subcanvas.java~42~

利用Java 开发的一个手机版的潜艇游戏。游戏实现的重点就是屏幕的绘制滚动技术和碰撞检测技术

        Image fire = null;
        for (int j = 0; j < this.enemyVector.size(); j++) {
            EnemySub enemySub = (EnemySub) enemyVector.elementAt(j);
            //当生命周期结束
            if (!enemySub.getLifeState()) {
                fire = ResObj.createImage("/res/fire.png");
                enemySub.setImage(fire, fire.getWidth(),
                                  fire.getHeight());
                enemyVector.removeElementAt(j);

                //消灭一艘敌人潜艇,  同时更新监听数组
                SpriteChanged spriteChanged = new SpriteChanged(enemySub,
                        layerManager);
                spriteChanged.start();

                spriteChanged = null;
                enemySub = null;

                this.nCurrentEnemy--;
                this.nTotalEnemy--;
            } else {
                enemySub.tick();
            }
        }
        fire = null;
    }


    /**
     * 触发玩家船只
     */
    private void tickShip() {
        if (!ship.getLifeState()) {
            nState = GAME_OVER;
        }
    }

    /**
     * 触发鱼雷
     */
    protected void tickTorpedo() {
        //触发玩家发射的鱼雷
        //如果某个鱼雷元素已经结束生命周期, 则置null, 并从数组中删除
        for (int j = 0; j < this.torpedoVector.size(); j++) {
            Torpedo torpedo = (Torpedo) torpedoVector.elementAt(j);

            //当生命周期结束
            if (!torpedo.getLifeState()) {
                torpedoVector.removeElementAt(j);
                this.layerManager.remove(torpedo);
                torpedo = null;
            } else {
                torpedo.tick();
            }
        }

        //触发敌方潜艇发射的鱼雷
        for (int j = 0; j < this.enemyTorpedoVector.size(); j++) {
            Torpedo torpedo = (Torpedo) enemyTorpedoVector.elementAt(j);

            //当生命周期结束
            if (!torpedo.getLifeState()) {
                enemyTorpedoVector.removeElementAt(j);
                this.layerManager.remove(torpedo);
                torpedo = null;
            } else {
                torpedo.tick();
            }
        }
    }

    /**
     * 清楚游戏中的数据信息
     */
    private void clear() {
        this.nLevel = 4;
        this.nTotalEnemy = this.nLevel * 10;
        this.nCurrentEnemy = 0;
        nTriggerCount = 0;
        nDensity = nLevel - 1;
        this.nCurrentEnemyLimit = this.nLevel * 2;
    }

    /**重新设置图层显示区域
     * @param xShip      玩家船只的x位置
     * @param width      玩家船只的宽度
     */
    public void adjustViewWindow(int xShip, int width) {
        if (this.bUserViewWindow) {
            xPosOfView = xShip + (width / 2) - (nViewWidth / 2);
            if (xPosOfView < 0) {
                xPosOfView = 0;
            }
            if (xPosOfView > (WORLD_WIDTH - nViewWidth)) {
                xPosOfView = WORLD_WIDTH - nViewWidth;
            }

            layerManager.setViewWindow(xPosOfView, yPosofView,
                                       nViewWidth, nViewHeight);
        }
    }


    /**
     *  画布重画事件,替代Canvas中的paint()事件, 根据不同的游戏状态（nState）画出游戏画面
     */
    public synchronized void paintCanvas(Graphics g) {
        switch (nState) {
        case GAME_INIT: //游戏第一次启动
            g.setColor(255, 255, 255);
            g.fillRect(0, 0, mainWidth, mainHeight);

            //重新绘制图层
            if (this.layerManager != null) {
                this.layerManager = null;
                this.layerManager = new LayerManager();

                if (bUserViewWindow) {
                    this.layerManager.setViewWindow(xPosOfView, yPosofView,
                            nViewWidth, nViewHeight);
                }
            }

            //重新绘制玩家潜艇
            if (ship != null) {
                ship = null;
                ship = new Ship(this, ResObj.createImage("/res/ship.png"),
                                getWidth() / 3, 0, layerManager);
            }

