pix.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_UTIL_PIX_HH
# define MLN_UTIL_PIX_HH


# include <mln/core/concept/image.hh>


namespace mln
{

  namespace select
  {

    template <typename P>
    struct p_of : P
    {
      operator typename P::psite() const
      {
        return this->p();
      }
    };

  }

  namespace util
  {

    template <typename I>
    struct pix
    {

      typedef mln_psite(I) psite;

      typedef mln_value(I) value;

      pix(const Image<I>& ima, const mln_psite(I)& p);

      const I& ima() const;

      const mln_psite(I)& p() const;

      mln_rvalue(I) v() const;

    private:

      const I& ima_;

      //
      // FIXME: Do we want a reference here?
      // I (Z) guess we don't since I got invalid values
      // when converting a pixter to a util::pix.
      // The automatic conversion creates a temporary psite which invalided
      // this reference once it was destroyed. see 'operator util::pix()' in
      // core/pixter2d.hh.
      //
      const mln_psite(I) p_;
    };


# ifndef MLN_INCLUDE_ONLY

    template <typename I>
    inline
    pix<I>::pix(const Image<I>& ima, const mln_psite(I)& p)
      : ima_(exact(ima)),
        p_(p)
    {
      mln_postcondition(exact(ima).is_valid());
    }

    template <typename I>
    inline
    const I&
    pix<I>::ima() const
    {
      mln_precondition(ima_.is_valid());
      return ima_;
    }

    template <typename I>
    inline
    const mln_psite(I)&
    pix<I>::p() const
    {
      mln_precondition(ima_.is_valid());
      mln_precondition(ima_.has(p_));
      return p_;
    }

    template <typename I>
    inline
    mln_rvalue(I)
    pix<I>::v() const
    {
      mln_precondition(ima_.is_valid());
      mln_precondition(ima_.has(p_));
      return ima_(p_);
    }

# endif // ! MLN_INCLUDE_ONLY

  } // end of namespace mln::util

} // end of namespace mln


# include <mln/make/pix.hh>


#endif // ! MLN_UTIL_PIX_HH