[algorithms][envelope][spherical] move existing implementation of

envelope(box, mbr) to separate file and add implementation for
envelope(box, mbr) for boxes in the spherical equatorial and geographic
coordinate systems

include/boost/geometry/algorithms/detail/envelope/box.hpp

@@ -0,0 +1,128 @@
+// Boost.Geometry (aka GGL, Generic Geometry Library)
+
+// Copyright (c) 2007-2015 Barend Gehrels, Amsterdam, the Netherlands.
+// Copyright (c) 2008-2015 Bruno Lalande, Paris, France.
+// Copyright (c) 2009-2015 Mateusz Loskot, London, UK.
+
+// This file was modified by Oracle on 2015.
+// Modifications copyright (c) 2015, Oracle and/or its affiliates.
+
+// Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
+
+// Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
+// (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
+
+// 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_ALGORITHMS_DETAIL_ENVELOPE_BOX_HPP
+#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_ENVELOPE_BOX_HPP
+
+#include <boost/geometry/core/access.hpp>
+#include <boost/geometry/core/cs.hpp>
+#include <boost/geometry/core/coordinate_system.hpp>
+#include <boost/geometry/core/coordinate_type.hpp>
+#include <boost/geometry/core/tags.hpp>
+
+#include <boost/geometry/util/math.hpp>
+#include <boost/geometry/util/normalize_spheroidal_coordinates.hpp>
+#include <boost/geometry/util/convert_on_spheroid.hpp>
+
+#include <boost/geometry/algorithms/assign.hpp>
+#include <boost/geometry/algorithms/convert.hpp>
+
+#include <boost/geometry/algorithms/dispatch/envelope.hpp>
+
+
+namespace boost { namespace geometry
+{
+
+#ifndef DOXYGEN_NO_DETAIL
+namespace detail { namespace envelope
+{
+
+
+struct envelope_box_on_spheroid
+{
+    template <typename Box>
+    static inline bool is_band(Box const& box)
+    {
+        typedef typename coordinate_type<Box>::type coordinate_type;
+        coordinate_type const period = math::detail::constants_on_spheroid
+            <
+                coordinate_type,
+                typename coordinate_system<Box>::type::units
+            >::period();
+
+        coordinate_type longitude_diff = geometry::get<max_corner, 0>(box)
+            - geometry::get<min_corner, 0>(box);
+
+        return ! math::smaller(math::abs(longitude_diff), period);
+    }
+
+    template<typename BoxIn, typename BoxOut>
+    static inline void apply(BoxIn const& box_in, BoxOut& mbr)
+    {
+        typedef typename coordinate_type<BoxOut>::type box_out_coordinate_type;
+        typedef typename coordinate_system<BoxOut>::type::units mbr_units_type;
+
+        bool const band = is_band(box_in);
+
+        mbr = math::convert_box<BoxOut>(box_in);
+        box_out_coordinate_type lon1 = geometry::get<min_corner, 0>(mbr);
+        box_out_coordinate_type lat1 = geometry::get<min_corner, 1>(mbr);
+        box_out_coordinate_type lon2 = geometry::get<max_corner, 0>(mbr);
+        box_out_coordinate_type lat2 = geometry::get<max_corner, 1>(mbr);
+
+        math::normalize_spheroidal_box_coordinates
+            <
+                mbr_units_type
+            >(lon1, lat1, lon2, lat2, band);
+
+        assign_values(mbr, lon1, lat1, lon2, lat2);
+    }
+};
+
+
+template <typename CSTag>
+struct envelope_box
+{
+    template<typename BoxIn, typename BoxOut>
+    static inline void apply(BoxIn const& box_in, BoxOut& mbr)
+    {
+        geometry::convert(box_in, mbr);
+    }
+};
+
+template <>
+struct envelope_box<spherical_equatorial_tag>
+    : envelope_box_on_spheroid
+{};
+
+template <>
+struct envelope_box<geographic_tag>
+    : envelope_box_on_spheroid
+{};
+
+
+}} // namespace detail::envelope
+#endif // DOXYGEN_NO_DETAIL
+
+#ifndef DOXYGEN_NO_DISPATCH
+namespace dispatch
+{
+
+
+template <typename Box>
+struct envelope<Box, box_tag>
+    : detail::envelope::envelope_box<typename cs_tag<Box>::type>
+{};
+
+
+} // namespace dispatch
+#endif
+
+}} // namespace boost::geometry
+
+#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_ENVELOPE_BOX_HPP