std::size_t hash_value(const CGAL::Segment_2<Kernel>& segment)
{
std::size_t seed = 0;
boost::hash_combine(seed, segment.source());
boost::hash_combine(seed, segment.target());
return seed;
}
// get the point position on segment
// in [0,1] if its on the interior
static Kernel::FT point_position( const CGAL::Segment_2<Kernel>& seg, const CGAL::Point_2<Kernel>& pt )
{
CGAL::Point_2<Kernel> pA = seg.source();
CGAL::Point_2<Kernel> pB = seg.target();
Kernel::FT num = pt.x() - pA.x();
Kernel::FT den = pB.x() - pA.x();
if ( den == 0 ) {
num = pt.y() - pA.y();
den = pB.y() - pA.y();
}
return num / den;
}