Formalize directional shadow runtime contracts

engine/src/Rendering/Shadow/DirectionalShadowRuntime.cpp

@@ -0,0 +1,44 @@
+#include "Rendering/Shadow/DirectionalShadowRuntime.h"
+
+#include "Rendering/Execution/CameraFramePlan.h"
+#include "Rendering/Shadow/DirectionalShadowData.h"
+
+namespace XCEngine {
+namespace Rendering {
+
+bool DirectionalShadowRuntime::ResolveExecutionState(
+    const CameraFramePlan& plan,
+    DirectionalShadowExecutionState& outShadowState) {
+    outShadowState = {};
+    outShadowState.shadowCasterRequest = plan.shadowCaster;
+
+    if (outShadowState.shadowCasterRequest.IsRequested()) {
+        return outShadowState.shadowCasterRequest.IsValid();
+    }
+
+    if (!plan.directionalShadow.IsValid()) {
+        return true;
+    }
+
+    const DirectionalShadowSurfaceAllocation* shadowAllocation =
+        m_surfaceCache.Resolve(plan.request.context, plan.directionalShadow);
+    if (shadowAllocation == nullptr || !shadowAllocation->IsValid()) {
+        return false;
+    }
+
+    outShadowState.shadowCasterRequest.surface = shadowAllocation->surface;
+    outShadowState.shadowCasterRequest.clearFlags = RenderClearFlags::Depth;
+    if (!outShadowState.shadowCasterRequest.hasCameraDataOverride) {
+        outShadowState.shadowCasterRequest.hasCameraDataOverride = true;
+        outShadowState.shadowCasterRequest.cameraDataOverride = plan.directionalShadow.cameraData;
+    }
+
+    outShadowState.shadowData =
+        BuildRenderDirectionalShadowData(
+            plan.directionalShadow,
+            shadowAllocation->depthShaderView);
+    return true;
+}
+
+} // namespace Rendering
+} // namespace XCEngine