adj_higher_dim_connected_n_face_iter.hh

// Copyright (C) 2008, 2009 EPITA Research and Development Laboratory (LRDE)
//
// This file is part of Olena.
//
// Olena is free software: you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free
// Software Foundation, version 2 of the License.
//
// Olena 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
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Olena.  If not, see <http://www.gnu.org/licenses/>.
//
// As a special exception, you may use this file as part of a free
// software project without restriction.  Specifically, if other files
// instantiate templates or use macros or inline functions from this
// file, or you compile this file and link it with other files to produce
// an executable, this file does not by itself cause the resulting
// executable to be covered by the GNU General Public License.  This
// exception does not however invalidate any other reasons why the
// executable file might be covered by the GNU General Public License.

#ifndef MLN_TOPO_ADJ_HIGHER_DIM_CONNECTED_N_FACE_ITER_HH
# define MLN_TOPO_ADJ_HIGHER_DIM_CONNECTED_N_FACE_ITER_HH


# include <set>

# include <mln/topo/internal/complex_relative_iterator_base.hh>
# include <mln/topo/algebraic_face.hh>


namespace mln
{

  namespace topo
  {

    // Forward declarations.
    template <unsigned D> class complex;
    namespace internal
    {
      template <unsigned D> class adj_higher_dim_connected_n_face_iterator;
    }


    /*----------------------------------------------------.
    | topo::adj_higher_dim_connected_n_face_fwd_iter<D>.  |
    `----------------------------------------------------*/

    //
    template <unsigned D>
    class adj_higher_dim_connected_n_face_fwd_iter
      : public internal::forward_complex_relative_iterator_base< topo::face<D>,
                                                                 algebraic_face<D>,
                                                                 adj_higher_dim_connected_n_face_fwd_iter<D> >,
        private internal::adj_higher_dim_connected_n_face_iterator<D>
    {
      // Tech note: we use topo::face to help g++-2.95.
    private:
      typedef adj_higher_dim_connected_n_face_fwd_iter<D> self_;
      typedef internal::forward_complex_relative_iterator_base< topo::face<D>,
                                                                algebraic_face<D>,
                                                                self_ > super_;

    public:
      adj_higher_dim_connected_n_face_fwd_iter();
      template <typename Fref>
      adj_higher_dim_connected_n_face_fwd_iter(const Fref& f_ref);

      void update_adj_faces_();
    };


    /*----------------------------------------------------.
    | topo::adj_higher_dim_connected_n_face_bkd_iter<D>.  |
    `----------------------------------------------------*/

    //
    template <unsigned D>
    class adj_higher_dim_connected_n_face_bkd_iter
      : public internal::backward_complex_relative_iterator_base< topo::face<D>,
                                                                  algebraic_face<D>,
                                                                  adj_higher_dim_connected_n_face_bkd_iter<D> >,
        private internal::adj_higher_dim_connected_n_face_iterator<D>
    {
      // Tech note: we use topo::face to help g++-2.95.
    private:
      typedef adj_higher_dim_connected_n_face_bkd_iter<D> self_;
      typedef internal::backward_complex_relative_iterator_base< topo::face<D>,
                                                                 algebraic_face<D>,
                                                                 self_ > super_;

    public:
      adj_higher_dim_connected_n_face_bkd_iter();
      template <typename Fref>
      adj_higher_dim_connected_n_face_bkd_iter(const Fref& f_ref);

      void update_adj_faces_();
    };


    /*--------------------------------------------------------------.
    | topo::internal::adj_higher_dim_connected_n_face_iterator<D>.  |
    `--------------------------------------------------------------*/

    namespace internal
    {

      template <unsigned D>
      class adj_higher_dim_connected_n_face_iterator
      {
      protected:
        void update_adj_faces__(const topo::face<D>& center,
                                std::vector< algebraic_face<D> >& adj_faces);
      };

