Merge branch 'master' into docking

This will be part of 1.89.7 Tagged relase.

.github/workflows/build.yml

@@ -479,8 +479,8 @@ jobs:
         wget -q https://github.com/emscripten-core/emsdk/archive/master.tar.gz
         tar -xvf master.tar.gz
         emsdk-master/emsdk update
-        emsdk-master/emsdk install latest
-        emsdk-master/emsdk activate latest
+        emsdk-master/emsdk install 3.1.37
+        emsdk-master/emsdk activate 3.1.37
 
     - name: Build example_sdl2_opengl3 with Emscripten
       run: |

backends/imgui_impl_allegro5.cpp

@@ -462,8 +462,9 @@ void ImGui_ImplAllegro5_Shutdown()
     if (bd->ClipboardTextData)
         al_free(bd->ClipboardTextData);
 
-    io.BackendPlatformUserData = nullptr;
     io.BackendPlatformName = io.BackendRendererName = nullptr;
+    io.BackendPlatformUserData = nullptr;
+    io.BackendFlags &= ~ImGuiBackendFlags_HasMouseCursors;
     IM_DELETE(bd);
 }
 

backends/imgui_impl_android.cpp

@@ -269,6 +269,8 @@ bool ImGui_ImplAndroid_Init(ANativeWindow* window)
 
 void ImGui_ImplAndroid_Shutdown()
 {
+    ImGuiIO& io = ImGui::GetIO();
+    io.BackendPlatformName = nullptr;
 }
 
 void ImGui_ImplAndroid_NewFrame()

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) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -12,6 +13,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
 //  2021-05-19: DirectX10: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
@@ -75,6 +77,10 @@ static ImGui_ImplDX10_Data* ImGui_ImplDX10_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX10_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX10_InitPlatformInterface();
+static void ImGui_ImplDX10_ShutdownPlatformInterface();
+
 // Functions
 static void ImGui_ImplDX10_SetupRenderState(ImDrawData* draw_data, ID3D10Device* ctx)
 {
@@ -537,6 +543,7 @@ 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;
@@ -553,6 +560,8 @@ bool    ImGui_ImplDX10_Init(ID3D10Device* device)
     if (pDXGIAdapter) pDXGIAdapter->Release();
     bd->pd3dDevice->AddRef();
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplDX10_InitPlatformInterface();
     return true;
 }
 
@@ -562,11 +571,13 @@ void ImGui_ImplDX10_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplDX10_ShutdownPlatformInterface();
     ImGui_ImplDX10_InvalidateDeviceObjects();
     if (bd->pFactory) { bd->pFactory->Release(); }
     if (bd->pd3dDevice) { bd->pd3dDevice->Release(); }
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -578,3 +589,127 @@ void ImGui_ImplDX10_NewFrame()
     if (!bd->pFontSampler)
         ImGui_ImplDX10_CreateDeviceObjects();
 }
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplDX10_ViewportData
+{
+    IDXGISwapChain*         SwapChain;
+    ID3D10RenderTargetView* RTView;
+
+    ImGui_ImplDX10_ViewportData()   { SwapChain = nullptr; RTView = nullptr; }
+    ~ImGui_ImplDX10_ViewportData()  { IM_ASSERT(SwapChain == nullptr && RTView == nullptr); }
+};
+
+static void ImGui_ImplDX10_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplDX10_Data* bd = ImGui_ImplDX10_GetBackendData();
+    ImGui_ImplDX10_ViewportData* vd = IM_NEW(ImGui_ImplDX10_ViewportData)();
+    viewport->RendererUserData = vd;
+
+    // PlatformHandleRaw should always be a HWND, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL_Window*).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+
+    // Create swap chain
+    DXGI_SWAP_CHAIN_DESC sd;
+    ZeroMemory(&sd, sizeof(sd));
+    sd.BufferDesc.Width = (UINT)viewport->Size.x;
+    sd.BufferDesc.Height = (UINT)viewport->Size.y;
+    sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
+    sd.SampleDesc.Count = 1;
+    sd.SampleDesc.Quality = 0;
+    sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
+    sd.BufferCount = 1;
+    sd.OutputWindow = hwnd;
+    sd.Windowed = TRUE;
+    sd.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
+    sd.Flags = 0;
+
+    IM_ASSERT(vd->SwapChain == nullptr && vd->RTView == nullptr);
+    bd->pFactory->CreateSwapChain(bd->pd3dDevice, &sd, &vd->SwapChain);
+
+    // Create the render target
+    if (vd->SwapChain)
+    {
+        ID3D10Texture2D* pBackBuffer;
+        vd->SwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+        bd->pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &vd->RTView);
+        pBackBuffer->Release();
+    }
+}
+
+static void ImGui_ImplDX10_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 here since we didn't create the data for it.
+    if (ImGui_ImplDX10_ViewportData* vd = (ImGui_ImplDX10_ViewportData*)viewport->RendererUserData)
+    {
+        if (vd->SwapChain)
+            vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        if (vd->RTView)
+            vd->RTView->Release();
+        vd->RTView = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplDX10_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplDX10_Data* bd = ImGui_ImplDX10_GetBackendData();
+    ImGui_ImplDX10_ViewportData* vd = (ImGui_ImplDX10_ViewportData*)viewport->RendererUserData;
+    if (vd->RTView)
+    {
+        vd->RTView->Release();
+        vd->RTView = nullptr;
+    }
+    if (vd->SwapChain)
+    {
+        ID3D10Texture2D* pBackBuffer = nullptr;
+        vd->SwapChain->ResizeBuffers(0, (UINT)size.x, (UINT)size.y, DXGI_FORMAT_UNKNOWN, 0);
+        vd->SwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+        if (pBackBuffer == nullptr) { fprintf(stderr, "ImGui_ImplDX10_SetWindowSize() failed creating buffers.\n"); return; }
+        bd->pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &vd->RTView);
+        pBackBuffer->Release();
+    }
+}
+
+static void ImGui_ImplDX10_RenderViewport(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX10_Data* bd = ImGui_ImplDX10_GetBackendData();
+    ImGui_ImplDX10_ViewportData* vd = (ImGui_ImplDX10_ViewportData*)viewport->RendererUserData;
+    ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+    bd->pd3dDevice->OMSetRenderTargets(1, &vd->RTView, nullptr);
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+        bd->pd3dDevice->ClearRenderTargetView(vd->RTView, (float*)&clear_color);
+    ImGui_ImplDX10_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplDX10_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX10_ViewportData* vd = (ImGui_ImplDX10_ViewportData*)viewport->RendererUserData;
+    vd->SwapChain->Present(0, 0); // Present without vsync
+}
+
+void ImGui_ImplDX10_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX10_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX10_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX10_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX10_RenderViewport;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX10_SwapBuffers;
+}
+
+void ImGui_ImplDX10_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+

backends/imgui_impl_dx10.h

@@ -4,8 +4,9 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'ID3D10ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
-// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this. 
+// 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.
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs

backends/imgui_impl_dx11.cpp

@@ -4,6 +4,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'ID3D11ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -12,6 +13,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
 //  2021-05-19: DirectX11: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
@@ -76,6 +78,10 @@ static ImGui_ImplDX11_Data* ImGui_ImplDX11_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX11_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX11_InitPlatformInterface();
+static void ImGui_ImplDX11_ShutdownPlatformInterface();
+
 // Functions
 static void ImGui_ImplDX11_SetupRenderState(ImDrawData* draw_data, ID3D11DeviceContext* ctx)
 {
@@ -549,6 +555,7 @@ 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;
@@ -568,6 +575,9 @@ bool    ImGui_ImplDX11_Init(ID3D11Device* device, ID3D11DeviceContext* device_co
     bd->pd3dDevice->AddRef();
     bd->pd3dDeviceContext->AddRef();
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplDX11_InitPlatformInterface();
+
     return true;
 }
 
@@ -577,12 +587,14 @@ void ImGui_ImplDX11_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplDX11_ShutdownPlatformInterface();
     ImGui_ImplDX11_InvalidateDeviceObjects();
     if (bd->pFactory)             { bd->pFactory->Release(); }
     if (bd->pd3dDevice)           { bd->pd3dDevice->Release(); }
     if (bd->pd3dDeviceContext)    { bd->pd3dDeviceContext->Release(); }
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -594,3 +606,126 @@ void ImGui_ImplDX11_NewFrame()
     if (!bd->pFontSampler)
         ImGui_ImplDX11_CreateDeviceObjects();
 }
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplDX11_ViewportData
+{
+    IDXGISwapChain*                 SwapChain;
+    ID3D11RenderTargetView*         RTView;
+
+    ImGui_ImplDX11_ViewportData()   { SwapChain = nullptr; RTView = nullptr; }
+    ~ImGui_ImplDX11_ViewportData()  { IM_ASSERT(SwapChain == nullptr && RTView == nullptr); }
+};
+
+static void ImGui_ImplDX11_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    ImGui_ImplDX11_ViewportData* vd = IM_NEW(ImGui_ImplDX11_ViewportData)();
+    viewport->RendererUserData = vd;
+
+    // PlatformHandleRaw should always be a HWND, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL_Window*).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+
+    // Create swap chain
+    DXGI_SWAP_CHAIN_DESC sd;
+    ZeroMemory(&sd, sizeof(sd));
+    sd.BufferDesc.Width = (UINT)viewport->Size.x;
+    sd.BufferDesc.Height = (UINT)viewport->Size.y;
+    sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
+    sd.SampleDesc.Count = 1;
+    sd.SampleDesc.Quality = 0;
+    sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
+    sd.BufferCount = 1;
+    sd.OutputWindow = hwnd;
+    sd.Windowed = TRUE;
+    sd.SwapEffect = DXGI_SWAP_EFFECT_DISCARD;
+    sd.Flags = 0;
+
+    IM_ASSERT(vd->SwapChain == nullptr && vd->RTView == nullptr);
+    bd->pFactory->CreateSwapChain(bd->pd3dDevice, &sd, &vd->SwapChain);
+
+    // Create the render target
+    if (vd->SwapChain)
+    {
+        ID3D11Texture2D* pBackBuffer;
+        vd->SwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+        bd->pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &vd->RTView);
+        pBackBuffer->Release();
+    }
+}
+
+static void ImGui_ImplDX11_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == nullptr since we didn't create the data for it.
+    if (ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData)
+    {
+        if (vd->SwapChain)
+            vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        if (vd->RTView)
+            vd->RTView->Release();
+        vd->RTView = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplDX11_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData;
+    if (vd->RTView)
+    {
+        vd->RTView->Release();
+        vd->RTView = nullptr;
+    }
+    if (vd->SwapChain)
+    {
+        ID3D11Texture2D* pBackBuffer = nullptr;
+        vd->SwapChain->ResizeBuffers(0, (UINT)size.x, (UINT)size.y, DXGI_FORMAT_UNKNOWN, 0);
+        vd->SwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
+        if (pBackBuffer == nullptr) { fprintf(stderr, "ImGui_ImplDX11_SetWindowSize() failed creating buffers.\n"); return; }
+        bd->pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, &vd->RTView);
+        pBackBuffer->Release();
+    }
+}
+
+static void ImGui_ImplDX11_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX11_Data* bd = ImGui_ImplDX11_GetBackendData();
+    ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData;
+    ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+    bd->pd3dDeviceContext->OMSetRenderTargets(1, &vd->RTView, nullptr);
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+        bd->pd3dDeviceContext->ClearRenderTargetView(vd->RTView, (float*)&clear_color);
+    ImGui_ImplDX11_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplDX11_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX11_ViewportData* vd = (ImGui_ImplDX11_ViewportData*)viewport->RendererUserData;
+    vd->SwapChain->Present(0, 0); // Present without vsync
+}
+
+static void ImGui_ImplDX11_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX11_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX11_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX11_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX11_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX11_SwapBuffers;
+}
+
+static void ImGui_ImplDX11_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}

backends/imgui_impl_dx11.h

@@ -4,8 +4,9 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'ID3D11ShaderResourceView*' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
-// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this. 
+// 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.
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs

backends/imgui_impl_dx12.cpp

@@ -4,6 +4,8 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'D3D12_GPU_DESCRIPTOR_HANDLE' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+//      FIXME: The transition from removing a viewport and moving the window in an existing hosted viewport tends to flicker.
 
 // Important: to compile on 32-bit systems, this backend requires code to be compiled with '#define ImTextureID ImU64'.
 // This is because we need ImTextureID to carry a 64-bit value and by default ImTextureID is defined as void*.
@@ -20,6 +22,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
 //  2021-05-19: DirectX12: Replaced direct access to ImDrawCmd::TextureId with a call to ImDrawCmd::GetTexID(). (will become a requirement)
@@ -50,7 +53,6 @@
 #endif
 
 // DirectX data
-struct ImGui_ImplDX12_RenderBuffers;
 struct ImGui_ImplDX12_Data
 {
     ID3D12Device*               pd3dDevice;
@@ -63,10 +65,7 @@ struct ImGui_ImplDX12_Data
     ID3D12DescriptorHeap*       pd3dSrvDescHeap;
     UINT                        numFramesInFlight;
 
-    ImGui_ImplDX12_RenderBuffers* pFrameResources;
-    UINT                        frameIndex;
-
-    ImGui_ImplDX12_Data()       { memset((void*)this, 0, sizeof(*this)); frameIndex = UINT_MAX; }
+    ImGui_ImplDX12_Data()       { memset((void*)this, 0, sizeof(*this)); }
 };
 
 // Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
@@ -85,11 +84,88 @@ struct ImGui_ImplDX12_RenderBuffers
     int                 VertexBufferSize;
 };
 
+// Buffers used for secondary viewports created by the multi-viewports systems
+struct ImGui_ImplDX12_FrameContext
+{
+    ID3D12CommandAllocator*         CommandAllocator;
+    ID3D12Resource*                 RenderTarget;
+    D3D12_CPU_DESCRIPTOR_HANDLE     RenderTargetCpuDescriptors;
+};
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+// Main viewport created by application will only use the Resources field.
+// Secondary viewports created by this backend will use all the fields (including Window fields),
+struct ImGui_ImplDX12_ViewportData
+{
+    // Window
+    ID3D12CommandQueue*             CommandQueue;
+    ID3D12GraphicsCommandList*      CommandList;
+    ID3D12DescriptorHeap*           RtvDescHeap;
+    IDXGISwapChain3*                SwapChain;
+    ID3D12Fence*                    Fence;
+    UINT64                          FenceSignaledValue;
+    HANDLE                          FenceEvent;
+    UINT                            NumFramesInFlight;
+    ImGui_ImplDX12_FrameContext*    FrameCtx;
+
+    // Render buffers
+    UINT                            FrameIndex;
+    ImGui_ImplDX12_RenderBuffers*   FrameRenderBuffers;
+
+    ImGui_ImplDX12_ViewportData(UINT num_frames_in_flight)
+    {
+        CommandQueue = nullptr;
+        CommandList = nullptr;
+        RtvDescHeap = nullptr;
+        SwapChain = nullptr;
+        Fence = nullptr;
+        FenceSignaledValue = 0;
+        FenceEvent = nullptr;
+        NumFramesInFlight = num_frames_in_flight;
+        FrameCtx = new ImGui_ImplDX12_FrameContext[NumFramesInFlight];
+        FrameIndex = UINT_MAX;
+        FrameRenderBuffers = new ImGui_ImplDX12_RenderBuffers[NumFramesInFlight];
+
+        for (UINT i = 0; i < NumFramesInFlight; ++i)
+        {
+            FrameCtx[i].CommandAllocator = nullptr;
+            FrameCtx[i].RenderTarget = nullptr;
+
+            // Create buffers with a default size (they will later be grown as needed)
+            FrameRenderBuffers[i].IndexBuffer = nullptr;
+            FrameRenderBuffers[i].VertexBuffer = nullptr;
+            FrameRenderBuffers[i].VertexBufferSize = 5000;
+            FrameRenderBuffers[i].IndexBufferSize = 10000;
+        }
+    }
+    ~ImGui_ImplDX12_ViewportData()
+    {
+        IM_ASSERT(CommandQueue == nullptr && CommandList == nullptr);
+        IM_ASSERT(RtvDescHeap == nullptr);
+        IM_ASSERT(SwapChain == nullptr);
+        IM_ASSERT(Fence == nullptr);
+        IM_ASSERT(FenceEvent == nullptr);
+
+        for (UINT i = 0; i < NumFramesInFlight; ++i)
+        {
+            IM_ASSERT(FrameCtx[i].CommandAllocator == nullptr && FrameCtx[i].RenderTarget == nullptr);
+            IM_ASSERT(FrameRenderBuffers[i].IndexBuffer == nullptr && FrameRenderBuffers[i].VertexBuffer == nullptr);
+        }
+
+        delete[] FrameCtx; FrameCtx = nullptr;
+        delete[] FrameRenderBuffers; FrameRenderBuffers = nullptr;
+    }
+};
+
 struct VERTEX_CONSTANT_BUFFER_DX12
 {
     float   mvp[4][4];
 };
 
+// Forward Declarations
+static void ImGui_ImplDX12_InitPlatformInterface();
+static void ImGui_ImplDX12_ShutdownPlatformInterface();
+
 // Functions
 static void ImGui_ImplDX12_SetupRenderState(ImDrawData* draw_data, ID3D12GraphicsCommandList* ctx, ImGui_ImplDX12_RenderBuffers* fr)
 {
@@ -163,11 +239,10 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
     if (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f)
         return;
 
-    // FIXME: I'm assuming that this only gets called once per frame!
-    // If not, we can't just re-allocate the IB or VB, we'll have to do a proper allocator.
     ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
-    bd->frameIndex = bd->frameIndex + 1;
-    ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[bd->frameIndex % bd->numFramesInFlight];
+    ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)draw_data->OwnerViewport->RendererUserData;
+    vd->FrameIndex++;
+    ImGui_ImplDX12_RenderBuffers* fr = &vd->FrameRenderBuffers[vd->FrameIndex % bd->numFramesInFlight];
 
     // Create and grow vertex/index buffers if needed
     if (fr->VertexBuffer == nullptr || fr->VertexBufferSize < draw_data->TotalVtxCount)
@@ -674,6 +749,13 @@ bool    ImGui_ImplDX12_CreateDeviceObjects()
     return true;
 }
 
+static void ImGui_ImplDX12_DestroyRenderBuffers(ImGui_ImplDX12_RenderBuffers* render_buffers)
+{
+    SafeRelease(render_buffers->IndexBuffer);
+    SafeRelease(render_buffers->VertexBuffer);
+    render_buffers->IndexBufferSize = render_buffers->VertexBufferSize = 0;
+}
+
 void    ImGui_ImplDX12_InvalidateDeviceObjects()
 {
     ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
@@ -685,13 +767,6 @@ void    ImGui_ImplDX12_InvalidateDeviceObjects()
     SafeRelease(bd->pPipelineState);
     SafeRelease(bd->pFontTextureResource);
     io.Fonts->SetTexID(0); // We copied bd->pFontTextureView to io.Fonts->TexID so let's clear that as well.
-
-    for (UINT i = 0; i < bd->numFramesInFlight; i++)
-    {
-        ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[i];
-        SafeRelease(fr->IndexBuffer);
-        SafeRelease(fr->VertexBuffer);
-    }
 }
 
 bool ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FORMAT rtv_format, ID3D12DescriptorHeap* cbv_srv_heap,
@@ -705,25 +780,21 @@ bool ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FO
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_dx12";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplDX12_InitPlatformInterface();
 
     bd->pd3dDevice = device;
     bd->RTVFormat = rtv_format;
     bd->hFontSrvCpuDescHandle = font_srv_cpu_desc_handle;
     bd->hFontSrvGpuDescHandle = font_srv_gpu_desc_handle;
-    bd->pFrameResources = new ImGui_ImplDX12_RenderBuffers[num_frames_in_flight];
     bd->numFramesInFlight = num_frames_in_flight;
     bd->pd3dSrvDescHeap = cbv_srv_heap;
-    bd->frameIndex = UINT_MAX;
 
-    // Create buffers with a default size (they will later be grown as needed)
-    for (int i = 0; i < num_frames_in_flight; i++)
-    {
-        ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[i];
-        fr->IndexBuffer = nullptr;
-        fr->VertexBuffer = nullptr;
-        fr->IndexBufferSize = 10000;
-        fr->VertexBufferSize = 5000;
-    }
+    // Create a dummy ImGui_ImplDX12_ViewportData holder for the main viewport,
+    // Since this is created and managed by the application, we will only use the ->Resources[] fields.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->RendererUserData = IM_NEW(ImGui_ImplDX12_ViewportData)(bd->numFramesInFlight);
 
     return true;
 }
@@ -734,11 +805,24 @@ 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 | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -750,3 +834,243 @@ void ImGui_ImplDX12_NewFrame()
     if (!bd->pPipelineState)
         ImGui_ImplDX12_CreateDeviceObjects();
 }
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplDX12_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    ImGui_ImplDX12_ViewportData* vd = IM_NEW(ImGui_ImplDX12_ViewportData)(bd->numFramesInFlight);
+    viewport->RendererUserData = vd;
+
+    // PlatformHandleRaw should always be a HWND, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL_Window*).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+
+    vd->FrameIndex = UINT_MAX;
+
+    // Create command queue.
+    D3D12_COMMAND_QUEUE_DESC queue_desc = {};
+    queue_desc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
+    queue_desc.Type = D3D12_COMMAND_LIST_TYPE_DIRECT;
+
+    HRESULT res = S_OK;
+    res = bd->pd3dDevice->CreateCommandQueue(&queue_desc, IID_PPV_ARGS(&vd->CommandQueue));
+    IM_ASSERT(res == S_OK);
+
+    // Create command allocator.
+    for (UINT i = 0; i < bd->numFramesInFlight; ++i)
+    {
+        res = bd->pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&vd->FrameCtx[i].CommandAllocator));
+        IM_ASSERT(res == S_OK);
+    }
+
+    // Create command list.
+    res = bd->pd3dDevice->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, vd->FrameCtx[0].CommandAllocator, nullptr, IID_PPV_ARGS(&vd->CommandList));
+    IM_ASSERT(res == S_OK);
+    vd->CommandList->Close();
+
+    // Create fence.
+    res = bd->pd3dDevice->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_PPV_ARGS(&vd->Fence));
+    IM_ASSERT(res == S_OK);
+
+    vd->FenceEvent = CreateEvent(nullptr, FALSE, FALSE, nullptr);
+    IM_ASSERT(vd->FenceEvent != nullptr);
+
+    // Create swap chain
+    // FIXME-VIEWPORT: May want to copy/inherit swap chain settings from the user/application.
+    DXGI_SWAP_CHAIN_DESC1 sd1;
+    ZeroMemory(&sd1, sizeof(sd1));
+    sd1.BufferCount = bd->numFramesInFlight;
+    sd1.Width = (UINT)viewport->Size.x;
+    sd1.Height = (UINT)viewport->Size.y;
+    sd1.Format = bd->RTVFormat;
+    sd1.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
+    sd1.SampleDesc.Count = 1;
+    sd1.SampleDesc.Quality = 0;
+    sd1.SwapEffect = DXGI_SWAP_EFFECT_FLIP_DISCARD;
+    sd1.AlphaMode = DXGI_ALPHA_MODE_UNSPECIFIED;
+    sd1.Scaling = DXGI_SCALING_STRETCH;
+    sd1.Stereo = FALSE;
+
+    IDXGIFactory4* dxgi_factory = nullptr;
+    res = ::CreateDXGIFactory1(IID_PPV_ARGS(&dxgi_factory));
+    IM_ASSERT(res == S_OK);
+
+    IDXGISwapChain1* swap_chain = nullptr;
+    res = dxgi_factory->CreateSwapChainForHwnd(vd->CommandQueue, hwnd, &sd1, nullptr, nullptr, &swap_chain);
+    IM_ASSERT(res == S_OK);
+
+    dxgi_factory->Release();
+
+    // Or swapChain.As(&mSwapChain)
+    IM_ASSERT(vd->SwapChain == nullptr);
+    swap_chain->QueryInterface(IID_PPV_ARGS(&vd->SwapChain));
+    swap_chain->Release();
+
+    // Create the render targets
+    if (vd->SwapChain)
+    {
+        D3D12_DESCRIPTOR_HEAP_DESC desc = {};
+        desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_RTV;
+        desc.NumDescriptors = bd->numFramesInFlight;
+        desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
+        desc.NodeMask = 1;
+
+        HRESULT hr = bd->pd3dDevice->CreateDescriptorHeap(&desc, IID_PPV_ARGS(&vd->RtvDescHeap));
+        IM_ASSERT(hr == S_OK);
+
+        SIZE_T rtv_descriptor_size = bd->pd3dDevice->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_RTV);
+        D3D12_CPU_DESCRIPTOR_HANDLE rtv_handle = vd->RtvDescHeap->GetCPUDescriptorHandleForHeapStart();
+        for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        {
+            vd->FrameCtx[i].RenderTargetCpuDescriptors = rtv_handle;
+            rtv_handle.ptr += rtv_descriptor_size;
+        }
+
+        ID3D12Resource* back_buffer;
+        for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        {
+            IM_ASSERT(vd->FrameCtx[i].RenderTarget == nullptr);
+            vd->SwapChain->GetBuffer(i, IID_PPV_ARGS(&back_buffer));
+            bd->pd3dDevice->CreateRenderTargetView(back_buffer, nullptr, vd->FrameCtx[i].RenderTargetCpuDescriptors);
+            vd->FrameCtx[i].RenderTarget = back_buffer;
+        }
+    }
+
+    for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        ImGui_ImplDX12_DestroyRenderBuffers(&vd->FrameRenderBuffers[i]);
+}
+
+static void ImGui_WaitForPendingOperations(ImGui_ImplDX12_ViewportData* vd)
+{
+    HRESULT hr = S_FALSE;
+    if (vd && vd->CommandQueue && vd->Fence && vd->FenceEvent)
+    {
+        hr = vd->CommandQueue->Signal(vd->Fence, ++vd->FenceSignaledValue);
+        IM_ASSERT(hr == S_OK);
+        ::WaitForSingleObject(vd->FenceEvent, 0); // Reset any forgotten waits
+        hr = vd->Fence->SetEventOnCompletion(vd->FenceSignaledValue, vd->FenceEvent);
+        IM_ASSERT(hr == S_OK);
+        ::WaitForSingleObject(vd->FenceEvent, INFINITE);
+    }
+}
+
+static void ImGui_ImplDX12_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    if (ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData)
+    {
+        ImGui_WaitForPendingOperations(vd);
+
+        SafeRelease(vd->CommandQueue);
+        SafeRelease(vd->CommandList);
+        SafeRelease(vd->SwapChain);
+        SafeRelease(vd->RtvDescHeap);
+        SafeRelease(vd->Fence);
+        ::CloseHandle(vd->FenceEvent);
+        vd->FenceEvent = nullptr;
+
+        for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        {
+            SafeRelease(vd->FrameCtx[i].RenderTarget);
+            SafeRelease(vd->FrameCtx[i].CommandAllocator);
+            ImGui_ImplDX12_DestroyRenderBuffers(&vd->FrameRenderBuffers[i]);
+        }
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplDX12_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData;
+
+    ImGui_WaitForPendingOperations(vd);
+
+    for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        SafeRelease(vd->FrameCtx[i].RenderTarget);
+
+    if (vd->SwapChain)
+    {
+        ID3D12Resource* back_buffer = nullptr;
+        vd->SwapChain->ResizeBuffers(0, (UINT)size.x, (UINT)size.y, DXGI_FORMAT_UNKNOWN, 0);
+        for (UINT i = 0; i < bd->numFramesInFlight; i++)
+        {
+            vd->SwapChain->GetBuffer(i, IID_PPV_ARGS(&back_buffer));
+            bd->pd3dDevice->CreateRenderTargetView(back_buffer, nullptr, vd->FrameCtx[i].RenderTargetCpuDescriptors);
+            vd->FrameCtx[i].RenderTarget = back_buffer;
+        }
+    }
+}
+
+static void ImGui_ImplDX12_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
+    ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData;
+
+    ImGui_ImplDX12_FrameContext* frame_context = &vd->FrameCtx[vd->FrameIndex % bd->numFramesInFlight];
+    UINT back_buffer_idx = vd->SwapChain->GetCurrentBackBufferIndex();
+
+    const ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+    D3D12_RESOURCE_BARRIER barrier = {};
+    barrier.Type = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
+    barrier.Flags = D3D12_RESOURCE_BARRIER_FLAG_NONE;
+    barrier.Transition.pResource = vd->FrameCtx[back_buffer_idx].RenderTarget;
+    barrier.Transition.Subresource = D3D12_RESOURCE_BARRIER_ALL_SUBRESOURCES;
+    barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_PRESENT;
+    barrier.Transition.StateAfter = D3D12_RESOURCE_STATE_RENDER_TARGET;
+
+    // Draw
+    ID3D12GraphicsCommandList* cmd_list = vd->CommandList;
+
+    frame_context->CommandAllocator->Reset();
+    cmd_list->Reset(frame_context->CommandAllocator, nullptr);
+    cmd_list->ResourceBarrier(1, &barrier);
+    cmd_list->OMSetRenderTargets(1, &vd->FrameCtx[back_buffer_idx].RenderTargetCpuDescriptors, FALSE, nullptr);
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+        cmd_list->ClearRenderTargetView(vd->FrameCtx[back_buffer_idx].RenderTargetCpuDescriptors, (float*)&clear_color, 0, nullptr);
+    cmd_list->SetDescriptorHeaps(1, &bd->pd3dSrvDescHeap);
+
+    ImGui_ImplDX12_RenderDrawData(viewport->DrawData, cmd_list);
+
+    barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_RENDER_TARGET;
+    barrier.Transition.StateAfter = D3D12_RESOURCE_STATE_PRESENT;
+    cmd_list->ResourceBarrier(1, &barrier);
+    cmd_list->Close();
+
+    vd->CommandQueue->Wait(vd->Fence, vd->FenceSignaledValue);
+    vd->CommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&cmd_list);
+    vd->CommandQueue->Signal(vd->Fence, ++vd->FenceSignaledValue);
+}
+
+static void ImGui_ImplDX12_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData;
+
+    vd->SwapChain->Present(0, 0);
+    while (vd->Fence->GetCompletedValue() < vd->FenceSignaledValue)
+        ::SwitchToThread();
+}
+
+void ImGui_ImplDX12_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX12_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX12_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX12_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX12_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX12_SwapBuffers;
+}
+
+void ImGui_ImplDX12_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}

backends/imgui_impl_dx12.h

@@ -4,6 +4,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'D3D12_GPU_DESCRIPTOR_HANDLE' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // Important: to compile on 32-bit systems, this backend requires code to be compiled with '#define ImTextureID ImU64'.
 // See imgui_impl_dx12.cpp file for details.

backends/imgui_impl_dx9.cpp

@@ -4,6 +4,7 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'LPDIRECT3DTEXTURE9' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -12,6 +13,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
 //  2021-06-25: DirectX9: Explicitly disable texture state stages after >= 1.
@@ -71,6 +73,12 @@ static ImGui_ImplDX9_Data* ImGui_ImplDX9_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplDX9_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplDX9_InitPlatformInterface();
+static void ImGui_ImplDX9_ShutdownPlatformInterface();
+static void ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows();
+static void ImGui_ImplDX9_InvalidateDeviceObjectsForPlatformWindows();
+
 // Functions
 static void ImGui_ImplDX9_SetupRenderState(ImDrawData* draw_data)
 {
@@ -267,6 +275,11 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
         global_vtx_offset += cmd_list->VtxBuffer.Size;
     }
 
+    // When using multi-viewports, it appears that there's an odd logic in DirectX9 which prevent subsequent windows
+    // from rendering until the first window submits at least one draw call, even once. That's our workaround. (see #2560)
+    if (global_vtx_offset == 0)
+        bd->pd3dDevice->DrawIndexedPrimitive(D3DPT_TRIANGLELIST, 0, 0, 0, 0, 0);
+
     // Restore the DX9 transform
     bd->pd3dDevice->SetTransform(D3DTS_WORLD, &last_world);
     bd->pd3dDevice->SetTransform(D3DTS_VIEW, &last_view);
@@ -287,10 +300,14 @@ bool ImGui_ImplDX9_Init(IDirect3DDevice9* device)
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_dx9";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     bd->pd3dDevice = device;
     bd->pd3dDevice->AddRef();
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplDX9_InitPlatformInterface();
+
     return true;
 }
 
@@ -300,10 +317,12 @@ void ImGui_ImplDX9_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplDX9_ShutdownPlatformInterface();
     ImGui_ImplDX9_InvalidateDeviceObjects();
     if (bd->pd3dDevice) { bd->pd3dDevice->Release(); }
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -356,6 +375,7 @@ bool ImGui_ImplDX9_CreateDeviceObjects()
         return false;
     if (!ImGui_ImplDX9_CreateFontsTexture())
         return false;
+    ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows();
     return true;
 }
 
@@ -367,6 +387,7 @@ 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()
@@ -377,3 +398,145 @@ void ImGui_ImplDX9_NewFrame()
     if (!bd->FontTexture)
         ImGui_ImplDX9_CreateDeviceObjects();
 }
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplDX9_ViewportData
+{
+    IDirect3DSwapChain9*    SwapChain;
+    D3DPRESENT_PARAMETERS   d3dpp;
+
+    ImGui_ImplDX9_ViewportData()  { SwapChain = nullptr; ZeroMemory(&d3dpp, sizeof(D3DPRESENT_PARAMETERS)); }
+    ~ImGui_ImplDX9_ViewportData() { IM_ASSERT(SwapChain == nullptr); }
+};
+
+static void ImGui_ImplDX9_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplDX9_Data* bd = ImGui_ImplDX9_GetBackendData();
+    ImGui_ImplDX9_ViewportData* vd = IM_NEW(ImGui_ImplDX9_ViewportData)();
+    viewport->RendererUserData = vd;
+
+    // PlatformHandleRaw should always be a HWND, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL_Window*).
+    // Some backends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the HWND.
+    HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hwnd != 0);
+
+    ZeroMemory(&vd->d3dpp, sizeof(D3DPRESENT_PARAMETERS));
+    vd->d3dpp.Windowed = TRUE;
+    vd->d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
+    vd->d3dpp.BackBufferWidth = (UINT)viewport->Size.x;
+    vd->d3dpp.BackBufferHeight = (UINT)viewport->Size.y;
+    vd->d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
+    vd->d3dpp.hDeviceWindow = hwnd;
+    vd->d3dpp.EnableAutoDepthStencil = FALSE;
+    vd->d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
+    vd->d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;   // Present without vsync
+
+    HRESULT hr = bd->pd3dDevice->CreateAdditionalSwapChain(&vd->d3dpp, &vd->SwapChain); IM_UNUSED(hr);
+    IM_ASSERT(hr == D3D_OK);
+    IM_ASSERT(vd->SwapChain != nullptr);
+}
+
+static void ImGui_ImplDX9_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
+    if (ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData)
+    {
+        if (vd->SwapChain)
+            vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        ZeroMemory(&vd->d3dpp, sizeof(D3DPRESENT_PARAMETERS));
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplDX9_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplDX9_Data* bd = ImGui_ImplDX9_GetBackendData();
+    ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData;
+    if (vd->SwapChain)
+    {
+        vd->SwapChain->Release();
+        vd->SwapChain = nullptr;
+        vd->d3dpp.BackBufferWidth = (UINT)size.x;
+        vd->d3dpp.BackBufferHeight = (UINT)size.y;
+        HRESULT hr = bd->pd3dDevice->CreateAdditionalSwapChain(&vd->d3dpp, &vd->SwapChain); IM_UNUSED(hr);
+        IM_ASSERT(hr == D3D_OK);
+    }
+}
+
+static void ImGui_ImplDX9_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX9_Data* bd = ImGui_ImplDX9_GetBackendData();
+    ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData;
+    ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+
+    LPDIRECT3DSURFACE9 render_target = nullptr;
+    LPDIRECT3DSURFACE9 last_render_target = nullptr;
+    LPDIRECT3DSURFACE9 last_depth_stencil = nullptr;
+    vd->SwapChain->GetBackBuffer(0, D3DBACKBUFFER_TYPE_MONO, &render_target);
+    bd->pd3dDevice->GetRenderTarget(0, &last_render_target);
+    bd->pd3dDevice->GetDepthStencilSurface(&last_depth_stencil);
+    bd->pd3dDevice->SetRenderTarget(0, render_target);
+    bd->pd3dDevice->SetDepthStencilSurface(nullptr);
+
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+    {
+        D3DCOLOR clear_col_dx = D3DCOLOR_RGBA((int)(clear_color.x*255.0f), (int)(clear_color.y*255.0f), (int)(clear_color.z*255.0f), (int)(clear_color.w*255.0f));
+        bd->pd3dDevice->Clear(0, nullptr, D3DCLEAR_TARGET, clear_col_dx, 1.0f, 0);
+    }
+
+    ImGui_ImplDX9_RenderDrawData(viewport->DrawData);
+
+    // Restore render target
+    bd->pd3dDevice->SetRenderTarget(0, last_render_target);
+    bd->pd3dDevice->SetDepthStencilSurface(last_depth_stencil);
+    render_target->Release();
+    last_render_target->Release();
+    if (last_depth_stencil) last_depth_stencil->Release();
+}
+
+static void ImGui_ImplDX9_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplDX9_ViewportData* vd = (ImGui_ImplDX9_ViewportData*)viewport->RendererUserData;
+    HRESULT hr = vd->SwapChain->Present(nullptr, nullptr, vd->d3dpp.hDeviceWindow, nullptr, 0);
+    // Let main application handle D3DERR_DEVICELOST by resetting the device.
+    IM_ASSERT(hr == D3D_OK || hr == D3DERR_DEVICELOST);
+}
+
+static void ImGui_ImplDX9_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX9_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX9_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX9_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX9_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX9_SwapBuffers;
+}
+
+static void ImGui_ImplDX9_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
+static void ImGui_ImplDX9_CreateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (!platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplDX9_CreateWindow(platform_io.Viewports[i]);
+}
+
+static void ImGui_ImplDX9_InvalidateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplDX9_DestroyWindow(platform_io.Viewports[i]);
+}

backends/imgui_impl_dx9.h

@@ -4,8 +4,9 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'LPDIRECT3DTEXTURE9' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
-// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this. 
+// 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.
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs

backends/imgui_impl_glfw.cpp

@@ -9,6 +9,10 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLFW_KEY_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+
+// Issues:
+//  [ ] Platform: Multi-viewport support: ParentViewportID not honored, and so io.ConfigViewportsNoDefaultParent has no effect (minor).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -17,10 +21,13 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2023-06-12: Accept glfwGetTime() not returning a monotonically increasing value. This seems to happens on some Windows setup when peripherals disconnect, and is likely to also happen on browser + Emscripten. (#6491)
 //  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen/ImGuiMouseSource_Pen on Windows ONLY, using a custom WndProc hook. (#2702)
 //  2023-03-16: Inputs: Fixed key modifiers handling on secondary viewports (docking branch). Broken on 2023/01/04. (#6248, #6034)
 //  2023-03-14: Emscripten: Avoid using glfwGetError() and glfwGetGamepadState() which are not correctly implemented in Emscripten emulation. (#6240)
 //  2023-02-03: Emscripten: Registering custom low-level mouse wheel handler to get more accurate scrolling impulses on Emscripten. (#4019, #6096)
+//  2023-01-18: Handle unsupported glfwGetVideoMode() call on e.g. Emscripten.
 //  2023-01-04: Inputs: Fixed mods state on Linux when using Alt-GR text input (e.g. German keyboard layout), could lead to broken text input. Revert a 2022/01/17 change were we resumed using mods provided by GLFW, turns out they were faulty.
 //  2022-11-22: Perform a dummy glfwGetError() read to cancel missing names with glfwGetKeyName(). (#5908)
 //  2022-10-18: Perform a dummy glfwGetError() read to cancel missing mouse cursors errors. Using GLFW_VERSION_COMBINED directly. (#5785)
@@ -92,11 +99,29 @@
 
 // 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()
@@ -117,8 +142,10 @@ struct ImGui_ImplGlfw_Data
     GLFWwindow*             MouseWindow;
     GLFWcursor*             MouseCursors[ImGuiMouseCursor_COUNT];
     ImVec2                  LastValidMousePos;
+    GLFWwindow*             KeyOwnerWindows[GLFW_KEY_LAST];
     bool                    InstalledCallbacks;
     bool                    CallbacksChainForAllWindows;
+    bool                    WantUpdateMonitors;
 
     // Chain GLFW callbacks: our callbacks will call the user's previously installed callbacks, if any.
     GLFWwindowfocusfun      PrevUserCallbackWindowFocus;
@@ -148,6 +175,11 @@ static ImGui_ImplGlfw_Data* ImGui_ImplGlfw_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplGlfw_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplGlfw_UpdateMonitors();
+static void ImGui_ImplGlfw_InitPlatformInterface();
+static void ImGui_ImplGlfw_ShutdownPlatformInterface();
+
 // Functions
 static const char* ImGui_ImplGlfw_GetClipboardText(void* user_data)
 {
@@ -361,6 +393,9 @@ 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();
@@ -388,6 +423,13 @@ void ImGui_ImplGlfw_CursorPosCallback(GLFWwindow* window, double x, double y)
         return;
 
     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);
 }
@@ -428,7 +470,8 @@ void ImGui_ImplGlfw_CharCallback(GLFWwindow* window, unsigned int c)
 
 void ImGui_ImplGlfw_MonitorCallback(GLFWmonitor*, int)
 {
-	// Unused in 'master' branch but 'docking' branch will use this, so we declare it ahead of it so if you have to install callbacks you can install this one too.
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    bd->WantUpdateMonitors = true;
 }
 
 #ifdef __EMSCRIPTEN__
@@ -473,6 +516,22 @@ static LRESULT CALLBACK ImGui_ImplGlfw_WndProc(HWND hWnd, UINT msg, WPARAM wPara
     case WM_XBUTTONDOWN: case WM_XBUTTONDBLCLK: case WM_XBUTTONUP:
         ImGui::GetIO().AddMouseSourceEvent(GetMouseSourceFromMessageExtraInfo());
         break;
+
+    // We have submitted https://github.com/glfw/glfw/pull/1568 to allow GLFW to support "transparent inputs".
+    // In the meanwhile we implement custom per-platform workarounds here (FIXME-VIEWPORT: Implement same work-around for Linux/OSX!)
+#if !GLFW_HAS_MOUSE_PASSTHROUGH && GLFW_HAS_WINDOW_HOVERED
+    case WM_NCHITTEST:
+    {
+        // Let mouse pass-through the window. This will allow the backend to call io.AddMouseViewportEvent() properly (which is OPTIONAL).
+        // The ImGuiViewportFlags_NoInputs flag is set while dragging a viewport, as want to detect the window behind the one we are dragging.
+        // If you cannot easily access those viewport flags from your windowing/event code: you may manually synchronize its state e.g. in
+        // your main loop after calling UpdatePlatformWindows(). Iterate all viewports/platform windows and pass the flag to your windowing system.
+        ImGuiViewport* viewport = (ImGuiViewport*)::GetPropA(hWnd, "IMGUI_VIEWPORT");
+        if (viewport && (viewport->Flags & ImGuiViewportFlags_NoInputs))
+            return HTTRANSPARENT;
+        break;
+    }
+#endif
     }
     return ::CallWindowProc(bd->GlfwWndProc, hWnd, msg, wParam, lParam);
 }
@@ -542,9 +601,16 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     io.BackendPlatformName = "imgui_impl_glfw";
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+#ifndef __EMSCRIPTEN__
+    io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;    // We can create multi-viewports on the Platform side (optional)
+#endif
+#if GLFW_HAS_MOUSE_PASSTHROUGH || (GLFW_HAS_WINDOW_HOVERED && defined(_WIN32))
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
+#endif
 
     bd->Window = window;
     bd->Time = 0.0;
+    bd->WantUpdateMonitors = true;
 
     io.SetClipboardTextFn = ImGui_ImplGlfw_SetClipboardText;
     io.GetClipboardTextFn = ImGui_ImplGlfw_GetClipboardText;
@@ -586,8 +652,13 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     emscripten_set_wheel_callback(EMSCRIPTEN_EVENT_TARGET_DOCUMENT, nullptr, false, ImGui_ImplEmscripten_WheelCallback);
 #endif
 
+    // Update monitors the first time (note: monitor callback are broken in GLFW 3.2 and earlier, see github.com/glfw/glfw/issues/784)
+    ImGui_ImplGlfw_UpdateMonitors();
+    glfwSetMonitorCallback(ImGui_ImplGlfw_MonitorCallback);
+
     // Set platform dependent data in viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->PlatformHandle = (void*)bd->Window;
 #ifdef _WIN32
     main_viewport->PlatformHandleRaw = glfwGetWin32Window(bd->Window);
 #elif defined(__APPLE__)
@@ -595,6 +666,8 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
 #else
     IM_UNUSED(main_viewport);
 #endif
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplGlfw_InitPlatformInterface();
 
     // Windows: register a WndProc hook so we can intercept some messages.
 #ifdef _WIN32
@@ -628,6 +701,8 @@ void ImGui_ImplGlfw_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplGlfw_ShutdownPlatformInterface();
+
     if (bd->InstalledCallbacks)
         ImGui_ImplGlfw_RestoreCallbacks(bd->Window);
 
@@ -643,6 +718,7 @@ void ImGui_ImplGlfw_Shutdown()
 
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad | ImGuiBackendFlags_PlatformHasViewports | ImGuiBackendFlags_HasMouseHoveredViewport);
     IM_DELETE(bd);
 }
 
@@ -650,6 +726,7 @@ static void ImGui_ImplGlfw_UpdateMouseData()
 {
     ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
     ImGuiIO& io = ImGui::GetIO();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
 
     if (glfwGetInputMode(bd->Window, GLFW_CURSOR) == GLFW_CURSOR_DISABLED)
     {
@@ -657,9 +734,12 @@ static void ImGui_ImplGlfw_UpdateMouseData()
         return;
     }
 
-    // (those braces are here to reduce diff with multi-viewports support in 'docking' branch)
+    ImGuiID mouse_viewport_id = 0;
+    const ImVec2 mouse_pos_prev = io.MousePos;
+    for (int n = 0; n < platform_io.Viewports.Size; n++)
     {
-        GLFWwindow* window = bd->Window;
+        ImGuiViewport* viewport = platform_io.Viewports[n];
+        GLFWwindow* window = (GLFWwindow*)viewport->PlatformHandle;
 
 #ifdef __EMSCRIPTEN__
         const bool is_window_focused = true;
@@ -669,19 +749,53 @@ static void ImGui_ImplGlfw_UpdateMouseData()
         if (is_window_focused)
         {
             // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
+            // When multi-viewports are enabled, all Dear ImGui positions are same as OS positions.
             if (io.WantSetMousePos)
-                glfwSetCursorPos(window, (double)io.MousePos.x, (double)io.MousePos.y);
+                glfwSetCursorPos(window, (double)(mouse_pos_prev.x - viewport->Pos.x), (double)(mouse_pos_prev.y - viewport->Pos.y));
 
