[AndEngine学习教程] 第9节 CollisionDetection 实体碰撞检测

最新推荐文章于 2024-12-17 18:40:18 发布
最新推荐文章于 2024-12-17 18:40:18 发布
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分类专栏： AndEngine
本文介绍了一个基于SmoothCamera的碰撞检测实现案例，通过一个可操作的精灵与一个动态变化的矩形进行碰撞检测，实现了碰撞时颜色变化的视觉效果。

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转自：http://blog.youkuaiyun.com/cen616899547/article/details/8151822

1.本节要点

通过一个可操作的精灵,来与一个固定循环变化的矩形检测是否产生碰撞,当产生碰撞的时候,矩形的颜色为红色,

否则矩形的颜色为绿色

2.新学内容

1.学会使用SmoothCamera类,这个类是一个平滑的照相机类,可以满足背景自动填充,平滑过渡的效果.先看看它的构成吧:

[java] view plain copy print ?
  1. public class SmoothCameraextends ZoomCamera 
public class SmoothCamera extends ZoomCamera
是继承于SmoothCamera的类,而SmoothCamera从文字上就可以看出它是一个支持缩放效果的类,因此使用起来就很方便了,

构造方法为:

[java] view plain copy print ?
  1. public SmoothCamera(finalfloat pX, finalfloat pY, finalfloat pWidth, finalfloat pHeight, finalfloat pMaxVelocityX, finalfloat pMaxVelocityY, finalfloat pMaxZoomFactorChange) {
  2. super(pX, pY, pWidth, pHeight);
  3. this.mMaxVelocityX = pMaxVelocityX;
  4. this.mMaxVelocityY = pMaxVelocityY;
  5. this.mMaxZoomFactorChange = pMaxZoomFactorChange;
  7. this.mTargetCenterX =this.getCenterX();
  8. this.mTargetCenterY = this.getCenterY();
  10. this.mTargetZoomFactor = 1.0f;
  11. } 
public SmoothCamera(final float pX, final float pY, final float pWidth, final float pHeight, final float pMaxVelocityX, final float pMaxVelocityY, final float pMaxZoomFactorChange) {
		super(pX, pY, pWidth, pHeight);
		this.mMaxVelocityX = pMaxVelocityX;
		this.mMaxVelocityY = pMaxVelocityY;
		this.mMaxZoomFactorChange = pMaxZoomFactorChange;

		this.mTargetCenterX = this.getCenterX();
		this.mTargetCenterY = this.getCenterY();

		this.mTargetZoomFactor = 1.0f;
	}

为了体现效果,我刻意的把背景图片做成720*640大小,而手机的屏幕分辨率大小为800*480,但是依然可以看到全屏的效果.相当不错的哦!

以下的是我使用到的背景图片:

2.为场景Scene注册刷新句柄,用来监听每次实体间是否产生碰撞.然后进行相应的事物处理,具体调用方法为:

[java] view plain copy print ?
  1. mScene.registerUpdateHandler(new IUpdateHandler());
mScene.registerUpdateHandler(new IUpdateHandler());

3.内部代码初始化设计

1.本节使用到4个实体,一个是人脸,另外一个是矩形,最后2个是控制器,内部成员变量设计为:

[java] view plain copy print ?
  1. private staticfinal int CAMERA_WIDTH =800;
  2. private staticfinal int CAMERA_HEIGHT =480;
  4. private SmoothCamera mCamera;
  5. private SpriteBackground mBackground;
  6. private TiledTextureRegion mControlBaseRegion;
  7. private TiledTextureRegion mControlKnobRegion;
  8. private TiledTextureRegion mFaceRegion;
private static final int CAMERA_WIDTH = 800;
	private static final int CAMERA_HEIGHT = 480;
	
	private SmoothCamera mCamera;
	private SpriteBackground mBackground;
	private TiledTextureRegion mControlBaseRegion;
	private TiledTextureRegion mControlKnobRegion;
	private TiledTextureRegion mFaceRegion;


