ceph/src/boost/boost/geometry/strategies/cartesian/line_interpolate.hpp

   1 // Boost.Geometry
   2
   3 // Copyright (c) 2018-2021, Oracle and/or its affiliates.
   4
   5 // Contributed and/or modified by Vissarion Fysikopoulos, on behalf of Oracle
   6 // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
   7
   8 // Licensed under the Boost Software License version 1.0.
   9 // http://www.boost.org/users/license.html
  10
  11 #ifndef BOOST_GEOMETRY_STRATEGIES_CARTESIAN_LINE_INTERPOLATE_HPP
  12 #define BOOST_GEOMETRY_STRATEGIES_CARTESIAN_LINE_INTERPOLATE_HPP
  13
  14 #include <boost/geometry/core/assert.hpp>
  15 #include <boost/geometry/core/coordinate_dimension.hpp>
  16 #include <boost/geometry/core/coordinate_type.hpp>
  17 #include <boost/geometry/strategies/line_interpolate.hpp>
  18 #include <boost/geometry/strategies/cartesian/distance_pythagoras.hpp>
  19 #include <boost/geometry/util/algorithm.hpp>
  20 #include <boost/geometry/util/select_calculation_type.hpp>
  21
  22
  23 namespace boost { namespace geometry
  24 {
  25
  26 namespace strategy { namespace line_interpolate
  27 {
  28
  29
  30 /*!
  31 \brief Interpolate point on a cartesian segment.
  32 \ingroup strategies
  33 \tparam CalculationType \tparam_calculation
  34 \tparam DistanceStrategy The underlying point-point distance strategy
  35
  36 \qbk{
  37 [heading See also]
  38 \* [link geometry.reference.algorithms.line_interpolate.line_interpolate_4_with_strategy line_interpolate (with strategy)]
  39 }
  40
  41 */
  42 template
  43 <
  44     typename CalculationType = void,
  45     typename DistanceStrategy = distance::pythagoras<CalculationType>
  46 >
  47 class cartesian
  48 {
  49 public:
  50     template <typename Point, typename Fraction, typename Distance>
  51     inline void apply(Point const& p0,
  52                       Point const& p1,
  53                       Fraction const& fraction,
  54                       Point & p,
  55                       Distance const&) const
  56     {
  57         typedef typename select_calculation_type_alt
  58             <
  59                 CalculationType, Point
  60             >::type calc_t;
  61         typedef typename coordinate_type<Point>::type coord_t;
  62
  63         //segment convex combination: p0*fraction + p1*(1-fraction)
  64         Fraction const one_minus_fraction = 1-fraction;
  65         geometry::detail::for_each_dimension<Point>([&](auto dimension)
  66         {
  67             // NOTE: numeric_cast is a leftover from convert, it could probably be ommited.
  68             // NOTE: the order of points is different than in the formula above
  69             //       this is also a leftover from the previous implementation
  70             calc_t coord0 = boost::numeric_cast<calc_t>(get<dimension>(p0));
  71             calc_t coord1 = boost::numeric_cast<calc_t>(get<dimension>(p1));
  72             calc_t result = calc_t(coord1 * fraction) + calc_t(coord0 * one_minus_fraction);
  73             set<dimension>(p, boost::numeric_cast<coord_t>(result));
  74         });
  75     }
  76 };
  77
  78
  79 #ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
  80 namespace services
  81 {
  82
  83 template <>
  84 struct default_strategy<cartesian_tag>
  85 {
  86     typedef strategy::line_interpolate::cartesian<> type;
  87 };
  88
  89
  90 } // namespace services
  91 #endif // DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
  92
  93
  94 }} // namespace strategy::line_interpolate
  95
  96
  97 }} // namespace boost::geometry
  98
  99 #endif // BOOST_GEOMETRY_STRATEGIES_CARTESIAN_LINE_INTERPOLATE_HPP