mirror of https://github.com/CGAL/cgal
47 lines
1.7 KiB
C++
47 lines
1.7 KiB
C++
//! \file examples/Surface_sweep_2/plane_sweep.cpp
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// Computing intersection points among curves using the surface-sweep alg.
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#include <list>
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#include <cassert>
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#include <CGAL/Exact_predicates_exact_constructions_kernel.h>
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#include <CGAL/Arr_segment_traits_2.h>
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#include <CGAL/Surface_sweep_2_algorithms.h>
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typedef CGAL::Exact_predicates_exact_constructions_kernel Kernel;
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typedef Kernel::Point_2 Point_2;
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typedef CGAL::Arr_segment_traits_2<Kernel> Traits_2;
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typedef Traits_2::Curve_2 Segment_2;
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int main()
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{
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// Construct the input segments.
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Segment_2 segments[] = {Segment_2 (Point_2 (1, 5), Point_2 (8, 5)),
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Segment_2 (Point_2 (1, 1), Point_2 (8, 8)),
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Segment_2 (Point_2 (3, 1), Point_2 (3, 8)),
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Segment_2 (Point_2 (8, 5), Point_2 (8, 8))};
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// Compute all intersection points.
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std::list<Point_2> pts;
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CGAL::compute_intersection_points(segments, segments + 4,
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std::back_inserter(pts));
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// Print the result.
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std::cout << "Found " << pts.size() << " intersection points: " << std::endl;
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std::copy(pts.begin(), pts.end(),
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std::ostream_iterator<Point_2>(std::cout, "\n"));
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// Compute the non-intersecting sub-segments induced by the input segments.
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std::list<Segment_2> sub_segs;
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CGAL::compute_subcurves(segments, segments + 4, std::back_inserter(sub_segs));
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std::cout << "Found " << sub_segs.size()
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<< " interior-disjoint sub-segments." << std::endl;
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assert(CGAL::do_curves_intersect (segments, segments + 4));
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return 0;
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}
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