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Diffstat (limited to 'boost/geometry/arithmetic/dot_product.hpp')
-rw-r--r-- | boost/geometry/arithmetic/dot_product.hpp | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/boost/geometry/arithmetic/dot_product.hpp b/boost/geometry/arithmetic/dot_product.hpp new file mode 100644 index 0000000000..13fe968779 --- /dev/null +++ b/boost/geometry/arithmetic/dot_product.hpp @@ -0,0 +1,82 @@ +// Boost.Geometry (aka GGL, Generic Geometry Library) + +// Copyright (c) 2008-2012 Bruno Lalande, Paris, France. +// Copyright (c) 2008-2012 Barend Gehrels, Amsterdam, the Netherlands. +// Copyright (c) 2009-2012 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 |