is_simple_point.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_TOPO_SKELETON_IS_SIMPLE_POINT_HH
# define MLN_TOPO_SKELETON_IS_SIMPLE_POINT_HH


# include <mln/core/concept/image.hh>
# include <mln/core/alias/point2d.hh>
# include <mln/core/alias/neighb2d.hh>

namespace mln
{

  namespace topo
  {

    namespace skeleton
    {

      template <typename I, typename N>
      bool
      is_simple_point(const Image<I>& ima,
                      const Neighborhood<N>& nbh,
                      const mln_site(I)& p);


# ifndef MLN_INCLUDE_ONLY


      namespace internal
      {


        static const unsigned char nb_connexity_c8[256] =
        {
          0,  1,  1,  1,   1,  2,  1,  1,   1,  1,  1,  1,   2,  2,  1,  1,
          1,  2,  1,  1,   1,  2,  1,  1,   2,  2,  1,  1,   2,  2,  1,  1,
          1,  2,  2,  2,   2,  3,  2,  2,   1,  1,  1,  1,   2,  2,  1,  1,
          2,  3,  2,  2,   2,  3,  2,  2,   2,  2,  1,  1,   2,  2,  1,  1,

          1,  2,  2,  2,   2,  3,  2,  2,   1,  1,  1,  1,   2,  2,  1,  1,
          1,  2,  1,  1,   1,  2,  1,  1,   1,  1,  1,  1,   1,  1,  1,  1,
          1,  2,  2,  2,   2,  3,  2,  2,   1,  1,  1,  1,   2,  2,  1,  1,
          1,  2,  1,  1,   1,  2,  1,  1,   1,  1,  1,  1,   1,  1,  1,  1,

          1,  2,  2,  2,   2,  3,  2,  2,   2,  2,  2,  2,   3,  3,  2,  2,
          1,  2,  1,  1,   1,  2,  1,  1,   2,  2,  1,  1,   2,  2,  1,  1,
          2,  3,  3,  3,   3,  4,  3,  3,   2,  2,  2,  2,   3,  3,  2,  2,
          2,  3,  2,  2,   2,  3,  2,  2,   2,  2,  1,  1,   2,  2,  1,  1,

          1,  2,  2,  2,   2,  3,  2,  2,   1,  1,  1,  1,   2,  2,  1,  1,
          1,  2,  1,  1,   1,  2,  1,  1,   1,  1,  1,  1,   1,  1,  1,  1,
          1,  2,  2,  2,   2,  3,  2,  2,   1,  1,  1,  1,   2,  2,  1,  1,
          1,  2,  1,  1,   1,  2,  1,  1,   1,  1,  1,  1,   1,  1,  1,  1
        };

        static const unsigned char nb_connexity_c4[256] =
        {
          0,  0,  1,  1,   0,  0,  1,  1,   1,  1,  2,  1,   1,  1,  2,  1,
          1,  1,  2,  2,   1,  1,  1,  1,   2,  2,  3,  2,   2,  2,  2,  1,
          0,  0,  1,  1,   0,  0,  1,  1,   1,  1,  2,  1,   1,  1,  2,  1,
          1,  1,  2,  2,   1,  1,  1,  1,   2,  2,  3,  2,   2,  2,  2,  1,

          1,  1,  2,  2,   1,  1,  2,  2,   2,  2,  3,  2,   2,  2,  3,  2,
          2,  2,  3,  3,   2,  2,  2,  2,   3,  3,  4,  3,   3,  3,  3,  2,
          1,  1,  2,  2,   1,  1,  2,  2,   1,  1,  2,  1,   1,  1,  2,  1,
          2,  2,  3,  3,   2,  2,  2,  2,   2,  2,  3,  2,   2,  2,  2,  1,

          0,  0,  1,  1,   0,  0,  1,  1,   1,  1,  2,  1,   1,  1,  2,  1,
          1,  1,  2,  2,   1,  1,  1,  1,   2,  2,  3,  2,   2,  2,  2,  1,
          0,  0,  1,  1,   0,  0,  1,  1,   1,  1,  2,  1,   1,  1,  2,  1,
          1,  1,  2,  2,   1,  1,  1,  1,   2,  2,  3,  2,   2,  2,  2,  1,

