let b_arcs = [];

​

let count = 15;

let speed = 3;

​

function setup() {

  createCanvas(400, 400);

  angleMode(DEGREES);

  for (let i=0; i<count; i++){

    arcs[i] = new Arc((180/count) * (count - (i)), speed, (i+1)*15);

  }

  for (let i=0; i<count; i++){

    b_arcs[i] = new Arc((180/count) * (count - (i)), speed, (i+1)*15);

  }

​

}

​

function draw() {

  background(0);

  translate(width/2, height/2);

​

  push();

  rotate(180);

  for (let i=0; i<count; i++){

    arcs[i].update();

    arcs[i].display();

  }

  pop();

​

  for (let i=0; i<count; i++){

    b_arcs[i].update();

    b_arcs[i].display();

  }

}

​

class Arc {

  constructor(pos, vel, size){

    this.pos = pos;

    this.vel = vel;

    this.size = size;

  }

  update(){

    this.pos = constrain(this.pos, 0, 180);

    if (this.pos >= 180 || this.pos <= 0) {

      this.vel = this.vel * -1;

    }

    this.pos = this.pos + this.vel;

  }

  display(){

    noFill();

    stroke(255);

    strokeWeight(3);

    arc(0, 0, this.size, this.size, 0, this.pos);

  }

}