Merge branch 'master' into docking

# Conflicts:
#	backends/imgui_impl_dx10.cpp
#	backends/imgui_impl_dx11.cpp
#	backends/imgui_impl_dx12.cpp
#	backends/imgui_impl_dx9.cpp
#	backends/imgui_impl_opengl3.cpp
#	backends/imgui_impl_win32.cpp
#	docs/CHANGELOG.txt
#	examples/example_glfw_vulkan/main.cpp
#	examples/example_sdl_vulkan/main.cpp
#	imgui.cpp

.github/workflows/build.yml

@@ -3,8 +3,16 @@ name: build
 on:
   push:
   pull_request:
-  schedule:
-    - cron:  '0 9 * * *'
+  workflow_run:
+    # Use a workflow as a trigger of scheduled builds. Forked repositories can disable scheduled builds by disabling
+    # "scheduled" workflow, while maintaining ability to perform local CI builds.
+    workflows:
+      - scheduled
+    branches:
+      - master
+      - docking
+    types:
+      - requested
 
 jobs:
   Windows:
@@ -98,22 +106,22 @@ jobs:
       - name: Build Win32 example_glfw_opengl3
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_opengl3/example_glfw_opengl3.vcxproj /p:Platform=Win32 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build Win32 example_glfw_vulkan
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_vulkan/example_glfw_vulkan.vcxproj /p:Platform=Win32 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build Win32 example_sdl_vulkan
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_vulkan/example_sdl_vulkan.vcxproj /p:Platform=Win32 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build Win32 example_sdl_opengl2
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_opengl2/example_sdl_opengl2.vcxproj /p:Platform=Win32 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build Win32 example_sdl_opengl3
         shell: cmd
@@ -122,7 +130,7 @@ jobs:
       - name: Build Win32 example_sdl_directx11
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_directx11/example_sdl_directx11.vcxproj /p:Platform=Win32 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build Win32 example_win32_directx9
         shell: cmd
@@ -135,12 +143,12 @@ jobs:
       - name: Build Win32 example_win32_directx11
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx11/example_win32_directx11.vcxproj /p:Platform=Win32 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build x64 example_glfw_opengl2
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_glfw_opengl2/example_glfw_opengl2.vcxproj /p:Platform=x64 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build x64 example_glfw_opengl3
         shell: cmd
@@ -153,17 +161,17 @@ jobs:
       - name: Build x64 example_sdl_vulkan
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_vulkan/example_sdl_vulkan.vcxproj /p:Platform=x64 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build x64 example_sdl_opengl2
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_opengl2/example_sdl_opengl2.vcxproj /p:Platform=x64 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build x64 example_sdl_opengl3
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_sdl_opengl3/example_sdl_opengl3.vcxproj /p:Platform=x64 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build x64 example_sdl_directx11
         shell: cmd
@@ -172,17 +180,17 @@ jobs:
       - name: Build x64 example_win32_directx9
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx9/example_win32_directx9.vcxproj /p:Platform=x64 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build x64 example_win32_directx10
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx10/example_win32_directx10.vcxproj /p:Platform=x64 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build x64 example_win32_directx11
         shell: cmd
         run: '"%MSBUILD_PATH%\MSBuild.exe" examples/example_win32_directx11/example_win32_directx11.vcxproj /p:Platform=x64 /p:Configuration=Release'
-        if: github.event_name == 'schedule'
+        if: github.event_name == 'workflow_run'
 
       - name: Build x64 example_win32_directx12
         shell: cmd
@@ -344,17 +352,17 @@ jobs:
 
     - name: Build example_glfw_opengl3
       run: make -C examples/example_glfw_opengl3
-      if: github.event_name == 'schedule'
+      if: github.event_name == 'workflow_run'
 
     - name: Build example_sdl_opengl2
       run: make -C examples/example_sdl_opengl2
-      if: github.event_name == 'schedule'
+      if: github.event_name == 'workflow_run'
 
     - name: Build example_sdl_opengl3
       run: make -C examples/example_sdl_opengl3
 
