feat(sprite): 添加偏移量支持并优化NPK精灵创建

添加Sprite类的偏移量属性，支持设置和获取偏移量
修改NPK精灵创建逻辑，自动设置帧偏移量
注释掉main.cpp中不必要的锚点设置

Frostbite2D/include/frostbite2D/2d/sprite.h

@@ -45,6 +45,10 @@ public:
 
   void SetSizeToTexture();
 
+  const Vec2& GetOffset() const { return offset_; }
+  void SetOffset(const Vec2& offset);
+  void SetOffset(float x, float y);
+
 private:
   void updateTransform();
   Shader* getActiveShader() const;
@@ -57,6 +61,7 @@ private:
   bool flippedX_ = false;
   bool flippedY_ = false;
   BlendMode blendMode_ = BlendMode::Normal;
+  Vec2 offset_ = Vec2::Zero();
   Transform2D transform_;
 
   static constexpr const char* DEFAULT_SHADER = "sprite";

Frostbite2D/src/frostbite2D/2d/sprite.cpp

@@ -90,7 +90,12 @@ void Sprite::Render() {
     shader->use();
   }
   
-  renderer.getBatch().submitQuad(quad, GetWorldTransform(), texture_, shader, blendMode_);
+  Transform2D worldTransform = GetWorldTransform();
+  if (offset_ != Vec2::Zero()) {
+    worldTransform = Transform2D::translation(offset_.x, offset_.y) * worldTransform;
+  }
+  
+  renderer.getBatch().submitQuad(quad, worldTransform, texture_, shader, blendMode_);
 
   RenderChildren();
 }
@@ -137,6 +142,15 @@ void Sprite::SetSizeToTexture() {
   }
 }
 
+void Sprite::SetOffset(const Vec2& offset) {
+  offset_ = offset;
+}
+
+void Sprite::SetOffset(float x, float y) {
+  offset_.x = x;
+  offset_.y = y;
+}
+
 void Sprite::updateTransform() {
   Vec2 pos = GetPosition();
   float rotation = GetRotation();
@@ -223,12 +237,18 @@ Ptr<Sprite> Sprite::createFromNpk(const std::string& imgPath, size_t frameIndex)
         convertedData[i + 3] = a;
       }
       
-      return createFromMemory(
+      auto sprite = createFromMemory(
         convertedData.data(),
         frame.width,
         frame.height,
         4
       );
+      
+      if (sprite) {
+        sprite->SetOffset(static_cast<float>(frame.xPos), static_cast<float>(frame.yPos));
+      }
+      
+      return sprite;
     }
   }
   

Game/src/main.cpp

@@ -64,7 +64,7 @@ int main(int argc, char **argv) {
 
   if (ani) {
     SDL_Log("Animation created successfully");
-    ani->SetAnchor(Vec2(0.5f, 0.5f));
+    // ani->SetAnchor(Vec2(0.5f, 0.5f));
     ani->SetPosition(640, 360);
     menuScene->AddChild(ani);
   }