let sc;

let z = 0;

​

function setup() {

  sc = 4*width;

  n = 1200;

  phi = (1 + sqrt(5)) * PI

  createCanvas(400, 400);

  background(220);

}

​

function draw() {

  if (frameCount <= n && (cos(frameCount * phi) < 0)) {

    translate(width, height / 2);

    let x = sc * sqrt(frameCount / n) * cos(frameCount * phi);

    let y = sc * sqrt(frameCount / n) * sin(frameCount * phi);

    line(x, y, 1.1 * x, 1.1 * y);

    z++;

  }

}