FM / overlay

/usr/include/boost/geometry/algorithms/detail/overlay/

/usr/include/boost/geometry/algorithms/detail/overlay

Name	Size	Mode	Actions
add_rings.hpp	5964	0644	edit dl rm
append_no_duplicates.hpp	2101	0644	edit dl rm
append_no_dups_or_spikes.hpp	7434	0644	edit dl rm
assign_parents.hpp	14577	0644	edit dl rm
backtrack_check_si.hpp	6371	0644	edit dl rm
check_enrich.hpp	5361	0644	edit dl rm
clip_linestring.hpp	8718	0644	edit dl rm
cluster_exits.hpp	7817	0644	edit dl rm
cluster_info.hpp	1010	0644	edit dl rm
convert_ring.hpp	3113	0644	edit dl rm
copy_segments.hpp	11481	0644	edit dl rm
copy_segment_point.hpp	11107	0644	edit dl rm
debug_turn_info.hpp	1947	0644	edit dl rm
do_reverse.hpp	1246	0644	edit dl rm
enrichment_info.hpp	2343	0644	edit dl rm
enrich_intersection_points.hpp	19008	0644	edit dl rm
follow.hpp	16907	0644	edit dl rm
follow_linear_linear.hpp	15711	0644	edit dl rm
get_distance_measure.hpp	5092	0644	edit dl rm
get_intersection_points.hpp	4265	0644	edit dl rm
get_relative_order.hpp	3260	0644	edit dl rm
get_ring.hpp	3700	0644	edit dl rm
get_turns.hpp	42078	0644	edit dl rm
get_turn_info.hpp	45746	0644	edit dl rm
get_turn_info_for_endpoint.hpp	25337	0644	edit dl rm
get_turn_info_helpers.hpp	19708	0644	edit dl rm
get_turn_info_la.hpp	34941	0644	edit dl rm
get_turn_info_ll.hpp	28380	0644	edit dl rm
handle_colocations.hpp	28604	0644	edit dl rm
handle_self_turns.hpp	9962	0644	edit dl rm
inconsistent_turns_exception.hpp	1043	0644	edit dl rm
intersection_box_box.hpp	2623	0644	edit dl rm
intersection_insert.hpp	47296	0644	edit dl rm
is_self_turn.hpp	1611	0644	edit dl rm
less_by_segment_ratio.hpp	6161	0644	edit dl rm
linear_linear.hpp	9562	0644	edit dl rm
needs_self_turns.hpp	1911	0644	edit dl rm
overlay.hpp	15706	0644	edit dl rm
overlay_type.hpp	1746	0644	edit dl rm
pointlike_areal.hpp	9593	0644	edit dl rm
pointlike_linear.hpp	11547	0644	edit dl rm
pointlike_pointlike.hpp	11878	0644	edit dl rm
range_in_geometry.hpp	5066	0644	edit dl rm
ring_properties.hpp	2135	0644	edit dl rm
segment_as_subrange.hpp	1488	0644	edit dl rm
segment_identifier.hpp	3555	0644	edit dl rm
select_rings.hpp	12362	0644	edit dl rm
self_turn_points.hpp	10814	0644	edit dl rm
sort_by_side.hpp	22216	0644	edit dl rm
stream_info.hpp	2383	0644	edit dl rm
traversal.hpp	34432	0644	edit dl rm
traversal_info.hpp	1469	0644	edit dl rm
traversal_ring_creator.hpp	15319	0644	edit dl rm
traversal_switch_detector.hpp	22642	0644	edit dl rm
traverse.hpp	3256	0644	edit dl rm
turn_info.hpp	4468	0644	edit dl rm
visit_info.hpp	2350	0644	edit dl rm

Edit: /usr/include/boost/geometry/algorithms/detail/overlay/clip_linestring.hpp (8718B)

// Boost.Geometry (aka GGL, Generic Geometry Library)

// This file was modified by Oracle on 2015, 2018.
// Modifications copyright (c) 2015-2018 Oracle and/or its affiliates.

