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source: code/trunk/src/external/bullet/BulletCollision/CollisionShapes/btCylinderShape.cpp @ 10986

Last change on this file since 10986 was 8393, checked in by rgrieder, 14 years ago

Updated Bullet from v2.77 to v2.78.
(I'm not going to make a branch for that since the update from 2.74 to 2.77 hasn't been tested that much either).

You will HAVE to do a complete RECOMPILE! I tested with MSVC and MinGW and they both threw linker errors at me.

  • Property svn:eol-style set to native
File size: 7.3 KB
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1/*
2Bullet Continuous Collision Detection and Physics Library
3Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org
4
5This software is provided 'as-is', without any express or implied warranty.
6In no event will the authors be held liable for any damages arising from the use of this software.
7Permission is granted to anyone to use this software for any purpose,
8including commercial applications, and to alter it and redistribute it freely,
9subject to the following restrictions:
10
111. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
122. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
133. This notice may not be removed or altered from any source distribution.
14*/
15
16#include "btCylinderShape.h"
17
18btCylinderShape::btCylinderShape (const btVector3& halfExtents)
19:btConvexInternalShape(),
20m_upAxis(1)
21{
22        btVector3 margin(getMargin(),getMargin(),getMargin());
23        m_implicitShapeDimensions = (halfExtents * m_localScaling) - margin;
24        m_shapeType = CYLINDER_SHAPE_PROXYTYPE;
25}
26
27
28btCylinderShapeX::btCylinderShapeX (const btVector3& halfExtents)
29:btCylinderShape(halfExtents)
30{
31        m_upAxis = 0;
32
33}
34
35
36btCylinderShapeZ::btCylinderShapeZ (const btVector3& halfExtents)
37:btCylinderShape(halfExtents)
38{
39        m_upAxis = 2;
40
41}
42
43void btCylinderShape::getAabb(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const
44{
45        btTransformAabb(getHalfExtentsWithoutMargin(),getMargin(),t,aabbMin,aabbMax);
46}
47
48void    btCylinderShape::calculateLocalInertia(btScalar mass,btVector3& inertia) const
49{
50
51//Until Bullet 2.77 a box approximation was used, so uncomment this if you need backwards compatibility
52//#define USE_BOX_INERTIA_APPROXIMATION 1
53#ifndef USE_BOX_INERTIA_APPROXIMATION
54
55        /*
56        cylinder is defined as following:
57        *
58        * - principle axis aligned along y by default, radius in x, z-value not used
59        * - for btCylinderShapeX: principle axis aligned along x, radius in y direction, z-value not used
60        * - for btCylinderShapeZ: principle axis aligned along z, radius in x direction, y-value not used
61        *
62        */
63
64        btScalar radius2;       // square of cylinder radius
65        btScalar height2;       // square of cylinder height
66        btVector3 halfExtents = getHalfExtentsWithMargin();     // get cylinder dimension
67        btScalar div12 = mass / 12.f;
68        btScalar div4 = mass / 4.f;
69        btScalar div2 = mass / 2.f;
70        int idxRadius, idxHeight;
71
72        switch (m_upAxis)       // get indices of radius and height of cylinder
73        {
74                case 0:         // cylinder is aligned along x
75                        idxRadius = 1;
76                        idxHeight = 0;
77                        break;
78                case 2:         // cylinder is aligned along z
79                        idxRadius = 0;
80                        idxHeight = 2;
81                        break;
82                default:        // cylinder is aligned along y
83                        idxRadius = 0;
84                        idxHeight = 1;
85        }
86
87        // calculate squares
88        radius2 = halfExtents[idxRadius] * halfExtents[idxRadius];
89        height2 = btScalar(4.) * halfExtents[idxHeight] * halfExtents[idxHeight];
90
91        // calculate tensor terms
92        btScalar t1 = div12 * height2 + div4 * radius2;
93        btScalar t2 = div2 * radius2;
94
95        switch (m_upAxis)       // set diagonal elements of inertia tensor
96        {
97                case 0:         // cylinder is aligned along x
98                        inertia.setValue(t2,t1,t1);
99                        break;
100                case 2:         // cylinder is aligned along z
101                        inertia.setValue(t1,t1,t2);
102                        break;
103                default:        // cylinder is aligned along y
104                        inertia.setValue(t1,t2,t1);
105        }
106#else //USE_BOX_INERTIA_APPROXIMATION
107        //approximation of box shape
108        btVector3 halfExtents = getHalfExtentsWithMargin();
109
110        btScalar lx=btScalar(2.)*(halfExtents.x());
111        btScalar ly=btScalar(2.)*(halfExtents.y());
