text: var a = 0;
  
  var sponge = [];
  
  function setup() {
    createCanvas(400, 400, WEBGL);
  
    // An array of Box objects
    // Star with one
    var b = new Box(0, 0, 0, 200);
    sponge.push(b);
  }
  
  function mousePressed() {
    // Generate the next set of boxes
    var next = [];
    for (var i = 0; i < sponge.length; i++) {
      var b = sponge[i];
      var newBoxes = b.generate();
      next = next.concat(newBoxes);
    }
    sponge = next;
  }
  
  function draw() {
    background(51);
    rotateX(a);
    rotateY(a * 0.4);
    rotateZ(a * 0.1);
    // Show what you've got!
    for (var i = 0; i < sponge.length; i++) {
      sponge[i].show();
    }
    a += 0.01;
  }