class Particle {
  PVector loc;
  PVector vel;
  PVector acc;
  float ms;
  float distance;
  
  Particle(PVector a, PVector v, PVector l, float ms_) {
    acc = a;
    vel = v;
    loc = l;
    ms = ms_;
  }
 
  void run() {
    update();
    render();
  }

  void update() {
    vel.add(acc);
    loc.add(vel);
    acc = new PVector();   
  }
 
  void render() {
    float cl = map(vel.mag(), 0, 5.0, 0, 60);  
    float al = map(vel.mag(), 0, 1.2, 0, 30); 
    float m = map(millis(), 0, 20000, 0, 30);   
    if(millis() < 20000){            
        stroke(cl, 99, 99, m);
    }
    else stroke(cl, 99, 99, al);   
    point(loc.x,loc.y);
  }
 
 void add_force(PVector force) { 
    force.div(ms);
    vel.add(force);
  }  
  PVector getLocation() {
    return loc;
  } 
  void move(PVector target) {
    acc.add(steer(target));
  }  

  PVector steer(PVector target) {
    PVector steer;
    PVector desired = PVector.sub(target,loc);
    float d = desired.mag();
    desired.normalize();
    desired.mult(10.0);
    steer = PVector.sub(desired,vel);
    steer.limit(4.0f);
    steer.div(ms);
    return steer;
  }
}

float numPart = 2000;
float r = 40.0;
float[] th = {0.0f, 0.5f, 1.0f, 1.5f, 2.0f, 2.5f, 3.0f, 3.5f, 4.0f, 4.5f, 5.0f, 5.5f, 6.0f, 6.5f};
float[] xx = {0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f};
float[] yy = {0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f}; 
float x, y;
float inx, iny;
PVector centerLoc;


ArrayList particles1 = new ArrayList();
ArrayList particles2 = new ArrayList();
ArrayList particles3 = new ArrayList();
ArrayList particles4 = new ArrayList();
ArrayList particles5 = new ArrayList();
ArrayList particles6 = new ArrayList();
ArrayList particles7 = new ArrayList();
ArrayList particles8 = new ArrayList();
ArrayList particles9 = new ArrayList();
ArrayList particles10 = new ArrayList();
ArrayList particles11 = new ArrayList();
ArrayList particles12 = new ArrayList();
ArrayList particles13 = new ArrayList();

void setup()
{
  size(640, 480, P2D);
  colorMode(HSB, 360, 100, 100, 100);
  smooth();
  inx = width/2;
  iny = height/2;
  for(int i=0; i<numPart; i++){
    x = r * cos(th[0]);
    y = r * sin(th[0]);
    x += inx;
    y += iny;
    particles1.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,70.0f)));
    particles2.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,50.0f)));
    particles3.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,70.0f)));
    particles4.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,50.0f)));
    particles5.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,70.0f)));
    particles6.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,50.0f)));
    particles7.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,70.0f)));
    particles8.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,50.0f)));
    particles9.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,70.0f)));
    particles10.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,50.0f)));
    particles11.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,70.0f)));
    particles12.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,50.0f)));
    particles13.add(new Particle(new PVector(), new PVector(), new PVector(x, y, 0), random(10.0f,70.0f)));
    th[0] += 0.1;
  }
  centerLoc = new PVector(width/2, height/2, 0);
}

void draw()
{
    background(1, 100, 0, 100);

    for(int z=0; z<13; z++)
    {
      xx[z] = r * cos(th[z+1]);
      yy[z] = r * sin(th[z+1]);
      xx[z] += inx;
      yy[z] += iny;
      xx[z] += random(-20.0, 20.0);
      yy[z] += random(-20.0, 20.0);   
      th[z+1] += 0.001f; 
    }
    

    for (int i = particles1.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles1.get(i);
      prt.run();
      prt.move(new PVector(xx[0],yy[0],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(1.2f); 
      prt.add_force(diff);     
    }
    for (int i = particles2.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles2.get(i);
      prt.run();  
      prt.move(new PVector(xx[1],yy[1],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(0.6f); 
      prt.add_force(diff);     
    }
    for (int i = particles3.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles3.get(i);
      prt.run();  
      prt.move(new PVector(xx[2],yy[2],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(1.2f); 
      prt.add_force(diff);     
    }
    for (int i = particles4.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles4.get(i);
      prt.run();
      prt.move(new PVector(xx[3],yy[3],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(0.6f); 
      prt.add_force(diff);     
    }
    for (int i = particles5.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles5.get(i);
      prt.run();  
      prt.move(new PVector(xx[4],yy[4],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(1.2f); 
      prt.add_force(diff);
    }
    for (int i = particles6.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles6.get(i);
      prt.run();  
      prt.move(new PVector(xx[5],yy[5],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(0.6f); 
      prt.add_force(diff);     
    }
    for (int i = particles7.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles7.get(i);
      prt.run();
      prt.move(new PVector(xx[6],yy[6],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(1.2f); 
      prt.add_force(diff);     
    }
    for (int i = particles8.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles8.get(i);
      prt.run();  
      prt.move(new PVector(xx[7],yy[7],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(0.6f); 
      prt.add_force(diff);     
    }
    for (int i = particles9.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles9.get(i);
      prt.run();  
      prt.move(new PVector(xx[8],yy[8],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(1.2f); 
      prt.add_force(diff);     
    }
    for (int i = particles10.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles10.get(i);
      prt.run();
      prt.move(new PVector(xx[9],yy[9],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(0.6f); 
      prt.add_force(diff);     
    }
    for (int i = particles11.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles11.get(i);
      prt.run();  
      prt.move(new PVector(xx[10],yy[10],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(1.2f); 
      prt.add_force(diff);     
    }
    for (int i = particles12.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles12.get(i);
      prt.run();  
      prt.move(new PVector(xx[11],yy[11],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(0.6f); 
      prt.add_force(diff);     
    }
    for (int i = particles13.size()-1; i >= 0; i--) {
      Particle prt = (Particle) particles13.get(i);
      prt.run();  
      prt.move(new PVector(xx[12],yy[12],0));
      PVector diff = PVector.sub(centerLoc,prt.getLocation()); 
      diff.normalize(); 
      diff.mult(1.2f); 
      prt.add_force(diff);     
    }

    fill(0, 0, 0);
    noStroke();
    
    ellipse(width/2, height/2, 65, 65);
}