var ran_factor1=10;
var ran_factor2=5;
var fill_trans=100;
var thick=3;
var t;

function setup() {
  createCanvas(600,600);
  noStroke();
  fill(235,fill_trans);
  t=1;
}

function draw() {
  var i,j,k;
  t++;
  background(0);
  k_max=0.1*(t%8+random(10,12));
  for (k=0; k<k_max; k++) {
    for (i=2*thick; i<width; i+=2*thick) {
        for (j=2*thick; j<height; j+=2*thick) {
            if (random(2)<1) {
                rect(i,j,k+random(ran_factor1),k+random(ran_factor2))
            } else {
                ellipse(i,j,k+random(ran_factor1),k+random(ran_factor2));
            }
        }
    }
  }
}