          1,  1,  2,  2,   1,  1,  2,  2,   2,  2,  3,  2,   2,  2,  3,  2,
          1,  1,  2,  2,   1,  1,  1,  1,   2,  2,  3,  2,   2,  2,  2,  1,
          1,  1,  2,  2,   1,  1,  2,  2,   1,  1,  2,  1,   1,  1,  2,  1,
          1,  1,  2,  2,   1,  1,  1,  1,   1,  1,  2,  1,   1,  1,  1,  1
        };



        template <typename I, typename N>
        inline
        unsigned
        nb_connexity2d(const I& ima,
                       const N& nbh,
                       const mln_site(I)& p,
                       bool object)
        {
          unsigned res = 0;

          mln_bkd_niter(N) n(c8(), p);
          for_all(n)
          {
            res = (res << 1);
            if (ima.domain().has(n) && ima(n) == object)
              res = res | 1;
          }

          if (nbh == c8())
            return nb_connexity_c8[res];
          else
          {
            mln_assertion(nbh == c4());
            return nb_connexity_c4[res];
          }
        }


        template <typename N>
        neighb2d
        complement2d(const Neighborhood<N>& nbh_)
        {
          const N& nbh = exact(nbh_);
          mln_precondition(nbh.is_valid());
          mln_precondition(nbh == c4() || nbh == c8());

          if (nbh == c4())
            return c8();
          else
            return c4();
        }


        // Tests.

        template <typename I, typename N>
        inline
        void
        is_simple_point_tests(const Image<I>& ima_,
                              const Neighborhood<N>& nbh_,
                              const mln_site(I)& p)
        {
          const I& ima = exact(ima_);
          const N& nbh = exact(nbh_);

          mln_assertion(nbh == c4() || nbh == c8());
          mln_precondition(ima.is_valid());
          mln_precondition(nbh.is_valid());

          (void) ima;
          (void) nbh;
          (void) p;
        }

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



      // Implementations

      namespace impl
      {

        template <typename I, typename N>
        inline
        bool
        is_simple_point2d(const Image<I>& ima_,
                          const Neighborhood<N>& nbh_,
                          const point2d& p)
        {
          const I& ima = exact(ima_);
          const N& nbh = exact(nbh_);

          internal::is_simple_point_tests(ima, nbh, p);

          bool b = (internal::nb_connexity2d(ima, nbh, p, true) == 1)
            && (internal::nb_connexity2d(ima, internal::complement2d(nbh),
                                         p, false) == 1);

          trace::exiting("topo::skeleton::is_simple_point2d");
          return b;
        }

      } // end of namespace mln::topo::skeleton::impl




      // Dispatch

      namespace internal
      {

        template <typename I, typename N>
        inline
        bool
        is_simple_point_dispatch(const Image<I>& ima,
                                 const Neighborhood<N>& nbh,
                                 const point2d& p)
        {
          return impl::is_simple_point2d(ima, nbh, p);
        }


        template <typename I, typename N>
        inline
        bool
        is_simple_point_dispatch(const Image<I>& ima,
                                 const Neighborhood<N>& nbh,
                                 const mln_site(I)& p)
        {
          mlc_abort(I)::check();
          return false;
        }

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





      // Facade

      template <typename I, typename N>
      inline
      bool
      is_simple_point(const Image<I>& ima,
                      const Neighborhood<N>& nbh,
                      const mln_site(I)& p)
      {
        trace::entering("topo::skeleton::is_simple_point2d");

        internal::is_simple_point_tests(ima, nbh, p);

        bool b = internal::is_simple_point_dispatch(ima, nbh, p);

        trace::exiting("topo::skeleton::is_simple_point2d");
        return b;
      }


# endif // MLN_TOPO_SKELETON_INCLUDE_ONLY

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

  } // end of namespace mln::topo

} // end of namespace mln

#endif // ! MLN_TOPO_SKELETON_IS_SIMPLE_POINT_HH