createCanvas(600, 600);

}

​

function draw() {

  background(255);

​

  if (mouseX < width / 10) {

    fill("red");

    rect(0, 0, width / 10, height);

  } else if (mouseX < 10 * 2) {

    fill("red");

    rect(2* width / 10, 0, width / 10, height);

    // We are in the room

  } else if (mouseX < width) {

    // Drawing the third rect

    fill("red");

    rect(3 * width / 10, 0, width / 10, height);

  }

}