGui_ImplSDL3_ViewportData)();
+    vd->Window = window;
+    vd->WindowID = SDL_GetWindowID(window);
+    vd->WindowOwned = false;
+    vd->GLContext = (SDL_GLContext)sdl_gl_context;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = (void*)(intptr_t)vd->WindowID;
+}
+
+static void ImGui_ImplSDL3_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #if defined(__clang__)

backends/imgui_impl_sdl3.h

@@ -1,16 +1,17 @@
-// dear imgui: Platform Backend for SDL3 (*EXPERIMENTAL*)
-// This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)
+// dear imgui: Platform Backend for SDL3
+// This needs to be used along with a Renderer (e.g. SDL_GPU, DirectX11, OpenGL3, Vulkan..)
 // (Info: SDL3 is a cross-platform general purpose library for handling windows, inputs, graphics context creation, etc.)
 
-// (**IMPORTANT: SDL 3.0.0 is NOT YET RELEASED AND CURRENTLY HAS A FAST CHANGING API. THIS CODE BREAKS OFTEN AS SDL3 CHANGES.**)
-
 // Implemented features:
 //  [X] Platform: Clipboard support.
 //  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen.
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy SDL_SCANCODE_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
-//  [X] Platform: IME support.
+//  [x] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable' -> the OS animation effect when window gets created/destroyed is problematic. SDL2 backend doesn't have issue.
+// Missing features or Issues:
+//  [ ] Platform: Multi-viewport: Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [x] Platform: IME support. Position somehow broken in SDL3 + app needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_sdlgpu3.cpp

@@ -4,6 +4,8 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use simply cast a reference to your SDL_GPUTextureSamplerBinding to ImTextureID.
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // The aim of imgui_impl_sdlgpu3.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -21,13 +23,16 @@
 //   Calling the function is MANDATORY, otherwise the ImGui will not upload neither the vertex nor the index buffer for the GPU. See imgui_impl_sdlgpu3.cpp for more info.
 
 // CHANGELOG
-//  2025-01-09: SDL_Gpu: Added the SDL_GPU3 backend.
+//  2025-01-16: Renamed ImGui_ImplSDLGPU3_InitInfo::GpuDevice to Device.
+//  2025-01-09: SDL_GPU: Added the SDL_GPU3 backend.
 
 #include "imgui.h"
 #ifndef IMGUI_DISABLE
 #include "imgui_impl_sdlgpu3.h"
 #include "imgui_impl_sdlgpu3_shaders.h"
 
+// SDL_GPU Data
+
 // Reusable buffers used for rendering 1 current in-flight frame, for ImGui_ImplSDLGPU3_RenderDrawData()
 struct ImGui_ImplSDLGPU3_FrameData
 {
@@ -37,10 +42,9 @@ struct ImGui_ImplSDLGPU3_FrameData
     uint32_t            IndexBufferSize  = 0;
 };
 
-// SDL_GPU Data
 struct ImGui_ImplSDLGPU3_Data
 {
-    ImGui_ImplSDLGPU3_InitInfo   GPUInitInfo;
+    ImGui_ImplSDLGPU3_InitInfo   InitInfo;
 
     // Graphics pipeline & shaders
     SDL_GPUShader*               VertexShader   = nullptr;
@@ -57,8 +61,6 @@ struct ImGui_ImplSDLGPU3_Data
 };
 
 // Forward Declarations
-static bool ImGui_ImplSDLGPU3_CreateDeviceObjects();
-static void ImGui_ImplSDLGPU3_DestroyDeviceObjects();
 static void ImGui_ImplSDLGPU3_DestroyFrameData();
 
 //-----------------------------------------------------------------------------
@@ -89,8 +91,8 @@ static void ImGui_ImplSDLGPU3_SetupRenderState(ImDrawData* draw_data, SDL_GPUGra
         SDL_GPUBufferBinding index_buffer_binding = {};
         index_buffer_binding.buffer = fd->IndexBuffer;
         index_buffer_binding.offset = 0;
-        SDL_BindGPUVertexBuffers(render_pass,0,&vertex_buffer_binding,1);
-        SDL_BindGPUIndexBuffer(render_pass,&index_buffer_binding,sizeof(ImDrawIdx) == 2 ? SDL_GPU_INDEXELEMENTSIZE_16BIT : SDL_GPU_INDEXELEMENTSIZE_32BIT);
+        SDL_BindGPUVertexBuffers(render_pass,0, &vertex_buffer_binding, 1);
+        SDL_BindGPUIndexBuffer(render_pass, &index_buffer_binding, sizeof(ImDrawIdx) == 2 ? SDL_GPU_INDEXELEMENTSIZE_16BIT : SDL_GPU_INDEXELEMENTSIZE_32BIT);
     }
 
     // Setup viewport
@@ -101,7 +103,7 @@ static void ImGui_ImplSDLGPU3_SetupRenderState(ImDrawData* draw_data, SDL_GPUGra
     viewport.h = (float)fb_height;
     viewport.min_depth = 0.0f;
     viewport.max_depth = 1.0f;
-    SDL_SetGPUViewport(render_pass,&viewport);
+    SDL_SetGPUViewport(render_pass, &viewport);
 
     // Setup scale and translation
     // Our visible imgui space lies from draw_data->DisplayPps (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayPos is (0,0) for single viewport apps.
@@ -116,16 +118,17 @@ static void ImGui_ImplSDLGPU3_SetupRenderState(ImDrawData* draw_data, SDL_GPUGra
 static void CreateOrResizeBuffer(SDL_GPUBuffer** buffer, uint32_t* old_size, uint32_t new_size, SDL_GPUBufferUsageFlags usage)
 {
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
-    ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
+    ImGui_ImplSDLGPU3_InitInfo* v = &bd->InitInfo;
 
-    SDL_WaitForGPUIdle(v->GpuDevice);
-    SDL_ReleaseGPUBuffer(v->GpuDevice, *buffer);
+    // Even though this is fairly rarely called.
+    SDL_WaitForGPUIdle(v->Device);
+    SDL_ReleaseGPUBuffer(v->Device, *buffer);
 
     SDL_GPUBufferCreateInfo buffer_info = {};
     buffer_info.usage = usage;
     buffer_info.size = new_size;
     buffer_info.props = 0;
-    *buffer = SDL_CreateGPUBuffer(v->GpuDevice, &buffer_info);
+    *buffer = SDL_CreateGPUBuffer(v->Device, &buffer_info);
     *old_size = new_size;
     IM_ASSERT(*buffer != nullptr && "Failed to create GPU Buffer, call SDL_GetError() for more information");
 }
@@ -142,7 +145,7 @@ void Imgui_ImplSDLGPU3_PrepareDrawData(ImDrawData* draw_data, SDL_GPUCommandBuff
         return;
 
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
-    ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
+    ImGui_ImplSDLGPU3_InitInfo* v = &bd->InitInfo;
     ImGui_ImplSDLGPU3_FrameData* fd = &bd->MainWindowFrameData;
 
     uint32_t vertex_size = draw_data->TotalVtxCount * sizeof(ImDrawVert);
@@ -160,13 +163,13 @@ void Imgui_ImplSDLGPU3_PrepareDrawData(ImDrawData* draw_data, SDL_GPUCommandBuff
     index_transferbuffer_info.usage = SDL_GPU_TRANSFERBUFFERUSAGE_UPLOAD;
     index_transferbuffer_info.size = index_size;
 
-    SDL_GPUTransferBuffer* vertex_transferbuffer = SDL_CreateGPUTransferBuffer(v->GpuDevice, &vertex_transferbuffer_info);
+    SDL_GPUTransferBuffer* vertex_transferbuffer = SDL_CreateGPUTransferBuffer(v->Device, &vertex_transferbuffer_info);
     IM_ASSERT(vertex_transferbuffer != nullptr && "Failed to create the vertex transfer buffer, call SDL_GetError() for more information");
-    SDL_GPUTransferBuffer* index_transferbuffer = SDL_CreateGPUTransferBuffer(v->GpuDevice, &index_transferbuffer_info);
+    SDL_GPUTransferBuffer* index_transferbuffer = SDL_CreateGPUTransferBuffer(v->Device, &index_transferbuffer_info);
     IM_ASSERT(index_transferbuffer != nullptr && "Failed to create the index transfer buffer, call SDL_GetError() for more information");
 
-    ImDrawVert* vtx_dst = (ImDrawVert*)SDL_MapGPUTransferBuffer(v->GpuDevice, vertex_transferbuffer, true);
-    ImDrawIdx*  idx_dst = (ImDrawIdx*)SDL_MapGPUTransferBuffer(v->GpuDevice, index_transferbuffer, true);
+    ImDrawVert* vtx_dst = (ImDrawVert*)SDL_MapGPUTransferBuffer(v->Device, vertex_transferbuffer, true);
+    ImDrawIdx*  idx_dst = (ImDrawIdx*)SDL_MapGPUTransferBuffer(v->Device, index_transferbuffer, true);
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* draw_list = draw_data->CmdLists[n];
@@ -175,8 +178,8 @@ void Imgui_ImplSDLGPU3_PrepareDrawData(ImDrawData* draw_data, SDL_GPUCommandBuff
         vtx_dst += draw_list->VtxBuffer.Size;
         idx_dst += draw_list->IdxBuffer.Size;
     }
-    SDL_UnmapGPUTransferBuffer(v->GpuDevice, vertex_transferbuffer);
-    SDL_UnmapGPUTransferBuffer(v->GpuDevice, index_transferbuffer);
+    SDL_UnmapGPUTransferBuffer(v->Device, vertex_transferbuffer);
+    SDL_UnmapGPUTransferBuffer(v->Device, index_transferbuffer);
 
     SDL_GPUTransferBufferLocation vertex_buffer_location = {};
     vertex_buffer_location.offset = 0;
@@ -196,11 +199,11 @@ void Imgui_ImplSDLGPU3_PrepareDrawData(ImDrawData* draw_data, SDL_GPUCommandBuff
     index_buffer_region.size = index_size;
 
     SDL_GPUCopyPass* copy_pass = SDL_BeginGPUCopyPass(command_buffer);
-    SDL_UploadToGPUBuffer(copy_pass, &vertex_buffer_location, &vertex_buffer_region,true);
-    SDL_UploadToGPUBuffer(copy_pass, &index_buffer_location, &index_buffer_region,true);
+    SDL_UploadToGPUBuffer(copy_pass, &vertex_buffer_location, &vertex_buffer_region, true);
+    SDL_UploadToGPUBuffer(copy_pass, &index_buffer_location, &index_buffer_region, true);
     SDL_EndGPUCopyPass(copy_pass);
-    SDL_ReleaseGPUTransferBuffer(v->GpuDevice, index_transferbuffer);
-    SDL_ReleaseGPUTransferBuffer(v->GpuDevice, vertex_transferbuffer);
+    SDL_ReleaseGPUTransferBuffer(v->Device, index_transferbuffer);
+    SDL_ReleaseGPUTransferBuffer(v->Device, vertex_transferbuffer);
 }
 
 void ImGui_ImplSDLGPU3_RenderDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffer* command_buffer, SDL_GPURenderPass* render_pass, SDL_GPUGraphicsPipeline* pipeline)
@@ -278,16 +281,16 @@ void ImGui_ImplSDLGPU3_RenderDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffe
     SDL_SetGPUScissor(render_pass, &scissor_rect);
 }
 
-bool ImGui_ImplSDLGPU3_CreateFontsTexture()
+void ImGui_ImplSDLGPU3_CreateFontsTexture()
 {
     ImGuiIO& io = ImGui::GetIO();
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
-    ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
+    ImGui_ImplSDLGPU3_InitInfo* v = &bd->InitInfo;
 
     // Destroy existing texture (if any)
     if (bd->FontTexture)
     {
-        SDL_WaitForGPUIdle(v->GpuDevice);
+        SDL_WaitForGPUIdle(v->Device);
         ImGui_ImplSDLGPU3_DestroyFontsTexture();
     }
 
@@ -308,7 +311,7 @@ bool ImGui_ImplSDLGPU3_CreateFontsTexture()
         texture_info.num_levels = 1;
         texture_info.sample_count = SDL_GPU_SAMPLECOUNT_1;
 
-        bd->FontTexture = SDL_CreateGPUTexture(v->GpuDevice, &texture_info);
+        bd->FontTexture = SDL_CreateGPUTexture(v->Device, &texture_info);
         IM_ASSERT(bd->FontTexture && "Failed to create font texture, call SDL_GetError() for more info");
     }
 
@@ -317,39 +320,37 @@ bool ImGui_ImplSDLGPU3_CreateFontsTexture()
 
     // Create all the upload structures and upload:
     {
-        SDL_GPUTransferBufferCreateInfo font_transferbuffer_info = {};
-        font_transferbuffer_info.usage = SDL_GPU_TRANSFERBUFFERUSAGE_UPLOAD;
-        font_transferbuffer_info.size = upload_size;
+        SDL_GPUTransferBufferCreateInfo transferbuffer_info = {};
+        transferbuffer_info.usage = SDL_GPU_TRANSFERBUFFERUSAGE_UPLOAD;
+        transferbuffer_info.size = upload_size;
 
-        SDL_GPUTransferBuffer* font_transferbuffer = SDL_CreateGPUTransferBuffer(v->GpuDevice, &font_transferbuffer_info);
-        IM_ASSERT(font_transferbuffer != nullptr && "Failed to create font transfer buffer, call SDL_GetError() for more information");
+        SDL_GPUTransferBuffer* transferbuffer = SDL_CreateGPUTransferBuffer(v->Device, &transferbuffer_info);
+        IM_ASSERT(transferbuffer != nullptr && "Failed to create font transfer buffer, call SDL_GetError() for more information");
 
-        void* texture_ptr = SDL_MapGPUTransferBuffer(v->GpuDevice, font_transferbuffer, false);
+        void* texture_ptr = SDL_MapGPUTransferBuffer(v->Device, transferbuffer, false);
         memcpy(texture_ptr, pixels, upload_size);
-        SDL_UnmapGPUTransferBuffer(v->GpuDevice, font_transferbuffer);
+        SDL_UnmapGPUTransferBuffer(v->Device, transferbuffer);
 
-        SDL_GPUTextureTransferInfo font_transfer_info = {};
-        font_transfer_info.offset = 0;
-        font_transfer_info.transfer_buffer = font_transferbuffer;
+        SDL_GPUTextureTransferInfo transfer_info = {};
+        transfer_info.offset = 0;
+        transfer_info.transfer_buffer = transferbuffer;
 
-        SDL_GPUTextureRegion font_texture_region = {};
-        font_texture_region.texture = bd->FontTexture;
-        font_texture_region.w = width;
-        font_texture_region.h = height;
-        font_texture_region.d = 1;
+        SDL_GPUTextureRegion texture_region = {};
+        texture_region.texture = bd->FontTexture;
+        texture_region.w = width;
+        texture_region.h = height;
+        texture_region.d = 1;
 
-        SDL_GPUCommandBuffer* cmd = SDL_AcquireGPUCommandBuffer(v->GpuDevice);
+        SDL_GPUCommandBuffer* cmd = SDL_AcquireGPUCommandBuffer(v->Device);
         SDL_GPUCopyPass* copy_pass = SDL_BeginGPUCopyPass(cmd);
-        SDL_UploadToGPUTexture(copy_pass, &font_transfer_info, &font_texture_region, false);
+        SDL_UploadToGPUTexture(copy_pass, &transfer_info, &texture_region, false);
         SDL_EndGPUCopyPass(copy_pass);
         SDL_SubmitGPUCommandBuffer(cmd);
-        SDL_ReleaseGPUTransferBuffer(v->GpuDevice, font_transferbuffer);
+        SDL_ReleaseGPUTransferBuffer(v->Device, transferbuffer);
     }
 
     // Store our identifier
     io.Fonts->SetTexID((ImTextureID)&bd->FontBinding);
-
-    return true;
 }
 
 // You probably never need to call this, as it is called by ImGui_ImplSDLGPU3_CreateFontsTexture() and ImGui_ImplSDLGPU3_Shutdown().
@@ -357,10 +358,10 @@ void ImGui_ImplSDLGPU3_DestroyFontsTexture()
 {
     ImGuiIO& io = ImGui::GetIO();
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
-    ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
+    ImGui_ImplSDLGPU3_InitInfo* v = &bd->InitInfo;
     if (bd->FontTexture)
     {
-        SDL_ReleaseGPUTexture(v->GpuDevice, bd->FontTexture);
+        SDL_ReleaseGPUTexture(v->Device, bd->FontTexture);
         bd->FontBinding.texture = nullptr;
         bd->FontTexture = nullptr;
     }
@@ -371,9 +372,9 @@ static void Imgui_ImplSDLGPU3_CreateShaders()
 {
     // Create the shader modules
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
-    ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
+    ImGui_ImplSDLGPU3_InitInfo* v = &bd->InitInfo;
 
-    const char* driver = SDL_GetGPUDeviceDriver(v->GpuDevice);
+    const char* driver = SDL_GetGPUDeviceDriver(v->Device);
 
     SDL_GPUShaderCreateInfo vertex_shader_info = {};
     vertex_shader_info.entrypoint = "main";
@@ -422,8 +423,8 @@ static void Imgui_ImplSDLGPU3_CreateShaders()
         fragment_shader_info.code_size = sizeof(metallib_fragment);
     }
 #endif
-    bd->VertexShader = SDL_CreateGPUShader(v->GpuDevice, &vertex_shader_info);
-    bd->FragmentShader = SDL_CreateGPUShader(v->GpuDevice, &fragment_shader_info);
+    bd->VertexShader = SDL_CreateGPUShader(v->Device, &vertex_shader_info);
+    bd->FragmentShader = SDL_CreateGPUShader(v->Device, &fragment_shader_info);
     IM_ASSERT(bd->VertexShader != nullptr && "Failed to create vertex shader, call SDL_GetError() for more information");
     IM_ASSERT(bd->FragmentShader != nullptr && "Failed to create fragment shader, call SDL_GetError() for more information");
 }
@@ -431,7 +432,7 @@ static void Imgui_ImplSDLGPU3_CreateShaders()
 static void ImGui_ImplSDLGPU3_CreateGraphicsPipeline()
 {
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
-    ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
+    ImGui_ImplSDLGPU3_InitInfo* v = &bd->InitInfo;
     Imgui_ImplSDLGPU3_CreateShaders();
 
     SDL_GPUVertexBufferDescription vertex_buffer_desc[1];
@@ -507,14 +508,14 @@ static void ImGui_ImplSDLGPU3_CreateGraphicsPipeline()
     pipeline_info.depth_stencil_state = depth_stencil_state;
     pipeline_info.target_info = target_info;
 
-    bd->Pipeline = SDL_CreateGPUGraphicsPipeline(v->GpuDevice, &pipeline_info);
+    bd->Pipeline = SDL_CreateGPUGraphicsPipeline(v->Device, &pipeline_info);
     IM_ASSERT(bd->Pipeline != nullptr && "Failed to create graphics pipeline, call SDL_GetError() for more information");
 }
 
-bool ImGui_ImplSDLGPU3_CreateDeviceObjects()
+void ImGui_ImplSDLGPU3_CreateDeviceObjects()
 {
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
-    ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
+    ImGui_ImplSDLGPU3_InitInfo* v = &bd->InitInfo;
 
     if (!bd->FontSampler)
     {
@@ -529,27 +530,26 @@ bool ImGui_ImplSDLGPU3_CreateDeviceObjects()
         sampler_info.mip_lod_bias = 0.0f;
         sampler_info.min_lod = -1000.0f;
         sampler_info.max_lod = 1000.0f;
-        sampler_info.enable_anisotropy = true;
+        sampler_info.enable_anisotropy = false;
         sampler_info.max_anisotropy = 1.0f;
         sampler_info.enable_compare = false;
 
-        bd->FontSampler = SDL_CreateGPUSampler(v->GpuDevice, &sampler_info);
+        bd->FontSampler = SDL_CreateGPUSampler(v->Device, &sampler_info);
         bd->FontBinding.sampler = bd->FontSampler;
         IM_ASSERT(bd->FontSampler != nullptr && "Failed to create font sampler, call SDL_GetError() for more information");
     }
 
     ImGui_ImplSDLGPU3_CreateGraphicsPipeline();
-
-    return true;
+    ImGui_ImplSDLGPU3_CreateFontsTexture();
 }
 
 void ImGui_ImplSDLGPU3_DestroyFrameData()
 {
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
-    ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
+    ImGui_ImplSDLGPU3_InitInfo* v = &bd->InitInfo;
 
-    SDL_ReleaseGPUBuffer(v->GpuDevice, bd->MainWindowFrameData.VertexBuffer);
-    SDL_ReleaseGPUBuffer(v->GpuDevice, bd->MainWindowFrameData.IndexBuffer);
+    SDL_ReleaseGPUBuffer(v->Device, bd->MainWindowFrameData.VertexBuffer);
+    SDL_ReleaseGPUBuffer(v->Device, bd->MainWindowFrameData.IndexBuffer);
     bd->MainWindowFrameData.VertexBuffer = nullptr;
     bd->MainWindowFrameData.IndexBuffer = nullptr;
     bd->MainWindowFrameData.VertexBufferSize = 0;
@@ -559,15 +559,15 @@ void ImGui_ImplSDLGPU3_DestroyFrameData()
 void ImGui_ImplSDLGPU3_DestroyDeviceObjects()
 {
     ImGui_ImplSDLGPU3_Data* bd = ImGui_ImplSDLGPU3_GetBackendData();
-    ImGui_ImplSDLGPU3_InitInfo* v = &bd->GPUInitInfo;
+    ImGui_ImplSDLGPU3_InitInfo* v = &bd->InitInfo;
 
     ImGui_ImplSDLGPU3_DestroyFrameData();
     ImGui_ImplSDLGPU3_DestroyFontsTexture();
 
-    if (bd->VertexShader)   { SDL_ReleaseGPUShader(v->GpuDevice, bd->VertexShader); bd->VertexShader = nullptr;}
-    if (bd->FragmentShader) { SDL_ReleaseGPUShader(v->GpuDevice, bd->FragmentShader); bd->FragmentShader = nullptr;}
-    if (bd->FontSampler)    { SDL_ReleaseGPUSampler(v->GpuDevice, bd->FontSampler); bd->FontSampler = nullptr;}
-    if (bd->Pipeline)       { SDL_ReleaseGPUGraphicsPipeline(v->GpuDevice, bd->Pipeline); bd->Pipeline = nullptr;}
+    if (bd->VertexShader)   { SDL_ReleaseGPUShader(v->Device, bd->VertexShader); bd->VertexShader = nullptr;}
+    if (bd->FragmentShader) { SDL_ReleaseGPUShader(v->Device, bd->FragmentShader); bd->FragmentShader = nullptr;}
+    if (bd->FontSampler)    { SDL_ReleaseGPUSampler(v->Device, bd->FontSampler); bd->FontSampler = nullptr;}
+    if (bd->Pipeline)       { SDL_ReleaseGPUGraphicsPipeline(v->Device, bd->Pipeline); bd->Pipeline = nullptr;}
 }
 
 bool ImGui_ImplSDLGPU3_Init(ImGui_ImplSDLGPU3_InitInfo* info)
@@ -582,10 +582,10 @@ bool ImGui_ImplSDLGPU3_Init(ImGui_ImplSDLGPU3_InitInfo* info)
     io.BackendRendererName = "imgui_impl_sdlgpu3";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
 
-    IM_ASSERT(info->GpuDevice != nullptr);
+    IM_ASSERT(info->Device != nullptr);
     IM_ASSERT(info->ColorTargetFormat != SDL_GPU_TEXTUREFORMAT_INVALID);
 
-    bd->GPUInitInfo = *info;
+    bd->InitInfo = *info;
 
     ImGui_ImplSDLGPU3_CreateDeviceObjects();
 

backends/imgui_impl_sdlgpu3.h

@@ -4,6 +4,8 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use simply cast a reference to your SDL_GPUTextureSamplerBinding to ImTextureID.
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // The aim of imgui_impl_sdlgpu3.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -29,18 +31,21 @@
 // - Remember to set ColorTargetFormat to the correct format. If you're rendering to the swapchain, call SDL_GetGPUSwapchainTextureFormat to query the right value
 struct ImGui_ImplSDLGPU3_InitInfo
 {
-    SDL_GPUDevice*       GpuDevice          = nullptr;
+    SDL_GPUDevice*       Device             = nullptr;
     SDL_GPUTextureFormat ColorTargetFormat  = SDL_GPU_TEXTUREFORMAT_INVALID;
     SDL_GPUSampleCount   MSAASamples        = SDL_GPU_SAMPLECOUNT_1;
 };
 
 // Follow "Getting Started" link and check examples/ folder to learn about using backends!
-IMGUI_IMPL_API bool    ImGui_ImplSDLGPU3_Init(ImGui_ImplSDLGPU3_InitInfo* info);
-IMGUI_IMPL_API void    ImGui_ImplSDLGPU3_Shutdown();
-IMGUI_IMPL_API void    ImGui_ImplSDLGPU3_NewFrame();
-IMGUI_IMPL_API void    Imgui_ImplSDLGPU3_PrepareDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffer* command_buffer);
-IMGUI_IMPL_API void    ImGui_ImplSDLGPU3_RenderDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffer* command_buffer, SDL_GPURenderPass* render_pass, SDL_GPUGraphicsPipeline* pipeline = nullptr);
-IMGUI_IMPL_API bool    ImGui_ImplSDLGPU3_CreateFontsTexture();
-IMGUI_IMPL_API void    ImGui_ImplSDLGPU3_DestroyFontsTexture();
+IMGUI_IMPL_API bool     ImGui_ImplSDLGPU3_Init(ImGui_ImplSDLGPU3_InitInfo* info);
+IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_Shutdown();
+IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_NewFrame();
+IMGUI_IMPL_API void     Imgui_ImplSDLGPU3_PrepareDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffer* command_buffer);
+IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_RenderDrawData(ImDrawData* draw_data, SDL_GPUCommandBuffer* command_buffer, SDL_GPURenderPass* render_pass, SDL_GPUGraphicsPipeline* pipeline = nullptr);
+
+IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_CreateDeviceObjects();
+IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_DestroyDeviceObjects();
+IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_CreateFontsTexture();
+IMGUI_IMPL_API void     ImGui_ImplSDLGPU3_DestroyFontsTexture();
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_sdlrenderer2.cpp

@@ -1,16 +1,20 @@
 // dear imgui: Renderer Backend for SDL_Renderer for SDL2
 // (Requires: SDL 2.0.17+)
 
-// Note how 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.
-// If your application will want to render any non trivial amount of graphics other than UI,
-// please be aware that SDL_Renderer currently offers a limited graphic API to the end-user and
-// it might be difficult to step out of those boundaries.
+// Note that SDL_Renderer is an _optional_ component of SDL2, which IMHO is now largely obsolete.
+// For a multi-platform app consider using other technologies:
+// - SDL3+SDL_GPU: SDL_GPU is SDL3 new graphics abstraction API. You will need to update to SDL3.
+// - SDL2+DirectX, SDL2+OpenGL, SDL2+Vulkan: combine SDL with dedicated renderers.
+// If your application wants to render any non trivial amount of graphics other than UI,
+// please be aware that SDL_Renderer currently offers a limited graphic API to the end-user
+// and it might be difficult to step out of those boundaries.
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+// 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.
@@ -21,6 +25,7 @@
 // - Introduction, links and more at the top of imgui.cpp
 
 // CHANGELOG
+//  2025-01-18: Use endian-dependent RGBA32 texture format, to match SDL_Color.
 //  2024-10-09: Expose selected render state in ImGui_ImplSDLRenderer2_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
 //  2024-05-14: *BREAKING CHANGE* ImGui_ImplSDLRenderer3_RenderDrawData() requires SDL_Renderer* passed as parameter.
 //  2023-05-30: Renamed imgui_impl_sdlrenderer.h/.cpp to imgui_impl_sdlrenderer2.h/.cpp to accommodate for upcoming SDL3.
@@ -97,10 +102,10 @@ void ImGui_ImplSDLRenderer2_Shutdown()
 
 static void ImGui_ImplSDLRenderer2_SetupRenderState(SDL_Renderer* renderer)
 {
-	// Clear out any viewports and cliprect set by the user
+    // Clear out any viewports and cliprect set by the user
     // FIXME: Technically speaking there are lots of other things we could backup/setup/restore during our render process.
-	SDL_RenderSetViewport(renderer, nullptr);
-	SDL_RenderSetClipRect(renderer, nullptr);
+    SDL_RenderSetViewport(renderer, nullptr);
+    SDL_RenderSetClipRect(renderer, nullptr);
 }
 
 void ImGui_ImplSDLRenderer2_NewFrame()
@@ -114,21 +119,21 @@ void ImGui_ImplSDLRenderer2_NewFrame()
 
 void ImGui_ImplSDLRenderer2_RenderDrawData(ImDrawData* draw_data, SDL_Renderer* renderer)
 {
-	// If there's a scale factor set by the user, use that instead
+    // If there's a scale factor set by the user, use that instead
     // If the user has specified a scale factor to SDL_Renderer already via SDL_RenderSetScale(), SDL will scale whatever we pass
     // to SDL_RenderGeometryRaw() by that scale factor. In that case we don't want to be also scaling it ourselves here.
     float rsx = 1.0f;
-	float rsy = 1.0f;
-	SDL_RenderGetScale(renderer, &rsx, &rsy);
+    float rsy = 1.0f;
+    SDL_RenderGetScale(renderer, &rsx, &rsy);
     ImVec2 render_scale;
-	render_scale.x = (rsx == 1.0f) ? draw_data->FramebufferScale.x : 1.0f;
-	render_scale.y = (rsy == 1.0f) ? draw_data->FramebufferScale.y : 1.0f;
+    render_scale.x = (rsx == 1.0f) ? draw_data->FramebufferScale.x : 1.0f;
+    render_scale.y = (rsy == 1.0f) ? draw_data->FramebufferScale.y : 1.0f;
 
-	// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
-	int fb_width = (int)(draw_data->DisplaySize.x * render_scale.x);
-	int fb_height = (int)(draw_data->DisplaySize.y * render_scale.y);
-	if (fb_width == 0 || fb_height == 0)
-		return;
+    // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
+    int fb_width = (int)(draw_data->DisplaySize.x * render_scale.x);
+    int fb_height = (int)(draw_data->DisplaySize.y * render_scale.y);
+    if (fb_width == 0 || fb_height == 0)
+        return;
 
     // Backup SDL_Renderer state that will be modified to restore it afterwards
     struct BackupSDLRendererState
@@ -151,9 +156,9 @@ void ImGui_ImplSDLRenderer2_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
     render_state.Renderer = renderer;
     platform_io.Renderer_RenderState = &render_state;
 
-	// Will project scissor/clipping rectangles into framebuffer space
-	ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
-	ImVec2 clip_scale = render_scale;
+    // Will project scissor/clipping rectangles into framebuffer space
+    ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
+    ImVec2 clip_scale = render_scale;
 
     // Render command lists
     for (int n = 0; n < draw_data->CmdListsCount; n++)
@@ -198,7 +203,7 @@ void ImGui_ImplSDLRenderer2_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
 #endif
 
                 // Bind texture, Draw
-				SDL_Texture* tex = (SDL_Texture*)pcmd->GetTexID();
+                SDL_Texture* tex = (SDL_Texture*)pcmd->GetTexID();
                 SDL_RenderGeometryRaw(renderer, tex,
                     xy, (int)sizeof(ImDrawVert),
                     color, (int)sizeof(ImDrawVert),
@@ -228,7 +233,7 @@ bool ImGui_ImplSDLRenderer2_CreateFontsTexture()
 
     // Upload texture to graphics system
     // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
-    bd->FontTexture = SDL_CreateTexture(bd->Renderer, SDL_PIXELFORMAT_ABGR8888, SDL_TEXTUREACCESS_STATIC, width, height);
+    bd->FontTexture = SDL_CreateTexture(bd->Renderer, SDL_PIXELFORMAT_RGBA32, SDL_TEXTUREACCESS_STATIC, width, height);
     if (bd->FontTexture == nullptr)
     {
         SDL_Log("error creating texture");

backends/imgui_impl_sdlrenderer2.h

@@ -1,16 +1,20 @@
 // dear imgui: Renderer Backend for SDL_Renderer for SDL2
 // (Requires: SDL 2.0.17+)
 
-// Note how 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.
-// If your application will want to render any non trivial amount of graphics other than UI,
-// please be aware that SDL_Renderer currently offers a limited graphic API to the end-user and
-// it might be difficult to step out of those boundaries.
+// Note that SDL_Renderer is an _optional_ component of SDL2, which IMHO is now largely obsolete.
+// For a multi-platform app consider using other technologies:
+// - SDL3+SDL_GPU: SDL_GPU is SDL3 new graphics abstraction API. You will need to update to SDL3.
+// - SDL2+DirectX, SDL2+OpenGL, SDL2+Vulkan: combine SDL with dedicated renderers.
+// If your application wants to render any non trivial amount of graphics other than UI,
+// please be aware that SDL_Renderer currently offers a limited graphic API to the end-user
+// and it might be difficult to step out of those boundaries.
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_sdlrenderer3.cpp

@@ -1,18 +1,20 @@
 // dear imgui: Renderer Backend for SDL_Renderer for SDL3
-// (Requires: SDL 3.0.0+)
+// (Requires: SDL 3.1.8+)
 
-// (**IMPORTANT: SDL 3.0.0 is NOT YET RELEASED AND CURRENTLY HAS A FAST CHANGING API. THIS CODE BREAKS OFTEN AS SDL3 CHANGES.**)
-
-// Note how 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.
-// If your application will want to render any non trivial amount of graphics other than UI,
-// please be aware that SDL_Renderer currently offers a limited graphic API to the end-user and
-// it might be difficult to step out of those boundaries.
+// Note that SDL_Renderer is an _optional_ component of SDL3, which IMHO is now largely obsolete.
+// For a multi-platform app consider using other technologies:
+// - SDL3+SDL_GPU: SDL_GPU is SDL3 new graphics abstraction API.
+// - SDL3+DirectX, SDL3+OpenGL, SDL3+Vulkan: combine SDL with dedicated renderers.
+// If your application wants to render any non trivial amount of graphics other than UI,
+// please be aware that SDL_Renderer currently offers a limited graphic API to the end-user
+// and it might be difficult to step out of those boundaries.
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+// 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.
@@ -23,6 +25,7 @@
 // - Introduction, links and more at the top of imgui.cpp
 
 // CHANGELOG
+//  2025-01-18: Use endian-dependent RGBA32 texture format, to match SDL_Color.
 //  2024-10-09: Expose selected render state in ImGui_ImplSDLRenderer3_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
 //  2024-07-01: Update for SDL3 api changes: SDL_RenderGeometryRaw() uint32 version was removed (SDL#9009).
 //  2024-05-14: *BREAKING CHANGE* ImGui_ImplSDLRenderer3_RenderDrawData() requires SDL_Renderer* passed as parameter.
@@ -98,10 +101,10 @@ void ImGui_ImplSDLRenderer3_Shutdown()
 
 static void ImGui_ImplSDLRenderer3_SetupRenderState(SDL_Renderer* renderer)
 {
-	// Clear out any viewports and cliprect set by the user
+    // Clear out any viewports and cliprect set by the user
     // FIXME: Technically speaking there are lots of other things we could backup/setup/restore during our render process.
-	SDL_SetRenderViewport(renderer, nullptr);
-	SDL_SetRenderClipRect(renderer, nullptr);
+    SDL_SetRenderViewport(renderer, nullptr);
+    SDL_SetRenderClipRect(renderer, nullptr);
 }
 
 void ImGui_ImplSDLRenderer3_NewFrame()
@@ -135,21 +138,21 @@ void ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
 {
     ImGui_ImplSDLRenderer3_Data* bd = ImGui_ImplSDLRenderer3_GetBackendData();
 
-	// If there's a scale factor set by the user, use that instead
+    // If there's a scale factor set by the user, use that instead
     // If the user has specified a scale factor to SDL_Renderer already via SDL_RenderSetScale(), SDL will scale whatever we pass
     // to SDL_RenderGeometryRaw() by that scale factor. In that case we don't want to be also scaling it ourselves here.
     float rsx = 1.0f;
-	float rsy = 1.0f;
-	SDL_GetRenderScale(renderer, &rsx, &rsy);
+    float rsy = 1.0f;
+    SDL_GetRenderScale(renderer, &rsx, &rsy);
     ImVec2 render_scale;
-	render_scale.x = (rsx == 1.0f) ? draw_data->FramebufferScale.x : 1.0f;
-	render_scale.y = (rsy == 1.0f) ? draw_data->FramebufferScale.y : 1.0f;
+    render_scale.x = (rsx == 1.0f) ? draw_data->FramebufferScale.x : 1.0f;
+    render_scale.y = (rsy == 1.0f) ? draw_data->FramebufferScale.y : 1.0f;
 
-	// Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
-	int fb_width = (int)(draw_data->DisplaySize.x * render_scale.x);
-	int fb_height = (int)(draw_data->DisplaySize.y * render_scale.y);
-	if (fb_width == 0 || fb_height == 0)
-		return;
+    // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
+    int fb_width = (int)(draw_data->DisplaySize.x * render_scale.x);
+    int fb_height = (int)(draw_data->DisplaySize.y * render_scale.y);
+    if (fb_width == 0 || fb_height == 0)
+        return;
 
     // Backup SDL_Renderer state that will be modified to restore it afterwards
     struct BackupSDLRendererState
@@ -174,9 +177,9 @@ void ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
     render_state.Renderer = renderer;
     platform_io.Renderer_RenderState = &render_state;
 
-	// Will project scissor/clipping rectangles into framebuffer space
-	ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
-	ImVec2 clip_scale = render_scale;
+    // Will project scissor/clipping rectangles into framebuffer space
+    ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
+    ImVec2 clip_scale = render_scale;
 
     // Render command lists
     for (int n = 0; n < draw_data->CmdListsCount; n++)
@@ -217,7 +220,7 @@ void ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_data, SDL_Renderer*
                 const SDL_Color* color = (const SDL_Color*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + offsetof(ImDrawVert, col)); // SDL 2.0.19+
 
                 // Bind texture, Draw
-				SDL_Texture* tex = (SDL_Texture*)pcmd->GetTexID();
+                SDL_Texture* tex = (SDL_Texture*)pcmd->GetTexID();
                 SDL_RenderGeometryRaw8BitColor(renderer, bd->ColorBuffer, tex,
                     xy, (int)sizeof(ImDrawVert),
                     color, (int)sizeof(ImDrawVert),
@@ -247,7 +250,7 @@ bool ImGui_ImplSDLRenderer3_CreateFontsTexture()
 
     // Upload texture to graphics system
     // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
-    bd->FontTexture = SDL_CreateTexture(bd->Renderer, SDL_PIXELFORMAT_ABGR8888, SDL_TEXTUREACCESS_STATIC, width, height);
+    bd->FontTexture = SDL_CreateTexture(bd->Renderer, SDL_PIXELFORMAT_RGBA32, SDL_TEXTUREACCESS_STATIC, width, height);
     if (bd->FontTexture == nullptr)
     {
         SDL_Log("error creating texture");

backends/imgui_impl_sdlrenderer3.h

@@ -1,18 +1,20 @@
 // dear imgui: Renderer Backend for SDL_Renderer for SDL3
-// (Requires: SDL 3.0.0+)
+// (Requires: SDL 3.1.8+)
 
-// (**IMPORTANT: SDL 3.0.0 is NOT YET RELEASED AND CURRENTLY HAS A FAST CHANGING API. THIS CODE BREAKS OFTEN AS SDL3 CHANGES.**)
-
-// Note how 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.
-// If your application will want to render any non trivial amount of graphics other than UI,
-// please be aware that SDL_Renderer currently offers a limited graphic API to the end-user and
-// it might be difficult to step out of those boundaries.
+// Note that SDL_Renderer is an _optional_ component of SDL3, which IMHO is now largely obsolete.
+// For a multi-platform app consider using other technologies:
+// - SDL3+SDL_GPU: SDL_GPU is SDL3 new graphics abstraction API.
+// - SDL3+DirectX, SDL3+OpenGL, SDL3+Vulkan: combine SDL with dedicated renderers.
+// If your application wants to render any non trivial amount of graphics other than UI,
+// please be aware that SDL_Renderer currently offers a limited graphic API to the end-user
+// and it might be difficult to step out of those boundaries.
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_vulkan.cpp

@@ -5,6 +5,7 @@
 //  [!] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Call ImGui_ImplVulkan_AddTexture() to register one. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [x] Renderer: Multi-viewport / platform windows. With issues (flickering when creating a new viewport).
 
 // The aim of imgui_impl_vulkan.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -26,6 +27,9 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-02-14: *BREAKING CHANGE*: Added uint32_t api_version to ImGui_ImplVulkan_LoadFunctions().
+//  2025-02-13: Vulkan: Added ApiVersion field in ImGui_ImplVulkan_InitInfo. Default to header version if unspecified. Dynamic rendering path loads "vkCmdBeginRendering/vkCmdEndRendering" (without -KHR suffix) on API 1.3. (#8326)
 //  2025-01-09: Vulkan: Added IMGUI_IMPL_VULKAN_MINIMUM_IMAGE_SAMPLER_POOL_SIZE to clarify how many image sampler descriptors are expected to be available in descriptor pool. (#6642)
 //  2025-01-06: Vulkan: Added more ImGui_ImplVulkanH_XXXX helper functions to simplify our examples.
 //  2024-12-11: Vulkan: Fixed setting VkSwapchainCreateInfoKHR::preTransform for platforms not supporting VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR. (#8222)
@@ -51,7 +55,7 @@
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2022-10-04: Vulkan: Added experimental ImGui_ImplVulkan_RemoveTexture() for api symmetry. (#914, #5738).
 //  2022-01-20: Vulkan: Added support for ImTextureID as VkDescriptorSet. User need to call ImGui_ImplVulkan_AddTexture(). Building for 32-bit targets requires '#define ImTextureID ImU64'. (#914).
-//  2021-10-15: Vulkan: Call vkCmdSetScissor() at the end of render a full-viewport to reduce likehood of issues with people using VK_DYNAMIC_STATE_SCISSOR in their app without calling vkCmdSetScissor() explicitly every frame.
+//  2021-10-15: Vulkan: Call vkCmdSetScissor() at the end of render a full-viewport to reduce likelihood of issues with people using VK_DYNAMIC_STATE_SCISSOR in their app without calling vkCmdSetScissor() explicitly every frame.
 //  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: Vulkan: Fix mapped memory validation error when buffer sizes are not multiple of VkPhysicalDeviceLimits::nonCoherentAtomSize.
 //  2021-02-18: Vulkan: Change blending equation to preserve alpha in output buffer.
@@ -104,6 +108,7 @@ void ImGui_ImplVulkan_DestroyFrameRenderBuffers(VkDevice device, ImGui_ImplVulka
 void ImGui_ImplVulkan_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVulkan_WindowRenderBuffers* buffers, const VkAllocationCallbacks* allocator);
 void ImGui_ImplVulkanH_DestroyFrame(VkDevice device, ImGui_ImplVulkanH_Frame* fd, const VkAllocationCallbacks* allocator);
 void ImGui_ImplVulkanH_DestroyFrameSemaphores(VkDevice device, ImGui_ImplVulkanH_FrameSemaphores* fsd, const VkAllocationCallbacks* allocator);
+void ImGui_ImplVulkanH_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);
 
@@ -120,15 +125,18 @@ static bool g_FunctionsLoaded = true;
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkAllocateCommandBuffers) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkAllocateDescriptorSets) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkAllocateMemory) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkAcquireNextImageKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkBeginCommandBuffer) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkBindBufferMemory) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkBindImageMemory) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBeginRenderPass) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindDescriptorSets) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindIndexBuffer) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindPipeline) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindVertexBuffers) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdCopyBufferToImage) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdDrawIndexed) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdEndRenderPass) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdPipelineBarrier) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdPushConstants) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdSetScissor) \
@@ -179,13 +187,17 @@ static bool g_FunctionsLoaded = true;
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceCapabilitiesKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceFormatsKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfacePresentModesKHR) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceSupportKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetSwapchainImagesKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkMapMemory) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueuePresentKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueueSubmit) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueueWaitIdle) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkResetCommandPool) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkResetFences) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkUnmapMemory) \
-    IMGUI_VULKAN_FUNC_MAP_MACRO(vkUpdateDescriptorSets)
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkUpdateDescriptorSets) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkWaitForFences)
 
 // Define function pointers
 #define IMGUI_VULKAN_FUNC_DEF(func) static PFN_##func func;
@@ -216,7 +228,7 @@ struct ImGui_ImplVulkan_WindowRenderBuffers
 {
     uint32_t            Index;
     uint32_t            Count;
-    ImGui_ImplVulkan_FrameRenderBuffers* FrameRenderBuffers;
+    ImVector<ImGui_ImplVulkan_FrameRenderBuffers> FrameRenderBuffers;
 };
 
 struct ImGui_ImplVulkan_Texture
@@ -229,6 +241,20 @@ struct ImGui_ImplVulkan_Texture
     ImGui_ImplVulkan_Texture() { memset((void*)this, 0, sizeof(*this)); }
 };
 
+// For multi-viewport support:
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplVulkan_ViewportData
+{
+    ImGui_ImplVulkanH_Window                Window;                 // Used by secondary viewports only
+    ImGui_ImplVulkan_WindowRenderBuffers    RenderBuffers;          // Used by all viewports
+    bool                                    WindowOwned;
+    bool                                    SwapChainNeedRebuild;   // Flag when viewport swapchain resized in the middle of processing a frame
+    bool                                    SwapChainSuboptimal;    // Flag when VK_SUBOPTIMAL_KHR was returned.
+
+    ImGui_ImplVulkan_ViewportData() { WindowOwned = SwapChainNeedRebuild = SwapChainSuboptimal = false; memset(&RenderBuffers, 0, sizeof(RenderBuffers)); }
+    ~ImGui_ImplVulkan_ViewportData() { }
+};
+
 // Vulkan data
 struct ImGui_ImplVulkan_Data
 {
@@ -237,7 +263,8 @@ struct ImGui_ImplVulkan_Data
     VkPipelineCreateFlags       PipelineCreateFlags;
     VkDescriptorSetLayout       DescriptorSetLayout;
     VkPipelineLayout            PipelineLayout;
-    VkPipeline                  Pipeline;
+    VkPipeline                  Pipeline;               // pipeline for main render pass (created by app)
+    VkPipeline                  PipelineForViewports;   // pipeline for secondary viewports (created by backend)
     VkShaderModule              ShaderModuleVert;
     VkShaderModule              ShaderModuleFrag;
     VkDescriptorPool            DescriptorPool;
@@ -262,6 +289,10 @@ struct ImGui_ImplVulkan_Data
 // SHADERS
 //-----------------------------------------------------------------------------
 
+// Forward Declarations
+static void ImGui_ImplVulkan_InitMultiViewportSupport();
+static void ImGui_ImplVulkan_ShutdownMultiViewportSupport();
+
 // backends/vulkan/glsl_shader.vert, compiled with:
 // # glslangValidator -V -x -o glsl_shader.vert.u32 glsl_shader.vert
 /*
@@ -499,14 +530,16 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
     if (pipeline == VK_NULL_HANDLE)
         pipeline = bd->Pipeline;
 
-    // Allocate array to store enough vertex/index buffers
-    ImGui_ImplVulkan_WindowRenderBuffers* wrb = &bd->MainWindowRenderBuffers;
-    if (wrb->FrameRenderBuffers == nullptr)
+    // Allocate array to store enough vertex/index buffers. Each unique viewport gets its own storage.
+    ImGui_ImplVulkan_ViewportData* viewport_renderer_data = (ImGui_ImplVulkan_ViewportData*)draw_data->OwnerViewport->RendererUserData;
+    IM_ASSERT(viewport_renderer_data != nullptr);
+    ImGui_ImplVulkan_WindowRenderBuffers* wrb = &viewport_renderer_data->RenderBuffers;
+    if (wrb->FrameRenderBuffers.Size == 0)
     {
         wrb->Index = 0;
         wrb->Count = v->ImageCount;
-        wrb->FrameRenderBuffers = (ImGui_ImplVulkan_FrameRenderBuffers*)IM_ALLOC(sizeof(ImGui_ImplVulkan_FrameRenderBuffers) * wrb->Count);
-        memset((void*)wrb->FrameRenderBuffers, 0, sizeof(ImGui_ImplVulkan_FrameRenderBuffers) * wrb->Count);
+        wrb->FrameRenderBuffers.resize(wrb->Count);
+        memset((void*)wrb->FrameRenderBuffers.Data, 0, wrb->FrameRenderBuffers.size_in_bytes());
     }
     IM_ASSERT(wrb->Count == v->ImageCount);
     wrb->Index = (wrb->Index + 1) % wrb->Count;
@@ -1065,7 +1098,7 @@ void    ImGui_ImplVulkan_DestroyDeviceObjects()
 {
     ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
     ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
-    ImGui_ImplVulkan_DestroyWindowRenderBuffers(v->Device, &bd->MainWindowRenderBuffers, v->Allocator);
+    ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(v->Device, v->Allocator);
     ImGui_ImplVulkan_DestroyFontsTexture();
 
     if (bd->TexCommandBuffer)     { vkFreeCommandBuffers(v->Device, bd->TexCommandPool, 1, &bd->TexCommandBuffer); bd->TexCommandBuffer = VK_NULL_HANDLE; }
@@ -1076,15 +1109,39 @@ void    ImGui_ImplVulkan_DestroyDeviceObjects()
     if (bd->DescriptorSetLayout)  { vkDestroyDescriptorSetLayout(v->Device, bd->DescriptorSetLayout, v->Allocator); bd->DescriptorSetLayout = VK_NULL_HANDLE; }
     if (bd->PipelineLayout)       { vkDestroyPipelineLayout(v->Device, bd->PipelineLayout, v->Allocator); bd->PipelineLayout = VK_NULL_HANDLE; }
     if (bd->Pipeline)             { vkDestroyPipeline(v->Device, bd->Pipeline, v->Allocator); bd->Pipeline = VK_NULL_HANDLE; }
+    if (bd->PipelineForViewports) { vkDestroyPipeline(v->Device, bd->PipelineForViewports, v->Allocator); bd->PipelineForViewports = VK_NULL_HANDLE; }
     if (bd->DescriptorPool)       { vkDestroyDescriptorPool(v->Device, bd->DescriptorPool, v->Allocator); bd->DescriptorPool = VK_NULL_HANDLE; }
 }
 
-bool    ImGui_ImplVulkan_LoadFunctions(PFN_vkVoidFunction(*loader_func)(const char* function_name, void* user_data), void* user_data)
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+static void ImGui_ImplVulkan_LoadDynamicRenderingFunctions(uint32_t api_version, PFN_vkVoidFunction(*loader_func)(const char* function_name, void* user_data), void* user_data)
+{
+    // Manually load those two (see #5446, #8326, #8365)
+    ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR = reinterpret_cast<PFN_vkCmdBeginRenderingKHR>(loader_func(api_version < VK_API_VERSION_1_3 ? "vkCmdBeginRenderingKHR" : "vkCmdBeginRendering", user_data));
+    ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR = reinterpret_cast<PFN_vkCmdEndRenderingKHR>(loader_func(api_version < VK_API_VERSION_1_3 ? "vkCmdEndRenderingKHR" : "vkCmdEndRendering", user_data));
+}
+#endif
+
+// If unspecified by user, assume that ApiVersion == HeaderVersion
+ // We don't care about other versions than 1.3 for our checks, so don't need to make this exhaustive (e.g. with all #ifdef VK_VERSION_1_X checks)
+static uint32_t ImGui_ImplVulkan_GetDefaultApiVersion()
+{
+#ifdef VK_HEADER_VERSION_COMPLETE
+    return VK_HEADER_VERSION_COMPLETE;
+#else
+    return VK_API_VERSION_1_0;
+#endif
+}
+
+bool    ImGui_ImplVulkan_LoadFunctions(uint32_t api_version, PFN_vkVoidFunction(*loader_func)(const char* function_name, void* user_data), void* user_data)
 {
     // Load function pointers
     // You can use the default Vulkan loader using:
-    //      ImGui_ImplVulkan_LoadFunctions([](const char* function_name, void*) { return vkGetInstanceProcAddr(your_vk_isntance, function_name); });
+    //      ImGui_ImplVulkan_LoadFunctions(VK_API_VERSION_1_3, [](const char* function_name, void*) { return vkGetInstanceProcAddr(your_vk_isntance, function_name); });
     // But this would be roughly equivalent to not setting VK_NO_PROTOTYPES.
+    if (api_version == 0)
+        api_version = ImGui_ImplVulkan_GetDefaultApiVersion();
+
 #ifdef IMGUI_IMPL_VULKAN_USE_LOADER
 #define IMGUI_VULKAN_FUNC_LOAD(func) \
     func = reinterpret_cast<decltype(func)>(loader_func(#func, user_data)); \
@@ -1094,9 +1151,7 @@ bool    ImGui_ImplVulkan_LoadFunctions(PFN_vkVoidFunction(*loader_func)(const ch
 #undef IMGUI_VULKAN_FUNC_LOAD
 
 #ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
-    // Manually load those two (see #5446)
-    ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR = reinterpret_cast<PFN_vkCmdBeginRenderingKHR>(loader_func("vkCmdBeginRenderingKHR", user_data));
-    ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR = reinterpret_cast<PFN_vkCmdEndRenderingKHR>(loader_func("vkCmdEndRenderingKHR", user_data));
+    ImGui_ImplVulkan_LoadDynamicRenderingFunctions(api_version, loader_func, user_data);
 #endif
 #else
     IM_UNUSED(loader_func);
@@ -1111,12 +1166,14 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info)
 {
     IM_ASSERT(g_FunctionsLoaded && "Need to call ImGui_ImplVulkan_LoadFunctions() if IMGUI_IMPL_VULKAN_NO_PROTOTYPES or VK_NO_PROTOTYPES are set!");
 
+    if (info->ApiVersion == 0)
+        info->ApiVersion = ImGui_ImplVulkan_GetDefaultApiVersion();
+
     if (info->UseDynamicRendering)
     {
 #ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
 #ifndef IMGUI_IMPL_VULKAN_USE_LOADER
-        ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR = reinterpret_cast<PFN_vkCmdBeginRenderingKHR>(vkGetInstanceProcAddr(info->Instance, "vkCmdBeginRenderingKHR"));
-        ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR = reinterpret_cast<PFN_vkCmdEndRenderingKHR>(vkGetInstanceProcAddr(info->Instance, "vkCmdEndRenderingKHR"));
+        ImGui_ImplVulkan_LoadDynamicRenderingFunctions(info->ApiVersion, [](const char* function_name, void* user_data) { return vkGetInstanceProcAddr((VkInstance)user_data, function_name); }, (void*)info->Instance);
 #endif
         IM_ASSERT(ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR != nullptr);
         IM_ASSERT(ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR != nullptr);
@@ -1134,6 +1191,7 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info)
     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);
@@ -1152,6 +1210,12 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info)
 
     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)();
+
+    ImGui_ImplVulkan_InitMultiViewportSupport();
+
     return true;
 }
 
