var colors = [];

var diamter;



function setup() {

  createCanvas(windowWidth,

               windowHeight);

  noStroke();



  diameter = 38;



  colors.push(color(25, 115, 40));

  colors.push(color(105, 120, 200));

  colors.push(color(80, 25, 240));

  colors.push(color(120, 255, 255));

  colors.push(color(170, 255, 175));

  colors.push(color(255, 255, 128));

}



function draw() {

  background(255, 255, 255);

  var xoff = 0, yoff = 0;

  for (var y = 0; y <= height; y += diameter * sqrt(3) / 2) {

    for (var x = 0; x <= width; x += diameter) {

      xoff = (yoff % 2) ? diameter / 2 : 0;

      var amplitude = abs(sin(x + xoff + 0.01 * frameCount));

      fill(getColor(amplitude));      

      ellipse(x + xoff, y, diameter * amplitude);

    }

    yoff = yoff + 1;

  }

}



function getColor(t) {

  t = constrain(t, 0.000, 0.9999);

  var p = t * (colors.length - 1);

  var from = floor(p);

  return lerpColor(colors[from], colors[from + 1], p - from);

}