ImGui renderer: added option to control srgb->linear color conversion

DiligentGraphics · Jun 9, 2023 · e2b3d90 · e2b3d90
1 parent 66e2439
commit e2b3d90
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Showing 3 changed files with 38 additions and 14 deletions.
diff --git a/Imgui/interface/ImGuiDiligentRenderer.hpp b/Imgui/interface/ImGuiDiligentRenderer.hpp
@@ -49,6 +49,7 @@ struct IShaderResourceVariable;
 struct ImGuiDiligentCreateInfo;
 enum TEXTURE_FORMAT : Uint16;
 enum SURFACE_TRANSFORM : Uint32;
+enum IMGUI_COLOR_CONVERSION_MODE : Uint8;
 
 class ImGuiDiligentRenderer
 {
@@ -78,14 +79,15 @@ class ImGuiDiligentRenderer
     RefCntAutoPtr<IShaderResourceBinding> m_pSRB;
     IShaderResourceVariable*              m_pTextureVar = nullptr;
 
-    const TEXTURE_FORMAT m_BackBufferFmt;
-    const TEXTURE_FORMAT m_DepthBufferFmt;
-    Uint32               m_VertexBufferSize    = 0;
-    Uint32               m_IndexBufferSize     = 0;
-    Uint32               m_RenderSurfaceWidth  = 0;
-    Uint32               m_RenderSurfaceHeight = 0;
-    SURFACE_TRANSFORM    m_SurfacePreTransform = SURFACE_TRANSFORM_IDENTITY;
-    bool                 m_BaseVertexSupported = false;
+    const TEXTURE_FORMAT              m_BackBufferFmt;
+    const TEXTURE_FORMAT              m_DepthBufferFmt;
+    Uint32                            m_VertexBufferSize    = 0;
+    Uint32                            m_IndexBufferSize     = 0;
+    Uint32                            m_RenderSurfaceWidth  = 0;
+    Uint32                            m_RenderSurfaceHeight = 0;
+    SURFACE_TRANSFORM                 m_SurfacePreTransform = SURFACE_TRANSFORM_IDENTITY;
+    const IMGUI_COLOR_CONVERSION_MODE m_ColorConversionMode;
+    bool                              m_BaseVertexSupported = false;
 };
 
 } // namespace Diligent
diff --git a/Imgui/interface/ImGuiImplDiligent.hpp b/Imgui/interface/ImGuiImplDiligent.hpp
@@ -41,6 +41,25 @@ enum SURFACE_TRANSFORM : Uint32;
 
 class ImGuiDiligentRenderer;
 
+/// Conversion mode to apply to imgui colors.
+///
+/// \remarks    Imgui colors are defined in sRGB space.
+///             Depending on the use case, they may need
+///             to be converted to linear space.
+enum IMGUI_COLOR_CONVERSION_MODE : Uint8
+{
+    /// Select the color conversion mode automatically:
+    /// * Use SRGB_TO_LINEAR mode for sRGB framebuffers
+    /// * Use NONE mode for non-sRGB framebuffers
+    IMGUI_COLOR_CONVERSION_MODE_AUTO = 0,
+
+    /// Always perform srgb-to-linear conversion.
+    IMGUI_COLOR_CONVERSION_MODE_SRGB_TO_LINEAR,
+
+    /// Do not perform any color conversion.
+    IMGUI_COLOR_CONVERSION_MODE_NONE
+};
+
 struct ImGuiDiligentCreateInfo
 {
     static constexpr Uint32 DefaultInitialVBSize = 1024;
@@ -51,6 +70,8 @@ struct ImGuiDiligentCreateInfo
     TEXTURE_FORMAT BackBufferFmt  = {};
     TEXTURE_FORMAT DepthBufferFmt = {};
 
+    IMGUI_COLOR_CONVERSION_MODE ColorConversion = IMGUI_COLOR_CONVERSION_MODE_AUTO;
+
     Uint32 InitialVertexBufferSize = DefaultInitialVBSize;
     Uint32 InitialIndexBufferSize  = DefaultInitialIBSize;
 

diff --git a/Imgui/src/ImGuiDiligentRenderer.cpp b/Imgui/src/ImGuiDiligentRenderer.cpp
@@ -411,11 +411,12 @@ fragment PSOut ps_main(VSOut in [[stage_in]],
 
 ImGuiDiligentRenderer::ImGuiDiligentRenderer(const ImGuiDiligentCreateInfo& CI) :
     // clang-format off
-    m_pDevice         {CI.pDevice},
-    m_BackBufferFmt   {CI.BackBufferFmt},
-    m_DepthBufferFmt  {CI.DepthBufferFmt},
-    m_VertexBufferSize{CI.InitialVertexBufferSize},
-    m_IndexBufferSize {CI.InitialIndexBufferSize}
+    m_pDevice            {CI.pDevice},
+    m_BackBufferFmt      {CI.BackBufferFmt},
+    m_DepthBufferFmt     {CI.DepthBufferFmt},
+    m_VertexBufferSize   {CI.InitialVertexBufferSize},
+    m_IndexBufferSize    {CI.InitialIndexBufferSize},
+    m_ColorConversionMode{CI.ColorConversion}
 // clang-format on
 {
     //Check base vertex support
@@ -469,7 +470,7 @@ void ImGuiDiligentRenderer::CreateDeviceObjects()
     ShaderCI.SourceLanguage = SHADER_SOURCE_LANGUAGE_DEFAULT;
 
     const auto IsSRB = GetTextureFormatAttribs(m_BackBufferFmt).ComponentType == COMPONENT_TYPE_UNORM_SRGB;
-    if (IsSRB)
+    if ((m_ColorConversionMode == IMGUI_COLOR_CONVERSION_MODE_AUTO && IsSRB) || (m_ColorConversionMode == IMGUI_COLOR_CONVERSION_MODE_SRGB_TO_LINEAR))
     {
         static constexpr ShaderMacro Macros[] =
             {