public void setParticlesPerSecond(double pps) {
		this.particlesPerSecond = pps;
		
		int n = (int) (pps * 2.5);
		((ArrayList<Particle>) this.particles).ensureCapacity(n);
		for (int i = 0; i < n; ++i) {
			this.particles.add(new Particle());
		}
	}