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author | dan miller | 2007-10-19 05:24:38 +0000 |
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committer | dan miller | 2007-10-19 05:24:38 +0000 |
commit | f205de7847da7ae1c10212d82e7042d0100b4ce0 (patch) | |
tree | 9acc9608a6880502aaeda43af52c33e278e95b9c /libraries/ode-0.9/ode/src/odemath.cpp | |
parent | trying to fix my screwup part deux (diff) | |
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from the start... checking in ode-0.9
Diffstat (limited to 'libraries/ode-0.9/ode/src/odemath.cpp')
-rw-r--r-- | libraries/ode-0.9/ode/src/odemath.cpp | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/libraries/ode-0.9/ode/src/odemath.cpp b/libraries/ode-0.9/ode/src/odemath.cpp new file mode 100644 index 0000000..11bc84e --- /dev/null +++ b/libraries/ode-0.9/ode/src/odemath.cpp | |||
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1 | /************************************************************************* | ||
2 | * * | ||
3 | * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. * | ||
4 | * All rights reserved. Email: russ@q12.org Web: www.q12.org * | ||
5 | * * | ||
6 | * This library is free software; you can redistribute it and/or * | ||
7 | * modify it under the terms of EITHER: * | ||
8 | * (1) The GNU Lesser General Public License as published by the Free * | ||
9 | * Software Foundation; either version 2.1 of the License, or (at * | ||
10 | * your option) any later version. The text of the GNU Lesser * | ||
11 | * General Public License is included with this library in the * | ||
12 | * file LICENSE.TXT. * | ||
13 | * (2) The BSD-style license that is included with this library in * | ||
14 | * the file LICENSE-BSD.TXT. * | ||
15 | * * | ||
16 | * This library is distributed in the hope that it will be useful, * | ||
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of * | ||
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files * | ||
19 | * LICENSE.TXT and LICENSE-BSD.TXT for more details. * | ||
20 | * * | ||
21 | *************************************************************************/ | ||
22 | |||
23 | #include <ode/common.h> | ||
24 | #include <ode/odemath.h> | ||
25 | |||
26 | // get some math functions under windows | ||
27 | #ifdef WIN32 | ||
28 | #include <float.h> | ||
29 | #ifndef CYGWIN // added by andy for cygwin | ||
30 | #undef copysign | ||
31 | #define copysign(a,b) ((dReal)_copysign(a,b)) | ||
32 | #endif // added by andy for cygwin | ||
33 | #endif | ||
34 | |||
35 | #undef dNormalize3 | ||
36 | #undef dNormalize4 | ||
37 | |||
38 | |||
39 | // this may be called for vectors `a' with extremely small magnitude, for | ||
40 | // example the result of a cross product on two nearly perpendicular vectors. | ||
41 | // we must be robust to these small vectors. to prevent numerical error, | ||
42 | // first find the component a[i] with the largest magnitude and then scale | ||
43 | // all the components by 1/a[i]. then we can compute the length of `a' and | ||
44 | // scale the components by 1/l. this has been verified to work with vectors | ||
45 | // containing the smallest representable numbers. | ||
46 | |||
47 | int dSafeNormalize3 (dVector3 a) | ||
