From: David Wells <drwells@email.unc.edu>
Date: Sat, 6 Apr 2024 17:17:54 +0000 (-0400)
Subject: TriaAccessor: permit calling set_combined_face_orientation() in 2d.
X-Git-Tag: v9.6.0-rc1~382^2~4
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d00345ce47125e5261f861402e6f7eb0a529c4b1;p=dealii.git

TriaAccessor: permit calling set_combined_face_orientation() in 2d.
---

diff --git a/include/deal.II/grid/tria_accessor.h b/include/deal.II/grid/tria_accessor.h
index ebc3dbd051..1b783c7d26 100644
--- a/include/deal.II/grid/tria_accessor.h
+++ b/include/deal.II/grid/tria_accessor.h
@@ -1818,10 +1818,8 @@ private:
 
   /**
    * Set the combined face orientation (i.e., the integer that uniquely encodes
-   * the orientation, flip, and rotation).
-   *
-   * It is only possible to set the face_orientation of cells in 3d (i.e.
-   * <code>structdim==3 && dim==3</code>).
+   * the orientation, flip, and rotation). This function is only implemented for
+   * objects which have faces, i.e., for structdim == dim.
    *
    * @ingroup reordering
    */
diff --git a/include/deal.II/grid/tria_accessor.templates.h b/include/deal.II/grid/tria_accessor.templates.h
index 6538ea24ce..6fd99cee44 100644
--- a/include/deal.II/grid/tria_accessor.templates.h
+++ b/include/deal.II/grid/tria_accessor.templates.h
@@ -862,25 +862,36 @@ namespace internal
       template <int structdim, int dim, int spacedim>
       inline static void
       set_combined_face_orientation(
-        const TriaAccessor<structdim, dim, spacedim> &,
-        const unsigned int,
-        const unsigned char)
-      {
-        DEAL_II_ASSERT_UNREACHABLE();
-      }
-
-
-
-      inline static void
-      set_combined_face_orientation(const TriaAccessor<3, 3, 3> &accessor,
-                                    const unsigned int           face,
-                                    const unsigned char combined_orientation)
+        const TriaAccessor<structdim, dim, spacedim> &accessor,
+        const unsigned int                            face,
+        const unsigned char                           combined_orientation)
       {
+        Assert(structdim == dim,
+               ExcMessage("This function can only be used on objects that are "
+                          "cells and not on objects which bound cells."));
         AssertIndexRange(face, accessor.n_faces());
-        accessor.tria->levels[accessor.present_level]
-          ->face_orientations.set_combined_orientation(
-            accessor.present_index * GeometryInfo<3>::faces_per_cell + face,
-            combined_orientation);
+
+        if (dim == 1)
+          Assert(combined_orientation ==
+                   ReferenceCell::default_combined_face_orientation(),
+                 ExcMessage("In 1d, faces do not have an orientation, so the "
+                            "only valid value is the default."));
+        else if (dim == 2)
+          Assert(combined_orientation ==
+                     ReferenceCell::default_combined_face_orientation() ||
+                   combined_orientation ==
+                     ReferenceCell::reversed_combined_line_orientation(),
+                 ExcMessage(
+                   "In 2d, the only valid values of the combined orientation "
+                   "are the standard orientation or the reversed line "
+                   "orientation."));
+
+        // face_orientations is not set up in 1d
+        if (dim != 1)
+          accessor.tria->levels[accessor.present_level]
+            ->face_orientations.set_combined_orientation(
+              accessor.present_index * GeometryInfo<dim>::faces_per_cell + face,
+              combined_orientation);
       }
 
       /**