get_sph_ptr Subroutine

    subroutine get_sph_ptr(self, region_id, sph_ptr)
        class(type_material_manager), intent(inout), target :: self
        integer(int32), intent(in) :: region_id
        class(abst_sph), intent(inout), pointer :: sph_ptr
        integer(int32) :: model_index

        model_index = self%region_id_map(region_id)

        if (model_index == 0) then
            print *, "Error: Invalid region_id in get_sph_ptr:", region_id
            nullify (sph_ptr)
            call exit(-1)
        end if

        sph_ptr => self%sph(model_index)%p

    end subroutine get_sph_ptr