diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 352cdcb3..888593e0 100644
--- a/.github/workflows/build.yml
+++ b/.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: ''
diff --git a/.github/workflows/scheduled.yml b/.github/workflows/scheduled.yml
new file mode 100644
index 00000000..2a08578f
--- /dev/null
+++ b/.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
diff --git a/.github/workflows/static-analysis.yml b/.github/workflows/static-analysis.yml
index 7a9b573e..d3b7d50b 100644
--- a/.github/workflows/static-analysis.yml
+++ b/.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: ''
diff --git a/backends/imgui_impl_allegro5.cpp b/backends/imgui_impl_allegro5.cpp
index db608e02..c4832b6b 100644
--- a/backends/imgui_impl_allegro5.cpp
+++ b/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).
diff --git a/backends/imgui_impl_dx10.cpp b/backends/imgui_impl_dx10.cpp
index a504dcbe..bacc7051 100644
--- a/backends/imgui_impl_dx10.cpp
+++ b/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);
diff --git a/backends/imgui_impl_dx11.cpp b/backends/imgui_impl_dx11.cpp
index 42d764a5..81c3ac11 100644
--- a/backends/imgui_impl_dx11.cpp
+++ b/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);
diff --git a/backends/imgui_impl_dx12.cpp b/backends/imgui_impl_dx12.cpp
index f6d6c472..7c02ada6 100644
--- a/backends/imgui_impl_dx12.cpp
+++ b/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;
     }
diff --git a/backends/imgui_impl_dx9.cpp b/backends/imgui_impl_dx9.cpp
index c3eb2c69..d3124e9e 100644
--- a/backends/imgui_impl_dx9.cpp
+++ b/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);
diff --git a/backends/imgui_impl_metal.mm b/backends/imgui_impl_metal.mm
index cab733da..6dcc7267 100644
--- a/backends/imgui_impl_metal.mm
+++ b/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 ImGui_ImplMetal_DestroyDeviceObjects()
     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;
diff --git a/backends/imgui_impl_opengl2.cpp b/backends/imgui_impl_opengl2.cpp
index d8a49ea5..de6219d4 100644
--- a/backends/imgui_impl_opengl2.cpp
+++ b/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);
diff --git a/backends/imgui_impl_opengl3.cpp b/backends/imgui_impl_opengl3.cpp
index f0d54676..f6883c51 100644
--- a/backends/imgui_impl_opengl3.cpp
+++ b/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);
diff --git a/backends/imgui_impl_vulkan.cpp b/backends/imgui_impl_vulkan.cpp
index e7e528c8..2e0085a7 100644
--- a/backends/imgui_impl_vulkan.cpp
+++ b/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;
 
diff --git a/backends/imgui_impl_wgpu.cpp b/backends/imgui_impl_wgpu.cpp
index 089dbfd7..1eb290a3 100644
--- a/backends/imgui_impl_wgpu.cpp
+++ b/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;
diff --git a/backends/imgui_impl_win32.cpp b/backends/imgui_impl_win32.cpp
index 29b7df45..64a4820b 100644
--- a/backends/imgui_impl_win32.cpp
+++ b/backends/imgui_impl_win32.cpp
@@ -30,6 +30,7 @@ typedef DWORD (WINAPI *PFN_XInputGetState)(DWORD, XINPUT_STATE*);
 // 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.
+//  2021-02-17: Fixed ImGui_ImplWin32_EnableDpiAwareness() attempting to get SetProcessDpiAwareness from shcore.dll on Windows 8 whereas it is only supported on Windows 8.1.
 //  2021-01-25: Inputs: Dynamically loading XInput DLL.
 //  2020-12-04: Misc: Fixed setting of io.DisplaySize to invalid/uninitialized data when after hwnd has been closed.
 //  2020-03-03: Inputs: Calling AddInputCharacterUTF16() to support surrogate pairs leading to codepoint >= 0x10000 (for more complete CJK inputs)
@@ -496,7 +497,9 @@ static BOOL IsWindowsVersionOrGreater(WORD major, WORD minor, WORD sp)
     cond = ::VerSetConditionMask(cond, VER_SERVICEPACKMAJOR, VER_GREATER_EQUAL);
     return ::VerifyVersionInfoW(&osvi, mask, cond);
 }
-#define IsWindows8Point1OrGreater()  IsWindowsVersionOrGreater(HIBYTE(0x0602), LOBYTE(0x0602), 0) // _WIN32_WINNT_WINBLUE
+#define IsWindowsVistaOrGreater()   IsWindowsVersionOrGreater(HIBYTE(0x0600), LOBYTE(0x0600), 0) // _WIN32_WINNT_VISTA
+#define IsWindows8OrGreater()       IsWindowsVersionOrGreater(HIBYTE(0x0602), LOBYTE(0x0602), 0) // _WIN32_WINNT_WIN8
+#define IsWindows8Point1OrGreater() IsWindowsVersionOrGreater(HIBYTE(0x0603), LOBYTE(0x0603), 0) // _WIN32_WINNT_WINBLUE
 #endif
 
 #ifndef DPI_ENUMS_DECLARED
diff --git a/docs/BACKENDS.md b/docs/BACKENDS.md
index 7a723cc7..ad9a0235 100644
--- a/docs/BACKENDS.md
+++ b/docs/BACKENDS.md
@@ -9,13 +9,13 @@ your application or engine to easily integrate Dear ImGui.** Each backend is typ
   e.g. Windows ([imgui_impl_win32.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_win32.cpp)), GLFW ([imgui_impl_glfw.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_glfw.cpp)), SDL2 ([imgui_impl_sdl.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_sdl.cpp)), etc.
 
 - The 'Renderer' backends are in charge of: creating atlas texture, rendering imgui draw data.<BR>
-  e.g. DirectX11 ([imgui_impl_dx11.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_dx11.cpp)), OpenGL/WebGL ([imgui_impl_opengl3.cpp]((https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_opengl3.cpp)), Vulkan ([imgui_impl_vulkan.cpp]((https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_vulkan.cpp)), etc.
+  e.g. DirectX11 ([imgui_impl_dx11.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_dx11.cpp)), OpenGL/WebGL ([imgui_impl_opengl3.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_opengl3.cpp), Vulkan ([imgui_impl_vulkan.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_vulkan.cpp), etc.
 
 - For some high-level frameworks, a single backend usually handle both 'Platform' and 'Renderer' parts.<BR>
   e.g. Allegro 5 ([imgui_impl_allegro5.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_allegro5.cpp)), Marmalade ([imgui_impl_marmalade.cpp](https://github.com/ocornut/imgui/blob/master/backends/imgui_impl_marmalade.cpp)). If you end up creating a custom backend for your engine, you may want to do the same.
 
