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 | btScalar distance=btScalar(0.); |
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57 | btVector3 normalInB(btScalar(0.),btScalar(0.),btScalar(0.)); |
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58 | btVector3 pointOnA,pointOnB; |
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59 | btTransform localTransA = input.m_transformA; |
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60 | btTransform localTransB = input.m_transformB; |
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61 | btVector3 positionOffset = (localTransA.getOrigin() + localTransB.getOrigin()) * btScalar(0.5); |
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62 | localTransA.getOrigin() -= positionOffset; |
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63 | localTransB.getOrigin() -= positionOffset; |
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64 | |
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65 | |
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66 | btScalar marginA = m_minkowskiA->getMarginNonVirtual(); |
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67 | btScalar marginB = m_minkowskiB->getMarginNonVirtual(); |
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68 | |
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69 | #ifdef TEST_NON_VIRTUAL |
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70 | btScalar marginAv = m_minkowskiA->getMargin(); |
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71 | btScalar marginBv = m_minkowskiB->getMargin(); |
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72 | |
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73 | btAssert(marginA == marginAv); |
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74 | btAssert(marginB == marginBv); |
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75 | #endif //TEST_NON_VIRTUAL |
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76 | |
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77 | gNumGjkChecks++; |
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78 | |
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79 | #ifdef DEBUG_SPU_COLLISION_DETECTION |
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80 | spu_printf("inside gjk\n"); |
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81 | #endif |
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82 | //for CCD we don't use margins |
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83 | if (m_ignoreMargin) |
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84 | { |
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85 | marginA = btScalar(0.); |
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86 | marginB = btScalar(0.); |
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87 | #ifdef DEBUG_SPU_COLLISION_DETECTION |
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88 | spu_printf("ignoring margin\n"); |
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89 | #endif |
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90 | } |
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91 | |
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92 | m_curIter = 0; |
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93 | int gGjkMaxIter = 1000;//this is to catch invalid input, perhaps check for #NaN? |
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94 | m_cachedSeparatingAxis.setValue(0,1,0); |
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95 | |
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96 | bool isValid = false; |
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97 | bool checkSimplex = false; |
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98 | bool checkPenetration = true; |
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99 | m_degenerateSimplex = 0; |
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100 | |
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101 | m_lastUsedMethod = -1; |
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102 | |
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103 | { |
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104 | btScalar squaredDistance = SIMD_INFINITY; |
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105 | btScalar delta = btScalar(0.); |
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106 | |
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107 | btScalar margin = marginA + marginB; |
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108 | |
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109 | |
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110 | |
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111 | m_simplexSolver->reset(); |
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112 | |
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113 | for ( ; ; ) |
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114 | //while (true) |
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115 | { |
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116 | |
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117 | btVector3 seperatingAxisInA = (-m_cachedSeparatingAxis)* input.m_transformA.getBasis(); |
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118 | btVector3 seperatingAxisInB = m_cachedSeparatingAxis* input.m_transformB.getBasis(); |
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119 | |
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120 | #ifdef TEST_NON_VIRTUAL |
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121 | btVector3 pInAv = m_minkowskiA->localGetSupportingVertexWithoutMargin(seperatingAxisInA); |
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122 | btVector3 qInBv = m_minkowskiB->localGetSupportingVertexWithoutMargin(seperatingAxisInB); |
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123 | #endif |
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124 | btVector3 pInA = m_minkowskiA->localGetSupportVertexWithoutMarginNonVirtual(seperatingAxisInA); |
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125 | btVector3 qInB = m_minkowskiB->localGetSupportVertexWithoutMarginNonVirtual(seperatingAxisInB); |
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126 | #ifdef TEST_NON_VIRTUAL |
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127 | btAssert((pInAv-pInA).length() < 0.0001); |
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128 | btAssert((qInBv-qInB).length() < 0.0001); |
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129 | #endif // |
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130 | |
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131 | btPoint3 pWorld = localTransA(pInA); |
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132 | btPoint3 qWorld = localTransB(qInB); |
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133 | |
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134 | #ifdef DEBUG_SPU_COLLISION_DETECTION |
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135 | spu_printf("got local supporting vertices\n"); |
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136 | #endif |
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137 | |
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138 | btVector3 w = pWorld - qWorld; |
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139 | delta = m_cachedSeparatingAxis.dot(w); |
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140 | |
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141 | // potential exit, they don't overlap |
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142 | if ((delta > btScalar(0.0)) && (delta * delta > squaredDistance * input.m_maximumDistanceSquared)) |
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143 | { |
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144 | checkPenetration = false; |
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145 | break; |
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146 | } |
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147 | |
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148 | //exit 0: the new point is already in the simplex, or we didn't come any closer |
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149 | if (m_simplexSolver->inSimplex(w)) |
