Do Not Fill Guard Cells with Inverse FFTs, Unless for Field Damping (#2045)

* Do Not Always Fill Guard Cells with Inverse FFTs

* Query psatd.fill_guards from Inputs

* Clean Up and Reduce Style Changes

* Fix Bug for Periodic Single Box

* Clean Up and Reduce Style Changes

* Fix Bug for RZ PSATD

* Remove Input Parameter, Default 0 Unless Damping

* Fix CI Tests (2D)

* Fix CI Tests (3D)

1 files changed, 6 insertions, 2 deletions

diff --git a/Source/FieldSolver/SpectralSolver/SpectralAlgorithms/SpectralBaseAlgorithm.cpp b/Source/FieldSolver/SpectralSolver/SpectralAlgorithms/SpectralBaseAlgorithm.cpp
index e57302cc4..4445705cb 100644
--- a/Source/FieldSolver/SpectralSolver/SpectralAlgorithms/SpectralBaseAlgorithm.cpp
+++ b/Source/FieldSolver/SpectralSolver/SpectralAlgorithms/SpectralBaseAlgorithm.cpp
@@ -30,8 +30,10 @@ using namespace amrex;
 SpectralBaseAlgorithm::SpectralBaseAlgorithm(const SpectralKSpace& spectral_kspace,
     const amrex::DistributionMapping& dm,
     const int norder_x, const int norder_y,
-    const int norder_z, const bool nodal):
+    const int norder_z, const bool nodal,
+    const amrex::IntVect& fill_guards):
     // Compute and assign the modified k vectors
+        m_fill_guards(fill_guards),
         modified_kx_vec(spectral_kspace.getModifiedKComponent(dm,0,norder_x,nodal)),
 #if (AMREX_SPACEDIM==3)
         modified_ky_vec(spectral_kspace.getModifiedKComponent(dm,1,norder_y,nodal)),
@@ -62,6 +64,8 @@ SpectralBaseAlgorithm::ComputeSpectralDivE (
     field_data.ForwardTransform(lev, *Efield[1], Idx::Ey, 0 );
     field_data.ForwardTransform(lev, *Efield[2], Idx::Ez, 0 );
 
+    const amrex::IntVect& fill_guards = m_fill_guards;
+
     // Loop over boxes
     for (MFIter mfi(field_data.fields); mfi.isValid(); ++mfi){
 
@@ -101,5 +105,5 @@ SpectralBaseAlgorithm::ComputeSpectralDivE (
     }
 
     // Backward Fourier transform
-    field_data.BackwardTransform(lev, divE, Idx::divE, 0 );
+    field_data.BackwardTransform(lev, divE, Idx::divE, 0, fill_guards);
 }