2.引擎资源的加载

[java] view plain copy print ?
  1. @Override
  2. public EngineOptions onCreateEngineOptions() {
  3. // TODO Auto-generated method stub
  4. mCamera = new SmoothCamera(0,0, CAMERA_WIDTH, CAMERA_HEIGHT, 10,10, 3);
  5. EngineOptions mEngineOptions = new EngineOptions(true, ScreenOrientation.LANDSCAPE_SENSOR,new RatioResolutionPolicy(CAMERA_WIDTH,CAMERA_HEIGHT),mCamera);
  6. return mEngineOptions;
  7. }
  9. @Override
  10. public void onCreateResources(
  11. OnCreateResourcesCallback pOnCreateResourcesCallback)
  12. throws Exception {
  13. // TODO Auto-generated method stub
  14. BitmapTextureAtlas mTexture = new BitmapTextureAtlas(getTextureManager(),1024, 1024, TextureOptions.BILINEAR_PREMULTIPLYALPHA);
  15. final TiledTextureRegion mBackgroundRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture,this, "bg.png",0, 0,1, 1);
  16. final Sprite mBackgroundSprite =new Sprite(0,0, CAMERA_WIDTH, CAMERA_HEIGHT, mBackgroundRegion, getVertexBufferObjectManager());
  17. mBackground = new SpriteBackground(mBackgroundSprite);
  19. mControlBaseRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture,this, "onscreen_control_base.png",720, 0,1, 1);
  20. mControlKnobRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture,this, "onscreen_control_knob.png",848, 0,1, 1);
  21. mFaceRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture,this, "face_box.png",912, 0,1, 1);
  23. mTexture.load();
  24. pOnCreateResourcesCallback.onCreateResourcesFinished();
  25. } 
@Override
	public EngineOptions onCreateEngineOptions() {
		// TODO Auto-generated method stub
		mCamera = new SmoothCamera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT, 10, 10, 3);
		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(), 1024, 1024, TextureOptions.BILINEAR_PREMULTIPLYALPHA);
		final TiledTextureRegion mBackgroundRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture, this, "bg.png", 0, 0, 1, 1);
		final Sprite mBackgroundSprite = new Sprite(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT, mBackgroundRegion, getVertexBufferObjectManager());
		mBackground = new SpriteBackground(mBackgroundSprite);
		
		mControlBaseRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture, this, "onscreen_control_base.png", 720, 0, 1, 1);
		mControlKnobRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture, this, "onscreen_control_knob.png", 848, 0, 1, 1);
		mFaceRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture, this, "face_box.png", 912, 0, 1, 1);
		
		mTexture.load();
		pOnCreateResourcesCallback.onCreateResourcesFinished();
	}

4.场景设计
1.添加多点触摸支持和场景基础设施

[java] view plain copy print ?
  1. if(MultiTouch.isSupported(this)){
  2. this.mEngine.setTouchController(new MultiTouchController());//多点触摸
  3. }
  5. Scene mScene = new Scene();
  6. mScene.setBackground(mBackground);
  8. final float centerX = (CAMERA_WIDTH - mFaceRegion.getWidth()) /2;
  9. final float centerY = (CAMERA_HEIGHT - mFaceRegion.getHeight()) /2; 
if(MultiTouch.isSupported(this)){
			this.mEngine.setTouchController(new MultiTouchController());//多点触摸		
		}
		
		Scene mScene = new Scene();
		mScene.setBackground(mBackground);
		
		final float centerX = (CAMERA_WIDTH - mFaceRegion.getWidth()) / 2;
		final float centerY = (CAMERA_HEIGHT - mFaceRegion.getHeight()) / 2;

2.构建相应的精灵任务:

2.1 布置人脸:

[java] view plain copy print ?
  1. final MySprite mFace = new MySprite(centerX - 50, centerY,80, 80, mFaceRegion, getVertexBufferObjectManager());
final MySprite mFace = new MySprite(centerX - 50, centerY, 80, 80, mFaceRegion, getVertexBufferObjectManager());
2.2 不知受碰撞检测的矩形

[java] view plain copy print ?
  1. final Rectangle mRectangle =new Rectangle(centerX + 10, centerY,80,80,getVertexBufferObjectManager());
  2. mRectangle.registerEntityModifier(new LoopEntityModifier(new ParallelEntityModifier(
  3. new ScaleModifier(2,0.5f, 2.0f),new ScaleModifier(2,2.0f,1.0f),new RotationModifier(4,0.0f,360.0f) ))); 
final Rectangle mRectangle = new Rectangle(centerX + 10, centerY, 80,80,getVertexBufferObjectManager());
		mRectangle.registerEntityModifier(new LoopEntityModifier(new ParallelEntityModifier(
				new ScaleModifier(2, 0.5f, 2.0f),new ScaleModifier(2, 2.0f,1.0f),new RotationModifier(4,0.0f,360.0f) )));
添加相应的modifier后,矩形就会动态的变幻了.

