You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and dots ('.'), can be up to 35 characters long. Letters must be lowercase.
144 lines
3.5 KiB
144 lines
3.5 KiB
// Boost.Geometry (aka GGL, Generic Geometry Library) |
|
|
|
// Copyright (c) 2009-2011 Mateusz Loskot, London, UK. |
|
// Copyright (c) 2009-2011 Barend Gehrels, Amsterdam, the Netherlands. |
|
|
|
// 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_STRATEGIES_CARTESIAN_CENTROID_WEIGHTED_LENGTH_HPP |
|
#define BOOST_GEOMETRY_STRATEGIES_CARTESIAN_CENTROID_WEIGHTED_LENGTH_HPP |
|
|
|
#include <boost/geometry/algorithms/distance.hpp> |
|
#include <boost/geometry/arithmetic/arithmetic.hpp> |
|
#include <boost/geometry/util/select_most_precise.hpp> |
|
#include <boost/geometry/strategies/centroid.hpp> |
|
#include <boost/geometry/strategies/default_distance_result.hpp> |
|
|
|
// Helper geometry |
|
#include <boost/geometry/geometries/point.hpp> |
|
|
|
|
|
namespace boost { namespace geometry |
|
{ |
|
|
|
namespace strategy { namespace centroid |
|
{ |
|
|
|
namespace detail |
|
{ |
|
|
|
template <typename Type, std::size_t DimensionCount> |
|
struct weighted_length_sums |
|
{ |
|
typedef typename geometry::model::point |
|
< |
|
Type, DimensionCount, |
|
cs::cartesian |
|
> work_point; |
|
|
|
Type length; |
|
work_point average_sum; |
|
|
|
inline weighted_length_sums() |
|
: length(Type()) |
|
{ |
|
geometry::assign_zero(average_sum); |
|
} |
|
}; |
|
} |
|
|
|
template |
|
< |
|
typename Point, |
|
typename PointOfSegment = Point |
|
> |
|
class weighted_length |
|
{ |
|
private : |
|
typedef typename select_most_precise |
|
< |
|
typename default_distance_result<Point>::type, |
|
typename default_distance_result<PointOfSegment>::type |
|
>::type distance_type; |
|
|
|
public : |
|
typedef detail::weighted_length_sums |
|
< |
|
distance_type, |
|
geometry::dimension<Point>::type::value |
|
> state_type; |
|
|
|
static inline void apply(PointOfSegment const& p1, |
|
PointOfSegment const& p2, state_type& state) |
|
{ |
|
distance_type const d = geometry::distance(p1, p2); |
|
state.length += d; |
|
|
|
typename state_type::work_point weighted_median; |
|
geometry::assign_zero(weighted_median); |
|
geometry::add_point(weighted_median, p1); |
|
geometry::add_point(weighted_median, p2); |
|
geometry::multiply_value(weighted_median, d/2); |
|
geometry::add_point(state.average_sum, weighted_median); |
|
} |
|
|
|
static inline bool result(state_type const& state, Point& centroid) |
|
{ |
|
distance_type const zero = distance_type(); |
|
if (! geometry::math::equals(state.length, zero)) |
|
{ |
|
assign_zero(centroid); |
|
add_point(centroid, state.average_sum); |
|
divide_value(centroid, state.length); |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
}; |
|
|
|
#ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS |
|
|
|
namespace services |
|
{ |
|
|
|
|
|
// Register this strategy for linear geometries, in all dimensions |
|
|
|
template <std::size_t N, typename Point, typename Geometry> |
|
struct default_strategy |
|
< |
|
cartesian_tag, |
|
linear_tag, |
|
N, |
|
Point, |
|
Geometry |
|
> |
|
{ |
|
typedef weighted_length |
|
< |
|
Point, |
|
typename point_type<Geometry>::type |
|
> type; |
|
}; |
|
|
|
|
|
} // namespace services |
|
|
|
|
|
#endif // DOXYGEN_NO_STRATEGY_SPECIALIZATIONS |
|
|
|
|
|
}} // namespace strategy::centroid |
|
|
|
|
|
}} // namespace boost::geometry |
|
|
|
|
|
#endif // BOOST_GEOMETRY_STRATEGIES_CARTESIAN_CENTROID_WEIGHTED_LENGTH_HPP
|
|
|