box.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_CORE_CONCEPT_BOX_HH
# define MLN_CORE_CONCEPT_BOX_HH


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


namespace mln
{

  template <typename E>
  struct Box : public Site_Set<E>
  {
    /*
      const site& pmin() const;
      const site& pmax() const;
    */

    unsigned len(unsigned i) const;

    // Box associated type.
    typedef const E& q_box;

    const E& bbox() const;

    unsigned nsites() const;

    bool is_empty() const;

  protected:
    Box();
  };




  template <typename Bl, typename Br>
  bool operator<=(const Box<Bl>& lhs, const Box<Br>& rhs);


  template <typename Bl, typename Br>
  bool operator<(const Box<Bl>& lhs, const Box<Br>& rhs);




# ifndef MLN_INCLUDE_ONLY

  // Box<E>

  template <typename E>
  inline
  const E& Box<E>::bbox() const
  {
    return exact(*this);
  }

  template <typename E>
  inline
  unsigned Box<E>::len(unsigned i) const
  {
    return
      exact(this)->is_valid()
      ? 1 + exact(this)->pmax()[i] - exact(this)->pmin()[i]
      : 0u;
  }

  template <typename E>
  inline
  Box<E>::Box()
  {
    typedef mln_site(E) site;
    site (E::*m1)() const = & E::pmin;
    m1 = 0;
    site (E::*m2)() const = & E::pmax;
    m2 = 0;
  }

  template <typename E>
  inline
  unsigned
  Box<E>::nsites() const
  {
    if (! exact(this)->is_valid())
      return 0;
    unsigned count = 1;
    typedef mln_site(E) P; // Helps g++-3.3.5.
    for (unsigned i = 0; i < P::dim; ++i)
      count *= exact(this)->len(i);
    return count;
  }

  template <typename E>
  inline
  bool
  Box<E>::is_empty() const
  {
    // A non-valid box is empty.
    return ! exact(this)->is_valid();
  }


  // Operators.

  template <typename Bl, typename Br>
  inline
  bool operator<=(const Box<Bl>& lhs_, const Box<Br>& rhs_)
  {
    // FIXME: Same grid!
    const Bl& lhs = exact(lhs_);
    const Br& rhs = exact(rhs_);
    typedef mln_site(Bl) P;
    for (unsigned i = 0; i < P::dim; ++i)
      if (lhs.pmin()[i] < rhs.pmin()[i] ||
          lhs.pmax()[i] > rhs.pmax()[i])
        return false;
    return true;
  }

  template <typename Bl, typename Br>
  inline
  bool operator<(const Box<Bl>& lhs_, const Box<Br>& rhs_)
  {
    // FIXME: Same grid!
    const Bl& lhs = exact(lhs_);
    const Br& rhs = exact(rhs_);
    return lhs <= rhs && ! (lhs == rhs);
  }

# endif // ! MLN_INCLUDE_ONLY

} // end of namespace mln


#endif // ! MLN_CORE_CONCEPT_BOX_HH