let r1 = 100;

let r2 = 80;

​

function setup() {

  createCanvas(400, 400);

}

​

function draw() {

  background(0);

  strokeWeight(3);

  t += 0.01;

  let x = noise(t) * width;

  let y = noise(t + 50) * height;

  let x2 = noise(t + 100) * width;

  let y2 = noise(t + 150) * height;

  if ((abs(x - x2) < (r1 + r2)/2) && 

     (abs(y - y2) < (r1 + r2)/2)) {

    fill(255, 0, 0);

    stroke(255, 0, 0);

  } else {

    noFill();

    stroke(255);

  }

  circle(x, y, r1);

  circle(x2, y2, r2);

}

​

​