1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans https://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 "btPoint2PointConstraint.h"
17 #include "BulletDynamics/Dynamics/btRigidBody.h"
18 #include <new>
19
btPoint2PointConstraint(btRigidBody & rbA,btRigidBody & rbB,const btVector3 & pivotInA,const btVector3 & pivotInB)20 btPoint2PointConstraint::btPoint2PointConstraint(btRigidBody& rbA, btRigidBody& rbB, const btVector3& pivotInA, const btVector3& pivotInB)
21 : btTypedConstraint(POINT2POINT_CONSTRAINT_TYPE, rbA, rbB), m_pivotInA(pivotInA), m_pivotInB(pivotInB), m_flags(0), m_useSolveConstraintObsolete(false)
22 {
23 }
24
btPoint2PointConstraint(btRigidBody & rbA,const btVector3 & pivotInA)25 btPoint2PointConstraint::btPoint2PointConstraint(btRigidBody& rbA, const btVector3& pivotInA)
26 : btTypedConstraint(POINT2POINT_CONSTRAINT_TYPE, rbA), m_pivotInA(pivotInA), m_pivotInB(rbA.getCenterOfMassTransform()(pivotInA)), m_flags(0), m_useSolveConstraintObsolete(false)
27 {
28 }
29
buildJacobian()30 void btPoint2PointConstraint::buildJacobian()
31 {
32 ///we need it for both methods
33 {
34 m_appliedImpulse = btScalar(0.);
35
36 btVector3 normal(0, 0, 0);
37
38 for (int i = 0; i < 3; i++)
39 {
40 normal[i] = 1;
41 new (&m_jac[i]) btJacobianEntry(
42 m_rbA.getCenterOfMassTransform().getBasis().transpose(),
43 m_rbB.getCenterOfMassTransform().getBasis().transpose(),
44 m_rbA.getCenterOfMassTransform() * m_pivotInA - m_rbA.getCenterOfMassPosition(),
45 m_rbB.getCenterOfMassTransform() * m_pivotInB - m_rbB.getCenterOfMassPosition(),
46 normal,
47 m_rbA.getInvInertiaDiagLocal(),
48 m_rbA.getInvMass(),
49 m_rbB.getInvInertiaDiagLocal(),
50 m_rbB.getInvMass());
51 normal[i] = 0;
52 }
53 }
54 }
55
getInfo1(btConstraintInfo1 * info)56 void btPoint2PointConstraint::getInfo1(btConstraintInfo1* info)
57 {
58 getInfo1NonVirtual(info);
59 }
60
getInfo1NonVirtual(btConstraintInfo1 * info)61 void btPoint2PointConstraint::getInfo1NonVirtual(btConstraintInfo1* info)
62 {
63 if (m_useSolveConstraintObsolete)
64 {
65 info->m_numConstraintRows = 0;
66 info->nub = 0;
67 }
68 else
69 {
70 info->m_numConstraintRows = 3;
71 info->nub = 3;
72 }
73 }
74
getInfo2(btConstraintInfo2 * info)75 void btPoint2PointConstraint::getInfo2(btConstraintInfo2* info)
76 {
77 getInfo2NonVirtual(info, m_rbA.getCenterOfMassTransform(), m_rbB.getCenterOfMassTransform());
78 }
79
getInfo2NonVirtual(btConstraintInfo2 * info,const btTransform & body0_trans,const btTransform & body1_trans)80 void btPoint2PointConstraint::getInfo2NonVirtual(btConstraintInfo2* info, const btTransform& body0_trans, const btTransform& body1_trans)
81 {
82 btAssert(!m_useSolveConstraintObsolete);
83
84 //retrieve matrices
85
86 // anchor points in global coordinates with respect to body PORs.
