]>
Commit | Line | Data |
---|---|---|
1 | // Boost.Geometry (aka GGL, Generic Geometry Library) | |
2 | ||
3 | // Copyright (c) 2008-2012 Bruno Lalande, Paris, France. | |
4 | // Copyright (c) 2008-2012 Barend Gehrels, Amsterdam, the Netherlands. | |
5 | // Copyright (c) 2009-2012 Mateusz Loskot, London, UK. | |
6 | ||
7 | // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library | |
8 | // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands. | |
9 | ||
10 | // Use, modification and distribution is subject to the Boost Software License, | |
11 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
12 | // http://www.boost.org/LICENSE_1_0.txt) | |
13 | ||
14 | #ifndef BOOST_GEOMETRY_ARITHMETIC_DOT_PRODUCT_HPP | |
15 | #define BOOST_GEOMETRY_ARITHMETIC_DOT_PRODUCT_HPP | |
16 | ||
17 | ||
18 | #include <cstddef> | |
19 | ||
20 | #include <boost/concept/requires.hpp> | |
21 | ||
22 | #include <boost/geometry/geometries/concepts/point_concept.hpp> | |
23 | #include <boost/geometry/util/select_coordinate_type.hpp> | |
24 | ||
25 | namespace boost { namespace geometry | |
26 | { | |
27 | ||
28 | #ifndef DOXYGEN_NO_DETAIL | |
29 | namespace detail | |
30 | { | |
31 | ||
32 | template <typename P1, typename P2, std::size_t Dimension, std::size_t DimensionCount> | |
33 | struct dot_product_maker | |
34 | { | |
35 | typedef typename select_coordinate_type<P1, P2>::type coordinate_type; | |
36 | ||
37 | static inline coordinate_type apply(P1 const& p1, P2 const& p2) | |
38 | { | |
39 | return get<Dimension>(p1) * get<Dimension>(p2) | |
40 | + dot_product_maker<P1, P2, Dimension+1, DimensionCount>::apply(p1, p2); | |
41 | } | |
42 | }; | |
43 | ||
44 | template <typename P1, typename P2, std::size_t DimensionCount> | |
45 | struct dot_product_maker<P1, P2, DimensionCount, DimensionCount> | |
46 | { | |
47 | typedef typename select_coordinate_type<P1, P2>::type coordinate_type; | |
48 | ||
49 | static inline coordinate_type apply(P1 const& p1, P2 const& p2) | |
50 | { | |
51 | return get<DimensionCount>(p1) * get<DimensionCount>(p2); | |
52 | } | |
53 | }; | |
54 | ||
55 | } // namespace detail | |
56 | #endif // DOXYGEN_NO_DETAIL | |
57 | ||
58 | ||
59 | /*! | |
60 | \brief Computes the dot product (or scalar product) of 2 vectors (points). | |
61 | \ingroup arithmetic | |
62 | \tparam Point1 \tparam_point | |
63 | \tparam Point2 \tparam_point | |
64 | \param p1 first point | |
65 | \param p2 second point | |
66 | \return the dot product | |
67 | */ | |
68 | template <typename Point1, typename Point2> | |
69 | inline typename select_coordinate_type<Point1, Point2>::type dot_product( | |
70 | Point1 const& p1, Point2 const& p2) | |
71 | { | |
72 | BOOST_CONCEPT_ASSERT( (concepts::ConstPoint<Point1>) ); | |
73 | BOOST_CONCEPT_ASSERT( (concepts::ConstPoint<Point2>) ); | |
74 | ||
75 | return detail::dot_product_maker | |
76 | < | |
77 | Point1, Point2, | |
78 | 0, dimension<Point1>::type::value - 1 | |
79 | >::apply(p1, p2); | |
80 | } | |
81 | ||
82 | }} // namespace boost::geometry | |
83 | ||
84 | #endif // BOOST_GEOMETRY_ARITHMETIC_DOT_PRODUCT_HPP |