VTKFile.h

// Copyright (C) 2020 Garth N. Wells
//
// This file is part of DOLFINx (https://www.fenicsproject.org)
//
// SPDX-License-Identifier:    LGPL-3.0-or-later
 
#pragma once
 
#include <concepts>
#include <dolfinx/common/MPI.h>
#include <dolfinx/common/types.h>
#include <filesystem>
#include <functional>
#include <memory>
#include <string>
#include <string_view>
 
namespace pugi
{
class xml_document;
}
 
namespace dolfinx::fem
{
template <dolfinx::scalar T, std::floating_point U>
class Function;
}
 
namespace dolfinx::mesh
{
template <std::floating_point T>
class Mesh;
}
 
namespace dolfinx::io
{

class VTKFile
{
public:
  VTKFile(MPI_Comm comm, const std::filesystem::path& filename,
          std::string_view file_mode);
 
  // Copy constructor (deleted)
  VTKFile(const VTKFile& file) = delete;

  VTKFile(VTKFile&& file) noexcept;

  ~VTKFile();
 
  // Copy assignment (deleted)
  VTKFile& operator=(const VTKFile& file) = delete;

  VTKFile& operator=(VTKFile&& file) noexcept;

  void close();

  void flush();

  template <std::floating_point U>
  void write(const mesh::Mesh<U>& mesh, double t = 0.0);

  template <dolfinx::scalar T, std::floating_point U = scalar_value_t<T>>
  void
  write(const std::vector<std::reference_wrapper<const fem::Function<T, U>>>& u,
        double t);
 
private:
  std::unique_ptr<pugi::xml_document> _pvd_xml;
 
  std::filesystem::path _filename;
 
  // MPI communicator
  dolfinx::MPI::Comm _comm;
};
} // namespace dolfinx::io