Merge pull request #16388 from drwells/adjust-line-dof-index-combined…

…-orientation

Use the combined orientation in another FiniteElement function.

doc/news/changes/incompatibilities/20231221DavidWells

@@ -1,6 +1,7 @@
-Changed: FiniteElement::adjust_quad_dof_index_for_face_orientation() and
-FiniteElement::face_to_cell_index() now use the standardized
-<tt>combined_orientation</tt> orientation encoding as input arguments rather
-than three booleans.
+Changed: FiniteElement::adjust_quad_dof_index_for_face_orientation(),
+FiniteElement::face_to_cell_index(), and
+FiniteElement::adjust_line_dof_index_for_line_orientation() now use the
+standardized <tt>combined_orientation</tt> orientation encoding as input
+arguments rather than one or three booleans.
 <br>
 (David Wells, 2023/12/21)

include/deal.II/fe/fe.h

@@ -1524,15 +1524,17 @@ class FiniteElement : public Subscriptor, public FiniteElementData<dim>
       ReferenceCell::default_combined_face_orientation()) const;
 
   /**
-   * For lines with non-standard line_orientation in 3d, the dofs on lines
-   * have to be permuted in order to be combined with the correct shape
-   * functions. Given a local dof @p index on a line, return the local index,
-   * if the line has non-standard line_orientation. In 2d and 1d there is no
-   * need for permutation, so the given index is simply returned.
+   * Given a local dof @p index on a line and the orientation @p
+   * combined_orientation of that line, return the local dof which accounts for
+   * @p combined_orientation.
+   *
+   * @note In both 1d and all-quadrilateral meshes in 2d all lines have the
+   * standard orientation.
    */
   unsigned int
-  adjust_line_dof_index_for_line_orientation(const unsigned int index,
-                                             const bool line_orientation) const;
+  adjust_line_dof_index_for_line_orientation(
+    const unsigned int  index,
+    const unsigned char combined_orientation) const;
 
   /**
    * Return in which of the vector components of this finite element the @p

include/deal.II/grid/tria_accessor.templates.h

@@ -1104,7 +1104,7 @@ namespace internal
        * cell->line_orientation(), 1d specialization
        */
       template <int dim, int spacedim>
-      static std::array<unsigned int, 1>
+      static std::array<unsigned char, 1>
       get_line_orientations_of_cell(const TriaAccessor<1, dim, spacedim> &)
       {
         Assert(false, ExcInternalError());
@@ -1118,14 +1118,17 @@ namespace internal
        * cell->line_orientation(), 2d specialization
        */
       template <int dim, int spacedim>
-      static std::array<bool, 4>
+      static std::array<unsigned char, 4>
       get_line_orientations_of_cell(const TriaAccessor<2, dim, spacedim> &cell)
       {
         // For 2d cells the access cell->line_orientation() is already
         // efficient
-        std::array<bool, 4> line_orientations = {};
+        std::array<unsigned char, 4> line_orientations = {};
         for (const unsigned int line : cell.line_indices())
-          line_orientations[line] = cell.line_orientation(line);
+          line_orientations[line] =
+            cell.line_orientation(line) == true ?
+              ReferenceCell::default_combined_face_orientation() :
+              ReferenceCell::reversed_combined_line_orientation();
         return line_orientations;
       }
 
@@ -1136,10 +1139,10 @@ namespace internal
        * cell->line_orientation(), 3d specialization
        */
       template <int dim, int spacedim>
-      static std::array<bool, 12>
+      static std::array<unsigned char, 12>
       get_line_orientations_of_cell(const TriaAccessor<3, dim, spacedim> &cell)
       {
-        std::array<bool, 12> line_orientations = {};
+        std::array<unsigned char, 12> line_orientations = {};
 
         // For hexahedra, the classical access via quads -> lines is too
         // inefficient. Unroll this code here to allow the compiler to inline

source/fe/fe.cc

@@ -683,14 +683,19 @@ FiniteElement<dim, spacedim>::adjust_quad_dof_index_for_face_orientation(
 template <int dim, int spacedim>
 unsigned int
 FiniteElement<dim, spacedim>::adjust_line_dof_index_for_line_orientation(
-  const unsigned int index,
-  const bool         line_orientation) const
+  const unsigned int  index,
+  const unsigned char combined_orientation) const
 {
   // We orient quads (and 1D meshes are always oriented) so always skip those
   // cases
   //
   // TODO - we may want to change this in the future: see also the notes in
   // face_to_cell_index()
+  Assert(combined_orientation ==
+             ReferenceCell::default_combined_face_orientation() ||
+           combined_orientation ==
+             ReferenceCell::reversed_combined_line_orientation(),
+         ExcInternalError());
   if (this->reference_cell() == ReferenceCells::Line ||
       this->reference_cell() == ReferenceCells::Quadrilateral)
     return index;
@@ -699,7 +704,8 @@ FiniteElement<dim, spacedim>::adjust_line_dof_index_for_line_orientation(
   Assert(adjust_line_dof_index_for_line_orientation_table.size() ==
            this->n_dofs_per_line(),
          ExcInternalError());
-  if (line_orientation)
+  if (combined_orientation ==
+      ReferenceCell::default_combined_face_orientation())
     return index;
   else
     return index + adjust_line_dof_index_for_line_orientation_table[index];