class Ripple {
  float x, y;
  float max_r, r;
  float step;
  boolean FINISHED = false;
  float max_brightness;
  float thickness;
   
  Ripple(float x, float y, float r) {
    this.x = x;
    this.y = y;
    this.max_r = r;
    this.r = 0;
    step = random(0.3, 0.8);
    max_brightness = 210;
    thickness = random(1, 5);
  }
   
  /*****************************
  * Update object state
  */
  void update() {
    if (r <= max_r) {   // If r is smaller than max radius
      r = r + (step * 2);      // then keep expanding,
    } else {
      FINISHED = true;  // otherwise put the object into dead state.
    }
  }
 
  /*****************************
  * Draw the ripple
  */ 
  void display() {
    noFill();
    stroke(0, max_brightness, max_brightness, 255 * (max_r - r) / max_r);
    strokeWeight(1);
    ellipse(this.x, this.y, this.r, this.r);
  }
   
  /*****************************
  * Return object state
  */
  boolean finished() {
    return FINISHED;
  }
}