[AndEngine学习教程] 第8节 ParticleSystem 粒子系统

转自：http://blog.youkuaiyun.com/cen616899547/article/details/8148627

 

1.本节要点

本节主要基于粒子系统实现火焰视觉效果的模拟

2.新学习内容

1.SpriteParticleSystem的介绍,这个类是集成自ParticleSystem<Sprite]>的,从源码可以看出

[java] view plain copy print ?

1. public class SpriteParticleSystemextends ParticleSystem<Sprite> {
2. // ===========================================================
3. // Constants
4. // ===========================================================
6. // ===========================================================
7. // Fields
8. // ===========================================================
10. // ===========================================================
11. // Constructors
12. // ===========================================================
14. public SpriteParticleSystem(final IParticleEmitter pParticleEmitter,final float pRateMinimum,final float pRateMaximum,final int pParticlesMaximum,final ITextureRegion pTextureRegion, final VertexBufferObjectManager pVertexBufferObjectManager) {
15. this(0,0, pParticleEmitter, pRateMinimum, pRateMaximum, pParticlesMaximum, pTextureRegion, pVertexBufferObjectManager);
16. }
18. public SpriteParticleSystem(finalfloat pX, finalfloat pY, final IParticleEmitter pParticleEmitter,final float pRateMinimum,final float pRateMaximum,final int pParticlesMaximum,final ITextureRegion pTextureRegion, final VertexBufferObjectManager pVertexBufferObjectManager) {
19. super(pX, pY, new IEntityFactory<Sprite>() {
20. @Override
21. public Sprite create(finalfloat pX, finalfloat pY) {
22. return new Sprite(pX, pY, pTextureRegion, pVertexBufferObjectManager);
23. }
24. }, pParticleEmitter, pRateMinimum, pRateMaximum, pParticlesMaximum);
25. }
27. protected SpriteParticleSystem(finalfloat pX, finalfloat pY, final IEntityFactory<Sprite> pEntityFactory,final IParticleEmitter pParticleEmitter,final float pRateMinimum,final float pRateMaximum,final int pParticlesMaximum) {
28. super(pX, pY, pEntityFactory, pParticleEmitter, pRateMinimum, pRateMaximum, pParticlesMaximum);
29. }
31. // ===========================================================
32. // Getter & Setter
33. // ===========================================================
35. // ===========================================================
36. // Methods for/from SuperClass/Interfaces
37. // ===========================================================
39. // ===========================================================
40. // Methods
41. // ===========================================================
43. // ===========================================================
44. // Inner and Anonymous Classes
45. // ===========================================================
46. }

public class SpriteParticleSystem extends ParticleSystem<Sprite> {
	// ===========================================================
	// Constants
	// ===========================================================

	// ===========================================================
	// Fields
	// ===========================================================

	// ===========================================================
	// Constructors
	// ===========================================================

	public SpriteParticleSystem(final IParticleEmitter pParticleEmitter, final float pRateMinimum, final float pRateMaximum, final int pParticlesMaximum, final ITextureRegion pTextureRegion, final VertexBufferObjectManager pVertexBufferObjectManager) {
		this(0, 0, pParticleEmitter, pRateMinimum, pRateMaximum, pParticlesMaximum, pTextureRegion, pVertexBufferObjectManager);
	}

	public SpriteParticleSystem(final float pX, final float pY, final IParticleEmitter pParticleEmitter, final float pRateMinimum, final float pRateMaximum, final int pParticlesMaximum, final ITextureRegion pTextureRegion, final VertexBufferObjectManager pVertexBufferObjectManager) {
		super(pX, pY, new IEntityFactory<Sprite>() {
			@Override
			public Sprite create(final float pX, final float pY) {
				return new Sprite(pX, pY, pTextureRegion, pVertexBufferObjectManager);
			}
		}, pParticleEmitter, pRateMinimum, pRateMaximum, pParticlesMaximum);
	}

	protected SpriteParticleSystem(final float pX, final float pY, final IEntityFactory<Sprite> pEntityFactory, final IParticleEmitter pParticleEmitter, final float pRateMinimum, final float pRateMaximum, final int pParticlesMaximum) {
		super(pX, pY, pEntityFactory, pParticleEmitter, pRateMinimum, pRateMaximum, pParticlesMaximum);
	}

	// ===========================================================
	// Getter & Setter
	// ===========================================================

	// ===========================================================
	// Methods for/from SuperClass/Interfaces
	// ===========================================================

	// ===========================================================
	// Methods
	// ===========================================================

	// ===========================================================
	// Inner and Anonymous Classes
	// ===========================================================
}

2.在SpriteParticleSystem中引出了IParticleEmitter的概念,在AndEngine中,常用的几种粒子发射器有:

:圆环粒子发射器

PointParticleEmitter:点状粒子发射器

RectangleParticleEmitter:矩形例子粒子器

根据名称几可以大概知道发射出来的粒子形状

在本节当中主要使用到CircleParticleEmitter环形粒子源码如下:

[java] view plain copy print ?