 An application usually combines 1 Platform backend + 1 Renderer backend + main Dear ImGui sources.
-For example, the [example_win32_directx11](https://github.com/ocornut/imgui/tree/master/examples/example_win32_directx11) application combines imgui_impl_win32.cpp + imgui_impl_dx11.cpp. See [EXAMPLES.MD](https://github.com/ocornut/imgui/blob/master/docs/EXAMPLES.md) for details.
+For example, the [example_win32_directx11](https://github.com/ocornut/imgui/tree/master/examples/example_win32_directx11) application combines imgui_impl_win32.cpp + imgui_impl_dx11.cpp. There are 20+ examples in the [examples/](https://github.com/ocornut/imgui/blob/master/examples/) folder. See [EXAMPLES.MD](https://github.com/ocornut/imgui/blob/master/docs/EXAMPLES.md) for details.
 
 
 ### What are backends
@@ -36,7 +36,7 @@ Dear ImGui is highly portable and only requires a few things to run and render,
  - Optional: multi-viewports support.
  etc.
 
-This is essentially what each backends are doing + obligatory portability cruft.
+This is essentially what each backends are doing + obligatory portability cruft. Using default backends ensure you can get all those features including the ones that would be harder to implement on your side (e.g. multi-viewports support).
 
 It is important to understand the difference between the core Dear ImGui library (files in the root folder)
 and backends which we are describing here (backends/ folder).
@@ -46,6 +46,11 @@ and backends which we are describing here (backends/ folder).
   e.g. you can get creative and use software rendering or render remotely on a different machine.
 
 
+### Integrating a backend
+
+See "Getting Started" section of [EXAMPLES.MD](https://github.com/ocornut/imgui/blob/master/docs/EXAMPLES.md) for more details.
+
+
 ### List of backends
 
 In the [backends/](https://github.com/ocornut/imgui/blob/master/backends) folder:
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index eab9da23..e1ef0359 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -103,6 +103,30 @@ Other changes:
   to make the examples main.cpp easier to read.
 
 
+-----------------------------------------------------------------------
+ VERSION 1.82 WIP (In Progresss)
+-----------------------------------------------------------------------
+
+Breaking Changes:
+
+- Style: renamed rarely used style.CircleSegmentMaxError (old default = 1.60f)
+  to style.CircleTessellationMaxError (new default = 0.30f) as its meaning changed. (#3808) [@thedmd]
+
+Other Changes:
+
+- ImDrawList: AddCircle, AddCircleFilled(): Tweaked default segment count calculation to honor MaxError
+  with more accuracy. Made default segment count always even for better looking result. (#3808) [@thedmd]
+- ImDrawList: AddCircle, AddCircleFilled(): New default for style.
+- Backends: OpenGL, Vulkan, DX9, DX10, DX11, DX12, Metal, WebGPU, Allegro: Rework blending equation to
+  preserve alpha in output buffer (using SrcBlendAlpha = ONE, DstBlendAlpha = ONE_MINUS_SRC_ALPHA consistently
+  accross all backends), facilitating compositing of the output buffer with another buffer.
+  (#2693, #2764, #2766, #2873, #3447, #3813, #3816) [@ocornut, @thedmd, @ShawnM427, @Ubpa, @aiekick]
+- Examples: Reworked setup of clear color to be compatible with transparent values.
+- CI: Use a dedicated "scheduled" workflow to trigger scheduled builds. Forks may disable this workflow if
+  scheduled builds builds are not required. [@rokups]
+>>>>>>> master
+
+
 -----------------------------------------------------------------------
  VERSION 1.81 (Released 2021-02-10)
 -----------------------------------------------------------------------
@@ -135,9 +159,9 @@ Other Changes:
      - Code using (0,0) as a way to signify "upper-left of the host window" should use GetMainViewport()->Pos.
      - Code using io.DisplaySize as a way to signify "size of the host window" should use GetMainViewport()->Size.
   - We are also exposing a work area in ImGuiViewport ('WorkPos', 'WorkSize' vs 'Pos', 'Size' for full area):
-     - For a Platform Window, the work area is generally the full area minus space used by menu-bars. 
+     - For a Platform Window, the work area is generally the full area minus space used by menu-bars.
      - For a Platform Monitor, the work area is generally the full area minus space used by task-bars.
-  - All of this has been the case in 'docking' branch for a long time. What we've done is merely merging 
+  - All of this has been the case in 'docking' branch for a long time. What we've done is merely merging
     a small chunk of the multi-viewport logic into 'master' to standardize some concepts ahead of time.
 - Tables: Fixed PopItemWidth() or multi-components items not restoring per-colum ItemWidth correctly. (#3760)
 - Window: Fixed minor title bar text clipping issue when FramePadding is small/zero and there are no
diff --git a/examples/example_allegro5/main.cpp b/examples/example_allegro5/main.cpp
index e228e6ab..f38e92c9 100644
--- a/examples/example_allegro5/main.cpp
+++ b/examples/example_allegro5/main.cpp
@@ -122,7 +122,7 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
-        al_clear_to_color(al_map_rgba_f(clear_color.x, clear_color.y, clear_color.z, clear_color.w));
+        al_clear_to_color(al_map_rgba_f(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w));
         ImGui_ImplAllegro5_RenderDrawData(ImGui::GetDrawData());
         al_flip_display();
     }
diff --git a/examples/example_apple_metal/main.mm b/examples/example_apple_metal/main.mm
index 015aee90..273811d3 100644
--- a/examples/example_apple_metal/main.mm
+++ b/examples/example_apple_metal/main.mm
@@ -245,7 +245,7 @@
     MTLRenderPassDescriptor* renderPassDescriptor = view.currentRenderPassDescriptor;
     if (renderPassDescriptor != nil)
     {
-        renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(clear_color[0], clear_color[1], clear_color[2], clear_color[3]);
+        renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(clear_color[0] * clear_color[3], clear_color[1] * clear_color[3], clear_color[2] * clear_color[3], clear_color[3]);
 
         // Here, you could do additional rendering work, including other passes as necessary.
 
diff --git a/examples/example_apple_opengl2/main.mm b/examples/example_apple_opengl2/main.mm
index d6d37e88..bb269c8b 100644
--- a/examples/example_apple_opengl2/main.mm
+++ b/examples/example_apple_opengl2/main.mm
@@ -97,7 +97,7 @@
     GLsizei height = (GLsizei)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
     glViewport(0, 0, width, height);
 
