var _gutter = 40;
var _numX, _numY;
var _angle;
var _frequency = 3;
var _size;

function setup() {
  createCanvas(windowWidth,windowHeight);
  frameRate(20);
  smooth();
  noStroke();
   _numX = width/_gutter;
  _numY = height/_gutter;
  _angle = 0;
}

function draw() {
  background(0,30);
  fill(255);
  rectMode(CENTER);
  for (var i = 1; i < _numX; i++) {
    for (var j = 1; j < _numY; j++) {
      _size = cos((PI/4*i)+(PI/4*j)+radians(_angle))*20;
      ellipse(_gutter*i, _gutter*j,_size,_size);
    }
  }
  _angle += _frequency;
}