1. public class CircleParticleEmitterextends BaseCircleParticleEmitter {
2. // ===========================================================
3. // Constants
4. // ===========================================================
6. // ===========================================================
7. // Fields
8. // ===========================================================
10. // ===========================================================
11. // Constructors
12. // ===========================================================
14. public CircleParticleEmitter(finalfloat pCenterX, finalfloat pCenterY, finalfloat pRadius) {
15. super(pCenterX, pCenterY, pRadius);
16. }
18. public CircleParticleEmitter(finalfloat pCenterX, finalfloat pCenterY, finalfloat pRadiusX, finalfloat pRadiusY) {
19. super(pCenterX, pCenterY, pRadiusX, pRadiusY);
20. }
22. // ===========================================================
23. // Getter & Setter
24. // ===========================================================
26. // ===========================================================
27. // Methods for/from SuperClass/Interfaces
28. // ===========================================================
30. @Override
31. public void getPositionOffset(finalfloat[] pOffset) {
32. final float random = MathUtils.RANDOM.nextFloat() * MathConstants.PI *2;
33. pOffset[VERTEX_INDEX_X] = this.mCenterX + FloatMath.cos(random) *this.mRadiusX * MathUtils.RANDOM.nextFloat();
34. pOffset[VERTEX_INDEX_Y] = this.mCenterY + FloatMath.sin(random) *this.mRadiusY * MathUtils.RANDOM.nextFloat();
35. }
37. // ===========================================================
38. // Methods
39. // ===========================================================
41. // ===========================================================
42. // Inner and Anonymous Classes
43. // ===========================================================
44. }

public class CircleParticleEmitter extends BaseCircleParticleEmitter {
	// ===========================================================
	// Constants
	// ===========================================================

	// ===========================================================
	// Fields
	// ===========================================================

	// ===========================================================
	// Constructors
	// ===========================================================

	public CircleParticleEmitter(final float pCenterX, final float pCenterY, final float pRadius) {
		super(pCenterX, pCenterY, pRadius);
	}

	public CircleParticleEmitter(final float pCenterX, final float pCenterY, final float pRadiusX, final float pRadiusY) {
		super(pCenterX, pCenterY, pRadiusX, pRadiusY);
	}

	// ===========================================================
	// Getter & Setter
	// ===========================================================

	// ===========================================================
	// Methods for/from SuperClass/Interfaces
	// ===========================================================

	@Override
	public void getPositionOffset(final float[] pOffset) {
		final float random = MathUtils.RANDOM.nextFloat() * MathConstants.PI * 2;
		pOffset[VERTEX_INDEX_X] = this.mCenterX + FloatMath.cos(random) * this.mRadiusX * MathUtils.RANDOM.nextFloat();
		pOffset[VERTEX_INDEX_Y] = this.mCenterY + FloatMath.sin(random) * this.mRadiusY * MathUtils.RANDOM.nextFloat();
	}

	// ===========================================================
	// Methods
	// ===========================================================

	// ===========================================================
	// Inner and Anonymous Classes
	// ===========================================================
}

3.内容初始化

这里要实现的东西很简单,只有一张图片,用作粒子系统用的

[java] view plain copy print ?

1. private staticfinal int CAMERA_WIDTH =800;
2. private staticfinal int CAMERA_HEIGHT =480;
4. private Camera mCamera;
5. private TiledTextureRegion mParticleRegion;
9. @Override
10. public EngineOptions onCreateEngineOptions() {
11. // TODO Auto-generated method stub
12. mCamera = new Camera(0,0,CAMERA_WIDTH, CAMERA_HEIGHT);
13. EngineOptions mEngineOptions = new EngineOptions(true, ScreenOrientation.LANDSCAPE_SENSOR,new RatioResolutionPolicy(CAMERA_WIDTH, CAMERA_HEIGHT), mCamera);
16. return mEngineOptions;
17. }
19. @Override
20. public void onCreateResources(
21. OnCreateResourcesCallback pOnCreateResourcesCallback)
22. throws Exception {
23. // TODO Auto-generated method stub
24. BitmapTextureAtlas mTexture = new BitmapTextureAtlas(getTextureManager(),32, 32, TextureOptions.BILINEAR_PREMULTIPLYALPHA);
25. mParticleRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture,this, "particle_point.png",0, 0,1,1);
26. mTexture.load();
28. pOnCreateResourcesCallback.onCreateResourcesFinished();
29. }

private static final int CAMERA_WIDTH = 800;
	private static final int CAMERA_HEIGHT = 480;
	
	private Camera mCamera;
	private TiledTextureRegion mParticleRegion;
	
	
	
