重なるCMYの円

/**
 * interlapping CMY circles
 * 
 * @author aadebdeb
 * @date 2017/02/19
 */

var colors;
var isDarkest = true;

function setup() {
  createCanvas(windowWidth, windowHeight);
  frameRate(30);
  noStroke();
  colors = [
    color(255, 255, 0),
    color(255, 0, 255),
    color(0, 255, 255),
  ];
}

function mousePressed() {
  isDarkest = !isDarkest;
}

function draw() {
  blendMode(BLEND);
  if (isDarkest) {
    background(255);
    blendMode(DARKEST);
  } else {
    background(0);
    blendMode(LIGHTEST);
  }
  var r = 50;
  for (var x = -2; x * sqrt(3) / 2 * r <= width + r; x++) {
      var w = x * sqrt(3) / 2 * r;
    for (var y = -2; y * 3 / 2 * r <= height + r; y++) {
      var h = y * 3 / 2 * r;
      h += (x + y) % 2 == 0 ? r / 4: -r / 4;
      noStroke();
      for (var i = 0; i < 3; i++) {
        fill(colors[i]);
        var angle = TWO_PI / 3 * i + frameCount * 0.04 + (x + y) * 0.07;
        angle += (x + y) % 2 == 0? -HALF_PI: HALF_PI;
        ellipse(w + r * cos(angle), h + r * sin(angle), 25, 25);
      }
    }
  }
}