| 1 | /* | 
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| 2 | Bullet Continuous Collision Detection and Physics Library | 
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| 3 | Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/ | 
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| 4 |  | 
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| 5 | This software is provided 'as-is', without any express or implied warranty. | 
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| 6 | In no event will the authors be held liable for any damages arising from the use of this software. | 
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| 7 | Permission is granted to anyone to use this software for any purpose, | 
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| 8 | including commercial applications, and to alter it and redistribute it freely, | 
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| 9 | subject to the following restrictions: | 
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| 10 |  | 
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| 11 | 1. 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. | 
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| 12 | 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. | 
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| 13 | 3. This notice may not be removed or altered from any source distribution. | 
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| 14 | */ | 
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| 15 |  | 
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| 16 | #include "btGjkPairDetector.h" | 
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| 17 | #include "BulletCollision/CollisionShapes/btConvexShape.h" | 
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| 18 | #include "BulletCollision/NarrowPhaseCollision/btSimplexSolverInterface.h" | 
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| 19 | #include "BulletCollision/NarrowPhaseCollision/btConvexPenetrationDepthSolver.h" | 
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| 20 |  | 
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| 21 |  | 
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| 22 |  | 
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| 23 | #if defined(DEBUG) || defined (_DEBUG) | 
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| 24 | //#define TEST_NON_VIRTUAL 1 | 
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| 25 | #include <stdio.h> //for debug printf | 
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| 26 | #ifdef __SPU__ | 
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| 27 | #include <spu_printf.h> | 
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| 28 | #define printf spu_printf | 
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| 29 | //#define DEBUG_SPU_COLLISION_DETECTION 1 | 
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| 30 | #endif //__SPU__ | 
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| 31 | #endif | 
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| 32 |  | 
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| 33 | //must be above the machine epsilon | 
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| 34 | #define REL_ERROR2 btScalar(1.0e-6) | 
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| 35 |  | 
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| 36 | //temp globals, to improve GJK/EPA/penetration calculations | 
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| 37 | int gNumDeepPenetrationChecks = 0; | 
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| 38 | int gNumGjkChecks = 0; | 
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| 39 |  | 
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| 40 |  | 
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| 41 |  | 
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| 42 | btGjkPairDetector::btGjkPairDetector(const btConvexShape* objectA,const btConvexShape* objectB,btSimplexSolverInterface* simplexSolver,btConvexPenetrationDepthSolver*  penetrationDepthSolver) | 
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| 43 | :m_cachedSeparatingAxis(btScalar(0.),btScalar(0.),btScalar(1.)), | 
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| 44 | m_penetrationDepthSolver(penetrationDepthSolver), | 
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| 45 | m_simplexSolver(simplexSolver), | 
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| 46 | m_minkowskiA(objectA), | 
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| 47 | m_minkowskiB(objectB), | 
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| 48 | m_ignoreMargin(false), | 
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| 49 | m_lastUsedMethod(-1), | 
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| 50 | m_catchDegeneracies(1) | 
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| 51 | { | 
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| 52 | } | 
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| 53 |  | 
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| 54 | void btGjkPairDetector::getClosestPoints(const ClosestPointInput& input,Result& output,class btIDebugDraw* debugDraw,bool swapResults) | 
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| 55 | { | 
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| 56 | m_cachedSeparatingDistance = 0.f; | 
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| 57 |  | 
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| 58 | btScalar distance=btScalar(0.); | 
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| 59 | btVector3       normalInB(btScalar(0.),btScalar(0.),btScalar(0.)); | 
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| 60 | btVector3 pointOnA,pointOnB; | 
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| 61 | btTransform     localTransA = input.m_transformA; | 
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| 62 | btTransform localTransB = input.m_transformB; | 
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| 63 | btVector3 positionOffset = (localTransA.getOrigin() + localTransB.getOrigin()) * btScalar(0.5); | 
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| 64 | localTransA.getOrigin() -= positionOffset; | 
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| 65 | localTransB.getOrigin() -= positionOffset; | 
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| 66 |  | 
