gmsh_io.h

Go to the documentation of this file.

// The libMesh Finite Element Library.
// Copyright (C) 2002-2025 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_GMSH_IO_H
#define LIBMESH_GMSH_IO_H

// Local includes
#include "libmesh/libmesh_common.h"
#include "libmesh/mesh_input.h"
#include "libmesh/mesh_output.h"

// C++ includes
#include <cstddef>

namespace libMesh
{

// Forward declarations
class MeshBase;



class GmshIO : public MeshInput<MeshBase>,
               public MeshOutput<MeshBase>
{
public:

  explicit
  GmshIO (MeshBase & mesh);

  explicit
  GmshIO (const MeshBase & mesh);

  virtual void read (const std::string & name) override;

  virtual void write (const std::string & name) override;

  using MeshOutput<MeshBase>::write_nodal_data;

  virtual void write_nodal_data (const std::string &,
                                 const std::vector<Number> &,
                                 const std::vector<std::string> &) override;

  bool & binary ();

  bool & write_lower_dimensional_elements ();

private:
  void read_mesh (std::istream & in);

  void write_mesh (std::ostream & out);

  void write_post (const std::string &,
                   const std::vector<Number> * = nullptr,
                   const std::vector<std::string> * = nullptr);

  bool _binary;

  bool _write_lower_dimensional_elements;

  struct ElementDefinition
  {
    ElementDefinition(ElemType type_in,
                      unsigned gmsh_type_in,
                      unsigned dim_in,
                      unsigned nnodes_in) :
      type(type_in),
      gmsh_type(gmsh_type_in),
      dim(dim_in),
      nnodes(nnodes_in)
    {}

    ElemType type;
    unsigned int gmsh_type;
    unsigned int dim;
    unsigned int nnodes;
    std::vector<unsigned int> nodes;
  };

  struct ElementMaps
  {
    // Helper function to add a (key, value) pair to both maps
    void add_def(const ElementDefinition & eledef)
    {
      out.emplace(eledef.type, eledef);
      in.emplace(eledef.gmsh_type, eledef);
    }

    std::map<ElemType, ElementDefinition> out;
    std::map<unsigned int, ElementDefinition> in;
  };

  static ElementMaps _element_maps;

  static ElementMaps build_element_maps();
};


} // namespace libMesh

#endif // LIBMESH_GMSH_IO_H