   MacOS:
-    runs-on: macOS-latest
+    runs-on: macos-latest
     steps:
     - uses: actions/checkout@v2
 
@@ -392,7 +400,7 @@ jobs:
 
     - name: Build example_glfw_opengl3
       run: make -C examples/example_glfw_opengl3
-      if: github.event_name == 'schedule'
+      if: github.event_name == 'workflow_run'
 
     - name: Build example_glfw_metal
       run: make -C examples/example_glfw_metal
@@ -402,7 +410,7 @@ jobs:
 
     - name: Build example_sdl_opengl2
       run: make -C examples/example_sdl_opengl2
-      if: github.event_name == 'schedule'
+      if: github.event_name == 'workflow_run'
 
     - name: Build example_sdl_opengl3
       run: make -C examples/example_sdl_opengl3
@@ -414,7 +422,7 @@ jobs:
       run: xcodebuild -project examples/example_apple_opengl2/example_apple_opengl2.xcodeproj -target example_osx_opengl2
 
   iOS:
-    runs-on: macOS-latest
+    runs-on: macos-latest
     steps:
     - uses: actions/checkout@v2
 
@@ -460,7 +468,7 @@ jobs:
         discord-webhook: ${{ secrets.DISCORD_CI_WEBHOOK }}
         github-token: ${{ github.token }}
         action-task: discord-jobs
-        discord-filter: "'{{ github.branch }}'.match(/master|docking|tables/g) != null && '{{ run.conclusion }}' != '{{ last_run.conclusion }}'"
+        discord-filter: "'{{ github.branch }}'.match(/master|docking/g) != null && '{{ run.conclusion }}' != '{{ last_run.conclusion }}'"
         discord-username: GitHub Actions
         discord-job-new-failure-message: ''
         discord-job-fixed-failure-message: ''

.github/workflows/scheduled.yml

@@ -0,0 +1,15 @@
+#
+# This is a dummy workflow used to trigger scheduled builds. Forked repositories most likely should disable this
+# workflow to avoid daily builds of inactive repositories.
+#
+name: scheduled
+
+on:
+  schedule:
+    - cron:  '0 9 * * *'
+
+jobs:
+  scheduled:
+    runs-on: ubuntu-latest
+    steps:
+      - run: exit 0

.github/workflows/static-analysis.yml

@@ -1,8 +1,12 @@
 name: static-analysis
 
 on:
-  push: {}
-  pull_request: {}
+  workflow_run:
+    # Perform static analysis together with build workflow. Build triggers of "build" workflow do not need to be repeated here.
+    workflows:
+      - build
+    types:
+      - requested
 
 jobs:
   PVS-Studio:
@@ -51,7 +55,7 @@ jobs:
         discord-webhook: ${{ secrets.DISCORD_CI_WEBHOOK }}
         github-token: ${{ github.token }}
         action-task: discord-jobs
-        discord-filter: "'{{ github.branch }}'.match(/master|docking|tables/g) != null && '{{ run.conclusion }}' != '{{ last_run.conclusion }}'"
+        discord-filter: "'{{ github.branch }}'.match(/master|docking/g) != null && '{{ run.conclusion }}' != '{{ last_run.conclusion }}'"
         discord-username: GitHub Actions
         discord-job-new-failure-message: ''
         discord-job-fixed-failure-message: ''

backends/imgui_impl_allegro5.cpp

@@ -15,6 +15,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2021-02-18: Change blending equation to preserve alpha in output buffer.
 //  2020-08-10: Inputs: Fixed horizontal mouse wheel direction.
 //  2019-12-05: Inputs: Added support for ImGuiMouseCursor_NotAllowed mouse cursor.
 //  2019-07-21: Inputs: Added mapping for ImGuiKey_KeyPadEnter.
@@ -68,7 +69,7 @@ struct ImDrawVertAllegro
 static void ImGui_ImplAllegro5_SetupRenderState(ImDrawData* draw_data)
 {
     // Setup blending
-    al_set_blender(ALLEGRO_ADD, ALLEGRO_ALPHA, ALLEGRO_INVERSE_ALPHA);
+    al_set_separate_blender(ALLEGRO_ADD, ALLEGRO_ALPHA, ALLEGRO_INVERSE_ALPHA, ALLEGRO_ADD, ALLEGRO_ONE, ALLEGRO_INVERSE_ALPHA);
 
