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source: code/trunk/src/external/bullet/BulletCollision/CollisionShapes/btMultiSphereShape.cpp @ 7306

Last change on this file since 7306 was 5781, checked in by rgrieder, 15 years ago

Reverted trunk again. We might want to find a way to delete these revisions again (x3n's changes are still available as diff in the commit mails).

  • Property svn:eol-style set to native
File size: 3.7 KB
Line 
1/*
2Bullet Continuous Collision Detection and Physics Library
3Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
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 "btMultiSphereShape.h"
17#include "BulletCollision/CollisionShapes/btCollisionMargin.h"
18#include "LinearMath/btQuaternion.h"
19
20btMultiSphereShape::btMultiSphereShape (const btVector3& inertiaHalfExtents,const btVector3* positions,const btScalar* radi,int numSpheres)
21:btConvexInternalShape (), m_inertiaHalfExtents(inertiaHalfExtents)
22{
23        m_shapeType = MULTI_SPHERE_SHAPE_PROXYTYPE;
24        btScalar startMargin = btScalar(1e30);
25
26        m_numSpheres = numSpheres;
27        for (int i=0;i<m_numSpheres;i++)
28        {
29                m_localPositions[i] = positions[i];
30                m_radi[i] = radi[i];
31                if (radi[i] < startMargin)
32                        startMargin = radi[i];
33        }
34        setMargin(startMargin);
35
36}
37
38
39
40 
41 btVector3      btMultiSphereShape::localGetSupportingVertexWithoutMargin(const btVector3& vec0)const
42{
43        int i;
44        btVector3 supVec(0,0,0);
45
46        btScalar maxDot(btScalar(-1e30));
47
48
49        btVector3 vec = vec0;
50        btScalar lenSqr = vec.length2();
51        if (lenSqr < (SIMD_EPSILON*SIMD_EPSILON))
52        {
53                vec.setValue(1,0,0);
54        } else
55        {
56                btScalar rlen = btScalar(1.) / btSqrt(lenSqr );
57                vec *= rlen;
58        }
59
60        btVector3 vtx;
61        btScalar newDot;
62
63        const btVector3* pos = &m_localPositions[0];
64        const btScalar* rad = &m_radi[0];
65
66        for (i=0;i<m_numSpheres;i++)
67        {
68                vtx = (*pos) +vec*m_localScaling*(*rad) - vec * getMargin();
69                pos++;
70                rad++;
71                newDot = vec.dot(vtx);
72                if (newDot > maxDot)
73                {
74                        maxDot = newDot;
75                        supVec = vtx;
76                }
77        }
78
79        return supVec;
80
81}
82
83 void   btMultiSphereShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
84{
85
86        for (int j=0;j<numVectors;j++)
87        {
88                btScalar maxDot(btScalar(-1e30));
89
90                const btVector3& vec = vectors[j];
91
92                btVector3 vtx;
93                btScalar newDot;
94
95                const btVector3* pos = &m_localPositions[0];
96                const btScalar* rad = &m_radi[0];
97
98                for (int i=0;i<m_numSpheres;i++)
99                {
100                        vtx = (*pos) +vec*m_localScaling*(*rad) - vec * getMargin();
101                        pos++;
102                        rad++;
103                        newDot = vec.dot(vtx);
104                        if (newDot > maxDot)
105                        {
106                                maxDot = newDot;
107                                supportVerticesOut[j] = vtx;
108                        }
109                }
110        }
111}
112
113
114
115
116
117
118
119
120void    btMultiSphereShape::calculateLocalInertia(btScalar mass,btVector3& inertia) const
121{
122        //as an approximation, take the inertia of the box that bounds the spheres
123
124        btTransform ident;
125        ident.setIdentity();
126//      btVector3 aabbMin,aabbMax;
127
128//      getAabb(ident,aabbMin,aabbMax);
129
130        btVector3 halfExtents = m_inertiaHalfExtents;//(aabbMax - aabbMin)* btScalar(0.5);
131
132        btScalar margin = CONVEX_DISTANCE_MARGIN;
133
134        btScalar lx=btScalar(2.)*(halfExtents[0]+margin);
135        btScalar ly=btScalar(2.)*(halfExtents[1]+margin);
136        btScalar lz=btScalar(2.)*(halfExtents[2]+margin);
137        const btScalar x2 = lx*lx;
138        const btScalar y2 = ly*ly;
139        const btScalar z2 = lz*lz;
140        const btScalar scaledmass = mass * btScalar(.08333333);
141
142        inertia[0] = scaledmass * (y2+z2);
143        inertia[1] = scaledmass * (x2+z2);
144        inertia[2] = scaledmass * (x2+y2);
145
146}
147
148
149
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