1 files changed, 147 insertions, 0 deletions
diff --git a/boost/geometry/algorithms/detail/closest_feature/geometry_to_range.hpp b/boost/geometry/algorithms/detail/closest_feature/geometry_to_range.hpp
new file mode 100644
index 0000000000..c7558b4ff1
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+++ b/boost/geometry/algorithms/detail/closest_feature/geometry_to_range.hpp
@@ -0,0 +1,147 @@
+// 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/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_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
+        RangeIterator it = first;
+        for (++it; 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