let t2 = 10;

let t3 = 50;

let t4 = 60;

​

let r1 = 50;

let r2 = 60;

​

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(200);

  noStroke();

  let x1 = map(noise(t1), 0, 1, 0, width);

  let y1 = map(noise(t2), 0, 1, 0, height);

  let x2 = noise(t3) * width;

  let y2 = noise(t4) * height; 

  if (dist(x1, y1, x2, y2) < (r1 + r2)/2) {

    fill(255, 0, 0);

  } else {

    fill(0);

  }

  circle(x1, y1, r1);

  circle(x2, y2, r2);

  t1 += 0.007;

  t2 += 0.007;

  t3 += 0.02;

  t4 += 0.02;

}