@@ -1161,10 +1225,21 @@ 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_ShutdownMultiViewportSupport();
+
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
-    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -1184,10 +1259,12 @@ void ImGui_ImplVulkan_SetMinImageCount(uint32_t min_image_count)
     if (bd->VulkanInitInfo.MinImageCount == min_image_count)
         return;
 
+    IM_ASSERT(0); // FIXME-VIEWPORT: Unsupported. Need to recreate all swap chains!
     ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
     VkResult err = vkDeviceWaitIdle(v->Device);
     check_vk_result(err);
-    ImGui_ImplVulkan_DestroyWindowRenderBuffers(v->Device, &bd->MainWindowRenderBuffers, v->Allocator);
+    ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(v->Device, v->Allocator);
+
     bd->VulkanInitInfo.MinImageCount = min_image_count;
 }
 
@@ -1250,8 +1327,7 @@ void ImGui_ImplVulkan_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVulk
 {
     for (uint32_t n = 0; n < buffers->Count; n++)
         ImGui_ImplVulkan_DestroyFrameRenderBuffers(device, &buffers->FrameRenderBuffers[n], allocator);
-    IM_FREE(buffers->FrameRenderBuffers);
-    buffers->FrameRenderBuffers = nullptr;
+    buffers->FrameRenderBuffers.clear();
     buffers->Index = 0;
     buffers->Count = 0;
 }
@@ -1460,15 +1536,11 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
         ImGui_ImplVulkanH_DestroyFrame(device, &wd->Frames[i], allocator);
     for (uint32_t i = 0; i < wd->SemaphoreCount; i++)
         ImGui_ImplVulkanH_DestroyFrameSemaphores(device, &wd->FrameSemaphores[i], allocator);
-    IM_FREE(wd->Frames);
-    IM_FREE(wd->FrameSemaphores);
-    wd->Frames = nullptr;
-    wd->FrameSemaphores = nullptr;
+    wd->Frames.clear();
+    wd->FrameSemaphores.clear();
     wd->ImageCount = 0;
     if (wd->RenderPass)
         vkDestroyRenderPass(device, wd->RenderPass, allocator);
-    if (wd->Pipeline)
-        vkDestroyPipeline(device, wd->Pipeline, allocator);
 
     // If min image count was not specified, request different count of images dependent on selected present mode
     if (min_image_count == 0)
@@ -1518,12 +1590,11 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
         err = vkGetSwapchainImagesKHR(device, wd->Swapchain, &wd->ImageCount, backbuffers);
         check_vk_result(err);
 
-        IM_ASSERT(wd->Frames == nullptr && wd->FrameSemaphores == nullptr);
         wd->SemaphoreCount = wd->ImageCount + 1;
-        wd->Frames = (ImGui_ImplVulkanH_Frame*)IM_ALLOC(sizeof(ImGui_ImplVulkanH_Frame) * wd->ImageCount);
-        wd->FrameSemaphores = (ImGui_ImplVulkanH_FrameSemaphores*)IM_ALLOC(sizeof(ImGui_ImplVulkanH_FrameSemaphores) * wd->SemaphoreCount);
-        memset((void*)wd->Frames, 0, sizeof(wd->Frames[0]) * wd->ImageCount);
-        memset((void*)wd->FrameSemaphores, 0, sizeof(wd->FrameSemaphores[0]) * wd->SemaphoreCount);
+        wd->Frames.resize(wd->ImageCount);
+        wd->FrameSemaphores.resize(wd->SemaphoreCount);
+        memset(wd->Frames.Data, 0, wd->Frames.size_in_bytes());
+        memset(wd->FrameSemaphores.Data, 0, wd->FrameSemaphores.size_in_bytes());
         for (uint32_t i = 0; i < wd->ImageCount; i++)
             wd->Frames[i].Backbuffer = backbuffers[i];
     }
@@ -1621,6 +1692,7 @@ 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);
 }
 
@@ -1633,11 +1705,8 @@ void ImGui_ImplVulkanH_DestroyWindow(VkInstance instance, VkDevice device, ImGui
         ImGui_ImplVulkanH_DestroyFrame(device, &wd->Frames[i], allocator);
     for (uint32_t i = 0; i < wd->SemaphoreCount; i++)
         ImGui_ImplVulkanH_DestroyFrameSemaphores(device, &wd->FrameSemaphores[i], allocator);
-    IM_FREE(wd->Frames);
-    IM_FREE(wd->FrameSemaphores);
-    wd->Frames = nullptr;
-    wd->FrameSemaphores = nullptr;
-    vkDestroyPipeline(device, wd->Pipeline, allocator);
+    wd->Frames.clear();
+    wd->FrameSemaphores.clear();
     vkDestroyRenderPass(device, wd->RenderPass, allocator);
     vkDestroySwapchainKHR(device, wd->Swapchain, allocator);
     vkDestroySurfaceKHR(instance, wd->Surface, allocator);
@@ -1665,6 +1734,296 @@ void ImGui_ImplVulkanH_DestroyFrameSemaphores(VkDevice device, ImGui_ImplVulkanH
     fsd->ImageAcquiredSemaphore = fsd->RenderCompleteSemaphore = VK_NULL_HANDLE;
 }
 
+void ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(VkDevice device, const VkAllocationCallbacks* allocator)
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int n = 0; n < platform_io.Viewports.Size; n++)
+        if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)platform_io.Viewports[n]->RendererUserData)
+            ImGui_ImplVulkan_DestroyWindowRenderBuffers(device, &vd->RenderBuffers, allocator);
+}
+
+//--------------------------------------------------------------------------------------------------------
+// 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
+    ImVector<VkFormat> requestSurfaceImageFormats;
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+    for (uint32_t n = 0; n < v->PipelineRenderingCreateInfo.colorAttachmentCount; n++)
+        requestSurfaceImageFormats.push_back(v->PipelineRenderingCreateInfo.pColorAttachmentFormats[n]);
+#endif
+    const VkFormat defaultFormats[] = { VK_FORMAT_B8G8R8A8_UNORM, VK_FORMAT_R8G8B8A8_UNORM, VK_FORMAT_B8G8R8_UNORM, VK_FORMAT_R8G8B8_UNORM };
+    for (VkFormat format : defaultFormats)
+        requestSurfaceImageFormats.push_back(format);
+
+    const VkColorSpaceKHR requestSurfaceColorSpace = VK_COLORSPACE_SRGB_NONLINEAR_KHR;
+    wd->SurfaceFormat = ImGui_ImplVulkanH_SelectSurfaceFormat(v->PhysicalDevice, wd->Surface, requestSurfaceImageFormats.Data, (size_t)requestSurfaceImageFormats.Size, requestSurfaceColorSpace);
+
+    // Select Present Mode
+    // FIXME-VULKAN: Even thought mailbox seems to get us maximum framerate with a single window, it halves framerate with a second window etc. (w/ Nvidia and SDK 1.82.1)
+    VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_MAILBOX_KHR, VK_PRESENT_MODE_IMMEDIATE_KHR, VK_PRESENT_MODE_FIFO_KHR };
+    wd->PresentMode = ImGui_ImplVulkanH_SelectPresentMode(v->PhysicalDevice, wd->Surface, &present_modes[0], IM_ARRAYSIZE(present_modes));
+    //printf("[vulkan] Secondary window selected PresentMode = %d\n", wd->PresentMode);
+
+    // Create SwapChain, RenderPass, Framebuffer, etc.
+    wd->ClearEnable = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? false : true;
+    wd->UseDynamicRendering = v->UseDynamicRendering;
+    ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, wd, v->QueueFamily, v->Allocator, (int)viewport->Size.x, (int)viewport->Size.y, v->MinImageCount);
+    vd->WindowOwned = true;
+
+    // Create pipeline (shared by all secondary viewports)
+    if (bd->PipelineForViewports == VK_NULL_HANDLE)
+        ImGui_ImplVulkan_CreatePipeline(v->Device, v->Allocator, VK_NULL_HANDLE, wd->RenderPass, VK_SAMPLE_COUNT_1_BIT, &bd->PipelineForViewports, 0);
+}
+
+static void ImGui_ImplVulkan_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData)
+    {
+        ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+        if (vd->WindowOwned)
+            ImGui_ImplVulkanH_DestroyWindow(v->Instance, v->Device, &vd->Window, v->Allocator);
+        ImGui_ImplVulkan_DestroyWindowRenderBuffers(v->Device, &vd->RenderBuffers, v->Allocator);
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplVulkan_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
+    if (vd == nullptr) // This is nullptr for the main viewport (which is left to the user/app to handle)
+        return;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+    vd->Window.ClearEnable = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? false : true;
+    ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, &vd->Window, v->QueueFamily, v->Allocator, (int)size.x, (int)size.y, v->MinImageCount);
+}
+
+static void ImGui_ImplVulkan_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
+    ImGui_ImplVulkanH_Window* wd = &vd->Window;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+    VkResult err;
+
+    if (vd->SwapChainNeedRebuild || vd->SwapChainSuboptimal)
+    {
+        ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, wd, v->QueueFamily, v->Allocator, (int)viewport->Size.x, (int)viewport->Size.y, v->MinImageCount);
+        vd->SwapChainNeedRebuild = vd->SwapChainSuboptimal = false;
+    }
+
+    ImGui_ImplVulkanH_Frame* fd = nullptr;
+    ImGui_ImplVulkanH_FrameSemaphores* fsd = &wd->FrameSemaphores[wd->SemaphoreIndex];
+    {
+        {
+            err = vkAcquireNextImageKHR(v->Device, wd->Swapchain, UINT64_MAX, fsd->ImageAcquiredSemaphore, VK_NULL_HANDLE, &wd->FrameIndex);
+            if (err == VK_ERROR_OUT_OF_DATE_KHR)
+            {
+                vd->SwapChainNeedRebuild = true; // Since we are not going to swap this frame anyway, it's ok that recreation happens on next frame.
+                return;
+            }
+            if (err == VK_SUBOPTIMAL_KHR)
+                vd->SwapChainSuboptimal = true;
+            else
+                check_vk_result(err);
+            fd = &wd->Frames[wd->FrameIndex];
+        }
+        for (;;)
+        {
+            err = vkWaitForFences(v->Device, 1, &fd->Fence, VK_TRUE, 100);
+            if (err == VK_SUCCESS) break;
+            if (err == VK_TIMEOUT) continue;
+            check_vk_result(err);
+        }
+        {
+            err = vkResetCommandPool(v->Device, fd->CommandPool, 0);
+            check_vk_result(err);
+            VkCommandBufferBeginInfo info = {};
+            info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
+            info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
+            err = vkBeginCommandBuffer(fd->CommandBuffer, &info);
+            check_vk_result(err);
+        }
+        {
+            ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+            memcpy(&wd->ClearValue.color.float32[0], &clear_color, 4 * sizeof(float));
+        }
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+        if (v->UseDynamicRendering)
+        {
+            // Transition swapchain image to a layout suitable for drawing.
+            VkImageMemoryBarrier barrier = {};
+            barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
+            barrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
+            barrier.oldLayout = VK_IMAGE_LAYOUT_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, bd->PipelineForViewports);
+
+    {
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+        if (v->UseDynamicRendering)
+        {
+            ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR(fd->CommandBuffer);
+
+            // Transition image to a layout suitable for presentation
+            VkImageMemoryBarrier barrier = {};
+            barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
+            barrier.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
+            barrier.oldLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+            barrier.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
+            barrier.image = fd->Backbuffer;
+            barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+            barrier.subresourceRange.levelCount = 1;
+            barrier.subresourceRange.layerCount = 1;
+            vkCmdPipelineBarrier(fd->CommandBuffer, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT, VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT, 0, 0, nullptr, 0, nullptr, 1, &barrier);
+        }
+        else
+#endif
+        {
+            vkCmdEndRenderPass(fd->CommandBuffer);
+        }
+        {
+            VkPipelineStageFlags wait_stage = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
+            VkSubmitInfo info = {};
+            info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
+            info.waitSemaphoreCount = 1;
+            info.pWaitSemaphores = &fsd->ImageAcquiredSemaphore;
+            info.pWaitDstStageMask = &wait_stage;
+            info.commandBufferCount = 1;
+            info.pCommandBuffers = &fd->CommandBuffer;
+            info.signalSemaphoreCount = 1;
+            info.pSignalSemaphores = &fsd->RenderCompleteSemaphore;
+
+            err = vkEndCommandBuffer(fd->CommandBuffer);
+            check_vk_result(err);
+            err = vkResetFences(v->Device, 1, &fd->Fence);
+            check_vk_result(err);
+            err = vkQueueSubmit(v->Queue, 1, &info, fd->Fence);
+            check_vk_result(err);
+        }
+    }
+}
+
+static void ImGui_ImplVulkan_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
+    ImGui_ImplVulkanH_Window* wd = &vd->Window;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+
+    if (vd->SwapChainNeedRebuild) // Frame data became invalid in the middle of rendering
+        return;
+
+    VkResult err;
+    uint32_t present_index = wd->FrameIndex;
+
+    ImGui_ImplVulkanH_FrameSemaphores* fsd = &wd->FrameSemaphores[wd->SemaphoreIndex];
+    VkPresentInfoKHR info = {};
+    info.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
+    info.waitSemaphoreCount = 1;
+    info.pWaitSemaphores = &fsd->RenderCompleteSemaphore;
+    info.swapchainCount = 1;
+    info.pSwapchains = &wd->Swapchain;
+    info.pImageIndices = &present_index;
+    err = vkQueuePresentKHR(v->Queue, &info);
+    if (err == VK_ERROR_OUT_OF_DATE_KHR)
+    {
+        vd->SwapChainNeedRebuild = true;
+        return;
+    }
+    if (err == VK_SUBOPTIMAL_KHR)
+        vd->SwapChainSuboptimal = true;
+    else
+        check_vk_result(err);
+    wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->SemaphoreCount; // Now we can use the next set of semaphores
+}
+
+void ImGui_ImplVulkan_InitMultiViewportSupport()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    if (ImGui::GetIO().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_ShutdownMultiViewportSupport()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 //-----------------------------------------------------------------------------
 
 #endif // #ifndef IMGUI_DISABLE

backends/imgui_impl_vulkan.h

@@ -5,6 +5,7 @@
 //  [!] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Call ImGui_ImplVulkan_AddTexture() to register one. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+//  [x] Renderer: Multi-viewport / platform windows. With issues (flickering when creating a new viewport).
 
 // The aim of imgui_impl_vulkan.h/.cpp is to be usable in your engine without any modification.
 // IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
@@ -75,16 +76,17 @@
 //   - When using dynamic rendering, set UseDynamicRendering=true and fill PipelineRenderingCreateInfo structure.
 struct ImGui_ImplVulkan_InitInfo
 {
+    uint32_t                        ApiVersion;                 // Fill with API version of Instance, e.g. VK_API_VERSION_1_3 or your value of VkApplicationInfo::apiVersion. May be lower than header version (VK_HEADER_VERSION_COMPLETE)
     VkInstance                      Instance;
     VkPhysicalDevice                PhysicalDevice;
     VkDevice                        Device;
     uint32_t                        QueueFamily;
     VkQueue                         Queue;
-    VkDescriptorPool                DescriptorPool;               // See requirements in note above; ignored if using DescriptorPoolSize > 0
-    VkRenderPass                    RenderPass;                   // Ignored if using dynamic rendering
-    uint32_t                        MinImageCount;                // >= 2
-    uint32_t                        ImageCount;                   // >= MinImageCount
-    VkSampleCountFlagBits           MSAASamples;                  // 0 defaults to VK_SAMPLE_COUNT_1_BIT
+    VkDescriptorPool                DescriptorPool;             // See requirements in note above; ignored if using DescriptorPoolSize > 0
+    VkRenderPass                    RenderPass;                 // Ignored if using dynamic rendering
+    uint32_t                        MinImageCount;              // >= 2
+    uint32_t                        ImageCount;                 // >= MinImageCount
+    VkSampleCountFlagBits           MSAASamples;                // 0 defaults to VK_SAMPLE_COUNT_1_BIT
 
     // (Optional)
     VkPipelineCache                 PipelineCache;
@@ -103,7 +105,7 @@ struct ImGui_ImplVulkan_InitInfo
     // (Optional) Allocation, Debugging
     const VkAllocationCallbacks*    Allocator;
     void                            (*CheckVkResultFn)(VkResult err);
-    VkDeviceSize                    MinAllocationSize;      // Minimum allocation size. Set to 1024*1024 to satisfy zealous best practices validation layer and waste a little memory.
+    VkDeviceSize                    MinAllocationSize;          // Minimum allocation size. Set to 1024*1024 to satisfy zealous best practices validation layer and waste a little memory.
 };
 
 // Follow "Getting Started" link and check examples/ folder to learn about using backends!
@@ -123,7 +125,7 @@ IMGUI_IMPL_API void             ImGui_ImplVulkan_RemoveTexture(VkDescriptorSet d
 
 // Optional: load Vulkan functions with a custom function loader
 // This is only useful with IMGUI_IMPL_VULKAN_NO_PROTOTYPES / VK_NO_PROTOTYPES
-IMGUI_IMPL_API bool             ImGui_ImplVulkan_LoadFunctions(PFN_vkVoidFunction(*loader_func)(const char* function_name, void* user_data), void* user_data = nullptr);
+IMGUI_IMPL_API bool             ImGui_ImplVulkan_LoadFunctions(uint32_t api_version, PFN_vkVoidFunction(*loader_func)(const char* function_name, void* user_data), void* user_data = nullptr);
 
 // [BETA] Selected render state data shared with callbacks.
 // This is temporarily stored in GetPlatformIO().Renderer_RenderState during the ImGui_ImplVulkan_RenderDrawData() call.
@@ -161,8 +163,8 @@ struct ImGui_ImplVulkanH_Frame;
 struct ImGui_ImplVulkanH_Window;
 
 // Helpers
-IMGUI_IMPL_API void                 ImGui_ImplVulkanH_CreateOrResizeWindow(VkInstance instance, VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wnd, uint32_t queue_family, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count);
-IMGUI_IMPL_API void                 ImGui_ImplVulkanH_DestroyWindow(VkInstance instance, VkDevice device, ImGui_ImplVulkanH_Window* wnd, const VkAllocationCallbacks* allocator);
+IMGUI_IMPL_API void                 ImGui_ImplVulkanH_CreateOrResizeWindow(VkInstance instance, VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, uint32_t queue_family, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count);
+IMGUI_IMPL_API void                 ImGui_ImplVulkanH_DestroyWindow(VkInstance instance, VkDevice device, ImGui_ImplVulkanH_Window* wd, const VkAllocationCallbacks* allocator);
 IMGUI_IMPL_API VkSurfaceFormatKHR   ImGui_ImplVulkanH_SelectSurfaceFormat(VkPhysicalDevice physical_device, VkSurfaceKHR surface, const VkFormat* request_formats, int request_formats_count, VkColorSpaceKHR request_color_space);
 IMGUI_IMPL_API VkPresentModeKHR     ImGui_ImplVulkanH_SelectPresentMode(VkPhysicalDevice physical_device, VkSurfaceKHR surface, const VkPresentModeKHR* request_modes, int request_modes_count);
 IMGUI_IMPL_API VkPhysicalDevice     ImGui_ImplVulkanH_SelectPhysicalDevice(VkInstance instance);
@@ -199,7 +201,6 @@ struct ImGui_ImplVulkanH_Window
     VkSurfaceFormatKHR  SurfaceFormat;
     VkPresentModeKHR    PresentMode;
     VkRenderPass        RenderPass;
-    VkPipeline          Pipeline;               // The window pipeline may uses a different VkRenderPass than the one passed in ImGui_ImplVulkan_InitInfo
     bool                UseDynamicRendering;
     bool                ClearEnable;
     VkClearValue        ClearValue;
@@ -207,8 +208,8 @@ struct ImGui_ImplVulkanH_Window
     uint32_t            ImageCount;             // Number of simultaneous in-flight frames (returned by vkGetSwapchainImagesKHR, usually derived from min_image_count)
     uint32_t            SemaphoreCount;         // Number of simultaneous in-flight frames + 1, to be able to use it in vkAcquireNextImageKHR
     uint32_t            SemaphoreIndex;         // Current set of swapchain wait semaphores we're using (needs to be distinct from per frame data)
-    ImGui_ImplVulkanH_Frame*            Frames;
-    ImGui_ImplVulkanH_FrameSemaphores*  FrameSemaphores;
+    ImVector<ImGui_ImplVulkanH_Frame>           Frames;
+    ImVector<ImGui_ImplVulkanH_FrameSemaphores> FrameSemaphores;
 
     ImGui_ImplVulkanH_Window()
     {

backends/imgui_impl_wgpu.cpp

@@ -6,6 +6,8 @@
 //  [X] Renderer: User texture binding. Use 'WGPUTextureView' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+// 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.
@@ -17,6 +19,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-02-26: Recreate image bind groups during render. (#8426, #8046, #7765, #8027) + Update for latest webgpu-native changes.
 //  2024-10-14: Update Dawn support for change of string usages. (#8082, #8083)
 //  2024-10-07: Expose selected render state in ImGui_ImplWGPU_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
 //  2024-10-07: Changed default texture sampler to Clamp instead of Repeat/Wrap.
@@ -40,6 +43,8 @@
 //  2021-02-18: Change blending equation to preserve alpha in output buffer.
 //  2021-01-28: Initial version.
 
+#include "imgui.h"
+
 // When targeting native platforms (i.e. NOT emscripten), one of IMGUI_IMPL_WEBGPU_BACKEND_DAWN
 // or IMGUI_IMPL_WEBGPU_BACKEND_WGPU must be provided. See imgui_impl_wgpu.h for more details.
 #ifndef __EMSCRIPTEN__
@@ -52,14 +57,19 @@
     #endif
 #endif
 
-#include "imgui.h"
 #ifndef IMGUI_DISABLE
 #include "imgui_impl_wgpu.h"
 #include <limits.h>
 #include <webgpu/webgpu.h>
 
+#ifdef IMGUI_IMPL_WEBGPU_BACKEND_DAWN
+// Dawn renamed WGPUProgrammableStageDescriptor to WGPUComputeState (see: https://github.com/webgpu-native/webgpu-headers/pull/413)
+// Using type alias until WGPU adopts the same naming convention (#8369)
+using WGPUProgrammableStageDescriptor = WGPUComputeState;
+#endif
+
 // Dear ImGui prototypes from imgui_internal.h
-extern ImGuiID ImHashData(const void* data_p, size_t data_size, ImU32 seed = 0);
+extern ImGuiID ImHashData(const void* data_p, size_t data_size, ImU32 seed);
 #define MEMALIGN(_SIZE,_ALIGN)        (((_SIZE) + ((_ALIGN) - 1)) & ~((_ALIGN) - 1))    // Memory align (copied from IM_ALIGN() macro).
 
 // WebGPU data
@@ -71,7 +81,6 @@ struct RenderResources
     WGPUBuffer          Uniforms = nullptr;             // Shader uniforms
     WGPUBindGroup       CommonBindGroup = nullptr;      // Resources bind-group to bind the common resources to pipeline
     ImGuiStorage        ImageBindGroups;                // Resources bind-group to bind the font/image resources to pipeline (this is a key->value map)
-    WGPUBindGroup       ImageBindGroup = nullptr;       // Default font-resource of Dear ImGui
     WGPUBindGroupLayout ImageBindGroupLayout = nullptr; // Cache layout used for the image bind group. Avoids allocating unnecessary JS objects when working with WebASM
 };
 
@@ -245,7 +254,6 @@ static void SafeRelease(RenderResources& res)
     SafeRelease(res.Sampler);
     SafeRelease(res.Uniforms);
     SafeRelease(res.CommonBindGroup);
-    SafeRelease(res.ImageBindGroup);
     SafeRelease(res.ImageBindGroupLayout);
 };
 
@@ -261,14 +269,14 @@ static WGPUProgrammableStageDescriptor ImGui_ImplWGPU_CreateShaderModule(const c
 {
     ImGui_ImplWGPU_Data* bd = ImGui_ImplWGPU_GetBackendData();
 
-#ifdef IMGUI_IMPL_WEBGPU_BACKEND_DAWN
-	WGPUShaderSourceWGSL wgsl_desc = {};
+#if defined(IMGUI_IMPL_WEBGPU_BACKEND_DAWN) || defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
+    WGPUShaderSourceWGSL wgsl_desc = {};
     wgsl_desc.chain.sType = WGPUSType_ShaderSourceWGSL;
-	wgsl_desc.code = { wgsl_source, WGPU_STRLEN };
+    wgsl_desc.code = { wgsl_source, WGPU_STRLEN };
 #else
-	WGPUShaderModuleWGSLDescriptor wgsl_desc = {};
+    WGPUShaderModuleWGSLDescriptor wgsl_desc = {};
     wgsl_desc.chain.sType = WGPUSType_ShaderModuleWGSLDescriptor;
-	wgsl_desc.code = wgsl_source;
+    wgsl_desc.code = wgsl_source;
 #endif
 
     WGPUShaderModuleDescriptor desc = {};
@@ -276,7 +284,8 @@ static WGPUProgrammableStageDescriptor ImGui_ImplWGPU_CreateShaderModule(const c
 
     WGPUProgrammableStageDescriptor stage_desc = {};
     stage_desc.module = wgpuDeviceCreateShaderModule(bd->wgpuDevice, &desc);
-#ifdef IMGUI_IMPL_WEBGPU_BACKEND_DAWN
+
+#if defined(IMGUI_IMPL_WEBGPU_BACKEND_DAWN) || defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
     stage_desc.entryPoint = { "main", WGPU_STRLEN };
 #else
     stage_desc.entryPoint = "main";
@@ -393,7 +402,7 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder
         {
             nullptr,
             "Dear ImGui Vertex buffer",
-#ifdef IMGUI_IMPL_WEBGPU_BACKEND_DAWN
+#if defined(IMGUI_IMPL_WEBGPU_BACKEND_DAWN) || defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
             WGPU_STRLEN,
 #endif
             WGPUBufferUsage_CopyDst | WGPUBufferUsage_Vertex,
@@ -420,7 +429,7 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder
         {
             nullptr,
             "Dear ImGui Index buffer",
-#ifdef IMGUI_IMPL_WEBGPU_BACKEND_DAWN
+#if defined(IMGUI_IMPL_WEBGPU_BACKEND_DAWN) || defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
             WGPU_STRLEN,
 #endif
             WGPUBufferUsage_CopyDst | WGPUBufferUsage_Index,
@@ -485,18 +494,14 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder
             {
                 // Bind custom texture
                 ImTextureID tex_id = pcmd->GetTexID();
-                ImGuiID tex_id_hash = ImHashData(&tex_id, sizeof(tex_id));
-                auto bind_group = bd->renderResources.ImageBindGroups.GetVoidPtr(tex_id_hash);
-                if (bind_group)
+                ImGuiID tex_id_hash = ImHashData(&tex_id, sizeof(tex_id), 0);
+                WGPUBindGroup bind_group = (WGPUBindGroup)bd->renderResources.ImageBindGroups.GetVoidPtr(tex_id_hash);
+                if (!bind_group)
                 {
-                    wgpuRenderPassEncoderSetBindGroup(pass_encoder, 1, (WGPUBindGroup)bind_group, 0, nullptr);
-                }
-                else
-                {
-                    WGPUBindGroup image_bind_group = ImGui_ImplWGPU_CreateImageBindGroup(bd->renderResources.ImageBindGroupLayout, (WGPUTextureView)tex_id);
-                    bd->renderResources.ImageBindGroups.SetVoidPtr(tex_id_hash, image_bind_group);
-                    wgpuRenderPassEncoderSetBindGroup(pass_encoder, 1, image_bind_group, 0, nullptr);
+                    bind_group = ImGui_ImplWGPU_CreateImageBindGroup(bd->renderResources.ImageBindGroupLayout, (WGPUTextureView)tex_id);
+                    bd->renderResources.ImageBindGroups.SetVoidPtr(tex_id_hash, bind_group);
                 }
+                wgpuRenderPassEncoderSetBindGroup(pass_encoder, 1, (WGPUBindGroup)bind_group, 0, nullptr);
 
                 // Project scissor/clipping rectangles into framebuffer space
                 ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
@@ -518,6 +523,16 @@ void ImGui_ImplWGPU_RenderDrawData(ImDrawData* draw_data, WGPURenderPassEncoder
         global_idx_offset += draw_list->IdxBuffer.Size;
         global_vtx_offset += draw_list->VtxBuffer.Size;
     }
+
+    // Remove all ImageBindGroups
+    ImGuiStorage& image_bind_groups = bd->renderResources.ImageBindGroups;
+    for (int i = 0; i < image_bind_groups.Data.Size; i++)
+    {
+        WGPUBindGroup bind_group = (WGPUBindGroup)image_bind_groups.Data[i].val_p;
+        SafeRelease(bind_group);
+    }
+    image_bind_groups.Data.resize(0);
+
     platform_io.Renderer_RenderState = nullptr;
 }
 
@@ -533,7 +548,7 @@ static void ImGui_ImplWGPU_CreateFontsTexture()
     // Upload texture to graphics system
     {
         WGPUTextureDescriptor tex_desc = {};
-#ifdef IMGUI_IMPL_WEBGPU_BACKEND_DAWN
+#if defined(IMGUI_IMPL_WEBGPU_BACKEND_DAWN) || defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
         tex_desc.label = { "Dear ImGui Font Texture", WGPU_STRLEN };
 #else
         tex_desc.label = "Dear ImGui Font Texture";
@@ -561,12 +576,20 @@ static void ImGui_ImplWGPU_CreateFontsTexture()
 
     // Upload texture data
     {
+#if defined(IMGUI_IMPL_WEBGPU_BACKEND_DAWN) || defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
+        WGPUTexelCopyTextureInfo dst_view = {};
+#else
         WGPUImageCopyTexture dst_view = {};
+#endif
         dst_view.texture = bd->renderResources.FontTexture;
         dst_view.mipLevel = 0;
         dst_view.origin = { 0, 0, 0 };
         dst_view.aspect = WGPUTextureAspect_All;
+#if defined(IMGUI_IMPL_WEBGPU_BACKEND_DAWN) || defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
+        WGPUTexelCopyBufferLayout layout = {};
+#else
         WGPUTextureDataLayout layout = {};
+#endif
         layout.offset = 0;
         layout.bytesPerRow = width * size_pp;
         layout.rowsPerImage = height;
@@ -600,7 +623,7 @@ static void ImGui_ImplWGPU_CreateUniformBuffer()
     {
         nullptr,
         "Dear ImGui Uniform buffer",
-#ifdef IMGUI_IMPL_WEBGPU_BACKEND_DAWN
+#if defined(IMGUI_IMPL_WEBGPU_BACKEND_DAWN) || defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
         WGPU_STRLEN,
 #endif
         WGPUBufferUsage_CopyDst | WGPUBufferUsage_Uniform,
@@ -666,9 +689,15 @@ bool ImGui_ImplWGPU_CreateDeviceObjects()
     // Vertex input configuration
     WGPUVertexAttribute attribute_desc[] =
     {
+#ifdef IMGUI_IMPL_WEBGPU_BACKEND_DAWN
+        { nullptr, WGPUVertexFormat_Float32x2, (uint64_t)offsetof(ImDrawVert, pos), 0 },
+        { nullptr, WGPUVertexFormat_Float32x2, (uint64_t)offsetof(ImDrawVert, uv),  1 },
+        { nullptr, WGPUVertexFormat_Unorm8x4,  (uint64_t)offsetof(ImDrawVert, col), 2 },
+#else
         { WGPUVertexFormat_Float32x2, (uint64_t)offsetof(ImDrawVert, pos), 0 },
         { WGPUVertexFormat_Float32x2, (uint64_t)offsetof(ImDrawVert, uv),  1 },
         { WGPUVertexFormat_Unorm8x4,  (uint64_t)offsetof(ImDrawVert, col), 2 },
+#endif
     };
 
     WGPUVertexBufferLayout buffer_layouts[1];
@@ -708,7 +737,7 @@ bool ImGui_ImplWGPU_CreateDeviceObjects()
     // Create depth-stencil State
     WGPUDepthStencilState depth_stencil_state = {};
     depth_stencil_state.format = bd->depthStencilFormat;
-#ifdef IMGUI_IMPL_WEBGPU_BACKEND_DAWN
+#if defined(IMGUI_IMPL_WEBGPU_BACKEND_DAWN) || defined(IMGUI_IMPL_WEBGPU_BACKEND_WGPU)
     depth_stencil_state.depthWriteEnabled = WGPUOptionalBool_False;
 #else
     depth_stencil_state.depthWriteEnabled = false;
@@ -743,11 +772,7 @@ bool ImGui_ImplWGPU_CreateDeviceObjects()
     common_bg_descriptor.entryCount = sizeof(common_bg_entries) / sizeof(WGPUBindGroupEntry);
     common_bg_descriptor.entries = common_bg_entries;
     bd->renderResources.CommonBindGroup = wgpuDeviceCreateBindGroup(bd->wgpuDevice, &common_bg_descriptor);
-
-    WGPUBindGroup image_bind_group = ImGui_ImplWGPU_CreateImageBindGroup(bg_layouts[1], bd->renderResources.FontTextureView);
-    bd->renderResources.ImageBindGroup = image_bind_group;
     bd->renderResources.ImageBindGroupLayout = bg_layouts[1];
-    bd->renderResources.ImageBindGroups.SetVoidPtr(ImHashData(&bd->renderResources.FontTextureView, sizeof(ImTextureID)), image_bind_group);
 
     SafeRelease(vertex_shader_desc.module);
     SafeRelease(pixel_shader_desc.module);
@@ -807,7 +832,6 @@ bool ImGui_ImplWGPU_Init(ImGui_ImplWGPU_InitInfo* init_info)
     bd->renderResources.Uniforms = nullptr;
     bd->renderResources.CommonBindGroup = nullptr;
     bd->renderResources.ImageBindGroups.Data.reserve(100);
-    bd->renderResources.ImageBindGroup = nullptr;
     bd->renderResources.ImageBindGroupLayout = nullptr;
 
     // Create buffers with a default size (they will later be grown as needed)

backends/imgui_impl_wgpu.h

@@ -13,6 +13,8 @@
 //  [X] Renderer: User texture binding. Use 'WGPUTextureView' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
+// 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.

backends/imgui_impl_win32.cpp

@@ -7,6 +7,7 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy VK_* values are obsolete since 1.87 and not supported since 1.91.5]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility (ImGuiBackendFlags_HasMouseCursors). Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -21,6 +22,13 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2025-03-10: When dealing with OEM keys, use scancodes instead of translated keycodes to choose ImGuiKey values. (#7136, #7201, #7206, #7306, #7670, #7672, #8468)
+//  2025-02-21: [Docking] WM_SETTINGCHANGE's SPI_SETWORKAREA message also triggers a refresh of monitor list. (#8415)
+//  2025-02-18: Added ImGuiMouseCursor_Wait and ImGuiMouseCursor_Progress mouse cursor support.
+//  2024-11-21: [Docking] Fixed a crash when multiple processes are running with multi-viewports, caused by misusage of GetProp(). (#8162, #8069)
+//  2024-10-28: [Docking] Rely on property stored inside HWND to retrieve context/viewport, should facilitate attempt to use this for parallel contexts. (#8069)
+//  2024-09-16: [Docking] Inputs: fixed an issue where a viewport destroyed while clicking would hog mouse tracking and temporary lead to incorrect update of HoveredWindow. (#7971)
 //  2024-07-08: Inputs: Fixed ImGuiMod_Super being mapped to VK_APPS instead of VK_LWIN||VK_RWIN. (#7768)
 //  2023-10-05: Inputs: Added support for extra ImGuiKey values: F13 to F24 function keys, app back/forward keys.
 //  2023-09-25: Inputs: Synthesize key-down event on key-up for VK_SNAPSHOT / ImGuiKey_PrintScreen as Windows doesn't emit it (same behavior as GLFW/SDL).
@@ -103,6 +111,11 @@ typedef DWORD(WINAPI* PFN_XInputGetState)(DWORD, XINPUT_STATE*);
 #pragma GCC diagnostic ignored "-Wcast-function-type"       // warning: cast between incompatible function types (for loader)
 #endif
 
+// Forward Declarations
+static void ImGui_ImplWin32_InitMultiViewportSupport(bool platform_has_own_dc);
+static void ImGui_ImplWin32_ShutdownMultiViewportSupport();
+static void ImGui_ImplWin32_UpdateMonitors();
+
 struct ImGui_ImplWin32_Data
 {
     HWND                        hWnd;
@@ -113,6 +126,7 @@ struct ImGui_ImplWin32_Data
     INT64                       TicksPerSecond;
     ImGuiMouseCursor            LastMouseCursor;
     UINT32                      KeyboardCodePage;
+    bool                        WantUpdateMonitors;
 
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
     bool                        HasGamepad;
@@ -167,6 +181,8 @@ 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->TicksPerSecond = perf_frequency;
@@ -174,10 +190,17 @@ static bool ImGui_ImplWin32_InitEx(void* hwnd, bool platform_has_own_dc)
     bd->LastMouseCursor = ImGuiMouseCursor_COUNT;
     ImGui_ImplWin32_UpdateKeyboardCodePage(io);
 
-    // Set platform dependent data in viewport
+    // Update monitor a first time during init
+    ImGui_ImplWin32_UpdateMonitors();
+
+    // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = main_viewport->PlatformHandleRaw = (void*)bd->hWnd;
-    IM_UNUSED(platform_has_own_dc); // Used in 'docking' branch
+
+    // Be aware that GetPropA()/SetPropA() may be accessed from other processes.
+    // So as we store a pointer in IMGUI_CONTEXT we need to make sure we only call GetPropA() on windows owned by our process.
+    ::SetPropA(bd->hWnd, "IMGUI_CONTEXT", ImGui::GetCurrentContext());
+    ImGui_ImplWin32_InitMultiViewportSupport(platform_has_own_dc);
 
     // Dynamically load XInput library
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
@@ -220,6 +243,9 @@ void    ImGui_ImplWin32_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ::SetPropA(bd->hWnd, "IMGUI_CONTEXT", nullptr);
+    ImGui_ImplWin32_ShutdownMultiViewportSupport();
+
     // Unload XInput library
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
     if (bd->XInputDLL)
@@ -228,7 +254,7 @@ 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);
 }
 
@@ -256,6 +282,8 @@ static bool ImGui_ImplWin32_UpdateMouseCursor(ImGuiIO& io, ImGuiMouseCursor imgu
         case ImGuiMouseCursor_ResizeNESW:   win32_cursor = IDC_SIZENESW; break;
         case ImGuiMouseCursor_ResizeNWSE:   win32_cursor = IDC_SIZENWSE; break;
         case ImGuiMouseCursor_Hand:         win32_cursor = IDC_HAND; break;
+        case ImGuiMouseCursor_Wait:         win32_cursor = IDC_WAIT; break;
+        case ImGuiMouseCursor_Progress:     win32_cursor = IDC_APPSTARTING; break;
         case ImGuiMouseCursor_NotAllowed:   win32_cursor = IDC_NO; break;
         }
         ::SetCursor(::LoadCursor(nullptr, win32_cursor));
@@ -298,32 +326,69 @@ static void ImGui_ImplWin32_UpdateKeyModifiers(ImGuiIO& io)
     io.AddKeyEvent(ImGuiMod_Super, IsVkDown(VK_LWIN) || IsVkDown(VK_RWIN));
 }
 
-static void ImGui_ImplWin32_UpdateMouseData(ImGuiIO& io)
+static ImGuiViewport* ImGui_ImplWin32_FindViewportByPlatformHandle(ImGuiPlatformIO& platform_io, HWND hwnd)
+{
+    // We cannot use ImGui::FindViewportByPlatformHandle() because it doesn't take a context.
+    // When called from ImGui_ImplWin32_WndProcHandler_PlatformWindow() we don't assume that context is bound.
+    //return ImGui::FindViewportByPlatformHandle((void*)hwnd);
+    for (ImGuiViewport* viewport : platform_io.Viewports)
+        if (viewport->PlatformHandle == hwnd)
+            return viewport;
+    return nullptr;
+}
+
+// This code supports multi-viewports (multiple OS Windows mapped into different Dear ImGui viewports)
+// Because of that, it is a little more complicated than your typical single-viewport binding code!
+static void ImGui_ImplWin32_UpdateMouseData(ImGuiIO& io, ImGuiPlatformIO& platform_io)
 {
     ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData(io);
     IM_ASSERT(bd->hWnd != 0);
 
+    POINT mouse_screen_pos;
+    bool has_mouse_screen_pos = ::GetCursorPos(&mouse_screen_pos) != 0;
+
     HWND focused_window = ::GetForegroundWindow();
-    const bool is_app_focused = (focused_window == bd->hWnd);
+    const bool is_app_focused = (focused_window && (focused_window == bd->hWnd || ::IsChild(focused_window, bd->hWnd) || ImGui_ImplWin32_FindViewportByPlatformHandle(platform_io, focused_window)));
     if (is_app_focused)
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when io.ConfigNavMoveSetMousePos is enabled by user)
+        // When multi-viewports are enabled, all Dear ImGui positions are same as OS positions.
         if (io.WantSetMousePos)
         {
             POINT pos = { (int)io.MousePos.x, (int)io.MousePos.y };
-            if (::ClientToScreen(bd->hWnd, &pos))
-                ::SetCursorPos(pos.x, pos.y);
+            if ((io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) == 0)
+                ::ClientToScreen(focused_window, &pos);
+            ::SetCursorPos(pos.x, pos.y);
         }
 
         // (Optional) Fallback to provide mouse position when focused (WM_MOUSEMOVE already provides this when hovered or captured)
         // This also fills a short gap when clicking non-client area: WM_NCMOUSELEAVE -> modal OS move -> gap -> WM_NCMOUSEMOVE
-        if (!io.WantSetMousePos && bd->MouseTrackedArea == 0)
+        if (!io.WantSetMousePos && bd->MouseTrackedArea == 0 && has_mouse_screen_pos)
         {
-            POINT pos;
-            if (::GetCursorPos(&pos) && ::ScreenToClient(bd->hWnd, &pos))
-                io.AddMousePosEvent((float)pos.x, (float)pos.y);
+            // Single viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
+            // (This is the position you can get with ::GetCursorPos() + ::ScreenToClient() or WM_MOUSEMOVE.)
+            // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+            // (This is the position you can get with ::GetCursorPos() or WM_MOUSEMOVE + ::ClientToScreen(). In theory adding viewport->Pos to a client position would also be the same.)
+            POINT mouse_pos = mouse_screen_pos;
+            if (!(io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable))
+                ::ScreenToClient(bd->hWnd, &mouse_pos);
+            io.AddMousePosEvent((float)mouse_pos.x, (float)mouse_pos.y);
         }
     }
+
+    // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+    // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+    // - [X] Win32 backend correctly ignore viewports with the _NoInputs flag (here using ::WindowFromPoint with WM_NCHITTEST + HTTRANSPARENT in WndProc does that)
+    //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+    //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+    //       by the backend, and use its flawed heuristic to guess the viewport behind.
+    // - [X] Win32 backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+    ImGuiID mouse_viewport_id = 0;
+    if (has_mouse_screen_pos)
+        if (HWND hovered_hwnd = ::WindowFromPoint(mouse_screen_pos))
+            if (ImGuiViewport* viewport = ImGui_ImplWin32_FindViewportByPlatformHandle(platform_io, hovered_hwnd))
+                mouse_viewport_id = viewport->ID;
+    io.AddMouseViewportEvent(mouse_viewport_id);
 }
 
 // Gamepad navigation mapping
@@ -384,16 +449,50 @@ static void ImGui_ImplWin32_UpdateGamepads(ImGuiIO& io)
 #endif
 }
 
+static BOOL CALLBACK ImGui_ImplWin32_UpdateMonitors_EnumFunc(HMONITOR monitor, HDC, LPRECT, LPARAM)
+{
+    MONITORINFO info = {};
+    info.cbSize = sizeof(MONITORINFO);
+    if (!::GetMonitorInfo(monitor, &info))
+        return TRUE;
+    ImGuiPlatformMonitor imgui_monitor;
+    imgui_monitor.MainPos = ImVec2((float)info.rcMonitor.left, (float)info.rcMonitor.top);
+    imgui_monitor.MainSize = ImVec2((float)(info.rcMonitor.right - info.rcMonitor.left), (float)(info.rcMonitor.bottom - info.rcMonitor.top));
+    imgui_monitor.WorkPos = ImVec2((float)info.rcWork.left, (float)info.rcWork.top);
+    imgui_monitor.WorkSize = ImVec2((float)(info.rcWork.right - info.rcWork.left), (float)(info.rcWork.bottom - info.rcWork.top));
+    imgui_monitor.DpiScale = ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
+    imgui_monitor.PlatformHandle = (void*)monitor;
+    if (imgui_monitor.DpiScale <= 0.0f)
+        return TRUE; // Some accessibility applications are declaring virtual monitors with a DPI of 0, see #7902.
+    ImGuiPlatformIO& io = ImGui::GetPlatformIO();
+    if (info.dwFlags & MONITORINFOF_PRIMARY)
+        io.Monitors.push_front(imgui_monitor);
+    else
+        io.Monitors.push_back(imgui_monitor);
+    return TRUE;
+}
+
+static void ImGui_ImplWin32_UpdateMonitors()
+{
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    ImGui::GetPlatformIO().Monitors.resize(0);
+    ::EnumDisplayMonitors(nullptr, nullptr, ImGui_ImplWin32_UpdateMonitors_EnumFunc, 0);
+    bd->WantUpdateMonitors = false;
+}
+
 void    ImGui_ImplWin32_NewFrame()
 {
     ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
     IM_ASSERT(bd != nullptr && "Context or backend not initialized? Did you call ImGui_ImplWin32_Init()?");
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
     // Setup display size (every frame to accommodate for window resizing)
     RECT rect = { 0, 0, 0, 0 };
     ::GetClientRect(bd->hWnd, &rect);
     io.DisplaySize = ImVec2((float)(rect.right - rect.left), (float)(rect.bottom - rect.top));
+    if (bd->WantUpdateMonitors)
+        ImGui_ImplWin32_UpdateMonitors();
 
     // Setup time step
     INT64 current_time = 0;
@@ -402,7 +501,7 @@ void    ImGui_ImplWin32_NewFrame()
     bd->Time = current_time;
 
     // Update OS mouse position
-    ImGui_ImplWin32_UpdateMouseData(io);
+    ImGui_ImplWin32_UpdateMouseData(io, platform_io);
 
     // Process workarounds for known Windows key handling issues
     ImGui_ImplWin32_ProcessKeyEventsWorkarounds(io);
@@ -428,6 +527,8 @@ ImGuiKey ImGui_ImplWin32_KeyEventToImGuiKey(WPARAM wParam, LPARAM lParam)
     if ((wParam == VK_RETURN) && (HIWORD(lParam) & KF_EXTENDED))
         return ImGuiKey_KeypadEnter;
 
+    const int scancode = (int)LOBYTE(HIWORD(lParam));
+    //IMGUI_DEBUG_LOG("scancode %3d, keycode = 0x%02X\n", scancode, wParam);
     switch (wParam)
     {
         case VK_TAB: return ImGuiKey_Tab;
@@ -445,17 +546,17 @@ ImGuiKey ImGui_ImplWin32_KeyEventToImGuiKey(WPARAM wParam, LPARAM lParam)
         case VK_SPACE: return ImGuiKey_Space;
         case VK_RETURN: return ImGuiKey_Enter;
         case VK_ESCAPE: return ImGuiKey_Escape;
-        case VK_OEM_7: return ImGuiKey_Apostrophe;
+        //case VK_OEM_7: return ImGuiKey_Apostrophe;
         case VK_OEM_COMMA: return ImGuiKey_Comma;
-        case VK_OEM_MINUS: return ImGuiKey_Minus;
+        //case VK_OEM_MINUS: return ImGuiKey_Minus;
         case VK_OEM_PERIOD: return ImGuiKey_Period;
-        case VK_OEM_2: return ImGuiKey_Slash;
-        case VK_OEM_1: return ImGuiKey_Semicolon;
-        case VK_OEM_PLUS: return ImGuiKey_Equal;
-        case VK_OEM_4: return ImGuiKey_LeftBracket;
-        case VK_OEM_5: return ImGuiKey_Backslash;
-        case VK_OEM_6: return ImGuiKey_RightBracket;
-        case VK_OEM_3: return ImGuiKey_GraveAccent;
+        //case VK_OEM_2: return ImGuiKey_Slash;
+        //case VK_OEM_1: return ImGuiKey_Semicolon;
+        //case VK_OEM_PLUS: return ImGuiKey_Equal;
+        //case VK_OEM_4: return ImGuiKey_LeftBracket;
+        //case VK_OEM_5: return ImGuiKey_Backslash;
+        //case VK_OEM_6: return ImGuiKey_RightBracket;
+        //case VK_OEM_3: return ImGuiKey_GraveAccent;
         case VK_CAPITAL: return ImGuiKey_CapsLock;
         case VK_SCROLL: return ImGuiKey_ScrollLock;
         case VK_NUMLOCK: return ImGuiKey_NumLock;
@@ -547,8 +648,28 @@ ImGuiKey ImGui_ImplWin32_KeyEventToImGuiKey(WPARAM wParam, LPARAM lParam)
         case VK_F24: return ImGuiKey_F24;
         case VK_BROWSER_BACK: return ImGuiKey_AppBack;
         case VK_BROWSER_FORWARD: return ImGuiKey_AppForward;
-        default: return ImGuiKey_None;
+        default: break;
     }
+
+    // Fallback to scancode
+    // https://handmade.network/forums/t/2011-keyboard_inputs_-_scancodes,_raw_input,_text_input,_key_names
+    switch (scancode)
+    {
+    case 41: return ImGuiKey_GraveAccent;  // VK_OEM_8 in EN-UK, VK_OEM_3 in EN-US, VK_OEM_7 in FR, VK_OEM_5 in DE, etc.
+    case 12: return ImGuiKey_Minus;
+    case 13: return ImGuiKey_Equal;
+    case 26: return ImGuiKey_LeftBracket;
+    case 27: return ImGuiKey_RightBracket;
+    case 86: return ImGuiKey_Oem102;
+    case 43: return ImGuiKey_Backslash;
+    case 39: return ImGuiKey_Semicolon;
+    case 40: return ImGuiKey_Apostrophe;
+    case 51: return ImGuiKey_Comma;
+    case 52: return ImGuiKey_Period;
+    case 53: return ImGuiKey_Slash;
+    }
+
+    return ImGuiKey_None;
 }
 
 // Allow compilation with old Windows SDK. MinGW doesn't have default _WIN32_WINNT/WINVER versions.
@@ -618,8 +739,11 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandlerEx(HWND hwnd, UINT msg, WPA
             bd->MouseTrackedArea = area;
         }
         POINT mouse_pos = { (LONG)GET_X_LPARAM(lParam), (LONG)GET_Y_LPARAM(lParam) };
-        if (msg == WM_NCMOUSEMOVE && ::ScreenToClient(hwnd, &mouse_pos) == FALSE) // WM_NCMOUSEMOVE are provided in absolute coordinates.
-            return 0;
+        bool want_absolute_pos = (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) != 0;
+        if (msg == WM_MOUSEMOVE && want_absolute_pos)    // WM_MOUSEMOVE are client-relative coordinates.
+            ::ClientToScreen(hwnd, &mouse_pos);
+        if (msg == WM_NCMOUSEMOVE && !want_absolute_pos) // WM_NCMOUSEMOVE are absolute coordinates.
+            ::ScreenToClient(hwnd, &mouse_pos);
         io.AddMouseSourceEvent(mouse_source);
         io.AddMousePosEvent((float)mouse_pos.x, (float)mouse_pos.y);
         return 0;
@@ -765,6 +889,13 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandlerEx(HWND hwnd, UINT msg, WPA
             bd->WantUpdateHasGamepad = true;
 #endif
         return 0;
+    case WM_DISPLAYCHANGE:
+        bd->WantUpdateMonitors = true;
+        return 0;
+    case WM_SETTINGCHANGE:
+        if (wParam == SPI_SETWORKAREA)
+            bd->WantUpdateMonitors = true;
+        return 0;
     }
     return 0;
 }
@@ -790,9 +921,9 @@ static BOOL _IsWindowsVersionOrGreater(WORD major, WORD minor, WORD)
 {
     typedef LONG(WINAPI* PFN_RtlVerifyVersionInfo)(OSVERSIONINFOEXW*, ULONG, ULONGLONG);
     static PFN_RtlVerifyVersionInfo RtlVerifyVersionInfoFn = nullptr;
-	if (RtlVerifyVersionInfoFn == nullptr)
-		if (HMODULE ntdllModule = ::GetModuleHandleA("ntdll.dll"))
-			RtlVerifyVersionInfoFn = (PFN_RtlVerifyVersionInfo)GetProcAddress(ntdllModule, "RtlVerifyVersionInfo");
+    if (RtlVerifyVersionInfoFn == nullptr)
+        if (HMODULE ntdllModule = ::GetModuleHandleA("ntdll.dll"))
+            RtlVerifyVersionInfoFn = (PFN_RtlVerifyVersionInfo)GetProcAddress(ntdllModule, "RtlVerifyVersionInfo");
     if (RtlVerifyVersionInfoFn == nullptr)
         return FALSE;
 
@@ -800,10 +931,10 @@ static BOOL _IsWindowsVersionOrGreater(WORD major, WORD minor, WORD)
     ULONGLONG conditionMask = 0;
     versionInfo.dwOSVersionInfoSize = sizeof(RTL_OSVERSIONINFOEXW);
     versionInfo.dwMajorVersion = major;
-	versionInfo.dwMinorVersion = minor;
-	VER_SET_CONDITION(conditionMask, VER_MAJORVERSION, VER_GREATER_EQUAL);
-	VER_SET_CONDITION(conditionMask, VER_MINORVERSION, VER_GREATER_EQUAL);
-	return (RtlVerifyVersionInfoFn(&versionInfo, VER_MAJORVERSION | VER_MINORVERSION, conditionMask) == 0) ? TRUE : FALSE;
+    versionInfo.dwMinorVersion = minor;
+    VER_SET_CONDITION(conditionMask, VER_MAJORVERSION, VER_GREATER_EQUAL);
+    VER_SET_CONDITION(conditionMask, VER_MINORVERSION, VER_GREATER_EQUAL);
+    return (RtlVerifyVersionInfoFn(&versionInfo, VER_MAJORVERSION | VER_MINORVERSION, conditionMask) == 0) ? TRUE : FALSE;
 }
 
