1 files changed, 150 insertions, 0 deletions
diff --git a/boost/geometry/algorithms/detail/distance/segment_to_segment.hpp b/boost/geometry/algorithms/detail/distance/segment_to_segment.hpp
new file mode 100644
index 0000000000..2dcde64946
--- /dev/null
+++ b/boost/geometry/algorithms/detail/distance/segment_to_segment.hpp
@@ -0,0 +1,150 @@
+// 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_SEGMENT_TO_SEGMENT_HPP
+#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_DISTANCE_SEGMENT_TO_SEGMENT_HPP
+
+#include <algorithm>
+#include <iterator>
+
+#include <boost/core/addressof.hpp>
+
+#include <boost/geometry/core/point_type.hpp>
+#include <boost/geometry/core/tags.hpp>
+
+#include <boost/geometry/strategies/distance.hpp>
+#include <boost/geometry/strategies/tags.hpp>
+
+#include <boost/geometry/algorithms/assign.hpp>
+#include <boost/geometry/algorithms/intersects.hpp>
+
+#include <boost/geometry/algorithms/detail/distance/is_comparable.hpp>
+
+#include <boost/geometry/algorithms/dispatch/distance.hpp>
+
+
+namespace boost { namespace geometry
+{
+
+
+#ifndef DOXYGEN_NO_DETAIL
+namespace detail { namespace distance
+{
+
+
+
+// compute segment-segment distance
+template<typename Segment1, typename Segment2, typename Strategy>
+class segment_to_segment
+{
+private:
+    typedef typename strategy::distance::services::comparable_type
+        <
+            Strategy
+        >::type comparable_strategy;
+
+    typedef typename strategy::distance::services::return_type
+        <
+            comparable_strategy,
+            typename point_type<Segment1>::type,
+            typename point_type<Segment2>::type
+        >::type comparable_return_type;
+
+public:
+    typedef typename strategy::distance::services::return_type
+        <
+            Strategy,
+            typename point_type<Segment1>::type,
+            typename point_type<Segment2>::type
+        >::type return_type;
+
+    static inline return_type
+    apply(Segment1 const& segment1, Segment2 const& segment2,
+          Strategy const& strategy)
+    {
+        if (geometry::intersects(segment1, segment2))
+        {
+            return 0;
+        }
+
+        typename point_type<Segment1>::type p[2];
+        detail::assign_point_from_index<0>(segment1, p[0]);
+        detail::assign_point_from_index<1>(segment1, p[1]);
+
+        typename point_type<Segment2>::type q[2];
+        detail::assign_point_from_index<0>(segment2, q[0]);
+        detail::assign_point_from_index<1>(segment2, q[1]);
+
+        comparable_strategy cstrategy =
+            strategy::distance::services::get_comparable
+                <
+                    Strategy
+                >::apply(strategy);
+
+        comparable_return_type d[4];
+        d[0] = cstrategy.apply(q[0], p[0], p[1]);
+        d[1] = cstrategy.apply(q[1], p[0], p[1]);
+        d[2] = cstrategy.apply(p[0], q[0], q[1]);
+        d[3] = cstrategy.apply(p[1], q[0], q[1]);
+
+        std::size_t imin = std::distance(boost::addressof(d[0]),
+                                         std::min_element(d, d + 4));
+
+        if (is_comparable<Strategy>::value)
+        {
+            return d[imin];
+        }
+
+        switch (imin)
+        {
+        case 0:
+            return strategy.apply(q[0], p[0], p[1]);
+        case 1:
+            return strategy.apply(q[1], p[0], p[1]);
+        case 2:
+            return strategy.apply(p[0], q[0], q[1]);
+        default:
+            return strategy.apply(p[1], q[0], q[1]);
+        }
+    }
+};
+
+
+
+
+}} // namespace detail::distance
+#endif // DOXYGEN_NO_DETAIL
+
+
+#ifndef DOXYGEN_NO_DISPATCH
+namespace dispatch
+{
+
+
+
+// segment-segment
+template <typename Segment1, typename Segment2, typename Strategy>
+struct distance
+    <
+        Segment1, Segment2, Strategy, segment_tag, segment_tag,
+        strategy_tag_distance_point_segment, false
+    >
+    : detail::distance::segment_to_segment<Segment1, Segment2, Strategy>
+{};
+
+
+
+} // namespace dispatch
+#endif // DOXYGEN_NO_DISPATCH
+
+
+}} // namespace boost::geometry
+
+
+#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_DISTANCE_SEGMENT_TO_SEGMENT_HPP