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source: code/branches/physics/src/bullet/BulletCollision/CollisionShapes/btPolyhedralConvexShape.cpp @ 1963

Last change on this file since 1963 was 1963, checked in by rgrieder, 16 years ago

Added Bullet physics engine.

  • Property svn:eol-style set to native
File size: 4.4 KB
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[1963]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 "BulletCollision/CollisionShapes/btPolyhedralConvexShape.h"
17
18btPolyhedralConvexShape::btPolyhedralConvexShape() :btConvexInternalShape(),
19m_localAabbMin(1,1,1),
20m_localAabbMax(-1,-1,-1),
21m_isLocalAabbValid(false),
22m_optionalHull(0)
23{
24
25}
26
27
28btVector3       btPolyhedralConvexShape::localGetSupportingVertexWithoutMargin(const btVector3& vec0)const
29{
30        int i;
31        btVector3 supVec(0,0,0);
32
33        btScalar maxDot(btScalar(-1e30));
34
35        btVector3 vec = vec0;
36        btScalar lenSqr = vec.length2();
37        if (lenSqr < btScalar(0.0001))
38        {
39                vec.setValue(1,0,0);
40        } else
41        {
42                btScalar rlen = btScalar(1.) / btSqrt(lenSqr );
43                vec *= rlen;
44        }
45
46        btVector3 vtx;
47        btScalar newDot;
48
49        for (i=0;i<getNumVertices();i++)
50        {
51                getVertex(i,vtx);
52                newDot = vec.dot(vtx);
53                if (newDot > maxDot)
54                {
55                        maxDot = newDot;
56                        supVec = vtx;
57                }
58        }
59
60        return supVec;
61
62}
63
64void    btPolyhedralConvexShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
65{
66        int i;
67
68        btVector3 vtx;
69        btScalar newDot;
70
71        for (i=0;i<numVectors;i++)
72        {
73                supportVerticesOut[i][3] = btScalar(-1e30);
74        }
75
76        for (int j=0;j<numVectors;j++)
77        {
78       
79                const btVector3& vec = vectors[j];
80
81                for (i=0;i<getNumVertices();i++)
82                {
83                        getVertex(i,vtx);
84                        newDot = vec.dot(vtx);
85                        if (newDot > supportVerticesOut[j][3])
86                        {
87                                //WARNING: don't swap next lines, the w component would get overwritten!
88                                supportVerticesOut[j] = vtx;
89                                supportVerticesOut[j][3] = newDot;
90                        }
91                }
92        }
93}
94
95
96
97void    btPolyhedralConvexShape::calculateLocalInertia(btScalar mass,btVector3& inertia) const
98{
99        //not yet, return box inertia
100
101        btScalar margin = getMargin();
102
103        btTransform ident;
104        ident.setIdentity();
105        btVector3 aabbMin,aabbMax;
106        getAabb(ident,aabbMin,aabbMax);
107        btVector3 halfExtents = (aabbMax-aabbMin)*btScalar(0.5);
108
109        btScalar lx=btScalar(2.)*(halfExtents.x()+margin);
110        btScalar ly=btScalar(2.)*(halfExtents.y()+margin);
111        btScalar lz=btScalar(2.)*(halfExtents.z()+margin);
112        const btScalar x2 = lx*lx;
113        const btScalar y2 = ly*ly;
114        const btScalar z2 = lz*lz;
115        const btScalar scaledmass = mass * btScalar(0.08333333);
116
117        inertia = scaledmass * (btVector3(y2+z2,x2+z2,x2+y2));
118
119}
120
121
122
123void btPolyhedralConvexShape::getAabb(const btTransform& trans,btVector3& aabbMin,btVector3& aabbMax) const
124{
125        getNonvirtualAabb(trans,aabbMin,aabbMax,getMargin());
126}
127
128
129
130void    btPolyhedralConvexShape::setLocalScaling(const btVector3& scaling)
131{
132        btConvexInternalShape::setLocalScaling(scaling);
133        recalcLocalAabb();
134}
135
136void    btPolyhedralConvexShape::recalcLocalAabb()
137{
138        m_isLocalAabbValid = true;
139       
140        #if 1
141        static const btVector3 _directions[] =
142        {
143                btVector3( 1.,  0.,  0.),
144                btVector3( 0.,  1.,  0.),
145                btVector3( 0.,  0.,  1.),
146                btVector3( -1., 0.,  0.),
147                btVector3( 0., -1.,  0.),
148                btVector3( 0.,  0., -1.)
149        };
150       
151        btVector3 _supporting[] =
152        {
153                btVector3( 0., 0., 0.),
154                btVector3( 0., 0., 0.),
155                btVector3( 0., 0., 0.),
156                btVector3( 0., 0., 0.),
157                btVector3( 0., 0., 0.),
158                btVector3( 0., 0., 0.)
159        };
160       
161        batchedUnitVectorGetSupportingVertexWithoutMargin(_directions, _supporting, 6);
162       
163        for ( int i = 0; i < 3; ++i )
164        {
165                m_localAabbMax[i] = _supporting[i][i] + m_collisionMargin;
166                m_localAabbMin[i] = _supporting[i + 3][i] - m_collisionMargin;
167        }
168       
169        #else
170
171        for (int i=0;i<3;i++)
172        {
173                btVector3 vec(btScalar(0.),btScalar(0.),btScalar(0.));
174                vec[i] = btScalar(1.);
175                btVector3 tmp = localGetSupportingVertex(vec);
176                m_localAabbMax[i] = tmp[i]+m_collisionMargin;
177                vec[i] = btScalar(-1.);
178                tmp = localGetSupportingVertex(vec);
179                m_localAabbMin[i] = tmp[i]-m_collisionMargin;
180        }
181        #endif
182}
183
184
185
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