Expose Additional Masks in the Fortran Interface

[Andris-R]

Would it be possible to expose the Fine Mask, Point Mask, and Overlap Mask creation routines through the Fortran interface?
At the moment, only the Owner Mask is available. Having the other mask functionality available from Fortran as well would be very helpful.

[Andris-R]

This is the prototype I came up with for creating a fine mask. The code compiles and runs, but I haven't verified the output yet.

I'd really appreciate any feedback, as I'm not a C++ developer and I'm still getting familiar with AMReX's internals.

Once I've finished implementing and validating the fine mask, I plan to submit a pull request.

I'd also appreciate any suggestions on how best to test the code.

  subroutine amrex_imultifab_build_fine_mask (msk, cba, cdm, fba, rr, crse_value, fine_value)
    type(amrex_imultifab), intent(inout) :: msk
    type(amrex_boxarray), intent(in) :: cba
    type(amrex_distromap), intent(in) :: cdm
    type(amrex_boxarray), intent(in) :: fba
    integer, intent(in) :: rr
    integer, intent(in) :: crse_value
    integer, intent(in) :: fine_value
    call amrex_imultifab_destroy(msk)
    msk%owner = .true.
    msk%nc = 1
    msk%ng(1:ndims) = 0
    msk%ba = cba
    msk%dm = cdm
    call amrex_fi_new_fine_imultifab(msk%p, msk%ba%p, msk%dm%p, fba%p, rr, crse_value, fine_value)
  end subroutine amrex_imultifab_build_fine_mask

    void amrex_fi_new_fine_imultifab (iMultiFab*& msk, const BoxArray*& cba, const DistributionMapping*& cdm, const BoxArray*& fba, int rr, int crse_value, int fine_value)
    {
        msk = new iMultiFab(makeFineMask(*cba, *cdm, *fba, IntVect{AMREX_D_DECL(rr,rr,rr)}, crse_value, fine_value));
        cba = &(msk->boxArray());
        cdm = &(msk->DistributionMap());
    }