bufferexamplecanvas.java

java卡马克屏幕缓冲算法演示

package redduke.game.j2me.example;

import javax.microedition.lcdui.Canvas;
import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;

import redduke.game.j2me.ReddukeBuffer;

public class BufferExampleCanvas extends Canvas {	
	PaintObject p=new PaintObject();
	ReddukeBuffer rb=new ReddukeBuffer(p,50,50,10,10);	
	protected void paint(Graphics g) {
		g.setColor(0xffffff);
		g.fillRect(0,0,getWidth(),getHeight());
		rb.paint(g,getWidth()/2-rb.getWidth()/2,5);
		g.setColor(0xff0000);
		g.drawRect(getWidth()/2-rb.getWidth()/2,5,rb.getWidth(),rb.getHeight());
		
		Image buf=rb.getBuffer();
		g.drawImage(buf,getWidth()/2-buf.getWidth()/2,70,0);
		g.drawRect(getWidth()/2-buf.getWidth()/2,70,buf.getWidth(),buf.getHeight());
		g.drawLine(getWidth()/2-buf.getWidth()/2,70+rb.getBufOffy()%buf.getHeight(),getWidth()/2+buf.getWidth()/2,70+rb.getBufOffy()%buf.getHeight());
		g.drawLine(getWidth()/2-buf.getWidth()/2+rb.getBufOffx()%buf.getWidth(),70,getWidth()/2-buf.getWidth()/2+rb.getBufOffx()%buf.getWidth(),70+buf.getHeight());
		
		p.paint(g,5,getHeight()-p.getHeight()-5);
		g.drawRect(5+rb.getBufOffx(),getHeight()-p.getHeight()-5+rb.getBufOffy(),buf.getWidth(),buf.getHeight());
		g.drawRect(5+rb.getOffx(),getHeight()-p.getHeight()-5+rb.getOffy(),rb.getWidth(),rb.getHeight());
	}

	protected void keyPressed(int keyCode) {
		switch(getGameAction(keyCode))
		{
			case UP:
				rb.scroll(0,-5);
				break;
			case DOWN:
				rb.scroll(0,5);
				break;
			case LEFT:
				rb.scroll(-5,0);
				break;
			case RIGHT:
				rb.scroll(5,0);
				break;
		}
		repaint();
	}
}