import org.jbox2d.particle.ParticleGroupDef; //导入依赖的package包/类
/**
 * Create a particle group whose properties have been defined. No reference to the definition is
 * retained.
 * 
 * @warning This function is locked during callbacks.
 */
public ParticleGroup createParticleGroup(ParticleGroupDef def) {
  assert (isLocked() == false);
  if (isLocked()) {
    return null;
  }
  ParticleGroup g = m_particleSystem.createParticleGroup(def);
  return g;
}
 

import org.jbox2d.particle.ParticleGroupDef; //导入依赖的package包/类
public DwParticleSpawn(World world, DwViewportTransform transform){
  this.world = world;
  this.transform = transform;
  this.pdestroyer = new DwParticleDestroyer(world, transform);
  this.group_def  = new ParticleGroupDef();
  
  this.group_def.setColor(new Color3f(1,0.35f, 0.15f));
  this.group_def.flags = ParticleType.b2_waterParticle | ParticleType.b2_viscousParticle;
  this.group_def.groupFlags = 0;
  
  setCircleShape(30);
}