add_ghostFromFiner Subroutine

  recursive subroutine add_ghostFromFiner( elemID, levelDesc, minLevel,     &
    &                                      tree, updated, foundPos, stencil )
    ! -------------------------------------------------------------------- !
    !> requested treeID
    integer(kind=long_k), intent(in) :: elemID
    !> minimum level fluid element in the tree
    integer, intent(in) :: minLevel
    !> the level descriptor to be filled
    type(tem_levelDesc_type), intent(inout) :: levelDesc(minLevel:)
    !> tree information
    type(treelmesh_type), intent(in) :: tree
    ! position of elemID in elem%tID list
    integer, intent(out) :: foundPos
    !> was the current element updated in this call?
    logical, intent(out) :: updated
    !> current stencil definition
    type( tem_stencilHeader_type ), intent(in) :: stencil
    ! -------------------------------------------------------------------- !
    integer :: iChild, level
    integer(kind=long_k) :: children(8), property
    logical :: wasAdded, childUpdated
    integer :: childPos(8)
    type(tem_path_type) :: childPath
    ! -------------------------------------------------------------------- !
    ! Set as not updated by default
    updated = .false.

    ! Create the ghostFromFiner
    level = tem_LevelOf( elemID )
    call append( me         = levelDesc( level )%elem, &
      &          tID        = elemID,                  &
      &          eType      = eT_ghostFromFiner,       &
      &          property   = 0_long_k,                &
      &          sourceProc = tree%global%myPart+1,    &
      &          pos        = foundPos,                &
      &          wasAdded   = wasAdded                 )

    if( wasAdded ) then

      updated = .true.
      children = tem_directChildren( elemID )
      childPos = 0 ! reset child positions. non-existing children are 0
      ! reset property
      property = 0_long_k
      ! if added elemID is more than level coarser than available child treeID
      ! in original treeID list then add all children between level and
      ! neighLevel
      do iChild = 1, 8

        ! Return position in the treeIDlist
        childPath  = tem_PathOf( children( iChild ))
        childPos( iChild ) = tem_PosOfPath( childPath, tree%pathList )

        if( childPos( iChild ) < 0 ) then
           ! This child does NOT exists, recusively add it as a ghostFromFiner.
           call add_ghostFromFiner( elemID    = children( iChild ),    &
             &                      levelDesc = levelDesc,             &
             &                      minLevel  = minlevel,              &
             &                      tree      = tree,                  &
             &                      foundPos  = childPos( iChild ),    &
             &                      updated   = childUpdated,          &
             &                      stencil   = stencil                )
           ! Unify all properties of the children
           property = ieor( property,                  &
             &              levelDesc(level+1)         &
             &                %elem                    &
             &                %property                &
             &                %val( childPos(iChild) ) )
           updated = ( updated .or. childUpdated )
        else
          ! This child is a Fluid, i.e. already exists in element list
          childPos( iChild ) = PositionOfVal( &
            &   levelDesc( level+1 )%elem%tID, children(iChild) )
        end if
      end do ! iChild = 1, 8

      ! Now reconstruct current element's neighborhood
      ! based on the children's information
      call tem_find_BCs_fromFiner( childPos     = childPos,   &
        &                          sourceLevel  = level + 1,  &
        &                          targetLevel  = level,      &
        &                          targetPos    = foundPos,   &
        &                          levelDesc    = levelDesc,  &
        &                          minLevel     = minLevel,   &
        &                          stencil      = stencil     )

    else
      ! ghostFromFiner element was not added
      ! Hence, we found available information which now has to be returned
      updated = .false.
    end if

  end subroutine add_ghostFromFiner