Line data    Source code

       1            0 : // Distributed under the MIT License.
       2              : // See LICENSE.txt for details.
       3              : 
       4              : #pragma once
       5              : 
       6              : #include <boost/range/combine.hpp>
       7              : #include <boost/tuple/tuple.hpp>
       8              : #include <cstddef>
       9              : 
      10              : #include "DataStructures/Index.hpp"
      11              : #include "DataStructures/SliceIterator.hpp"
      12              : #include "DataStructures/Tensor/Tensor.hpp"
      13              : #include "DataStructures/Variables.hpp"
      14              : #include "Utilities/Gsl.hpp"
      15              : #include "Utilities/TMPL.hpp"
      16              : 
      17              : /// @{
      18              : /*!
      19              :  * \ingroup DataStructuresGroup
      20              :  * \brief Slices volume `Tensor`s into a `Variables`
      21              :  *
      22              :  * The slice has a constant logical coordinate in direction `sliced_dim`,
      23              :  * slicing the volume at `fixed_index` in that dimension.  For
      24              :  * example, to get the lower boundary of `sliced_dim`, pass `0` for
      25              :  * `fixed_index`; to get the upper boundary, pass
      26              :  * `extents[sliced_dim] - 1`.
      27              :  */
      28              : template <typename... TagsToSlice, size_t VolumeDim>
      29            1 : void data_on_slice(
      30              :     const gsl::not_null<Variables<tmpl::list<TagsToSlice...>>*> interface_vars,
      31              :     const Index<VolumeDim>& element_extents, const size_t sliced_dim,
      32              :     const size_t fixed_index, const typename TagsToSlice::type&... tensors) {
      33              :   const size_t interface_grid_points =
      34              :       element_extents.slice_away(sliced_dim).product();
      35              :   if (interface_vars->number_of_grid_points() != interface_grid_points) {
      36              :     *interface_vars =
      37              :         Variables<tmpl::list<TagsToSlice...>>(interface_grid_points);
      38              :   }
      39              :   for (SliceIterator si(element_extents, sliced_dim, fixed_index); si; ++si) {
      40              :     const auto lambda = [&si](auto& interface_tensor,
      41              :                               const auto& volume_tensor) {
      42              :       for (decltype(auto) interface_and_volume_tensor_components :
      43              :            boost::combine(interface_tensor, volume_tensor)) {
      44              :         boost::get<0>(
      45              :             interface_and_volume_tensor_components)[si.slice_offset()] =
      46              :             boost::get<1>(
      47              :                 interface_and_volume_tensor_components)[si.volume_offset()];
      48              :       }
      49              :       return '0';
      50              :     };
      51              :     expand_pack(lambda(get<TagsToSlice>(*interface_vars), tensors)...);
      52              :   }
      53              : }
      54              : 
      55              : template <typename... TagsToSlice, size_t VolumeDim>
      56            1 : Variables<tmpl::list<TagsToSlice...>> data_on_slice(
      57              :     const Index<VolumeDim>& element_extents, const size_t sliced_dim,
      58              :     const size_t fixed_index, const typename TagsToSlice::type&... tensors) {
      59              :   Variables<tmpl::list<TagsToSlice...>> interface_vars(
      60              :       element_extents.slice_away(sliced_dim).product());
      61              :   data_on_slice<TagsToSlice...>(make_not_null(&interface_vars), element_extents,
      62              :                                 sliced_dim, fixed_index, tensors...);
      63              :   return interface_vars;
      64              : }
      65              : /// @}