129 lines
3.4 KiB
C++
129 lines
3.4 KiB
C++
// Boost.Geometry (aka GGL, Generic Geometry Library)
|
|
|
|
// Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
|
|
// Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
|
|
// Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
|
|
|
|
// This file was modified by Oracle on 2018, 2019.
|
|
// Modifications copyright (c) 2018, 2019, Oracle and/or its affiliates.
|
|
|
|
// Contributed and/or modified by Adam Wulkiewicz, 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_STRATEGIES_CARTESIAN_POINT_IN_POLY_FRANKLIN_HPP
|
|
#define BOOST_GEOMETRY_STRATEGIES_CARTESIAN_POINT_IN_POLY_FRANKLIN_HPP
|
|
|
|
|
|
#include <boost/geometry/core/access.hpp>
|
|
#include <boost/geometry/core/coordinate_type.hpp>
|
|
#include <boost/geometry/util/select_calculation_type.hpp>
|
|
|
|
|
|
namespace boost { namespace geometry
|
|
{
|
|
|
|
namespace strategy { namespace within
|
|
{
|
|
|
|
/*!
|
|
\brief Within detection using cross counting
|
|
\ingroup strategies
|
|
\tparam Point \tparam_point
|
|
\tparam PointOfSegment \tparam_segment_point
|
|
\tparam CalculationType \tparam_calculation
|
|
\author adapted from Randolph Franklin algorithm
|
|
\author Barend and Maarten, 1995
|
|
\author Revised for templatized library, Barend Gehrels, 2007
|
|
\return true if point is in ring, works for closed rings in both directions
|
|
\note Does NOT work correctly for point ON border
|
|
|
|
\qbk{
|
|
[heading See also]
|
|
[link geometry.reference.algorithms.within.within_3_with_strategy within (with strategy)]
|
|
}
|
|
*/
|
|
|
|
template
|
|
<
|
|
typename Point_, // for backward compatibility
|
|
typename PointOfSegment_ = Point_, // for backward compatibility
|
|
typename CalculationType = void
|
|
>
|
|
class franklin
|
|
{
|
|
template <typename Point, typename PointOfSegment>
|
|
struct calculation_type
|
|
: select_calculation_type
|
|
<
|
|
Point,
|
|
PointOfSegment,
|
|
CalculationType
|
|
>
|
|
{};
|
|
|
|
/*! subclass to keep state */
|
|
class crossings
|
|
{
|
|
bool crosses;
|
|
|
|
public :
|
|
|
|
friend class franklin;
|
|
inline crossings()
|
|
: crosses(false)
|
|
{}
|
|
};
|
|
|
|
public :
|
|
|
|
typedef crossings state_type;
|
|
|
|
template <typename Point, typename PointOfSegment>
|
|
static inline bool apply(Point const& point,
|
|
PointOfSegment const& seg1, PointOfSegment const& seg2,
|
|
crossings& state)
|
|
{
|
|
typedef typename calculation_type<Point, PointOfSegment>::type calc_t;
|
|
|
|
calc_t const& px = get<0>(point);
|
|
calc_t const& py = get<1>(point);
|
|
calc_t const& x1 = get<0>(seg1);
|
|
calc_t const& y1 = get<1>(seg1);
|
|
calc_t const& x2 = get<0>(seg2);
|
|
calc_t const& y2 = get<1>(seg2);
|
|
|
|
if (
|
|
( (y2 <= py && py < y1) || (y1 <= py && py < y2) )
|
|
&& (px < (x1 - x2) * (py - y2) / (y1 - y2) + x2)
|
|
)
|
|
{
|
|
state.crosses = ! state.crosses;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static inline int result(crossings const& state)
|
|
{
|
|
return state.crosses ? 1 : -1;
|
|
}
|
|
};
|
|
|
|
|
|
|
|
}} // namespace strategy::within
|
|
|
|
|
|
|
|
|
|
|
|
}} // namespace boost::geometry
|
|
|
|
|
|
#endif // BOOST_GEOMETRY_STRATEGIES_CARTESIAN_POINT_IN_POLY_FRANKLIN_HPP
|