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             : /// @}