| // Boost.Geometry (aka GGL, Generic Geometry Library) |
| |
| // Copyright (c) 2007-2011 Barend Gehrels, Amsterdam, the Netherlands. |
| // Copyright (c) 2008-2011 Bruno Lalande, Paris, France. |
| // Copyright (c) 2009-2011 Mateusz Loskot, London, UK. |
| |
| // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library |
| // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands. |
| |
| // Use, modification and distribution is subject to the Boost Software License, |
| // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| |
| #ifndef BOOST_GEOMETRY_ALGORITHMS_COMPARABLE_DISTANCE_HPP |
| #define BOOST_GEOMETRY_ALGORITHMS_COMPARABLE_DISTANCE_HPP |
| |
| |
| #include <boost/geometry/algorithms/distance.hpp> |
| |
| |
| namespace boost { namespace geometry |
| { |
| |
| |
| /*! |
| \brief \brief_calc2{comparable distance measurement} |
| \ingroup distance |
| \details The free function comparable_distance does not necessarily calculate the distance, |
| but it calculates a distance measure such that two distances are comparable to each other. |
| For example: for the Cartesian coordinate system, Pythagoras is used but the square root |
| is not taken, which makes it faster and the results of two point pairs can still be |
| compared to each other. |
| \tparam Geometry1 first geometry type |
| \tparam Geometry2 second geometry type |
| \param geometry1 \param_geometry |
| \param geometry2 \param_geometry |
| \return \return_calc{comparable distance} |
| |
| \qbk{[include reference/algorithms/comparable_distance.qbk]} |
| */ |
| template <typename Geometry1, typename Geometry2> |
| inline typename default_distance_result<Geometry1, Geometry2>::type comparable_distance( |
| Geometry1 const& geometry1, Geometry2 const& geometry2) |
| { |
| concept::check<Geometry1 const>(); |
| concept::check<Geometry2 const>(); |
| |
| typedef typename point_type<Geometry1>::type point1_type; |
| typedef typename point_type<Geometry2>::type point2_type; |
| |
| // Define a point-point-distance-strategy |
| // for either the normal case, either the reversed case |
| |
| typedef typename strategy::distance::services::comparable_type |
| < |
| typename boost::mpl::if_c |
| < |
| geometry::reverse_dispatch |
| <Geometry1, Geometry2>::type::value, |
| typename strategy::distance::services::default_strategy |
| <point_tag, point2_type, point1_type>::type, |
| typename strategy::distance::services::default_strategy |
| <point_tag, point1_type, point2_type>::type |
| >::type |
| >::type strategy_type; |
| |
| return distance(geometry1, geometry2, strategy_type()); |
| } |
| |
| |
| }} // namespace boost::geometry |
| |
| |
| #endif // BOOST_GEOMETRY_ALGORITHMS_COMPARABLE_DISTANCE_HPP |