​

function setup() {

  createCanvas(400, 400);

  x = 2 * width / 3;

  y = 2 * height / 3;

  s = 0.5

}

​

function draw() {

  background(0);

  push();

  scale(s);

  translate(width / 2 / s - x, height / 2 / s - y);

  noStroke();

  fill(100);

  rectMode(CENTER);

  rect(0, 0, 10, 10);

  rect(width / 2, height / 2, 25, 25);

  rect(width / 3, height / 3, 50, 50);

  rect(2 * width / 3, 2 * height / 3, 75, 75);

  pop();

}