createCanvas(400, 400);

  background(220);

}

​

function draw() {

  let clearDrawing = ellipse(20, 20, 20, 20);

  textAlign(CENTER);

  textSize(10);

  text("X", 20, 23);

}

​

function mouseDragged() {

  line(mouseX, mouseY, pmouseX, pmouseY);

  // prevent default

  return false;

}

​

function mousePressed() {

  let mx = mouseX;

  let my = mouseY;

  if ((mx > 20 && mx < 40) && (my > 20 && my < 40)) {

    background(220);

  }

}

​