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150 | { |
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151 | m_degenerateSimplex = 1; |
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152 | checkSimplex = true; |
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153 | break; |
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154 | } |
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155 | // are we getting any closer ? |
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156 | btScalar f0 = squaredDistance - delta; |
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157 | btScalar f1 = squaredDistance * REL_ERROR2; |
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158 | |
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159 | if (f0 <= f1) |
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160 | { |
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161 | if (f0 <= btScalar(0.)) |
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162 | { |
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163 | m_degenerateSimplex = 2; |
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164 | } |
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165 | checkSimplex = true; |
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166 | break; |
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167 | } |
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168 | |
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169 | #ifdef DEBUG_SPU_COLLISION_DETECTION |
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170 | spu_printf("addVertex 1\n"); |
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171 | #endif |
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172 | //add current vertex to simplex |
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173 | m_simplexSolver->addVertex(w, pWorld, qWorld); |
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174 | #ifdef DEBUG_SPU_COLLISION_DETECTION |
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175 | spu_printf("addVertex 2\n"); |
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176 | #endif |
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177 | //calculate the closest point to the origin (update vector v) |
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178 | if (!m_simplexSolver->closest(m_cachedSeparatingAxis)) |
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179 | { |
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180 | m_degenerateSimplex = 3; |
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181 | checkSimplex = true; |
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182 | break; |
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183 | } |
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184 | |
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185 | if(m_cachedSeparatingAxis.length2()<REL_ERROR2) |
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186 | { |
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187 | m_degenerateSimplex = 6; |
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188 | checkSimplex = true; |
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189 | break; |
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190 | } |
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191 | |
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192 | btScalar previousSquaredDistance = squaredDistance; |
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193 | squaredDistance = m_cachedSeparatingAxis.length2(); |
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194 | |
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195 | //redundant m_simplexSolver->compute_points(pointOnA, pointOnB); |
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196 | |
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197 | //are we getting any closer ? |
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198 | if (previousSquaredDistance - squaredDistance <= SIMD_EPSILON * previousSquaredDistance) |
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199 | { |
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200 | m_simplexSolver->backup_closest(m_cachedSeparatingAxis); |
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201 | checkSimplex = true; |
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202 | break; |
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203 | } |
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204 | |
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205 | //degeneracy, this is typically due to invalid/uninitialized worldtransforms for a btCollisionObject |
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206 | if (m_curIter++ > gGjkMaxIter) |
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207 | { |
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208 | #if defined(DEBUG) || defined (_DEBUG) || defined (DEBUG_SPU_COLLISION_DETECTION) |
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209 | |
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210 | printf("btGjkPairDetector maxIter exceeded:%i\n",m_curIter); |
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211 | printf("sepAxis=(%f,%f,%f), squaredDistance = %f, shapeTypeA=%i,shapeTypeB=%i\n", |
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212 | m_cachedSeparatingAxis.getX(), |
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213 | m_cachedSeparatingAxis.getY(), |
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214 | m_cachedSeparatingAxis.getZ(), |
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215 | squaredDistance, |
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216 | m_minkowskiA->getShapeType(), |
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217 | m_minkowskiB->getShapeType()); |
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218 | |
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219 | #endif |
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220 | break; |
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221 | |
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222 | } |
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223 | |
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224 | |
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225 | bool check = (!m_simplexSolver->fullSimplex()); |
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226 | //bool check = (!m_simplexSolver->fullSimplex() && squaredDistance > SIMD_EPSILON * m_simplexSolver->maxVertex()); |
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227 | |
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228 | if (!check) |
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229 | { |
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230 | //do we need this backup_closest here ? |
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231 | m_simplexSolver->backup_closest(m_cachedSeparatingAxis); |
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232 | break; |
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233 | } |
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234 | } |
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235 | |
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236 | if (checkSimplex) |
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237 | { |
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238 | m_simplexSolver->compute_points(pointOnA, pointOnB); |
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239 | normalInB = pointOnA-pointOnB; |
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240 | btScalar lenSqr = m_cachedSeparatingAxis.length2(); |
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241 | //valid normal |
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242 | if (lenSqr < 0.0001) |
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243 | { |
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244 | m_degenerateSimplex = 5; |
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245 | } |
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246 | if (lenSqr > SIMD_EPSILON*SIMD_EPSILON) |
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247 | { |
