import java.awt.*;
import java.applet.*;

public class SerialImage2 extends Applet implements Runnable
{
	int SPF;//動(dòng)畫(huà)播放發(fā)幀數(shù)的倒數(shù)
	int sx,sy; //圖象來(lái)源區(qū)域
	Image animation;
	MediaTracker mt ;
	Thread newThread;
	Image offScreen;//次畫(huà)面
	Graphics drawOffScreen;//繪制次畫(huà)面的Graphics
	
	public void init()
	{
		SPF = 100;
		mt = new MediaTracker(this);
		animation = getImage(getDocumentBase(), "images/cg0432.gif");
		mt.addImage(animation, 0);
		try
		{
			showStatus("圖象加載中...");
			mt.waitForAll();	
		}	
		catch (InterruptedException e) {}
		
		offScreen = createImage(250, 250);//建立次畫(huà)面
		drawOffScreen = offScreen.getGraphics();
	}	
	
	public void start()
	{
		//建立并啟動(dòng)新線程
		newThread = new Thread(this);
		newThread.start();	
	}
	public void stop()
	{
		newThread = null;
	}
	
	public void paint(Graphics g)
	{
		//下面清除次畫(huà)面
		drawOffScreen.clearRect(0, 0, 250, 250);
		
		//在次畫(huà)面繪制圖象
		drawOffScreen.drawImage(animation, 0, 0, 250, 250, 
								sx, sy, sx + 250, sy + 250,this);	
		g.drawImage(offScreen, 0, 0, 250, 250, this);
	}
	public void update(Graphics g)
	{
		paint(g);	
	}
	public void run()
	{
		while (newThread != null)
		{
			repaint();
			try
			{
				Thread.sleep(SPF);
				//計(jì)算來(lái)源區(qū)域
				//下面是原始的，因?yàn)閳D片有更改，所以自己寫(xiě)一段
//				sx += 128;
//				if (sx == 640)
//				{
//					sy += 96;
//					sx = 0;
//					if (sy == 480)
//						sy = 0;	
//				}	
				sx += 250;
				if (sx == 1750)
					sx = 0;
			}	
			catch (InterruptedException e) {}
		}	
	}
}