} 100

} 128

} 100

} 128

} 100

} 128

#include <AMReX_BCRec.H>

#include <cmath>
#include <iostream>

  const int nlevels = 2;
  ghext->leveldata.resize(nlevels);
  for (int level = 0; level < nlevels; ++level) {
    GHExt::LevelData &leveldata = ghext->leveldata.at(level);
    leveldata.level = level;

  // Domain
  const RealBox domain({AMREX_D_DECL(xmin, ymin, zmin)},
                       {AMREX_D_DECL(xmax, ymax, zmax)});
  // Maximum number of levels
  const int maxlevels = 1;
  // Number of coarse grid cells
  const Vector<int> ncells{ncells_x, ncells_y, ncells_z};
  const int coord = -1; // undefined?

    // Define box array
    IntVect box_lo(AMREX_D_DECL(0, 0, 0));
    IntVect box_hi(AMREX_D_DECL(ncells_x - 1, ncells_y - 1, ncells_z - 1));
    Box box(box_lo, box_hi);
    leveldata.grids.define(box);

  // Refinement ratios
  const Vector<IntVect> reffacts; // empty

    // Break up box array into chunks no larger than max_grid_size along
    // each direction
    const int max_grid_size = 32;
    leveldata.grids.maxSize(max_grid_size);

  // Periodic in all directions
  const Array<int, dim> periodic{1, 1, 1};

    // Define physical box
    RealBox domain({AMREX_D_DECL(xmin, ymin, zmin)},
                   {AMREX_D_DECL(xmax, ymax, zmax)});

  ghext->amrmesh = make_unique<AmrMesh>(domain, maxlevels, ncells, coord,
                                        reffacts, periodic);
  const int max_grid_size = 32;
  ghext->amrmesh->SetMaxGridSize(max_grid_size);
  ghext->amrmesh->MakeNewGrids(0.0);

    // Define geometry
    Vector<int> is_periodic(AMREX_SPACEDIM, 1); // periodic in all directions
    leveldata.geom.define(box, &domain, CoordSys::cartesian,
                          is_periodic.data());

  CCTK_VINFO("Geometry:");
  cout << ghext->amrmesh->Geom(0) << "\n";
  CCTK_VINFO("BoxArray:");
  cout << ghext->amrmesh->boxArray(0) << "\n";
  CCTK_VINFO("DistributionMap:");
  cout << ghext->amrmesh->DistributionMap(0) << "\n";

    // Distributed boxes
    leveldata.dmap = DistributionMapping(leveldata.grids);

  const int nlevels = 1;
  ghext->leveldata.resize(nlevels);
  for (int level = 0; level < nlevels; ++level) {
    GHExt::LevelData &leveldata = ghext->leveldata.at(level);
    leveldata.level = level;

            leveldata.grids, leveldata.dmap, groupdata.numvars, ghost_size);

            ghext->amrmesh->boxArray(leveldata.level),
            ghext->amrmesh->DistributionMap(leveldata.level), groupdata.numvars,
            ghost_size);

#include <AMReX_BoxArray.H>
#include <AMReX_DistributionMapping.H>
#include <AMReX_Geometry.H>

#include <AMReX_AmrMesh.H>

static_assert(
    AMREX_SPACEDIM == dim,
    "AMReX's number of dimensions must be the same as Cactus's cctk_dim");

static_assert(AMREX_SPACEDIM == dim,
              "AMReX's AMREX_SPACEDIM must be the same as Cactus's cctk_dim");

  // AMReX grid structure
  unique_ptr<AmrMesh> amrmesh;

    // AMReX grid structure
    BoxArray grids;
    Geometry geom;
    DistributionMapping dmap;

      // each MultiFab has numvars components

                                 leveldata.geom, cctk_time, cctk_iteration);

                                 ghext->amrmesh->Geom(leveldata.level),
                                 cctk_time, cctk_iteration);

  for (int d = 0; d < dim; ++d)

  for (int d = 0; d < dim; ++d) {

  for (int d = 0; d < dim; ++d)

  }

  for (int d = 0; d < dim; ++d)

  for (int d = 0; d < dim; ++d) {

  for (int d = 0; d < dim; ++d)

  }

        groupdata.mfab.at(tl)->FillBoundary(leveldata.geom.periodicity());

        groupdata.mfab.at(tl)->FillBoundary(
            ghext->amrmesh->Geom(leveldata.level).periodicity());