Optimized Animation class.

zhenliang · Apr 26, 2011 · a32a0dc · a32a0dc
1 parent 1f2b7ec
commit a32a0dc
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Showing 2 changed files with 92 additions and 94 deletions.
diff --git a/engine/animation.cpp b/engine/animation.cpp
@@ -2,10 +2,10 @@
 
 namespace
 {
-const int DEFAULT_ROW = 1;
-const int DEFAULT_COLUMN = 1;
-const int DEFAULT_TOTAL_FRAMES = DEFAULT_ROW * DEFAULT_COLUMN;
-const float DEFAULT_FPS = 10.0f;
+  const int DEFAULT_ROW = 1;
+  const int DEFAULT_COLUMN = 1;
+  const int DEFAULT_TOTAL_FRAMES = DEFAULT_ROW * DEFAULT_COLUMN;
+  const float DEFAULT_FPS = 10.0f;
 }
 
 Animation::Animation()
@@ -22,20 +22,19 @@ Animation::Animation()
 }
 
 Animation::Animation(const Image& img, int row, int column, int totalFrames, float fps,
-					 const Vector2f& position /*= Vector2f(0, 0)*/,
-					 const Vector2f& scale /*= Vector2f(1, 1)*/,
-					 float rotation /*= 0.f*/,
-					 const Color& col /*= Color(255, 255, 255, 255)*/)
-: Sprite(img, position, scale, rotation, col)
-, row_(DEFAULT_ROW)
-, column_(DEFAULT_COLUMN)
-, totalFrames_(DEFAULT_TOTAL_FRAMES)
-, fps_(DEFAULT_FPS)
-, curFrame_()
-, timePerFrame_(1.0f/DEFAULT_FPS)
-, timeSinceLastFrame_()
+                     const Vector2f& position /*= Vector2f(0, 0)*/,
+                     const Vector2f& scale /*= Vector2f(1, 1)*/, float rotation /*= 0.f*/,
+                     const Color& col /*= Color(255, 255, 255, 255)*/)
+                     : Sprite(img, position, scale, rotation, col)
+                     , row_(DEFAULT_ROW)
+                     , column_(DEFAULT_COLUMN)
+                     , totalFrames_(DEFAULT_TOTAL_FRAMES)
+                     , fps_(DEFAULT_FPS)
+                     , curFrame_()
+                     , timePerFrame_(1.0f/DEFAULT_FPS)
+                     , timeSinceLastFrame_()
 {
-	UpdateSubRect();
+  RecomputeSubRect();
 }
 
 Animation::~Animation()
@@ -45,70 +44,72 @@ Animation::~Animation()
 
 void Animation::Update( float delta )
 {
-	UpdateCurFrame(delta);
-	UpdateSubRect();
-}
+  if (timeSinceLastFrame_ >= timePerFrame_)
+  {
+    while (timeSinceLastFrame_ >= timePerFrame_)
+    {
+#if 0 // 这种方法在 timeSinceLastFrame 过大的时候会占用太多时间
 
-void Animation::SetFPS( float val )
-{
-	fps_ = val;
-	timePerFrame_ = 1.0f / fps_;
-}
+      timeSinceLastFrame_ -= timePerFrame_;
+      if (++curFrame_ >= totalFrames_)
+        curFrame_ = 0;
 
-void Animation::UpdateSubRect()
-{
-	assert(GetImage());
-	float width = GetImage()->GetWidth() / column_;
-	float height = GetImage()->GetHeight() / row_;
-	float x = width * (curFrame_ % column_);
-	float y = height * (curFrame_ % row_);
-	IntRect subRect(x, y, x + width, y + height);
-	SetSubRect(subRect);
+#else // 用触发避免了 timeSiceLastFarm 的性能损失，但在通常时候都比第一种方法耗时多
+
+      int cnt = timeSinceLastFrame_ / timePerFrame_;
+      timeSinceLastFrame_ -= cnt * timePerFrame_;
+      curFrame_ += cnt;
+      if (curFrame_ >= totalFrames_)
+        curFrame_ = 0;
+#endif
+    }
+
+    RecomputeSubRect();
+  }
+
+  timeSinceLastFrame_ += delta;
 }
 
 void Animation::SetRow( int val )
 {
-	row_ = val;
-	UpdateTotalFrames();
-	UpdateSubRect();
+  row_ = val;
+  RecomputeTotalFrames();
+  RecomputeSubRect();
 }
 
 void Animation::SetColumn( int val )
 {
-	column_ = val;
-	UpdateTotalFrames();
-	UpdateSubRect();
+  column_ = val;
+  RecomputeTotalFrames();
+  RecomputeSubRect();
 }
 