             // (Optional) Fallback to provide mouse position when focused (ImGui_ImplGlfw_CursorPosCallback already provides this when hovered or captured)
             if (bd->MouseWindow == nullptr)
             {
                 double mouse_x, mouse_y;
                 glfwGetCursorPos(window, &mouse_x, &mouse_y);
+                if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+                {
+                    // Single viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
+                    // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+                    int window_x, window_y;
+                    glfwGetWindowPos(window, &window_x, &window_y);
+                    mouse_x += window_x;
+                    mouse_y += window_y;
+                }
                 bd->LastValidMousePos = ImVec2((float)mouse_x, (float)mouse_y);
                 io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
             }
         }
+
+        // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+        // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+        // - [X] GLFW >= 3.3 backend ON WINDOWS ONLY does correctly ignore viewports with the _NoInputs flag.
+        // - [!] GLFW <= 3.2 backend CANNOT correctly ignore viewports with the _NoInputs flag, and CANNOT reported Hovered Viewport because of mouse capture.
+        //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+        //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+        //       by the backend, and use its flawed heuristic to guess the viewport behind.
+        // - [X] GLFW backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+        // FIXME: This is currently only correct on Win32. See what we do below with the WM_NCHITTEST, missing an equivalent for other systems.
+        // See https://github.com/glfw/glfw/issues/1236 if you want to help in making this a GLFW feature.
+#if GLFW_HAS_MOUSE_PASSTHROUGH || (GLFW_HAS_WINDOW_HOVERED && defined(_WIN32))
+        const bool window_no_input = (viewport->Flags & ImGuiViewportFlags_NoInputs) != 0;
+#if GLFW_HAS_MOUSE_PASSTHROUGH
+        glfwSetWindowAttrib(window, GLFW_MOUSE_PASSTHROUGH, window_no_input);
+#endif
+        if (glfwGetWindowAttrib(window, GLFW_HOVERED) && !window_no_input)
+            mouse_viewport_id = viewport->ID;
+#else
+        // We cannot use bd->MouseWindow maintained from CursorEnter/Leave callbacks, because it is locked to the window capturing mouse.
+#endif
     }
+
+    if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)
+        io.AddMouseViewportEvent(mouse_viewport_id);
 }
 
 static void ImGui_ImplGlfw_UpdateMouseCursor()
@@ -692,9 +806,10 @@ 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
@@ -763,6 +878,48 @@ static void ImGui_ImplGlfw_UpdateGamepads()
     #undef MAP_ANALOG
 }
 
+static void ImGui_ImplGlfw_UpdateMonitors()
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    bd->WantUpdateMonitors = false;
+
+    int monitors_count = 0;
+    GLFWmonitor** glfw_monitors = glfwGetMonitors(&monitors_count);
+    if (monitors_count == 0) // Preserve existing monitor list if there are none. Happens on macOS sleeping (#5683)
+        return;
+
+    platform_io.Monitors.resize(0);
+    for (int n = 0; n < monitors_count; n++)
+    {
+        ImGuiPlatformMonitor monitor;
+        int x, y;
+        glfwGetMonitorPos(glfw_monitors[n], &x, &y);
+        const GLFWvidmode* vid_mode = glfwGetVideoMode(glfw_monitors[n]);
+        if (vid_mode == nullptr)
+            continue; // Failed to get Video mode (e.g. Emscripten does not support this function)
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)x, (float)y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)vid_mode->width, (float)vid_mode->height);
+#if GLFW_HAS_MONITOR_WORK_AREA
+        int w, h;
+        glfwGetMonitorWorkarea(glfw_monitors[n], &x, &y, &w, &h);
+        if (w > 0 && h > 0) // Workaround a small GLFW issue reporting zero on monitor changes: https://github.com/glfw/glfw/pull/1761
+        {
+            monitor.WorkPos = ImVec2((float)x, (float)y);
+            monitor.WorkSize = ImVec2((float)w, (float)h);
+        }
+#endif
+#if GLFW_HAS_PER_MONITOR_DPI
+        // Warning: the validity of monitor DPI information on Windows depends on the application DPI awareness settings, which generally needs to be set in the manifest or at runtime.
+        float x_scale, y_scale;
+        glfwGetMonitorContentScale(glfw_monitors[n], &x_scale, &y_scale);
+        monitor.DpiScale = x_scale;
+#endif
+        monitor.PlatformHandle = (void*)glfw_monitors[n]; // [...] GLFW doc states: "guaranteed to be valid only until the monitor configuration changes"
+        platform_io.Monitors.push_back(monitor);
+    }
+}
+
 void ImGui_ImplGlfw_NewFrame()
 {
     ImGuiIO& io = ImGui::GetIO();
@@ -777,9 +934,14 @@ void ImGui_ImplGlfw_NewFrame()
     io.DisplaySize = ImVec2((float)w, (float)h);
     if (w > 0 && h > 0)
         io.DisplayFramebufferScale = ImVec2((float)display_w / (float)w, (float)display_h / (float)h);
+    if (bd->WantUpdateMonitors)
+        ImGui_ImplGlfw_UpdateMonitors();
 
     // Setup time step
+    // (Accept glfwGetTime() not returning a monotonically increasing value. Seems to happens on disconnecting peripherals and probably on VMs and Emscripten, see #6491, #6189, #6114, #3644)
     double current_time = glfwGetTime();
+    if (current_time <= bd->Time)
+        current_time = bd->Time + 0.00001f;
     io.DeltaTime = bd->Time > 0.0 ? (float)(current_time - bd->Time) : (float)(1.0f / 60.0f);
     bd->Time = current_time;
 
@@ -790,6 +952,343 @@ void ImGui_ImplGlfw_NewFrame()
     ImGui_ImplGlfw_UpdateGamepads();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplGlfw_ViewportData
+{
+    GLFWwindow* Window;
+    bool        WindowOwned;
+    int         IgnoreWindowPosEventFrame;
+    int         IgnoreWindowSizeEventFrame;
+
+    ImGui_ImplGlfw_ViewportData()  { Window = nullptr; WindowOwned = false; IgnoreWindowSizeEventFrame = IgnoreWindowPosEventFrame = -1; }
+    ~ImGui_ImplGlfw_ViewportData() { IM_ASSERT(Window == nullptr); }
+};
+
+static void ImGui_ImplGlfw_WindowCloseCallback(GLFWwindow* window)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+        viewport->PlatformRequestClose = true;
+}
+
+// GLFW may dispatch window pos/size events after calling glfwSetWindowPos()/glfwSetWindowSize().
+// However: depending on the platform the callback may be invoked at different time:
+// - on Windows it appears to be called within the glfwSetWindowPos()/glfwSetWindowSize() call
+// - on Linux it is queued and invoked during glfwPollEvents()
+// Because the event doesn't always fire on glfwSetWindowXXX() we use a frame counter tag to only
+// ignore recent glfwSetWindowXXX() calls.
+static void ImGui_ImplGlfw_WindowPosCallback(GLFWwindow* window, int, int)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+    {
+        if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+        {
+            bool ignore_event = (ImGui::GetFrameCount() <= vd->IgnoreWindowPosEventFrame + 1);
+            //data->IgnoreWindowPosEventFrame = -1;
+            if (ignore_event)
+                return;
+        }
+        viewport->PlatformRequestMove = true;
+    }
+}
+
+static void ImGui_ImplGlfw_WindowSizeCallback(GLFWwindow* window, int, int)
+{
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle(window))
+    {
+        if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+        {
+            bool ignore_event = (ImGui::GetFrameCount() <= vd->IgnoreWindowSizeEventFrame + 1);
+            //data->IgnoreWindowSizeEventFrame = -1;
+            if (ignore_event)
+                return;
+        }
+        viewport->PlatformRequestResize = true;
+    }
+}
+
+static void ImGui_ImplGlfw_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = IM_NEW(ImGui_ImplGlfw_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    // GLFW 3.2 unfortunately always set focus on glfwCreateWindow() if GLFW_VISIBLE is set, regardless of GLFW_FOCUSED
+    // With GLFW 3.3, the hint GLFW_FOCUS_ON_SHOW fixes this problem
+    glfwWindowHint(GLFW_VISIBLE, false);
+    glfwWindowHint(GLFW_FOCUSED, false);
+#if GLFW_HAS_FOCUS_ON_SHOW
+    glfwWindowHint(GLFW_FOCUS_ON_SHOW, false);
+ #endif
+    glfwWindowHint(GLFW_DECORATED, (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? false : true);
+#if GLFW_HAS_WINDOW_TOPMOST
+    glfwWindowHint(GLFW_FLOATING, (viewport->Flags & ImGuiViewportFlags_TopMost) ? true : false);
+#endif
+    GLFWwindow* share_window = (bd->ClientApi == GlfwClientApi_OpenGL) ? bd->Window : nullptr;
+    vd->Window = glfwCreateWindow((int)viewport->Size.x, (int)viewport->Size.y, "No Title Yet", nullptr, share_window);
+    vd->WindowOwned = true;
+    viewport->PlatformHandle = (void*)vd->Window;
+#ifdef _WIN32
+    viewport->PlatformHandleRaw = glfwGetWin32Window(vd->Window);
+#elif defined(__APPLE__)
+    viewport->PlatformHandleRaw = (void*)glfwGetCocoaWindow(vd->Window);
+#endif
+    glfwSetWindowPos(vd->Window, (int)viewport->Pos.x, (int)viewport->Pos.y);
+
+    // Install GLFW callbacks for secondary viewports
+    glfwSetWindowFocusCallback(vd->Window, ImGui_ImplGlfw_WindowFocusCallback);
+    glfwSetCursorEnterCallback(vd->Window, ImGui_ImplGlfw_CursorEnterCallback);
+    glfwSetCursorPosCallback(vd->Window, ImGui_ImplGlfw_CursorPosCallback);
+    glfwSetMouseButtonCallback(vd->Window, ImGui_ImplGlfw_MouseButtonCallback);
+    glfwSetScrollCallback(vd->Window, ImGui_ImplGlfw_ScrollCallback);
+    glfwSetKeyCallback(vd->Window, ImGui_ImplGlfw_KeyCallback);
+    glfwSetCharCallback(vd->Window, ImGui_ImplGlfw_CharCallback);
+    glfwSetWindowCloseCallback(vd->Window, ImGui_ImplGlfw_WindowCloseCallback);
+    glfwSetWindowPosCallback(vd->Window, ImGui_ImplGlfw_WindowPosCallback);
+    glfwSetWindowSizeCallback(vd->Window, ImGui_ImplGlfw_WindowSizeCallback);
+    if (bd->ClientApi == GlfwClientApi_OpenGL)
+    {
+        glfwMakeContextCurrent(vd->Window);
+        glfwSwapInterval(0);
+    }
+}
+
+static void ImGui_ImplGlfw_DestroyWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    if (ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData)
+    {
+        if (vd->WindowOwned)
+        {
+#if !GLFW_HAS_MOUSE_PASSTHROUGH && GLFW_HAS_WINDOW_HOVERED && defined(_WIN32)
+            HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+            ::RemovePropA(hwnd, "IMGUI_VIEWPORT");
+#endif
+
+            // Release any keys that were pressed in the window being destroyed and are still held down,
+            // because we will not receive any release events after window is destroyed.
+            for (int i = 0; i < IM_ARRAYSIZE(bd->KeyOwnerWindows); i++)
+                if (bd->KeyOwnerWindows[i] == vd->Window)
+                    ImGui_ImplGlfw_KeyCallback(vd->Window, i, 0, GLFW_RELEASE, 0); // Later params are only used for main viewport, on which this function is never called.
+
+            glfwDestroyWindow(vd->Window);
+        }
+        vd->Window = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplGlfw_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+
+#if defined(_WIN32)
+    // GLFW hack: Hide icon from task bar
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+    if (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon)
+    {
+        LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
+        ex_style &= ~WS_EX_APPWINDOW;
+        ex_style |= WS_EX_TOOLWINDOW;
+        ::SetWindowLong(hwnd, GWL_EXSTYLE, ex_style);
+    }
+
+    // GLFW hack: install hook for WM_NCHITTEST message handler
+#if !GLFW_HAS_MOUSE_PASSTHROUGH && GLFW_HAS_WINDOW_HOVERED && defined(_WIN32)
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ::SetPropA(hwnd, "IMGUI_VIEWPORT", viewport);
+    IM_ASSERT(bd->GlfwWndProc == (WNDPROC)::GetWindowLongPtr(hwnd, GWLP_WNDPROC));
+    ::SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR)ImGui_ImplGlfw_WndProc);
+#endif
+
+#if !GLFW_HAS_FOCUS_ON_SHOW
+    // GLFW hack: GLFW 3.2 has a bug where glfwShowWindow() also activates/focus the window.
+    // The fix was pushed to GLFW repository on 2018/01/09 and should be included in GLFW 3.3 via a GLFW_FOCUS_ON_SHOW window attribute.
+    // See https://github.com/glfw/glfw/issues/1189
+    // FIXME-VIEWPORT: Implement same work-around for Linux/OSX in the meanwhile.
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+    {
+        ::ShowWindow(hwnd, SW_SHOWNA);
+        return;
+    }
+#endif
+#endif
+
+    glfwShowWindow(vd->Window);
+}
+
+static ImVec2 ImGui_ImplGlfw_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    int x = 0, y = 0;
+    glfwGetWindowPos(vd->Window, &x, &y);
+    return ImVec2((float)x, (float)y);
+}
+
+static void ImGui_ImplGlfw_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    vd->IgnoreWindowPosEventFrame = ImGui::GetFrameCount();
+    glfwSetWindowPos(vd->Window, (int)pos.x, (int)pos.y);
+}
+
+static ImVec2 ImGui_ImplGlfw_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    int w = 0, h = 0;
+    glfwGetWindowSize(vd->Window, &w, &h);
+    return ImVec2((float)w, (float)h);
+}
+
+static void ImGui_ImplGlfw_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+#if __APPLE__ && !GLFW_HAS_OSX_WINDOW_POS_FIX
+    // Native OS windows are positioned from the bottom-left corner on macOS, whereas on other platforms they are
+    // positioned from the upper-left corner. GLFW makes an effort to convert macOS style coordinates, however it
+    // doesn't handle it when changing size. We are manually moving the window in order for changes of size to be based
+    // on the upper-left corner.
+    int x, y, width, height;
+    glfwGetWindowPos(vd->Window, &x, &y);
+    glfwGetWindowSize(vd->Window, &width, &height);
+    glfwSetWindowPos(vd->Window, x, y - height + size.y);
+#endif
+    vd->IgnoreWindowSizeEventFrame = ImGui::GetFrameCount();
+    glfwSetWindowSize(vd->Window, (int)size.x, (int)size.y);
+}
+
+static void ImGui_ImplGlfw_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    glfwSetWindowTitle(vd->Window, title);
+}
+
+static void ImGui_ImplGlfw_SetWindowFocus(ImGuiViewport* viewport)
+{
+#if GLFW_HAS_FOCUS_WINDOW
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    glfwFocusWindow(vd->Window);
+#else
+    // FIXME: What are the effect of not having this function? At the moment imgui doesn't actually call SetWindowFocus - we set that up ahead, will answer that question later.
+    (void)viewport;
+#endif
+}
+
+static bool ImGui_ImplGlfw_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    return glfwGetWindowAttrib(vd->Window, GLFW_FOCUSED) != 0;
+}
+
+static bool ImGui_ImplGlfw_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    return glfwGetWindowAttrib(vd->Window, GLFW_ICONIFIED) != 0;
+}
+
+#if GLFW_HAS_WINDOW_ALPHA
+static void ImGui_ImplGlfw_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    glfwSetWindowOpacity(vd->Window, alpha);
+}
+#endif
+
+static void ImGui_ImplGlfw_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    if (bd->ClientApi == GlfwClientApi_OpenGL)
+        glfwMakeContextCurrent(vd->Window);
+}
+
+static void ImGui_ImplGlfw_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    if (bd->ClientApi == GlfwClientApi_OpenGL)
+    {
+        glfwMakeContextCurrent(vd->Window);
+        glfwSwapBuffers(vd->Window);
+    }
+}
+
+//--------------------------------------------------------------------------------------------------------
+// Vulkan support (the Vulkan renderer needs to call a platform-side support function to create the surface)
+//--------------------------------------------------------------------------------------------------------
+
+// Avoid including <vulkan.h> so we can build without it
+#if GLFW_HAS_VULKAN
+#ifndef VULKAN_H_
+#define VK_DEFINE_HANDLE(object) typedef struct object##_T* object;
+#if defined(__LP64__) || defined(_WIN64) || defined(__x86_64__) || defined(_M_X64) || defined(__ia64) || defined (_M_IA64) || defined(__aarch64__) || defined(__powerpc64__)
+#define VK_DEFINE_NON_DISPATCHABLE_HANDLE(object) typedef struct object##_T *object;
+#else
+#define VK_DEFINE_NON_DISPATCHABLE_HANDLE(object) typedef uint64_t object;
+#endif
+VK_DEFINE_HANDLE(VkInstance)
+VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkSurfaceKHR)
+struct VkAllocationCallbacks;
+enum VkResult { VK_RESULT_MAX_ENUM = 0x7FFFFFFF };
+#endif // VULKAN_H_
+extern "C" { extern GLFWAPI VkResult glfwCreateWindowSurface(VkInstance instance, GLFWwindow* window, const VkAllocationCallbacks* allocator, VkSurfaceKHR* surface); }
+static int ImGui_ImplGlfw_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_instance, const void* vk_allocator, ImU64* out_vk_surface)
+{
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGui_ImplGlfw_ViewportData* vd = (ImGui_ImplGlfw_ViewportData*)viewport->PlatformUserData;
+    IM_UNUSED(bd);
+    IM_ASSERT(bd->ClientApi == GlfwClientApi_Vulkan);
+    VkResult err = glfwCreateWindowSurface((VkInstance)vk_instance, vd->Window, (const VkAllocationCallbacks*)vk_allocator, (VkSurfaceKHR*)out_vk_surface);
+    return (int)err;
+}
+#endif // GLFW_HAS_VULKAN
+
+static void ImGui_ImplGlfw_InitPlatformInterface()
+{
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGui_ImplGlfw_Data* bd = ImGui_ImplGlfw_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplGlfw_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplGlfw_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplGlfw_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplGlfw_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplGlfw_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplGlfw_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplGlfw_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplGlfw_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplGlfw_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplGlfw_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplGlfw_SetWindowTitle;
+    platform_io.Platform_RenderWindow = ImGui_ImplGlfw_RenderWindow;
+    platform_io.Platform_SwapBuffers = ImGui_ImplGlfw_SwapBuffers;
+#if GLFW_HAS_WINDOW_ALPHA
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplGlfw_SetWindowAlpha;
+#endif
+#if GLFW_HAS_VULKAN
+    platform_io.Platform_CreateVkSurface = ImGui_ImplGlfw_CreateVkSurface;
+#endif
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplGlfw_ViewportData* vd = IM_NEW(ImGui_ImplGlfw_ViewportData)();
+    vd->Window = bd->Window;
+    vd->WindowOwned = false;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = (void*)bd->Window;
+}
+
+static void ImGui_ImplGlfw_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif

backends/imgui_impl_glfw.h

@@ -1,13 +1,18 @@
 // dear imgui: Platform Backend for GLFW
 // This needs to be used along with a Renderer (e.g. OpenGL3, Vulkan, WebGPU..)
 // (Info: GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
+// (Requires: GLFW 3.1+. Prefer GLFW 3.3+ for full feature support.)
 
 // Implemented features:
 //  [X] Platform: Clipboard support.
 //  [X] Platform: Mouse support. Can discriminate Mouse/TouchScreen/Pen (Windows only).
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy GLFW_KEY_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
-//  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+//  [x] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange' (note: the resizing cursors requires GLFW 3.4+).
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+
+// Issues:
+//  [ ] Platform: Multi-viewport support: ParentViewportID not honored, and so io.ConfigViewportsNoDefaultParent has no effect (minor).
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_glut.cpp

@@ -21,6 +21,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-04-17: BREAKING: Removed call to ImGui::NewFrame() from ImGui_ImplGLUT_NewFrame(). Needs to be called from the main application loop, like with every other backends.
 //  2022-09-26: Inputs: Renamed ImGuiKey_ModXXX introduced in 1.87 to ImGuiMod_XXX (old names still supported).
 //  2022-01-26: Inputs: replaced short-lived io.AddKeyModsEvent() (added two weeks ago) with io.AddKeyEvent() using ImGuiKey_ModXXX flags. Sorry for the confusion.
 //  2022-01-17: Inputs: calling new io.AddMousePosEvent(), io.AddMouseButtonEvent(), io.AddMouseWheelEvent() API (1.87+).
@@ -190,6 +191,8 @@ void ImGui_ImplGLUT_InstallFuncs()
 
 void ImGui_ImplGLUT_Shutdown()
 {
+    ImGuiIO& io = ImGui::GetIO();
+    io.BackendPlatformName = nullptr;
 }
 
 void ImGui_ImplGLUT_NewFrame()
@@ -202,9 +205,6 @@ void ImGui_ImplGLUT_NewFrame()
         delta_time_ms = 1;
     io.DeltaTime = delta_time_ms / 1000.0f;
     g_Time = current_time;
-
-    // Start the frame
-    ImGui::NewFrame();
 }
 
 static void ImGui_ImplGLUT_UpdateKeyModifiers()

backends/imgui_impl_metal.h

@@ -4,8 +4,9 @@
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'MTLTexture' as ImTextureID. Read the FAQ about ImTextureID!
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
-// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this. 
+// 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.
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs

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) with 16-bit indices.
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -12,6 +13,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Metal: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-08-23: Metal: Update deprecated property 'sampleCount'->'rasterSampleCount'.
 //  2022-07-05: Metal: Add dispatch synchronization.
 //  2022-06-30: Metal: Use __bridge for ARC based systems.
@@ -34,6 +36,12 @@
 #import <time.h>
 #import <Metal/Metal.h>
 
+// Forward Declarations
+static void ImGui_ImplMetal_InitPlatformInterface();
+static void ImGui_ImplMetal_ShutdownPlatformInterface();
+static void ImGui_ImplMetal_CreateDeviceObjectsForPlatformWindows();
+static void ImGui_ImplMetal_InvalidateDeviceObjectsForPlatformWindows();
+
 #pragma mark - Support classes
 
 // A wrapper around a MTLBuffer object that knows the last time it was reused
@@ -126,17 +134,29 @@ bool ImGui_ImplMetal_Init(id<MTLDevice> device)
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_metal";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     bd->SharedMetalContext = [[MetalContext alloc] init];
     bd->SharedMetalContext.device = device;
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplMetal_InitPlatformInterface();
+
     return true;
 }
 
 void ImGui_ImplMetal_Shutdown()
 {
+    ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData();
+    IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
+    ImGui_ImplMetal_ShutdownPlatformInterface();
     ImGui_ImplMetal_DestroyDeviceObjects();
     ImGui_ImplMetal_DestroyBackendData();
+
+    ImGuiIO& io = ImGui::GetIO();
+    io.BackendRendererName = nullptr;
+    io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
 }
 
 void ImGui_ImplMetal_NewFrame(MTLRenderPassDescriptor* renderPassDescriptor)
@@ -354,6 +374,7 @@ bool ImGui_ImplMetal_CreateDeviceObjects(id<MTLDevice> device)
     depthStencilDescriptor.depthWriteEnabled = NO;
     depthStencilDescriptor.depthCompareFunction = MTLCompareFunctionAlways;
     bd->SharedMetalContext.depthStencilState = [device newDepthStencilStateWithDescriptor:depthStencilDescriptor];
+    ImGui_ImplMetal_CreateDeviceObjectsForPlatformWindows();
     ImGui_ImplMetal_CreateFontsTexture(device);
 
     return true;
@@ -363,9 +384,155 @@ void ImGui_ImplMetal_DestroyDeviceObjects()
 {
     ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData();
     ImGui_ImplMetal_DestroyFontsTexture();
+    ImGui_ImplMetal_InvalidateDeviceObjectsForPlatformWindows();
     [bd->SharedMetalContext.renderPipelineStateCache removeAllObjects];
 }
 
+#pragma mark - Multi-viewport support
+
+#import <QuartzCore/CAMetalLayer.h>
+
+#if TARGET_OS_OSX
+#import <Cocoa/Cocoa.h>
+#endif
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the back-end to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+struct ImGuiViewportDataMetal
+{
+    CAMetalLayer*               MetalLayer;
+    id<MTLCommandQueue>         CommandQueue;
+    MTLRenderPassDescriptor*    RenderPassDescriptor;
+    void*                       Handle = nullptr;
+    bool                        FirstFrame = true;
+};
+
+static void ImGui_ImplMetal_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplMetal_Data* bd = ImGui_ImplMetal_GetBackendData();
+    ImGuiViewportDataMetal* data = IM_NEW(ImGuiViewportDataMetal)();
+    viewport->RendererUserData = data;
+
+    // PlatformHandleRaw should always be a NSWindow*, whereas PlatformHandle might be a higher-level handle (e.g. GLFWWindow*, SDL_Window*).
+    // Some back-ends will leave PlatformHandleRaw == 0, in which case we assume PlatformHandle will contain the NSWindow*.
+    void* handle = viewport->PlatformHandleRaw ? viewport->PlatformHandleRaw : viewport->PlatformHandle;
+    IM_ASSERT(handle != nullptr);
+
+    id<MTLDevice> device = bd->SharedMetalContext.device;
+    CAMetalLayer* layer = [CAMetalLayer layer];
+    layer.device = device;
+    layer.framebufferOnly = YES;
+    layer.pixelFormat = bd->SharedMetalContext.framebufferDescriptor.colorPixelFormat;
+#if TARGET_OS_OSX
+    NSWindow* window = (__bridge NSWindow*)handle;
+    NSView* view = window.contentView;
+    view.layer = layer;
+    view.wantsLayer = YES;
+#endif
+    data->MetalLayer = layer;
+    data->CommandQueue = [device newCommandQueue];
+    data->RenderPassDescriptor = [[MTLRenderPassDescriptor alloc] init];
+    data->Handle = handle;
+}
+
+static void ImGui_ImplMetal_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
+    if (ImGuiViewportDataMetal* data = (ImGuiViewportDataMetal*)viewport->RendererUserData)
+        IM_DELETE(data);
+    viewport->RendererUserData = nullptr;
+}
+
+inline static CGSize MakeScaledSize(CGSize size, CGFloat scale)
+{
+    return CGSizeMake(size.width * scale, size.height * scale);
+}
+
+static void ImGui_ImplMetal_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGuiViewportDataMetal* data = (ImGuiViewportDataMetal*)viewport->RendererUserData;
+    data->MetalLayer.drawableSize = MakeScaledSize(CGSizeMake(size.x, size.y), viewport->DpiScale);
+}
+
+static void ImGui_ImplMetal_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGuiViewportDataMetal* data = (ImGuiViewportDataMetal*)viewport->RendererUserData;
+
+#if TARGET_OS_OSX
+    void* handle = viewport->PlatformHandleRaw ? viewport->PlatformHandleRaw : viewport->PlatformHandle;
+    NSWindow* window = (__bridge NSWindow*)handle;
+
+    // Always render the first frame, regardless of occlusionState, to avoid an initial flicker
+    if ((window.occlusionState & NSWindowOcclusionStateVisible) == 0 && !data->FirstFrame)
+    {
+        // Do not render windows which are completely occluded. Calling -[CAMetalLayer nextDrawable] will hang for
+        // approximately 1 second if the Metal layer is completely occluded.
+        return;
+    }
+    data->FirstFrame = false;
+
+    viewport->DpiScale = (float)window.backingScaleFactor;
+    if (data->MetalLayer.contentsScale != viewport->DpiScale)
+    {
+        data->MetalLayer.contentsScale = viewport->DpiScale;
+        data->MetalLayer.drawableSize = MakeScaledSize(window.frame.size, viewport->DpiScale);
+    }
+    viewport->DrawData->FramebufferScale = ImVec2(viewport->DpiScale, viewport->DpiScale);
+#endif
+
+    id <CAMetalDrawable> drawable = [data->MetalLayer nextDrawable];
+    if (drawable == nil)
+        return;
+
+    MTLRenderPassDescriptor* renderPassDescriptor = data->RenderPassDescriptor;
+    renderPassDescriptor.colorAttachments[0].texture = drawable.texture;
+    renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(0, 0, 0, 0);
+    if ((viewport->Flags & ImGuiViewportFlags_NoRendererClear) == 0)
+        renderPassDescriptor.colorAttachments[0].loadAction = MTLLoadActionClear;
+
+    id <MTLCommandBuffer> commandBuffer = [data->CommandQueue commandBuffer];
+    id <MTLRenderCommandEncoder> renderEncoder = [commandBuffer renderCommandEncoderWithDescriptor:renderPassDescriptor];
+    ImGui_ImplMetal_RenderDrawData(viewport->DrawData, commandBuffer, renderEncoder);
+    [renderEncoder endEncoding];
+
+    [commandBuffer presentDrawable:drawable];
+    [commandBuffer commit];
+}
+
+static void ImGui_ImplMetal_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplMetal_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplMetal_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplMetal_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplMetal_RenderWindow;
+}
+
+static void ImGui_ImplMetal_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
+static void ImGui_ImplMetal_CreateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (!platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplMetal_CreateWindow(platform_io.Viewports[i]);
+}
+
+static void ImGui_ImplMetal_InvalidateDeviceObjectsForPlatformWindows()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int i = 1; i < platform_io.Viewports.Size; i++)
+        if (platform_io.Viewports[i]->RendererUserData)
+            ImGui_ImplMetal_DestroyWindow(platform_io.Viewports[i]);
+}
+
 #pragma mark - MetalBuffer implementation
 
 @implementation MetalBuffer

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'.
 
 // 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 +20,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2021-12-08: OpenGL: Fixed mishandling of the the ImDrawCmd::IdxOffset field! This is an old bug but it never had an effect until some internal rendering changes in 1.86.
 //  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
@@ -79,6 +81,10 @@ static ImGui_ImplOpenGL2_Data* ImGui_ImplOpenGL2_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL2_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplOpenGL2_InitPlatformInterface();
+static void ImGui_ImplOpenGL2_ShutdownPlatformInterface();
+
 // Functions
 bool    ImGui_ImplOpenGL2_Init()
 {
@@ -89,6 +95,10 @@ bool    ImGui_ImplOpenGL2_Init()
     ImGui_ImplOpenGL2_Data* bd = IM_NEW(ImGui_ImplOpenGL2_Data)();
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_opengl2";
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;    // We can create multi-viewports on the Renderer side (optional)
+
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplOpenGL2_InitPlatformInterface();
 
     return true;
 }
@@ -99,9 +109,11 @@ void    ImGui_ImplOpenGL2_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplOpenGL2_ShutdownPlatformInterface();
     ImGui_ImplOpenGL2_DestroyDeviceObjects();
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasViewports;
     IM_DELETE(bd);
 }
 
@@ -293,6 +305,34 @@ void    ImGui_ImplOpenGL2_DestroyDeviceObjects()
     ImGui_ImplOpenGL2_DestroyFontsTexture();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplOpenGL2_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+    {
+        ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+        glClear(GL_COLOR_BUFFER_BIT);
+    }
+    ImGui_ImplOpenGL2_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplOpenGL2_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL2_RenderWindow;
+}
+
+static void ImGui_ImplOpenGL2_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif

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'.
 
 // 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_opengl3.cpp

@@ -5,7 +5,13 @@
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
-//  [x] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+//  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+
+// About WebGL/ES:
+// - You need to '#define IMGUI_IMPL_OPENGL_ES2' or '#define IMGUI_IMPL_OPENGL_ES3' to use WebGL or OpenGL ES.
+// - This is done automatically on iOS, Android and Emscripten targets.
+// - For other targets, the define needs to be visible from the imgui_impl_opengl3.cpp compilation unit. If unsure, define globally or in imconfig.h.
 
 // 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.
@@ -14,6 +20,10 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2023-06-20: OpenGL: Fixed erroneous use glGetIntegerv(GL_CONTEXT_PROFILE_MASK) on contexts lower than 3.2. (#6539, #6333)
+//  2023-05-09: OpenGL: Support for glBindSampler() backup/restore on ES3. (#6375)
+//  2023-04-18: OpenGL: Restore front and back polygon mode separately when supported by context. (#6333)
 //  2023-03-23: OpenGL: Properly restoring "no shader program bound" if it was the case prior to running the rendering function. (#6267, #6220, #6224)
 //  2023-03-15: OpenGL: Fixed GL loader crash when GL_VERSION returns NULL. (#6154, #4445, #3530)
 //  2023-03-06: OpenGL: Fixed restoration of a potentially deleted OpenGL program, by calling glIsProgram(). (#6220, #6224)
@@ -175,8 +185,8 @@
 #define IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
 #endif
 
-// Desktop GL 3.3+ has glBindSampler()
-#if !defined(IMGUI_IMPL_OPENGL_ES2) && !defined(IMGUI_IMPL_OPENGL_ES3) && defined(GL_VERSION_3_3)
+// Desktop GL 3.3+ and GL ES 3.0+ have glBindSampler()
+#if !defined(IMGUI_IMPL_OPENGL_ES2) && (defined(IMGUI_IMPL_OPENGL_ES3) || defined(GL_VERSION_3_3))
 #define IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
 #endif
 
@@ -204,6 +214,10 @@ struct ImGui_ImplOpenGL3_Data
 {
     GLuint          GlVersion;               // Extracted at runtime using GL_MAJOR_VERSION, GL_MINOR_VERSION queries (e.g. 320 for GL 3.2)
     char            GlslVersionString[32];   // Specified by user or detected based on compile time GL settings.
+    bool            GlProfileIsES2;
+    bool            GlProfileIsES3;
+    bool            GlProfileIsCompat;
+    GLint           GlProfileMask;
     GLuint          FontTexture;
     GLuint          ShaderHandle;
     GLint           AttribLocationTex;       // Uniforms location
@@ -227,6 +241,10 @@ static ImGui_ImplOpenGL3_Data* ImGui_ImplOpenGL3_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL3_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplOpenGL3_InitPlatformInterface();
+static void ImGui_ImplOpenGL3_ShutdownPlatformInterface();
+
 // OpenGL vertex attribute state (for ES 1.0 and ES 2.0 only)
 #ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
 struct ImGui_ImplOpenGL3_VtxAttribState
@@ -272,7 +290,12 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     io.BackendRendererName = "imgui_impl_opengl3";
 
     // Query for GL version (e.g. 320 for GL 3.2)
-#if !defined(IMGUI_IMPL_OPENGL_ES2)
+#if defined(IMGUI_IMPL_OPENGL_ES2)
+    // GLES 2
+    bd->GlVersion = 200;
+    bd->GlProfileIsES2 = true;
+#else
+    // Desktop or GLES 3
     GLint major = 0;
     GLint minor = 0;
     glGetIntegerv(GL_MAJOR_VERSION, &major);
@@ -284,6 +307,15 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
         sscanf(gl_version, "%d.%d", &major, &minor);
     }
     bd->GlVersion = (GLuint)(major * 100 + minor * 10);
+#if defined(GL_CONTEXT_PROFILE_MASK)
+    if (bd->GlVersion >= 320)
+        glGetIntegerv(GL_CONTEXT_PROFILE_MASK, &bd->GlProfileMask);
+    bd->GlProfileIsCompat = (bd->GlProfileMask & GL_CONTEXT_COMPATIBILITY_PROFILE_BIT) != 0;
+#endif
+
+#if defined(IMGUI_IMPL_OPENGL_ES3)
+    bd->GlProfileIsES3 = true;
+#endif
 
     bd->UseBufferSubData = false;
     /*
@@ -294,18 +326,17 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
             bd->UseBufferSubData = true;
 #endif
     */
-#else
-    bd->GlVersion = 200; // GLES 2
 #endif
 
 #ifdef IMGUI_IMPL_OPENGL_DEBUG
-    printf("GL_MAJOR_VERSION = %d\nGL_MINOR_VERSION = %d\nGL_VENDOR = '%s'\nGL_RENDERER = '%s'\n", major, minor, (const char*)glGetString(GL_VENDOR), (const char*)glGetString(GL_RENDERER)); // [DEBUG]
+    printf("GlVersion = %d\nGlProfileIsCompat = %d\nGlProfileMask = 0x%X\nGlProfileIsES2 = %d, GlProfileIsES3 = %d\nGL_VENDOR = '%s'\nGL_RENDERER = '%s'\n", bd->GlVersion, bd->GlProfileIsCompat, bd->GlProfileMask, bd->GlProfileIsES2, bd->GlProfileIsES3, (const char*)glGetString(GL_VENDOR), (const char*)glGetString(GL_RENDERER)); // [DEBUG]
 #endif
 
 #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_VTX_OFFSET
     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.
@@ -343,6 +374,9 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     }
 #endif
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplOpenGL3_InitPlatformInterface();
+
     return true;
 }
 
@@ -352,9 +386,11 @@ void    ImGui_ImplOpenGL3_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplOpenGL3_ShutdownPlatformInterface();
     ImGui_ImplOpenGL3_DestroyDeviceObjects();
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -420,8 +456,8 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid
     glUniformMatrix4fv(bd->AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]);
 
 #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
-    if (bd->GlVersion >= 330)
-        glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 may set that otherwise.
+    if (bd->GlVersion >= 330 || bd->GlProfileIsES3)
+        glBindSampler(0, 0); // We use combined texture/sampler state. Applications using GL 3.3 and GL ES 3.0 may set that otherwise.
 #endif
 
     (void)vertex_array_object;
@@ -459,7 +495,7 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
     GLuint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&last_program);
     GLuint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, (GLint*)&last_texture);
 #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
-    GLuint last_sampler; if (bd->GlVersion >= 330) { glGetIntegerv(GL_SAMPLER_BINDING, (GLint*)&last_sampler); } else { last_sampler = 0; }
+    GLuint last_sampler; if (bd->GlVersion >= 330 || bd->GlProfileIsES3) { glGetIntegerv(GL_SAMPLER_BINDING, (GLint*)&last_sampler); } else { last_sampler = 0; }
 #endif
     GLuint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, (GLint*)&last_array_buffer);
 #ifndef IMGUI_IMPL_OPENGL_USE_VERTEX_ARRAY
@@ -586,7 +622,7 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
     if (last_program == 0 || glIsProgram(last_program)) glUseProgram(last_program);
     glBindTexture(GL_TEXTURE_2D, last_texture);
 #ifdef IMGUI_IMPL_OPENGL_MAY_HAVE_BIND_SAMPLER
-    if (bd->GlVersion >= 330)
+    if (bd->GlVersion >= 330 || bd->GlProfileIsES3)
         glBindSampler(0, last_sampler);
 #endif
     glActiveTexture(last_active_texture);
@@ -612,8 +648,18 @@ void    ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data)
 #endif
 
 #ifdef IMGUI_IMPL_HAS_POLYGON_MODE
-    glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
-#endif
+    // Desktop OpenGL 3.0 and OpenGL 3.1 had separate polygon draw modes for front-facing and back-facing faces of polygons
+    if (bd->GlVersion <= 310 || bd->GlProfileIsCompat)
+    {
+        glPolygonMode(GL_FRONT, (GLenum)last_polygon_mode[0]);
+        glPolygonMode(GL_BACK, (GLenum)last_polygon_mode[1]);
+    }
+    else
+    {
+        glPolygonMode(GL_FRONT_AND_BACK, (GLenum)last_polygon_mode[0]);
+    }
+#endif // IMGUI_IMPL_HAS_POLYGON_MODE
+
     glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
     glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
     (void)bd; // Not all compilation paths use this
@@ -898,6 +944,34 @@ void    ImGui_ImplOpenGL3_DestroyDeviceObjects()
     ImGui_ImplOpenGL3_DestroyFontsTexture();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplOpenGL3_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+    {
+        ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+        glClear(GL_COLOR_BUFFER_BIT);
+    }
+    ImGui_ImplOpenGL3_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplOpenGL3_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL3_RenderWindow;
+}
+
+static void ImGui_ImplOpenGL3_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 #if defined(__GNUC__)
 #pragma GCC diagnostic pop
 #endif

backends/imgui_impl_opengl3.h

@@ -5,7 +5,13 @@
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
-//  [x] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+//  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices (Desktop OpenGL only).
+//  [X] Renderer: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+
+// About WebGL/ES:
+// - You need to '#define IMGUI_IMPL_OPENGL_ES2' or '#define IMGUI_IMPL_OPENGL_ES3' to use WebGL or OpenGL ES.
+// - This is done automatically on iOS, Android and Emscripten targets.
+// - For other targets, the define needs to be visible from the imgui_impl_opengl3.cpp compilation unit. If unsure, define globally or in imconfig.h.
 
 // 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_opengl3_loader.h

@@ -118,7 +118,7 @@ extern "C" {
 ** included as <GL/glcorearb.h>.
 **
 ** glcorearb.h includes only APIs in the latest OpenGL core profile
-** implementation together with APIs in newer ARB extensions which
+** implementation together with APIs in newer ARB extensions which 
 ** can be supported by the core profile. It does not, and never will
 ** include functionality removed from the core profile, such as
 ** fixed-function vertex and fragment processing.
@@ -154,6 +154,8 @@ typedef khronos_uint8_t GLubyte;
 #define GL_ONE                            1
 #define GL_SRC_ALPHA                      0x0302
 #define GL_ONE_MINUS_SRC_ALPHA            0x0303
+#define GL_FRONT                          0x0404
+#define GL_BACK                           0x0405
 #define GL_FRONT_AND_BACK                 0x0408
 #define GL_POLYGON_MODE                   0x0B40
 #define GL_CULL_FACE                      0x0B44
@@ -373,6 +375,8 @@ GLAPI void APIENTRY glGenVertexArrays (GLsizei n, GLuint *arrays);
 typedef struct __GLsync *GLsync;
 typedef khronos_uint64_t GLuint64;
 typedef khronos_int64_t GLint64;
+#define GL_CONTEXT_COMPATIBILITY_PROFILE_BIT 0x00000002
+#define GL_CONTEXT_PROFILE_MASK           0x9126
 typedef void (APIENTRYP PFNGLDRAWELEMENTSBASEVERTEXPROC) (GLenum mode, GLsizei count, GLenum type, const void *indices, GLint basevertex);
 typedef void (APIENTRYP PFNGLGETINTEGER64I_VPROC) (GLenum target, GLuint index, GLint64 *data);
 #ifdef GL_GLEXT_PROTOTYPES

backends/imgui_impl_osx.h

@@ -10,6 +10,7 @@
 //  [X] Platform: OSX clipboard is supported within core Dear ImGui (no specific code in this backend).
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: IME support.
+//  [X] Platform: Multi-viewport / platform windows.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_osx.mm

@@ -10,6 +10,7 @@
 //  [X] Platform: OSX clipboard is supported within core Dear ImGui (no specific code in this backend).
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: IME support.
+//  [X] Platform: Multi-viewport / platform windows.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -25,6 +26,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2023-04-09: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_Pen.
 //  2023-02-01: Fixed scroll wheel scaling for devices emitting events with hasPreciseScrollingDeltas==false (e.g. non-Apple mices).
 //  2022-11-02: Fixed mouse coordinates before clicking the host window.
@@ -75,6 +77,7 @@ struct ImGui_ImplOSX_Data
     KeyEventResponder*          KeyEventResponder;
     NSTextInputContext*         InputContext;
     id                          Monitor;
+    NSWindow*                   Window;
 
     ImGui_ImplOSX_Data()        { memset(this, 0, sizeof(*this)); }
 };
@@ -86,6 +89,9 @@ static void                     ImGui_ImplOSX_DestroyBackendData()  { IM_DELETE(
 static inline CFTimeInterval    GetMachAbsoluteTimeInSeconds()      { return (CFTimeInterval)(double)(clock_gettime_nsec_np(CLOCK_UPTIME_RAW) / 1e9); }
 
 // Forward Declarations
+static void ImGui_ImplOSX_InitPlatformInterface();
+static void ImGui_ImplOSX_ShutdownPlatformInterface();
+static void ImGui_ImplOSX_UpdateMonitors();
 static void ImGui_ImplOSX_AddTrackingArea(NSView* _Nonnull view);
 static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
 
@@ -229,6 +235,7 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
 
 - (void)onApplicationBecomeActive:(NSNotification*)aNotification;
 - (void)onApplicationBecomeInactive:(NSNotification*)aNotification;
+- (void)displaysDidChange:(NSNotification*)aNotification;
 
 @end
 
@@ -246,6 +253,11 @@ static bool ImGui_ImplOSX_HandleEvent(NSEvent* event, NSView* view);
     io.AddFocusEvent(false);
 }
 
+- (void)displaysDidChange:(NSNotification*)aNotification
+{
+    ImGui_ImplOSX_UpdateMonitors();
+}
+
 @end
 
 // Functions
@@ -393,9 +405,16 @@ bool ImGui_ImplOSX_Init(NSView* view)
     // Setup backend capabilities flags
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;           // We can honor GetMouseCursor() values (optional)
     //io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+    io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;      // We can create multi-viewports on the Platform side (optional)
+    //io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
     io.BackendPlatformName = "imgui_impl_osx";
 
     bd->Observer = [ImGuiObserver new];
+    bd->Window = view.window ?: NSApp.orderedWindows.firstObject;
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->PlatformHandle = main_viewport->PlatformHandleRaw = (__bridge_retained void*)bd->Window;
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplOSX_InitPlatformInterface();
 
