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+// 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