Chris@102: // Boost.Geometry (aka GGL, Generic Geometry Library)
Chris@102: // Copyright (c) 2012-2014 Barend Gehrels, Amsterdam, the Netherlands.
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_BUFFER_POINT_SQUARE_HPP
Chris@102: #define BOOST_GEOMETRY_STRATEGIES_CARTESIAN_BUFFER_POINT_SQUARE_HPP
Chris@102: 
Chris@102: #include <cstddef>
Chris@102: 
Chris@102: #include <boost/range.hpp>
Chris@102: 
Chris@102: #include <boost/geometry/util/math.hpp>
Chris@102: 
Chris@102: #include <boost/geometry/strategies/buffer.hpp>
Chris@102: 
Chris@102: 
Chris@102: namespace boost { namespace geometry
Chris@102: {
Chris@102: 
Chris@102: namespace strategy { namespace buffer
Chris@102: {
Chris@102: 
Chris@102: /*!
Chris@102: \brief Create a squared form buffer around a point
Chris@102: \ingroup strategies
Chris@102: \details This strategy can be used as PointStrategy for the buffer algorithm.
Chris@102:     It creates a square from each point, where the point lies in the center.
Chris@102:     It can be applied for points and multi_points, but also for a linestring (if it is degenerate,
Chris@102:     so consisting of only one point) and for polygons (if it is degenerate).
Chris@102:     This strategy is only applicable for Cartesian coordinate systems.
Chris@102: 
Chris@102: \qbk{
Chris@102: [heading Example]
Chris@102: [buffer_point_square]
Chris@102: [heading Output]
Chris@102: [$img/strategies/buffer_point_square.png]
Chris@102: [heading See also]
Chris@102: \* [link geometry.reference.algorithms.buffer.buffer_7_with_strategies buffer (with strategies)]
Chris@102: \* [link geometry.reference.strategies.strategy_buffer_point_circle point_circle]
Chris@102: }
Chris@102:  */
Chris@102: class point_square
Chris@102: {
Chris@102:     template
Chris@102:     <
Chris@102:         typename Point,
Chris@102:         typename DistanceType,
Chris@102:         typename OutputRange
Chris@102:     >
Chris@102:     inline void add_point(Point const& point,
Chris@102:                 DistanceType const& distance,
Chris@102:                 DistanceType const& x,
Chris@102:                 DistanceType const& y,
Chris@102:                 OutputRange& output_range) const
Chris@102:     {
Chris@102:         typename boost::range_value<OutputRange>::type p;
Chris@102:         set<0>(p, get<0>(point) + x * distance);
Chris@102:         set<1>(p, get<1>(point) + y * distance);
Chris@102:         output_range.push_back(p);
Chris@102:     }
Chris@102: 
Chris@102:     template
Chris@102:     <
Chris@102:         typename Point,
Chris@102:         typename DistanceType,
Chris@102:         typename OutputRange
Chris@102:     >
Chris@102:     inline void add_points(Point const& point,
Chris@102:                 DistanceType const& distance,
Chris@102:                 OutputRange& output_range) const
Chris@102:     {
Chris@102:         add_point(point, distance, -1.0, -1.0, output_range);
Chris@102:         add_point(point, distance, -1.0, +1.0, output_range);
Chris@102:         add_point(point, distance, +1.0, +1.0, output_range);
Chris@102:         add_point(point, distance, +1.0, -1.0, output_range);
Chris@102: 
Chris@102:         // Close it:
Chris@102:         output_range.push_back(output_range.front());
Chris@102:     }
Chris@102: 
Chris@102: public :
Chris@102: 
Chris@102: #ifndef DOXYGEN_SHOULD_SKIP_THIS
Chris@102:     //! Fills output_range with a square around point using distance_strategy
Chris@102:     template
Chris@102:     <
Chris@102:         typename Point,
Chris@102:         typename DistanceStrategy,
Chris@102:         typename OutputRange
Chris@102:     >
Chris@102:     inline void apply(Point const& point,
Chris@102:                 DistanceStrategy const& distance_strategy,
Chris@102:                 OutputRange& output_range) const
Chris@102:     {
Chris@102:         add_points(point, distance_strategy.apply(point, point,
Chris@102:                         strategy::buffer::buffer_side_left), output_range);
Chris@102:     }
Chris@102: #endif // DOXYGEN_SHOULD_SKIP_THIS
Chris@102: 
Chris@102: };
Chris@102: 
Chris@102: 
Chris@102: }} // namespace strategy::buffer
Chris@102: 
Chris@102: }} // namespace boost::geometry
Chris@102: 
Chris@102: #endif // BOOST_GEOMETRY_STRATEGIES_CARTESIAN_BUFFER_POINT_SQUARE_HPP