1 /* 2 Bullet Continuous Collision Detection and Physics Library 3 Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/ 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 17 #include "btPoint2PointConstraint.h" 18 #include "BulletDynamics/Dynamics/btRigidBody.h" 19 #include <new> 20 21 22 23 24 25 btPoint2PointConstraint::btPoint2PointConstraint(btRigidBody& rbA,btRigidBody& rbB, const btVector3& pivotInA,const btVector3& pivotInB) 26 :btTypedConstraint(POINT2POINT_CONSTRAINT_TYPE,rbA,rbB),m_pivotInA(pivotInA),m_pivotInB(pivotInB), 27 m_flags(0), 28 m_useSolveConstraintObsolete(false) 29 { 30 31 } 32 33 34 btPoint2PointConstraint::btPoint2PointConstraint(btRigidBody& rbA,const btVector3& pivotInA) 35 :btTypedConstraint(POINT2POINT_CONSTRAINT_TYPE,rbA),m_pivotInA(pivotInA),m_pivotInB(rbA.getCenterOfMassTransform()(pivotInA)), 36 m_flags(0), 37 m_useSolveConstraintObsolete(false) 38 { 39 40 } 41 42 void btPoint2PointConstraint::buildJacobian() 43 { 44 45 ///we need it for both methods 46 { 47 m_appliedImpulse = btScalar(0.); 48 49 btVector3 normal(0,0,0); 50 51 for (int i=0;i<3;i++) 52 { 53 normal[i] = 1; 54 new (&m_jac[i]) btJacobianEntry( 55 m_rbA.getCenterOfMassTransform().getBasis().transpose(), 56 m_rbB.getCenterOfMassTransform().getBasis().transpose(), 57 m_rbA.getCenterOfMassTransform()*m_pivotInA - m_rbA.getCenterOfMassPosition(), 58 m_rbB.getCenterOfMassTransform()*m_pivotInB - m_rbB.getCenterOfMassPosition(), 59 normal, 60 m_rbA.getInvInertiaDiagLocal(), 61 m_rbA.getInvMass(), 62 m_rbB.getInvInertiaDiagLocal(), 63 m_rbB.getInvMass()); 64 normal[i] = 0; 65 } 66 } 67 68 69 } 70 71 void btPoint2PointConstraint::getInfo1 (btConstraintInfo1* info) 72 { 73 getInfo1NonVirtual(info); 74 } 75 76 void btPoint2PointConstraint::getInfo1NonVirtual (btConstraintInfo1* info) 77 { 78 if (m_useSolveConstraintObsolete) 79 { 80 info->m_numConstraintRows = 0; 81 info->nub = 0; 82 } else 83 { 84 info->m_numConstraintRows = 3; 85 info->nub = 3; 86 } 87 } 88 89 90 91 92 void btPoint2PointConstraint::getInfo2 (btConstraintInfo2* info) 93 { 94 getInfo2NonVirtual(info, m_rbA.getCenterOfMassTransform(),m_rbB.getCenterOfMassTransform()); 95 } 96 97 void btPoint2PointConstraint::getInfo2NonVirtual (btConstraintInfo2* info, const btTransform& body0_trans, const btTransform& body1_trans) 98 { 99 btAssert(!m_useSolveConstraintObsolete); 100 101 //retrieve matrices 102 103 // anchor points in global coordinates with respect to body PORs. 104 105 // set jacobian 106 info->m_J1linearAxis[0] = 1; 107 info->m_J1linearAxis[info->rowskip+1] = 1; 108 info->m_J1linearAxis[2*info->rowskip+2] = 1; 109 110 btVector3 a1 = body0_trans.getBasis()*getPivotInA(); 111 { 112 btVector3* angular0 = (btVector3*)(info->m_J1angularAxis); 113 btVector3* angular1 = (btVector3*)(info->m_J1angularAxis+info->rowskip); 114 btVector3* angular2 = (btVector3*)(info->m_J1angularAxis+2*info->rowskip); 