| // 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_LENGTH_HPP |
| #define BOOST_GEOMETRY_ALGORITHMS_LENGTH_HPP |
| |
| #include <iterator> |
| |
| #include <boost/range.hpp> |
| |
| #include <boost/mpl/if.hpp> |
| #include <boost/type_traits.hpp> |
| |
| #include <boost/geometry/core/cs.hpp> |
| #include <boost/geometry/core/closure.hpp> |
| |
| #include <boost/geometry/geometries/concepts/check.hpp> |
| |
| #include <boost/geometry/algorithms/assign.hpp> |
| #include <boost/geometry/algorithms/detail/calculate_null.hpp> |
| #include <boost/geometry/views/closeable_view.hpp> |
| #include <boost/geometry/strategies/distance.hpp> |
| #include <boost/geometry/strategies/default_length_result.hpp> |
| |
| |
| namespace boost { namespace geometry |
| { |
| |
| |
| #ifndef DOXYGEN_NO_DETAIL |
| namespace detail { namespace length |
| { |
| |
| |
| template<typename Segment, typename Strategy> |
| struct segment_length |
| { |
| static inline typename default_length_result<Segment>::type apply( |
| Segment const& segment, Strategy const& strategy) |
| { |
| typedef typename point_type<Segment>::type point_type; |
| point_type p1, p2; |
| geometry::detail::assign_point_from_index<0>(segment, p1); |
| geometry::detail::assign_point_from_index<1>(segment, p2); |
| return strategy.apply(p1, p2); |
| } |
| }; |
| |
| /*! |
| \brief Internal, calculates length of a linestring using iterator pairs and |
| specified strategy |
| \note for_each could be used here, now that point_type is changed by boost |
| range iterator |
| */ |
| template<typename Range, typename Strategy, closure_selector Closure> |
| struct range_length |
| { |
| typedef typename default_length_result<Range>::type return_type; |
| |
| static inline return_type apply( |
| Range const& range, Strategy const& strategy) |
| { |
| typedef typename closeable_view<Range const, Closure>::type view_type; |
| typedef typename boost::range_iterator |
| < |
| view_type const |
| >::type iterator_type; |
| |
| return_type sum = return_type(); |
| view_type view(range); |
| iterator_type it = boost::begin(view), end = boost::end(view); |
| if(it != end) |
| { |
| for(iterator_type previous = it++; |
| it != end; |
| ++previous, ++it) |
| { |
| // Add point-point distance using the return type belonging |
| // to strategy |
| sum += strategy.apply(*previous, *it); |
| } |
| } |
| |
| return sum; |
| } |
| }; |
| |
| |
| }} // namespace detail::length |
| #endif // DOXYGEN_NO_DETAIL |
| |
| |
| #ifndef DOXYGEN_NO_DISPATCH |
| namespace dispatch |
| { |
| |
| |
| template <typename Tag, typename Geometry, typename Strategy> |
| struct length : detail::calculate_null |
| < |
| typename default_length_result<Geometry>::type, |
| Geometry, |
| Strategy |
| > |
| {}; |
| |
| |
| template <typename Geometry, typename Strategy> |
| struct length<linestring_tag, Geometry, Strategy> |
| : detail::length::range_length<Geometry, Strategy, closed> |
| {}; |
| |
| |
| // RING: length is currently 0; it might be argued that it is the "perimeter" |
| |
| |
| template <typename Geometry, typename Strategy> |
| struct length<segment_tag, Geometry, Strategy> |
| : detail::length::segment_length<Geometry, Strategy> |
| {}; |
| |
| |
| } // namespace dispatch |
| #endif // DOXYGEN_NO_DISPATCH |
| |
| |
| /*! |
| \brief \brief_calc{length} |
| \ingroup length |
| \details \details_calc{length, length (the sum of distances between consecutive points)}. \details_default_strategy |
| \tparam Geometry \tparam_geometry |
| \param geometry \param_geometry |
| \return \return_calc{length} |
| |
| \qbk{[include reference/algorithms/length.qbk]} |
| \qbk{[length] [length_output]} |
| */ |
| template<typename Geometry> |
| inline typename default_length_result<Geometry>::type length( |
| Geometry const& geometry) |
| { |
| concept::check<Geometry const>(); |
| |
| typedef typename strategy::distance::services::default_strategy |
| < |
| point_tag, typename point_type<Geometry>::type |
| >::type strategy_type; |
| |
| return dispatch::length |
| < |
| typename tag<Geometry>::type, |
| Geometry, |
| strategy_type |
| >::apply(geometry, strategy_type()); |
| } |
| |
| |
| /*! |
| \brief \brief_calc{length} \brief_strategy |
| \ingroup length |
| \details \details_calc{length, length (the sum of distances between consecutive points)} \brief_strategy. \details_strategy_reasons |
| \tparam Geometry \tparam_geometry |
| \tparam Strategy \tparam_strategy{distance} |
| \param geometry \param_geometry |
| \param strategy \param_strategy{distance} |
| \return \return_calc{length} |
| |
| \qbk{distinguish,with strategy} |
| \qbk{[include reference/algorithms/length.qbk]} |
| \qbk{[length_with_strategy] [length_with_strategy_output]} |
| */ |
| template<typename Geometry, typename Strategy> |
| inline typename default_length_result<Geometry>::type length( |
| Geometry const& geometry, Strategy const& strategy) |
| { |
| concept::check<Geometry const>(); |
| |
| return dispatch::length |
| < |
| typename tag<Geometry>::type, |
| Geometry, |
| Strategy |
| >::apply(geometry, strategy); |
| } |
| |
| |
| }} // namespace boost::geometry |
| |
| #endif // BOOST_GEOMETRY_ALGORITHMS_LENGTH_HPP |