​

​

var randomThreshold = 0.01;

var back;

​

​

function setup() {

  randomSeed(56);

  pixelDensity(1);

  createCanvas(400, 400);

  canvas.style.width = "100%";

  canvas.style.height = "100%";

  loadPixels();

  for(var i = 0; i < pixels.length; i += 4) {

    pixels[i] = 0;

    pixels[i+1] = 0;

    pixels[i+2] = 0;

    pixels[i+3] = 255 * (random(100) > randomThreshold*100);

  }

  updatePixels();

}

​

function draw() {

  loadPixels();

  for(var x = 0; x < width; x++) {

    for(var y = 0; y < height; y++) {

      var neighbours = [[x-1, y], [x-1, y-1], [x, y-1], [x+1, y-1], [x+1, y], [x+1, y+1], [x, y+1], [x-1, y+1]];

      var num = 0;

      for(var [x_, y_] of neighbours) {

        num += 1 * (pixels[index(x_, y_)] > 0);

      }

      var ind = index(x, y);

      if(num < 2) pixels[ind] = 0;

      if(num == 3) pixels[ind] = 255;

      if(num > 3) pixels[ind] = 0;

    }

  }

  updatePixels();

}

​

function index(x, y) {

  if(x < 0) x = width - 1;

  if(x > width-1) x = 0;

  if(y < 0) y = height - 1;

  if(y > height-1) y = 0;

  return (y * width + x) * 4 + 3;

}

​