[util][math][spherical][geographic][normalize] introduce free function

normalize_spheroidal_box_coordinates() that normalizes the coordinates
of a box in the spherical equatorial and geographic coordinate systems

include/boost/geometry/util/normalize_spheroidal_box_coordinates.hpp

@@ -0,0 +1,158 @@
+// Boost.Geometry (aka GGL, Generic Geometry Library)
+
+// Copyright (c) 2015, 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_UTIL_NORMALIZE_SPHEROIDAL_BOX_COORDINATES_HPP
+#define BOOST_GEOMETRY_UTIL_NORMALIZE_SPHEROIDAL_BOX_COORDINATES_HPP
+
+#include <boost/assert.hpp>
+
+#include <boost/geometry/util/math.hpp>
+#include <boost/geometry/util/normalize_spheroidal_coordinates.hpp>
+
+
+namespace boost { namespace geometry
+{
+
+namespace math 
+{
+
+#ifndef DOXYGEN_NO_DETAIL
+namespace detail
+{
+
+
+template <typename Units, typename CoordinateType>
+class normalize_spheroidal_box_coordinates
+{
+private:
+    typedef normalize_spheroidal_coordinates<Units, CoordinateType> normalize;
+    typedef constants_on_spheroid<CoordinateType, Units> constants;
+
+    static inline bool is_band(CoordinateType const& longitude1,
+                               CoordinateType const& longitude2)
+    {
+        return ! math::smaller(math::abs(longitude1 - longitude2),
+                               constants::period());
+    }
+
+public:
+    static inline void apply(CoordinateType& longitude1,
+                             CoordinateType& latitude1,
+                             CoordinateType& longitude2,
+                             CoordinateType& latitude2,
+                             bool band)
+    {
+        normalize::apply(longitude1, latitude1, false);
+        normalize::apply(longitude2, latitude2, false);
+
+        if (math::equals(latitude1, constants::min_latitude())
+            && math::equals(latitude2, constants::min_latitude()))
+        {
+            // box degenerates to the south pole
+            longitude1 = longitude2 = CoordinateType(0);
+        }
+        else if (math::equals(latitude1, constants::max_latitude())
+                 && math::equals(latitude2, constants::max_latitude()))
+        {
+            // box degenerates to the north pole
+            longitude1 = longitude2 = CoordinateType(0);
+        }
+        else if (band)
+        {
+            // the box is a band between two small circles (parallel
+            // to the equator) on the spheroid
+            longitude1 = constants::min_longitude();
+            longitude2 = constants::max_longitude();
+        }
+        else if (longitude1 > longitude2)
+        {
+            // the box crosses the antimeridian, so we need to adjust
+            // the longitudes
+            longitude2 += constants::period();
+        }
+
+        BOOST_ASSERT(! math::larger(latitude1, latitude2));
+        BOOST_ASSERT(! math::smaller(latitude1, constants::min_latitude()));
+        BOOST_ASSERT(! math::larger(latitude2, constants::max_latitude()));
+        BOOST_ASSERT(! math::larger(longitude1, longitude2));
+        BOOST_ASSERT(! math::smaller(longitude1, constants::min_longitude()));
+        BOOST_ASSERT
+            (! math::larger(longitude2 - longitude1, constants::period()));
+    }
+
+    static inline void apply(CoordinateType& longitude1,
+                             CoordinateType& latitude1,
+                             CoordinateType& longitude2,
+                             CoordinateType& latitude2)
+    {
+        bool const band = is_band(longitude1, longitude2);
+
+        apply(longitude1, latitude1, longitude2, latitude2, band);
+    }
+};
+
+
+} // namespace detail
+#endif // DOXYGEN_NO_DETAIL
+
+
+/*!
+\brief Short utility to normalize the coordinates of a box on a spheroid
+\tparam Units The units of the coordindate system in the spheroid
+\tparam CoordinateType The type of the coordinates
+\param longitude1 Minimum longitude of the box
+\param latitude1 Minimum latitude of the box
+\param longitude2 Maximum longitude of the box
+\param latitude2 Maximum latitude of the box
+\ingroup utility
+*/
+template <typename Units, typename CoordinateType>
+inline void normalize_spheroidal_box_coordinates(CoordinateType& longitude1,
+                                                 CoordinateType& latitude1,
+                                                 CoordinateType& longitude2,
+                                                 CoordinateType& latitude2)
+{
+    detail::normalize_spheroidal_box_coordinates
+        <
+            Units, CoordinateType
+        >::apply(longitude1, latitude1, longitude2, latitude2);
+}
+
+/*!
+\brief Short utility to normalize the coordinates of a box on a spheroid
+\tparam Units The units of the coordindate system in the spheroid
+\tparam CoordinateType The type of the coordinates
+\param longitude1 Minimum longitude of the box
+\param latitude1 Minimum latitude of the box
+\param longitude2 Maximum longitude of the box
+\param latitude2 Maximum latitude of the box
+\param band Indicates whether the box should be treated as a band or
+       not and avoid the computation done in the other version of the function
+\ingroup utility
+*/
+template <typename Units, typename CoordinateType>
+inline void normalize_spheroidal_box_coordinates(CoordinateType& longitude1,
+                                                 CoordinateType& latitude1,
+                                                 CoordinateType& longitude2,
+                                                 CoordinateType& latitude2,
+                                                 bool band)
+{
+    detail::normalize_spheroidal_box_coordinates
+        <
+            Units, CoordinateType
+        >::apply(longitude1, latitude1, longitude2, latitude2, band);
+}
+
+
+} // namespace math
+
+
+}} // namespace boost::geometry
+
+#endif // BOOST_GEOMETRY_UTIL_NORMALIZE_SPHEROIDAL_BOX_COORDINATES_HPP