public void prePaint() {
        BufferStrategy bf = f.getBufferStrategy();
	Graphics g = null;
	
	try {
		g = bf.getDrawGraphics();
		
		// It is assumed that mySprite is created somewhere else.
		// This is just an example for passing off the Graphics object.
		this.paintAll(g);
		
	} finally {
		// It is best to dispose() a Graphics object when done with it.
		g.dispose();
	}
	
	// Shows the contents of the backbuffer on the screen.
	bf.show();
        
        
    }