(转)[AndEngine学习教程] 第4节 制作人物动画

1.回顾

    在上一节我们制作一个可以变幻的图形,这节将基于上一节的内容,制作一个行走的人物动画.在这里就称它为战士吧!呵呵!!!!

2.新使用到的资源

   1.RepeatingSpriteBackground 游戏场景中使用到的背景绘制策略,本节中使用到草坪背景,由于背景大小是可以自动调节的,

       不可能绘制一张固定大小的图片来作为背景.一方面占用空间大不说,另一方面背景图片经过缩放后效果也不好

   2.PathModifier 为战士设定行走路径.需要说明的是:这里的路径是两点间的直线路径.比如只需要设定起点和终点.战士就会

      沿着这两点间的直线进行移动

3.源代码陈述

      1.关于RepeatingSpriteBackground  ,这是一种重复绘制背景图片的策略,此类继承于 SpriteBackground ,有两个构造函数:

       

 /**
      * @param pCameraWidth
      * @param pCameraHeight
      * @param pTextureManager
      * @param pBitmapTextureAtlasSource needs to be a power of two as otherwise the <code>repeating</code> feature doesn't work.
      */
     public RepeatingSpriteBackground(final float pCameraWidth, final float pCameraHeight, final TextureManager pTextureManager, final IBitmapTextureAt              lasSource pBitmapTextureAtlasSource, final VertexBufferObjectManager pVertexBufferObjectManager) throws IllegalArgumentException {
         this(pCameraWidth, pCameraHeight, pTextureManager, pBitmapTextureAtlasSource, 1, pVertexBufferObjectManager);
     }

     public RepeatingSpriteBackground(final float pCameraWidth, final float pCameraHeight, final TextureManager pTextureManager, final IBitmapTextureAt                 lasSource pBitmapTextureAtlasSource, final float pScale, final VertexBufferObjectManager pVertexBufferObjectManager) throws IllegalArgumentException {
         super(null);

         this.mScale = pScale;
         this.mEntity = this.loadSprite(pCameraWidth, pCameraHeight, pTextureManager, pBitmapTextureAtlasSource, pVertexBufferObjectManager);
     }

本例子中使用到的是第一种构造函数,实现形式如下:

  

        private static final int CAMERA_WIDTH=800;
 private static final int CAMERA_HEIGHT=480;
 private Camera mCamera;
 private RepeatingSpriteBackground mGrassBackground;
 private TiledTextureRegion mPlayerTextureRegion;
 private BitmapTextureAtlas mTexture;

 @Override
 public EngineOptions onCreateEngineOptions() {
     // TODO Auto-generated method stub
     mCamera = new Camera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT);
     EngineOptions engineOptions = new EngineOptions(true,ScreenOrientation.LANDSCAPE_SENSOR, new RatioResolutionPolicy(CAMERA_WIDTH,CAMERA_HEIGHT), mCamera);
     return engineOptions;
 }

 @Override
 public void onCreateResources(
         OnCreateResourcesCallback pOnCreateResourcesCallback)
         throws Exception {
     // TODO Auto-generated method stub
     this.mTexture = new BitmapTextureAtlas(getTextureManager(), 128, 128, TextureOptions.BILINEAR_PREMULTIPLYALPHA);
     this.mPlayerTextureRegion = BitmapTextureAtlasTextureRegionFactory.createTiledFromAsset(mTexture, this,"player.png", 0,0,3, 4);
     this.mGrassBackground = new RepeatingSpriteBackground(CAMERA_WIDTH, CAMERA_HEIGHT, getTextureManager(), AssetBitmapTextureAtlasSource.create(getAssets(), "background_grass.png"), getVertexBufferObjectManager());

     mTexture.load();
     pOnCreateResourcesCallback.onCreateResourcesFinished();
 }

然后在onCreateScene(OnCreateSceneCallback pOnCreateSceneCallback)函数中实现  

 Scene mScene = new Scene();
 mScene.setBackground(mGrassBackground);
 pOnCreateSceneCallback.onCreateSceneFinished(mScene);

这样就把重复是的背景放置完成.

