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// TODO include statements
FiniteDifferenceSolver::EvolveB ( VectorField Bfield,
ConstVectorField Efield,
amrex::Real dt ) {
// Select algorithm (The choice of algorithm is a runtime option,
// but we compile code for each algorithm, using templates)
if (fdtd_algo == MaxwellSolverAlgo::Yee){
EvolveB <YeeAlgorithm> ( Bfield, Efield, dt );
} else if (fdtd_algo == MaxwellSolverAlgo::CKC) {
EvolveB <CKCAlgorithm> ( Bfield, Efield, dt );
} else {
amrex::Abort("Unknown algorithm");
}
)
template<typename algo>
FiniteDifferenceSolver::EvolveB ( VectorField Bfield,
ConstVectorField Efield,
amrex::Real dt ) {
// Loop through the grids, and over the tiles within each grid
#ifdef _OPENMP
#pragma omp parallel if (Gpu::notInLaunchRegion())
#endif
for ( MFIter mfi(*Bx, TilingIfNotGPU()); mfi.isValid(); ++mfi ) {
// Extract field data for this grid/tile
auto const& Bx = Bfield[0]->array(mfi);
auto const& By = Bfield[1]->array(mfi);
auto const& Bz = Bfield[2]->array(mfi);
auto const& Ex = Efield[0]->array(mfi);
auto const& Ey = Efield[1]->array(mfi);
auto const& Ez = Efield[2]->array(mfi);
// Extract stencil coefficients
Real const* AMREX_RESTRICT coefs_x = stencil_coefs_x.dataPtr();
Real const* AMREX_RESTRICT coefs_y = stencil_coefs_y.dataPtr();
Real const* AMREX_RESTRICT coefs_z = stencil_coefs_z.dataPtr();
// Extract tileboxes for which to loop
const Box& tbx = mfi.tilebox(Bx_nodal_flag);
const Box& tby = mfi.tilebox(By_nodal_flag);
const Box& tbz = mfi.tilebox(Bz_nodal_flag);
// Loop over the cells and update the fields
amrex::ParallelFor(tbx, tby, tbz,
[=] AMREX_GPU_DEVICE (int i, int j, int k){
Bx(i, j, k) += dt * algo::UpwardDz( Ey, i, j, k, coefs_z)
- dt * algo::UpwardDy( Ez, i, j, k, coefs_y);
},
[=] AMREX_GPU_DEVICE (int i, int j, int k){
By(i, j, k) += dt * algo::UpwardDx( Ez, i, j, k, coefs_x)
- dt * algo::UpwardDz( Ex, i, j, k, coefs_z);
},
[=] AMREX_GPU_DEVICE (int i, int j, int k){
Bz(i, j, k) += dt * algo::UpwardDy( Ex, i, j, k, coefs_y)
- dt * algo::UpwardDx( Ey, i, j, k, coefs_x);
}
);
}
};
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