* vertices within a cell. If false (the default), then use the "old-style"
* ordering of vertices within cells used by deal.II before version 5.2 and
* as explained in the documentation of this class.
+ *
+ * @deprecated Use GridTools::invert_all_negative_measure_cells() instead.
*/
+ DEAL_II_DEPRECATED_EARLY
static void
invert_all_cells_of_negative_grid(
const std::vector<Point<spacedim>> &all_vertices,
std::vector<unsigned int> & considered_vertices,
const double tol = 1e-12);
+ /**
+ * Grids generated by grid generators may have an orientation of cells which
+ * is the inverse of the orientation required by deal.II.
+ *
+ * In 2d and 3d this function checks whether all cells have negative or
+ * positive measure/volume. In the former case, all cells are inverted. It
+ * does nothing in 1d.
+ *
+ * The inversion of cells might also work when only a subset of all cells
+ * have negative volume. However, grids consisting of a mixture of negative
+ * and positively oriented cells are very likely to be broken. Therefore, an
+ * exception is thrown, in case cells are not uniformly oriented.
+ *
+ * @note This function should be called before GridTools::consistently_order_cells().
+ *
+ * @param all_vertices The vertices of the mesh.
+ * @param cells The array of CellData objects that describe the mesh's topology.
+ */
+ template <int dim, int spacedim>
+ void
+ invert_all_negative_measure_cells(
+ const std::vector<Point<spacedim>> &all_vertices,
+ std::vector<CellData<dim>> & cells);
+
/*@}*/
/**
* @name Rotating, stretching and otherwise transforming meshes
cells[n_cells - 1].vertices[GeometryInfo<3>::ucd_to_deal[7]] =
(1 + n_rotations) % 4;
- GridReordering<dim>::invert_all_cells_of_negative_grid(vertices,
- cells,
- true);
+ GridTools::invert_all_negative_measure_cells(vertices, cells);
tria.create_triangulation(vertices, cells, SubCellData());
}
// TODO: the functions below (GridTools::delete_unused_vertices(),
- // GridTools::invert_all_cells_of_negative_grid(),
+ // GridTools::invert_all_negative_measure_cells(),
// GridReordering::reorder_cells()) need to be
// revisited for simplex/mixed meshes
GridTools::delete_unused_vertices(vertices, cells, subcelldata);
if (dim == spacedim)
- GridReordering<dim, spacedim>::invert_all_cells_of_negative_grid(
- vertices, cells, true);
+ GridTools::invert_all_negative_measure_cells(vertices, cells);
GridReordering<dim, spacedim>::reorder_cells(cells, true);
tria->create_triangulation(vertices, cells, subcelldata);
GridTools::delete_unused_vertices(vertices, cells, subcelldata);
if (dim == spacedim)
- GridReordering<dim, spacedim>::invert_all_cells_of_negative_grid(vertices,
- cells,
- true);
+ GridTools::invert_all_negative_measure_cells(vertices, cells);
GridReordering<dim, spacedim>::reorder_cells(cells, true);
GridTools::delete_unused_vertices(vertices, cells, subcelldata);
// ... and cells
if (dim == spacedim)
- GridReordering<dim, spacedim>::invert_all_cells_of_negative_grid(vertices,
- cells,
- true);
+ GridTools::invert_all_negative_measure_cells(vertices, cells);
GridReordering<dim, spacedim>::reorder_cells(cells, true);
tria->create_triangulation(vertices, cells, subcelldata);
}
// do some clean-up on vertices...
GridTools::delete_unused_vertices(vertices, cells, subcelldata);
// ...and cells
- GridReordering<dim, spacedim>::invert_all_cells_of_negative_grid(vertices,
- cells,
- true);
+ GridTools::invert_all_negative_measure_cells(vertices, cells);
GridReordering<dim, spacedim>::reorder_cells(cells, true);
tria->create_triangulation(vertices, cells, subcelldata);
}
// do some clean-up on vertices...
