collidetest2.java

java手机程序开发随书光盘源代码

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.util.*;

public class CollideTest2 extends MIDlet{

	Display display;
	MyCanvas myCanvas;

	public CollideTest2(){
		display = Display.getDisplay(this);
		myCanvas = new MyCanvas();
	}

	public void startApp(){
		display.setCurrent(myCanvas);
	}

	public void pauseApp(){
	}

	public void destroyApp(boolean unconditional){
	}

	class MyCanvas extends Canvas implements CommandListener{

		Command exitCmd;
		Image offScreen;
		Image mySpriteImage;
		Sprite[] mySprite = new Sprite[2];
		Timer timer;

		public MyCanvas(){

			timer = new Timer();

			if(!isDoubleBuffered()){
				offScreen = Image.createImage(getWidth(), getHeight());
			}

			try{
				mySpriteImage = Image.createImage("/mysprite.png");
			}
			catch(Exception ex){}

			for(int i=0;i<mySprite.length;i++){
				mySprite[i] = new Sprite(this, mySpriteImage);
			}

			exitCmd = new Command("退出", Command.EXIT, 1);
			addCommand(exitCmd);
			setCommandListener(this);
		}

		public void paint(Graphics g){

			Graphics old = g;
			boolean collide = false;

			if(offScreen != null){
				g = offScreen.getGraphics();
			}

			g.setColor(0xFFFFFF);
			g.fillRect(0, 0, getWidth(), getHeight());

			for(int i=0;i<mySprite.length;i++){
				mySprite[i].draw(g);
			}

			if(g != old){
				old.drawImage(offScreen, 0, 0, Graphics.LEFT|Graphics.TOP);
			}
		}

		public void showNotify(){
			super.showNotify();
			timer.schedule(new CollideCheck(this), 0, 200);
		}

		public void hideNotify(){
			timer.cancel();
		}

		public void keyPressed(int keyCode){
			int gameAction = getGameAction(keyCode);
			switch(gameAction){
			case Canvas.UP:
				mySprite[0].y-=1;
				repaint();
			break;
			case Canvas.DOWN:
				mySprite[0].y+=1;
				repaint();
			break;
			case Canvas.LEFT:
				mySprite[0].x-=1;
				repaint();
			break;
			case Canvas.RIGHT:
				mySprite[0].x+=1;
				repaint();
			break;
			}
		}

		public void keyReleased(int keyCode){
		}

		public void keyRepeated(int keyCode){
		}

		public void commandAction(Command c, Displayable d){

			if(c == exitCmd){
				destroyApp(true);
				notifyDestroyed();
			}
		}
	}

	class Sprite{

		int x, y;
		int width, height;
		Image image;
		MyCanvas canvas;
		Random random = new Random();
		boolean collide = false;
		int[][] range = {{2, 7, 4, 14},
			             {6, 1, 20, 26},
			             {8, 28, 25, 7}};

		public Sprite(MyCanvas canvas,Image image){
			this.canvas = canvas;
			x = Math.abs(random.nextInt())%canvas.getWidth();
			y = Math.abs(random.nextInt())%canvas.getHeight();
			this.image = image;
			width = image.getWidth();
			height = image.getHeight();
		}

		public boolean isCollided(Sprite other){

			for(int i=0;i<range.length;i++){
				int x1 =  range[i][0];
				int y1 =  range[i][1];
				int w1 =  range[i][2];
				int h1 =  range[i][3];
				for(int j=0;j<other.range.length;j++){
					int x2 =  other.range[j][0];
					int y2 =  other.range[j][1];
					int w2 =  other.range[j][2];
					int h2 =  other.range[j][3];
					if((((x+x1+w1)>=other.x+x2&&(x+x1<=other.x+x2)) ||
					   (x+x1<=(other.x+x2+w2) && x+x1>=other.x+x2))&&
			           (((y+y1+h1)>=other.y+y2&&(y+y1<=other.y+y2)) ||
			           (y+y1<=(other.y+y2+h2) && y+y1>=other.y+y2))){
		    	    	return true;
		    	    }
		   		}
			}

			return false;
		}

		public void draw(Graphics g){
			g.drawImage(image, x, y, Graphics.LEFT|Graphics.TOP);
			g.setColor(0);
			for(int i=0;i<range.length;i++)
				g.drawRect(x+range[i][0], y+range[i][1], range[i][2], range[i][3]);
			if(collide){
				g.setColor(0xff0000);
				g.drawLine(x, y, x+width, y+height);
				g.drawLine(x+width, y, x, y+height);
				collide = false;
			}
		}
	}

	class CollideCheck extends TimerTask{

		MyCanvas canvas;

		public CollideCheck(MyCanvas canvas){
			this.canvas = canvas;
		}

		public void run(){
			for(int i=0;i<canvas.mySprite.length;i++){
				for(int j=0;j<canvas.mySprite.length;j++){
					if(i != j){
						canvas.mySprite[i].collide =
						 	canvas.mySprite[i].isCollided(canvas.mySprite[j]);
						if(canvas.mySprite[i].collide) break;
					}
				}
			}
		}
	}
}