mg_base.h

// ---------------------------------------------------------------------
//
// Copyright (C) 1999 - 2018 by the deal.II authors
//
// This file is part of the deal.II library.
//
// The deal.II library is free software; you can use it, 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.
// The full text of the license can be found in the file LICENSE.md at
// the top level directory of deal.II.
//
// ---------------------------------------------------------------------

#ifndef dealii_mg_base_h
#define dealii_mg_base_h

/*
 * This file contains some abstract base classes
 * used by Multigrid.
 */

#include <deal.II/base/config.h>

#include <deal.II/base/smartpointer.h>
#include <deal.II/base/subscriptor.h>

#include <deal.II/lac/vector.h>


DEAL_II_NAMESPACE_OPEN



template <typename VectorType>
class MGMatrixBase : public Subscriptor
{
public:
  /*
   * Virtual destructor.
   */
  virtual ~MGMatrixBase() override = default;

  virtual void
  vmult(const unsigned int level,
        VectorType &       dst,
        const VectorType & src) const = 0;

  virtual void
  vmult_add(const unsigned int level,
            VectorType &       dst,
            const VectorType & src) const = 0;

  virtual void
  Tvmult(const unsigned int level,
         VectorType &       dst,
         const VectorType & src) const = 0;

  virtual void
  Tvmult_add(const unsigned int level,
             VectorType &       dst,
             const VectorType & src) const = 0;

  virtual unsigned int
  get_minlevel() const = 0;

  virtual unsigned int
  get_maxlevel() const = 0;
};


template <typename VectorType>
class MGCoarseGridBase : public Subscriptor
{
public:
  virtual ~MGCoarseGridBase() override = default;

  virtual void
  operator()(const unsigned int level,
             VectorType &       dst,
             const VectorType & src) const = 0;
};


template <typename VectorType>
class MGTransferBase : public Subscriptor
{
public:
  virtual ~MGTransferBase() override = default;

  virtual void
  prolongate(const unsigned int to_level,
             VectorType &       dst,
             const VectorType & src) const = 0;

  virtual void
  restrict_and_add(const unsigned int from_level,
                   VectorType &       dst,
                   const VectorType & src) const = 0;
};



template <typename VectorType>
class MGSmootherBase : public Subscriptor
{
public:
  virtual ~MGSmootherBase() override = default;

  virtual void
  clear() = 0;

  virtual void
  smooth(const unsigned int level,
         VectorType &       u,
         const VectorType & rhs) const = 0;

  virtual void
  apply(const unsigned int level, VectorType &u, const VectorType &rhs) const;
};

DEAL_II_NAMESPACE_CLOSE

#endif