AndEngine之DEMO学习（五）SpriteBatchExample

一如既往，先上代码再说事。

package org.andengine.examples;


import org.andengine.engine.camera.Camera;
import org.andengine.engine.options.EngineOptions;
import org.andengine.engine.options.ScreenOrientation;
import org.andengine.engine.options.resolutionpolicy.RatioResolutionPolicy;
import org.andengine.entity.scene.Scene;
import org.andengine.entity.scene.background.Background;
import org.andengine.entity.sprite.Sprite;
import org.andengine.entity.sprite.batch.DynamicSpriteBatch;
import org.andengine.entity.sprite.batch.SpriteBatch;
import org.andengine.entity.util.FPSLogger;
import org.andengine.opengl.texture.TextureOptions;
import org.andengine.opengl.texture.atlas.bitmap.BitmapTextureAtlas;
import org.andengine.opengl.texture.atlas.bitmap.BitmapTextureAtlasTextureRegionFactory;
import org.andengine.opengl.texture.region.ITextureRegion;
import org.andengine.ui.activity.SimpleBaseGameActivity;

public class SpriteBatchExample extends SimpleBaseGameActivity {
	
	private static final int CAMERA_WIDTH = 720;
	private static final int CAMERA_HEIGHT = 480;

	private BitmapTextureAtlas mBitmapTextureAtlas;
	private ITextureRegion mFaceTextureRegion;

	@Override
	public EngineOptions onCreateEngineOptions() {
		final Camera camera = new Camera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT);

		return new EngineOptions(true, ScreenOrientation.LANDSCAPE_FIXED, new RatioResolutionPolicy(CAMERA_WIDTH, CAMERA_HEIGHT), camera);
	}

	@Override
	public void onCreateResources() {
		BitmapTextureAtlasTextureRegionFactory.setAssetBasePath("gfx/");

		this.mBitmapTextureAtlas = new BitmapTextureAtlas(this.getTextureManager(), 32, 32, TextureOptions.BILINEAR);
		this.mFaceTextureRegion = BitmapTextureAtlasTextureRegionFactory.createFromAsset(this.mBitmapTextureAtlas, this, "face_box.png", 0, 0);
		this.mBitmapTextureAtlas.load();
	}

	@Override
	public Scene onCreateScene() {
		this.mEngine.registerUpdateHandler(new FPSLogger());

		final Scene scene = new Scene();
		scene.setBackground(new Background(0.09804f, 0.6274f, 0.8784f));

		/* Calculate the coordinates for the face, so its centered on the camera. */
		final float centerX = (CAMERA_WIDTH - this.mFaceTextureRegion.getWidth()) / 2;
		final float centerY = (CAMERA_HEIGHT - this.mFaceTextureRegion.getHeight()) / 2;
		
		final Sprite faceSprite1 = new Sprite(-50, 0, this.mFaceTextureRegion, this.getVertexBufferObjectManager()); 
		final Sprite faceSprite2 = new Sprite(50, 0, this.mFaceTextureRegion, this.getVertexBufferObjectManager());
		
		faceSprite1.setScale(2);
		faceSprite2.setRotation(45);

		/* Create the face and add it to the scene. */
		final SpriteBatch dynamicSpriteBatch = new DynamicSpriteBatch(this.mBitmapTextureAtlas, 2, this.getVertexBufferObjectManager()) {
			@Override
			public boolean onUpdateSpriteBatch() {
				this.draw(faceSprite1);
				this.draw(faceSprite2);
				return true;
			}
		};
		
		final SpriteBatch staticSpriteBatch = new SpriteBatch(this.mBitmapTextureAtlas, 2, this.getVertexBufferObjectManager());
		staticSpriteBatch.draw(this.mFaceTextureRegion, -50, 0, this.mFaceTextureRegion.getWidth(), this.mFaceTextureRegion.getHeight(), 2, 2, 1, 1, 1, 1);
		staticSpriteBatch.draw(this.mFaceTextureRegion, 50, 0, this.mFaceTextureRegion.getWidth(), this.mFaceTextureRegion.getHeight(), 45, 1, 1, 1, 1);
		staticSpriteBatch.submit();

		dynamicSpriteBatch.setPosition(centerX, centerY - 50);
		staticSpriteBatch.setPosition(centerX, centerY + 50);
		
		scene.attachChild(dynamicSpriteBatch);
		scene.attachChild(staticSpriteBatch);

		return scene;
	}
}

这是Simple中的最后一个例子，说明SpriteBatch的使用，我们知道精灵无非是一个纹理和他对应范围的组合；那精灵族可以直观的把它看成同一纹理对应多个范围的形式。我们可以通过draw方法在其中增加新的显示范围，包括定义其大小方向等等，但是mTexture是不能改变的，相当于同一张图片渲染了多次。例子中提供了动态和静态精灵族两种实现，区别在于动态精灵族无需在初始化的时候指定范围，当需要渲染的时候他会回调onUpdateSpriteBatch让程序更加当时情况设置。切记精灵族的范围添加完成之后一定要提交，这样才能完成渲染，动态的提交写如begin方法里面，我们可以不管。下面给一个SpriteBatch的类图：

好了，也是一个没有太多东西的内容，感觉Android给出的例子还是很贴心的，Simple部分就结束了。下面一部分是Modifier&Animation，讲如何让实体运动起来。