gamecanvas.java

一個J2ME寫的射擊游戲,不錯不錯

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

class GameCanvas extends Canvas implements Runnable, CommandListener {
	private int					screenWidth;
	private int					screenHeight;
	private SpaceShooter		spaceShooter;
	private Image				titleImg;
	private MyShip			myShip			= new MyShip();
	private MyMissile[]		myMissiles		= new MyMissile[] {
		new MyMissile(),
		new MyMissile(),
		new MyMissile(),
		new MyMissile(),
		new MyMissile()
	};
	private int			myMissileCount;

	private UFO[]			ufos           		= new UFO[] {
		new UFO(myShip),
		new UFO(myShip),
		new UFO(myShip),
		new UFO(myShip),
		new UFO(myShip),
		new UFO(myShip),
		new UFO(myShip)
	};
	private int			ufoCount;
	private UFOMissile[]		ufoMissiles		= new UFOMissile[] {
		new UFOMissile(),
		new UFOMissile(),
		new UFOMissile(),
		new UFOMissile(),
		new UFOMissile(),
		new UFOMissile(),
		new UFOMissile(),
		new UFOMissile(),
		new UFOMissile(),
		new UFOMissile()
	};
	private int			ufoMissileCount;
	private static final long	DRAW_INTERVAL		= 100;
	private	boolean			isPaused;
	private boolean			isStopped;
	private int			tickCount4UFO;
	private Random			random				= new Random();

	private Command				startCmd		= new Command("Start", Command.SCREEN, 5);
	private Command				exitCmd			= new Command("Exit", Command.SCREEN, 1);
	private Command				pauseCmd		= new Command("Pause", Command.SCREEN, 5);
	private Command				resumeCmd		= new Command("Resume", Command.SCREEN, 5);
	private Command				quitCmd			= new Command("Quit", Command.SCREEN, 1);

	private long				score;
	private long				highScore		= 0;
	private static final long	        DEFAULT_SCORE		= 100;

	/** 储存生命点数的变量 */
	private int				lives;
	private int				livesup=1;
	private static final int	DEFAULT_LIVES		= 9;
	
	private Font				defFont			= Font.getDefaultFont();
	private static final int	SCORE_AREA		 = Font.getDefaultFont().getHeight();
	private static final short	TITLE			= 0;
	private static final short	GAME_START		= 1;
	private static final short	GAME_PLAYING		= 2;
	private static final short	GAME_END		= 5;
	private short			gameState;

	/** 构造函数 */
	GameCanvas(SpaceShooter spaceShooter) {
		this.spaceShooter = spaceShooter;
		screenWidth = getWidth();
		screenHeight = getHeight();
		try {
			titleImg = Image.createImage("/title.png");
		}catch(Exception e) {}

		setCommandListener(this);
		gameState = TITLE;
	}

	/** 进行游戏之初始化的方法 */
	private void doGameInit() {
		score = 0;
		myShip.setX((screenWidth - myShip.getWidth()) /2);
		myShip.setY(screenHeight - myShip.getHeight());
		myShip.setHit(false);//清除Hit状态
		lives = DEFAULT_LIVES;

		for(int i=0; i < myMissiles.length; i++) {
			myMissiles[i].setAlive(false);
		}
		myMissileCount = 0;

		for(int i=0; i < ufos.length; i++) {
			ufos[i].setAlive(false);
		}
		ufoCount = 0;
		for(int i=0; i < ufoMissiles.length; i++) {
			ufoMissiles[i].setAlive(false);
		}
		ufoMissileCount = 0;
		tickCount4UFO = 0;
		isStopped = false;
		isPaused = false;
	}

	void doStartApp() {
		switch(gameState) {
			case TITLE:		
				doTitle();
			break;

			case GAME_START:	
			case GAME_PLAYING:	
				
				isPaused = true;
				
				isStopped = true;
				removeCommand(pauseCmd);
				removeCommand(resumeCmd);
				addCommand(resumeCmd);
			break;

			default:		
				isPaused = false;
			break;
		}
	}

	void doPauseApp() {
		switch(gameState) {
			case TITLE:		
			break;

			default:		

				isPaused = true;
				isStopped = true;
			break;
		}
	}

	private void doTitle() {
		gameState = TITLE;
		removeCommand(pauseCmd);
		removeCommand(resumeCmd);
		removeCommand(quitCmd);
		repaint();
		addCommand(exitCmd);
		addCommand(startCmd);
	}

	private void doThreadStart() {
		new Thread(this).start();
	}

	private void doGameStop() {
		isStopped = true;
		setHighScore(score);
	}

	private void doPauseOrResume() {
		if(isPaused) {
			isPaused = false;
			isStopped = false;
			doThreadStart();
		}else {
			isPaused = true;
			doGameStop();
		}// end if
		repaint();
	}


	protected void paint(Graphics g) {
		g.setColor(0x00000000);
		g.fillRect(0, 0, screenWidth, screenHeight);

		g.setFont(defFont);

