初始提交: UE5.3项目基础框架

Plugins/CesiumForUnreal/Source/CesiumRuntime/Private/CesiumViewExtension.h

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+// Copyright 2020-2024 CesiumGS, Inc. and Contributors
+
+#pragma once
+
+#include "Containers/Queue.h"
+#include "Containers/Set.h"
+#include "Runtime/Renderer/Private/ScenePrivate.h"
+#include "SceneTypes.h"
+#include "SceneView.h"
+#include "SceneViewExtension.h"
+#include <Cesium3DTilesSelection/TileOcclusionRendererProxy.h>
+#include <cstdint>
+#include <unordered_set>
+
+class ACesium3DTileset;
+
+class CesiumViewExtension : public FSceneViewExtensionBase {
+private:
+  // Occlusion results for a single view.
+  struct PrimitiveOcclusionResult {
+    PrimitiveOcclusionResult(
+        const FPrimitiveComponentId primitiveId,
+        float lastConsideredTime,
+        float lastPixelsPercentage,
+        bool occlusionStateWasDefiniteLastFrame,
+        bool wasOccludedLastFrame)
+        : PrimitiveId(primitiveId),
+          LastConsideredTime(lastConsideredTime),
+          LastPixelsPercentage(lastPixelsPercentage),
+          OcclusionStateWasDefiniteLastFrame(
+              occlusionStateWasDefiniteLastFrame),
+          WasOccludedLastFrame(wasOccludedLastFrame) {}
+
+    PrimitiveOcclusionResult(const FPrimitiveOcclusionHistory& renderer)
+        : PrimitiveId(renderer.PrimitiveId),
+          LastConsideredTime(renderer.LastConsideredTime),
+          LastPixelsPercentage(renderer.LastPixelsPercentage),
+          OcclusionStateWasDefiniteLastFrame(
+              renderer.OcclusionStateWasDefiniteLastFrame),
+          WasOccludedLastFrame(renderer.WasOccludedLastFrame) {}
+
+    FPrimitiveComponentId PrimitiveId;
+    float LastConsideredTime;
+    float LastPixelsPercentage;
+    bool OcclusionStateWasDefiniteLastFrame;
+    bool WasOccludedLastFrame;
+  };
+
+  // Defines how PrimitiveOcclusionResult is stored in a TSet
+  struct PrimitiveOcclusionResultKeyFuncs
+      : BaseKeyFuncs<PrimitiveOcclusionResult, FPrimitiveComponentId> {
+    typedef FPrimitiveComponentId KeyInitType;
+
+    static KeyInitType GetSetKey(const PrimitiveOcclusionResult& Element) {
+      return Element.PrimitiveId;
+    }
+
+    static bool Matches(KeyInitType A, KeyInitType B) { return A == B; }
+
+    static uint32 GetKeyHash(KeyInitType Key) {
+      return GetTypeHash(Key.PrimIDValue);
+    }
+  };
+
+  // The occlusion results for a single view.
+  struct SceneViewOcclusionResults {
+    const FSceneView* pView = nullptr;
+    TSet<PrimitiveOcclusionResult, PrimitiveOcclusionResultKeyFuncs>
+        PrimitiveOcclusionResults{};
+  };
+
+  // A collection of occlusion results by view.
+  struct AggregatedOcclusionUpdate {
+    std::vector<SceneViewOcclusionResults> occlusionResultsByView{};
+  };
+
+  // The current collection of occlusion results for this frame.
+  AggregatedOcclusionUpdate _currentAggregation_renderThread{};
+  AggregatedOcclusionUpdate _currentOcclusionResults{};
+
+  // A queue to pass occlusion results from the render thread to the game
+  // thread.
+  TQueue<AggregatedOcclusionUpdate, EQueueMode::Spsc> _occlusionResultsQueue;
+
+  // A queue to recycle the previously-allocated occlusion result sets. The
+  // game thread recycles the sets by moving them into the queue and sending
+  // them back to the render thread.
+  TQueue<
+      TSet<PrimitiveOcclusionResult, PrimitiveOcclusionResultKeyFuncs>,
+      EQueueMode::Spsc>
+      _recycledOcclusionResultSets;
+
+  // The last known frame number. This is used to determine when an occlusion
+  // results aggregation is complete.
+  int64_t _frameNumber_renderThread = -1;
+
+  std::atomic<bool> _isEnabled = false;
+
+public:
+  CesiumViewExtension(const FAutoRegister& autoRegister);
+  ~CesiumViewExtension();
+
+  Cesium3DTilesSelection::TileOcclusionState getPrimitiveOcclusionState(
+      const FPrimitiveComponentId& id,
+      bool previouslyOccluded,
+      float frameTimeCutoff) const;
+
+  void SetupViewFamily(FSceneViewFamily& InViewFamily) override;
+  void SetupView(FSceneViewFamily& InViewFamily, FSceneView& InView) override;
+  void BeginRenderViewFamily(FSceneViewFamily& InViewFamily) override;
+  void PostRenderViewFamily_RenderThread(
+      FRDGBuilder& GraphBuilder,
+      FSceneViewFamily& InViewFamily) override;
+
+  void SetEnabled(bool enabled);
+};