Formalize directional shadow runtime contracts

engine/src/Rendering/Shadow/DirectionalShadowData.cpp

@@ -0,0 +1,33 @@
+#include "Rendering/Shadow/DirectionalShadowData.h"
+
+namespace XCEngine {
+namespace Rendering {
+
+RenderDirectionalShadowData BuildRenderDirectionalShadowData(
+    const DirectionalShadowRenderPlan& plan,
+    RHI::RHIResourceView* shadowMapView) {
+    RenderDirectionalShadowData shadowData = {};
+    if (!plan.IsValid() || shadowMapView == nullptr) {
+        return shadowData;
+    }
+
+    shadowData.enabled = true;
+    shadowData.viewProjection = plan.cameraData.viewProjection;
+    shadowData.shadowMap = shadowMapView;
+    const float texelWorldSize = plan.texelWorldSize > Math::EPSILON
+        ? plan.texelWorldSize
+        : (plan.orthographicHalfExtent > Math::EPSILON && plan.mapWidth > 0u
+            ? (plan.orthographicHalfExtent * 2.0f) / static_cast<float>(plan.mapWidth)
+            : 0.0f);
+    shadowData.mapMetrics.inverseMapSize = Math::Vector2(
+        1.0f / static_cast<float>(plan.mapWidth),
+        1.0f / static_cast<float>(plan.mapHeight));
+    shadowData.mapMetrics.worldTexelSize = texelWorldSize;
+    shadowData.sampling.enabled = 1.0f;
+    shadowData.sampling.settings = plan.sampling;
+    shadowData.casterBias.settings = plan.casterBias;
+    return shadowData;
+}
+
+} // namespace Rendering
+} // namespace XCEngine