     // Load cursors. Some of them are undocumented.
     bd->MouseCursorHidden = false;
@@ -476,13 +495,21 @@ bool ImGui_ImplOSX_Init(NSView* view)
 void ImGui_ImplOSX_Shutdown()
 {
     ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
+
     bd->Observer = nullptr;
     if (bd->Monitor != nullptr)
     {
         [NSEvent removeMonitor:bd->Monitor];
         bd->Monitor = nullptr;
     }
+
+    ImGui_ImplOSX_ShutdownPlatformInterface();
     ImGui_ImplOSX_DestroyBackendData();
+    ImGuiIO& io = ImGui::GetIO();
+    io.BackendPlatformName = nullptr;
+    io.BackendPlatformUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasGamepad | ImGuiBackendFlags_PlatformHasViewports);
 }
 
 static void ImGui_ImplOSX_UpdateMouseCursor()
@@ -659,14 +686,23 @@ 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;
@@ -793,3 +829,283 @@ static void ImGui_ImplOSX_AddTrackingArea(NSView* _Nonnull view)
         return event;
     }];
 }
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the back-end to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+struct ImGuiViewportDataOSX
+{
+    NSWindow*               Window;
+    bool                    WindowOwned;
+
+    ImGuiViewportDataOSX()  { WindowOwned = false; }
+    ~ImGuiViewportDataOSX() { IM_ASSERT(Window == nil); }
+};
+
+@interface ImGui_ImplOSX_Window: NSWindow
+@end
+
+@implementation ImGui_ImplOSX_Window
+
+- (BOOL)canBecomeKeyWindow
+{
+    return YES;
+}
+
+@end
+
+static void ConvertNSRect(NSScreen* screen, NSRect* r)
+{
+    r->origin.y = screen.frame.size.height - r->origin.y - r->size.height;
+}
+
+static void ImGui_ImplOSX_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGuiViewportDataOSX* data = IM_NEW(ImGuiViewportDataOSX)();
+    viewport->PlatformUserData = data;
+
+    NSScreen* screen = bd->Window.screen;
+    NSRect rect = NSMakeRect(viewport->Pos.x, viewport->Pos.y, viewport->Size.x, viewport->Size.y);
+    ConvertNSRect(screen, &rect);
+
+    NSWindowStyleMask styleMask = 0;
+    if (viewport->Flags & ImGuiViewportFlags_NoDecoration)
+        styleMask |= NSWindowStyleMaskBorderless;
+    else
+        styleMask |= NSWindowStyleMaskTitled | NSWindowStyleMaskResizable | NSWindowStyleMaskClosable | NSWindowStyleMaskMiniaturizable;
+
+    NSWindow* window = [[ImGui_ImplOSX_Window alloc] initWithContentRect:rect
+                                                               styleMask:styleMask
+                                                                 backing:NSBackingStoreBuffered
+                                                                   defer:YES
+                                                                  screen:screen];
+    if (viewport->Flags & ImGuiViewportFlags_TopMost)
+        [window setLevel:NSFloatingWindowLevel];
+
+    window.title = @"Untitled";
+    window.opaque = YES;
+
+    KeyEventResponder* view = [[KeyEventResponder alloc] initWithFrame:rect];
+    if (floor(NSAppKitVersionNumber) > NSAppKitVersionNumber10_6)
+        [view setWantsBestResolutionOpenGLSurface:YES];
+
+    window.contentView = view;
+
+    data->Window = window;
+    data->WindowOwned = true;
+    viewport->PlatformRequestResize = false;
+    viewport->PlatformHandle = viewport->PlatformHandleRaw = (__bridge_retained void*)window;
+}
+
+static void ImGui_ImplOSX_DestroyWindow(ImGuiViewport* viewport)
+{
+    NSWindow* window = (__bridge_transfer NSWindow*)viewport->PlatformHandleRaw;
+    window = nil;
+
+    if (ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData)
+    {
+        NSWindow* window = data->Window;
+        if (window != nil && data->WindowOwned)
+        {
+            window.contentView = nil;
+            window.contentViewController = nil;
+            [window orderOut:nil];
+        }
+        data->Window = nil;
+        IM_DELETE(data);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = viewport->PlatformHandleRaw = nullptr;
+}
+
+static void ImGui_ImplOSX_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+        [data->Window orderFront:nil];
+    else
+        [data->Window makeKeyAndOrderFront:nil];
+
+    [data->Window setIsVisible:YES];
+}
+
+static ImVec2 ImGui_ImplOSX_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    NSWindow* window = data->Window;
+    NSScreen* screen = window.screen;
+    NSSize size = screen.frame.size;
+    NSRect frame = window.frame;
+    NSRect rect = window.contentLayoutRect;
+    return ImVec2(frame.origin.x, size.height - frame.origin.y - rect.size.height);
+}
+
+static void ImGui_ImplOSX_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    NSWindow* window = data->Window;
+    NSSize size = window.frame.size;
+
+    NSRect r = NSMakeRect(pos.x, pos.y, size.width, size.height);
+    ConvertNSRect(window.screen, &r);
+    [window setFrameOrigin:r.origin];
+}
+
+static ImVec2 ImGui_ImplOSX_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    NSWindow* window = data->Window;
+    NSSize size = window.contentLayoutRect.size;
+    return ImVec2(size.width, size.height);
+}
+
+static void ImGui_ImplOSX_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    NSWindow* window = data->Window;
+    NSRect rect = window.frame;
+    rect.origin.y -= (size.y - rect.size.height);
+    rect.size.width = size.x;
+    rect.size.height = size.y;
+    [window setFrame:rect display:YES];
+}
+
+static void ImGui_ImplOSX_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+    [data->Window makeKeyAndOrderFront:bd->Window];
+}
+
+static bool ImGui_ImplOSX_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    return data->Window.isKeyWindow;
+}
+
+static bool ImGui_ImplOSX_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    return data->Window.isMiniaturized;
+}
+
+static void ImGui_ImplOSX_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    data->Window.title = [NSString stringWithUTF8String:title];
+}
+
+static void ImGui_ImplOSX_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+    IM_ASSERT(alpha >= 0.0f && alpha <= 1.0f);
+
+    data->Window.alphaValue = alpha;
+}
+
+static float ImGui_ImplOSX_GetWindowDpiScale(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)viewport->PlatformUserData;
+    IM_ASSERT(data->Window != 0);
+
+    return data->Window.backingScaleFactor;
+}
+
+static void ImGui_ImplOSX_UpdateMonitors()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Monitors.resize(0);
+
+    for (NSScreen* screen in NSScreen.screens)
+    {
+        NSRect frame = screen.frame;
+        NSRect visibleFrame = screen.visibleFrame;
+
+        ImGuiPlatformMonitor imgui_monitor;
+        imgui_monitor.MainPos = ImVec2(frame.origin.x, frame.origin.y);
+        imgui_monitor.MainSize = ImVec2(frame.size.width, frame.size.height);
+        imgui_monitor.WorkPos = ImVec2(visibleFrame.origin.x, visibleFrame.origin.y);
+        imgui_monitor.WorkSize = ImVec2(visibleFrame.size.width, visibleFrame.size.height);
+        imgui_monitor.DpiScale = screen.backingScaleFactor;
+        imgui_monitor.PlatformHandle = (__bridge_retained void*)screen;
+
+        platform_io.Monitors.push_back(imgui_monitor);
+    }
+}
+
+static void ImGui_ImplOSX_InitPlatformInterface()
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    ImGui_ImplOSX_UpdateMonitors();
+
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplOSX_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplOSX_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplOSX_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplOSX_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplOSX_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplOSX_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplOSX_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplOSX_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplOSX_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplOSX_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplOSX_SetWindowTitle;
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplOSX_SetWindowAlpha;
+    platform_io.Platform_GetWindowDpiScale = ImGui_ImplOSX_GetWindowDpiScale; // FIXME-DPI
+
+    // Register main window handle (which is owned by the main application, not by us)
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGuiViewportDataOSX* data = IM_NEW(ImGuiViewportDataOSX)();
+    data->Window = bd->Window;
+    data->WindowOwned = false;
+    main_viewport->PlatformUserData = data;
+    main_viewport->PlatformHandle = (__bridge void*)bd->Window;
+
+    [NSNotificationCenter.defaultCenter addObserver:bd->Observer
+                                           selector:@selector(displaysDidChange:)
+                                               name:NSApplicationDidChangeScreenParametersNotification
+                                             object:nil];
+}
+
+static void ImGui_ImplOSX_ShutdownPlatformInterface()
+{
+    ImGui_ImplOSX_Data* bd = ImGui_ImplOSX_GetBackendData();
+    [NSNotificationCenter.defaultCenter removeObserver:bd->Observer
+                                                  name:NSApplicationDidChangeScreenParametersNotification
+                                                object:nil];
+    bd->Observer = nullptr;
+    bd->Window = nullptr;
+    if (bd->Monitor != nullptr)
+    {
+        [NSEvent removeMonitor:bd->Monitor];
+        bd->Monitor = nullptr;
+    }
+
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGuiViewportDataOSX* data = (ImGuiViewportDataOSX*)main_viewport->PlatformUserData;
+    IM_DELETE(data);
+    main_viewport->PlatformUserData = nullptr;
+    ImGui::DestroyPlatformWindows();
+}

backends/imgui_impl_sdl2.cpp

@@ -9,7 +9,10 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy SDL_SCANCODE_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
-//  [X] Platform: Basic IME support. App needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// Missing features:
+//  [ ] Platform: Multi-viewport + Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [x] Platform: Basic IME support. App needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -18,6 +21,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2023-04-06: Inputs: Avoid calling SDL_StartTextInput()/SDL_StopTextInput() as they don't only pertain to IME. It's unclear exactly what their relation is to IME. (#6306)
 //  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen. (#2702)
 //  2023-02-23: Accept SDL_GetPerformanceCounter() not returning a monotonically increasing value. (#6189, #6114, #3644)
@@ -42,7 +46,7 @@
 //  2022-01-10: Inputs: calling new io.AddKeyEvent(), io.AddKeyModsEvent() + io.SetKeyEventNativeData() API (1.87+). Support for full ImGuiKey range.
 //  2021-08-17: Calling io.AddFocusEvent() on SDL_WINDOWEVENT_FOCUS_GAINED/SDL_WINDOWEVENT_FOCUS_LOST.
 //  2021-07-29: Inputs: MousePos is correctly reported when the host platform window is hovered but not focused (using SDL_GetMouseFocus() + SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH, requires SDL 2.0.5+)
-//  2021-06-29: *BREAKING CHANGE* Removed 'SDL_Window* window' parameter to ImGui_ImplSDL2_NewFrame() which was unnecessary.
+//  2021-06:29: *BREAKING CHANGE* Removed 'SDL_Window* window' parameter to ImGui_ImplSDL2_NewFrame() which was unnecessary.
 //  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
 //  2021-03-22: Rework global mouse pos availability check listing supported platforms explicitly, effectively fixing mouse access on Raspberry Pi. (#2837, #3950)
 //  2020-05-25: Misc: Report a zero display-size when window is minimized, to be consistent with other backends.
@@ -82,6 +86,7 @@
 #endif
 
 // SDL
+// (the multi-viewports feature requires SDL features supported from SDL 2.0.4+. SDL 2.0.5+ is highly recommended)
 #include <SDL.h>
 #include <SDL_syswm.h>
 #if defined(__APPLE__)
@@ -93,7 +98,15 @@
 #else
 #define SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE    0
 #endif
+#define SDL_HAS_WINDOW_ALPHA                SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_ALWAYS_ON_TOP               SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_USABLE_DISPLAY_BOUNDS       SDL_VERSION_ATLEAST(2,0,5)
+#define SDL_HAS_PER_MONITOR_DPI             SDL_VERSION_ATLEAST(2,0,4)
 #define SDL_HAS_VULKAN                      SDL_VERSION_ATLEAST(2,0,6)
+#define SDL_HAS_DISPLAY_EVENT               SDL_VERSION_ATLEAST(2,0,9)
+#if !SDL_HAS_VULKAN
+static const Uint32 SDL_WINDOW_VULKAN = 0x10000000;
+#endif
 
 // SDL Data
 struct ImGui_ImplSDL2_Data
@@ -108,6 +121,9 @@ struct ImGui_ImplSDL2_Data
     int             PendingMouseLeaveFrame;
     char*           ClipboardTextData;
     bool            MouseCanUseGlobalState;
+    bool            MouseCanReportHoveredViewport;  // This is hard to use/unreliable on SDL so we'll set ImGuiBackendFlags_HasMouseHoveredViewport dynamically based on state.
+    bool            UseVulkan;
+    bool            WantUpdateMonitors;
 
     ImGui_ImplSDL2_Data()   { memset((void*)this, 0, sizeof(*this)); }
 };
@@ -121,6 +137,11 @@ static ImGui_ImplSDL2_Data* ImGui_ImplSDL2_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplSDL2_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplSDL2_UpdateMonitors();
+static void ImGui_ImplSDL2_InitPlatformInterface(SDL_Window* window, void* sdl_gl_context);
+static void ImGui_ImplSDL2_ShutdownPlatformInterface();
+
 // Functions
 static const char* ImGui_ImplSDL2_GetClipboardText(void*)
 {
@@ -137,13 +158,13 @@ static void ImGui_ImplSDL2_SetClipboardText(void*, const char* text)
 }
 
 // Note: native IME will only display if user calls SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1") _before_ SDL_CreateWindow().
-static void ImGui_ImplSDL2_SetPlatformImeData(ImGuiViewport*, ImGuiPlatformImeData* data)
+static void ImGui_ImplSDL2_SetPlatformImeData(ImGuiViewport* viewport, ImGuiPlatformImeData* data)
 {
     if (data->WantVisible)
     {
         SDL_Rect r;
-        r.x = (int)data->InputPos.x;
-        r.y = (int)data->InputPos.y;
+        r.x = (int)(data->InputPos.x - viewport->Pos.x);
+        r.y = (int)(data->InputPos.y - viewport->Pos.y + data->InputLineHeight);
         r.w = 1;
         r.h = (int)data->InputLineHeight;
         SDL_SetTextInputRect(&r);
@@ -287,6 +308,13 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
         case SDL_MOUSEMOTION:
         {
             ImVec2 mouse_pos((float)event->motion.x, (float)event->motion.y);
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                int window_x, window_y;
+                SDL_GetWindowPosition(SDL_GetWindowFromID(event->motion.windowID), &window_x, &window_y);
+                mouse_pos.x += window_x;
+                mouse_pos.y += window_y;
+            }
             io.AddMouseSourceEvent(event->motion.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMousePosEvent(mouse_pos.x, mouse_pos.y);
             return true;
@@ -338,6 +366,15 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
             io.SetKeyEventNativeData(key, event->key.keysym.sym, event->key.keysym.scancode, event->key.keysym.scancode); // To support legacy indexing (<1.87 user code). Legacy backend uses SDLK_*** as indices to IsKeyXXX() functions.
             return true;
         }
+#if SDL_HAS_DISPLAY_EVENT
+        case SDL_DISPLAYEVENT:
+        {
+            // 2.0.26 has SDL_DISPLAYEVENT_CONNECTED/SDL_DISPLAYEVENT_DISCONNECTED/SDL_DISPLAYEVENT_ORIENTATION,
+            // so change of DPI/Scaling are not reflected in this event. (SDL3 has it)
+            bd->WantUpdateMonitors = true;
+            return true;
+        }
+#endif
         case SDL_WINDOWEVENT:
         {
             // - When capturing mouse, SDL will send a bunch of conflicting LEAVE/ENTER event on every mouse move, but the final ENTER tends to be right.
@@ -355,15 +392,26 @@ bool ImGui_ImplSDL2_ProcessEvent(const SDL_Event* event)
                 bd->PendingMouseLeaveFrame = ImGui::GetFrameCount() + 1;
             if (window_event == SDL_WINDOWEVENT_FOCUS_GAINED)
                 io.AddFocusEvent(true);
-            else if (event->window.event == SDL_WINDOWEVENT_FOCUS_LOST)
+            else if (window_event == SDL_WINDOWEVENT_FOCUS_LOST)
                 io.AddFocusEvent(false);
+            if (window_event == SDL_WINDOWEVENT_CLOSE || window_event == SDL_WINDOWEVENT_MOVED || window_event == SDL_WINDOWEVENT_RESIZED)
+                if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)SDL_GetWindowFromID(event->window.windowID)))
+                {
+                    if (window_event == SDL_WINDOWEVENT_CLOSE)
+                        viewport->PlatformRequestClose = true;
+                    if (window_event == SDL_WINDOWEVENT_MOVED)
+                        viewport->PlatformRequestMove = true;
+                    if (window_event == SDL_WINDOWEVENT_RESIZED)
+                        viewport->PlatformRequestResize = true;
+                    return true;
+                }
             return true;
         }
     }
     return false;
 }
 
-static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer)
+static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer, void* sdl_gl_context)
 {
     ImGuiIO& io = ImGui::GetIO();
     IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
@@ -383,12 +431,23 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer)
     ImGui_ImplSDL2_Data* bd = IM_NEW(ImGui_ImplSDL2_Data)();
     io.BackendPlatformUserData = (void*)bd;
     io.BackendPlatformName = "imgui_impl_sdl2";
-    io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;       // We can honor GetMouseCursor() values (optional)
-    io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;        // We can honor io.WantSetMousePos requests (optional, rarely used)
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;           // We can honor GetMouseCursor() values (optional)
+    io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;            // We can honor io.WantSetMousePos requests (optional, rarely used)
+    if (mouse_can_use_global_state)
+        io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;  // We can create multi-viewports on the Platform side (optional)
 
     bd->Window = window;
     bd->Renderer = renderer;
+
+    // SDL on Linux/OSX doesn't report events for unfocused windows (see https://github.com/ocornut/imgui/issues/4960)
+    // We will use 'MouseCanReportHoveredViewport' to set 'ImGuiBackendFlags_HasMouseHoveredViewport' dynamically each frame.
     bd->MouseCanUseGlobalState = mouse_can_use_global_state;
+#ifndef __APPLE__
+    bd->MouseCanReportHoveredViewport = bd->MouseCanUseGlobalState;
+#else
+    bd->MouseCanReportHoveredViewport = false;
+#endif
+    bd->WantUpdateMonitors = true;
 
     io.SetClipboardTextFn = ImGui_ImplSDL2_SetClipboardText;
     io.GetClipboardTextFn = ImGui_ImplSDL2_GetClipboardText;
@@ -409,6 +468,7 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer)
     // Set platform dependent data in viewport
     // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->PlatformHandle = (void*)window;
     main_viewport->PlatformHandleRaw = nullptr;
     SDL_SysWMinfo info;
     SDL_VERSION(&info.version);
@@ -442,13 +502,17 @@ static bool ImGui_ImplSDL2_Init(SDL_Window* window, SDL_Renderer* renderer)
     SDL_SetHint(SDL_HINT_MOUSE_AUTO_CAPTURE, "0");
 #endif
 
+    // We need SDL_CaptureMouse(), SDL_GetGlobalMouseState() from SDL 2.0.4+ to support multiple viewports.
+    // We left the call to ImGui_ImplSDL2_InitPlatformInterface() outside of #ifdef to avoid unused-function warnings.
+    if ((io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) && (io.BackendFlags & ImGuiBackendFlags_PlatformHasViewports))
+        ImGui_ImplSDL2_InitPlatformInterface(window, sdl_gl_context);
+
     return true;
 }
 
 bool ImGui_ImplSDL2_InitForOpenGL(SDL_Window* window, void* sdl_gl_context)
 {
-    IM_UNUSED(sdl_gl_context); // Viewport branch will need this.
-    return ImGui_ImplSDL2_Init(window, nullptr);
+    return ImGui_ImplSDL2_Init(window, nullptr, sdl_gl_context);
 }
 
 bool ImGui_ImplSDL2_InitForVulkan(SDL_Window* window)
@@ -456,7 +520,11 @@ bool ImGui_ImplSDL2_InitForVulkan(SDL_Window* window)
 #if !SDL_HAS_VULKAN
     IM_ASSERT(0 && "Unsupported");
 #endif
-    return ImGui_ImplSDL2_Init(window, nullptr);
+    if (!ImGui_ImplSDL2_Init(window, nullptr, nullptr))
+        return false;
+    ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
+    bd->UseVulkan = true;
+    return true;
 }
 
 bool ImGui_ImplSDL2_InitForD3D(SDL_Window* window)
@@ -464,17 +532,17 @@ bool ImGui_ImplSDL2_InitForD3D(SDL_Window* window)
 #if !defined(_WIN32)
     IM_ASSERT(0 && "Unsupported");
 #endif
-    return ImGui_ImplSDL2_Init(window, nullptr);
+    return ImGui_ImplSDL2_Init(window, nullptr, nullptr);
 }
 
 bool ImGui_ImplSDL2_InitForMetal(SDL_Window* window)
 {
-    return ImGui_ImplSDL2_Init(window, nullptr);
+    return ImGui_ImplSDL2_Init(window, nullptr, nullptr);
 }
 
 bool ImGui_ImplSDL2_InitForSDLRenderer(SDL_Window* window, SDL_Renderer* renderer)
 {
-    return ImGui_ImplSDL2_Init(window, renderer);
+    return ImGui_ImplSDL2_Init(window, renderer, nullptr);
 }
 
 void ImGui_ImplSDL2_Shutdown()
@@ -483,6 +551,8 @@ void ImGui_ImplSDL2_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplSDL2_ShutdownPlatformInterface();
+
     if (bd->ClipboardTextData)
         SDL_free(bd->ClipboardTextData);
     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
@@ -491,9 +561,11 @@ void ImGui_ImplSDL2_Shutdown()
 
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
+    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();
@@ -504,25 +576,57 @@ static void ImGui_ImplSDL2_UpdateMouseData()
     // SDL_CaptureMouse() let the OS know e.g. that our imgui drag outside the SDL window boundaries shouldn't e.g. trigger other operations outside
     SDL_CaptureMouse((bd->MouseButtonsDown != 0) ? SDL_TRUE : SDL_FALSE);
     SDL_Window* focused_window = SDL_GetKeyboardFocus();
-    const bool is_app_focused = (bd->Window == focused_window);
+    const bool is_app_focused = (focused_window && (bd->Window == focused_window || ImGui::FindViewportByPlatformHandle((void*)focused_window)));
 #else
+    SDL_Window* focused_window = bd->Window;
     const bool is_app_focused = (SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0; // SDL 2.0.3 and non-windowed systems: single-viewport only
 #endif
+
     if (is_app_focused)
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
         if (io.WantSetMousePos)
-            SDL_WarpMouseInWindow(bd->Window, (int)io.MousePos.x, (int)io.MousePos.y);
+        {
+#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+                SDL_WarpMouseGlobal((int)io.MousePos.x, (int)io.MousePos.y);
+            else
+#endif
+                SDL_WarpMouseInWindow(bd->Window, (int)io.MousePos.x, (int)io.MousePos.y);
+        }
 
         // (Optional) Fallback to provide mouse position when focused (SDL_MOUSEMOTION already provides this when hovered or captured)
         if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0)
         {
-            int window_x, window_y, mouse_x_global, mouse_y_global;
-            SDL_GetGlobalMouseState(&mouse_x_global, &mouse_y_global);
-            SDL_GetWindowPosition(bd->Window, &window_x, &window_y);
-            io.AddMousePosEvent((float)(mouse_x_global - window_x), (float)(mouse_y_global - window_y));
+            // Single-viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
+            // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+            int mouse_x, mouse_y, window_x, window_y;
+            SDL_GetGlobalMouseState(&mouse_x, &mouse_y);
+            if (!(io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable))
+            {
+                SDL_GetWindowPosition(focused_window, &window_x, &window_y);
+                mouse_x -= window_x;
+                mouse_y -= window_y;
+            }
+            io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
         }
     }
+
+    // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+    // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+    // - [!] SDL backend does NOT correctly ignore viewports with the _NoInputs flag.
+    //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+    //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+    //       by the backend, and use its flawed heuristic to guess the viewport behind.
+    // - [X] SDL backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+    if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)
+    {
+        ImGuiID mouse_viewport_id = 0;
+        if (SDL_Window* sdl_mouse_window = SDL_GetWindowFromID(bd->MouseWindowID))
+            if (ImGuiViewport* mouse_viewport = ImGui::FindViewportByPlatformHandle((void*)sdl_mouse_window))
+                mouse_viewport_id = mouse_viewport->ID;
+        io.AddMouseViewportEvent(mouse_viewport_id);
+    }
 }
 
 static void ImGui_ImplSDL2_UpdateMouseCursor()
@@ -597,6 +701,39 @@ static void ImGui_ImplSDL2_UpdateGamepads()
     #undef MAP_ANALOG
 }
 
+// FIXME: Note that doesn't update with DPI/Scaling change only as SDL2 doesn't have an event for it (SDL3 has).
+static void ImGui_ImplSDL2_UpdateMonitors()
+{
+    ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Monitors.resize(0);
+    bd->WantUpdateMonitors = false;
+    int display_count = SDL_GetNumVideoDisplays();
+    for (int n = 0; n < display_count; n++)
+    {
+        // Warning: the validity of monitor DPI information on Windows depends on the application DPI awareness settings, which generally needs to be set in the manifest or at runtime.
+        ImGuiPlatformMonitor monitor;
+        SDL_Rect r;
+        SDL_GetDisplayBounds(n, &r);
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+#if SDL_HAS_USABLE_DISPLAY_BOUNDS
+        SDL_GetDisplayUsableBounds(n, &r);
+        monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+#endif
+#if SDL_HAS_PER_MONITOR_DPI
+        // FIXME-VIEWPORT: On MacOS SDL reports actual monitor DPI scale, ignoring OS configuration. We may want to set
+        //  DpiScale to cocoa_window.backingScaleFactor here.
+        float dpi = 0.0f;
+        if (!SDL_GetDisplayDPI(n, &dpi, nullptr, nullptr))
+            monitor.DpiScale = dpi / 96.0f;
+#endif
+        monitor.PlatformHandle = (void*)(intptr_t)n;
+        platform_io.Monitors.push_back(monitor);
+    }
+}
+
 void ImGui_ImplSDL2_NewFrame()
 {
     ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
@@ -617,6 +754,10 @@ void ImGui_ImplSDL2_NewFrame()
     if (w > 0 && h > 0)
         io.DisplayFramebufferScale = ImVec2((float)display_w / w, (float)display_h / h);
 
+    // Update monitors
+    if (bd->WantUpdateMonitors)
+        ImGui_ImplSDL2_UpdateMonitors();
+
     // Setup time step (we don't use SDL_GetTicks() because it is using millisecond resolution)
     // (Accept SDL_GetPerformanceCounter() not returning a monotonically increasing value. Happens in VMs and Emscripten, see #6189, #6114, #3644)
     static Uint64 frequency = SDL_GetPerformanceFrequency();
@@ -633,6 +774,13 @@ void ImGui_ImplSDL2_NewFrame()
         io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
     }
 
+    // Our io.AddMouseViewportEvent() calls will only be valid when not capturing.
+    // Technically speaking testing for 'bd->MouseButtonsDown == 0' would be more rygorous, but testing for payload reduces noise and potential side-effects.
+    if (bd->MouseCanReportHoveredViewport && ImGui::GetDragDropPayload() == nullptr)
+        io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport;
+    else
+        io.BackendFlags &= ~ImGuiBackendFlags_HasMouseHoveredViewport;
+
     ImGui_ImplSDL2_UpdateMouseData();
     ImGui_ImplSDL2_UpdateMouseCursor();
 
@@ -640,6 +788,253 @@ void ImGui_ImplSDL2_NewFrame()
     ImGui_ImplSDL2_UpdateGamepads();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplSDL2_ViewportData
+{
+    SDL_Window*     Window;
+    Uint32          WindowID;
+    bool            WindowOwned;
+    SDL_GLContext   GLContext;
+
+    ImGui_ImplSDL2_ViewportData() { Window = nullptr; WindowID = 0; WindowOwned = false; GLContext = nullptr; }
+    ~ImGui_ImplSDL2_ViewportData() { IM_ASSERT(Window == nullptr && GLContext == nullptr); }
+};
+
+static void ImGui_ImplSDL2_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_Data* bd = ImGui_ImplSDL2_GetBackendData();
+    ImGui_ImplSDL2_ViewportData* vd = IM_NEW(ImGui_ImplSDL2_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL2_ViewportData* main_viewport_data = (ImGui_ImplSDL2_ViewportData*)main_viewport->PlatformUserData;
+
+    // Share GL resources with main context
+    bool use_opengl = (main_viewport_data->GLContext != nullptr);
+    SDL_GLContext backup_context = nullptr;
+    if (use_opengl)
+    {
+        backup_context = SDL_GL_GetCurrentContext();
+        SDL_GL_SetAttribute(SDL_GL_SHARE_WITH_CURRENT_CONTEXT, 1);
+        SDL_GL_MakeCurrent(main_viewport_data->Window, main_viewport_data->GLContext);
+    }
+
+    Uint32 sdl_flags = 0;
+    sdl_flags |= use_opengl ? SDL_WINDOW_OPENGL : (bd->UseVulkan ? SDL_WINDOW_VULKAN : 0);
+    sdl_flags |= SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_ALLOW_HIGHDPI;
+    sdl_flags |= SDL_WINDOW_HIDDEN;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? SDL_WINDOW_BORDERLESS : 0;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? 0 : SDL_WINDOW_RESIZABLE;
+#if !defined(_WIN32)
+    // See SDL hack in ImGui_ImplSDL2_ShowWindow().
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon) ? SDL_WINDOW_SKIP_TASKBAR : 0;
+#endif
+#if SDL_HAS_ALWAYS_ON_TOP
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_TopMost) ? SDL_WINDOW_ALWAYS_ON_TOP : 0;
+#endif
+    vd->Window = SDL_CreateWindow("No Title Yet", (int)viewport->Pos.x, (int)viewport->Pos.y, (int)viewport->Size.x, (int)viewport->Size.y, sdl_flags);
+    vd->WindowOwned = true;
+    if (use_opengl)
+    {
+        vd->GLContext = SDL_GL_CreateContext(vd->Window);
+        SDL_GL_SetSwapInterval(0);
+    }
+    if (use_opengl && backup_context)
+        SDL_GL_MakeCurrent(vd->Window, backup_context);
+
+    viewport->PlatformHandle = (void*)vd->Window;
+    viewport->PlatformHandleRaw = nullptr;
+    SDL_SysWMinfo info;
+    SDL_VERSION(&info.version);
+    if (SDL_GetWindowWMInfo(vd->Window, &info))
+    {
+#if defined(SDL_VIDEO_DRIVER_WINDOWS)
+        viewport->PlatformHandleRaw = info.info.win.window;
+#elif defined(__APPLE__) && defined(SDL_VIDEO_DRIVER_COCOA)
+        viewport->PlatformHandleRaw = (void*)info.info.cocoa.window;
+#endif
+    }
+}
+
+static void ImGui_ImplSDL2_DestroyWindow(ImGuiViewport* viewport)
+{
+    if (ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData)
+    {
+        if (vd->GLContext && vd->WindowOwned)
+            SDL_GL_DeleteContext(vd->GLContext);
+        if (vd->Window && vd->WindowOwned)
+            SDL_DestroyWindow(vd->Window);
+        vd->GLContext = nullptr;
+        vd->Window = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplSDL2_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+#if defined(_WIN32)
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+
+    // SDL hack: Hide icon from task bar
+    // Note: SDL 2.0.6+ has a SDL_WINDOW_SKIP_TASKBAR flag which is supported under Windows but the way it create the window breaks our seamless transition.
+    if (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon)
+    {
+        LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
+        ex_style &= ~WS_EX_APPWINDOW;
+        ex_style |= WS_EX_TOOLWINDOW;
+        ::SetWindowLong(hwnd, GWL_EXSTYLE, ex_style);
+    }
+
+    // SDL hack: SDL always activate/focus windows :/
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+    {
+        ::ShowWindow(hwnd, SW_SHOWNA);
+        return;
+    }
+#endif
+
+    SDL_ShowWindow(vd->Window);
+}
+
+static ImVec2 ImGui_ImplSDL2_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    int x = 0, y = 0;
+    SDL_GetWindowPosition(vd->Window, &x, &y);
+    return ImVec2((float)x, (float)y);
+}
+
+static void ImGui_ImplSDL2_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowPosition(vd->Window, (int)pos.x, (int)pos.y);
+}
+
+static ImVec2 ImGui_ImplSDL2_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    int w = 0, h = 0;
+    SDL_GetWindowSize(vd->Window, &w, &h);
+    return ImVec2((float)w, (float)h);
+}
+
+static void ImGui_ImplSDL2_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowSize(vd->Window, (int)size.x, (int)size.y);
+}
+
+static void ImGui_ImplSDL2_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowTitle(vd->Window, title);
+}
+
+#if SDL_HAS_WINDOW_ALPHA
+static void ImGui_ImplSDL2_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowOpacity(vd->Window, alpha);
+}
+#endif
+
+static void ImGui_ImplSDL2_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    SDL_RaiseWindow(vd->Window);
+}
+
+static bool ImGui_ImplSDL2_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    return (SDL_GetWindowFlags(vd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0;
+}
+
+static bool ImGui_ImplSDL2_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    return (SDL_GetWindowFlags(vd->Window) & SDL_WINDOW_MINIMIZED) != 0;
+}
+
+static void ImGui_ImplSDL2_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    if (vd->GLContext)
+        SDL_GL_MakeCurrent(vd->Window, vd->GLContext);
+}
+
+static void ImGui_ImplSDL2_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    if (vd->GLContext)
+    {
+        SDL_GL_MakeCurrent(vd->Window, vd->GLContext);
+        SDL_GL_SwapWindow(vd->Window);
+    }
+}
+
+// Vulkan support (the Vulkan renderer needs to call a platform-side support function to create the surface)
+// SDL is graceful enough to _not_ need <vulkan/vulkan.h> so we can safely include this.
+#if SDL_HAS_VULKAN
+#include <SDL_vulkan.h>
+static int ImGui_ImplSDL2_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_instance, const void* vk_allocator, ImU64* out_vk_surface)
+{
+    ImGui_ImplSDL2_ViewportData* vd = (ImGui_ImplSDL2_ViewportData*)viewport->PlatformUserData;
+    (void)vk_allocator;
+    SDL_bool ret = SDL_Vulkan_CreateSurface(vd->Window, (VkInstance)vk_instance, (VkSurfaceKHR*)out_vk_surface);
+    return ret ? 0 : 1; // ret ? VK_SUCCESS : VK_NOT_READY
+}
+#endif // SDL_HAS_VULKAN
+
+static void ImGui_ImplSDL2_InitPlatformInterface(SDL_Window* window, void* sdl_gl_context)
+{
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplSDL2_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplSDL2_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplSDL2_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplSDL2_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplSDL2_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplSDL2_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplSDL2_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplSDL2_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplSDL2_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplSDL2_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplSDL2_SetWindowTitle;
+    platform_io.Platform_RenderWindow = ImGui_ImplSDL2_RenderWindow;
+    platform_io.Platform_SwapBuffers = ImGui_ImplSDL2_SwapBuffers;
+#if SDL_HAS_WINDOW_ALPHA
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplSDL2_SetWindowAlpha;
+#endif
+#if SDL_HAS_VULKAN
+    platform_io.Platform_CreateVkSurface = ImGui_ImplSDL2_CreateVkSurface;
+#endif
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL2_ViewportData* vd = IM_NEW(ImGui_ImplSDL2_ViewportData)();
+    vd->Window = window;
+    vd->WindowID = SDL_GetWindowID(window);
+    vd->WindowOwned = false;
+    vd->GLContext = sdl_gl_context;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = vd->Window;
+}
+
+static void ImGui_ImplSDL2_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif

backends/imgui_impl_sdl2.h

@@ -8,7 +8,10 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy SDL_SCANCODE_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
-//  [X] Platform: Basic IME support. App needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
+// Missing features:
+//  [ ] Platform: Multi-viewport + Minimized windows seems to break mouse wheel events (at least under Windows).
+//  [x] Platform: Basic IME support. App needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.

backends/imgui_impl_sdl3.cpp

@@ -9,7 +9,9 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy SDL_SCANCODE_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [x] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable' -> the OS animation effect when window gets created/destroyed is problematic. SDL2 backend doesn't have issue.
 // Missing features:
+//  [ ] Platform: Multi-viewport + Minimized windows seems to break mouse wheel events (at least under Windows).
 //  [x] Platform: Basic IME support. Position somehow broken in SDL3 + app needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
@@ -19,6 +21,8 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2023-05-04: Fixed build on Emscripten/iOS/Android. (#6391)
 //  2023-04-06: Inputs: Avoid calling SDL_StartTextInput()/SDL_StopTextInput() as they don't only pertain to IME. It's unclear exactly what their relation is to IME. (#6306)
 //  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen. (#2702)
 //  2023-02-23: Accept SDL_GetPerformanceCounter() not returning a monotonically increasing value. (#6189, #6114, #3644)
@@ -59,6 +63,9 @@ struct ImGui_ImplSDL3_Data
     int             PendingMouseLeaveFrame;
     char*           ClipboardTextData;
     bool            MouseCanUseGlobalState;
+    bool            MouseCanReportHoveredViewport;  // This is hard to use/unreliable on SDL so we'll set ImGuiBackendFlags_HasMouseHoveredViewport dynamically based on state.
+    bool            UseVulkan;
+    bool            WantUpdateMonitors;
 
     ImGui_ImplSDL3_Data()   { memset((void*)this, 0, sizeof(*this)); }
 };
@@ -72,6 +79,11 @@ static ImGui_ImplSDL3_Data* ImGui_ImplSDL3_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplSDL3_Data*)ImGui::GetIO().BackendPlatformUserData : nullptr;
 }
 
+// Forward Declarations
+static void ImGui_ImplSDL3_UpdateMonitors();
+static void ImGui_ImplSDL3_InitPlatformInterface(SDL_Window* window, void* sdl_gl_context);
+static void ImGui_ImplSDL3_ShutdownPlatformInterface();
+
 // Functions
 static const char* ImGui_ImplSDL3_GetClipboardText(void*)
 {
@@ -87,13 +99,13 @@ static void ImGui_ImplSDL3_SetClipboardText(void*, const char* text)
     SDL_SetClipboardText(text);
 }
 
-static void ImGui_ImplSDL3_SetPlatformImeData(ImGuiViewport*, ImGuiPlatformImeData* data)
+static void ImGui_ImplSDL3_SetPlatformImeData(ImGuiViewport* viewport, ImGuiPlatformImeData* data)
 {
     if (data->WantVisible)
     {
         SDL_Rect r;
-        r.x = (int)data->InputPos.x;
-        r.y = (int)data->InputPos.y;
+        r.x = (int)(data->InputPos.x - viewport->Pos.x);
+        r.y = (int)(data->InputPos.y - viewport->Pos.y + data->InputLineHeight);
         r.w = 1;
         r.h = (int)data->InputLineHeight;
         SDL_SetTextInputRect(&r);
@@ -237,6 +249,13 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
         case SDL_EVENT_MOUSE_MOTION:
         {
             ImVec2 mouse_pos((float)event->motion.x, (float)event->motion.y);
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                int window_x, window_y;
+                SDL_GetWindowPosition(SDL_GetWindowFromID(event->motion.windowID), &window_x, &window_y);
+                mouse_pos.x += window_x;
+                mouse_pos.y += window_y;
+            }
             io.AddMouseSourceEvent(event->motion.which == SDL_TOUCH_MOUSEID ? ImGuiMouseSource_TouchScreen : ImGuiMouseSource_Mouse);
             io.AddMousePosEvent(mouse_pos.x, mouse_pos.y);
             return true;
@@ -283,6 +302,15 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
             io.SetKeyEventNativeData(key, event->key.keysym.sym, event->key.keysym.scancode, event->key.keysym.scancode); // To support legacy indexing (<1.87 user code). Legacy backend uses SDLK_*** as indices to IsKeyXXX() functions.
             return true;
         }
+        case SDL_EVENT_DISPLAY_ORIENTATION:
+        case SDL_EVENT_DISPLAY_CONNECTED:
+        case SDL_EVENT_DISPLAY_DISCONNECTED:
+        case SDL_EVENT_DISPLAY_MOVED:
+        case SDL_EVENT_DISPLAY_CONTENT_SCALE_CHANGED:
+        {
+            bd->WantUpdateMonitors = true;
+            return true;
+        }
         case SDL_EVENT_WINDOW_MOUSE_ENTER:
         {
             bd->MouseWindowID = event->window.windowID;
@@ -304,11 +332,25 @@ bool ImGui_ImplSDL3_ProcessEvent(const SDL_Event* event)
         case SDL_EVENT_WINDOW_FOCUS_LOST:
             io.AddFocusEvent(false);
             return true;
+        case SDL_EVENT_WINDOW_CLOSE_REQUESTED:
+        case SDL_EVENT_WINDOW_MOVED:
+        case SDL_EVENT_WINDOW_RESIZED:
+            if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)SDL_GetWindowFromID(event->window.windowID)))
+            {
+                if (event->type == SDL_EVENT_WINDOW_CLOSE_REQUESTED)
+                    viewport->PlatformRequestClose = true;
+                if (event->type == SDL_EVENT_WINDOW_MOVED)
+                    viewport->PlatformRequestMove = true;
+                if (event->type == SDL_EVENT_WINDOW_RESIZED)
+                    viewport->PlatformRequestResize = true;
+                return true;
+            }
+            return true;
     }
     return false;
 }
 
-static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer)
+static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer, void* sdl_gl_context)
 {
     ImGuiIO& io = ImGui::GetIO();
     IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
@@ -330,10 +372,21 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer)
     io.BackendPlatformName = "imgui_impl_sdl3";
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;           // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;            // We can honor io.WantSetMousePos requests (optional, rarely used)
+    if (mouse_can_use_global_state)
+        io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;  // We can create multi-viewports on the Platform side (optional)
 
     bd->Window = window;
     bd->Renderer = renderer;
+
+    // SDL on Linux/OSX doesn't report events for unfocused windows (see https://github.com/ocornut/imgui/issues/4960)
+    // We will use 'MouseCanReportHoveredViewport' to set 'ImGuiBackendFlags_HasMouseHoveredViewport' dynamically each frame.
     bd->MouseCanUseGlobalState = mouse_can_use_global_state;
+#ifndef __APPLE__
+    bd->MouseCanReportHoveredViewport = bd->MouseCanUseGlobalState;
+#else
+    bd->MouseCanReportHoveredViewport = false;
+#endif
+    bd->WantUpdateMonitors = true;
 
     io.SetClipboardTextFn = ImGui_ImplSDL3_SetClipboardText;
     io.GetClipboardTextFn = ImGui_ImplSDL3_GetClipboardText;
@@ -354,6 +407,7 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer)
     // Set platform dependent data in viewport
     // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->PlatformHandle = (void*)window;
     main_viewport->PlatformHandleRaw = nullptr;
     SDL_SysWMinfo info;
     if (SDL_GetWindowWMInfo(window, &info, SDL_SYSWM_CURRENT_VERSION) == 0)
@@ -370,27 +424,34 @@ static bool ImGui_ImplSDL3_Init(SDL_Window* window, SDL_Renderer* renderer)
     // (This is unfortunately a global SDL setting, so enabling it might have a side-effect on your application.
     // It is unlikely to make a difference, but if your app absolutely needs to ignore the initial on-focus click:
     // you can ignore SDL_EVENT_MOUSE_BUTTON_DOWN events coming right after a SDL_WINDOWEVENT_FOCUS_GAINED)
-#ifdef SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH
     SDL_SetHint(SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH, "1");
-#endif
 
     // From 2.0.22: Disable auto-capture, this is preventing drag and drop across multiple windows (see #5710)
-#ifdef SDL_HINT_MOUSE_AUTO_CAPTURE
     SDL_SetHint(SDL_HINT_MOUSE_AUTO_CAPTURE, "0");
-#endif
+
+    // SDL 3.x : see https://github.com/libsdl-org/SDL/issues/6659
+    SDL_SetHint("SDL_BORDERLESS_WINDOWED_STYLE", "0");
+
+    // We need SDL_CaptureMouse(), SDL_GetGlobalMouseState() from SDL 2.0.4+ to support multiple viewports.
+    // We left the call to ImGui_ImplSDL3_InitPlatformInterface() outside of #ifdef to avoid unused-function warnings.
+    if ((io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) && (io.BackendFlags & ImGuiBackendFlags_PlatformHasViewports))
+        ImGui_ImplSDL3_InitPlatformInterface(window, sdl_gl_context);
 
     return true;
 }
 
 bool ImGui_ImplSDL3_InitForOpenGL(SDL_Window* window, void* sdl_gl_context)
 {
-    IM_UNUSED(sdl_gl_context); // Viewport branch will need this.
-    return ImGui_ImplSDL3_Init(window, nullptr);
+    return ImGui_ImplSDL3_Init(window, nullptr, sdl_gl_context);
 }
 
 bool ImGui_ImplSDL3_InitForVulkan(SDL_Window* window)
 {
-    return ImGui_ImplSDL3_Init(window, 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)
@@ -398,17 +459,17 @@ bool ImGui_ImplSDL3_InitForD3D(SDL_Window* window)
 #if !defined(_WIN32)
     IM_ASSERT(0 && "Unsupported");
 #endif
-    return ImGui_ImplSDL3_Init(window, nullptr);
+    return ImGui_ImplSDL3_Init(window, nullptr, nullptr);
 }
 
 bool ImGui_ImplSDL3_InitForMetal(SDL_Window* window)
 {
-    return ImGui_ImplSDL3_Init(window, nullptr);
+    return ImGui_ImplSDL3_Init(window, nullptr, nullptr);
 }
 
 bool ImGui_ImplSDL3_InitForSDLRenderer(SDL_Window* window, SDL_Renderer* renderer)
 {
-    return ImGui_ImplSDL3_Init(window, renderer);
+    return ImGui_ImplSDL3_Init(window, renderer, nullptr);
 }
 
 void ImGui_ImplSDL3_Shutdown()
@@ -417,6 +478,8 @@ void ImGui_ImplSDL3_Shutdown()
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplSDL3_ShutdownPlatformInterface();
+
     if (bd->ClipboardTextData)
         SDL_free(bd->ClipboardTextData);
     for (ImGuiMouseCursor cursor_n = 0; cursor_n < ImGuiMouseCursor_COUNT; cursor_n++)
@@ -425,9 +488,11 @@ void ImGui_ImplSDL3_Shutdown()
 
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
+    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();
@@ -438,27 +503,57 @@ static void ImGui_ImplSDL3_UpdateMouseData()
     // SDL_CaptureMouse() let the OS know e.g. that our imgui drag outside the SDL window boundaries shouldn't e.g. trigger other operations outside
     SDL_CaptureMouse((bd->MouseButtonsDown != 0) ? SDL_TRUE : SDL_FALSE);
     SDL_Window* focused_window = SDL_GetKeyboardFocus();
-    const bool is_app_focused = (bd->Window == focused_window);
+    const bool is_app_focused = (focused_window && (bd->Window == focused_window || ImGui::FindViewportByPlatformHandle((void*)focused_window)));
 #else
+    SDL_Window* focused_window = bd->Window;
     const bool is_app_focused = (SDL_GetWindowFlags(bd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0; // SDL 2.0.3 and non-windowed systems: single-viewport only
 #endif
     if (is_app_focused)
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
         if (io.WantSetMousePos)
-            SDL_WarpMouseInWindow(bd->Window, io.MousePos.x, io.MousePos.y);
+        {
+#if SDL_HAS_CAPTURE_AND_GLOBAL_MOUSE
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+                SDL_WarpMouseGlobal(io.MousePos.x, io.MousePos.y);
+            else
+#endif
+                SDL_WarpMouseInWindow(bd->Window, io.MousePos.x, io.MousePos.y);
+        }
 
         // (Optional) Fallback to provide mouse position when focused (SDL_EVENT_MOUSE_MOTION already provides this when hovered or captured)
         if (bd->MouseCanUseGlobalState && bd->MouseButtonsDown == 0)
         {
             // Single-viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
-            float mouse_x_global, mouse_y_global;
+            // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+            float mouse_x, mouse_y;
             int window_x, window_y;
-            SDL_GetGlobalMouseState(&mouse_x_global, &mouse_y_global);
-            SDL_GetWindowPosition(focused_window, &window_x, &window_y);
-            io.AddMousePosEvent(mouse_x_global - window_x, mouse_y_global - window_y);
+            SDL_GetGlobalMouseState(&mouse_x, &mouse_y);
+            if (!(io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable))
+            {
+                SDL_GetWindowPosition(focused_window, &window_x, &window_y);
+                mouse_x -= window_x;
+                mouse_y -= window_y;
+            }
+            io.AddMousePosEvent((float)mouse_x, (float)mouse_y);
         }
     }
+
+    // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+    // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+    // - [!] SDL backend does NOT correctly ignore viewports with the _NoInputs flag.
+    //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+    //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+    //       by the backend, and use its flawed heuristic to guess the viewport behind.
+    // - [X] SDL backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+    if (io.BackendFlags & ImGuiBackendFlags_HasMouseHoveredViewport)
+    {
+        ImGuiID mouse_viewport_id = 0;
+        if (SDL_Window* sdl_mouse_window = SDL_GetWindowFromID(bd->MouseWindowID))
+            if (ImGuiViewport* mouse_viewport = ImGui::FindViewportByPlatformHandle((void*)sdl_mouse_window))
+                mouse_viewport_id = mouse_viewport->ID;
+        io.AddMouseViewportEvent(mouse_viewport_id);
+    }
 }
 
 static void ImGui_ImplSDL3_UpdateMouseCursor()
@@ -533,6 +628,35 @@ static void ImGui_ImplSDL3_UpdateGamepads()
     #undef MAP_ANALOG
 }
 