     // Setup orthographic projection matrix
     // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right).

backends/imgui_impl_dx10.cpp

@@ -13,6 +13,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2021-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2021-02-18: DirectX10: Change blending equation to preserve alpha in output buffer.
 //  2019-07-21: DirectX10: Backup, clear and restore Geometry Shader is any is bound when calling ImGui_ImplDX10_RenderDrawData().
 //  2019-05-29: DirectX10: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
 //  2019-04-30: DirectX10: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
@@ -445,8 +446,8 @@ bool    ImGui_ImplDX10_CreateDeviceObjects()
         desc.SrcBlend = D3D10_BLEND_SRC_ALPHA;
         desc.DestBlend = D3D10_BLEND_INV_SRC_ALPHA;
         desc.BlendOp = D3D10_BLEND_OP_ADD;
-        desc.SrcBlendAlpha = D3D10_BLEND_INV_SRC_ALPHA;
-        desc.DestBlendAlpha = D3D10_BLEND_ZERO;
+        desc.SrcBlendAlpha = D3D10_BLEND_ONE;
+        desc.DestBlendAlpha = D3D10_BLEND_INV_SRC_ALPHA;
         desc.BlendOpAlpha = D3D10_BLEND_OP_ADD;
         desc.RenderTargetWriteMask[0] = D3D10_COLOR_WRITE_ENABLE_ALL;
         g_pd3dDevice->CreateBlendState(&desc, &g_pBlendState);

backends/imgui_impl_dx11.cpp

@@ -13,6 +13,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2021-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2021-02-18: DirectX11: Change blending equation to preserve alpha in output buffer.
 //  2019-08-01: DirectX11: Fixed code querying the Geometry Shader state (would generally error with Debug layer enabled).
 //  2019-07-21: DirectX11: Backup, clear and restore Geometry Shader is any is bound when calling ImGui_ImplDX10_RenderDrawData. Clearing Hull/Domain/Compute shaders without backup/restore.
 //  2019-05-29: DirectX11: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
@@ -457,8 +458,8 @@ bool    ImGui_ImplDX11_CreateDeviceObjects()
         desc.RenderTarget[0].SrcBlend = D3D11_BLEND_SRC_ALPHA;
         desc.RenderTarget[0].DestBlend = D3D11_BLEND_INV_SRC_ALPHA;
         desc.RenderTarget[0].BlendOp = D3D11_BLEND_OP_ADD;
-        desc.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_INV_SRC_ALPHA;
-        desc.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_ZERO;
+        desc.RenderTarget[0].SrcBlendAlpha = D3D11_BLEND_ONE;
+        desc.RenderTarget[0].DestBlendAlpha = D3D11_BLEND_INV_SRC_ALPHA;
         desc.RenderTarget[0].BlendOpAlpha = D3D11_BLEND_OP_ADD;
         desc.RenderTarget[0].RenderTargetWriteMask = D3D11_COLOR_WRITE_ENABLE_ALL;
         g_pd3dDevice->CreateBlendState(&desc, &g_pBlendState);