 #define _IsWindowsVistaOrGreater()   _IsWindowsVersionOrGreater(HIBYTE(0x0600), LOBYTE(0x0600), 0) // _WIN32_WINNT_VISTA
@@ -829,6 +960,10 @@ 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
@@ -861,16 +996,16 @@ float ImGui_ImplWin32_GetDpiScaleForMonitor(void* monitor)
     UINT xdpi = 96, ydpi = 96;
     if (_IsWindows8Point1OrGreater())
     {
-		static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
-		static PFN_GetDpiForMonitor GetDpiForMonitorFn = nullptr;
-		if (GetDpiForMonitorFn == nullptr && shcore_dll != nullptr)
+        static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
+        static PFN_GetDpiForMonitor GetDpiForMonitorFn = nullptr;
+        if (GetDpiForMonitorFn == nullptr && shcore_dll != nullptr)
             GetDpiForMonitorFn = (PFN_GetDpiForMonitor)::GetProcAddress(shcore_dll, "GetDpiForMonitor");
-		if (GetDpiForMonitorFn != nullptr)
-		{
-			GetDpiForMonitorFn((HMONITOR)monitor, MDT_EFFECTIVE_DPI, &xdpi, &ydpi);
+        if (GetDpiForMonitorFn != nullptr)
+        {
+            GetDpiForMonitorFn((HMONITOR)monitor, MDT_EFFECTIVE_DPI, &xdpi, &ydpi);
             IM_ASSERT(xdpi == ydpi); // Please contact me if you hit this assert!
-			return xdpi / 96.0f;
-		}
+            return xdpi / 96.0f;
+        }
     }
 #ifndef NOGDI
     const HDC dc = ::GetDC(nullptr);
@@ -928,6 +1063,386 @@ void ImGui_ImplWin32_EnableAlphaCompositing(void* hwnd)
     }
 }
 
+//---------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* PlatformUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplWin32_ViewportData
+{
+    HWND    Hwnd;               // Stored in ImGuiViewport::PlatformHandle + PlatformHandleRaw
+    HWND    HwndParent;
+    bool    HwndOwned;
+    DWORD   DwStyle;
+    DWORD   DwExStyle;
+
+    ImGui_ImplWin32_ViewportData() { Hwnd = HwndParent = nullptr; HwndOwned = false;  DwStyle = DwExStyle = 0; }
+    ~ImGui_ImplWin32_ViewportData() { IM_ASSERT(Hwnd == nullptr); }
+};
+
+static void ImGui_ImplWin32_GetWin32StyleFromViewportFlags(ImGuiViewportFlags flags, DWORD* out_style, DWORD* out_ex_style)
+{
+    if (flags & ImGuiViewportFlags_NoDecoration)
+        *out_style = WS_POPUP;
+    else
+        *out_style = WS_OVERLAPPEDWINDOW;
+
+    if (flags & ImGuiViewportFlags_NoTaskBarIcon)
+        *out_ex_style = WS_EX_TOOLWINDOW;
+    else
+        *out_ex_style = WS_EX_APPWINDOW;
+
+    if (flags & ImGuiViewportFlags_TopMost)
+        *out_ex_style |= WS_EX_TOPMOST;
+}
+
+static HWND ImGui_ImplWin32_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 = ::CreateWindowExW(
+        vd->DwExStyle, L"ImGui Platform", L"Untitled", vd->DwStyle,       // Style, class name, window name
+        rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top,    // Window area
+        vd->HwndParent, nullptr, ::GetModuleHandle(nullptr), nullptr);          // Owner window, Menu, Instance, Param
+    vd->HwndOwned = true;
+    viewport->PlatformRequestResize = false;
+    viewport->PlatformHandle = viewport->PlatformHandleRaw = vd->Hwnd;
+
+    // Secondary viewports store their imgui context
+    ::SetPropA(vd->Hwnd, "IMGUI_CONTEXT", ImGui::GetCurrentContext());
+}
+
+static void ImGui_ImplWin32_DestroyWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    if (ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData)
+    {
+        if (::GetCapture() == vd->Hwnd)
+        {
+            // Transfer capture so if we started dragging from a window that later disappears, we'll still receive the MOUSEUP event.
+            ::ReleaseCapture();
+            ::SetCapture(bd->hWnd);
+        }
+        if (vd->Hwnd && vd->HwndOwned)
+            ::DestroyWindow(vd->Hwnd);
+        vd->Hwnd = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplWin32_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+
+    // ShowParent() also brings parent to front, which is not always desirable,
+    // so we temporarily disable parenting. (#7354)
+    if (vd->HwndParent != NULL)
+        ::SetWindowLongPtr(vd->Hwnd, GWLP_HWNDPARENT, (LONG_PTR)nullptr);
+
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+        ::ShowWindow(vd->Hwnd, SW_SHOWNA);
+    else
+        ::ShowWindow(vd->Hwnd, SW_SHOW);
+
+    // Restore
+    if (vd->HwndParent != NULL)
+        ::SetWindowLongPtr(vd->Hwnd, GWLP_HWNDPARENT, (LONG_PTR)vd->HwndParent);
+}
+
+static void ImGui_ImplWin32_UpdateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+
+    // Update Win32 parent if it changed _after_ creation
+    // Unlike style settings derived from configuration flags, this is more likely to change for advanced apps that are manipulating ParentViewportID manually.
+    HWND new_parent = ImGui_ImplWin32_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_UpdateWin32StyleFromWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    vd->DwStyle = ::GetWindowLongW(vd->Hwnd, GWL_STYLE);
+    vd->DwExStyle = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE);
+}
+
+static void ImGui_ImplWin32_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    RECT rect = { (LONG)pos.x, (LONG)pos.y, (LONG)pos.x, (LONG)pos.y };
+    if (viewport->Flags & ImGuiViewportFlags_OwnedByApp)
+        ImGui_ImplWin32_UpdateWin32StyleFromWindow(viewport); // Not our window, poll style before using
+    ::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle);
+    ::SetWindowPos(vd->Hwnd, nullptr, rect.left, rect.top, 0, 0, SWP_NOZORDER | SWP_NOSIZE | SWP_NOACTIVATE);
+}
+
+static ImVec2 ImGui_ImplWin32_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    RECT rect;
+    ::GetClientRect(vd->Hwnd, &rect);
+    return ImVec2(float(rect.right - rect.left), float(rect.bottom - rect.top));
+}
+
+static void ImGui_ImplWin32_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    RECT rect = { 0, 0, (LONG)size.x, (LONG)size.y };
+    if (viewport->Flags & ImGuiViewportFlags_OwnedByApp)
+        ImGui_ImplWin32_UpdateWin32StyleFromWindow(viewport); // Not our window, poll style before using
+    ::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle); // Client to Screen
+    ::SetWindowPos(vd->Hwnd, nullptr, 0, 0, rect.right - rect.left, rect.bottom - rect.top, SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE);
+}
+
+static void ImGui_ImplWin32_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    ::BringWindowToTop(vd->Hwnd);
+    ::SetForegroundWindow(vd->Hwnd);
+    ::SetFocus(vd->Hwnd);
+}
+
+static bool ImGui_ImplWin32_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    return ::GetForegroundWindow() == vd->Hwnd;
+}
+
+static bool ImGui_ImplWin32_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    return ::IsIconic(vd->Hwnd) != 0;
+}
+
+static void ImGui_ImplWin32_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    // ::SetWindowTextA() doesn't properly handle UTF-8 so we explicitely convert our string.
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    int n = ::MultiByteToWideChar(CP_UTF8, 0, title, -1, nullptr, 0);
+    ImVector<wchar_t> title_w;
+    title_w.resize(n);
+    ::MultiByteToWideChar(CP_UTF8, 0, title, -1, title_w.Data, n);
+
+    // Calling SetWindowTextW() in a project where UNICODE is not set doesn't work but there's a trick
+    // which is to pass it directly to the DefWindowProcW() handler.
+    // See: https://stackoverflow.com/questions/9410681/setwindowtextw-in-an-ansi-project
+    //::SetWindowTextW(vd->Hwnd, title_w.Data);
+    ::DefWindowProcW(vd->Hwnd, WM_SETTEXT, 0, (LPARAM)title_w.Data);
+}
+
+static void ImGui_ImplWin32_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    IM_ASSERT(alpha >= 0.0f && alpha <= 1.0f);
+    if (alpha < 1.0f)
+    {
+        DWORD ex_style = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE) | WS_EX_LAYERED;
+        ::SetWindowLongW(vd->Hwnd, GWL_EXSTYLE, ex_style);
+        ::SetLayeredWindowAttributes(vd->Hwnd, 0, (BYTE)(255 * alpha), LWA_ALPHA);
+    }
+    else
+    {
+        DWORD ex_style = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE) & ~WS_EX_LAYERED;
+        ::SetWindowLongW(vd->Hwnd, GWL_EXSTYLE, ex_style);
+    }
+}
+
+static float ImGui_ImplWin32_GetWindowDpiScale(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    return ImGui_ImplWin32_GetDpiScaleForHwnd(vd->Hwnd);
+}
+
+// FIXME-DPI: Testing DPI related ideas
+static void ImGui_ImplWin32_OnChangedViewport(ImGuiViewport* viewport)
+{
+    (void)viewport;
+#if 0
+    ImGuiStyle default_style;
+    //default_style.WindowPadding = ImVec2(0, 0);
+    //default_style.WindowBorderSize = 0.0f;
+    //default_style.ItemSpacing.y = 3.0f;
+    //default_style.FramePadding = ImVec2(0, 0);
+    default_style.ScaleAllSizes(viewport->DpiScale);
+    ImGuiStyle& style = ImGui::GetStyle();
+    style = default_style;
+#endif
+}
+
+namespace ImGui { extern ImGuiIO& GetIO(ImGuiContext*); extern ImGuiPlatformIO& GetPlatformIO(ImGuiContext*); }
+
+static LRESULT CALLBACK ImGui_ImplWin32_WndProcHandler_PlatformWindow(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    // Allow secondary viewport WndProc to be called regardless of current context
+    ImGuiContext* ctx = (ImGuiContext*)::GetPropA(hWnd, "IMGUI_CONTEXT");
+    if (ctx == NULL)
+        return DefWindowProc(hWnd, msg, wParam, lParam); // unlike ImGui_ImplWin32_WndProcHandler() we are called directly by Windows, we can't just return 0.
+
+    ImGuiIO& io = ImGui::GetIO(ctx);
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO(ctx);
+    LRESULT result = 0;
+    if (ImGui_ImplWin32_WndProcHandlerEx(hWnd, msg, wParam, lParam, io))
+        result = true;
+    else if (ImGuiViewport* viewport = ImGui_ImplWin32_FindViewportByPlatformHandle(platform_io, hWnd))
+    {
+        switch (msg)
+        {
+        case WM_CLOSE:
+            viewport->PlatformRequestClose = true;
+            break;
+        case WM_MOVE:
+            viewport->PlatformRequestMove = true;
+            break;
+        case WM_SIZE:
+            viewport->PlatformRequestResize = true;
+            break;
+        case WM_MOUSEACTIVATE:
+            if (viewport->Flags & ImGuiViewportFlags_NoFocusOnClick)
+                result = MA_NOACTIVATE;
+            break;
+        case WM_NCHITTEST:
+            // Let mouse pass-through the window. This will allow the backend to call io.AddMouseViewportEvent() correctly. (which is optional).
+            // The ImGuiViewportFlags_NoInputs flag is set while dragging a viewport, as want to detect the window behind the one we are dragging.
+            // If you cannot easily access those viewport flags from your windowing/event code: you may manually synchronize its state e.g. in
+            // your main loop after calling UpdatePlatformWindows(). Iterate all viewports/platform windows and pass the flag to your windowing system.
+            if (viewport->Flags & ImGuiViewportFlags_NoInputs)
+                result = HTTRANSPARENT;
+            break;
+        }
+    }
+    if (result == 0)
+        result = DefWindowProc(hWnd, msg, wParam, lParam);
+    return result;
+}
+
+static void ImGui_ImplWin32_InitMultiViewportSupport(bool platform_has_own_dc)
+{
+    WNDCLASSEXW wcex;
+    wcex.cbSize = sizeof(WNDCLASSEXW);
+    wcex.style = CS_HREDRAW | CS_VREDRAW | (platform_has_own_dc ? CS_OWNDC : 0);
+    wcex.lpfnWndProc = ImGui_ImplWin32_WndProcHandler_PlatformWindow;
+    wcex.cbClsExtra = 0;
+    wcex.cbWndExtra = 0;
+    wcex.hInstance = ::GetModuleHandle(nullptr);
+    wcex.hIcon = nullptr;
+    wcex.hCursor = nullptr;
+    wcex.hbrBackground = (HBRUSH)(COLOR_BACKGROUND + 1);
+    wcex.lpszMenuName = nullptr;
+    wcex.lpszClassName = L"ImGui Platform";
+    wcex.hIconSm = nullptr;
+    ::RegisterClassExW(&wcex);
+
+    ImGui_ImplWin32_UpdateMonitors();
+
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplWin32_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplWin32_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplWin32_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplWin32_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplWin32_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplWin32_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplWin32_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplWin32_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplWin32_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplWin32_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplWin32_SetWindowTitle;
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplWin32_SetWindowAlpha;
+    platform_io.Platform_UpdateWindow = ImGui_ImplWin32_UpdateWindow;
+    platform_io.Platform_GetWindowDpiScale = ImGui_ImplWin32_GetWindowDpiScale; // FIXME-DPI
+    platform_io.Platform_OnChangedViewport = ImGui_ImplWin32_OnChangedViewport; // FIXME-DPI
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    ImGui_ImplWin32_ViewportData* vd = IM_NEW(ImGui_ImplWin32_ViewportData)();
+    vd->Hwnd = bd->hWnd;
+    vd->HwndOwned = false;
+    main_viewport->PlatformUserData = vd;
+}
+
+static void ImGui_ImplWin32_ShutdownMultiViewportSupport()
+{
+    ::UnregisterClassW(L"ImGui Platform", ::GetModuleHandle(nullptr));
+    ImGui::DestroyPlatformWindows();
+}
+
 //---------------------------------------------------------------------------------------------------------
 
 #if defined(__GNUC__)

backends/imgui_impl_win32.h

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

docs/CONTRIBUTING.md

@@ -34,7 +34,7 @@ Only if you:
 
 Then please [use the Discussions forums](https://github.com/ocornut/imgui/discussions) instead of opening an issue.
 
-If Dear ImGui is successfully showing in your app and you have used Dear ImGui before, you can open an Issue. Any form of discussions is welcome as a new issue. 
+If Dear ImGui is successfully showing in your app and you have used Dear ImGui before, you can open an Issue. Any form of discussions is welcome as a new issue.
 
 ## How to open an issue
 
@@ -52,7 +52,7 @@ Steps:
 - **Please INCLUDE CODE. Provide a Minimal, Complete, and Verifiable Example ([MCVE](https://stackoverflow.com/help/mcve)) to demonstrate your problem**. An ideal submission includes a small piece of code that anyone can paste into one of the examples applications (examples/../main.cpp) or demo (imgui_demo.cpp) to understand and reproduce it. **Narrowing your problem to its shortest and purest form is the easiest way to understand it, explain it and fix it**. Please test your shortened code to ensure it exhibits the problem. **Often while creating the MCVE you will solve the problem!** Many questions that are missing a standalone verifiable example are missing the actual cause of their issue in the description, which ends up wasting everyone's time.
 - **Attach screenshots (or GIF/video) to clarify the context**. They often convey useful information that is omitted by the description. You can drag pictures/files in the message edit box. Avoid using 3rd party image hosting services, prefer the long-term longevity of GitHub attachments (you can drag pictures into your post). On Windows, you can use [ScreenToGif](https://www.screentogif.com/) to easily capture .gif files.
 - **If you are discussing an assert or a crash, please provide a debugger callstack**. Never state "it crashes" without additional information. If you don't know how to use a debugger and retrieve a callstack, learning about it will be useful.
-- **Please make sure that your project has asserts enabled.** Calls to IM_ASSERT() are scattered in the code to help catch common issues. When an assert is triggered read the comments around it. By default IM_ASSERT() calls the standard assert() function. To verify that your asserts are enabled, add the line `IM_ASSERT(false);` in your main() function. Your application should display an error message and abort. If your application doesn't report an error, your asserts are disabled. 
+- **Please make sure that your project has asserts enabled.** Calls to IM_ASSERT() are scattered in the code to help catch common issues. When an assert is triggered read the comments around it. By default IM_ASSERT() calls the standard assert() function. To verify that your asserts are enabled, add the line `IM_ASSERT(false);` in your main() function. Your application should display an error message and abort. If your application doesn't report an error, your asserts are disabled.
 - Please state if you have made substantial modifications to your copy of Dear ImGui or the back-end.
 - If you are not calling Dear ImGui directly from C++, please provide information about your Language and the wrapper/binding you are using.
 - Be mindful that messages are being sent to the mailbox of "Watching" users. Try to proofread your messages before sending them. Edits are not seen by those users unless they browse the site.
@@ -65,17 +65,17 @@ If you have been using Dear ImGui for a while or have been using C/C++ for sever
 
 ## How to open a Pull Request
 
-- **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.** PR should be crafted both in the interest of the end-users and also to ease the maintainer into understanding and accepting it. 
+- **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.** PR should be crafted both in the interest of the end-users and also to ease the maintainer into understanding and accepting it.
 - Many PRs are useful to demonstrate a need and a possible solution but aren't adequate for merging (causing other issues, not seeing other aspects of the big picture, etc.). In doubt, don't hesitate to push a PR because that is always the first step toward pointing toward a problem, and finding the mergeable solution! Even if a PR stays unmerged for a long time, its presence can be useful for other users and helps toward finding a general solution.
-- **When adding a feature,** please describe the usage context (how you intend to use it, why you need it, etc.). Be mindful of [The XY Problem](http://xyproblem.info/). 
+- **When adding a feature,** please describe the usage context (how you intend to use it, why you need it, etc.). Be mindful of [The XY Problem](http://xyproblem.info/).
 - **When fixing a warning or compilation problem,** please post the compiler log and specify the compiler version and platform you are using.
 - **Attach screenshots (or GIF/video) to clarify the context and demonstrate the feature at a glance.** You can drag pictures/files in the message edit box. Prefer the long-term longevity of GitHub attachments over 3rd party hosting (you can drag pictures into your post).
-- **Make sure your code follows the coding style already used in the codebase:** 4 spaces indentations (no tabs), `local_variable`, `FunctionName()`, `MemberName`, `// Text Comment`, `//CodeComment();`, C-style casts, etc.. We don't use modern C++ idioms and tend to use only a minimum of C++11 features. The applications under examples/ are generally less consistent because they sometimes try to mimic the coding style often adopted by a certain ecosystem (e.g. DirectX-related code tend to use the style of their sample). 
+- **Make sure your code follows the coding style already used in the codebase:** 4 spaces indentations (no tabs), `local_variable`, `FunctionName()`, `MemberName`, `// Text Comment`, `//CodeComment();`, C-style casts, etc.. We don't use modern C++ idioms and tend to use only a minimum of C++11 features. The applications under examples/ are generally less consistent because they sometimes try to mimic the coding style often adopted by a certain ecosystem (e.g. DirectX-related code tend to use the style of their sample).
 - **Make sure you create a branch dedicated to the pull request**. In Git, 1 PR is associated to 1 branch. If you keep pushing to the same branch after you submitted the PR, your new commits will appear in the PR (we can still cherry-pick individual commits).
 
 ## Copyright / Contributor License Agreement
 
 Any code you submit will become part of the repository and be distributed under the [Dear ImGui license](https://github.com/ocornut/imgui/blob/master/LICENSE.txt). By submitting code to the project you agree that the code is your work and that you can give it to the project.
 
-You also agree by submitting your code that you grant all transferrable rights to the code to the project maintainer, including for example re-licensing the code, modifying the code, and distributing it in source or binary forms. Specifically, this includes a requirement that you assign copyright to the project maintainer. For this reason, do not modify any copyright statements in files in any PRs.
+You also agree by submitting your code that you grant all transferable rights to the code to the project maintainer, including for example re-licensing the code, modifying the code, and distributing it in source or binary forms. Specifically, this includes a requirement that you assign copyright to the project maintainer. For this reason, do not modify any copyright statements in files in any PRs.
 

docs/FAQ.md

@@ -233,7 +233,7 @@ for (int n = 0; n < 3; n++)
 ImGui::End();
 </pre>
 </td>
-</tr>    
+</tr>
 </table>
 
 A primer on labels and the ID Stack...
@@ -543,7 +543,7 @@ The short answer is: obtain the desired DPI scale, load your fonts resized with
 
 Your application may want to detect DPI change and reload the fonts and reset style between frames.
 
-Your ui code  should avoid using hardcoded constants for size and positioning. Prefer to express values as multiple of reference values such as `ImGui::GetFontSize()` or `ImGui::GetFrameHeight()`. So e.g. instead of seeing a hardcoded height of 500 for a given item/window, you may want to use `30*ImGui::GetFontSize()` instead.
+Your UI code should avoid using hardcoded constants for size and positioning. Prefer to express values as multiple of reference values such as `ImGui::GetFontSize()` or `ImGui::GetFrameHeight()`. So e.g. instead of seeing a hardcoded height of 500 for a given item/window, you may want to use `30*ImGui::GetFontSize()` instead.
 
 Down the line Dear ImGui will provide a variety of standardized reference values to facilitate using this.
 
@@ -562,7 +562,8 @@ Please note that if you are not using multi-viewports with multi-monitors using
 
 On Windows, in addition to scaling the font size (make sure to round to an integer) and using `style.ScaleAllSizes()`, you will need to inform Windows that your application is DPI aware. If this is not done, Windows will scale the application window and the UI text will be blurry. Potential solutions to indicate DPI awareness on Windows are:
 
-- For SDL: the flag `SDL_WINDOW_ALLOW_HIGHDPI` needs to be passed to `SDL_CreateWindow()``.
+- For SDL2: the flag `SDL_WINDOW_ALLOW_HIGHDPI` needs to be passed to `SDL_CreateWindow()`.
+- For SDL3: the flag `SDL_WINDOW_HIGH_PIXEL_DENSITY` needs to be passed to `SDL_CreateWindow()`.
 - For GLFW: this is done automatically.
 - For other Windows projects with other backends, or wrapper projects:
   - We provide a `ImGui_ImplWin32_EnableDpiAwareness()` helper method in the Win32 backend.
@@ -666,7 +667,7 @@ You may take a look at:
 
 Yes. People have written game editors, data browsers, debuggers, profilers, and all sorts of non-trivial tools with the library. In my experience, the simplicity of the API is very empowering. Your UI runs close to your live data. Make the tools always-on and everybody in the team will be inclined to create new tools (as opposed to more "offline" UI toolkits where only a fraction of your team effectively creates tools). The list of sponsors below is also an indicator that serious game teams have been using the library.
 
-Dear ImGui is very programmer centric and the immediate-mode GUI paradigm might require you to readjust some habits before you can realize its full potential. Dear ImGui is about making things that are simple, efficient, and powerful.
+Dear ImGui is very programmer-centric and the immediate-mode GUI paradigm might require you to readjust some habits before you can realize its full potential. Dear ImGui is about making things that are simple, efficient, and powerful.
 
 Dear ImGui is built to be efficient and scalable toward the needs for AAA-quality applications running all day. The IMGUI paradigm offers different opportunities for optimization than the more typical RMGUI paradigm.
 

docs/FONTS.md

@@ -110,9 +110,7 @@ ImGui::PopFont();
 **For advanced options create a ImFontConfig structure and pass it to the AddFont() function (it will be copied internally):**
 ```cpp
 ImFontConfig config;
-config.OversampleH = 2;
-config.OversampleV = 1;
-config.GlyphExtraSpacing.x = 1.0f;
+config.RasterizerDensity = 2.0f;
 ImFont* font = io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, &config);
 ```
 

docs/TODO.txt

@@ -9,7 +9,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - doc: add a proper documentation system (maybe relying on automation? #435)
  - doc: checklist app to verify backends/integration of imgui (test inputs, rendering, callback, etc.).
  - doc/tips: tips of the day: website? applet in imgui_club?
- 
+
  - window: preserve/restore relative focus ordering (persistent or not), and e.g. of multiple reappearing windows (#2304) -> also see docking reference to same #.
  - window: calling SetNextWindowSize() every frame with <= 0 doesn't do anything, may be useful to allow (particularly when used for a single axis). (#690)
  - window: add a way for very transient windows (non-saved, temporary overlay over hundreds of objects) to "clean" up from the global window list. perhaps a lightweight explicit cleanup pass.
@@ -22,7 +22,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - window: using SetWindowPos() inside Begin() and moving the window with the mouse reacts a very ugly glitch. We should just defer the SetWindowPos() call.
  - window: GetWindowSize() returns (0,0) when not calculated? (#1045)
  - window: investigate better auto-positioning for new windows.
- - window: top most window flag? more z-order contrl? (#2574)
+ - window: top most window flag? more z-order control? (#2574)
  - window/size: manually triggered auto-fit (double-click on grip) shouldn't resize window down to viewport size?
  - window/size: how to allow to e.g. auto-size vertically to fit contents, but be horizontally resizable? Assuming SetNextWindowSize() is modified to treat -1.0f on each axis as "keep as-is" (would be good but might break erroneous code): Problem is UpdateWindowManualResize() and lots of code treat (window->AutoFitFramesX > 0 || window->AutoFitFramesY > 0) together.
  - window/opt: freeze window flag: if not focused/hovered, return false, render with previous ImDrawList. and/or reduce refresh rate. -> this may require enforcing that it is illegal to submit contents if Begin returns false.
@@ -57,7 +57,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - widgets: start exposing PushItemFlag() and ImGuiItemFlags
  - widgets: alignment options in style (e.g. center Selectable, Right-Align within Button, etc.) #1260
  - widgets: activate by identifier (trigger button, focus given id)
- - widgets: custom glyph/shapes replacements for stock sapes. (also #6090 #2431 #2235 #6517)
+ - widgets: custom glyph/shapes replacements for stock shapes. (also #6090 #2431 #2235 #6517)
  - widgets: coloredit: keep reporting as active when picker is on?
  - widgets: group/scalarn functions: expose more per-component information. e.g. store NextItemData.ComponentIdx set by scalarn function, groups can expose them back somehow.
  - selectable: using (size.x == 0.0f) and (SelectableTextAlign.x > 0.0f) followed by SameLine() is currently not supported.
@@ -127,7 +127,35 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - separator: width, thickness, centering (#1643, #2657)
  - splitter: formalize the splitter idiom into an official api (we want to handle n-way split) (#319)
 
- - docking: merge docking branch (#2109)
+ - docking: B: ordering currently held in tab bar should be implicitly held by windows themselves (also see #2304)
+ - docking: B- tab bar: the order/focus restoring code could be part of TabBar and not DockNode? (#8)
+ - docking: B~ rework code to be able to lazily create tab bar instance in a single place. The _Unsorted tab flag could be replacing a trailing-counter in DockNode?
+ - docking: B~ fully track windows/settings reference in dock nodes. perhaps find a representation that allows facilitate use of dock builder functions.
+ - docking: B~ Unreal style document system (requires low-level controls of dockspace serialization fork/copy/delete). this is mostly working but the DockBuilderXXX api are not exposed/finished.
+ - docking: B: when docking outer, perform size locking on neighbors nodes the same way we do it with splitters, so other nodes are not resized.
+ - docking: B~ central node resizing behavior incorrect.
+ - docking: B: changing title font/style per-window is not supported as dock nodes are created in NewFrame.
+ - docking: B- dock node inside its own viewports creates 1 temporary viewport per window on startup before ditching them (doesn't affect the user nor request platform windows to be created, but unnecessary)
+ - docking: B- resize sibling locking behavior may be less desirable if we merged same-axis sibling in a same node level?
+ - docking: B- single visible node part of a hidden split hierarchy (OnlyNodeWithWindows != NULL) should show a normal title bar (not a tab bar)
+ - docking: B~ SetNextWindowDock() calls (with conditional) -> defer everything to DockContextUpdate (repro: Documents->[X]Windows->Dock 1 elsewhere->Click Redock All
+ - docking: B~ tidy up tab list popup buttons features (available with manual tab-bar, see ImGuiTabBarFlags_NoTabListPopupButton code, not used by docking nodes)
+ - docking: B- SetNextWindowDockId(0) with a second Begin() in the frame will asserts
+ - docking: B: resize grip drawn in host window typically appears under scrollbar.
+ - docking: B: resize grip auto-resize on multiple node hierarchy doesn't make much sense or should be improved?
+ - docking: B- SetNextWindowFocus() doesn't seem to apply if the window is hidden this frame, need repro (#4)
+ - docking: B- resizing a dock tree small currently has glitches (overlapping collapse and close button, etc.)
+ - docking: B- dpi: look at interaction with the hi-dpi and multi-dpi stuff.
+ - docking: B- tab bar: appearing on first frame with a dumb layout would do less harm that not appearing? (when behind dynamic branch) or store titles + render in EndTabBar()
+ - docking: B- tab bar: make selected tab always shows its full title?
+ - docking: B- hide close button on single tab bar?
+ - docking: B- nav: design interactions so nav controls can dock/undock
+ - docking: B- dockspace: flag to lock the dock tree and/or sizes (ImGuiDockNodeFlags_Locked?)
+ - docking: B- reintroduce collapsing a floating dock node. also collapsing a docked dock node!
+ - docking: B- allow dragging a non-floating dock node by clicking on the title-bar-looking section (not just the collapse/menu button)
+ - docking: B- option to remember undocked window size? (instead of keeping their docked size) (relate to #2104)
+ - docking: C- nav: CTRL+TAB highlighting tabs shows the mismatch between focus-stack and tab-order (not visible in VS because it doesn't highlight the tabs)
+ - docking: C- after a dock/undock, the Scrollbar Status update in Begin() should use an updated e.g. size_y_for_scrollbars to avoid a 1 frame scrollbar flicker.
 
  - tabs: "there is currently a problem because TabItem() will try to submit their own tooltip after 0.50 second, and this will have the effect of making your tooltip flicker once." -> tooltip priority work (WIP branch)
  - tabs: make EndTabBar fail if users doesn't respect BeginTabBar return value, for consistency/future-proofing.
@@ -137,7 +165,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - image/image button: misalignment on padded/bordered button?
  - image/image button: parameters are confusing, image() has tint_col,border_col whereas imagebutton() has bg_col/tint_col. Even thou they are different parameters ordering could be more consistent. can we fix that?
  - slider: allow using the [-]/[+] buttons used by InputFloat()/InputInt()
- - slider: add dragging-based widgets to edit values with mouse (on 2 axises), saving screen real-estate.
+ - slider: add dragging-based widgets to edit values with mouse (on 2 axes), saving screen real-estate.
  - slider: tint background based on value (e.g. v_min -> v_max, or use 0.0f either side of the sign)
  - slider: relative dragging? + precision dragging
  - slider: step option (#1183)
@@ -213,7 +241,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - log: let user copy any window content to clipboard easily (CTRL+C on windows? while moving it? context menu?). code is commented because it fails with multiple Begin/End pairs.
  - log: obsolete LogButtons().... (was: LogButtons() options for specifying depth and/or hiding depth slider)
 
- - filters: set a current filter that certains items (e.g. tree node) can automatically query to hide themselves
+ - filters: set a current filter that certain items (e.g. tree node) can automatically query to hide themselves
  - filters: handle wild-cards (with implicit leading/trailing *), reg-exprs
  - filters: fuzzy matches (may use code at blog.forrestthewoods.com/4cffeed33fdb)
 
@@ -279,7 +307,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - nav: expose wrap around flags/logic to allow e.g. grid based layout (pressing NavRight on the right-most element would go to the next row, etc.). see internal's NavMoveRequestTryWrapping().
  - nav: patterns to make it possible for arrows key to update selection (see JustMovedTo in range_select branch)
  - nav: restore/find nearest NavId when current one disappear (e.g. pressed a button that disappear, or perhaps auto restoring when current button change name)
- - nav: SetItemDefaultFocus() level of priority, so widget like Selectable when inside a popup could claim a low-priority default focus on the first selected iem
+ - nav: SetItemDefaultFocus() level of priority, so widgets like Selectable when inside a popup could claim a low-priority default focus on the first selected item
  - nav: holding space to repeat a button doesn't show button activated during hold.
  - nav: NavFlattened: init requests don't work properly on flattened siblings.
  - nav: NavFlattened: pageup/pagedown/home/end don't work properly on flattened siblings.
@@ -299,6 +327,20 @@ 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)
@@ -329,7 +371,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - backends: opengl: explicitly disable GL_STENCIL_TEST in bindings.
  - backends: vulkan: viewport: support for synchronized swapping of multiple swap chains.
  - backends: bgfx: https://gist.github.com/RichardGale/6e2b74bc42b3005e08397236e4be0fd0
- - backends: emscriptem: with refactored examples, we could provide a direct imgui_impl_emscripten platform layer (see eg. https://github.com/floooh/sokol-samples/blob/master/html5/imgui-emsc.cc#L42)
+ - backends: emscripten: with refactored examples, we could provide a direct imgui_impl_emscripten platform layer (see eg. https://github.com/floooh/sokol-samples/blob/master/html5/imgui-emsc.cc#L42)
 
  - bindings: ways to use clang ast dump to generate bindings or helpers for bindings? (e.g. clang++ -Xclang -ast-dump=json imgui.h) (--> use https://github.com/dearimgui/dear_bindings)
 