+static void ImGui_ImplSDL3_UpdateMonitors()
+{
+    ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Monitors.resize(0);
+    bd->WantUpdateMonitors = false;
+
+    int display_count;
+    SDL_DisplayID* displays = SDL_GetDisplays(&display_count);
+    for (int n = 0; n < display_count; n++)
+    {
+        // Warning: the validity of monitor DPI information on Windows depends on the application DPI awareness settings, which generally needs to be set in the manifest or at runtime.
+        SDL_DisplayID display_id = displays[n];
+        ImGuiPlatformMonitor monitor;
+        SDL_Rect r;
+        SDL_GetDisplayBounds(display_id, &r);
+        monitor.MainPos = monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.MainSize = monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+        SDL_GetDisplayUsableBounds(display_id, &r);
+        monitor.WorkPos = ImVec2((float)r.x, (float)r.y);
+        monitor.WorkSize = ImVec2((float)r.w, (float)r.h);
+        // FIXME-VIEWPORT: On MacOS SDL reports actual monitor DPI scale, ignoring OS configuration. We may want to set
+        //  DpiScale to cocoa_window.backingScaleFactor here.
+        monitor.DpiScale = SDL_GetDisplayContentScale(display_id);
+        monitor.PlatformHandle = (void*)(intptr_t)n;
+        platform_io.Monitors.push_back(monitor);
+    }
+}
+
 void ImGui_ImplSDL3_NewFrame()
 {
     ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
@@ -550,6 +674,10 @@ void ImGui_ImplSDL3_NewFrame()
     if (w > 0 && h > 0)
         io.DisplayFramebufferScale = ImVec2((float)display_w / w, (float)display_h / h);
 
+    // Update monitors
+    if (bd->WantUpdateMonitors)
+        ImGui_ImplSDL3_UpdateMonitors();
+
     // Setup time step (we don't use SDL_GetTicks() because it is using millisecond resolution)
     // (Accept SDL_GetPerformanceCounter() not returning a monotonically increasing value. Happens in VMs and Emscripten, see #6189, #6114, #3644)
     static Uint64 frequency = SDL_GetPerformanceFrequency();
@@ -566,6 +694,13 @@ void ImGui_ImplSDL3_NewFrame()
         io.AddMousePosEvent(-FLT_MAX, -FLT_MAX);
     }
 
+    // Our io.AddMouseViewportEvent() calls will only be valid when not capturing.
+    // Technically speaking testing for 'bd->MouseButtonsDown == 0' would be more rygorous, but testing for payload reduces noise and potential side-effects.
+    if (bd->MouseCanReportHoveredViewport && ImGui::GetDragDropPayload() == nullptr)
+        io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport;
+    else
+        io.BackendFlags &= ~ImGuiBackendFlags_HasMouseHoveredViewport;
+
     ImGui_ImplSDL3_UpdateMouseData();
     ImGui_ImplSDL3_UpdateMouseCursor();
 
@@ -573,7 +708,242 @@ void ImGui_ImplSDL3_NewFrame()
     ImGui_ImplSDL3_UpdateGamepads();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplSDL3_ViewportData
+{
+    SDL_Window*     Window;
+    Uint32          WindowID;
+    bool            WindowOwned;
+    SDL_GLContext   GLContext;
+
+    ImGui_ImplSDL3_ViewportData() { Window = nullptr; WindowID = 0; WindowOwned = false; GLContext = nullptr; }
+    ~ImGui_ImplSDL3_ViewportData() { IM_ASSERT(Window == nullptr && GLContext == nullptr); }
+};
+
+static void ImGui_ImplSDL3_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_Data* bd = ImGui_ImplSDL3_GetBackendData();
+    ImGui_ImplSDL3_ViewportData* vd = IM_NEW(ImGui_ImplSDL3_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL3_ViewportData* main_viewport_data = (ImGui_ImplSDL3_ViewportData*)main_viewport->PlatformUserData;
+
+    // Share GL resources with main context
+    bool use_opengl = (main_viewport_data->GLContext != nullptr);
+    SDL_GLContext backup_context = nullptr;
+    if (use_opengl)
+    {
+        backup_context = SDL_GL_GetCurrentContext();
+        SDL_GL_SetAttribute(SDL_GL_SHARE_WITH_CURRENT_CONTEXT, 1);
+        SDL_GL_MakeCurrent(main_viewport_data->Window, main_viewport_data->GLContext);
+    }
+
+    Uint32 sdl_flags = 0;
+    sdl_flags |= use_opengl ? SDL_WINDOW_OPENGL : (bd->UseVulkan ? SDL_WINDOW_VULKAN : 0);
+    sdl_flags |= SDL_GetWindowFlags(bd->Window);
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? SDL_WINDOW_BORDERLESS : 0;
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoDecoration) ? 0 : SDL_WINDOW_RESIZABLE;
+#if !defined(_WIN32)
+    // See SDL hack in ImGui_ImplSDL3_ShowWindow().
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon) ? SDL_WINDOW_SKIP_TASKBAR : 0;
+#endif
+    sdl_flags |= (viewport->Flags & ImGuiViewportFlags_TopMost) ? SDL_WINDOW_ALWAYS_ON_TOP : 0;
+    vd->Window = SDL_CreateWindow("No Title Yet", (int)viewport->Size.x, (int)viewport->Size.y, sdl_flags);
+    SDL_SetWindowPosition(vd->Window, (int)viewport->Pos.x, (int)viewport->Pos.y);
+    vd->WindowOwned = true;
+    if (use_opengl)
+    {
+        vd->GLContext = SDL_GL_CreateContext(vd->Window);
+        SDL_GL_SetSwapInterval(0);
+    }
+    if (use_opengl && backup_context)
+        SDL_GL_MakeCurrent(vd->Window, backup_context);
+
+    viewport->PlatformHandle = (void*)vd->Window;
+    viewport->PlatformHandleRaw = nullptr;
+    SDL_SysWMinfo info;
+    if (SDL_GetWindowWMInfo(vd->Window, &info, SDL_SYSWM_CURRENT_VERSION))
+    {
+#if defined(SDL_VIDEO_DRIVER_WINDOWS)
+        viewport->PlatformHandleRaw = info.info.win.window;
+#elif defined(__APPLE__) && defined(SDL_VIDEO_DRIVER_COCOA)
+        viewport->PlatformHandleRaw = (void*)info.info.cocoa.window;
+#endif
+    }
+}
+
+static void ImGui_ImplSDL3_DestroyWindow(ImGuiViewport* viewport)
+{
+    if (ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData)
+    {
+        if (vd->GLContext && vd->WindowOwned)
+            SDL_GL_DeleteContext(vd->GLContext);
+        if (vd->Window && vd->WindowOwned)
+            SDL_DestroyWindow(vd->Window);
+        vd->GLContext = nullptr;
+        vd->Window = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplSDL3_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+#if defined(_WIN32)
+    HWND hwnd = (HWND)viewport->PlatformHandleRaw;
+
+    // SDL hack: Hide icon from task bar
+    // Note: SDL 2.0.6+ has a SDL_WINDOW_SKIP_TASKBAR flag which is supported under Windows but the way it create the window breaks our seamless transition.
+    if (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon)
+    {
+        LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
+        ex_style &= ~WS_EX_APPWINDOW;
+        ex_style |= WS_EX_TOOLWINDOW;
+        ::SetWindowLong(hwnd, GWL_EXSTYLE, ex_style);
+    }
+
+    // SDL hack: SDL always activate/focus windows :/
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+    {
+        ::ShowWindow(hwnd, SW_SHOWNA);
+        return;
+    }
+#endif
+
+    SDL_ShowWindow(vd->Window);
+}
+
+static ImVec2 ImGui_ImplSDL3_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    int x = 0, y = 0;
+    SDL_GetWindowPosition(vd->Window, &x, &y);
+    return ImVec2((float)x, (float)y);
+}
+
+static void ImGui_ImplSDL3_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowPosition(vd->Window, (int)pos.x, (int)pos.y);
+}
+
+static ImVec2 ImGui_ImplSDL3_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    int w = 0, h = 0;
+    SDL_GetWindowSize(vd->Window, &w, &h);
+    return ImVec2((float)w, (float)h);
+}
+
+static void ImGui_ImplSDL3_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowSize(vd->Window, (int)size.x, (int)size.y);
+}
+
+static void ImGui_ImplSDL3_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowTitle(vd->Window, title);
+}
+
+static void ImGui_ImplSDL3_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    SDL_SetWindowOpacity(vd->Window, alpha);
+}
+
+static void ImGui_ImplSDL3_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    SDL_RaiseWindow(vd->Window);
+}
+
+static bool ImGui_ImplSDL3_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    return (SDL_GetWindowFlags(vd->Window) & SDL_WINDOW_INPUT_FOCUS) != 0;
+}
+
+static bool ImGui_ImplSDL3_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    return (SDL_GetWindowFlags(vd->Window) & SDL_WINDOW_MINIMIZED) != 0;
+}
+
+static void ImGui_ImplSDL3_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    if (vd->GLContext)
+        SDL_GL_MakeCurrent(vd->Window, vd->GLContext);
+}
+
+static void ImGui_ImplSDL3_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    if (vd->GLContext)
+    {
+        SDL_GL_MakeCurrent(vd->Window, vd->GLContext);
+        SDL_GL_SwapWindow(vd->Window);
+    }
+}
+
+// Vulkan support (the Vulkan renderer needs to call a platform-side support function to create the surface)
+// SDL is graceful enough to _not_ need <vulkan/vulkan.h> so we can safely include this.
+#include <SDL3/SDL_vulkan.h>
+static int ImGui_ImplSDL3_CreateVkSurface(ImGuiViewport* viewport, ImU64 vk_instance, const void* vk_allocator, ImU64* out_vk_surface)
+{
+    ImGui_ImplSDL3_ViewportData* vd = (ImGui_ImplSDL3_ViewportData*)viewport->PlatformUserData;
+    (void)vk_allocator;
+    SDL_bool ret = SDL_Vulkan_CreateSurface(vd->Window, (VkInstance)vk_instance, (VkSurfaceKHR*)out_vk_surface);
+    return ret ? 0 : 1; // ret ? VK_SUCCESS : VK_NOT_READY
+}
+
+static void ImGui_ImplSDL3_InitPlatformInterface(SDL_Window* window, void* sdl_gl_context)
+{
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplSDL3_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplSDL3_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplSDL3_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplSDL3_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplSDL3_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplSDL3_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplSDL3_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplSDL3_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplSDL3_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplSDL3_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplSDL3_SetWindowTitle;
+    platform_io.Platform_RenderWindow = ImGui_ImplSDL3_RenderWindow;
+    platform_io.Platform_SwapBuffers = ImGui_ImplSDL3_SwapBuffers;
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplSDL3_SetWindowAlpha;
+    platform_io.Platform_CreateVkSurface = ImGui_ImplSDL3_CreateVkSurface;
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplSDL3_ViewportData* vd = IM_NEW(ImGui_ImplSDL3_ViewportData)();
+    vd->Window = window;
+    vd->WindowID = SDL_GetWindowID(window);
+    vd->WindowOwned = false;
+    vd->GLContext = sdl_gl_context;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = vd->Window;
+}
+
+static void ImGui_ImplSDL3_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif
-

backends/imgui_impl_sdl3.h

@@ -9,7 +9,9 @@
 //  [X] Platform: Keyboard support. Since 1.87 we are using the io.AddKeyEvent() function. Pass ImGuiKey values to all key functions e.g. ImGui::IsKeyPressed(ImGuiKey_Space). [Legacy SDL_SCANCODE_* values will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [x] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable' -> the OS animation effect when window gets created/destroyed is problematic. SDL2 backend doesn't have issue.
 // Missing features:
+//  [ ] Platform: Multi-viewport + Minimized windows seems to break mouse wheel events (at least under Windows).
 //  [x] Platform: Basic IME support. Position somehow broken in SDL3 + app needs to call 'SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");' before SDL_CreateWindow()!.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.

backends/imgui_impl_sdlrenderer.h

@@ -1,29 +0,0 @@
-// dear imgui: Renderer Backend for SDL_Renderer
-// (Requires: SDL 2.0.17+)
-
-// Important to understand: SDL_Renderer is an _optional_ component of SDL.
-// 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 offers a limited graphic API to the end-user and it might
-// be difficult to step out of those boundaries.
-// However, we understand it is a convenient choice to get an app started easily.
-
-// Implemented features:
-//  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
-//  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
-
-#pragma once
-#include "imgui.h"      // IMGUI_IMPL_API
-
-struct SDL_Renderer;
-
-IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer_Init(SDL_Renderer* renderer);
-IMGUI_IMPL_API void     ImGui_ImplSDLRenderer_Shutdown();
-IMGUI_IMPL_API void     ImGui_ImplSDLRenderer_NewFrame();
-IMGUI_IMPL_API void     ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data);
-
-// Called by Init/NewFrame/Shutdown
-IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer_CreateFontsTexture();
-IMGUI_IMPL_API void     ImGui_ImplSDLRenderer_DestroyFontsTexture();
-IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer_CreateDeviceObjects();
-IMGUI_IMPL_API void     ImGui_ImplSDLRenderer_DestroyDeviceObjects();

backends/imgui_impl_sdlrenderer2.cpp

@@ -1,22 +1,24 @@
-// dear imgui: Renderer Backend for SDL_Renderer
+// dear imgui: Renderer Backend for SDL_Renderer for SDL2
 // (Requires: SDL 2.0.17+)
 
-// Important to understand: SDL_Renderer is an _optional_ component of SDL.
+// 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 offers a limited graphic API to the end-user and it might
-// be difficult to step out of those boundaries.
-// However, we understand it is a convenient choice to get an app started easily.
+// 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) with 16-bit indices.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
 
 // You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs
 
 // CHANGELOG
+//  2023-05-30: Renamed imgui_impl_sdlrenderer.h/.cpp to imgui_impl_sdlrenderer2.h/.cpp to accommodate for upcoming SDL3.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2021-12-21: Update SDL_RenderGeometryRaw() format to work with SDL 2.0.19.
 //  2021-12-03: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
@@ -24,7 +26,7 @@
 //  2021-09-21: Initial version.
 
 #include "imgui.h"
-#include "imgui_impl_sdlrenderer.h"
+#include "imgui_impl_sdlrenderer2.h"
 #if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
 #include <stddef.h>     // intptr_t
 #else
@@ -44,31 +46,31 @@
 #endif
 
 // SDL_Renderer data
-struct ImGui_ImplSDLRenderer_Data
+struct ImGui_ImplSDLRenderer2_Data
 {
     SDL_Renderer*   SDLRenderer;
     SDL_Texture*    FontTexture;
-    ImGui_ImplSDLRenderer_Data() { memset((void*)this, 0, sizeof(*this)); }
+    ImGui_ImplSDLRenderer2_Data() { memset((void*)this, 0, sizeof(*this)); }
 };
 
 // Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
 // It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
-static ImGui_ImplSDLRenderer_Data* ImGui_ImplSDLRenderer_GetBackendData()
+static ImGui_ImplSDLRenderer2_Data* ImGui_ImplSDLRenderer2_GetBackendData()
 {
-    return ImGui::GetCurrentContext() ? (ImGui_ImplSDLRenderer_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
+    return ImGui::GetCurrentContext() ? (ImGui_ImplSDLRenderer2_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
 }
 
 // Functions
-bool ImGui_ImplSDLRenderer_Init(SDL_Renderer* renderer)
+bool ImGui_ImplSDLRenderer2_Init(SDL_Renderer* renderer)
 {
     ImGuiIO& io = ImGui::GetIO();
     IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
     IM_ASSERT(renderer != nullptr && "SDL_Renderer not initialized!");
 
     // Setup backend capabilities flags
-    ImGui_ImplSDLRenderer_Data* bd = IM_NEW(ImGui_ImplSDLRenderer_Data)();
+    ImGui_ImplSDLRenderer2_Data* bd = IM_NEW(ImGui_ImplSDLRenderer2_Data)();
     io.BackendRendererUserData = (void*)bd;
-    io.BackendRendererName = "imgui_impl_sdlrenderer";
+    io.BackendRendererName = "imgui_impl_sdlrenderer2";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
 
     bd->SDLRenderer = renderer;
@@ -76,22 +78,23 @@ bool ImGui_ImplSDLRenderer_Init(SDL_Renderer* renderer)
     return true;
 }
 
-void ImGui_ImplSDLRenderer_Shutdown()
+void ImGui_ImplSDLRenderer2_Shutdown()
 {
-    ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+    ImGui_ImplSDLRenderer2_Data* bd = ImGui_ImplSDLRenderer2_GetBackendData();
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
-    ImGui_ImplSDLRenderer_DestroyDeviceObjects();
+    ImGui_ImplSDLRenderer2_DestroyDeviceObjects();
 
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
     IM_DELETE(bd);
 }
 
-static void ImGui_ImplSDLRenderer_SetupRenderState()
+static void ImGui_ImplSDLRenderer2_SetupRenderState()
 {
-	ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+	ImGui_ImplSDLRenderer2_Data* bd = ImGui_ImplSDLRenderer2_GetBackendData();
 
 	// 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.
@@ -99,18 +102,18 @@ static void ImGui_ImplSDLRenderer_SetupRenderState()
 	SDL_RenderSetClipRect(bd->SDLRenderer, nullptr);
 }
 
-void ImGui_ImplSDLRenderer_NewFrame()
+void ImGui_ImplSDLRenderer2_NewFrame()
 {
-    ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
-    IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplSDLRenderer_Init()?");
+    ImGui_ImplSDLRenderer2_Data* bd = ImGui_ImplSDLRenderer2_GetBackendData();
+    IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplSDLRenderer2_Init()?");
 
     if (!bd->FontTexture)
-        ImGui_ImplSDLRenderer_CreateDeviceObjects();
+        ImGui_ImplSDLRenderer2_CreateDeviceObjects();
 }
 
-void ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data)
+void ImGui_ImplSDLRenderer2_RenderDrawData(ImDrawData* draw_data)
 {
-	ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+	ImGui_ImplSDLRenderer2_Data* bd = ImGui_ImplSDLRenderer2_GetBackendData();
 
 	// 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
@@ -145,7 +148,7 @@ void ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data)
 	ImVec2 clip_scale = render_scale;
 
     // Render command lists
-    ImGui_ImplSDLRenderer_SetupRenderState();
+    ImGui_ImplSDLRenderer2_SetupRenderState();
     for (int n = 0; n < draw_data->CmdListsCount; n++)
     {
         const ImDrawList* cmd_list = draw_data->CmdLists[n];
@@ -160,7 +163,7 @@ void ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data)
                 // User callback, registered via ImDrawList::AddCallback()
                 // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
                 if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
-                    ImGui_ImplSDLRenderer_SetupRenderState();
+                    ImGui_ImplSDLRenderer2_SetupRenderState();
                 else
                     pcmd->UserCallback(cmd_list, pcmd);
             }
@@ -205,10 +208,10 @@ void ImGui_ImplSDLRenderer_RenderDrawData(ImDrawData* draw_data)
 }
 
 // Called by Init/NewFrame/Shutdown
-bool ImGui_ImplSDLRenderer_CreateFontsTexture()
+bool ImGui_ImplSDLRenderer2_CreateFontsTexture()
 {
     ImGuiIO& io = ImGui::GetIO();
-    ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+    ImGui_ImplSDLRenderer2_Data* bd = ImGui_ImplSDLRenderer2_GetBackendData();
 
     // Build texture atlas
     unsigned char* pixels;
@@ -233,10 +236,10 @@ bool ImGui_ImplSDLRenderer_CreateFontsTexture()
     return true;
 }
 
-void ImGui_ImplSDLRenderer_DestroyFontsTexture()
+void ImGui_ImplSDLRenderer2_DestroyFontsTexture()
 {
     ImGuiIO& io = ImGui::GetIO();
-    ImGui_ImplSDLRenderer_Data* bd = ImGui_ImplSDLRenderer_GetBackendData();
+    ImGui_ImplSDLRenderer2_Data* bd = ImGui_ImplSDLRenderer2_GetBackendData();
     if (bd->FontTexture)
     {
         io.Fonts->SetTexID(0);
@@ -245,14 +248,14 @@ void ImGui_ImplSDLRenderer_DestroyFontsTexture()
     }
 }
 
-bool ImGui_ImplSDLRenderer_CreateDeviceObjects()
+bool ImGui_ImplSDLRenderer2_CreateDeviceObjects()
 {
-    return ImGui_ImplSDLRenderer_CreateFontsTexture();
+    return ImGui_ImplSDLRenderer2_CreateFontsTexture();
 }
 
-void ImGui_ImplSDLRenderer_DestroyDeviceObjects()
+void ImGui_ImplSDLRenderer2_DestroyDeviceObjects()
 {
-    ImGui_ImplSDLRenderer_DestroyFontsTexture();
+    ImGui_ImplSDLRenderer2_DestroyFontsTexture();
 }
 
 #if defined(__clang__)

backends/imgui_impl_sdlrenderer2.h

@@ -0,0 +1,30 @@
+// 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.
+
+// Implemented features:
+//  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
+//  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
+
+#pragma once
+#include "imgui.h"      // IMGUI_IMPL_API
+
+struct SDL_Renderer;
+
+IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer2_Init(SDL_Renderer* renderer);
+IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_Shutdown();
+IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_NewFrame();
+IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_RenderDrawData(ImDrawData* draw_data);
+
+// Called by Init/NewFrame/Shutdown
+IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer2_CreateFontsTexture();
+IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_DestroyFontsTexture();
+IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer2_CreateDeviceObjects();
+IMGUI_IMPL_API void     ImGui_ImplSDLRenderer2_DestroyDeviceObjects();

backends/imgui_impl_sdlrenderer3.cpp

@@ -0,0 +1,258 @@
+// dear imgui: Renderer Backend for SDL_Renderer for SDL3
+// (Requires: SDL 3.0.0+)
+
+// 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.
+
+// Implemented features:
+//  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
+//  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
+
+// You can copy and use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// CHANGELOG
+//  2023-05-30: Initial version.
+
+#include "imgui.h"
+#include "imgui_impl_sdlrenderer3.h"
+#if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
+#include <stddef.h>     // intptr_t
+#else
+#include <stdint.h>     // intptr_t
+#endif
+
+// Clang warnings with -Weverything
+#if defined(__clang__)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wsign-conversion"    // warning: implicit conversion changes signedness
+#endif
+
+// SDL
+#include <SDL3/SDL.h>
+#if !SDL_VERSION_ATLEAST(3,0,0)
+#error This backend requires SDL 3.0.0+
+#endif
+
+// SDL_Renderer data
+struct ImGui_ImplSDLRenderer3_Data
+{
+    SDL_Renderer*   SDLRenderer;
+    SDL_Texture*    FontTexture;
+    ImGui_ImplSDLRenderer3_Data() { memset((void*)this, 0, sizeof(*this)); }
+};
+
+// Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
+// It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
+static ImGui_ImplSDLRenderer3_Data* ImGui_ImplSDLRenderer3_GetBackendData()
+{
+    return ImGui::GetCurrentContext() ? (ImGui_ImplSDLRenderer3_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
+}
+
+// Functions
+bool ImGui_ImplSDLRenderer3_Init(SDL_Renderer* renderer)
+{
+    ImGuiIO& io = ImGui::GetIO();
+    IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
+    IM_ASSERT(renderer != nullptr && "SDL_Renderer not initialized!");
+
+    // Setup backend capabilities flags
+    ImGui_ImplSDLRenderer3_Data* bd = IM_NEW(ImGui_ImplSDLRenderer3_Data)();
+    io.BackendRendererUserData = (void*)bd;
+    io.BackendRendererName = "imgui_impl_sdlrenderer3";
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+
+    bd->SDLRenderer = renderer;
+
+    return true;
+}
+
+void ImGui_ImplSDLRenderer3_Shutdown()
+{
+    ImGui_ImplSDLRenderer3_Data* bd = ImGui_ImplSDLRenderer3_GetBackendData();
+    IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
+    ImGuiIO& io = ImGui::GetIO();
+
+    ImGui_ImplSDLRenderer3_DestroyDeviceObjects();
+
+    io.BackendRendererName = nullptr;
+    io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
+    IM_DELETE(bd);
+}
+
+static void ImGui_ImplSDLRenderer3_SetupRenderState()
+{
+	ImGui_ImplSDLRenderer3_Data* bd = ImGui_ImplSDLRenderer3_GetBackendData();
+
+	// 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(bd->SDLRenderer, nullptr);
+	SDL_SetRenderClipRect(bd->SDLRenderer, nullptr);
+}
+
+void ImGui_ImplSDLRenderer3_NewFrame()
+{
+    ImGui_ImplSDLRenderer3_Data* bd = ImGui_ImplSDLRenderer3_GetBackendData();
+    IM_ASSERT(bd != nullptr && "Did you call ImGui_ImplSDLRenderer3_Init()?");
+
+    if (!bd->FontTexture)
+        ImGui_ImplSDLRenderer3_CreateDeviceObjects();
+}
+
+void ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_data)
+{
+	ImGui_ImplSDLRenderer3_Data* bd = ImGui_ImplSDLRenderer3_GetBackendData();
+
+	// 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(bd->SDLRenderer, &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;
+
+	// 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
+    {
+        SDL_Rect    Viewport;
+        bool        ClipEnabled;
+        SDL_Rect    ClipRect;
+    };
+    BackupSDLRendererState old = {};
+    old.ClipEnabled = SDL_RenderClipEnabled(bd->SDLRenderer) == SDL_TRUE;
+    SDL_GetRenderViewport(bd->SDLRenderer, &old.Viewport);
+    SDL_GetRenderClipRect(bd->SDLRenderer, &old.ClipRect);
+
+	// 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
+    ImGui_ImplSDLRenderer3_SetupRenderState();
+    for (int n = 0; n < draw_data->CmdListsCount; n++)
+    {
+        const ImDrawList* cmd_list = draw_data->CmdLists[n];
+        const ImDrawVert* vtx_buffer = cmd_list->VtxBuffer.Data;
+        const ImDrawIdx* idx_buffer = cmd_list->IdxBuffer.Data;
+
+        for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
+        {
+            const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
+            if (pcmd->UserCallback)
+            {
+                // User callback, registered via ImDrawList::AddCallback()
+                // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
+                if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
+                    ImGui_ImplSDLRenderer3_SetupRenderState();
+                else
+                    pcmd->UserCallback(cmd_list, pcmd);
+            }
+            else
+            {
+                // 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);
+                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);
+                if (clip_min.x < 0.0f) { clip_min.x = 0.0f; }
+                if (clip_min.y < 0.0f) { clip_min.y = 0.0f; }
+                if (clip_max.x > (float)fb_width) { clip_max.x = (float)fb_width; }
+                if (clip_max.y > (float)fb_height) { clip_max.y = (float)fb_height; }
+                if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
+                    continue;
+
+                SDL_Rect r = { (int)(clip_min.x), (int)(clip_min.y), (int)(clip_max.x - clip_min.x), (int)(clip_max.y - clip_min.y) };
+                SDL_SetRenderClipRect(bd->SDLRenderer, &r);
+
+                const float* xy = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, pos));
+                const float* uv = (const float*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, uv));
+#if SDL_VERSION_ATLEAST(2,0,19)
+                const SDL_Color* color = (const SDL_Color*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, col)); // SDL 2.0.19+
+#else
+                const int* color = (const int*)(const void*)((const char*)(vtx_buffer + pcmd->VtxOffset) + IM_OFFSETOF(ImDrawVert, col)); // SDL 2.0.17 and 2.0.18
+#endif
+
+                // Bind texture, Draw
+				SDL_Texture* tex = (SDL_Texture*)pcmd->GetTexID();
+                SDL_RenderGeometryRaw(bd->SDLRenderer, tex,
+                    xy, (int)sizeof(ImDrawVert),
+                    color, (int)sizeof(ImDrawVert),
+                    uv, (int)sizeof(ImDrawVert),
+                    cmd_list->VtxBuffer.Size - pcmd->VtxOffset,
+                    idx_buffer + pcmd->IdxOffset, pcmd->ElemCount, sizeof(ImDrawIdx));
+            }
+        }
+    }
+
+    // Restore modified SDL_Renderer state
+    SDL_SetRenderViewport(bd->SDLRenderer, &old.Viewport);
+    SDL_SetRenderClipRect(bd->SDLRenderer, old.ClipEnabled ? &old.ClipRect : nullptr);
+}
+
+// Called by Init/NewFrame/Shutdown
+bool ImGui_ImplSDLRenderer3_CreateFontsTexture()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplSDLRenderer3_Data* bd = ImGui_ImplSDLRenderer3_GetBackendData();
+
+    // Build texture atlas
+    unsigned char* pixels;
+    int width, height;
+    io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);   // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
+
+    // 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->SDLRenderer, SDL_PIXELFORMAT_ABGR8888, SDL_TEXTUREACCESS_STATIC, width, height);
+    if (bd->FontTexture == nullptr)
+    {
+        SDL_Log("error creating texture");
+        return false;
+    }
+    SDL_UpdateTexture(bd->FontTexture, nullptr, pixels, 4 * width);
+    SDL_SetTextureBlendMode(bd->FontTexture, SDL_BLENDMODE_BLEND);
+    SDL_SetTextureScaleMode(bd->FontTexture, SDL_SCALEMODE_LINEAR);
+
+    // Store our identifier
+    io.Fonts->SetTexID((ImTextureID)(intptr_t)bd->FontTexture);
+
+    return true;
+}
+
+void ImGui_ImplSDLRenderer3_DestroyFontsTexture()
+{
+    ImGuiIO& io = ImGui::GetIO();
+    ImGui_ImplSDLRenderer3_Data* bd = ImGui_ImplSDLRenderer3_GetBackendData();
+    if (bd->FontTexture)
+    {
+        io.Fonts->SetTexID(0);
+        SDL_DestroyTexture(bd->FontTexture);
+        bd->FontTexture = nullptr;
+    }
+}
+
+bool ImGui_ImplSDLRenderer3_CreateDeviceObjects()
+{
+    return ImGui_ImplSDLRenderer3_CreateFontsTexture();
+}
+
+void ImGui_ImplSDLRenderer3_DestroyDeviceObjects()
+{
+    ImGui_ImplSDLRenderer3_DestroyFontsTexture();
+}
+
+#if defined(__clang__)
+#pragma clang diagnostic pop
+#endif

backends/imgui_impl_sdlrenderer3.h

@@ -0,0 +1,30 @@
+// dear imgui: Renderer Backend for SDL_Renderer for SDL3
+// (Requires: SDL 3.0.0+)
+
+// 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.
+
+// Implemented features:
+//  [X] Renderer: User texture binding. Use 'SDL_Texture*' as ImTextureID. Read the FAQ about ImTextureID!
+//  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+// Missing features:
+//  [ ] Renderer: Multi-viewport support (multiple windows).
+
+#pragma once
+#include "imgui.h"      // IMGUI_IMPL_API
+
+struct SDL_Renderer;
+
+IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer3_Init(SDL_Renderer* renderer);
+IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_Shutdown();
+IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_NewFrame();
+IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_RenderDrawData(ImDrawData* draw_data);
+
+// Called by Init/NewFrame/Shutdown
+IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer3_CreateFontsTexture();
+IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_DestroyFontsTexture();
+IMGUI_IMPL_API bool     ImGui_ImplSDLRenderer3_CreateDeviceObjects();
+IMGUI_IMPL_API void     ImGui_ImplSDLRenderer3_DestroyDeviceObjects();

backends/imgui_impl_vulkan.cpp

@@ -2,8 +2,9 @@
 // This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
 
 // Implemented features:
-//  [!] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
+//  [x] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [x] Renderer: Multi-viewport / platform windows. With issues (flickering when creating a new viewport).
 
 // Important: on 32-bit systems, user texture binding is only supported if your imconfig file has '#define ImTextureID ImU64'.
 // This is because we need ImTextureID to carry a 64-bit value and by default ImTextureID is defined as void*.
@@ -30,6 +31,8 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2023-07-04: Vulkan: Added optional support for VK_KHR_dynamic_rendering. User needs to set init_info->UseDynamicRendering = true and init_info->ColorAttachmentFormat.
 //  2023-01-02: Vulkan: Fixed sampler passed to ImGui_ImplVulkan_AddTexture() not being honored + removed a bunch of duplicate code.
 //  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
 //  2022-10-04: Vulkan: Added experimental ImGui_ImplVulkan_RemoveTexture() for api symetry. (#914, #5738).
@@ -94,6 +97,18 @@ struct ImGui_ImplVulkanH_WindowRenderBuffers
     ImGui_ImplVulkanH_FrameRenderBuffers*   FrameRenderBuffers;
 };
 
+// For multi-viewport support:
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplVulkan_ViewportData
+{
+    bool                                    WindowOwned;
+    ImGui_ImplVulkanH_Window                Window;             // Used by secondary viewports only
+    ImGui_ImplVulkanH_WindowRenderBuffers   RenderBuffers;      // Used by all viewports
+
+    ImGui_ImplVulkan_ViewportData()         { WindowOwned = false; memset(&RenderBuffers, 0, sizeof(RenderBuffers)); }
+    ~ImGui_ImplVulkan_ViewportData()        { }
+};
+
 // Vulkan data
 struct ImGui_ImplVulkan_Data
 {
@@ -134,6 +149,7 @@ void ImGui_ImplVulkanH_DestroyFrame(VkDevice device, ImGui_ImplVulkanH_Frame* fd
 void ImGui_ImplVulkanH_DestroyFrameSemaphores(VkDevice device, ImGui_ImplVulkanH_FrameSemaphores* fsd, const VkAllocationCallbacks* allocator);
 void ImGui_ImplVulkanH_DestroyFrameRenderBuffers(VkDevice device, ImGui_ImplVulkanH_FrameRenderBuffers* buffers, const VkAllocationCallbacks* allocator);
 void ImGui_ImplVulkanH_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVulkanH_WindowRenderBuffers* buffers, const VkAllocationCallbacks* allocator);
+void ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(VkDevice device, const VkAllocationCallbacks* allocator);
 void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count);
 void ImGui_ImplVulkanH_CreateWindowCommandBuffers(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, uint32_t queue_family, const VkAllocationCallbacks* allocator);
 
@@ -204,7 +220,18 @@ static bool g_FunctionsLoaded = true;
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetSwapchainImagesKHR) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkMapMemory) \
     IMGUI_VULKAN_FUNC_MAP_MACRO(vkUnmapMemory) \
-    IMGUI_VULKAN_FUNC_MAP_MACRO(vkUpdateDescriptorSets)
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkUpdateDescriptorSets) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceSupportKHR) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkWaitForFences) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBeginRenderPass) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdEndRenderPass) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueuePresentKHR) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkBeginCommandBuffer) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkEndCommandBuffer) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkResetFences) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueueSubmit) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkResetCommandPool) \
+    IMGUI_VULKAN_FUNC_MAP_MACRO(vkAcquireNextImageKHR)
 
 // Define function pointers
 #define IMGUI_VULKAN_FUNC_DEF(func) static PFN_##func func;
@@ -212,10 +239,20 @@ IMGUI_VULKAN_FUNC_MAP(IMGUI_VULKAN_FUNC_DEF)
 #undef IMGUI_VULKAN_FUNC_DEF
 #endif // VK_NO_PROTOTYPES
 
+#if defined(VK_VERSION_1_3) || defined(VK_KHR_dynamic_rendering)
+#define IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+static PFN_vkCmdBeginRenderingKHR   ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR;
+static PFN_vkCmdEndRenderingKHR     ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR;
+#endif
+
 //-----------------------------------------------------------------------------
 // SHADERS
 //-----------------------------------------------------------------------------
 
+// Forward Declarations
+static void ImGui_ImplVulkan_InitPlatformInterface();
+static void ImGui_ImplVulkan_ShutdownPlatformInterface();
+
 // glsl_shader.vert, compiled with:
 // # glslangValidator -V -x -o glsl_shader.vert.u32 glsl_shader.vert
 /*
@@ -447,8 +484,10 @@ void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer comm
     if (pipeline == VK_NULL_HANDLE)
         pipeline = bd->Pipeline;
 
-    // Allocate array to store enough vertex/index buffers
-    ImGui_ImplVulkanH_WindowRenderBuffers* wrb = &bd->MainWindowRenderBuffers;
+    // Allocate array to store enough vertex/index buffers. Each unique viewport gets its own storage.
+    ImGui_ImplVulkan_ViewportData* viewport_renderer_data = (ImGui_ImplVulkan_ViewportData*)draw_data->OwnerViewport->RendererUserData;
+    IM_ASSERT(viewport_renderer_data != nullptr);
+    ImGui_ImplVulkanH_WindowRenderBuffers* wrb = &viewport_renderer_data->RenderBuffers;
     if (wrb->FrameRenderBuffers == nullptr)
     {
         wrb->Index = 0;
@@ -840,6 +879,19 @@ static void ImGui_ImplVulkan_CreatePipeline(VkDevice device, const VkAllocationC
     info.layout = bd->PipelineLayout;
     info.renderPass = renderPass;
     info.subpass = subpass;
+
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+    VkPipelineRenderingCreateInfoKHR pipelineRenderingCreateInfo = {};
+    pipelineRenderingCreateInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR;
+    pipelineRenderingCreateInfo.colorAttachmentCount = 1;
+    pipelineRenderingCreateInfo.pColorAttachmentFormats = &bd->VulkanInitInfo.ColorAttachmentFormat;
+    if (bd->VulkanInitInfo.UseDynamicRendering)
+    {
+        info.pNext = &pipelineRenderingCreateInfo;
+        info.renderPass = VK_NULL_HANDLE; // Just make sure it's actually nullptr.
+    }
+#endif
+
     VkResult err = vkCreateGraphicsPipelines(device, pipelineCache, 1, &info, allocator, pipeline);
     check_vk_result(err);
 }
@@ -925,7 +977,7 @@ void    ImGui_ImplVulkan_DestroyDeviceObjects()
 {
     ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
     ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
-    ImGui_ImplVulkanH_DestroyWindowRenderBuffers(v->Device, &bd->MainWindowRenderBuffers, v->Allocator);
+    ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(v->Device, v->Allocator);
     ImGui_ImplVulkan_DestroyFontUploadObjects();
 
     if (bd->ShaderModuleVert)     { vkDestroyShaderModule(v->Device, bd->ShaderModuleVert, v->Allocator); bd->ShaderModuleVert = VK_NULL_HANDLE; }
@@ -952,10 +1004,17 @@ bool    ImGui_ImplVulkan_LoadFunctions(PFN_vkVoidFunction(*loader_func)(const ch
         return false;
     IMGUI_VULKAN_FUNC_MAP(IMGUI_VULKAN_FUNC_LOAD)
 #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));
+#endif
 #else
     IM_UNUSED(loader_func);
     IM_UNUSED(user_data);
 #endif
+
     g_FunctionsLoaded = true;
     return true;
 }
@@ -964,6 +1023,20 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass rend
 {
     IM_ASSERT(g_FunctionsLoaded && "Need to call ImGui_ImplVulkan_LoadFunctions() if IMGUI_IMPL_VULKAN_NO_PROTOTYPES or VK_NO_PROTOTYPES are set!");
 
+    if (info->UseDynamicRendering)
+    {
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+#ifndef VK_NO_PROTOTYPES
+        ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR = reinterpret_cast<PFN_vkCmdBeginRenderingKHR>(vkGetInstanceProcAddr(info->Instance, "vkCmdBeginRenderingKHR"));
+        ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR = reinterpret_cast<PFN_vkCmdEndRenderingKHR>(vkGetInstanceProcAddr(info->Instance, "vkCmdEndRenderingKHR"));
+#endif
+        IM_ASSERT(ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR != nullptr);
+        IM_ASSERT(ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR != nullptr);
+#else
+        IM_ASSERT(0 && "Can't use dynamic rendering when neither VK_VERSION_1_3 or VK_KHR_dynamic_rendering is defined.");
+#endif
+    }
+
     ImGuiIO& io = ImGui::GetIO();
     IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");
 
@@ -972,6 +1045,7 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass rend
     io.BackendRendererUserData = (void*)bd;
     io.BackendRendererName = "imgui_impl_vulkan";
     io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     IM_ASSERT(info->Instance != VK_NULL_HANDLE);
     IM_ASSERT(info->PhysicalDevice != VK_NULL_HANDLE);
@@ -980,7 +1054,8 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass rend
     IM_ASSERT(info->DescriptorPool != VK_NULL_HANDLE);
     IM_ASSERT(info->MinImageCount >= 2);
     IM_ASSERT(info->ImageCount >= info->MinImageCount);
-    IM_ASSERT(render_pass != VK_NULL_HANDLE);
+    if (info->UseDynamicRendering == false)
+        IM_ASSERT(render_pass != VK_NULL_HANDLE);
 
     bd->VulkanInitInfo = *info;
     bd->RenderPass = render_pass;
@@ -988,6 +1063,13 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass rend
 
     ImGui_ImplVulkan_CreateDeviceObjects();
 
+    // Our render function expect RendererUserData to be storing the window render buffer we need (for the main viewport we won't use ->Window)
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->RendererUserData = IM_NEW(ImGui_ImplVulkan_ViewportData)();
+
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplVulkan_InitPlatformInterface();
+
     return true;
 }
 
@@ -997,9 +1079,21 @@ void ImGui_ImplVulkan_Shutdown()
     IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    // First destroy objects in all viewports
     ImGui_ImplVulkan_DestroyDeviceObjects();
+
+    // Manually delete main viewport render data in-case we haven't initialized for viewports
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)main_viewport->RendererUserData)
+        IM_DELETE(vd);
+    main_viewport->RendererUserData = nullptr;
+
+    // Clean up windows
+    ImGui_ImplVulkan_ShutdownPlatformInterface();
+
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasViewports);
     IM_DELETE(bd);
 }
 
@@ -1017,10 +1111,12 @@ void ImGui_ImplVulkan_SetMinImageCount(uint32_t min_image_count)
     if (bd->VulkanInitInfo.MinImageCount == min_image_count)
         return;
 
+    IM_ASSERT(0); // FIXME-VIEWPORT: Unsupported. Need to recreate all swap chains!
     ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
     VkResult err = vkDeviceWaitIdle(v->Device);
     check_vk_result(err);
-    ImGui_ImplVulkanH_DestroyWindowRenderBuffers(v->Device, &bd->MainWindowRenderBuffers, v->Allocator);
+    ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(v->Device, v->Allocator);
+
     bd->VulkanInitInfo.MinImageCount = min_image_count;
 }
 
@@ -1296,6 +1392,7 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
         vkDestroySwapchainKHR(device, old_swapchain, allocator);
 
     // Create the Render Pass
+    if (wd->UseDynamicRendering == false)
     {
         VkAttachmentDescription attachment = {};
         attachment.format = wd->SurfaceFormat.format;
@@ -1358,6 +1455,7 @@ void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, V
     }
 
     // Create Framebuffer
+    if (wd->UseDynamicRendering == false)
     {
         VkImageView attachment[1];
         VkFramebufferCreateInfo info = {};
@@ -1384,6 +1482,7 @@ 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);
 }
 
@@ -1448,3 +1547,261 @@ void ImGui_ImplVulkanH_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVul
     buffers->Index = 0;
     buffers->Count = 0;
 }
+
+void ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(VkDevice device, const VkAllocationCallbacks* allocator)
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    for (int n = 0; n < platform_io.Viewports.Size; n++)
+        if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)platform_io.Viewports[n]->RendererUserData)
+            ImGui_ImplVulkanH_DestroyWindowRenderBuffers(device, &vd->RenderBuffers, allocator);
+}
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplVulkan_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = IM_NEW(ImGui_ImplVulkan_ViewportData)();
+    viewport->RendererUserData = vd;
+    ImGui_ImplVulkanH_Window* wd = &vd->Window;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+
+    // Create surface
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    VkResult err = (VkResult)platform_io.Platform_CreateVkSurface(viewport, (ImU64)v->Instance, (const void*)v->Allocator, (ImU64*)&wd->Surface);
+    check_vk_result(err);
+
+    // Check for WSI support
+    VkBool32 res;
+    vkGetPhysicalDeviceSurfaceSupportKHR(v->PhysicalDevice, v->QueueFamily, wd->Surface, &res);
+    if (res != VK_TRUE)
+    {
+        IM_ASSERT(0); // Error: no WSI support on physical device
+        return;
+    }
+
+    // Select Surface Format
+    const VkFormat requestSurfaceImageFormat[] = { VK_FORMAT_B8G8R8A8_UNORM, VK_FORMAT_R8G8B8A8_UNORM, VK_FORMAT_B8G8R8_UNORM, VK_FORMAT_R8G8B8_UNORM };
+    const VkColorSpaceKHR requestSurfaceColorSpace = VK_COLORSPACE_SRGB_NONLINEAR_KHR;
+    wd->SurfaceFormat = ImGui_ImplVulkanH_SelectSurfaceFormat(v->PhysicalDevice, wd->Surface, requestSurfaceImageFormat, (size_t)IM_ARRAYSIZE(requestSurfaceImageFormat), requestSurfaceColorSpace);
+
+    // Select Present Mode
+    // FIXME-VULKAN: Even thought mailbox seems to get us maximum framerate with a single window, it halves framerate with a second window etc. (w/ Nvidia and SDK 1.82.1)
+    VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_MAILBOX_KHR, VK_PRESENT_MODE_IMMEDIATE_KHR, VK_PRESENT_MODE_FIFO_KHR };
+    wd->PresentMode = ImGui_ImplVulkanH_SelectPresentMode(v->PhysicalDevice, wd->Surface, &present_modes[0], IM_ARRAYSIZE(present_modes));
+    //printf("[vulkan] Secondary window selected PresentMode = %d\n", wd->PresentMode);
+
+    // Create SwapChain, RenderPass, Framebuffer, etc.
+    wd->ClearEnable = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? false : true;
+    wd->UseDynamicRendering = v->UseDynamicRendering;
+    ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, wd, v->QueueFamily, v->Allocator, (int)viewport->Size.x, (int)viewport->Size.y, v->MinImageCount);
+    vd->WindowOwned = true;
+}
+
+static void ImGui_ImplVulkan_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData)
+    {
+        ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+        if (vd->WindowOwned)
+            ImGui_ImplVulkanH_DestroyWindow(v->Instance, v->Device, &vd->Window, v->Allocator);
+        ImGui_ImplVulkanH_DestroyWindowRenderBuffers(v->Device, &vd->RenderBuffers, v->Allocator);
+        IM_DELETE(vd);
+    }
+    viewport->RendererUserData = nullptr;
+}
+
+static void ImGui_ImplVulkan_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
+    if (vd == nullptr) // This is nullptr for the main viewport (which is left to the user/app to handle)
+        return;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+    vd->Window.ClearEnable = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? false : true;
+    ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, &vd->Window, v->QueueFamily, v->Allocator, (int)size.x, (int)size.y, v->MinImageCount);
+}
+
+static void ImGui_ImplVulkan_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
+    ImGui_ImplVulkanH_Window* wd = &vd->Window;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+    VkResult err;
+
+    ImGui_ImplVulkanH_Frame* fd = &wd->Frames[wd->FrameIndex];
+    ImGui_ImplVulkanH_FrameSemaphores* fsd = &wd->FrameSemaphores[wd->SemaphoreIndex];
+    {
+        {
+          err = vkAcquireNextImageKHR(v->Device, wd->Swapchain, UINT64_MAX, fsd->ImageAcquiredSemaphore, VK_NULL_HANDLE, &wd->FrameIndex);
+          check_vk_result(err);
+          fd = &wd->Frames[wd->FrameIndex];
+        }
+        for (;;)
+        {
+            err = vkWaitForFences(v->Device, 1, &fd->Fence, VK_TRUE, 100);
+            if (err == VK_SUCCESS) break;
+            if (err == VK_TIMEOUT) continue;
+            check_vk_result(err);
+        }
+        {
+            err = vkResetCommandPool(v->Device, fd->CommandPool, 0);
+            check_vk_result(err);
+            VkCommandBufferBeginInfo info = {};
+            info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
+            info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
+            err = vkBeginCommandBuffer(fd->CommandBuffer, &info);
+            check_vk_result(err);
+        }
+        {
+            ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+            memcpy(&wd->ClearValue.color.float32[0], &clear_color, 4 * sizeof(float));
+        }
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+        if (v->UseDynamicRendering)
+        {
+            // Transition swapchain image to a layout suitable for drawing.
+            VkImageMemoryBarrier barrier = {};
+            barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
+            barrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
+            barrier.oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
+            barrier.newLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+            barrier.image = fd->Backbuffer;
+            barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+            barrier.subresourceRange.levelCount = 1;
+            barrier.subresourceRange.layerCount = 1;
+            vkCmdPipelineBarrier(fd->CommandBuffer, VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT, 0, 0, nullptr, 0, nullptr, 1, &barrier);
+
+            VkRenderingAttachmentInfo attachmentInfo = {};
+            attachmentInfo.sType = VK_STRUCTURE_TYPE_RENDERING_ATTACHMENT_INFO_KHR;
+            attachmentInfo.imageView = fd->BackbufferView;
+            attachmentInfo.imageLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+            attachmentInfo.resolveMode = VK_RESOLVE_MODE_NONE;
+            attachmentInfo.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
+            attachmentInfo.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
+            attachmentInfo.clearValue = wd->ClearValue;
+
+            VkRenderingInfo renderingInfo = {};
+            renderingInfo.sType = VK_STRUCTURE_TYPE_RENDERING_INFO_KHR;
+            renderingInfo.renderArea.extent.width = wd->Width;
+            renderingInfo.renderArea.extent.height = wd->Height;
+            renderingInfo.layerCount = 1;
+            renderingInfo.viewMask = 0;
+            renderingInfo.colorAttachmentCount = 1;
+            renderingInfo.pColorAttachments = &attachmentInfo;
+
+            ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR(fd->CommandBuffer, &renderingInfo);
+        }
+        else
+#endif
+        {
+            VkRenderPassBeginInfo info = {};
+            info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
+            info.renderPass = wd->RenderPass;
+            info.framebuffer = fd->Framebuffer;
+            info.renderArea.extent.width = wd->Width;
+            info.renderArea.extent.height = wd->Height;
+            info.clearValueCount = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? 0 : 1;
+            info.pClearValues = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? nullptr : &wd->ClearValue;
+            vkCmdBeginRenderPass(fd->CommandBuffer, &info, VK_SUBPASS_CONTENTS_INLINE);
+        }
+    }
+
+    ImGui_ImplVulkan_RenderDrawData(viewport->DrawData, fd->CommandBuffer, wd->Pipeline);
+
+    {
+#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
+        if (v->UseDynamicRendering)
+        {
+            ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR(fd->CommandBuffer);
+
+            // Transition image to a layout suitable for presentation
+            VkImageMemoryBarrier barrier = {};
+            barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
+            barrier.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
+            barrier.oldLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
+            barrier.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
+            barrier.image = fd->Backbuffer;
+            barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
+            barrier.subresourceRange.levelCount = 1;
+            barrier.subresourceRange.layerCount = 1;
+            vkCmdPipelineBarrier(fd->CommandBuffer, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT, VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT, 0, 0, nullptr, 0, nullptr, 1, &barrier);
+        }
+        else
+#endif
+        {
+            vkCmdEndRenderPass(fd->CommandBuffer);
+        }
+        {
+            VkPipelineStageFlags wait_stage = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
+            VkSubmitInfo info = {};
+            info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
+            info.waitSemaphoreCount = 1;
+            info.pWaitSemaphores = &fsd->ImageAcquiredSemaphore;
+            info.pWaitDstStageMask = &wait_stage;
+            info.commandBufferCount = 1;
+            info.pCommandBuffers = &fd->CommandBuffer;
+            info.signalSemaphoreCount = 1;
+            info.pSignalSemaphores = &fsd->RenderCompleteSemaphore;
+
+            err = vkEndCommandBuffer(fd->CommandBuffer);
+            check_vk_result(err);
+            err = vkResetFences(v->Device, 1, &fd->Fence);
+            check_vk_result(err);
+            err = vkQueueSubmit(v->Queue, 1, &info, fd->Fence);
+            check_vk_result(err);
+        }
+    }
+}
+
+static void ImGui_ImplVulkan_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
+    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
+    ImGui_ImplVulkanH_Window* wd = &vd->Window;
+    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
+
+    VkResult err;
+    uint32_t present_index = wd->FrameIndex;
+
+    ImGui_ImplVulkanH_FrameSemaphores* fsd = &wd->FrameSemaphores[wd->SemaphoreIndex];
+    VkPresentInfoKHR info = {};
+    info.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
+    info.waitSemaphoreCount = 1;
+    info.pWaitSemaphores = &fsd->RenderCompleteSemaphore;
+    info.swapchainCount = 1;
+    info.pSwapchains = &wd->Swapchain;
+    info.pImageIndices = &present_index;
+    err = vkQueuePresentKHR(v->Queue, &info);
+    if (err == VK_ERROR_OUT_OF_DATE_KHR || err == VK_SUBOPTIMAL_KHR)
+        ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, &vd->Window, v->QueueFamily, v->Allocator, (int)viewport->Size.x, (int)viewport->Size.y, v->MinImageCount);
+    else
+        check_vk_result(err);
+
+    wd->FrameIndex = (wd->FrameIndex + 1) % wd->ImageCount;         // This is for the next vkWaitForFences()
+    wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->ImageCount; // Now we can use the next set of semaphores
+}
+
+void ImGui_ImplVulkan_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        IM_ASSERT(platform_io.Platform_CreateVkSurface != nullptr && "Platform needs to setup the CreateVkSurface handler.");
+    platform_io.Renderer_CreateWindow = ImGui_ImplVulkan_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplVulkan_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplVulkan_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplVulkan_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplVulkan_SwapBuffers;
+}
+
+void ImGui_ImplVulkan_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}

backends/imgui_impl_vulkan.h

@@ -2,8 +2,9 @@
 // This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)
 
 // Implemented features:
-//  [!] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
+//  [x] Renderer: User texture binding. Use 'VkDescriptorSet' as ImTextureID. Read the FAQ about ImTextureID! See https://github.com/ocornut/imgui/pull/914 for discussions.
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
+//  [x] Renderer: Multi-viewport / platform windows. With issues (flickering when creating a new viewport).
 
