<!DOCTYPE html>
<!--
Copyright (c) 2014 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 src="/gl-matrix-min.js"></script>

<script>
'use strict';

tr.exportTo('tr.b', function() {
  function clamp(x, lo, hi) {
    return Math.min(Math.max(x, lo), hi);
  }

  function lerp(percentage, lo, hi) {
    var range = hi - lo;
    return lo + percentage * range;
  }

  function deg2rad(deg) {
    return (Math.PI * deg) / 180.0;
  }

  var tmp_vec2 = vec2.create();
  var tmp_vec2b = vec2.create();
  var tmp_vec4 = vec4.create();
  var tmp_mat2d = mat2d.create();

  vec2.createFromArray = function(arr) {
    if (arr.length != 2)
      throw new Error('Should be length 2');
    var v = vec2.create();
    vec2.set(v, arr[0], arr[1]);
    return v;
  };

  vec2.createXY = function(x, y) {
    var v = vec2.create();
    vec2.set(v, x, y);
    return v;
  };

  vec2.toString = function(a) {
    return '[' + a[0] + ', ' + a[1] + ']';
  };

  vec2.addTwoScaledUnitVectors = function(out, u1, scale1, u2, scale2) {
    // out = u1 * scale1 + u2 * scale2
    vec2.scale(tmp_vec2, u1, scale1);
    vec2.scale(tmp_vec2b, u2, scale2);
    vec2.add(out, tmp_vec2, tmp_vec2b);
  };

  vec2.interpolatePiecewiseFunction = function(points, x) {
    if (x < points[0][0])
      return points[0][1];
    for (var i = 1; i < points.length; ++i) {
      if (x < points[i][0]) {
        var percent = (x - points[i - 1][0]) /
                      (points[i][0] - points[i - 1][0]);
        return lerp(percent, points[i - 1][1], points[i][1]);
      }
    }
    return points[points.length - 1][1];
  };

  vec3.createXYZ = function(x, y, z) {
    var v = vec3.create();
    vec3.set(v, x, y, z);
    return v;
  };

  vec3.toString = function(a) {
    return 'vec3(' + a[0] + ', ' + a[1] + ', ' + a[2] + ')';
  }

  mat2d.translateXY = function(out, x, y) {
    vec2.set(tmp_vec2, x, y);
    mat2d.translate(out, out, tmp_vec2);
  }

  mat2d.scaleXY = function(out, x, y) {
    vec2.set(tmp_vec2, x, y);
    mat2d.scale(out, out, tmp_vec2);
  }

  vec4.unitize = function(out, a) {
    out[0] = a[0] / a[3];
    out[1] = a[1] / a[3];
    out[2] = a[2] / a[3];
    out[3] = 1;
    return out;
  }

  vec2.copyFromVec4 = function(out, a) {
    vec4.unitize(tmp_vec4, a);
    vec2.copy(out, tmp_vec4);
  }

  return {
    clamp: clamp,
    lerp: lerp,
    deg2rad: deg2rad
  };

});
</script>