-	glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+	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_ImplOpenGL2_RenderDrawData(draw_data);
 
diff --git a/examples/example_emscripten_opengl3/main.cpp b/examples/example_emscripten_opengl3/main.cpp
index 66e0cb3f..b828e9f0 100644
--- a/examples/example_emscripten_opengl3/main.cpp
+++ b/examples/example_emscripten_opengl3/main.cpp
@@ -168,7 +168,7 @@ static void main_loop(void* arg)
     ImGui::Render();
     SDL_GL_MakeCurrent(g_Window, g_GLContext);
     glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
-    glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+    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());
     SDL_GL_SwapWindow(g_Window);
diff --git a/examples/example_emscripten_wgpu/main.cpp b/examples/example_emscripten_wgpu/main.cpp
index 9b72ba9b..a9da9320 100644
--- a/examples/example_emscripten_wgpu/main.cpp
+++ b/examples/example_emscripten_wgpu/main.cpp
@@ -205,7 +205,7 @@ static void main_loop(void* window)
     WGPURenderPassColorAttachmentDescriptor color_attachments = {};
     color_attachments.loadOp = WGPULoadOp_Clear;
     color_attachments.storeOp = WGPUStoreOp_Store;
-    color_attachments.clearColor = { clear_color.x, clear_color.y, clear_color.z, clear_color.w };
+    color_attachments.clearColor = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
     color_attachments.attachment = wgpuSwapChainGetCurrentTextureView(wgpu_swap_chain);
     WGPURenderPassDescriptor render_pass_desc = {};
     render_pass_desc.colorAttachmentCount = 1;
diff --git a/examples/example_glfw_metal/main.mm b/examples/example_glfw_metal/main.mm
index d818dba0..2ef6acdf 100644
--- a/examples/example_glfw_metal/main.mm
+++ b/examples/example_glfw_metal/main.mm
@@ -99,7 +99,7 @@ int main(int, char**)
             id<CAMetalDrawable> drawable = [layer nextDrawable];
 
             id<MTLCommandBuffer> commandBuffer = [commandQueue commandBuffer];
-            renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(clear_color[0], clear_color[1], clear_color[2], clear_color[3]);
+            renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(clear_color[0] * clear_color[3], clear_color[1] * clear_color[3], clear_color[2] * clear_color[3], clear_color[3]);
             renderPassDescriptor.colorAttachments[0].texture = drawable.texture;
             renderPassDescriptor.colorAttachments[0].loadAction = MTLLoadActionClear;
             renderPassDescriptor.colorAttachments[0].storeAction = MTLStoreActionStore;
diff --git a/examples/example_glfw_opengl2/main.cpp b/examples/example_glfw_opengl2/main.cpp
index 732ceaed..8cc32328 100644
--- a/examples/example_glfw_opengl2/main.cpp
+++ b/examples/example_glfw_opengl2/main.cpp
@@ -144,7 +144,7 @@ int main(int, char**)
         int display_w, display_h;
         glfwGetFramebufferSize(window, &display_w, &display_h);
         glViewport(0, 0, display_w, display_h);
-        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+        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);
 
         // If you are using this code with non-legacy OpenGL header/contexts (which you should not, prefer using imgui_impl_opengl3.cpp!!),
diff --git a/examples/example_glfw_opengl3/main.cpp b/examples/example_glfw_opengl3/main.cpp
index 6fa93d13..f1ac8cd0 100644
--- a/examples/example_glfw_opengl3/main.cpp
+++ b/examples/example_glfw_opengl3/main.cpp
@@ -208,7 +208,7 @@ int main(int, char**)
         int display_w, display_h;
         glfwGetFramebufferSize(window, &display_w, &display_h);
         glViewport(0, 0, display_w, display_h);
-        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+        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());
     	
diff --git a/examples/example_glfw_vulkan/main.cpp b/examples/example_glfw_vulkan/main.cpp
index baad2195..a2d45b8d 100644
--- a/examples/example_glfw_vulkan/main.cpp
+++ b/examples/example_glfw_vulkan/main.cpp
@@ -530,7 +530,10 @@ int main(int, char**)
         ImGui::Render();
         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);
-        memcpy(&wd->ClearValue.color.float32[0], &clear_color, 4 * sizeof(float));
+        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);
 
diff --git a/examples/example_glut_opengl2/main.cpp b/examples/example_glut_opengl2/main.cpp
index e61e2b21..ee6d3d20 100644
--- a/examples/example_glut_opengl2/main.cpp
+++ b/examples/example_glut_opengl2/main.cpp
@@ -76,7 +76,7 @@ void glut_display_func()
     ImGui::Render();
     ImGuiIO& io = ImGui::GetIO();
     glViewport(0, 0, (GLsizei)io.DisplaySize.x, (GLsizei)io.DisplaySize.y);
-    glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+    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);
     //glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context where shaders may be bound, but prefer using the GL3+ code.
     ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
diff --git a/examples/example_sdl_directx11/main.cpp b/examples/example_sdl_directx11/main.cpp
index 11dc8a0a..c9953f2f 100644
--- a/examples/example_sdl_directx11/main.cpp
+++ b/examples/example_sdl_directx11/main.cpp
@@ -167,8 +167,9 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
+        const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
         g_pd3dDeviceContext->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
-        g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, (float*)&clear_color);
+        g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
 
         // Update and Render additional Platform Windows
diff --git a/examples/example_sdl_metal/main.mm b/examples/example_sdl_metal/main.mm
index 1f33503d..efbccf4c 100644
--- a/examples/example_sdl_metal/main.mm
+++ b/examples/example_sdl_metal/main.mm
@@ -107,7 +107,7 @@ int main(int, char**)
             id<CAMetalDrawable> drawable = [layer nextDrawable];
 
             id<MTLCommandBuffer> commandBuffer = [commandQueue commandBuffer];
-            renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(clear_color[0], clear_color[1], clear_color[2], clear_color[3]);
+            renderPassDescriptor.colorAttachments[0].clearColor = MTLClearColorMake(clear_color[0] * clear_color[3], clear_color[1] * clear_color[3], clear_color[2] * clear_color[3], clear_color[3]);
             renderPassDescriptor.colorAttachments[0].texture = drawable.texture;
             renderPassDescriptor.colorAttachments[0].loadAction = MTLLoadActionClear;
             renderPassDescriptor.colorAttachments[0].storeAction = MTLStoreActionStore;
diff --git a/examples/example_sdl_opengl2/main.cpp b/examples/example_sdl_opengl2/main.cpp
index 388512cc..eeba665d 100644
--- a/examples/example_sdl_opengl2/main.cpp
+++ b/examples/example_sdl_opengl2/main.cpp
@@ -149,7 +149,7 @@ int main(int, char**)
         // Rendering
         ImGui::Render();
         glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
-        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+        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);
         //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());
diff --git a/examples/example_sdl_opengl3/main.cpp b/examples/example_sdl_opengl3/main.cpp
index 4b1896ac..51775fca 100644
--- a/examples/example_sdl_opengl3/main.cpp
+++ b/examples/example_sdl_opengl3/main.cpp
@@ -210,7 +210,7 @@ int main(int, char**)
         // Rendering
         ImGui::Render();
         glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y);
-        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+        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());
 
diff --git a/examples/example_sdl_vulkan/main.cpp b/examples/example_sdl_vulkan/main.cpp
index 59827fb0..22ed3af6 100644
--- a/examples/example_sdl_vulkan/main.cpp
+++ b/examples/example_sdl_vulkan/main.cpp
@@ -531,7 +531,10 @@ int main(int, char**)
         ImGui::Render();
         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);
-        memcpy(&wd->ClearValue.color.float32[0], &clear_color, 4 * sizeof(float));
+        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);
 
diff --git a/examples/example_win32_directx10/main.cpp b/examples/example_win32_directx10/main.cpp
index 49589536..34247b4a 100644
--- a/examples/example_win32_directx10/main.cpp
+++ b/examples/example_win32_directx10/main.cpp
@@ -154,8 +154,9 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
+        const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
         g_pd3dDevice->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
-        g_pd3dDevice->ClearRenderTargetView(g_mainRenderTargetView, (float*)&clear_color);
+        g_pd3dDevice->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX10_RenderDrawData(ImGui::GetDrawData());
 
