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Diffstat (limited to 'thirdparty/bullet/BulletDynamics/ConstraintSolver/btJacobianEntry.h')
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diff --git a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btJacobianEntry.h b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btJacobianEntry.h new file mode 100644 index 0000000000..125580d199 --- /dev/null +++ b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btJacobianEntry.h @@ -0,0 +1,155 @@ +/* +Bullet Continuous Collision Detection and Physics Library +Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/ + +This software is provided 'as-is', without any express or implied warranty. +In no event will the authors be held liable for any damages arising from the use of this software. +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it freely, +subject to the following restrictions: + +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. +2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. +3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef BT_JACOBIAN_ENTRY_H +#define BT_JACOBIAN_ENTRY_H + +#include "LinearMath/btMatrix3x3.h" + + +//notes: +// Another memory optimization would be to store m_1MinvJt in the remaining 3 w components +// which makes the btJacobianEntry memory layout 16 bytes +// if you only are interested in angular part, just feed massInvA and massInvB zero + +/// Jacobian entry is an abstraction that allows to describe constraints +/// it can be used in combination with a constraint solver +/// Can be used to relate the effect of an impulse to the constraint error +ATTRIBUTE_ALIGNED16(class) btJacobianEntry +{ +public: + btJacobianEntry() {}; + //constraint between two different rigidbodies + btJacobianEntry( + const btMatrix3x3& world2A, + const btMatrix3x3& world2B, + const btVector3& rel_pos1,const btVector3& rel_pos2, + const btVector3& jointAxis, + const btVector3& inertiaInvA, + const btScalar massInvA, + const btVector3& inertiaInvB, + const btScalar massInvB) + :m_linearJointAxis(jointAxis) + { + m_aJ = world2A*(rel_pos1.cross(m_linearJointAxis)); + m_bJ = world2B*(rel_pos2.cross(-m_linearJointAxis)); + m_0MinvJt = inertiaInvA * m_aJ; + m_1MinvJt = inertiaInvB * m_bJ; + m_Adiag = massInvA + m_0MinvJt.dot(m_aJ) + massInvB + m_1MinvJt.dot(m_bJ); + + btAssert(m_Adiag > btScalar(0.0)); + } + + //angular constraint between two different rigidbodies + btJacobianEntry(const btVector3& jointAxis, + const btMatrix3x3& world2A, + const btMatrix3x3& world2B, + const btVector3& inertiaInvA, + const btVector3& inertiaInvB) + :m_linearJointAxis(btVector3(btScalar(0.),btScalar(0.),btScalar(0.))) + { + m_aJ= world2A*jointAxis; + m_bJ = world2B*-jointAxis; + m_0MinvJt = inertiaInvA * m_aJ; + m_1MinvJt = inertiaInvB * m_bJ; + m_Adiag = m_0MinvJt.dot(m_aJ) + m_1MinvJt.dot(m_bJ); + + btAssert(m_Adiag > btScalar(0.0)); + } + + //angular constraint between two different rigidbodies + btJacobianEntry(const btVector3& axisInA, + const btVector3& axisInB, + const btVector3& inertiaInvA, + const btVector3& inertiaInvB) + : m_linearJointAxis(btVector3(btScalar(0.),btScalar(0.),btScalar(0.))) + , m_aJ(axisInA) + , m_bJ(-axisInB) + { + m_0MinvJt = inertiaInvA * m_aJ; + m_1MinvJt = inertiaInvB * m_bJ; + m_Adiag = m_0MinvJt.dot(m_aJ) + m_1MinvJt.dot(m_bJ); + + btAssert(m_Adiag > btScalar(0.0)); + } + + //constraint on one rigidbody + btJacobianEntry( + const btMatrix3x3& world2A, + const btVector3& rel_pos1,const btVector3& rel_pos2, + const btVector3& jointAxis, + const btVector3& inertiaInvA, + const btScalar massInvA) + :m_linearJointAxis(jointAxis) + { + m_aJ= world2A*(rel_pos1.cross(jointAxis)); + m_bJ = world2A*(rel_pos2.cross(-jointAxis)); + m_0MinvJt = inertiaInvA * m_aJ; + m_1MinvJt = btVector3(btScalar(0.),btScalar(0.),btScalar(0.)); + m_Adiag = massInvA + m_0MinvJt.dot(m_aJ); + + btAssert(m_Adiag > btScalar(0.0)); + } + + btScalar getDiagonal() const { return m_Adiag; } + + // for two constraints on the same rigidbody (for example vehicle friction) + btScalar getNonDiagonal(const btJacobianEntry& jacB, const btScalar massInvA) const + { + const btJacobianEntry& jacA = *this; + btScalar lin = massInvA * jacA.m_linearJointAxis.dot(jacB.m_linearJointAxis); + btScalar ang = jacA.m_0MinvJt.dot(jacB.m_aJ); + return lin + ang; + } + + + + // for two constraints on sharing two same rigidbodies (for example two contact points between two rigidbodies) + btScalar getNonDiagonal(const btJacobianEntry& jacB,const btScalar massInvA,const btScalar massInvB) const + { + const btJacobianEntry& jacA = *this; + btVector3 lin = jacA.m_linearJointAxis * jacB.m_linearJointAxis; + btVector3 ang0 = jacA.m_0MinvJt * jacB.m_aJ; + btVector3 ang1 = jacA.m_1MinvJt * jacB.m_bJ; + btVector3 lin0 = massInvA * lin ; + btVector3 lin1 = massInvB * lin; + btVector3 sum = ang0+ang1+lin0+lin1; + return sum[0]+sum[1]+sum[2]; + } + + btScalar getRelativeVelocity(const btVector3& linvelA,const btVector3& angvelA,const btVector3& linvelB,const btVector3& angvelB) + { + btVector3 linrel = linvelA - linvelB; + btVector3 angvela = angvelA * m_aJ; + btVector3 angvelb = angvelB * m_bJ; + linrel *= m_linearJointAxis; + angvela += angvelb; + angvela += linrel; + btScalar rel_vel2 = angvela[0]+angvela[1]+angvela[2]; + return rel_vel2 + SIMD_EPSILON; + } +//private: + + btVector3 m_linearJointAxis; + btVector3 m_aJ; + btVector3 m_bJ; + btVector3 m_0MinvJt; + btVector3 m_1MinvJt; + //Optimization: can be stored in the w/last component of one of the vectors + btScalar m_Adiag; + +}; + +#endif //BT_JACOBIAN_ENTRY_H |