! $Id: UserCodeMod.F90,v 1.15 2011/06/30 05:58:53 theurich Exp $
!
! Earth System Modeling Framework
! Copyright 2002-2011, University Corporation for Atmospheric Research,
! Massachusetts Institute of Technology, Geophysical Fluid Dynamics
! Laboratory, University of Michigan, National Centers for Environmental
! Prediction, Los Alamos National Laboratory, Argonne National Laboratory,
! NASA Goddard Space Flight Center.
! Licensed under the University of Illinois-NCSA License.
!
!==============================================================================

    module UserCodeMod

    use ESMF

    implicit none
    private :: countX, countY, haloWidth, nPEsX, nPEsY, distgridX, distgridY
    integer :: countX=50, countY=30
    integer :: haloWidth=2
    integer :: nPEsX=3, nPEsY=2
    integer, dimension(3) :: distgridX = (/ 10, 15, 25 /)
    integer, dimension(2) :: distgridY = (/ 12, 18 /)

    public UserGetPEDecomposition
    public UserGetIGridCoords
    public UserGetIGridDistribution
    public UserGetHalo
    public UserGetPointer2D
    public UserGetPointer3D

    contains


    subroutine UserGetPEDecomposition(x, y)
    ! dummy routine to return a logical decomposition of PEs

    integer, intent(out) :: x
    integer, intent(out) :: y

    x = nPEsX
    y = nPEsY

    end subroutine UserGetPEDecomposition


    subroutine UserGetIGridCoords(coordX, coordY)
    ! Dummy routine to return igrid axes coordinates.
    ! Please note that currently all of the ESMF_IGridCreate functions refer to
    ! counts as the number of igrid cells and not vertices, but the coordinates
    ! are defined at vertex points.  So there should be count+1 number of
    ! coordinates.

    real(ESMF_KIND_R8), dimension(:), pointer :: coordX
    real(ESMF_KIND_R8), dimension(:), pointer :: coordY

    integer :: i

    allocate(coordX(countX+1), &
             coordY(countY+1))

    coordX(1) = 0.0d0
    do i = 2, countX+1
      coordX(i) = coordX(i-1) + 1.0d0
    enddo
    coordY(1) = 0.0d0
    do i = 2, countY+1
      coordY(i) = coordY(i-1) + 2.0d0
    enddo

    end subroutine UserGetIGridCoords


    subroutine UserGetIGridDistribution(distX, distY)
    ! Dummy routine to return a distribution of igrid cells.

    integer, dimension(:), pointer :: distX
    integer, dimension(:), pointer :: distY

    allocate(distX(size(distgridX)), &
             distY(size(distgridY)))

    distX = distgridX
    distY = distgridY

    end subroutine UserGetIGridDistribution


    subroutine UserGetPointer2D(f90ptr, myX, myY)
    ! Dummy routine to return a fortran pointer, sized appropriately for this
    ! PE according to the set distribution of igrid cells and the prescribed
    ! haloWidth.

    real(ESMF_KIND_R8), dimension(:,:), pointer :: f90ptr
    integer, intent(in) :: myX
    integer, intent(in) :: myY

    allocate(f90ptr(distgridX(myX)+2*haloWidth,distgridY(myY)+2*haloWidth))
    f90ptr = 1.0d0

    end subroutine UserGetPointer2D


    subroutine UserGetPointer3D(f90ptr, myX, myY)
    ! Dummy routine to return a fortran pointer, sized appropriately for this
    ! PE according to the set distribution of igrid cells and the prescribed
    ! haloWidth.

    real(ESMF_KIND_R8), dimension(:,:,:), pointer :: f90ptr
    integer, intent(in) :: myX
    integer, intent(in) :: myY

    allocate(f90ptr(5,distgridX(myX)+2*haloWidth,distgridY(myY)+2*haloWidth))
    f90ptr = 2.0d0

    end subroutine UserGetPointer3D


    subroutine UserGetHalo(halo)
    ! Dummy routine to return a prescribed halo width.

    integer, intent(out) :: halo

    halo = haloWidth
    
    end subroutine UserGetHalo

    end module UserCodeMod