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| 67 | #ifdef __SPU__ | 
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| 68 | btScalar marginA = m_minkowskiA->getMarginNonVirtual(); | 
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| 69 | btScalar marginB = m_minkowskiB->getMarginNonVirtual(); | 
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| 70 | #else | 
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| 71 | btScalar marginA = m_minkowskiA->getMargin(); | 
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| 72 | btScalar marginB = m_minkowskiB->getMargin(); | 
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| 73 | #ifdef TEST_NON_VIRTUAL | 
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| 74 | btScalar marginAv = m_minkowskiA->getMarginNonVirtual(); | 
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| 75 | btScalar marginBv = m_minkowskiB->getMarginNonVirtual(); | 
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| 76 | btAssert(marginA == marginAv); | 
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| 77 | btAssert(marginB == marginBv); | 
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| 78 | #endif //TEST_NON_VIRTUAL | 
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| 79 | #endif | 
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| 80 |  | 
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| 81 |  | 
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| 82 |  | 
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| 83 | gNumGjkChecks++; | 
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| 84 |  | 
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| 85 | #ifdef DEBUG_SPU_COLLISION_DETECTION | 
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| 86 | spu_printf("inside gjk\n"); | 
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| 87 | #endif | 
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| 88 | //for CCD we don't use margins | 
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| 89 | if (m_ignoreMargin) | 
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| 90 | { | 
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| 91 | marginA = btScalar(0.); | 
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| 92 | marginB = btScalar(0.); | 
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| 93 | #ifdef DEBUG_SPU_COLLISION_DETECTION | 
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| 94 | spu_printf("ignoring margin\n"); | 
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| 95 | #endif | 
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| 96 | } | 
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| 97 |  | 
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| 98 | m_curIter = 0; | 
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| 99 | int gGjkMaxIter = 1000;//this is to catch invalid input, perhaps check for #NaN? | 
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| 100 | m_cachedSeparatingAxis.setValue(0,1,0); | 
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| 101 |  | 
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| 102 | bool isValid = false; | 
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| 103 | bool checkSimplex = false; | 
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| 104 | bool checkPenetration = true; | 
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| 105 | m_degenerateSimplex = 0; | 
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| 106 |  | 
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| 107 | m_lastUsedMethod = -1; | 
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| 108 |  | 
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| 109 | { | 
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| 110 | btScalar squaredDistance = SIMD_INFINITY; | 
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| 111 | btScalar delta = btScalar(0.); | 
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| 112 |  | 
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| 113 | btScalar margin = marginA + marginB; | 
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| 114 |  | 
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| 115 |  | 
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| 116 |  | 
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| 117 | m_simplexSolver->reset(); | 
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| 118 |  | 
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| 119 | for ( ; ; ) | 
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| 120 | //while (true) | 
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| 121 | { | 
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| 122 |  | 
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| 123 | btVector3 seperatingAxisInA = (-m_cachedSeparatingAxis)* input.m_transformA.getBasis(); | 
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| 124 | btVector3 seperatingAxisInB = m_cachedSeparatingAxis* input.m_transformB.getBasis(); | 
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| 125 |  | 
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| 126 | #ifdef __SPU__ | 
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| 127 | btVector3 pInA = m_minkowskiA->localGetSupportVertexWithoutMarginNonVirtual(seperatingAxisInA); | 
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| 128 | btVector3 qInB = m_minkowskiB->localGetSupportVertexWithoutMarginNonVirtual(seperatingAxisInB); | 
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| 129 | #else | 
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| 130 | btVector3 pInA = m_minkowskiA->localGetSupportingVertexWithoutMargin(seperatingAxisInA); | 
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| 131 | btVector3 qInB = m_minkowskiB->localGetSupportingVertexWithoutMargin(seperatingAxisInB); | 
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| 132 | #ifdef TEST_NON_VIRTUAL | 
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| 133 | btVector3 pInAv = m_minkowskiA->localGetSupportingVertexWithoutMargin(seperatingAxisInA); | 
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| 134 | btVector3 qInBv = m_minkowskiB->localGetSupportingVertexWithoutMargin(seperatingAxisInB); | 
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| 135 | btAssert((pInAv-pInA).length() < 0.0001); | 
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| 136 | btAssert((qInBv-qInB).length() < 0.0001); | 
