<!DOCTYPE html>
<!--
Copyright (c) 2015 The Chromium Authors. All rights reserved.
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->
<link rel="import" href="/base/base.html">
<script>
'use strict';

/**
 * @fileoverview Provides color scheme related functions.
 */
tr.exportTo('tr.ui.b', function() {

  function boundChannel(v) {
    return Math.min(255, Math.max(0, Math.floor(v)));
  }

  function brightenColor(c) {
    var k;
    if (c.r >= 240 && c.g >= 240 && c.b >= 240)
      k = 0.80;
    else
      k = 1.45;

    return {
      r: boundChannel(c.r * k),
      g: boundChannel(c.g * k),
      b: boundChannel(c.b * k)
    };
  }
  function desaturateColor(c) {
    var value = boundChannel((c.r + c.g + c.b) / 3);
    return { r: value, g: value, b: value };
  }
  function colorToRGBString(c) {
    return 'rgb(' + c.r + ',' + c.g + ',' + c.b + ')';
  }
  function colorToRGBAString(c, a) {
    return 'rgba(' + c.r + ',' + c.g + ',' + c.b + ',' + a + ')';
  }

  return {
    brightenColor: brightenColor,
    desaturateColor: desaturateColor,
    colorToRGBString: colorToRGBString,
    colorToRGBAString: colorToRGBAString
  };
});
</script>