| // Boost.Geometry (aka GGL, Generic Geometry Library) |
| |
| // Copyright (c) 2011 Barend Gehrels, 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_STRATEGIES_SPHERICAL_SSF_HPP |
| #define BOOST_GEOMETRY_STRATEGIES_SPHERICAL_SSF_HPP |
| |
| #include <boost/mpl/if.hpp> |
| #include <boost/type_traits.hpp> |
| |
| #include <boost/geometry/core/cs.hpp> |
| #include <boost/geometry/core/access.hpp> |
| #include <boost/geometry/core/radian_access.hpp> |
| |
| #include <boost/geometry/util/select_coordinate_type.hpp> |
| #include <boost/geometry/util/math.hpp> |
| |
| #include <boost/geometry/strategies/side.hpp> |
| //#include <boost/geometry/strategies/concepts/side_concept.hpp> |
| |
| |
| namespace boost { namespace geometry |
| { |
| |
| |
| namespace strategy { namespace side |
| { |
| |
| |
| /*! |
| \brief Check at which side of a Great Circle segment a point lies |
| left of segment (> 0), right of segment (< 0), on segment (0) |
| \ingroup strategies |
| \tparam CalculationType \tparam_calculation |
| */ |
| template <typename CalculationType = void> |
| class spherical_side_formula |
| { |
| |
| public : |
| template <typename P1, typename P2, typename P> |
| static inline int apply(P1 const& p1, P2 const& p2, P const& p) |
| { |
| typedef typename boost::mpl::if_c |
| < |
| boost::is_void<CalculationType>::type::value, |
| |
| // Select at least a double... |
| typename select_most_precise |
| < |
| typename select_most_precise |
| < |
| typename select_most_precise |
| < |
| typename coordinate_type<P1>::type, |
| typename coordinate_type<P2>::type |
| >::type, |
| typename coordinate_type<P>::type |
| >::type, |
| double |
| >::type, |
| CalculationType |
| >::type coordinate_type; |
| |
| // Convenient shortcuts |
| typedef coordinate_type ct; |
| ct const lambda1 = get_as_radian<0>(p1); |
| ct const delta1 = get_as_radian<1>(p1); |
| ct const lambda2 = get_as_radian<0>(p2); |
| ct const delta2 = get_as_radian<1>(p2); |
| ct const lambda = get_as_radian<0>(p); |
| ct const delta = get_as_radian<1>(p); |
| |
| // Create temporary points (vectors) on unit a sphere |
| ct const cos_delta1 = cos(delta1); |
| ct const c1x = cos_delta1 * cos(lambda1); |
| ct const c1y = cos_delta1 * sin(lambda1); |
| ct const c1z = sin(delta1); |
| |
| ct const cos_delta2 = cos(delta2); |
| ct const c2x = cos_delta2 * cos(lambda2); |
| ct const c2y = cos_delta2 * sin(lambda2); |
| ct const c2z = sin(delta2); |
| |
| // (Third point is converted directly) |
| ct const cos_delta = cos(delta); |
| |
| // Apply the "Spherical Side Formula" as presented on my blog |
| ct const dist |
| = (c1y * c2z - c1z * c2y) * cos_delta * cos(lambda) |
| + (c1z * c2x - c1x * c2z) * cos_delta * sin(lambda) |
| + (c1x * c2y - c1y * c2x) * sin(delta); |
| |
| ct zero = ct(); |
| return dist > zero ? 1 |
| : dist < zero ? -1 |
| : 0; |
| } |
| }; |
| |
| |
| #ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS |
| namespace services |
| { |
| |
| /*template <typename CalculationType> |
| struct default_strategy<spherical_polar_tag, CalculationType> |
| { |
| typedef spherical_side_formula<CalculationType> type; |
| };*/ |
| |
| template <typename CalculationType> |
| struct default_strategy<spherical_equatorial_tag, CalculationType> |
| { |
| typedef spherical_side_formula<CalculationType> type; |
| }; |
| |
| template <typename CalculationType> |
| struct default_strategy<geographic_tag, CalculationType> |
| { |
| typedef spherical_side_formula<CalculationType> type; |
| }; |
| |
| } |
| #endif |
| |
| }} // namespace strategy::side |
| |
| }} // namespace boost::geometry |
| |
| |
| #endif // BOOST_GEOMETRY_STRATEGIES_SPHERICAL_SSF_HPP |