    } // end of namespace mln::topo::internal



# ifndef MLN_INCLUDE_ONLY

    /*----------------------------------------------------.
    | topo::adj_higher_dim_connected_n_face_fwd_iter<D>.  |
    `----------------------------------------------------*/

    template <unsigned D>
    inline
    adj_higher_dim_connected_n_face_fwd_iter<D>::adj_higher_dim_connected_n_face_fwd_iter()
    {
    }

    template <unsigned D>
    template <typename Fref>
    inline
    adj_higher_dim_connected_n_face_fwd_iter<D>::adj_higher_dim_connected_n_face_fwd_iter(const Fref& f_ref)
      : super_(f_ref)
    {
    }

    /* FIXME: Most of this code is shared by
       adj_higher_dim_connected_n_face_{fwd,bkd}_iter<D> and
       adj_higher_dim_connected_n_face_{fwd,bkd}_iter<D>).  Find a way
       to factor this, maybe through a common (implementation) base
       class.  */
    template <unsigned D>
    inline
    void
    adj_higher_dim_connected_n_face_fwd_iter<D>::update_adj_faces_()
    {
      mln_precondition(this->c_);
      // Delegate computation to base class.
      this->update_adj_faces__(*this->c_, this->adj_faces_);
    }


    /*----------------------------------------------------.
    | topo::adj_higher_dim_connected_n_face_bkd_iter<D>.  |
    `----------------------------------------------------*/

    template <unsigned D>
    inline
    adj_higher_dim_connected_n_face_bkd_iter<D>::adj_higher_dim_connected_n_face_bkd_iter()
    {
    }

    template <unsigned D>
    template <typename Fref>
    inline
    adj_higher_dim_connected_n_face_bkd_iter<D>::adj_higher_dim_connected_n_face_bkd_iter(const Fref& f_ref)
      : super_(f_ref)
    {
    }

    template <unsigned D>
    inline
    void
    adj_higher_dim_connected_n_face_bkd_iter<D>::update_adj_faces_()
    {
      mln_precondition(this->c_);
      // Delegate computation to base class.
      this->update_adj_faces__(*this->c_, this->adj_faces_);
    }


    /*--------------------------------------------------------------.
    | topo::internal::adj_higher_dim_connected_n_face_iterator<D>.  |
    `--------------------------------------------------------------*/

    namespace internal
    {

      /* FIXME: Factor
         topo::internal::adj_lower_dim_connected_n_face_iterator<D> and
         topo::internal::adj_higher_dim_connected_n_face_iterator<D>.  */

      template <unsigned D>
      inline
      void
      adj_higher_dim_connected_n_face_iterator<D>::update_adj_faces__(const topo::face<D>& center,
                                                                      std::vector< algebraic_face<D> >& adj_faces)
      {
        // Reset the result container.
        adj_faces.clear();

        /* A set of faces containing the same values as ADJ_FACES, used
           to quickly check whether a candidate face has already been
           added to the pool of adjacent faces. We use an std::set
           because the lookup is cheaper (O(log(n)) vs O(n) for a
           vector, where n is the size of the containers.  */
        std::set< algebraic_face<D> > faces_set;
        typedef std::vector< algebraic_face<D> > faces_t;

        // The set of (n+1)-faces adjacent to CENTER.
        faces_t shared_higher_faces = center.higher_dim_adj_faces();
        for (typename faces_t::const_iterator slf = shared_higher_faces.begin();
             slf != shared_higher_faces.end(); ++slf)
          {
            /* The n-faces sharing an adjacent (n+1)-face with CENTER.
               Note that this set contains CENTER itself.  */
            faces_t adj_n_faces = slf->lower_dim_adj_faces();
            for (typename faces_t::const_iterator af = adj_n_faces.begin();
                 af != adj_n_faces.end(); ++af)
              {
                /* Ensure that 1. we are not adding CENTER to the result;
                   and 2. that we are not adding an already added
                   processed face.  */
                if (*af != center &&
                    faces_set.find(*af) == faces_set.end())
                  {
                    adj_faces.push_back(*af);
                    faces_set.insert(*af);
                  }
              }
          }
      }

    } // end of namespace mln::topo::internal

# endif // ! MLN_INCLUDE_ONLY

  } // end of namespace mln::topo

} // end of namespace mln

#endif // ! MLN_TOPO_ADJ_HIGHER_DIM_CONNECTED_N_FACE_ITER_HH