Quiero mostrar una franja triangular cuando el usuario cambia el dedo en la pantalla. No estoy seguro de cómo hacerlo con AndEngine, usando un sistema de partículas o usando sprites o usando algo de Triangle Strip ...

No he escrito ningún código porque me llama la atención que hacer. Estoy subiendo una imagen, por favor comparta sus ideas.

Actualiza

alguien ha hecho esto en Iphone pero desafortunadamente no estoy familiarizado con la sintaxis del lenguaje, por favor ayúdenme a entender algo de este códigohttps: //github.com/hiepnd/CCBlad

** Efecto que quiero **

Complete Android Project Descargar

http: //www.andengine.org/forums/resources/complete-runnable-project/130

He hecho este código pero no pude obtener el efecto deseado ...

    package org.az.algo.examples;

import javax.microedition.khronos.opengles.GL10;

import org.anddev.andengine.engine.Engine;
import org.anddev.andengine.engine.camera.Camera;
import org.anddev.andengine.engine.options.EngineOptions;
import org.anddev.andengine.engine.options.EngineOptions.ScreenOrientation;
import org.anddev.andengine.engine.options.resolutionpolicy.RatioResolutionPolicy;
import org.anddev.andengine.entity.particle.ParticleSystem;
import org.anddev.andengine.entity.particle.emitter.RectangleParticleEmitter;
import org.anddev.andengine.entity.particle.initializer.AlphaInitializer;
import org.anddev.andengine.entity.particle.initializer.ColorInitializer;
import org.anddev.andengine.entity.particle.initializer.GravityInitializer;
import org.anddev.andengine.entity.particle.initializer.RotationInitializer;
import org.anddev.andengine.entity.particle.modifier.AlphaModifier;
import org.anddev.andengine.entity.particle.modifier.ColorModifier;
import org.anddev.andengine.entity.particle.modifier.ExpireModifier;
import org.anddev.andengine.entity.scene.Scene;
import org.anddev.andengine.entity.scene.Scene.IOnSceneTouchListener;
import org.anddev.andengine.entity.sprite.Sprite;
import org.anddev.andengine.entity.util.FPSLogger;
import org.anddev.andengine.input.touch.TouchEvent;
import org.anddev.andengine.opengl.texture.TextureOptions;
import org.anddev.andengine.opengl.texture.atlas.bitmap.BitmapTextureAtlas;
import org.anddev.andengine.opengl.texture.atlas.bitmap.BitmapTextureAtlasTextureRegionFactory;
import org.anddev.andengine.opengl.texture.region.TextureRegion;

import android.view.ViewGroup.MarginLayoutParams;
import android.widget.Toast;


public class ParticleSystemSimpleExample extends BaseExample {
    // ===========================================================
    // Constants
    // ===========================================================

    private static final int CAMERA_WIDTH = 720;
    private static final int CAMERA_HEIGHT = 480;

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

    private Camera mCamera;
    private BitmapTextureAtlas mBitmapTextureAtlas;
    private TextureRegion mParticleTextureRegion;
    private BitmapTextureAtlas mBitmapTextureAtlasStreak;
    private TextureRegion mStreadTextureRegion;

    private Sprite[] mSprite = new Sprite[20];
    private int mIndex = 0;

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

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

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

    @Override
    public Engine onLoadEngine() {
        Toast.makeText(this, "Touch the screen to move the particlesystem.", Toast.LENGTH_LONG).show();
        this.mCamera = new Camera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT);
        return new Engine(new EngineOptions(true, ScreenOrientation.LANDSCAPE, new RatioResolutionPolicy(CAMERA_WIDTH, CAMERA_HEIGHT), this.mCamera));
    }

    @Override
    public void onLoadResources() {
        this.mBitmapTextureAtlas = new BitmapTextureAtlas(32, 32, TextureOptions.BILINEAR_PREMULTIPLYALPHA);
        this.mParticleTextureRegion = BitmapTextureAtlasTextureRegionFactory.createFromAsset(this.mBitmapTextureAtlas, this, "gfx/particle_point.png", 0, 0);

        this.mBitmapTextureAtlasStreak = new BitmapTextureAtlas(128, 16, TextureOptions.BILINEAR_PREMULTIPLYALPHA);     
        this.mStreadTextureRegion = BitmapTextureAtlasTextureRegionFactory.createFromAsset(this.mBitmapTextureAtlasStreak, this, "gfx/streak1.png", 0, 0);

        this.mEngine.getTextureManager().loadTextures(this.mBitmapTextureAtlas, this.mBitmapTextureAtlasStreak);
    }

