<div id="container"></div>
<script id="vertexShader" type="x-shader/x-vertex">

  void main() {
    gl_Position = vec4(position, 1.0);
  }

</script>

<script id="fragmentShader" type="x-shader/x-fragment">

  uniform vec2 iResolution;
  uniform float iGlobalTime;
  
  // Some utils first

  // From Stackoveflow
  // http://stackoverflow.com/questions/15095909/from-rgb-to-hsv-in-opengl-glsl
  vec3 hsv2rgb(vec3 c)
  {
      vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
      vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
      return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
  }

  // Simplex 2D noise
  // from https://gist.github.com/patriciogonzalezvivo/670c22f3966e662d2f83
  vec3 permute(vec3 x) { return mod(((x*34.0)+1.0)*x, 289.0); }

  float snoise(vec2 v){
      const vec4 C = vec4(0.211324865405187, 0.366025403784439,
                          -0.577350269189626, 0.024390243902439);
      vec2 i  = floor(v + dot(v, C.yy) );
      vec2 x0 = v -   i + dot(i, C.xx);
      vec2 i1;
      i1 = (x0.x > x0.y) ? vec2(1.0, 0.0) : vec2(0.0, 1.0);
      vec4 x12 = x0.xyxy + C.xxzz;
      x12.xy -= i1;
      i = mod(i, 289.0);
      vec3 p = permute( permute( i.y + vec3(0.0, i1.y, 1.0 ))
                       + i.x + vec3(0.0, i1.x, 1.0 ));
      vec3 m = max(0.5 - vec3(dot(x0,x0), dot(x12.xy,x12.xy),
                              dot(x12.zw,x12.zw)), 0.0);
      m = m*m ;
      m = m*m ;
      vec3 x = 2.0 * fract(p * C.www) - 1.0;
      vec3 h = abs(x) - 0.5;
      vec3 ox = floor(x + 0.5);
      vec3 a0 = x - ox;
      m *= 1.79284291400159 - 0.85373472095314 * ( a0*a0 + h*h );
      vec3 g;
      g.x  = a0.x  * x0.x  + h.x  * x0.y;
      g.yz = a0.yz * x12.xz + h.yz * x12.yw;
      return 130.0 * dot(m, g);
  }

  // This is my code
  void main(void)
  {
    vec2 uv = gl_FragCoord.xy / iResolution.xy;
    float xnoise = snoise(vec2(uv.x, iGlobalTime / 5.0 + 10000.0));
    float ynoise = snoise(vec2(uv.y, iGlobalTime / 5.0 + 500.0));
    vec2 t = vec2(xnoise, ynoise);
    float s1 = snoise(uv + t / 2.0 + snoise(uv + snoise(uv + t/3.0) / 5.0));
    float s2 = snoise(uv + snoise(uv + s1) / 7.0);
    vec3 hsv = vec3(s1, 1.0, 1.0-s2);
    vec3 rgb = hsv2rgb(hsv);
    gl_FragColor = vec4(rgb, 1.0);
  }

</script>

html, body {
  margin: 0;
  height: 100%;
}

canvas {
  display: block;
}

var container;
var camera, scene, renderer;
var uniforms;
var startTime;

init();
animate();

function init() {
  container = document.getElementById('container');

  startTime = Date.now();
  camera = new THREE.Camera();
  camera.position.z = 1;

  scene = new THREE.Scene();

  var geometry = new THREE.PlaneBufferGeometry(16, 9);

  uniforms = {
    iGlobalTime: { type: "f", value: 1.0 },
    iResolution: { type: "v2", value: new THREE.Vector2() }
  };

  var material = new THREE.ShaderMaterial( {

    uniforms: uniforms,
    vertexShader: document.getElementById('vertexShader').textContent,
    fragmentShader: document.getElementById('fragmentShader').textContent

  } );

  var mesh = new THREE.Mesh(geometry, material);
  scene.add(mesh);

  renderer = new THREE.WebGLRenderer();
  container.appendChild(renderer.domElement);

  onWindowResize();

  window.addEventListener('resize', onWindowResize, false);
}

function onWindowResize(event) {
  uniforms.iResolution.value.x = window.innerWidth;
  uniforms.iResolution.value.y = window.innerHeight;

  renderer.setSize(window.innerWidth, window.innerHeight);
}

function animate() {
  requestAnimationFrame(animate);
  render();
}

function render() {
  var currentTime = Date.now();
  uniforms.iGlobalTime.value = (currentTime - startTime) * 0.001;
  renderer.render(scene, camera);
}