2.3 布置移动控制器和方向控制器

[java] view plain copy print ?
  1. final AnalogOnScreenControl mSpeedController =new AnalogOnScreenControl(30,CAMERA_HEIGHT - mControlBaseRegion.getHeight() -20,
  2. mCamera, mControlBaseRegion, mControlKnobRegion, 0.1f,100,getVertexBufferObjectManager(),
  3. new IAnalogOnScreenControlListener(){
  5. @Override
  6. public void onControlChange(
  7. BaseOnScreenControl pBaseOnScreenControl,
  8. float pValueX, float pValueY) {
  9. // TODO Auto-generated method stub
  10. if(pValueX == 0 && pValueY ==0){
  11. mFace.setVelocity(0,0);
  12. }
  14. else
  15. {
  16. mFace.setVelocity(pValueX*100, pValueY*100);
  17. }
  18. }
  20. @Override
  21. public void onControlClick(
  22. AnalogOnScreenControl pAnalogOnScreenControl) {
  23. // TODO Auto-generated method stub
  25. }
  28. });
  31. final AnalogOnScreenControl mRotationController =new AnalogOnScreenControl(CAMERA_WIDTH - mControlBaseRegion.getWidth() -30,
  32. CAMERA_HEIGHT - mControlBaseRegion.getHeight() - 20,
  33. mCamera, mControlBaseRegion, mControlKnobRegion, 0.1f,100,getVertexBufferObjectManager(),
  34. new IAnalogOnScreenControlListener(){
  36. @Override
  37. public void onControlChange(
  38. BaseOnScreenControl pBaseOnScreenControl,
  39. float pValueX, float pValueY) {
  40. // TODO Auto-generated method stub
  41. if(pValueX == 0 && pValueY == 0){
  42. mFace.setRotation(0.0f);
  43. }
  45. else
  46. {
  47. mFace.setRotation(MathUtils.radToDeg(MathUtils.atan2(pValueY, pValueX)));
  48. }
  49. }
  51. @Override
  52. public void onControlClick(
  53. AnalogOnScreenControl pAnalogOnScreenControl) {
  54. // TODO Auto-generated method stub
  56. }
  59. }); 
final AnalogOnScreenControl mSpeedController = new AnalogOnScreenControl(30,CAMERA_HEIGHT -  mControlBaseRegion.getHeight() - 20,
				mCamera, mControlBaseRegion, mControlKnobRegion, 0.1f, 100,getVertexBufferObjectManager(),
				new IAnalogOnScreenControlListener(){

					@Override
					public void onControlChange(
							BaseOnScreenControl pBaseOnScreenControl,
							float pValueX, float pValueY) {
						// TODO Auto-generated method stub
						if(pValueX == 0 && pValueY == 0){
							mFace.setVelocity(0, 0);
						}
						
						else
						{
							mFace.setVelocity(pValueX*100, pValueY*100);
						}
					}

					@Override
					public void onControlClick(
							AnalogOnScreenControl pAnalogOnScreenControl) {
						// TODO Auto-generated method stub
						
					}


		});
		
		
		final AnalogOnScreenControl mRotationController = new AnalogOnScreenControl(CAMERA_WIDTH - mControlBaseRegion.getWidth() - 30,
				CAMERA_HEIGHT -  mControlBaseRegion.getHeight() - 20,
				mCamera, mControlBaseRegion, mControlKnobRegion, 0.1f, 100,getVertexBufferObjectManager(),
				new IAnalogOnScreenControlListener(){

					@Override
					public void onControlChange(
							BaseOnScreenControl pBaseOnScreenControl,
							float pValueX, float pValueY) {
						// TODO Auto-generated method stub
						if(pValueX == 0 && pValueY == 0){
							mFace.setRotation(0.0f);
						}
						
						else
						{
							mFace.setRotation(MathUtils.radToDeg(MathUtils.atan2(pValueY, pValueX)));
						}
					}

					@Override
					public void onControlClick(
							AnalogOnScreenControl pAnalogOnScreenControl) {
						// TODO Auto-generated method stub
						
					}


		});
2.4 把所有角色搬到场景中

[java] view plain copy print ?
  1. mSpeedController.getControlBase().setBlendFunction(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
  2. mRotationController.getControlBase().setBlendFunction(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
  4. mScene.attachChild(mFace);
  5. mScene.attachChild(mRectangle);
  6. mScene.setChildScene(mSpeedController);
  7. mSpeedController.setChildScene(mRotationController);
  9. pOnCreateSceneCallback.onCreateSceneFinished(mScene); 
mSpeedController.getControlBase().setBlendFunction(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
		mRotationController.getControlBase().setBlendFunction(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
		
		mScene.attachChild(mFace);
		mScene.attachChild(mRectangle);
		mScene.setChildScene(mSpeedController);
		mSpeedController.setChildScene(mRotationController);
		
		pOnCreateSceneCallback.onCreateSceneFinished(mScene);

5.在场景中注册刷新监听事件

[java] view plain copy print ?
  1. mScene.registerUpdateHandler(new IUpdateHandler(){
  3. @Override
  4. public void onUpdate(float pSecondsElapsed) {
  5. // TODO Auto-generated method stub
  6. if(mRectangle.collidesWith(mFace)){
  7. mRectangle.setColor(1.0f,0.0f, 0.0f);
  8. }
  10. else
  11. {
  12. mRectangle.setColor(0.0f,1.0f,0.0f);
  13. }
  14. }
  16. @Override
  17. public void reset() {
  18. // TODO Auto-generated method stub
  20. }
  23. }); 
mScene.registerUpdateHandler(new IUpdateHandler(){

			@Override
			public void onUpdate(float pSecondsElapsed) {
				// TODO Auto-generated method stub
				if(mRectangle.collidesWith(mFace)){
					mRectangle.setColor(1.0f, 0.0f, 0.0f);
				}
				
				else
				{
					mRectangle.setColor(0.0f,1.0f,0.0f);
				}
			}

			@Override
			public void reset() {
				// TODO Auto-generated method stub
				
			}

		
		});
有了这个监听后,场景每次的刷新都可以添加处理事件了.所以基本上就完成任务了,呵呵


6.辅助自定义类

[java] view plain copy print ?
  1. public class MySpriteextends Sprite{
  3. public MySprite(float pX,float pY, float pWidth,float pHeight,
  4. ITextureRegion pTextureRegion,
  5. VertexBufferObjectManager pVertexBufferObjectManager) {
  6. super(pX, pY, pWidth, pHeight, pTextureRegion, pVertexBufferObjectManager);
  7. // TODO Auto-generated constructor stub
  8. }
  10. private float mVelocityX =0;
  11. private float mVelocityY =0;
  15. @Override
  16. protected void onManagedUpdate(float pSecondsElapsed) {
  17. // TODO Auto-generated method stub
  18. this.mX += mVelocityX * pSecondsElapsed;
  19. this.mY += mVelocityY * pSecondsElapsed;
  21. this.setPosition(mX, mY);
  23. super.onManagedUpdate(pSecondsElapsed);
  24. }
  26. void setVelocity(float vX,float vY){
  27. mVelocityX = vX;
  28. mVelocityY = vY;
  29. }
  31. } 
public class MySprite extends Sprite{

		public MySprite(float pX, float pY, float pWidth, float pHeight,
				ITextureRegion pTextureRegion,
				VertexBufferObjectManager pVertexBufferObjectManager) {
			super(pX, pY, pWidth, pHeight, pTextureRegion, pVertexBufferObjectManager);
			// TODO Auto-generated constructor stub
		}

		private float mVelocityX = 0;
		private float mVelocityY = 0;
		
		
		
		@Override
		protected void onManagedUpdate(float pSecondsElapsed) {
			// TODO Auto-generated method stub
			this.mX += mVelocityX * pSecondsElapsed;
			this.mY += mVelocityY * pSecondsElapsed;
			
			this.setPosition(mX, mY);
			
			super.onManagedUpdate(pSecondsElapsed);
		}

		void setVelocity(float vX, float vY){
			mVelocityX = vX;
			mVelocityY = vY;
		}
		
	}

7.运行演示

通过碰撞检测运行的结果如下:







本例子源代码:http://download.youkuaiyun.com/detail/cen616899547/4737237

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连续碰撞检测（Continuous Collision Detection, CCD）是一种用于处理物体在运动过程中可能发生的碰撞的技术。与传统的离散碰撞检测（Discrete Collision Detection, DCD）不同，CCD旨在解决快速移动物体在帧与帧之间可能“穿透”其他物体的问题。以下是关于CCD的详细讨论，包括其原理、常用方法、实现方式和注意事项。穿透问题：连续检测：线性插值：时间参数化：射线投射：GJK算法：Swept Volume：以下是一个简单的CCD实现示例，使用线性插值和射线投
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