code: public void clearSystem(boolean additive) {
  		system = new ParticleSystem("org/newdawn/slick/data/particle.tga", 2000);
  		if (additive) {
  			system.setBlendingMode(ParticleSystem.BLEND_ADDITIVE);
  		}
  		system.setRemoveCompletedEmitters(false);
  	}
docs: Clear the particle system held in this canvas
  
  @param additive
  True if the particle system should be set to additive