115 btVector3 a1neg = -a1; 116 a1neg.getSkewSymmetricMatrix(angular0,angular1,angular2); 117 } 118 119 info->m_J2linearAxis[0] = -1; 120 info->m_J2linearAxis[info->rowskip+1] = -1; 121 info->m_J2linearAxis[2*info->rowskip+2] = -1; 122 123 btVector3 a2 = body1_trans.getBasis()*getPivotInB(); 124 125 { 126 // btVector3 a2n = -a2; 127 btVector3* angular0 = (btVector3*)(info->m_J2angularAxis); 128 btVector3* angular1 = (btVector3*)(info->m_J2angularAxis+info->rowskip); 129 btVector3* angular2 = (btVector3*)(info->m_J2angularAxis+2*info->rowskip); 130 a2.getSkewSymmetricMatrix(angular0,angular1,angular2); 131 } 132 133 134 135 // set right hand side 136 btScalar currERP = (m_flags & BT_P2P_FLAGS_ERP) ? m_erp : info->erp; 137 btScalar k = info->fps * currERP; 138 int j; 139 for (j=0; j<3; j++) 140 { 141 info->m_constraintError[j*info->rowskip] = k * (a2[j] + body1_trans.getOrigin()[j] - a1[j] - body0_trans.getOrigin()[j]); 142 //printf("info->m_constraintError[%d]=%f\n",j,info->m_constraintError[j]); 143 } 144 if(m_flags & BT_P2P_FLAGS_CFM) 145 { 146 for (j=0; j<3; j++) 147 { 148 info->cfm[j*info->rowskip] = m_cfm; 149 } 150 } 151 152 btScalar impulseClamp = m_setting.m_impulseClamp;// 153 for (j=0; j<3; j++) 154 { 155 if (m_setting.m_impulseClamp > 0) 156 { 157 info->m_lowerLimit[j*info->rowskip] = -impulseClamp; 158 info->m_upperLimit[j*info->rowskip] = impulseClamp; 159 } 160 } 161 info->m_damping = m_setting.m_damping; 162 163 } 164 165 166 167 void btPoint2PointConstraint::updateRHS(btScalar timeStep) 168 { 169 (void)timeStep; 170 171 } 172 173 ///override the default global value of a parameter (such as ERP or CFM), optionally provide the axis (0..5). 174 ///If no axis is provided, it uses the default axis for this constraint. 175 void btPoint2PointConstraint::setParam(int num, btScalar value, int axis) 176 { 177 if(axis != -1) 178 { 179 btAssertConstrParams(0); 180 } 181 else 182 { 183 switch(num) 184 { 185 case BT_CONSTRAINT_ERP : 186 case BT_CONSTRAINT_STOP_ERP : 187 m_erp = value; 188 m_flags |= BT_P2P_FLAGS_ERP; 189 break; 190 case BT_CONSTRAINT_CFM : 191 case BT_CONSTRAINT_STOP_CFM : 192 m_cfm = value; 193 m_flags |= BT_P2P_FLAGS_CFM; 194 break; 195 default: 196 btAssertConstrParams(0); 197 } 198 } 199 } 200 201 ///return the local value of parameter 202 btScalar btPoint2PointConstraint::getParam(int num, int axis) const 203 { 204 btScalar retVal(SIMD_INFINITY); 205 if(axis != -1) 206 { 207 btAssertConstrParams(0); 208 } 209 else 210 { 211 switch(num) 212 { 213 case BT_CONSTRAINT_ERP : 214 case BT_CONSTRAINT_STOP_ERP : 215 btAssertConstrParams(m_flags & BT_P2P_FLAGS_ERP); 216 retVal = m_erp; 217 break; 218 case BT_CONSTRAINT_CFM : 219 case BT_CONSTRAINT_STOP_CFM : 220 btAssertConstrParams(m_flags & BT_P2P_FLAGS_CFM); 221 retVal = m_cfm; 222 break; 223 default: 224 btAssertConstrParams(0); 225 } 226 } 227 return retVal; 228 } 229 230
