mirror of
https://github.com/godotengine/godot.git
synced 2025-10-31 13:41:03 +00:00
239 lines
7.4 KiB
C++
239 lines
7.4 KiB
C++
/*
|
|
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.
|
|
*/
|
|
|
|
#include "btSolve2LinearConstraint.h"
|
|
|
|
#include "BulletDynamics/Dynamics/btRigidBody.h"
|
|
#include "LinearMath/btVector3.h"
|
|
#include "btJacobianEntry.h"
|
|
|
|
void btSolve2LinearConstraint::resolveUnilateralPairConstraint(
|
|
btRigidBody* body1,
|
|
btRigidBody* body2,
|
|
|
|
const btMatrix3x3& world2A,
|
|
const btMatrix3x3& world2B,
|
|
|
|
const btVector3& invInertiaADiag,
|
|
const btScalar invMassA,
|
|
const btVector3& linvelA, const btVector3& angvelA,
|
|
const btVector3& rel_posA1,
|
|
const btVector3& invInertiaBDiag,
|
|
const btScalar invMassB,
|
|
const btVector3& linvelB, const btVector3& angvelB,
|
|
const btVector3& rel_posA2,
|
|
|
|
btScalar depthA, const btVector3& normalA,
|
|
const btVector3& rel_posB1, const btVector3& rel_posB2,
|
|
btScalar depthB, const btVector3& normalB,
|
|
btScalar& imp0, btScalar& imp1)
|
|
{
|
|
(void)linvelA;
|
|
(void)linvelB;
|
|
(void)angvelB;
|
|
(void)angvelA;
|
|
|
|
imp0 = btScalar(0.);
|
|
imp1 = btScalar(0.);
|
|
|
|
btScalar len = btFabs(normalA.length()) - btScalar(1.);
|
|
if (btFabs(len) >= SIMD_EPSILON)
|
|
return;
|
|
|
|
btAssert(len < SIMD_EPSILON);
|
|
|
|
//this jacobian entry could be re-used for all iterations
|
|
btJacobianEntry jacA(world2A, world2B, rel_posA1, rel_posA2, normalA, invInertiaADiag, invMassA,
|
|
invInertiaBDiag, invMassB);
|
|
btJacobianEntry jacB(world2A, world2B, rel_posB1, rel_posB2, normalB, invInertiaADiag, invMassA,
|
|
invInertiaBDiag, invMassB);
|
|
|
|
//const btScalar vel0 = jacA.getRelativeVelocity(linvelA,angvelA,linvelB,angvelB);
|
|
//const btScalar vel1 = jacB.getRelativeVelocity(linvelA,angvelA,linvelB,angvelB);
|
|
|
|
const btScalar vel0 = normalA.dot(body1->getVelocityInLocalPoint(rel_posA1) - body2->getVelocityInLocalPoint(rel_posA1));
|
|
const btScalar vel1 = normalB.dot(body1->getVelocityInLocalPoint(rel_posB1) - body2->getVelocityInLocalPoint(rel_posB1));
|
|
|
|
// btScalar penetrationImpulse = (depth*contactTau*timeCorrection) * massTerm;//jacDiagABInv
|
|
btScalar massTerm = btScalar(1.) / (invMassA + invMassB);
|
|
|
|
// calculate rhs (or error) terms
|
|
const btScalar dv0 = depthA * m_tau * massTerm - vel0 * m_damping;
|
|
const btScalar dv1 = depthB * m_tau * massTerm - vel1 * m_damping;
|
|
|
|
// dC/dv * dv = -C
|
|
|
|
// jacobian * impulse = -error
|
|
//
|
|
|
|
//impulse = jacobianInverse * -error
|
|
|
|
// inverting 2x2 symmetric system (offdiagonal are equal!)
|
|
//
|
|
|
|
btScalar nonDiag = jacA.getNonDiagonal(jacB, invMassA, invMassB);
|
|
btScalar invDet = btScalar(1.0) / (jacA.getDiagonal() * jacB.getDiagonal() - nonDiag * nonDiag);
|
|
|
|
//imp0 = dv0 * jacA.getDiagonal() * invDet + dv1 * -nonDiag * invDet;
|
|
//imp1 = dv1 * jacB.getDiagonal() * invDet + dv0 * - nonDiag * invDet;
|
|
|
|
imp0 = dv0 * jacA.getDiagonal() * invDet + dv1 * -nonDiag * invDet;
|
|
imp1 = dv1 * jacB.getDiagonal() * invDet + dv0 * -nonDiag * invDet;
|
|
|
|
//[a b] [d -c]
|
|
//[c d] inverse = (1 / determinant) * [-b a] where determinant is (ad - bc)
|
|
|
|
//[jA nD] * [imp0] = [dv0]
|
|
//[nD jB] [imp1] [dv1]
|
|
}
|
|
|
|
void btSolve2LinearConstraint::resolveBilateralPairConstraint(
|
|
btRigidBody* body1,
|
|
btRigidBody* body2,
|
|
const btMatrix3x3& world2A,
|
|
const btMatrix3x3& world2B,
|
|
|
|
const btVector3& invInertiaADiag,
|
|
const btScalar invMassA,
|
|
const btVector3& linvelA, const btVector3& angvelA,
|
|
const btVector3& rel_posA1,
