摄像机系统，和子对象绑定

include/sprite_actor.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+#include <string>
+
+#include <actor.hpp>
+
+namespace boundard {
+
+class SpriteActor : public Actor {
+   public:
+    SpriteActor(std::string name, Game& game, std::shared_ptr<Mesh> mesh)
+        : Actor(std::move(name), game), mesh_(std::move(mesh)) {}
+
+    const std::shared_ptr<Mesh>& mesh() const override { return mesh_; }
+    void set_mesh(std::shared_ptr<Mesh> mesh) override { mesh_ = std::move(mesh); }
+
+   private:
+    std::shared_ptr<Mesh> mesh_;
+};
+
+}  // namespace boundard