		String drawSt;
		int drawX, drawY, stWidth;
		int stHeight = defFont.getHeight();

		switch(gameState) {
			case TITLE:
				drawX = (screenWidth - titleImg.getWidth()) /2;
				g.drawImage(titleImg, drawX, 0, Graphics.TOP|Graphics.LEFT);

				g.setColor(0x00FFFFFF);
				g.setFont(defFont);
				drawSt = "High Score";
				drawX = (screenWidth - defFont.stringWidth(drawSt)) / 2;
				drawY = titleImg.getHeight() -5;
				g.drawString(drawSt, drawX, drawY, Graphics.TOP|Graphics.LEFT);
				drawX = drawX + defFont.stringWidth(drawSt) - defFont.stringWidth(String.valueOf(highScore));
				drawY = drawY + stHeight;
				g.drawString(String.valueOf(highScore), drawX, drawY, Graphics.TOP|Graphics.LEFT);
				drawSt = "xinlei";
				drawX = (screenWidth - defFont.stringWidth(drawSt)) / 2;
				drawY = getHeight() - stHeight *2;
				g.drawString(drawSt, drawX, drawY, Graphics.TOP|Graphics.LEFT);

				drawSt = "sallon-hhh.com";
				drawX = (screenWidth - defFont.stringWidth(drawSt)) / 2;
				drawY = drawY + stHeight;
				g.drawString(drawSt, drawX, drawY, Graphics.TOP|Graphics.LEFT);
			return;

			case GAME_START:
				g.setColor(0x00FFFFFF);
				drawSt = "Ready go !";
				stWidth = defFont.stringWidth(drawSt);
				drawX = (screenWidth - stWidth) / 2;
				drawY = (screenHeight - stHeight) / 2;
				g.drawString(drawSt, drawX, drawY, Graphics.TOP|Graphics.LEFT);
			return;

			case GAME_PLAYING:
			case GAME_END:
				g.setColor(0x00FFFFFF);
				drawSt = "S:" + String.valueOf(score);
				g.drawString(drawSt, 0, 0, Graphics.TOP|Graphics.LEFT);
				drawSt = "L:" + String.valueOf(lives);
				g.drawString(drawSt, screenWidth- defFont.stringWidth(drawSt), 0, Graphics.TOP|Graphics.LEFT);
				myShip.doDraw(g);

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

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

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

				switch(gameState) {
					case GAME_PLAYING:
						if(isPaused) {
						drawSt = "Pause";
						}else {
		
							return;
						}
					break;

					case GAME_END:
						drawSt = "Game over";
					break;

					default:
					return;
				}
				stWidth = defFont.stringWidth(drawSt);
				drawX = (screenWidth-stWidth) / 2;
				drawY = (screenHeight - (stHeight)) / 2;

				g.setColor(0x00BBBBBB);
				g.fillRoundRect(drawX-2, drawY+2, stWidth+9, stHeight+2, 5, 5);
				g.setColor(0x00000000);
				g.fillRoundRect(drawX-6, drawY-2, stWidth+11, stHeight+4, 5, 5);
				g.setColor(0x00FFFFFF);
				g.fillRoundRect(drawX-4, drawY, stWidth+7, stHeight, 5, 5);

				
				g.setColor(0x00000000);
				g.drawString(drawSt, drawX, drawY, Graphics.TOP|Graphics.LEFT);
			break;
		}
	}

	public void commandAction(Command c, Displayable s) {
		if(c == startCmd) {
			doGameInit();
			gameState = GAME_START;
			doThreadStart();

		}else if(c == exitCmd) {
			spaceShooter.doExit();

		}else if(c == pauseCmd) {
			removeCommand(pauseCmd);
			addCommand(resumeCmd);
			doPauseOrResume();

		}else if(c == resumeCmd) {
			removeCommand(resumeCmd);
			addCommand(pauseCmd);
			doPauseOrResume();

		}else if(c == quitCmd) {
			doGameStop();
			removeCommand(pauseCmd);
			removeCommand(resumeCmd);
			removeCommand(quitCmd);
			doTitle();
		}
	}