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/******************************************************************************
* SOFA, Simulation Open-Framework Architecture, version 1.0 beta 4 *
* (c) 2006-2009 MGH, INRIA, USTL, UJF, CNRS *
* *
* This library is free software; you can redistribute it and/or modify it *
* under the terms of the GNU Lesser General Public License as published by *
* the Free Software Foundation; either version 2.1 of the License, or (at *
* your option) any later version. *
* *
* This library is distributed in the hope that it will be useful, but WITHOUT *
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or *
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License *
* for more details. *
* *
* You should have received a copy of the GNU Lesser General Public License *
* along with this library; if not, write to the Free Software Foundation, *
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. *
*******************************************************************************
* SOFA :: Modules *
* *
* Authors: The SOFA Team and external contributors (see Authors.txt) *
* *
* Contact information: contact@sofa-framework.org *
******************************************************************************/
#include <sofa/component/odesolver/EulerSolver.h>
#include <sofa/helper/Quater.h>
#include <sofa/core/ObjectFactory.h>
#include <math.h>
#include <iostream>
#define SOFA_NO_VMULTIOP
namespace sofa
{
namespace component
{
namespace odesolver
{
using namespace sofa::defaulttype;
using namespace sofa::helper;
using namespace core::componentmodel::behavior;
int EulerSolverClass = core::RegisterObject("A simple explicit time integrator")
.add< EulerSolver >()
.addAlias("Euler")
.addAlias("EulerExplicit")
.addAlias("ExplicitEuler")
.addAlias("EulerExplicitSolver")
.addAlias("ExplicitEulerSolver")
;
SOFA_DECL_CLASS(Euler);
EulerSolver::EulerSolver()
:
symplectic( initData( &symplectic, true, "symplectic", "If true, the velocities are updated before the positions and the method is symplectic (more robust). If false, the positions are updated before the velocities (standard Euler, less robust).") )
{
}
typedef simulation::Node::ctime_t ctime_t;
void EulerSolver::solve(double dt)
{
MultiVector pos(this, VecId::position());
MultiVector vel(this, VecId::velocity());
MultiVector acc(this, VecId::dx());
MultiVector f(this, VecId::force());
//---------------------------------------------------------------
//DEBUGGING TOOLS
// bool printLog = f_printLog.getValue();
//---------------------------------------------------------------
addSeparateGravity(dt); // v += dt*g . Used if mass wants to added G separately from the other forces to v.
computeForce(f);
// if( printLog )
// {
// serr<<"EulerSolver, dt = "<< dt <<sendl;
// serr<<"EulerSolver, initial x = "<< pos <<sendl;
// serr<<"EulerSolver, initial v = "<< vel <<sendl;
// serr<<"EulerSolver, f = "<< f <<sendl;
// }
accFromF(acc, f);
projectResponse(acc);
// if( printLog )
// {
// serr<<"EulerSolver, a = "<< acc <<sendl;
// }
#ifdef SOFA_HAVE_LAPACK
if (constraintAcc.getValue())
{
solveConstraint(VecId::dx());
}
#endif
// update state
#ifdef SOFA_NO_VMULTIOP // unoptimized version
if( symplectic.getValue() )
{
vel.peq(acc,dt);
#ifdef SOFA_HAVE_LAPACK
if (constraintVel.getValue())
{
solveConstraint(VecId::velocity());
}
#endif
pos.peq(vel,dt);
#ifdef SOFA_HAVE_LAPACK
if (constraintPos.getValue())
{
solveConstraint(VecId::position(),!constraintVel.getValue());
}
#endif
}
else
{
pos.peq(vel,dt);
#ifdef SOFA_HAVE_LAPACK
bool propagateCorrectOfPositionOnVelocity = !constraintVel.getValue();
solveConstraint(VecId::position(), propagateCorrectOfPositionOnVelocity);
if (propagateCorrectOfPositionOnVelocity)
{
simulation::MechanicalPropagatePositionAndVelocityVisitor propPosAndVelocity;
propPosAndVelocity.execute(this->getContext());
}
else
{
simulation::MechanicalPropagatePositionVisitor propPos;
propPos.execute(this->getContext());
}
#endif
vel.peq(acc,dt);
#ifdef SOFA_HAVE_LAPACK
if (constraintVel.getValue())
{
solveConstraint(VecId::velocity());
}
#endif
}
#else // single-operation optimization
{
typedef core::componentmodel::behavior::BaseMechanicalState::VMultiOp VMultiOp;
VMultiOp ops;
ops.resize(2);
// change order of operations depending on the sympletic flag
int op_vel = (symplectic.getValue()?0:1);
int op_pos = (symplectic.getValue()?1:0);
ops[op_vel].first = (VecId)vel;
ops[op_vel].second.push_back(std::make_pair((VecId)vel,1.0));
ops[op_vel].second.push_back(std::make_pair((VecId)acc,dt));
ops[op_pos].first = (VecId)pos;
ops[op_pos].second.push_back(std::make_pair((VecId)pos,1.0));
ops[op_pos].second.push_back(std::make_pair((VecId)vel,dt));
simulation::MechanicalVMultiOpVisitor vmop(ops);
vmop.execute(this->getContext());
#ifdef SOFA_HAVE_LAPACK
applyConstraints();
#endif
}
#endif
// if( printLog )
// {
// serr<<"EulerSolver, final x = "<< pos <<sendl;
// serr<<"EulerSolver, final v = "<< vel <<sendl;
// }
}
} // namespace odesolver
} // namespace component
} // namespace sofa
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