feat(动画): 添加角色动作合成纹理功能

实现角色动作的离屏渲染合成功能，支持获取合成纹理及其相关信息：
1. 新增CanvasActor用于离屏渲染
2. 新增RenderTexture封装FBO和纹理
3. 扩展Renderer支持离屏渲染到纹理
4. 为CharacterAnimation添加合成纹理生成逻辑
5. 在调试界面添加合成纹理预览功能

Game/include/character/CharacterAnimation.h

@@ -3,6 +3,7 @@
 #include "character/CharacterDataLoader.h"
 #include "character/CharacterEquipmentManager.h"
 #include <frostbite2D/2d/actor.h>
+#include <frostbite2D/2d/canvas_actor.h>
 #include <frostbite2D/animation/animation.h>
 #include <frostbite2D/base/RefPtr.h>
 #include <functional>
@@ -21,9 +22,20 @@ public:
   using ActionFrameFlagCallback = std::function<void(int)>;
   using ActionEndCallback = std::function<void()>;
 
+  struct CompositeFrameInfo {
+    bool valid = false;
+    Rect localBounds;
+    Vec2 originInTexture = Vec2::Zero();
+    Vec2 groundAnchorInTexture = Vec2::Zero();
+    int width = 1;
+    int height = 1;
+  };
+
   bool Init(CharacterObject* parent,
             const character::CharacterConfig& config,
             const CharacterEquipmentManager& equipmentManager);
+  void Update(float deltaTime) override;
+  void Render() override;
 
   bool SetAction(const std::string& actionName);
   void SetDirection(int direction);
@@ -39,6 +51,12 @@ public:
   animation::AniFrame GetCurrentFrameInfo() const;
   void SetActionFrameFlagCallback(ActionFrameFlagCallback callback);
   void SetActionEndCallback(ActionEndCallback callback);
+  bool HasCompositeTexture() const;
+  Ptr<Texture> GetCompositeTexture() const;
+  Vec2 GetCompositeTextureSize() const;
+  Vec2 GetCompositeOriginInTexture() const;
+  Vec2 GetCompositeGroundAnchorInTexture() const;
+  uint64 GetCompositeVersion() const { return compositeVersion_; }
 
 private:
   static std::string FormatImgPath(std::string path, Animation::ReplaceData data);
@@ -46,6 +64,15 @@ private:
   Animation* GetCurrentPrimaryAnimation() const;
   void RefreshRuntimeCallbacks();
   bool shouldSkipMissingAnimation(const std::string& aniPath);
+  void BuildCompositeActionFrames();
+  CompositeFrameInfo ComputeCompositeFrameInfo(const std::vector<RefPtr<Animation>>& animations,
+                                               int direction) const;
+  CompositeFrameInfo GetCurrentCompositeFrameInfo() const;
+  uint64 CaptureCurrentRenderSignature() const;
+  void MarkCompositeDirty();
+  void UpdateCompositeCamera();
+  void RefreshCompositeTextureIfNeeded();
+  void RenderCurrentActionToCompositeCanvas();
 
   void CreateAnimationBySlot(const std::string& actionName,
                              const std::string& slotName,
@@ -61,6 +88,11 @@ private:
   ActionEndCallback actionEndCallback_;
   std::unordered_set<std::string> missingAnimationPaths_;
   size_t skippedMissingAnimationCount_ = 0;
+  RefPtr<CanvasActor> compositeCanvas_ = nullptr;
+  std::map<std::string, CompositeFrameInfo> compositeFrameInfoByAction_;
+  bool compositeDirty_ = true;
+  uint64 compositeVersion_ = 0;
+  uint64 lastCompositeSignature_ = 0;
 };
 
 } // namespace frostbite2D