Chris@102: // Boost.Geometry (aka GGL, Generic Geometry Library)
Chris@102: 
Chris@102: // Copyright (c) 2011-2012 Barend Gehrels, Amsterdam, the Netherlands.
Chris@102: 
Chris@102: // This file was modified by Oracle on 2014.
Chris@102: // Modifications copyright (c) 2014 Oracle and/or its affiliates.
Chris@102: 
Chris@102: // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
Chris@102: 
Chris@102: // Use, modification and distribution is subject to the Boost Software License,
Chris@102: // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@102: // http://www.boost.org/LICENSE_1_0.txt)
Chris@102: 
Chris@102: #ifndef BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_MAPPING_SSF_HPP
Chris@102: #define BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_MAPPING_SSF_HPP
Chris@102: 
Chris@102: 
Chris@102: #include <boost/core/ignore_unused.hpp>
Chris@102: 
Chris@102: #include <boost/geometry/core/radius.hpp>
Chris@102: 
Chris@102: #include <boost/geometry/util/math.hpp>
Chris@102: #include <boost/geometry/util/promote_floating_point.hpp>
Chris@102: #include <boost/geometry/util/select_calculation_type.hpp>
Chris@102: 
Chris@102: #include <boost/geometry/strategies/side.hpp>
Chris@102: #include <boost/geometry/strategies/spherical/ssf.hpp>
Chris@102: 
Chris@102: 
Chris@102: namespace boost { namespace geometry
Chris@102: {
Chris@102: 
Chris@102: namespace strategy { namespace side
Chris@102: {
Chris@102: 
Chris@102: 
Chris@102: // An enumeration type defining types of mapping of geographical
Chris@102: // latitude to spherical latitude.
Chris@102: // See: http://en.wikipedia.org/wiki/Great_ellipse
Chris@102: //      http://en.wikipedia.org/wiki/Latitude#Auxiliary_latitudes
Chris@102: enum mapping_type { mapping_geodetic, mapping_reduced, mapping_geocentric };
Chris@102: 
Chris@102: 
Chris@102: #ifndef DOXYGEN_NO_DETAIL
Chris@102: namespace detail
Chris@102: {
Chris@102: 
Chris@102: template <typename Spheroid, mapping_type Mapping>
Chris@102: struct mapper
Chris@102: {
Chris@102:     explicit inline mapper(Spheroid const& /*spheroid*/) {}
Chris@102: 
Chris@102:     template <typename CalculationType>
Chris@102:     static inline CalculationType const& apply(CalculationType const& lat)
Chris@102:     {
Chris@102:         return lat;
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: template <typename Spheroid>
Chris@102: struct mapper<Spheroid, mapping_reduced>
Chris@102: {
Chris@102:     typedef typename promote_floating_point
Chris@102:         <
Chris@102:             typename radius_type<Spheroid>::type
Chris@102:         >::type fraction_type;
Chris@102: 
Chris@102:     explicit inline mapper(Spheroid const& spheroid)
Chris@102:     {
Chris@102:         fraction_type const a = geometry::get_radius<0>(spheroid);
Chris@102:         fraction_type const b = geometry::get_radius<2>(spheroid);
Chris@102:         b_div_a = b / a;
Chris@102:     }
Chris@102: 
Chris@102:     template <typename CalculationType>
Chris@102:     inline CalculationType apply(CalculationType const& lat) const
Chris@102:     {
Chris@102:         return atan(static_cast<CalculationType>(b_div_a) * tan(lat));
Chris@102:     }
Chris@102: 
Chris@102:     fraction_type b_div_a;
Chris@102: };
Chris@102: 
Chris@102: template <typename Spheroid>
Chris@102: struct mapper<Spheroid, mapping_geocentric>
Chris@102: {
Chris@102:     typedef typename promote_floating_point
Chris@102:         <
Chris@102:             typename radius_type<Spheroid>::type
Chris@102:         >::type fraction_type;
Chris@102: 
Chris@102:     explicit inline mapper(Spheroid const& spheroid)
Chris@102:     {
Chris@102:         fraction_type const a = geometry::get_radius<0>(spheroid);
Chris@102:         fraction_type const b = geometry::get_radius<2>(spheroid);
Chris@102:         sqr_b_div_a = b / a;
Chris@102:         sqr_b_div_a *= sqr_b_div_a;
Chris@102:     }
Chris@102: 
Chris@102:     template <typename CalculationType>
Chris@102:     inline CalculationType apply(CalculationType const& lat) const
Chris@102:     {
Chris@102:         return atan(static_cast<CalculationType>(sqr_b_div_a) * tan(lat));
Chris@102:     }
Chris@102: 
Chris@102:     fraction_type sqr_b_div_a;
Chris@102: };
Chris@102: 
Chris@102: }
Chris@102: #endif // DOXYGEN_NO_DETAIL
Chris@102: 
Chris@102: 
Chris@102: /*!