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248 | btScalar rlen = btScalar(1.) / btSqrt(lenSqr ); |
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249 | normalInB *= rlen; //normalize |
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250 | btScalar s = btSqrt(squaredDistance); |
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251 | |
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252 | btAssert(s > btScalar(0.0)); |
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253 | pointOnA -= m_cachedSeparatingAxis * (marginA / s); |
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254 | pointOnB += m_cachedSeparatingAxis * (marginB / s); |
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255 | distance = ((btScalar(1.)/rlen) - margin); |
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256 | isValid = true; |
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257 | |
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258 | m_lastUsedMethod = 1; |
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259 | } else |
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260 | { |
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261 | m_lastUsedMethod = 2; |
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262 | } |
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263 | } |
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264 | |
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265 | bool catchDegeneratePenetrationCase = |
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266 | (m_catchDegeneracies && m_penetrationDepthSolver && m_degenerateSimplex && ((distance+margin) < 0.01)); |
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267 | |
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268 | //if (checkPenetration && !isValid) |
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269 | if (checkPenetration && (!isValid || catchDegeneratePenetrationCase )) |
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270 | { |
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271 | //penetration case |
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272 | |
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273 | //if there is no way to handle penetrations, bail out |
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274 | if (m_penetrationDepthSolver) |
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275 | { |
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276 | // Penetration depth case. |
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277 | btVector3 tmpPointOnA,tmpPointOnB; |
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278 | |
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279 | gNumDeepPenetrationChecks++; |
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280 | |
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281 | bool isValid2 = m_penetrationDepthSolver->calcPenDepth( |
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282 | *m_simplexSolver, |
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283 | m_minkowskiA,m_minkowskiB, |
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284 | localTransA,localTransB, |
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285 | m_cachedSeparatingAxis, tmpPointOnA, tmpPointOnB, |
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286 | debugDraw,input.m_stackAlloc |
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287 | ); |
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288 | |
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289 | if (isValid2) |
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290 | { |
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291 | btVector3 tmpNormalInB = tmpPointOnB-tmpPointOnA; |
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292 | btScalar lenSqr = tmpNormalInB.length2(); |
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293 | if (lenSqr > (SIMD_EPSILON*SIMD_EPSILON)) |
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294 | { |
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295 | tmpNormalInB /= btSqrt(lenSqr); |
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296 | btScalar distance2 = -(tmpPointOnA-tmpPointOnB).length(); |
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297 | //only replace valid penetrations when the result is deeper (check) |
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298 | if (!isValid || (distance2 < distance)) |
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299 | { |
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300 | distance = distance2; |
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301 | pointOnA = tmpPointOnA; |
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302 | pointOnB = tmpPointOnB; |
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303 | normalInB = tmpNormalInB; |
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304 | isValid = true; |
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305 | m_lastUsedMethod = 3; |
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306 | } else |
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307 | { |
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308 | |
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309 | } |
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310 | } else |
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311 | { |
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312 | //isValid = false; |
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313 | m_lastUsedMethod = 4; |
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314 | } |
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315 | } else |
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316 | { |
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317 | m_lastUsedMethod = 5; |
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318 | } |
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319 | |
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320 | } |
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321 | } |
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322 | } |
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323 | |
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324 | if (isValid) |
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325 | { |
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326 | #ifdef __SPU__ |
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327 | //spu_printf("distance\n"); |
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328 | #endif //__CELLOS_LV2__ |
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329 | |
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330 | |
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331 | #ifdef DEBUG_SPU_COLLISION_DETECTION |
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332 | spu_printf("output 1\n"); |
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333 | #endif |
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334 | output.addContactPoint( |
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335 | normalInB, |
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336 | pointOnB+positionOffset, |
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337 | distance); |
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338 | |
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339 | #ifdef DEBUG_SPU_COLLISION_DETECTION |
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340 | spu_printf("output 2\n"); |
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341 | #endif |
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342 | //printf("gjk add:%f",distance); |
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343 | } |
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344 | |
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345 | |
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346 | } |
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347 | |
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348 | |
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349 | |
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350 | |
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351 | |
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