|
|
const btVector3& invInertiaBDiag,
|
|
const btScalar invMassB,
|
|
const btVector3& linvelB, const btVector3& angvelB,
|
|
const btVector3& rel_posA2,
|
|
|
|
btScalar depthA, const btVector3& normalA,
|
|
const btVector3& rel_posB1, const btVector3& rel_posB2,
|
|
btScalar depthB, const btVector3& normalB,
|
|
btScalar& imp0, btScalar& imp1)
|
|
{
|
|
(void)linvelA;
|
|
(void)linvelB;
|
|
(void)angvelA;
|
|
(void)angvelB;
|
|
|
|
imp0 = btScalar(0.);
|
|
imp1 = btScalar(0.);
|
|
|
|
btScalar len = btFabs(normalA.length()) - btScalar(1.);
|
|
if (btFabs(len) >= SIMD_EPSILON)
|
|
return;
|
|
|
|
btAssert(len < SIMD_EPSILON);
|
|
|
|
//this jacobian entry could be re-used for all iterations
|
|
btJacobianEntry jacA(world2A, world2B, rel_posA1, rel_posA2, normalA, invInertiaADiag, invMassA,
|
|
invInertiaBDiag, invMassB);
|
|
btJacobianEntry jacB(world2A, world2B, rel_posB1, rel_posB2, normalB, invInertiaADiag, invMassA,
|
|
invInertiaBDiag, invMassB);
|
|
|
|
//const btScalar vel0 = jacA.getRelativeVelocity(linvelA,angvelA,linvelB,angvelB);
|
|
//const btScalar vel1 = jacB.getRelativeVelocity(linvelA,angvelA,linvelB,angvelB);
|
|
|
|
const btScalar vel0 = normalA.dot(body1->getVelocityInLocalPoint(rel_posA1) - body2->getVelocityInLocalPoint(rel_posA1));
|
|
const btScalar vel1 = normalB.dot(body1->getVelocityInLocalPoint(rel_posB1) - body2->getVelocityInLocalPoint(rel_posB1));
|
|
|
|
// calculate rhs (or error) terms
|
|
const btScalar dv0 = depthA * m_tau - vel0 * m_damping;
|
|
const btScalar dv1 = depthB * m_tau - vel1 * m_damping;
|
|
|
|
// dC/dv * dv = -C
|
|
|
|
// jacobian * impulse = -error
|
|
//
|
|
|
|
//impulse = jacobianInverse * -error
|
|
|
|
// inverting 2x2 symmetric system (offdiagonal are equal!)
|
|
//
|
|
|
|
btScalar nonDiag = jacA.getNonDiagonal(jacB, invMassA, invMassB);
|
|
btScalar invDet = btScalar(1.0) / (jacA.getDiagonal() * jacB.getDiagonal() - nonDiag * nonDiag);
|
|
|
|
//imp0 = dv0 * jacA.getDiagonal() * invDet + dv1 * -nonDiag * invDet;
|
|
//imp1 = dv1 * jacB.getDiagonal() * invDet + dv0 * - nonDiag * invDet;
|
|
|
|
imp0 = dv0 * jacA.getDiagonal() * invDet + dv1 * -nonDiag * invDet;
|
|
imp1 = dv1 * jacB.getDiagonal() * invDet + dv0 * -nonDiag * invDet;
|
|
|
|
//[a b] [d -c]
|
|
//[c d] inverse = (1 / determinant) * [-b a] where determinant is (ad - bc)
|
|
|
|
//[jA nD] * [imp0] = [dv0]
|
|
//[nD jB] [imp1] [dv1]
|
|
|
|
if (imp0 > btScalar(0.0))
|
|
{
|
|
if (imp1 > btScalar(0.0))
|
|
{
|
|
//both positive
|
|
}
|
|
else
|
|
{
|
|
imp1 = btScalar(0.);
|
|
|
|
// now imp0>0 imp1<0
|
|
imp0 = dv0 / jacA.getDiagonal();
|
|
if (imp0 > btScalar(0.0))
|
|
{
|
|
}
|
|
else
|
|
{
|
|
imp0 = btScalar(0.);
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
imp0 = btScalar(0.);
|
|
|
|
imp1 = dv1 / jacB.getDiagonal();
|
|
if (imp1 <= btScalar(0.0))
|
|
{
|
|
imp1 = btScalar(0.);
|
|
// now imp0>0 imp1<0
|
|
imp0 = dv0 / jacA.getDiagonal();
|
|
if (imp0 > btScalar(0.0))
|
|
{
|
|
}
|
|
else
|
|
{
|
|
imp0 = btScalar(0.);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
void btSolve2LinearConstraint::resolveAngularConstraint( const btMatrix3x3& invInertiaAWS,
|
|
const btScalar invMassA,
|
|
const btVector3& linvelA,const btVector3& angvelA,
|
|
const btVector3& rel_posA1,
|
|
const btMatrix3x3& invInertiaBWS,
|
|
const btScalar invMassB,
|
|
const btVector3& linvelB,const btVector3& angvelB,
|
|
const btVector3& rel_posA2,
|
|
|
|
btScalar depthA, const btVector3& normalA,
|
|
const btVector3& rel_posB1,const btVector3& rel_posB2,
|
|
btScalar depthB, const btVector3& normalB,
|
|
btScalar& imp0,btScalar& imp1)
|
|
{
|
|
|
|
}
|
|
*/
|