​

let count = 1; 

let spacing = 15;

​

let start = [];

let vel = [];

​

let s = 0;

let v = 1;

​

let angle = 0;

​

​

function setup() {

  createCanvas(400, 400);

  angleMode(DEGREES);

  // for (let i=0; i<count; i++){

  //   start[i] = 0; 

  //   vel[i] = 1;

  // }

}

​

function draw() {

  background(255);

  translate(width/2, height/2);

  noFill();

  strokeWeight(4);

  s = constrain(s, 0, 180);

  arc(0, 0, 100, 100, angle -180, angle + (-180 + s));

  arc(0, 0, 100, 100, angle + 0, angle + s)

  if (s <= 0){

      v = v * -1;

    } else if (s >= 180) {

      v = v * -1;

    }

  s = s + v;

//   for (let i=0; i<count; i++){

//     stroke(0);

//     start[i] = constrain(start[i], 0, 180); 

//     arc(0, 0, (i+1)*spacing, (i+1)*spacing, angle + (-180), angle + (-180 + start[i]));

//     arc(0, 0, (i+1)*spacing, (i+1)*spacing, angle + 0, angle + start[i]);

//     if (start[i] <= 0){

//       vel[i] = vel[i] * -1;

//     } else if (start[i] >= 180) {

//       vel[i] = vel[i] * -1;

//     }

//     start[i] = start[i] + vel[i];

//     angle = angle + 0.1;

​

//   }

​

}

​