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| 137 | #endif // | 
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| 138 | #endif //__SPU__ | 
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| 139 |  | 
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| 140 | btVector3  pWorld = localTransA(pInA); | 
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| 141 | btVector3  qWorld = localTransB(qInB); | 
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| 142 |  | 
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| 143 | #ifdef DEBUG_SPU_COLLISION_DETECTION | 
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| 144 | spu_printf("got local supporting vertices\n"); | 
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| 145 | #endif | 
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| 146 |  | 
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| 147 | btVector3 w     = pWorld - qWorld; | 
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| 148 | delta = m_cachedSeparatingAxis.dot(w); | 
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| 149 |  | 
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| 150 | // potential exit, they don't overlap | 
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| 151 | if ((delta > btScalar(0.0)) && (delta * delta > squaredDistance * input.m_maximumDistanceSquared)) | 
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| 152 | { | 
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| 153 | checkSimplex=true; | 
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| 154 | //checkPenetration = false; | 
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| 155 | break; | 
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| 156 | } | 
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| 157 |  | 
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| 158 | //exit 0: the new point is already in the simplex, or we didn't come any closer | 
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| 159 | if (m_simplexSolver->inSimplex(w)) | 
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| 160 | { | 
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| 161 | m_degenerateSimplex = 1; | 
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| 162 | checkSimplex = true; | 
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| 163 | break; | 
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| 164 | } | 
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| 165 | // are we getting any closer ? | 
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| 166 | btScalar f0 = squaredDistance - delta; | 
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| 167 | btScalar f1 = squaredDistance * REL_ERROR2; | 
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| 168 |  | 
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| 169 | if (f0 <= f1) | 
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| 170 | { | 
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| 171 | if (f0 <= btScalar(0.)) | 
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| 172 | { | 
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| 173 | m_degenerateSimplex = 2; | 
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| 174 | } | 
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| 175 | checkSimplex = true; | 
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| 176 | break; | 
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| 177 | } | 
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| 178 |  | 
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| 179 | #ifdef DEBUG_SPU_COLLISION_DETECTION | 
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| 180 | spu_printf("addVertex 1\n"); | 
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| 181 | #endif | 
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| 182 | //add current vertex to simplex | 
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| 183 | m_simplexSolver->addVertex(w, pWorld, qWorld); | 
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| 184 | #ifdef DEBUG_SPU_COLLISION_DETECTION | 
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| 185 | spu_printf("addVertex 2\n"); | 
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| 186 | #endif | 
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| 187 | //calculate the closest point to the origin (update vector v) | 
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| 188 | if (!m_simplexSolver->closest(m_cachedSeparatingAxis)) | 
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| 189 | { | 
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| 190 | m_degenerateSimplex = 3; | 
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| 191 | checkSimplex = true; | 
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| 192 | break; | 
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| 193 | } | 
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| 194 |  | 
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| 195 | if(m_cachedSeparatingAxis.length2()<REL_ERROR2) | 
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| 196 | { | 
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| 197 | m_degenerateSimplex = 6; | 
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| 198 | checkSimplex = true; | 
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| 199 | break; | 
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| 200 | } | 
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| 201 |  | 
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| 202 | btScalar previousSquaredDistance = squaredDistance; | 
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| 203 | squaredDistance = m_cachedSeparatingAxis.length2(); | 
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| 204 |  | 
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| 205 | //redundant m_simplexSolver->compute_points(pointOnA, pointOnB); | 
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| 206 |  | 
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| 207 | //are we getting any closer ? | 
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| 208 | if (previousSquaredDistance - squaredDistance <= SIMD_EPSILON * previousSquaredDistance) | 
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| 209 | { | 
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| 210 | m_simplexSolver->backup_closest(m_cachedSeparatingAxis); | 
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| 211 | checkSimplex = true; | 
