Chris@16: // Boost.Geometry (aka GGL, Generic Geometry Library)
Chris@16: 
Chris@16: // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
Chris@16: 
Chris@16: // Use, modification and distribution is subject to the Boost Software License,
Chris@16: // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_GEOMETRY_POLICIES_COMPARE_HPP
Chris@16: #define BOOST_GEOMETRY_POLICIES_COMPARE_HPP
Chris@16: 
Chris@16: 
Chris@16: #include <cstddef>
Chris@16: 
Chris@16: #include <boost/geometry/strategies/compare.hpp>
Chris@16: #include <boost/geometry/util/math.hpp>
Chris@16: 
Chris@16: 
Chris@16: namespace boost { namespace geometry
Chris@16: {
Chris@16: 
Chris@16: 
Chris@16: #ifndef DOXYGEN_NO_DETAIL
Chris@16: namespace detail { namespace compare
Chris@16: {
Chris@16: 
Chris@16: 
Chris@16: template
Chris@16: <
Chris@16:     int Direction,
Chris@16:     typename Point,
Chris@16:     typename Strategy,
Chris@16:     std::size_t Dimension,
Chris@16:     std::size_t DimensionCount
Chris@16: >
Chris@16: struct compare_loop
Chris@16: {
Chris@16:     typedef typename strategy::compare::detail::select_strategy
Chris@16:         <
Chris@16:             Strategy, Direction, Point, Dimension
Chris@16:         >::type compare_type;
Chris@16: 
Chris@16:     typedef typename geometry::coordinate_type<Point>::type coordinate_type;
Chris@16: 
Chris@16:     static inline bool apply(Point const& left, Point const& right)
Chris@16:     {
Chris@16:         coordinate_type const& cleft = geometry::get<Dimension>(left);
Chris@16:         coordinate_type const& cright = geometry::get<Dimension>(right);
Chris@16: 
Chris@16:         if (geometry::math::equals(cleft, cright))
Chris@16:         {
Chris@16:             return compare_loop
Chris@16:                 <
Chris@16:                     Direction, Point, Strategy,
Chris@16:                     Dimension + 1, DimensionCount
Chris@16:                 >::apply(left, right);
Chris@16:         }
Chris@16:         else
Chris@16:         {
Chris@16:             compare_type compare;
Chris@16:             return compare(cleft, cright);
Chris@16:         }
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template
Chris@16: <
Chris@16:     int Direction,
Chris@16:     typename Point,
Chris@16:     typename Strategy,
Chris@16:     std::size_t DimensionCount
Chris@16: >
Chris@16: struct compare_loop<Direction, Point, Strategy, DimensionCount, DimensionCount>
Chris@16: {
Chris@16:     static inline bool apply(Point const&, Point const&)
Chris@16:     {
Chris@16:         // On coming here, points are equal. Return true if
Chris@16:         // direction = 0 (equal), false if -1/1 (greater/less)
Chris@16:         return Direction == 0;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: template <int Direction, typename Point, typename Strategy>
Chris@16: struct compare_in_all_dimensions
Chris@16: {
Chris@16:     inline bool operator()(Point const& left, Point const& right) const
Chris@16:     {
Chris@16:         return detail::compare::compare_loop
Chris@16:             <
Chris@16:                 Direction, Point, Strategy,
Chris@16:                 0, geometry::dimension<Point>::type::value
Chris@16:             >::apply(left, right);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: template <typename Point, typename Strategy, std::size_t Dimension>
Chris@16: class compare_in_one_dimension
Chris@16: {
Chris@16:     Strategy compare;
Chris@16: 
Chris@16: public :
Chris@16:     inline bool operator()(Point const& left, Point const& right) const
Chris@16:     {
Chris@16:         typedef typename geometry::coordinate_type<Point>::type coordinate_type;
Chris@16: 
Chris@16:         coordinate_type const& cleft = get<Dimension>(left);
Chris@16:         coordinate_type const& cright = get<Dimension>(right);
Chris@16:         return compare(cleft, cright);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: }} // namespace detail::compare
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: #ifndef DOXYGEN_NO_DISPATCH
Chris@16: namespace dispatch
Chris@16: {
Chris@16: 
Chris@16: template
Chris@16: <
Chris@16:     int Direction,
Chris@16:     typename Point,
Chris@16:     typename Strategy,
Chris@16:     int Dimension
Chris@16: >
Chris@16: struct compare_geometries
Chris@16:     : detail::compare::compare_in_one_dimension
Chris@16:         <
Chris@16:             Point,
Chris@16:             typename strategy::compare::detail::select_strategy
Chris@16:                 <
Chris@16:                     Strategy, Direction, Point, Dimension
Chris@16:                 >::type,
Chris@16:             Dimension
Chris@16:         >
Chris@16: {};
Chris@16: 
Chris@16: 
Chris@16: // Specialization with -1: compare in all dimensions
Chris@16: template <int Direction, typename Point, typename Strategy>
Chris@16: struct compare_geometries<Direction, Point, Strategy, -1>
Chris@16:     : detail::compare::compare_in_all_dimensions<Direction, Point, Strategy>
Chris@16: {};
Chris@16: 
Chris@16: 
Chris@16: 
Chris@16: } // namespace dispatch
Chris@16: #endif // DOXYGEN_NO_DISPATCH
Chris@16: 
Chris@16: 
Chris@16: /*!