 // Important: on 32-bit systems, user texture binding is only supported if your imconfig file has '#define ImTextureID ImU64'.
 // See imgui_impl_vulkan.cpp file for details.
@@ -59,6 +60,12 @@ struct ImGui_ImplVulkan_InitInfo
     uint32_t                        MinImageCount;          // >= 2
     uint32_t                        ImageCount;             // >= MinImageCount
     VkSampleCountFlagBits           MSAASamples;            // >= VK_SAMPLE_COUNT_1_BIT (0 -> default to VK_SAMPLE_COUNT_1_BIT)
+
+    // Dynamic Rendering (Optional)
+    bool                            UseDynamicRendering;    // Need to explicitly enable VK_KHR_dynamic_rendering extension to use this, even for Vulkan 1.3.
+    VkFormat                        ColorAttachmentFormat;  // Required for dynamic rendering
+
+    // Allocation, Debugging
     const VkAllocationCallbacks*    Allocator;
     void                            (*CheckVkResultFn)(VkResult err);
 };
@@ -139,6 +146,7 @@ struct ImGui_ImplVulkanH_Window
     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;
     uint32_t            FrameIndex;             // Current frame being rendered to (0 <= FrameIndex < FrameInFlightCount)

backends/imgui_impl_wgpu.cpp

@@ -751,6 +751,7 @@ void ImGui_ImplWGPU_Shutdown()
 
     io.BackendRendererName = nullptr;
     io.BackendRendererUserData = nullptr;
+    io.BackendFlags &= ~ImGuiBackendFlags_RendererHasVtxOffset;
     IM_DELETE(bd);
 }
 

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 will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -35,6 +36,8 @@ typedef DWORD (WINAPI *PFN_XInputGetState)(DWORD, XINPUT_STATE*);
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2023-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2023-04-19: Added ImGui_ImplWin32_InitForOpenGL() to facilitate combining raw Win32/Winapi with OpenGL. (#3218)
 //  2023-04-04: Inputs: Added support for io.AddMouseSourceEvent() to discriminate ImGuiMouseSource_Mouse/ImGuiMouseSource_TouchScreen/ImGuiMouseSource_Pen. (#2702)
 //  2023-02-15: Inputs: Use WM_NCMOUSEMOVE / WM_NCMOUSELEAVE to track mouse position over non-client area (e.g. OS decorations) when app is not focused. (#6045, #6162)
 //  2023-02-02: Inputs: Flipping WM_MOUSEHWHEEL (horizontal mouse-wheel) value to match other backends and offer consistent horizontal scrolling direction. (#4019, #6096, #1463)
@@ -83,6 +86,11 @@ typedef DWORD (WINAPI *PFN_XInputGetState)(DWORD, XINPUT_STATE*);
 //  2017-10-23: Inputs: Using Win32 ::SetCapture/::GetCapture() to retrieve mouse positions outside the client area when dragging.
 //  2016-11-12: Inputs: Only call Win32 ::SetCursor(nullptr) when io.MouseDrawCursor is set.
 
+// Forward Declarations
+static void ImGui_ImplWin32_InitPlatformInterface(bool platformHasOwnDC);
+static void ImGui_ImplWin32_ShutdownPlatformInterface();
+static void ImGui_ImplWin32_UpdateMonitors();
+
 struct ImGui_ImplWin32_Data
 {
     HWND                        hWnd;
@@ -92,6 +100,7 @@ struct ImGui_ImplWin32_Data
     INT64                       Time;
     INT64                       TicksPerSecond;
     ImGuiMouseCursor            LastMouseCursor;
+    bool                        WantUpdateMonitors;
 
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
     bool                        HasGamepad;
@@ -114,7 +123,7 @@ static ImGui_ImplWin32_Data* ImGui_ImplWin32_GetBackendData()
 }
 
 // Functions
-bool    ImGui_ImplWin32_Init(void* hwnd)
+static bool ImGui_ImplWin32_InitEx(void* hwnd, bool platform_has_own_dc)
 {
     ImGuiIO& io = ImGui::GetIO();
     IM_ASSERT(io.BackendPlatformUserData == nullptr && "Already initialized a platform backend!");
@@ -131,14 +140,20 @@ bool    ImGui_ImplWin32_Init(void* hwnd)
     io.BackendPlatformName = "imgui_impl_win32";
     io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors;         // We can honor GetMouseCursor() values (optional)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
+    io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports;    // We can create multi-viewports on the Platform side (optional)
+    io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can call io.AddMouseViewportEvent() with correct data (optional)
 
     bd->hWnd = (HWND)hwnd;
+    bd->WantUpdateMonitors = true;
     bd->TicksPerSecond = perf_frequency;
     bd->Time = perf_counter;
     bd->LastMouseCursor = ImGuiMouseCursor_COUNT;
 
-    // Set platform dependent data in viewport
-    ImGui::GetMainViewport()->PlatformHandleRaw = (void*)hwnd;
+    // Our mouse update function expect PlatformHandle to be filled for the main viewport
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    main_viewport->PlatformHandle = main_viewport->PlatformHandleRaw = (void*)bd->hWnd;
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplWin32_InitPlatformInterface(platform_has_own_dc);
 
     // Dynamically load XInput library
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
@@ -164,12 +179,25 @@ bool    ImGui_ImplWin32_Init(void* hwnd)
     return true;
 }
 
+IMGUI_IMPL_API bool     ImGui_ImplWin32_Init(void* hwnd)
+{
+    return ImGui_ImplWin32_InitEx(hwnd, false);
+}
+
+IMGUI_IMPL_API bool     ImGui_ImplWin32_InitForOpenGL(void* hwnd)
+{
+    // OpenGL needs CS_OWNDC
+    return ImGui_ImplWin32_InitEx(hwnd, true);
+}
+
 void    ImGui_ImplWin32_Shutdown()
 {
     ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
     IM_ASSERT(bd != nullptr && "No platform backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplWin32_ShutdownPlatformInterface();
+
     // Unload XInput library
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
     if (bd->XInputDLL)
@@ -178,6 +206,7 @@ void    ImGui_ImplWin32_Shutdown()
 
     io.BackendPlatformName = nullptr;
     io.BackendPlatformUserData = nullptr;
+    io.BackendFlags &= ~(ImGuiBackendFlags_HasMouseCursors | ImGuiBackendFlags_HasSetMousePos | ImGuiBackendFlags_HasGamepad | ImGuiBackendFlags_PlatformHasViewports | ImGuiBackendFlags_HasMouseHoveredViewport);
     IM_DELETE(bd);
 }
 
@@ -251,33 +280,59 @@ static void ImGui_ImplWin32_UpdateKeyModifiers()
     io.AddKeyEvent(ImGuiMod_Super, IsVkDown(VK_APPS));
 }
 
+// This code supports multi-viewports (multiple OS Windows mapped into different Dear ImGui viewports)
+// Because of that, it is a little more complicated than your typical single-viewport binding code!
 static void ImGui_ImplWin32_UpdateMouseData()
 {
     ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
     ImGuiIO& io = ImGui::GetIO();
     IM_ASSERT(bd->hWnd != 0);
 
+    POINT mouse_screen_pos;
+    bool has_mouse_screen_pos = ::GetCursorPos(&mouse_screen_pos) != 0;
+
     HWND focused_window = ::GetForegroundWindow();
-    const bool is_app_focused = (focused_window == bd->hWnd);
+    const bool is_app_focused = (focused_window && (focused_window == bd->hWnd || ::IsChild(focused_window, bd->hWnd) || ImGui::FindViewportByPlatformHandle((void*)focused_window)));
     if (is_app_focused)
     {
         // (Optional) Set OS mouse position from Dear ImGui if requested (rarely used, only when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
+        // When multi-viewports are enabled, all Dear ImGui positions are same as OS positions.
         if (io.WantSetMousePos)
         {
             POINT pos = { (int)io.MousePos.x, (int)io.MousePos.y };
-            if (::ClientToScreen(bd->hWnd, &pos))
-                ::SetCursorPos(pos.x, pos.y);
+            if ((io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) == 0)
+                ::ClientToScreen(focused_window, &pos);
+            ::SetCursorPos(pos.x, pos.y);
         }
 
         // (Optional) Fallback to provide mouse position when focused (WM_MOUSEMOVE already provides this when hovered or captured)
         // This also fills a short gap when clicking non-client area: WM_NCMOUSELEAVE -> modal OS move -> gap -> WM_NCMOUSEMOVE
-        if (!io.WantSetMousePos && bd->MouseTrackedArea == 0)
+        if (!io.WantSetMousePos && bd->MouseTrackedArea == 0 && has_mouse_screen_pos)
         {
-            POINT pos;
-            if (::GetCursorPos(&pos) && ::ScreenToClient(bd->hWnd, &pos))
-                io.AddMousePosEvent((float)pos.x, (float)pos.y);
+            // Single viewport mode: mouse position in client window coordinates (io.MousePos is (0,0) when the mouse is on the upper-left corner of the app window)
+            // (This is the position you can get with ::GetCursorPos() + ::ScreenToClient() or WM_MOUSEMOVE.)
+            // Multi-viewport mode: mouse position in OS absolute coordinates (io.MousePos is (0,0) when the mouse is on the upper-left of the primary monitor)
+            // (This is the position you can get with ::GetCursorPos() or WM_MOUSEMOVE + ::ClientToScreen(). In theory adding viewport->Pos to a client position would also be the same.)
+            POINT mouse_pos = mouse_screen_pos;
+            if (!(io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable))
+                ::ScreenToClient(bd->hWnd, &mouse_pos);
+            io.AddMousePosEvent((float)mouse_pos.x, (float)mouse_pos.y);
         }
     }
+
+    // (Optional) When using multiple viewports: call io.AddMouseViewportEvent() with the viewport the OS mouse cursor is hovering.
+    // If ImGuiBackendFlags_HasMouseHoveredViewport is not set by the backend, Dear imGui will ignore this field and infer the information using its flawed heuristic.
+    // - [X] Win32 backend correctly ignore viewports with the _NoInputs flag (here using ::WindowFromPoint with WM_NCHITTEST + HTTRANSPARENT in WndProc does that)
+    //       Some backend are not able to handle that correctly. If a backend report an hovered viewport that has the _NoInputs flag (e.g. when dragging a window
+    //       for docking, the viewport has the _NoInputs flag in order to allow us to find the viewport under), then Dear ImGui is forced to ignore the value reported
+    //       by the backend, and use its flawed heuristic to guess the viewport behind.
+    // - [X] Win32 backend correctly reports this regardless of another viewport behind focused and dragged from (we need this to find a useful drag and drop target).
+    ImGuiID mouse_viewport_id = 0;
+    if (has_mouse_screen_pos)
+        if (HWND hovered_hwnd = ::WindowFromPoint(mouse_screen_pos))
+            if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)hovered_hwnd))
+                mouse_viewport_id = viewport->ID;
+    io.AddMouseViewportEvent(mouse_viewport_id);
 }
 
 // Gamepad navigation mapping
@@ -337,6 +392,35 @@ static void ImGui_ImplWin32_UpdateGamepads()
 #endif // #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
 }
 
+static BOOL CALLBACK ImGui_ImplWin32_UpdateMonitors_EnumFunc(HMONITOR monitor, HDC, LPRECT, LPARAM)
+{
+    MONITORINFO info = {};
+    info.cbSize = sizeof(MONITORINFO);
+    if (!::GetMonitorInfo(monitor, &info))
+        return TRUE;
+    ImGuiPlatformMonitor imgui_monitor;
+    imgui_monitor.MainPos = ImVec2((float)info.rcMonitor.left, (float)info.rcMonitor.top);
+    imgui_monitor.MainSize = ImVec2((float)(info.rcMonitor.right - info.rcMonitor.left), (float)(info.rcMonitor.bottom - info.rcMonitor.top));
+    imgui_monitor.WorkPos = ImVec2((float)info.rcWork.left, (float)info.rcWork.top);
+    imgui_monitor.WorkSize = ImVec2((float)(info.rcWork.right - info.rcWork.left), (float)(info.rcWork.bottom - info.rcWork.top));
+    imgui_monitor.DpiScale = ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
+    imgui_monitor.PlatformHandle = (void*)monitor;
+    ImGuiPlatformIO& io = ImGui::GetPlatformIO();
+    if (info.dwFlags & MONITORINFOF_PRIMARY)
+        io.Monitors.push_front(imgui_monitor);
+    else
+        io.Monitors.push_back(imgui_monitor);
+    return TRUE;
+}
+
+static void ImGui_ImplWin32_UpdateMonitors()
+{
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    ImGui::GetPlatformIO().Monitors.resize(0);
+    ::EnumDisplayMonitors(nullptr, nullptr, ImGui_ImplWin32_UpdateMonitors_EnumFunc, 0);
+    bd->WantUpdateMonitors = false;
+}
+
 void    ImGui_ImplWin32_NewFrame()
 {
     ImGuiIO& io = ImGui::GetIO();
@@ -347,6 +431,8 @@ void    ImGui_ImplWin32_NewFrame()
     RECT rect = { 0, 0, 0, 0 };
     ::GetClientRect(bd->hWnd, &rect);
     io.DisplaySize = ImVec2((float)(rect.right - rect.left), (float)(rect.bottom - rect.top));
+    if (bd->WantUpdateMonitors)
+        ImGui_ImplWin32_UpdateMonitors();
 
     // Setup time step
     INT64 current_time = 0;
@@ -548,8 +634,11 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
             bd->MouseTrackedArea = area;
         }
         POINT mouse_pos = { (LONG)GET_X_LPARAM(lParam), (LONG)GET_Y_LPARAM(lParam) };
-        if (msg == WM_NCMOUSEMOVE && ::ScreenToClient(hwnd, &mouse_pos) == FALSE) // WM_NCMOUSEMOVE are provided in absolute coordinates.
-            break;
+        bool want_absolute_pos = (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable) != 0;
+        if (msg == WM_MOUSEMOVE && want_absolute_pos)    // WM_MOUSEMOVE are client-relative coordinates.
+            ::ClientToScreen(hwnd, &mouse_pos);
+        if (msg == WM_NCMOUSEMOVE && !want_absolute_pos) // WM_NCMOUSEMOVE are absolute coordinates.
+            ::ScreenToClient(hwnd, &mouse_pos);
         io.AddMouseSourceEvent(mouse_source);
         io.AddMousePosEvent((float)mouse_pos.x, (float)mouse_pos.y);
         break;
@@ -681,6 +770,9 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
             bd->WantUpdateHasGamepad = true;
 #endif
         return 0;
+    case WM_DISPLAYCHANGE:
+        bd->WantUpdateMonitors = true;
+        return 0;
     }
     return 0;
 }
@@ -745,6 +837,10 @@ 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
@@ -845,3 +941,345 @@ void ImGui_ImplWin32_EnableAlphaCompositing(void* hwnd)
 }
 
 //---------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
+struct ImGui_ImplWin32_ViewportData
+{
+    HWND    Hwnd;
+    HWND    HwndParent;
+    bool    HwndOwned;
+    DWORD   DwStyle;
+    DWORD   DwExStyle;
+
+    ImGui_ImplWin32_ViewportData() { Hwnd = HwndParent = nullptr; HwndOwned = false;  DwStyle = DwExStyle = 0; }
+    ~ImGui_ImplWin32_ViewportData() { IM_ASSERT(Hwnd == nullptr); }
+};
+
+static void ImGui_ImplWin32_GetWin32StyleFromViewportFlags(ImGuiViewportFlags flags, DWORD* out_style, DWORD* out_ex_style)
+{
+    if (flags & ImGuiViewportFlags_NoDecoration)
+        *out_style = WS_POPUP;
+    else
+        *out_style = WS_OVERLAPPEDWINDOW;
+
+    if (flags & ImGuiViewportFlags_NoTaskBarIcon)
+        *out_ex_style = WS_EX_TOOLWINDOW;
+    else
+        *out_ex_style = WS_EX_APPWINDOW;
+
+    if (flags & ImGuiViewportFlags_TopMost)
+        *out_ex_style |= WS_EX_TOPMOST;
+}
+
+static HWND ImGui_ImplWin32_GetHwndFromViewportID(ImGuiID viewport_id)
+{
+    if (viewport_id != 0)
+        if (ImGuiViewport* viewport = ImGui::FindViewportByID(viewport_id))
+            return (HWND)viewport->PlatformHandle;
+    return nullptr;
+}
+
+static void ImGui_ImplWin32_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = IM_NEW(ImGui_ImplWin32_ViewportData)();
+    viewport->PlatformUserData = vd;
+
+    // Select style and parent window
+    ImGui_ImplWin32_GetWin32StyleFromViewportFlags(viewport->Flags, &vd->DwStyle, &vd->DwExStyle);
+    vd->HwndParent = ImGui_ImplWin32_GetHwndFromViewportID(viewport->ParentViewportId);
+
+    // Create window
+    RECT rect = { (LONG)viewport->Pos.x, (LONG)viewport->Pos.y, (LONG)(viewport->Pos.x + viewport->Size.x), (LONG)(viewport->Pos.y + viewport->Size.y) };
+    ::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle);
+    vd->Hwnd = ::CreateWindowEx(
+        vd->DwExStyle, _T("ImGui Platform"), _T("Untitled"), vd->DwStyle,       // Style, class name, window name
+        rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top,    // Window area
+        vd->HwndParent, nullptr, ::GetModuleHandle(nullptr), nullptr);          // Owner window, Menu, Instance, Param
+    vd->HwndOwned = true;
+    viewport->PlatformRequestResize = false;
+    viewport->PlatformHandle = viewport->PlatformHandleRaw = vd->Hwnd;
+}
+
+static void ImGui_ImplWin32_DestroyWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    if (ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData)
+    {
+        if (::GetCapture() == vd->Hwnd)
+        {
+            // Transfer capture so if we started dragging from a window that later disappears, we'll still receive the MOUSEUP event.
+            ::ReleaseCapture();
+            ::SetCapture(bd->hWnd);
+        }
+        if (vd->Hwnd && vd->HwndOwned)
+            ::DestroyWindow(vd->Hwnd);
+        vd->Hwnd = nullptr;
+        IM_DELETE(vd);
+    }
+    viewport->PlatformUserData = viewport->PlatformHandle = nullptr;
+}
+
+static void ImGui_ImplWin32_ShowWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
+        ::ShowWindow(vd->Hwnd, SW_SHOWNA);
+    else
+        ::ShowWindow(vd->Hwnd, SW_SHOW);
+}
+
+static void ImGui_ImplWin32_UpdateWindow(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+
+    // Update Win32 parent if it changed _after_ creation
+    // Unlike style settings derived from configuration flags, this is more likely to change for advanced apps that are manipulating ParentViewportID manually.
+    HWND new_parent = ImGui_ImplWin32_GetHwndFromViewportID(viewport->ParentViewportId);
+    if (new_parent != vd->HwndParent)
+    {
+        // Win32 windows can either have a "Parent" (for WS_CHILD window) or an "Owner" (which among other thing keeps window above its owner).
+        // Our Dear Imgui-side concept of parenting only mostly care about what Win32 call "Owner".
+        // The parent parameter of CreateWindowEx() sets up Parent OR Owner depending on WS_CHILD flag. In our case an Owner as we never use WS_CHILD.
+        // Calling ::SetParent() here would be incorrect: it will create a full child relation, alter coordinate system and clipping.
+        // Calling ::SetWindowLongPtr() with GWLP_HWNDPARENT seems correct although poorly documented.
+        // https://devblogs.microsoft.com/oldnewthing/20100315-00/?p=14613
+        vd->HwndParent = new_parent;
+        ::SetWindowLongPtr(vd->Hwnd, GWLP_HWNDPARENT, (LONG_PTR)vd->HwndParent);
+    }
+
+    // (Optional) Update Win32 style if it changed _after_ creation.
+    // Generally they won't change unless configuration flags are changed, but advanced uses (such as manually rewriting viewport flags) make this useful.
+    DWORD new_style;
+    DWORD new_ex_style;
+    ImGui_ImplWin32_GetWin32StyleFromViewportFlags(viewport->Flags, &new_style, &new_ex_style);
+
+    // Only reapply the flags that have been changed from our point of view (as other flags are being modified by Windows)
+    if (vd->DwStyle != new_style || vd->DwExStyle != new_ex_style)
+    {
+        // (Optional) Update TopMost state if it changed _after_ creation
+        bool top_most_changed = (vd->DwExStyle & WS_EX_TOPMOST) != (new_ex_style & WS_EX_TOPMOST);
+        HWND insert_after = top_most_changed ? ((viewport->Flags & ImGuiViewportFlags_TopMost) ? HWND_TOPMOST : HWND_NOTOPMOST) : 0;
+        UINT swp_flag = top_most_changed ? 0 : SWP_NOZORDER;
+
+        // Apply flags and position (since it is affected by flags)
+        vd->DwStyle = new_style;
+        vd->DwExStyle = new_ex_style;
+        ::SetWindowLong(vd->Hwnd, GWL_STYLE, vd->DwStyle);
+        ::SetWindowLong(vd->Hwnd, GWL_EXSTYLE, vd->DwExStyle);
+        RECT rect = { (LONG)viewport->Pos.x, (LONG)viewport->Pos.y, (LONG)(viewport->Pos.x + viewport->Size.x), (LONG)(viewport->Pos.y + viewport->Size.y) };
+        ::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle); // Client to Screen
+        ::SetWindowPos(vd->Hwnd, insert_after, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, swp_flag | SWP_NOACTIVATE | SWP_FRAMECHANGED);
+        ::ShowWindow(vd->Hwnd, SW_SHOWNA); // This is necessary when we alter the style
+        viewport->PlatformRequestMove = viewport->PlatformRequestResize = true;
+    }
+}
+
+static ImVec2 ImGui_ImplWin32_GetWindowPos(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    POINT pos = { 0, 0 };
+    ::ClientToScreen(vd->Hwnd, &pos);
+    return ImVec2((float)pos.x, (float)pos.y);
+}
+
+static void ImGui_ImplWin32_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    RECT rect = { (LONG)pos.x, (LONG)pos.y, (LONG)pos.x, (LONG)pos.y };
+    ::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle);
+    ::SetWindowPos(vd->Hwnd, nullptr, rect.left, rect.top, 0, 0, SWP_NOZORDER | SWP_NOSIZE | SWP_NOACTIVATE);
+}
+
+static ImVec2 ImGui_ImplWin32_GetWindowSize(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    RECT rect;
+    ::GetClientRect(vd->Hwnd, &rect);
+    return ImVec2(float(rect.right - rect.left), float(rect.bottom - rect.top));
+}
+
+static void ImGui_ImplWin32_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    RECT rect = { 0, 0, (LONG)size.x, (LONG)size.y };
+    ::AdjustWindowRectEx(&rect, vd->DwStyle, FALSE, vd->DwExStyle); // Client to Screen
+    ::SetWindowPos(vd->Hwnd, nullptr, 0, 0, rect.right - rect.left, rect.bottom - rect.top, SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE);
+}
+
+static void ImGui_ImplWin32_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    ::BringWindowToTop(vd->Hwnd);
+    ::SetForegroundWindow(vd->Hwnd);
+    ::SetFocus(vd->Hwnd);
+}
+
+static bool ImGui_ImplWin32_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    return ::GetForegroundWindow() == vd->Hwnd;
+}
+
+static bool ImGui_ImplWin32_GetWindowMinimized(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    return ::IsIconic(vd->Hwnd) != 0;
+}
+
+static void ImGui_ImplWin32_SetWindowTitle(ImGuiViewport* viewport, const char* title)
+{
+    // ::SetWindowTextA() doesn't properly handle UTF-8 so we explicitely convert our string.
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    int n = ::MultiByteToWideChar(CP_UTF8, 0, title, -1, nullptr, 0);
+    ImVector<wchar_t> title_w;
+    title_w.resize(n);
+    ::MultiByteToWideChar(CP_UTF8, 0, title, -1, title_w.Data, n);
+    ::SetWindowTextW(vd->Hwnd, title_w.Data);
+}
+
+static void ImGui_ImplWin32_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    IM_ASSERT(alpha >= 0.0f && alpha <= 1.0f);
+    if (alpha < 1.0f)
+    {
+        DWORD style = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE) | WS_EX_LAYERED;
+        ::SetWindowLongW(vd->Hwnd, GWL_EXSTYLE, style);
+        ::SetLayeredWindowAttributes(vd->Hwnd, 0, (BYTE)(255 * alpha), LWA_ALPHA);
+    }
+    else
+    {
+        DWORD style = ::GetWindowLongW(vd->Hwnd, GWL_EXSTYLE) & ~WS_EX_LAYERED;
+        ::SetWindowLongW(vd->Hwnd, GWL_EXSTYLE, style);
+    }
+}
+
+static float ImGui_ImplWin32_GetWindowDpiScale(ImGuiViewport* viewport)
+{
+    ImGui_ImplWin32_ViewportData* vd = (ImGui_ImplWin32_ViewportData*)viewport->PlatformUserData;
+    IM_ASSERT(vd->Hwnd != 0);
+    return ImGui_ImplWin32_GetDpiScaleForHwnd(vd->Hwnd);
+}
+
+// FIXME-DPI: Testing DPI related ideas
+static void ImGui_ImplWin32_OnChangedViewport(ImGuiViewport* viewport)
+{
+    (void)viewport;
+#if 0
+    ImGuiStyle default_style;
+    //default_style.WindowPadding = ImVec2(0, 0);
+    //default_style.WindowBorderSize = 0.0f;
+    //default_style.ItemSpacing.y = 3.0f;
+    //default_style.FramePadding = ImVec2(0, 0);
+    default_style.ScaleAllSizes(viewport->DpiScale);
+    ImGuiStyle& style = ImGui::GetStyle();
+    style = default_style;
+#endif
+}
+
+static LRESULT CALLBACK ImGui_ImplWin32_WndProcHandler_PlatformWindow(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
+        return true;
+
+    if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)hWnd))
+    {
+        switch (msg)
+        {
+        case WM_CLOSE:
+            viewport->PlatformRequestClose = true;
+            return 0;
+        case WM_MOVE:
+            viewport->PlatformRequestMove = true;
+            break;
+        case WM_SIZE:
+            viewport->PlatformRequestResize = true;
+            break;
+        case WM_MOUSEACTIVATE:
+            if (viewport->Flags & ImGuiViewportFlags_NoFocusOnClick)
+                return MA_NOACTIVATE;
+            break;
+        case WM_NCHITTEST:
+            // Let mouse pass-through the window. This will allow the backend to call io.AddMouseViewportEvent() correctly. (which is optional).
+            // The ImGuiViewportFlags_NoInputs flag is set while dragging a viewport, as want to detect the window behind the one we are dragging.
+            // If you cannot easily access those viewport flags from your windowing/event code: you may manually synchronize its state e.g. in
+            // your main loop after calling UpdatePlatformWindows(). Iterate all viewports/platform windows and pass the flag to your windowing system.
+            if (viewport->Flags & ImGuiViewportFlags_NoInputs)
+                return HTTRANSPARENT;
+            break;
+        }
+    }
+
+    return DefWindowProc(hWnd, msg, wParam, lParam);
+}
+
+static void ImGui_ImplWin32_InitPlatformInterface(bool platform_has_own_dc)
+{
+    WNDCLASSEX wcex;
+    wcex.cbSize = sizeof(WNDCLASSEX);
+    wcex.style = CS_HREDRAW | CS_VREDRAW | (platform_has_own_dc ? CS_OWNDC : 0);
+    wcex.lpfnWndProc = ImGui_ImplWin32_WndProcHandler_PlatformWindow;
+    wcex.cbClsExtra = 0;
+    wcex.cbWndExtra = 0;
+    wcex.hInstance = ::GetModuleHandle(nullptr);
+    wcex.hIcon = nullptr;
+    wcex.hCursor = nullptr;
+    wcex.hbrBackground = (HBRUSH)(COLOR_BACKGROUND + 1);
+    wcex.lpszMenuName = nullptr;
+    wcex.lpszClassName = _T("ImGui Platform");
+    wcex.hIconSm = nullptr;
+    ::RegisterClassEx(&wcex);
+
+    ImGui_ImplWin32_UpdateMonitors();
+
+    // Register platform interface (will be coupled with a renderer interface)
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Platform_CreateWindow = ImGui_ImplWin32_CreateWindow;
+    platform_io.Platform_DestroyWindow = ImGui_ImplWin32_DestroyWindow;
+    platform_io.Platform_ShowWindow = ImGui_ImplWin32_ShowWindow;
+    platform_io.Platform_SetWindowPos = ImGui_ImplWin32_SetWindowPos;
+    platform_io.Platform_GetWindowPos = ImGui_ImplWin32_GetWindowPos;
+    platform_io.Platform_SetWindowSize = ImGui_ImplWin32_SetWindowSize;
+    platform_io.Platform_GetWindowSize = ImGui_ImplWin32_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplWin32_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplWin32_GetWindowFocus;
+    platform_io.Platform_GetWindowMinimized = ImGui_ImplWin32_GetWindowMinimized;
+    platform_io.Platform_SetWindowTitle = ImGui_ImplWin32_SetWindowTitle;
+    platform_io.Platform_SetWindowAlpha = ImGui_ImplWin32_SetWindowAlpha;
+    platform_io.Platform_UpdateWindow = ImGui_ImplWin32_UpdateWindow;
+    platform_io.Platform_GetWindowDpiScale = ImGui_ImplWin32_GetWindowDpiScale; // FIXME-DPI
+    platform_io.Platform_OnChangedViewport = ImGui_ImplWin32_OnChangedViewport; // FIXME-DPI
+
+    // Register main window handle (which is owned by the main application, not by us)
+    // This is mostly for simplicity and consistency, so that our code (e.g. mouse handling etc.) can use same logic for main and secondary viewports.
+    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
+    ImGui_ImplWin32_Data* bd = ImGui_ImplWin32_GetBackendData();
+    ImGui_ImplWin32_ViewportData* vd = IM_NEW(ImGui_ImplWin32_ViewportData)();
+    vd->Hwnd = bd->hWnd;
+    vd->HwndOwned = false;
+    main_viewport->PlatformUserData = vd;
+    main_viewport->PlatformHandle = (void*)bd->hWnd;
+}
+
+static void ImGui_ImplWin32_ShutdownPlatformInterface()
+{
+    ::UnregisterClass(_T("ImGui Platform"), ::GetModuleHandle(nullptr));
+    ImGui::DestroyPlatformWindows();
+}
+
+//---------------------------------------------------------------------------------------------------------

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 will also be supported unless IMGUI_DISABLE_OBSOLETE_KEYIO is set]
 //  [X] Platform: Gamepad support. Enabled with 'io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad'.
 //  [X] Platform: Mouse cursor shape and visibility. Disable with 'io.ConfigFlags |= ImGuiConfigFlags_NoMouseCursorChange'.
+//  [X] Platform: Multi-viewport support (multiple windows). Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
@@ -17,6 +18,7 @@
 #include "imgui.h"      // IMGUI_IMPL_API
 
 IMGUI_IMPL_API bool     ImGui_ImplWin32_Init(void* hwnd);
+IMGUI_IMPL_API bool     ImGui_ImplWin32_InitForOpenGL(void* hwnd);
 IMGUI_IMPL_API void     ImGui_ImplWin32_Shutdown();
 IMGUI_IMPL_API void     ImGui_ImplWin32_NewFrame();
 

docs/BACKENDS.md

@@ -76,7 +76,8 @@ List of Renderer Backends:
     imgui_impl_metal.mm       ; Metal (with ObjC)
     imgui_impl_opengl2.cpp    ; OpenGL 2 (legacy, fixed pipeline <- don't use with modern OpenGL context)
     imgui_impl_opengl3.cpp    ; OpenGL 3/4, OpenGL ES 2, OpenGL ES 3 (modern programmable pipeline)
-    imgui_impl_sdlrenderer.cpp; SDL_Renderer (optional component of SDL2 available from SDL 2.0.18+)
+    imgui_impl_sdlrenderer2.cpp ; SDL_Renderer (optional component of SDL2 available from SDL 2.0.18+)
+    imgui_impl_sdlrenderer3.cpp ; SDL_Renderer (optional component of SDL3 available from SDL 3.0.0+)
     imgui_impl_vulkan.cpp     ; Vulkan
     imgui_impl_wgpu.cpp       ; WebGPU
 

docs/CHANGELOG.txt

@@ -30,11 +30,274 @@ HOW TO UPDATE?
   and API updates have been a little more frequent lately. They are documented below and in imgui.cpp and should not affect all users.
 - Please report any issue!
 
