public void AddParticle(Particle newParticle, bool background)
 {
     for (int i = 0; i < particles.Length; i++)
     {
         if (particles[i] == null)
         {
             particles[i] = newParticle;
             particles[i].Background = background;
             break;
         }
     }
 }
 public void AddParticle(Particle newParticle)
 {
     AddParticle(newParticle, false);
 }