2013-08-04 46 views
0
@Override 
public void run() { 
    super.run(); 

    final float timePerFrame = 1000/Options.MAX_FPS; 
    float timeDiff; 
    while(!isInterrupted() && isRunning) { 
     timeDiff = System.currentTimeMillis(); 
     mController.refresh(); 
     timeDiff = timePerFrame - (timeDiff - System.currentTimeMillis()); 

     try { 
       Thread.sleep(Math.max(Math.round(timeDiff), 0)); 
     } catch(InterruptedException e) { 
      // do nothing 
      e.printStackTrace(); 
     } 
    } 
    Log.e("GameThread", "Thread dead."); 
} 

这是我的线程基本上在做什么。我的绘图线程突然停止的原因是什么?

Options.MAX_FPS = 30; 

要限制帧每秒,每个刷新之间有某种休眠时间。刷新方法如下所示:

public synchronized void refresh(){mrotation = Math.round((360 +((-1)* mAccelerometer [0] * 4.5f))%360); mObject.setRotation(mRotation);

// get canvas from surfaceview 
    if(mSurfaceHolder != null) { 
     // do all calculations. 
     if(Looper.myLooper() == Looper.getMainLooper()) { 
      log("on main thread!"); 
     } else { 
      log("Not on main thread"); 
     } 


     Canvas mCanvas = mSurfaceHolder.lockCanvas(); 
     if (mCanvas != null) { 
      // shift x offset 
      mScreenWidth = mCanvas.getWidth(); 
      mScreenHeight = mCanvas.getHeight(); 

      // draw black background, clear everything. 
      mCanvas.drawRect(new Rect(0,0,mScreenWidth, mScreenHeight), mBlackPaint); 

      // shift & draw all viewobjects if still visible 

      for(ViewObject view: mViewObjectList.toArray(new ViewObject[mViewObjectList.size()])) { 
       view.shiftX(-1 * Options.Gameplay.Environment.MOVING_SPEED); 
       if(view.getX() + view.getWidth() < 0) { 
        mViewObjectList.remove(view); 
       } 
       if(view.getCurrentBitmap() != null) 
        mCanvas.drawBitmap(view.getCurrentBitmap(), new Rect(0,0,view.getCurrentBitmap().getWidth(), view.getCurrentBitmap().getHeight()), new Rect(view.getX(), view.getY(), view.getX()+ view.getWidth(), view.getY()+view.getHeight()), new Paint()); 

       view.nextFrame(); 
      } 

      // draw object 
      final Bitmap sBitmap = mObject.getCurrentBitmap(); 
      mObject.nextFrame(); 
      if(sBitmap != null) { 
       mCanvas.drawBitmap(sBitmap, new Rect(0, 0, sBitmap.getWidth(), sBitmap.getHeight()), new Rect(mObject.getX(), mObject.getY(), sBitmap.getWidth(), sBitmap.getHeight()), new Paint()); 
      } else log("bitmap = null!"); 
     } 

     mSurfaceHolder.unlockCanvasAndPost(mCanvas); 
    } 
} 

线程继续运行一段时间后,背景元素都被吸收(即使我的旋转不工作相当尚未,但这是另一个故事。),背景“似乎”移动(像侧),但在某个随机时间点,没有任何ADB LogCat消息(不限于应用程序,而是整个LogCat输出) - 线程停止。没有更多的绘图。没有。我没有调用中断或设置isRunning为false,因为“Thread dead”。消息不会写入LogCat中。 我不知道发生了什么。 感谢您的帮助。

回答

1

您有:

enter code here`timeDiff = System.currentTimeMillis(); 
// refresh, which takes some time I guess 
timeDiff = timePerFrame - (timeDiff - System.currentTimeMillis()); 

所以System.currentTimeMillis的()在后面,因此比大的timeDiff。括号中的术语将为负数 - 因此您将添加到timePerFrame,timeDiff将不会减少。

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