mesh_tet_interface.h

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// The libMesh Finite Element Library.
// Copyright (C) 2002-2026 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner

// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.

// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


#ifndef LIBMESH_MESH_TET_INTERFACE_H
#define LIBMESH_MESH_TET_INTERFACE_H

#include "libmesh/libmesh_config.h"

// Local includes
#include "libmesh/bounding_box.h"
#include "libmesh/enum_elem_type.h"
#include "libmesh/point.h" // used for specifying holes

// C++ includes
#include <cstddef>
#include <map>
#include <memory>
#include <string>
#include <vector>

namespace libMesh
{
// Forward Declarations
class UnstructuredMesh;
class Elem;

class MeshTetInterface
{
public:

  explicit
  MeshTetInterface (UnstructuredMesh & mesh);

  virtual ~MeshTetInterface();

  Real & desired_volume() {return _desired_volume;}

  bool & smooth_after_generating() {return _smooth_after_generating;}

  ElemType & elem_type() {return _elem_type;}

  void attach_hole_list(std::unique_ptr<std::vector<std::unique_ptr<UnstructuredMesh>>> holes);

  virtual void triangulate () = 0;

  void set_verbosity(unsigned int v);

protected:

  unsigned int _verbosity;

  static BoundingBox volume_to_surface_mesh (UnstructuredMesh & mesh);

  enum SurfaceIntegrity {
    NON_TRI3 = 1,           // a non-TRI3 element is found
    MISSING_NEIGHBOR = 2,   // an element with a nullptr-neighbor is found
    EMPTY_MESH = 3,         // the mesh is empty
    MISSING_BACKLINK = 4,   // an element neighbor isn't linked back to it
    BAD_NEIGHBOR_NODES = 5, // an element neighbor isn't linked to expected nodes
    NON_ORIENTED = 6,       // an element neighbor has inconsistent orientation
    BAD_NEIGHBOR_LINKS = 7, // an element neighbor has other inconsistent links
    DEGENERATE_ELEMENT = 8, // an element has zero area
    DEGENERATE_MESH = 9     // the mesh clearly bounds zero volume
  };

  [[nodiscard]] std::set<SurfaceIntegrity> check_hull_integrity() const;

  [[nodiscard]] std::set<SurfaceIntegrity> improve_hull_integrity();

  void process_hull_integrity_result(const std::set<SurfaceIntegrity> & result) const;

  void delete_2D_hull_elements();

  Real _desired_volume;

  bool _smooth_after_generating;

  ElemType _elem_type;

  UnstructuredMesh & _mesh;

  std::unique_ptr<std::vector<std::unique_ptr<UnstructuredMesh>>> _holes;
};


// ------------------------------------------------------------
// MeshTetInterface class member functions
inline
void
MeshTetInterface::set_verbosity(unsigned int v)
{
  this->_verbosity = v;
}


} // namespace libMesh

#endif // LIBMESH_MESH_TET_INTERFACE_H