examples/example_allegro5/README.md

@@ -24,9 +24,9 @@ You may install Allegro using vcpkg:
 git clone https://github.com/Microsoft/vcpkg
 cd vcpkg
 bootstrap-vcpkg.bat
-vcpkg install allegro5 --triplet=x86-windows	; for win32
-vcpkg install allegro5 --triplet=x64-windows	; for win64
-vcpkg integrate install						    ; register include / libs in Visual Studio
+vcpkg install allegro5 --triplet=x86-windows    ; for win32
+vcpkg install allegro5 --triplet=x64-windows    ; for win64
+vcpkg integrate install                         ; register include / libs in Visual Studio
 ```
 
 Build:

examples/example_allegro5/main.cpp

@@ -40,6 +40,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;      // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();

examples/example_android_opengl3/android/app/build.gradle

@@ -42,5 +42,5 @@ repositories {
     mavenCentral()
 }
 dependencies {
-    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
+    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
 }

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

@@ -60,11 +60,21 @@
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Renderer backend
     ImGui_ImplMetal_Init(_device);
 
@@ -129,7 +139,7 @@
     if (renderPassDescriptor == nil)
     {
         [commandBuffer commit];
-		return;
+        return;
     }
 
     // Start the Dear ImGui frame
@@ -192,9 +202,16 @@
     [renderEncoder popDebugGroup];
     [renderEncoder endEncoding];
 
-	// Present
+    // 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

@@ -47,11 +47,21 @@
     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 +146,13 @@
 
     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_glfw_metal/main.mm

@@ -33,11 +33,21 @@ 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 +79,7 @@ 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 +167,13 @@ 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

@@ -52,11 +52,23 @@ 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();
@@ -155,6 +167,17 @@ 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

@@ -83,11 +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_ImplGlfw_InitForOpenGL(window, true);
 #ifdef __EMSCRIPTEN__
@@ -190,6 +202,17 @@ int main(int, char**)
         glClear(GL_COLOR_BUFFER_BIT);
         ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            GLFWwindow* backup_current_context = glfwGetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            glfwMakeContextCurrent(backup_current_context);
+        }
+
         glfwSwapBuffers(window);
     }
 #ifdef __EMSCRIPTEN__

examples/example_glfw_vulkan/CMakeLists.txt

@@ -15,7 +15,9 @@ set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DVK_PROTOTYPES")
 set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DVK_PROTOTYPES")
 
 # GLFW
-set(GLFW_DIR ../../../glfw) # Set this to point to an up-to-date GLFW repo
+if(NOT GLFW_DIR)
+   set(GLFW_DIR ../../../glfw) # Set this to point to an up-to-date GLFW repo
+endif()
 option(GLFW_BUILD_EXAMPLES "Build the GLFW example programs" OFF)
 option(GLFW_BUILD_TESTS "Build the GLFW test programs" OFF)
 option(GLFW_BUILD_DOCS "Build the GLFW documentation" OFF)

examples/example_glfw_vulkan/main.cpp

@@ -61,7 +61,7 @@ static void glfw_error_callback(int error, const char* description)
 }
 static void check_vk_result(VkResult err)
 {
-    if (err == 0)
+    if (err == VK_SUCCESS)
         return;
     fprintf(stderr, "[vulkan] Error: VkResult = %d\n", err);
     if (err < 0)
@@ -263,17 +263,15 @@ static void CleanupVulkanWindow()
 
 static void FrameRender(ImGui_ImplVulkanH_Window* wd, ImDrawData* draw_data)
 {
-    VkResult err;
-
     VkSemaphore image_acquired_semaphore  = wd->FrameSemaphores[wd->SemaphoreIndex].ImageAcquiredSemaphore;
     VkSemaphore render_complete_semaphore = wd->FrameSemaphores[wd->SemaphoreIndex].RenderCompleteSemaphore;
-    err = vkAcquireNextImageKHR(g_Device, wd->Swapchain, UINT64_MAX, image_acquired_semaphore, VK_NULL_HANDLE, &wd->FrameIndex);
+    VkResult err = vkAcquireNextImageKHR(g_Device, wd->Swapchain, UINT64_MAX, image_acquired_semaphore, VK_NULL_HANDLE, &wd->FrameIndex);
     if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
-    {
         g_SwapChainRebuild = true;
+    if (err == VK_ERROR_OUT_OF_DATE_KHR)
         return;
-    }
-    check_vk_result(err);
+    if (err != VK_SUBOPTIMAL_KHR)
+        check_vk_result(err);
 
     ImGui_ImplVulkanH_Frame* fd = &wd->Frames[wd->FrameIndex];
     {
@@ -342,11 +340,11 @@ static void FramePresent(ImGui_ImplVulkanH_Window* wd)
     info.pImageIndices = &wd->FrameIndex;
     VkResult err = vkQueuePresentKHR(g_Queue, &info);
     if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
-    {
         g_SwapChainRebuild = true;
+    if (err == VK_ERROR_OUT_OF_DATE_KHR)
         return;
-    }
-    check_vk_result(err);
+    if (err != VK_SUBOPTIMAL_KHR)
+        check_vk_result(err);
     wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->SemaphoreCount; // Now we can use the next set of semaphores
 }
 
@@ -390,14 +388,27 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //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 = {};
+    //init_info.ApiVersion = VK_API_VERSION_1_3;              // Pass in your value of VkApplicationInfo::apiVersion, otherwise will default to header version.
     init_info.Instance = g_Instance;
     init_info.PhysicalDevice = g_PhysicalDevice;
     init_info.Device = g_Device;
@@ -505,17 +516,25 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
-        ImDrawData* draw_data = ImGui::GetDrawData();
-        const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
-        if (!is_minimized)
+        ImDrawData* main_draw_data = ImGui::GetDrawData();
+        const bool main_is_minimized = (main_draw_data->DisplaySize.x <= 0.0f || main_draw_data->DisplaySize.y <= 0.0f);
+        wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
+        wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
+        wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
+        wd->ClearValue.color.float32[3] = clear_color.w;
+        if (!main_is_minimized)
+            FrameRender(wd, main_draw_data);
+
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
         {
-            wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
-            wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
-            wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
-            wd->ClearValue.color.float32[3] = clear_color.w;
-            FrameRender(wd, draw_data);
-            FramePresent(wd);
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
         }
+
+        // Present Main Platform Window
+        if (!main_is_minimized)
+            FramePresent(wd);
     }
 
     // Cleanup

examples/example_glfw_wgpu/main.cpp

@@ -93,6 +93,7 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();

examples/example_glut_opengl2/main.cpp

@@ -61,6 +61,7 @@ int main(int argc, char** argv)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -78,7 +79,6 @@ 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

@@ -71,11 +71,23 @@ 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);
@@ -181,6 +193,13 @@ 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

@@ -24,11 +24,21 @@ 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 +178,13 @@ int main(int, char**)
             ImGui::Render();
             ImGui_ImplMetal_RenderDrawData(ImGui::GetDrawData(), commandBuffer, renderEncoder);
 
+            // Update and Render additional Platform Windows
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                ImGui::UpdatePlatformWindows();
+                ImGui::RenderPlatformWindowsDefault();
+            }
+
             [renderEncoder popDebugGroup];
             [renderEncoder endEncoding];
 

examples/example_sdl2_opengl2/main.cpp

@@ -57,11 +57,23 @@ 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();
@@ -160,6 +172,19 @@ 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

@@ -97,11 +97,23 @@ 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);
@@ -207,6 +219,19 @@ 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

@@ -59,6 +59,7 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();

examples/example_sdl2_vulkan/main.cpp

@@ -49,7 +49,7 @@ static bool                     g_SwapChainRebuild = false;
 
 static void check_vk_result(VkResult err)
 {
-    if (err == 0)
+    if (err == VK_SUCCESS)
         return;
     fprintf(stderr, "[vulkan] Error: VkResult = %d\n", err);
     if (err < 0)
@@ -217,7 +217,7 @@ static void SetupVulkanWindow(ImGui_ImplVulkanH_Window* wd, VkSurfaceKHR surface
     wd->SurfaceFormat = ImGui_ImplVulkanH_SelectSurfaceFormat(g_PhysicalDevice, wd->Surface, requestSurfaceImageFormat, (size_t)IM_ARRAYSIZE(requestSurfaceImageFormat), requestSurfaceColorSpace);
 
     // Select Present Mode
-#ifdef APP_UNLIMITED_FRAME_RATE
+#ifdef APP_USE_UNLIMITED_FRAME_RATE
     VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_MAILBOX_KHR, VK_PRESENT_MODE_IMMEDIATE_KHR, VK_PRESENT_MODE_FIFO_KHR };
 #else
     VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_FIFO_KHR };
@@ -251,17 +251,15 @@ static void CleanupVulkanWindow()
 
 static void FrameRender(ImGui_ImplVulkanH_Window* wd, ImDrawData* draw_data)
 {
-    VkResult err;
-
     VkSemaphore image_acquired_semaphore  = wd->FrameSemaphores[wd->SemaphoreIndex].ImageAcquiredSemaphore;
     VkSemaphore render_complete_semaphore = wd->FrameSemaphores[wd->SemaphoreIndex].RenderCompleteSemaphore;
-    err = vkAcquireNextImageKHR(g_Device, wd->Swapchain, UINT64_MAX, image_acquired_semaphore, VK_NULL_HANDLE, &wd->FrameIndex);
+    VkResult err = vkAcquireNextImageKHR(g_Device, wd->Swapchain, UINT64_MAX, image_acquired_semaphore, VK_NULL_HANDLE, &wd->FrameIndex);
     if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
-    {
         g_SwapChainRebuild = true;
+    if (err == VK_ERROR_OUT_OF_DATE_KHR)
         return;
-    }
-    check_vk_result(err);
+    if (err != VK_SUBOPTIMAL_KHR)
+        check_vk_result(err);
 
     ImGui_ImplVulkanH_Frame* fd = &wd->Frames[wd->FrameIndex];
     {
@@ -330,11 +328,11 @@ static void FramePresent(ImGui_ImplVulkanH_Window* wd)
     info.pImageIndices = &wd->FrameIndex;
     VkResult err = vkQueuePresentKHR(g_Queue, &info);
     if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
-    {
         g_SwapChainRebuild = true;
+    if (err == VK_ERROR_OUT_OF_DATE_KHR)
         return;
-    }
-    check_vk_result(err);
+    if (err != VK_SUBOPTIMAL_KHR)
+        check_vk_result(err);
     wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->SemaphoreCount; // Now we can use the next set of semaphores
 }
 
@@ -390,14 +388,27 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //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 = {};
+    //init_info.ApiVersion = VK_API_VERSION_1_3;              // Pass in your value of VkApplicationInfo::apiVersion, otherwise will default to header version.
     init_info.Instance = g_Instance;
     init_info.PhysicalDevice = g_PhysicalDevice;
     init_info.Device = g_Device;
@@ -514,17 +525,25 @@ 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/Makefile

@@ -54,11 +54,11 @@ ifeq ($(UNAME_S), Darwin) #APPLE
 endif
 
 ifeq ($(OS), Windows_NT)
-    ECHO_MESSAGE = "MinGW"
-    LIBS += -lgdi32 -lopengl32 -limm32 `pkg-config --static --libs sdl3`
+	ECHO_MESSAGE = "MinGW"
+	LIBS += -lgdi32 -lopengl32 -limm32 `pkg-config --static --libs sdl3`
 
-    CXXFLAGS += `pkg-config --cflags sdl3`
-    CFLAGS = $(CXXFLAGS)
+	CXXFLAGS += `pkg-config --cflags sdl3`
+	CFLAGS = $(CXXFLAGS)
 endif
 
 ##---------------------------------------------------------------------

examples/example_sdl3_opengl3/main.cpp

@@ -18,7 +18,6 @@
 #include <SDL3/SDL_opengl.h>
 #endif
 
-// This example doesn't compile with Emscripten yet! Awaiting SDL3 support.
 #ifdef __EMSCRIPTEN__
 #include "../libs/emscripten/emscripten_mainloop_stub.h"
 #endif
@@ -27,6 +26,7 @@
 int main(int, char**)
 {
     // Setup SDL
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below until the main loop starts would likely be your SDL_AppInit() function]
     if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
     {
         printf("Error: SDL_Init(): %s\n", SDL_GetError());
@@ -93,11 +93,23 @@ 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);
@@ -140,6 +152,7 @@ int main(int, char**)
         // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
+        // [If using SDL_MAIN_USE_CALLBACKS: call ImGui_ImplSDL3_ProcessEvent() from your SDL_AppEvent() function]
         SDL_Event event;
         while (SDL_PollEvent(&event))
         {
@@ -149,6 +162,8 @@ int main(int, char**)
             if (event.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED && event.window.windowID == SDL_GetWindowID(window))
                 done = true;
         }
+
+        // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppIterate() function]
         if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED)
         {
             SDL_Delay(10);
@@ -203,6 +218,19 @@ 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__
@@ -210,6 +238,7 @@ int main(int, char**)
 #endif
 
     // Cleanup
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppQuit() function]
     ImGui_ImplOpenGL3_Shutdown();
     ImGui_ImplSDL3_Shutdown();
     ImGui::DestroyContext();

examples/example_sdl3_sdlgpu3/Makefile

@@ -43,11 +43,11 @@ ifeq ($(UNAME_S), Darwin) #APPLE
 endif
 
 ifeq ($(OS), Windows_NT)
-    ECHO_MESSAGE = "MinGW"
-    LIBS += -lgdi32 -limm32 `pkg-config --static --libs sdl3`
+	ECHO_MESSAGE = "MinGW"
+	LIBS += -lgdi32 -limm32 `pkg-config --static --libs sdl3`
 
-    CXXFLAGS += `pkg-config --cflags sdl3`
-    CFLAGS = $(CXXFLAGS)
+	CXXFLAGS += `pkg-config --cflags sdl3`
+	CFLAGS = $(CXXFLAGS)
 endif
 
 ##---------------------------------------------------------------------

examples/example_sdl3_sdlgpu3/main.cpp

@@ -7,7 +7,7 @@
 // - Introduction, links and more at the top of imgui.cpp
 
 // Important note to the reader who wish to integrate imgui_impl_sdlgpu3.cpp/.h in their own engine/app.
-// - Unline other backends, the user must call the function Imgui_ImplSDLGPU_PrepareDrawData BEFORE issuing a SDL_GPURenderPass containing ImGui_ImplSDLGPU_RenderDrawData.
+// - Unlike other backends, the user must call the function Imgui_ImplSDLGPU_PrepareDrawData() BEFORE issuing a SDL_GPURenderPass containing ImGui_ImplSDLGPU_RenderDrawData.
 //   Calling the function is MANDATORY, otherwise the ImGui will not upload neither the vertex nor the index buffer for the GPU. See imgui_impl_sdlgpu3.cpp for more info.
 
 #include "imgui.h"
@@ -26,7 +26,8 @@
 int main(int, char**)
 {
     // Setup SDL
-    if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD) != 0)
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below until the main loop starts would likely be your SDL_AppInit() function]
+    if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
     {
         printf("Error: SDL_Init(): %s\n", SDL_GetError());
         return -1;
@@ -54,6 +55,7 @@ int main(int, char**)
         printf("Error: SDL_ClaimWindowForGPUDevice(): %s\n", SDL_GetError());
         return -1;
     }
+    SDL_SetGPUSwapchainParameters(gpu_device, window, SDL_GPU_SWAPCHAINCOMPOSITION_SDR, SDL_GPU_PRESENTMODE_MAILBOX);
 
     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
@@ -69,7 +71,7 @@ int main(int, char**)
     // Setup Platform/Renderer backends
     ImGui_ImplSDL3_InitForSDLGPU(window);
     ImGui_ImplSDLGPU3_InitInfo init_info = {};
-    init_info.GpuDevice = gpu_device;
+    init_info.Device = gpu_device;
     init_info.ColorTargetFormat = SDL_GetGPUSwapchainTextureFormat(gpu_device, window);
     init_info.MSAASamples = SDL_GPU_SAMPLECOUNT_1;
     ImGui_ImplSDLGPU3_Init(&init_info);
@@ -104,6 +106,7 @@ int main(int, char**)
         // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
+        // [If using SDL_MAIN_USE_CALLBACKS: call ImGui_ImplSDL3_ProcessEvent() from your SDL_AppEvent() function]
         SDL_Event event;
         while (SDL_PollEvent(&event))
         {
@@ -113,6 +116,8 @@ int main(int, char**)
             if (event.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED && event.window.windowID == SDL_GetWindowID(window))
                 done = true;
         }
+
+        // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppIterate() function]
         if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED)
         {
             SDL_Delay(10);
@@ -140,7 +145,7 @@ int main(int, char**)
             ImGui::Checkbox("Another Window", &show_another_window);
 
             ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
-            ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
+            ImGui::ColorEdit4("clear color", (float*)&clear_color); // Edit 3 floats representing a color
 
             if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
                 counter++;
@@ -179,7 +184,7 @@ int main(int, char**)
             // Setup and start a render pass
             SDL_GPUColorTargetInfo target_info = {};
             target_info.texture = swapchain_texture;
-            target_info.clear_color = SDL_FColor{ clear_color.x,clear_color.y,clear_color.z,clear_color.w };
+            target_info.clear_color = SDL_FColor { clear_color.x, clear_color.y, clear_color.z, clear_color.w };
             target_info.load_op = SDL_GPU_LOADOP_CLEAR;
             target_info.store_op = SDL_GPU_STOREOP_STORE;
             target_info.mip_level = 0;
@@ -196,7 +201,9 @@ int main(int, char**)
         // Submit the command buffer
         SDL_SubmitGPUCommandBuffer(command_buffer);
     }
+
     // Cleanup
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppQuit() function]
     SDL_WaitForGPUIdle(gpu_device);
     ImGui_ImplSDL3_Shutdown();
     ImGui_ImplSDLGPU3_Shutdown();

examples/example_sdl3_sdlrenderer3/Makefile

@@ -34,7 +34,7 @@ endif
 
 ifeq ($(UNAME_S), Darwin) #APPLE
 	ECHO_MESSAGE = "Mac OS X"
-	LIBS += -framework OpenGL -framework Cocoa -framework IOKit -framework CoreVideo `sdl3-config --libs`
+	LIBS += -framework Cocoa -framework IOKit -framework CoreVideo `sdl3-config --libs`
 	LIBS += -L/usr/local/lib -L/opt/local/lib
 
 	CXXFLAGS += `pkg-config sdl3 --cflags`
@@ -43,11 +43,11 @@ ifeq ($(UNAME_S), Darwin) #APPLE
 endif
 
 ifeq ($(OS), Windows_NT)
-    ECHO_MESSAGE = "MinGW"
-    LIBS += -lgdi32 -lopengl32 -limm32 `pkg-config --static --libs sdl3`
+	ECHO_MESSAGE = "MinGW"
+	LIBS += -lgdi32 -limm32 `pkg-config --static --libs sdl3`
 
-    CXXFLAGS += `pkg-config --cflags sdl3`
-    CFLAGS = $(CXXFLAGS)
+	CXXFLAGS += `pkg-config --cflags sdl3`
+	CFLAGS = $(CXXFLAGS)
 endif
 
 ##---------------------------------------------------------------------

examples/example_sdl3_sdlrenderer3/main.cpp

@@ -15,16 +15,16 @@
 #include "imgui_impl_sdlrenderer3.h"
 #include <stdio.h>
 #include <SDL3/SDL.h>
-#if defined(IMGUI_IMPL_OPENGL_ES2)
-#include <SDL3/SDL_opengles2.h>
-#else
-#include <SDL3/SDL_opengl.h>
+
+#ifdef __EMSCRIPTEN__
+#include "../libs/emscripten/emscripten_mainloop_stub.h"
 #endif
 
 // Main code
 int main(int, char**)
 {
     // Setup SDL
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below until the main loop starts would likely be your SDL_AppInit() function]
     if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
     {
         printf("Error: SDL_Init(): %s\n", SDL_GetError());
@@ -32,7 +32,7 @@ int main(int, char**)
     }
 
     // Create window with SDL_Renderer graphics context
-    Uint32 window_flags = SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN;
+    Uint32 window_flags = SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN;
     SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+SDL_Renderer example", 1280, 720, window_flags);
     if (window == nullptr)
     {
@@ -55,6 +55,7 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -102,6 +103,7 @@ int main(int, char**)
         // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
+        // [If using SDL_MAIN_USE_CALLBACKS: call ImGui_ImplSDL3_ProcessEvent() from your SDL_AppEvent() function]
         SDL_Event event;
         while (SDL_PollEvent(&event))
         {
@@ -111,6 +113,8 @@ int main(int, char**)
             if (event.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED && event.window.windowID == SDL_GetWindowID(window))
                 done = true;
         }
+
+        // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppIterate() function]
         if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED)
         {
             SDL_Delay(10);
@@ -172,6 +176,7 @@ int main(int, char**)
 #endif
 
     // Cleanup
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppQuit() function]
     ImGui_ImplSDLRenderer3_Shutdown();
     ImGui_ImplSDL3_Shutdown();
     ImGui::DestroyContext();

examples/example_sdl3_vulkan/main.cpp

@@ -54,7 +54,7 @@ static bool                     g_SwapChainRebuild = false;
 
 static void check_vk_result(VkResult err)
 {
-    if (err == 0)
+    if (err == VK_SUCCESS)
         return;
     fprintf(stderr, "[vulkan] Error: VkResult = %d\n", err);
     if (err < 0)
@@ -222,7 +222,7 @@ static void SetupVulkanWindow(ImGui_ImplVulkanH_Window* wd, VkSurfaceKHR surface
     wd->SurfaceFormat = ImGui_ImplVulkanH_SelectSurfaceFormat(g_PhysicalDevice, wd->Surface, requestSurfaceImageFormat, (size_t)IM_ARRAYSIZE(requestSurfaceImageFormat), requestSurfaceColorSpace);
 
     // Select Present Mode
-#ifdef APP_UNLIMITED_FRAME_RATE
+#ifdef APP_USE_UNLIMITED_FRAME_RATE
     VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_MAILBOX_KHR, VK_PRESENT_MODE_IMMEDIATE_KHR, VK_PRESENT_MODE_FIFO_KHR };
 #else
     VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_FIFO_KHR };
@@ -256,17 +256,15 @@ static void CleanupVulkanWindow()
 
 static void FrameRender(ImGui_ImplVulkanH_Window* wd, ImDrawData* draw_data)
 {
-    VkResult err;
-
     VkSemaphore image_acquired_semaphore  = wd->FrameSemaphores[wd->SemaphoreIndex].ImageAcquiredSemaphore;
     VkSemaphore render_complete_semaphore = wd->FrameSemaphores[wd->SemaphoreIndex].RenderCompleteSemaphore;
-    err = vkAcquireNextImageKHR(g_Device, wd->Swapchain, UINT64_MAX, image_acquired_semaphore, VK_NULL_HANDLE, &wd->FrameIndex);
+    VkResult err = vkAcquireNextImageKHR(g_Device, wd->Swapchain, UINT64_MAX, image_acquired_semaphore, VK_NULL_HANDLE, &wd->FrameIndex);
     if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
-    {
         g_SwapChainRebuild = true;
+    if (err == VK_ERROR_OUT_OF_DATE_KHR)
         return;
-    }
-    check_vk_result(err);
+    if (err != VK_SUBOPTIMAL_KHR)
+        check_vk_result(err);
 
     ImGui_ImplVulkanH_Frame* fd = &wd->Frames[wd->FrameIndex];
     {
@@ -335,11 +333,11 @@ static void FramePresent(ImGui_ImplVulkanH_Window* wd)
     info.pImageIndices = &wd->FrameIndex;
     VkResult err = vkQueuePresentKHR(g_Queue, &info);
     if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
-    {
         g_SwapChainRebuild = true;
+    if (err == VK_ERROR_OUT_OF_DATE_KHR)
         return;
-    }
-    check_vk_result(err);
+    if (err != VK_SUBOPTIMAL_KHR)
+        check_vk_result(err);
     wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->SemaphoreCount; // Now we can use the next set of semaphores
 }
 
@@ -347,7 +345,8 @@ static void FramePresent(ImGui_ImplVulkanH_Window* wd)
 int main(int, char**)
 {
     // Setup SDL
-    if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD) != 0)
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below until the main loop starts would likely be your SDL_AppInit() function]
+    if (!SDL_Init(SDL_INIT_VIDEO | SDL_INIT_GAMEPAD))
     {
         printf("Error: SDL_Init(): %s\n", SDL_GetError());
         return -1;
@@ -394,14 +393,27 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //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_ImplSDL3_InitForVulkan(window);
     ImGui_ImplVulkan_InitInfo init_info = {};
+    //init_info.ApiVersion = VK_API_VERSION_1_3;              // Pass in your value of VkApplicationInfo::apiVersion, otherwise will default to header version.
     init_info.Instance = g_Instance;
     init_info.PhysicalDevice = g_PhysicalDevice;
     init_info.Device = g_Device;
@@ -448,6 +460,7 @@ int main(int, char**)
         // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
+        // [If using SDL_MAIN_USE_CALLBACKS: call ImGui_ImplSDL3_ProcessEvent() from your SDL_AppEvent() function]
         SDL_Event event;
         while (SDL_PollEvent(&event))
         {
@@ -457,6 +470,8 @@ int main(int, char**)
             if (event.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED && event.window.windowID == SDL_GetWindowID(window))
                 done = true;
         }
+
+        // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppIterate() function]
         if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED)
         {
             SDL_Delay(10);
@@ -518,20 +533,29 @@ 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
+    // [If using SDL_MAIN_USE_CALLBACKS: all code below would likely be your SDL_AppQuit() function]
     err = vkDeviceWaitIdle(g_Device);
     check_vk_result(err);
     ImGui_ImplVulkan_Shutdown();

examples/example_win32_directx10/main.cpp

@@ -54,11 +54,23 @@ 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);
@@ -167,6 +179,13 @@ int main(int, char**)
         g_pd3dDevice->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX10_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         // Present
         HRESULT hr = g_pSwapChain->Present(1, 0);   // Present with vsync
         //HRESULT hr = g_pSwapChain->Present(0, 0); // Present without vsync
@@ -186,7 +205,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain

examples/example_win32_directx11/main.cpp

@@ -54,11 +54,28 @@ 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);
@@ -167,6 +184,13 @@ int main(int, char**)
         g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         // Present
         HRESULT hr = g_pSwapChain->Present(1, 0);   // Present with vsync
         //HRESULT hr = g_pSwapChain->Present(0, 0); // Present without vsync
@@ -186,7 +210,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain
@@ -241,6 +264,10 @@ 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);
 
@@ -269,6 +296,15 @@ 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

@@ -23,8 +23,8 @@
 #endif
 
 // Config for example app
-static const int APP_NUM_FRAMES_IN_FLIGHT = 3;
-static const int APP_NUM_BACK_BUFFERS = 3;
+static const int APP_NUM_FRAMES_IN_FLIGHT = 2;
+static const int APP_NUM_BACK_BUFFERS = 2;
 static const int APP_SRV_HEAP_SIZE = 64;
 
 struct FrameContext
@@ -54,7 +54,7 @@ struct ExampleDescriptorHeapAllocator
         HeapHandleIncrement = device->GetDescriptorHandleIncrementSize(HeapType);
         FreeIndices.reserve((int)desc.NumDescriptors);
         for (int n = desc.NumDescriptors; n > 0; n--)
-            FreeIndices.push_back(n);
+            FreeIndices.push_back(n - 1);
     }
     void Destroy()
     {
@@ -133,11 +133,23 @@ 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);
 
@@ -154,6 +166,9 @@ int main(int, char**)
     init_info.SrvDescriptorFreeFn = [](ImGui_ImplDX12_InitInfo*, D3D12_CPU_DESCRIPTOR_HANDLE cpu_handle, D3D12_GPU_DESCRIPTOR_HANDLE gpu_handle)            { return g_pd3dSrvDescHeapAlloc.Free(cpu_handle, gpu_handle); };
     ImGui_ImplDX12_Init(&init_info);
 
+    // Before 1.91.6: our signature was using a single descriptor. From 1.92, specifying SrvDescriptorAllocFn/SrvDescriptorFreeFn will be required to benefit from new features.
+    //ImGui_ImplDX12_Init(g_pd3dDevice, APP_NUM_FRAMES_IN_FLIGHT, DXGI_FORMAT_R8G8B8A8_UNORM, g_pd3dSrvDescHeap, g_pd3dSrvDescHeap->GetCPUDescriptorHandleForHeapStart(), g_pd3dSrvDescHeap->GetGPUDescriptorHandleForHeapStart());
+
     // 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.
@@ -272,6 +287,13 @@ 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();
+        }
+
         // Present
         HRESULT hr = g_pSwapChain->Present(1, 0);   // Present with vsync
         //HRESULT hr = g_pSwapChain->Present(0, 0); // Present without vsync
@@ -298,7 +320,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain

examples/example_win32_directx9/main.cpp

@@ -52,11 +52,23 @@ 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);
@@ -177,6 +189,14 @@ int main(int, char**)
             ImGui_ImplDX9_RenderDrawData(ImGui::GetDrawData());
             g_pd3dDevice->EndScene();
         }
+
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         HRESULT result = g_pd3dDevice->Present(nullptr, nullptr, nullptr, nullptr);
         if (result == D3DERR_DEVICELOST)
             g_DeviceLost = true;
@@ -195,7 +215,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     if ((g_pD3D = Direct3DCreate9(D3D_SDK_VERSION)) == nullptr)
@@ -231,6 +250,10 @@ 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);
 
@@ -259,6 +282,15 @@ 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/build_mingw.bat

@@ -1,4 +1,4 @@
-@REM Build for MINGW64 or 32 from MSYS2. 
+@REM Build for MINGW64 or 32 from MSYS2.
 @set OUT_DIR=Debug
 @set OUT_EXE=example_win32_opengl3
 @set INCLUDES=-I../.. -I../../backends

examples/example_win32_opengl3/main.cpp

@@ -33,6 +33,42 @@ 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 +98,39 @@ 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.
@@ -163,6 +223,16 @@ int main(int, char**)
         glClear(GL_COLOR_BUFFER_BIT);
         ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+
+            // Restore the OpenGL rendering context to the main window DC, since platform windows might have changed it.
+            wglMakeCurrent(g_MainWindow.hDC, g_hRC);
+        }
+
         // Present
         ::SwapBuffers(g_MainWindow.hDC);
     }

examples/example_win32_vulkan/main.cpp

@@ -50,7 +50,7 @@ static bool                     g_SwapChainRebuild = false;
 
 static void check_vk_result(VkResult err)
 {
-    if (err == 0)
+    if (err == VK_SUCCESS)
         return;
     fprintf(stderr, "[vulkan] Error: VkResult = %d\n", err);
     if (err < 0)
@@ -252,17 +252,15 @@ static void CleanupVulkanWindow()
 
 static void FrameRender(ImGui_ImplVulkanH_Window* wd, ImDrawData* draw_data)
 {
-    VkResult err;
-
     VkSemaphore image_acquired_semaphore  = wd->FrameSemaphores[wd->SemaphoreIndex].ImageAcquiredSemaphore;
     VkSemaphore render_complete_semaphore = wd->FrameSemaphores[wd->SemaphoreIndex].RenderCompleteSemaphore;
-    err = vkAcquireNextImageKHR(g_Device, wd->Swapchain, UINT64_MAX, image_acquired_semaphore, VK_NULL_HANDLE, &wd->FrameIndex);
+    VkResult err = vkAcquireNextImageKHR(g_Device, wd->Swapchain, UINT64_MAX, image_acquired_semaphore, VK_NULL_HANDLE, &wd->FrameIndex);
     if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
-    {
         g_SwapChainRebuild = true;
+    if (err == VK_ERROR_OUT_OF_DATE_KHR)
         return;
-    }
-    check_vk_result(err);
+    if (err != VK_SUBOPTIMAL_KHR)
+        check_vk_result(err);
 
     ImGui_ImplVulkanH_Frame* fd = &wd->Frames[wd->FrameIndex];
     {
@@ -331,16 +329,26 @@ static void FramePresent(ImGui_ImplVulkanH_Window* wd)
     info.pImageIndices = &wd->FrameIndex;
     VkResult err = vkQueuePresentKHR(g_Queue, &info);
     if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
-    {
         g_SwapChainRebuild = true;
+    if (err == VK_ERROR_OUT_OF_DATE_KHR)
         return;
-    }
-    check_vk_result(err);
+    if (err != VK_SUBOPTIMAL_KHR)
+        check_vk_result(err);
     wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->SemaphoreCount; // Now we can use the next set of semaphores
 }
 
 LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 
+// FIXME: This code would ideally be inside imgui_impl_win32.cpp, it would create a dependency on Vulkan headers in imgui_impl_win32.cpp
+static int ImGui_ImplWin32_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_instance, const void* vk_allocator, ImU64* out_vk_surface)
+{
+    VkWin32SurfaceCreateInfoKHR createInfo = {};
+    createInfo.sType = VK_STRUCTURE_TYPE_WIN32_SURFACE_CREATE_INFO_KHR;
+    createInfo.hwnd = (HWND)viewport->PlatformHandleRaw;
+    createInfo.hinstance = ::GetModuleHandle(nullptr);
+    return (int)vkCreateWin32SurfaceKHR((VkInstance)vk_instance, &createInfo, (VkAllocationCallbacks*)vk_allocator, (VkSurfaceKHR*)out_vk_surface);
+}
+
 // Main code
 int main(int, char**)
 {
@@ -381,14 +389,29 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.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_ImplWin32_Init(hwnd);
+    ImGui::GetPlatformIO().Platform_CreateVkSurface = ImGui_ImplWin32_CreateVkSurface;
+
     ImGui_ImplVulkan_InitInfo init_info = {};
+    //init_info.ApiVersion = VK_API_VERSION_1_3;              // Pass in your value of VkApplicationInfo::apiVersion, otherwise will default to header version.
     init_info.Instance = g_Instance;
     init_info.PhysicalDevice = g_PhysicalDevice;
     init_info.Device = g_Device;
@@ -487,17 +510,25 @@ 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

imconfig.h

@@ -88,8 +88,7 @@
 
 //---- Use FreeType + plutosvg or lunasvg to render OpenType SVG fonts (SVGinOT)
 // Only works in combination with IMGUI_ENABLE_FREETYPE.
-// - lunasvg is currently easier to acquire/install, as e.g. it is part of vcpkg.
-// - plutosvg will support more fonts and may load them faster. It currently requires to be built manually but it is fairly easy. See misc/freetype/README for instructions.
+// - plutosvg is currently easier to install, as e.g. it is part of vcpkg. It will support more fonts and may load them faster. See misc/freetype/README for instructions.
 // - Both require headers to be available in the include path + program to be linked with the library code (not provided).
 // - (note: lunasvg implementation is based on Freetype's rsvg-port.c which is licensed under CeCILL-C Free Software License Agreement)
 //#define IMGUI_ENABLE_FREETYPE_PLUTOSVG

imgui.h

@@ -1,4 +1,4 @@
-// dear imgui, v1.91.7
+// dear imgui, v1.91.9
 // (headers)
 
 // Help:
@@ -28,9 +28,11 @@
 
 // Library Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM >= 12345')
-#define IMGUI_VERSION       "1.91.7"
-#define IMGUI_VERSION_NUM   19170
+#define IMGUI_VERSION       "1.91.9"
+#define IMGUI_VERSION_NUM   19190
 #define IMGUI_HAS_TABLE
+#define IMGUI_HAS_VIEWPORT          // Viewport WIP branch
+#define IMGUI_HAS_DOCK              // Docking WIP branch
 
 /*
 
@@ -43,13 +45,13 @@ Index of this file:
 // [SECTION] Helpers: Debug log, Memory allocations macros, ImVector<>
 // [SECTION] ImGuiStyle
 // [SECTION] ImGuiIO
-// [SECTION] Misc data structures (ImGuiInputTextCallbackData, ImGuiSizeCallbackData, ImGuiPayload)
+// [SECTION] Misc data structures (ImGuiInputTextCallbackData, ImGuiSizeCallbackData, ImGuiWindowClass, ImGuiPayload)
 // [SECTION] Helpers (ImGuiOnceUponAFrame, ImGuiTextFilter, ImGuiTextBuffer, ImGuiStorage, ImGuiListClipper, Math Operators, ImColor)
 // [SECTION] Multi-Select API flags and structures (ImGuiMultiSelectFlags, ImGuiMultiSelectIO, ImGuiSelectionRequest, ImGuiSelectionBasicStorage, ImGuiSelectionExternalStorage)
 // [SECTION] Drawing API (ImDrawCallback, ImDrawCmd, ImDrawIdx, ImDrawVert, ImDrawChannel, ImDrawListSplitter, ImDrawFlags, ImDrawListFlags, ImDrawList, ImDrawData)
 // [SECTION] Font API (ImFontConfig, ImFontGlyph, ImFontGlyphRangesBuilder, ImFontAtlasFlags, ImFontAtlas, ImFont)
 // [SECTION] Viewports (ImGuiViewportFlags, ImGuiViewport)
-// [SECTION] ImGuiPlatformIO + other Platform Dependent Interfaces (ImGuiPlatformImeData)
+// [SECTION] ImGuiPlatformIO + other Platform Dependent Interfaces (ImGuiPlatformMonitor, ImGuiPlatformImeData)
 // [SECTION] Obsolete functions and types
 
 */
@@ -158,7 +160,7 @@ typedef unsigned int        ImU32;  // 32-bit unsigned integer (often used to st
 typedef signed   long long  ImS64;  // 64-bit signed integer
 typedef unsigned long long  ImU64;  // 64-bit unsigned integer
 
-// Forward declarations
+// Forward declarations: ImDrawList, ImFontAtlas layer
 struct ImDrawChannel;               // Temporary storage to output draw commands out of order, used by ImDrawListSplitter and ImDrawList::ChannelsSplit()
 struct ImDrawCmd;                   // A single draw command within a parent ImDrawList (generally maps to 1 GPU draw call, unless it is a callback)
 struct ImDrawData;                  // All draw command lists required to render the frame + pos/size coordinates to use for the projection matrix.
@@ -173,6 +175,8 @@ struct ImFontConfig;                // Configuration data when adding a font or
 struct ImFontGlyph;                 // A single font glyph (code point + coordinates within in ImFontAtlas + offset)
 struct ImFontGlyphRangesBuilder;    // Helper to build glyph ranges from text/string data
 struct ImColor;                     // Helper functions to create a color that can be converted to either u32 or float4 (*OBSOLETE* please avoid using)
+
+// Forward declarations: ImGui layer
 struct ImGuiContext;                // Dear ImGui context (opaque structure, unless including imgui_internal.h)
 struct ImGuiIO;                     // Main configuration and I/O between your application and ImGui (also see: ImGuiPlatformIO)
 struct ImGuiInputTextCallbackData;  // Shared state of InputText() when using custom ImGuiInputTextCallback (rare/advanced use)
@@ -181,8 +185,9 @@ struct ImGuiListClipper;            // Helper to manually clip large list of ite
 struct ImGuiMultiSelectIO;          // Structure to interact with a BeginMultiSelect()/EndMultiSelect() block
 struct ImGuiOnceUponAFrame;         // Helper for running a block of code not more than once a frame
 struct ImGuiPayload;                // User data payload for drag and drop operations
-struct ImGuiPlatformIO;             // Interface between platform/renderer backends and ImGui (e.g. Clipboard, IME hooks). Extends ImGuiIO. In docking branch, this gets extended to support multi-viewports.
+struct ImGuiPlatformIO;             // Interface between platform/renderer backends and ImGui (e.g. Clipboard, IME, Multi-Viewport support). Extends ImGuiIO.
 struct ImGuiPlatformImeData;        // Platform IME data for io.PlatformSetImeDataFn() function.
+struct ImGuiPlatformMonitor;        // Multi-viewport support: user-provided bounds for each connected monitor/display. Used when positioning popups and tooltips to avoid them straddling monitors
 struct ImGuiSelectionBasicStorage;  // Optional helper to store multi-selection state + apply multi-selection requests.
 struct ImGuiSelectionExternalStorage;//Optional helper to apply multi-selection requests to existing randomly accessible storage.
 struct ImGuiSelectionRequest;       // A selection request (stored in ImGuiMultiSelectIO)
@@ -194,7 +199,8 @@ struct ImGuiTableSortSpecs;         // Sorting specifications for a table (often
 struct ImGuiTableColumnSortSpecs;   // Sorting specification for one column of a table
 struct ImGuiTextBuffer;             // Helper to hold and append into a text buffer (~string builder)
 struct ImGuiTextFilter;             // Helper to parse and apply text filters (e.g. "aaaaa[,bbbbb][,ccccc]")
-struct ImGuiViewport;               // A Platform Window (always only one in 'master' branch), in the future may represent Platform Monitor
+struct ImGuiViewport;               // A Platform Window (always 1 unless multi-viewport are enabled. One per platform window to output to). In the future may represent Platform Monitor
+struct ImGuiWindowClass;            // Window class (rare/advanced uses: provide hints to the platform backend via altered viewport flags and parent/child info)
 
 // Enumerations
 // - We don't use strongly typed enums much because they add constraints (can't extend in private code, can't store typed in bit fields, extra casting on iteration)
@@ -228,6 +234,7 @@ typedef int ImGuiChildFlags;        // -> enum ImGuiChildFlags_      // Flags: f
 typedef int ImGuiColorEditFlags;    // -> enum ImGuiColorEditFlags_  // Flags: for ColorEdit4(), ColorPicker4() etc.
 typedef int ImGuiConfigFlags;       // -> enum ImGuiConfigFlags_     // Flags: for io.ConfigFlags
 typedef int ImGuiComboFlags;        // -> enum ImGuiComboFlags_      // Flags: for BeginCombo()
+typedef int ImGuiDockNodeFlags;     // -> enum ImGuiDockNodeFlags_   // Flags: for DockSpace()
 typedef int ImGuiDragDropFlags;     // -> enum ImGuiDragDropFlags_   // Flags: for BeginDragDropSource(), AcceptDragDropPayload()
 typedef int ImGuiFocusedFlags;      // -> enum ImGuiFocusedFlags_    // Flags: for IsWindowFocused()
 typedef int ImGuiHoveredFlags;      // -> enum ImGuiHoveredFlags_    // Flags: for IsItemHovered(), IsWindowHovered() etc.
@@ -399,10 +406,12 @@ namespace ImGui
     IMGUI_API bool          IsWindowFocused(ImGuiFocusedFlags flags=0); // is current window focused? or its root/child, depending on flags. see flags for options.
     IMGUI_API bool          IsWindowHovered(ImGuiHoveredFlags flags=0); // is current window hovered and hoverable (e.g. not blocked by a popup/modal)? See ImGuiHoveredFlags_ for options. IMPORTANT: If you are trying to check whether your mouse should be dispatched to Dear ImGui or to your underlying app, you should not use this function! Use the 'io.WantCaptureMouse' boolean for that! Refer to FAQ entry "How can I tell whether to dispatch mouse/keyboard to Dear ImGui or my application?" for details.
     IMGUI_API ImDrawList*   GetWindowDrawList();                        // get draw list associated to the current window, to append your own drawing primitives
+    IMGUI_API float         GetWindowDpiScale();                        // get DPI scale currently associated to the current window's viewport.
     IMGUI_API ImVec2        GetWindowPos();                             // get current window position in screen space (IT IS UNLIKELY YOU EVER NEED TO USE THIS. Consider always using GetCursorScreenPos() and GetContentRegionAvail() instead)
     IMGUI_API ImVec2        GetWindowSize();                            // get current window size (IT IS UNLIKELY YOU EVER NEED TO USE THIS. Consider always using GetCursorScreenPos() and GetContentRegionAvail() instead)
     IMGUI_API float         GetWindowWidth();                           // get current window width (IT IS UNLIKELY YOU EVER NEED TO USE THIS). Shortcut for GetWindowSize().x.
     IMGUI_API float         GetWindowHeight();                          // get current window height (IT IS UNLIKELY YOU EVER NEED TO USE THIS). Shortcut for GetWindowSize().y.
+    IMGUI_API ImGuiViewport*GetWindowViewport();                        // get viewport currently associated to the current window.
 
     // Window manipulation
     // - Prefer using SetNextXXX functions (before Begin) rather that SetXXX functions (after Begin).
@@ -414,6 +423,7 @@ namespace ImGui
     IMGUI_API void          SetNextWindowFocus();                                                       // set next window to be focused / top-most. call before Begin()
     IMGUI_API void          SetNextWindowScroll(const ImVec2& scroll);                                  // set next window scrolling value (use < 0.0f to not affect a given axis).
     IMGUI_API void          SetNextWindowBgAlpha(float alpha);                                          // set next window background color alpha. helper to easily override the Alpha component of ImGuiCol_WindowBg/ChildBg/PopupBg. you may also use ImGuiWindowFlags_NoBackground.
+    IMGUI_API void          SetNextWindowViewport(ImGuiID viewport_id);                                 // set next window viewport
     IMGUI_API void          SetWindowPos(const ImVec2& pos, ImGuiCond cond = 0);                        // (not recommended) set current window position - call within Begin()/End(). prefer using SetNextWindowPos(), as this may incur tearing and side-effects.
     IMGUI_API void          SetWindowSize(const ImVec2& size, ImGuiCond cond = 0);                      // (not recommended) set current window size - call within Begin()/End(). set to ImVec2(0, 0) to force an auto-fit. prefer using SetNextWindowSize(), as this may incur tearing and minor side-effects.
     IMGUI_API void          SetWindowCollapsed(bool collapsed, ImGuiCond cond = 0);                     // (not recommended) set current window collapsed state. prefer using SetNextWindowCollapsed().
@@ -542,7 +552,7 @@ namespace ImGui
     IMGUI_API void          LabelTextV(const char* label, const char* fmt, va_list args)    IM_FMTLIST(2);
     IMGUI_API void          BulletText(const char* fmt, ...)                                IM_FMTARGS(1); // shortcut for Bullet()+Text()
     IMGUI_API void          BulletTextV(const char* fmt, va_list args)                      IM_FMTLIST(1);
-    IMGUI_API void          SeparatorText(const char* label);                               // currently: formatted text with an horizontal line
+    IMGUI_API void          SeparatorText(const char* label);                               // currently: formatted text with a horizontal line
 
     // Widgets: Main
     // - Most widgets return true when the value has been changed or when pressed/selected
@@ -564,9 +574,10 @@ namespace ImGui
     // Widgets: Images
     // - Read about ImTextureID here: https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples
     // - 'uv0' and 'uv1' are texture coordinates. Read about them from the same link above.
-    // - Note that Image() may add +2.0f to provided size if a border is visible, ImageButton() adds style.FramePadding*2.0f to provided size.
+    // - Image() pads adds style.ImageBorderSize on each side, ImageButton() adds style.FramePadding on each side.
     // - ImageButton() draws a background based on regular Button() color + optionally an inner background if specified.
-    IMGUI_API void          Image(ImTextureID user_texture_id, const ImVec2& image_size, const ImVec2& uv0 = ImVec2(0, 0), const ImVec2& uv1 = ImVec2(1, 1), const ImVec4& tint_col = ImVec4(1, 1, 1, 1), const ImVec4& border_col = ImVec4(0, 0, 0, 0));
+    IMGUI_API void          Image(ImTextureID user_texture_id, const ImVec2& image_size, const ImVec2& uv0 = ImVec2(0, 0), const ImVec2& uv1 = ImVec2(1, 1));
+    IMGUI_API void          ImageWithBg(ImTextureID user_texture_id, const ImVec2& image_size, const ImVec2& uv0 = ImVec2(0, 0), const ImVec2& uv1 = ImVec2(1, 1), const ImVec4& bg_col = ImVec4(0, 0, 0, 0), const ImVec4& tint_col = ImVec4(1, 1, 1, 1));
     IMGUI_API bool          ImageButton(const char* str_id, ImTextureID user_texture_id, const ImVec2& image_size, const ImVec2& uv0 = ImVec2(0, 0), const ImVec2& uv1 = ImVec2(1, 1), const ImVec4& bg_col = ImVec4(0, 0, 0, 0), const ImVec4& tint_col = ImVec4(1, 1, 1, 1));
 
     // Widgets: Combo Box (Dropdown)
@@ -867,6 +878,26 @@ namespace ImGui
     IMGUI_API bool          TabItemButton(const char* label, ImGuiTabItemFlags flags = 0);      // create a Tab behaving like a button. return true when clicked. cannot be selected in the tab bar.
     IMGUI_API void          SetTabItemClosed(const char* tab_or_docked_window_label);           // notify TabBar or Docking system of a closed tab/window ahead (useful to reduce visual flicker on reorderable tab bars). For tab-bar: call after BeginTabBar() and before Tab submissions. Otherwise call with a window name.
 
+    // Docking
+    // [BETA API] Enable with io.ConfigFlags |= ImGuiConfigFlags_DockingEnable.
+    // Note: You can use most Docking facilities without calling any API. You DO NOT need to call DockSpace() to use Docking!
+    // - Drag from window title bar or their tab to dock/undock. Hold SHIFT to disable docking.
+    // - Drag from window menu button (upper-left button) to undock an entire node (all windows).
+    // - When io.ConfigDockingWithShift == true, you instead need to hold SHIFT to enable docking.
+    // About dockspaces:
+    // - Use DockSpaceOverViewport() to create a window covering the screen or a specific viewport + a dockspace inside it.
+    //   This is often used with ImGuiDockNodeFlags_PassthruCentralNode to make it transparent.
+    // - Use DockSpace() to create an explicit dock node _within_ an existing window. See Docking demo for details.
+    // - Important: Dockspaces need to be submitted _before_ any window they can host. Submit it early in your frame!
+    // - Important: Dockspaces need to be kept alive if hidden, otherwise windows docked into it will be undocked.
+    //   e.g. if you have multiple tabs with a dockspace inside each tab: submit the non-visible dockspaces with ImGuiDockNodeFlags_KeepAliveOnly.
+    IMGUI_API ImGuiID       DockSpace(ImGuiID dockspace_id, const ImVec2& size = ImVec2(0, 0), ImGuiDockNodeFlags flags = 0, const ImGuiWindowClass* window_class = NULL);
+    IMGUI_API ImGuiID       DockSpaceOverViewport(ImGuiID dockspace_id = 0, const ImGuiViewport* viewport = NULL, ImGuiDockNodeFlags flags = 0, const ImGuiWindowClass* window_class = NULL);
+    IMGUI_API void          SetNextWindowDockID(ImGuiID dock_id, ImGuiCond cond = 0);           // set next window dock id
+    IMGUI_API void          SetNextWindowClass(const ImGuiWindowClass* window_class);           // set next window class (control docking compatibility + provide hints to platform backend via custom viewport flags and platform parent/child relationship)
+    IMGUI_API ImGuiID       GetWindowDockID();
+    IMGUI_API bool          IsWindowDocked();                                                   // is current window docked into another window?
+
     // Logging/Capture
     // - All text output from the interface can be captured into tty/file/clipboard. By default, tree nodes are automatically opened during logging.
     IMGUI_API void          LogToTTY(int auto_open_depth = -1);                                 // start logging to tty (stdout)
@@ -904,7 +935,7 @@ namespace ImGui
     IMGUI_API void          PopClipRect();
 
     // Focus, Activation
-    IMGUI_API void          SetItemDefaultFocus();                                              // make last item the default focused item of of a newly appearing window.
+    IMGUI_API void          SetItemDefaultFocus();                                              // make last item the default focused item of a newly appearing window.
     IMGUI_API void          SetKeyboardFocusHere(int offset = 0);                               // focus keyboard on the next widget. Use positive 'offset' to access sub components of a multiple component widget. Use -1 to access previous widget.
 
     // Keyboard/Gamepad Navigation
@@ -941,8 +972,8 @@ namespace ImGui
     IMGUI_API ImGuiViewport* GetMainViewport();                                                 // return primary/default viewport. This can never be NULL.
 
     // Background/Foreground Draw Lists
-    IMGUI_API ImDrawList*   GetBackgroundDrawList();                                            // this draw list will be the first rendered one. Useful to quickly draw shapes/text behind dear imgui contents.
-    IMGUI_API ImDrawList*   GetForegroundDrawList();                                            // this draw list will be the last rendered one. Useful to quickly draw shapes/text over dear imgui contents.
+    IMGUI_API ImDrawList*   GetBackgroundDrawList(ImGuiViewport* viewport = NULL);              // get background draw list for the given viewport or viewport associated to the current window. this draw list will be the first rendering one. Useful to quickly draw shapes/text behind dear imgui contents.
+    IMGUI_API ImDrawList*   GetForegroundDrawList(ImGuiViewport* viewport = NULL);              // get foreground draw list for the given viewport or viewport associated to the current window. this draw list will be the top-most rendered one. Useful to quickly draw shapes/text over dear imgui contents.
 
     // Miscellaneous Utilities
     IMGUI_API bool          IsRectVisible(const ImVec2& size);                                  // test if rectangle (of given size, starting from cursor position) is visible / not clipped.
@@ -972,7 +1003,7 @@ namespace ImGui
     IMGUI_API bool          IsKeyReleased(ImGuiKey key);                                        // was key released (went from Down to !Down)?
     IMGUI_API bool          IsKeyChordPressed(ImGuiKeyChord key_chord);                         // was key chord (mods + key) pressed, e.g. you can pass 'ImGuiMod_Ctrl | ImGuiKey_S' as a key-chord. This doesn't do any routing or focus check, please consider using Shortcut() function instead.
     IMGUI_API int           GetKeyPressedAmount(ImGuiKey key, float repeat_delay, float rate);  // uses provided repeat rate/delay. return a count, most often 0 or 1 but might be >1 if RepeatRate is small enough that DeltaTime > RepeatRate
-    IMGUI_API const char*   GetKeyName(ImGuiKey key);                                           // [DEBUG] returns English name of the key. Those names a provided for debugging purpose and are not meant to be saved persistently not compared.
+    IMGUI_API const char*   GetKeyName(ImGuiKey key);                                           // [DEBUG] returns English name of the key. Those names are provided for debugging purpose and are not meant to be saved persistently nor compared.
     IMGUI_API void          SetNextFrameWantCaptureKeyboard(bool want_capture_keyboard);        // Override io.WantCaptureKeyboard flag next frame (said flag is left for your application to handle, typically when true it instructs your app to ignore inputs). e.g. force capture keyboard when your widget is being hovered. This is equivalent to setting "io.WantCaptureKeyboard = want_capture_keyboard"; after the next NewFrame() call.
 
     // Inputs Utilities: Shortcut Testing & Routing [BETA]
@@ -1009,6 +1040,7 @@ namespace ImGui
     IMGUI_API bool          IsMouseClicked(ImGuiMouseButton button, bool repeat = false);       // did mouse button clicked? (went from !Down to Down). Same as GetMouseClickedCount() == 1.
     IMGUI_API bool          IsMouseReleased(ImGuiMouseButton button);                           // did mouse button released? (went from Down to !Down)
     IMGUI_API bool          IsMouseDoubleClicked(ImGuiMouseButton button);                      // did mouse button double-clicked? Same as GetMouseClickedCount() == 2. (note that a double-click will also report IsMouseClicked() == true)
+    IMGUI_API bool          IsMouseReleasedWithDelay(ImGuiMouseButton button, float delay);     // delayed mouse release (use very sparingly!). Generally used with 'delay >= io.MouseDoubleClickTime' + combined with a 'io.MouseClickedLastCount==1' test. This is a very rarely used UI idiom, but some apps use this: e.g. MS Explorer single click on an icon to rename.
     IMGUI_API int           GetMouseClickedCount(ImGuiMouseButton button);                      // return the number of successive mouse-clicks at the time where a click happen (otherwise 0).
     IMGUI_API bool          IsMouseHoveringRect(const ImVec2& r_min, const ImVec2& r_max, bool clip = true);// is mouse hovering given bounding rect (in screen space). clipped by current clipping settings, but disregarding of other consideration of focus/window ordering/popup-block.
     IMGUI_API bool          IsMousePosValid(const ImVec2* mouse_pos = NULL);                    // by convention we use (-FLT_MAX,-FLT_MAX) to denote that there is no mouse available
@@ -1056,6 +1088,15 @@ namespace ImGui
     IMGUI_API void*         MemAlloc(size_t size);
     IMGUI_API void          MemFree(void* ptr);
 
+    // (Optional) Platform/OS interface for multi-viewport support
+    // Read comments around the ImGuiPlatformIO structure for more details.
+    // Note: You may use GetWindowViewport() to get the current viewport of the current window.
+    IMGUI_API void          UpdatePlatformWindows();                                // call in main loop. will call CreateWindow/ResizeWindow/etc. platform functions for each secondary viewport, and DestroyWindow for each inactive viewport.
+    IMGUI_API void          RenderPlatformWindowsDefault(void* platform_render_arg = NULL, void* renderer_render_arg = NULL); // call in main loop. will call RenderWindow/SwapBuffers platform functions for each secondary viewport which doesn't have the ImGuiViewportFlags_Minimized flag set. May be reimplemented by user for custom rendering needs.
+    IMGUI_API void          DestroyPlatformWindows();                               // call DestroyWindow platform functions for all viewports. call from backend Shutdown() if you need to close platform windows before imgui shutdown. otherwise will be called by DestroyContext().
+    IMGUI_API ImGuiViewport* FindViewportByID(ImGuiID id);                          // this is a helper for backends.
+    IMGUI_API ImGuiViewport* FindViewportByPlatformHandle(void* platform_handle);   // this is a helper for backends. the type platform_handle is decided by the backend (e.g. HWND, MyWindow*, GLFWwindow* etc.)
+
 } // namespace ImGui
 
 //-----------------------------------------------------------------------------
@@ -1086,11 +1127,13 @@ enum ImGuiWindowFlags_
