// Boost.Geometry (aka GGL, Generic Geometry Library)
|
|
// Copyright (c) 2014, Oracle and/or its affiliates.
|
|
// Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
|
|
// Licensed under the Boost Software License version 1.0.
|
// http://www.boost.org/users/license.html
|
|
#ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_CLOSEST_FEATURE_GEOMETRY_TO_RANGE_HPP
|
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_CLOSEST_FEATURE_GEOMETRY_TO_RANGE_HPP
|
|
#include <iterator>
|
|
#include <boost/geometry/core/assert.hpp>
|
#include <boost/geometry/core/point_type.hpp>
|
#include <boost/geometry/strategies/distance.hpp>
|
#include <boost/geometry/util/math.hpp>
|
|
#include <boost/geometry/algorithms/dispatch/distance.hpp>
|
|
|
namespace boost { namespace geometry
|
{
|
|
#ifndef DOXYGEN_NO_DETAIL
|
namespace detail { namespace closest_feature
|
{
|
|
|
|
// returns the range iterator the realizes the closest
|
// distance between the geometry and the element of the range
|
class geometry_to_range
|
{
|
private:
|
template
|
<
|
typename Geometry,
|
typename RangeIterator,
|
typename Strategy,
|
typename Distance
|
>
|
static inline void apply(Geometry const& geometry,
|
RangeIterator first,
|
RangeIterator last,
|
Strategy const& strategy,
|
RangeIterator& it_min,
|
Distance& dist_min)
|
{
|
BOOST_GEOMETRY_ASSERT( first != last );
|
|
Distance const zero = Distance(0);
|
|
// start with first distance
|
it_min = first;
|
dist_min = dispatch::distance
|
<
|
Geometry,
|
typename std::iterator_traits<RangeIterator>::value_type,
|
Strategy
|
>::apply(geometry, *it_min, strategy);
|
|
// check if other elements in the range are closer
|
for (RangeIterator it = ++first; it != last; ++it)
|
{
|
Distance dist = dispatch::distance
|
<
|
Geometry,
|
typename std::iterator_traits<RangeIterator>::value_type,
|
Strategy
|
>::apply(geometry, *it, strategy);
|
|
if (geometry::math::equals(dist, zero))
|
{
|
dist_min = dist;
|
it_min = it;
|
return;
|
}
|
else if (dist < dist_min)
|
{
|
dist_min = dist;
|
it_min = it;
|
}
|
}
|
}
|
|
public:
|
template
|
<
|
typename Geometry,
|
typename RangeIterator,
|
typename Strategy,
|
typename Distance
|
>
|
static inline RangeIterator apply(Geometry const& geometry,
|
RangeIterator first,
|
RangeIterator last,
|
Strategy const& strategy,
|
Distance& dist_min)
|
{
|
RangeIterator it_min;
|
apply(geometry, first, last, strategy, it_min, dist_min);
|
|
return it_min;
|
}
|
|
|
template
|
<
|
typename Geometry,
|
typename RangeIterator,
|
typename Strategy
|
>
|
static inline RangeIterator apply(Geometry const& geometry,
|
RangeIterator first,
|
RangeIterator last,
|
Strategy const& strategy)
|
{
|
typename strategy::distance::services::return_type
|
<
|
Strategy,
|
typename point_type<Geometry>::type,
|
typename point_type
|
<
|
typename std::iterator_traits
|
<
|
RangeIterator
|
>::value_type
|
>::type
|
>::type dist_min;
|
|
return apply(geometry, first, last, strategy, dist_min);
|
}
|
};
|
|
|
|
}} // namespace detail::closest_feature
|
#endif // DOXYGEN_NO_DETAIL
|
|
}} // namespace boost::geometry
|
|
|
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_CLOSEST_FEATURE_GEOMETRY_TO_RANGE_HPP
|