Chris@102: \brief Check at which side of a geographical segment a point lies
Chris@102:          left of segment (> 0), right of segment (< 0), on segment (0).
Chris@102:          The check is performed by mapping the geographical coordinates
Chris@102:          to spherical coordinates and using spherical_side_formula.
Chris@102: \ingroup strategies
Chris@102: \tparam Spheroid The reference spheroid model
Chris@102: \tparam Mapping The type of mapping of geographical to spherical latitude
Chris@102: \tparam CalculationType \tparam_calculation
Chris@102:  */
Chris@102: template <typename Spheroid,
Chris@102:           mapping_type Mapping = mapping_geodetic,
Chris@102:           typename CalculationType = void>
Chris@102: class mapping_spherical_side_formula
Chris@102: {
Chris@102: 
Chris@102: public :
Chris@102:     inline mapping_spherical_side_formula()
Chris@102:         : m_mapper(Spheroid())
Chris@102:     {}
Chris@102: 
Chris@102:     explicit inline mapping_spherical_side_formula(Spheroid const& spheroid)
Chris@102:         : m_mapper(spheroid)
Chris@102:     {}
Chris@102: 
Chris@102:     template <typename P1, typename P2, typename P>
Chris@102:     inline int apply(P1 const& p1, P2 const& p2, P const& p)
Chris@102:     {
Chris@102:         typedef typename promote_floating_point
Chris@102:             <
Chris@102:                 typename select_calculation_type_alt
Chris@102:                     <
Chris@102:                         CalculationType,
Chris@102:                         P1, P2, P
Chris@102:                     >::type
Chris@102:             >::type calculation_type;
Chris@102: 
Chris@102:         calculation_type lon1 = get_as_radian<0>(p1);
Chris@102:         calculation_type lat1 = m_mapper.template apply<calculation_type>(get_as_radian<1>(p1));
Chris@102:         calculation_type lon2 = get_as_radian<0>(p2);
Chris@102:         calculation_type lat2 = m_mapper.template apply<calculation_type>(get_as_radian<1>(p2));
Chris@102:         calculation_type lon = get_as_radian<0>(p);
Chris@102:         calculation_type lat = m_mapper.template apply<calculation_type>(get_as_radian<1>(p));
Chris@102: 
Chris@102:         return detail::spherical_side_formula(lon1, lat1, lon2, lat2, lon, lat);
Chris@102:     }
Chris@102: 
Chris@102: private:
Chris@102:     side::detail::mapper<Spheroid, Mapping> const m_mapper;
Chris@102: };
Chris@102: 
Chris@102: // The specialization for geodetic latitude which can be used directly
Chris@102: template <typename Spheroid,
Chris@102:           typename CalculationType>
Chris@102: class mapping_spherical_side_formula<Spheroid, mapping_geodetic, CalculationType>
Chris@102: {
Chris@102: 
Chris@102: public :
Chris@102:     inline mapping_spherical_side_formula() {}
Chris@102:     explicit inline mapping_spherical_side_formula(Spheroid const& /*spheroid*/) {}
Chris@102: 
Chris@102:     template <typename P1, typename P2, typename P>
Chris@102:     static inline int apply(P1 const& p1, P2 const& p2, P const& p)
Chris@102:     {
Chris@102:         return spherical_side_formula<CalculationType>::apply(p1, p2, p);
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: }} // namespace strategy::side
Chris@102: 
Chris@102: }} // namespace boost::geometry
Chris@102: 
Chris@102: #endif // BOOST_GEOMETRY_STRATEGIES_GEOGRAPHIC_MAPPING_SSF_HPP