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| 212 | break; | 
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| 213 | } | 
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| 214 |  | 
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| 215 | //degeneracy, this is typically due to invalid/uninitialized worldtransforms for a btCollisionObject | 
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| 216 | if (m_curIter++ > gGjkMaxIter) | 
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| 217 | { | 
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| 218 | #if defined(DEBUG) || defined (_DEBUG) || defined (DEBUG_SPU_COLLISION_DETECTION) | 
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| 219 |  | 
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| 220 | printf("btGjkPairDetector maxIter exceeded:%i\n",m_curIter); | 
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| 221 | printf("sepAxis=(%f,%f,%f), squaredDistance = %f, shapeTypeA=%i,shapeTypeB=%i\n", | 
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| 222 | m_cachedSeparatingAxis.getX(), | 
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| 223 | m_cachedSeparatingAxis.getY(), | 
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| 224 | m_cachedSeparatingAxis.getZ(), | 
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| 225 | squaredDistance, | 
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| 226 | m_minkowskiA->getShapeType(), | 
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| 227 | m_minkowskiB->getShapeType()); | 
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| 228 |  | 
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| 229 | #endif | 
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| 230 | break; | 
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| 231 |  | 
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| 232 | } | 
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| 233 |  | 
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| 234 |  | 
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| 235 | bool check = (!m_simplexSolver->fullSimplex()); | 
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| 236 | //bool check = (!m_simplexSolver->fullSimplex() && squaredDistance > SIMD_EPSILON * m_simplexSolver->maxVertex()); | 
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| 237 |  | 
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| 238 | if (!check) | 
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| 239 | { | 
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| 240 | //do we need this backup_closest here ? | 
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| 241 | m_simplexSolver->backup_closest(m_cachedSeparatingAxis); | 
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| 242 | break; | 
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| 243 | } | 
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| 244 | } | 
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| 245 |  | 
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| 246 | if (checkSimplex) | 
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| 247 | { | 
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| 248 | m_simplexSolver->compute_points(pointOnA, pointOnB); | 
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| 249 | normalInB = pointOnA-pointOnB; | 
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| 250 | btScalar lenSqr = m_cachedSeparatingAxis.length2(); | 
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| 251 | //valid normal | 
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| 252 | if (lenSqr < 0.0001) | 
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| 253 | { | 
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| 254 | m_degenerateSimplex = 5; | 
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| 255 | } | 
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| 256 | if (lenSqr > SIMD_EPSILON*SIMD_EPSILON) | 
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| 257 | { | 
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| 258 | btScalar rlen = btScalar(1.) / btSqrt(lenSqr ); | 
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| 259 | normalInB *= rlen; //normalize | 
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| 260 | btScalar s = btSqrt(squaredDistance); | 
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| 261 |  | 
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| 262 | btAssert(s > btScalar(0.0)); | 
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| 263 | pointOnA -= m_cachedSeparatingAxis * (marginA / s); | 
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| 264 | pointOnB += m_cachedSeparatingAxis * (marginB / s); | 
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| 265 | distance = ((btScalar(1.)/rlen) - margin); | 
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| 266 | isValid = true; | 
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| 267 |  | 
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| 268 | m_lastUsedMethod = 1; | 
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| 269 | } else | 
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| 270 | { | 
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| 271 | m_lastUsedMethod = 2; | 
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| 272 | } | 
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| 273 | } | 
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| 274 |  | 
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| 275 | bool catchDegeneratePenetrationCase = | 
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| 276 | (m_catchDegeneracies && m_penetrationDepthSolver && m_degenerateSimplex && ((distance+margin) < 0.01)); | 
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| 277 |  | 
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| 278 | //if (checkPenetration && !isValid) | 
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| 279 | if (checkPenetration && (!isValid || catchDegeneratePenetrationCase )) | 
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| 280 | { | 
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| 281 | //penetration case | 
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| 282 |  | 
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| 283 | //if there is no way to handle penetrations, bail out | 
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| 284 | if (m_penetrationDepthSolver) | 
