Formalize fullscreen render request contract

engine/include/XCEngine/Rendering/Planning/CameraRenderRequest.h

@@ -109,6 +109,20 @@ inline bool HasValidColorTarget(const RenderSurface& surface) {
            surface.GetRenderAreaHeight() > 0;
 }
 
+inline bool HasValidSurfaceSampleDescription(const RenderSurface& surface) {
+    const uint32_t sampleCount = surface.GetSampleCount();
+    const uint32_t sampleQuality = surface.GetSampleQuality();
+    return sampleCount > 0u &&
+           (sampleCount > 1u || sampleQuality == 0u);
+}
+
+inline bool HasValidSingleSampleColorSource(const RenderSurface& surface) {
+    return HasValidColorTarget(surface) &&
+           HasValidSurfaceSampleDescription(surface) &&
+           surface.GetSampleCount() == 1u &&
+           surface.GetSampleQuality() == 0u;
+}
+
 struct DirectionalShadowRenderPlan {
     bool enabled = false;
     Math::Vector3 lightDirection = Math::Vector3::Back();
@@ -149,6 +163,7 @@ struct ObjectIdRenderRequest {
 struct FullscreenPassRenderRequest {
     RenderSurface sourceSurface;
     RHI::RHIResourceView* sourceColorView = nullptr;
+    RHI::ResourceStates sourceColorState = RHI::ResourceStates::Common;
     RenderSurface destinationSurface;
     RenderPassSequence* passes = nullptr;
 
@@ -165,10 +180,15 @@ struct FullscreenPassRenderRequest {
     }
 
     bool IsValid() const {
+        const bool sourceStateIsUsable =
+            sourceSurface.IsAutoTransitionEnabled() ||
+            sourceColorState == RHI::ResourceStates::PixelShaderResource;
         return passes != nullptr &&
-               HasValidColorTarget(sourceSurface) &&
+               HasValidSingleSampleColorSource(sourceSurface) &&
                sourceColorView != nullptr &&
-               HasValidColorTarget(destinationSurface);
+               sourceStateIsUsable &&
+               HasValidColorTarget(destinationSurface) &&
+               HasValidSurfaceSampleDescription(destinationSurface);
     }
 };
 
@@ -322,6 +342,17 @@ struct CameraRenderRequest {
         }
     }
 
+    RHI::ResourceStates GetSourceColorState(CameraFrameStage stage) const {
+        switch (stage) {
+        case CameraFrameStage::PostProcess:
+            return postProcess.IsRequested() ? postProcess.sourceColorState : RHI::ResourceStates::Common;
+        case CameraFrameStage::FinalOutput:
+            return finalOutput.IsRequested() ? finalOutput.sourceColorState : RHI::ResourceStates::Common;
+        default:
+            return RHI::ResourceStates::Common;
+        }
+    }
+
     bool RequiresIntermediateSceneColor() const {
         return postProcess.IsRequested() || finalOutput.IsRequested();
     }