private void initUpdateThread() {
		updateThread = new Thread(new Runnable() {
			public void run() {
				long startTime = 0;
				long delay = 0;
				long waitTime = 1000 / 60;
				while (updateThread != null) {
					startTime = System.currentTimeMillis();
					update();
					delay = waitTime - (System.currentTimeMillis() - startTime);
					if (delay > 0) {
						try {
							Thread.sleep(delay);
						} catch (InterruptedException e) {
							updateThread = null;
						}
					}
				}
			}
		});
		updateThread.start();
	}