(9)、andengine之CardinalSplineMoveModifier基数样条移动修改器

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.modifier.CardinalSplineMoveModifier;
import org.andengine.entity.modifier.CardinalSplineMoveModifier.CardinalSplineMoveModifierConfig;
import org.andengine.entity.modifier.DelayModifier;
import org.andengine.entity.modifier.ParallelEntityModifier;
import org.andengine.entity.modifier.RotationModifier;
import org.andengine.entity.modifier.SequenceEntityModifier;
import org.andengine.entity.primitive.Rectangle;
import org.andengine.entity.scene.Scene;
import org.andengine.entity.scene.background.Background;
import org.andengine.entity.util.FPSLogger;
import org.andengine.ui.activity.SimpleBaseGameActivity;
import org.andengine.util.math.MathUtils;
import org.andengine.util.modifier.ease.EaseLinear;

import android.opengl.GLES20;
import android.util.DisplayMetrics;
/**
 * 创建一个矩阵按照设定的路径跑，然后停止在终点
 */
public class CardinalSplineMoveModifierActivity extends SimpleBaseGameActivity
{
 private static int winWidth = 854;
 private static int winHeight = 480;
 
 private static final float RECTANGLE_SIZE = 25.0f;
 
 //时间(秒)
 private static final float DURATION = 4.0f;
 
 private static float[][] controlPointXy1;
 
 @Override
 public EngineOptions onCreateEngineOptions()
 {
  setScreenDisplay();
  Camera carmea = new Camera(0, 0, winWidth, winHeight);
  return new EngineOptions
    (
     true,
     ScreenOrientation.LANDSCAPE_FIXED,
     new RatioResolutionPolicy(winWidth, winHeight),
     carmea
    );
 }

 @Override
 protected void onCreateResources()
 {

 }

 @Override
 protected Scene onCreateScene()
 {
  this.mEngine.registerUpdateHandler(new FPSLogger());
  Scene scene = new Scene();
  scene.setBackground(new Background(0, 0, 0));
  
  Rectangle rectangle = new Rectangle(-RECTANGLE_SIZE, -RECTANGLE_SIZE, RECTANGLE_SIZE, RECTANGLE_SIZE, this.getVertexBufferObjectManager());
  rectangle.setBlendFunction(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE);
  //设置矩形颜色(使用了引擎的随机数)
  rectangle.setColor(MathUtils.random(0.0f, 1.0f), MathUtils.random(0.0f, 1.0f), MathUtils.random(0.0f, 1.0f), 0.5f);
  
  /*
   * 控制点的配置
   * CardinalSplineMoveModifierConfig中记录了控制点和张力，CardinalSplineMoveModifier根据配置文件计算出改变的路径。
   * 通过源码发现：(控制点)pControlPointCount最小为4个，(张力)pTension取值范围 [-1, 1]
   */
  CardinalSplineMoveModifierConfig cardinalSplineMoveModifierConfig1 = new CardinalSplineMoveModifierConfig(controlPointXy1.length, 1);
  
  //填充(设置)控制点(跟上面配置的个数要匹配)
  for (int i = 0; i < controlPointXy1.length; i++)
  {
   // pIndex  ：控制点下标;pX,pY ： 控制点左边(x,y)
   cardinalSplineMoveModifierConfig1.setControlPoint(i, controlPointXy1[i][0], controlPointXy1[i][1]);
  }
  //顺序实体修改器
  SequenceEntityModifier sequenceEntityModifier = new SequenceEntityModifier
    (
      //延时播放
      new DelayModifier(MathUtils.random(0, DURATION * 2f)),
      //无限循环，相当于根据控制点从下到上跑完左边
     /* new LoopEntityModifier
      (*/
        new ParallelEntityModifier
        (
          /*
           * 基数样条移动修改器
           * CardinalSplineMoveModifier：类似于PathModifier，但移动的效果更真实。
           * 实体接近弯道时，转弯更流畅，或扭转方向更平滑，这其实看起来相当不错
           */
          new CardinalSplineMoveModifier(DURATION, cardinalSplineMoveModifierConfig1, EaseLinear.getInstance()),
          new RotationModifier(DURATION, -45, -315)
        )
     // )
      
    );
  rectangle.registerEntityModifier(sequenceEntityModifier);
  
  scene.attachChild(rectangle);
  
  return scene;
 }
 
 /**
  * 设置屏幕大小
  */
 private void setScreenDisplay()
 {
  DisplayMetrics displayMetrics = new DisplayMetrics();
  getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
  winWidth = displayMetrics.widthPixels;
  winHeight = displayMetrics.heightPixels;
  
  //左边控制点的x,y
  controlPointXy1 = new float[][]
  {
   {2.0f*(winWidth/4)-RECTANGLE_SIZE/2 , 3.5f*(winHeight/4)-RECTANGLE_SIZE/2},
   {1.0f*(winWidth/4)-RECTANGLE_SIZE/2 , 2.0f*(winHeight/4)-RECTANGLE_SIZE/2},
   {1.5f*(winWidth/4)-RECTANGLE_SIZE/2 , 1.0f*(winHeight/4)-RECTANGLE_SIZE/2},
   {2.0f*(winWidth/4)-RECTANGLE_SIZE/2 , 1.5f*(winHeight/4)-RECTANGLE_SIZE/2}
  };
  
 }

}