| // 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_STRATEGIES_CARTESIAN_SIDE_BY_TRIANGLE_HPP |
| #define BOOST_GEOMETRY_STRATEGIES_CARTESIAN_SIDE_BY_TRIANGLE_HPP |
| |
| #include <boost/mpl/if.hpp> |
| #include <boost/type_traits.hpp> |
| |
| #include <boost/geometry/core/access.hpp> |
| |
| #include <boost/geometry/util/select_coordinate_type.hpp> |
| |
| #include <boost/geometry/strategies/side.hpp> |
| |
| |
| namespace boost { namespace geometry |
| { |
| |
| namespace strategy { namespace side |
| { |
| |
| /*! |
| \brief Check at which side of a 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 side_by_triangle |
| { |
| public : |
| |
| // Template member function, because it is not always trivial |
| // or convenient to explicitly mention the typenames in the |
| // strategy-struct itself. |
| |
| // Types can be all three different. Therefore it is |
| // not implemented (anymore) as "segment" |
| |
| 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, |
| 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, |
| CalculationType |
| >::type coordinate_type; |
| |
| //std::cout << "side: " << typeid(coordinate_type).name() << std::endl; |
| coordinate_type const x = get<0>(p); |
| coordinate_type const y = get<1>(p); |
| |
| coordinate_type const sx1 = get<0>(p1); |
| coordinate_type const sy1 = get<1>(p1); |
| coordinate_type const sx2 = get<0>(p2); |
| coordinate_type const sy2 = get<1>(p2); |
| |
| // Promote float->double, small int->int |
| typedef typename select_most_precise |
| < |
| coordinate_type, |
| double |
| >::type promoted_type; |
| |
| promoted_type const dx = sx2 - sx1; |
| promoted_type const dy = sy2 - sy1; |
| promoted_type const dpx = x - sx1; |
| promoted_type const dpy = y - sy1; |
| |
| promoted_type const s = dx * dpy - dy * dpx; |
| |
| promoted_type zero = promoted_type(); |
| return math::equals(s, zero) ? 0 |
| : s > zero ? 1 |
| : -1; |
| } |
| }; |
| |
| |
| #ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS |
| namespace services |
| { |
| |
| template <typename CalculationType> |
| struct default_strategy<cartesian_tag, CalculationType> |
| { |
| typedef side_by_triangle<CalculationType> type; |
| }; |
| |
| } |
| #endif |
| |
| }} // namespace strategy::side |
| |
| }} // namespace boost::geometry |
| |
| |
| #endif // BOOST_GEOMETRY_STRATEGIES_CARTESIAN_SIDE_BY_TRIANGLE_HPP |