display_edge.hh

// Copyright (C) 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_WORLD_INTER_PIXEL_DISPLAY_EDGE_HH
# define MLN_WORLD_INTER_PIXEL_DISPLAY_EDGE_HH


# include <mln/core/image/image2d.hh>
# include <mln/core/image/dmorph/image_if.hh>
# include <mln/data/fill.hh>
# include <mln/world/inter_pixel/is_separator.hh>
# include <mln/opt/at.hh>

namespace mln
{

  namespace world
  {

    namespace inter_pixel
    {

      template <typename I>
      inline
      I display_edge(const I& ima, mln_value(I) bg, unsigned zoom);

# ifndef MLN_INCLUDE_ONLY


      template <typename I>
      inline
      I display_edge(const I& ima, mln_value(I) bg, unsigned zoom)
      {
        box2d b = ima.bbox();
        I output(make::box2d(((b.pmin()[0] + 1) / 2) * (zoom + 1),
                             ((b.pmin()[1] + 1) / 2) * (zoom + 1),
                             ((b.pmax()[0] + 1) / 2 + 1) * (zoom + 1) - 2,
                             ((b.pmax()[1] + 1) / 2 + 1) * (zoom + 1) - 2));
        data::fill(output, bg);
        typedef image_if<const I, is_separator> edge_t;
        edge_t edge = ima | is_separator();
        mln_piter(edge_t) p(edge.domain());
        for_all(p)
          if (p.row() % 2) // horizontal edge
          {
            unsigned row = (p.row() / 2 + 1) * (zoom + 1) - 1;
            unsigned col = (p.col() / 2) * (zoom + 1);
            for (unsigned i = 0; i < zoom; ++i)
              opt::at(output, row, col + i) = ima(p);
          }
          else // vertical edge
          {
            unsigned row = (p.row() / 2) * (zoom + 1);
            unsigned col = (p.col() / 2 + 1) * (zoom + 1) - 1;
            for (unsigned i = 0; i < zoom; ++i)
              opt::at(output, row + i, col) = ima(p);
          }
        return output;
      }


# endif // ! MLN_INCLUDE_ONLY

    } // end of namespace mln::world::inter_pixel

  } // end of namespace mln::world

} // end of namespace mln

#endif // ! MLN_WORLD_INTER_PIXEL_DISPLAY_EDGE_HH