     ImGuiWindowFlags_NoNavInputs            = 1 << 16,  // No keyboard/gamepad navigation within the window
     ImGuiWindowFlags_NoNavFocus             = 1 << 17,  // No focusing toward this window with keyboard/gamepad navigation (e.g. skipped by CTRL+TAB)
     ImGuiWindowFlags_UnsavedDocument        = 1 << 18,  // Display a dot next to the title. When used in a tab/docking context, tab is selected when clicking the X + closure is not assumed (will wait for user to stop submitting the tab). Otherwise closure is assumed when pressing the X, so if you keep submitting the tab may reappear at end of tab bar.
+    ImGuiWindowFlags_NoDocking              = 1 << 19,  // Disable docking of this window
     ImGuiWindowFlags_NoNav                  = ImGuiWindowFlags_NoNavInputs | ImGuiWindowFlags_NoNavFocus,
     ImGuiWindowFlags_NoDecoration           = ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoCollapse,
     ImGuiWindowFlags_NoInputs               = ImGuiWindowFlags_NoMouseInputs | ImGuiWindowFlags_NoNavInputs | ImGuiWindowFlags_NoNavFocus,
 
     // [Internal]
+    ImGuiWindowFlags_DockNodeHost           = 1 << 23,  // Don't use! For internal use by Begin()/NewFrame()
     ImGuiWindowFlags_ChildWindow            = 1 << 24,  // Don't use! For internal use by BeginChild()
     ImGuiWindowFlags_Tooltip                = 1 << 25,  // Don't use! For internal use by BeginTooltip()
     ImGuiWindowFlags_Popup                  = 1 << 26,  // Don't use! For internal use by BeginPopup()
@@ -1174,7 +1217,7 @@ enum ImGuiInputTextFlags_
     ImGuiInputTextFlags_NoUndoRedo          = 1 << 16,  // Disable undo/redo. Note that input text owns the text data while active, if you want to provide your own undo/redo stack you need e.g. to call ClearActiveID().
 
     // Elide display / Alignment
-    ImGuiInputTextFlags_ElideLeft			= 1 << 17,	// When text doesn't fit, elide left side to ensure right side stays visible. Useful for path/filenames. Single-line only!
+    ImGuiInputTextFlags_ElideLeft           = 1 << 17,  // When text doesn't fit, elide left side to ensure right side stays visible. Useful for path/filenames. Single-line only!
 
     // Callback features
     ImGuiInputTextFlags_CallbackCompletion  = 1 << 18,  // Callback on pressing TAB (for completion handling)
@@ -1315,7 +1358,7 @@ enum ImGuiFocusedFlags_
     ImGuiFocusedFlags_RootWindow                    = 1 << 1,   // Test from root window (top most parent of the current hierarchy)
     ImGuiFocusedFlags_AnyWindow                     = 1 << 2,   // Return true if any window is focused. Important: If you are trying to tell how to dispatch your low-level inputs, do NOT use this. Use 'io.WantCaptureMouse' instead! Please read the FAQ!
     ImGuiFocusedFlags_NoPopupHierarchy              = 1 << 3,   // Do not consider popup hierarchy (do not treat popup emitter as parent of popup) (when used with _ChildWindows or _RootWindow)
-    //ImGuiFocusedFlags_DockHierarchy               = 1 << 4,   // Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
+    ImGuiFocusedFlags_DockHierarchy                 = 1 << 4,   // Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
     ImGuiFocusedFlags_RootAndChildWindows           = ImGuiFocusedFlags_RootWindow | ImGuiFocusedFlags_ChildWindows,
 };
 
@@ -1329,7 +1372,7 @@ enum ImGuiHoveredFlags_
     ImGuiHoveredFlags_RootWindow                    = 1 << 1,   // IsWindowHovered() only: Test from root window (top most parent of the current hierarchy)
     ImGuiHoveredFlags_AnyWindow                     = 1 << 2,   // IsWindowHovered() only: Return true if any window is hovered
     ImGuiHoveredFlags_NoPopupHierarchy              = 1 << 3,   // IsWindowHovered() only: Do not consider popup hierarchy (do not treat popup emitter as parent of popup) (when used with _ChildWindows or _RootWindow)
-    //ImGuiHoveredFlags_DockHierarchy               = 1 << 4,   // IsWindowHovered() only: Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
+    ImGuiHoveredFlags_DockHierarchy                 = 1 << 4,   // IsWindowHovered() only: Consider docking hierarchy (treat dockspace host as parent of docked window) (when used with _ChildWindows or _RootWindow)
     ImGuiHoveredFlags_AllowWhenBlockedByPopup       = 1 << 5,   // Return true even if a popup window is normally blocking access to this item/window
     //ImGuiHoveredFlags_AllowWhenBlockedByModal     = 1 << 6,   // Return true even if a modal popup window is normally blocking access to this item/window. FIXME-TODO: Unavailable yet.
     ImGuiHoveredFlags_AllowWhenBlockedByActiveItem  = 1 << 7,   // Return true even if an active item is blocking access to this item/window. Useful for Drag and Drop patterns.
@@ -1359,6 +1402,27 @@ enum ImGuiHoveredFlags_
     ImGuiHoveredFlags_NoSharedDelay                 = 1 << 17,  // IsItemHovered() only: Disable shared delay system where moving from one item to the next keeps the previous timer for a short time (standard for tooltips with long delays)
 };
 
+// Flags for ImGui::DockSpace(), shared/inherited by child nodes.
+// (Some flags can be applied to individual nodes directly)
+// FIXME-DOCK: Also see ImGuiDockNodeFlagsPrivate_ which may involve using the WIP and internal DockBuilder api.
+enum ImGuiDockNodeFlags_
+{
+    ImGuiDockNodeFlags_None                         = 0,
+    ImGuiDockNodeFlags_KeepAliveOnly                = 1 << 0,   //       // Don't display the dockspace node but keep it alive. Windows docked into this dockspace node won't be undocked.
+    //ImGuiDockNodeFlags_NoCentralNode              = 1 << 1,   //       // Disable Central Node (the node which can stay empty)
+    ImGuiDockNodeFlags_NoDockingOverCentralNode     = 1 << 2,   //       // Disable docking over the Central Node, which will be always kept empty.
+    ImGuiDockNodeFlags_PassthruCentralNode          = 1 << 3,   //       // Enable passthru dockspace: 1) DockSpace() will render a ImGuiCol_WindowBg background covering everything excepted the Central Node when empty. Meaning the host window should probably use SetNextWindowBgAlpha(0.0f) prior to Begin() when using this. 2) When Central Node is empty: let inputs pass-through + won't display a DockingEmptyBg background. See demo for details.
+    ImGuiDockNodeFlags_NoDockingSplit               = 1 << 4,   //       // Disable other windows/nodes from splitting this node.
+    ImGuiDockNodeFlags_NoResize                     = 1 << 5,   // Saved // Disable resizing node using the splitter/separators. Useful with programmatically setup dockspaces.
+    ImGuiDockNodeFlags_AutoHideTabBar               = 1 << 6,   //       // Tab bar will automatically hide when there is a single window in the dock node.
+    ImGuiDockNodeFlags_NoUndocking                  = 1 << 7,   //       // Disable undocking this node.
+
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+    ImGuiDockNodeFlags_NoSplit                      = ImGuiDockNodeFlags_NoDockingSplit, // Renamed in 1.90
+    ImGuiDockNodeFlags_NoDockingInCentralNode       = ImGuiDockNodeFlags_NoDockingOverCentralNode, // Renamed in 1.90
+#endif
+};
+
 // Flags for ImGui::BeginDragDropSource(), ImGui::AcceptDragDropPayload()
 enum ImGuiDragDropFlags_
 {
@@ -1489,6 +1553,7 @@ enum ImGuiKey : int
     ImGuiKey_KeypadEqual,
     ImGuiKey_AppBack,               // Available on some keyboard/mouses. Often referred as "Browser Back"
     ImGuiKey_AppForward,
+    ImGuiKey_Oem102,                // Non-US backslash.
 
     // Gamepad (some of those are analog values, 0.0f to 1.0f)                          // NAVIGATION ACTION
     // (download controller mapping PNG/PSD at http://dearimgui.com/controls_sheets)
@@ -1589,6 +1654,15 @@ enum ImGuiConfigFlags_
     ImGuiConfigFlags_NoMouseCursorChange    = 1 << 5,   // Instruct backend to not alter mouse cursor shape and visibility. Use if the backend cursor changes are interfering with yours and you don't want to use SetMouseCursor() to change mouse cursor. You may want to honor requests from imgui by reading GetMouseCursor() yourself instead.
     ImGuiConfigFlags_NoKeyboard             = 1 << 6,   // Instruct dear imgui to disable keyboard inputs and interactions. This is done by ignoring keyboard events and clearing existing states.
 
+    // [BETA] Docking
+    ImGuiConfigFlags_DockingEnable          = 1 << 7,   // Docking enable flags.
+
+    // [BETA] Viewports
+    // When using viewports it is recommended that your default value for ImGuiCol_WindowBg is opaque (Alpha=1.0) so transition to a viewport won't be noticeable.
+    ImGuiConfigFlags_ViewportsEnable        = 1 << 10,  // Viewport enable flags (require both ImGuiBackendFlags_PlatformHasViewports + ImGuiBackendFlags_RendererHasViewports set by the respective backends)
+    ImGuiConfigFlags_DpiEnableScaleViewports= 1 << 14,  // [BETA: Don't use] FIXME-DPI: Reposition and resize imgui windows when the DpiScale of a viewport changed (mostly useful for the main viewport hosting other window). Note that resizing the main window itself is up to your application.
+    ImGuiConfigFlags_DpiEnableScaleFonts    = 1 << 15,  // [BETA: Don't use] FIXME-DPI: Request bitmap-scaled fonts to match DpiScale. This is a very low-quality workaround. The correct way to handle DPI is _currently_ to replace the atlas and/or fonts in the Platform_OnChangedViewport callback, but this is all early work in progress.
+
     // User storage (to allow your backend/engine to communicate to code that may be shared between multiple projects. Those flags are NOT used by core Dear ImGui)
     ImGuiConfigFlags_IsSRGB                 = 1 << 20,  // Application is SRGB-aware.
     ImGuiConfigFlags_IsTouchScreen          = 1 << 21,  // Application is using a touch screen instead of a mouse.
@@ -1607,6 +1681,11 @@ enum ImGuiBackendFlags_
     ImGuiBackendFlags_HasMouseCursors       = 1 << 1,   // Backend Platform supports honoring GetMouseCursor() value to change the OS cursor shape.
     ImGuiBackendFlags_HasSetMousePos        = 1 << 2,   // Backend Platform supports io.WantSetMousePos requests to reposition the OS mouse position (only used if io.ConfigNavMoveSetMousePos is set).
     ImGuiBackendFlags_RendererHasVtxOffset  = 1 << 3,   // Backend Renderer supports ImDrawCmd::VtxOffset. This enables output of large meshes (64K+ vertices) while still using 16-bit indices.
+
+    // [BETA] Viewports
+    ImGuiBackendFlags_PlatformHasViewports  = 1 << 10,  // Backend Platform supports multiple viewports.
+    ImGuiBackendFlags_HasMouseHoveredViewport=1 << 11,  // Backend Platform supports calling io.AddMouseViewportEvent() with the viewport under the mouse. IF POSSIBLE, ignore viewports with the ImGuiViewportFlags_NoInputs flag (Win32 backend, GLFW 3.30+ backend can do this, SDL backend cannot). If this cannot be done, Dear ImGui needs to use a flawed heuristic to find the viewport under.
+    ImGuiBackendFlags_RendererHasViewports  = 1 << 12,  // Backend Renderer supports multiple viewports.
 };
 
 // Enumeration for PushStyleColor() / PopStyleColor()
@@ -1652,6 +1731,8 @@ enum ImGuiCol_
     ImGuiCol_TabDimmed,             // Tab background, when tab-bar is unfocused & tab is unselected
     ImGuiCol_TabDimmedSelected,     // Tab background, when tab-bar is unfocused & tab is selected
     ImGuiCol_TabDimmedSelectedOverline,//..horizontal overline, when tab-bar is unfocused & tab is selected
+    ImGuiCol_DockingPreview,        // Preview overlay color when about to docking something
+    ImGuiCol_DockingEmptyBg,        // Background color for empty node (e.g. CentralNode with no window docked into it)
     ImGuiCol_PlotLines,
     ImGuiCol_PlotLinesHovered,
     ImGuiCol_PlotHistogram,
@@ -1711,6 +1792,7 @@ enum ImGuiStyleVar_
     ImGuiStyleVar_ScrollbarRounding,        // float     ScrollbarRounding
     ImGuiStyleVar_GrabMinSize,              // float     GrabMinSize
     ImGuiStyleVar_GrabRounding,             // float     GrabRounding
+    ImGuiStyleVar_ImageBorderSize,          // float     ImageBorderSize
     ImGuiStyleVar_TabRounding,              // float     TabRounding
     ImGuiStyleVar_TabBorderSize,            // float     TabBorderSize
     ImGuiStyleVar_TabBarBorderSize,         // float     TabBarBorderSize
@@ -1722,6 +1804,7 @@ enum ImGuiStyleVar_
     ImGuiStyleVar_SeparatorTextBorderSize,  // float     SeparatorTextBorderSize
     ImGuiStyleVar_SeparatorTextAlign,       // ImVec2    SeparatorTextAlign
     ImGuiStyleVar_SeparatorTextPadding,     // ImVec2    SeparatorTextPadding
+    ImGuiStyleVar_DockingSeparatorSize,     // float     DockingSeparatorSize
     ImGuiStyleVar_COUNT
 };
 
@@ -1751,10 +1834,16 @@ enum ImGuiColorEditFlags_
     ImGuiColorEditFlags_NoDragDrop      = 1 << 9,   //              // ColorEdit: disable drag and drop target. ColorButton: disable drag and drop source.
     ImGuiColorEditFlags_NoBorder        = 1 << 10,  //              // ColorButton: disable border (which is enforced by default)
 
+    // Alpha preview
+    // - Prior to 1.91.8 (2025/01/21): alpha was made opaque in the preview by default using old name ImGuiColorEditFlags_AlphaPreview.
+    // - We now display the preview as transparent by default. You can use ImGuiColorEditFlags_AlphaOpaque to use old behavior.
+    // - The new flags may be combined better and allow finer controls.
+    ImGuiColorEditFlags_AlphaOpaque     = 1 << 11,  //              // ColorEdit, ColorPicker, ColorButton: disable alpha in the preview,. Contrary to _NoAlpha it may still be edited when calling ColorEdit4()/ColorPicker4(). For ColorButton() this does the same as _NoAlpha.
+    ImGuiColorEditFlags_AlphaNoBg       = 1 << 12,  //              // ColorEdit, ColorPicker, ColorButton: disable rendering a checkerboard background behind transparent color.
+    ImGuiColorEditFlags_AlphaPreviewHalf= 1 << 13,  //              // ColorEdit, ColorPicker, ColorButton: display half opaque / half transparent preview.
+
     // User Options (right-click on widget to change some of them).
     ImGuiColorEditFlags_AlphaBar        = 1 << 16,  //              // ColorEdit, ColorPicker: show vertical alpha bar/gradient in picker.
-    ImGuiColorEditFlags_AlphaPreview    = 1 << 17,  //              // ColorEdit, ColorPicker, ColorButton: display preview as a transparent color over a checkerboard, instead of opaque.
-    ImGuiColorEditFlags_AlphaPreviewHalf= 1 << 18,  //              // ColorEdit, ColorPicker, ColorButton: display half opaque / half checkerboard, instead of opaque.
     ImGuiColorEditFlags_HDR             = 1 << 19,  //              // (WIP) ColorEdit: Currently only disable 0.0f..1.0f limits in RGBA edition (note: you probably want to use ImGuiColorEditFlags_Float flag as well).
     ImGuiColorEditFlags_DisplayRGB      = 1 << 20,  // [Display]    // ColorEdit: override _display_ type among RGB/HSV/Hex. ColorPicker: select any combination using one or more of RGB/HSV/Hex.
     ImGuiColorEditFlags_DisplayHSV      = 1 << 21,  // [Display]    // "
@@ -1771,12 +1860,16 @@ enum ImGuiColorEditFlags_
     ImGuiColorEditFlags_DefaultOptions_ = ImGuiColorEditFlags_Uint8 | ImGuiColorEditFlags_DisplayRGB | ImGuiColorEditFlags_InputRGB | ImGuiColorEditFlags_PickerHueBar,
 
     // [Internal] Masks
+    ImGuiColorEditFlags_AlphaMask_      = ImGuiColorEditFlags_NoAlpha | ImGuiColorEditFlags_AlphaOpaque | ImGuiColorEditFlags_AlphaNoBg | ImGuiColorEditFlags_AlphaPreviewHalf,
     ImGuiColorEditFlags_DisplayMask_    = ImGuiColorEditFlags_DisplayRGB | ImGuiColorEditFlags_DisplayHSV | ImGuiColorEditFlags_DisplayHex,
     ImGuiColorEditFlags_DataTypeMask_   = ImGuiColorEditFlags_Uint8 | ImGuiColorEditFlags_Float,
     ImGuiColorEditFlags_PickerMask_     = ImGuiColorEditFlags_PickerHueWheel | ImGuiColorEditFlags_PickerHueBar,
     ImGuiColorEditFlags_InputMask_      = ImGuiColorEditFlags_InputRGB | ImGuiColorEditFlags_InputHSV,
 
     // Obsolete names
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+    ImGuiColorEditFlags_AlphaPreview = 0,         // [Removed in 1.91.8] This is the default now. Will display a checkerboard unless ImGuiColorEditFlags_AlphaNoBg is set.
+#endif
     //ImGuiColorEditFlags_RGB = ImGuiColorEditFlags_DisplayRGB, ImGuiColorEditFlags_HSV = ImGuiColorEditFlags_DisplayHSV, ImGuiColorEditFlags_HEX = ImGuiColorEditFlags_DisplayHex  // [renamed in 1.69]
 };
 
@@ -1820,6 +1913,8 @@ enum ImGuiMouseCursor_
     ImGuiMouseCursor_ResizeNESW,        // When hovering over the bottom-left corner of a window
     ImGuiMouseCursor_ResizeNWSE,        // When hovering over the bottom-right corner of a window
     ImGuiMouseCursor_Hand,              // (Unused by Dear ImGui functions. Use for e.g. hyperlinks)
+    ImGuiMouseCursor_Wait,              // When waiting for something to process/load.
+    ImGuiMouseCursor_Progress,          // When waiting for something to process/load, but application is still interactive.
     ImGuiMouseCursor_NotAllowed,        // When hovering something with disallowed interaction. Usually a crossed circle.
     ImGuiMouseCursor_COUNT
 };
@@ -2133,6 +2228,7 @@ struct ImGuiStyle
     ImVec2      WindowPadding;              // Padding within a window.
     float       WindowRounding;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows. Large values tend to lead to variety of artifacts and are not recommended.
     float       WindowBorderSize;           // Thickness of border around windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly).
+    float       WindowBorderHoverPadding;   // Hit-testing extent outside/inside resizing border. Also extend determination of hovered window. Generally meaningfully larger than WindowBorderSize to make it easy to reach borders.
     ImVec2      WindowMinSize;              // Minimum window size. This is a global setting. If you want to constrain individual windows, use SetNextWindowSizeConstraints().
     ImVec2      WindowTitleAlign;           // Alignment for title bar text. Defaults to (0.0f,0.5f) for left-aligned,vertically centered.
     ImGuiDir    WindowMenuButtonPosition;   // Side of the collapsing/docking button in the title bar (None/Left/Right). Defaults to ImGuiDir_Left.
@@ -2154,9 +2250,11 @@ struct ImGuiStyle
     float       GrabMinSize;                // Minimum width/height of a grab box for slider/scrollbar.
     float       GrabRounding;               // Radius of grabs corners rounding. Set to 0.0f to have rectangular slider grabs.
     float       LogSliderDeadzone;          // The size in pixels of the dead-zone around zero on logarithmic sliders that cross zero.
+    float       ImageBorderSize;            // Thickness of border around Image() calls.
     float       TabRounding;                // Radius of upper corners of a tab. Set to 0.0f to have rectangular tabs.
     float       TabBorderSize;              // Thickness of border around tabs.
-    float       TabMinWidthForCloseButton;  // Minimum width for close button to appear on an unselected tab when hovered. Set to 0.0f to always show when hovering, set to FLT_MAX to never show close button unless selected.
+    float       TabCloseButtonMinWidthSelected;     // -1: always visible. 0.0f: visible when hovered. >0.0f: visible when hovered if minimum width.
+    float       TabCloseButtonMinWidthUnselected;   // -1: always visible. 0.0f: visible when hovered. >0.0f: visible when hovered if minimum width. FLT_MAX: never show close button when unselected.
     float       TabBarBorderSize;           // Thickness of tab-bar separator, which takes on the tab active color to denote focus.
     float       TabBarOverlineSize;         // Thickness of tab-bar overline, which highlights the selected tab-bar.
     float       TableAngledHeadersAngle;    // Angle of angled headers (supported values range from -50.0f degrees to +50.0f degrees).
@@ -2169,12 +2267,15 @@ struct ImGuiStyle
     ImVec2      SeparatorTextPadding;       // Horizontal offset of text from each edge of the separator + spacing on other axis. Generally small values. .y is recommended to be == FramePadding.y.
     ImVec2      DisplayWindowPadding;       // Apply to regular windows: amount which we enforce to keep visible when moving near edges of your screen.
     ImVec2      DisplaySafeAreaPadding;     // Apply to every windows, menus, popups, tooltips: amount where we avoid displaying contents. Adjust if you cannot see the edges of your screen (e.g. on a TV where scaling has not been configured).
+    float       DockingSeparatorSize;       // Thickness of resizing border between docked windows
     float       MouseCursorScale;           // Scale software rendered mouse cursor (when io.MouseDrawCursor is enabled). We apply per-monitor DPI scaling over this scale. May be removed later.
     bool        AntiAliasedLines;           // Enable anti-aliased lines/borders. Disable if you are really tight on CPU/GPU. Latched at the beginning of the frame (copied to ImDrawList).
     bool        AntiAliasedLinesUseTex;     // Enable anti-aliased lines/borders using textures where possible. Require backend to render with bilinear filtering (NOT point/nearest filtering). Latched at the beginning of the frame (copied to ImDrawList).
     bool        AntiAliasedFill;            // Enable anti-aliased edges around filled shapes (rounded rectangles, circles, etc.). Disable if you are really tight on CPU/GPU. Latched at the beginning of the frame (copied to ImDrawList).
     float       CurveTessellationTol;       // Tessellation tolerance when using PathBezierCurveTo() without a specific number of segments. Decrease for highly tessellated curves (higher quality, more polygons), increase to reduce quality.
     float       CircleTessellationMaxError; // Maximum error (in pixels) allowed when using AddCircle()/AddCircleFilled() or drawing rounded corner rectangles with no explicit segment count specified. Decrease for higher quality but more geometry.
+
+    // Colors
     ImVec4      Colors[ImGuiCol_COUNT];
 
     // Behaviors
@@ -2187,6 +2288,11 @@ struct ImGuiStyle
 
     IMGUI_API ImGuiStyle();
     IMGUI_API void ScaleAllSizes(float scale_factor);
+
+    // Obsolete names
+#ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
+    // TabMinWidthForCloseButton = TabCloseButtonMinWidthUnselected // Renamed in 1.91.9.
+#endif
 };
 
 //-----------------------------------------------------------------------------
@@ -2242,6 +2348,18 @@ struct ImGuiIO
     bool        ConfigNavCursorVisibleAuto;     // = true           // Using directional navigation key makes the cursor visible. Mouse click hides the cursor.
     bool        ConfigNavCursorVisibleAlways;   // = false          // Navigation cursor is always visible.
 
+    // Docking options (when ImGuiConfigFlags_DockingEnable is set)
+    bool        ConfigDockingNoSplit;           // = false          // Simplified docking mode: disable window splitting, so docking is limited to merging multiple windows together into tab-bars.
+    bool        ConfigDockingWithShift;         // = false          // Enable docking with holding Shift key (reduce visual noise, allows dropping in wider space)
+    bool        ConfigDockingAlwaysTabBar;      // = false          // [BETA] [FIXME: This currently creates regression with auto-sizing and general overhead] Make every single floating window display within a docking node.
+    bool        ConfigDockingTransparentPayload;// = false          // [BETA] Make window or viewport transparent when docking and only display docking boxes on the target viewport. Useful if rendering of multiple viewport cannot be synced. Best used with ConfigViewportsNoAutoMerge.
+
+    // Viewport options (when ImGuiConfigFlags_ViewportsEnable is set)
+    bool        ConfigViewportsNoAutoMerge;     // = false;         // Set to make all floating imgui windows always create their own viewport. Otherwise, they are merged into the main host viewports when overlapping it. May also set ImGuiViewportFlags_NoAutoMerge on individual viewport.
+    bool        ConfigViewportsNoTaskBarIcon;   // = false          // Disable default OS task bar icon flag for secondary viewports. When a viewport doesn't want a task bar icon, ImGuiViewportFlags_NoTaskBarIcon will be set on it.
+    bool        ConfigViewportsNoDecoration;    // = true           // Disable default OS window decoration flag for secondary viewports. When a viewport doesn't want window decorations, ImGuiViewportFlags_NoDecoration will be set on it. Enabling decoration can create subsequent issues at OS levels (e.g. minimum window size).
+    bool        ConfigViewportsNoDefaultParent; // = false          // Disable default OS parenting to main viewport for secondary viewports. By default, viewports are marked with ParentViewportId = <main_viewport>, expecting the platform backend to setup a parent/child relationship between the OS windows (some backend may ignore this). Set to true if you want the default to be 0, then all viewports will be top-level OS windows.
+
     // Miscellaneous options
     // (you can visualize and interact with all options in 'Demo->Configuration')
     bool        MouseDrawCursor;                // = false          // Request ImGui to draw a mouse cursor for you (if you are on a platform without a mouse cursor). Cannot be easily renamed to 'io.ConfigXXX' because this is frequently used by backend implementations.
@@ -2297,7 +2415,8 @@ struct ImGuiIO
     // - Code should use PushID()/PopID() in loops, or append "##xx" to same-label identifiers.
     // - Empty label e.g. Button("") == same ID as parent widget/node. Use Button("##xx") instead!
     // - See FAQ https://github.com/ocornut/imgui/blob/master/docs/FAQ.md#q-about-the-id-stack-system
-    bool        ConfigDebugHighlightIdConflicts;// = true           // Highlight and show an error message when multiple items have conflicting identifiers.
+    bool        ConfigDebugHighlightIdConflicts;// = true           // Highlight and show an error message popup when multiple items have conflicting identifiers.
+    bool        ConfigDebugHighlightIdConflictsShowItemPicker;//=true // Show "Item Picker" button in aforementioned popup.
 
     // Tools to test correct Begin/End and BeginChild/EndChild behaviors.
     // - Presently Begin()/End() and BeginChild()/EndChild() needs to ALWAYS be called in tandem, regardless of return value of BeginXXX()
@@ -2338,6 +2457,7 @@ struct ImGuiIO
     IMGUI_API void  AddMouseButtonEvent(int button, bool down);             // Queue a mouse button change
     IMGUI_API void  AddMouseWheelEvent(float wheel_x, float wheel_y);       // Queue a mouse wheel update. wheel_y<0: scroll down, wheel_y>0: scroll up, wheel_x<0: scroll right, wheel_x>0: scroll left.
     IMGUI_API void  AddMouseSourceEvent(ImGuiMouseSource source);           // Queue a mouse source change (Mouse/TouchScreen/Pen)
+    IMGUI_API void  AddMouseViewportEvent(ImGuiID id);                      // Queue a mouse hovered viewport. Requires backend to set ImGuiBackendFlags_HasMouseHoveredViewport to call this (for multi-viewport support).
     IMGUI_API void  AddFocusEvent(bool focused);                            // Queue a gain/loss of focus for the application (generally based on OS/platform focus of your window)
     IMGUI_API void  AddInputCharacter(unsigned int c);                      // Queue a new character input
     IMGUI_API void  AddInputCharacterUTF16(ImWchar16 c);                    // Queue a new character input from a UTF-16 character, it can be a surrogate
@@ -2386,6 +2506,7 @@ struct ImGuiIO
     float       MouseWheel;                         // Mouse wheel Vertical: 1 unit scrolls about 5 lines text. >0 scrolls Up, <0 scrolls Down. Hold SHIFT to turn vertical scroll into horizontal scroll.
     float       MouseWheelH;                        // Mouse wheel Horizontal. >0 scrolls Left, <0 scrolls Right. Most users don't have a mouse with a horizontal wheel, may not be filled by all backends.
     ImGuiMouseSource MouseSource;                   // Mouse actual input peripheral (Mouse/TouchScreen/Pen).
+    ImGuiID     MouseHoveredViewport;               // (Optional) Modify using io.AddMouseViewportEvent(). With multi-viewports: viewport the OS mouse is hovering. If possible _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag is much better (few backends can handle that). Set io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport if you can provide this info. If you don't imgui will infer the value using the rectangles and last focused time of the viewports it knows about (ignoring other OS windows).
     bool        KeyCtrl;                            // Keyboard modifier down: Control
     bool        KeyShift;                           // Keyboard modifier down: Shift
     bool        KeyAlt;                             // Keyboard modifier down: Alt
@@ -2403,12 +2524,14 @@ struct ImGuiIO
     ImU16       MouseClickedCount[5];               // == 0 (not clicked), == 1 (same as MouseClicked[]), == 2 (double-clicked), == 3 (triple-clicked) etc. when going from !Down to Down
     ImU16       MouseClickedLastCount[5];           // Count successive number of clicks. Stays valid after mouse release. Reset after another click is done.
     bool        MouseReleased[5];                   // Mouse button went from Down to !Down
+    double      MouseReleasedTime[5];               // Time of last released (rarely used! but useful to handle delayed single-click when trying to disambiguate them from double-click).
     bool        MouseDownOwned[5];                  // Track if button was clicked inside a dear imgui window or over void blocked by a popup. We don't request mouse capture from the application if click started outside ImGui bounds.
     bool        MouseDownOwnedUnlessPopupClose[5];  // Track if button was clicked inside a dear imgui window.
     bool        MouseWheelRequestAxisSwap;          // On a non-Mac system, holding SHIFT requests WheelY to perform the equivalent of a WheelX event. On a Mac system this is already enforced by the system.
-    bool        MouseCtrlLeftAsRightClick;          // (OSX) Set to true when the current click was a ctrl-click that spawned a simulated right click
+    bool        MouseCtrlLeftAsRightClick;          // (OSX) Set to true when the current click was a Ctrl+click that spawned a simulated right click
     float       MouseDownDuration[5];               // Duration the mouse button has been down (0.0f == just clicked)
     float       MouseDownDurationPrev[5];           // Previous time the mouse button has been down
+    ImVec2      MouseDragMaxDistanceAbs[5];         // Maximum distance, absolute, on each axis, of how much mouse has traveled from the clicking point
     float       MouseDragMaxDistanceSqr[5];         // Squared maximum distance of how much mouse has traveled from the clicking point (used for moving thresholds)
     float       PenPressure;                        // Touch/Pen pressure (0.0f to 1.0f, should be >0.0f only when MouseDown[0] == true). Helper storage currently unused by Dear ImGui.
     bool        AppFocusLost;                       // Only modify via AddFocusEvent()
@@ -2492,6 +2615,28 @@ struct ImGuiSizeCallbackData
     ImVec2  DesiredSize;    // Read-write.  Desired size, based on user's mouse position. Write to this field to restrain resizing.
 };
 
+// [ALPHA] Rarely used / very advanced uses only. Use with SetNextWindowClass() and DockSpace() functions.
+// Important: the content of this class is still highly WIP and likely to change and be refactored
+// before we stabilize Docking features. Please be mindful if using this.
+// Provide hints:
+// - To the platform backend via altered viewport flags (enable/disable OS decoration, OS task bar icons, etc.)
+// - To the platform backend for OS level parent/child relationships of viewport.
+// - To the docking system for various options and filtering.
+struct ImGuiWindowClass
+{
+    ImGuiID             ClassId;                    // User data. 0 = Default class (unclassed). Windows of different classes cannot be docked with each others.
+    ImGuiID             ParentViewportId;           // Hint for the platform backend. -1: use default. 0: request platform backend to not parent the platform. != 0: request platform backend to create a parent<>child relationship between the platform windows. Not conforming backends are free to e.g. parent every viewport to the main viewport or not.
+    ImGuiID             FocusRouteParentWindowId;   // ID of parent window for shortcut focus route evaluation, e.g. Shortcut() call from Parent Window will succeed when this window is focused.
+    ImGuiViewportFlags  ViewportFlagsOverrideSet;   // Viewport flags to set when a window of this class owns a viewport. This allows you to enforce OS decoration or task bar icon, override the defaults on a per-window basis.
+    ImGuiViewportFlags  ViewportFlagsOverrideClear; // Viewport flags to clear when a window of this class owns a viewport. This allows you to enforce OS decoration or task bar icon, override the defaults on a per-window basis.
+    ImGuiTabItemFlags   TabItemFlagsOverrideSet;    // [EXPERIMENTAL] TabItem flags to set when a window of this class gets submitted into a dock node tab bar. May use with ImGuiTabItemFlags_Leading or ImGuiTabItemFlags_Trailing.
+    ImGuiDockNodeFlags  DockNodeFlagsOverrideSet;   // [EXPERIMENTAL] Dock node flags to set when a window of this class is hosted by a dock node (it doesn't have to be selected!)
+    bool                DockingAlwaysTabBar;        // Set to true to enforce single floating windows of this class always having their own docking node (equivalent of setting the global io.ConfigDockingAlwaysTabBar)
+    bool                DockingAllowUnclassed;      // Set to true to allow windows of this class to be docked/merged with an unclassed window. // FIXME-DOCK: Move to DockNodeFlags override?
+
+    ImGuiWindowClass() { memset(this, 0, sizeof(*this)); ParentViewportId = (ImGuiID)-1; DockingAllowUnclassed = true; }
+};
+
 // Data payload for Drag and Drop operations: AcceptDragDropPayload(), GetDragDropPayload()
 struct ImGuiPayload
 {
@@ -2571,10 +2716,11 @@ struct ImGuiTextBuffer
     ImGuiTextBuffer()   { }
     inline char         operator[](int i) const { IM_ASSERT(Buf.Data != NULL); return Buf.Data[i]; }
     const char*         begin() const           { return Buf.Data ? &Buf.front() : EmptyString; }
-    const char*         end() const             { return Buf.Data ? &Buf.back() : EmptyString; }   // Buf is zero-terminated, so end() will point on the zero-terminator
+    const char*         end() const             { return Buf.Data ? &Buf.back() : EmptyString; } // Buf is zero-terminated, so end() will point on the zero-terminator
     int                 size() const            { return Buf.Size ? Buf.Size - 1 : 0; }
     bool                empty() const           { return Buf.Size <= 1; }
     void                clear()                 { Buf.clear(); }
+    void                resize(int size)        { if (Buf.Size > size) Buf.Data[size] = 0; Buf.resize(size ? size + 1 : 0, 0); } // Similar to resize(0) on ImVector: empty string but don't free buffer.
     void                reserve(int capacity)   { Buf.reserve(capacity); }
     const char*         c_str() const           { return Buf.Data ? Buf.Data : EmptyString; }
     IMGUI_API void      append(const char* str, const char* str_end = NULL);
@@ -2923,7 +3069,7 @@ struct ImGuiSelectionExternalStorage
 
 // The maximum line width to bake anti-aliased textures for. Build atlas with ImFontAtlasFlags_NoBakedLines to disable baking.
 #ifndef IM_DRAWLIST_TEX_LINES_WIDTH_MAX
-#define IM_DRAWLIST_TEX_LINES_WIDTH_MAX     (63)
+#define IM_DRAWLIST_TEX_LINES_WIDTH_MAX     (32)
 #endif
 
 // ImDrawCallback: Draw callbacks for advanced uses [configurable type: override in imconfig.h]
@@ -2997,7 +3143,6 @@ struct ImDrawChannel
     ImVector<ImDrawIdx>         _IdxBuffer;
 };
 
-
 // Split/Merge functions are used to split the draw list into different layers which can be drawn into out of order.
 // This is used by the Columns/Tables API, so items of each column can be batched together in a same draw call.
 struct ImDrawListSplitter
@@ -3118,7 +3263,7 @@ struct ImDrawList
 
     // General polygon
     // - Only simple polygons are supported by filling functions (no self-intersections, no holes).
-    // - Concave polygon fill is more expensive than convex one: it has O(N^2) complexity. Provided as a convenience fo user but not used by main library.
+    // - Concave polygon fill is more expensive than convex one: it has O(N^2) complexity. Provided as a convenience for the user but not used by the main library.
     IMGUI_API void  AddPolyline(const ImVec2* points, int num_points, ImU32 col, ImDrawFlags flags, float thickness);
     IMGUI_API void  AddConvexPolyFilled(const ImVec2* points, int num_points, ImU32 col);
     IMGUI_API void  AddConcavePolyFilled(const ImVec2* points, int num_points, ImU32 col);
@@ -3211,7 +3356,7 @@ struct ImDrawList
 struct ImDrawData
 {
     bool                Valid;              // Only valid after Render() is called and before the next NewFrame() is called.
-    int                 CmdListsCount;      // Number of ImDrawList* to render (should always be == CmdLists.size)
+    int                 CmdListsCount;      // Number of ImDrawList* to render
     int                 TotalIdxCount;      // For convenience, sum of all ImDrawList's IdxBuffer.Size
     int                 TotalVtxCount;      // For convenience, sum of all ImDrawList's VtxBuffer.Size
     ImVector<ImDrawList*> CmdLists;         // Array of ImDrawList* to render. The ImDrawLists are owned by ImGuiContext and only pointed to from here.
@@ -3232,26 +3377,28 @@ struct ImDrawData
 // [SECTION] Font API (ImFontConfig, ImFontGlyph, ImFontAtlasFlags, ImFontAtlas, ImFontGlyphRangesBuilder, ImFont)
 //-----------------------------------------------------------------------------
 
+// A font input/source (we may rename this to ImFontSource in the future)
 struct ImFontConfig
 {
     void*           FontData;               //          // TTF/OTF data
     int             FontDataSize;           //          // TTF/OTF data size
     bool            FontDataOwnedByAtlas;   // true     // TTF/OTF data ownership taken by the container ImFontAtlas (will delete memory itself).
-    int             FontNo;                 // 0        // Index of font within TTF/OTF file
-    float           SizePixels;             //          // Size in pixels for rasterizer (more or less maps to the resulting font height).
-    int             OversampleH;            // 2        // Rasterize at higher quality for sub-pixel positioning. Note the difference between 2 and 3 is minimal. You can reduce this to 1 for large glyphs save memory. Read https://github.com/nothings/stb/blob/master/tests/oversample/README.md for details.
-    int             OversampleV;            // 1        // Rasterize at higher quality for sub-pixel positioning. This is not really useful as we don't use sub-pixel positions on the Y axis.
+    bool            MergeMode;              // false    // Merge into previous ImFont, so you can combine multiple inputs font into one ImFont (e.g. ASCII font + icons + Japanese glyphs). You may want to use GlyphOffset.y when merge font of different heights.
     bool            PixelSnapH;             // false    // Align every glyph AdvanceX to pixel boundaries. Useful e.g. if you are merging a non-pixel aligned font with the default font. If enabled, you can set OversampleH/V to 1.
-    ImVec2          GlyphExtraSpacing;      // 0, 0     // Extra spacing (in pixels) between glyphs when rendered: essentially add to glyph->AdvanceX. Only X axis is supported for now.
+    int             FontNo;                 // 0        // Index of font within TTF/OTF file
+    int             OversampleH;            // 0 (2)    // Rasterize at higher quality for sub-pixel positioning. 0 == auto == 1 or 2 depending on size. Note the difference between 2 and 3 is minimal. You can reduce this to 1 for large glyphs save memory. Read https://github.com/nothings/stb/blob/master/tests/oversample/README.md for details.
+    int             OversampleV;            // 0 (1)    // Rasterize at higher quality for sub-pixel positioning. 0 == auto == 1. This is not really useful as we don't use sub-pixel positions on the Y axis.
+    float           SizePixels;             //          // Size in pixels for rasterizer (more or less maps to the resulting font height).
+    //ImVec2        GlyphExtraSpacing;      // 0, 0     // (REMOVED IN 1.91.9: use GlyphExtraAdvanceX)
     ImVec2          GlyphOffset;            // 0, 0     // Offset all glyphs from this font input.
     const ImWchar*  GlyphRanges;            // NULL     // THE ARRAY DATA NEEDS TO PERSIST AS LONG AS THE FONT IS ALIVE. Pointer to a user-provided list of Unicode range (2 value per range, values are inclusive, zero-terminated list).
     float           GlyphMinAdvanceX;       // 0        // Minimum AdvanceX for glyphs, set Min to align font icons, set both Min/Max to enforce mono-space font
     float           GlyphMaxAdvanceX;       // FLT_MAX  // Maximum AdvanceX for glyphs
-    bool            MergeMode;              // false    // Merge into previous ImFont, so you can combine multiple inputs font into one ImFont (e.g. ASCII font + icons + Japanese glyphs). You may want to use GlyphOffset.y when merge font of different heights.
+    float           GlyphExtraAdvanceX;     // 0        // Extra spacing (in pixels) between glyphs. Please contact us if you are using this.
     unsigned int    FontBuilderFlags;       // 0        // Settings for custom font builder. THIS IS BUILDER IMPLEMENTATION DEPENDENT. Leave as zero if unsure.
     float           RasterizerMultiply;     // 1.0f     // Linearly brighten (>1.0f) or darken (<1.0f) font output. Brightening small fonts may be a good workaround to make them more readable. This is a silly thing we may remove in the future.
     float           RasterizerDensity;      // 1.0f     // DPI scale for rasterization, not altering other font metrics: make it easy to swap between e.g. a 100% and a 400% fonts for a zooming display. IMPORTANT: If you increase this it is expected that you increase font scale accordingly, otherwise quality may look lowered.
-    ImWchar         EllipsisChar;           // 0        // Explicitly specify unicode codepoint of ellipsis character. When fonts are being merged first specified ellipsis will be used.
+    ImWchar         EllipsisChar;           // 0        // Explicitly specify Unicode codepoint of ellipsis character. When fonts are being merged first specified ellipsis will be used.
 
     // [Internal]
     char            Name[40];               // Name (strictly to ease debugging)
@@ -3267,7 +3414,7 @@ struct ImFontGlyph
     unsigned int    Colored : 1;        // Flag to indicate glyph is colored and should generally ignore tinting (make it usable with no shift on little-endian as this is used in loops)
     unsigned int    Visible : 1;        // Flag to indicate glyph has no visible pixels (e.g. space). Allow early out when rendering.
     unsigned int    Codepoint : 30;     // 0x0000..0x10FFFF
-    float           AdvanceX;           // Distance to next character (= data from font + ImFontConfig::GlyphExtraSpacing.x baked in)
+    float           AdvanceX;           // Horizontal distance to advance layout with
     float           X0, Y0, X1, Y1;     // Glyph corners
     float           U0, V0, U1, V1;     // Texture coordinates
 };
@@ -3341,8 +3488,8 @@ struct ImFontAtlas
     IMGUI_API ImFont*           AddFontFromMemoryCompressedTTF(const void* compressed_font_data, int compressed_font_data_size, float size_pixels, const ImFontConfig* font_cfg = NULL, const ImWchar* glyph_ranges = NULL); // 'compressed_font_data' still owned by caller. Compress with binary_to_compressed_c.cpp.
     IMGUI_API ImFont*           AddFontFromMemoryCompressedBase85TTF(const char* compressed_font_data_base85, float size_pixels, const ImFontConfig* font_cfg = NULL, const ImWchar* glyph_ranges = NULL);              // 'compressed_font_data_base85' still owned by caller. Compress with binary_to_compressed_c.cpp with -base85 parameter.
     IMGUI_API void              ClearInputData();           // Clear input data (all ImFontConfig structures including sizes, TTF data, glyph ranges, etc.) = all the data used to build the texture and fonts.
+    IMGUI_API void              ClearFonts();               // Clear input+output font data (same as ClearInputData() + glyphs storage, UV coordinates).
     IMGUI_API void              ClearTexData();             // Clear output texture data (CPU side). Saves RAM once the texture has been copied to graphics memory.
-    IMGUI_API void              ClearFonts();               // Clear output font data (glyphs storage, UV coordinates).
     IMGUI_API void              Clear();                    // Clear all input and output.
 
     // Build atlas, retrieve pixel data.
@@ -3375,7 +3522,7 @@ struct ImFontAtlas
     IMGUI_API const ImWchar*    GetGlyphRangesVietnamese();             // Default + Vietnamese characters
 
     //-------------------------------------------
-    // [BETA] Custom Rectangles/Glyphs API
+    // [ALPHA] Custom Rectangles/Glyphs API
     //-------------------------------------------
 
     // You can request arbitrary rectangles to be packed into the atlas, for your own purposes.
@@ -3391,21 +3538,21 @@ struct ImFontAtlas
 
     // [Internal]
     IMGUI_API void              CalcCustomRectUV(const ImFontAtlasCustomRect* rect, ImVec2* out_uv_min, ImVec2* out_uv_max) const;
-    IMGUI_API bool              GetMouseCursorTexData(ImGuiMouseCursor cursor, ImVec2* out_offset, ImVec2* out_size, ImVec2 out_uv_border[2], ImVec2 out_uv_fill[2]);
 
     //-------------------------------------------
     // Members
     //-------------------------------------------
 
+    // Input
     ImFontAtlasFlags            Flags;              // Build flags (see ImFontAtlasFlags_)
     ImTextureID                 TexID;              // User data to refer to the texture once it has been uploaded to user's graphic systems. It is passed back to you during rendering via the ImDrawCmd structure.
     int                         TexDesiredWidth;    // Texture width desired by user before Build(). Must be a power-of-two. If have many glyphs your graphics API have texture size restrictions you may want to increase texture width to decrease height.
     int                         TexGlyphPadding;    // FIXME: Should be called "TexPackPadding". Padding between glyphs within texture in pixels. Defaults to 1. If your rendering method doesn't rely on bilinear filtering you may set this to 0 (will also need to set AntiAliasedLinesUseTex = false).
-    bool                        Locked;             // Marked as Locked by ImGui::NewFrame() so attempt to modify the atlas will assert.
     void*                       UserData;           // Store your own atlas related user-data (if e.g. you have multiple font atlas).
 
     // [Internal]
     // NB: Access texture data via GetTexData*() calls! Which will setup a default font for you.
+    bool                        Locked;             // Marked as Locked by ImGui::NewFrame() so attempt to modify the atlas will assert.
     bool                        TexReady;           // Set when texture was built matching current font input
     bool                        TexPixelsUseColors; // Tell whether our texture data is known to use colors (rather than just alpha channel), in order to help backend select a format.
     unsigned char*              TexPixelsAlpha8;    // 1 component per pixel, each component is unsigned 8-bit. Total size = TexWidth * TexHeight
@@ -3416,7 +3563,7 @@ struct ImFontAtlas
     ImVec2                      TexUvWhitePixel;    // Texture coordinates to a white pixel
     ImVector<ImFont*>           Fonts;              // Hold all the fonts returned by AddFont*. Fonts[0] is the default font upon calling ImGui::NewFrame(), use ImGui::PushFont()/PopFont() to change the current font.
     ImVector<ImFontAtlasCustomRect> CustomRects;    // Rectangles for packing custom texture data into the atlas.
-    ImVector<ImFontConfig>      ConfigData;         // Configuration data
+    ImVector<ImFontConfig>      Sources;            // Source/configuration data
     ImVec4                      TexUvLines[IM_DRAWLIST_TEX_LINES_WIDTH_MAX + 1];  // UVs for baked anti-aliased lines
 
     // [Internal] Font builder
@@ -3428,8 +3575,8 @@ struct ImFontAtlas
     int                         PackIdLines;        // Custom texture rectangle ID for baked anti-aliased lines
 
     // [Obsolete]
-    //typedef ImFontAtlasCustomRect    CustomRect;         // OBSOLETED in 1.72+
-    //typedef ImFontGlyphRangesBuilder GlyphRangesBuilder; // OBSOLETED in 1.67+
+    //typedef ImFontAtlasCustomRect    CustomRect;              // OBSOLETED in 1.72+
+    //typedef ImFontGlyphRangesBuilder GlyphRangesBuilder;      // OBSOLETED in 1.67+
 };
 
 // Font runtime data and rendering
@@ -3437,40 +3584,41 @@ struct ImFontAtlas
 struct ImFont
 {
     // [Internal] Members: Hot ~20/24 bytes (for CalcTextSize)
-    ImVector<float>             IndexAdvanceX;      // 12-16 // out //            // Sparse. Glyphs->AdvanceX in a directly indexable way (cache-friendly for CalcTextSize functions which only this info, and are often bottleneck in large UI).
+    ImVector<float>             IndexAdvanceX;      // 12-16 // out // Sparse. Glyphs->AdvanceX in a directly indexable way (cache-friendly for CalcTextSize functions which only this info, and are often bottleneck in large UI).
     float                       FallbackAdvanceX;   // 4     // out // = FallbackGlyph->AdvanceX
-    float                       FontSize;           // 4     // in  //            // Height of characters/line, set during loading (don't change after loading)
+    float                       FontSize;           // 4     // in  // Height of characters/line, set during loading (don't change after loading)
 
     // [Internal] Members: Hot ~28/40 bytes (for RenderText loop)
-    ImVector<ImWchar>           IndexLookup;        // 12-16 // out //            // Sparse. Index glyphs by Unicode code-point.
-    ImVector<ImFontGlyph>       Glyphs;             // 12-16 // out //            // All glyphs.
-    const ImFontGlyph*          FallbackGlyph;      // 4-8   // out // = FindGlyph(FontFallbackChar)
+    ImVector<ImU16>             IndexLookup;        // 12-16 // out // Sparse. Index glyphs by Unicode code-point.
+    ImVector<ImFontGlyph>       Glyphs;             // 12-16 // out // All glyphs.
+    ImFontGlyph*                FallbackGlyph;      // 4-8   // out // = FindGlyph(FontFallbackChar)
 
     // [Internal] Members: Cold ~32/40 bytes
-    // Conceptually ConfigData[] is the list of font sources merged to create this font.
-    ImFontAtlas*                ContainerAtlas;     // 4-8   // out //            // What we has been loaded into
-    const ImFontConfig*         ConfigData;         // 4-8   // in  //            // Pointer within ContainerAtlas->ConfigData to ConfigDataCount instances
-    short                       ConfigDataCount;    // 2     // in  // ~ 1        // Number of ImFontConfig involved in creating this font. Bigger than 1 when merging multiple font sources into one ImFont.
+    // Conceptually Sources[] is the list of font sources merged to create this font.
+    ImFontAtlas*                ContainerAtlas;     // 4-8   // out // What we has been loaded into
+    ImFontConfig*               Sources;            // 4-8   // in  // Pointer within ContainerAtlas->Sources[], to SourcesCount instances
+    short                       SourcesCount;       // 2     // in  // Number of ImFontConfig involved in creating this font. Usually 1, or >1 when merging multiple font sources into one ImFont.
     short                       EllipsisCharCount;  // 1     // out // 1 or 3
-    ImWchar                     EllipsisChar;       // 2-4   // out // = '...'/'.'// Character used for ellipsis rendering.
-    ImWchar                     FallbackChar;       // 2-4   // out // = FFFD/'?' // Character used if a glyph isn't found.
-    float                       EllipsisWidth;      // 4     // out               // Width
-    float                       EllipsisCharStep;   // 4     // out               // Step between characters when EllipsisCount > 0
+    ImWchar                     EllipsisChar;       // 2-4   // out // Character used for ellipsis rendering ('...').
+    ImWchar                     FallbackChar;       // 2-4   // out // Character used if a glyph isn't found (U+FFFD, '?')
+    float                       EllipsisWidth;      // 4     // out // Total ellipsis Width
+    float                       EllipsisCharStep;   // 4     // out // Step between characters when EllipsisCount > 0
+    float                       Scale;              // 4     // in  // Base font scale (1.0f), multiplied by the per-window font scale which you can adjust with SetWindowFontScale()
+    float                       Ascent, Descent;    // 4+4   // out // Ascent: distance from top to bottom of e.g. 'A' [0..FontSize] (unscaled)
+    int                         MetricsTotalSurface;// 4     // out // Total surface in pixels to get an idea of the font rasterization/texture cost (not exact, we approximate the cost of padding between glyphs)
     bool                        DirtyLookupTables;  // 1     // out //
-    float                       Scale;              // 4     // in  // = 1.f      // Base font scale, multiplied by the per-window font scale which you can adjust with SetWindowFontScale()
-    float                       Ascent, Descent;    // 4+4   // out //            // Ascent: distance from top to bottom of e.g. 'A' [0..FontSize] (unscaled)
-    int                         MetricsTotalSurface;// 4     // out //            // Total surface in pixels to get an idea of the font rasterization/texture cost (not exact, we approximate the cost of padding between glyphs)
-    ImU8                        Used4kPagesMap[(IM_UNICODE_CODEPOINT_MAX+1)/4096/8]; // 2 bytes if ImWchar=ImWchar16, 34 bytes if ImWchar==ImWchar32. Store 1-bit for each block of 4K codepoints that has one active glyph. This is mainly used to facilitate iterations across all used codepoints.
+    ImU8                        Used8kPagesMap[(IM_UNICODE_CODEPOINT_MAX+1)/8192/8]; // 1 bytes if ImWchar=ImWchar16, 16 bytes if ImWchar==ImWchar32. Store 1-bit for each block of 4K codepoints that has one active glyph. This is mainly used to facilitate iterations across all used codepoints.
 
     // Methods
     IMGUI_API ImFont();
     IMGUI_API ~ImFont();
-    IMGUI_API const ImFontGlyph*FindGlyph(ImWchar c);
-    IMGUI_API const ImFontGlyph*FindGlyphNoFallback(ImWchar c);
-    float                       GetCharAdvance(ImWchar c)           { return ((int)c < IndexAdvanceX.Size) ? IndexAdvanceX[(int)c] : FallbackAdvanceX; }
-    bool                        IsLoaded() const                    { return ContainerAtlas != NULL; }
-    const char*                 GetDebugName() const                { return ConfigData ? ConfigData->Name : "<unknown>"; }
+    IMGUI_API ImFontGlyph*      FindGlyph(ImWchar c);
+    IMGUI_API ImFontGlyph*      FindGlyphNoFallback(ImWchar c);
+    float                       GetCharAdvance(ImWchar c)       { return ((int)c < IndexAdvanceX.Size) ? IndexAdvanceX[(int)c] : FallbackAdvanceX; }
+    bool                        IsLoaded() const                { return ContainerAtlas != NULL; }
+    const char*                 GetDebugName() const            { return Sources ? Sources->Name : "<unknown>"; }
 
+    // [Internal] Don't use!
     // 'max_width' stops rendering after a certain width (could be turned into a 2d size). FLT_MAX to disable.
     // 'wrap_width' enable automatic word-wrapping across multiple lines to fit into given width. 0.0f to disable.
     IMGUI_API ImVec2            CalcTextSizeA(float size, float max_width, float wrap_width, const char* text_begin, const char* text_end = NULL, const char** remaining = NULL); // utf8
@@ -3484,7 +3632,6 @@ struct ImFont
     IMGUI_API void              GrowIndex(int new_size);
     IMGUI_API void              AddGlyph(const ImFontConfig* src_cfg, ImWchar c, float x0, float y0, float x1, float y1, float u0, float v0, float u1, float v1, float advance_x);
     IMGUI_API void              AddRemapChar(ImWchar dst, ImWchar src, bool overwrite_dst = true); // Makes 'dst' character/glyph points to 'src' character/glyph. Currently needs to be called AFTER fonts have been built.
-    IMGUI_API void              SetGlyphVisible(ImWchar c, bool visible);
     IMGUI_API bool              IsGlyphRangeUnused(unsigned int c_begin, unsigned int c_last);
 };
 
@@ -3498,11 +3645,24 @@ enum ImGuiViewportFlags_
     ImGuiViewportFlags_None                     = 0,
     ImGuiViewportFlags_IsPlatformWindow         = 1 << 0,   // Represent a Platform Window
     ImGuiViewportFlags_IsPlatformMonitor        = 1 << 1,   // Represent a Platform Monitor (unused yet)
-    ImGuiViewportFlags_OwnedByApp               = 1 << 2,   // Platform Window: Is created/managed by the application (rather than a dear imgui backend)
+    ImGuiViewportFlags_OwnedByApp               = 1 << 2,   // Platform Window: Is created/managed by the user application? (rather than our backend)
+    ImGuiViewportFlags_NoDecoration             = 1 << 3,   // Platform Window: Disable platform decorations: title bar, borders, etc. (generally set all windows, but if ImGuiConfigFlags_ViewportsDecoration is set we only set this on popups/tooltips)
+    ImGuiViewportFlags_NoTaskBarIcon            = 1 << 4,   // Platform Window: Disable platform task bar icon (generally set on popups/tooltips, or all windows if ImGuiConfigFlags_ViewportsNoTaskBarIcon is set)
+    ImGuiViewportFlags_NoFocusOnAppearing       = 1 << 5,   // Platform Window: Don't take focus when created.
+    ImGuiViewportFlags_NoFocusOnClick           = 1 << 6,   // Platform Window: Don't take focus when clicked on.
+    ImGuiViewportFlags_NoInputs                 = 1 << 7,   // Platform Window: Make mouse pass through so we can drag this window while peaking behind it.
+    ImGuiViewportFlags_NoRendererClear          = 1 << 8,   // Platform Window: Renderer doesn't need to clear the framebuffer ahead (because we will fill it entirely).
+    ImGuiViewportFlags_NoAutoMerge              = 1 << 9,   // Platform Window: Avoid merging this window into another host window. This can only be set via ImGuiWindowClass viewport flags override (because we need to now ahead if we are going to create a viewport in the first place!).
+    ImGuiViewportFlags_TopMost                  = 1 << 10,  // Platform Window: Display on top (for tooltips only).
+    ImGuiViewportFlags_CanHostOtherWindows      = 1 << 11,  // Viewport can host multiple imgui windows (secondary viewports are associated to a single window). // FIXME: In practice there's still probably code making the assumption that this is always and only on the MainViewport. Will fix once we add support for "no main viewport".
+
+    // Output status flags (from Platform)
+    ImGuiViewportFlags_IsMinimized              = 1 << 12,  // Platform Window: Window is minimized, can skip render. When minimized we tend to avoid using the viewport pos/size for clipping window or testing if they are contained in the viewport.
+    ImGuiViewportFlags_IsFocused                = 1 << 13,  // Platform Window: Window is focused (last call to Platform_GetWindowFocus() returned true)
 };
 
 // - Currently represents the Platform Window created by the application which is hosting our Dear ImGui windows.
-// - In 'docking' branch with multi-viewport enabled, we extend this concept to have multiple active viewports.
+// - With multi-viewport enabled, we extend this concept to have multiple active viewports.
 // - In the future we will extend this concept further to also represent Platform Monitor and support a "no main platform window" operation mode.
 // - About Main Area vs Work Area:
 //   - Main Area = entire viewport.
@@ -3516,12 +3676,26 @@ struct ImGuiViewport
     ImVec2              Size;                   // Main Area: Size of the viewport.
     ImVec2              WorkPos;                // Work Area: Position of the viewport minus task bars, menus bars, status bars (>= Pos)
     ImVec2              WorkSize;               // Work Area: Size of the viewport minus task bars, menu bars, status bars (<= Size)
+    float               DpiScale;               // 1.0f = 96 DPI = No extra scale.
+    ImGuiID             ParentViewportId;       // (Advanced) 0: no parent. Instruct the platform backend to setup a parent/child relationship between platform windows.
+    ImDrawData*         DrawData;               // The ImDrawData corresponding to this viewport. Valid after Render() and until the next call to NewFrame().
 
     // Platform/Backend Dependent Data
-    void*               PlatformHandle;         // void* to hold higher-level, platform window handle (e.g. HWND, GLFWWindow*, SDL_Window*)
-    void*               PlatformHandleRaw;      // void* to hold lower-level, platform-native window handle (under Win32 this is expected to be a HWND, unused for other platforms)
+    // Our design separate the Renderer and Platform backends to facilitate combining default backends with each others.
+    // When our create your own backend for a custom engine, it is possible that both Renderer and Platform will be handled
+    // by the same system and you may not need to use all the UserData/Handle fields.
+    // The library never uses those fields, they are merely storage to facilitate backend implementation.
+    void*               RendererUserData;       // void* to hold custom data structure for the renderer (e.g. swap chain, framebuffers etc.). generally set by your Renderer_CreateWindow function.
+    void*               PlatformUserData;       // void* to hold custom data structure for the OS / platform (e.g. windowing info, render context). generally set by your Platform_CreateWindow function.
+    void*               PlatformHandle;         // void* to hold higher-level, platform window handle (e.g. HWND for Win32 backend, Uint32 WindowID for SDL, GLFWWindow* for GLFW), for FindViewportByPlatformHandle().
+    void*               PlatformHandleRaw;      // void* to hold lower-level, platform-native window handle (always HWND on Win32 platform, unused for other platforms).
+    bool                PlatformWindowCreated;  // Platform window has been created (Platform_CreateWindow() has been called). This is false during the first frame where a viewport is being created.
+    bool                PlatformRequestMove;    // Platform window requested move (e.g. window was moved by the OS / host window manager, authoritative position will be OS window position)
+    bool                PlatformRequestResize;  // Platform window requested resize (e.g. window was resized by the OS / host window manager, authoritative size will be OS window size)
+    bool                PlatformRequestClose;   // Platform window requested closure (e.g. window was moved by the OS / host window manager, e.g. pressing ALT-F4)
 
     ImGuiViewport()     { memset(this, 0, sizeof(*this)); }
+    ~ImGuiViewport()    { IM_ASSERT(PlatformUserData == NULL && RendererUserData == NULL); }
 
     // Helpers
     ImVec2              GetCenter() const       { return ImVec2(Pos.x + Size.x * 0.5f, Pos.y + Size.y * 0.5f); }
@@ -3529,7 +3703,53 @@ struct ImGuiViewport
 };
 
 //-----------------------------------------------------------------------------
-// [SECTION] Platform Dependent Interfaces
+// [SECTION] ImGuiPlatformIO + other Platform Dependent Interfaces (ImGuiPlatformMonitor, ImGuiPlatformImeData)
+//-----------------------------------------------------------------------------
+
+// [BETA] (Optional) Multi-Viewport Support!
+// If you are new to Dear ImGui and trying to integrate it into your engine, you can probably ignore this for now.
+//
+// This feature allows you to seamlessly drag Dear ImGui windows outside of your application viewport.
+// This is achieved by creating new Platform/OS windows on the fly, and rendering into them.
+// Dear ImGui manages the viewport structures, and the backend create and maintain one Platform/OS window for each of those viewports.
+//
+// See Recap:   https://github.com/ocornut/imgui/wiki/Multi-Viewports
+// See Glossary https://github.com/ocornut/imgui/wiki/Glossary for details about some of the terminology.
+//
+// About the coordinates system:
+// - When multi-viewports are enabled, all Dear ImGui coordinates become absolute coordinates (same as OS coordinates!)
+// - So e.g. ImGui::SetNextWindowPos(ImVec2(0,0)) will position a window relative to your primary monitor!
+// - If you want to position windows relative to your main application viewport, use ImGui::GetMainViewport()->Pos as a base position.
+//
+// Steps to use multi-viewports in your application, when using a default backend from the examples/ folder:
+// - Application:  Enable feature with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// - Backend:      The backend initialization will setup all necessary ImGuiPlatformIO's functions and update monitors info every frame.
+// - Application:  In your main loop, call ImGui::UpdatePlatformWindows(), ImGui::RenderPlatformWindowsDefault() after EndFrame() or Render().
+// - Application:  Fix absolute coordinates used in ImGui::SetWindowPos() or ImGui::SetNextWindowPos() calls.
+//
+// Steps to use multi-viewports in your application, when using a custom backend:
+// - Important:    THIS IS NOT EASY TO DO and comes with many subtleties not described here!
+//                 It's also an experimental feature, so some of the requirements may evolve.
+//                 Consider using default backends if you can. Either way, carefully follow and refer to examples/ backends for details.
+// - Application:  Enable feature with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// - Backend:      Hook ImGuiPlatformIO's Platform_* and Renderer_* callbacks (see below).
+//                 Set 'io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports' and 'io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports'.
+//                 Update ImGuiPlatformIO's Monitors list every frame.
+//                 Update MousePos every frame, in absolute coordinates.
+// - Application:  In your main loop, call ImGui::UpdatePlatformWindows(), ImGui::RenderPlatformWindowsDefault() after EndFrame() or Render().
+//                 You may skip calling RenderPlatformWindowsDefault() if its API is not convenient for your needs. Read comments below.
+// - Application:  Fix absolute coordinates used in ImGui::SetWindowPos() or ImGui::SetNextWindowPos() calls.
+//
+// About ImGui::RenderPlatformWindowsDefault():
+// - This function is a mostly a _helper_ for the common-most cases, and to facilitate using default backends.
+// - You can check its simple source code to understand what it does.
+//   It basically iterates secondary viewports and call 4 functions that are setup in ImGuiPlatformIO, if available:
+//     Platform_RenderWindow(), Renderer_RenderWindow(), Platform_SwapBuffers(), Renderer_SwapBuffers()
+//   Those functions pointers exists only for the benefit of RenderPlatformWindowsDefault().
+// - If you have very specific rendering needs (e.g. flipping multiple swap-chain simultaneously, unusual sync/threading issues, etc.),
+//   you may be tempted to ignore RenderPlatformWindowsDefault() and write customized code to perform your renderingg.
+//   You may decide to setup the platform_io's *RenderWindow and *SwapBuffers pointers and call your functions through those pointers,
+//   or you may decide to never setup those pointers and call your code directly. They are a convenience, not an obligatory interface.
 //-----------------------------------------------------------------------------
 
 // Access via ImGui::GetPlatformIO()
@@ -3538,7 +3758,7 @@ struct ImGuiPlatformIO
     IMGUI_API ImGuiPlatformIO();
 
     //------------------------------------------------------------------
-    // Interface with OS and Platform backend
+    // Input - Interface with OS and Platform backend (most common stuff)
     //------------------------------------------------------------------
 
     // Optional: Access OS clipboard
@@ -3548,7 +3768,7 @@ struct ImGuiPlatformIO
     void*       Platform_ClipboardUserData;
 
     // Optional: Open link/folder/file in OS Shell
-    // (default to use ShellExecuteA() on Windows, system() on Linux/Mac)
+    // (default to use ShellExecuteW() on Windows, system() on Linux/Mac)
     bool        (*Platform_OpenInShellFn)(ImGuiContext* ctx, const char* path);
     void*       Platform_OpenInShellUserData;
 
@@ -3563,21 +3783,89 @@ struct ImGuiPlatformIO
     ImWchar     Platform_LocaleDecimalPoint;     // '.'
 
     //------------------------------------------------------------------
-    // Interface with Renderer Backend
+    // Input - Interface with Renderer Backend
     //------------------------------------------------------------------
 
     // Written by some backends during ImGui_ImplXXXX_RenderDrawData() call to point backend_specific ImGui_ImplXXXX_RenderState* structure.
     void*       Renderer_RenderState;
+
+    //------------------------------------------------------------------
+    // Input - Interface with Platform & Renderer backends for Multi-Viewport support
+    //------------------------------------------------------------------
+
+    // For reference, the second column shows which function are generally calling the Platform Functions:
+    //   N = ImGui::NewFrame()                        ~ beginning of the dear imgui frame: read info from platform/OS windows (latest size/position)
+    //   F = ImGui::Begin(), ImGui::EndFrame()        ~ during the dear imgui frame
+    //   U = ImGui::UpdatePlatformWindows()           ~ after the dear imgui frame: create and update all platform/OS windows
+    //   R = ImGui::RenderPlatformWindowsDefault()    ~ render
+    //   D = ImGui::DestroyPlatformWindows()          ~ shutdown
+    // The general idea is that NewFrame() we will read the current Platform/OS state, and UpdatePlatformWindows() will write to it.
+
+    // The handlers are designed so we can mix and match two imgui_impl_xxxx files, one Platform backend and one Renderer backend.
+    // Custom engine backends will often provide both Platform and Renderer interfaces together and so may not need to use all functions.
+    // Platform functions are typically called _before_ their Renderer counterpart, apart from Destroy which are called the other way.
+
+    // Platform Backend functions (e.g. Win32, GLFW, SDL) ------------------- Called by -----
+    void    (*Platform_CreateWindow)(ImGuiViewport* vp);                    // . . U . .  // Create a new platform window for the given viewport
+    void    (*Platform_DestroyWindow)(ImGuiViewport* vp);                   // N . U . D  //
+    void    (*Platform_ShowWindow)(ImGuiViewport* vp);                      // . . U . .  // Newly created windows are initially hidden so SetWindowPos/Size/Title can be called on them before showing the window
+    void    (*Platform_SetWindowPos)(ImGuiViewport* vp, ImVec2 pos);        // . . U . .  // Set platform window position (given the upper-left corner of client area)
+    ImVec2  (*Platform_GetWindowPos)(ImGuiViewport* vp);                    // N . . . .  //
+    void    (*Platform_SetWindowSize)(ImGuiViewport* vp, ImVec2 size);      // . . U . .  // Set platform window client area size (ignoring OS decorations such as OS title bar etc.)
+    ImVec2  (*Platform_GetWindowSize)(ImGuiViewport* vp);                   // N . . . .  // Get platform window client area size
+    void    (*Platform_SetWindowFocus)(ImGuiViewport* vp);                  // N . . . .  // Move window to front and set input focus
+    bool    (*Platform_GetWindowFocus)(ImGuiViewport* vp);                  // . . U . .  //
+    bool    (*Platform_GetWindowMinimized)(ImGuiViewport* vp);              // N . . . .  // Get platform window minimized state. When minimized, we generally won't attempt to get/set size and contents will be culled more easily
+    void    (*Platform_SetWindowTitle)(ImGuiViewport* vp, const char* str); // . . U . .  // Set platform window title (given an UTF-8 string)
+    void    (*Platform_SetWindowAlpha)(ImGuiViewport* vp, float alpha);     // . . U . .  // (Optional) Setup global transparency (not per-pixel transparency)
+    void    (*Platform_UpdateWindow)(ImGuiViewport* vp);                    // . . U . .  // (Optional) Called by UpdatePlatformWindows(). Optional hook to allow the platform backend from doing general book-keeping every frame.
+    void    (*Platform_RenderWindow)(ImGuiViewport* vp, void* render_arg);  // . . . R .  // (Optional) Main rendering (platform side! This is often unused, or just setting a "current" context for OpenGL bindings). 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+    void    (*Platform_SwapBuffers)(ImGuiViewport* vp, void* render_arg);   // . . . R .  // (Optional) Call Present/SwapBuffers (platform side! This is often unused!). 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+    float   (*Platform_GetWindowDpiScale)(ImGuiViewport* vp);               // N . . . .  // (Optional) [BETA] FIXME-DPI: DPI handling: Return DPI scale for this viewport. 1.0f = 96 DPI.
+    void    (*Platform_OnChangedViewport)(ImGuiViewport* vp);               // . F . . .  // (Optional) [BETA] FIXME-DPI: DPI handling: Called during Begin() every time the viewport we are outputting into changes, so backend has a chance to swap fonts to adjust style.
+    ImVec4  (*Platform_GetWindowWorkAreaInsets)(ImGuiViewport* vp);         // N . . . .  // (Optional) [BETA] Get initial work area inset for the viewport (won't be covered by main menu bar, dockspace over viewport etc.). Default to (0,0),(0,0). 'safeAreaInsets' in iOS land, 'DisplayCutout' in Android land.
+    int     (*Platform_CreateVkSurface)(ImGuiViewport* vp, ImU64 vk_inst, const void* vk_allocators, ImU64* out_vk_surface); // (Optional) For a Vulkan Renderer to call into Platform code (since the surface creation needs to tie them both).
+
+    // Renderer Backend functions (e.g. DirectX, OpenGL, Vulkan) ------------ Called by -----
+    void    (*Renderer_CreateWindow)(ImGuiViewport* vp);                    // . . U . .  // Create swap chain, frame buffers etc. (called after Platform_CreateWindow)
+    void    (*Renderer_DestroyWindow)(ImGuiViewport* vp);                   // N . U . D  // Destroy swap chain, frame buffers etc. (called before Platform_DestroyWindow)
+    void    (*Renderer_SetWindowSize)(ImGuiViewport* vp, ImVec2 size);      // . . U . .  // Resize swap chain, frame buffers etc. (called after Platform_SetWindowSize)
+    void    (*Renderer_RenderWindow)(ImGuiViewport* vp, void* render_arg);  // . . . R .  // (Optional) Clear framebuffer, setup render target, then render the viewport->DrawData. 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+    void    (*Renderer_SwapBuffers)(ImGuiViewport* vp, void* render_arg);   // . . . R .  // (Optional) Call Present/SwapBuffers. 'render_arg' is the value passed to RenderPlatformWindowsDefault().
+
+    // (Optional) Monitor list
+    // - Updated by: app/backend. Update every frame to dynamically support changing monitor or DPI configuration.
+    // - Used by: dear imgui to query DPI info, clamp popups/tooltips within same monitor and not have them straddle monitors.
+    ImVector<ImGuiPlatformMonitor>  Monitors;
+
+    //------------------------------------------------------------------
+    // Output - List of viewports to render into platform windows
+    //------------------------------------------------------------------
+
+    // Viewports list (the list is updated by calling ImGui::EndFrame or ImGui::Render)
+    // (in the future we will attempt to organize this feature to remove the need for a "main viewport")
+    ImVector<ImGuiViewport*>        Viewports;          // Main viewports, followed by all secondary viewports.
+};
+
+// (Optional) This is required when enabling multi-viewport. Represent the bounds of each connected monitor/display and their DPI.
+// We use this information for multiple DPI support + clamping the position of popups and tooltips so they don't straddle multiple monitors.
+struct ImGuiPlatformMonitor
+{
+    ImVec2  MainPos, MainSize;      // Coordinates of the area displayed on this monitor (Min = upper left, Max = bottom right)
+    ImVec2  WorkPos, WorkSize;      // Coordinates without task bars / side bars / menu bars. Used to avoid positioning popups/tooltips inside this region. If you don't have this info, please copy the value for MainPos/MainSize.
+    float   DpiScale;               // 1.0f = 96 DPI
+    void*   PlatformHandle;         // Backend dependant data (e.g. HMONITOR, GLFWmonitor*, SDL Display Index, NSScreen*)
+    ImGuiPlatformMonitor()          { MainPos = MainSize = WorkPos = WorkSize = ImVec2(0, 0); DpiScale = 1.0f; PlatformHandle = NULL; }
 };
 
 // (Optional) Support for IME (Input Method Editor) via the platform_io.Platform_SetImeDataFn() function.
 struct ImGuiPlatformImeData
 {
-    bool    WantVisible;        // A widget wants the IME to be visible
-    ImVec2  InputPos;           // Position of the input cursor
-    float   InputLineHeight;    // Line height
+    bool    WantVisible;            // A widget wants the IME to be visible
+    ImVec2  InputPos;               // Position of the input cursor
+    float   InputLineHeight;        // Line height
 
-    ImGuiPlatformImeData() { memset(this, 0, sizeof(*this)); }
+    ImGuiPlatformImeData()          { memset(this, 0, sizeof(*this)); }
 };
 
 //-----------------------------------------------------------------------------
@@ -3589,6 +3877,8 @@ struct ImGuiPlatformImeData
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
 namespace ImGui
 {
+    // OBSOLETED in 1.91.9 (from February 2025)
+    IMGUI_API void      Image(ImTextureID user_texture_id, const ImVec2& image_size, const ImVec2& uv0, const ImVec2& uv1, const ImVec4& tint_col, const ImVec4& border_col); // <-- border_col was removed in favor of ImGuiCol_ImageBorder.
     // OBSOLETED in 1.91.0 (from July 2024)
     static inline void  PushButtonRepeat(bool repeat)                           { PushItemFlag(ImGuiItemFlags_ButtonRepeat, repeat); }
     static inline void  PopButtonRepeat()                                       { PopItemFlag(); }

imgui_draw.cpp

@@ -1,4 +1,4 @@
-// dear imgui, v1.91.7
+// dear imgui, v1.91.9
 // (drawing and font code)
 
 /*
@@ -68,6 +68,7 @@ Index of this file:
 #pragma clang diagnostic ignored "-Wunsafe-buffer-usage"            // warning: 'xxx' is an unsafe pointer used for buffer access
 #pragma clang diagnostic ignored "-Wnontrivial-memaccess"           // warning: first argument in call to 'memset' is a pointer to non-trivially copyable type
 #pragma clang diagnostic ignored "-Wcast-qual"                      // warning: cast from 'const xxxx *' to 'xxx *' drops const qualifier
+#pragma clang diagnostic ignored "-Wswitch-default"                 // warning: 'switch' missing 'default' label
 #elif defined(__GNUC__)
 #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
@@ -143,6 +144,7 @@ namespace IMGUI_STB_NAMESPACE
 #define STBTT_fabs(x)       ImFabs(x)
 #define STBTT_ifloor(x)     ((int)ImFloor(x))
 #define STBTT_iceil(x)      ((int)ImCeil(x))
+#define STBTT_strlen(x)     ImStrlen(x)
 #define STBTT_STATIC
 #define STB_TRUETYPE_IMPLEMENTATION
 #else
@@ -222,6 +224,8 @@ void ImGui::StyleColorsDark(ImGuiStyle* dst)
     colors[ImGuiCol_TabDimmed]              = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabDimmedSelected]      = ImLerp(colors[ImGuiCol_TabSelected],  colors[ImGuiCol_TitleBg], 0.40f);
     colors[ImGuiCol_TabDimmedSelectedOverline] = ImVec4(0.50f, 0.50f, 0.50f, 0.00f);
+    colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_HeaderActive] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(0.61f, 0.61f, 0.61f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(1.00f, 0.43f, 0.35f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -285,6 +289,8 @@ void ImGui::StyleColorsClassic(ImGuiStyle* dst)
     colors[ImGuiCol_TabDimmed]              = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabDimmedSelected]      = ImLerp(colors[ImGuiCol_TabSelected],  colors[ImGuiCol_TitleBg], 0.40f);
     colors[ImGuiCol_TabDimmedSelectedOverline] = ImVec4(0.53f, 0.53f, 0.87f, 0.00f);
+    colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_Header] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -349,6 +355,8 @@ void ImGui::StyleColorsLight(ImGuiStyle* dst)
     colors[ImGuiCol_TabDimmed]              = ImLerp(colors[ImGuiCol_Tab],          colors[ImGuiCol_TitleBg], 0.80f);
     colors[ImGuiCol_TabDimmedSelected]      = ImLerp(colors[ImGuiCol_TabSelected],  colors[ImGuiCol_TitleBg], 0.40f);
     colors[ImGuiCol_TabDimmedSelectedOverline] = ImVec4(0.26f, 0.59f, 1.00f, 0.00f);
+    colors[ImGuiCol_DockingPreview]         = colors[ImGuiCol_Header] * ImVec4(1.0f, 1.0f, 1.0f, 0.7f);
+    colors[ImGuiCol_DockingEmptyBg]         = ImVec4(0.20f, 0.20f, 0.20f, 1.00f);
     colors[ImGuiCol_PlotLines]              = ImVec4(0.39f, 0.39f, 0.39f, 1.00f);
     colors[ImGuiCol_PlotLinesHovered]       = ImVec4(1.00f, 0.43f, 0.35f, 1.00f);
     colors[ImGuiCol_PlotHistogram]          = ImVec4(0.90f, 0.70f, 0.00f, 1.00f);
@@ -374,6 +382,7 @@ void ImGui::StyleColorsLight(ImGuiStyle* dst)
 ImDrawListSharedData::ImDrawListSharedData()
 {
     memset(this, 0, sizeof(*this));
+    InitialFringeScale = 1.0f;
     for (int i = 0; i < IM_ARRAYSIZE(ArcFastVtx); i++)
     {
         const float a = ((float)i * 2 * IM_PI) / (float)IM_ARRAYSIZE(ArcFastVtx);
@@ -433,7 +442,7 @@ void ImDrawList::_ResetForNewFrame()
     _Path.resize(0);
     _Splitter.Clear();
     CmdBuffer.push_back(ImDrawCmd());
-    _FringeScale = 1.0f;
+    _FringeScale = _Data->InitialFringeScale;
 }
 
 void ImDrawList::_ClearFreeMemory()
@@ -1669,8 +1678,7 @@ void ImDrawList::AddText(ImFont* font, float font_size, const ImVec2& pos, ImU32
     // Accept null ranges
     if (text_begin == text_end || text_begin[0] == 0)
         return;
-    if (text_end == NULL)
-        text_end = text_begin + strlen(text_begin);
+    // No need to strlen() here: font->RenderText() will do it and may early out.
 
     // Pull default font/size from the shared ImDrawListSharedData instance
     if (font == NULL)
@@ -1693,7 +1701,7 @@ void ImDrawList::AddText(ImFont* font, float font_size, const ImVec2& pos, ImU32
 
 void ImDrawList::AddText(const ImVec2& pos, ImU32 col, const char* text_begin, const char* text_end)
 {
-    AddText(NULL, 0.0f, pos, col, text_begin, text_end);
+    AddText(_Data->Font, _Data->FontSize, pos, col, text_begin, text_end);
 }
 
 void ImDrawList::AddImage(ImTextureID user_texture_id, const ImVec2& p_min, const ImVec2& p_max, const ImVec2& uv_min, const ImVec2& uv_max, ImU32 col)
@@ -2375,8 +2383,8 @@ ImFontConfig::ImFontConfig()
 {
     memset(this, 0, sizeof(*this));
     FontDataOwnedByAtlas = true;
-    OversampleH = 2;
-    OversampleV = 1;
+    OversampleH = 0; // Auto == 1 or 2 depending on size
+    OversampleV = 0; // Auto == 1
     GlyphMaxAdvanceX = FLT_MAX;
     RasterizerMultiply = 1.0f;
     RasterizerDensity = 1.0f;
@@ -2402,13 +2410,13 @@ ImFontConfig::ImFontConfig()
 // - ImFontAtlas::AddCustomRectRegular()
 // - ImFontAtlas::AddCustomRectFontGlyph()
 // - ImFontAtlas::CalcCustomRectUV()
-// - ImFontAtlas::GetMouseCursorTexData()
+// - ImFontAtlasGetMouseCursorTexData()
 // - ImFontAtlas::Build()
 // - ImFontAtlasBuildMultiplyCalcLookupTable()
 // - ImFontAtlasBuildMultiplyRectAlpha8()
 // - ImFontAtlasBuildWithStbTruetype()
 // - ImFontAtlasGetBuilderForStbTruetype()
-// - ImFontAtlasUpdateConfigDataPointers()
+// - ImFontAtlasUpdateSourcesPointers()
 // - ImFontAtlasBuildSetupFont()
 // - ImFontAtlasBuildPackCustomRects()
 // - ImFontAtlasBuildRender8bppRectFromString()
@@ -2466,6 +2474,8 @@ static const ImVec2 FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[ImGuiMouseCursor_COUNT][3
     { ImVec2(73,0), ImVec2(17,17), ImVec2( 8, 8) }, // ImGuiMouseCursor_ResizeNESW
     { ImVec2(55,0), ImVec2(17,17), ImVec2( 8, 8) }, // ImGuiMouseCursor_ResizeNWSE
     { ImVec2(91,0), ImVec2(17,22), ImVec2( 5, 0) }, // ImGuiMouseCursor_Hand
+    { ImVec2(0,3),  ImVec2(12,19), ImVec2(0, 0) },  // ImGuiMouseCursor_Wait       // Arrow + custom code in ImGui::RenderMouseCursor()
+    { ImVec2(0,3),  ImVec2(12,19), ImVec2(0, 0) },  // ImGuiMouseCursor_Progress   // Arrow + custom code in ImGui::RenderMouseCursor()
     { ImVec2(109,0),ImVec2(13,15), ImVec2( 6, 7) }, // ImGuiMouseCursor_NotAllowed
 };
 
@@ -2485,7 +2495,7 @@ ImFontAtlas::~ImFontAtlas()
 void    ImFontAtlas::ClearInputData()
 {
     IM_ASSERT(!Locked && "Cannot modify a locked ImFontAtlas between NewFrame() and EndFrame/Render()!");
-    for (ImFontConfig& font_cfg : ConfigData)
+    for (ImFontConfig& font_cfg : Sources)
         if (font_cfg.FontData && font_cfg.FontDataOwnedByAtlas)
         {
             IM_FREE(font_cfg.FontData);
@@ -2494,12 +2504,12 @@ void    ImFontAtlas::ClearInputData()
 
     // When clearing this we lose access to the font name and other information used to build the font.
     for (ImFont* font : Fonts)
-        if (font->ConfigData >= ConfigData.Data && font->ConfigData < ConfigData.Data + ConfigData.Size)
+        if (font->Sources >= Sources.Data && font->Sources < Sources.Data + Sources.Size)
         {
-            font->ConfigData = NULL;
-            font->ConfigDataCount = 0;
+            font->Sources = NULL;
+            font->SourcesCount = 0;
         }
-    ConfigData.clear();
+    Sources.clear();
     CustomRects.clear();
     PackIdMouseCursors = PackIdLines = -1;
     // Important: we leave TexReady untouched
@@ -2521,6 +2531,7 @@ void    ImFontAtlas::ClearTexData()
 void    ImFontAtlas::ClearFonts()
 {
     IM_ASSERT(!Locked && "Cannot modify a locked ImFontAtlas between NewFrame() and EndFrame/Render()!");
+    ClearInputData();
     Fonts.clear_delete();
     TexReady = false;
 }
@@ -2573,8 +2584,7 @@ ImFont* ImFontAtlas::AddFont(const ImFontConfig* font_cfg)
     IM_ASSERT(!Locked && "Cannot modify a locked ImFontAtlas between NewFrame() and EndFrame/Render()!");
     IM_ASSERT(font_cfg->FontData != NULL && font_cfg->FontDataSize > 0);
     IM_ASSERT(font_cfg->SizePixels > 0.0f && "Is ImFontConfig struct correctly initialized?");
-    IM_ASSERT(font_cfg->OversampleH > 0 && font_cfg->OversampleV > 0 && "Is ImFontConfig struct correctly initialized?");
-    IM_ASSERT(font_cfg->RasterizerDensity > 0.0f);
+    IM_ASSERT(font_cfg->RasterizerDensity > 0.0f && "Is ImFontConfig struct correctly initialized?");
 
     // Create new font
     if (!font_cfg->MergeMode)
@@ -2582,8 +2592,8 @@ ImFont* ImFontAtlas::AddFont(const ImFontConfig* font_cfg)
     else
         IM_ASSERT(Fonts.Size > 0 && "Cannot use MergeMode for the first font"); // When using MergeMode make sure that a font has already been added before. You can use ImGui::GetIO().Fonts->AddFontDefault() to add the default imgui font.
 
-    ConfigData.push_back(*font_cfg);
-    ImFontConfig& new_font_cfg = ConfigData.back();
+    Sources.push_back(*font_cfg);
+    ImFontConfig& new_font_cfg = Sources.back();
     if (new_font_cfg.DstFont == NULL)
         new_font_cfg.DstFont = Fonts.back();
     if (!new_font_cfg.FontDataOwnedByAtlas)
@@ -2599,8 +2609,8 @@ ImFont* ImFontAtlas::AddFont(const ImFontConfig* font_cfg)
     // - We may support it better later and remove this rounding.
     new_font_cfg.SizePixels = ImTrunc(new_font_cfg.SizePixels);
 
-    // Pointers to ConfigData and BuilderData are otherwise dangling
-    ImFontAtlasUpdateConfigDataPointers(this);
+    // Pointers to Sources data are otherwise dangling
+    ImFontAtlasUpdateSourcesPointers(this);
 
     // Invalidate texture
     TexReady = false;
@@ -2670,7 +2680,7 @@ ImFont* ImFontAtlas::AddFontFromFileTTF(const char* filename, float size_pixels,
     {
         // Store a short copy of filename into into the font name for convenience
         const char* p;
-        for (p = filename + strlen(filename); p > filename && p[-1] != '/' && p[-1] != '\\'; p--) {}
+        for (p = filename + ImStrlen(filename); p > filename && p[-1] != '/' && p[-1] != '\\'; p--) {}
         ImFormatString(font_cfg.Name, IM_ARRAYSIZE(font_cfg.Name), "%s, %.0fpx", p, size_pixels);
     }
     return AddFontFromMemoryTTF(data, (int)data_size, size_pixels, &font_cfg, glyph_ranges);
@@ -2705,7 +2715,7 @@ ImFont* ImFontAtlas::AddFontFromMemoryCompressedTTF(const void* compressed_ttf_d
 
 ImFont* ImFontAtlas::AddFontFromMemoryCompressedBase85TTF(const char* compressed_ttf_data_base85, float size_pixels, const ImFontConfig* font_cfg, const ImWchar* glyph_ranges)
 {
-    int compressed_ttf_size = (((int)strlen(compressed_ttf_data_base85) + 4) / 5) * 4;
+    int compressed_ttf_size = (((int)ImStrlen(compressed_ttf_data_base85) + 4) / 5) * 4;
     void* compressed_ttf = IM_ALLOC((size_t)compressed_ttf_size);
     Decode85((const unsigned char*)compressed_ttf_data_base85, (unsigned char*)compressed_ttf);
     ImFont* font = AddFontFromMemoryCompressedTTF(compressed_ttf, compressed_ttf_size, size_pixels, font_cfg, glyph_ranges);
@@ -2752,24 +2762,24 @@ void ImFontAtlas::CalcCustomRectUV(const ImFontAtlasCustomRect* rect, ImVec2* ou
     *out_uv_max = ImVec2((float)(rect->X + rect->Width) * TexUvScale.x, (float)(rect->Y + rect->Height) * TexUvScale.y);
 }
 
-bool ImFontAtlas::GetMouseCursorTexData(ImGuiMouseCursor cursor_type, ImVec2* out_offset, ImVec2* out_size, ImVec2 out_uv_border[2], ImVec2 out_uv_fill[2])
+bool ImFontAtlasGetMouseCursorTexData(ImFontAtlas* atlas, ImGuiMouseCursor cursor_type, ImVec2* out_offset, ImVec2* out_size, ImVec2 out_uv_border[2], ImVec2 out_uv_fill[2])
 {
     if (cursor_type <= ImGuiMouseCursor_None || cursor_type >= ImGuiMouseCursor_COUNT)
         return false;
-    if (Flags & ImFontAtlasFlags_NoMouseCursors)
+    if (atlas->Flags & ImFontAtlasFlags_NoMouseCursors)
         return false;
 
-    IM_ASSERT(PackIdMouseCursors != -1);
-    ImFontAtlasCustomRect* r = GetCustomRectByIndex(PackIdMouseCursors);
+    IM_ASSERT(atlas->PackIdMouseCursors != -1);
+    ImFontAtlasCustomRect* r = atlas->GetCustomRectByIndex(atlas->PackIdMouseCursors);
     ImVec2 pos = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type][0] + ImVec2((float)r->X, (float)r->Y);
     ImVec2 size = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type][1];
     *out_size = size;
     *out_offset = FONT_ATLAS_DEFAULT_TEX_CURSOR_DATA[cursor_type][2];
-    out_uv_border[0] = (pos) * TexUvScale;
-    out_uv_border[1] = (pos + size) * TexUvScale;
+    out_uv_border[0] = (pos) * atlas->TexUvScale;
+    out_uv_border[1] = (pos + size) * atlas->TexUvScale;
     pos.x += FONT_ATLAS_DEFAULT_TEX_DATA_W + 1;
-    out_uv_fill[0] = (pos) * TexUvScale;
-    out_uv_fill[1] = (pos + size) * TexUvScale;
+    out_uv_fill[0] = (pos) * atlas->TexUvScale;
+    out_uv_fill[1] = (pos + size) * atlas->TexUvScale;
     return true;
 }
 
@@ -2778,7 +2788,7 @@ bool    ImFontAtlas::Build()
     IM_ASSERT(!Locked && "Cannot modify a locked ImFontAtlas between NewFrame() and EndFrame/Render()!");
 
     // Default font is none are specified
-    if (ConfigData.Size == 0)
+    if (Sources.Size == 0)
         AddFontDefault();
 
     // Select builder
@@ -2820,6 +2830,13 @@ void    ImFontAtlasBuildMultiplyRectAlpha8(const unsigned char table[256], unsig
             *data = table[*data];
 }
 
+void ImFontAtlasBuildGetOversampleFactors(const ImFontConfig* src, int* out_oversample_h, int* out_oversample_v)
+{
+    // Automatically disable horizontal oversampling over size 36
+    *out_oversample_h = (src->OversampleH != 0) ? src->OversampleH : (src->SizePixels * src->RasterizerDensity > 36.0f || src->PixelSnapH) ? 1 : 2;
+    *out_oversample_v = (src->OversampleV != 0) ? src->OversampleV : 1;
+}
+
 #ifdef IMGUI_ENABLE_STB_TRUETYPE
 // Temporary data for one source font (multiple source fonts can be merged into one destination ImFont)
 // (C++03 doesn't allow instancing ImVector<> with function-local types so we declare the type here.)
@@ -2860,7 +2877,7 @@ static void UnpackBitVectorToFlatIndexList(const ImBitVector* in, ImVector<int>*
 
 static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
 {
-    IM_ASSERT(atlas->ConfigData.Size > 0);
+    IM_ASSERT(atlas->Sources.Size > 0);
 
     ImFontAtlasBuildInit(atlas);
 
@@ -2874,32 +2891,32 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
     // Temporary storage for building
     ImVector<ImFontBuildSrcData> src_tmp_array;
     ImVector<ImFontBuildDstData> dst_tmp_array;
-    src_tmp_array.resize(atlas->ConfigData.Size);
+    src_tmp_array.resize(atlas->Sources.Size);
     dst_tmp_array.resize(atlas->Fonts.Size);
     memset(src_tmp_array.Data, 0, (size_t)src_tmp_array.size_in_bytes());
     memset(dst_tmp_array.Data, 0, (size_t)dst_tmp_array.size_in_bytes());
 
     // 1. Initialize font loading structure, check font data validity
-    for (int src_i = 0; src_i < atlas->ConfigData.Size; src_i++)
+    for (int src_i = 0; src_i < atlas->Sources.Size; src_i++)
     {
         ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
-        ImFontConfig& cfg = atlas->ConfigData[src_i];
-        IM_ASSERT(cfg.DstFont && (!cfg.DstFont->IsLoaded() || cfg.DstFont->ContainerAtlas == atlas));
+        ImFontConfig& src = atlas->Sources[src_i];
+        IM_ASSERT(src.DstFont && (!src.DstFont->IsLoaded() || src.DstFont->ContainerAtlas == atlas));
 
-        // Find index from cfg.DstFont (we allow the user to set cfg.DstFont. Also it makes casual debugging nicer than when storing indices)
+        // Find index from src.DstFont (we allow the user to set cfg.DstFont. Also it makes casual debugging nicer than when storing indices)
         src_tmp.DstIndex = -1;
         for (int output_i = 0; output_i < atlas->Fonts.Size && src_tmp.DstIndex == -1; output_i++)
-            if (cfg.DstFont == atlas->Fonts[output_i])
+            if (src.DstFont == atlas->Fonts[output_i])
                 src_tmp.DstIndex = output_i;
         if (src_tmp.DstIndex == -1)
         {
-            IM_ASSERT(src_tmp.DstIndex != -1); // cfg.DstFont not pointing within atlas->Fonts[] array?
+            IM_ASSERT(src_tmp.DstIndex != -1); // src.DstFont not pointing within atlas->Fonts[] array?
             return false;
         }
         // Initialize helper structure for font loading and verify that the TTF/OTF data is correct
-        const int font_offset = stbtt_GetFontOffsetForIndex((unsigned char*)cfg.FontData, cfg.FontNo);
+        const int font_offset = stbtt_GetFontOffsetForIndex((unsigned char*)src.FontData, src.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))
+        if (!stbtt_InitFont(&src_tmp.FontInfo, (unsigned char*)src.FontData, font_offset))
         {
             IM_ASSERT(0 && "stbtt_InitFont(): failed to parse FontData. It is correct and complete? Check FontDataSize.");
             return false;
@@ -2907,7 +2924,7 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
 
         // Measure highest codepoints
         ImFontBuildDstData& dst_tmp = dst_tmp_array[src_tmp.DstIndex];
-        src_tmp.SrcRanges = cfg.GlyphRanges ? cfg.GlyphRanges : atlas->GetGlyphRangesDefault();
+        src_tmp.SrcRanges = src.GlyphRanges ? src.GlyphRanges : atlas->GetGlyphRangesDefault();
         for (const ImWchar* src_range = src_tmp.SrcRanges; src_range[0] && src_range[1]; src_range += 2)
         {
             // Check for valid range. This may also help detect *some* dangling pointers, because a common
@@ -2985,26 +3002,30 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
         buf_rects_out_n += src_tmp.GlyphsCount;
         buf_packedchars_out_n += src_tmp.GlyphsCount;
 
+        // Automatic selection of oversampling parameters
+        ImFontConfig& src = atlas->Sources[src_i];
+        int oversample_h, oversample_v;
+        ImFontAtlasBuildGetOversampleFactors(&src, &oversample_h, &oversample_v);
+
         // 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 = src.SizePixels * src.RasterizerDensity;
         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;
         src_tmp.PackRange.chardata_for_range = src_tmp.PackedChars;
-        src_tmp.PackRange.h_oversample = (unsigned char)cfg.OversampleH;
-        src_tmp.PackRange.v_oversample = (unsigned char)cfg.OversampleV;
+        src_tmp.PackRange.h_oversample = (unsigned char)oversample_h;
+        src_tmp.PackRange.v_oversample = (unsigned char)oversample_v;
 
         // 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 = (src.SizePixels > 0.0f) ? stbtt_ScaleForPixelHeight(&src_tmp.FontInfo, src.SizePixels * src.RasterizerDensity) : stbtt_ScaleForMappingEmToPixels(&src_tmp.FontInfo, -src.SizePixels * src.RasterizerDensity);
         for (int glyph_i = 0; glyph_i < src_tmp.GlyphsList.Size; glyph_i++)
         {
             int x0, y0, x1, y1;
             const int glyph_index_in_font = stbtt_FindGlyphIndex(&src_tmp.FontInfo, src_tmp.GlyphsList[glyph_i]);
             IM_ASSERT(glyph_index_in_font != 0);
-            stbtt_GetGlyphBitmapBoxSubpixel(&src_tmp.FontInfo, glyph_index_in_font, scale * cfg.OversampleH, scale * cfg.OversampleV, 0, 0, &x0, &y0, &x1, &y1);
-            src_tmp.Rects[glyph_i].w = (stbrp_coord)(x1 - x0 + pack_padding + cfg.OversampleH - 1);
-            src_tmp.Rects[glyph_i].h = (stbrp_coord)(y1 - y0 + pack_padding + cfg.OversampleV - 1);
+            stbtt_GetGlyphBitmapBoxSubpixel(&src_tmp.FontInfo, glyph_index_in_font, scale * oversample_h, scale * oversample_v, 0, 0, &x0, &y0, &x1, &y1);
+            src_tmp.Rects[glyph_i].w = (stbrp_coord)(x1 - x0 + pack_padding + oversample_h - 1);
+            src_tmp.Rects[glyph_i].h = (stbrp_coord)(y1 - y0 + pack_padding + oversample_v - 1);
             total_surface += src_tmp.Rects[glyph_i].w * src_tmp.Rects[glyph_i].h;
         }
     }
@@ -3056,7 +3077,7 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
     // 8. Render/rasterize font characters into the texture
     for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
     {
-        ImFontConfig& cfg = atlas->ConfigData[src_i];
+        ImFontConfig& src = atlas->Sources[src_i];
         ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
         if (src_tmp.GlyphsCount == 0)
             continue;
@@ -3064,10 +3085,10 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
         stbtt_PackFontRangesRenderIntoRects(&spc, &src_tmp.FontInfo, &src_tmp.PackRange, 1, src_tmp.Rects);
 
         // Apply multiply operator
-        if (cfg.RasterizerMultiply != 1.0f)
+        if (src.RasterizerMultiply != 1.0f)
         {
             unsigned char multiply_table[256];
-            ImFontAtlasBuildMultiplyCalcLookupTable(multiply_table, cfg.RasterizerMultiply);
+            ImFontAtlasBuildMultiplyCalcLookupTable(multiply_table, src.RasterizerMultiply);
             stbrp_rect* r = &src_tmp.Rects[0];
             for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++, r++)
                 if (r->was_packed)
@@ -3085,22 +3106,22 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
     {
         // When merging fonts with MergeMode=true:
         // - We can have multiple input fonts writing into a same destination font.
-        // - dst_font->ConfigData is != from cfg which is our source configuration.
+        // - dst_font->Sources is != from src which is our source configuration.
         ImFontBuildSrcData& src_tmp = src_tmp_array[src_i];
-        ImFontConfig& cfg = atlas->ConfigData[src_i];
-        ImFont* dst_font = cfg.DstFont;
+        ImFontConfig& src = atlas->Sources[src_i];
+        ImFont* dst_font = src.DstFont;
 
-        const float font_scale = stbtt_ScaleForPixelHeight(&src_tmp.FontInfo, cfg.SizePixels);
+        const float font_scale = stbtt_ScaleForPixelHeight(&src_tmp.FontInfo, src.SizePixels);
         int unscaled_ascent, unscaled_descent, unscaled_line_gap;
         stbtt_GetFontVMetrics(&src_tmp.FontInfo, &unscaled_ascent, &unscaled_descent, &unscaled_line_gap);
 
         const float ascent = ImCeil(unscaled_ascent * font_scale);
         const float descent = ImFloor(unscaled_descent * font_scale);
-        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);
+        ImFontAtlasBuildSetupFont(atlas, dst_font, &src, ascent, descent);
+        const float font_off_x = src.GlyphOffset.x;
+        const float font_off_y = src.GlyphOffset.y + IM_ROUND(dst_font->Ascent);
 
-        const float inv_rasterization_scale = 1.0f / cfg.RasterizerDensity;
+        const float inv_rasterization_scale = 1.0f / src.RasterizerDensity;
 
         for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++)
         {
@@ -3114,7 +3135,7 @@ static bool ImFontAtlasBuildWithStbTruetype(ImFontAtlas* atlas)
             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(&src, (ImWchar)codepoint, x0, y0, x1, y1, q.s0, q.t0, q.s1, q.t1, pc.xadvance * inv_rasterization_scale);
         }
     }
 
@@ -3134,17 +3155,17 @@ const ImFontBuilderIO* ImFontAtlasGetBuilderForStbTruetype()
 
 #endif // IMGUI_ENABLE_STB_TRUETYPE
 
-void ImFontAtlasUpdateConfigDataPointers(ImFontAtlas* atlas)
+void ImFontAtlasUpdateSourcesPointers(ImFontAtlas* atlas)
 {
-    for (ImFontConfig& font_cfg : atlas->ConfigData)
+    for (ImFontConfig& src : atlas->Sources)
     {
-        ImFont* font = font_cfg.DstFont;
-        if (!font_cfg.MergeMode)
+        ImFont* font = src.DstFont;
+        if (!src.MergeMode)
         {
-            font->ConfigData = &font_cfg;
-            font->ConfigDataCount = 0;
+            font->Sources = &src;
+            font->SourcesCount = 0;
         }
-        font->ConfigDataCount++;
+        font->SourcesCount++;
     }
 }
 
@@ -3154,7 +3175,7 @@ void ImFontAtlasBuildSetupFont(ImFontAtlas* atlas, ImFont* font, ImFontConfig* f
     {
         font->ClearOutputData();
         font->FontSize = font_config->SizePixels;
-        IM_ASSERT(font->ConfigData == font_config);
+        IM_ASSERT(font->Sources == font_config);
         font->ContainerAtlas = atlas;
         font->Ascent = ascent;
         font->Descent = descent;
@@ -3339,7 +3360,7 @@ void ImFontAtlasBuildFinish(ImFontAtlas* atlas)
         if (r->Font == NULL || r->GlyphID == 0)
             continue;
 
-        // Will ignore ImFontConfig settings: GlyphMinAdvanceX, GlyphMinAdvanceY, GlyphExtraSpacing, PixelSnapH
+        // Will ignore ImFontConfig settings: GlyphMinAdvanceX, GlyphMinAdvanceY, PixelSnapH
         IM_ASSERT(r->Font->ContainerAtlas == atlas);
         ImVec2 uv0, uv1;
         atlas->CalcCustomRectUV(r, &uv0, &uv1);
@@ -3675,21 +3696,8 @@ void ImFontGlyphRangesBuilder::BuildRanges(ImVector<ImWchar>* out_ranges)
 
 ImFont::ImFont()
 {
-    FontSize = 0.0f;
-    FallbackAdvanceX = 0.0f;
-    FallbackChar = 0;
-    EllipsisChar = 0;
-    EllipsisWidth = EllipsisCharStep = 0.0f;
-    EllipsisCharCount = 0;
-    FallbackGlyph = NULL;
-    ContainerAtlas = NULL;
-    ConfigData = NULL;
-    ConfigDataCount = 0;
-    DirtyLookupTables = false;
+    memset(this, 0, sizeof(*this));
     Scale = 1.0f;
-    Ascent = Descent = 0.0f;
-    MetricsTotalSurface = 0;
-    memset(Used4kPagesMap, 0, sizeof(Used4kPagesMap));
 }
 
 ImFont::~ImFont()
@@ -3709,7 +3717,7 @@ void    ImFont::ClearOutputData()
     DirtyLookupTables = true;
     Ascent = Descent = 0.0f;
     MetricsTotalSurface = 0;
-    memset(Used4kPagesMap, 0, sizeof(Used4kPagesMap));
+    memset(Used8kPagesMap, 0, sizeof(Used8kPagesMap));
 }
 
 static ImWchar FindFirstExistingGlyph(ImFont* font, const ImWchar* candidate_chars, int candidate_chars_count)
@@ -3732,17 +3740,17 @@ void ImFont::BuildLookupTable()
     IndexAdvanceX.clear();
     IndexLookup.clear();
     DirtyLookupTables = false;
-    memset(Used4kPagesMap, 0, sizeof(Used4kPagesMap));
+    memset(Used8kPagesMap, 0, sizeof(Used8kPagesMap));
     GrowIndex(max_codepoint + 1);
     for (int i = 0; i < Glyphs.Size; i++)
     {
         int codepoint = (int)Glyphs[i].Codepoint;
         IndexAdvanceX[codepoint] = Glyphs[i].AdvanceX;
-        IndexLookup[codepoint] = (ImWchar)i;
+        IndexLookup[codepoint] = (ImU16)i;
 
         // Mark 4K page as used
-        const int page_n = codepoint / 4096;
-        Used4kPagesMap[page_n >> 3] |= 1 << (page_n & 7);
+        const int page_n = codepoint / 8192;
+        Used8kPagesMap[page_n >> 3] |= 1 << (page_n & 7);
     }
 
     // Create a glyph to handle TAB
@@ -3756,12 +3764,14 @@ void ImFont::BuildLookupTable()
         tab_glyph.Codepoint = '\t';
         tab_glyph.AdvanceX *= IM_TABSIZE;
         IndexAdvanceX[(int)tab_glyph.Codepoint] = (float)tab_glyph.AdvanceX;
-        IndexLookup[(int)tab_glyph.Codepoint] = (ImWchar)(Glyphs.Size - 1);
+        IndexLookup[(int)tab_glyph.Codepoint] = (ImU16)(Glyphs.Size - 1);
     }
 
     // Mark special glyphs as not visible (note that AddGlyph already mark as non-visible glyphs with zero-size polygons)
-    SetGlyphVisible((ImWchar)' ', false);
-    SetGlyphVisible((ImWchar)'\t', false);
+    if (ImFontGlyph* glyph = (ImFontGlyph*)(void*)FindGlyph((ImWchar)' '))
+        glyph->Visible = false;
+    if (ImFontGlyph* glyph = (ImFontGlyph*)(void*)FindGlyph((ImWchar)'\t'))
+        glyph->Visible = false;
 
     // Setup Fallback character
     const ImWchar fallback_chars[] = { (ImWchar)IM_UNICODE_CODEPOINT_INVALID, (ImWchar)'?', (ImWchar)' ' };
@@ -3784,7 +3794,7 @@ void ImFont::BuildLookupTable()
     // Setup Ellipsis character. It is required for rendering elided text. We prefer using U+2026 (horizontal ellipsis).
     // However some old fonts may contain ellipsis at U+0085. Here we auto-detect most suitable ellipsis character.
     // FIXME: Note that 0x2026 is rarely included in our font ranges. Because of this we are more likely to use three individual dots.
-    const ImWchar ellipsis_chars[] = { ConfigData->EllipsisChar, (ImWchar)0x2026, (ImWchar)0x0085 };
+    const ImWchar ellipsis_chars[] = { Sources->EllipsisChar, (ImWchar)0x2026, (ImWchar)0x0085 };
     const ImWchar dots_chars[] = { (ImWchar)'.', (ImWchar)0xFF0E };
     if (EllipsisChar == 0)
         EllipsisChar = FindFirstExistingGlyph(this, ellipsis_chars, IM_ARRAYSIZE(ellipsis_chars));
@@ -3804,57 +3814,51 @@ void ImFont::BuildLookupTable()
     }
 }
 
-// API is designed this way to avoid exposing the 4K page size
+// API is designed this way to avoid exposing the 8K page size
 // e.g. use with IsGlyphRangeUnused(0, 255)
 bool ImFont::IsGlyphRangeUnused(unsigned int c_begin, unsigned int c_last)
 {
-    unsigned int page_begin = (c_begin / 4096);
-    unsigned int page_last = (c_last / 4096);
+    unsigned int page_begin = (c_begin / 8192);
+    unsigned int page_last = (c_last / 8192);
     for (unsigned int page_n = page_begin; page_n <= page_last; page_n++)
-        if ((page_n >> 3) < sizeof(Used4kPagesMap))
-            if (Used4kPagesMap[page_n >> 3] & (1 << (page_n & 7)))
+        if ((page_n >> 3) < sizeof(Used8kPagesMap))
+            if (Used8kPagesMap[page_n >> 3] & (1 << (page_n & 7)))
                 return false;
     return true;
 }
 
-void ImFont::SetGlyphVisible(ImWchar c, bool visible)
-{
-    if (ImFontGlyph* glyph = (ImFontGlyph*)(void*)FindGlyph((ImWchar)c))
-        glyph->Visible = visible ? 1 : 0;
-}
-
 void ImFont::GrowIndex(int new_size)
 {
     IM_ASSERT(IndexAdvanceX.Size == IndexLookup.Size);
     if (new_size <= IndexLookup.Size)
         return;
     IndexAdvanceX.resize(new_size, -1.0f);
-    IndexLookup.resize(new_size, (ImWchar)-1);
+    IndexLookup.resize(new_size, (ImU16)-1);
 }
 
 // x0/y0/x1/y1 are offset from the character upper-left layout position, in pixels. Therefore x0/y0 are often fairly close to zero.
 // Not to be mistaken with texture coordinates, which are held by u0/v0/u1/v1 in normalized format (0.0..1.0 on each texture axis).
-// 'cfg' is not necessarily == 'this->ConfigData' because multiple source fonts+configs can be used to build one target font.
-void ImFont::AddGlyph(const ImFontConfig* cfg, ImWchar codepoint, float x0, float y0, float x1, float y1, float u0, float v0, float u1, float v1, float advance_x)
+// 'src' is not necessarily == 'this->Sources' because multiple source fonts+configs can be used to build one target font.
+void ImFont::AddGlyph(const ImFontConfig* src, ImWchar codepoint, float x0, float y0, float x1, float y1, float u0, float v0, float u1, float v1, float advance_x)
 {
-    if (cfg != NULL)
+    if (src != NULL)
     {
         // Clamp & recenter if needed
         const float advance_x_original = advance_x;
-        advance_x = ImClamp(advance_x, cfg->GlyphMinAdvanceX, cfg->GlyphMaxAdvanceX);
+        advance_x = ImClamp(advance_x, src->GlyphMinAdvanceX, src->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 = src->PixelSnapH ? ImTrunc((advance_x - advance_x_original) * 0.5f) : (advance_x - advance_x_original) * 0.5f;
             x0 += char_off_x;
             x1 += char_off_x;
         }
 
         // Snap to pixel
-        if (cfg->PixelSnapH)
+        if (src->PixelSnapH)
             advance_x = IM_ROUND(advance_x);
 
-        // Bake spacing
-        advance_x += cfg->GlyphExtraSpacing.x;
+        // Bake extra spacing
+        advance_x += src->GlyphExtraAdvanceX;
     }
 
     int glyph_idx = Glyphs.Size;
@@ -3872,6 +3876,7 @@ void ImFont::AddGlyph(const ImFontConfig* cfg, ImWchar codepoint, float x0, floa
     glyph.U1 = u1;
     glyph.V1 = v1;
     glyph.AdvanceX = advance_x;
+    IM_ASSERT(Glyphs.Size < 0xFFFF); // IndexLookup[] hold 16-bit values and -1 is reserved.
 
     // Compute rough surface usage metrics (+1 to account for average padding, +0.99 to round)
     // We use (U1-U0)*TexWidth instead of X1-X0 to account for oversampling.
@@ -3885,33 +3890,33 @@ void ImFont::AddRemapChar(ImWchar dst, ImWchar src, bool overwrite_dst)
     IM_ASSERT(IndexLookup.Size > 0);    // Currently this can only be called AFTER the font has been built, aka after calling ImFontAtlas::GetTexDataAs*() function.
     unsigned int index_size = (unsigned int)IndexLookup.Size;
 
-    if (dst < index_size && IndexLookup.Data[dst] == (ImWchar)-1 && !overwrite_dst) // 'dst' already exists
+    if (dst < index_size && IndexLookup.Data[dst] == (ImU16)-1 && !overwrite_dst) // 'dst' already exists
         return;
     if (src >= index_size && dst >= index_size) // both 'dst' and 'src' don't exist -> no-op
         return;
 
     GrowIndex(dst + 1);
-    IndexLookup[dst] = (src < index_size) ? IndexLookup.Data[src] : (ImWchar)-1;
+    IndexLookup[dst] = (src < index_size) ? IndexLookup.Data[src] : (ImU16)-1;
     IndexAdvanceX[dst] = (src < index_size) ? IndexAdvanceX.Data[src] : 1.0f;
 }
 
 // Find glyph, return fallback if missing
-const ImFontGlyph* ImFont::FindGlyph(ImWchar c)
+ImFontGlyph* ImFont::FindGlyph(ImWchar c)
 {
     if (c >= (size_t)IndexLookup.Size)
         return FallbackGlyph;
-    const ImWchar i = IndexLookup.Data[c];
-    if (i == (ImWchar)-1)
+    const ImU16 i = IndexLookup.Data[c];
+    if (i == (ImU16)-1)
         return FallbackGlyph;
     return &Glyphs.Data[i];
 }
 
-const ImFontGlyph* ImFont::FindGlyphNoFallback(ImWchar c)
+ImFontGlyph* ImFont::FindGlyphNoFallback(ImWchar c)
 {
     if (c >= (size_t)IndexLookup.Size)
         return NULL;
-    const ImWchar i = IndexLookup.Data[c];
-    if (i == (ImWchar)-1)
+    const ImU16 i = IndexLookup.Data[c];
+    if (i == (ImU16)-1)
         return NULL;
     return &Glyphs.Data[i];
 }
@@ -4032,7 +4037,7 @@ const char* ImFont::CalcWordWrapPositionA(float scale, const char* text, const c
 ImVec2 ImFont::CalcTextSizeA(float size, float max_width, float wrap_width, const char* text_begin, const char* text_end, const char** remaining)
 {
     if (!text_end)
-        text_end = text_begin + strlen(text_begin); // FIXME-OPT: Need to avoid this.
+        text_end = text_begin + ImStrlen(text_begin); // FIXME-OPT: Need to avoid this.
 
     const float line_height = size;
     const float scale = size / FontSize;
@@ -4125,15 +4130,15 @@ void ImFont::RenderChar(ImDrawList* draw_list, float size, const ImVec2& pos, Im
 // Note: as with every ImDrawList drawing function, this expects that the font atlas texture is bound.
 void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, ImU32 col, const ImVec4& clip_rect, const char* text_begin, const char* text_end, float wrap_width, bool cpu_fine_clip)
 {
-    if (!text_end)
-        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);
     if (y > clip_rect.w)
         return;
 
+    if (!text_end)
+        text_end = text_begin + ImStrlen(text_begin); // ImGui:: functions generally already provides a valid text_end, so this is merely to handle direct calls.
+
     const float scale = size / FontSize;
     const float line_height = FontSize * scale;
     const float origin_x = x;
@@ -4144,7 +4149,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, Im
     if (y + line_height < clip_rect.y)
         while (y + line_height < clip_rect.y && s < text_end)
         {
-            const char* line_end = (const char*)memchr(s, '\n', text_end - s);
+            const char* line_end = (const char*)ImMemchr(s, '\n', text_end - s);
             if (word_wrap_enabled)
             {
                 // FIXME-OPT: This is not optimal as do first do a search for \n before calling CalcWordWrapPositionA().
@@ -4168,7 +4173,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, Im
         float y_end = y;
         while (y_end < clip_rect.w && s_end < text_end)
         {
-            s_end = (const char*)memchr(s_end, '\n', text_end - s_end);
+            s_end = (const char*)ImMemchr(s_end, '\n', text_end - s_end);
             s_end = s_end ? s_end + 1 : text_end;
             y_end += line_height;
         }
@@ -4316,6 +4321,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, const ImVec2& pos, Im
 // - RenderArrow()
 // - RenderBullet()
 // - RenderCheckMark()
+// - RenderArrowDockMenu()
 // - RenderArrowPointingAt()
 // - RenderRectFilledRangeH()
 // - RenderRectFilledWithHole()
@@ -4390,6 +4396,14 @@ 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;
@@ -4475,6 +4489,17 @@ 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_internal.h

@@ -1,4 +1,4 @@
-// dear imgui, v1.91.7
+// dear imgui, v1.91.9
 // (internal structures/api)
 
 // You may use this file to debug, understand or extend Dear ImGui features but we don't provide any guarantee of forward compatibility.
@@ -14,6 +14,7 @@ Index of this file:
 // [SECTION] Macros
 // [SECTION] Generic helpers
 // [SECTION] ImDrawList support
+// [SECTION] Style support
 // [SECTION] Data types support
 // [SECTION] Widgets support: flags, enums, data structures
 // [SECTION] Popup support
@@ -130,17 +131,27 @@ Index of this file:
 // [SECTION] Forward declarations
 //-----------------------------------------------------------------------------
 
+// Utilities
+// (other types which are not forwarded declared are: ImBitArray<>, ImSpan<>, ImSpanAllocator<>, ImPool<>, ImChunkStream<>)
 struct ImBitVector;                 // Store 1-bit per value
 struct ImRect;                      // An axis-aligned rectangle (2 points)
+struct ImGuiTextIndex;              // Maintain a line index for a text buffer.
+
+// ImDrawList/ImFontAtlas
 struct ImDrawDataBuilder;           // Helper to build a ImDrawData instance
 struct ImDrawListSharedData;        // Data shared between all ImDrawList instances
+
+// ImGui
 struct ImGuiBoxSelectState;         // Box-selection state (currently used by multi-selection, could potentially be used by others)
 struct ImGuiColorMod;               // Stacked color modifier, backup of modified data so we can restore it
 struct ImGuiContext;                // Main Dear ImGui context
 struct ImGuiContextHook;            // Hook for extensions like ImGuiTestEngine
-struct ImGuiDataVarInfo;            // Variable information (e.g. to access style variables from an enum)
 struct ImGuiDataTypeInfo;           // Type information associated to a ImGuiDataType enum
 struct ImGuiDeactivatedItemData;    // Data for IsItemDeactivated()/IsItemDeactivatedAfterEdit() function.
+struct ImGuiDockContext;            // Docking system context
+struct ImGuiDockRequest;            // Docking system dock/undock queued request
+struct ImGuiDockNode;               // Docking system node (hold a list of Windows OR two child dock nodes)
+struct ImGuiDockNodeSettings;       // Storage for a dock node in .ini file (we preserve those even if the associated dock node isn't active during the session)
 struct ImGuiErrorRecoveryState;     // Storage of stack sizes for error handling and recovery
 struct ImGuiGroupData;              // Stacked storage data for BeginGroup()/EndGroup()
 struct ImGuiInputTextState;         // Internal state of the currently focused/edited text input box
@@ -159,6 +170,7 @@ struct ImGuiOldColumns;             // Storage data for a columns set for legacy
 struct ImGuiPopupData;              // Storage for current popup stack
 struct ImGuiSettingsHandler;        // Storage for one type registered in the .ini file
 struct ImGuiStyleMod;               // Stacked style modifier, backup of modified data so we can restore it
+struct ImGuiStyleVarInfo;           // Style variable information (e.g. to access style variables from an enum)
 struct ImGuiTabBar;                 // Storage for a tab bar
 struct ImGuiTabItem;                // Storage for a tab item (within a tab bar)
 struct ImGuiTable;                  // Storage for a table
@@ -172,12 +184,14 @@ struct ImGuiTreeNodeStackData;      // Temporary storage for TreeNode().
 struct ImGuiTypingSelectState;      // Storage for GetTypingSelectRequest()
 struct ImGuiTypingSelectRequest;    // Storage for GetTypingSelectRequest() (aimed to be public)
 struct ImGuiWindow;                 // Storage for one window
+struct ImGuiWindowDockStyle;        // Storage for window-style data which needs to be stored for docking purpose
 struct ImGuiWindowTempData;         // Temporary storage for one window (that's the data which in theory we could ditch at the end of the frame, in practice we currently keep it for each window)
 struct ImGuiWindowSettings;         // Storage for a window .ini settings (we keep one of those even if the actual window wasn't instanced during this session)
 
 // Enumerations
 // Use your programming IDE "Go to definition" facility on the names of the center columns to find the actual flags/enum lists.
 enum ImGuiLocKey : int;                 // -> enum ImGuiLocKey              // Enum: a localization entry for translation.
+typedef int ImGuiDataAuthority;         // -> enum ImGuiDataAuthority_      // Enum: for storing the source authority (dock node vs window) of a field
 typedef int ImGuiLayoutType;            // -> enum ImGuiLayoutType_         // Enum: Horizontal or vertical
 
 // Flags
@@ -211,6 +225,9 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 // [SECTION] Macros
 //-----------------------------------------------------------------------------
 
+// Internal Drag and Drop payload types. String starting with '_' are reserved for Dear ImGui.
+#define IMGUI_PAYLOAD_TYPE_WINDOW       "_IMWINDOW"     // Payload == ImGuiWindow*
+
 // Debug Printing Into TTY
 // (since IMGUI_VERSION_NUM >= 18729: IMGUI_DEBUG_LOG was reworked into IMGUI_DEBUG_PRINTF (and removed framecount from it). If you were using a #define IMGUI_DEBUG_LOG please rename)
 #ifndef IMGUI_DEBUG_PRINTF
@@ -222,7 +239,7 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 #endif
 
 // Debug Logging for ShowDebugLogWindow(). This is designed for relatively rare events so please don't spam.
-#define IMGUI_DEBUG_LOG_ERROR(...)      do { ImGuiContext& g2 = *GImGui; if (g2.DebugLogFlags & ImGuiDebugLogFlags_EventError) IMGUI_DEBUG_LOG(__VA_ARGS__); else g2.DebugLogSkippedErrors++; } while (0)
+#define IMGUI_DEBUG_LOG_ERROR(...)      do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventError)       IMGUI_DEBUG_LOG(__VA_ARGS__); else g.DebugLogSkippedErrors++; } while (0)
 #define IMGUI_DEBUG_LOG_ACTIVEID(...)   do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventActiveId)    IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
 #define IMGUI_DEBUG_LOG_FOCUS(...)      do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventFocus)       IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
 #define IMGUI_DEBUG_LOG_POPUP(...)      do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventPopup)       IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
@@ -232,6 +249,8 @@ extern IMGUI_API ImGuiContext* GImGui;  // Current implicit context pointer
 #define IMGUI_DEBUG_LOG_IO(...)         do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventIO)          IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
 #define IMGUI_DEBUG_LOG_FONT(...)       do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventFont)        IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
 #define IMGUI_DEBUG_LOG_INPUTROUTING(...) do{if (g.DebugLogFlags & ImGuiDebugLogFlags_EventInputRouting)IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
+#define IMGUI_DEBUG_LOG_DOCKING(...)    do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventDocking)     IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
+#define IMGUI_DEBUG_LOG_VIEWPORT(...)   do { if (g.DebugLogFlags & ImGuiDebugLogFlags_EventViewport)    IMGUI_DEBUG_LOG(__VA_ARGS__); } while (0)
 
 // Static Asserts
 #define IM_STATIC_ASSERT(_COND)         static_assert(_COND, "")
@@ -359,11 +378,14 @@ static inline void      ImQsort(void* base, size_t count, size_t size_of_element
 IMGUI_API ImU32         ImAlphaBlendColors(ImU32 col_a, ImU32 col_b);
 
 // Helpers: Bit manipulation
-static inline bool      ImIsPowerOfTwo(int v)           { return v != 0 && (v & (v - 1)) == 0; }
-static inline bool      ImIsPowerOfTwo(ImU64 v)         { return v != 0 && (v & (v - 1)) == 0; }
-static inline int       ImUpperPowerOfTwo(int v)        { v--; v |= v >> 1; v |= v >> 2; v |= v >> 4; v |= v >> 8; v |= v >> 16; v++; return v; }
+static inline bool      ImIsPowerOfTwo(int v)               { return v != 0 && (v & (v - 1)) == 0; }
+static inline bool      ImIsPowerOfTwo(ImU64 v)             { return v != 0 && (v & (v - 1)) == 0; }
+static inline int       ImUpperPowerOfTwo(int v)            { v--; v |= v >> 1; v |= v >> 2; v |= v >> 4; v |= v >> 8; v |= v >> 16; v++; return v; }
+static inline unsigned int ImCountSetBits(unsigned int v)   { unsigned int count = 0; while (v > 0) { v = v & (v - 1); count++; } return count; }
 
 // Helpers: String
+#define ImStrlen strlen
+#define ImMemchr memchr
 IMGUI_API int           ImStricmp(const char* str1, const char* str2);                      // Case insensitive compare.
 IMGUI_API int           ImStrnicmp(const char* str1, const char* str2, size_t count);       // Case insensitive compare to a certain count.
 IMGUI_API void          ImStrncpy(char* dst, const char* src, size_t count);                // Copy to a certain count and always zero terminate (strncpy doesn't).
@@ -462,7 +484,7 @@ static inline double ImRsqrt(double x)          { return 1.0 / sqrt(x); }
 template<typename T> static inline T ImMin(T lhs, T rhs)                        { return lhs < rhs ? lhs : rhs; }
 template<typename T> static inline T ImMax(T lhs, T rhs)                        { return lhs >= rhs ? lhs : rhs; }
 template<typename T> static inline T ImClamp(T v, T mn, T mx)                   { return (v < mn) ? mn : (v > mx) ? mx : v; }
-template<typename T> static inline T ImLerp(T a, T b, float t)                  { return (T)(a + (b - a) * (T)t); }
+template<typename T> static inline T ImLerp(T a, T b, float t)                  { return (T)(a + (b - a) * t); }
 template<typename T> static inline void ImSwap(T& a, T& b)                      { T tmp = a; a = b; b = tmp; }
 template<typename T> static inline T ImAddClampOverflow(T a, T b, T mn, T mx)   { if (b < 0 && (a < mn - b)) return mn; if (b > 0 && (a > mx - b)) return mx; return a + b; }
 template<typename T> static inline T ImSubClampOverflow(T a, T b, T mn, T mx)   { if (b > 0 && (a < mn + b)) return mn; if (b < 0 && (a > mx + b)) return mx; return a - b; }
@@ -736,6 +758,7 @@ struct ImGuiTextIndex
 
 // Helper: ImGuiStorage
 IMGUI_API ImGuiStoragePair* ImLowerBound(ImGuiStoragePair* in_begin, ImGuiStoragePair* in_end, ImGuiID key);
+
 //-----------------------------------------------------------------------------
 // [SECTION] ImDrawList support
 //-----------------------------------------------------------------------------
@@ -778,8 +801,9 @@ struct IMGUI_API ImDrawListSharedData
     float           FontScale;                  // Current/default font scale (== FontSize / Font->FontSize)
     float           CurveTessellationTol;       // Tessellation tolerance when using PathBezierCurveTo()
     float           CircleSegmentMaxError;      // Number of circle segments to use per pixel of radius for AddCircle() etc
-    ImVec4          ClipRectFullscreen;         // Value for PushClipRectFullscreen()
+    float           InitialFringeScale;         // Initial scale to apply to AA fringe
     ImDrawListFlags InitialFlags;               // Initial flags at the beginning of the frame (it is possible to alter flags on a per-drawlist basis afterwards)
+    ImVec4          ClipRectFullscreen;         // Value for PushClipRectFullscreen()
     ImVector<ImVec2> TempBuffer;                // Temporary write buffer
 
     // Lookup tables
@@ -800,17 +824,38 @@ struct ImDrawDataBuilder
 };
 
 //-----------------------------------------------------------------------------
-// [SECTION] Data types support
+// [SECTION] Style support
 //-----------------------------------------------------------------------------
 
-struct ImGuiDataVarInfo
+struct ImGuiStyleVarInfo
 {
-    ImGuiDataType   Type;
-    ImU32           Count;      // 1+
-    ImU32           Offset;     // Offset in parent structure
+    ImU32           Count : 8;      // 1+
+    ImGuiDataType   DataType : 8;
+    ImU32           Offset : 16;    // Offset in parent structure
     void* GetVarPtr(void* parent) const { return (void*)((unsigned char*)parent + Offset); }
 };
 
+// Stacked color modifier, backup of modified data so we can restore it
+struct ImGuiColorMod
+{
+    ImGuiCol        Col;
+    ImVec4          BackupValue;
+};
+
+// Stacked style modifier, backup of modified data so we can restore it. Data type inferred from the variable.
+struct ImGuiStyleMod
+{
+    ImGuiStyleVar   VarIdx;
+    union           { int BackupInt[2]; float BackupFloat[2]; };
+    ImGuiStyleMod(ImGuiStyleVar idx, int v)     { VarIdx = idx; BackupInt[0] = v; }
+    ImGuiStyleMod(ImGuiStyleVar idx, float v)   { VarIdx = idx; BackupFloat[0] = v; }
+    ImGuiStyleMod(ImGuiStyleVar idx, ImVec2 v)  { VarIdx = idx; BackupFloat[0] = v.x; BackupFloat[1] = v.y; }
+};
+
+//-----------------------------------------------------------------------------
+// [SECTION] Data types support
+//-----------------------------------------------------------------------------
+
 struct ImGuiDataTypeStorage
 {
     ImU8        Data[8];        // Opaque storage to fit any data up to ImGuiDataType_COUNT
@@ -828,7 +873,7 @@ struct ImGuiDataTypeInfo
 // Extend ImGuiDataType_
 enum ImGuiDataTypePrivate_
 {
-    ImGuiDataType_Pointer = ImGuiDataType_COUNT + 1,
+    ImGuiDataType_Pointer = ImGuiDataType_COUNT,
     ImGuiDataType_ID,
 };
 
@@ -892,7 +937,7 @@ enum ImGuiItemStatusFlags_
 enum ImGuiHoveredFlagsPrivate_
 {
     ImGuiHoveredFlags_DelayMask_                    = ImGuiHoveredFlags_DelayNone | ImGuiHoveredFlags_DelayShort | ImGuiHoveredFlags_DelayNormal | ImGuiHoveredFlags_NoSharedDelay,
-    ImGuiHoveredFlags_AllowedMaskForIsWindowHovered = ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_AnyWindow | ImGuiHoveredFlags_NoPopupHierarchy | ImGuiHoveredFlags_AllowWhenBlockedByPopup | ImGuiHoveredFlags_AllowWhenBlockedByActiveItem | ImGuiHoveredFlags_ForTooltip | ImGuiHoveredFlags_Stationary,
+    ImGuiHoveredFlags_AllowedMaskForIsWindowHovered = ImGuiHoveredFlags_ChildWindows | ImGuiHoveredFlags_RootWindow | ImGuiHoveredFlags_AnyWindow | ImGuiHoveredFlags_NoPopupHierarchy | ImGuiHoveredFlags_DockHierarchy | ImGuiHoveredFlags_AllowWhenBlockedByPopup | ImGuiHoveredFlags_AllowWhenBlockedByActiveItem | ImGuiHoveredFlags_ForTooltip | ImGuiHoveredFlags_Stationary,
     ImGuiHoveredFlags_AllowedMaskForIsItemHovered   = ImGuiHoveredFlags_AllowWhenBlockedByPopup | ImGuiHoveredFlags_AllowWhenBlockedByActiveItem | ImGuiHoveredFlags_AllowWhenOverlapped | ImGuiHoveredFlags_AllowWhenDisabled | ImGuiHoveredFlags_NoNavOverride | ImGuiHoveredFlags_ForTooltip | ImGuiHoveredFlags_Stationary | ImGuiHoveredFlags_DelayMask_,
 };
 
@@ -1029,23 +1074,6 @@ enum ImGuiPlotType
     ImGuiPlotType_Histogram,
 };
 
-// Stacked color modifier, backup of modified data so we can restore it
-struct ImGuiColorMod
-{
-    ImGuiCol        Col;
-    ImVec4          BackupValue;
-};
-
-// Stacked style modifier, backup of modified data so we can restore it. Data type inferred from the variable.
-struct ImGuiStyleMod
-{
-    ImGuiStyleVar   VarIdx;
-    union           { int BackupInt[2]; float BackupFloat[2]; };
-    ImGuiStyleMod(ImGuiStyleVar idx, int v)     { VarIdx = idx; BackupInt[0] = v; }
-    ImGuiStyleMod(ImGuiStyleVar idx, float v)   { VarIdx = idx; BackupFloat[0] = v; }
-    ImGuiStyleMod(ImGuiStyleVar idx, ImVec2 v)  { VarIdx = idx; BackupFloat[0] = v.x; BackupFloat[1] = v.y; }
-};
-
 // Storage data for BeginComboPreview()/EndComboPreview()
 struct IMGUI_API ImGuiComboPreviewData
 {
@@ -1186,33 +1214,45 @@ enum ImGuiNextWindowDataFlags_
     ImGuiNextWindowDataFlags_HasFocus           = 1 << 5,
     ImGuiNextWindowDataFlags_HasBgAlpha         = 1 << 6,
     ImGuiNextWindowDataFlags_HasScroll          = 1 << 7,
-    ImGuiNextWindowDataFlags_HasChildFlags      = 1 << 8,
-    ImGuiNextWindowDataFlags_HasRefreshPolicy   = 1 << 9,
+    ImGuiNextWindowDataFlags_HasWindowFlags     = 1 << 8,
+    ImGuiNextWindowDataFlags_HasChildFlags      = 1 << 9,
+    ImGuiNextWindowDataFlags_HasRefreshPolicy   = 1 << 10,
+    ImGuiNextWindowDataFlags_HasViewport        = 1 << 11,
+    ImGuiNextWindowDataFlags_HasDock            = 1 << 12,
+    ImGuiNextWindowDataFlags_HasWindowClass     = 1 << 13,
 };
 
 // Storage for SetNexWindow** functions
 struct ImGuiNextWindowData
 {
-    ImGuiNextWindowDataFlags    Flags;
+    ImGuiNextWindowDataFlags    HasFlags;
+
+    // Members below are NOT cleared. Always rely on HasFlags.
     ImGuiCond                   PosCond;
     ImGuiCond                   SizeCond;
     ImGuiCond                   CollapsedCond;
+    ImGuiCond                   DockCond;
     ImVec2                      PosVal;
     ImVec2                      PosPivotVal;
     ImVec2                      SizeVal;
     ImVec2                      ContentSizeVal;
     ImVec2                      ScrollVal;
+    ImGuiWindowFlags            WindowFlags;            // Only honored by BeginTable()
     ImGuiChildFlags             ChildFlags;
+    bool                        PosUndock;
     bool                        CollapsedVal;
     ImRect                      SizeConstraintRect;
     ImGuiSizeCallback           SizeCallback;
     void*                       SizeCallbackUserData;
     float                       BgAlphaVal;             // Override background alpha
+    ImGuiID                     ViewportId;
+    ImGuiID                     DockId;
+    ImGuiWindowClass            WindowClass;
     ImVec2                      MenuBarOffsetMinVal;    // (Always on) This is not exposed publicly, so we don't clear it and it doesn't have a corresponding flag (could we? for consistency?)
     ImGuiWindowRefreshFlags     RefreshFlagsVal;
 
     ImGuiNextWindowData()       { memset(this, 0, sizeof(*this)); }
-    inline void ClearFlags()    { Flags = ImGuiNextWindowDataFlags_None; }
+    inline void ClearFlags()    { HasFlags = ImGuiNextWindowDataFlags_None; }
 };
 
 enum ImGuiNextItemDataFlags_
@@ -1229,7 +1269,8 @@ struct ImGuiNextItemData
 {
     ImGuiNextItemDataFlags      HasFlags;           // Called HasFlags instead of Flags to avoid mistaking this
     ImGuiItemFlags              ItemFlags;          // Currently only tested/used for ImGuiItemFlags_AllowOverlap and ImGuiItemFlags_HasSelectionUserData.
-    // Non-flags members are NOT cleared by ItemAdd() meaning they are still valid during NavProcessItem()
+
+    // Members below are NOT cleared by ItemAdd() meaning they are still valid during e.g. NavProcessItem(). Always rely on HasFlags.
     ImGuiID                     FocusScopeId;       // Set by SetNextItemSelectionUserData()
     ImGuiSelectionUserData      SelectionUserData;  // Set by SetNextItemSelectionUserData() (note that NULL/0 is a valid value, we use -1 == ImGuiSelectionUserData_Invalid to mark invalid values)
     float                       Width;              // Set by SetNextItemWidth()
@@ -1297,6 +1338,7 @@ struct ImGuiWindowStackData
     ImGuiLastItemData       ParentLastItemDataBackup;
     ImGuiErrorRecoveryState StackSizesInBegin;          // Store size of various stacks for asserting
     bool                    DisabledOverrideReenable;   // Non-child window override disabled flag
+    float                   DisabledOverrideReenableAlphaBackup;
 };
 
 struct ImGuiShrinkWidthItem
@@ -1385,6 +1427,7 @@ enum ImGuiInputEventType
     ImGuiInputEventType_MousePos,
     ImGuiInputEventType_MouseWheel,
     ImGuiInputEventType_MouseButton,
+    ImGuiInputEventType_MouseViewport,
     ImGuiInputEventType_Key,
     ImGuiInputEventType_Text,
     ImGuiInputEventType_Focus,
@@ -1405,6 +1448,7 @@ enum ImGuiInputSource
 struct ImGuiInputEventMousePos      { float PosX, PosY; ImGuiMouseSource MouseSource; };
 struct ImGuiInputEventMouseWheel    { float WheelX, WheelY; ImGuiMouseSource MouseSource; };
 struct ImGuiInputEventMouseButton   { int Button; bool Down; ImGuiMouseSource MouseSource; };
+struct ImGuiInputEventMouseViewport { ImGuiID HoveredViewportID; };
 struct ImGuiInputEventKey           { ImGuiKey Key; bool Down; float AnalogValue; };
 struct ImGuiInputEventText          { unsigned int Char; };
 struct ImGuiInputEventAppFocused    { bool Focused; };
@@ -1419,6 +1463,7 @@ struct ImGuiInputEvent
         ImGuiInputEventMousePos     MousePos;       // if Type == ImGuiInputEventType_MousePos
         ImGuiInputEventMouseWheel   MouseWheel;     // if Type == ImGuiInputEventType_MouseWheel
         ImGuiInputEventMouseButton  MouseButton;    // if Type == ImGuiInputEventType_MouseButton
+        ImGuiInputEventMouseViewport MouseViewport; // if Type == ImGuiInputEventType_MouseViewport
         ImGuiInputEventKey          Key;            // if Type == ImGuiInputEventType_Key
         ImGuiInputEventText         Text;           // if Type == ImGuiInputEventType_Text
         ImGuiInputEventAppFocused   AppFocused;     // if Type == ImGuiInputEventType_Focus
@@ -1812,8 +1857,155 @@ struct IMGUI_API ImGuiMultiSelectState
 // [SECTION] Docking support
 //-----------------------------------------------------------------------------
 
+#define DOCKING_HOST_DRAW_CHANNEL_BG 0  // Dock host: background fill
+#define DOCKING_HOST_DRAW_CHANNEL_FG 1  // Dock host: decorations and contents
+
 #ifdef IMGUI_HAS_DOCK
-// <this is filled in 'docking' branch>
+
+// Extend ImGuiDockNodeFlags_
+enum ImGuiDockNodeFlagsPrivate_
+{
+    // [Internal]
+    ImGuiDockNodeFlags_DockSpace                = 1 << 10,  // Saved // A dockspace is a node that occupy space within an existing user window. Otherwise the node is floating and create its own window.
+    ImGuiDockNodeFlags_CentralNode              = 1 << 11,  // Saved // The central node has 2 main properties: stay visible when empty, only use "remaining" spaces from its neighbor.
+    ImGuiDockNodeFlags_NoTabBar                 = 1 << 12,  // Saved // Tab bar is completely unavailable. No triangle in the corner to enable it back.
+    ImGuiDockNodeFlags_HiddenTabBar             = 1 << 13,  // Saved // Tab bar is hidden, with a triangle in the corner to show it again (NB: actual tab-bar instance may be destroyed as this is only used for single-window tab bar)
+    ImGuiDockNodeFlags_NoWindowMenuButton       = 1 << 14,  // Saved // Disable window/docking menu (that one that appears instead of the collapse button)
+    ImGuiDockNodeFlags_NoCloseButton            = 1 << 15,  // Saved // Disable close button
+    ImGuiDockNodeFlags_NoResizeX                = 1 << 16,  //       //
+    ImGuiDockNodeFlags_NoResizeY                = 1 << 17,  //       //
+    ImGuiDockNodeFlags_DockedWindowsInFocusRoute= 1 << 18,  //       // Any docked window will be automatically be focus-route chained (window->ParentWindowForFocusRoute set to this) so Shortcut() in this window can run when any docked window is focused.
+
+    // Disable docking/undocking actions in this dockspace or individual node (existing docked nodes will be preserved)
+    // Those are not exposed in public because the desirable sharing/inheriting/copy-flag-on-split behaviors are quite difficult to design and understand.
+    // The two public flags ImGuiDockNodeFlags_NoDockingOverCentralNode/ImGuiDockNodeFlags_NoDockingSplit don't have those issues.
+    ImGuiDockNodeFlags_NoDockingSplitOther      = 1 << 19,  //       // Disable this node from splitting other windows/nodes.
+    ImGuiDockNodeFlags_NoDockingOverMe          = 1 << 20,  //       // Disable other windows/nodes from being docked over this node.
+    ImGuiDockNodeFlags_NoDockingOverOther       = 1 << 21,  //       // Disable this node from being docked over another window or non-empty node.
+    ImGuiDockNodeFlags_NoDockingOverEmpty       = 1 << 22,  //       // Disable this node from being docked over an empty node (e.g. DockSpace with no other windows)
+    ImGuiDockNodeFlags_NoDocking                = ImGuiDockNodeFlags_NoDockingOverMe | ImGuiDockNodeFlags_NoDockingOverOther | ImGuiDockNodeFlags_NoDockingOverEmpty | ImGuiDockNodeFlags_NoDockingSplit | ImGuiDockNodeFlags_NoDockingSplitOther,
+
+    // Masks
+    ImGuiDockNodeFlags_SharedFlagsInheritMask_  = ~0,
+    ImGuiDockNodeFlags_NoResizeFlagsMask_       = (int)ImGuiDockNodeFlags_NoResize | ImGuiDockNodeFlags_NoResizeX | ImGuiDockNodeFlags_NoResizeY,
+
+    // When splitting, those local flags are moved to the inheriting child, never duplicated
+    ImGuiDockNodeFlags_LocalFlagsTransferMask_  = (int)ImGuiDockNodeFlags_NoDockingSplit | ImGuiDockNodeFlags_NoResizeFlagsMask_ | (int)ImGuiDockNodeFlags_AutoHideTabBar | ImGuiDockNodeFlags_CentralNode | ImGuiDockNodeFlags_NoTabBar | ImGuiDockNodeFlags_HiddenTabBar | ImGuiDockNodeFlags_NoWindowMenuButton | ImGuiDockNodeFlags_NoCloseButton,
+    ImGuiDockNodeFlags_SavedFlagsMask_          = ImGuiDockNodeFlags_NoResizeFlagsMask_ | ImGuiDockNodeFlags_DockSpace | ImGuiDockNodeFlags_CentralNode | ImGuiDockNodeFlags_NoTabBar | ImGuiDockNodeFlags_HiddenTabBar | ImGuiDockNodeFlags_NoWindowMenuButton | ImGuiDockNodeFlags_NoCloseButton,
+};
+
+// Store the source authority (dock node vs window) of a field
+enum ImGuiDataAuthority_
+{
+    ImGuiDataAuthority_Auto,
+    ImGuiDataAuthority_DockNode,
+    ImGuiDataAuthority_Window,
+};
+
+enum ImGuiDockNodeState
+{
+    ImGuiDockNodeState_Unknown,
+    ImGuiDockNodeState_HostWindowHiddenBecauseSingleWindow,
+    ImGuiDockNodeState_HostWindowHiddenBecauseWindowsAreResizing,
+    ImGuiDockNodeState_HostWindowVisible,
+};
+
+// sizeof() 156~192
+struct IMGUI_API ImGuiDockNode
+{
+    ImGuiID                 ID;
+    ImGuiDockNodeFlags      SharedFlags;                // (Write) Flags shared by all nodes of a same dockspace hierarchy (inherited from the root node)
+    ImGuiDockNodeFlags      LocalFlags;                 // (Write) Flags specific to this node
+    ImGuiDockNodeFlags      LocalFlagsInWindows;        // (Write) Flags specific to this node, applied from windows
+    ImGuiDockNodeFlags      MergedFlags;                // (Read)  Effective flags (== SharedFlags | LocalFlagsInNode | LocalFlagsInWindows)
+    ImGuiDockNodeState      State;
+    ImGuiDockNode*          ParentNode;
+    ImGuiDockNode*          ChildNodes[2];              // [Split node only] Child nodes (left/right or top/bottom). Consider switching to an array.
+    ImVector<ImGuiWindow*>  Windows;                    // Note: unordered list! Iterate TabBar->Tabs for user-order.
+    ImGuiTabBar*            TabBar;
+    ImVec2                  Pos;                        // Current position
+    ImVec2                  Size;                       // Current size
+    ImVec2                  SizeRef;                    // [Split node only] Last explicitly written-to size (overridden when using a splitter affecting the node), used to calculate Size.
+    ImGuiAxis               SplitAxis;                  // [Split node only] Split axis (X or Y)
+    ImGuiWindowClass        WindowClass;                // [Root node only]
+    ImU32                   LastBgColor;
+
+    ImGuiWindow*            HostWindow;
+    ImGuiWindow*            VisibleWindow;              // Generally point to window which is ID is == SelectedTabID, but when CTRL+Tabbing this can be a different window.
+    ImGuiDockNode*          CentralNode;                // [Root node only] Pointer to central node.
+    ImGuiDockNode*          OnlyNodeWithWindows;        // [Root node only] Set when there is a single visible node within the hierarchy.
+    int                     CountNodeWithWindows;       // [Root node only]
+    int                     LastFrameAlive;             // Last frame number the node was updated or kept alive explicitly with DockSpace() + ImGuiDockNodeFlags_KeepAliveOnly
+    int                     LastFrameActive;            // Last frame number the node was updated.
+    int                     LastFrameFocused;           // Last frame number the node was focused.
+    ImGuiID                 LastFocusedNodeId;          // [Root node only] Which of our child docking node (any ancestor in the hierarchy) was last focused.
+    ImGuiID                 SelectedTabId;              // [Leaf node only] Which of our tab/window is selected.
+    ImGuiID                 WantCloseTabId;             // [Leaf node only] Set when closing a specific tab/window.
+    ImGuiID                 RefViewportId;              // Reference viewport ID from visible window when HostWindow == NULL.
+    ImGuiDataAuthority      AuthorityForPos         :3;
+    ImGuiDataAuthority      AuthorityForSize        :3;
+    ImGuiDataAuthority      AuthorityForViewport    :3;
+    bool                    IsVisible               :1; // Set to false when the node is hidden (usually disabled as it has no active window)
+    bool                    IsFocused               :1;
+    bool                    IsBgDrawnThisFrame      :1;
+    bool                    HasCloseButton          :1; // Provide space for a close button (if any of the docked window has one). Note that button may be hidden on window without one.
+    bool                    HasWindowMenuButton     :1;
+    bool                    HasCentralNodeChild     :1;
+    bool                    WantCloseAll            :1; // Set when closing all tabs at once.
+    bool                    WantLockSizeOnce        :1;
+    bool                    WantMouseMove           :1; // After a node extraction we need to transition toward moving the newly created host window
+    bool                    WantHiddenTabBarUpdate  :1;
+    bool                    WantHiddenTabBarToggle  :1;
+
+    ImGuiDockNode(ImGuiID id);
+    ~ImGuiDockNode();
+    bool                    IsRootNode() const      { return ParentNode == NULL; }
+    bool                    IsDockSpace() const     { return (MergedFlags & ImGuiDockNodeFlags_DockSpace) != 0; }
+    bool                    IsFloatingNode() const  { return ParentNode == NULL && (MergedFlags & ImGuiDockNodeFlags_DockSpace) == 0; }
+    bool                    IsCentralNode() const   { return (MergedFlags & ImGuiDockNodeFlags_CentralNode) != 0; }
+    bool                    IsHiddenTabBar() const  { return (MergedFlags & ImGuiDockNodeFlags_HiddenTabBar) != 0; } // Hidden tab bar can be shown back by clicking the small triangle
+    bool                    IsNoTabBar() const      { return (MergedFlags & ImGuiDockNodeFlags_NoTabBar) != 0; }     // Never show a tab bar
+    bool                    IsSplitNode() const     { return ChildNodes[0] != NULL; }
+    bool                    IsLeafNode() const      { return ChildNodes[0] == NULL; }
+    bool                    IsEmpty() const         { return ChildNodes[0] == NULL && Windows.Size == 0; }
+    ImRect                  Rect() const            { return ImRect(Pos.x, Pos.y, Pos.x + Size.x, Pos.y + Size.y); }
+
+    void                    SetLocalFlags(ImGuiDockNodeFlags flags) { LocalFlags = flags; UpdateMergedFlags(); }
+    void                    UpdateMergedFlags()     { MergedFlags = SharedFlags | LocalFlags | LocalFlagsInWindows; }
+};
+
+// List of colors that are stored at the time of Begin() into Docked Windows.
+// We currently store the packed colors in a simple array window->DockStyle.Colors[].
+// A better solution may involve appending into a log of colors in ImGuiContext + store offsets into those arrays in ImGuiWindow,
+// but it would be more complex as we'd need to double-buffer both as e.g. drop target may refer to window from last frame.
+enum ImGuiWindowDockStyleCol
+{
+    ImGuiWindowDockStyleCol_Text,
+    ImGuiWindowDockStyleCol_TabHovered,
+    ImGuiWindowDockStyleCol_TabFocused,
+    ImGuiWindowDockStyleCol_TabSelected,
+    ImGuiWindowDockStyleCol_TabSelectedOverline,
+    ImGuiWindowDockStyleCol_TabDimmed,
+    ImGuiWindowDockStyleCol_TabDimmedSelected,
+    ImGuiWindowDockStyleCol_TabDimmedSelectedOverline,
+    ImGuiWindowDockStyleCol_COUNT
+};
+
+// We don't store style.Alpha: dock_node->LastBgColor embeds it and otherwise it would only affect the docking tab, which intuitively I would say we don't want to.
+struct ImGuiWindowDockStyle
+{
+    ImU32 Colors[ImGuiWindowDockStyleCol_COUNT];
+};
+
+struct ImGuiDockContext
+{
+    ImGuiStorage                    Nodes;          // Map ID -> ImGuiDockNode*: Active nodes
+    ImVector<ImGuiDockRequest>      Requests;
+    ImVector<ImGuiDockNodeSettings> NodesSettings;
+    bool                            WantFullRebuild;
+    ImGuiDockContext()              { memset(this, 0, sizeof(*this)); }
+};
+
 #endif // #ifdef IMGUI_HAS_DOCK
 
 //-----------------------------------------------------------------------------
@@ -1824,10 +2016,24 @@ struct IMGUI_API ImGuiMultiSelectState
 // Every instance of ImGuiViewport is in fact a ImGuiViewportP.
 struct ImGuiViewportP : public ImGuiViewport
 {
+    ImGuiWindow*        Window;                 // Set when the viewport is owned by a window (and ImGuiViewportFlags_CanHostOtherWindows is NOT set)
+    int                 Idx;
+    int                 LastFrameActive;        // Last frame number this viewport was activated by a window
+    int                 LastFocusedStampCount;  // Last stamp number from when a window hosted by this viewport was focused (by comparing this value between two viewport we have an implicit viewport z-order we use as fallback)
+    ImGuiID             LastNameHash;
+    ImVec2              LastPos;
+    ImVec2              LastSize;
+    float               Alpha;                  // Window opacity (when dragging dockable windows/viewports we make them transparent)
+    float               LastAlpha;
+    bool                LastFocusedHadNavWindow;// Instead of maintaining a LastFocusedWindow (which may harder to correctly maintain), we merely store weither NavWindow != NULL last time the viewport was focused.
+    short               PlatformMonitor;
     int                 BgFgDrawListsLastFrame[2]; // Last frame number the background (0) and foreground (1) draw lists were used
     ImDrawList*         BgFgDrawLists[2];       // Convenience background (0) and foreground (1) draw lists. We use them to draw software mouser cursor when io.MouseDrawCursor is set and to draw most debug overlays.
     ImDrawData          DrawDataP;
     ImDrawDataBuilder   DrawDataBuilder;        // Temporary data while building final ImDrawData
+    ImVec2              LastPlatformPos;
+    ImVec2              LastPlatformSize;
+    ImVec2              LastRendererSize;
 
     // Per-viewport work area
     // - Insets are >= 0.0f values, distance from viewport corners to work area.
@@ -1838,8 +2044,9 @@ struct ImGuiViewportP : public ImGuiViewport
     ImVec2              BuildWorkInsetMin;      // Work Area inset accumulator for current frame, to become next frame's WorkInset
     ImVec2              BuildWorkInsetMax;      // "
 
-    ImGuiViewportP()    { BgFgDrawListsLastFrame[0] = BgFgDrawListsLastFrame[1] = -1; BgFgDrawLists[0] = BgFgDrawLists[1] = NULL; }
-    ~ImGuiViewportP()   { if (BgFgDrawLists[0]) IM_DELETE(BgFgDrawLists[0]); if (BgFgDrawLists[1]) IM_DELETE(BgFgDrawLists[1]); }
+    ImGuiViewportP()                    { Window = NULL; Idx = -1; LastFrameActive = BgFgDrawListsLastFrame[0] = BgFgDrawListsLastFrame[1] = LastFocusedStampCount = -1; LastNameHash = 0; Alpha = LastAlpha = 1.0f; LastFocusedHadNavWindow = false; PlatformMonitor = -1; BgFgDrawLists[0] = BgFgDrawLists[1] = NULL; LastPlatformPos = LastPlatformSize = LastRendererSize = ImVec2(FLT_MAX, FLT_MAX); }
+    ~ImGuiViewportP()                   { if (BgFgDrawLists[0]) IM_DELETE(BgFgDrawLists[0]); if (BgFgDrawLists[1]) IM_DELETE(BgFgDrawLists[1]); }
+    void    ClearRequestFlags()         { PlatformRequestClose = PlatformRequestMove = PlatformRequestResize = false; }
 
     // Calculate work rect pos/size given a set of offset (we have 1 pair of offset for rect locked from last frame data, and 1 pair for currently building rect)
     ImVec2  CalcWorkRectPos(const ImVec2& inset_min) const                           { return ImVec2(Pos.x + inset_min.x, Pos.y + inset_min.y); }
@@ -1862,14 +2069,19 @@ struct ImGuiViewportP : public ImGuiViewport
 struct ImGuiWindowSettings
 {
     ImGuiID     ID;
-    ImVec2ih    Pos;
+    ImVec2ih    Pos;            // NB: Settings position are stored RELATIVE to the viewport! Whereas runtime ones are absolute positions.
     ImVec2ih    Size;
+    ImVec2ih    ViewportPos;
+    ImGuiID     ViewportId;
+    ImGuiID     DockId;         // ID of last known DockNode (even if the DockNode is invisible because it has only 1 active window), or 0 if none.
+    ImGuiID     ClassId;        // ID of window class if specified
+    short       DockOrder;      // Order of the last time the window was visible within its DockNode. This is used to reorder windows that are reappearing on the same frame. Same value between windows that were active and windows that were none are possible.
     bool        Collapsed;
     bool        IsChild;
     bool        WantApply;      // Set when loaded from .ini data (to enable merging/loading .ini data into an already running context)
     bool        WantDelete;     // Set to invalidate/delete the settings entry
 
-    ImGuiWindowSettings()       { memset(this, 0, sizeof(*this)); }
+    ImGuiWindowSettings()       { memset(this, 0, sizeof(*this)); DockOrder = -1; }
     char* GetName()             { return (char*)(this + 1); }
 };
 
@@ -1905,6 +2117,9 @@ enum ImGuiLocKey : int
     ImGuiLocKey_WindowingUntitled,
     ImGuiLocKey_OpenLink_s,
     ImGuiLocKey_CopyLink,
+    ImGuiLocKey_DockingHideTabBar,
+    ImGuiLocKey_DockingHoldShiftToDock,
+    ImGuiLocKey_DockingDragToUndockOrMoveNode,
     ImGuiLocKey_COUNT
 };
 
@@ -1949,8 +2164,8 @@ enum ImGuiDebugLogFlags_
     ImGuiDebugLogFlags_EventIO              = 1 << 7,
     ImGuiDebugLogFlags_EventFont            = 1 << 8,
     ImGuiDebugLogFlags_EventInputRouting    = 1 << 9,
-    ImGuiDebugLogFlags_EventDocking         = 1 << 10,  // Unused in this branch
-    ImGuiDebugLogFlags_EventViewport        = 1 << 11,  // Unused in this branch
+    ImGuiDebugLogFlags_EventDocking         = 1 << 10,
+    ImGuiDebugLogFlags_EventViewport        = 1 << 11,
 
     ImGuiDebugLogFlags_EventMask_           = ImGuiDebugLogFlags_EventError | ImGuiDebugLogFlags_EventActiveId | ImGuiDebugLogFlags_EventFocus | ImGuiDebugLogFlags_EventPopup | ImGuiDebugLogFlags_EventNav | ImGuiDebugLogFlags_EventClipper | ImGuiDebugLogFlags_EventSelection | ImGuiDebugLogFlags_EventIO | ImGuiDebugLogFlags_EventFont | ImGuiDebugLogFlags_EventInputRouting | ImGuiDebugLogFlags_EventDocking | ImGuiDebugLogFlags_EventViewport,
     ImGuiDebugLogFlags_OutputToTTY          = 1 << 20,  // Also send output to TTY
@@ -1984,7 +2199,7 @@ struct ImGuiMetricsConfig
     bool        ShowDrawCmdMesh = true;
     bool        ShowDrawCmdBoundingBoxes = true;
     bool        ShowTextEncodingViewer = false;
-    bool        ShowAtlasTintedWithTextColor = false;
+    bool        ShowDockingNodes = false;
     int         ShowWindowsRectsType = -1;
     int         ShowTablesRectsType = -1;
     int         HighlightMonitorIdx = -1;
@@ -2011,6 +2226,7 @@ struct ImGuiIDStackTool
     ImVector<ImGuiStackLevelInfo> Results;
     bool                    CopyToClipboardOnCtrlC;
     float                   CopyToClipboardLastTime;
+    ImGuiTextBuffer         ResultPathBuf;
 
     ImGuiIDStackTool()      { memset(this, 0, sizeof(*this)); CopyToClipboardLastTime = -FLT_MAX; }
 };
@@ -2044,15 +2260,18 @@ struct ImGuiContext
     ImGuiIO                 IO;
     ImGuiPlatformIO         PlatformIO;
     ImGuiStyle              Style;
+    ImGuiConfigFlags        ConfigFlagsCurrFrame;               // = g.IO.ConfigFlags at the time of NewFrame()
+    ImGuiConfigFlags        ConfigFlagsLastFrame;
     ImFont*                 Font;                               // (Shortcut) == FontStack.empty() ? IO.Font : FontStack.back()
     float                   FontSize;                           // (Shortcut) == FontBaseSize * g.CurrentWindow->FontWindowScale == window->FontSize(). Text height for current window.
     float                   FontBaseSize;                       // (Shortcut) == IO.FontGlobalScale * Font->Scale * Font->FontSize. Base text height.
     float                   FontScale;                          // == FontSize / Font->FontSize
-    float                   CurrentDpiScale;                    // Current window/viewport DpiScale
+    float                   CurrentDpiScale;                    // Current window/viewport DpiScale == CurrentViewport->DpiScale
     ImDrawListSharedData    DrawListSharedData;
     double                  Time;
     int                     FrameCount;
     int                     FrameCountEnded;
+    int                     FrameCountPlatformEnded;
     int                     FrameCountRendered;
     ImGuiID                 WithinEndChildID;                   // Set within EndChild()
     bool                    WithinFrameScope;                   // Set by NewFrame(), cleared by EndFrame()
@@ -2075,13 +2294,13 @@ struct ImGuiContext
     ImVector<ImGuiWindowStackData> CurrentWindowStack;
     ImGuiStorage            WindowsById;                        // Map window's ImGuiID to ImGuiWindow*
     int                     WindowsActiveCount;                 // Number of unique windows submitted by frame
-    ImVec2                  WindowsHoverPadding;                // Padding around resizable windows for which hovering on counts as hovering the window == ImMax(style.TouchExtraPadding, WINDOWS_HOVER_PADDING).
+    float                   WindowsBorderHoverPadding;          // Padding around resizable windows for which hovering on counts as hovering the window == ImMax(style.TouchExtraPadding, style.WindowBorderHoverPadding). This isn't so multi-dpi friendly.
     ImGuiID                 DebugBreakInWindow;                 // Set to break in Begin() call.
     ImGuiWindow*            CurrentWindow;                      // Window being drawn into
     ImGuiWindow*            HoveredWindow;                      // Window the mouse is hovering. Will typically catch mouse inputs.
     ImGuiWindow*            HoveredWindowUnderMovingWindow;     // Hovered window ignoring MovingWindow. Only set if MovingWindow is set.
     ImGuiWindow*            HoveredWindowBeforeClear;           // Window the mouse is hovering. Filled even with _NoMouse. This is currently useful for multi-context compositors.
-    ImGuiWindow*            MovingWindow;                       // Track the window we clicked on (in order to preserve focus). The actual window that is moved is generally MovingWindow->RootWindow.
+    ImGuiWindow*            MovingWindow;                       // Track the window we clicked on (in order to preserve focus). The actual window that is moved is generally MovingWindow->RootWindowDockTree.
     ImGuiWindow*            WheelingWindow;                     // Track the window we started mouse-wheeling on. Until a timer elapse or mouse has moved, generally keep scrolling the same window even if during the course of scrolling the mouse ends up hovering a child window.
     ImVec2                  WheelingWindowRefMousePos;
     int                     WheelingWindowStartFrame;           // This may be set one frame before WheelingWindow is != NULL
@@ -2158,7 +2377,16 @@ struct ImGuiContext
     ImVector<ImGuiTreeNodeStackData>TreeNodeStack;              // Stack for TreeNode()
 
     // Viewports
-    ImVector<ImGuiViewportP*> Viewports;                        // Active viewports (Size==1 in 'master' branch). Each viewports hold their copy of ImDrawData.
+    ImVector<ImGuiViewportP*> Viewports;                        // Active viewports (always 1+, and generally 1 unless multi-viewports are enabled). Each viewports hold their copy of ImDrawData.
+    ImGuiViewportP*         CurrentViewport;                    // We track changes of viewport (happening in Begin) so we can call Platform_OnChangedViewport()
+    ImGuiViewportP*         MouseViewport;
+    ImGuiViewportP*         MouseLastHoveredViewport;           // Last known viewport that was hovered by mouse (even if we are not hovering any viewport any more) + honoring the _NoInputs flag.
+    ImGuiID                 PlatformLastFocusedViewportId;
+    ImGuiPlatformMonitor    FallbackMonitor;                    // Virtual monitor used as fallback if backend doesn't provide monitor information.
+    ImRect                  PlatformMonitorsFullWorkRect;       // Bounding box of all platform monitors
+    int                     ViewportCreatedCount;               // Unique sequential creation counter (mostly for testing/debugging)
+    int                     PlatformWindowsCreatedCount;        // Unique sequential creation counter (mostly for testing/debugging)
+    int                     ViewportFocusedStampCount;          // Every time the front-most window changes, we stamp its viewport with an incrementing counter
 
     // Keyboard/Gamepad Navigation
     bool                    NavCursorVisible;                   // Nav focus cursor/rectangle is visible? We hide it after a mouse click. We show it after a nav move.
@@ -2328,6 +2556,12 @@ struct ImGuiContext
     // Platform support
     ImGuiPlatformImeData    PlatformImeData;                    // Data updated by current frame
     ImGuiPlatformImeData    PlatformImeDataPrev;                // Previous frame data. When changed we call the platform_io.Platform_SetImeDataFn() handler.
+    ImGuiID                 PlatformImeViewport;
+
+    // Extensions
+    // FIXME: We could provide an API to register one slot in an array held in ImGuiContext?
+    ImGuiDockContext        DockContext;
+    void                    (*DockNodeWindowMenuHandler)(ImGuiContext* ctx, ImGuiDockNode* node, ImGuiTabBar* tab_bar);
 
     // Settings
     bool                    SettingsLoaded;
@@ -2386,6 +2620,7 @@ struct ImGuiContext
     ImGuiMetricsConfig      DebugMetricsConfig;
     ImGuiIDStackTool        DebugIDStackTool;
     ImGuiDebugAllocInfo     DebugAllocInfo;
+    ImGuiDockNode*          DebugHoveredDockNode;               // Hovered dock node.
 
     // Misc
     float                   FramerateSecPerFrame[60];           // Calculate estimate of framerate for user over the last 60 frames..
@@ -2449,6 +2684,12 @@ struct IMGUI_API ImGuiWindowTempData
     ImGuiLayoutType         ParentLayoutType;       // Layout type of parent window at the time of Begin()
     ImU32                   ModalDimBgColor;
 
+    // Status flags
+    ImGuiItemStatusFlags    WindowItemStatusFlags;
+    ImGuiItemStatusFlags    ChildItemStatusFlags;
+    ImGuiItemStatusFlags    DockTabItemStatusFlags;
+    ImRect                  DockTabItemRect;
+
     // Local parameters stacks
     // We store the current settings outside of the vectors to increase memory locality (reduce cache misses). The vectors are rarely modified. Also it allows us to not heap allocate for short-lived windows which are not using those settings.
     float                   ItemWidth;              // Current item width (>0.0: width in pixels, <0.0: align xx pixels to the right of window).
@@ -2463,9 +2704,13 @@ struct IMGUI_API ImGuiWindow
     ImGuiContext*           Ctx;                                // Parent UI context (needs to be set explicitly by parent).
     char*                   Name;                               // Window name, owned by the window.
     ImGuiID                 ID;                                 // == ImHashStr(Name)
-    ImGuiWindowFlags        Flags;                              // See enum ImGuiWindowFlags_
+    ImGuiWindowFlags        Flags, FlagsPreviousFrame;          // See enum ImGuiWindowFlags_
     ImGuiChildFlags         ChildFlags;                         // Set when window is a child window. See enum ImGuiChildFlags_
+    ImGuiWindowClass        WindowClass;                        // Advanced users only. Set with SetNextWindowClass()
     ImGuiViewportP*         Viewport;                           // Always set in Begin(). Inactive windows may have a NULL value here if their viewport was discarded.
+    ImGuiID                 ViewportId;                         // We backup the viewport id (since the viewport may disappear or never be created if the window is inactive)
+    ImVec2                  ViewportPos;                        // We backup the viewport position (since the viewport may disappear or never be created if the window is inactive)
+    int                     ViewportAllowPlatformMonitorExtend; // Reset to -1 every frame (index is guaranteed to be valid between NewFrame..EndFrame), only used in the Appearing frame of a tooltip/popup to enforce clamping to a given monitor
     ImVec2                  Pos;                                // Position (always rounded-up to nearest pixel)
     ImVec2                  Size;                               // Current size (==SizeFull or collapsed title bar size)
     ImVec2                  SizeFull;                           // Size when non collapsed
@@ -2481,6 +2726,7 @@ struct IMGUI_API ImGuiWindow
     float                   DecoInnerSizeX1, DecoInnerSizeY1;   // Applied AFTER/OVER InnerRect. Specialized for Tables as they use specialized form of clipping and frozen rows/columns are inside InnerRect (and not part of regular decoration sizes).
     int                     NameBufLen;                         // Size of buffer storing Name. May be larger than strlen(Name)!
     ImGuiID                 MoveId;                             // == window->GetID("#MOVE")
+    ImGuiID                 TabId;                              // == window->GetID("#TAB")
     ImGuiID                 ChildId;                            // ID of corresponding item in parent window (for navigation to return from child window to parent window)
     ImGuiID                 PopupId;                            // ID in the popup stack when this window is used as a popup/menu (because we use generic Name/ID for recycling)
     ImVec2                  Scroll;
@@ -2490,6 +2736,9 @@ struct IMGUI_API ImGuiWindow
     ImVec2                  ScrollTargetEdgeSnapDist;           // 0.0f = no snapping, >0.0f snapping threshold
     ImVec2                  ScrollbarSizes;                     // Size taken by each scrollbars on their smaller axis. Pay attention! ScrollbarSizes.x == width of the vertical scrollbar, ScrollbarSizes.y = height of the horizontal scrollbar.
     bool                    ScrollbarX, ScrollbarY;             // Are scrollbars visible?
+    bool                    ScrollbarXStabilizeEnabled;         // Was ScrollbarX previously auto-stabilized?
+    ImU8                    ScrollbarXStabilizeToggledHistory;  // Used to stabilize scrollbar visibility in case of feedback loops
+    bool                    ViewportOwned;
     bool                    Active;                             // Set to true on Begin(), unless Collapsed
     bool                    WasActive;
     bool                    WriteAccessed;                      // Set to true when any widget access the current window
@@ -2519,6 +2768,7 @@ struct IMGUI_API ImGuiWindow
     ImGuiCond               SetWindowPosAllowFlags : 8;         // store acceptable condition flags for SetNextWindowPos() use.
     ImGuiCond               SetWindowSizeAllowFlags : 8;        // store acceptable condition flags for SetNextWindowSize() use.
     ImGuiCond               SetWindowCollapsedAllowFlags : 8;   // store acceptable condition flags for SetNextWindowCollapsed() use.
+    ImGuiCond               SetWindowDockAllowFlags : 8;        // store acceptable condition flags for SetNextWindowDock() use.
     ImVec2                  SetWindowPosVal;                    // store window position when using a non-zero Pivot (position set needs to be processed when we know the window size)
     ImVec2                  SetWindowPosPivot;                  // store window pivot for positioning. ImVec2(0, 0) when positioning from top-left corner; ImVec2(0.5f, 0.5f) for centering; ImVec2(1, 1) for bottom right.
 
@@ -2538,11 +2788,15 @@ struct IMGUI_API ImGuiWindow
     ImVec2ih                HitTestHoleOffset;
 
     int                     LastFrameActive;                    // Last frame number the window was Active.
+    int                     LastFrameJustFocused;               // Last frame number the window was made Focused.
     float                   LastTimeActive;                     // Last timestamp the window was Active (using float as we don't need high precision there)
     float                   ItemWidthDefault;
     ImGuiStorage            StateStorage;
     ImVector<ImGuiOldColumns> ColumnsStorage;
     float                   FontWindowScale;                    // User scale multiplier per-window, via SetWindowFontScale()
+    float                   FontWindowScaleParents;
+    float                   FontDpiScale;
+    float                   FontRefSize;                        // This is a copy of window->CalcFontSize() at the time of Begin(), trying to phase out CalcFontSize() especially as it may be called on non-current window.
     int                     SettingsOffset;                     // Offset into SettingsWindows[] (offsets are always valid as we only grow the array from the back)
 
     ImDrawList*             DrawList;                           // == &DrawListInst (for backward compatibility reason with code using imgui_internal.h we keep this a pointer)
@@ -2551,6 +2805,7 @@ struct IMGUI_API ImGuiWindow
     ImGuiWindow*            ParentWindowInBeginStack;
     ImGuiWindow*            RootWindow;                         // Point to ourself or first ancestor that is not a child window. Doesn't cross through popups/dock nodes.
     ImGuiWindow*            RootWindowPopupTree;                // Point to ourself or first ancestor that is not a child window. Cross through popups parent<>child.
+    ImGuiWindow*            RootWindowDockTree;                 // Point to ourself or first ancestor that is not a child window. Cross through dock nodes.
     ImGuiWindow*            RootWindowForTitleBarHighlight;     // Point to ourself or first ancestor which will display TitleBgActive color when this window is active.
     ImGuiWindow*            RootWindowForNav;                   // Point to ourself or first ancestor which doesn't have the NavFlattened flag.
     ImGuiWindow*            ParentWindowForFocusRoute;          // Set to manual link a window to its logical parent so that Shortcut() chain are honoerd (e.g. Tool linked to Document)
@@ -2565,6 +2820,17 @@ struct IMGUI_API ImGuiWindow
     int                     MemoryDrawListVtxCapacity;
     bool                    MemoryCompacted;                    // Set when window extraneous data have been garbage collected
 
+    // Docking
+    bool                    DockIsActive        :1;             // When docking artifacts are actually visible. When this is set, DockNode is guaranteed to be != NULL. ~~ (DockNode != NULL) && (DockNode->Windows.Size > 1).
+    bool                    DockNodeIsVisible   :1;
+    bool                    DockTabIsVisible    :1;             // Is our window visible this frame? ~~ is the corresponding tab selected?
+    bool                    DockTabWantClose    :1;
+    short                   DockOrder;                          // Order of the last time the window was visible within its DockNode. This is used to reorder windows that are reappearing on the same frame. Same value between windows that were active and windows that were none are possible.
+    ImGuiWindowDockStyle    DockStyle;
+    ImGuiDockNode*          DockNode;                           // Which node are we docked into. Important: Prefer testing DockIsActive in many cases as this will still be set when the dock node is hidden.
+    ImGuiDockNode*          DockNodeAsHost;                     // Which node are we owning (for parent windows)
+    ImGuiID                 DockId;                             // Backup of last valid DockNode->ID, so single window remember their dock node id even when they are not bound any more
+
 public:
     ImGuiWindow(ImGuiContext* context, const char* name);
     ~ImGuiWindow();
@@ -2577,7 +2843,7 @@ public:
 
     // We don't use g.FontSize because the window may be != g.CurrentWindow.
     ImRect      Rect() const            { return ImRect(Pos.x, Pos.y, Pos.x + Size.x, Pos.y + Size.y); }
-    float       CalcFontSize() const    { ImGuiContext& g = *Ctx; float scale = g.FontBaseSize * FontWindowScale; if (ParentWindow) scale *= ParentWindow->FontWindowScale; return scale; }
+    float       CalcFontSize() const    { ImGuiContext& g = *Ctx; return g.FontBaseSize * FontWindowScale * FontDpiScale * FontWindowScaleParents; }
     ImRect      TitleBarRect() const    { return ImRect(Pos, ImVec2(Pos.x + SizeFull.x, Pos.y + TitleBarHeight)); }
     ImRect      MenuBarRect() const     { float y1 = Pos.y + TitleBarHeight; return ImRect(Pos.x, y1, Pos.x + SizeFull.x, y1 + MenuBarHeight); }
