collidetest1.java

射击游戏中判断是否被击中 在动作游戏中判断是否吃到宝物

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

public class CollideTest1 extends MIDlet{

	Display display;
	MyCanvas myCanvas;

	public CollideTest1(){
		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;
		Image enemySpriteImage;
		Sprite mySprite;
		Sprite[] enemySprite = new Sprite[3];

		public MyCanvas(){

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

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

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

			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());

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

			for(int i=0;i<enemySprite.length;i++){
				collide = mySprite.isCollided(enemySprite[i]);
				if(collide) break;
			}

			if(collide){
				g.setColor(0);
				g.drawString("发生碰撞",
						 	 getWidth()/2,
						 	 getHeight()/2,
						 	 Graphics.LEFT|Graphics.TOP);
			}

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

		public void keyPressed(int keyCode){
			int gameAction = getGameAction(keyCode);
			switch(gameAction){
			case Canvas.UP:
				mySprite.y-=2;
				repaint();
			break;
			case Canvas.DOWN:
				mySprite.y+=2;
				repaint();
			break;
			case Canvas.LEFT:
				mySprite.x-=2;
				repaint();
			break;
			case Canvas.RIGHT:
				mySprite.x+=2;
				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;

		public Sprite(MyCanvas canvas,Image image){
			this.canvas = canvas;
			x = Math.abs(new Random().nextInt())%canvas.getWidth();
			y = Math.abs(new Random().nextInt())%canvas.getHeight();
			this.image = image;
			width = image.getWidth();
			height = image.getHeight();
			System.out.println(""+x+","+y);
		}

		public boolean isCollided(Sprite otherSprite){
			boolean result = false;
			if((((x+width)>=otherSprite.x && x<=otherSprite.x) ||
			   (x<=(otherSprite.x+otherSprite.width)&& x>=otherSprite.x))&&
			   (((y+height)>=otherSprite.y&&(y<=otherSprite.y)) ||
			   (y<=(otherSprite.y+otherSprite.height) && y>=otherSprite.y))){
				result = true;
			}
			return result;
		}

		public void draw(Graphics g){

			g.drawImage(image, x, y, Graphics.LEFT|Graphics.TOP);
		}
	}

}