evaluate_FOAG_spacetime_scalarByTreeID Subroutine

  recursive subroutine evaluate_FOAG_spacetime_scalarByTreeID( fun, varsys, &
    & elempos, time, tree, nElems, nDofs, res                               )
    !--------------------------------------------------------------------------!
    !> Description of the method to obtain the variables, here some preset
    !! values might be stored, like the space time function to use or the
    !! required variables.
    class(tem_varSys_op_type), intent(in) :: fun

    !> The variable system to obtain the variable from.
    type(tem_varSys_type), intent(in) :: varSys

    !> Position of the TreeID of the element to get the variable for in the
    !! global treeID list.
    integer, intent(in) :: elempos(:)

    !> Point in time at which to evaluate the variable.
    type(tem_time_type), intent(in)  :: time

    !> global treelm mesh info
    type(treelmesh_type), intent(in) :: tree

    !> Number of values to obtain for this variable (vectorized access).
    integer, intent(in) :: nElems

    !> Number of degrees of freedom within an element.
    integer, intent(in) :: nDofs

    !> Resulting values for the requested variable.
    !!
    !! Linearized array dimension:
    !! (n requested entries) x (nComponents of this variable)
    !! x (nDegrees of freedom)
    !! Access: (iElem-1)*fun%nComponents*nDofs +
    !!         (iDof-1)*fun%nComponents + iComp
    real(kind=rk), intent(out) :: res(:)
    !--------------------------------------------------------------------------!
    ! --------------------------------------------------------------------------
    type(tem_st_fun_listElem_type), pointer :: fPtr
    ! -------------------------------------------------------------------------!
    !call C_F_POINTER( fun%method_Data, fPtr )
    ! avoid compiler warning about unused varsys
    call C_F_POINTER( varsys%method%val(fun%mypos)%method_Data, fPtr )

    ! assuming nDofs = 1
    if (nDofs > 1) then
      write(logUnit(1),*) 'Spacetime function does not support nDofs>1'
      call tem_abort()
    end if

    res(:) = tem_spacetime_for( me      = fPtr%val(1),             &
         &                      treeIDs = tree%treeID(elemPos(:)), &
         &                      tree    = tree,                    &
         &                      time    = time,                    &
         &                      n       = nElems                   )

  end subroutine evaluate_FOAG_spacetime_scalarByTreeID