48 | { | ||
49 | dReal a0,a1,a2,aa0,aa1,aa2,l; | ||
50 | dAASSERT (a); | ||
51 | a0 = a[0]; | ||
52 | a1 = a[1]; | ||
53 | a2 = a[2]; | ||
54 | aa0 = dFabs(a0); | ||
55 | aa1 = dFabs(a1); | ||
56 | aa2 = dFabs(a2); | ||
57 | if (aa1 > aa0) { | ||
58 | if (aa2 > aa1) { | ||
59 | goto aa2_largest; | ||
60 | } | ||
61 | else { // aa1 is largest | ||
62 | a0 /= aa1; | ||
63 | a2 /= aa1; | ||
64 | l = dRecipSqrt (a0*a0 + a2*a2 + 1); | ||
65 | a[0] = a0*l; | ||
66 | a[1] = dCopySign(l,a1); | ||
67 | a[2] = a2*l; | ||
68 | } | ||
69 | } | ||
70 | else { | ||
71 | if (aa2 > aa0) { | ||
72 | aa2_largest: // aa2 is largest | ||
73 | a0 /= aa2; | ||
74 | a1 /= aa2; | ||
75 | l = dRecipSqrt (a0*a0 + a1*a1 + 1); | ||
76 | a[0] = a0*l; | ||
77 | a[1] = a1*l; | ||
78 | a[2] = dCopySign(l,a2); | ||
79 | } | ||
80 | else { // aa0 is largest | ||
81 | if (aa0 <= 0) { | ||
82 | a[0] = 1; // if all a's are zero, this is where we'll end up. | ||
83 | a[1] = 0; // return a default unit length vector. | ||
84 | a[2] = 0; | ||
85 | return 0; | ||
86 | } | ||
87 | a1 /= aa0; | ||
88 | a2 /= aa0; | ||
89 | l = dRecipSqrt (a1*a1 + a2*a2 + 1); | ||
90 | a[0] = dCopySign(l,a0); | ||
91 | a[1] = a1*l; | ||
92 | a[2] = a2*l; | ||
93 | } | ||
94 | } | ||
95 | return 1; | ||
96 | } | ||
97 | |||
98 | /* OLD VERSION */ | ||
99 | /* | ||
100 | void dNormalize3 (dVector3 a) | ||
101 | { | ||
102 | dIASSERT (a); | ||
103 | dReal l = dDOT(a,a); | ||
104 | if (l > 0) { | ||
105 | l = dRecipSqrt(l); | ||
106 | a[0] *= l; | ||
107 | a[1] *= l; | ||
108 | a[2] *= l; | ||
109 | } | ||
110 | else { | ||
111 | a[0] = 1; | ||
112 | a[1] = 0; | ||
113 | a[2] = 0; | ||
114 | } | ||
115 | } | ||
116 | */ | ||
117 | |||
118 | void dNormalize3(dVector3 a) | ||
119 | { | ||
120 | _dNormalize3(a); | ||
121 | } | ||
122 | |||
123 | |||
124 | int dSafeNormalize4 (dVector4 a) | ||
125 | { | ||
126 | dAASSERT (a); | ||
127 | dReal l = dDOT(a,a)+a[3]*a[3]; | ||
128 | if (l > 0) { | ||
129 | l = dRecipSqrt(l); | ||
130 | a[0] *= l; | ||
131 | a[1] *= l; | ||
132 | a[2] *= l; | ||
133 | a[3] *= l; | ||
134 | return 1; | ||
135 | } | ||
136 | else { | ||
137 | a[0] = 1; | ||
138 | a[1] = 0; | ||
139 | a[2] = 0; | ||
140 | a[3] = 0; | ||
141 | return 0; | ||
142 | } | ||
143 | } | ||
144 | |||
145 | void dNormalize4(dVector4 a) | ||
146 | { | ||
147 | _dNormalize4(a); | ||
148 | } | ||
149 | |||
150 | |||
151 | void dPlaneSpace (const dVector3 n, dVector3 p, dVector3 q) | ||
152 | { | ||
153 | dAASSERT (n && p && q); | ||
154 | if (dFabs(n[2]) > M_SQRT1_2) { | ||
155 | // choose p in y-z plane | ||
156 | dReal a = n[1]*n[1] + n[2]*n[2]; | ||
157 | dReal k = dRecipSqrt (a); | ||
158 | p[0] = 0; | ||
159 | p[1] = -n[2]*k; | ||
160 | p[2] = n[1]*k; | ||
161 | // set q = n x p | ||
162 | q[0] = a*k; | ||
163 | q[1] = -n[0]*p[2]; | ||
164 | q[2] = n[0]*p[1]; | ||
165 | } | ||
166 | else { | ||
167 | // choose p in x-y plane | ||
168 | dReal a = n[0]*n[0] + n[1]*n[1]; | ||
169 | dReal k = dRecipSqrt (a); | ||
170 | p[0] = -n[1]*k; | ||
171 | p[1] = n[0]*k; | ||
172 | p[2] = 0; | ||
173 | // set q = n x p | ||
174 | q[0] = -n[2]*p[1]; | ||
175 | q[1] = n[2]*p[0]; | ||
176 | q[2] = a*k; | ||
177 | } | ||
178 | } | ||