         // Update and Render additional Platform Windows
diff --git a/examples/example_win32_directx11/main.cpp b/examples/example_win32_directx11/main.cpp
index e6a098d6..9b371e60 100644
--- a/examples/example_win32_directx11/main.cpp
+++ b/examples/example_win32_directx11/main.cpp
@@ -161,8 +161,9 @@ int main(int, char**)
 
         // Rendering
         ImGui::Render();
+        const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
         g_pd3dDeviceContext->OMSetRenderTargets(1, &g_mainRenderTargetView, NULL);
-        g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, (float*)&clear_color);
+        g_pd3dDeviceContext->ClearRenderTargetView(g_mainRenderTargetView, clear_color_with_alpha);
         ImGui_ImplDX11_RenderDrawData(ImGui::GetDrawData());
 
         // Update and Render additional Platform Windows
diff --git a/examples/example_win32_directx12/main.cpp b/examples/example_win32_directx12/main.cpp
index 5cec3616..ab1fd85f 100644
--- a/examples/example_win32_directx12/main.cpp
+++ b/examples/example_win32_directx12/main.cpp
@@ -205,7 +205,8 @@ int main(int, char**)
         g_pd3dCommandList->ResourceBarrier(1, &barrier);
 
         // Render Dear ImGui graphics
-        g_pd3dCommandList->ClearRenderTargetView(g_mainRenderTargetDescriptor[backBufferIdx], (float*)&clear_color, 0, NULL);
+        const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
+        g_pd3dCommandList->ClearRenderTargetView(g_mainRenderTargetDescriptor[backBufferIdx], clear_color_with_alpha, 0, NULL);
         g_pd3dCommandList->OMSetRenderTargets(1, &g_mainRenderTargetDescriptor[backBufferIdx], FALSE, NULL);
         g_pd3dCommandList->SetDescriptorHeaps(1, &g_pd3dSrvDescHeap);
         ImGui_ImplDX12_RenderDrawData(ImGui::GetDrawData(), g_pd3dCommandList);
@@ -348,9 +349,11 @@ bool CreateDeviceD3D(HWND hWnd)
     {
         IDXGIFactory4* dxgiFactory = NULL;
         IDXGISwapChain1* swapChain1 = NULL;
-        if (CreateDXGIFactory1(IID_PPV_ARGS(&dxgiFactory)) != S_OK ||
-            dxgiFactory->CreateSwapChainForHwnd(g_pd3dCommandQueue, hWnd, &sd, NULL, NULL, &swapChain1) != S_OK ||
-            swapChain1->QueryInterface(IID_PPV_ARGS(&g_pSwapChain)) != S_OK)
+        if (CreateDXGIFactory1(IID_PPV_ARGS(&dxgiFactory)) != S_OK)
+            return false;
+        if (dxgiFactory->CreateSwapChainForHwnd(g_pd3dCommandQueue, hWnd, &sd, NULL, NULL, &swapChain1) != S_OK)
+            return false;
+        if (swapChain1->QueryInterface(IID_PPV_ARGS(&g_pSwapChain)) != S_OK)
             return false;
         swapChain1->Release();
         dxgiFactory->Release();
diff --git a/examples/example_win32_directx9/main.cpp b/examples/example_win32_directx9/main.cpp
index c7da3211..1c1a040c 100644
--- a/examples/example_win32_directx9/main.cpp
+++ b/examples/example_win32_directx9/main.cpp
@@ -155,7 +155,7 @@ int main(int, char**)
         g_pd3dDevice->SetRenderState(D3DRS_ZENABLE, FALSE);
         g_pd3dDevice->SetRenderState(D3DRS_ALPHABLENDENABLE, FALSE);
         g_pd3dDevice->SetRenderState(D3DRS_SCISSORTESTENABLE, FALSE);
-        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));
+        D3DCOLOR clear_col_dx = D3DCOLOR_RGBA((int)(clear_color.x*clear_color.w*255.0f), (int)(clear_color.y*clear_color.w*255.0f), (int)(clear_color.z*clear_color.w*255.0f), (int)(clear_color.w*255.0f));
         g_pd3dDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, clear_col_dx, 1.0f, 0);
         if (g_pd3dDevice->BeginScene() >= 0)
         {
@@ -200,7 +200,7 @@ bool CreateDeviceD3D(HWND hWnd)
     ZeroMemory(&g_d3dpp, sizeof(g_d3dpp));
     g_d3dpp.Windowed = TRUE;
     g_d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
-    g_d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
+    g_d3dpp.BackBufferFormat = D3DFMT_UNKNOWN; // Need to use an explicit format with alpha if needing per-pixel alpha composition.
     g_d3dpp.EnableAutoDepthStencil = TRUE;
     g_d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
     g_d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_ONE;           // Present with vsync
diff --git a/imgui.cpp b/imgui.cpp
index 3b6b9ab4..29071b2c 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -1,4 +1,4 @@
-// dear imgui, v1.81
+// dear imgui, v1.82 WIP
 // (main code and documentation)
 
 // Help:
@@ -376,15 +376,16 @@ CODE
  When you are not sure about a old symbol or function name, try using the Search/Find function of your IDE to look for comments or references in all imgui files.
  You can read releases logs https://github.com/ocornut/imgui/releases for more details.
 
- (Docking/Viewport Branch)
- - 2020/XX/XX (1.XX) - when multi-viewports are enabled, all positions will be in your natural OS coordinates space. It means that:
+(Docking/Viewport Branch)
+ - 2021/XX/XX (1.XX) - when multi-viewports are enabled, all 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.
                           you may 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.
- - 2020/XX/XX (1.XX) - Moved IME support functions from io.ImeSetInputScreenPosFn, io.ImeWindowHandle to the PlatformIO api.
+ - 2021/XX/XX (1.XX) - Moved IME support functions from io.ImeSetInputScreenPosFn, io.ImeWindowHandle to the PlatformIO api.
 