+-----------------------------------------------------------------------
+ DOCKING+MULTI-VIEWPORT BRANCH (In Progress)
+-----------------------------------------------------------------------
+
+DOCKING FEATURES
+(see https://github.com/ocornut/imgui/wiki/Docking for quick intro)
+
+- Added Docking system: [BETA] (#2109, #351)
+  - Added ImGuiConfigFlags_DockingEnable flag to enable Docking.
+    Set with `io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;`.
+  - Added DockSpace(), DockSpaceOverViewport() API.
+  - Added ImGuiDockNodeFlags flags for DockSpace().
+  - Added SetNextWindowDockID(), SetNextWindowClass() API.
+  - Added GetWindowDockID(), IsWindowDocked() API.
+  - Added ImGuiWindowFlags_NoDocking window flag to disable the possibility for a window to be docked.
+    Popup, Menu and Child windows always have the ImGuiWindowFlags_NoDocking flag set.
+  - Added ImGuiWindowClass to specify advanced docking/viewport related flags via SetNextWindowClass().
+  - Added io.ConfigDockingNoSplit option.
+  - Added io.ConfigDockingWithShift option.
+  - Added io.ConfigDockingAlwaysTabBar option.
+  - Added io.ConfigDockingTransparentPayload option.
+  - Style: Added ImGuiCol_DockingPreview, ImGuiCol_DockingEmptyBg colors.
+  - Demo: Added "DockSpace" example app showcasing use of explicit dockspace nodes.
+
+MULTI-VIEWPORT FEATURES
+(see https://github.com/ocornut/imgui/wiki/Multi-Viewports for quick intro)
+
+Breaking Changes:
+
+- IMPORTANT: When multi-viewports are enabled (with io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable),
+  all coordinates/positions will be in your natural OS coordinates space. It means that:
+   - Reference to hard-coded positions such as in SetNextWindowPos(ImVec2(0,0)) are _probably_ not what you want anymore.
+     Use GetMainViewport()->Pos to offset hard-coded positions, e.g. SetNextWindowPos(GetMainViewport()->Pos).
+   - Likewise io.MousePos and GetMousePos() will use OS coordinates.
+     If you query mouse positions to interact with non-imgui coordinates you will need to offset them.
+     e.g. subtract GetWindowViewport()->Pos.
+- IO: Removed io.DisplayVisibleMin, io.DisplayVisibleMax settings (they were marked obsoleted, used to clip within the (0,0)..(DisplaySize) range).
+
+Other changes:
+(FIXME: This need a fuller explanation!)
+
+- Added ImGuiPlatformIO structure and GetPlatformIO().
+  - Similarly to ImGuiIO and GetIO(), this structure is the main point of communication for backends supporting multi-viewports.
+  - Backend sets functions in ImGuiPlatformIO to manipulate platform windows.
+  - ImGuiPlatformIO::Monitors is a list of platform monitors (input from backend)
+  - ImGuiPlatformIO::Viewports is a list of viewports (output from dear imgui)
+- Added ImGuiPlatformMonitor to feed OS monitor information in the ImGuiPlatformIO::Monitors.
+- Added GetWindowViewport(), SetNextWindowViewport().
+- Added GetWindowDpiScale().
+- Added GetOverlayDrawList(ImGuiViewport* viewport).
+  The no-parameter version of GetOverlayDrawList() return the overlay for the current window's viewport.
+- Added UpdatePlatformWindows(), RenderPlatformWindowsDefault(), DestroyPlatformWindows() for usage in application setup.
+- Added FindViewportByID(), FindViewportByPlatformHandle() for usage by backends.
+- Added ImGuiConfigFlags_ViewportsEnable configuration flag and other viewport options.
+- Added io.ConfigViewportsNoAutoMerge option.
+- Added io.ConfigViewportsNoTaskBarIcon option.
+- Added io.ConfigViewportsNoDecoration option.
+- Added io.ConfigViewportsNoDefaultParent option.
+- Added ImGuiBackendFlags_PlatformHasViewports, ImGuiBackendFlags_RendererHasViewports, ImGuiBackendFlags_HasMouseHoveredViewport backend flags.
+- Added io.AddMouseViewportEvent() (optional _even_ for multi-viewport support, tied to ImGuiBackendFlags_HasMouseHoveredViewport flag).
+- Expanded ImGuiViewport structure, ImGuiViewportFlags flags.
+- Added ImGuiWindowClass and SetNextWindowClass() for passing viewport related hints to the OS/platform back-end.
+- Examples: Renderer: OpenGL2, OpenGL3, DirectX9, DirectX10, DirectX11, DirectX12, Vulkan: Added support for multi-viewports.
+- Examples: Platforms: Win32, GLFW, SDL2: Added support for multi-viewports.
+  Note that Linux/Mac still have inconsistent support for multi-viewports. If you want to help see https://github.com/ocornut/imgui/issues/2117.
+
+
+-----------------------------------------------------------------------
+ VERSION 1.89.7 (Released 2023-07-04)
+-----------------------------------------------------------------------
+
+Decorated log and release notes: https://github.com/ocornut/imgui/releases/tag/v1.89.7
+
+Breaking changes:
+
+- Moved io.HoverDelayShort/io.HoverDelayNormal to style.HoverDelayShort/style.HoverDelayNormal.
+  As the fields were added in 1.89 and expected to be left unchanged by most users, or only
+  tweaked once during app initialisation, we are exceptionally accepting the breakage.
+  Majority of users should not even notice.
+- Overlapping items: (#6512, #3909, #517)
+  - Added 'SetNextItemAllowOverlap()' (called before an item) as a replacement for using
+    'SetItemAllowOverlap()' (called after an item). This is roughly equivalent to using the
+    legacy 'SetItemAllowOverlap()' call (public API) + ImGuiButtonFlags_AllowOverlap (internal).
+  - Obsoleted 'SetItemAllowOverlap()': it didn't and couldn't work reliably since 1.89 (2022-11-15),
+    and relied on ambiguously defined design. Use 'SetNextItemAllowOverlap()' before item instead.
+  - Renamed 'ImGuiTreeNodeFlags_AllowItemOverlap' to 'ImGuiTreeNodeFlags_AllowOverlap'.
+  - Renamed 'ImGuiSelectableFlags_AllowItemOverlap' to 'ImGuiSelectableFlags_AllowOverlap'
+  - Kept redirecting enums (will obsolete).
+
+Other changes:
+
+- Tooltips/IsItemHovered() related changes:
+  - Tooltips: Added SetItemTooltip() and BeginItemTooltip() functions.
+    They are shortcuts for the common idiom of using IsItemHovered().
+    - SetItemTooltip("Hello")   == if (IsItemHovered(ImGuiHoveredFlags_Tooltip)) { SetTooltip("Hello"); }
+    - BeginItemTooltip()        == IsItemHovered(ImGuiHoveredFlags_Tooltip) && BeginTooltip()
+    The newly added ImGuiHoveredFlags_Tooltip is meant to facilitate standardizing
+    mouse hovering delays and rules for a given application.
+    The previously common idiom of using 'if (IsItemHovered()) { SetTooltip(...); }'
+    won't use delay or stationary test.
+  - IsItemHovered: Added ImGuiHoveredFlags_Stationary to require mouse being
+    stationary when hovering a new item. Added style.HoverStationaryDelay (~0.15 sec).
+    Once the mouse has been stationary once the state is preserved for same item. (#1485)
+  - IsItemHovered: Added ImGuiHoveredFlags_ForTooltip as a shortcut for pulling flags
+    from style.HoverFlagsForTooltipMouse or style.HoverFlagsForTooltipNav depending
+    on active inputs (#1485)
+    - style.HoverFlagsForTooltipMouse defaults to 'ImGuiHoveredFlags_Stationary | ImGuiHoveredFlags_DelayShort'
+    - style.HoverFlagsForTooltipNav defaults to 'ImGuiHoveredFlags_NoSharedDelay | ImGuiHoveredFlags_DelayNormal'.
+  - Tooltips: Tweak default offset for non-drag and drop tooltips so underlying items
+    isn't covered as much. (Match offset for drag and drop tooltips)
+  - IsItemHovered: Tweaked default value of style.HoverDelayNormal from 0.30 to 0.40,
+    Tweaked default value of style.HoverDelayShort from 0.10 to 0.15. (#1485)
+  - IsItemHovered: Added ImGuiHoveredFlags_AllowWhenOverlappedByWindow to ignore window-overlap only.
+    Option ImGuiHoveredFlags_AllowWhenOverlapped now expand into a combination of both
+    _AllowWhenOverlappedByWindow + _AllowWhenOverlappedByItem, matching old behavior.
+- Overlapping items: (#6512, #3909, #517)
+  - Most item types should now work with SetNextItemAllowOverlap(). (#6512, #3909, #517)
+  - Fixed first frame of an overlap highlighting underlying item if previous frame didn't hover anything.
+  - IsItemHovered: Changed to return false when querying an item using AllowOverlap mode which
+    is being overlapped. Added ImGuiHoveredFlags_AllowWhenOverlappedByItem to opt-out. (#6512, #3909, #517)
+  - Selectable, TreeNode: When using ImGuiSelectableFlags_AllowOverlap/ImGuiTreeNodeFlags_AllowOverlap
+    and holding item held, overlapping widgets won't appear as hovered. (#6512, #3909)
+- IsWindowHovered: Added support for ImGuiHoveredFlags_Stationary.
+- IsWindowHovered, IsItemHovered: Assert when passed any unsupported flags.
+- Tables: Fixed a regression in 1.89.6 leading to the first column of tables with either
+  ScrollX or ScrollY flags from being impossible to resize. (#6503)
+- CollapsingHeader/TreeNode: Fixed text padding when using _Framed+_Leaf flags. (#6549) [@BobbyAnguelov]
+- InputText: Fixed not returning true when buffer is cleared while using the
+  ImGuiInputTextFlags_EscapeClearsAll flag. (#5688, #2620)
+- InputText: Fixed a crash on deactivating a ReadOnly buffer. (#6570, #6292, #4714)
+- InputText: ImGuiInputTextCallbackData::InsertChars() accept (NULL,NULL) range, in order to conform
+  to common idioms (e.g. passing .data(), .data() + .size() from a null string). (#6565, #6566, #3615)
+- Combo: Made simple/legacy Combo() function not returns true when picking already selected item.
+  This is consistent with other widgets. If you need something else, you can use BeginCombo(). (#1182)
+- Clipper: Rework inner logic to allow functioning with a zero-clear constructor.
+  This is order to facilitate usage for language bindings (e.g cimgui or dear_binding)
+  where user may not be calling a constructor manually. (#5856)
+- Drag and Drop: Apply default behavior of drag source not reporting itself as hovered
+  at lower-level, so DragXXX, SliderXXX, InputXXX, Plot widgets are fulfilling it.
+  (Behavior doesn't apply when ImGuiDragDropFlags_SourceNoDisableHover is set).
+- Modals: In the case of nested modal, made sure that focused or appearing windows are
+  moved below the lowest blocking modal (rather than the highest one). (#4317)
+- GetKeyName(): Fixed assert with ImGuiMod_XXX values when IMGUI_DISABLE_OBSOLETE_KEYIO is set.
+- Debug Tools: Added 'io.ConfigDebugIniSettings' option to save .ini data with extra
+  comments. Currently mainly for inspecting Docking .ini data, but makes saving slower.
+- Demo: Added more developed "Widgets->Tooltips" section. (#1485)
+- Backends: OpenGL3: Fixed support for glBindSampler() backup/restore on ES3. (#6375, #6508) [@jsm174]
+- Backends: OpenGL3: Fixed erroneous use glGetIntegerv(GL_CONTEXT_PROFILE_MASK) on contexts
+  lower than 3.2. (#6539, #6333) [@krumelmonster]
+- Backends: Vulkan: Added optional support for VK_KHR_dynamic_rendering (Vulkan 1.3+) in the
+  backend for applications using it. User needs to set 'init_info->UseDynamicRendering = true'
+  and 'init_info->ColorAttachmentFormat'. RenderPass becomes unused. (#5446, #5037) [@spnda, @cmarcelo]
+- Backends: GLFW: Accept glfwGetTime() not returning a monotonically increasing value.
+  This seems to happens on some Windows setup when peripherals disconnect, and is likely
+  to also happen on browser+Emscripten. Matches similar 1.89.4 fix in SDL backend. (#6491)
+- Examples: Win32+OpenGL3: Changed DefWindowProc() to DefWindowProcW() to match other examples
+  and support the example app being compiled without UNICODE. (#6516, #5725, #5961, #5975) [@yenixing]
+
+Docking+Viewports Branch:
+
+- Viewports+Docking: Fixed extraneous viewport+platform-window recreation in various
+  combination of showing or hiding windows, docking with/without split, undocking.
+  While with some backends and without OS decorations, some extraneous window recreation
+  were visibly not noticeable, they would typically become noticeable when enabling
+  OS decorations on those windows (e.g. Windows title bar fade-in/animation).
+- Viewports: Closing a viewport via OS/platform means (e.g. OS close button or task-bar menu),
+  mark all windows in this viewport as closed.
+- Docking: Fixed one-frame flickering on reappearing windows binding to a dock node
+  where a later-submitted window was already bound.
+- Docking: Fixed dragging from title-bar empty space (regression from 1.88 related to
+  keeping ID alive when calling low-level ButtonBehavior() directly). (#5181, #2645)
+- Docking: [Internal] DockBuilderDockWindow() API calls don't clear docking order
+  if the target node is same as existing one.
+- Backends: Win32: Added support for changing ParentViewportID after viewport creation.
+
+
+-----------------------------------------------------------------------
+ VERSION 1.89.6 (Released 2023-05-31)
+-----------------------------------------------------------------------
+
+Decorated log and release notes: https://github.com/ocornut/imgui/releases/tag/v1.89.6
+
+Breaking changes:
+
+- Clipper: Commented out obsolete redirection constructor which was marked obsolete in 1.79:
+   'ImGuiListClipper(int items_count, float items_height)' --> Use 'ImGuiListClipper() + clipper.Begin()'.
+- Clipper: Renamed ForceDisplayRangeByIndices() to IncludeRangeByIndices(), kept
+  inline redirection function (introduced in 1.86 and rarely used). (#6424, #3841)
+- Commented out obsolete/redirecting functions that were marked obsolete more than two years ago:
+   - ListBoxHeader()  -> use BeginListBox()
+   - ListBoxFooter()  -> use EndListBox()
+   - Note how two variants of ListBoxHeader() existed. Check commented versions in imgui.h for refeence.
+- Backends: SDL_Renderer: Renamed 'imgui_impl_sdlrenderer.h/cpp' to 'imgui_impl_sdlrenderer2.h/cpp',
+  in order to accomodate for upcoming SDL3 and change in its SDL_Renderer API. (#6286)
+- Backends: GLUT: Removed call to ImGui::NewFrame() from ImGui_ImplGLUT_NewFrame().
+  It needs to be called from the main app loop, like with every other backends. (#6337) [@GereonV]
+
+Other changes:
+
+- Window: Fixed resizing from upper border when io.ConfigWindowsMoveFromTitleBarOnly is set. (#6390)
+- Tables: Fixed a small miscalculation in TableHeader() leading to an empty tooltip
+  showing when a sorting column has no visible name. (#6342) [@lukaasm]
+- Tables: Fixed command merging when compiling with VS2013 (one array on stack was not
+  initialized on VS2013. Unsure if due to a bug or UB/standard conformance). (#6377)
+- InputText: Avoid setting io.WantTextInputNextFrame during the deactivation frame.
+  (#6341) [@lukaasm]
+- Drag, Sliders: if the format string doesn't contain any %, CTRL+Click to input text will
+  use the default format specifier for the type. Allow display/input of raw value when using
+  "enums" patterns (display label instead of value) + allow using when value is hidden. (#6405)
+- Nav: Record/restore preferred position on each given axis after a movement on that axis,
+  then score movement on the other axis using this as a bias. This allows going up and down
+  between e.g. a large header spanning horizontal space and three-ways-columns, landing
+  on the same column as before.
+- Nav: Fixed navigation within tables/columns where item boundaries goes beyond columns limits,
+  unclipped bounding boxes would interfere with other columns. (#2221) [@zzzyap, @ocornut]
+- Nav: Fixed CTRL+Tab into a root window with only childs with _NavFlattened flags
+  erroneously initializing default nav layer to menu layer.
+- Menus: Fixed an issue when opening a menu hierarchy in a given menu-bar would allow
+  opening another via simple hovering. (#3496, #4797)
+- Fonts: Fixed crash when merging fonts and the first font has no valid glyph. (#6446) [@JaedanC]
+- Fonts: Fixed crash when manually specifying an EllipsisChar that doesn't exist. (#6480)
+- Misc: Added ImVec2 unary minus operator. (#6368) [@Koostosh]
+- Debug Tools: Debug Log: Fixed not parsing 0xXXXXXXXX values for geo-locating on mouse
+  hover hover when the identifier is at the end of the line. (#5855)
+- Debug Tools: Added 'io.ConfigDebugIgnoreFocusLoss' option to disable 'io.AddFocusEvent(false)'
+  handling. May facilitate interactions with a debugger when focus loss leads to clearing
+  inputs data. (#4388, #4921)
+- Backends: Clear bits sets io.BackendFlags on backend Shutdown(). (#6334, #6335] [@GereonV]
+  Potentially this would facilitate switching runtime backend mid-session.
+- Backends: Win32: Added ImGui_ImplWin32_InitForOpenGL() to facilitate combining raw
+  Win32/Winapi with OpenGL. (#3218)
+- Backends: OpenGL3: Restore front and back polygon mode separately when supported
+  by context (Desktop 3.0, 3.1, or 3.2+ with compat bit). (#6333) [@GereonV]
+- Backends: OpenGL3: Support for glBindSampler() backup/restore on ES3. (#6375) [@jsm174]
+- Backends: SDL3: Fixed build on Emscripten/iOS/Android. (#6391) [@jo-codegirl]
+- Backends: SDLRenderer3: Added SDL_Renderer for SDL3 backend. (#6286) [@Carcons, @ocornut]
+- Examples: Added native Win32+OpenGL3 example. We don't recommend using this setup but we
+  provide it for completeness. (#3218, #5170, #6086, #2772, #2600, #2359, #2022, #1553) [@learn-more]
+- Examples: Vulkan: Use integrated GPU if nothing else is available. (#6359) [@kimidaisuki22]
+- Examples: DX9, DX10, DX11: Queue framebuffer resize instead of processing in WM_SIZE,
+  as some drivers tends to only cleanup after existing the native resize modal loop. (#6374)
+- Examples: Added SDL3+SDL_Renderer example. (#6286)
+- Examples: Updated all Visual Studio projects and batches to use /utf-8 argument.
+
+Docking+Viewports Branch:
+
+- Viewports: Fixed platform-side focus (e.g. Alt+Tab) from leading to accidental
+  closure of Modal windows. Regression from 1.89.5. (#6357, #6299)
+- Viewports: Fixed loss of imgui-side focus when dragging a secondary viewport back in
+  main viewport, due to platform-side handling changes. Regression from 1.89.5 (#6299)
+- Viewports: Avoid applying imgui-side focus when focus change is due to a viewport
+  destruction. Fixes erroneous popup closure on closing a previous popup. (#6462, #6299)
+- Viewports: Added void* ImGuiPlatformMonitor::PlatformHandle field (backend-dependant),
+  for usage by user code.
+- Backends: GLFW: Preserve monitor list when there are no monitor, may briefly
+  happen when recovering from macOS sleeping mode. (#5683) [@Guistac]
+- Backends: SDL2: Update monitor list when receiving a display event. (#6348)
+  Note however that SDL2 currently doesn't have an event for a DPI/Scaling change,
+  so monitor data won't be updated in this situation.
+- Backends: SDL3: Update monitor list when receiving a display event. (#6348)
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.5 (Released 2023-04-13)
 -----------------------------------------------------------------------
 
+Decorated log and release notes: https://github.com/ocornut/imgui/releases/tag/v1.89.5
+
 Other changes:
 
 - InputText: Reworked prev/next-word behavior to more closely match Visual Studio
@@ -85,7 +348,6 @@ Other changes:
   is to other IME function such as SDL_SetTextInputRect(). (#6306, #6071, #1953)
 - Backends: GLFW: Added support on Win32 only for io.AddMouseSourceEvent() to discriminate
   Mouse/TouchScreen/Pen. (#2334, #2702)
-- Backends: GLFW: Fixed key modifiers handling on secondary viewports. (#6248, #6034) [@aiekick]
 - Backends: Android: Added support for io.AddMouseSourceEvent() to discriminate Mouse/TouchScreen/Pen.
   (#6315) [@PathogenDavid]
 - Backends: OSX: Added support for io.AddMouseSourceEvent() to discriminate Mouse/Pen.
@@ -101,11 +363,23 @@ Other changes:
 - TestSuite: Added variety of new regression tests and improved/amended existing ones
   in imgui_test_engine/ repo. [@PathogenDavid, @ocornut]
 
+Docking+Viewports Branch:
+
+- Viewports: Setting focus from Platform/OS (e.g. via decoration, or Alt-Tab) sets corresponding
+  focus at Dear ImGui level (generally last focused window in the viewport). (#6299)
+- Docking: Fixed using GetItemXXX() or IsItemXXX() functions after a DockSpace(). (#6217)
+- Backends: GLFW: Fixed key modifiers handling on secondary viewports. (#6248, #6034) [@aiekick]
+- Backends: GLFW: Fixed Emscripten erroneously enabling multi-viewport support, leading to assert. (#5683)
+- Backends: SDL2/SDL3: Fixed IME text input rectangle position with viewports. (#6071, #1953)
+- Backends: SDL3: Fixed for compilation with multi-viewports. (#6255) [@P3RK4N]
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.4 (Released 2023-03-14)
 -----------------------------------------------------------------------
 
+Decorated log and release notes: https://github.com/ocornut/imgui/releases/tag/v1.89.4
+
 Breaking Changes:
 
 - Renamed PushAllowKeyboardFocus()/PopAllowKeyboardFocus() to PushTabStop()/PopTabStop().
@@ -173,7 +447,6 @@ Other changes:
   and ImGuiConfigFlags_NavEnableGamepad by default. (#787)
 - Internals: Misc tweaks to facilitate applying an explicit-context patch. (#5856) [@Dragnalith]
 
-
 -----------------------------------------------------------------------
  VERSION 1.89.3 (Released 2023-02-14)
 -----------------------------------------------------------------------
@@ -274,6 +547,10 @@ Other changes:
 - Examples: SDL2+SDL_Renderer: Added call to SDL_RenderSetScale() to fix display on a
   Retina display (albeit lower-res as our other unmodified examples). (#6121, #6065, #5931).
 
+Docking+Viewports Branch:
+
+- Backends: GLFW: Handle unsupported glfwGetVideoMode() for Emscripten. (#6096)
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.2 (Released 2023-01-05)
@@ -324,6 +601,17 @@ All changes:
 - Backends: Vulkan: Fixed sampler passed to ImGui_ImplVulkan_AddTexture() not being honored as we were using
   an immutable sampler. (#5502, #6001, #914) [@martin-ejdestig, @rytisss]
 
+Docking+Viewports Branch:
+
+- Docking: Internals: fixed DockBuilderCopyDockSpace() crashing when windows not in the
+  remapping list are docked on the left or top side of a split. (#6035)
+- Docking: fixed DockSpace() with ImGuiDockNodeFlags_KeepAliveOnly marking current window
+  as written to, even if it doesn't technically submit an item. This allow using KeepAliveOnly
+  from any window location. (#6037)
+- Backends: OSX: fixed typo in ImGui_ImplOSX_GetWindowSize that would cause issues when resiing
+  from OS decorations, if they are enabled on secondary viewports. (#6009) [@sivu]
+- Backends: Metal: fixed secondary viewport rendering. (#6015) [@dmirty-kuzmenko]
+
 
 -----------------------------------------------------------------------
  VERSION 1.89.1 (Released 2022-11-24)
@@ -350,6 +638,13 @@ Other changes:
 - Backends: GLFW: cancel out errors emitted by glfwGetKeyName() when a name is missing. (#5908)
 - Backends: WebGPU: fixed validation error with default depth buffer settings. (#5869, #5914) [@kdchambers]
 
+Docking+Viewports Branch:
+
+- Viewports: Fixed collapsed windows setting ImGuiViewportFlags_NoRendererClear without
+  making title bar color opaque, leading to potential texture/fb garbage being visible.
+  Right now as we don't fully support transparent viewports (#2766), so we turn that
+  'TitleBgCollapsed' color opaque just lke we do for 'WindowBG' on uncollapsed windows.
+
 
 -----------------------------------------------------------------------
  VERSION 1.89 (Released 2022-11-15)
@@ -456,7 +751,7 @@ Other Changes:
 - ColorEdit3: fixed id collision leading to an assertion. (#5707)
 - IsItemHovered: Added ImGuiHoveredFlags_DelayNormal and ImGuiHoveredFlags_DelayShort flags,
   allowing to introduce a shared delay for tooltip idioms. The delays are respectively
-  io.HoverDelayNormal (default to 0.30f) and io.HoverDelayFast (default to 0.10f). (#1485)
+  io.HoverDelayNormal (default to 0.30f) and io.HoverDelayShort (default to 0.10f). (#1485)
 - IsItemHovered: Added ImGuiHoveredFlags_NoSharedDelay to disable sharing delays between items,
   so moving from one item to a nearby one will requires delay to elapse again. (#1485)
 - Tables: activating an ID (e.g. clicking button inside) column doesn't prevent columns
@@ -541,6 +836,23 @@ Other Changes:
 - Backends: Vulkan: Added experimental ImGui_ImplVulkan_RemoveTexture() for api symetry. (#914, #5738).
 - Backends: WebGPU: fixed rendering when a depth buffer is enabled. (#5869) [@brainlag]
 
+Docking+Viewports Branch:
+
+- Docking: Fixed incorrect focus highlight on docking node when focusing a menu. (#5702)
+- Docking, Nav: Fixed using gamepad/keyboard navigation not being able enter menu layer when
+  it only contained the standard Collapse/Close buttons and no actual menu. (#5463, #4792)
+- Docking: Fixed regression introduced in v1.87 when docked window content not rendered
+  while switching between with CTRL+Tab. [@rokups]
+- Docking: Fixed amending into an existing tab bar from rendering invisible items. (#5515)
+- Docking: Made spacing between dock nodes not a dropping gap. When hovering it only
+  outer-docking drop markers are visible.
+- Docking+Viewports: Fixed undocking window node causing parent viewports to become unresponsive
+  in certain situation (e.g. hidden tab bar). (#5503) [@rokups]
+- Backends: SDL: Fixed building backend under non-OSX Apple targets (e.g. iPhone). (#5665)
+- Backends: SDL: Fixed drag'n drop crossing a viewport border losing mouse coordinates. (#5710, #5012)
+- Backends: GLFW: Fixed leftover static variable preventing from changing or
+  reinitializing backend while application is running. (#4616, #5434) [@rtoumazet]
+
 
 -----------------------------------------------------------------------
  VERSION 1.88 (Released 2022-06-21)
@@ -675,6 +987,26 @@ Other Changes:
 - Examples: Emscripten+WebGPU: Fix building for latest WebGPU specs. (#3632)
 - Examples: OSX+Metal, OSX+OpenGL: Removed now-unnecessary calls to ImGui_ImplOSX_HandleEvent(). (#4821)
 
+Docking+Viewports Branch:
+
+- Docking: Fixed floating docked nodes not being clamped into viewport workrect to stay reachable
+  when io.ConfigWindowsMoveFromTitleBarOnly is true and multi-viewports are disabled. (#5044)
+- Docking: Fixed a regression where moving window would be interrupted after undocking a tab
+  when io.ConfigDockingAlwaysTabBar is true. (#5324) [@rokups]
+- Docking: Fixed incorrect focus highlight on docking node when focusing empty central node
+  or a child window which was manually injected into a dockspace window.
+- Docking, Modal: Fixed a crash when opening popup from a parent which is being docked on the same frame. (#5401)
+- Viewports: Fixed an issue where MouseViewport was lagging by a frame when using 1.87 Input Queue.
+  A common side-effect would be that when releasing a window drag the underlying window would highlight
+  for a frame. (#5837, #4921) [@cfillion]
+- Viewports: Fixed translating a host viewport from briefly altering the size of AlwaysAutoResize windows. (#5057)
+- Viewports: Fixed main viewport size not matching ImDrawData::DisplaySize for one frame during resize
+  when multi-viewports are disabled. (#4900)
+- Backends: SDL: Fixed dragging out main viewport broken on some SDL setups. (#5012) [@rokups]
+- Backends: OSX: Added support for multi-viewports. [@stuartcarnie, @metarutaiga] (#4821, #2778)
+- Backends: Metal: Added support for multi-viewports. [@stuartcarnie, @metarutaiga] (#4821, #2778)
+- Examples: OSX+Metal, SDL+Metal, GLFW+Metal: Added support for multi-viewports. [@rokups]
+
 
 -----------------------------------------------------------------------
  VERSION 1.87 (Released 2022-02-07)
@@ -817,6 +1149,29 @@ Other Changes:
 - Backends: WebGPU: Fixed incorrect size parameters in wgpuRenderPassEncoderSetIndexBuffer() and
   wgpuRenderPassEncoderSetVertexBuffer() calls. (#4891) [@FeepsDev]
 
+Docking+Viewports Branch:
+
+- Docking: Fixed a CTRL+TAB crash when aiming at an empty docked window. (#4792)
+- Docking: Tabs use their own identifier instead of the Window identifier.
+  (This will invalidate some stored .ini data such as last selected tab, sorry!)
+- Docking: Fixed size constraints not working on single window holding on a dock id (still doesn't work on docked windows).
+- Docking: Fixed CTRL+TAB back into a docked window not selecting menu layer when no item are on main layer.
+- Viewports, IO: Added io.AddMouseViewportEvent() function to queue hovered viewport change (when known by backend).
+- Viewports: Relaxed specs for backend supporting ImGuiBackendFlags_HasMouseHoveredViewport: it is now _optional_
+  for the backend to have to ignore viewports with the _NoInputs flag when call io.AddMouseViewportEvent(). It is
+  much better if they can (Win32 and GLFW 3.3+ backends can, SDL and GLFW 3.2 backends cannot, they are lacking data).
+  A concrete example is: when dragging a viewport for docking, the viewport is marked with _NoInputs to allow us
+  to pick the target viewports for docking. If the backend reports a viewport with _NoInputs when calling the
+  io.AddMouseViewportEvent() function, then Dear ImGui will revert to its flawed heuristic to find the viewport under.
+  By lowering those specs, we allow the SDL and more backend to support this, only relying on the heuristic in a few
+  drag and drop situations rather that relying on it everywhere.
+- Viewports: Fixed a CTRL+TAB crash with viewports enabled when the window list needs to appears in
+  its own viewport (regression from 1.86). (#4023, #787)
+- Viewports: Fixed active InputText() from preventing viewports to merge. (#4212)
+- Backends: SDL: Added support for ImGuiBackendFlags_HasMouseHoveredViewport now that its specs have been lowered.
+- (Breaking) Removed ImGuiPlatformIO::Platform_SetImeInputPos() in favor of newly standardized
+  io.SetPlatformImeDataFn() function. Should not affect more than default backends.
+
 
 -----------------------------------------------------------------------
  VERSION 1.86 (Released 2021-12-22)
@@ -876,7 +1231,7 @@ Other Changes:
   Fixes issue where e.g. drag and dropping an item and scrolling ensure the item source location is
   still submitted. (#3841, #1725) [@GamingMinds-DanielC, @ocornut]
 - Clipper: added ForceDisplayRangeByIndices() to force a given item (or several) to be stepped out
-  during a clipping operation. (#3841) [@@GamingMinds-DanielC]
+  during a clipping operation. (#3841) [@GamingMinds-DanielC]
 - Clipper: rework so gamepad/keyboard navigation doesn't create spikes in number of items requested
   by the clipper to display. (#3841)
 - Clipper: fixed content height declaration slightly mismatching the value of when not using a clipper.
@@ -915,6 +1270,24 @@ Other Changes:
   wgpuRenderPassEncoderSetIndexBuffer() functions as validation layers appears to not do what the
   in-flux specs says. (#4766) [@meshula]
 
+Docking+Viewports Branch:
+
+- Docking: Revert removal of io.ConfigDockingWithShift config option (removed in 1.83). (#4643)
+- Docking: Fixed a bug undocking windows docked into a non-visible or _KeepAliveOnly dockspace
+  when unrelated windows submitted before the dockspace have dynamic visibility. (#4757)
+- Docking, Style: Docked windows honor ImGuiCol_WindowBg. (#2700, #2539)
+- Docking, Style: Docked windows honor display their border properly. (#2522)
+- Docking: Fixed incorrectly rounded tab bars for dock node that are not at the top of their dock tree.
+- Docking: Fixed single-frame node pos/size inconsistencies when window stop or start being submitted.
+- Docking: Prevent docking any window created above a popup/modal. (#4317)
+- Viewports: Made it possible to explicitly assign ImGuiWindowClass::ParentViewportId to 0 in order
+  to ensure a window is not parented. Previously this would use the global default (which might be 0,
+  but not always as it would depend on io.ConfigViewportsNoDefaultParent). (#3152, #2871)
+- Viewports: Fixed tooltip in own viewport over modal from being incorrectly dimmed. (#4729)
+- Viewports: Fixed CTRL+TAB highlight outline on docked windows not always fitting in host viewport.
+- Backends: Made it possible to shutdown default Platform Backends before the Renderer backends. (#4656)
+- Disabled: Fixed nested BeginDisabled()/EndDisabled() bug in Docking branch due to bad merge. (#4655, #4452, #4453, #4462)
+
 
 -----------------------------------------------------------------------
  VERSION 1.85 (Released 2021-10-12)
@@ -933,6 +1306,10 @@ Breaking Changes:
   Can use 'GetWindowContentRegionMax().x - GetWindowContentRegionMin().x' instead but it's not
   very useful in practice, and the only use of it in the demo was illfit.
   Using 'GetContentRegionAvail().x' is generally a better choice.
+- (Docking branch) IsWindowFocused() and IsWindowHovered() with only the _ChildWindows flag
+  and without the _RootWindow flag used to leak docking hierarchy, so a docked window would
+  return as the child of the window hosting the dockspace. This was inconsistent and incorrect
+  with other behaviors so we fixed it. Added a new _DockHierarchy flag to opt-in this behavior.
 
 Other Changes:
 
@@ -1006,6 +1383,29 @@ Other Changes:
 - Backends: All renderers: Normalize clipping rect handling across backends. (#4464)
 - Examples: Added SDL + SDL_Renderer example in "examples/example_sdl_sdlrenderer/" folder. (#3926) [@1bsyl]
 
+Docking+Viewports Branch:
+
+- IsWindowFocused: Fixed using ImGuiFocusedFlags_ChildWindows (without _RootWindow) from leaking the
+  docking hierarchy. Added ImGuiFocusedFlags_DockHierarchy flag to consider docking hierarchy in the test.
+- IsWindowHovered: Fixed using ImGuiHoveredFlags_ChildWindows (without _RootWindow) from leaking the
+  docking hierarchy. Added ImGuiHoveredFlags_DockHierarchy flag to consider docking hierarchy in the test.
+- Nav: Fixed an issue with losing focus on docked windows when pressing Alt while keyboard navigation
+  is disabled. (#4547, #4439) [@PathogenDavid]
+- Docking: Fixed IsItemHovered() and functions depending on it (e.g. BeginPopupContextItem()) when
+  called after Begin() on a docked window (broken 2021/03/04). (#3851)
+- Docking: Improved resizing system so that non-central zone are better at keeping their fixed size.
+  The algorithm is still not handling the allocation of size ideally for nested sibling, but it got better.
+- Docking: Fixed settings load issue when mouse wheeling. (#4310)
+- Docking: Fixed manually created floating node with a central node from not hiding when windows are gone.
+- Docking + Drag and Drop: Fixed using BeginDragDropSource() or BeginDragDropTarget() inside a Begin()
+  that returned false because the window is docked. (#4515)
+- Viewports: Fixed a crash while a window owning its viewport disappear while being dragged.
+  It would manifest when e.g. reconfiguring dock nodes while dragging.
+- Viewports: Fixed unnecessary creation of temporary viewports when multiple docked windows
+  got reassigned to a new node (created mid-frame) which already has a HostWindow.
+- Viewports: Fixed window with viewport ini data immediately merged into a host viewport from
+  leaving a temporary viewport alive for a frame (would leak into backend).
+
 
 -----------------------------------------------------------------------
  VERSION 1.84.2 (Released 2021-08-23)
@@ -1142,6 +1542,25 @@ Other Changes:
 - Examples: Updated all .vcxproj to VS2015 (toolset v140) to facilitate usage with vcpkg.
 - Examples: SDL2: Accommodate  for vcpkg install having headers in SDL2/SDL.h vs SDL.h.
 
+Docking+Viewports Branch:
+
+- Docking: Clicking on the right-most close button of a docking node closes all windows. (#4186)
+- Docking: Fix IsWindowAppearing() and ImGuiCond_Appearing on docked windows. (#4177, #3982, #1497, #1061)
+- Docking: Fix crash using DockBuilderRemoveNode() in some situations. (#3111, #3179, #3203, #4295) [@hsimyu]
+- Docking: Fix crash when a dock node gets re-qualified as dockspace>floating>dockspace, which tends to happen
+  when incorrectly calling DockBuilderAddNode() without ImGuiDockNodeFlags_Dockspace and using it as a Dockspace
+  on the next frame after the floating window hosting the node has been automatically created. (#3203, #4295)
+- Docking: Reworked node flags saving/inheritance so that flags enforced by docked windows via the
+  DockNodeFlagsOverrideSet mechanism are are not left in empty dockspace nodes once the windows gets undocked.
+  (#4292, #3834, #3633, #3521, #3492, #3335, #2999, #2648)
+- Docking: (Internal/Experimental) Removed DockNodeFlagsOverrideClear flags from ImGuiWindowClass as
+  it is ambiguous how to apply them and we haven't got a use out of them yet.
+- Docking: Fixed ImGuiWindowFlags_UnsavedDocument clipping label in docked windows when there are
+  no close button. (#5745)
+- Viewports: Fix popup/tooltip created without a parent window from being given a ParentViewportId value
+  from the implicit/fallback window. (#4236, #2409)
+- Backends: Vulkan: Fix the use of the incorrect fence for secondary viewports. (#4208) [@FunMiles]
+
 
 -----------------------------------------------------------------------
  VERSION 1.83 (Released 2021-05-24)
@@ -1226,6 +1645,22 @@ Other Changes:
 - Docs: Improvements to description of using colored glyphs/emojis. (#4169, #3369)
 - Docs: Improvements to minor mistakes in documentation comments (#3923) [@ANF-Studios]
 
+Docking+Viewports Branch:
+
+- [Breaking] Removed io.ConfigDockingWithShift config option. Behavior always equivalent to having the
+  option set to false (dock/undock by default, hold shift to avoid docking). (#2109)
+- Docking: DockSpace() returns its node ID.
+- Docking: Dockspace() never draws a background. (#3924)
+- Docking: Undocking nodes/windows covering most of the monitor max their size down to 90% to ease manipulations.
+- Docking: Docking node tab bar honors ItemInnerSpacing.x before first tab. (#4130)
+- Docking: Tweak rendering and alignment of dock node menu marker. (#4130)
+- Docking: Fixed restoring of tab order within a dockspace or a split node.
+- Docking: Fixed reappearing docked windows with no close button showing a tab with extraneous space for one frame.
+- Docking: Fixed multiple simultaneously reappearing window from appearing undocked for one frame.
+- Viewports: Hotfix for crash in monitor array access, caused by 4b9bc4902. (#3967)
+- Backends, Viewports: GLFW: Add a workaround for stuck keys after closing a GLFW window (#3837).
+- Backends, Viewports: Vulkan: Rebuild swapchain on VK_SUBOPTIMAL_KHR. (#3881)
+
 
 -----------------------------------------------------------------------
  VERSION 1.82 (Released 2021-02-15)
@@ -1321,6 +1756,13 @@ Other Changes:
   scheduled builds builds are not required. [@rokups]
 - Log/Capture: Added LogTextV, a va_list variant of LogText. [@PathogenDavid]
 
+Docking+Viewports Branch:
+
+- Viewports: Fix setting of ImGuiViewportFlags_NoRendererClear. (#3213)
+- Viewports: Added GetViewportPlatformMonitor() with a safety net to keep code portable.
+- Viewports, Backends: SDL: Fix missing ImGuiBackendFlags_HasSetMousePos flag in docking branch.
+- Viewports, Backends: GLFW: Fix application of WantSetMousePos. (#1542, #787)
+
 
 -----------------------------------------------------------------------
  VERSION 1.81 (Released 2021-02-10)
@@ -1402,6 +1844,17 @@ Other Changes:
 - Examples: WebGPU: Added Emscripten+WebGPU example. (#3632) [@bfierz]
 - Backends: GLFW: Added ImGui_ImplGlfw_InitForOther() initialization call to use with non OpenGL API. (#3632)
 
+Docking+Viewports Branch:
+
+- Docking: Fix losing docking information on closed windows for which the hosting node was split. (#3716) [@GamingMinds-DanielC]
+- Docking: Fix gap in hit test hole when using ImGuiDockNodeFlags_PassthruCentralNode touching the edge of a viewport. (#3733)
+- Viewports: (Breaking) removed ImGuiPlatformIO::MainViewport which is now pretty much unused and duplicate
+  (and misleading as we will evolve the concept).
+- Viewports: (Breaking) turned ImGuiViewport::GetWorkPos(), ImGuiViewport::GetWorkSize() into regular fields
+  (WorkPos, WorkSize) before exposing in master branch.
+- Viewports: Fix issue inferring viewport z-order when new popups gets created. (#3734) + Metrics updates.
+- Viewports, Backends: Vulkan: handle VK_ERROR_OUT_OF_DATE_KHR when resizing secondary viewport (#3766, #3758)
+
 
 -----------------------------------------------------------------------
  VERSION 1.80 (Released 2021-01-21)
@@ -1521,6 +1974,14 @@ Other Changes:
 - Docs: Split examples/README.txt into docs/BACKENDS.md and docs/EXAMPLES.md, and improved them.
 - Docs: Consistently renamed all occurrences of "binding" and "back-end" to "backend" in comments and docs.
 
+Docking+Viewports Branch:
+
+- Docking: Docked windows honor change of tab and text colors. (#2771)
+- Docking: Support for appending into existing tab-bar made to work with Docking + internal helper DockNodeBeginAmendTabBar().
+- Docking: Added experimental TabItemFlagsOverrideSet to ImGuiWindowClass.
+- Viewports: Fixed incorrect whitening of popups above a modal if both use their own viewport.
+- Viewports: Backends: Vulkan: Fixed build, removed extraneous pipeline creation. (#3459, #3579)
+
 
 -----------------------------------------------------------------------
  VERSION 1.79 (Released 2020-10-08)
@@ -1615,6 +2076,21 @@ Other Changes:
 - Examples: DX12: Added '#define ImTextureID ImU64' in project and build files to also allow building
   on 32-bit systems. Added project to default Visual Studio solution file. (#301)
 
+Docking+Viewports Branch:
+
+- Docking: DockSpace() emits ItemSize() properly (useful when not filling all space).
+- Docking: Fixed docking while hovering a child window. (#3420) broken by 85a661d. Improve metrics debugging.
+- Docking: Fix honoring payload filter with overlapping nodes (we incorrectly over-relied on g.HoveredDockNode
+  when making change for #3398).
+- Docking: Fix handling of WindowMenuButtonPosition == ImGuiDir_None in Docking Nodes. (#3499)
+- Viewports: Fixed a rare edge-case if the window targeted by CTRL+Tab stops being rendered.
+- Viewports, Backends: DX12: Make secondary viewport format match main viewport one (#3462) {@BeastLe9enD]
+- Viewports: Backends: Vulkan: Removed unused shader code. Fix leaks. Avoid unnecessary pipeline creation for main
+  viewport. (#3459) + Add ImGui_ImplVulkanH_CreateWindowSwapChain in ImGui_ImplVulkanH_CreateOrResizeWindow().
+- Viewports: Backends: DirectX9: Recover from D3DERR_DEVICELOST on secondary viewports. (#3424)
+- Viewports, Backends: Win32: Fix toggling of ImGuiViewportFlags_TopMost (#3477) [@Kodokuna]
+- Viewports: Backends: GLFW: Workaround for cases where glfwGetMonitorWorkarea fails (#3457) [@dougbinks]
+
 
 -----------------------------------------------------------------------
  VERSION 1.78 (Released 2020-08-18)
@@ -1716,6 +2192,23 @@ Other Changes:
 - Examples: Vulkan: Fixed GLFW+Vulkan and SDL+Vulkan clear color not being set. (#3390) [@RoryO]
 - CI: Emscripten has stopped their support for their fastcomp backend, switching to latest sdk [@Xipiryon]
 
+Docking+Viewports Branch:
+
+- Docking: Made DockBuilderAddNode() automatically call DockBuilderRemoveNode(). (#3399, #2109)
+- Docking: Storing HoveredDockNode in context which can be useful for easily detecting e.g. hovering an
+  empty node. (#3398)
+- Docking: Fixed docking overlay bits appearing at (0,0), because of 43bd80a. Most typically noticeable
+  when disabling multi-viewport.
+- Docking: Workaround recovery for node created without the _DockSpace flags later becoming a DockSpace. (#3340)
+- Docking: Rework size allocations to recover when there's no enough room for nodes + do not hold on
+  _WantLockSizeOnce forever. (#3328)
+- Docking: Rework size allocation to allow user code to override node sizes. Not all edge cases will be
+  properly handled but this is a step toward toolbar emitting size constraints.
+- Docking: Added experimental flags to perform more docking filtering and disable resize per axis.
+  Designed for toolbar patterns.
+- Viewports, Backends, GLFW: Use GLFW_MOUSE_PASSTHROUGH when available.
+- Viewports, Backends: DX12: Fixed issue on shutdown when viewports are disabled. (#3347)
+
 
 -----------------------------------------------------------------------
  VERSION 1.77 (Released 2020-06-29)
@@ -1807,6 +2300,17 @@ Other Changes:
 - Examples: Apple: Fixed example_apple_metal and example_apple_opengl2 using imgui_impl_osx.mm
   not forwarding right and center mouse clicks. (#3260) [@nburrus]
 
+Docking+Viewports Branch:
+
+- Viewports: Don't set ImGuiViewportFlags_NoRendererClear when ImGuiWindowFlags_NoBackground is set. (#3213)
+- Viewports: Report minimized viewports as zero DisplaySize to be consistent with main branch. (#1542)
+- Docking, Settings: Allow reload of settings data at runtime. (#2573)
+- Backends, GLFW: Fix windows resizing incorrectly on Linux due to GLFW firing window positioning
+  callbacks on next frame after window is resized manually. (#2117)
+- Backends: DX12: Fix OBJECT_DELETED_WHILE_STILL_IN_USE on viewport resizing. (#3210)
+- Backends: DX12: Fix for crash caused by early resource release. (#3121)
+- Backends, Win32: Request monitor update when DPI awareness is enabled to make sure they have the correct DPI settings.
+
 
 -----------------------------------------------------------------------
  VERSION 1.76 (Released 2020-04-12)
@@ -1879,6 +2383,20 @@ Other Changes:
 - Examples: SDL+DX11: Fixed resizing main window. (#3057) [@joeslay]
 - Examples: Added SDL+Metal example application. (#3017) [@coding-jackalope]
 
+Docking+Viewports Branch:
+
+- Docking: Fixed assert preventing dockspace from being created instead a hidden tab. (#3101)
+- Viewports: Fixed secondary viewports accidentally merging into a minimized host viewport. (#3118)
+- Viewports, Docking: Added per-viewport work area system for e.g. menu-bars. Fixed DockspaceOverViewport()
+  and demo code (overlay etc) accordingly. (#3035, #2889, #2474, #1542, #2109)
+- Viewports: Improve menu positioning in multi-monitor setups. [@rokups]
+- Viewports: Software mouse cursor is also scaled by current DpiScale. (amend #939)
+- Viewports: Avoid manually clipping resize grips and borders, which messes up with automation ability
+  to locate those items. Also simpler and more standard.
+- Viewports: Fix for UWP in the imgui_impl_win32.cpp IME handler. (#2895, #2892).
+- Viewports: Bunch of extra of comments to facilitate setting up multi-viewports.
+- Viewports, GLFW: Avoid using window positioning workaround for GLFW 3.3+ versions that have it fixed.
+
 
 -----------------------------------------------------------------------
  VERSION 1.75 (Released 2020-02-10)
@@ -1977,6 +2495,21 @@ Other Changes:
 - Examples: Metal: Wrapped main loop in @autoreleasepool block to ensure allocations get freed
   even if underlying system event loop gets paused due to app nap. (#2910, #2917) [@bear24rw]
 
+Docking+Viewports Branch:
+
+- Docking + Nav: Fixed messed up Ctrl+Tab order with docked windows.
+- Docking + Nav: Fixed failing to restore NavId when refocusing a child within a docked window.
+- Docking + Nav: Fixed failing to restore NavId when refocusing due to missing nav window (when
+  it stops being submitted).
+- Docking: Fixed a bug where the tab bar of a hidden dockspace would keep requesting focus. (#2960)
+- Docking: Added experimental DockNodeFlagsOverrideSet/DockNodeFlagsOverrideClear flags in ImGuiWindowClass
+  (currently experimenting with toolbar idioms).
+- Viewports: Fix resizing viewport-owning windows when mouse pos is outside the InnerClipRect
+  (can happen with OS decoration enabled).
+- Viewports: Preserve last known size for minimized main viewport to be consistent with secondary viewports.
+- Backends: SDL: Honor NoTaskBarIcon flag under non Win32 OS. (#2117)
+- Backends: GLFW, SDL: Platform monitors declared properly even if multi-viewport is not enabled.
+
 
 -----------------------------------------------------------------------
  VERSION 1.74 (Released 2019-11-25)
@@ -2056,6 +2589,14 @@ Other Changes:
 - CI: Set up a bunch of continuous-integration tests using GitHub Actions. We now compile many of the example
   applications on Windows, Linux, MacOS, iOS, Emscripten. Removed Travis integration. (#2865) [@rokups]
 
+Docking+Viewports Branch:
+
+- Docking: Can undock from the small triangle button. (#2109,. #2645)
+- Docking: Fixed node->HasCloseButton not honoring ImGuiDockNodeFlags_NoCloseButton in a floating node,
+  leading to empty space at the right of tab-bars with those flags. (#2109)
+- Docking: Made docked windows not use style.ChildRounding.
+- Multi-viewports: Added multi-viewport support in the DX12 back-end. (#2851) [@obfuscate]
+
 
 -----------------------------------------------------------------------
  VERSION 1.73 (Released 2019-09-24)
@@ -2118,6 +2659,28 @@ Other Changes:
 - Misc: Updated stb_rect_pack.h from 0.99 to 1.00 (fixes by @rygorous: off-by-1 bug in best-fit heuristic,
   fix handling of rectangles too large to fit inside texture). (#2762) [@tido64]
 
+Docking+Viewports Branch:
+
+- Docking: Fix BeginDocked() path that creates node so that SetNextWindowDockID() doesn't immediately discard the node. (#2109)
+- Docking: Fix for node created at the same time as windows that are still resizing (typically with
+  io.ConfigDockingAlwaysTabBar) to not be zero/min sized. (#2109). The fix delays their visibility by one frame,
+  which is not ideal but not very problematic as the .ini data gets populated after that.
+- Docking: Fix a crash that could occur with a malformed ini file (DockNode Parent value pointing to a missing node).
+- Viewport: Fix modal/popup window being stuck in unowned hidden viewport associated to fallback window without stealing
+  it back. Fix modal reference viewport when opened outside of another window. (#1542)
+- Viewport: Modals don't need to set ImGuiViewportFlags_NoFocusOnClick, this also mitigate the issue described by #2445,
+  which becomes particularly bad with unfocused modal. (#1542)
+- Viewport: better case case where host window gets moved and resized simultaneous (toggling maximized state).
+  There's no perfect solution there, than using io.ConfigViewportsNoAutoMerge = false. (#1542)
+- Viewport, Docking: Fixed incorrect assignment of IsFallbackWindow which would tag dock node host windows created
+  in NewFrame() as such, messing with popup viewport inheritance.
+- Viewport: Fixed issue where resize grip would display as hovered while mouse is still off the OS bounds so a click
+  would miss it and focus the OS window behind expected one. (#1542)
+- Viewport: Fix to allow multiple shutdown / calls to DestroyPlatformWindows(). (#2769)
+- Viewport: Backends: GLFW: Fix setting window size on macOS (#2767, #2117) [@rokups]
+- Viewport: Backends: GLFW+Linux: Fix window having incorrect size after uncollapse. (#2756, #2117) [@rokups]
+- Viewport: Backends: DirectX9: Workaround for windows not refreshing when main viewport has no draw call. (#2560)
+
 
 -----------------------------------------------------------------------
  VERSION 1.72b (Released 2019-07-31)
@@ -2220,6 +2783,25 @@ Other Changes:
   (#2482, #2632) [@josiahmanson]
 - Examples: Added SDL2+DirectX11 example application. (#2632, #2612, #2482) [@vincenthamm]
 
+Docking+Viewports Branch:
+
+- Docking: Making it possible to undock a node by clicking on the tab bar / title bar for the node. (#2645).
+- Docking: Explicitly inhibit constraint when docked for now. Fix clipping issue related to constraints. (#2690).
+- Docking: Fixed dragging/resizing from OS decoration not marking settings as dirty.
+- Docking: Renamed io.ConfigDockingTabBarOnSingleWindows to io.ConfigDockingAlwaysTabBar.
+  Added ImGuiWindowClass::DockingAlwaysTabBar to set on individual windows.
+- Docking: Perform simple check: assert if Docking or Viewport are enabled exactly on frame 1 (instead of frame 0
+  or later), which is a common user error leading to loss of .ini data on load.
+- Docking: Fix so that an appearing window making a dock node reappear won't have a zero-size on its first frame.
+- Docking: Fixed using ImGuiDockNodeFlags_AutoHideTabBar with io.ConfigDockingTabBarOnSingleWindows.
+- Docking: Added ImGuiDockNode to .natvis file.
+- Docking: Fixed support for large meshes in GetBackgroundDrawList(), GetForegroundDrawList(). (#2638)
+- Viewport: Fix monitor dpi info not being copied to main viewport when multi-viewports are not enabled. (#2621, #1676)
+- Viewport: Refactored ImGuiWindowClass's ViewportFlagsOverrideMask + ViewportFlagsOverrideValue into
+  ViewportFlagsOverrideSet + ViewportFlagsOverrideClear which appears easier to grasp. (#1542)
+- Viewport: Added ImGuiViewportFlags_NoAutoMerge to prevent merging into host viewport in a per-window basis
+  via the ImGuiWindowClass override mechanism. (#1542)
+
 
 -----------------------------------------------------------------------
  VERSION 1.71 (Released 2019-06-12)
@@ -2559,6 +3141,7 @@ Breaking Changes:
 - Renamed ImFontAtlas::GlyphRangesBuilder to ImFontGlyphRangesBuilder. Kept redirection typedef (will obsolete).
 
 Other Changes:
+
 - Added BETA api for Tab Bar/Tabs widgets: (#261, #351)
   - Added BeginTabBar(), EndTabBar(), BeginTabItem(), EndTabItem(), SetTabItemClosed() API.
   - Added ImGuiTabBarFlags flags for BeginTabBar().

docs/CONTRIBUTING.md

@@ -11,7 +11,7 @@
 ## Getting Started & General Advice
 
 - Article: [How To Ask Good Questions](https://bit.ly/3nwRnx1).
-- Please browse the [Wiki](https://github.com/ocornut/imgui/wiki) to find code snippets, links and other resources (e.g. [Useful extensions](https://github.com/ocornut/imgui/wiki/Useful-Extensions)).
+- Please browse the [Wiki](https://github.com/ocornut/imgui/wiki) to find code snippets, links and other resources (e.g. [Getting Started](https://github.com/ocornut/imgui/wiki/Getting-Started), [Useful extensions](https://github.com/ocornut/imgui/wiki/Useful-Extensions)).
 - Please read [docs/FAQ.md](https://github.com/ocornut/imgui/blob/master/docs/FAQ.md).
 - Please read [docs/FONTS.md](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md) if your question relates to fonts or text.
 - Please read one of the [examples/](https://github.com/ocornut/imgui/tree/master/examples) application if your question relates to setting up Dear ImGui.

docs/EXAMPLES.md

@@ -171,11 +171,10 @@ This uses more modern GL calls and custom shaders. <BR>
 This support building with Emscripten and targetting WebGL.<BR>
 Prefer using that if you are using modern GL or WebGL in your application.
 