-void Animation::UpdateTotalFrames()
+void Animation::SetTotalFrames( int val )
 {
-	int maxFrame = row_ * column_;
-	totalFrames_ = std::min(totalFrames_, maxFrame);
+  assert(val >= 1);
+  assert(val <= row_ * column_);
+  totalFrames_ = val;
 }
 
-void Animation::SetTotalFrames( int val )
+void Animation::SetFPS( float val )
 {
-	assert(val >= 1);
-	assert(val <= row_ * column_);
-	totalFrames_ = val;
+  fps_ = val;
+  timePerFrame_ = 1.0f / fps_;
 }
 
-void Animation::UpdateCurFrame(float delta)
+void Animation::RecomputeSubRect()
 {
-	while (timeSinceLastFrame_ >= timePerFrame_)
-	{
-#if 0 // 这种方法在 timeSinceLastFrame 过大的时候会占用太多时间
-		timeSinceLastFrame_ -= timePerFrame_;
-		if (++curFrame_ >= totalFrames_)
-			curFrame_ = 0;
-#else // 用触发避免了 timeSiceLastFarm 的性能损失，但在通常时候都比第一种方法耗时多
-        int cnt = timeSinceLastFrame_ / timePerFrame_;
-        timeSinceLastFrame_ -= cnt * timePerFrame_;
-        curFrame_ += cnt;
-        if (curFrame_ >= totalFrames_)
-            curFrame_ = 0;
-#endif
-	}
+  assert(GetImage());
+  float width = GetImage()->GetWidth() / column_;
+  float height = GetImage()->GetHeight() / row_;
+  float x = width * (curFrame_ % column_);
+  float y = height * (curFrame_ % row_);
+  IntRect subRect(x, y, x + width, y + height);
+  SetSubRect(subRect);
+}
 
-	timeSinceLastFrame_ += delta;
-}
+void Animation::RecomputeTotalFrames()
+{
+  int maxFrame = row_ * column_;
+  totalFrames_ = std::min(totalFrames_, maxFrame);
+}
diff --git a/engine/animation.h b/engine/animation.h
@@ -5,38 +5,35 @@
 class ENGINE_API Animation : public Sprite
 {
 public:
-	Animation();	
-	Animation(const Image& img, int row, int column, int totalFrames, float fps,
-		const Vector2f& position = Vector2f(0, 0),
-		const Vector2f& scale = Vector2f(1, 1),
-		float rotation = 0.f,
-		const Color& col = Color(255, 255, 255, 255));
-	virtual ~Animation();
-
-	void Update(float delta);
-
-	int GetRow() const;
-	int GetColumn() const { return column_; }
-	int GetTotalFrames() const { return totalFrames_; }
-	float GetFPS() const { return fps_; }
-
-	void SetRow(int val);
-	void SetColumn(int val);
-	void SetTotalFrames(int val);
-	void SetFPS(float val);
+  Animation();
+  Animation(const Image& img, int row, int column, int totalFrames, float fps,
+    const Vector2f& position = Vector2f(0, 0), const Vector2f& scale = Vector2f(1, 1),
+    float rotation = 0.f, const Color& col = Color(255, 255, 255, 255));
+  virtual ~Animation();
+
+  void Update(float delta);
+
+  int GetRow() const;
+  int GetColumn() const { return column_; }
+  int GetTotalFrames() const { return totalFrames_; }
+  float GetFPS() const { return fps_; }
+
+  void SetRow(int val);
+  void SetColumn(int val);
+  void SetTotalFrames(int val);
+  void SetFPS(float val);
 
 private:
-	void UpdateSubRect();
-	void UpdateTotalFrames();
-	void UpdateCurFrame(float delta);
+  void RecomputeSubRect();
+  void RecomputeTotalFrames();
 
 protected:
-	int row_;
-	int column_;
-	int totalFrames_;
-	float fps_;
-
-	int curFrame_;
-	float timePerFrame_;
-	float timeSinceLastFrame_;
+  int row_;
+  int column_;
+  int totalFrames_;
+  float fps_;
+
+  int curFrame_;
+  float timePerFrame_;
+  float timeSinceLastFrame_;
 };