115 lines
3.7 KiB
C++
115 lines
3.7 KiB
C++
// Boost.Geometry (aka GGL, Generic Geometry Library)
|
|
|
|
// Copyright (c) 2012-2014 Barend Gehrels, Amsterdam, the Netherlands.
|
|
|
|
// This file was modified by Oracle on 2018.
|
|
// Modifications copyright (c) 2018, Oracle and/or its affiliates.
|
|
|
|
// Contributed and/or modified by Adam Wulkiewicz, on behalf of Oracle
|
|
|
|
// 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_STRATEGIES_CARTESIAN_BUFFER_END_FLAT_HPP
|
|
#define BOOST_GEOMETRY_STRATEGIES_CARTESIAN_BUFFER_END_FLAT_HPP
|
|
|
|
#include <boost/geometry/core/coordinate_type.hpp>
|
|
#include <boost/geometry/strategies/buffer.hpp>
|
|
#include <boost/geometry/strategies/tags.hpp>
|
|
#include <boost/geometry/strategies/side.hpp>
|
|
#include <boost/geometry/util/math.hpp>
|
|
#include <boost/geometry/util/select_most_precise.hpp>
|
|
|
|
namespace boost { namespace geometry
|
|
{
|
|
|
|
|
|
namespace strategy { namespace buffer
|
|
{
|
|
|
|
|
|
/*!
|
|
\brief Let the buffer create flat ends
|
|
\ingroup strategies
|
|
\details This strategy can be used as EndStrategy for the buffer algorithm.
|
|
It creates a flat end for each linestring-end. It can be applied
|
|
for (multi)linestrings. Also it is applicable for spikes in (multi)polygons.
|
|
This strategy is only applicable for Cartesian coordinate systems.
|
|
|
|
\qbk{
|
|
[heading Example]
|
|
[buffer_end_flat]
|
|
[heading Output]
|
|
[$img/strategies/buffer_end_flat.png]
|
|
[heading See also]
|
|
\* [link geometry.reference.algorithms.buffer.buffer_7_with_strategies buffer (with strategies)]
|
|
\* [link geometry.reference.strategies.strategy_buffer_end_round end_round]
|
|
}
|
|
*/
|
|
class end_flat
|
|
{
|
|
|
|
public :
|
|
|
|
#ifndef DOXYGEN_SHOULD_SKIP_THIS
|
|
//! Fills output_range with a flat end
|
|
template <typename Point, typename RangeOut, typename DistanceStrategy>
|
|
inline void apply(Point const& penultimate_point,
|
|
Point const& perp_left_point,
|
|
Point const& ultimate_point,
|
|
Point const& perp_right_point,
|
|
buffer_side_selector side,
|
|
DistanceStrategy const& distance,
|
|
RangeOut& range_out) const
|
|
{
|
|
typedef typename coordinate_type<Point>::type coordinate_type;
|
|
|
|
typedef typename geometry::select_most_precise
|
|
<
|
|
coordinate_type,
|
|
double
|
|
>::type promoted_type;
|
|
|
|
promoted_type const dist_left = distance.apply(penultimate_point, ultimate_point, buffer_side_left);
|
|
promoted_type const dist_right = distance.apply(penultimate_point, ultimate_point, buffer_side_right);
|
|
|
|
bool reversed = (side == buffer_side_left && dist_right < 0 && -dist_right > dist_left)
|
|
|| (side == buffer_side_right && dist_left < 0 && -dist_left > dist_right)
|
|
;
|
|
if (reversed)
|
|
{
|
|
range_out.push_back(perp_right_point);
|
|
range_out.push_back(perp_left_point);
|
|
}
|
|
else
|
|
{
|
|
range_out.push_back(perp_left_point);
|
|
range_out.push_back(perp_right_point);
|
|
}
|
|
// Don't add the ultimate_point (endpoint of the linestring).
|
|
// The buffer might be generated completely at one side.
|
|
// In other cases it does no harm but is further useless
|
|
}
|
|
|
|
template <typename NumericType>
|
|
static inline NumericType max_distance(NumericType const& distance)
|
|
{
|
|
return distance;
|
|
}
|
|
|
|
//! Returns the piece_type (flat end)
|
|
static inline piece_type get_piece_type()
|
|
{
|
|
return buffered_flat_end;
|
|
}
|
|
#endif // DOXYGEN_SHOULD_SKIP_THIS
|
|
};
|
|
|
|
|
|
}} // namespace strategy::buffer
|
|
|
|
}} // namespace boost::geometry
|
|
|
|
#endif // BOOST_GEOMETRY_STRATEGIES_CARTESIAN_BUFFER_END_FLAT_HPP
|