Question

我是游戏开发的新手，并尝试使用AndEngine构建赛车游戏。当我的精灵（汽车）与硬币发生碰撞时，它会播放声音并消失我使用平铺地图编辑器来加载我的硬币对象平铺地图编辑器中的坐标系统将反转，该坐标系统为地图和anndngine gles 2 - 锚点中心创建xml。我以为tmxExtension会处理这个转换.. 到目前为止，我正在计算每个对象位置并在xml编辑器中更改其位置以更正位置。还有其他更简单的方法吗？

以下是我加载地图的代码：

private void createLevel() {
    coins = new LinkedList < Sprite > ();
    try {

        final TMXLoader tmxLoader = new TMXLoader(activity.getAssets(), engine.getTextureManager(),
        TextureOptions.BILINEAR_PREMULTIPLYALPHA, vbom);

        this.mTMXTiledMap = tmxLoader.loadFromAsset("tmx/uom_map_test2.tmx");
    } catch (final TMXLoadException e) {
        Debug.e(e);
    }

    FixtureDef wallFixtureDef = PhysicsFactory.createFixtureDef(0, 0.5f, 0.5f);
    Rectangle rect1 = new Rectangle(
    0,
    0,
    1,
    camera.getBoundsYMax(),
    vbom);
    Body wall1 = PhysicsFactory.createBoxBody(physicsWorld, rect1, BodyType.StaticBody, wallFixtureDef);
    wall1.setUserData(wall1);

    FixtureDef wallFixtureDef2 = PhysicsFactory.createFixtureDef(0, 0.5f, 0.5f);
    Rectangle rect2 = new Rectangle(
    1100,
    0,
    1,
    camera.getBoundsYMax(),
    vbom);
    Body wall2 = PhysicsFactory.createBoxBody(physicsWorld, rect2, BodyType.StaticBody, wallFixtureDef2);


    for (final TMXObjectGroup group: this.mTMXTiledMap.getTMXObjectGroups()) {
        for (final TMXObject object: group.getTMXObjects()) {

            if (object.getName().equals("coin")) {
                Sprite coin = new Sprite(object.getX(), object.getY(), object.getWidth(), object.getHeight(), resourcesManager.coinTextureRegion, vbom);
                FixtureDef coinFixtureDef = PhysicsFactory.createFixtureDef(0, 0.3f, 0.3f);

                Body bod = PhysicsFactory.createBoxBody(physicsWorld, coin, BodyType.DynamicBody, coinFixtureDef);
                bod.setUserData("coin");
                coins.add(coin);
                coin.setUserData(bod);

            } else if (object.getName().equals("sea")) {
                FixtureDef seaFixtureDef = PhysicsFactory.createFixtureDef(0, 0, 0f);
                Rectangle rect = new Rectangle(
                object.getX(),
                object.getY(),
                object.getWidth(),
                object.getHeight(),
                vbom);

                Body bod = PhysicsFactory.createBoxBody(physicsWorld, rect, BodyType.DynamicBody, seaFixtureDef);
                bod.setUserData("sea");

            }


        }

    }

    /*for(TMXLayer layer : this.mTMXTiledMap.getTMXLayers()){
           layer.detachSelf();
           layer.setPosition(0,0);
           attachChild(layer);*/

    for (int layerID = 0; layerID < this.mTMXTiledMap.getTMXLayers().size(); layerID++) {
        this.mTMXTiledMap.getTMXLayers().get(layerID).detachSelf();
        attachChild(this.mTMXTiledMap.getTMXLayers().get(layerID));

        //       layer0:sea              layer1:grass               layer2:road

        for (int i = 0; i < coins.size(); i++) {
            this.attachChild(coins.get(i));
        }

        camera.setBounds(0, 0, mTMXTiledMap.getWidth(), mTMXTiledMap.getHeight());
        camera.setBoundsEnabled(true);



    }
}

另外，我使用联系人监听器来管理硬币碰撞

public void beginContact(Contact contact) {
    Body a = null, b = null;
    // TODO Auto-generated method stub
    try {
        a = contact.getFixtureA().getBody();
        b = contact.getFixtureB().getBody();
    } catch (NullPointerException n) {
        //do nothing
    }

    if (a != null && b != null) {

        if (a.getUserData() != null && b.getUserData() != null) {
            if (a.getUserData().equals("player") && b.getUserData().equals("coin") || b.getUserData().equals("player") && a.getUserData().equals("coin")) {

                if (a.getUserData().equals("coin")) {
                    removeCoins(a);
                    resourcesManager.coinCollect.play();
                    addToScore(10);
                    showLevelCleared();
                } else if (b.getUserData().equals("coin")) {
                    removeCoins(b);
                    resourcesManager.coinCollect.play();
                    addToScore(5);
                }
            }
        }
    } 
}

然而并非所有的硬币和＃39;检测到碰撞。我得到了一个空的pointerException，这就是为什么我包含了一个catch 有什么理由吗？

Answer 1

我建议不要创建一个单独的timerhandler来检查碰撞，而是在onManagedUpdate中执行所有这些操作

Andengine coin pickup nullpointer例外

1 个答案: