Implement ImGui additive rendering. (#152)

UnleashedRecomp/gpu/imgui/imgui_common.h

@@ -22,6 +22,7 @@ enum class ImGuiCallback : int32_t
     SetOutline = -6,
     SetProceduralOrigin = -7,
     // -8 is ImDrawCallback_ResetRenderState, don't use!
+    SetAdditive = -9
 };
 
 union ImGuiCallbackData
@@ -64,6 +65,11 @@ union ImGuiCallbackData
     {
         float proceduralOrigin[2];
     } setProceduralOrigin;
+
+    struct
+    {
+        bool enabled;
+    } setAdditive;
 };
 
 extern ImGuiCallbackData* AddImGuiCallback(ImGuiCallback callback);

UnleashedRecomp/gpu/rhi/plume_render_interface_types.h

@@ -1127,7 +1127,7 @@ namespace plume {
             desc.srcBlend = RenderBlend::SRC_ALPHA;
             desc.dstBlend = RenderBlend::INV_SRC_ALPHA;
             desc.blendOp = RenderBlendOperation::ADD;
-            desc.srcBlendAlpha = RenderBlend::ONE;
+            desc.srcBlendAlpha = RenderBlend::SRC_ALPHA;
             desc.dstBlendAlpha = RenderBlend::INV_SRC_ALPHA;
             desc.blendOpAlpha = RenderBlendOperation::ADD;
             return desc;

UnleashedRecomp/gpu/video.cpp

@@ -1141,6 +1141,7 @@ static constexpr size_t SAMPLER_DESCRIPTOR_SIZE = 1024;
 static std::unique_ptr<GuestTexture> g_imFontTexture;
 static std::unique_ptr<RenderPipelineLayout> g_imPipelineLayout;
 static std::unique_ptr<RenderPipeline> g_imPipeline;
+static std::unique_ptr<RenderPipeline> g_imAdditivePipeline;
 
 template<typename T>
 static void ExecuteCopyCommandList(const T& function)
@@ -1309,6 +1310,9 @@ static void CreateImGuiBackend()
     pipelineDesc.inputSlotsCount = 1;
     g_imPipeline = g_device->createGraphicsPipeline(pipelineDesc);
 
+    pipelineDesc.renderTargetBlend[0].dstBlend = RenderBlend::ONE;
+    g_imAdditivePipeline = g_device->createGraphicsPipeline(pipelineDesc);
+
 #ifndef ENABLE_IM_FONT_ATLAS_SNAPSHOT
     ImFontAtlasSnapshot snapshot;
     snapshot.Snap();
@@ -2091,9 +2095,10 @@ static void ProcDrawImGui(const RenderCommand& cmd)
     SetFramebuffer(g_backBuffer, nullptr, false);
 
     auto& commandList = g_commandLists[g_frame];
+    auto pipeline = g_imPipeline.get();
 
     commandList->setGraphicsPipelineLayout(g_imPipelineLayout.get());
-    commandList->setPipeline(g_imPipeline.get());
+    commandList->setPipeline(pipeline);
     commandList->setGraphicsDescriptorSet(g_textureDescriptorSet.get(), 0);
     commandList->setGraphicsDescriptorSet(g_samplerDescriptorSet.get(), 1);
 
@@ -2167,6 +2172,16 @@ static void ProcDrawImGui(const RenderCommand& cmd)
                 case ImGuiCallback::SetProceduralOrigin:
                     setPushConstants(&pushConstants.proceduralOrigin, &callbackData->setProceduralOrigin, sizeof(callbackData->setProceduralOrigin));
                     break;
+                case ImGuiCallback::SetAdditive:
+                {
+                    auto pipelineToSet = callbackData->setAdditive.enabled ? g_imAdditivePipeline.get() : g_imPipeline.get();
+                    if (pipeline != pipelineToSet)
+                    {
+                        commandList->setPipeline(pipelineToSet);
+                        pipeline = pipelineToSet;
+                    }
+                    break;
+                }
                 default:
                     assert(false && "Unknown ImGui callback type.");
                     break;

UnleashedRecomp/ui/imgui_utils.h

@@ -108,6 +108,17 @@ inline void ResetProceduralOrigin()
     SetProceduralOrigin({ 0.0f, 0.0f });
 }
 
+inline void SetAdditive(bool enabled)
+{
+    auto callbackData = AddImGuiCallback(ImGuiCallback::SetAdditive);
+    callbackData->setAdditive.enabled = enabled;
+}
+
+inline void ResetAdditive()
+{
+    SetAdditive(false);
+}
+
 inline float Scale(float size)
 {
     return size * g_aspectRatioScale;

UnleashedRecomp/ui/installer_wizard.cpp

@@ -613,13 +613,15 @@ static void DrawContainer(ImVec2 min, ImVec2 max, bool isTextArea)
     );
     double gridOverlayAlpha = ComputeMotionInstaller(g_appearTime, g_disappearTime, CONTAINER_INNER_TIME, CONTAINER_INNER_DURATION);
 
-    const uint32_t gridColor = IM_COL32(0, 33, 0, (isTextArea ? 128 : 255) * gridAlpha);
+    const uint32_t gridColor = IM_COL32(0, 33, 0, (isTextArea ? 223 : 255) * gridAlpha);
     const uint32_t gridOverlayColor = IM_COL32(0, 32, 0, 128 * gridOverlayAlpha);
 
     float gridSize = Scale(GRID_SIZE);
 
     SetShaderModifier(IMGUI_SHADER_MODIFIER_CHECKERBOARD);
+    SetAdditive(true);
     drawList->AddRectFilled(min, max, gridColor);
+    SetAdditive(false);
     SetShaderModifier(IMGUI_SHADER_MODIFIER_NONE);
 
     if (isTextArea)