fe_q_base.h

// ---------------------------------------------------------------------
//
// Copyright (C) 2000 - 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 at
// the top level of the deal.II distribution.
//
// ---------------------------------------------------------------------

#ifndef dealii_fe_q_base_h
#define dealii_fe_q_base_h

#include <deal.II/base/config.h>
#include <deal.II/fe/fe_poly.h>
#include <deal.II/base/thread_management.h>

DEAL_II_NAMESPACE_OPEN



template <class PolynomialType, int dim=PolynomialType::dimension, int spacedim=dim>
class FE_Q_Base : public FE_Poly<PolynomialType,dim,spacedim>
{
public:
  FE_Q_Base (const PolynomialType &poly_space,
             const FiniteElementData<dim> &fe_data,
             const std::vector<bool> &restriction_is_additive_flags);

  virtual void
  get_interpolation_matrix (const FiniteElement<dim,spacedim> &source,
                            FullMatrix<double>       &matrix) const;


  virtual void
  get_face_interpolation_matrix (const FiniteElement<dim,spacedim> &source,
                                 FullMatrix<double>       &matrix) const;

  virtual void
  get_subface_interpolation_matrix (const FiniteElement<dim,spacedim> &source,
                                    const unsigned int        subface,
                                    FullMatrix<double>       &matrix) const;

  virtual bool has_support_on_face (const unsigned int shape_index,
                                    const unsigned int face_index) const;

  virtual const FullMatrix<double> &
  get_restriction_matrix (const unsigned int child,
                          const RefinementCase<dim> &refinement_case=RefinementCase<dim>::isotropic_refinement) const;

  virtual const FullMatrix<double> &
  get_prolongation_matrix (const unsigned int child,
                           const RefinementCase<dim> &refinement_case=RefinementCase<dim>::isotropic_refinement) const;

  virtual
  unsigned int face_to_cell_index (const unsigned int face_dof_index,
                                   const unsigned int face,
                                   const bool face_orientation = true,
                                   const bool face_flip        = false,
                                   const bool face_rotation    = false) const;

  virtual std::pair<Table<2,bool>, std::vector<unsigned int> >
  get_constant_modes () const;

  virtual bool hp_constraints_are_implemented () const;

  virtual
  std::vector<std::pair<unsigned int, unsigned int> >
  hp_vertex_dof_identities (const FiniteElement<dim,spacedim> &fe_other) const;

  virtual
  std::vector<std::pair<unsigned int, unsigned int> >
  hp_line_dof_identities (const FiniteElement<dim,spacedim> &fe_other) const;

  virtual
  std::vector<std::pair<unsigned int, unsigned int> >
  hp_quad_dof_identities (const FiniteElement<dim,spacedim> &fe_other) const;

  virtual
  FiniteElementDomination::Domination
  compare_for_face_domination (const FiniteElement<dim,spacedim> &fe_other) const;

  DeclExceptionMsg (ExcFEQCannotHaveDegree0,
                    "FE_Q can only be used for polynomial degrees "
                    "greater than zero. If you want an element of polynomial "
                    "degree zero, then it cannot be continuous and you "
                    "will want to use FE_DGQ<dim>(0).");

protected:
  static std::vector<unsigned int> get_dpo_vector(const unsigned int degree);

  void initialize (const std::vector<Point<1> > &support_points_1d);

  void initialize_constraints (const std::vector<Point<1> > &points);

  void initialize_unit_support_points (const std::vector<Point<1> > &points);

  void initialize_unit_face_support_points (const std::vector<Point<1> > &points);

  void initialize_quad_dof_index_permutation ();

  struct Implementation;

  /*
   * Declare implementation friend.
   */
  friend struct FE_Q_Base<PolynomialType,dim,spacedim>::Implementation;

private:
  /*
   * Mutex for protecting initialization of restriction and embedding matrix.
   */
  mutable Threads::Mutex mutex;

  /*
   * The highest polynomial degree of the underlying tensor product space
   * without any enrichment. For FE_Q*(p) this is p. Note that enrichments
   * may lead to a difference to degree.
   */
  const unsigned int q_degree;
};


DEAL_II_NAMESPACE_CLOSE

#endif