// perform xor
public static Paths ClipperXor(this Polygon clip, Polygon subject)
{
var subj = new Paths();
subj.Add(subject.ToClipperPath());
var clp = new Paths();
clp.Add(clip.ToClipperPath());
var result = new Paths();
var c = new Clipper();
c.Execute(ClipType.ctXor, result, PolyFillType.pftPositive, PolyFillType.pftPositive);
return result;
}
public static bool IsOutside(this Vector2 point, Polygon poly)
{
var p = new IntPoint(point.X, point.Y);
return Clipper.PointInPolygon(p, poly.ToClipperPath()) != 1;
}