 
+ - 2021/02/17 (1.82) - renamed rarely used style.CircleSegmentMaxError (old default = 1.60f) to style.CircleTessellationMaxError (new default = 0.30f) as the meaning of the value changed.
  - 2021/02/03 (1.81) - renamed ListBoxHeader(const char* label, ImVec2 size) to BeginListBox(). Kept inline redirection function (will obsolete).
                      - removed ListBoxHeader(const char* label, int items_count, int height_in_items = -1) in favor of specifying size. Kept inline redirection function (will obsolete).
                      - renamed ListBoxFooter() to EndListBox(). Kept inline redirection function (will obsolete).
@@ -1011,7 +1012,7 @@ ImGuiStyle::ImGuiStyle()
     AntiAliasedLinesUseTex  = true;             // Enable anti-aliased lines/borders using textures where possible. Require backend to render with bilinear filtering.
     AntiAliasedFill         = true;             // Enable anti-aliased filled shapes (rounded rectangles, circles, etc.).
     CurveTessellationTol    = 1.25f;            // Tessellation tolerance when using PathBezierCurveTo() without a specific number of segments. Decrease for highly tessellated curves (higher quality, more polygons), increase to reduce quality.
-    CircleSegmentMaxError   = 1.60f;            // Maximum error (in pixels) allowed when using AddCircle()/AddCircleFilled() or drawing rounded corner rectangles with no explicit segment count specified. Decrease for higher quality but more geometry.
+    CircleTessellationMaxError = 0.30f;         // Maximum error (in pixels) allowed when using AddCircle()/AddCircleFilled() or drawing rounded corner rectangles with no explicit segment count specified. Decrease for higher quality but more geometry.
 
     // Default theme
     ImGui::StyleColorsDark(this);
@@ -4009,7 +4010,7 @@ void ImGui::NewFrame()
         virtual_space.Add(g.Viewports[n]->GetMainRect());
     g.DrawListSharedData.ClipRectFullscreen = virtual_space.ToVec4();
     g.DrawListSharedData.CurveTessellationTol = g.Style.CurveTessellationTol;
-    g.DrawListSharedData.SetCircleSegmentMaxError(g.Style.CircleSegmentMaxError);
+    g.DrawListSharedData.SetCircleTessellationMaxError(g.Style.CircleTessellationMaxError);
     g.DrawListSharedData.InitialFlags = ImDrawListFlags_None;
     if (g.Style.AntiAliasedLines)
         g.DrawListSharedData.InitialFlags |= ImDrawListFlags_AntiAliasedLines;
@@ -5385,9 +5386,10 @@ static ImGuiWindow* GetWindowForTitleAndMenuHeight(ImGuiWindow* window)
     return (window->DockNodeAsHost && window->DockNodeAsHost->VisibleWindow) ? window->DockNodeAsHost->VisibleWindow : window;
 }
 
-static ImVec2 CalcWindowSizeAfterConstraint(ImGuiWindow* window, ImVec2 new_size)
+static ImVec2 CalcWindowSizeAfterConstraint(ImGuiWindow* window, const ImVec2& size_desired)
 {
     ImGuiContext& g = *GImGui;
+    ImVec2 new_size = size_desired;
     if (g.NextWindowData.Flags & ImGuiNextWindowDataFlags_HasSizeConstraint)
     {
         // Using -1,-1 on either X/Y axis to preserve the current size.
@@ -7690,7 +7692,7 @@ static void ImGui::ErrorCheckNewFrameSanityChecks()
     IM_ASSERT(g.IO.Fonts->Fonts.Size > 0                                && "Font Atlas not built. Did you call io.Fonts->GetTexDataAsRGBA32() / GetTexDataAsAlpha8()?");
     IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded()                          && "Font Atlas not built. Did you call io.Fonts->GetTexDataAsRGBA32() / GetTexDataAsAlpha8()?");
     IM_ASSERT(g.Style.CurveTessellationTol > 0.0f                       && "Invalid style setting!");
-    IM_ASSERT(g.Style.CircleSegmentMaxError > 0.0f                      && "Invalid style setting!");
+    IM_ASSERT(g.Style.CircleTessellationMaxError  > 0.0f                && "Invalid style setting!");
     IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f            && "Invalid style setting!"); // Allows us to avoid a few clamps in color computations
     IM_ASSERT(g.Style.WindowMinSize.x >= 1.0f && g.Style.WindowMinSize.y >= 1.0f && "Invalid style setting.");
     IM_ASSERT(g.Style.WindowMenuButtonPosition == ImGuiDir_None || g.Style.WindowMenuButtonPosition == ImGuiDir_Left || g.Style.WindowMenuButtonPosition == ImGuiDir_Right);
diff --git a/imgui.h b/imgui.h
index e17a8200..e6033f28 100644
--- a/imgui.h
+++ b/imgui.h
@@ -1,4 +1,4 @@
-// dear imgui, v1.81
+// dear imgui, v1.82 WIP
 // (headers)
 
 // Help:
@@ -60,8 +60,8 @@ Index of this file:
 
 // Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens)
-#define IMGUI_VERSION               "1.81"
-#define IMGUI_VERSION_NUM           18100
+#define IMGUI_VERSION               "1.82 WIP"
+#define IMGUI_VERSION_NUM           18101
 #define IMGUI_CHECKVERSION()        ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx))
 #define IMGUI_HAS_TABLE
 #define IMGUI_HAS_VIEWPORT          // Viewport WIP branch
@@ -711,7 +711,7 @@ namespace ImGui
     // - You may manually submit headers using TableNextRow() + TableHeader() calls, but this is only useful in
     //   some advanced use cases (e.g. adding custom widgets in header row).
     // - Use TableSetupScrollFreeze() to lock columns/rows so they stay visible when scrolled.
-    IMGUI_API void          TableSetupColumn(const char* label, ImGuiTableColumnFlags flags = 0, float init_width_or_weight = 0.0f, ImU32 user_id = 0);
+    IMGUI_API void          TableSetupColumn(const char* label, ImGuiTableColumnFlags flags = 0, float init_width_or_weight = 0.0f, ImGuiID user_id = 0);
     IMGUI_API void          TableSetupScrollFreeze(int cols, int rows); // lock columns/rows so they stay visible when scrolled.
     IMGUI_API void          TableHeadersRow();                          // submit all headers cells based on data provided to TableSetupColumn() + submit context menu
     IMGUI_API void          TableHeader(const char* label);             // submit one header cell manually (rarely used)
@@ -721,7 +721,7 @@ namespace ImGui
     //   since last call, or the first time. Make sure to set 'SpecsDirty = false' after sorting, else you may
     //   wastefully sort your data every frame!
     // - Lifetime: don't hold on this pointer over multiple frames or past any subsequent call to BeginTable().
-    IMGUI_API ImGuiTableSortSpecs* TableGetSortSpecs();                        // get latest sort specs for the table (NULL if not sorting).
+    IMGUI_API ImGuiTableSortSpecs*  TableGetSortSpecs();                        // get latest sort specs for the table (NULL if not sorting).
     // Tables: Miscellaneous functions
     // - Functions args 'int column_n' treat the default value of -1 as the same as passing the current column index.
     IMGUI_API int                   TableGetColumnCount();                      // return number of columns (value passed to BeginTable)
@@ -1795,7 +1795,7 @@ struct ImGuiStyle
     bool        AntiAliasedLinesUseTex;     // Enable anti-aliased lines/borders using textures where possible. Require backend to render with bilinear filtering. Latched at the beginning of the frame (copied to ImDrawList).
     bool        AntiAliasedFill;            // Enable anti-aliased edges around filled shapes (rounded rectangles, circles, etc.). Disable if you are really tight on CPU/GPU. Latched at the beginning of the frame (copied to ImDrawList).
     float       CurveTessellationTol;       // Tessellation tolerance when using PathBezierCurveTo() without a specific number of segments. Decrease for highly tessellated curves (higher quality, more polygons), increase to reduce quality.
-    float       CircleSegmentMaxError;      // Maximum error (in pixels) allowed when using AddCircle()/AddCircleFilled() or drawing rounded corner rectangles with no explicit segment count specified. Decrease for higher quality but more geometry.
+    float       CircleTessellationMaxError; // Maximum error (in pixels) allowed when using AddCircle()/AddCircleFilled() or drawing rounded corner rectangles with no explicit segment count specified. Decrease for higher quality but more geometry.
     ImVec4      Colors[ImGuiCol_COUNT];
 