Chris@16: \brief Less functor, to sort points in ascending order.
Chris@16: \ingroup compare
Chris@16: \details This functor compares points and orders them on x,
Chris@16:     then on y, then on z coordinate.
Chris@16: \tparam Geometry the geometry
Chris@16: \tparam Dimension the dimension to sort on, defaults to -1,
Chris@16:     indicating ALL dimensions. That's to say, first on x,
Chris@16:     on equal x-es then on y, etc.
Chris@16:     If a dimension is specified, only that dimension is considered
Chris@16: \tparam Strategy underlying coordinate comparing functor,
Chris@16:     defaults to the default comparison strategies
Chris@16:     related to the point coordinate system. If specified, the specified
Chris@16:     strategy is used. This can e.g. be std::less<double>.
Chris@16: */
Chris@16: template
Chris@16: <
Chris@16:     typename Point,
Chris@16:     int Dimension = -1,
Chris@16:     typename Strategy = strategy::compare::default_strategy
Chris@16: >
Chris@16: struct less
Chris@16:     : dispatch::compare_geometries
Chris@16:         <
Chris@16:             1, // indicates ascending
Chris@16:             Point,
Chris@16:             Strategy,
Chris@16:             Dimension
Chris@16:         >
Chris@16: {
Chris@16:     typedef Point first_argument_type;
Chris@16:     typedef Point second_argument_type;
Chris@16:     typedef bool result_type;
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: /*!
Chris@16: \brief Greater functor
Chris@16: \ingroup compare
Chris@16: \details Can be used to sort points in reverse order
Chris@16: \see Less functor
Chris@16: */
Chris@16: template
Chris@16: <
Chris@16:     typename Point,
Chris@16:     int Dimension = -1,
Chris@16:     typename Strategy = strategy::compare::default_strategy
Chris@16: >
Chris@16: struct greater
Chris@16:     : dispatch::compare_geometries
Chris@16:         <
Chris@16:             -1,  // indicates descending
Chris@16:             Point,
Chris@16:             Strategy,
Chris@16:             Dimension
Chris@16:         >
Chris@16: {};
Chris@16: 
Chris@16: 
Chris@16: /*!
Chris@16: \brief Equal To functor, to compare if points are equal
Chris@16: \ingroup compare
Chris@16: \tparam Geometry the geometry
Chris@16: \tparam Dimension the dimension to compare on, defaults to -1,
Chris@16:     indicating ALL dimensions.
Chris@16:     If a dimension is specified, only that dimension is considered
Chris@16: \tparam Strategy underlying coordinate comparing functor
Chris@16: */
Chris@16: template
Chris@16: <
Chris@16:     typename Point,
Chris@16:     int Dimension = -1,
Chris@16:     typename Strategy = strategy::compare::default_strategy
Chris@16: >
Chris@16: struct equal_to
Chris@16:     : dispatch::compare_geometries
Chris@16:         <
Chris@16:             0,
Chris@16:             Point,
Chris@16:             Strategy,
Chris@16:             Dimension
Chris@16:         >
Chris@16: {};
Chris@16: 
Chris@16: 
Chris@16: }} // namespace boost::geometry
Chris@16: 
Chris@16: 
Chris@16: #endif // BOOST_GEOMETRY_POLICIES_COMPARE_HPP