Chris@102: // Boost.Geometry (aka GGL, Generic Geometry Library)
Chris@102: 
Chris@102: // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
Chris@102: // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
Chris@102: // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
Chris@102: 
Chris@102: // This file was modified by Oracle on 2015.
Chris@102: // Modifications copyright (c) 2015 Oracle and/or its affiliates.
Chris@102: 
Chris@102: // Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
Chris@102: 
Chris@102: // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
Chris@102: // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
Chris@102: 
Chris@102: // Use, modification and distribution is subject to the Boost Software License,
Chris@102: // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
Chris@102: // http://www.boost.org/LICENSE_1_0.txt)
Chris@102: 
Chris@102: #ifndef BOOST_GEOMETRY_STRATEGIES_CARTESIAN_CENTROID_AVERAGE_HPP
Chris@102: #define BOOST_GEOMETRY_STRATEGIES_CARTESIAN_CENTROID_AVERAGE_HPP
Chris@102: 
Chris@102: 
Chris@102: #include <cstddef>
Chris@102: 
Chris@102: #include <boost/geometry/algorithms/assign.hpp>
Chris@102: #include <boost/geometry/arithmetic/arithmetic.hpp>
Chris@102: #include <boost/geometry/core/coordinate_type.hpp>
Chris@102: #include <boost/geometry/core/point_type.hpp>
Chris@102: #include <boost/geometry/strategies/centroid.hpp>
Chris@102: 
Chris@102: 
Chris@102: namespace boost { namespace geometry
Chris@102: {
Chris@102: 
Chris@102: namespace strategy { namespace centroid
Chris@102: {
Chris@102: 
Chris@102: 
Chris@102: /*!
Chris@102: \brief Centroid calculation taking average of points
Chris@102: \ingroup strategies
Chris@102: */
Chris@102: template
Chris@102: <
Chris@102:     typename PointCentroid,
Chris@102:     typename Point = PointCentroid
Chris@102: >
Chris@102: class average
Chris@102: {
Chris@102: private :
Chris@102: 
Chris@102:     /*! subclass to keep state */
Chris@102:     class sum
Chris@102:     {
Chris@102:         friend class average;
Chris@102:         std::size_t count;
Chris@102:         PointCentroid centroid;
Chris@102: 
Chris@102:     public :
Chris@102:         inline sum()
Chris@102:             : count(0)
Chris@102:         {
Chris@102:             assign_zero(centroid);
Chris@102:         }
Chris@102:     };
Chris@102: 
Chris@102: public :
Chris@102:     typedef sum state_type;
Chris@102:     typedef PointCentroid centroid_point_type;
Chris@102:     typedef Point point_type;
Chris@102: 
Chris@102:     static inline void apply(Point const& p, sum& state)
Chris@102:     {
Chris@102:         add_point(state.centroid, p);
Chris@102:         state.count++;
Chris@102:     }
Chris@102: 
Chris@102:     static inline bool result(sum const& state, PointCentroid& centroid)
Chris@102:     {
Chris@102:         centroid = state.centroid;
Chris@102:         if ( state.count > 0 )
Chris@102:         {
Chris@102:             divide_value(centroid, state.count);
Chris@102:             return true;
Chris@102:         }
Chris@102:         return false;
Chris@102:     }
Chris@102: 
Chris@102: };
Chris@102: 
Chris@102: 
Chris@102: #ifndef DOXYGEN_NO_STRATEGY_SPECIALIZATIONS
Chris@102: 
Chris@102: 
Chris@102: namespace services
Chris@102: {
Chris@102: 
Chris@102: template <typename Point, std::size_t DimensionCount, typename Geometry>
Chris@102: struct default_strategy
Chris@102: <
Chris@102:     cartesian_tag,
Chris@102:     pointlike_tag,
Chris@102:     DimensionCount,
Chris@102:     Point,
Chris@102:     Geometry
Chris@102: >
Chris@102: {
Chris@102:     typedef average
Chris@102:         <
Chris@102:             Point,
Chris@102:             typename point_type<Geometry>::type
Chris@102:         > type;
Chris@102: };
Chris@102: 
Chris@102: } // namespace services
Chris@102: 
Chris@102: #endif
Chris@102: 
Chris@102: 
Chris@102: }} // namespace strategy::centroid
Chris@102: 
Chris@102: 
Chris@102: }} // namespace boost::geometry
Chris@102: 
Chris@102: 
Chris@102: #endif // BOOST_GEOMETRY_STRATEGIES_CARTESIAN_CENTROID_AVERAGE_HPP