snake_fwd.hh

// Copyright (C) 2007, 2008, 2009, 2010 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_CANVAS_BROWSING_SNAKE_FWD_HH
# define MLN_CANVAS_BROWSING_SNAKE_FWD_HH


# include <mln/core/concept/browsing.hh>
# include <mln/geom/size2d.hh>


namespace mln
{

  namespace canvas
  {

    namespace browsing
    {


      struct snake_fwd_t : public Browsing< snake_fwd_t >
      {
        template <typename F>
        void operator()(F& f) const;
      };

      extern const snake_fwd_t snake_fwd;

# ifndef MLN_INCLUDE_ONLY

#  ifndef MLN_WO_GLOBAL_VARS

      const snake_fwd_t snake_fwd;

#  endif // ! MLN_WO_GLOBAL_VARS


      template <typename F>
      inline
      void
      snake_fwd_t::operator()(F& f) const
      {
        // Fixme: check the dimension of the input
//      mlc_equal(mln_trait_image_dimension(I)(),
//                trait::image::dimension::two_d)::check();
        trace::entering("canvas::browsing::snake_fwd");
        mln_precondition(f.input.is_valid());
        def::coord
          min_row = geom::min_row(f.input), max_row = geom::max_row(f.input),
          min_col = geom::min_col(f.input), max_col = geom::max_col(f.input);

        // p
        f.p = f.input.bbox().pmin();
        def::coord& row = f.p.row();
        def::coord& col = f.p.col();

        // initialization
        f.init();

        bool fwd = true;
        for (row = min_row; row <= max_row; ++row)
          // FIXME: Add "if (f.input.has(p))"?
          {
            // go down
            f.down();

            if (fwd)
              // browse line fwd
              while (col < max_col)
                {
                  ++col;
                  f.fwd();
                }
            else
              // browse line bkd
              while (col > min_col)
                {
                  --col;
                  f.bkd();
                }

            // change browsing
            fwd = ! fwd;
          }
        trace::exiting("canvas::browsing::snake_fwd");
      }

# endif // ! MLN_INCLUDE_ONLY

    } // end of namespace mln::canvas::browsing

  } // end of namespace mln::canvas

} // end of namespace mln


#endif // ! MLN_CANVAS_BROWSING_SNAKE_FWD_HH