-[example_sdl2_sdlrenderer/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_sdlrenderer/) <BR>
-SDL2 (Win32, Mac, Linux, etc.) + SDL_Renderer (most graphics backends are supported underneath) <BR>
+[example_sdl2_sdlrenderer2/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_sdlrenderer2/) <BR>
+SDL2 (Win32, Mac, Linux, etc.) + SDL_Renderer for SDL2 (most graphics backends are supported underneath) <BR>
 = main.cpp + imgui_impl_sdl2.cpp + imgui_impl_sdlrenderer.cpp <BR>
 This requires SDL 2.0.18+ (released November 2021) <BR>
-We do not really recommend using SDL_Renderer as it is a rather primitive API.
 
 [example_sdl2_vulkan/](https://github.com/ocornut/imgui/blob/master/examples/example_sdl2_vulkan/) <BR>
 SDL2 (Win32, Mac, Linux, etc.) + Vulkan example. <BR>
@@ -200,6 +199,10 @@ DirectX12 example, Windows only. <BR>
 = main.cpp + imgui_impl_win32.cpp + imgui_impl_dx12.cpp <BR>
 This is quite long and tedious, because: DirectX12.
 
+[example_win32_opengl3/](https://github.com/ocornut/imgui/blob/master/examples/example_win32_opengl3/) <BR>
+Raw Windows + OpenGL3 + example (modern, programmable pipeline) <BR>
+= main.cpp + imgui_impl_win32.cpp + imgui_impl_opengl3.cpp <BR>
+
 
 ### Miscellaneous
 

docs/FAQ.md

@@ -50,7 +50,8 @@ or view this file with any Markdown viewer.
 
 **This library is poorly documented at the moment and expects the user to be acquainted with C/C++.**
 - The [Wiki](https://github.com/ocornut/imgui/wiki) is a hub to many resources and links.
-- Dozens of standalone example applications using e.g. OpenGL/DirectX are provided in the [examples/](https://github.com/ocornut/imgui/blob/master/examples/) folder to explain how to integrate Dear ImGui with your own engine/application. You can run those applications and explore them.
+- Handy [Getting Started](https://github.com/ocornut/imgui/wiki/Getting-Started) guide to integrate Dear ImGui in an existing application.
+- 20+ standalone example applications using e.g. OpenGL/DirectX are provided in the [examples/](https://github.com/ocornut/imgui/blob/master/examples/) folder to explain how to integrate Dear ImGui with your own engine/application. You can run those applications and explore them.
 - See demo code in [imgui_demo.cpp](https://github.com/ocornut/imgui/blob/master/imgui_demo.cpp) and particularly the `ImGui::ShowDemoWindow()` function. The demo covers most features of Dear ImGui, so you can read the code and see its output.
 - See documentation: [Backends](https://github.com/ocornut/imgui/blob/master/docs/BACKENDS.md), [Examples](https://github.com/ocornut/imgui/blob/master/docs/EXAMPLES.md), [Fonts](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md).
 - See documentation and comments at the top of [imgui.cpp](https://github.com/ocornut/imgui/blob/master/imgui.cpp) + general API comments in [imgui.h](https://github.com/ocornut/imgui/blob/master/imgui.h).
@@ -557,7 +558,7 @@ backslash \ within a string literal, you need to write it double backslash "\\":
 
 ```cpp
 io.Fonts->AddFontFromFileTTF("MyFolder\MyFont.ttf", size);  // WRONG (you are escaping the M here!)
-io.Fonts->AddFontFromFileTTF("MyFolder\\MyFont.ttf", size;  // CORRECT (Windows only)
+io.Fonts->AddFontFromFileTTF("MyFolder\\MyFont.ttf", size); // CORRECT (Windows only)
 io.Fonts->AddFontFromFileTTF("MyFolder/MyFont.ttf", size);  // ALSO CORRECT
 ```
 
@@ -628,10 +629,11 @@ builder.BuildRanges(&ranges);                          // Build the final result
 io.Fonts->AddFontFromFileTTF("myfontfile.ttf", 16.0f, nullptr, ranges.Data);
 ```
 
-All your strings need to use UTF-8 encoding. In C++11 you can encode a string literal in UTF-8
-by using the u8"hello" syntax. Specifying literal in your source code using a local code page
-(such as CP-923 for Japanese or CP-1251 for Cyrillic) will NOT work!
-Otherwise, you can convert yourself to UTF-8 or load text data from a file already saved as UTF-8.
+All your strings need to use UTF-8 encoding.
+You need to tell your compiler to use UTF-8, or in C++11 you can encode a string literal in UTF-8 by using the u8"hello" syntax.
+Specifying literal in your source code using a local code page (such as CP-923 for Japanese or CP-1251 for Cyrillic) will NOT work!
+See [About UTF-8 Encoding](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md#about-utf-8-encoding) section
+of [FONTS.md](https://github.com/ocornut/imgui/blob/master/docs/FONTS.md) for details about UTF-8 Encoding.
 
 Text input: it is up to your application to pass the right character code by calling `io.AddInputCharacter()`.
 The applications in examples/ are doing that.
@@ -653,7 +655,7 @@ You may take a look at:
 - [Quotes](https://github.com/ocornut/imgui/wiki/Quotes)
 - [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui)
 - [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors)
-- [Gallery](https://github.com/ocornut/imgui/issues/5886)
+- [Gallery](https://github.com/ocornut/imgui/issues/6478)
 
 ##### [Return to Index](#index)
 
@@ -665,7 +667,7 @@ Yes. People have written game editors, data browsers, debuggers, profilers, and
 
 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 that the more typical RMGUI paradigm.
+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.
 
 ##### [Return to Index](#index)
 
@@ -673,7 +675,7 @@ Dear ImGui is built to be efficient and scalable toward the needs for AAA-qualit
 
 ### Q: Can you reskin the look of Dear ImGui?
 
-Somehow. You can alter the look of the interface to some degree: changing colors, sizes, padding, rounding, and fonts. However, as Dear ImGui is designed and optimized to create debug tools, the amount of skinning you can apply is limited. There is only so much you can stray away from the default look and feel of the interface. Dear ImGui is NOT designed to create a user interface for games, although with ingenious use of the low-level API you can do it.
+Somewhat. You can alter the look of the interface to some degree: changing colors, sizes, padding, rounding, and fonts. However, as Dear ImGui is designed and optimized to create debug tools, the amount of skinning you can apply is limited. There is only so much you can stray away from the default look and feel of the interface. Dear ImGui is NOT designed to create a user interface for games, although with ingenious use of the low-level API you can do it.
 
 A reasonably skinned application may look like (screenshot from [#2529](https://github.com/ocornut/imgui/issues/2529#issuecomment-524281119)):
 ![minipars](https://user-images.githubusercontent.com/314805/63589441-d9794f00-c5b1-11e9-8d96-cfc1b93702f7.png)
@@ -699,7 +701,7 @@ There is an auto-generated [c-api for Dear ImGui (cimgui)](https://github.com/ci
 - Individuals: you can support continued maintenance and development via PayPal donations. See [README](https://github.com/ocornut/imgui/blob/master/docs/README.md).
 - If you are experienced with Dear ImGui and C++, look at [GitHub Issues](https://github.com/ocornut/imgui/issues), [GitHub Discussions](https://github.com/ocornut/imgui/discussions), the [Wiki](https://github.com/ocornut/imgui/wiki), read [docs/TODO.txt](https://github.com/ocornut/imgui/blob/master/docs/TODO.txt), and see how you want to help and can help!
 - Disclose your usage of Dear ImGui via a dev blog post, a tweet, a screenshot, a mention somewhere, etc.
-You may post screenshots or links in the [gallery threads](https://github.com/ocornut/imgui/issues/5886). Visuals are ideal as they inspire other programmers. Disclosing your use of Dear ImGui helps the library grow credibility, and helps other teams and programmers with taking decisions.
+You may post screenshots or links in the [gallery threads](https://github.com/ocornut/imgui/issues/6478). Visuals are ideal as they inspire other programmers. Disclosing your use of Dear ImGui helps the library grow credibility, and helps other teams and programmers with taking decisions.
 - If you have issues or if you need to hack into the library, even if you don't expect any support it is useful that you share your issues or sometimes incomplete PR.
 
 ##### [Return to Index](#index)

docs/FONTS.md

@@ -12,41 +12,118 @@ In the [misc/fonts/](https://github.com/ocornut/imgui/tree/master/misc/fonts) fo
 
 ## Index
 - [Readme First](#readme-first)
+- [About Filenames](#about-filenames)
+- [About UTF-8 Encoding](#about-utf-8-encoding)
+- [Debug Tools](#debug-tools)
 - [How should I handle DPI in my application?](#how-should-i-handle-dpi-in-my-application)
-- [Fonts Loading Instructions](#font-loading-instructions)
+- [Fonts Loading Instructions](#fonts-loading-instructions)
 - [Using Icon Fonts](#using-icon-fonts)
 - [Using FreeType Rasterizer (imgui_freetype)](#using-freetype-rasterizer-imgui_freetype)
 - [Using Colorful Glyphs/Emojis](#using-colorful-glyphsemojis)
 - [Using Custom Glyph Ranges](#using-custom-glyph-ranges)
 - [Using Custom Colorful Icons](#using-custom-colorful-icons)
 - [Using Font Data Embedded In Source Code](#using-font-data-embedded-in-source-code)
-- [About filenames](#about-filenames)
 - [Credits/Licenses For Fonts Included In Repository](#creditslicenses-for-fonts-included-in-repository)
 - [Font Links](#font-links)
 
 ---------------------------------------
- ## Readme First
 
-- You can use the `Metrics/Debugger` window (available in `Demo>Tools`) to browse your fonts and understand what's going on if you have an issue. You can also reach it in `Demo->Tools->Style Editor->Fonts`. The same information are also available in the Style Editor under Fonts.
+## Readme First
+
+**A vast majority of font and text related issues encountered comes from 3 things:**
+- Invalid filename due to use of `\` or unexpected working directory. See [About Filenames](#about-filenames). AddFontXXX functions should assert if the filename is incorrect.
+- Invalid UTF-8 encoding of your non-ASCII strings. See [About UTF-8 Encoding](#about-utf-8-encoding). Use the encoding viewer to confirm yours is correct.
+- You need to load a font with explicit glyph ranges if you want to use non-ASCII characters. See [Fonts Loading Instructions](#fonts-loading-instructions). Use Metrics/Debugger->Fonts to confirm loaded fonts and loaded glyph ranges.
+
+The third point is a current constraint of Dear ImGui (which we will lift in the future): when loading a font you need to specify which characters glyphs to load.
+All loaded fonts glyphs are rendered into a single texture atlas ahead of time. Calling either of `io.Fonts->GetTexDataAsAlpha8()`, `io.Fonts->GetTexDataAsRGBA32()` or `io.Fonts->Build()` will build the atlas. This is generally called by the Renderer backend, e.g. `ImGui_ImplDX11_NewFrame()` calls it.
+
+**If you use custom glyphs ranges, make sure the array is persistent** and available during the calls to `GetTexDataAsAlpha8()/GetTexDataAsRGBA32()/Build()`.
+
+##### [Return to Index](#index)
+
+## About Filenames
+
+**Please note that many new C/C++ users have issues loading their files _because the filename they provide is wrong_ due to incorrect assumption of what is the current directory.**
+
+Two things to watch for:
+
+(1) In C/C++ and most programming languages if you want to use a backslash `\` within a string literal, you need to write it double backslash `\\`. At it happens, Windows uses backslashes as a path separator, so be mindful.
+```cpp
+io.Fonts->AddFontFromFileTTF("MyFiles\MyImage01.jpg", ...);   // This is INCORRECT!!
+io.Fonts->AddFontFromFileTTF("MyFiles\\MyImage01.jpg", ...);  // This is CORRECT
+```
+In some situations, you may also use `/` path separator under Windows.
+
+(2) Make sure your IDE/debugger settings starts your executable from the right working (current) directory. In Visual Studio you can change your working directory in project `Properties > General > Debugging > Working Directory`. People assume that their execution will start from the root folder of the project, where by default it often starts from the folder where object or executable files are stored.
+```cpp
+io.Fonts->AddFontFromFileTTF("MyImage01.jpg", ...);       // Relative filename depends on your Working Directory when running your program!
+io.Fonts->AddFontFromFileTTF("../MyImage01.jpg", ...);    // Load from the parent folder of your Working Directory
+```
+##### [Return to Index](#index)
+
+
+## About UTF-8 Encoding
+
+**For non-ASCII characters display, a common user issue is not passing correctly UTF-8 encoded strings.**
+
+(1) We provide a function `ImGui::DebugTextEncoding(const char* text)` which you can call to verify the content of your UTF-8 strings.
+This is a convenient way to confirm that your encoding is correct.
+
+```cpp
+ImGui::SeparatorText("CORRECT");
+ImGui::DebugTextEncoding(u8"こんにちは");
+
+ImGui::SeparatorText("INCORRECT");
+ImGui::DebugTextEncoding("こんにちは");
+```
+![UTF-8 Encoding viewer](https://github.com/ocornut/imgui/assets/8225057/61c1696a-9a94-46c5-9627-cf91211111f0)
+
+You can also find this tool under `Metrics/Debuggers->Tools->UTF-8 Encoding viewer` if you want to paste from clipboard, but this won't validate the UTF-8 encoding done by your compiler.
+
+(2) To encode in UTF-8:
+
+There are also compiler-specific ways to enforce UTF-8 encoding by default:
+
+- Visual Studio compiler: `/utf-8` command-line flag.
+- Visual Studio compiler: `#pragma execution_character_set("utf-8")` inside your code.
+- Since May 2023 we have changed the Visual Studio projects of all our examples to use `/utf-8` ([see commit](https://github.com/ocornut/imgui/commit/513af1efc9080857bbd10000d98f98f2a0c96803)).
+
+Or, since C++11, you can use the `u8"my text"` syntax to encode literal strings as UTF-8. e.g.:
+```cpp
+ImGui::Text(u8"hello");
+ImGui::Text(u8"こんにちは");   // this will always be encoded as UTF-8
+ImGui::Text("こんにちは");     // the encoding of this is depending on compiler settings/flags and may be incorrect.
+```
+
+Since C++20, because the C++ committee hate its users, they decided to change the `u8""` syntax to not return `const char*` but a new type `const char_t*` which doesn't cast to `const char*`.
+Because of type usage of `u8""` in C++20 is a little more tedious:
+```cpp
+ImGui::Text((const char*)u8"こんにちは");
+```
+We suggest using a macro in your codebase:
+```cpp
+#define U8(_S)    (const char*)u8##_S
+ImGui::Text(U8("こんにちは"));
+```
+##### [Return to Index](#index)
+
+
+## Debug Tools
+
+#### Metrics/Debugger->Fonts
+You can use the `Metrics/Debugger` window (available in `Demo>Tools`) to browse your fonts and understand what's going on if you have an issue. You can also reach it in `Demo->Tools->Style Editor->Fonts`. The same information are also available in the Style Editor under Fonts.
 
 ![Fonts debugging](https://user-images.githubusercontent.com/8225057/135429892-0e41ef8d-33c5-4991-bcf6-f997a0bcfd6b.png)
 
-- You can use the `UTF-8 Encoding viewer` in `Metrics/Debugger` to verify the content of your UTF-8 strings. From C/C++ code, you can call `ImGui::DebugTextEncoding("my string");` function to verify that your UTF-8 encoding is correct.
+#### UTF-8 Encoding Viewer**
+You can use the `UTF-8 Encoding viewer` in `Metrics/Debugger` to verify the content of your UTF-8 strings. From C/C++ code, you can call `ImGui::DebugTextEncoding("my string");` function to verify that your UTF-8 encoding is correct.
 
 ![UTF-8 Encoding viewer](https://user-images.githubusercontent.com/8225057/166505963-8a0d7899-8ee8-4558-abb2-1ae523dc02f9.png)
 
-- All loaded fonts glyphs are rendered into a single texture atlas ahead of time. Calling either of `io.Fonts->GetTexDataAsAlpha8()`, `io.Fonts->GetTexDataAsRGBA32()` or `io.Fonts->Build()` will build the atlas.
-
-- Make sure your font ranges data are persistent (available during the calls to `GetTexDataAsAlpha8()`/`GetTexDataAsRGBA32()/`Build()`.
-
-- Use C++11 u8"my text" syntax to encode literal strings as UTF-8. e.g.:
-```cpp
-u8"hello"
-u8"こんにちは"   // this will be encoded as UTF-8
-```
-
 ##### [Return to Index](#index)
 
+
 ## How should I handle DPI in my application?
 
 See [FAQ entry](https://github.com/ocornut/imgui/blob/master/docs/FAQ.md#q-how-should-i-handle-dpi-in-my-application).
@@ -54,7 +131,7 @@ See [FAQ entry](https://github.com/ocornut/imgui/blob/master/docs/FAQ.md#q-how-s
 ##### [Return to Index](#index)
 
 
-## Font Loading Instructions
+## Fonts Loading Instructions
 
 **Load default font:**
 ```cpp
@@ -62,7 +139,6 @@ ImGuiIO& io = ImGui::GetIO();
 io.Fonts->AddFontDefault();
 ```
 
-
 **Load .TTF/.OTF file with:**
 ```cpp
 ImGuiIO& io = ImGui::GetIO();
@@ -70,7 +146,6 @@ io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels);
 ```
 If you get an assert stating "Could not load font file!", your font filename is likely incorrect. Read "[About filenames](#about-filenames)" carefully.
 
-
 **Load multiple fonts:**
 ```cpp
 // Init
@@ -86,7 +161,6 @@ ImGui::Text("Hello with another font");
 ImGui::PopFont();
 ```
 
-
 **For advanced options create a ImFontConfig structure and pass it to the AddFont() function (it will be copied internally):**
 ```cpp
 ImFontConfig config;
@@ -96,7 +170,6 @@ config.GlyphExtraSpacing.x = 1.0f;
 ImFont* font = io.Fonts->AddFontFromFileTTF("font.ttf", size_pixels, &config);
 ```
 
-
 **Combine multiple fonts into one:**
 ```cpp
 // Load a first font
@@ -311,28 +384,6 @@ ImFont* font = io.Fonts->AddFontFromMemoryCompressedBase85TTF(compressed_data_ba
 
 ##### [Return to Index](#index)
 
-## About filenames
-
-**Please note that many new C/C++ users have issues loading their files _because the filename they provide is wrong_.**
-
-Two things to watch for:
-- Make sure your IDE/debugger settings starts your executable from the right working directory. In Visual Studio you can change your working directory in project `Properties > General > Debugging > Working Directory`. People assume that their execution will start from the root folder of the project, where by default it often starts from the folder where object or executable files are stored.
-```cpp
-// Relative filename depends on your Working Directory when running your program!
-io.Fonts->AddFontFromFileTTF("MyImage01.jpg", ...);
-
-// Load from the parent folder of your Working Directory
-io.Fonts->AddFontFromFileTTF("../MyImage01.jpg", ...);
-```
-- In C/C++ and most programming languages if you want to use a backslash `\` within a string literal, you need to write it double backslash `\\`. At it happens, Windows uses backslashes as a path separator, so be mindful.
-```cpp
-io.Fonts->AddFontFromFileTTF("MyFiles\MyImage01.jpg", ...);   // This is INCORRECT!!
-io.Fonts->AddFontFromFileTTF("MyFiles\\MyImage01.jpg", ...);  // This is CORRECT
-```
-In some situations, you may also use `/` path separator under Windows.
-
-##### [Return to Index](#index)
-
 ## Credits/Licenses For Fonts Included In Repository
 
 Some fonts files are available in the `misc/fonts/` folder:

docs/README.md

@@ -39,7 +39,7 @@ Dear ImGui is particularly suited to integration in game engines (for tooling),
 
 ### Usage
 
-**The core of Dear ImGui is self-contained within a few platform-agnostic files** which you can easily compile in your application/engine. They are all the files in the root folder of the repository (imgui*.cpp, imgui*.h). **No specific build process is required**. You can add the .cpp files into your existing project.
+**The core of Dear ImGui is self-contained within a few platform-agnostic files** which you can easily compile in your application/engine. They are all the files in the root folder of the repository (imgui*.cpp, imgui*.h). **No specific build process is required**. You can add the .cpp files into your existing project. See [Getting Started](https://github.com/ocornut/imgui/wiki/Getting-Started).
 
 **Backends for a variety of graphics API and rendering platforms** are provided in the [backends/](https://github.com/ocornut/imgui/tree/master/backends) folder, along with example applications in the [examples/](https://github.com/ocornut/imgui/tree/master/examples) folder. See the [Integration](#integration) section of this document for details. You may also create your own backend. Anywhere where you can render textured triangles, you can render Dear ImGui.
 
@@ -92,7 +92,7 @@ Dear ImGui allows you to **create elaborate tools** as well as very short-lived
 
 ### How it works
 
-Check out the Wiki's [About the IMGUI paradigm](https://github.com/ocornut/imgui/wiki#about-the-imgui-paradigm) section if you want to understand the core principles behind the IMGUI paradigm. An IMGUI tries to minimize superfluous state duplication, state synchronization, and state retention from the user's point of view. It is less error-prone (less code and fewer bugs) than traditional retained-mode interfaces, and lends itself to creating dynamic user interfaces.
+The IMGUI paradigm through its API tries to minimize superfluous state duplication, state synchronization, and state retention from the user's point of view. It is less error-prone (less code and fewer bugs) than traditional retained-mode interfaces, and lends itself to creating dynamic user interfaces. Check out the Wiki's [About the IMGUI paradigm](https://github.com/ocornut/imgui/wiki#about-the-imgui-paradigm) section for more details.
 
 Dear ImGui outputs vertex buffers and command lists that you can easily render in your application. The number of draw calls and state changes required to render them is fairly small. Because Dear ImGui doesn't know or touch graphics state directly, you can call its functions  anywhere in your code (e.g. in the middle of a running algorithm, or in the middle of your own rendering process). Refer to the sample applications in the examples/ folder for instructions on how to integrate Dear ImGui with your existing codebase.
 
@@ -108,7 +108,7 @@ Reading the changelogs is a good way to keep up to date with the things Dear ImG
 Calling the `ImGui::ShowDemoWindow()` function will create a demo window showcasing a variety of features and examples. The code is always available for reference in `imgui_demo.cpp`. [Here's how the demo looks](https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v167/v167-misc.png).
 
 You should be able to build the examples from sources. If you don't, let us know! If you want to have a quick look at some Dear ImGui features, you can download Windows binaries of the demo app here:
-- [imgui-demo-binaries-20220504.zip](https://www.dearimgui.com/binaries/imgui-demo-binaries-20220504.zip) (Windows, 1.88 WIP, built 2022/05/04, master) or [older binaries](https://www.dearimgui.com/binaries).
+- [imgui-demo-binaries-20230704.zip](https://www.dearimgui.com/binaries/imgui-demo-binaries-20230704.zip) (Windows, 1.89.7, built 2023/07/04, master) or [older binaries](https://www.dearimgui.com/binaries).
 
 The demo applications are not DPI aware so expect some blurriness on a 4K screen. For DPI awareness in your application, you can load/reload your font at a different scale and scale your style with `style.ScaleAllSizes()` (see [FAQ](https://www.dearimgui.com/faq)).
 
@@ -116,11 +116,11 @@ The demo applications are not DPI aware so expect some blurriness on a 4K screen
 
 On most platforms and when using C++, **you should be able to use a combination of the [imgui_impl_xxxx](https://github.com/ocornut/imgui/tree/master/backends) backends without modification** (e.g. `imgui_impl_win32.cpp` + `imgui_impl_dx11.cpp`). If your engine supports multiple platforms, consider using more imgui_impl_xxxx files instead of rewriting them: this will be less work for you, and you can get Dear ImGui running immediately. You can _later_ decide to rewrite a custom backend using your custom engine functions if you wish so.
 
-Integrating Dear ImGui within your custom engine is a matter of 1) wiring mouse/keyboard/gamepad inputs 2) uploading a texture to your GPU/render engine 3) providing a render function that can bind textures and render textured triangles. The [examples/](https://github.com/ocornut/imgui/tree/master/examples) folder is populated with applications doing just that. If you are an experienced programmer at ease with those concepts, it should take you less than two hours to integrate Dear ImGui into your custom engine. **Make sure to spend time reading the [FAQ](https://www.dearimgui.com/faq), comments, and the examples applications!**
+See [Getting Started](https://github.com/ocornut/imgui/wiki/Getting-Started). Integrating Dear ImGui within your custom engine is a matter of 1) wiring mouse/keyboard/gamepad inputs 2) uploading a texture to your GPU/render engine 3) providing a render function that can bind textures and render textured triangles, which is essentially what Backends are doing. The [examples/](https://github.com/ocornut/imgui/tree/master/examples) folder is populated with applications doing just that: setting up a window and using backends. If you follow [Getting Started](https://github.com/ocornut/imgui/wiki/Getting-Started) it should in theory takes you less than an hour to integrate Dear ImGui.  **Make sure to spend time reading the [FAQ](https://www.dearimgui.com/faq), comments, and the examples applications!**
 
 Officially maintained backends/bindings (in repository):
 - Renderers: DirectX9, DirectX10, DirectX11, DirectX12, Metal, OpenGL/ES/ES2, SDL_Renderer, Vulkan, WebGPU.
-- Platforms: GLFW, SDL2, Win32, Glut, OSX, Android.
+- Platforms: GLFW, SDL2/SDL3, Win32, Glut, OSX, Android.
 - Frameworks: Allegro5, Emscripten.
 
 [Third-party backends/bindings](https://github.com/ocornut/imgui/wiki/Bindings) wiki page:
@@ -135,7 +135,7 @@ Also see [Wiki](https://github.com/ocornut/imgui/wiki) for more links and ideas.
 
 ### Gallery
 
-For more user-submitted screenshots of projects using Dear ImGui, check out the [Gallery Threads](https://github.com/ocornut/imgui/issues/5886)!
+For more user-submitted screenshots of projects using Dear ImGui, check out the [Gallery Threads](https://github.com/ocornut/imgui/issues/6478)!
 
 For a list of third-party widgets and extensions, check out the [Useful Extensions/Widgets](https://github.com/ocornut/imgui/wiki/Useful-Extensions) wiki page.
 
@@ -148,7 +148,7 @@ For a list of third-party widgets and extensions, check out the [Useful Extensio
 
 See: [Frequently Asked Questions (FAQ)](https://github.com/ocornut/imgui/blob/master/docs/FAQ.md) where common questions are answered.
 
-See: [Wiki](https://github.com/ocornut/imgui/wiki) for many links, references, articles.
+See: [Getting Started](https://github.com/ocornut/imgui/wiki/Getting-Started) and [Wiki](https://github.com/ocornut/imgui/wiki) for many links, references, articles.
 
 See: [Articles about the IMGUI paradigm](https://github.com/ocornut/imgui/wiki#about-the-imgui-paradigm) to read/learn about the Immediate Mode GUI paradigm.
 
@@ -162,11 +162,11 @@ Private support is available for paying business customers (E-mail: _contact @ d
 
 **Which version should I get?**
 
-We occasionally tag [Releases](https://github.com/ocornut/imgui/releases) (with nice releases notes) but it is generally safe and recommended to sync to master/latest. The library is fairly stable and regressions tend to be fixed fast when reported. Advanced users may want to use the `docking` branch with [Multi-Viewport](https://github.com/ocornut/imgui/issues/1542) and [Docking](https://github.com/ocornut/imgui/issues/2109) features. This branch is kept in sync with master regularly.
+We occasionally tag [Releases](https://github.com/ocornut/imgui/releases) (with nice releases notes) but it is generally safe and recommended to sync to latest `master` or `docking` branch. The library is fairly stable and regressions tend to be fixed fast when reported. Advanced users may want to use the `docking` branch with [Multi-Viewport](https://github.com/ocornut/imgui/issues/1542) and [Docking](https://github.com/ocornut/imgui/issues/2109) features. This branch is kept in sync with master regularly.
 
 **Who uses Dear ImGui?**
 
-See the [Quotes](https://github.com/ocornut/imgui/wiki/Quotes), [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors), and [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui) Wiki pages for an idea of who is using Dear ImGui. Please add your game/software if you can! Also, see the [Gallery Threads](https://github.com/ocornut/imgui/issues/5886)!
+See the [Quotes](https://github.com/ocornut/imgui/wiki/Quotes), [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors), and [Software using Dear ImGui](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui) Wiki pages for an idea of who is using Dear ImGui. Please add your game/software if you can! Also, see the [Gallery Threads](https://github.com/ocornut/imgui/issues/6478)!
 
 How to help
 -----------

docs/TODO.txt

@@ -2,12 +2,12 @@ dear imgui
 ISSUES & TODO LIST
 
 Issue numbers (#) refer to GitHub issues listed at https://github.com/ocornut/imgui/issues/XXXX
-This list is not well maintained, most of the work happens on GitHub nowadays.
+THIS LIST IS NOT WELL MAINTAINED. MOST OF THE WORK HAPPENS ON GITHUB NOWADAYS.
 The list below consist mostly of ideas noted down before they are requested/discussed by users (at which point they usually exist on the github issue tracker).
 It's mostly a bunch of personal notes, probably incomplete. Feel free to query if you have any questions.
 
- - doc/test: add a proper documentation+regression testing system (#435)
- - doc/test: checklist app to verify backends/integration of imgui (test inputs, rendering, callback, etc.).
+ - 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?
  - doc/wiki: work on the wiki https://github.com/ocornut/imgui/wiki
 
@@ -18,7 +18,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - window: begin with *p_open == false could return false.
  - window: get size/pos helpers given names (see discussion in #249)
  - window: when window is very small, prioritize resize button over close button.
- - window: double-clicking on title bar to minimize isn't consistent, perhaps move to single-click on left-most collapse icon?
+ - window: double-clicking on title bar to minimize isn't consistent interaction, perhaps move to single-click on left-most collapse icon?
  - window: expose contents size. (#1045)
  - 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)
@@ -31,29 +31,26 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - window/child: allow resizing of child windows (possibly given min/max for each axis?.)
  - window/child: allow SetNextWindowContentSize() to work on child windows.
  - window/clipping: some form of clipping when DisplaySize (or corresponding viewport) is zero.
- - window/tabbing: add a way to signify that a window or docked window requires attention (e.g. blinking title bar).
- - window/id_stack: add e.g. window->GetIDFromPath() with support for leading / and ../ (#1390, #331)
+ - window/tabbing: add a way to signify that a window or docked window requires attention (e.g. blinking title bar, trying to click behind a modal).
+ - window/id_stack: add e.g. window->GetIDFromPath() with support for leading / and ../ (#1390, #331) -> model from test engine.
  ! scrolling: exposing horizontal scrolling with Shift+Wheel even when scrollbar is disabled expose lots of issues (#2424, #1463)
  - scrolling: while holding down a scrollbar, try to keep the same contents visible (at least while not moving mouse)
  - scrolling: allow immediately effective change of scroll after Begin() if we haven't appended items yet.
  - scrolling: forward mouse wheel scrolling to parent window when at the edge of scrolling limits? (useful for listbox,tables?)
- - scrolling/clipping: separator on the initial position of a window is not visible (cursorpos.y <= clippos.y). (2017-08-20: can't repro)
  - scrolling/style: shadows on scrollable areas to denote that there is more contents (see e.g. DaVinci Resolve ui)
 
  - drawdata: make it easy to deep-copy (or swap?) a full ImDrawData so user can easily save that data if they use threaded rendering. (e.g. #2646)
  ! drawlist: add CalcTextSize() func to facilitate consistent code from user pov (currently need to use ImGui or ImFont alternatives!)
  - drawlist: maintaining bounding box per command would allow to merge draw command when clipping isn't relied on (typical non-scrolling window or non-overflowing column would merge with previous command). (WIP branch)
- - drawlist: primitives/helpers to manipulate vertices post submission, so e.g. a quad/rect can be resized to fit later submitted content, _without_ using the ChannelSplit api
  - drawlist: make it easier to toggle AA per primitive, so we can use e.g. non-AA fill + AA borders more naturally
  - drawlist: non-AA strokes have gaps between points (#593, #288), glitch especially on RenderCheckmark() and ColorPicker4().
- - drawlist: rendering: provide a way for imgui to output to a single/global vertex buffer, re-order indices only at the end of the frame (ref: https://gist.github.com/floooh/10388a0afbe08fce9e617d8aefa7d302)
  - drawlist: callback: add an extra void* in ImDrawCallback to allow passing render-local data to the callback (would break API).
  - drawlist: AddRect vs AddLine position confusing (#2441)
  - drawlist/opt: store rounded corners in texture to use 1 quad per corner (filled and wireframe) to lower the cost of rounding. (#1962)
  - drawlist/opt: AddRect() axis aligned pixel aligned (no-aa) could use 8 triangles instead of 16 and no normal calculation.
  - drawlist/opt: thick AA line could be doable in same number of triangles as 1.0 AA line by storing gradient+full color in atlas.
 
- - main: IsItemHovered() info stored in a stack? so that 'if TreeNode() { Text; TreePop; } if IsHovered' return the hover state of the TreeNode?
+ - items: IsItemHovered() info stored in a stack? so that 'if TreeNode() { Text; TreePop; } if IsHovered' return the hover state of the TreeNode?
 
  - widgets: display mode: widget-label, label-widget (aligned on column or using fixed size), label-newline-tab-widget etc. (#395)
  - widgets: clean up widgets internal toward exposing everything and stabilizing imgui_internals.h.
@@ -61,8 +58,7 @@ 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: a way to represent "mixed" values, so e.g. all values replaced with *, including check-boxes, colors, etc. with support for multi-components widgets (e.g. SliderFloat3, make only "Y" mixed) (#2644)
- - widgets: checkbox: checkbox with custom glyph inside frame.
+ - widgets: custom glyph/shapes replacements for stock sapes. (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.
@@ -81,7 +77,6 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - input text: option to Tab after an Enter validation.
  - input text: add ImGuiInputTextFlags_EnterToApply? (off #218)
  - input text: easier ways to update buffer (from source char*) while owned. preserve some sort of cursor position for multi-line text.
- - input text: add flag (e.g. ImGuiInputTextFlags_EscapeClearsBuffer) to clear instead of revert. what to do with focus? (also see #2890)
  - input text: add discard flag (e.g. ImGuiInputTextFlags_DiscardActiveBuffer) or make it easier to clear active focus for text replacement during edition (#725)
  - input text: display bug when clicking a drag/slider after an input text in a different window has all-selected text (order dependent). actually a very old bug but no one appears to have noticed it.
  - input text: allow centering/positioning text so that ctrl+clicking Drag or Slider keeps the textual value at the same pixel position.
@@ -116,20 +111,14 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - tables: see https://github.com/ocornut/imgui/issues/2957#issuecomment-569726095
 
  - group: BeginGroup() needs a border option. (~#1496)
- - group: IsHovered() after EndGroup() covers whole AABB rather than the intersection of individual items. Is that desirable?
+ - group: IsItemHovered() after EndGroup() covers whole AABB rather than the intersection of individual items. Is that desirable?
  - group: merge deactivation/activation within same group (fwd WasEdited flag). (#2550)
 
 !- color: the color conversion helpers/types are a mess and needs sorting out.
  - color: (api breaking) ImGui::ColorConvertXXX functions should be loose ImColorConvertXX to match imgui_internals.h
 
- - plot: full featured plot/graph api w/ scrolling, zooming etc. all bell & whistle. why not!
- - plot: PlotLines() should use the polygon-stroke facilities, less vertices (currently issues with averaging normals)
- - plot: make it easier for user to draw extra stuff into the graph (e.g: draw basis, highlight certain points, 2d plots, multiple plots)
- - plot: "smooth" automatic scale over time, user give an input 0.0(full user scale) 1.0(full derived from value)
- - plot: option/feature: draw the zero line
- - plot: option/feature: draw grid, vertical markers
- - plot: option/feature: draw unit
- - plot: add a helper e.g. Plot(char* label, float value, float time_span=2.0f) that stores values and Plot them for you - probably another function name. and/or automatically allow to plot ANY displayed value (more reliance on stable ID)
+ - plot: full featured plot/graph api w/ scrolling, zooming etc. --> ImPlot
+ - (plot: deleted all other todo lines on 2023-06-28)
 
  - clipper: ability to disable the clipping through a simple flag/bool.
  - clipper: ability to run without knowing full count in advance.
@@ -140,21 +129,44 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - separator: width, thickness, centering (#1643)
  - splitter: formalize the splitter idiom into an official api (we want to handle n-way split) (#319)
 
- - dock: 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.
  - tabs: persistent order/focus in BeginTabBar() api (#261, #351)
- - tabs: TabItem could honor SetNextItemWidth()?
  - tabs: explicit api (even if internal) to cleanly manipulate tab order.
- - tabs: Mouse wheel over tab bar could scroll? (with shift?) (#2702)
 
  - 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?
- - image button: not taking an explicit id can be problematic. (#2464, #1390)
- - slider/drag: ctrl+click when format doesn't include a % character.. disable? display underlying value in default format? (see TempInputTextScalar)
  - slider: allow using the [-]/[+] buttons used by InputFloat()/InputInt()
- - slider: initial absolute click is imprecise. change to relative movement slider (same as scrollbar). (#1946)
  - slider: add dragging-based widgets to edit values with mouse (on 2 axises), 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
@@ -167,7 +179,6 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - drag float: added leeway on edge (e.g. a few invisible steps past the clamp limits)
 
  - combo: use clipper.
- - combo: flag for BeginCombo to not return true when unchanged (#1182)
  - combo: a way/helper to customize the combo preview (#1658) -> experimental BeginComboPreview()
  - combo/listbox: keyboard control. need InputText-like non-active focus + key handling. considering keyboard for custom listbox (pr #203)
  - listbox: multiple selection (WIP range-select branch)
@@ -189,7 +200,6 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
 
  - tooltip: drag and drop with tooltip near monitor edges lose/changes its last direction instead of locking one. The drag and drop tooltip should always follow without changing direction.
  - tooltip: allow to set the width of a tooltip to allow TextWrapped() etc. while keeping the height automatic.
- - tooltip: tooltips with delay timers? or general timer policy? (instantaneous vs timed): IsItemHovered() with timer + implicit aabb-id for items with no ID. (#1485) (WIP branch)
  - tooltip: drag tooltip hovering over source widget with IsItemHovered/SetTooltip flickers (WIP branch)
 
  - status-bar: add a per-window status bar helper similar to what menu-bar does. generalize concept of layer0 rect in window (can make _MenuBar window flag obsolete too).
@@ -198,7 +208,6 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - shortcuts: programmatically access shortcuts "Focus("&Save"))
  - menus: menu-bar: main menu-bar could affect clamping of windows position (~ akin to modifying DisplayMin)
  - menus: hovering from menu to menu on a menu-bar has 1 frame without any menu, which is a little annoying. ideally either 0 either longer.
- - menus: could merge draw call in most cases (how about storing an optional aabb in ImDrawCmd to move the burden of merging in a single spot).
  - menus: would be nice if the Selectable() supported horizontal alignment (must be given the equivalent of WorkRect.Max.x matching the position of the shortcut column)
 
  - tree node: add treenode/treepush int variants? not there because (void*) cast from int warns on some platforms/settings?
@@ -244,7 +253,6 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - drag and drop: drag source on a group object (would need e.g. an invisible button covering group in EndGroup) https://twitter.com/paniq/status/1121446364909535233
  - drag and drop: have some way to know when a drag begin from BeginDragDropSource() pov. (see 2018/01/11 post in #143)
  - drag and drop: allow preview tooltip to be submitted from a different place than the drag source. (#1725)
- - drag and drop: allow using with other mouse buttons (where activeid won't be set). (#1637)
  - drag and drop: make it easier and provide a demo to have tooltip both are source and target site, with a more detailed one on target site (tooltip ordering problem)
  - drag and drop: demo with reordering nodes (in a list, or a tree node). (#143)
  - drag and drop: test integrating with os drag and drop (make it easy to do a naive WM_DROPFILE integration)
@@ -296,10 +304,10 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - font/opt: Considering storing standalone AdvanceX table as 16-bit fixed point integer?
  - font/opt: Glyph currently 40 bytes (2+9*4). Consider storing UV as 16-bits integer? (->32 bytes). X0/Y0/X1/Y1 as 16 fixed-point integers? Or X0/Y0 as float and X1/Y1 as fixed8_8?
 
