| // Boost.Geometry (aka GGL, Generic Geometry Library) |
| |
| // Copyright (c) 2008-2011 Bruno Lalande, Paris, France. |
| // Copyright (c) 2008-2011 Barend Gehrels, Amsterdam, the Netherlands. |
| // 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_ARITHMETIC_DOT_PRODUCT_HPP |
| #define BOOST_GEOMETRY_ARITHMETIC_DOT_PRODUCT_HPP |
| |
| |
| #include <cstddef> |
| |
| #include <boost/concept/requires.hpp> |
| |
| #include <boost/geometry/geometries/concepts/point_concept.hpp> |
| #include <boost/geometry/util/select_coordinate_type.hpp> |
| |
| namespace boost { namespace geometry |
| { |
| |
| #ifndef DOXYGEN_NO_DETAIL |
| namespace detail |
| { |
| |
| template <typename P1, typename P2, std::size_t Dimension, std::size_t DimensionCount> |
| struct dot_product_maker |
| { |
| typedef typename select_coordinate_type<P1, P2>::type coordinate_type; |
| |
| static inline coordinate_type apply(P1 const& p1, P2 const& p2) |
| { |
| return get<Dimension>(p1) * get<Dimension>(p2) |
| + dot_product_maker<P1, P2, Dimension+1, DimensionCount>::apply(p1, p2); |
| } |
| }; |
| |
| template <typename P1, typename P2, std::size_t DimensionCount> |
| struct dot_product_maker<P1, P2, DimensionCount, DimensionCount> |
| { |
| typedef typename select_coordinate_type<P1, P2>::type coordinate_type; |
| |
| static inline coordinate_type apply(P1 const& p1, P2 const& p2) |
| { |
| return get<DimensionCount>(p1) * get<DimensionCount>(p2); |
| } |
| }; |
| |
| } // namespace detail |
| #endif // DOXYGEN_NO_DETAIL |
| |
| |
| /*! |
| \brief Computes the dot product (or scalar product) of 2 vectors (points). |
| \ingroup arithmetic |
| \param p1 first point |
| \param p2 second point |
| \return the dot product |
| */ |
| template <typename P1, typename P2> |
| inline typename select_coordinate_type<P1, P2>::type dot_product( |
| P1 const& p1, P2 const& p2) |
| { |
| BOOST_CONCEPT_ASSERT( (concept::ConstPoint<P1>) ); |
| BOOST_CONCEPT_ASSERT( (concept::ConstPoint<P2>) ); |
| |
| return detail::dot_product_maker |
| < |
| P1, P2, |
| 0, dimension<P1>::type::value - 1 |
| >::apply(p1, p2); |
| } |
| |
| }} // namespace boost::geometry |
| |
| #endif // BOOST_GEOMETRY_ARITHMETIC_DOT_PRODUCT_HPP |