#include <Geometry.H>

#include <PArray.H>

#include <MultiFab.H>

//***********************************************

// This can be moved into a C++ header file and #included here instead

#include <BLFort.H>

extern "C"

{

void work_on_data(Real* data, const int* ng, const int* nc,

const int* lo, const int* hi);

}

//***********************************************

void main_main ()

{

// define a box with bounds (0,0) to (15,15) in 2D

// or a box with bounds (0,0,0) to (15,15,15) in 3D

#if (BL_SPACEDIM == 2)

IntVect lo(0,0), hi(15,15);

#elif (BL_SPACEDIM == 3)

IntVect lo(0,0,0), hi(15,15,15);

#endif

Box bx(lo,hi);

BoxArray ba(bx); // ba has one 16^2 box

ba.maxSize(8); // ba now has four 8^2 boxes

// This stores the physical coordinates of the problem domain

RealBox real_box;

for (int n = 0; n < BL_SPACEDIM; n++)

{

real_box.setLo(n,-1.0);

real_box.setHi(n, 1.0);

}

// This says we are using Cartesian coordinates

int coord = 0;

// This says the domain is periodic in each direction

int is_per[BL_SPACEDIM];

for (int i = 0; i < BL_SPACEDIM; i++)

{

is_per[i] = 1;

}

// Define a Geometry object to store problem domain physical coordinates,

// incides, coordinate system, and periodicity

Geometry geom;

geom.define(bx, &real_box, coord, is_per);

// define a multifab with 2 components and 6 ghost cells

// We use the PArray class to help manage the memory

// (auto deallocation to prevent memory leaks)

int Ncomp = 2 , Nghost = 6;

// the "1" means only 1 MultiFab; you can declare more if needed

PArray <MultiFab> data(1,PArrayManage);

// build the "0th" MultiFab in the PArray

data.set(0, new MultiFab(ba, Ncomp, Nghost));

// MFIter is a "MultiFab Iterator" that loops over

// the grids in the MultiFab

for ( MFIter mfi(data[0]); mfi.isValid(); ++mfi)

{

// get the box associated with the current grid

const Box& bx = mfi.validbox();

work_on_data((data[0])[mfi].dataPtr(), &Nghost, &Ncomp,

bx.loVect(), bx.hiVect());

}

// fill periodic domain boundary and neighboring grid ghost cells

data[0].FillBoundary(geom.periodicity());

}

int main (int argc, char* argv[])

{

BoxLib::Initialize(argc,argv);

main_main();

BoxLib::Finalize();

return 0;

}