     IMGUI_API ImGuiStyle();
@@ -2565,6 +2565,7 @@ struct ImDrawList
     IMGUI_API void  _OnChangedClipRect();
     IMGUI_API void  _OnChangedTextureID();
     IMGUI_API void  _OnChangedVtxOffset();
+    IMGUI_API int   _CalcCircleAutoSegmentCount(float radius) const;
 };
 
 // All draw data to render a Dear ImGui frame
diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index 96cf24d1..aefc16f1 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -1,4 +1,4 @@
-// dear imgui, v1.81
+// dear imgui, v1.82 WIP
 // (demo code)
 
 // Help:
@@ -4913,6 +4913,9 @@ static void ShowDemoWindowTables()
         ImGui::TreePop();
     }
 
+    // In this example we'll expose most table flags and settings.
+    // For specific flags and settings refer to the corresponding section for more detailed explanation.
+    // This section is mostly useful to experiment with combining certain flags or settings with each others.
     //ImGui::SetNextItemOpen(true, ImGuiCond_Once); // [DEBUG]
     if (open_action != -1)
         ImGui::SetNextItemOpen(open_action != 0);
@@ -5051,7 +5054,7 @@ static void ShowDemoWindowTables()
             ImGui::TreePop();
         }
 
-        // Recreate/reset item list if we changed the number of items
+        // Update item list if we changed the number of items
         static ImVector<MyItem> items;
         static ImVector<int> selection;
         static bool items_need_sort = false;
@@ -5073,6 +5076,7 @@ static void ShowDemoWindowTables()
         ImVec2 table_scroll_cur, table_scroll_max; // For debug display
         const ImDrawList* table_draw_list = NULL;  // "
 
+        // Submit table
         const float inner_width_to_use = (flags & ImGuiTableFlags_ScrollX) ? inner_width_with_scroll : 0.0f;
         if (ImGui::BeginTable("table_advanced", 6, flags, outer_size_enabled ? outer_size_value : ImVec2(0, 0), inner_width_to_use))
         {
@@ -5131,9 +5135,9 @@ static void ShowDemoWindowTables()
                     const bool item_is_selected = selection.contains(item->ID);
                     ImGui::PushID(item->ID);
                     ImGui::TableNextRow(ImGuiTableRowFlags_None, row_min_height);
-                    ImGui::TableNextColumn();
 
                     // For the demo purpose we can select among different type of items submitted in the first column
+                    ImGui::TableSetColumnIndex(0);
                     char label[32];
                     sprintf(label, "%04d", item->ID);
                     if (contents_type == CT_Text)
@@ -5164,14 +5168,14 @@ static void ShowDemoWindowTables()
                         }
                     }
 
-                    if (ImGui::TableNextColumn())
+                    if (ImGui::TableSetColumnIndex(1))
                         ImGui::TextUnformatted(item->Name);
 
                     // Here we demonstrate marking our data set as needing to be sorted again if we modified a quantity,
                     // and we are currently sorting on the column showing the Quantity.
                     // To avoid triggering a sort while holding the button, we only trigger it when the button has been released.
                     // You will probably need a more advanced system in your code if you want to automatically sort when a specific entry changes.
-                    if (ImGui::TableNextColumn())
+                    if (ImGui::TableSetColumnIndex(2))
                     {
                         if (ImGui::SmallButton("Chop")) { item->Quantity += 1; }
                         if (sorts_specs_using_quantity && ImGui::IsItemDeactivated()) { items_need_sort = true; }
@@ -5180,16 +5184,16 @@ static void ShowDemoWindowTables()
                         if (sorts_specs_using_quantity && ImGui::IsItemDeactivated()) { items_need_sort = true; }
                     }
 
-                    if (ImGui::TableNextColumn())
+                    if (ImGui::TableSetColumnIndex(3))
                         ImGui::Text("%d", item->Quantity);
 
-                    ImGui::TableNextColumn();
+                    ImGui::TableSetColumnIndex(4);
                     if (show_wrapped_text)
                         ImGui::TextWrapped("Lorem ipsum dolor sit amet");
                     else
                         ImGui::Text("Lorem ipsum dolor sit amet");
 
-                    if (ImGui::TableNextColumn())
+                    if (ImGui::TableSetColumnIndex(5))
                         ImGui::Text("1234");
 
                     ImGui::PopID();
@@ -6108,22 +6112,42 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             if (style.CurveTessellationTol < 0.10f) style.CurveTessellationTol = 0.10f;
 
