gamecanvas.java

一個J2ME寫的射擊游戲,不錯不錯

	protected synchronized void keyPressed(int keyCode) {
		if(	gameState != GAME_PLAYING ||
			(gameState == GAME_PLAYING && isPaused)) {
			return;
		}

		//为清除按键时不处理
		if(keyCode == 0) return;	//for KDDI
		switch(keyCode) {
			case KEY_NUM4:
				doLeft();
			break;
			case KEY_NUM6:
				doRight();
			break;
			case KEY_NUM8:
				doDown();
			break;
			case KEY_NUM2:
				doUp();
			break;
			case KEY_NUM5:
				doFire();
			}			

		int gameCode = getGameAction(keyCode);
		switch(gameCode) {
			case LEFT:	//按下向左按键时
				doLeft();
			break;

			case RIGHT:	//按下向右按键时
				doRight();
			break;

			case DOWN:	//按下向下按键时
				doDown();
			break;
			case UP:	//按下向上按键时
				doUp();
			break;

			case FIRE://按下Fire按键时
				doFire();
		}
	}
	

	protected void keyRepeated(int keyCode) {
		keyPressed(keyCode);
	}

	/** 线程的运作部分 */
	public void run() {
		try {
			switch(gameState) {
				case GAME_START:	
					removeCommand(startCmd);
					removeCommand(exitCmd);

					repaint();
					Thread.sleep(1500);

					addCommand(quitCmd);
					if(! isPaused) {
						addCommand(pauseCmd);
					}

					gameState = GAME_PLAYING;

				case GAME_PLAYING:	
					repaint();
					boolean isGameOver = false;

					//开始游戏循环
					while(! isStopped) {
						repaint();

						myShip.doMove();

						//UFO处理
						for(int i=0; i < ufos.length; i++) {
							if(ufos[i].isAlive()) {
							//只处理在Alive状态的UFO
								//移动UFO
								ufos[i].doMove();
								if(! ufos[i].isAlive() ||
									ufos[i].getX()+ufos[i].getWidth() < 0 ||
									ufos[i].getX() > screenWidth) {
								//移动UFO之后不是Alive状态时
								//或是UFO跑到画面外时
									//设定UFO不是Alive状态，减少UFO数目
									ufos[i].setAlive(false);
									ufoCount--;

									//若UFO为命中状态的话，在分数中新增DEFAULT_SCORE
									if(ufos[i].isHit()) {score = score + DEFAULT_SCORE;
											if(score >=livesup*1000) {lives++;livesup++;}			
												}
								}else if(ufoMissileCount < ufoMissiles.length &&
										ufos[i].isDropBomb()) {
								//UFO在Alive状态下发射飞弹时
									//进行炸弹处理
									//在飞弹数组中寻找不是Alive状态的飞弹
									for(int j=0; j < ufoMissiles.length; j++) {
										if(! ufoMissiles[j].isAlive()) {
										//不是Alive状态的飞弹时
											//符合飞弹的座标来攻击
											ufoMissiles[j].setX((
												ufos[i].getWidth() - ufoMissiles[j].getWidth()) /2 +
														ufos[i].getX());
											ufoMissiles[j].setY(ufos[i].getY() + ufos[i].getHeight());
											ufoMissiles[j].setAlive(true);
											ufoMissileCount++;
											break;
										}
									}
								}
							}
						}// end for

						//UFO飞弹处理
						for(int i=0; i < ufoMissiles.length; i++) {
							if(ufoMissiles[i].isAlive()) {
							//只处理Alive状态的UFO飞弹
								//移动UFO飞弹
								ufoMissiles[i].doMove();

								//命中判定
								if(myShip.isOverlaps(ufoMissiles[i])) {
								//UFO飞弹与自机重叠时
									myShip.setHit(true);
									//删除飞弹
									ufoMissiles[i].setAlive(false);
									ufoMissileCount--;

									//减少生命点数
									lives--;
									if(lives < 1) {
									//当生命点数用完时
										removeCommand(pauseCmd);
										removeCommand(resumeCmd);
										removeCommand(quitCmd);
										isGameOver = true;
										break;
									}

								}else if(ufoMissiles[i].getY() > getHeight()) {
								//UFO飞弹跑到画面外时
									//将UFO飞弹设为无效
									ufoMissiles[i].setAlive(false);
									ufoMissileCount--;
								}
							}
						}

						//自机飞弹处理
						for(int i=0; i < myMissiles.length; i++) {
							if(myMissiles[i].isAlive()) {
							myMissiles[i].doMove();