87
88 // set jacobian
89 info->m_J1linearAxis[0] = 1;
90 info->m_J1linearAxis[info->rowskip + 1] = 1;
91 info->m_J1linearAxis[2 * info->rowskip + 2] = 1;
92
93 btVector3 a1 = body0_trans.getBasis() * getPivotInA();
94 {
95 btVector3* angular0 = (btVector3*)(info->m_J1angularAxis);
96 btVector3* angular1 = (btVector3*)(info->m_J1angularAxis + info->rowskip);
97 btVector3* angular2 = (btVector3*)(info->m_J1angularAxis + 2 * info->rowskip);
98 btVector3 a1neg = -a1;
99 a1neg.getSkewSymmetricMatrix(angular0, angular1, angular2);
100 }
101
102 info->m_J2linearAxis[0] = -1;
103 info->m_J2linearAxis[info->rowskip + 1] = -1;
104 info->m_J2linearAxis[2 * info->rowskip + 2] = -1;
105
106 btVector3 a2 = body1_trans.getBasis() * getPivotInB();
107
108 {
109 // btVector3 a2n = -a2;
110 btVector3* angular0 = (btVector3*)(info->m_J2angularAxis);
111 btVector3* angular1 = (btVector3*)(info->m_J2angularAxis + info->rowskip);
112 btVector3* angular2 = (btVector3*)(info->m_J2angularAxis + 2 * info->rowskip);
113 a2.getSkewSymmetricMatrix(angular0, angular1, angular2);
114 }
115
116 // set right hand side
117 btScalar currERP = (m_flags & BT_P2P_FLAGS_ERP) ? m_erp : info->erp;
118 btScalar k = info->fps * currERP;
119 int j;
120 for (j = 0; j < 3; j++)
121 {
122 info->m_constraintError[j * info->rowskip] = k * (a2[j] + body1_trans.getOrigin()[j] - a1[j] - body0_trans.getOrigin()[j]);
123 //printf("info->m_constraintError[%d]=%f\n",j,info->m_constraintError[j]);
124 }
125 if (m_flags & BT_P2P_FLAGS_CFM)
126 {
127 for (j = 0; j < 3; j++)
128 {
129 info->cfm[j * info->rowskip] = m_cfm;
130 }
131 }
132
133 btScalar impulseClamp = m_setting.m_impulseClamp; //
134 for (j = 0; j < 3; j++)
135 {
136 if (m_setting.m_impulseClamp > 0)
137 {
138 info->m_lowerLimit[j * info->rowskip] = -impulseClamp;
139 info->m_upperLimit[j * info->rowskip] = impulseClamp;
140 }
141 }
142 info->m_damping = m_setting.m_damping;
143 }
144
updateRHS(btScalar timeStep)145 void btPoint2PointConstraint::updateRHS(btScalar timeStep)
146 {
147 (void)timeStep;
148 }
149
150 ///override the default global value of a parameter (such as ERP or CFM), optionally provide the axis (0..5).
151 ///If no axis is provided, it uses the default axis for this constraint.
setParam(int num,btScalar value,int axis)152 void btPoint2PointConstraint::setParam(int num, btScalar value, int axis)
153 {
154 if (axis != -1)
155 {
156 btAssertConstrParams(0);
157 }
158 else
159 {
160 switch (num)
161 {
162 case BT_CONSTRAINT_ERP:
163 case BT_CONSTRAINT_STOP_ERP:
164 m_erp = value;
165 m_flags |= BT_P2P_FLAGS_ERP;
166 break;
167 case BT_CONSTRAINT_CFM:
168 case BT_CONSTRAINT_STOP_CFM:
169 m_cfm = value;
170 m_flags |= BT_P2P_FLAGS_CFM;
171 break;
172 default:
173 btAssertConstrParams(0);
174 }
175 }
176 }
177
178 ///return the local value of parameter
getParam(int num,int axis) const179 btScalar btPoint2PointConstraint::getParam(int num, int axis) const
180 {
181 btScalar retVal(SIMD_INFINITY);
182 if (axis != -1)
183 {
184 btAssertConstrParams(0);
185 }
186 else
187 {
188 switch (num)
189 {
190 case BT_CONSTRAINT_ERP:
191 case BT_CONSTRAINT_STOP_ERP:
192 btAssertConstrParams(m_flags & BT_P2P_FLAGS_ERP);
193 retVal = m_erp;
194 break;
195 case BT_CONSTRAINT_CFM:
196 case BT_CONSTRAINT_STOP_CFM:
197 btAssertConstrParams(m_flags & BT_P2P_FLAGS_CFM);
198 retVal = m_cfm;
199 break;
200 default:
201 btAssertConstrParams(0);
202 }
203 }
204 return retVal;
205 }
206