Feature: Added Element Methods (get_reference_coordinates, element_is_equal, t8_forest_leaf_face_orientation)

mesh_handle/element.hxx

@@ -401,6 +401,31 @@ class element: public TCompetences<element<TMeshClass, TCompetences...>>... {
     }
   }
 
+  /** Function to convert points in reference space of an element to points of the 
+   *  reference space of the tree.
+   * \param [in] ref_coords     Pointer to the reference coordinates of the element.
+   * \param [in] num_coords     Number of reference coordinates to convert.
+   * \param [out] tree_ref_coords Pointer to the reference coordinates of the tree.
+   */
+  void
+  get_reference_coordinates (const t8_3D_vec& ref_coords, std::size_t num_coords, t8_3D_vec& tree_ref_coords) const
+  {
+    t8_forest_get_scheme (m_mesh->m_forest)
+      ->element_get_reference_coords (get_tree_class (), m_element, ref_coords.data (), num_coords,
+                                      tree_ref_coords.data ());
+  }
+
+  /** Compute the orientation of a face of an element with respect to its neighbor.
+   *  \param [in] face The index of the face for which the orientation should be computed.
+   *  \return The orientation of the face with respect to its neighbor. Returns 0 if the face has no neighbor.
+   */
+  int
+  get_face_orientation (int face) const
+  {
+    return t8_forest_leaf_face_orientation (m_mesh->m_forest, m_tree_id, t8_forest_get_scheme (m_mesh->m_forest),
+                                            m_element, face);
+  }
+
   // --- Getter for face properties. ---
   /** The area of a face of the element.
    *  This is only an approximation.
@@ -583,6 +608,17 @@ class element: public TCompetences<element<TMeshClass, TCompetences...>>... {
     return m_is_ghost_element;
   }
 
+  /** Check if two elements are equal.
+   * \param [in] other The other element, this element is compared with. 
+   * \return           True if the elements are equal, false if they are not equal.
+  */
+  bool
+  is_equal (const SelfType& other) const
+  {
+    return t8_forest_get_scheme (m_mesh->m_forest)
+      ->element_is_equal (get_tree_class (), get_forest_element (), other.get_forest_element ());
+  }
+
  private:
   // --- Private member variables. ---
   TMeshClass* m_mesh;             /**< Pointer to the mesh the element is defined for. */

test/mesh_handle/t8_gtest_compare_handle_to_forest.cxx

@@ -26,6 +26,7 @@ along with t8code; if not, write to the Free Software Foundation, Inc.,
  */
 
 #include <gtest/gtest.h>
+#include <test/t8_gtest_macros.hxx>
 #include <t8.h>
 
 #include <mesh_handle/mesh.hxx>
@@ -63,6 +64,17 @@ TEST (t8_gtest_compare_handle_to_forest, compare_handle_to_forest)
       // --- Compare elements. ---
       EXPECT_EQ (mesh_iterator->get_local_tree_id (), itree);
       EXPECT_EQ (mesh_iterator->get_local_element_id (), ielem);
+      EXPECT_TRUE (mesh_iterator->is_equal (*mesh_iterator));
+      auto mesh_iterator_copy = mesh_iterator;
+      mesh_iterator_copy++;
+      if (mesh_iterator_copy != mesh.cend ()) {
+        EXPECT_FALSE (mesh_iterator->is_equal (*mesh_iterator_copy));
+      }
+      t8_3D_vec ref = { 0.2, 0.3, 1 };
+      t8_3D_vec a, b;
+      mesh_iterator->get_reference_coordinates (ref, 1, a);
+      scheme->element_get_reference_coords (tree_class, elem, ref.data (), 1, b.data ());
+      EXPECT_EQ (a, b);
       // --- Compare functionality. ---
       EXPECT_EQ (mesh_iterator->get_level (), scheme->element_get_level (tree_class, elem));
       EXPECT_EQ (mesh_iterator->get_num_faces (), scheme->element_get_num_faces (tree_class, elem));
@@ -96,6 +108,8 @@ TEST (t8_gtest_compare_handle_to_forest, compare_handle_to_forest)
           EXPECT_EQ (mesh_iterator->face_vertex_to_element_vertex (iface, ivertex),
                      scheme->element_get_face_corner (tree_class, elem, iface, ivertex));
         }
+        EXPECT_EQ (mesh_iterator->get_face_orientation (iface),
+                   t8_forest_leaf_face_orientation (forest, itree, scheme, elem, iface));
       }
       // --- Evolve mesh iterator. ---
       mesh_iterator++;

test/mesh_handle/t8_gtest_ghost.cxx

@@ -81,11 +81,17 @@ TEST_P (t8_mesh_ghost_test, check_ghosts)
   for (t8_locidx_t ighost = num_local_elements; ighost < num_local_elements + num_ghost_elements; ++ighost) {
     EXPECT_EQ (ighost, (*mesh)[ighost].get_element_handle_id ());
     EXPECT_TRUE ((*mesh)[ighost].is_ghost_element ());
+    EXPECT_TRUE ((*mesh)[ighost].is_equal ((*mesh)[ighost]));
     EXPECT_EQ (level, (*mesh)[ighost].get_level ());
     EXPECT_LE (0, (*mesh)[ighost].get_num_faces ());
     EXPECT_LE (0, (*mesh)[ighost].get_num_vertices ());
     EXPECT_LE (0, (*mesh)[ighost].get_volume ());
     EXPECT_LE (0, (*mesh)[ighost].get_diameter ());
+    t8_3D_vec ref = { 0.2, 0.3, 1 }, a;
+    (*mesh)[ighost].get_reference_coordinates (ref, 1, a);
+    for (const auto& coordinate : a) {
+      EXPECT_LE (0, coordinate);
+    }
     for (const auto& coordinate : (*mesh)[ighost].get_centroid ()) {
       EXPECT_TRUE (coordinate >= 0.0 && coordinate <= 1.0);
     }
@@ -104,6 +110,7 @@ TEST_P (t8_mesh_ghost_test, check_ghosts)
     }
     EXPECT_LT (0, (*mesh)[ighost].get_num_vertices_of_face (0));
     EXPECT_LE (0, (*mesh)[ighost].face_vertex_to_element_vertex (0, 0));
+    EXPECT_GE ((*mesh)[ighost].get_face_orientation (0), 0);
     // Check exemplary that caches work for ghost elements.
     EXPECT_TRUE ((*mesh)[ighost].volume_cache_filled ());
     EXPECT_LE (0, (*mesh)[ighost].get_volume ());