112        btScalar lz=btScalar(2.)*(halfExtents.z());
113
114        inertia.setValue(mass/(btScalar(12.0)) * (ly*ly + lz*lz),
115                                        mass/(btScalar(12.0)) * (lx*lx + lz*lz),
116                                        mass/(btScalar(12.0)) * (lx*lx + ly*ly));
117#endif //USE_BOX_INERTIA_APPROXIMATION
118}
119
120
121SIMD_FORCE_INLINE btVector3 CylinderLocalSupportX(const btVector3& halfExtents,const btVector3& v) 
122{
123const int cylinderUpAxis = 0;
124const int XX = 1;
125const int YY = 0;
126const int ZZ = 2;
127
128        //mapping depends on how cylinder local orientation is
129        // extents of the cylinder is: X,Y is for radius, and Z for height
130
131
132        btScalar radius = halfExtents[XX];
133        btScalar halfHeight = halfExtents[cylinderUpAxis];
134
135
136    btVector3 tmp;
137        btScalar d ;
138
139    btScalar s = btSqrt(v[XX] * v[XX] + v[ZZ] * v[ZZ]);
140    if (s != btScalar(0.0))
141        {
142        d = radius / s; 
143                tmp[XX] = v[XX] * d;
144                tmp[YY] = v[YY] < 0.0 ? -halfHeight : halfHeight;
145                tmp[ZZ] = v[ZZ] * d;
146                return tmp;
147        }
148    else
149        {
150            tmp[XX] = radius;
151                tmp[YY] = v[YY] < 0.0 ? -halfHeight : halfHeight;
152                tmp[ZZ] = btScalar(0.0);
153                return tmp;
154    }
155
156
157}
158
159
160
161
162
163
164inline  btVector3 CylinderLocalSupportY(const btVector3& halfExtents,const btVector3& v) 
165{
166
167const int cylinderUpAxis = 1;
168const int XX = 0;
169const int YY = 1;
170const int ZZ = 2;
171
172
173        btScalar radius = halfExtents[XX];
174        btScalar halfHeight = halfExtents[cylinderUpAxis];
175
176
177    btVector3 tmp;
178        btScalar d ;
179
180    btScalar s = btSqrt(v[XX] * v[XX] + v[ZZ] * v[ZZ]);
181    if (s != btScalar(0.0))
182        {
183        d = radius / s; 
184                tmp[XX] = v[XX] * d;
185                tmp[YY] = v[YY] < 0.0 ? -halfHeight : halfHeight;
186                tmp[ZZ] = v[ZZ] * d;
187                return tmp;
188        }
189    else
190        {
191            tmp[XX] = radius;
192                tmp[YY] = v[YY] < 0.0 ? -halfHeight : halfHeight;
193                tmp[ZZ] = btScalar(0.0);
194                return tmp;
195    }
196
197}
198
199inline btVector3 CylinderLocalSupportZ(const btVector3& halfExtents,const btVector3& v) 
200{
201const int cylinderUpAxis = 2;
202const int XX = 0;
203const int YY = 2;
204const int ZZ = 1;
205
206        //mapping depends on how cylinder local orientation is
207        // extents of the cylinder is: X,Y is for radius, and Z for height
208
209
210        btScalar radius = halfExtents[XX];
211        btScalar halfHeight = halfExtents[cylinderUpAxis];
212
213
214    btVector3 tmp;
215        btScalar d ;
216
217    btScalar s = btSqrt(v[XX] * v[XX] + v[ZZ] * v[ZZ]);
218    if (s != btScalar(0.0))
219        {
220        d = radius / s; 
221                tmp[XX] = v[XX] * d;
222                tmp[YY] = v[YY] < 0.0 ? -halfHeight : halfHeight;
223                tmp[ZZ] = v[ZZ] * d;
224                return tmp;
225        }
226    else
227        {
228            tmp[XX] = radius;
229                tmp[YY] = v[YY] < 0.0 ? -halfHeight : halfHeight;
230                tmp[ZZ] = btScalar(0.0);
231                return tmp;
232    }
233
234
235}
236
237btVector3       btCylinderShapeX::localGetSupportingVertexWithoutMargin(const btVector3& vec)const
238{
239        return CylinderLocalSupportX(getHalfExtentsWithoutMargin(),vec);
240}
241
242
243btVector3       btCylinderShapeZ::localGetSupportingVertexWithoutMargin(const btVector3& vec)const
244{
245        return CylinderLocalSupportZ(getHalfExtentsWithoutMargin(),vec);
246}
247btVector3       btCylinderShape::localGetSupportingVertexWithoutMargin(const btVector3& vec)const
248{
249        return CylinderLocalSupportY(getHalfExtentsWithoutMargin(),vec);
250}
251
252void    btCylinderShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
253{
254        for (int i=0;i<numVectors;i++)
255        {
256                supportVerticesOut[i] = CylinderLocalSupportY(getHalfExtentsWithoutMargin(),vectors[i]);
257        }
258}
259
260void    btCylinderShapeZ::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
261{
262        for (int i=0;i<numVectors;i++)
263        {
264                supportVerticesOut[i] = CylinderLocalSupportZ(getHalfExtentsWithoutMargin(),vectors[i]);
265        }
266}
267
268
269
270
271void    btCylinderShapeX::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
272{
273        for (int i=0;i<numVectors;i++)
274        {
275                supportVerticesOut[i] = CylinderLocalSupportX(getHalfExtentsWithoutMargin(),vectors[i]);
276        }
277}
278
279
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