GenericFunction.h

// Copyright (C) 2009 Anders Logg
//
// This file is part of DOLFIN.
//
// DOLFIN 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 3 of the License, or
// (at your option) any later version.
//
// DOLFIN 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 DOLFIN. If not, see <http://www.gnu.org/licenses/>.
//
// Modified by Garth N. Wells, 2009.
//
// First added:  2009-09-28
// Last changed: 2011-01-19

#ifndef __GENERIC_FUNCTION_H
#define __GENERIC_FUNCTION_H

#include <memory>
#include <Eigen/Dense>
#include <ufc.h>
#include <dolfin/common/Array.h>
#include <dolfin/common/Variable.h>

namespace dolfin
{

  class Mesh;
  class Cell;
  class Point;
  class FiniteElement;
  class FunctionSpace;


  class GenericFunction : public ufc::function, public Variable
  {
  public:

    GenericFunction();

    virtual ~GenericFunction();

    //--- Functions that must be implemented by sub-classes ---

    virtual std::size_t value_rank() const = 0;

    virtual std::size_t value_dimension(std::size_t i) const = 0;

    virtual std::vector<std::size_t> value_shape() const = 0;

    virtual void eval(Array<double>& values, const Array<double>& x,
                      const ufc::cell& cell) const;

    virtual void eval(Array<double>& values, const Array<double>& x) const;

    virtual void eval(Eigen::Ref<Eigen::VectorXd> values,
                      Eigen::Ref<const Eigen::VectorXd> x,
                      const ufc::cell& cell) const;

    virtual void eval(Eigen::Ref<Eigen::VectorXd> values,
                      Eigen::Ref<const Eigen::VectorXd> x) const;

    virtual void restrict(double* w,
                          const FiniteElement& element,
                          const Cell& dolfin_cell,
                          const double* coordinate_dofs,
                          const ufc::cell& ufc_cell) const = 0;

    virtual void compute_vertex_values(std::vector<double>& vertex_values,
                                       const Mesh& mesh) const = 0;

    //--- Optional functions to be implemented by sub-classes ---

    virtual void update() const {}

    //--- Convenience functions ---

    double operator() (double x) const;

    double operator() (double x, double y) const;

    double operator() (double x, double y, double z) const;

    double operator() (const Point& p) const;

    void operator() (Array<double>& values, double x) const;

    void operator() (Array<double>& values, double x, double y) const;

    void operator() (Array<double>& values, double x, double y, double z) const;

    void operator() (Array<double>& values, const Point& p) const;


    std::size_t value_size() const;

    //--- Implementation of ufc::function interface ---

    virtual void evaluate(double* values,
                          const double* coordinates,
                          const ufc::cell& cell) const override;

    virtual std::shared_ptr<const FunctionSpace> function_space() const = 0;

  protected:

    void restrict_as_ufc_function(double* w,
                                  const FiniteElement& element,
                                  const Cell& dolfin_cell,
                                  const double* coordinate_dofs,
                                  const ufc::cell& ufc_cell) const;

  };

}

#endif