								//命中判定
								for(int j=0; j < ufos.length; j++) {
									if(ufos[j].isAlive() && ! ufos[j].isHit()) {
									//当UFO为在Alive状态，而不是被击中状态时
										if(ufos[j].isOverlaps(myMissiles[i])) {
										//自机飞弹与UFO重叠时
											ufos[j].setHit(true);
											//删除飞弹
											myMissiles[i].setAlive(false);
											myMissileCount--;
											break;
										}
									}
								}
							}
							if(	myMissiles[i].isAlive() &&
								myMissiles[i].getY() + myMissiles[i].getHeight() < SCORE_AREA)
							{
							//从画面消失时
								//删除自机飞弹
								myMissiles[i].setAlive(false);
								myMissileCount--;
							}
						}// end for

						if(isGameOver) {
							removeCommand(pauseCmd);
							removeCommand(resumeCmd);
							removeCommand(quitCmd);

							//结束这个循环
							doGameStop();

							gameState = GAME_END;
							repaint();
							Thread.sleep(5000);
							doTitle();
							break;

						}else {
							doEmerge4UFO();
							Thread.sleep(DRAW_INTERVAL);
						}
					}// end while
				break;
			}
		}catch(Exception e) {}
	}

	/** 左按键被压下时所调用的方法 */
	private void doLeft() {
		int tmpX = myShip.getX() - (myShip.getWidth() /2);
		if(tmpX < 0) {
			tmpX = 0;
		}
		myShip.setX(tmpX);
	}

	private void doRight() {
		int tmpX = myShip.getX() + (myShip.getWidth() /2);
		if(tmpX > screenWidth -myShip.getWidth()) {
			tmpX = screenWidth -myShip.getWidth();
		}
		myShip.setX(tmpX);
	}
	private void doUp() {
		int tmpX = myShip.getY() - (myShip.getHeight() /2);
		if(tmpX <0) {
			tmpX = 0;
		}
		myShip.setY(tmpX);
	}
	private void doDown() {
		int tmpX = myShip.getY() + (myShip.getHeight() /2);
		if(tmpX > screenHeight -myShip.getHeight()) {
			tmpX = screenHeight -myShip.getHeight();
		}
		myShip.setY(tmpX);
	}

	/** 按下决定按键被调用的方法 */
	private void doFire() {
		if(myMissileCount < myMissiles.length) {
		for(int i=0; i < myMissiles.length; i++) {
				if(! myMissiles[i].isAlive()) {
				myMissiles[i].setX((myShip.getWidth() - myMissiles[i].getWidth()) /2 +
										myShip.getX());
					myMissiles[i].setY(myShip.getY() - myMissiles[i].getHeight());
					myMissiles[i].setAlive(true);
					myMissileCount++;
					break;
				}
			}
		}
	}


	private void doEmerge4UFO() {
		tickCount4UFO++;
		if(ufoCount < 1 || tickCount4UFO > 4) {
			tickCount4UFO = 0;

			if(ufoCount < ufos.length) {
			//UFO的数目比上限还少时

				//取得乱数的int值
				int tmpInt = random.nextInt() % 2;
				if(tmpInt == 1 || tmpInt == -1) {
					tmpInt = random.nextInt() % 2;
					UFO ufo;
					for(int i=0; i < ufos.length; i++) {
						if(! ufos[i].isAlive()) {
							if(tmpInt == 0) {
								tmpInt = random.nextInt() % 2;
								if(tmpInt < 0) tmpInt = tmpInt* (-1);
								ufos[i].setDirection(UFO.DIRECTION_RIGHT);
								ufos[i].setX(0 +2);
								ufos[i].setY(SCORE_AREA + (((ufos[i].getHeight() +2) *2) * tmpInt));

							}else {
								tmpInt = random.nextInt() % 2;
								if(tmpInt < 0) tmpInt = tmpInt* (-1);
								ufos[i].setDirection(UFO.DIRECTION_LEFT);
								ufos[i].setX((screenWidth - ufos[i].getWidth() / 2) -2);
								ufos[i].setY(SCORE_AREA +
											(((ufos[i].getHeight() +2) *2) * tmpInt) +
											(ufos[i].getHeight() +2));
							}
							ufos[i].setAlive(true);
							ufoCount++;
							break;
						}
					}
				}
			}
		}
	}

	private void setHighScore(long score) {
		if(score > highScore) {
			highScore = score;
		}
	}
}