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geometry.index: added path_intersection algorithm.

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[SVN r84131]
This commit is contained in:
Adam Wulkiewicz
2013-05-04 02:08:21 +00:00
parent 2b46aaf296
commit 66f91c3578
1 changed files with 90 additions and 0 deletions
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include/boost/geometry/index/detail/algorithms/path_intersection.hpp Normal file
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// Boost.Geometry Index
//
// n-dimensional box-linestring intersection
//
// Copyright (c) 2011-2013 Adam Wulkiewicz, Lodz, Poland.
//
// 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_INDEX_DETAIL_ALGORITHMS_PATH_INTERSECTION_HPP
#define BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_PATH_INTERSECTION_HPP
#include <boost/geometry/index/detail/algorithms/segment_intersection.hpp>
namespace boost { namespace geometry { namespace index { namespace detail {
namespace dispatch {
template <typename Indexable, typename LineString, typename Tag>
struct path_intersection
{
BOOST_MPL_ASSERT_MSG((false), NOT_IMPLEMENTED_FOR_THIS_GEOMETRY, (path_intersection));
};
template <typename Indexable, typename Linestring>
struct path_intersection<Indexable, Linestring, point_tag>
{
BOOST_MPL_ASSERT_MSG((false), SEGMENT_POINT_INTERSECTION_UNAVAILABLE, (path_intersection));
};
template <typename Indexable, typename Linestring>
struct path_intersection<Indexable, Linestring, box_tag>
{
typedef typename default_length_result<Linestring>::type length_type;
static inline bool apply(Indexable const& b, Linestring const& path, length_type & distance)
{
typedef typename ::boost::range_value<Linestring>::type point_type;
typedef typename default_relative_distance_type<Indexable, point_type>::type relative_distance_type;
typedef typename ::boost::range_const_iterator<Linestring>::type const_iterator;
if ( ::boost::size(path) < 2 )
return false;
const_iterator it0 = ::boost::begin(path);
const_iterator it1 = ::boost::begin(path) + 1;
const_iterator last = ::boost::end(path);
distance = 0;
for ( ; it1 != last ; ++it0, ++it1 )
{
typename default_distance_result<point_type, point_type>::type
dist = geometry::distance(*it0, *it1);
relative_distance_type rel_dist;
if ( index::detail::segment_intersection(b, *it0, *it1, rel_dist) )
{
distance += dist * rel_dist;
return true;
}
else
distance += dist;
}
return false;
}
};
} // namespace dispatch
// TODO - change the name e.g. to path_intersection_distance
// and segment_intersection e.g. to segment_intersection_relative_distance
template <typename Indexable, typename Linestring> inline
bool path_intersection(Indexable const& b,
Linestring const& path,
typename default_length_result<Linestring>::type & distance)
{
// TODO check Indexable and Linestring concepts
return dispatch::path_intersection<
Indexable, Linestring, typename detail::traits::tag<Indexable>::type
>::apply(b, path, distance);
}
}}}} // namespace boost::geometry::index::detail
#endif // BOOST_GEOMETRY_INDEX_DETAIL_ALGORITHMS_PATH_INTERSECTION_HPP