JSFiddle - React, Tailwind, and code Playground

by David Marshall

HTML

<div id='land'>
</div>
<div id='sky'>
</div>

CSS

.dirt{
  background: url('https://jaejunshimgdd.files.wordpress.com/2014/10/g_dirt_texture.jpg');
  width: 30px;
  height: 30px;
}
.back{
  z-index: -1;
  background: #2de2e2;
  width: 30px;
  height: 30px;
}
#sky{
  z-index:-1;
}
#land{
  z-index:1;
}

JavaScript

(function(global){
  var module = global.noise = {};

  function Grad(x, y, z) {
    this.x = x; this.y = y; this.z = z;
  }
  
  Grad.prototype.dot2 = function(x, y) {
    return this.x*x + this.y*y;
  };

  Grad.prototype.dot3 = function(x, y, z) {
    return this.x*x + this.y*y + this.z*z;
  };

  var grad3 = [new Grad(1,1,0),new Grad(-1,1,0),new Grad(1,-1,0),new Grad(-1,-1,0),
               new Grad(1,0,1),new Grad(-1,0,1),new Grad(1,0,-1),new Grad(-1,0,-1),
               new Grad(0,1,1),new Grad(0,-1,1),new Grad(0,1,-1),new Grad(0,-1,-1)];

  var p = [151,160,137,91,90,15,
  131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
  190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
  88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
  77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
  102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
  135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
  5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
  223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
  129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
  251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
  49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
  138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180];
  // To remove the need for index wrapping, double the permutation table length
  var perm = new Array(512);
  var gradP = new Array(512);

  // This isn't a very good seeding function, but it works ok. It supports 2^16
  // different seed values. Write something better if you need more seeds.
  module.seed = function(seed) {
    if(seed > 0 && seed < 1) {
      // Scale the seed out
      seed *= 65536;
    }

    seed = Math.floor(seed);
    if(seed < 256) {
...