Method add_geometry_data

cpp/dolfinx/io/xdmf_mesh.cpp:163–214

//-----------------------------------------------------------------------------
template <std::floating_point U>
void xdmf_mesh::add_geometry_data(MPI_Comm comm, pugi::xml_node& xml_node,
                                  hid_t h5_id, const std::string& path_prefix,
                                  const mesh::Geometry<U>& geometry)
{
  spdlog::info("Adding geometry data to node \"{}\"", xml_node.path('/'));
  auto map = geometry.index_map();
  assert(map);

  // Compute number of points (global) in mesh (equal to number of vertices
  // for affine meshes)
  const std::int64_t num_points = map->size_global();
  const std::int32_t num_points_local = map->size_local();

  // Add geometry node and attributes
  int gdim = geometry.dim();
  pugi::xml_node geometry_node = xml_node.append_child("Geometry");
  assert(geometry_node);
  assert(gdim > 0 and gdim <= 3);
  const std::string geometry_type = (gdim == 3) ? "XYZ" : "XY";
  geometry_node.append_attribute("GeometryType") = geometry_type.c_str();

  // Increase 1D to 2D because XDMF has no "X" geometry, use "XY"
  const int width = (gdim == 1) ? 2 : gdim;

  std::span<const U> _x = geometry.x();

  int num_values = num_points_local * width;
  std::vector<U> x(num_values, 0);

  if (width == 3)
    std::copy_n(_x.data(), num_values, x.begin());
  else
  {
    for (int i = 0; i < num_points_local; ++i)
    {
      std::copy_n(std::next(_x.begin(), 3 * i), gdim,
                  std::next(x.begin(), width * i));
    }
  }

  // Add geometry DataItem node
  const std::string h5_path = path_prefix + std::string("/geometry");
  const std::vector<std::int64_t> shape = {num_points, width};

  const std::int64_t num_local = num_points_local;
  std::int64_t offset = 0;
  MPI_Exscan(&num_local, &offset, 1, MPI_INT64_T, MPI_SUM, comm);
  const bool use_mpi_io = (dolfinx::MPI::size(comm) > 1);
  xdmf_utils::add_data_item(geometry_node, h5_id, h5_path,
                            std::span<const U>(x), offset, shape, "",
                            use_mpi_io);
}
//----------------------------------------------------------------------------
template <std::floating_point U>
void xdmf_mesh::add_mesh(MPI_Comm comm, pugi::xml_node& xml_node, hid_t h5_id,