class Swarm {
  Particle[] ps;
  int pCount = 0;
  int pMax = 100;
  int pInitial = int(random(10, 30));
  
  float x, y; // Position (centre of mass)
  float vx, vy; // Velocity
  
  Swarm() {
    x = random(padding, width - padding);
    y = random(padding, height - padding);
    vx = random(-4, 4);
    vy = random(-4, 4);
    ps = new Particle[pMax];
    for (int i = 0; i < pInitial; i++) {
      spawnParticle(x, y, int(random(0, 250)), (random(10) > 5));
    }
  }
  
  boolean spawnParticle(float px, float py, int age, boolean sex) {
    for (int i = 0; i < pMax; i++) {
      if (ps[i] == null) {
        ps[i] = new Particle(px, py, age, sex);
        ps[i].move(x, y);
        pCount++;
        return true;
      }
    }
    return false;
  }
  
  void move() {
    x += vx * random(3);
    y += vy * random(3);
    
    vx += random(-1, 1);
    vy += random(-1, 1);
    
    vx = max(min(vx, 2), -2);
    vy = max(min(vy, 2), -2);
    
    if ((x < padding) || (x > width - padding)) {
      vx *= -9;
    }
    if ((y < padding) || (y > height - padding)) {
      vy *= -9;
    }
    
    // Administer the particles
    int deadCount = 0;
    for (int i = 0; i < pCount; i++) {
      if (ps[i] != null) {
        if (ps[i].age >= 1000) {
          ps[i] = null;
          pCount--;
        } else {
          ps[i].move(x, y);
          // Check for spawning
          for (int j = i; j < pCount; j++) {
            if (ps[j] != null) {
              if ((ps[i].age > 250) && (ps[i].age < 750) &&
                  (ps[j].age > 250) && (ps[j].age < 750) &&
                  (ps[i].sex != ps[j].sex) &&
                  (ps[i].x < ps[j].x + ps[j].size / 2) &&
                  (ps[i].x > ps[j].x - ps[j].size / 2) &&
                  (ps[i].y < ps[j].y + ps[j].size / 2) &&
                  (ps[i].y > ps[j].y - ps[j].size / 2) &&
                  (random(10) > 7.5) &&
                  (ps[i].spawnTime == 0) && (ps[j].spawnTime == 0)) {
                if (spawnParticle((ps[i].x + ps[j].x) / 2, (ps[i].y + ps[j].y) / 2, 0, (random(10) > 5))) {
                  ps[i].vx = 0; ps[i].vy = 0;
                  ps[j].vx = 0; ps[j].vy = 0;
                  ps[i].spawnTime = 3;
                  ps[j].spawnTime = 3;
                }
              }
            }
          }
        }
      }
    }
    
    /*noFill();
    stroke(192, 10);
    strokeWeight(2);
    ellipse(x, y, 100, 100);*/
    //fill(166, 255, 52, 80);
    //ellipse(x, y, 24, 24);
    //pCount -= deadCount;
  }
}