blob: 54c2290740b6ba16834a6e8cef09e3d4c4ea1f3f (
plain)
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
|
// Copyright (c) 2012 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.
/**
* @fileoverview A 3D vector class. Proviudes some utility functions on
* 3-dimentional vectors.
*/
// Requires tumbler
/**
* Constructor for the Vector3 object. This class contains a 3-tuple that
* represents a vector in 3D space.
* @param {?number} opt_x The x-coordinate for this vector. If null or
* undefined, the x-coordinate value is set to 0.
* @param {?number} opt_y The y-coordinate for this vector. If null or
* undefined, the y-coordinate value is set to 0.
* @param {?number} opt_z The z-coordinate for this vector. If null or
* undefined, the z-coordinate value is set to 0.
* @constructor
*/
tumbler.Vector3 = function(opt_x, opt_y, opt_z) {
/**
* The vector's 3-tuple.
* @type {number}
*/
this.x = opt_x || 0;
this.y = opt_y || 0;
this.z = opt_z || 0;
}
/**
* Method to return the magnitude of a Vector3.
* @return {number} the magnitude of the vector.
*/
tumbler.Vector3.prototype.magnitude = function() {
return Math.sqrt(this.dot(this));
}
/**
* Normalize the vector in-place.
* @return {number} the magnitude of the vector.
*/
tumbler.Vector3.prototype.normalize = function() {
var mag = this.magnitude();
if (mag < tumbler.Vector3.DOUBLE_EPSILON)
return 0.0; // |this| is equivalent to the 0-vector, don't normalize.
this.scale(1.0 / mag);
return mag;
}
/**
* Scale the vector in-place by |s|.
* @param {!number} s The scale factor.
*/
tumbler.Vector3.prototype.scale = function(s) {
this.x *= s;
this.y *= s;
this.z *= s;
}
/**
* Compute the dot product: |this| . v.
* @param {!tumbler.Vector3} v The vector to dot.
* @return {number} the result of |this| . v.
*/
tumbler.Vector3.prototype.dot = function(v) {
return this.x * v.x + this.y * v.y + this.z * v.z;
}
/**
* Compute the cross product: |this| X v.
* @param {!tumbler.Vector3} v The vector to cross with.
* @return {tumbler.Vector3} the result of |this| X v.
*/
tumbler.Vector3.prototype.cross = function(v) {
var vCross = new tumbler.Vector3(this.y * v.z - this.z * v.y,
this.z * v.x - this.x * v.z,
this.x * v.y - this.y * v.x);
return vCross;
}
/**
* Real numbers that are less than this distance apart are considered
* equivalent.
* TODO(dspringer): It seems as though there should be a const like this
* in generally available somewhere.
* @type {number}
*/
tumbler.Vector3.DOUBLE_EPSILON = 1.0e-16;
|
