let y;

​

function setup() {

  createCanvas(400, 400);

  y = 20;

}

​

function draw() {

  background(0);

​

    if (active) {

    fill(255, 0, 0)

    for (y = 20; y < height; y = y + 20) {

      circle(20, y, 10);

    }

  } else {

    fill(255)

    for (y = 20; y < height; y = y + 20) {

      circle(20, y, 10);

​

    }

  }

    if (dist(mouseX, mouseY, 20, y) < 10 / 2) {

    active = false;

​

  }

  else {

    active = true;}

​

}