Android基本游戏循环实例分析

本文实例讲述了Android基本游戏循环。分享给大家供大家参考。具体如下：

// desired fps
private final static int  MAX_FPS = 50;
// maximum number of frames to be skipped
private final static int  MAX_frame_SKIPS = 5;
// the frame period
private final static int  frame_PERIOD = 1000 / MAX_FPS; 
@Override
public void run() {
  Canvas canvas;
  Log.d(TAG, "Starting game loop");
  long beginTime;   // the time when the cycle begun
  long timeDiff;   // the time it took for the cycle to execute
  int sleepTime;   // ms to sleep (<0 if we're behind)
  int framesSkipped; // number of frames being skipped 
  sleepTime = 0;
  while (running) {
    canvas = null;
    // try locking the canvas for exclusive pixel editing
    // in the surface
    try {
      canvas = this.surfaceHolder.lockCanvas();
      synchronized (surfaceHolder) {
 beginTime = System.currentTimeMillis();
 framesSkipped = 0; // resetting the frames skipped
 // update game state
 this.gamePanel.update();
 // render state to the screen
 // draws the canvas on the panel
 this.gamePanel.render(canvas);
 // calculate how long did the cycle take
 timeDiff = System.currentTimeMillis() - beginTime;
 // calculate sleep time
 sleepTime = (int)(frame_PERIOD - timeDiff);
 if (sleepTime > 0) {
   // if sleepTime > 0 we're OK
   try {
     // send the thread to sleep for a short period
     // very useful for battery saving
     Thread.sleep(sleepTime);
   } catch (InterruptedException e) {}
 }
 while (sleepTime < 0 && framesSkipped < MAX_frame_SKIPS) {
   // we need to catch up
   // update without rendering
   this.gamePanel.update();
   // add frame period to check if in next frame
   sleepTime += frame_PERIOD;
   framesSkipped++;
 }
      }
    } finally {
      // in case of an exception the surface is not left in
      // an inconsistent state
      if (canvas != null) {
 surfaceHolder.unlockCanvasAndPost(canvas);
      }
    }  // end finally
  }
}

希望本文所述对大家的Android程序设计有所帮助。