             // When editing the "Circle Segment Max Error" value, draw a preview of its effect on auto-tessellated circles.
-            ImGui::DragFloat("Circle Segment Max Error", &style.CircleSegmentMaxError, 0.01f, 0.10f, 10.0f, "%.2f");
+            ImGui::DragFloat("Circle Tessellation Max Error", &style.CircleTessellationMaxError , 0.005f, 0.10f, 5.0f, "%.2f", ImGuiSliderFlags_AlwaysClamp);
             if (ImGui::IsItemActive())
             {
                 ImGui::SetNextWindowPos(ImGui::GetCursorScreenPos());
                 ImGui::BeginTooltip();
-                ImVec2 p = ImGui::GetCursorScreenPos();
+                ImGui::TextUnformatted("(R = radius, N = number of segments)");
+                ImGui::Spacing();
                 ImDrawList* draw_list = ImGui::GetWindowDrawList();
-                float RAD_MIN = 10.0f, RAD_MAX = 80.0f;
-                float off_x = 10.0f;
-                for (int n = 0; n < 7; n++)
+                const float min_widget_width = ImGui::CalcTextSize("N: MMM\nR: MMM").x;
+                for (int n = 0; n < 8; n++)
                 {
-                    const float rad = RAD_MIN + (RAD_MAX - RAD_MIN) * (float)n / (7.0f - 1.0f);
-                    draw_list->AddCircle(ImVec2(p.x + off_x + rad, p.y + RAD_MAX), rad, ImGui::GetColorU32(ImGuiCol_Text), 0);
-                    off_x += 10.0f + rad * 2.0f;
+                    const float RAD_MIN = 5.0f;
+                    const float RAD_MAX = 70.0f;
+                    const float rad = RAD_MIN + (RAD_MAX - RAD_MIN) * (float)n / (8.0f - 1.0f);
+
+                    ImGui::BeginGroup();
+
+                    ImGui::Text("R: %.f\nN: %d", rad, draw_list->_CalcCircleAutoSegmentCount(rad));
+
+                    const float canvas_width = IM_MAX(min_widget_width, rad * 2.0f);
+                    const float offset_x     = floorf(canvas_width * 0.5f);
+                    const float offset_y     = floorf(RAD_MAX);
+
+                    const ImVec2 p1 = ImGui::GetCursorScreenPos();
+                    draw_list->AddCircle(ImVec2(p1.x + offset_x, p1.y + offset_y), rad, ImGui::GetColorU32(ImGuiCol_Text));
+                    ImGui::Dummy(ImVec2(canvas_width, RAD_MAX * 2));
+
+                    /*
+                    const ImVec2 p2 = ImGui::GetCursorScreenPos();
+                    draw_list->AddCircleFilled(ImVec2(p2.x + offset_x, p2.y + offset_y), rad, ImGui::GetColorU32(ImGuiCol_Text));
+                    ImGui::Dummy(ImVec2(canvas_width, RAD_MAX * 2));
+                    */
+
+                    ImGui::EndGroup();
+                    ImGui::SameLine();
                 }
-                ImGui::Dummy(ImVec2(off_x, RAD_MAX * 2.0f));
                 ImGui::EndTooltip();
             }
             ImGui::SameLine();
diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index c217ad8e..9bea967e 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp
@@ -1,4 +1,4 @@
-// dear imgui, v1.81
+// dear imgui, v1.82 WIP
 // (drawing and font code)
 
 /*
@@ -382,7 +382,7 @@ ImDrawListSharedData::ImDrawListSharedData()
     }
 }
 
-void ImDrawListSharedData::SetCircleSegmentMaxError(float max_error)
+void ImDrawListSharedData::SetCircleTessellationMaxError(float max_error)
 {
     if (CircleSegmentMaxError == max_error)
         return;
@@ -390,8 +390,7 @@ void ImDrawListSharedData::SetCircleSegmentMaxError(float max_error)
     for (int i = 0; i < IM_ARRAYSIZE(CircleSegmentCounts); i++)
     {
         const float radius = (float)i;
-        const int segment_count = (i > 0) ? IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(radius, CircleSegmentMaxError) : 0;
-        CircleSegmentCounts[i] = (ImU8)ImMin(segment_count, 255);
+        CircleSegmentCounts[i] = (ImU8)((i > 0) ? IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(radius, CircleSegmentMaxError) : 0);
     }
 }
 
@@ -549,6 +548,16 @@ void ImDrawList::_OnChangedVtxOffset()
     curr_cmd->VtxOffset = _CmdHeader.VtxOffset;
 }
 
+int ImDrawList::_CalcCircleAutoSegmentCount(float radius) const
+{
+    // Automatic segment count
+    const int radius_idx = (int)(radius + 0.999f); // ceil to never reduce accuracy
+    if (radius_idx < IM_ARRAYSIZE(_Data->CircleSegmentCounts))
+        return _Data->CircleSegmentCounts[radius_idx]; // Use cached value
+    else
+        return IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(radius, _Data->CircleSegmentMaxError);
+}
+
 // Render-level scissoring. This is passed down to your render function but not used for CPU-side coarse clipping. Prefer using higher-level ImGui::PushClipRect() to affect logic (hit-testing and widget culling)
 void ImDrawList::PushClipRect(ImVec2 cr_min, ImVec2 cr_max, bool intersect_with_current_clip_rect)
 {
@@ -1292,11 +1301,7 @@ void ImDrawList::AddCircle(const ImVec2& center, float radius, ImU32 col, int nu
     if (num_segments <= 0)
     {
         // Automatic segment count
-        const int radius_idx = (int)radius;
-        if (radius_idx < IM_ARRAYSIZE(_Data->CircleSegmentCounts))
-            num_segments = _Data->CircleSegmentCounts[radius_idx]; // Use cached value
-        else
-            num_segments = IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(radius, _Data->CircleSegmentMaxError);
+        num_segments = _CalcCircleAutoSegmentCount(radius);
     }
     else
     {
@@ -1322,11 +1327,7 @@ void ImDrawList::AddCircleFilled(const ImVec2& center, float radius, ImU32 col,
     if (num_segments <= 0)
     {
         // Automatic segment count
-        const int radius_idx = (int)radius;
-        if (radius_idx < IM_ARRAYSIZE(_Data->CircleSegmentCounts))
-            num_segments = _Data->CircleSegmentCounts[radius_idx]; // Use cached value
-        else
-            num_segments = IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(radius, _Data->CircleSegmentMaxError);
+        num_segments = _CalcCircleAutoSegmentCount(radius);
     }
     else
     {
diff --git a/imgui_internal.h b/imgui_internal.h
index b77f8db8..96236360 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -1,4 +1,4 @@
-// dear imgui, v1.81
+// dear imgui, v1.82 WIP
 // (internal structures/api)
 
 // You may use this file to debug, understand or extend ImGui features but we don't provide any guarantee of forward compatibility!
@@ -629,10 +629,20 @@ struct IMGUI_API ImChunkStream
 //-----------------------------------------------------------------------------
 
 // ImDrawList: Helper function to calculate a circle's segment count given its radius and a "maximum error" value.
-// FIXME: the minimum number of auto-segment may be undesirably high for very small radiuses (e.g. 1.0f)
-#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN                     12
+// Estimation of number of circle segment based on error is derived using method described in https://stackoverflow.com/a/2244088/15194693
+// Number of segments (N) is calculated using equation:
+//   N = ceil ( pi / acos(1 - error / r) )     where r > 0, error <= r
+// Our equation is significantly simpler that one in the post thanks for choosing segment that is
+// perpendicular to X axis. Follow steps in the article from this starting condition and you will
+// will get this result.
+//
+// Rendering circles with an odd number of segments, while mathematically correct will produce
+// asymmetrical results on the raster grid. Therefore we're rounding N to next even number (7->8, 8->8, 9->10 etc.)
+//
+#define IM_ROUNDUP_TO_EVEN(_V)                                  ((((_V) + 1) / 2) * 2)
+#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN                     4
 #define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX                     512
-#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(_RAD,_MAXERROR)    ImClamp((int)((IM_PI * 2.0f) / ImAcos(((_RAD) - (_MAXERROR)) / (_RAD))), IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN, IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX)
+#define IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_CALC(_RAD,_MAXERROR)    ImClamp(IM_ROUNDUP_TO_EVEN((int)ImCeil(IM_PI / ImAcos(1 - ImMin((_MAXERROR), (_RAD)) / (_RAD)))), IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MIN, IM_DRAWLIST_CIRCLE_AUTO_SEGMENT_MAX)
 