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| 285 | { | 
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| 286 | // Penetration depth case. | 
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| 287 | btVector3 tmpPointOnA,tmpPointOnB; | 
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| 288 |  | 
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| 289 | gNumDeepPenetrationChecks++; | 
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| 290 |  | 
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| 291 | bool isValid2 = m_penetrationDepthSolver->calcPenDepth( | 
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| 292 | *m_simplexSolver, | 
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| 293 | m_minkowskiA,m_minkowskiB, | 
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| 294 | localTransA,localTransB, | 
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| 295 | m_cachedSeparatingAxis, tmpPointOnA, tmpPointOnB, | 
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| 296 | debugDraw,input.m_stackAlloc | 
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| 297 | ); | 
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| 298 |  | 
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| 299 | if (isValid2) | 
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| 300 | { | 
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| 301 | btVector3 tmpNormalInB = tmpPointOnB-tmpPointOnA; | 
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| 302 | btScalar lenSqr = tmpNormalInB.length2(); | 
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| 303 | if (lenSqr > (SIMD_EPSILON*SIMD_EPSILON)) | 
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| 304 | { | 
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| 305 | tmpNormalInB /= btSqrt(lenSqr); | 
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| 306 | btScalar distance2 = -(tmpPointOnA-tmpPointOnB).length(); | 
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| 307 | //only replace valid penetrations when the result is deeper (check) | 
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| 308 | if (!isValid || (distance2 < distance)) | 
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| 309 | { | 
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| 310 | distance = distance2; | 
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| 311 | pointOnA = tmpPointOnA; | 
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| 312 | pointOnB = tmpPointOnB; | 
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| 313 | normalInB = tmpNormalInB; | 
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| 314 | isValid = true; | 
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| 315 | m_lastUsedMethod = 3; | 
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| 316 | } else | 
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| 317 | { | 
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| 318 |  | 
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| 319 | } | 
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| 320 | } else | 
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| 321 | { | 
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| 322 | //isValid = false; | 
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| 323 | m_lastUsedMethod = 4; | 
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| 324 | } | 
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| 325 | } else | 
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| 326 | { | 
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| 327 | m_lastUsedMethod = 5; | 
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| 328 | } | 
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| 329 |  | 
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| 330 | } | 
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| 331 | } | 
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| 332 | } | 
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| 333 |  | 
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| 334 | if (isValid) | 
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| 335 | { | 
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| 336 | #ifdef __SPU__ | 
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| 337 | //spu_printf("distance\n"); | 
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| 338 | #endif //__CELLOS_LV2__ | 
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| 339 |  | 
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| 340 |  | 
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| 341 | #ifdef DEBUG_SPU_COLLISION_DETECTION | 
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| 342 | spu_printf("output 1\n"); | 
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| 343 | #endif | 
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| 344 | m_cachedSeparatingAxis = normalInB; | 
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| 345 | m_cachedSeparatingDistance = distance; | 
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| 346 |  | 
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| 347 | output.addContactPoint( | 
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| 348 | normalInB, | 
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| 349 | pointOnB+positionOffset, | 
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| 350 | distance); | 
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| 351 |  | 
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| 352 | #ifdef DEBUG_SPU_COLLISION_DETECTION | 
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| 353 | spu_printf("output 2\n"); | 
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| 354 | #endif | 
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| 355 | //printf("gjk add:%f",distance); | 
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| 356 | } | 
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| 357 |  | 
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| 358 |  | 
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| 359 | } | 
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| 360 |  | 
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| 361 |  | 
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| 362 |  | 
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| 363 |  | 
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| 364 |  | 
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