GridTools::delete_unused_vertices(vertices, cells, subcelldata);
// ... and cells
- GridReordering<dim, spacedim>::invert_all_cells_of_negative_grid(vertices,
- cells,
- true);
+ GridTools::invert_all_negative_measure_cells(vertices, cells);
GridReordering<dim>::reorder_cells(cells, true);
tria->create_triangulation(vertices, cells, subcelldata);
}
AssertThrow(cells.size() > 0, ExcGmshNoCellInformation());
// TODO: the functions below (GridTools::delete_unused_vertices(),
- // GridTools::invert_all_cells_of_negative_grid(),
+ // GridTools::invert_all_negative_measure_cells(),
// GridReordering::reorder_cells()) need to be revisited
// for simplex/mixed meshes
GridTools::delete_unused_vertices(vertices, cells, subcelldata);
// ... and cells
if (dim == spacedim)
- GridReordering<dim, spacedim>::invert_all_cells_of_negative_grid(
- vertices, cells, true);
+ GridTools::invert_all_negative_measure_cells(vertices, cells);
GridReordering<dim, spacedim>::reorder_cells(cells, true);
}
tria->create_triangulation(vertices, cells, subcelldata);
AssertThrow(in, ExcIO());
// do some cleanup on cells
- GridReordering<dim, spacedim>::invert_all_cells_of_negative_grid(vertices,
- cells,
- true);
+ GridTools::invert_all_negative_measure_cells(vertices, cells);
GridReordering<dim, spacedim>::reorder_cells(cells, true);
tria->create_triangulation(vertices, cells, subcelldata);
}
GridTools::delete_unused_vertices(vertices, cells, subcelldata);
if (dim == spacedim)
- GridReordering<dim, spacedim>::invert_all_cells_of_negative_grid(vertices,
- cells,
- true);
+ GridTools::invert_all_negative_measure_cells(vertices, cells);
GridReordering<dim, spacedim>::reorder_cells(cells, true);
tria->create_triangulation(vertices, cells, subcelldata);
std::vector<CellData<2>> & cells,
const bool use_new_style_ordering)
{
- unsigned int vertices_lex[GeometryInfo<2>::vertices_per_cell];
- unsigned int n_negative_cells = 0;
-
- // GridTools::cell_measure requires the vertices to be in lexicographic
- // ordering
- auto copy_vertices_to_temp = [&](const CellData<2> &cell) {
- if (use_new_style_ordering)
- {
- std::copy(cell.vertices.begin(),
- cell.vertices.end(),
- std::begin(vertices_lex));
- }
- else
- {
- for (const unsigned int i : GeometryInfo<2>::vertex_indices())
- vertices_lex[GeometryInfo<2>::ucd_to_deal[i]] = cell.vertices[i];
- }
- };
+ if (!use_new_style_ordering)
+ reorder_old_to_new_style(cells);
- for (auto &cell : cells)
- {
- copy_vertices_to_temp(cell);
- if (GridTools::cell_measure<2>(all_vertices, vertices_lex) < 0)
- {
- ++n_negative_cells;
- if (use_new_style_ordering)
- std::swap(cell.vertices[1], cell.vertices[2]);
- else
- std::swap(cell.vertices[1], cell.vertices[3]);
-
- // Check whether the resulting cell is now ok.
- // If not, then the grid is seriously broken and
- // we just give up.
- copy_vertices_to_temp(cell);
- AssertThrow(GridTools::cell_measure<2>(all_vertices, vertices_lex) >
- 0,
- ExcInternalError());
- }
- }
+ GridTools::invert_all_negative_measure_cells(all_vertices, cells);
- // We assume that all cells of a grid have
- // either positive or negative volumes but
- // not both mixed. Although above reordering
- // might work also on single cells, grids
- // with both kind of cells are very likely to
- // be broken. Check for this here.
- AssertThrow(
- n_negative_cells == 0 || n_negative_cells == cells.size(),
- ExcMessage(
- std::string("This class assumes that either all cells have positive "
- "volume, or that all cells have been specified in an "
- "inverted vertex order so that their volume is negative. "
- "(In the latter case, this class automatically inverts "
- "every cell.) However, the mesh you have specified "
- "appears to have both cells with positive and cells with "
- "negative volume. You need to check your mesh which "
- "cells these are and how they got there.\n"
- "As a hint, of the total ") +
- std::to_string(cells.size()) + " cells in the mesh, " +
- std::to_string(n_negative_cells) + " appear to have a negative volume."));
+ if (!use_new_style_ordering)
+ reorder_new_to_old_style(cells);
}
std::vector<CellData<3>> & cells,
const bool use_new_style_ordering)
{
- unsigned int vertices_lex[GeometryInfo<3>::vertices_per_cell];
- unsigned int n_negative_cells = 0;
-
- // GridTools::cell_measure requires the vertices to be in lexicographic
- // ordering
- auto copy_vertices_to_temp = [&](const CellData<3> &cell) {
- if (use_new_style_ordering)
- {
- std::copy(cell.vertices.begin(),
- cell.vertices.end(),
- std::begin(vertices_lex));
- }
- else
- {
- for (const unsigned int i : GeometryInfo<3>::vertex_indices())
- vertices_lex[GeometryInfo<3>::ucd_to_deal[i]] = cell.vertices[i];
- }
- };
+ if (!use_new_style_ordering)
+ reorder_old_to_new_style(cells);
- for (auto &cell : cells)
- {
- copy_vertices_to_temp(cell);
- if (GridTools::cell_measure<3>(all_vertices, vertices_lex) < 0)
- {
- ++n_negative_cells;
- // reorder vertices: swap front and back face
- if (use_new_style_ordering)
- {
- std::swap(cell.vertices[0], cell.vertices[2]);
- std::swap(cell.vertices[1], cell.vertices[3]);
- std::swap(cell.vertices[4], cell.vertices[6]);
- std::swap(cell.vertices[5], cell.vertices[7]);
- }
- else
- {
- for (unsigned int i = 0; i < 4; ++i)
- std::swap(cell.vertices[i], cell.vertices[i + 4]);
- }
- copy_vertices_to_temp(cell);
-
- // Check whether the resulting cell is now ok.
