added ability to skip linear geometries

src/t8_cmesh/t8_cmesh_readmshfile.cxx

@@ -1194,8 +1194,8 @@ t8_cmesh_msh_file_4_read_eles (t8_cmesh_t cmesh, FILE *fp,
                   }
                 }
               }
-              /* Abort if not all nodes are on the surface */
-              if (!all_nodes_on_surface)
+              /* Abort if not all nodes are on the surface or if the surface is a plane */
+              if (!all_nodes_on_surface || occ_geometry->t8_geom_is_plane(surface_index))
               {
                 continue;
               }
@@ -1369,6 +1369,13 @@ t8_cmesh_msh_file_4_read_eles (t8_cmesh_t cmesh, FILE *fp,
                   edge_nodes[i_edge_node].entity_dim = 1;
                 }
               }
+
+              /* Abort if the edge is a line */
+              if (occ_geometry->t8_geom_is_line(edge_geometry_tag))
+              {
+                continue;
+              }
+
               edge_geometries[i_tree_edges] = edge_geometry_tag;
               tree_is_linked = 1;
               parameters[0] = edge_nodes[0].parameters[0];
@@ -1432,6 +1439,13 @@ t8_cmesh_msh_file_4_read_eles (t8_cmesh_t cmesh, FILE *fp,
                   edge_nodes[i_edge_node].entity_dim = 2;
                 }
               }
+
+              /* Abort if the edge is a line */
+              if (occ_geometry->t8_geom_is_line(edge_geometry_tag))
+              {
+                continue;
+              }
+
               edge_geometries[i_tree_edges + t8_eclass_num_edges[eclass]] = edge_geometry_tag;
               tree_is_linked = 1;
               parameters[0] = edge_nodes[0].parameters[0];

src/t8_geometry/t8_geometry_implementations/t8_geometry_occ.cxx

@@ -191,6 +191,7 @@ t8_geometry_occ::t8_geom_evaluate_occ_hex (t8_cmesh_t cmesh,
                                    active_tree_vertices, ref_coords,
                                    out_coords);
 
+  int                 tree_is_linear = 1;
   const int           num_edges = t8_eclass_num_edges[active_tree_class];
   const int           num_faces = t8_eclass_num_faces[active_tree_class];
   double              interpolated_coords[3],
@@ -213,6 +214,9 @@ t8_geometry_occ::t8_geom_evaluate_occ_hex (t8_cmesh_t cmesh,
       /* Check if only a surface or a curve is present. Abort if both is true. */
       T8_ASSERT (!(edges[i_edge] > 0) != !(edges[i_edge + num_edges] > 0));
 
+      /* tree carries a surface or an edge and is therefore not  */
+      tree_is_linear = 0;
+
       /* Interpolate coordinates between edge vertices. Due to the indices i_edge of the edges, the edges point in
        * direction of ref_coord i_edge / 4. Therefore, we can use ref_coords[i_edge / 4] for the interpolation.              
        *          6 -------E3------- 7
@@ -789,6 +793,22 @@ t8_geometry_occ::t8_geom_evaluate_occ_quad (t8_cmesh_t cmesh,
 
 /* Our indent skript has huge problems with c++ */
 /* *INDENT-OFF* */
+int
+t8_geometry_occ::t8_geom_is_line(const int curve_index) const
+{
+  const Handle_Geom_Curve curve  = t8_geom_get_occ_curve(curve_index);
+  const GeomAdaptor_Curve curve_adaptor (curve);
+  return curve_adaptor.GetType() == GeomAbs_Line;
+}
+
+int
+t8_geometry_occ::t8_geom_is_plane(const int surface_index) const
+{
+  const Handle_Geom_Surface surface = t8_geom_get_occ_surface (surface_index);
+  const GeomAdaptor_Surface surface_adaptor (surface);
+  return surface_adaptor.GetType() == GeomAbs_Plane;
+}
+
 const gp_Pnt
 t8_geometry_occ::t8_geom_get_occ_point (const int index) const
 {

src/t8_geometry/t8_geometry_implementations/t8_geometry_occ.hxx

@@ -140,6 +140,20 @@ public:
   virtual void 
   t8_geom_load_tree_data (t8_cmesh_t cmesh,
                           t8_gloidx_t gtreeid);
+
+  /** Check if a occ_curve is a line.
+   * \param [in] curve_index      The index of the occ_curve.
+   * \return                      1 if curve is a line, 0 if curve is not a line.
+   */
+  int
+  t8_geom_is_line(const int curve_index) const;
+
+  /** Check if a occ_surface is a plane.
+   * \param [in] surface_index      The index of the occ_surface.
+   * \return                        1 if surface is a plane linear, 0 if surface is not a plane.
+   */
+  int
+  t8_geom_is_plane(const int surface_index) const;
 
   /** Get an occ point from the occ_shape.
    * \param [in] index      The index of the point in the occ_shape.