volume.hh

// Copyright (C) 2007, 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_ACCU_SHAPE_VOLUME_HH
# define MLN_ACCU_SHAPE_VOLUME_HH


# include <mln/accu/internal/base.hh>
# include <mln/core/concept/meta_accumulator.hh>
# include <mln/math/diff_abs.hh>

# include <mln/util/pix.hh>
# include <mln/literal/zero.hh>

namespace mln
{

  namespace accu
  {

    namespace shape
    {

      template <typename I>
      struct volume
        : public mln::accu::internal::base< unsigned , volume<I> >
      {
        typedef util::pix<I> argument;
        typedef typename argument::value value;

        volume();

        void init();
        void take(const argument& pixel);
        void take(const volume<I>& other);

        void set_value(unsigned v);

        unsigned to_result() const;

        bool is_valid() const;

      protected:
        value ref_level__;
        unsigned area__;
        unsigned volume_;
      };


    } // end of mln::accu::shape


    namespace meta
    {

      namespace shape
      {


        struct volume : public Meta_Accumulator< volume >
        {
          template <typename I>
          struct with
          {
            typedef accu::shape::volume<I> ret;
          };
        };

      } // end of namespace mln::accu::meta::shape

    } // end of namespace mln::accu::meta

# ifndef MLN_INCLUDE_ONLY

    namespace shape
    {

      template <typename I>
      inline
      volume<I>::volume()
      {
        init();
      }

      template <typename I>
      inline
      void
      volume<I>::init()
      {
        ref_level__ = literal::zero;
        volume_ = 0;
        area__ = 0;
      }

      template <typename I>
      inline
      void
      volume<I>::take(const argument& pixel)
      {
        /* FIXME: Growing a component using this particular `take'
        routine won't work, since the update does not take care of
        the reference level to compute the new volume.  Maybe we
        could distinguish two cases:

        1. the empty accumulator case (which corresponds to the
        following code);
        2. the non-empty accumulator case (which sohuld act as in
        `take(const volume<I>& other)').

        Currently, the implementation is only valid if the
        accumulator was initialy empty before the call to
        `take(const argument&)'.  */
        ref_level__ = pixel.v();
        ++area__;
        ++volume_;
      }

      template <typename I>
      inline
      void
      volume<I>::take(const volume<I>& other)
      {
        area__ += other.area__;
        /* FIXME: Is it `t.area__' or `area__' ? Théo said it was
        the latter, but both the ISMM 2005 paper and Olena 0.11 use
        the former.  */
        volume_ +=
          other.volume_  +
          other.area__ * mln::math::diff_abs(other.ref_level__, ref_level__);
        // Member ref_level__ is not touched.
      }

      template <typename I>
      inline
      unsigned
      volume<I>::to_result() const
      {
        return volume_;
      }

      template <typename I>
      inline
      void
      volume<I>::set_value(unsigned v)
      {
        volume_ = v;
        // Reset the other members.
        ref_level__ = literal::zero;
        area__ = 0;
      }

      template <typename I>
      inline
      bool
      volume<I>::is_valid() const
      {
        return true;
      }

    } // end of namespace mln::accu::shape

# endif // ! MLN_INCLUDE_ONLY

  } // end of namespace mln::accu

} // end of namespace mln


#endif // ! MLN_ACCU_SHAPE_VOLUME_HH

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