- // If not, then the grid is seriously broken and
- // we just give up.
- AssertThrow(GridTools::cell_measure<3>(all_vertices, vertices_lex) >
- 0,
- ExcInternalError());
- }
- }
+ GridTools::invert_all_negative_measure_cells(all_vertices, cells);
- // We assume that all cells of a
- // grid have either positive or
- // negative volumes but not both
- // mixed. Although above reordering
- // might work also on single cells,
- // grids with both kind of cells
- // are very likely to be
- // broken. Check for this here.
- AssertThrow(n_negative_cells == 0 || n_negative_cells == cells.size(),
- ExcMessage("While sorting the cells that will be passed for "
- "creating a Triangulation object, deal.II found that "
- "some but not all cells have a negative volume. (If "
- "all cells had a negative volume, they would simply "
- "all have been inverted.) This usually happens in "
- "hand-generated meshes if one accidentally uses an "
- "incorrect convention for ordering the vertices in "
- "one or more cells; in that case, you may want to "
- "double check that you specified the vertex indices "
- "in their correct order. If you are reading a mesh "
- "that was created by a mesh generator, then this "
- "exception indicates that some of the cells created "
- "are so badly distorted that their volume becomes "
- "negative; this commonly occurs at complex geometric "
- "features, and you may see if the problem can be "
- "fixed by playing with the parameters that control "
- "mesh properties in your mesh generator, such as "
- "the number of cells, the mesh density, etc."));
+ if (!use_new_style_ordering)
+ reorder_new_to_old_style(cells);
}
+ template <int dim, int spacedim>
+ void
+ invert_all_negative_measure_cells(
+ const std::vector<Point<spacedim>> &all_vertices,
+ std::vector<CellData<dim>> & cells)
+ {
+ if (dim == 1)
+ return;
+ if (dim == 2 && spacedim == 3)
+ Assert(false, ExcNotImplemented());
+
+ std::size_t n_negative_cells = 0;
+ for (auto &cell : cells)
+ {
+ Assert(cell.vertices.size() ==
+ ReferenceCells::get_hypercube<dim>().n_vertices(),
+ ExcNotImplemented());
+ const ArrayView<const unsigned int> vertices(cell.vertices);
+ if (GridTools::cell_measure<dim>(all_vertices, vertices) < 0)
+ {
+ ++n_negative_cells;
+
+ // TODO: this only works for quads and hexes
+ if (dim == 2)
+ {
+ // flip the cell across the y = x line in 2D
+ std::swap(cell.vertices[1], cell.vertices[2]);
+ }
+ else if (dim == 3)
+ {
+ // swap the front and back faces in 3D
+ std::swap(cell.vertices[0], cell.vertices[2]);
+ std::swap(cell.vertices[1], cell.vertices[3]);
+ std::swap(cell.vertices[4], cell.vertices[6]);
+ std::swap(cell.vertices[5], cell.vertices[7]);
+ }
+
+ // Check whether the resulting cell is now ok.
+ // If not, then the grid is seriously broken and
+ // we just give up.
+ AssertThrow(GridTools::cell_measure<dim>(all_vertices, vertices) >
+ 0,
+ ExcInternalError());
+ }
+ }
+
+ // We assume that all cells of a grid have
+ // either positive or negative volumes but
+ // not both mixed. Although above reordering
+ // might work also on single cells, grids
+ // with both kind of cells are very likely to
+ // be broken. Check for this here.
+ AssertThrow(n_negative_cells == 0 || n_negative_cells == cells.size(),
+ ExcMessage(
+ std::string(
+ "This function assumes that either all cells have positive "
+ "volume, or that all cells have been specified in an "
+ "inverted vertex order so that their volume is negative. "
+ "(In the latter case, this class automatically inverts "
+ "every cell.) However, the mesh you have specified "
+ "appears to have both cells with positive and cells with "
+ "negative volume. You need to check your mesh which "
+ "cells these are and how they got there.\n"
+ "As a hint, of the total ") +
+ std::to_string(cells.size()) + " cells in the mesh, " +
+ std::to_string(n_negative_cells) +
+ " appear to have a negative volume."));
+ }
+
+
+
// define some transformations
namespace internal
{
std::vector<unsigned int> &,
double);
+ template void
+ invert_all_negative_measure_cells(
+ const std::vector<Point<deal_II_space_dimension>> &,
+ std::vector<CellData<deal_II_dimension>> &);
+
template void
shift<deal_II_dimension>(
const Tensor<1, deal_II_space_dimension> &,
projects / dealii.git / commitdiff