husley/index.html at master · p01/husley · GitHub

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<!doctype html>
<html>
<head>
<title>HUSley demo</title>
<style>

html {
  font-family: sans-serif;
  color: #333;
  background: #eee;
}

canvas {
  display: block;
  padding: 1px;
  border: 1px solid #ccc;
}

</style>
<script src="husley.js"></script>
</head>
<body>

  <h1>HUSLey demo</h1>
  <p>HUSLey is the most basic library offering a human-friendly HSL-like color representation preserving the lightness.</p>

  <input id="lightness" type="range" value="50" min="0" max="100" step="1"></input>
  <canvas id="output" width="360" height="100"></canvas>

<script>

window.addEventListener('load', function() {
  var lightness = document.getElementById('lightness');
  var ctx = document.getElementById('output').getContext('2d');
  var imageData = ctx.getImageData(0, 0, 360, 100);

  function update(e) {
    var l = Number(lightness.value) / 100;
    var data = imageData.data;
    var index = 0;
    for (var y = 100; y--; ) {
      var s = y / 100;
      for (var x = 0; x < 360; x++) {
        var h = x * Math.PI / 180;
        var rgb = HUSLey(h, s, l);
        data[index++] = rgb[0];
        data[index++] = rgb[1];
        data[index++] = rgb[2];
        data[index++] = 255;
      }
    }
    ctx.putImageData(imageData, 0, 0);
  };

  lightness.addEventListener('change', update);
  update();
});

</script>
</body>
</html>