Chris@16: // Boost.Geometry (aka GGL, Generic Geometry Library)
Chris@16: 
Chris@16: // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
Chris@16: // Copyright (c) 2008-2012 Barend Gehrels, Amsterdam, the Netherlands.
Chris@16: // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
Chris@16: 
Chris@16: // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
Chris@16: // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
Chris@16: 
Chris@16: // Use, modification and distribution is subject to the Boost Software License,
Chris@16: // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_GEOMETRY_ARITHMETIC_DOT_PRODUCT_HPP
Chris@16: #define BOOST_GEOMETRY_ARITHMETIC_DOT_PRODUCT_HPP
Chris@16: 
Chris@16: 
Chris@16: #include <cstddef>
Chris@16: 
Chris@16: #include <boost/concept/requires.hpp>
Chris@16: 
Chris@16: #include <boost/geometry/geometries/concepts/point_concept.hpp>
Chris@16: #include <boost/geometry/util/select_coordinate_type.hpp>
Chris@16: 
Chris@16: namespace boost { namespace geometry
Chris@16: {
Chris@16: 
Chris@16: #ifndef DOXYGEN_NO_DETAIL
Chris@16: namespace detail
Chris@16: {
Chris@16: 
Chris@16: template <typename P1, typename P2, std::size_t Dimension, std::size_t DimensionCount>
Chris@16: struct dot_product_maker
Chris@16: {
Chris@16:     typedef typename select_coordinate_type<P1, P2>::type coordinate_type;
Chris@16: 
Chris@16:     static inline coordinate_type apply(P1 const& p1, P2 const& p2)
Chris@16:     {
Chris@16:         return get<Dimension>(p1) * get<Dimension>(p2)
Chris@16:             + dot_product_maker<P1, P2, Dimension+1, DimensionCount>::apply(p1, p2);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <typename P1, typename P2, std::size_t DimensionCount>
Chris@16: struct dot_product_maker<P1, P2, DimensionCount, DimensionCount>
Chris@16: {
Chris@16:     typedef typename select_coordinate_type<P1, P2>::type coordinate_type;
Chris@16: 
Chris@16:     static inline coordinate_type apply(P1 const& p1, P2 const& p2)
Chris@16:     {
Chris@16:         return get<DimensionCount>(p1) * get<DimensionCount>(p2);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: } // namespace detail
Chris@16: #endif // DOXYGEN_NO_DETAIL
Chris@16: 
Chris@16: 
Chris@16: /*!
Chris@16:     \brief Computes the dot product (or scalar product) of 2 vectors (points).
Chris@16:     \ingroup arithmetic
Chris@101:     \tparam Point1 \tparam_point
Chris@101:     \tparam Point2 \tparam_point
Chris@16:     \param p1 first point
Chris@16:     \param p2 second point
Chris@16:     \return the dot product
Chris@16:  */
Chris@101: template <typename Point1, typename Point2>
Chris@101: inline typename select_coordinate_type<Point1, Point2>::type dot_product(
Chris@101:         Point1 const& p1, Point2 const& p2)
Chris@16: {
Chris@101:     BOOST_CONCEPT_ASSERT( (concept::ConstPoint<Point1>) );
Chris@101:     BOOST_CONCEPT_ASSERT( (concept::ConstPoint<Point2>) );
Chris@16: 
Chris@16:     return detail::dot_product_maker
Chris@16:         <
Chris@101:             Point1, Point2,
Chris@101:             0, dimension<Point1>::type::value - 1
Chris@16:         >::apply(p1, p2);
Chris@16: }
Chris@16: 
Chris@16: }} // namespace boost::geometry
Chris@16: 
Chris@16: #endif // BOOST_GEOMETRY_ARITHMETIC_DOT_PRODUCT_HPP