 // ImDrawList: You may set this to higher values (e.g. 2 or 3) to increase tessellation of fast rounded corners path.
 #ifndef IM_DRAWLIST_ARCFAST_TESSELLATION_MULTIPLIER
@@ -657,7 +667,7 @@ struct IMGUI_API ImDrawListSharedData
     const ImVec4*   TexUvLines;                 // UV of anti-aliased lines in the atlas
 
     ImDrawListSharedData();
-    void SetCircleSegmentMaxError(float max_error);
+    void SetCircleTessellationMaxError(float max_error);
 };
 
 struct ImDrawDataBuilder
@@ -2308,9 +2318,10 @@ struct ImGuiTable
     ImGuiTableColumnIdx         HeldHeaderColumn;           // Index of column header being held.
     ImGuiTableColumnIdx         ReorderColumn;              // Index of column being reordered. (not cleared)
     ImGuiTableColumnIdx         ReorderColumnDir;           // -1 or +1
+    ImGuiTableColumnIdx         LeftMostEnabledColumn;      // Index of left-most non-hidden column.
+    ImGuiTableColumnIdx         RightMostEnabledColumn;     // Index of right-most non-hidden column.
     ImGuiTableColumnIdx         LeftMostStretchedColumn;    // Index of left-most stretched column.
     ImGuiTableColumnIdx         RightMostStretchedColumn;   // Index of right-most stretched column.
-    ImGuiTableColumnIdx         RightMostEnabledColumn;     // Index of right-most non-hidden column.
     ImGuiTableColumnIdx         ContextPopupColumn;         // Column right-clicked on, of -1 if opening context menu from a neutral/empty spot
     ImGuiTableColumnIdx         FreezeRowsRequest;          // Requested frozen rows count
     ImGuiTableColumnIdx         FreezeRowsCount;            // Actual frozen row count (== FreezeRowsRequest, or == 0 when no scrolling offset)
@@ -2618,6 +2629,7 @@ namespace ImGui
     IMGUI_API void          TablePopBackgroundChannel();
 
     // Tables: Internals
+    inline    ImGuiTable*   GetCurrentTable() { ImGuiContext& g = *GImGui; return g.CurrentTable; }
     IMGUI_API ImGuiTable*   TableFindByID(ImGuiID id);
     IMGUI_API bool          BeginTableEx(const char* name, ImGuiID id, int columns_count, ImGuiTableFlags flags = 0, const ImVec2& outer_size = ImVec2(0, 0), float inner_width = 0.0f);
     IMGUI_API void          TableBeginInitMemory(ImGuiTable* table, int columns_count);
diff --git a/imgui_tables.cpp b/imgui_tables.cpp
index 61a84f9f..a34ab42f 100644
--- a/imgui_tables.cpp
+++ b/imgui_tables.cpp
@@ -1,4 +1,4 @@
-// dear imgui, v1.81
+// dear imgui, v1.82 WIP
 // (tables and columns code)
 
 /*
@@ -687,13 +687,14 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
     table->ColumnsEnabledCount = 0;
     table->EnabledMaskByIndex = 0x00;
     table->EnabledMaskByDisplayOrder = 0x00;
+    table->LeftMostEnabledColumn = -1;
     table->MinColumnWidth = ImMax(1.0f, g.Style.FramePadding.x * 1.0f); // g.Style.ColumnsMinSpacing; // FIXME-TABLE
 
     // [Part 1] Apply/lock Enabled and Order states. Calculate auto/ideal width for columns. Count fixed/stretch columns.
     // Process columns in their visible orders as we are building the Prev/Next indices.
     int count_fixed = 0;                // Number of columns that have fixed sizing policies
     int count_stretch = 0;              // Number of columns that have stretch sizing policies
-    int last_visible_column_idx = -1;
+    int prev_visible_column_idx = -1;
     bool has_auto_fit_request = false;
     bool has_resizable = false;
     float stretch_sum_width_auto = 0.0f;
@@ -741,14 +742,16 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
         }
 
         // Mark as enabled and link to previous/next enabled column
-        column->PrevEnabledColumn = (ImGuiTableColumnIdx)last_visible_column_idx;
+        column->PrevEnabledColumn = (ImGuiTableColumnIdx)prev_visible_column_idx;
         column->NextEnabledColumn = -1;
-        if (last_visible_column_idx != -1)
-            table->Columns[last_visible_column_idx].NextEnabledColumn = (ImGuiTableColumnIdx)column_n;
+        if (prev_visible_column_idx != -1)
+            table->Columns[prev_visible_column_idx].NextEnabledColumn = (ImGuiTableColumnIdx)column_n;
+        else
+            table->LeftMostEnabledColumn = (ImGuiTableColumnIdx)column_n;
         column->IndexWithinEnabledSet = table->ColumnsEnabledCount++;
         table->EnabledMaskByIndex |= (ImU64)1 << column_n;
         table->EnabledMaskByDisplayOrder |= (ImU64)1 << column->DisplayOrder;
-        last_visible_column_idx = column_n;
+        prev_visible_column_idx = column_n;
         IM_ASSERT(column->IndexWithinEnabledSet <= column->DisplayOrder);
 
         // Calculate ideal/auto column width (that's the width required for all contents to be visible without clipping)
@@ -778,8 +781,8 @@ void ImGui::TableUpdateLayout(ImGuiTable* table)
     }
     if ((table->Flags & ImGuiTableFlags_Sortable) && table->SortSpecsCount == 0 && !(table->Flags & ImGuiTableFlags_SortTristate))
         table->IsSortSpecsDirty = true;
-    table->RightMostEnabledColumn = (ImGuiTableColumnIdx)last_visible_column_idx;
-    IM_ASSERT(table->RightMostEnabledColumn >= 0);
+    table->RightMostEnabledColumn = (ImGuiTableColumnIdx)prev_visible_column_idx;
+    IM_ASSERT(table->LeftMostEnabledColumn >= 0 && table->RightMostEnabledColumn >= 0);
 
     // [Part 2] Disable child window clipping while fitting columns. This is not strictly necessary but makes it possible
     // to avoid the column fitting having to wait until the first visible frame of the child container (may or not be a good thing).
diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp
index b6175368..fb09a659 100644
--- a/imgui_widgets.cpp
+++ b/imgui_widgets.cpp
@@ -1,4 +1,4 @@
-// dear imgui, v1.81
+// dear imgui, v1.82 WIP
 // (widgets code)
 
 /*