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source: code/branches/kicklib/src/external/bullet/BulletCollision/NarrowPhaseCollision/btSubSimplexConvexCast.cpp @ 8073

Last change on this file since 8073 was 7983, checked in by rgrieder, 14 years ago

Updated Bullet Physics Engine from v2.74 to v2.77

  • Property svn:eol-style set to native
File size: 4.9 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
17#include "btSubSimplexConvexCast.h"
18#include "BulletCollision/CollisionShapes/btConvexShape.h"
19
20#include "BulletCollision/CollisionShapes/btMinkowskiSumShape.h"
21#include "BulletCollision/NarrowPhaseCollision/btSimplexSolverInterface.h"
22#include "btPointCollector.h"
23#include "LinearMath/btTransformUtil.h"
24
25btSubsimplexConvexCast::btSubsimplexConvexCast (const btConvexShape* convexA,const btConvexShape* convexB,btSimplexSolverInterface* simplexSolver)
26:m_simplexSolver(simplexSolver),
27m_convexA(convexA),m_convexB(convexB)
28{
29}
30
31///Typically the conservative advancement reaches solution in a few iterations, clip it to 32 for degenerate cases.
32///See discussion about this here http://continuousphysics.com/Bullet/phpBB2/viewtopic.php?t=565
33#ifdef BT_USE_DOUBLE_PRECISION
34#define MAX_ITERATIONS 64
35#else
36#define MAX_ITERATIONS 32
37#endif
38bool    btSubsimplexConvexCast::calcTimeOfImpact(
39                const btTransform& fromA,
40                const btTransform& toA,
41                const btTransform& fromB,
42                const btTransform& toB,
43                CastResult& result)
44{
45
46        m_simplexSolver->reset();
47
48        btVector3 linVelA,linVelB;
49        linVelA = toA.getOrigin()-fromA.getOrigin();
50        linVelB = toB.getOrigin()-fromB.getOrigin();
51
52        btScalar lambda = btScalar(0.);
53
54        btTransform interpolatedTransA = fromA;
55        btTransform interpolatedTransB = fromB;
56
57        ///take relative motion
58        btVector3 r = (linVelA-linVelB);
59        btVector3 v;
60       
61        btVector3 supVertexA = fromA(m_convexA->localGetSupportingVertex(-r*fromA.getBasis()));
62        btVector3 supVertexB = fromB(m_convexB->localGetSupportingVertex(r*fromB.getBasis()));
63        v = supVertexA-supVertexB;
64        int maxIter = MAX_ITERATIONS;
65
66        btVector3 n;
67        n.setValue(btScalar(0.),btScalar(0.),btScalar(0.));
68        bool hasResult = false;
69        btVector3 c;
70
71        btScalar lastLambda = lambda;
72
73
74        btScalar dist2 = v.length2();
75#ifdef BT_USE_DOUBLE_PRECISION
76        btScalar epsilon = btScalar(0.0001);
77#else
78        btScalar epsilon = btScalar(0.0001);
79#endif //BT_USE_DOUBLE_PRECISION
80        btVector3       w,p;
81        btScalar VdotR;
82       
83        while ( (dist2 > epsilon) && maxIter--)
84        {
85                supVertexA = interpolatedTransA(m_convexA->localGetSupportingVertex(-v*interpolatedTransA.getBasis()));
86                supVertexB = interpolatedTransB(m_convexB->localGetSupportingVertex(v*interpolatedTransB.getBasis()));
87                w = supVertexA-supVertexB;
88
89                btScalar VdotW = v.dot(w);
90
91                if (lambda > btScalar(1.0))
92                {
93                        return false;
94                }
95
96                if ( VdotW > btScalar(0.))
97                {
98                        VdotR = v.dot(r);
99
100                        if (VdotR >= -(SIMD_EPSILON*SIMD_EPSILON))
101                                return false;
102                        else
103                        {
104                                lambda = lambda - VdotW / VdotR;
105                                //interpolate to next lambda
106                                //      x = s + lambda * r;
107                                interpolatedTransA.getOrigin().setInterpolate3(fromA.getOrigin(),toA.getOrigin(),lambda);
108                                interpolatedTransB.getOrigin().setInterpolate3(fromB.getOrigin(),toB.getOrigin(),lambda);
109                                //m_simplexSolver->reset();
110                                //check next line
111                                 w = supVertexA-supVertexB;
112                                lastLambda = lambda;
113                                n = v;
114                                hasResult = true;
115                        }
116                } 
117                ///Just like regular GJK only add the vertex if it isn't already (close) to current vertex, it would lead to divisions by zero and NaN etc.
118                if (!m_simplexSolver->inSimplex(w))
119                        m_simplexSolver->addVertex( w, supVertexA , supVertexB);
120
121                if (m_simplexSolver->closest(v))
122                {
123                        dist2 = v.length2();
124                        hasResult = true;
125                        //todo: check this normal for validity
126                        //n=v;
127                        //printf("V=%f , %f, %f\n",v[0],v[1],v[2]);
128                        //printf("DIST2=%f\n",dist2);
129                        //printf("numverts = %i\n",m_simplexSolver->numVertices());
130                } else
131                {
132                        dist2 = btScalar(0.);
133                } 
134        }
135
136        //int numiter = MAX_ITERATIONS - maxIter;
137//      printf("number of iterations: %d", numiter);
138       
139        //don't report a time of impact when moving 'away' from the hitnormal
140       
141
142        result.m_fraction = lambda;
143        if (n.length2() >= (SIMD_EPSILON*SIMD_EPSILON))
144                result.m_normal = n.normalized();
145        else
146                result.m_normal = btVector3(btScalar(0.0), btScalar(0.0), btScalar(0.0));
147
148        //don't report time of impact for motion away from the contact normal (or causes minor penetration)
149        if (result.m_normal.dot(r)>=-result.m_allowedPenetration)
150                return false;
151
152        btVector3 hitA,hitB;
153        m_simplexSolver->compute_points(hitA,hitB);
154        result.m_hitPoint=hitB;
155        return true;
156}
157
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