// Contributed and/or modified by Menelaos Karavelas, on behalf of Oracle
// 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_ALGORITHMS_DETAIL_OVERLAY_CLIP_LINESTRING_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_CLIP_LINESTRING_HPP

#include <boost/range.hpp>

#include <boost/geometry/algorithms/clear.hpp>
#include <boost/geometry/algorithms/convert.hpp>

#include <boost/geometry/algorithms/detail/overlay/append_no_duplicates.hpp>

#include <boost/geometry/util/select_coordinate_type.hpp>
#include <boost/geometry/geometries/segment.hpp>

#include <boost/geometry/strategies/cartesian/point_in_point.hpp>

namespace boost { namespace geometry
{

namespace strategy { namespace intersection
{

/*!
    \brief Strategy: line clipping algorithm after Liang Barsky
    \ingroup overlay
    \details The Liang-Barsky line clipping algorithm clips a line with a clipping box.
    It is slightly adapted in the sense that it returns which points are clipped
    \tparam B input box type of clipping box
    \tparam P input/output point-type of segments to be clipped
    \note The algorithm is currently only implemented for 2D Cartesian points
    \note Though it is implemented in namespace strategy, and theoretically another
        strategy could be used, it is not (yet) updated to the general strategy concepts,
        and not (yet) splitted into a file in folder strategies
    \author Barend Gehrels, and the following recourses
    - A tutorial: http://www.skytopia.com/project/articles/compsci/clipping.html
    - a German applet (link broken): http://ls7-www.cs.uni-dortmund.de/students/projectgroups/acit/lineclip.shtml
*/
template<typename Box, typename Point>
class liang_barsky
{
private:
    typedef model::referring_segment<Point> segment_type;

template <typename CoordinateType, typename CalcType>
    inline bool check_edge(CoordinateType const& p, CoordinateType const& q, CalcType& t1, CalcType& t2) const
    {
        bool visible = true;

if(p < 0)
        {
            CalcType const r = static_cast<CalcType>(q) / p;
            if (r > t2)
                visible = false;
            else if (r > t1)
                t1 = r;
        }
        else if(p > 0)
        {
            CalcType const r = static_cast<CalcType>(q) / p;
            if (r < t1)
                visible = false;
            else if (r < t2)
                t2 = r;
        }
        else
        {
            if (q < 0)
                visible = false;
        }

return visible;
    }

public:

// TODO: Temporary, this strategy should be moved, it is cartesian-only

typedef strategy::within::cartesian_point_point equals_point_point_strategy_type;

static inline equals_point_point_strategy_type get_equals_point_point_strategy()
    {
        return equals_point_point_strategy_type();
    }

inline bool clip_segment(Box const& b, segment_type& s, bool& sp1_clipped, bool& sp2_clipped) const
    {
        typedef typename select_coordinate_type<Box, Point>::type coordinate_type;
        typedef typename select_most_precise<coordinate_type, double>::type calc_type;

calc_type t1 = 0;
        calc_type t2 = 1;

coordinate_type const dx = get<1, 0>(s) - get<0, 0>(s);
        coordinate_type const dy = get<1, 1>(s) - get<0, 1>(s);

coordinate_type const p1 = -dx;
        coordinate_type const p2 = dx;
        coordinate_type const p3 = -dy;
        coordinate_type const p4 = dy;

coordinate_type const q1 = get<0, 0>(s) - get<min_corner, 0>(b);
        coordinate_type const q2 = get<max_corner, 0>(b) - get<0, 0>(s);
        coordinate_type const q3 = get<0, 1>(s) - get<min_corner, 1>(b);
        coordinate_type const q4 = get<max_corner, 1>(b) - get<0, 1>(s);