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

        final Scene scene = new Scene();

//      final CircleOutlineParticleEmitter particleEmitter = new CircleOutlineParticleEmitter(CAMERA_WIDTH * 0.5f, CAMERA_HEIGHT * 0.5f + 20, 80);
        final RectangleParticleEmitter particleEmitter = new RectangleParticleEmitter(CAMERA_WIDTH * 0.5f, CAMERA_HEIGHT * 0.5f, 5f,5f);

//      final PointParticleEmitter particleEmitter = new PointParticleEmitter(10, 10);      
        final ParticleSystem particleSystem = new ParticleSystem(particleEmitter, 100, 100, 1000, this.mParticleTextureRegion);
        particleSystem.setParticlesSpawnEnabled(false);     

        scene.setOnSceneTouchListener(new IOnSceneTouchListener() {
            @Override
            public boolean onSceneTouchEvent(final Scene pScene, final TouchEvent pSceneTouchEvent) {               

                if(pSceneTouchEvent.getAction() == TouchEvent.ACTION_MOVE){                 

                    particleSystem.setParticlesSpawnEnabled(true);                  
                    particleEmitter.setCenter(pSceneTouchEvent.getX(), pSceneTouchEvent.getY());

                    mSprite[getIndex()].setPosition(pSceneTouchEvent.getX(), pSceneTouchEvent.getY());
                    mSprite[getIndex()].setVisible(true);

                }else if (pSceneTouchEvent.getAction() == TouchEvent.ACTION_UP){

                    particleSystem.setParticlesSpawnEnabled(false);
                    hideAll();

                }else if(pSceneTouchEvent.getAction() == TouchEvent.ACTION_DOWN){

                    particleSystem.reset();

                }

                return true;
            }
        });     

        particleSystem.addParticleInitializer(new ColorInitializer(1, 0, 0));
        particleSystem.addParticleInitializer(new AlphaInitializer(0));
        particleSystem.setBlendFunction(GL10.GL_SRC_ALPHA, GL10.GL_ONE);
//      particleSystem.addParticleInitializer(new VelocityInitializer(-2, 2, -20, -10));
        particleSystem.addParticleInitializer(new GravityInitializer());

//      particleSystem.addParticleModifier(new ScaleModifier(0.5f, 1.0f, 0, 1.5f));
        particleSystem.addParticleModifier(new ColorModifier(1, 1, 0, 0.5f, 0, 0, 0, 3));
        particleSystem.addParticleModifier(new ColorModifier(1, 1, 0.5f, 1, 0, 1, 4, 6));
        particleSystem.addParticleModifier(new AlphaModifier(0, 1, 0, 0.5f));
        particleSystem.addParticleModifier(new AlphaModifier(1, 0, 2.5f, 3.5f));
        particleSystem.addParticleModifier(new ExpireModifier(6, 6f));

        scene.attachChild(particleSystem);


        for(int i = 0; i < mSprite.length; i++){
            mSprite[i] = new Sprite(-20, 0, mStreadTextureRegion);
            mSprite[i].setVisible(false);
            scene.attachChild(mSprite[i]);
        }





        return scene;
    }

    @Override
    public void onLoadComplete() {

    }


    private int getIndex(){
        if(mIndex >= mSprite.length -1){
            mIndex = 0;
        }
        System.out.println("Index ........ "+mIndex);
        return mIndex++;
    }

    private void hideAll(){
        for(int i = 0; i<mSprite.length; i++){
            mSprite[i].setVisible(false);
            mSprite[i].setPosition(-CAMERA_WIDTH, 0);
        }
    }
    // ===========================================================
    // Methods
    // ===========================================================

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

image que utilicé con este código también se adjunta

Actualizad

efecto parcial logrado ... pero problema al deslizar rápidamente ... todos los proyectos completos se cargan aquíhttp: //www.andengine.org/forums/post31772.html#p3177