// -----------------------------------------------------------------------------
// COPY STATE BACK TO CPU FROM OPENMM
// -----------------------------------------------------------------------------
static void
myGetOpenMMState(MyOpenMMData* omm, bool wantEnergy,
double& timeInPs, double& energyInKcal,
MyAtomInfo atoms[])
{
int infoMask = 0;
infoMask = OpenMM::State::Positions;
if (wantEnergy) {
infoMask += OpenMM::State::Velocities; // for kinetic energy (cheap)
infoMask += OpenMM::State::Energy; // for pot. energy (expensive)
}
// Forces are also available (and cheap).
const OpenMM::State state = omm->context->getState(infoMask);
timeInPs = state.getTime(); // OpenMM time is in ps already
// Copy OpenMM positions into atoms array and change units from nm to Angstroms.
const std::vector<Vec3>& positionsInNm = state.getPositions();
for (int i=0; i < (int)positionsInNm.size(); ++i)
for (int j=0; j < 3; ++j)
atoms[i].posInAng[j] = positionsInNm[i][j] * OpenMM::AngstromsPerNm;
// If energy has been requested, obtain it and convert from kJ to kcal.
energyInKcal = 0;
if (wantEnergy)
energyInKcal = (state.getPotentialEnergy() + state.getKineticEnergy())
* OpenMM::KcalPerKJ;
}
// -----------------------------------------------------------------------------
// COPY STATE BACK TO CPU FROM OPENMM
// -----------------------------------------------------------------------------
static void
myGetOpenMMState(MyOpenMMData* omm, double& timeInPs,
std::vector<double>& atomPositionsInAng)
{
const OpenMM::State state = omm->context->getState(OpenMM::State::Positions, true);
timeInPs = state.getTime(); // OpenMM time is in ps already
// Copy OpenMM positions into output array and change units from nm to Angstroms.
const std::vector<Vec3>& positionsInNm = state.getPositions();
atomPositionsInAng.resize(3*positionsInNm.size());
for (int i=0; i < (int)positionsInNm.size(); ++i)
for (int j=0; j < 3; ++j)
atomPositionsInAng[3*i+j] = positionsInNm[i][j] * OpenMM::AngstromsPerNm;
}