            //创建背景图层
            this.createSeaBottom();
            this.layerManager.append(ship);
            ship.setHpLife(this.nLevel * 10);
            this.createSeaBackground();
            nState = GAME_RUN;
            break;
        case GAME_RUN: //游戏处于运行状态
            g.setColor(255, 255, 255);
            g.fillRect(0, 0, mainWidth, mainHeight);
            g.setColor(255, 0, 0);
            float fLifePercent = 100 * ship.getHpLife() / (nLevel * 10);
            StringBuffer str = new StringBuffer("Life:" + fLifePercent + "%");
            g.drawString(str.toString(), 0, 0, Graphics.LEFT | Graphics.TOP);
            if (rt.freeMemory() < (rt.totalMemory() * 4 / 5)) {
                rt.gc();
            }
            break;
        case GAME_NEXTROUND: //下一轮游戏
            //更新数据
            ship.setHpLife(nLevel * 10);
            ship.setPosition(mainWidth / 3, 0);
            if (this.nLevel >= 4) {
                nState = GAME_OVER;
            } else {
                this.nLevel++;
                controller.handleEvent(UIController.EventID.EVENT_NEXTROUND);
                //目前游戏只设计了四级关卡
                this.nTotalEnemy = this.nLevel * 10;
                this.nCurrentEnemy = 0;
                nTriggerCount = 0;
                this.nCurrentEnemyLimit = this.nLevel * 2;

                //暂时删除layerManager中所有文件，清空鱼雷与敌人潜艇数据
                //为更新图层做准备
                this.torpedoVector.removeAllElements();
                this.enemyVector.removeAllElements();

                //更新海底图层数据
                this.nDensity = (nDensity + 1) % 4;

                this.hideNotify();
                nState = GAME_INIT;
            }
            break;
        case GAME_OVER: //游戏结束
            threadAlive = false;
            g.setColor(0, 0, 0);
            g.fillRect(0, 0, getWidth(), getHeight());
            g.setColor(255, 0, 0);
            g.setFont(Font.getFont(Font.FACE_PROPORTIONAL, Font.STYLE_BOLD,
                                   Font.SIZE_LARGE));
            g.drawString("Game Over", getWidth() / 2, getHeight() / 2,
                         Graphics.BASELINE | Graphics.HCENTER);
            this.flushGraphics();
            try {
                thread.sleep(1000);
            } catch (InterruptedException ex) {
                ex.printStackTrace();
            }
            this.layerManager = null;
            this.removeCommand(this.pauseCommand);
            this.addCommand(startCommand);
            controller.handleEvent(UIController.EventID.EVENT_EXIT);
            return;
        default:
            break;
        }
        //在缓冲区重画
        this.layerManager.paint(g, 0, 0);
        this.flushGraphics();
    }

    /**
     * 创建海水背景
     */
    private void createSeaBackground() {
        if (this.nDensity >= 4) {
            nDensity = 0;
        }

        //创建海水背景图
        Image image = ResObj.createImage("/res/layer" +
                                         this.nDensity + ".png");

        layerSeaback = new TiledLayer(WIDTH_IN_TILES, HEIGHT_IN_TILES,
                                      image, TILE_WIDTH, TILE_HEIGHT);

        for (int row = 0; row < HEIGHT_IN_TILES; row++) {
            for (int column = 0; column < WIDTH_IN_TILES; column++) {
                layerSeaback.setCell(column, row,
                                     ResObj.createRandom(
                                             NUM_DENSITY_LAYER_TILES) +
                                     1);
            }
        }
        layerSeaback.setPosition(0, SHIP_HEIGHT);
        layerManager.append(layerSeaback);

        image = null;
    }

    /**
     * 创建海底背景
     */
    private void createSeaBottom() {

        Image bottomTitles = ResObj.createImage("/res/bottom.png");

        //将图片bottomTitles切成指定大小(TILE_WIDTH, TILE_HEIGHT)
        //创建一个指定维数(1, WIDTH_IN_TILES)的背景数组
        TiledLayer layer = new TiledLayer(WIDTH_IN_TILES, 1,
                                          bottomTitles, TILE_WIDTH, TILE_HEIGHT);

        for (int column = 0; column < WIDTH_IN_TILES; column++) {
            //将海底图层数组中的每个小格用原始图片的第i块来填充
            int i = ResObj.createRandom(NUM_DENSITY_LAYER_TILES) + 1;
            layer.setCell(column, 0, i);
        }
        layer.setPosition(0, mainHeight - bottomTitles.getHeight());
        layerManager.append(layer);

        bottomTitles = null;
    }


    public Ship getShip() {
        return this.ship;
    }

    public void setActive() {
        this.showNotify();
    }
}