Andengine 背景自动移动AutoParallaxBackground 1

在Andengine 用AutoParallaxBackground实现这个效果。

new AutoParallaxBackground(final float pRed, final float pGreen,final float pBlue,  背景颜色的三个值 红绿篮      

final float pParallaxChangePerSecond) 图片移动的速度

AutoParallaxBackground(float pRed, float pGreen, float pBlue, float pParallaxChangePerSecond)
ParallaxBackground.attachParallaxEntity(ParallaxEntity pParallaxEntity)往视差背景对象中加入一个背景实体
ParallaxEntity(float pParallaxFactor, Shape pShape)构建一个背景实体，第一个参数表示视差移动的因数，为负表示相对前景
或英雄反向移动。绝对值越大移动的越快，也就说这个因数是靠前的背景比后面的背景的绝对值大。

    private BitmapTextureAtlas    mAutoParallaxBackgroundTexture;
    public ITextureRegion mParallaxLayerBack;
    private ITextureRegion mParallaxLayerMid;
    private ITextureRegion mParallaxLayerFront;



private void initTexture() {
        this.mAutoParallaxBackgroundTexture = new BitmapTextureAtlas(
                mContext.getTextureManager(), 1024, 1024);
        this.mParallaxLayerFront = BitmapTextureAtlasTextureRegionFactory
                .createFromAsset(this.mAutoParallaxBackgroundTexture, mContext,
                        "parallax_background_layer_front.png", 0, 0);
        this.mParallaxLayerBack = BitmapTextureAtlasTextureRegionFactory
                .createFromAsset(this.mAutoParallaxBackgroundTexture, mContext,
                        "parallax_background_layer_back.png", 0, 188);
        this.mParallaxLayerMid = BitmapTextureAtlasTextureRegionFactory
                .createFromAsset(this.mAutoParallaxBackgroundTexture, mContext,
                        "parallax_background_layer_mid.png", 0, 669);
        this.mAutoParallaxBackgroundTexture.load();

        game_scene=initScene();
    }

    private Scene initScene() {
        Scene pScene = new Scene();
        mContext.getEngine().registerUpdateHandler(new FPSLogger());


        final AutoParallaxBackground autoParallaxBackground = new AutoParallaxBackground(
                0, 0, 0, 5);
        final VertexBufferObjectManager vertexBufferObjectManager = mContext
                .getVertexBufferObjectManager();
        

        autoParallaxBackground.attachParallaxEntity(new ParallaxEntity(0.0f,
                new Sprite(0, BaseData.CAMERA_HEIGHT
                        - this.mParallaxLayerBack.getHeight(),
                        this.mParallaxLayerBack, vertexBufferObjectManager)));
        autoParallaxBackground.attachParallaxEntity(new ParallaxEntity(-5.0f,
                new Sprite(0, 80, this.mParallaxLayerMid,
                        vertexBufferObjectManager)));
        autoParallaxBackground.attachParallaxEntity(new ParallaxEntity(-10.0f,
                new Sprite(0, BaseData.CAMERA_HEIGHT
                        - this.mParallaxLayerFront.getHeight(),
                        this.mParallaxLayerFront, vertexBufferObjectManager)));
        
        // 将这个背景设为场景的背
        pScene.setBackground(autoParallaxBackground);


        return pScene;

    }