3.重点介绍

    本例中用到一个72x128大小,3列4行的精灵战士

    

因此动画的创建方式为:

 final AnimatedSprite  player = new AnimatedSprite(10, 10, 48, 64, mPlayerTextureRegion, getVertexBufferObjectManager());
 mScene.attachChild(player);

这样就把战士般到了屏幕上,但是此时,战士还不会动,为了让它动起来可要花费点力气的.呵呵!.有什么办法呢?就是给战士注册 监听实体 ,

由于本例子要求的是战士按照设定路径移动,自然想到AndEngine中的Path类,定义一个可以围绕整个屏幕的path路线:

 final Path path = new Path(5).to(10, 10).to(10, CAMERA_HEIGHT - 74).to(CAMERA_WIDTH-58, CAMERA_HEIGHT - 74).to(CAMERA_WIDTH-58, 10).to(10, 10);

每个to函数为Path添加一个路径,最终形成一个从屏幕左上角->左下角->右下角->右上角->左上角的封闭路径.

有了以上基础,当然是添加基于Path类修改器啦.

 PathModifier pathModifier = new PathModifier(30.0f, path, new IPathModifierListener(){

             @Override
             public void onPathStarted(PathModifier pPathModifier,
                     IEntity pEntity) {
                 // TODO Auto-generated method stub

             }

             @Override
             public void onPathWaypointStarted(PathModifier pPathModifier,
                     IEntity pEntity, int pWaypointIndex) {
                 // TODO Auto-generated method stub
                 switch(pWaypointIndex) {
                 case 0:
                     player.animate(new long[]{200, 200, 200}, 6, 8, true);
                     break;
                 case 1:
                     player.animate(new long[]{200, 200, 200}, 3, 5, true);
                     break;
                 case 2:
                     player.animate(new long[]{200, 200, 200}, 0, 2, true);
                     break;
                 case 3:
                     player.animate(new long[]{200, 200, 200}, 9, 11, true);
                     break;
             }
             }

             @Override
             public void onPathWaypointFinished(PathModifier pPathModifier,
                     IEntity pEntity, int pWaypointIndex) {
                 // TODO Auto-generated method stub

             }

             @Override
             public void onPathFinished(PathModifier pPathModifier,
                     IEntity pEntity) {
                 // TODO Auto-generated method stub

             }



         },EaseSineInOut.getInstance());

战士行走动作的变化是一个基础动画,所以需要Animate方法.但是战士在每个位置脸朝向不一样的,所以到了每个 拐点的开始 处都

需要修改动画的脸部朝向,这样就更加逼真点.从图片可以看出他们的对应关系.需要说明的是player.animate()函数:

 public void animate(final long[] pFrameDurations, final int pFirstTileIndex, final int pLastTileIndex, final boolean pLoop) {
         this.animate(pFrameDurations, pFirstTileIndex, pLastTileIndex, pLoop, null);
     }

各个参数的含义为:(战士图片中可以看出:有4组动作,每组动作为3个画面)

   pFrameDurations:连续播放3个画面,三个long数据为每个动画的播放时间间隔,单位为毫秒;

   pFirstTileIndex:动画的其起始列,按照"Z"字形排列计数.
   pLastTileIndex:动画的结束序列,按照"Z"字形排列计数.
  pLoop:是否循环播放

为了让战士行走路径也能循环,在PathModifier的基础上增加LoopEntityModifier

 LoopEntityModifier loopModifier = new LoopEntityModifier(pathModifier, -1);

有了loopModifier,当然是把它绑定到player上啦

 player.registerEntityModifier(loopModifier);

至此,整个设计任务完成了,下面看看运行的结果图片:

本例子源代码:http://download.csdn.net/detail/cen616899547/4705911

转自：http://blog.csdn.net/cen616899547/article/details/8131842