1 /* 2 Bullet Continuous Collision Detection and Physics Library 3 Copyright (c) 2003-2009 Erwin Coumans http://bulletphysics.org 4 5 This software is provided 'as-is', without any express or implied warranty. 6 In no event will the authors be held liable for any damages arising from the use of this software. 7 Permission is granted to anyone to use this software for any purpose, 8 including commercial applications, and to alter it and redistribute it freely, 9 subject to the following restrictions: 10 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. 12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 13 3. This notice may not be removed or altered from any source distribution. 14 */ 15 16 #include "btTriangleMeshShape.h" 17 #include "LinearMath/btVector3.h" 18 #include "LinearMath/btQuaternion.h" 19 #include "btStridingMeshInterface.h" 20 #include "LinearMath/btAabbUtil2.h" 21 #include "BulletCollision/CollisionShapes/btCollisionMargin.h" 22 23 24 btTriangleMeshShape::btTriangleMeshShape(btStridingMeshInterface* meshInterface) 25 : btConcaveShape (), m_meshInterface(meshInterface) 26 { 27 m_shapeType = TRIANGLE_MESH_SHAPE_PROXYTYPE; 28 if(meshInterface->hasPremadeAabb()) 29 { 30 meshInterface->getPremadeAabb(&m_localAabbMin, &m_localAabbMax); 31 } 32 else 33 { 34 recalcLocalAabb(); 35 } 36 } 37 38 39 btTriangleMeshShape::~btTriangleMeshShape() 40 { 41 42 } 43 44 45 46 47 void btTriangleMeshShape::getAabb(const btTransform& trans,btVector3& aabbMin,btVector3& aabbMax) const 48 { 49 50 btVector3 localHalfExtents = btScalar(0.5)*(m_localAabbMax-m_localAabbMin); 51 localHalfExtents += btVector3(getMargin(),getMargin(),getMargin()); 52 btVector3 localCenter = btScalar(0.5)*(m_localAabbMax+m_localAabbMin); 53 54 btMatrix3x3 abs_b = trans.getBasis().absolute(); 55 56 btVector3 center = trans(localCenter); 57 58 btVector3 extent = localHalfExtents.dot3(abs_b[0], abs_b[1], abs_b[2]); 59 aabbMin = center - extent; 60 aabbMax = center + extent; 61 } 62 63 void btTriangleMeshShape::recalcLocalAabb() 64 { 65 for (int i=0;i<3;i++) 66 { 67 btVector3 vec(btScalar(0.),btScalar(0.),btScalar(0.)); 68 vec[i] = btScalar(1.); 69 btVector3 tmp = localGetSupportingVertex(vec); 70 m_localAabbMax[i] = tmp[i]+m_collisionMargin; 71 vec[i] = btScalar(-1.); 72 tmp = localGetSupportingVertex(vec); 73 m_localAabbMin[i] = tmp[i]-m_collisionMargin; 74 } 75 } 76 77 78 79 class SupportVertexCallback : public btTriangleCallback 80 { 81 82 btVector3 m_supportVertexLocal; 83 public: 84 85 btTransform m_worldTrans; 86 btScalar m_maxDot; 87 btVector3 m_supportVecLocal; 88 89 SupportVertexCallback(const btVector3& supportVecWorld,const btTransform& trans) 90 : m_supportVertexLocal(btScalar(0.),btScalar(0.),btScalar(0.)), m_worldTrans(trans) ,m_maxDot(btScalar(-BT_LARGE_FLOAT)) 91 92 { 93 m_supportVecLocal = supportVecWorld * m_worldTrans.getBasis(); 94 } 95 96 virtual void processTriangle( btVector3* triangle,int partId, int triangleIndex) 97 { 98 (void)partId; 99 (void)triangleIndex; 100 for (int i=0;i<3;i++) 101 { 102 btScalar dot = m_supportVecLocal.dot(triangle[i]); 103 if (dot > m_maxDot) 104 { 105 m_maxDot = dot; 106 m_supportVertexLocal = triangle[i]; 107 } 108 } 109 } 110 111 btVector3 GetSupportVertexWorldSpace() 112 { 113 return m_worldTrans(m_supportVertexLocal); 114 } 115 116 btVector3 GetSupportVertexLocal() 117 { 118 return m_supportVertexLocal; 119 } 120 121 }; 122 123 124 void btTriangleMeshShape::setLocalScaling(const btVector3& scaling) 125 { 126 m_meshInterface->setScaling(scaling); 127 recalcLocalAabb(); 128 } 129 130 const btVector3& btTriangleMeshShape::getLocalScaling() const 131 { 132 return m_meshInterface->getScaling(); 133 } 134 135 136 137 138 139 140 //#define DEBUG_TRIANGLE_MESH 141 142 143 144 void btTriangleMeshShape::processAllTriangles(btTriangleCallback* callback,const btVector3& aabbMin,const btVector3& aabbMax) const 145 { 146 struct FilteredCallback : public btInternalTriangleIndexCallback 147 { 148 btTriangleCallback* m_callback; 149 btVector3 m_aabbMin; 150 btVector3 m_aabbMax; 151 152 FilteredCallback(btTriangleCallback* callback,const btVector3& aabbMin,const btVector3& aabbMax) 153 :m_callback(callback), 154 m_aabbMin(aabbMin), 155 m_aabbMax(aabbMax) 156 { 157 } 158 159 virtual void internalProcessTriangleIndex(btVector3* triangle,int partId,int triangleIndex) 160 { 161 if (TestTriangleAgainstAabb2(&triangle[0],m_aabbMin,m_aabbMax)) 162 { 163 //check aabb in triangle-space, before doing this 164 m_callback->processTriangle(triangle,partId,triangleIndex); 165 } 166 167 } 168 169 }; 170 171 FilteredCallback filterCallback(callback,aabbMin,aabbMax); 172 173 m_meshInterface->InternalProcessAllTriangles(&filterCallback,aabbMin,aabbMax); 174 } 175 176 177 178 179 180 void btTriangleMeshShape::calculateLocalInertia(btScalar mass,btVector3& inertia) const 181 { 182 (void)mass; 183 //moving concave objects not supported 184 btAssert(0); 185 inertia.setValue(btScalar(0.),btScalar(0.),btScalar(0.)); 186 } 187 188 189 btVector3 btTriangleMeshShape::localGetSupportingVertex(const btVector3& vec) const 190 { 191 btVector3 supportVertex; 192 193 btTransform ident; 194 ident.setIdentity(); 195 196 SupportVertexCallback supportCallback(vec,ident); 197 198 btVector3 aabbMax(btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT),btScalar(BT_LARGE_FLOAT)); 199 200 processAllTriangles(&supportCallback,-aabbMax,aabbMax); 201 202 supportVertex = supportCallback.GetSupportVertexLocal(); 203 204 return supportVertex; 205 } 206 207 208
