createCanvas(400, 400);

}

​

function draw() {

  background(220);

  if (mouseX < width / 2) {

    drawRects();

  } else {

    drawLines();

  }

​

}

​

function drawLines() {

  line(0, 0, width, height);

  line(-10, 0, width - 10, height);

  line(10, 0, width + 10, height);

}

​

function drawRects() {

  rect(random(8, 12), 10, 50, 50);

  rect(340, 340, 50, 50);

​

}