backends/imgui_impl_dx12.cpp

@@ -18,6 +18,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2021-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2021-02-18: DirectX12: Change blending equation to preserve alpha in output buffer.
 //  2021-01-11: DirectX12: Improve Windows 7 compatibility (for D3D12On7) by loading d3d12.dll dynamically.
 //  2020-09-16: DirectX12: Avoid rendering calls with zero-sized scissor rectangle since it generates a validation layer warning.
 //  2020-09-08: DirectX12: Clarified support for building on 32-bit systems by redefining ImTextureID.
@@ -669,8 +670,8 @@ bool    ImGui_ImplDX12_CreateDeviceObjects()
         desc.RenderTarget[0].SrcBlend = D3D12_BLEND_SRC_ALPHA;
         desc.RenderTarget[0].DestBlend = D3D12_BLEND_INV_SRC_ALPHA;
         desc.RenderTarget[0].BlendOp = D3D12_BLEND_OP_ADD;
-        desc.RenderTarget[0].SrcBlendAlpha = D3D12_BLEND_INV_SRC_ALPHA;
-        desc.RenderTarget[0].DestBlendAlpha = D3D12_BLEND_ZERO;
+        desc.RenderTarget[0].SrcBlendAlpha = D3D12_BLEND_ONE;
+        desc.RenderTarget[0].DestBlendAlpha = D3D12_BLEND_INV_SRC_ALPHA;
         desc.RenderTarget[0].BlendOpAlpha = D3D12_BLEND_OP_ADD;
         desc.RenderTarget[0].RenderTargetWriteMask = D3D12_COLOR_WRITE_ENABLE_ALL;
     }

backends/imgui_impl_dx9.cpp

@@ -13,6 +13,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2021-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2021-02-18: DirectX9: Change blending equation to preserve alpha in output buffer.
 //  2019-05-29: DirectX9: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
 //  2019-04-30: DirectX9: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
 //  2019-03-29: Misc: Fixed erroneous assert in ImGui_ImplDX9_InvalidateDeviceObjects().
@@ -75,6 +76,9 @@ static void ImGui_ImplDX9_SetupRenderState(ImDrawData* draw_data)
     g_pd3dDevice->SetRenderState(D3DRS_BLENDOP, D3DBLENDOP_ADD);
     g_pd3dDevice->SetRenderState(D3DRS_SRCBLEND, D3DBLEND_SRCALPHA);
     g_pd3dDevice->SetRenderState(D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA);
+    g_pd3dDevice->SetRenderState(D3DRS_SEPARATEALPHABLENDENABLE, TRUE);
+    g_pd3dDevice->SetRenderState(D3DRS_SRCBLENDALPHA, D3DBLEND_ONE);
+    g_pd3dDevice->SetRenderState(D3DRS_DESTBLENDALPHA, D3DBLEND_INVSRCALPHA);
     g_pd3dDevice->SetRenderState(D3DRS_SCISSORTESTENABLE, TRUE);
     g_pd3dDevice->SetRenderState(D3DRS_SHADEMODE, D3DSHADE_GOURAUD);
     g_pd3dDevice->SetRenderState(D3DRS_FOGENABLE, FALSE);

backends/imgui_impl_metal.mm

@@ -13,6 +13,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2021-02-18: Metal: Change blending equation to preserve alpha in output buffer.
 //  2021-01-25: Metal: Fixed texture storage mode when building on Mac Catalyst.
 //  2019-05-29: Metal: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
 //  2019-04-30: Metal: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
@@ -388,10 +389,10 @@ - (void)enqueueReusableBuffer:(MetalBuffer *)buffer
     pipelineDescriptor.colorAttachments[0].pixelFormat = self.framebufferDescriptor.colorPixelFormat;
     pipelineDescriptor.colorAttachments[0].blendingEnabled = YES;
     pipelineDescriptor.colorAttachments[0].rgbBlendOperation = MTLBlendOperationAdd;
-    pipelineDescriptor.colorAttachments[0].alphaBlendOperation = MTLBlendOperationAdd;
     pipelineDescriptor.colorAttachments[0].sourceRGBBlendFactor = MTLBlendFactorSourceAlpha;
-    pipelineDescriptor.colorAttachments[0].sourceAlphaBlendFactor = MTLBlendFactorSourceAlpha;
     pipelineDescriptor.colorAttachments[0].destinationRGBBlendFactor = MTLBlendFactorOneMinusSourceAlpha;
+    pipelineDescriptor.colorAttachments[0].alphaBlendOperation = MTLBlendOperationAdd;
+    pipelineDescriptor.colorAttachments[0].sourceAlphaBlendFactor = MTLBlendFactorOne;
     pipelineDescriptor.colorAttachments[0].destinationAlphaBlendFactor = MTLBlendFactorOneMinusSourceAlpha;
     pipelineDescriptor.depthAttachmentPixelFormat = self.framebufferDescriptor.depthPixelFormat;
     pipelineDescriptor.stencilAttachmentPixelFormat = self.framebufferDescriptor.stencilPixelFormat;

