开始学习andEngine(3)

public class SpriteExample extends BaseExample {private static final int CAMERA_WIDTH = 480;//照着前一篇文章的例子写就行了，框架都打好了private static final int CAMERA_HEIGHT = 320;private Camera mCamera;private BitmapTextureAtlas mBitmapTextureAtlas;private TextureRegion mFaceTextureRegion;@Overridepublic Engine onLoadEngine() {this.mCamera = new Camera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT);return new Engine(new EngineOptions(true, ScreenOrientation.LANDSCAPE, new RatioResolutionPolicy(CAMERA_WIDTH, CAMERA_HEIGHT), this.mCamera));}@Overridepublic void onLoadResources() {this.mBitmapTextureAtlas = new BitmapTextureAtlas(32, 32, TextureOptions.BILINEAR_PREMULTIPLYALPHA);                //gfx是asset目录下的一个文件夹，里面有“face_box.png”这个图片BitmapTextureAtlasTextureRegionFactory.setAssetBasePath("gfx/");this.mFaceTextureRegion = BitmapTextureAtlasTextureRegionFactory.createFromAsset(this.mBitmapTextureAtlas, this, "face_box.png", 0, 0);this.mEngine.getTextureManager().loadTexture(this.mBitmapTextureAtlas);}@Overridepublic Scene onLoadScene() {this.mEngine.registerUpdateHandler(new FPSLogger());final Scene scene = new Scene();scene.setBackground(new ColorBackground(0.09804f, 0.6274f, 0.8784f));/* Calculate the coordinates for the face, so its centered on the camera. */final int centerX = (CAMERA_WIDTH - this.mFaceTextureRegion.getWidth()) / 2;final int centerY = (CAMERA_HEIGHT - this.mFaceTextureRegion.getHeight()) / 2;/* Create the face and add it to the scene. */final Sprite face = new Sprite(centerX, centerY, this.mFaceTextureRegion);scene.attachChild(face);return scene;}@Overridepublic void onLoadComplete() {}}

我学习的过程是，先试几个例子，学会用了，再问为什么。自己动手试一下SpriteExample.java 这个自带的例子，Sprite类的简单应用，在屏幕上显示一个精灵，可以增强自己的自信心。

ps: BitmapTextureAtlas的参数不能小于图片的大小，且必须为2的整数幂。TextureRegion定义了Texture上的一个矩形区域。Sprites使用TextureRegion使系统知道Sprite显示的是整个Texture的那部分。A TextureRegion defines a rectangle on the Texture. A TextureRegion is used by Sprites to let the system know what part of the big Texture the Sprite is showing