android - Andengine 粒子碰撞效果 (Android Game Dev)

Question

我有兴趣开发一个粒子引擎，我可以调用类似 .createCollisionEffect(pos x, pos y, float duration);

并且引擎将在指定的持续时间内创建一个随机方向的粒子刺激。我找到了以下代码，但我想使用 3 种不同的纹理，所以它随机选择了一种，但是我不确定如何管理时间和 3 种不同的纹理:我找到了以下代码:

    public ParticleSystem createParticleSystem(final TextureRegion textureRegion) {
    //X & Y for the particles to spawn at.
    final float particlesXSpawn = 400;
    final float particlesYSpawn = 300;

    //Max & min rate are the maximum particles per second and the minimum particles per second.
    final float maxRate = 10;
    final float minRate = 5;

    //This variable determines the maximum particles in the particle system.
    final int maxParticles = 100;

    //Particle emitter which will set all of the particles at a ertain point when they are initialized.
    final PointParticleEmitter pointParticleEmtitter = new PointParticleEmitter(particlesXSpawn, particlesYSpawn);

    //Creating the particle system.
    final ParticleSystem particleSystem = new ParticleSystem(pointParticleEmtitter, maxRate, minRate, maxParticles, textureRegion);

    //And now, lets create the initiallizers and modifiers.
    //Velocity initiallizer - will pick a random velocity from -20 to 20 on the x & y axes. Play around with this value.
    particleSystem.addParticleInitializer(new VelocityInitializer(-20, 20, -20, 20));

    //Acceleration initializer - gives all the particles the earth gravity (so they accelerate down).
    particleSystem.addParticleInitializer(new GravityInitializer());

    //And now, adding an alpha modifier, so particles slowly fade out. This makes a particle go from alpha = 1 to alpha = 0 in 3 seconds, starting exactly when the particle is spawned.
    particleSystem.addParticleModifier((IParticleModifier) new AlphaModifier(3, 1, 0));

    //Lastly, expire modifier. Make particles die after 3 seconds - their alpha reached 0.
    particleSystem.addParticleModifier(new ExpireModifier(3));  

    return particleSystem;
}

谁能提供一些指导？提前致谢!

Answer 1

您在上面的代码中已经掌握了基础知识。以下是如何执行您正在寻找的操作:

1. 创建粒子发射器
2. 创建粒子系统
3. 添加修改器和初始化器，使您的粒子具有您想要的行为。

现在是秘诀:

1. 停止粒子系统:particleSystem.setParticlesSpawnEnabled(false);

2. 在发生碰撞时，使用以下命令将粒子发射器移动到应该发射粒子的位置:particleEmitter.setCenter(xPosition , yPosition);

3. 启动 TimerHandler 以在生成粒子的时间结束时关闭粒子。 TimerHandler 是一个 Andengine 类，其工作方式类似于处理程序，但会随着游戏暂停和继续。

你应该这样做!