backends/imgui_impl_opengl2.cpp

@@ -92,6 +92,7 @@ static void ImGui_ImplOpenGL2_SetupRenderState(ImDrawData* draw_data, int fb_wid
     // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers, polygon fill.
     glEnable(GL_BLEND);
     glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    //glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA); // In order to composite our output buffer we need to preserve alpha
     glDisable(GL_CULL_FACE);
     glDisable(GL_DEPTH_TEST);
     glDisable(GL_STENCIL_TEST);

backends/imgui_impl_opengl3.cpp

@@ -15,6 +15,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2021-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2021-02-18: OpenGL: Change blending equation to preserve alpha in output buffer.
 //  2021-01-03: OpenGL: Backup, setup and restore GL_STENCIL_TEST state.
 //  2020-10-23: OpenGL: Backup, setup and restore GL_PRIMITIVE_RESTART state.
 //  2020-10-15: OpenGL: Use glGetString(GL_VERSION) instead of glGetIntegerv(GL_MAJOR_VERSION, ...) when the later returns zero (e.g. Desktop GL 2.x)
@@ -258,7 +259,7 @@ static void ImGui_ImplOpenGL3_SetupRenderState(ImDrawData* draw_data, int fb_wid
     // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
     glEnable(GL_BLEND);
     glBlendEquation(GL_FUNC_ADD);
-    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
     glDisable(GL_CULL_FACE);
     glDisable(GL_DEPTH_TEST);
     glDisable(GL_STENCIL_TEST);

backends/imgui_impl_vulkan.cpp

@@ -23,6 +23,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2021-02-18: Vulkan: Change blending equation to preserve alpha in output buffer.
 //  2021-01-27: Vulkan: Added support for custom function load and IMGUI_IMPL_VULKAN_NO_PROTOTYPES by using ImGui_ImplVulkan_LoadFunctions().
 //  2020-11-11: Vulkan: Added support for specifying which subpass to reference during VkPipeline creation.
 //  2020-09-07: Vulkan: Added VkPipeline parameter to ImGui_ImplVulkan_RenderDrawData (default to one passed to ImGui_ImplVulkan_Init).
@@ -832,8 +833,8 @@ static void ImGui_ImplVulkan_CreatePipeline(VkDevice device, const VkAllocationC
     color_attachment[0].srcColorBlendFactor = VK_BLEND_FACTOR_SRC_ALPHA;
     color_attachment[0].dstColorBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
     color_attachment[0].colorBlendOp = VK_BLEND_OP_ADD;
-    color_attachment[0].srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
-    color_attachment[0].dstAlphaBlendFactor = VK_BLEND_FACTOR_ZERO;
+    color_attachment[0].srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE;
+    color_attachment[0].dstAlphaBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
     color_attachment[0].alphaBlendOp = VK_BLEND_OP_ADD;
     color_attachment[0].colorWriteMask = VK_COLOR_COMPONENT_R_BIT | VK_COLOR_COMPONENT_G_BIT | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT;
 

backends/imgui_impl_wgpu.cpp

@@ -12,6 +12,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2021-02-18: Change blending equation to preserve alpha in output buffer.
 //  2021-01-28: Initial version.
 
 #include "imgui.h"
@@ -638,7 +639,7 @@ bool ImGui_ImplWGPU_CreateDeviceObjects()
     {
         color_state.format = g_renderTargetFormat;
         color_state.alphaBlend.operation = WGPUBlendOperation_Add;
-        color_state.alphaBlend.srcFactor = WGPUBlendFactor_SrcAlpha;
+        color_state.alphaBlend.srcFactor = WGPUBlendFactor_One;
         color_state.alphaBlend.dstFactor = WGPUBlendFactor_OneMinusSrcAlpha;
         color_state.colorBlend.operation = WGPUBlendOperation_Add;
         color_state.colorBlend.srcFactor = WGPUBlendFactor_SrcAlpha;