add callback on updating Node

minor

src/core/Node.cpp

@@ -62,10 +62,14 @@ namespace easy2d
 		if (pause_)
 			return;
 
-		OnUpdate(dt);
 		UpdateActions(this, dt);
 		UpdateTasks(dt);
 
+		if (cb_update_)
+			cb_update_(dt);
+
+		OnUpdate(dt);
+
 		if (!children_.IsEmpty())
 		{
 			NodePtr next;
@@ -225,11 +229,7 @@ namespace easy2d
 		dirty_transform_ = false;
 		dirty_transform_inverse_ = true;
 
-		// matrix multiplication is optimized by expression template
+		transform_matrix_ = transform_.ToMatrix();
-		transform_matrix_ = Matrix::Scaling(transform_.scale)
-			* Matrix::Skewing(transform_.skew.x, transform_.skew.y)
-			* Matrix::Rotation(transform_.rotation)
-			* Matrix::Translation(transform_.position);
 
 		Point offset{ -size_.x * anchor_.x, -size_.y * anchor_.y };
 		transform_matrix_.Translate(offset);

src/core/Node.h

@@ -45,6 +45,7 @@ namespace easy2d
 		friend class IntrusiveList<NodePtr>;
 
 		using Children = IntrusiveList<NodePtr>;
+		using UpdateCallback = std::function<void(Duration)>;
 
 	public:
 		Node();
@@ -351,6 +352,12 @@ namespace easy2d
 		// 节点更新是否暂停
 		inline bool IsUpdatePausing() const							{ return pause_; }
 
+		// 设置更新时的回调函数
+		inline void SetCallbackOnUpdate(UpdateCallback const& cb)	{ cb_update_ = cb; }
+
+		// 获取更新时的回调函数
+		inline UpdateCallback const& GetCallbackOnUpdate()			{ return cb_update_; }
+
 		// 设置默认锚点
 		static void SetDefaultAnchor(
 			float anchor_x,
@@ -384,6 +391,7 @@ namespace easy2d
 		Node*		parent_;
 		Scene*		scene_;
 		Children	children_;
+		UpdateCallback cb_update_;
 
 		mutable bool	dirty_transform_;
 		mutable bool	dirty_transform_inverse_;

src/core/Transform.hpp

@@ -46,5 +46,14 @@ namespace easy2d
 				skew == other.skew &&
 				rotation == other.rotation;
 		}
+
+		inline math::Matrix ToMatrix() const
+		{
+			// matrix multiplication is optimized by expression template
+			return Matrix::Scaling(scale)
+				* Matrix::Skewing(skew.x, skew.y)
+				* Matrix::Rotation(rotation)
+				* Matrix::Translation(position);
+		}
 	};
 }