int rate = 7;
int tickMS = rate;
int previous_stars = 0;
int time_stars = 0;

int rate2 = 1800;
int tickMS2 = rate;
int previous_stars2 = 0;
int time_stars2 = 0;

int starRadius = 20;
Star stars[] = new Star[1000];
Star stars2[] = new Star[1000];

void paintStars() {
  int current = millis();
  int elapsed = current - previous_stars;
  previous_stars = current;
  time_stars += elapsed;
  while(time_stars >= tickMS){
    time_stars -= tickMS;
    stars[(int)random(stars.length)].go();
    tickMS = int(random(rate/100,2*rate-(rate/100)));
  }
  
  if (stars.length > 0) {
    for (int i = stars.length-1; i > 0; i--) { 
      if(stars[i].alive){
        stars[i].display();
      }
    }
  }
}

void paintStars2() {
  int current = millis();
  int elapsed = current - previous_stars2;
  previous_stars2 = current;
  time_stars2 += elapsed;
  while(time_stars2 >= tickMS2){
    time_stars2 -= tickMS2;
    stars2[(int)random(stars.length)].go();
    tickMS2 = int(random(rate2/100,2*rate2-(rate/100)));
  }
  
  if (stars2.length > 0) {
    for (int i = stars2.length-1; i > 0; i--) { 
      if(stars2[i].alive){
        stars2[i].display();
      }
    }
  }
}



class Star {
  int x, y, init;
  int radius, bjitter, b; 
  int lifetime = 3600;
  boolean alive;
  PGraphics pg;
  Star(PGraphics pg_) {
    pg = pg_;
  }
  void go(){
    alive = true;
    x = (int)random(0,270);
    y = (int)random(0,270);
    init = millis();
    b = 255;
    bjitter = (int)random(-50, 50); 
    radius = starRadius;
  }
  void display() {
    b -= 10;
    pg.fill(255, b);
    pg.ellipse(x, y, radius, radius);
    radius -= .5;

    if (init + lifetime < millis()) {
      alive = false;
     }
  }
}