1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
|
<!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="/tracing/base/base.html">
<script src="/gl-matrix-min.js"></script>
<script>
'use strict';
// In node, the script-src for gl-matrix-min above brings in glmatrix into
// a module, instead of into the global scope. Whereas, Tracing code
// assumes that glMatrix is in the global scope. So, in Node only, we
// require() it in, and then take all its exports and shove them into the
// global scope by hand.
(function(global) {
if (tr.isNode) {
var glMatrixAbsPath = HTMLImportsLoader.hrefToAbsolutePath(
'/gl-matrix-min.js');
var glMatrixModule = require(glMatrixAbsPath);
for (var exportName in glMatrixModule) {
global[exportName] = glMatrixModule[exportName];
}
}
})(this);
</script>
<script>
'use strict';
tr.exportTo('tr.b', function() {
/* Returns true when x and y are within delta of each other. */
function approximately(x, y, delta) {
if (delta === undefined)
delta = 1e-9;
return Math.abs(x - y) < delta;
}
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 normalize(value, lo, hi) {
return (value - lo) / (hi - lo);
}
function deg2rad(deg) {
return (Math.PI * deg) / 180.0;
}
/* The Gauss error function gives the probability that a measurement (which is
* under the influence of normally distributed errors with standard deviation
* sigma = 1) is less than x from the mean value of the standard normal
* distribution.
* https://www.desmos.com/calculator/t1v4bdpske
*
* @param {number} x A tolerance for error.
* @return {number} The probability that a measurement is less than |x| from
* the mean value of the standard normal distribution.
*/
function erf(x) {
// save the sign of x
// erf(-x) = -erf(x);
var sign = (x >= 0) ? 1 : -1;
x = Math.abs(x);
// constants
var a1 = 0.254829592;
var a2 = -0.284496736;
var a3 = 1.421413741;
var a4 = -1.453152027;
var a5 = 1.061405429;
var p = 0.3275911;
// Abramowitz and Stegun formula 7.1.26
// maximum error: 1.5e-7
var t = 1.0 / (1.0 + p * x);
var y = 1.0 - (((((a5 * t + a4) * t) + a3) * t + a2) * t + a1) * t *
Math.exp(-x * x);
return sign * y;
}
var tmpVec2 = vec2.create();
var tmpVec2b = vec2.create();
var tmpVec4 = vec4.create();
var tmpMat2d = 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(tmpVec2, u1, scale1);
vec2.scale(tmpVec2b, u2, scale2);
vec2.add(out, tmpVec2, tmpVec2b);
};
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 = normalize(x, points[i - 1][0], points[i][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(tmpVec2, x, y);
mat2d.translate(out, out, tmpVec2);
};
mat2d.scaleXY = function(out, x, y) {
vec2.set(tmpVec2, x, y);
mat2d.scale(out, out, tmpVec2);
};
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(tmpVec4, a);
vec2.copy(out, tmpVec4);
};
return {
approximately: approximately,
clamp: clamp,
lerp: lerp,
normalize: normalize,
deg2rad: deg2rad,
erf: erf
};
});
</script>
|