	@Override
	public EngineOptions onCreateEngineOptions() {
		// TODO Auto-generated method stub
		mCamera = new Camera(0,0,CAMERA_WIDTH, CAMERA_HEIGHT);
		EngineOptions mEngineOptions = new EngineOptions(true, ScreenOrientation.LANDSCAPE_SENSOR, new RatioResolutionPolicy(CAMERA_WIDTH, CAMERA_HEIGHT), mCamera);
		
		
		return mEngineOptions;
	}

	@Override
	public void onCreateResources(
			OnCreateResourcesCallback pOnCreateResourcesCallback)
			throws Exception {
		// TODO Auto-generated method stub
		BitmapTextureAtlas mTexture = new BitmapTextureAtlas(getTextureManager(), 32, 32, TextureOptions.BILINEAR_PREMULTIPLYALPHA);
		mParticleRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture, this, "particle_point.png", 0, 0,1,1);
		mTexture.load();
		
		pOnCreateResourcesCallback.onCreateResourcesFinished();
	}

4.构建场景

[java] view plain copy print ?

1. @Override
2. public void onCreateScene(OnCreateSceneCallback pOnCreateSceneCallback)
3. throws Exception {
4. // TODO Auto-generated method stub
5. Scene mScene = new Scene();
7. CircleOutlineParticleEmitter mEmitter = new CircleOutlineParticleEmitter(CAMERA_WIDTH/2,CAMERA_HEIGHT/2,80);
8. SpriteParticleSystem mParticleSystem = new SpriteParticleSystem(CAMERA_WIDTH/2, CAMERA_HEIGHT/2,
9. mEmitter, 10, 200, 300, mParticleRegion, getVertexBufferObjectManager());
11. mParticleSystem.addParticleInitializer(new ColorParticleInitializer(1,0,0));
12. mParticleSystem.addParticleInitializer(new AlphaParticleInitializer(0));
13. mParticleSystem.addParticleInitializer(new VelocityParticleInitializer(-2,2, -20, -10));
14. mParticleSystem.addParticleInitializer(new RotationParticleInitializer(0.0f,360.0f));
15. mParticleSystem.addParticleInitializer(new ExpireParticleInitializer(0,6));
18. mParticleSystem.addParticleModifier(new ScaleParticleModifier(0,5,1.0f,2.5f));
19. mParticleSystem.addParticleModifier(new ColorParticleModifier(0,3,1,1, 0,0.5f, 0,0));
20. mParticleSystem.addParticleModifier(new ColorParticleModifier(4,6,1,1, 0.5f,1, 0,1));
21. mParticleSystem.addParticleModifier(new AlphaParticleModifier(0,1,0, 1));
22. mParticleSystem.addParticleModifier(new AlphaParticleModifier(5,6,1, 0));
25. mScene.attachChild(mParticleSystem);
26. pOnCreateSceneCallback.onCreateSceneFinished(mScene);
27. }

@Override
	public void onCreateScene(OnCreateSceneCallback pOnCreateSceneCallback)
			throws Exception {
		// TODO Auto-generated method stub
		Scene mScene = new Scene();
		
		CircleOutlineParticleEmitter mEmitter = new CircleOutlineParticleEmitter(CAMERA_WIDTH/2,CAMERA_HEIGHT/2,80);
		SpriteParticleSystem mParticleSystem = new SpriteParticleSystem(CAMERA_WIDTH/2, CAMERA_HEIGHT/2, 
				mEmitter, 10, 200, 300, mParticleRegion, getVertexBufferObjectManager());
		
		mParticleSystem.addParticleInitializer(new ColorParticleInitializer(1,0,0));
		mParticleSystem.addParticleInitializer(new AlphaParticleInitializer(0));
		mParticleSystem.addParticleInitializer(new VelocityParticleInitializer(-2, 2, -20, -10));
		mParticleSystem.addParticleInitializer(new RotationParticleInitializer(0.0f, 360.0f));
        mParticleSystem.addParticleInitializer(new ExpireParticleInitializer(0,6));
        
        
		mParticleSystem.addParticleModifier(new ScaleParticleModifier(0,5,1.0f,2.5f));
		mParticleSystem.addParticleModifier(new ColorParticleModifier(0,3,1, 1, 0, 0.5f, 0, 0));
		mParticleSystem.addParticleModifier(new ColorParticleModifier(4,6,1, 1, 0.5f, 1, 0, 1));
		mParticleSystem.addParticleModifier(new AlphaParticleModifier(0,1, 0, 1));
		mParticleSystem.addParticleModifier(new AlphaParticleModifier(5,6, 1, 0));
		
		
		mScene.attachChild(mParticleSystem);
		pOnCreateSceneCallback.onCreateSceneFinished(mScene);
	}

值得关注的是addParticleInitializer和addParticleModifier这两个函数,配合起来调整粒子集合的形状,颜色旋转,位移等

参数,呈现呈现出来的就是想要的火焰效果了;

http://download.youkuaiyun.com/detail/cen616899547/4733452

注意:源代码上有些地方比较旧,有不一致的地方,请以上面例子的代码为准!

最新经过修改的源代码:http://download.youkuaiyun.com/detail/cen616899547/4734139