Orbital System

/**
* Orbital System
*
* @auther aa_debdeb
* @date 2015/08/23
*/

int numCircles = 30;
ArrayList<Circle> circles;

void setup(){
  size(500, 500);
  noStroke();
  smooth();
  background(255);
  frameRate(30);
  circles = new ArrayList<Circle>();
  for(int i = 0; i < numCircles; i++){
    circles.add(new Circle());
  }
}

void draw(){
  background(255);
  for(int i = 0; i < numCircles; i++){
    circles.get(i).updateAngle();
    circles.get(i).draw();
  }
}

class Circle{

  float revolutionRadious;
  float angle;
  float angularVelocity;
  float cirlceRadious = 30;
  float colorR;
  float colorG;
  float colorB;
  
  Circle(){
    this.revolutionRadious = random(1) * 200 + 50;
    this.angle = 0.0;
    this.angularVelocity = (PI / 24.0) * (2.0 * random(1) - 1.0);
    this.colorR = (int)random(256);
    this.colorG = (int)random(256);
    this.colorB = (int)random(256);

  }
  
  void updateAngle(){
    this.angle += this.angularVelocity;
    if(this.angle < 0){
      this.angle = 2.0 * PI + this.angle;
    } else if(2.0 * PI < this.angle){
      this.angle = this.angle - 2.0 * PI;
    }
  }
  
  void draw(){
    fill(this.colorR, this.colorG, this.colorB);
    float x = this.revolutionRadious * cos(this.angle);
    float y = this.revolutionRadious * sin(this.angle);
    arc(x + width / 2, y + height / 2.0, cirlceRadious, cirlceRadious, 0, 2*PI);
  }
  
}