[distance] add implementation for distance computation between a polygon and a segment or a box

2026-02-11 11:52:11 +00:00 · 2014-05-08 14:57:11 +03:00
parent 26dfb26d69
commit 3051652a5b
1 changed files with 152 additions and 0 deletions
--- a/include/boost/geometry/algorithms/detail/distance/polygon_to_segment_or_box.hpp
+++ b/include/boost/geometry/algorithms/detail/distance/polygon_to_segment_or_box.hpp
@@ -0,0 +1,152 @@
+// 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_DISTANCE_POLYGON_TO_SEGMENT_OR_BOX_HPP
+#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_DISTANCE_POLYGON_TO_SEGMENT_OR_BOX_HPP
+
+#include <boost/range.hpp>
+
+#include <boost/geometry/core/exterior_ring.hpp>
+#include <boost/geometry/core/interior_rings.hpp>
+#include <boost/geometry/core/point_type.hpp>
+#include <boost/geometry/core/tags.hpp>
+
+#include <boost/geometry/strategies/default_distance_result.hpp>
+#include <boost/geometry/strategies/distance.hpp>
+#include <boost/geometry/strategies/distance_comparable_to_regular.hpp>
+#include <boost/geometry/strategies/tags.hpp>
+
+#include <boost/geometry/algorithms/assign.hpp>
+#include <boost/geometry/algorithms/within.hpp>
+#include <boost/geometry/algorithms/intersects.hpp>
+
+#include <boost/geometry/util/math.hpp>
+
+#include <boost/geometry/algorithms/dispatch/distance.hpp>
+
+#include <boost/geometry/algorithms/detail/distance/point_to_geometry.hpp>
+#include <boost/geometry/algorithms/detail/distance/range_to_segment_or_box.hpp>
+
+
+namespace boost { namespace geometry
+{
+
+#ifndef DOXYGEN_NO_DETAIL
+namespace detail { namespace distance
+{
+
+
+template <typename Polygon, typename SegmentOrBox, typename Strategy>
+struct polygon_to_segment_or_box
+{
+    typedef typename return_type
+        <
+            Strategy,
+            typename point_type<Polygon>::type,
+            typename point_type<SegmentOrBox>::type
+        >::type return_type;
+
+    typedef typename strategy::distance::services::comparable_type
+       <
+           Strategy
+       >::type comparable_strategy;
+
+    static inline return_type apply(Polygon const& polygon,
+                                    SegmentOrBox const& segment_or_box,
+                                    Strategy const& strategy)
+    {
+        typedef typename geometry::ring_type<Polygon>::type e_ring;
+        typedef typename geometry::interior_type<Polygon>::type i_rings;
+        typedef typename range_value<i_rings>::type i_ring;
+
+        if ( geometry::intersects(polygon, segment_or_box) )
+        {
+            return 0;
+        }
+
+        e_ring const& ext_ring = geometry::exterior_ring<Polygon>(polygon);
+        i_rings const& int_rings = geometry::interior_rings<Polygon>(polygon);
+
+        comparable_strategy cstrategy =
+            strategy::distance::services::get_comparable
+                <
+                    Strategy
+                >::apply(strategy);
+
+
+        return_type cd_min = range_to_segment_or_box
+            <
+                e_ring, SegmentOrBox, comparable_strategy
+            >::apply(ext_ring, segment_or_box, cstrategy, false);
+
+        typedef typename boost::range_iterator<i_rings const>::type iterator_type;
+        for (iterator_type it = boost::begin(int_rings);
+             it != boost::end(int_rings); ++it)
+        {
+            return_type cd = range_to_segment_or_box
+                <
+                    i_ring, SegmentOrBox, comparable_strategy
+                >::apply(*it, segment_or_box, cstrategy, false);
+
+            if ( cd < cd_min )
+            {
+                cd_min = cd;
+            }
+        }
+
+        return strategy::distance::services::comparable_to_regular
+            <
+                comparable_strategy,
+                Strategy,
+                Polygon,
+                SegmentOrBox
+            >::apply(cd_min);
+    }
+};
+
+
+}} // namespace detail::distance
+#endif // DOXYGEN_NO_DETAIL
+
+
+
+#ifndef DOXYGEN_NO_DETAIL
+namespace dispatch
+{
+
+
+template <typename Polygon, typename Segment, typename Strategy>
+struct distance
+    <
+        Polygon, Segment, Strategy, polygon_tag, segment_tag,
+        strategy_tag_distance_point_segment, false
+    >    
+    : detail::distance::polygon_to_segment_or_box<Polygon, Segment, Strategy>
+{};
+
+
+
+template <typename Polygon, typename Box, typename Strategy>
+struct distance
+    <
+        Polygon, Box, Strategy, polygon_tag, box_tag,
+        strategy_tag_distance_point_segment, false
+    >    
+    : detail::distance::polygon_to_segment_or_box<Polygon, Box, Strategy>
+{};
+
+
+
+} // namespace dispatch
+#endif // DOXYGEN_NO_DETAIL
+
+}} // namespace boost::geometry
+
+
+#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_DISTANCE_POLYGON_TO_SEGMENT_OR_BOX_HPP