if (check_edge(p1, q1, t1, t2)      // left
            && check_edge(p2, q2, t1, t2)   // right
            && check_edge(p3, q3, t1, t2)   // bottom
            && check_edge(p4, q4, t1, t2))   // top
        {
            sp1_clipped = t1 > 0;
            sp2_clipped = t2 < 1;

if (sp2_clipped)
            {
                set<1, 0>(s, get<0, 0>(s) + t2 * dx);
                set<1, 1>(s, get<0, 1>(s) + t2 * dy);
            }

if(sp1_clipped)
            {
                set<0, 0>(s, get<0, 0>(s) + t1 * dx);
                set<0, 1>(s, get<0, 1>(s) + t1 * dy);
            }

return true;
        }

return false;
    }

template<typename Linestring, typename OutputIterator>
    inline void apply(Linestring& line_out, OutputIterator out) const
    {
        if (!boost::empty(line_out))
        {
            *out = line_out;
            ++out;
            geometry::clear(line_out);
        }
    }
};

}} // namespace strategy::intersection

#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace intersection
{

/*!
    \brief Clips a linestring with a box
    \details A linestring is intersected (clipped) by the specified box
    and the resulting linestring, or pieces of linestrings, are sent to the specified output operator.
    \tparam OutputLinestring type of the output linestrings
    \tparam OutputIterator an output iterator which outputs linestrings
    \tparam Linestring linestring-type, for example a vector of points, matching the output-iterator type,
         the points should also match the input-iterator type
    \tparam Box box type
    \tparam Strategy strategy, a clipping strategy which should implement the methods "clip_segment" and "apply"
*/
template
<
    typename OutputLinestring,
    typename OutputIterator,
    typename Range,
    typename RobustPolicy,
    typename Box,
    typename Strategy
>
OutputIterator clip_range_with_box(Box const& b, Range const& range,
            RobustPolicy const&,
            OutputIterator out, Strategy const& strategy)
{
    if (boost::begin(range) == boost::end(range))
    {
        return out;
    }

typedef typename point_type<OutputLinestring>::type point_type;

OutputLinestring line_out;

typedef typename boost::range_iterator<Range const>::type iterator_type;
    iterator_type vertex = boost::begin(range);
    for(iterator_type previous = vertex++;
            vertex != boost::end(range);
            ++previous, ++vertex)
    {
        point_type p1, p2;
        geometry::convert(*previous, p1);
        geometry::convert(*vertex, p2);

// Clip the segment. Five situations:
        // 1. Segment is invisible, finish line if any (shouldn't occur)
        // 2. Segment is completely visible. Add (p1)-p2 to line
        // 3. Point 1 is invisible (clipped), point 2 is visible. Start new line from p1-p2...
        // 4. Point 1 is visible, point 2 is invisible (clipped). End the line with ...p2
        // 5. Point 1 and point 2 are both invisible (clipped). Start/finish an independant line p1-p2
        //
        // This results in:
        // a. if p1 is clipped, start new line
        // b. if segment is partly or completely visible, add the segment
        // c. if p2 is clipped, end the line

bool c1 = false;
        bool c2 = false;
        model::referring_segment<point_type> s(p1, p2);

if (!strategy.clip_segment(b, s, c1, c2))
        {
            strategy.apply(line_out, out);
        }
        else
        {
            // a. If necessary, finish the line and add a start a new one
            if (c1)
            {
                strategy.apply(line_out, out);
            }

// b. Add p1 only if it is the first point, then add p2
            if (boost::empty(line_out))
            {
                detail::overlay::append_with_duplicates(line_out, p1);
            }
            detail::overlay::append_no_duplicates(line_out, p2,
                                                  strategy.get_equals_point_point_strategy());

// c. If c2 is clipped, finish the line
            if (c2)
            {
                strategy.apply(line_out, out);
            }
        }

}

// Add last part
    strategy.apply(line_out, out);
    return out;
}

}} // namespace detail::intersection
#endif // DOXYGEN_NO_DETAIL

}} // namespace boost::geometry

#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_CLIP_LINESTRING_HPP

cmd: