Intersection of polygon with itself
Polygon and line clipping and offsetting library (C++, C#, Delphi)
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#194 Intersection of polygon with itself
Hi,
when computing the intersection of a certain polygon with itself, we get an empty list as a result (i.e., no intersection).
Coordinate list of this polygon: (1, 0), (0, 2), (0, 3)
Code to reproduce see below.
Question: did we do something wrong (e.g. wrong parameters to ClipperLib methods), or is this a bug?
Thanks in advance
Harald
#include "clipper.hpp"
#include <iostream>
int main()
{
ClipperLib::Path poly = {{1, 0}, {0, 2}, {0, 3}}; // WRONG
//ClipperLib::Path poly = {{1, 0}, {0, 1}, {0, 3}}; // OK
// add the paths to Clipper
ClipperLib::Clipper clipper;
clipper.AddPath(poly, ClipperLib::ptClip, true);
clipper.AddPath(poly, ClipperLib::ptSubject, true);
// compute intersections
ClipperLib::Paths intersections;
bool res=clipper.Execute(ClipperLib::ctIntersection, intersections, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
std::cout << "#intersections=" << intersections.size() << "\n";
return 0;
}
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