+ - nav: visual feedback on button press.
  - nav: some features such as PageUp/Down/Home/End should probably work without ImGuiConfigFlags_NavEnableKeyboard? (where do we draw the line? how about CTRL+Tab)
  ! nav: never clear NavId on some setup (e.g. gamepad centric)
  - nav: there's currently no way to completely clear focus with the keyboard. depending on patterns used by the application to dispatch inputs, it may be desirable.
- - nav: code to focus child-window on restoring NavId appears to have issue: e.g. when focus change is implicit because of window closure.
  - nav: Home/End behavior when navigable item is not fully visible at the edge of scrolling? should be backtrack to keep item into view?
  - nav: NavScrollToBringItemIntoView() with item bigger than view should focus top-right? Repro: using Nav in "About Window"
  - nav: wrap around 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().
@@ -320,12 +328,24 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - nav/menus: when using the main menu bar, even though we restore focus after, the underlying window loses its title bar highlight during menu manipulation. could we prevent it?
  - nav/menus: main menu bar currently cannot restore a nullptr focus. Could save NavWindow at the time of being focused, similarly to what popup do?
  - nav/menus: Alt,Up could open the first menu (e.g. "File") currently it tends to nav into the window/collapse menu. Do do that we would need custom transition?
- - nav/windowing: configure fade-in/fade-out delay on Ctrl+Tab?
  - nav/windowing: when CTRL+Tab/windowing is active, the HoveredWindow detection doesn't take account of the window display re-ordering.
  - 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)
 
- - inputs: we need an explicit flag about whether the platform window is focused, to be able to distinguish focused key releases vs alt-tabbing all release behaviors.
+ - 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)
@@ -351,7 +371,6 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - examples: provide a zero frame-rate/idle example.
  - examples: dx11/dx12: try to use new swapchain blit models (#2970)
  - backends: report it better when not able to create texture?
- - backends: apple: example_apple should be using modern GL3.
  - backends: glfw: could go idle when minimized? if (glfwGetWindowAttrib(window, GLFW_ICONIFIED)) { glfwWaitEvents(); continue; } // issue: DeltaTime will be super high on resume, perhaps provide a way to let impl know (#440)
  - backends: opengl: rename imgui_impl_opengl2 to impl_opengl_legacy and imgui_impl_opengl3 to imgui_impl_opengl? (#1900)
  - backends: opengl: could use a single vertex buffer and glBufferSubData for uploads?

examples/example_allegro5/README.md

@@ -32,5 +32,5 @@ vcpkg integrate install						    ; register include / libs in Visual Studio
 Build:
 ```
 set ALLEGRODIR=path_to_your_allegro5_folder
-cl /Zi /MD /I %ALLEGRODIR%\include /DIMGUI_USER_CONFIG=\"examples/example_allegro5/imconfig_allegro5.h\" /I .. /I ..\.. /I ..\..\backends main.cpp ..\..\backends\imgui_impl_allegro5.cpp ..\..\imgui*.cpp /link /LIBPATH:%ALLEGRODIR%\lib allegro-5.0.10-monolith-md.lib user32.lib
+cl /Zi /MD /utf-8 /I %ALLEGRODIR%\include /DIMGUI_USER_CONFIG=\"examples/example_allegro5/imconfig_allegro5.h\" /I .. /I ..\.. /I ..\..\backends main.cpp ..\..\backends\imgui_impl_allegro5.cpp ..\..\imgui*.cpp /link /LIBPATH:%ALLEGRODIR%\lib allegro-5.0.10-monolith-md.lib user32.lib
 ```

examples/example_allegro5/example_allegro5.vcxproj

@@ -91,6 +91,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -105,6 +106,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -122,6 +124,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -142,6 +145,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_allegro5/main.cpp

@@ -36,6 +36,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;      // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();

examples/example_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

@@ -56,11 +56,21 @@
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Renderer backend
     ImGui_ImplMetal_Init(_device);
 
@@ -191,6 +201,13 @@
 	// Present
     [commandBuffer presentDrawable:view.currentDrawable];
     [commandBuffer commit];
+
+    // Update and Render additional Platform Windows
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
 }
 
 -(void)mtkView:(MTKView*)view drawableSizeWillChange:(CGSize)size

examples/example_apple_opengl2/main.mm

@@ -43,11 +43,21 @@
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplOSX_Init(self);
     ImGui_ImplOpenGL2_Init();
@@ -132,6 +142,13 @@
 
     ImGui_ImplOpenGL2_RenderDrawData(draw_data);
 
+    // Update and Render additional Platform Windows
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        ImGui::UpdatePlatformWindows();
+        ImGui::RenderPlatformWindowsDefault();
+    }
+
     // Present
     [[self openGLContext] flushBuffer];
 

examples/example_glfw_metal/main.mm

@@ -29,11 +29,21 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;      // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;    // Enable Multi-Viewport / Platform Windows
 
     // Setup style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
@@ -65,7 +75,7 @@ int main(int, char**)
     id <MTLCommandQueue> commandQueue = [device newCommandQueue];
 
     // Setup Platform/Renderer backends
-    ImGui_ImplGlfw_InitForOpenGL(window, true);
+    ImGui_ImplGlfw_InitForOther(window, true);
     ImGui_ImplMetal_Init(device);
 
     NSWindow *nswin = glfwGetCocoaWindow(window);
@@ -153,6 +163,13 @@ int main(int, char**)
             ImGui::Render();
             ImGui_ImplMetal_RenderDrawData(ImGui::GetDrawData(), commandBuffer, renderEncoder);
 
+            // Update and Render additional Platform Windows
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                ImGui::UpdatePlatformWindows();
+                ImGui::RenderPlatformWindowsDefault();
+            }
+
             [renderEncoder popDebugGroup];
             [renderEncoder endEncoding];
 

examples/example_glfw_opengl2/build_win32.bat

@@ -5,4 +5,4 @@
 @set SOURCES=main.cpp ..\..\backends\imgui_impl_opengl2.cpp ..\..\backends\imgui_impl_glfw.cpp ..\..\imgui*.cpp
 @set LIBS=/LIBPATH:..\libs\glfw\lib-vc2010-32 glfw3.lib opengl32.lib gdi32.lib shell32.lib
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%
+cl /nologo /Zi /MD /utf-8 %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%

examples/example_glfw_opengl2/example_glfw_opengl2.vcxproj

@@ -91,6 +91,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -105,6 +106,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -122,6 +124,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -142,6 +145,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_glfw_opengl2/main.cpp

@@ -48,11 +48,23 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplGlfw_InitForOpenGL(window, true);
     ImGui_ImplOpenGL2_Init();
@@ -146,6 +158,17 @@ int main(int, char**)
         ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
         //glUseProgram(last_program);
 
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            GLFWwindow* backup_current_context = glfwGetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            glfwMakeContextCurrent(backup_current_context);
+        }
+
         glfwMakeContextCurrent(window);
         glfwSwapBuffers(window);
     }

examples/example_glfw_opengl3/build_win32.bat

@@ -5,4 +5,4 @@
 @set SOURCES=main.cpp ..\..\backends\imgui_impl_glfw.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp
 @set LIBS=/LIBPATH:..\libs\glfw\lib-vc2010-32 glfw3.lib opengl32.lib gdi32.lib shell32.lib
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%
+cl /nologo /Zi /MD /utf-8 %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%

examples/example_glfw_opengl3/example_glfw_opengl3.vcxproj

@@ -91,6 +91,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -105,6 +106,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -122,6 +124,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -142,6 +145,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_glfw_opengl3/main.cpp

@@ -73,11 +73,23 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplGlfw_InitForOpenGL(window, true);
     ImGui_ImplOpenGL3_Init(glsl_version);
@@ -172,6 +184,17 @@ int main(int, char**)
         glClear(GL_COLOR_BUFFER_BIT);
         ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            GLFWwindow* backup_current_context = glfwGetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            glfwMakeContextCurrent(backup_current_context);
+        }
+
         glfwSwapBuffers(window);
     }
 #ifdef __EMSCRIPTEN__

examples/example_glfw_vulkan/build_win32.bat

@@ -7,8 +7,8 @@
 
 @set OUT_DIR=Debug
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% /D ImTextureID=ImU64 %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%
+cl /nologo /Zi /MD /utf-8 %INCLUDES% /D ImTextureID=ImU64 %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%
 
 @set OUT_DIR=Release
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD /Ox /Oi %INCLUDES% /D ImTextureID=ImU64 %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%
+cl /nologo /Zi /MD /utf-8 /Ox /Oi %INCLUDES% /D ImTextureID=ImU64 %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%

examples/example_glfw_vulkan/build_win64.bat

@@ -6,8 +6,8 @@
 
 @set OUT_DIR=Debug
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% /D ImTextureID=ImU64 %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%
+cl /nologo /Zi /MD /utf-8 %INCLUDES% /D ImTextureID=ImU64 %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%
 
 @set OUT_DIR=Release
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD /Ox /Oi %INCLUDES% /D ImTextureID=ImU64 %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%
+cl /nologo /Zi /MD /utf-8 /Ox /Oi %INCLUDES% /D ImTextureID=ImU64 %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%

examples/example_glfw_vulkan/example_glfw_vulkan.vcxproj

@@ -92,6 +92,7 @@
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%VULKAN_SDK%\include;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>ImTextureID=ImU64;_MBCS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -107,6 +108,7 @@
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%VULKAN_SDK%\include;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>ImTextureID=ImU64;_MBCS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -125,6 +127,7 @@
       <AdditionalIncludeDirectories>..\..;..\..\backends;%VULKAN_SDK%\include;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
       <PreprocessorDefinitions>ImTextureID=ImU64;_MBCS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -146,6 +149,7 @@
       <AdditionalIncludeDirectories>..\..;..\..\backends;%VULKAN_SDK%\include;..\libs\glfw\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
       <PreprocessorDefinitions>ImTextureID=ImU64;_MBCS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_glfw_vulkan/main.cpp

@@ -99,6 +99,10 @@ static VkPhysicalDevice SetupVulkan_SelectPhysicalDevice()
         if (properties.deviceType == VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU)
             return device;
     }
+
+    // Use first GPU (Integrated) is a Discrete one is not available.
+    if (gpu_count > 0)
+        return gpus[0];
     return VK_NULL_HANDLE;
 }
 
@@ -419,11 +423,23 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplGlfw_InitForVulkan(window, true);
     ImGui_ImplVulkan_InitInfo init_info = {};
@@ -561,17 +577,25 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
-        ImDrawData* draw_data = ImGui::GetDrawData();
-        const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
-        if (!is_minimized)
+        ImDrawData* main_draw_data = ImGui::GetDrawData();
+        const bool main_is_minimized = (main_draw_data->DisplaySize.x <= 0.0f || main_draw_data->DisplaySize.y <= 0.0f);
+        wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
+        wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
+        wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
+        wd->ClearValue.color.float32[3] = clear_color.w;
+        if (!main_is_minimized)
+            FrameRender(wd, main_draw_data);
+
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
         {
-            wd->ClearValue.color.float32[0] = clear_color.x * clear_color.w;
-            wd->ClearValue.color.float32[1] = clear_color.y * clear_color.w;
-            wd->ClearValue.color.float32[2] = clear_color.z * clear_color.w;
-            wd->ClearValue.color.float32[3] = clear_color.w;
-            FrameRender(wd, draw_data);
-            FramePresent(wd);
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
         }
+
+        // Present Main Platform Window
+        if (!main_is_minimized)
+            FramePresent(wd);
     }
 
     // Cleanup

examples/example_glut_opengl2/example_glut_opengl2.vcxproj

@@ -91,6 +91,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>$(GLUT_INCLUDE_DIR);..\..;..\..\backends;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -105,6 +106,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>$(GLUT_INCLUDE_DIR);..\..;..\..\backends;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -122,6 +124,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>$(GLUT_INCLUDE_DIR);..\..;..\..\backends;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -142,6 +145,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>$(GLUT_INCLUDE_DIR);..\..;..\..\backends;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_glut_opengl2/main.cpp

@@ -57,6 +57,7 @@ int main(int argc, char** argv)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
@@ -74,7 +75,6 @@ int main(int argc, char** argv)
     // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
     ImGui_ImplGLUT_InstallFuncs();
 
-
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
@@ -107,6 +107,8 @@ void MainLoopStep()
     // Start the Dear ImGui frame
     ImGui_ImplOpenGL2_NewFrame();
     ImGui_ImplGLUT_NewFrame();
+    ImGui::NewFrame();
+    ImGuiIO& io = ImGui::GetIO();
 
     // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
     if (show_demo_window)
@@ -147,7 +149,6 @@ void MainLoopStep()
 
     // Rendering
     ImGui::Render();
-    ImGuiIO& io = ImGui::GetIO();
     glViewport(0, 0, (GLsizei)io.DisplaySize.x, (GLsizei)io.DisplaySize.y);
     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);

examples/example_null/build_win32.bat

@@ -1,3 +1,3 @@
 @REM Build for Visual Studio compiler. Run your copy of vcvars32.bat or vcvarsall.bat to setup command-line compiler.
 mkdir Debug
-cl /nologo /Zi /MD /I ..\.. %* *.cpp ..\..\*.cpp /FeDebug/example_null.exe /FoDebug/ /link gdi32.lib shell32.lib imm32.lib
+cl /nologo /Zi /MD /utf-8 /I ..\.. %* *.cpp ..\..\*.cpp /FeDebug/example_null.exe /FoDebug/ /link gdi32.lib shell32.lib imm32.lib

examples/example_sdl2_directx11/build_win32.bat

@@ -5,4 +5,4 @@
 @set SOURCES=main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_dx11.cpp ..\..\imgui*.cpp
 @set LIBS=/LIBPATH:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib /LIBPATH:"%DXSDK_DIR%/Lib/x86" d3d11.lib d3dcompiler.lib shell32.lib
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console
+cl /nologo /Zi /MD /utf-8 %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console

examples/example_sdl2_directx11/example_sdl2_directx11.vcxproj

@@ -92,6 +92,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -106,6 +107,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -123,6 +125,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -143,6 +146,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_sdl2_directx11/main.cpp

@@ -61,11 +61,23 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForD3D(window);
     ImGui_ImplDX11_Init(g_pd3dDevice, g_pd3dDeviceContext);
@@ -166,6 +178,13 @@ int main(int, char**)
         g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         g_pSwapChain->Present(1, 0); // Present with vsync
         //g_pSwapChain->Present(0, 0); // Present without vsync
     }

examples/example_sdl2_metal/main.mm

@@ -20,11 +20,21 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;      // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;    // Enable Multi-Viewport / Platform Windows
 
     // Setup style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
@@ -164,6 +174,13 @@ int main(int, char**)
             ImGui::Render();
             ImGui_ImplMetal_RenderDrawData(ImGui::GetDrawData(), commandBuffer, renderEncoder);
 
+            // Update and Render additional Platform Windows
+            if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+            {
+                ImGui::UpdatePlatformWindows();
+                ImGui::RenderPlatformWindowsDefault();
+            }
+
             [renderEncoder popDebugGroup];
             [renderEncoder endEncoding];
 

examples/example_sdl2_opengl2/build_win32.bat

@@ -5,4 +5,4 @@
 @set SOURCES=main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_opengl2.cpp ..\..\imgui*.cpp
 @set LIBS=/LIBPATH:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib opengl32.lib shell32.lib
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console
+cl /nologo /Zi /MD /utf-8 %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console

examples/example_sdl2_opengl2/example_sdl2_opengl2.vcxproj

@@ -91,6 +91,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -105,6 +106,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -122,6 +124,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -142,6 +145,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_sdl2_opengl2/main.cpp

@@ -47,11 +47,23 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
     ImGui_ImplOpenGL2_Init();
@@ -145,6 +157,19 @@ int main(int, char**)
         glClear(GL_COLOR_BUFFER_BIT);
         //glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context where shaders may be bound
         ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
+
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
+            SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
+        }
+
         SDL_GL_SwapWindow(window);
     }
 

examples/example_sdl2_opengl3/README.md

@@ -10,10 +10,10 @@ Use the provided project file (.vcxproj). Add to solution (imgui_examples.sln) i
 Use build_win32.bat or directly:
 ```
 set SDL2_DIR=path_to_your_sdl2_folder
-cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl2_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib opengl32.lib /subsystem:console
-#          ^^ include paths                  ^^ source files                                                                                    ^^ output exe                    ^^ output dir   ^^ libraries
+cl /Zi /MD /utf-8 /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl2_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib opengl32.lib /subsystem:console
+#                 ^^ include paths                  ^^ source files                                                                                    ^^ output exe                    ^^ output dir   ^^ libraries
 # or for 64-bit:
-cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl2_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x64 SDL2.lib SDL2main.lib opengl32.lib /subsystem:console
+cl /Zi /MD /utf-8 /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl2_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x64 SDL2.lib SDL2main.lib opengl32.lib /subsystem:console
 ```
 
 ## Linux and similar Unixes

examples/example_sdl2_opengl3/build_win32.bat

@@ -5,4 +5,4 @@
 @set SOURCES=main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp
 @set LIBS=/LIBPATH:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib opengl32.lib shell32.lib
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console
+cl /nologo /Zi /MD /utf-8 %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console

examples/example_sdl2_opengl3/example_sdl2_opengl3.vcxproj

@@ -91,6 +91,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -105,6 +106,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -122,6 +124,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -142,6 +145,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_sdl2_opengl3/main.cpp

@@ -74,11 +74,23 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
     ImGui_ImplOpenGL3_Init(glsl_version);
@@ -179,6 +191,19 @@ int main(int, char**)
         glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
         glClear(GL_COLOR_BUFFER_BIT);
         ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
+            SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
+        }
+
         SDL_GL_SwapWindow(window);
     }
 #ifdef __EMSCRIPTEN__

examples/example_sdl2_sdlrenderer/README.md

@@ -1,25 +0,0 @@
-
-# How to Build
-
-- On Windows with Visual Studio's CLI
-
-```
-set SDL2_DIR=path_to_your_sdl2_folder
-cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_sdlrenderer.cpp ..\..\imgui*.cpp /FeDebug/example_sdl2_sdlrenderer.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib /subsystem:console
-#          ^^ include paths                  ^^ source files                                                                                         ^^ output exe                         ^^ output dir  ^^ libraries
-# or for 64-bit:
-cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_sdlrenderer.cpp ..\..\imgui*.cpp /FeDebug/example_sdl2_sdlrenderer.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x64 SDL2.lib SDL2main.lib /subsystem:console
-```
-
-- On Linux and similar Unixes
-
-```
-c++ `sdl2-config --cflags` -I .. -I ../.. main.cpp ../../backends/imgui_impl_sdl2.cpp ../../backends/imgui_impl_sdlrenderer.cpp ../../imgui*.cpp `sdl2-config --libs` -lGL
-```
-
-- On Mac OS X
-
-```
-brew install sdl2
-c++ `sdl2-config --cflags` -I .. -I ../.. main.cpp ../../backends/imgui_impl_sdl2.cpp ../../backends/imgui_impl_sdlrenderer.cpp ../../imgui*.cpp `sdl2-config --libs` -framework OpenGl
-```

examples/example_sdl2_sdlrenderer2/Makefile

@@ -14,11 +14,11 @@
 #CXX = g++
 #CXX = clang++
 
-EXE = example_sdl2_sdlrenderer
+EXE = example_sdl2_sdlrenderer2
 IMGUI_DIR = ../..
 SOURCES = main.cpp
 SOURCES += $(IMGUI_DIR)/imgui.cpp $(IMGUI_DIR)/imgui_demo.cpp $(IMGUI_DIR)/imgui_draw.cpp $(IMGUI_DIR)/imgui_tables.cpp $(IMGUI_DIR)/imgui_widgets.cpp
-SOURCES += $(IMGUI_DIR)/backends/imgui_impl_sdl2.cpp $(IMGUI_DIR)/backends/imgui_impl_sdlrenderer.cpp
+SOURCES += $(IMGUI_DIR)/backends/imgui_impl_sdl2.cpp $(IMGUI_DIR)/backends/imgui_impl_sdlrenderer2.cpp
 OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES))))
 UNAME_S := $(shell uname -s)
 

examples/example_sdl2_sdlrenderer2/README.md

@@ -0,0 +1,25 @@
+
+# How to Build
+
+- On Windows with Visual Studio's CLI
+
+```
+set SDL2_DIR=path_to_your_sdl2_folder
+cl /Zi /MD /utf-8 /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_sdlrenderer2.cpp ..\..\imgui*.cpp /FeDebug/example_sdl2_sdlrenderer.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib /subsystem:console
+#                 ^^ include paths                  ^^ source files                                                                                         ^^ output exe                         ^^ output dir  ^^ libraries
+# or for 64-bit:
+cl /Zi /MD /utf-8 /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_sdlrenderer2.cpp ..\..\imgui*.cpp /FeDebug/example_sdl2_sdlrenderer.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x64 SDL2.lib SDL2main.lib /subsystem:console
+```
+
+- On Linux and similar Unixes
+
+```
+c++ `sdl2-config --cflags` -I .. -I ../.. main.cpp ../../backends/imgui_impl_sdl2.cpp ../../backends/imgui_impl_sdlrenderer2.cpp ../../imgui*.cpp `sdl2-config --libs` -lGL
+```
+
+- On Mac OS X
+
+```
+brew install sdl2
+c++ `sdl2-config --cflags` -I .. -I ../.. main.cpp ../../backends/imgui_impl_sdl2.cpp ../../backends/imgui_impl_sdlrenderer2.cpp ../../imgui*.cpp `sdl2-config --libs` -framework OpenGl
+```

examples/example_sdl2_sdlrenderer2/build_win32.bat

@@ -2,7 +2,7 @@
 @set OUT_DIR=Debug
 @set OUT_EXE=example_sdl2_sdlrenderer_
 @set INCLUDES=/I..\.. /I..\..\backends /I%SDL2_DIR%\include
-@set SOURCES=main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_sdlrenderer.cpp ..\..\imgui*.cpp
-@set LIBS=/LIBPATH:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib 
+@set SOURCES=main.cpp ..\..\backends\imgui_impl_sdl2.cpp ..\..\backends\imgui_impl_sdlrenderer2.cpp ..\..\imgui*.cpp
+@set LIBS=/LIBPATH:%SDL2_DIR%\lib\x86 SDL2.lib SDL2main.lib
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console
+cl /nologo /Zi /MD /utf-8 %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console

examples/example_sdl2_sdlrenderer2/example_sdl2_sdlrenderer2.vcxproj

@@ -20,8 +20,9 @@
   </ItemGroup>
   <PropertyGroup Label="Globals">
     <ProjectGuid>{0C0B2BEA-311F-473C-9652-87923EF639E3}</ProjectGuid>
-    <RootNamespace>example_sdl2_sdlrenderer</RootNamespace>
+    <RootNamespace>example_sdl2_sdlrenderer2</RootNamespace>
     <WindowsTargetPlatformVersion>8.1</WindowsTargetPlatformVersion>
+    <ProjectName>example_sdl2_sdlrenderer2</ProjectName>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
@@ -91,6 +92,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -105,6 +107,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -122,6 +125,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -142,6 +146,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL2_DIR%\include;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -161,7 +166,7 @@
     <ClCompile Include="..\..\imgui_tables.cpp" />
     <ClCompile Include="..\..\imgui_widgets.cpp" />
     <ClCompile Include="..\..\backends\imgui_impl_sdl2.cpp" />
-    <ClCompile Include="..\..\backends\imgui_impl_sdlrenderer.cpp" />
+    <ClCompile Include="..\..\backends\imgui_impl_sdlrenderer2.cpp" />
     <ClCompile Include="main.cpp" />
   </ItemGroup>
   <ItemGroup>
@@ -169,7 +174,7 @@
     <ClInclude Include="..\..\imgui.h" />
     <ClInclude Include="..\..\imgui_internal.h" />
     <ClInclude Include="..\..\backends\imgui_impl_sdl2.h" />
-    <ClInclude Include="..\..\backends\imgui_impl_sdlrenderer.h" />
+    <ClInclude Include="..\..\backends\imgui_impl_sdlrenderer2.h" />
   </ItemGroup>
   <ItemGroup>
     <None Include="..\..\misc\debuggers\imgui.natstepfilter" />
@@ -179,4 +184,4 @@
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
   </ImportGroup>
-</Project>
+</Project>

examples/example_sdl2_sdlrenderer2/example_sdl2_sdlrenderer2.vcxproj.filters

@@ -31,7 +31,7 @@
     <ClCompile Include="..\..\backends\imgui_impl_sdl2.cpp">
       <Filter>sources</Filter>
     </ClCompile>
-    <ClCompile Include="..\..\backends\imgui_impl_sdlrenderer.cpp">
+    <ClCompile Include="..\..\backends\imgui_impl_sdlrenderer2.cpp">
       <Filter>sources</Filter>
     </ClCompile>
   </ItemGroup>
@@ -45,7 +45,7 @@
     <ClInclude Include="..\..\imgui_internal.h">
       <Filter>imgui</Filter>
     </ClInclude>
-    <ClInclude Include="..\..\backends\imgui_impl_sdlrenderer.h">
+    <ClInclude Include="..\..\backends\imgui_impl_sdlrenderer2.h">
       <Filter>sources</Filter>
     </ClInclude>
     <ClInclude Include="..\..\backends\imgui_impl_sdl2.h">
@@ -61,4 +61,4 @@
       <Filter>imgui</Filter>
     </None>
   </ItemGroup>
-</Project>
+</Project>

examples/example_sdl2_sdlrenderer2/main.cpp

@@ -3,13 +3,12 @@
 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
 // Read online: https://github.com/ocornut/imgui/tree/master/docs
 
-// Important to understand: SDL_Renderer is an _optional_ component of SDL. We do not recommend you use SDL_Renderer
-// because it provides a rather limited API to the end-user. We provide this backend for the sake of completeness.
+// Important to understand: SDL_Renderer is an _optional_ component of SDL2.
 // For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.
 
 #include "imgui.h"
 #include "imgui_impl_sdl2.h"
-#include "imgui_impl_sdlrenderer.h"
+#include "imgui_impl_sdlrenderer2.h"
 #include <stdio.h>
 #include <SDL.h>
 
@@ -58,7 +57,7 @@ int main(int, char**)
 
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForSDLRenderer(window, renderer);
-    ImGui_ImplSDLRenderer_Init(renderer);
+    ImGui_ImplSDLRenderer2_Init(renderer);
 
     // 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.
@@ -101,7 +100,7 @@ int main(int, char**)
         }
 
         // Start the Dear ImGui frame
-        ImGui_ImplSDLRenderer_NewFrame();
+        ImGui_ImplSDLRenderer2_NewFrame();
         ImGui_ImplSDL2_NewFrame();
         ImGui::NewFrame();
 
@@ -147,12 +146,12 @@ int main(int, char**)
         SDL_RenderSetScale(renderer, io.DisplayFramebufferScale.x, io.DisplayFramebufferScale.y);
         SDL_SetRenderDrawColor(renderer, (Uint8)(clear_color.x * 255), (Uint8)(clear_color.y * 255), (Uint8)(clear_color.z * 255), (Uint8)(clear_color.w * 255));
         SDL_RenderClear(renderer);
-        ImGui_ImplSDLRenderer_RenderDrawData(ImGui::GetDrawData());
+        ImGui_ImplSDLRenderer2_RenderDrawData(ImGui::GetDrawData());
         SDL_RenderPresent(renderer);
     }
 
     // Cleanup
-    ImGui_ImplSDLRenderer_Shutdown();
+    ImGui_ImplSDLRenderer2_Shutdown();
     ImGui_ImplSDL2_Shutdown();
     ImGui::DestroyContext();
 

examples/example_sdl2_vulkan/build_win32.bat

@@ -7,4 +7,4 @@
 
 @set OUT_DIR=Debug
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% /D ImTextureID=ImU64 %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console
+cl /nologo /Zi /MD /utf-8 %INCLUDES% /D ImTextureID=ImU64 %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console

examples/example_sdl2_vulkan/example_sdl2_vulkan.vcxproj

@@ -92,6 +92,7 @@
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%VULKAN_SDK%\include;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>ImTextureID=ImU64;_MBCS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -107,6 +108,7 @@
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%VULKAN_SDK%\include;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <PreprocessorDefinitions>ImTextureID=ImU64;_MBCS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -125,6 +127,7 @@
       <AdditionalIncludeDirectories>..\..;..\..\backends;%VULKAN_SDK%\include;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
       <PreprocessorDefinitions>ImTextureID=ImU64;_MBCS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -146,6 +149,7 @@
       <AdditionalIncludeDirectories>..\..;..\..\backends;%VULKAN_SDK%\include;%SDL2_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL2;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
       <PreprocessorDefinitions>ImTextureID=ImU64;_MBCS;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_sdl2_vulkan/main.cpp

@@ -87,6 +87,10 @@ static VkPhysicalDevice SetupVulkan_SelectPhysicalDevice()
         if (properties.deviceType == VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU)
             return device;
     }
+
+    // Use first GPU (Integrated) is a Discrete one is not available.
+    if (gpu_count > 0)
+        return gpus[0];
     return VK_NULL_HANDLE;
 }
 
@@ -414,11 +418,23 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
+    //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForVulkan(window);
     ImGui_ImplVulkan_InitInfo init_info = {};
@@ -565,17 +581,25 @@ 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.emscripten

@@ -1,3 +1,7 @@
+
+# IMPORTANT: SDL3 IS IN DEVELOPMENT, AS OF 2023-05-30, EMSCRIPTEN DOESN'T SUPPORT SDL3 YET.
+# WE ARE LEAVING THIS MAKEFILE AROUND FOR THE DAY IT WILL SUPPORT IT.
+
 #
 # Makefile to use with SDL+emscripten
 # See https://emscripten.org/docs/getting_started/downloads.html

examples/example_sdl3_opengl3/README.md

@@ -10,10 +10,10 @@ Use the provided project file (.vcxproj). Add to solution (imgui_examples.sln) i
 Use build_win32.bat or directly:
 ```
 set SDL2_DIR=path_to_your_sdl3_folder
-cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl3.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl3_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x86 SDL3.lib opengl32.lib /subsystem:console
-#          ^^ include paths     ^^ source files                                                                                    ^^ output exe                    ^^ output dir   ^^ libraries
+cl /Zi /MD /utf-8 /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl3.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl3_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x86 SDL3.lib opengl32.lib /subsystem:console
+#                 ^^ include paths     ^^ source files                                                                                    ^^ output exe                    ^^ output dir   ^^ libraries
 # or for 64-bit:
-cl /Zi /MD /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl3.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl3_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x64 SDL3.lib SDL2mainopengl32.lib /subsystem:console
+cl /Zi /MD /utf-8 /I.. /I..\.. /I%SDL2_DIR%\include main.cpp ..\..\backends\imgui_impl_sdl3.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp /FeDebug/example_sdl3_opengl3.exe /FoDebug/ /link /libpath:%SDL2_DIR%\lib\x64 SDL3.lib SDL2mainopengl32.lib /subsystem:console
 ```
 
 ## Linux and similar Unixes
@@ -37,21 +37,4 @@ c++ `sdl3-config --cflags` -I .. -I ../.. -I ../../backends
 
 ## Emscripten
 
-**Building**
-
-You need to install Emscripten from https://emscripten.org/docs/getting_started/downloads.html, and have the environment variables set, as described in https://emscripten.org/docs/getting_started/downloads.html#installation-instructions
-
-- Depending on your configuration, in Windows you may need to run `emsdk/emsdk_env.bat` in your console to access the Emscripten command-line tools.
-- You may also refer to our [Continuous Integration setup](https://github.com/ocornut/imgui/tree/master/.github/workflows) for Emscripten setup.
-- Then build using `make -f Makefile.emscripten` while in the current directory.
-
-**Running an Emscripten project**
-
-To run on a local machine:
-- `make -f Makefile.emscripten serve` will use Python3 to spawn a local webserver, you can then browse http://localhost:8000 to access your build.
-- Otherwise, generally you will need a local webserver. Quoting [https://emscripten.org/docs/getting_started](https://emscripten.org/docs/getting_started/Tutorial.html#generating-html):<br>
-_"Unfortunately several browsers (including Chrome, Safari, and Internet Explorer) do not support file:// [XHR](https://emscripten.org/docs/site/glossary.html#term-xhr) requests, and can’t load extra files needed by the HTML (like a .wasm file, or packaged file data as mentioned lower down). For these browsers you’ll need to serve the files using a [local webserver](https://emscripten.org/docs/getting_started/FAQ.html#faq-local-webserver) and then open http://localhost:8000/hello.html."_
-- Emscripten SDK has a handy `emrun` command: `emrun web/index.html --browser firefox` which will spawn a temporary local webserver (in Firefox). See https://emscripten.org/docs/compiling/Running-html-files-with-emrun.html for details.
-- You may use Python 3 builtin webserver: `python -m http.server -d web` (this is what `make serve` uses).
-- You may use Python 2 builtin webserver: `cd web && python -m SimpleHTTPServer`.
-- If you are accessing the files over a network, certain browsers, such as Firefox, will restrict Gamepad API access to secure contexts only (e.g. https only).
+As of 2023-05-30 Emscripten doesn't support SDL3 yet.

examples/example_sdl3_opengl3/build_win32.bat

@@ -5,4 +5,4 @@
 @set SOURCES=main.cpp ..\..\backends\imgui_impl_sdl3.cpp ..\..\backends\imgui_impl_opengl3.cpp ..\..\imgui*.cpp
 @set LIBS=/LIBPATH:%SDL3_DIR%\lib\x86 SDL3.lib opengl32.lib shell32.lib
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console
+cl /nologo /Zi /MD /utf-8 %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console

examples/example_sdl3_opengl3/example_sdl3_opengl3.vcxproj

@@ -91,6 +91,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL3;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -105,6 +106,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL3;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -122,6 +124,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL3;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -142,6 +145,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL3;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_sdl3_opengl3/main.cpp

@@ -14,7 +14,7 @@
 #include <SDL3/SDL_opengl.h>
 #endif
 
-// This example can also compile and run with Emscripten! See 'Makefile.emscripten' for details.
+// This example doesn't compile with Emscripten yet! Awaiting SDL3 support.
 #ifdef __EMSCRIPTEN__
 #include "../libs/emscripten/emscripten_mainloop_stub.h"
 #endif
@@ -79,11 +79,23 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplSDL3_InitForOpenGL(window, gl_context);
     ImGui_ImplOpenGL3_Init(glsl_version);
@@ -184,6 +196,19 @@ int main(int, char**)
         glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
         glClear(GL_COLOR_BUFFER_BIT);
         ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
+        // Update and Render additional Platform Windows
+        // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
+        //  For this specific demo app we could also call SDL_GL_MakeCurrent(window, gl_context) directly)
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
+            SDL_GLContext backup_current_context = SDL_GL_GetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
+        }
+
         SDL_GL_SwapWindow(window);
     }
 #ifdef __EMSCRIPTEN__

examples/example_sdl3_sdlrenderer3/Makefile

@@ -0,0 +1,73 @@
+#
+# Cross Platform Makefile
+# Compatible with MSYS2/MINGW, Ubuntu 14.04.1 and Mac OS X
+#
+# You will need SDL3 (http://www.libsdl.org) which is still unreleased/unpackaged.
+
+#CXX = g++
+#CXX = clang++
+
+EXE = example_sdl3_sdlrenderer3
+IMGUI_DIR = ../..
+SOURCES = main.cpp
+SOURCES += $(IMGUI_DIR)/imgui.cpp $(IMGUI_DIR)/imgui_demo.cpp $(IMGUI_DIR)/imgui_draw.cpp $(IMGUI_DIR)/imgui_tables.cpp $(IMGUI_DIR)/imgui_widgets.cpp
+SOURCES += $(IMGUI_DIR)/backends/imgui_impl_sdl3.cpp $(IMGUI_DIR)/backends/imgui_impl_sdlrenderer3.cpp
+OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES))))
+UNAME_S := $(shell uname -s)
+LINUX_GL_LIBS = -lGL
+
+CXXFLAGS = -std=c++11 -I$(IMGUI_DIR) -I$(IMGUI_DIR)/backends
+CXXFLAGS += -g -Wall -Wformat
+LIBS =
+
+##---------------------------------------------------------------------
+## BUILD FLAGS PER PLATFORM
+##---------------------------------------------------------------------
+
+ifeq ($(UNAME_S), Linux) #LINUX
+	ECHO_MESSAGE = "Linux"
+	LIBS += -ldl `sdl3-config --libs`
+
+	CXXFLAGS += `sdl3-config --cflags`
+	CFLAGS = $(CXXFLAGS)
+endif
+
+ifeq ($(UNAME_S), Darwin) #APPLE
+	ECHO_MESSAGE = "Mac OS X"
+	LIBS += -framework OpenGL -framework Cocoa -framework IOKit -framework CoreVideo `sdl3-config --libs`
+	LIBS += -L/usr/local/lib -L/opt/local/lib
+
+	CXXFLAGS += `sdl3-config --cflags`
+	CXXFLAGS += -I/usr/local/include -I/opt/local/include
+	CFLAGS = $(CXXFLAGS)
+endif
+
+ifeq ($(OS), Windows_NT)
+    ECHO_MESSAGE = "MinGW"
+    LIBS += -lgdi32 -lopengl32 -limm32 `pkg-config --static --libs sdl3`
+
+    CXXFLAGS += `pkg-config --cflags sdl3`
+    CFLAGS = $(CXXFLAGS)
+endif
+
+##---------------------------------------------------------------------
+## BUILD RULES
+##---------------------------------------------------------------------
+
+%.o:%.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+%.o:$(IMGUI_DIR)/%.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+%.o:$(IMGUI_DIR)/backends/%.cpp
+	$(CXX) $(CXXFLAGS) -c -o $@ $<
+
+all: $(EXE)
+	@echo Build complete for $(ECHO_MESSAGE)
+
+$(EXE): $(OBJS)
+	$(CXX) -o $@ $^ $(CXXFLAGS) $(LIBS)
+
+clean:
+	rm -f $(EXE) $(OBJS)

examples/example_sdl3_sdlrenderer3/build_win32.bat

@@ -0,0 +1,8 @@
+@REM Build for Visual Studio compiler. Run your copy of vcvars32.bat or vcvarsall.bat to setup command-line compiler.
+@set OUT_DIR=Debug
+@set OUT_EXE=example_sdl3_sdlrenderer3
+@set INCLUDES=/I..\.. /I..\..\backends /I%SDL3_DIR%\include
+@set SOURCES=main.cpp ..\..\backends\imgui_impl_sdl3.cpp ..\..\backends\imgui_impl_sdlrenderer3.cpp ..\..\imgui*.cpp
+@set LIBS=/LIBPATH:%SDL3_DIR%\lib\x86 SDL3.lib
+mkdir %OUT_DIR%
+cl /nologo /Zi /MD /utf-8 %INCLUDES% %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS% /subsystem:console

examples/example_sdl3_sdlrenderer3/example_sdl3_sdlrenderer3.vcxproj

@@ -0,0 +1,186 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{C0290D21-3AD2-4A35-ABBC-A2F5F48326DA}</ProjectGuid>
+    <RootNamespace>example_sdl3_opengl3</RootNamespace>
+    <WindowsTargetPlatformVersion>8.1</WindowsTargetPlatformVersion>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>MultiByte</CharacterSet>
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets" Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <ImportGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <OutDir>$(ProjectDir)$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)$(Configuration)\</IntDir>
+    <IncludePath>$(IncludePath)</IncludePath>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <OutDir>$(ProjectDir)$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)$(Configuration)\</IntDir>
+    <IncludePath>$(IncludePath)</IncludePath>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <OutDir>$(ProjectDir)$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)$(Configuration)\</IntDir>
+    <IncludePath>$(IncludePath)</IncludePath>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <OutDir>$(ProjectDir)$(Configuration)\</OutDir>
+    <IntDir>$(ProjectDir)$(Configuration)\</IntDir>
+    <IncludePath>$(IncludePath)</IncludePath>
+  </PropertyGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL3;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+    <Link>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>%SDL3_DIR%\lib\x86;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>opengl32.lib;SDL3.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <SubSystem>Console</SubSystem>
+      <IgnoreSpecificDefaultLibraries>msvcrt.lib</IgnoreSpecificDefaultLibraries>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL3;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+    <Link>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <AdditionalLibraryDirectories>%SDL3_DIR%\lib\x64;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>opengl32.lib;SDL3.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <SubSystem>Console</SubSystem>
+      <IgnoreSpecificDefaultLibraries>msvcrt.lib</IgnoreSpecificDefaultLibraries>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL3;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+    <Link>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalLibraryDirectories>%SDL3_DIR%\lib\x86;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>opengl32.lib;SDL3.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <SubSystem>Console</SubSystem>
+      <IgnoreSpecificDefaultLibraries>
+      </IgnoreSpecificDefaultLibraries>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <ClCompile>
+      <WarningLevel>Level4</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <AdditionalIncludeDirectories>..\..;..\..\backends;%SDL3_DIR%\include;$(VcpkgCurrentInstalledDir)include\SDL3;%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
+      <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
+    </ClCompile>
+    <Link>
+      <GenerateDebugInformation>true</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+      <AdditionalLibraryDirectories>%SDL3_DIR%\lib\x64;%(AdditionalLibraryDirectories)</AdditionalLibraryDirectories>
+      <AdditionalDependencies>opengl32.lib;SDL3.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <SubSystem>Console</SubSystem>
+      <IgnoreSpecificDefaultLibraries>
+      </IgnoreSpecificDefaultLibraries>
+    </Link>
+  </ItemDefinitionGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\backends\imgui_impl_sdlrenderer3.cpp" />
+    <ClCompile Include="..\..\imgui.cpp" />
+    <ClCompile Include="..\..\imgui_demo.cpp" />
+    <ClCompile Include="..\..\imgui_draw.cpp" />
+    <ClCompile Include="..\..\imgui_tables.cpp" />
+    <ClCompile Include="..\..\imgui_widgets.cpp" />
+    <ClCompile Include="..\..\backends\imgui_impl_sdl3.cpp" />
+    <ClCompile Include="main.cpp" />
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\..\backends\imgui_impl_sdlrenderer3.h" />
+    <ClInclude Include="..\..\imconfig.h" />
+    <ClInclude Include="..\..\imgui.h" />
+    <ClInclude Include="..\..\imgui_internal.h" />
+    <ClInclude Include="..\..\backends\imgui_impl_sdl3.h" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="..\..\misc\debuggers\imgui.natstepfilter" />
+    <None Include="..\..\misc\debuggers\imgui.natvis" />
+    <None Include="..\README.txt" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  </ImportGroup>
+</Project>

examples/example_sdl3_sdlrenderer3/example_sdl3_sdlrenderer3.vcxproj.filters

@@ -0,0 +1,64 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <Filter Include="imgui">
+      <UniqueIdentifier>{20b90ce4-7fcb-4731-b9a0-075f875de82d}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="sources">
+      <UniqueIdentifier>{f18ab499-84e1-499f-8eff-9754361e0e52}</UniqueIdentifier>
+      <Extensions>cpp;c;cc;cxx;def;odl;idl;hpj;bat;asm;asmx</Extensions>
+    </Filter>
+  </ItemGroup>
+  <ItemGroup>
+    <ClCompile Include="..\..\imgui.cpp">
+      <Filter>imgui</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\imgui_demo.cpp">
+      <Filter>imgui</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\imgui_draw.cpp">
+      <Filter>imgui</Filter>
+    </ClCompile>
+    <ClCompile Include="main.cpp">
+      <Filter>sources</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\backends\imgui_impl_sdl3.cpp">
+      <Filter>sources</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\imgui_tables.cpp">
+      <Filter>imgui</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\imgui_widgets.cpp">
+      <Filter>imgui</Filter>
+    </ClCompile>
+    <ClCompile Include="..\..\backends\imgui_impl_sdlrenderer3.cpp">
+      <Filter>sources</Filter>
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="..\..\imconfig.h">
+      <Filter>imgui</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\imgui.h">
+      <Filter>imgui</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\imgui_internal.h">
+      <Filter>imgui</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\backends\imgui_impl_sdl3.h">
+      <Filter>sources</Filter>
+    </ClInclude>
+    <ClInclude Include="..\..\backends\imgui_impl_sdlrenderer3.h">
+      <Filter>sources</Filter>
+    </ClInclude>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="..\README.txt" />
+    <None Include="..\..\misc\debuggers\imgui.natvis">
+      <Filter>imgui</Filter>
+    </None>
+    <None Include="..\..\misc\debuggers\imgui.natstepfilter">
+      <Filter>imgui</Filter>
+    </None>
+  </ItemGroup>
+</Project>

examples/example_sdl3_sdlrenderer3/main.cpp

@@ -0,0 +1,174 @@
+// Dear ImGui: standalone example application for SDL3 + SDL_Renderer
+// (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)
+// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
+// Read online: https://github.com/ocornut/imgui/tree/master/docs
+
+// Important to understand: SDL_Renderer is an _optional_ component of SDL3.
+// For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.
+
+#include "imgui.h"
+#include "imgui_impl_sdl3.h"
+#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>
+#endif
+
+// Main code
+int main(int, char**)
+{
+    // Setup SDL
+    if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMEPAD) != 0)
+    {
+        printf("Error: SDL_Init(): %s\n", SDL_GetError());
+        return -1;
+    }
+
+    // Enable native IME.
+    SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
+
+    // Create window with SDL_Renderer graphics context
+    SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_HIDDEN);
+    SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL3+SDL_Renderer example", 1280, 720, window_flags);
+    if (window == nullptr)
+    {
+        printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
+        return -1;
+    }
+    SDL_Renderer* renderer = SDL_CreateRenderer(window, NULL, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);
+    if (renderer == nullptr)
+    {
+        SDL_Log("Error: SDL_CreateRenderer(): %s\n", SDL_GetError());
+        return -1;
+}
+    SDL_SetWindowPosition(window, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
+    SDL_ShowWindow(window);
+
+    // Setup Dear ImGui context
+    IMGUI_CHECKVERSION();
+    ImGui::CreateContext();
+    ImGuiIO& io = ImGui::GetIO(); (void)io;
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+
+    // Setup Dear ImGui style
+    ImGui::StyleColorsDark();
+    //ImGui::StyleColorsLight();
+
+    // Setup Platform/Renderer backends
+    ImGui_ImplSDL3_InitForSDLRenderer(window, renderer);
+    ImGui_ImplSDLRenderer3_Init(renderer);
+
+    // Load Fonts
+    // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
+    // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
+    // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
+    // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
+    // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
+    // - Read 'docs/FONTS.md' for more instructions and details.
+    // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
+    // - Our Emscripten build process allows embedding fonts to be accessible at runtime from the "fonts/" folder. See Makefile.emscripten for details.
+    //io.Fonts->AddFontDefault();
+    //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
+    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
+    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
+    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
+    //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
+    //IM_ASSERT(font != nullptr);
+
+    // Our state
+    bool show_demo_window = true;
+    bool show_another_window = false;
+    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
+
+    // Main loop
+    bool done = false;
+#ifdef __EMSCRIPTEN__
+    // For an Emscripten build we are disabling file-system access, so let's not attempt to do a fopen() of the imgui.ini file.
+    // You may manually call LoadIniSettingsFromMemory() to load settings from your own storage.
+    io.IniFilename = nullptr;
+    EMSCRIPTEN_MAINLOOP_BEGIN
+#else
+    while (!done)
+#endif
+    {
+        // Poll and handle events (inputs, window resize, etc.)
+        // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
+        // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
+        // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
+        // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
+        SDL_Event event;
+        while (SDL_PollEvent(&event))
+        {
+            ImGui_ImplSDL3_ProcessEvent(&event);
+            if (event.type == SDL_EVENT_QUIT)
+                done = true;
+            if (event.type == SDL_EVENT_WINDOW_CLOSE_REQUESTED && event.window.windowID == SDL_GetWindowID(window))
+                done = true;
+        }
+
+        // Start the Dear ImGui frame
+        ImGui_ImplSDLRenderer3_NewFrame();
+        ImGui_ImplSDL3_NewFrame();
+        ImGui::NewFrame();
+
+        // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
+        if (show_demo_window)
+            ImGui::ShowDemoWindow(&show_demo_window);
+
+        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
+        {
+            static float f = 0.0f;
+            static int counter = 0;
+
+            ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.
+
+            ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
+            ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
+            ImGui::Checkbox("Another Window", &show_another_window);
+
+            ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
+            ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
+
+            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
+                counter++;
+            ImGui::SameLine();
+            ImGui::Text("counter = %d", counter);
+
+            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
+            ImGui::End();
+        }
+
+        // 3. Show another simple window.
+        if (show_another_window)
+        {
+            ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
+            ImGui::Text("Hello from another window!");
+            if (ImGui::Button("Close Me"))
+                show_another_window = false;
+            ImGui::End();
+        }
+
+        // Rendering
+        ImGui::Render();
+        //SDL_RenderSetScale(renderer, io.DisplayFramebufferScale.x, io.DisplayFramebufferScale.y);
+        SDL_SetRenderDrawColor(renderer, (Uint8)(clear_color.x * 255), (Uint8)(clear_color.y * 255), (Uint8)(clear_color.z * 255), (Uint8)(clear_color.w * 255));
+        SDL_RenderClear(renderer);
+        ImGui_ImplSDLRenderer3_RenderDrawData(ImGui::GetDrawData());
+        SDL_RenderPresent(renderer);
+    }
+
+    // Cleanup
+    ImGui_ImplSDLRenderer3_Shutdown();
+    ImGui_ImplSDL3_Shutdown();
+    ImGui::DestroyContext();
+
+    SDL_DestroyRenderer(renderer);
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+
+    return 0;
+}

examples/example_win32_directx10/build_win32.bat

@@ -5,4 +5,4 @@
 @set SOURCES=main.cpp ..\..\backends\imgui_impl_win32.cpp ..\..\backends\imgui_impl_dx10.cpp ..\..\imgui*.cpp
 @set LIBS=/LIBPATH:"%DXSDK_DIR%/Lib/x86" d3d10.lib d3dcompiler.lib
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% /D UNICODE /D _UNICODE %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%
+cl /nologo /Zi /MD /utf-8 %INCLUDES% /D UNICODE /D _UNICODE %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%

examples/example_win32_directx10/example_win32_directx10.vcxproj

@@ -87,6 +87,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%(AdditionalIncludeDirectories);</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -100,6 +101,7 @@
       <WarningLevel>Level4</WarningLevel>
       <Optimization>Disabled</Optimization>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%(AdditionalIncludeDirectories);</AdditionalIncludeDirectories>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -116,6 +118,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%(AdditionalIncludeDirectories);</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -134,6 +137,7 @@
       <IntrinsicFunctions>true</IntrinsicFunctions>
       <AdditionalIncludeDirectories>..\..;..\..\backends;%(AdditionalIncludeDirectories);</AdditionalIncludeDirectories>
       <BufferSecurityCheck>false</BufferSecurityCheck>
+      <AdditionalOptions>/utf-8 %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>

examples/example_win32_directx10/main.cpp

@@ -12,6 +12,7 @@
 // Data
 static ID3D10Device*            g_pd3dDevice = nullptr;
 static IDXGISwapChain*          g_pSwapChain = nullptr;
+static UINT                     g_ResizeWidth = 0, g_ResizeHeight = 0;
 static ID3D10RenderTargetView*  g_mainRenderTargetView = nullptr;
 
 // Forward declarations of helper functions
@@ -48,11 +49,23 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
+    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
+    //io.ConfigViewportsNoAutoMerge = true;
+    //io.ConfigViewportsNoTaskBarIcon = true;
 
     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer backends
     ImGui_ImplWin32_Init(hwnd);
     ImGui_ImplDX10_Init(g_pd3dDevice);
@@ -95,6 +108,15 @@ int main(int, char**)
         if (done)
             break;
 
+        // Handle window resize (we don't resize directly in the WM_SIZE handler)
+        if (g_ResizeWidth != 0 && g_ResizeHeight != 0)
+        {
+            CleanupRenderTarget();
+            g_pSwapChain->ResizeBuffers(0, g_ResizeWidth, g_ResizeHeight, DXGI_FORMAT_UNKNOWN, 0);
+            g_ResizeWidth = g_ResizeHeight = 0;
+            CreateRenderTarget();
+        }
+
         // Start the Dear ImGui frame
         ImGui_ImplDX10_NewFrame();
         ImGui_ImplWin32_NewFrame();
@@ -144,6 +166,13 @@ int main(int, char**)
         g_pd3dDevice->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX10_RenderDrawData(ImGui::GetDrawData());
 
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         g_pSwapChain->Present(1, 0); // Present with vsync
         //g_pSwapChain->Present(0, 0); // Present without vsync
     }
@@ -160,7 +189,6 @@ int main(int, char**)
 }
 
 // Helper functions
-
 bool CreateDeviceD3D(HWND hWnd)
 {
     // Setup swap chain
@@ -228,12 +256,10 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
     switch (msg)
     {
     case WM_SIZE:
-        if (g_pd3dDevice != nullptr && wParam != SIZE_MINIMIZED)
-        {
-            CleanupRenderTarget();
-            g_pSwapChain->ResizeBuffers(0, (UINT)LOWORD(lParam), (UINT)HIWORD(lParam), DXGI_FORMAT_UNKNOWN, 0);
-            CreateRenderTarget();
-        }
+        if (wParam == SIZE_MINIMIZED)
+            return 0;
+        g_ResizeWidth = (UINT)LOWORD(lParam); // Queue resize
+        g_ResizeHeight = (UINT)HIWORD(lParam);
         return 0;
     case WM_SYSCOMMAND:
         if ((wParam & 0xfff0) == SC_KEYMENU) // Disable ALT application menu

examples/example_win32_directx11/build_win32.bat

@@ -5,5 +5,5 @@
 @set SOURCES=main.cpp ..\..\backends\imgui_impl_dx11.cpp ..\..\backends\imgui_impl_win32.cpp ..\..\imgui*.cpp
 @set LIBS=/LIBPATH:"%DXSDK_DIR%/Lib/x86" d3d11.lib d3dcompiler.lib
 mkdir %OUT_DIR%
-cl /nologo /Zi /MD %INCLUDES% /D UNICODE /D _UNICODE %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%
+cl /nologo /Zi /MD /utf-8 %INCLUDES% /D UNICODE /D _UNICODE %SOURCES% /Fe%OUT_DIR%/%OUT_EXE%.exe /Fo%OUT_DIR%/ /link %LIBS%