 };
@@ -2600,13 +2866,16 @@ enum ImGuiTabItemFlagsPrivate_
     ImGuiTabItemFlags_SectionMask_              = ImGuiTabItemFlags_Leading | ImGuiTabItemFlags_Trailing,
     ImGuiTabItemFlags_NoCloseButton             = 1 << 20,  // Track whether p_open was set or not (we'll need this info on the next frame to recompute ContentWidth during layout)
     ImGuiTabItemFlags_Button                    = 1 << 21,  // Used by TabItemButton, change the tab item behavior to mimic a button
+    ImGuiTabItemFlags_Invisible                 = 1 << 22,  // To reserve space e.g. with ImGuiTabItemFlags_Leading
+    ImGuiTabItemFlags_Unsorted                  = 1 << 23,  // [Docking] Trailing tabs with the _Unsorted flag will be sorted based on the DockOrder of their Window.
 };
 
-// Storage for one active tab item (sizeof() 40 bytes)
+// Storage for one active tab item (sizeof() 48 bytes)
 struct ImGuiTabItem
 {
     ImGuiID             ID;
     ImGuiTabItemFlags   Flags;
+    ImGuiWindow*        Window;                 // When TabItem is part of a DockNode's TabBar, we hold on to a window.
     int                 LastFrameVisible;
     int                 LastFrameSelected;      // This allows us to infer an ordered list of the last activated tabs with little maintenance
     float               Offset;                 // Position relative to beginning of tab
@@ -2773,7 +3042,7 @@ struct IMGUI_API ImGuiTable
 {
     ImGuiID                     ID;
     ImGuiTableFlags             Flags;
-    void*                       RawData;                    // Single allocation to hold Columns[], DisplayOrderToIndex[] and RowCellData[]
+    void*                       RawData;                    // Single allocation to hold Columns[], DisplayOrderToIndex[], and RowCellData[]
     ImGuiTableTempData*         TempData;                   // Transient data while table is active. Point within g.CurrentTableStack[]
     ImSpan<ImGuiTableColumn>    Columns;                    // Point within RawData[]
     ImSpan<ImGuiTableColumnIdx> DisplayOrderToIndex;        // Point within RawData[]. Store display order of columns (when not reordered, the values are 0...Count-1)
@@ -2787,7 +3056,7 @@ struct IMGUI_API ImGuiTable
     int                         ColumnsCount;               // Number of columns declared in BeginTable()
     int                         CurrentRow;
     int                         CurrentColumn;
-    ImS16                       InstanceCurrent;            // Count of BeginTable() calls with same ID in the same frame (generally 0). This is a little bit similar to BeginCount for a window, but multiple table with same ID look are multiple tables, they are just synched.
+    ImS16                       InstanceCurrent;            // Count of BeginTable() calls with same ID in the same frame (generally 0). This is a little bit similar to BeginCount for a window, but multiple tables with the same ID are multiple tables, they are just synced.
     ImS16                       InstanceInteracted;         // Mark which instance (generally 0) of the same ID is being interacted with
     float                       RowPosY1;
     float                       RowPosY2;
@@ -2819,7 +3088,7 @@ struct IMGUI_API ImGuiTable
     float                       AngledHeadersHeight;        // Set by TableAngledHeadersRow(), used in TableUpdateLayout()
     float                       AngledHeadersSlope;         // Set by TableAngledHeadersRow(), used in TableUpdateLayout()
     ImRect                      OuterRect;                  // Note: for non-scrolling table, OuterRect.Max.y is often FLT_MAX until EndTable(), unless a height has been specified in BeginTable().
-    ImRect                      InnerRect;                  // InnerRect but without decoration. As with OuterRect, for non-scrolling tables, InnerRect.Max.y is
+    ImRect                      InnerRect;                  // InnerRect but without decoration. As with OuterRect, for non-scrolling tables, InnerRect.Max.y is "
     ImRect                      WorkRect;
     ImRect                      InnerClipRect;
     ImRect                      BgClipRect;                 // We use this to cpu-clip cell background color fill, evolve during the frame as we cross frozen rows boundaries
@@ -2863,6 +3132,7 @@ struct IMGUI_API ImGuiTable
     ImGuiTableDrawChannelIdx    DummyDrawChannel;           // Redirect non-visible columns here.
     ImGuiTableDrawChannelIdx    Bg2DrawChannelCurrent;      // For Selectable() and other widgets drawing across columns after the freezing line. Index within DrawSplitter.Channels[]
     ImGuiTableDrawChannelIdx    Bg2DrawChannelUnfrozen;
+    ImS8                        NavLayer;                   // ImGuiNavLayer at the time of BeginTable().
     bool                        IsLayoutLocked;             // Set by TableUpdateLayout() which is called when beginning the first row.
     bool                        IsInsideRow;                // Set when inside TableBeginRow()/TableEndRow().
     bool                        IsInitializing;
@@ -2915,7 +3185,7 @@ struct IMGUI_API ImGuiTableTempData
     ImGuiTableTempData()        { memset(this, 0, sizeof(*this)); LastTimeActive = -1.0f; }
 };
 
-// sizeof() ~ 12
+// sizeof() ~ 16
 struct ImGuiTableColumnSettings
 {
     float                   WidthOrWeight;
@@ -2924,7 +3194,7 @@ struct ImGuiTableColumnSettings
     ImGuiTableColumnIdx     DisplayOrder;
     ImGuiTableColumnIdx     SortOrder;
     ImU8                    SortDirection : 2;
-    ImU8                    IsEnabled : 1; // "Visible" in ini file
+    ImS8                    IsEnabled : 2; // "Visible" in ini file
     ImU8                    IsStretch : 1;
 
     ImGuiTableColumnSettings()
@@ -2934,7 +3204,7 @@ struct ImGuiTableColumnSettings
         Index = -1;
         DisplayOrder = SortOrder = -1;
         SortDirection = ImGuiSortDirection_None;
-        IsEnabled = 1;
+        IsEnabled = -1;
         IsStretch = 0;
     }
 };
@@ -2965,7 +3235,8 @@ namespace ImGui
     // If this ever crashes because g.CurrentWindow is NULL, it means that either:
     // - ImGui::NewFrame() has never been called, which is illegal.
     // - You are calling ImGui functions after ImGui::EndFrame()/ImGui::Render() and before the next ImGui::NewFrame(), which is also illegal.
-    IMGUI_API ImGuiIO&      GetIOEx(ImGuiContext* ctx);
+    IMGUI_API ImGuiIO&         GetIO(ImGuiContext* ctx);
+    IMGUI_API ImGuiPlatformIO& GetPlatformIO(ImGuiContext* ctx);
     inline    ImGuiWindow*  GetCurrentWindowRead()      { ImGuiContext& g = *GImGui; return g.CurrentWindow; }
     inline    ImGuiWindow*  GetCurrentWindow()          { ImGuiContext& g = *GImGui; g.CurrentWindow->WriteAccessed = true; return g.CurrentWindow; }
     IMGUI_API ImGuiWindow*  FindWindowByID(ImGuiID id);
@@ -2973,7 +3244,7 @@ namespace ImGui
     IMGUI_API void          UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags flags, ImGuiWindow* parent_window);
     IMGUI_API void          UpdateWindowSkipRefresh(ImGuiWindow* window);
     IMGUI_API ImVec2        CalcWindowNextAutoFitSize(ImGuiWindow* window);
-    IMGUI_API bool          IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent, bool popup_hierarchy);
+    IMGUI_API bool          IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent, bool popup_hierarchy, bool dock_hierarchy);
     IMGUI_API bool          IsWindowWithinBeginStackOf(ImGuiWindow* window, ImGuiWindow* potential_parent);
     IMGUI_API bool          IsWindowAbove(ImGuiWindow* potential_above, ImGuiWindow* potential_below);
     IMGUI_API bool          IsWindowNavFocusable(ImGuiWindow* window);
@@ -2982,7 +3253,7 @@ namespace ImGui
     IMGUI_API void          SetWindowCollapsed(ImGuiWindow* window, bool collapsed, ImGuiCond cond = 0);
     IMGUI_API void          SetWindowHitTestHole(ImGuiWindow* window, const ImVec2& pos, const ImVec2& size);
     IMGUI_API void          SetWindowHiddenAndSkipItemsForCurrentFrame(ImGuiWindow* window);
-    inline void             SetWindowParentWindowForFocusRoute(ImGuiWindow* window, ImGuiWindow* parent_window) { window->ParentWindowForFocusRoute = parent_window; }
+    inline void             SetWindowParentWindowForFocusRoute(ImGuiWindow* window, ImGuiWindow* parent_window) { window->ParentWindowForFocusRoute = parent_window; } // You may also use SetNextWindowClass()'s FocusRouteParentWindowId field.
     inline ImRect           WindowRectAbsToRel(ImGuiWindow* window, const ImRect& r) { ImVec2 off = window->DC.CursorStartPos; return ImRect(r.Min.x - off.x, r.Min.y - off.y, r.Max.x - off.x, r.Max.y - off.y); }
     inline ImRect           WindowRectRelToAbs(ImGuiWindow* window, const ImRect& r) { ImVec2 off = window->DC.CursorStartPos; return ImRect(r.Min.x + off.x, r.Min.y + off.y, r.Max.x + off.x, r.Max.y + off.y); }
     inline ImVec2           WindowPosAbsToRel(ImGuiWindow* window, const ImVec2& p)  { ImVec2 off = window->DC.CursorStartPos; return ImVec2(p.x - off.x, p.y - off.y); }
@@ -3004,9 +3275,8 @@ namespace ImGui
     // Fonts, drawing
     IMGUI_API void          SetCurrentFont(ImFont* font);
     inline ImFont*          GetDefaultFont() { ImGuiContext& g = *GImGui; return g.IO.FontDefault ? g.IO.FontDefault : g.IO.Fonts->Fonts[0]; }
-    inline ImDrawList*      GetForegroundDrawList(ImGuiWindow* window) { IM_UNUSED(window); return GetForegroundDrawList(); } // This seemingly unnecessary wrapper simplifies compatibility between the 'master' and 'docking' branches.
-    IMGUI_API ImDrawList*   GetBackgroundDrawList(ImGuiViewport* viewport);                     // get background draw list for the given viewport. this draw list will be the first rendering one. Useful to quickly draw shapes/text behind dear imgui contents.
-    IMGUI_API ImDrawList*   GetForegroundDrawList(ImGuiViewport* viewport);                     // get foreground draw list for the given viewport. this draw list will be the last rendered one. Useful to quickly draw shapes/text over dear imgui contents.
+    IMGUI_API void          PushPasswordFont();
+    inline ImDrawList*      GetForegroundDrawList(ImGuiWindow* window) { return GetForegroundDrawList(window->Viewport); }
     IMGUI_API void          AddDrawListToDrawDataEx(ImDrawData* draw_data, ImVector<ImDrawList*>* out_list, ImDrawList* draw_list);
 
     // Init
@@ -3018,6 +3288,7 @@ namespace ImGui
     IMGUI_API void          UpdateHoveredWindowAndCaptureFlags();
     IMGUI_API void          FindHoveredWindowEx(const ImVec2& pos, bool find_first_and_in_any_viewport, ImGuiWindow** out_hovered_window, ImGuiWindow** out_hovered_window_under_moving_window);
     IMGUI_API void          StartMouseMovingWindow(ImGuiWindow* window);
+    IMGUI_API void          StartMouseMovingWindowOrNode(ImGuiWindow* window, ImGuiDockNode* node, bool undock);
     IMGUI_API void          UpdateMouseMovingWindowNewFrame();
     IMGUI_API void          UpdateMouseMovingWindowEndFrame();
 
@@ -3027,8 +3298,13 @@ namespace ImGui
     IMGUI_API void          CallContextHooks(ImGuiContext* context, ImGuiContextHookType type);
 
     // Viewports
+    IMGUI_API void          TranslateWindowsInViewport(ImGuiViewportP* viewport, const ImVec2& old_pos, const ImVec2& new_pos, const ImVec2& old_size, const ImVec2& new_size);
     IMGUI_API void          ScaleWindowsInViewport(ImGuiViewportP* viewport, float scale);
+    IMGUI_API void          DestroyPlatformWindow(ImGuiViewportP* viewport);
     IMGUI_API void          SetWindowViewport(ImGuiWindow* window, ImGuiViewportP* viewport);
+    IMGUI_API void          SetCurrentViewport(ImGuiWindow* window, ImGuiViewportP* viewport);
+    IMGUI_API const ImGuiPlatformMonitor*   GetViewportPlatformMonitor(ImGuiViewport* viewport);
+    IMGUI_API ImGuiViewportP*               FindHoveredViewportFromPlatformWindowStack(const ImVec2& mouse_platform_pos);
 
     // Settings
     IMGUI_API void                  MarkIniSettingsDirty();
@@ -3085,14 +3361,14 @@ namespace ImGui
     IMGUI_API bool          ItemHoverable(const ImRect& bb, ImGuiID id, ImGuiItemFlags item_flags);
     IMGUI_API bool          IsWindowContentHoverable(ImGuiWindow* window, ImGuiHoveredFlags flags = 0);
     IMGUI_API bool          IsClippedEx(const ImRect& bb, ImGuiID id);
-    IMGUI_API void          SetLastItemData(ImGuiID item_id, ImGuiItemFlags in_flags, ImGuiItemStatusFlags status_flags, const ImRect& item_rect);
+    IMGUI_API void          SetLastItemData(ImGuiID item_id, ImGuiItemFlags item_flags, ImGuiItemStatusFlags status_flags, const ImRect& item_rect);
     IMGUI_API ImVec2        CalcItemSize(ImVec2 size, float default_w, float default_h);
     IMGUI_API float         CalcWrapWidthForPos(const ImVec2& pos, float wrap_pos_x);
     IMGUI_API void          PushMultiItemsWidths(int components, float width_full);
     IMGUI_API void          ShrinkWidths(ImGuiShrinkWidthItem* items, int count, float width_excess);
 
     // Parameter stacks (shared)
-    IMGUI_API const ImGuiDataVarInfo* GetStyleVarInfo(ImGuiStyleVar idx);
+    IMGUI_API const ImGuiStyleVarInfo* GetStyleVarInfo(ImGuiStyleVar idx);
     IMGUI_API void          BeginDisabledOverrideReenable();
     IMGUI_API void          EndDisabledOverrideReenable();
 
@@ -3107,6 +3383,7 @@ namespace ImGui
 
     // Popups, Modals
     IMGUI_API bool          BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_window_flags);
+    IMGUI_API bool          BeginPopupMenuEx(ImGuiID id, const char* label, ImGuiWindowFlags extra_window_flags);
     IMGUI_API void          OpenPopupEx(ImGuiID id, ImGuiPopupFlags popup_flags = ImGuiPopupFlags_None);
     IMGUI_API void          ClosePopupToLevel(int remaining, bool restore_focus_to_window_under_popup);
     IMGUI_API void          ClosePopupsOverWindow(ImGuiWindow* ref_window, bool restore_focus_to_window_under_popup);
@@ -3243,6 +3520,61 @@ namespace ImGui
     IMGUI_API bool          TestShortcutRouting(ImGuiKeyChord key_chord, ImGuiID owner_id);
     IMGUI_API ImGuiKeyRoutingData* GetShortcutRoutingData(ImGuiKeyChord key_chord);
 
+    // Docking
+    // (some functions are only declared in imgui.cpp, see Docking section)
+    IMGUI_API void          DockContextInitialize(ImGuiContext* ctx);
+    IMGUI_API void          DockContextShutdown(ImGuiContext* ctx);
+    IMGUI_API void          DockContextClearNodes(ImGuiContext* ctx, ImGuiID root_id, bool clear_settings_refs); // Use root_id==0 to clear all
+    IMGUI_API void          DockContextRebuildNodes(ImGuiContext* ctx);
+    IMGUI_API void          DockContextNewFrameUpdateUndocking(ImGuiContext* ctx);
+    IMGUI_API void          DockContextNewFrameUpdateDocking(ImGuiContext* ctx);
+    IMGUI_API void          DockContextEndFrame(ImGuiContext* ctx);
+    IMGUI_API ImGuiID       DockContextGenNodeID(ImGuiContext* ctx);
+    IMGUI_API void          DockContextQueueDock(ImGuiContext* ctx, ImGuiWindow* target, ImGuiDockNode* target_node, ImGuiWindow* payload, ImGuiDir split_dir, float split_ratio, bool split_outer);
+    IMGUI_API void          DockContextQueueUndockWindow(ImGuiContext* ctx, ImGuiWindow* window);
+    IMGUI_API void          DockContextQueueUndockNode(ImGuiContext* ctx, ImGuiDockNode* node);
+    IMGUI_API void          DockContextProcessUndockWindow(ImGuiContext* ctx, ImGuiWindow* window, bool clear_persistent_docking_ref = true);
+    IMGUI_API void          DockContextProcessUndockNode(ImGuiContext* ctx, ImGuiDockNode* node);
+    IMGUI_API bool          DockContextCalcDropPosForDocking(ImGuiWindow* target, ImGuiDockNode* target_node, ImGuiWindow* payload_window, ImGuiDockNode* payload_node, ImGuiDir split_dir, bool split_outer, ImVec2* out_pos);
+    IMGUI_API ImGuiDockNode*DockContextFindNodeByID(ImGuiContext* ctx, ImGuiID id);
+    IMGUI_API void          DockNodeWindowMenuHandler_Default(ImGuiContext* ctx, ImGuiDockNode* node, ImGuiTabBar* tab_bar);
+    IMGUI_API bool          DockNodeBeginAmendTabBar(ImGuiDockNode* node);
+    IMGUI_API void          DockNodeEndAmendTabBar();
+    inline ImGuiDockNode*   DockNodeGetRootNode(ImGuiDockNode* node)                 { while (node->ParentNode) node = node->ParentNode; return node; }
+    inline bool             DockNodeIsInHierarchyOf(ImGuiDockNode* node, ImGuiDockNode* parent) { while (node) { if (node == parent) return true; node = node->ParentNode; } return false; }
+    inline int              DockNodeGetDepth(const ImGuiDockNode* node)              { int depth = 0; while (node->ParentNode) { node = node->ParentNode; depth++; } return depth; }
+    inline ImGuiID          DockNodeGetWindowMenuButtonId(const ImGuiDockNode* node) { return ImHashStr("#COLLAPSE", 0, node->ID); }
+    inline ImGuiDockNode*   GetWindowDockNode()                                      { ImGuiContext& g = *GImGui; return g.CurrentWindow->DockNode; }
+    IMGUI_API bool          GetWindowAlwaysWantOwnTabBar(ImGuiWindow* window);
+    IMGUI_API void          BeginDocked(ImGuiWindow* window, bool* p_open);
+    IMGUI_API void          BeginDockableDragDropSource(ImGuiWindow* window);
+    IMGUI_API void          BeginDockableDragDropTarget(ImGuiWindow* window);
+    IMGUI_API void          SetWindowDock(ImGuiWindow* window, ImGuiID dock_id, ImGuiCond cond);
+
+    // Docking - Builder function needs to be generally called before the node is used/submitted.
+    // - The DockBuilderXXX functions are designed to _eventually_ become a public API, but it is too early to expose it and guarantee stability.
+    // - Do not hold on ImGuiDockNode* pointers! They may be invalidated by any split/merge/remove operation and every frame.
+    // - To create a DockSpace() node, make sure to set the ImGuiDockNodeFlags_DockSpace flag when calling DockBuilderAddNode().
+    //   You can create dockspace nodes (attached to a window) _or_ floating nodes (carry its own window) with this API.
+    // - DockBuilderSplitNode() create 2 child nodes within 1 node. The initial node becomes a parent node.
+    // - If you intend to split the node immediately after creation using DockBuilderSplitNode(), make sure
+    //   to call DockBuilderSetNodeSize() beforehand. If you don't, the resulting split sizes may not be reliable.
+    // - Call DockBuilderFinish() after you are done.
+    IMGUI_API void          DockBuilderDockWindow(const char* window_name, ImGuiID node_id);
+    IMGUI_API ImGuiDockNode*DockBuilderGetNode(ImGuiID node_id);
+    inline ImGuiDockNode*   DockBuilderGetCentralNode(ImGuiID node_id)              { ImGuiDockNode* node = DockBuilderGetNode(node_id); if (!node) return NULL; return DockNodeGetRootNode(node)->CentralNode; }
+    IMGUI_API ImGuiID       DockBuilderAddNode(ImGuiID node_id = 0, ImGuiDockNodeFlags flags = 0);
+    IMGUI_API void          DockBuilderRemoveNode(ImGuiID node_id);                 // Remove node and all its child, undock all windows
+    IMGUI_API void          DockBuilderRemoveNodeDockedWindows(ImGuiID node_id, bool clear_settings_refs = true);
+    IMGUI_API void          DockBuilderRemoveNodeChildNodes(ImGuiID node_id);       // Remove all split/hierarchy. All remaining docked windows will be re-docked to the remaining root node (node_id).
+    IMGUI_API void          DockBuilderSetNodePos(ImGuiID node_id, ImVec2 pos);
+    IMGUI_API void          DockBuilderSetNodeSize(ImGuiID node_id, ImVec2 size);
+    IMGUI_API ImGuiID       DockBuilderSplitNode(ImGuiID node_id, ImGuiDir split_dir, float size_ratio_for_node_at_dir, ImGuiID* out_id_at_dir, ImGuiID* out_id_at_opposite_dir); // Create 2 child nodes in this parent node.
+    IMGUI_API void          DockBuilderCopyDockSpace(ImGuiID src_dockspace_id, ImGuiID dst_dockspace_id, ImVector<const char*>* in_window_remap_pairs);
+    IMGUI_API void          DockBuilderCopyNode(ImGuiID src_node_id, ImGuiID dst_node_id, ImVector<ImGuiID>* out_node_remap_pairs);
+    IMGUI_API void          DockBuilderCopyWindowSettings(const char* src_name, const char* dst_name);
+    IMGUI_API void          DockBuilderFinish(ImGuiID node_id);
+
     // [EXPERIMENTAL] Focus Scope
     // This is generally used to identify a unique input location (for e.g. a selection set)
     // There is one per window (automatically set in Begin), but:
@@ -3355,9 +3687,11 @@ namespace ImGui
     IMGUI_API bool          BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& bb, ImGuiTabBarFlags flags);
     IMGUI_API ImGuiTabItem* TabBarFindTabByID(ImGuiTabBar* tab_bar, ImGuiID tab_id);
     IMGUI_API ImGuiTabItem* TabBarFindTabByOrder(ImGuiTabBar* tab_bar, int order);
+    IMGUI_API ImGuiTabItem* TabBarFindMostRecentlySelectedTabForActiveWindow(ImGuiTabBar* tab_bar);
     IMGUI_API ImGuiTabItem* TabBarGetCurrentTab(ImGuiTabBar* tab_bar);
     inline int              TabBarGetTabOrder(ImGuiTabBar* tab_bar, ImGuiTabItem* tab) { return tab_bar->Tabs.index_from_ptr(tab); }
     IMGUI_API const char*   TabBarGetTabName(ImGuiTabBar* tab_bar, ImGuiTabItem* tab);
+    IMGUI_API void          TabBarAddTab(ImGuiTabBar* tab_bar, ImGuiTabItemFlags tab_flags, ImGuiWindow* window);
     IMGUI_API void          TabBarRemoveTab(ImGuiTabBar* tab_bar, ImGuiID tab_id);
     IMGUI_API void          TabBarCloseTab(ImGuiTabBar* tab_bar, ImGuiTabItem* tab);
     IMGUI_API void          TabBarQueueFocus(ImGuiTabBar* tab_bar, ImGuiTabItem* tab);
@@ -3366,6 +3700,7 @@ namespace ImGui
     IMGUI_API void          TabBarQueueReorderFromMousePos(ImGuiTabBar* tab_bar, ImGuiTabItem* tab, ImVec2 mouse_pos);
     IMGUI_API bool          TabBarProcessReorder(ImGuiTabBar* tab_bar);
     IMGUI_API bool          TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags, ImGuiWindow* docked_window);
+    IMGUI_API void          TabItemSpacing(const char* str_id, ImGuiTabItemFlags flags, float width);
     IMGUI_API ImVec2        TabItemCalcSize(const char* label, bool has_close_button_or_unsaved_marker);
     IMGUI_API ImVec2        TabItemCalcSize(ImGuiWindow* window);
     IMGUI_API void          TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImU32 col);
@@ -3394,8 +3729,10 @@ namespace ImGui
     IMGUI_API void          RenderBullet(ImDrawList* draw_list, ImVec2 pos, ImU32 col);
     IMGUI_API void          RenderCheckMark(ImDrawList* draw_list, ImVec2 pos, ImU32 col, float sz);
     IMGUI_API void          RenderArrowPointingAt(ImDrawList* draw_list, ImVec2 pos, ImVec2 half_sz, ImGuiDir direction, ImU32 col);
+    IMGUI_API void          RenderArrowDockMenu(ImDrawList* draw_list, ImVec2 p_min, float sz, ImU32 col);
     IMGUI_API void          RenderRectFilledRangeH(ImDrawList* draw_list, const ImRect& rect, ImU32 col, float x_start_norm, float x_end_norm, float rounding);
     IMGUI_API void          RenderRectFilledWithHole(ImDrawList* draw_list, const ImRect& outer, const ImRect& inner, ImU32 col, float rounding);
+    IMGUI_API ImDrawFlags   CalcRoundingFlagsForRectInRect(const ImRect& r_in, const ImRect& r_outer, float threshold);
 
     // Widgets
     IMGUI_API void          TextEx(const char* text, const char* text_end = NULL, ImGuiTextFlags flags = 0);
@@ -3409,7 +3746,7 @@ namespace ImGui
 
     // Widgets: Window Decorations
     IMGUI_API bool          CloseButton(ImGuiID id, const ImVec2& pos);
-    IMGUI_API bool          CollapseButton(ImGuiID id, const ImVec2& pos);
+    IMGUI_API bool          CollapseButton(ImGuiID id, const ImVec2& pos, ImGuiDockNode* dock_node);
     IMGUI_API void          Scrollbar(ImGuiAxis axis);
     IMGUI_API bool          ScrollbarEx(const ImRect& bb, ImGuiID id, ImGuiAxis axis, ImS64* p_scroll_v, ImS64 avail_v, ImS64 contents_v, ImDrawFlags draw_rounding_flags = 0);
     IMGUI_API ImRect        GetWindowScrollbarRect(ImGuiWindow* window, ImGuiAxis axis);
@@ -3457,6 +3794,7 @@ namespace ImGui
     inline bool             TempInputIsActive(ImGuiID id)       { ImGuiContext& g = *GImGui; return (g.ActiveId == id && g.TempInputId == id); }
     inline ImGuiInputTextState* GetInputTextState(ImGuiID id)   { ImGuiContext& g = *GImGui; return (id != 0 && g.InputTextState.ID == id) ? &g.InputTextState : NULL; } // Get input text state if active
     IMGUI_API void          SetNextItemRefVal(ImGuiDataType data_type, void* p_data);
+    inline bool             IsItemActiveAsInputText() { ImGuiContext& g = *GImGui; return g.ActiveId != 0 && g.ActiveId == g.LastItemData.ID && g.InputTextState.ID == g.LastItemData.ID; } // This may be useful to apply workaround that a based on distinguish whenever an item is active as a text input field.
 
     // Color
     IMGUI_API void          ColorTooltip(const char* text, const float* col, ImGuiColorEditFlags flags);
@@ -3501,6 +3839,7 @@ namespace ImGui
     IMGUI_API void          ShowFontAtlas(ImFontAtlas* atlas);
     IMGUI_API void          DebugHookIdInfo(ImGuiID id, ImGuiDataType data_type, const void* data_id, const void* data_id_end);
     IMGUI_API void          DebugNodeColumns(ImGuiOldColumns* columns);
+    IMGUI_API void          DebugNodeDockNode(ImGuiDockNode* node, const char* label);
     IMGUI_API void          DebugNodeDrawList(ImGuiWindow* window, ImGuiViewportP* viewport, const ImDrawList* draw_list, const char* label);
     IMGUI_API void          DebugNodeDrawCmdShowMeshAndBoundingBox(ImDrawList* out_draw_list, const ImDrawList* draw_list, const ImDrawCmd* draw_cmd, bool show_mesh, bool show_aabb);
     IMGUI_API void          DebugNodeFont(ImFont* font);
@@ -3517,6 +3856,7 @@ namespace ImGui
     IMGUI_API void          DebugNodeWindowsList(ImVector<ImGuiWindow*>* windows, const char* label);
     IMGUI_API void          DebugNodeWindowsListByBeginStackParent(ImGuiWindow** windows, int windows_size, ImGuiWindow* parent_in_begin_stack);
     IMGUI_API void          DebugNodeViewport(ImGuiViewportP* viewport);
+    IMGUI_API void          DebugNodePlatformMonitor(ImGuiPlatformMonitor* monitor, const char* label, int idx);
     IMGUI_API void          DebugRenderKeyboardPreview(ImDrawList* draw_list);
     IMGUI_API void          DebugRenderViewportThumbnail(ImDrawList* draw_list, ImGuiViewportP* viewport, const ImRect& bb);
 
@@ -3552,15 +3892,18 @@ struct ImFontBuilderIO
 #ifdef IMGUI_ENABLE_STB_TRUETYPE
 IMGUI_API const ImFontBuilderIO* ImFontAtlasGetBuilderForStbTruetype();
 #endif
-IMGUI_API void      ImFontAtlasUpdateConfigDataPointers(ImFontAtlas* atlas);
+IMGUI_API void      ImFontAtlasUpdateSourcesPointers(ImFontAtlas* atlas);
 IMGUI_API void      ImFontAtlasBuildInit(ImFontAtlas* atlas);
-IMGUI_API void      ImFontAtlasBuildSetupFont(ImFontAtlas* atlas, ImFont* font, ImFontConfig* font_config, float ascent, float descent);
+IMGUI_API void      ImFontAtlasBuildSetupFont(ImFontAtlas* atlas, ImFont* font, ImFontConfig* src, float ascent, float descent);
 IMGUI_API void      ImFontAtlasBuildPackCustomRects(ImFontAtlas* atlas, void* stbrp_context_opaque);
 IMGUI_API void      ImFontAtlasBuildFinish(ImFontAtlas* atlas);
 IMGUI_API void      ImFontAtlasBuildRender8bppRectFromString(ImFontAtlas* atlas, int x, int y, int w, int h, const char* in_str, char in_marker_char, unsigned char in_marker_pixel_value);
 IMGUI_API void      ImFontAtlasBuildRender32bppRectFromString(ImFontAtlas* atlas, int x, int y, int w, int h, const char* in_str, char in_marker_char, unsigned int in_marker_pixel_value);
 IMGUI_API void      ImFontAtlasBuildMultiplyCalcLookupTable(unsigned char out_table[256], float in_multiply_factor);
 IMGUI_API void      ImFontAtlasBuildMultiplyRectAlpha8(const unsigned char table[256], unsigned char* pixels, int x, int y, int w, int h, int stride);
+IMGUI_API void      ImFontAtlasBuildGetOversampleFactors(const ImFontConfig* src, int* out_oversample_h, int* out_oversample_v);
+
+IMGUI_API bool      ImFontAtlasGetMouseCursorTexData(ImFontAtlas* atlas, ImGuiMouseCursor cursor_type, ImVec2* out_offset, ImVec2* out_size, ImVec2 out_uv_border[2], ImVec2 out_uv_fill[2]);
 
 //-----------------------------------------------------------------------------
 // [SECTION] Test Engine specific hooks (imgui_test_engine)

imgui_tables.cpp

@@ -1,4 +1,4 @@
-// dear imgui, v1.91.7
+// dear imgui, v1.91.9
 // (tables and columns code)
 
 /*
@@ -221,6 +221,7 @@ Index of this file:
 #pragma clang diagnostic ignored "-Wunknown-pragmas"                // warning: unknown warning group 'xxx'
 #pragma clang diagnostic ignored "-Wold-style-cast"                 // warning: use of old-style cast                            // yes, they are more terse.
 #pragma clang diagnostic ignored "-Wfloat-equal"                    // warning: comparing floating point with == or != is unsafe // storing and comparing against same constants (typically 0.0f) is ok.
+#pragma clang diagnostic ignored "-Wformat"                         // warning: format specifies type 'int' but the argument has type 'unsigned int'
 #pragma clang diagnostic ignored "-Wformat-nonliteral"              // warning: format string is not a string literal            // passing non-literal to vsnformat(). yes, user passing incorrect format strings can crash the code.
 #pragma clang diagnostic ignored "-Wsign-conversion"                // warning: implicit conversion changes signedness
 #pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"  // warning: zero as null pointer constant                    // some standard header variations use #define NULL 0
@@ -230,6 +231,7 @@ Index of this file:
 #pragma clang diagnostic ignored "-Wimplicit-int-float-conversion"  // warning: implicit conversion from 'xxx' to 'float' may lose precision
 #pragma clang diagnostic ignored "-Wunsafe-buffer-usage"            // warning: 'xxx' is an unsafe pointer used for buffer access
 #pragma clang diagnostic ignored "-Wnontrivial-memaccess"           // warning: first argument in call to 'memset' is a pointer to non-trivially copyable type
+#pragma clang diagnostic ignored "-Wswitch-default"                 // warning: 'switch' missing 'default' label
 #elif defined(__GNUC__)
 #pragma GCC diagnostic ignored "-Wpragmas"                          // warning: unknown option after '#pragma GCC diagnostic' kind
 #pragma GCC diagnostic ignored "-Wfloat-equal"                      // warning: comparing floating-point with '==' or '!=' is unsafe
@@ -340,6 +342,7 @@ bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImG
     {
         ItemSize(outer_rect);
         ItemAdd(outer_rect, id);
+        g.NextWindowData.ClearFlags();
         return false;
     }
 
@@ -374,6 +377,7 @@ bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImG
     table->ColumnsCount = columns_count;
     table->IsLayoutLocked = false;
     table->InnerWidth = inner_width;
+    table->NavLayer = (ImS8)outer_window->DC.NavLayerCurrent;
     temp_data->UserOuterSize = outer_size;
 
     // Instance data (for instance 0, TableID == TableInstanceID)
@@ -414,12 +418,15 @@ bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImG
 
         // Reset scroll if we are reactivating it
         if ((previous_flags & (ImGuiTableFlags_ScrollX | ImGuiTableFlags_ScrollY)) == 0)
-            if ((g.NextWindowData.Flags & ImGuiNextWindowDataFlags_HasScroll) == 0)
+            if ((g.NextWindowData.HasFlags & ImGuiNextWindowDataFlags_HasScroll) == 0)
                 SetNextWindowScroll(ImVec2(0.0f, 0.0f));
 
         // Create scrolling region (without border and zero window padding)
-        ImGuiWindowFlags child_window_flags = (flags & ImGuiTableFlags_ScrollX) ? ImGuiWindowFlags_HorizontalScrollbar : ImGuiWindowFlags_None;
-        BeginChildEx(name, instance_id, outer_rect.GetSize(), ImGuiChildFlags_None, child_window_flags);
+        ImGuiChildFlags child_child_flags = (g.NextWindowData.HasFlags & ImGuiNextWindowDataFlags_HasChildFlags) ? g.NextWindowData.ChildFlags : ImGuiChildFlags_None;
+        ImGuiWindowFlags child_window_flags = (g.NextWindowData.HasFlags & ImGuiNextWindowDataFlags_HasWindowFlags) ? g.NextWindowData.WindowFlags : ImGuiWindowFlags_None;
+        if (flags & ImGuiTableFlags_ScrollX)
+            child_window_flags |= ImGuiWindowFlags_HorizontalScrollbar;
+        BeginChildEx(name, instance_id, outer_rect.GetSize(), child_child_flags, child_window_flags);
         table->InnerWindow = g.CurrentWindow;
         table->WorkRect = table->InnerWindow->WorkRect;
         table->OuterRect = table->InnerWindow->Rect();
@@ -572,6 +579,7 @@ bool    ImGui::BeginTableEx(const char* name, ImGuiID id, int columns_count, ImG
         // Initialize
         table->SettingsOffset = -1;
         table->IsSortSpecsDirty = true;
+        table->IsSettingsDirty = true; // Records itself into .ini file even when in default state (#7934)
         table->InstanceInteracted = -1;
         table->ContextPopupColumn = -1;
         table->ReorderColumn = table->ResizedColumn = table->LastResizedColumn = -1;
@@ -971,7 +979,7 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
     // [Part 4] Apply final widths based on requested widths
     const ImRect work_rect = table->WorkRect;
     const float width_spacings = (table->OuterPaddingX * 2.0f) + (table->CellSpacingX1 + table->CellSpacingX2) * (table->ColumnsEnabledCount - 1);
-    const float width_removed = (table->HasScrollbarYPrev && !table->InnerWindow->ScrollbarY) ? g.Style.ScrollbarSize : 0.0f; // To synchronize decoration width of synched tables with mismatching scrollbar state (#5920)
+    const float width_removed = (table->HasScrollbarYPrev && !table->InnerWindow->ScrollbarY) ? g.Style.ScrollbarSize : 0.0f; // To synchronize decoration width of synced tables with mismatching scrollbar state (#5920)
     const float width_avail = ImMax(1.0f, (((table->Flags & ImGuiTableFlags_ScrollX) && table->InnerWidth == 0.0f) ? table->InnerClipRect.GetWidth() : work_rect.GetWidth()) - width_removed);
     const float width_avail_for_stretched_columns = width_avail - width_spacings - sum_width_requests;
     float width_remaining_for_stretched_columns = width_avail_for_stretched_columns;
@@ -1050,7 +1058,8 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
         const int column_n = table->DisplayOrderToIndex[order_n];
         ImGuiTableColumn* column = &table->Columns[column_n];
 
-        column->NavLayerCurrent = (ImS8)(table->FreezeRowsCount > 0 ? ImGuiNavLayer_Menu : ImGuiNavLayer_Main); // Use Count NOT request so Header line changes layer when frozen
+        // Initial nav layer: using FreezeRowsCount, NOT FreezeRowsRequest, so Header line changes layer when frozen
+        column->NavLayerCurrent = (ImS8)(table->FreezeRowsCount > 0 ? ImGuiNavLayer_Menu : (ImGuiNavLayer)table->NavLayer);
 
         if (offset_x_frozen && table->FreezeColumnsCount == visible_n)
         {
@@ -1383,7 +1392,7 @@ void    ImGui::EndTable()
 
     // Setup inner scrolling range
     // FIXME: This ideally should be done earlier, in BeginTable() SetNextWindowContentSize call, just like writing to inner_window->DC.CursorMaxPos.y,
-    // but since the later is likely to be impossible to do we'd rather update both axises together.
+    // but since the later is likely to be impossible to do we'd rather update both axes together.
     if (table->Flags & ImGuiTableFlags_ScrollX)
     {
         const float outer_padding_for_border = (table->Flags & ImGuiTableFlags_BordersOuterV) ? TABLE_BORDER_SIZE : 0.0f;
@@ -1493,7 +1502,7 @@ void    ImGui::EndTable()
     if (inner_window != outer_window)
     {
         short backup_nav_layers_active_mask = inner_window->DC.NavLayersActiveMask;
-        inner_window->DC.NavLayersActiveMask |= 1 << ImGuiNavLayer_Main; // So empty table don't appear to navigate differently.
+        inner_window->DC.NavLayersActiveMask |= 1 << table->NavLayer; // So empty table don't appear to navigate differently.
         g.CurrentTable = NULL; // To avoid error recovery recursing
         EndChild();
         g.CurrentTable = table;
@@ -1558,6 +1567,31 @@ void    ImGui::EndTable()
     NavUpdateCurrentWindowIsScrollPushableX();
 }
 
+// Called in TableSetupColumn() when initializing and in TableLoadSettings() for defaults before applying stored settings.
+// 'init_mask' specify which fields to initialize.
+static void TableInitColumnDefaults(ImGuiTable* table, ImGuiTableColumn* column, ImGuiTableColumnFlags init_mask)
+{
+    ImGuiTableColumnFlags flags = column->Flags;
+    if (init_mask & ImGuiTableFlags_Resizable)
+    {
+        float init_width_or_weight = column->InitStretchWeightOrWidth;
+        column->WidthRequest = ((flags & ImGuiTableColumnFlags_WidthFixed) && init_width_or_weight > 0.0f) ? init_width_or_weight : -1.0f;
+        column->StretchWeight = (init_width_or_weight > 0.0f && (flags & ImGuiTableColumnFlags_WidthStretch)) ? init_width_or_weight : -1.0f;
+        if (init_width_or_weight > 0.0f) // Disable auto-fit if an explicit width/weight has been specified
+            column->AutoFitQueue = 0x00;
+    }
+    if (init_mask & ImGuiTableFlags_Reorderable)
+        column->DisplayOrder = (ImGuiTableColumnIdx)table->Columns.index_from_ptr(column);
+    if (init_mask & ImGuiTableFlags_Hideable)
+        column->IsUserEnabled = column->IsUserEnabledNextFrame = (flags & ImGuiTableColumnFlags_DefaultHide) ? 0 : 1;
+    if (init_mask & ImGuiTableFlags_Sortable)
+    {
+        // Multiple columns using _DefaultSort will be reassigned unique SortOrder values when building the sort specs.
+        column->SortOrder = (flags & ImGuiTableColumnFlags_DefaultSort) ? 0 : -1;
+        column->SortDirection = (flags & ImGuiTableColumnFlags_DefaultSort) ? ((flags & ImGuiTableColumnFlags_PreferSortDescending) ? (ImS8)ImGuiSortDirection_Descending : (ImU8)(ImGuiSortDirection_Ascending)) : (ImS8)ImGuiSortDirection_None;
+    }
+}
+
 // See "COLUMNS 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)
@@ -1586,7 +1620,7 @@ void ImGui::TableSetupColumn(const char* label, ImGuiTableColumnFlags flags, flo
         IM_ASSERT(init_width_or_weight <= 0.0f && "Can only specify width/weight if sizing policy is set explicitly in either Table or Column.");
 
     // When passing a width automatically enforce WidthFixed policy
-    // (whereas TableSetupColumnFlags would default to WidthAuto if table is not Resizable)
+    // (whereas TableSetupColumnFlags would default to WidthAuto if table is not resizable)
     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;
@@ -1604,27 +1638,10 @@ void ImGui::TableSetupColumn(const char* label, ImGuiTableColumnFlags flags, flo
     column->InitStretchWeightOrWidth = init_width_or_weight;
     if (table->IsInitializing)
     {
-        // Init width or weight
-        if (column->WidthRequest < 0.0f && column->StretchWeight < 0.0f)
-        {
-            if ((flags & ImGuiTableColumnFlags_WidthFixed) && init_width_or_weight > 0.0f)
-                column->WidthRequest = init_width_or_weight;
-            if (flags & ImGuiTableColumnFlags_WidthStretch)
-                column->StretchWeight = (init_width_or_weight > 0.0f) ? init_width_or_weight : -1.0f;
-
-            // Disable auto-fit if an explicit width/weight has been specified
-            if (init_width_or_weight > 0.0f)
-                column->AutoFitQueue = 0x00;
-        }
-
-        // Init default visibility/sort state
-        if ((flags & ImGuiTableColumnFlags_DefaultHide) && (table->SettingsLoadedFlags & ImGuiTableFlags_Hideable) == 0)
-            column->IsUserEnabled = column->IsUserEnabledNextFrame = false;
-        if (flags & ImGuiTableColumnFlags_DefaultSort && (table->SettingsLoadedFlags & ImGuiTableFlags_Sortable) == 0)
-        {
-            column->SortOrder = 0; // Multiple columns using _DefaultSort will be reassigned unique SortOrder values when building the sort specs.
-            column->SortDirection = (column->Flags & ImGuiTableColumnFlags_PreferSortDescending) ? (ImS8)ImGuiSortDirection_Descending : (ImU8)(ImGuiSortDirection_Ascending);
-        }
+        ImGuiTableFlags init_flags = ~0;
+        if (column->WidthRequest >= 0.0f || column->StretchWeight >= 0.0f)
+            init_flags &= ~ImGuiTableFlags_Resizable;
+        TableInitColumnDefaults(table, column, init_flags);
     }
 
     // Store name (append with zero-terminator in contiguous buffer)
@@ -1633,7 +1650,7 @@ void ImGui::TableSetupColumn(const char* label, ImGuiTableColumnFlags flags, flo
     if (label != NULL && label[0] != 0)
     {
         column->NameOffset = (ImS16)table->ColumnsNames.size();
-        table->ColumnsNames.append(label, label + strlen(label) + 1);
+        table->ColumnsNames.append(label, label + ImStrlen(label) + 1);
     }
 }
 
@@ -2032,7 +2049,7 @@ void ImGui::TableEndRow(ImGuiTable* table)
     if (unfreeze_rows_request)
     {
         for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
-            table->Columns[column_n].NavLayerCurrent = ImGuiNavLayer_Main;
+            table->Columns[column_n].NavLayerCurrent = table->NavLayer;
         const float y0 = ImMax(table->RowPosY2 + 1, table->InnerClipRect.Min.y);
         table_instance->LastFrozenHeight = y0 - table->OuterRect.Min.y;
 
@@ -2099,7 +2116,11 @@ bool ImGui::TableSetColumnIndex(int column_n)
     {
         if (table->CurrentColumn != -1)
             TableEndCell(table);
-        IM_ASSERT(column_n >= 0 && table->ColumnsCount);
+        if ((column_n >= 0 && column_n < table->ColumnsCount) == false)
+        {
+            IM_ASSERT_USER_ERROR(column_n >= 0 && column_n < table->ColumnsCount, "TableSetColumnIndex() invalid column index!");
+            return false;
+        }
         TableBeginCell(table, column_n);
     }
 
@@ -3712,6 +3733,14 @@ void ImGui::TableLoadSettings(ImGuiTable* table)
     table->SettingsLoadedFlags = settings->SaveFlags;
     table->RefScale = settings->RefScale;
 
+    // Initialize default columns settings
+    for (int column_n = 0; column_n < table->ColumnsCount; column_n++)
+    {
+        ImGuiTableColumn* column = &table->Columns[column_n];
+        TableInitColumnDefaults(table, column, ~0);
+        column->AutoFitQueue = 0x00;
+    }
+
     // Serialize ImGuiTableSettings/ImGuiTableColumnSettings into ImGuiTable/ImGuiTableColumn
     ImGuiTableColumnSettings* column_settings = settings->GetColumnSettings();
     ImU64 display_order_mask = 0;
@@ -3728,14 +3757,12 @@ void ImGui::TableLoadSettings(ImGuiTable* table)
                 column->StretchWeight = column_settings->WidthOrWeight;
             else
                 column->WidthRequest = column_settings->WidthOrWeight;
-            column->AutoFitQueue = 0x00;
         }
         if (settings->SaveFlags & ImGuiTableFlags_Reorderable)
             column->DisplayOrder = column_settings->DisplayOrder;
-        else
-            column->DisplayOrder = (ImGuiTableColumnIdx)column_n;
         display_order_mask |= (ImU64)1 << column->DisplayOrder;
-        column->IsUserEnabled = column->IsUserEnabledNextFrame = column_settings->IsEnabled;
+        if ((settings->SaveFlags & ImGuiTableFlags_Hideable) && column_settings->IsEnabled != -1)
+            column->IsUserEnabled = column->IsUserEnabledNextFrame = column_settings->IsEnabled == 1;
         column->SortOrder = column_settings->SortOrder;
         column->SortDirection = column_settings->SortDirection;
     }
@@ -3831,8 +3858,7 @@ static void TableSettingsHandler_WriteAll(ImGuiContext* ctx, ImGuiSettingsHandle
         const bool save_visible = (settings->SaveFlags & ImGuiTableFlags_Hideable) != 0;
         const bool save_order   = (settings->SaveFlags & ImGuiTableFlags_Reorderable) != 0;
         const bool save_sort    = (settings->SaveFlags & ImGuiTableFlags_Sortable) != 0;
-        if (!save_size && !save_visible && !save_order && !save_sort)
-            continue;
+        // We need to save the [Table] entry even if all the bools are false, since this records a table with "default settings".
 
         buf->reserve(buf->size() + 30 + settings->ColumnsCount * 50); // ballpark reserve
         buf->appendf("[%s][0x%08X,%d]\n", handler->TypeName, settings->ID, settings->ColumnsCount);

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/README.md

@@ -38,7 +38,7 @@ You can use the `ImGuiFreeTypeBuilderFlags_LoadColor` flag to load certain color
 
 ### Using OpenType SVG fonts (SVGinOT)
 - *SVG in Open Type* is a standard by Adobe and Mozilla for color OpenType and Open Font Format fonts. It allows font creators to embed complete SVG files within a font enabling full color and even animations.
-- Popular fonts such as [twemoji](https://github.com/13rac1/twemoji-color-font) and fonts made with [scfbuild](https://github.com/13rac1/scfbuild) is SVGinOT 
+- Popular fonts such as [twemoji](https://github.com/13rac1/twemoji-color-font) and fonts made with [scfbuild](https://github.com/13rac1/scfbuild) is SVGinOT.
 - Two alternatives are possible to render SVG fonts: use "lunasvg" or "plutosvg". plutosvg will support some more fonts (e.g. NotoColorEmoji-Regular) and may load them faster.
 
 #### Using lunasvg
@@ -48,15 +48,7 @@ Requires: [lunasvg](https://github.com/sammycage/lunasvg) v2.3.2 and above
 
 #### Using plutosvg (and plutovg)
 - Add `#define IMGUI_ENABLE_FREETYPE_PLUTOSVG` in your `imconfig.h`.
-- Compile and link with plutosvg *and* plutovg (which is required by plutosvg)
-
-_Compilation hints for plutovg_
-- Compile all source files in `plutovg/source/*.c`
-- Add include directory: `plutovg/include` + `plutovg/stb`
-
-_Compilation hints for plutosvg_
-- Compile `plutosvg/source/plutosvg.c`
-- Add include directory: `plutosvg/source`
-- Add define: `PLUTOSVG_HAS_FREETYPE`
-- Link with: plutovg, freetype
-
+- Get latest plutosvg binaries or build yourself. Under Windows you may use vcpkg with: `vcpkg install plutosvg --triplet=x64-windows`. Alternatively, if you build imgui from vcpkg, you just need to enable the plutosvg feature: `vcpkg install imgui[plutosvg] --triplet=x64-windows`
+- If you prefer to build plutosvg manually:
+    - Compilation hints for plutovg: Compile all source files in `plutovg/source/*.c` + Add include directory: `plutovg/include` + `plutovg/stb`
+    - Compilation hints for plutosvg: Compile `plutosvg/source/plutosvg.c` + Add include directory: `plutosvg/source` + Add define: `PLUTOSVG_HAS_FREETYPE` + Link with: plutovg, freetype

misc/freetype/imgui_freetype.cpp

@@ -33,7 +33,7 @@
 // - For correct results you need to be using sRGB and convert to linear space in the pixel shader output.
 // - The default dear imgui styles will be impacted by this change (alpha values will need tweaking).
 
-// FIXME: cfg.OversampleH, OversampleV are not supported (but perhaps not so necessary with this rasterizer).
+// FIXME: cfg.OversampleH, OversampleV are not supported, but generally not necessary with this rasterizer because Hinting makes everything look better.
 
 #include "imgui.h"
 #ifndef IMGUI_DISABLE
@@ -104,6 +104,9 @@ static FT_Error ImGuiLunasvgPortPresetSlot(FT_GlyphSlot slot, FT_Bool cache, FT_
 // Code
 //-------------------------------------------------------------------------
 
+#define FT_CEIL(X)      (((X + 63) & -64) / 64) // From SDL_ttf: Handy routines for converting from fixed point
+#define FT_SCALEFACTOR  64.0f
+
 namespace
 {
     // Glyph metrics:
@@ -163,7 +166,7 @@ namespace
     // NB: No ctor/dtor, explicitly call Init()/Shutdown()
     struct FreeTypeFont
     {
-        bool                    InitFont(FT_Library ft_library, const ImFontConfig& cfg, unsigned int extra_user_flags); // Initialize from an external data buffer. Doesn't copy data, and you must ensure it stays valid up to this object lifetime.
+        bool                    InitFont(FT_Library ft_library, const ImFontConfig& src, unsigned int extra_user_flags); // Initialize from an external data buffer. Doesn't copy data, and you must ensure it stays valid up to this object lifetime.
         void                    CloseFont();
         void                    SetPixelHeight(int pixel_height); // Change font pixel size. All following calls to RasterizeGlyph() will use this size
         const FT_Glyph_Metrics* LoadGlyph(uint32_t in_codepoint);
@@ -182,12 +185,9 @@ namespace
         float           InvRasterizationDensity;
     };
 
-    // From SDL_ttf: Handy routines for converting from fixed point
-    #define FT_CEIL(X)  (((X + 63) & -64) / 64)
-
-    bool FreeTypeFont::InitFont(FT_Library ft_library, const ImFontConfig& cfg, unsigned int extra_font_builder_flags)
+    bool FreeTypeFont::InitFont(FT_Library ft_library, const ImFontConfig& src, unsigned int extra_font_builder_flags)
     {
-        FT_Error error = FT_New_Memory_Face(ft_library, (uint8_t*)cfg.FontData, (uint32_t)cfg.FontDataSize, (uint32_t)cfg.FontNo, &Face);
+        FT_Error error = FT_New_Memory_Face(ft_library, (uint8_t*)src.FontData, (uint32_t)src.FontDataSize, (uint32_t)src.FontNo, &Face);
         if (error != 0)
             return false;
         error = FT_Select_Charmap(Face, FT_ENCODING_UNICODE);
@@ -195,7 +195,7 @@ namespace
             return false;
 
         // Convert to FreeType flags (NB: Bold and Oblique are processed separately)
-        UserFlags = cfg.FontBuilderFlags | extra_font_builder_flags;
+        UserFlags = src.FontBuilderFlags | extra_font_builder_flags;
 
         LoadFlags = 0;
         if ((UserFlags & ImGuiFreeTypeBuilderFlags_Bitmap) == 0)
@@ -222,11 +222,11 @@ namespace
         if (UserFlags & ImGuiFreeTypeBuilderFlags_LoadColor)
             LoadFlags |= FT_LOAD_COLOR;
 
-        RasterizationDensity = cfg.RasterizerDensity;
+        RasterizationDensity = src.RasterizerDensity;
         InvRasterizationDensity = 1.0f / RasterizationDensity;
 
         memset(&Info, 0, sizeof(Info));
-        SetPixelHeight((uint32_t)cfg.SizePixels);
+        SetPixelHeight((uint32_t)src.SizePixels);
 
         return true;
     }
@@ -269,11 +269,11 @@ namespace
         if (glyph_index == 0)
             return nullptr;
 
-		// If this crash for you: FreeType 2.11.0 has a crash bug on some bitmap/colored fonts.
-		// - https://gitlab.freedesktop.org/freetype/freetype/-/issues/1076
-		// - https://github.com/ocornut/imgui/issues/4567
-		// - https://github.com/ocornut/imgui/issues/4566
-		// You can use FreeType 2.10, or the patched version of 2.11.0 in VcPkg, or probably any upcoming FreeType version.
+        // If this crash for you: FreeType 2.11.0 has a crash bug on some bitmap/colored fonts.
+        // - https://gitlab.freedesktop.org/freetype/freetype/-/issues/1076
+        // - https://github.com/ocornut/imgui/issues/4567
+        // - https://github.com/ocornut/imgui/issues/4566
+        // You can use FreeType 2.10, or the patched version of 2.11.0 in VcPkg, or probably any upcoming FreeType version.
         FT_Error error = FT_Load_Glyph(Face, glyph_index, LoadFlags);
         if (error)
             return nullptr;
@@ -316,7 +316,7 @@ namespace
         out_glyph_info->Height = (int)ft_bitmap->rows;
         out_glyph_info->OffsetX = Face->glyph->bitmap_left;
         out_glyph_info->OffsetY = -Face->glyph->bitmap_top;
-        out_glyph_info->AdvanceX = (float)FT_CEIL(slot->advance.x);
+        out_glyph_info->AdvanceX = (float)slot->advance.x / FT_SCALEFACTOR;
         out_glyph_info->IsColored = (ft_bitmap->pixel_mode == FT_PIXEL_MODE_BGRA);
 
         return ft_bitmap;
@@ -443,7 +443,7 @@ struct ImFontBuildDstDataFT
 
 bool ImFontAtlasBuildWithFreeTypeEx(FT_Library ft_library, ImFontAtlas* atlas, unsigned int extra_flags)
 {
-    IM_ASSERT(atlas->ConfigData.Size > 0);
+    IM_ASSERT(atlas->Sources.Size > 0);
 
     ImFontAtlasBuildInit(atlas);
 
@@ -458,36 +458,36 @@ bool ImFontAtlasBuildWithFreeTypeEx(FT_Library ft_library, ImFontAtlas* atlas, u
     bool src_load_color = false;
     ImVector<ImFontBuildSrcDataFT> src_tmp_array;
     ImVector<ImFontBuildDstDataFT> dst_tmp_array;
-    src_tmp_array.resize(atlas->ConfigData.Size);
+    src_tmp_array.resize(atlas->Sources.Size);
     dst_tmp_array.resize(atlas->Fonts.Size);
     memset((void*)src_tmp_array.Data, 0, (size_t)src_tmp_array.size_in_bytes());
     memset((void*)dst_tmp_array.Data, 0, (size_t)dst_tmp_array.size_in_bytes());
 
     // 1. Initialize font loading structure, check font data validity
-    for (int src_i = 0; src_i < atlas->ConfigData.Size; src_i++)
+    for (int src_i = 0; src_i < atlas->Sources.Size; src_i++)
     {
         ImFontBuildSrcDataFT& src_tmp = src_tmp_array[src_i];
-        ImFontConfig& cfg = atlas->ConfigData[src_i];
+        ImFontConfig& src = atlas->Sources[src_i];
         FreeTypeFont& font_face = src_tmp.Font;
-        IM_ASSERT(cfg.DstFont && (!cfg.DstFont->IsLoaded() || cfg.DstFont->ContainerAtlas == atlas));
+        IM_ASSERT(src.DstFont && (!src.DstFont->IsLoaded() || src.DstFont->ContainerAtlas == atlas));
 
-        // Find index from cfg.DstFont (we allow the user to set cfg.DstFont. Also it makes casual debugging nicer than when storing indices)
+        // Find index from src.DstFont (we allow the user to set cfg.DstFont. Also it makes casual debugging nicer than when storing indices)
         src_tmp.DstIndex = -1;
         for (int output_i = 0; output_i < atlas->Fonts.Size && src_tmp.DstIndex == -1; output_i++)
-            if (cfg.DstFont == atlas->Fonts[output_i])
+            if (src.DstFont == atlas->Fonts[output_i])
                 src_tmp.DstIndex = output_i;
-        IM_ASSERT(src_tmp.DstIndex != -1); // cfg.DstFont not pointing within atlas->Fonts[] array?
+        IM_ASSERT(src_tmp.DstIndex != -1); // src.DstFont not pointing within atlas->Fonts[] array?
         if (src_tmp.DstIndex == -1)
             return false;
 
         // Load font
-        if (!font_face.InitFont(ft_library, cfg, extra_flags))
+        if (!font_face.InitFont(ft_library, src, extra_flags))
             return false;
 
         // Measure highest codepoints
-        src_load_color |= (cfg.FontBuilderFlags & ImGuiFreeTypeBuilderFlags_LoadColor) != 0;
+        src_load_color |= (src.FontBuilderFlags & ImGuiFreeTypeBuilderFlags_LoadColor) != 0;
         ImFontBuildDstDataFT& dst_tmp = dst_tmp_array[src_tmp.DstIndex];
-        src_tmp.SrcRanges = cfg.GlyphRanges ? cfg.GlyphRanges : atlas->GetGlyphRangesDefault();
+        src_tmp.SrcRanges = src.GlyphRanges ? src.GlyphRanges : atlas->GetGlyphRangesDefault();
         for (const ImWchar* src_range = src_tmp.SrcRanges; src_range[0] && src_range[1]; src_range += 2)
         {
             // Check for valid range. This may also help detect *some* dangling pointers, because a common
@@ -577,7 +577,7 @@ bool ImFontAtlasBuildWithFreeTypeEx(FT_Library ft_library, ImFontAtlas* atlas, u
     for (int src_i = 0; src_i < src_tmp_array.Size; src_i++)
     {
         ImFontBuildSrcDataFT& src_tmp = src_tmp_array[src_i];
-        ImFontConfig& cfg = atlas->ConfigData[src_i];
+        ImFontConfig& src = atlas->Sources[src_i];
         if (src_tmp.GlyphsCount == 0)
             continue;
 
@@ -585,10 +585,10 @@ bool ImFontAtlasBuildWithFreeTypeEx(FT_Library ft_library, ImFontAtlas* atlas, u
         buf_rects_out_n += src_tmp.GlyphsCount;
 
         // Compute multiply table if requested
-        const bool multiply_enabled = (cfg.RasterizerMultiply != 1.0f);
+        const bool multiply_enabled = (src.RasterizerMultiply != 1.0f);
         unsigned char multiply_table[256];
         if (multiply_enabled)
-            ImFontAtlasBuildMultiplyCalcLookupTable(multiply_table, cfg.RasterizerMultiply);
+            ImFontAtlasBuildMultiplyCalcLookupTable(multiply_table, src.RasterizerMultiply);
 
         // Gather the sizes of all rectangles we will need to pack
         for (int glyph_i = 0; glyph_i < src_tmp.GlyphsList.Size; glyph_i++)
@@ -687,18 +687,18 @@ bool ImFontAtlasBuildWithFreeTypeEx(FT_Library ft_library, ImFontAtlas* atlas, u
 
         // When merging fonts with MergeMode=true:
         // - We can have multiple input fonts writing into a same destination font.
-        // - dst_font->ConfigData is != from cfg which is our source configuration.
-        ImFontConfig& cfg = atlas->ConfigData[src_i];
-        ImFont* dst_font = cfg.DstFont;
+        // - dst_font->Sources is != from src which is our source configuration.
+        ImFontConfig& src = atlas->Sources[src_i];
+        ImFont* dst_font = src.DstFont;
 
         const float ascent = src_tmp.Font.Info.Ascender;
         const float descent = src_tmp.Font.Info.Descender;
-        ImFontAtlasBuildSetupFont(atlas, dst_font, &cfg, ascent, descent);
+        ImFontAtlasBuildSetupFont(atlas, dst_font, &src, ascent, descent);
 
         if (src_tmp.GlyphsCount == 0)
             continue;
-        const float font_off_x = cfg.GlyphOffset.x;
-        const float font_off_y = cfg.GlyphOffset.y + IM_ROUND(dst_font->Ascent);
+        const float font_off_x = src.GlyphOffset.x;
+        const float font_off_y = src.GlyphOffset.y + IM_ROUND(dst_font->Ascent);
 
         const int padding = atlas->TexGlyphPadding;
         for (int glyph_i = 0; glyph_i < src_tmp.GlyphsCount; glyph_i++)
@@ -724,7 +724,7 @@ bool ImFontAtlasBuildWithFreeTypeEx(FT_Library ft_library, ImFontAtlas* atlas, u
             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(&src, (ImWchar)src_glyph.Codepoint, x0, y0, x1, y1, u0, v0, u1, v1, info.AdvanceX * src_tmp.Font.InvRasterizationDensity);
 
             ImFontGlyph* dst_glyph = &dst_font->Glyphs.back();
             IM_ASSERT(dst_glyph->Codepoint == src_glyph.Codepoint);