1 ///////////////////////////////////////////////////////////////////////////
2 //
3 // Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
4 // Digital Ltd. LLC
5 //
6 // All rights reserved.
7 //
8 // Redistribution and use in source and binary forms, with or without
9 // modification, are permitted provided that the following conditions are
10 // met:
11 // * Redistributions of source code must retain the above copyright
12 // notice, this list of conditions and the following disclaimer.
13 // * Redistributions in binary form must reproduce the above
14 // copyright notice, this list of conditions and the following disclaimer
15 // in the documentation and/or other materials provided with the
16 // distribution.
17 // * Neither the name of Industrial Light & Magic nor the names of
18 // its contributors may be used to endorse or promote products derived
19 // from this software without specific prior written permission.
20 //
21 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 //
33 ///////////////////////////////////////////////////////////////////////////
34
35
36
37 #ifndef INCLUDED_IMATHVECALGO_H
38 #define INCLUDED_IMATHVECALGO_H
39
40 //-------------------------------------------------------------------------
41 //
42 // This file contains algorithms applied to or in conjunction
43 // with points (Imath::Vec2 and Imath::Vec3).
44 // The assumption made is that these functions are called much
45 // less often than the basic point functions or these functions
46 // require more support classes.
47 //
48 //-------------------------------------------------------------------------
49
50 #include "ImathVec.h"
51 #include "ImathLimits.h"
52
53 namespace Imath {
54
55
56 //-----------------------------------------------------------------
57 // Find the projection of vector t onto vector s (Vec2, Vec3, Vec4)
58 //-----------------------------------------------------------------
59
60 template <class Vec> Vec project (const Vec &s, const Vec &t);
61
62
63 //------------------------------------------------
64 // Find a vector that is perpendicular to s and
65 // in the same plane as s and t (Vec2, Vec3, Vec4)
66 //------------------------------------------------
67
68 template <class Vec> Vec orthogonal (const Vec &s, const Vec &t);
69
70
71 //-----------------------------------------------
72 // Find the direction of a ray s after reflection
73 // off a plane with normal t (Vec2, Vec3, Vec4)
74 //-----------------------------------------------
75
76 template <class Vec> Vec reflect (const Vec &s, const Vec &t);
77
78
79 //--------------------------------------------------------------------
80 // Find the vertex of triangle (v0, v1, v2) that is closest to point p
81 // (Vec2, Vec3, Vec4)
82 //--------------------------------------------------------------------
83
84 template <class Vec> Vec closestVertex (const Vec &v0,
85 const Vec &v1,
86 const Vec &v2,
87 const Vec &p);
88
89 //---------------
90 // Implementation
91 //---------------
92
93 template <class Vec>
94 Vec
project(const Vec & s,const Vec & t)95 project (const Vec &s, const Vec &t)
96 {
97 Vec sNormalized = s.normalized();
98 return sNormalized * (sNormalized ^ t);
99 }
100
101 template <class Vec>
102 Vec
orthogonal(const Vec & s,const Vec & t)103 orthogonal (const Vec &s, const Vec &t)
104 {
105 return t - project (s, t);
106 }
107
108 template <class Vec>
109 Vec
reflect(const Vec & s,const Vec & t)110 reflect (const Vec &s, const Vec &t)
111 {
112 return s - typename Vec::BaseType(2) * (s - project(t, s));
113 }
114
115 template <class Vec>
116 Vec
closestVertex(const Vec & v0,const Vec & v1,const Vec & v2,const Vec & p)117 closestVertex(const Vec &v0,
118 const Vec &v1,
119 const Vec &v2,
120 const Vec &p)
121 {
122 Vec nearest = v0;
123 typename Vec::BaseType neardot = (v0 - p).length2();
124 typename Vec::BaseType tmp = (v1 - p).length2();
125
126 if (tmp < neardot)
127 {
128 neardot = tmp;
129 nearest = v1;
130 }
131
132 tmp = (v2 - p).length2();
133
134 if (tmp < neardot)
135 {
136 neardot = tmp;
137 nearest = v2;
138 }
139
140 return nearest;
141 }
142
143
144 } // namespace Imath
145
146 #endif
147