CGAL::collinear_are_ordered_along_line

bool	collinear_are_ordered_along_line ( Point_2<Kernel> p, Point_2<Kernel> q, Point_2<Kernel> r)
		returns true, iff q lies between p and r. Precondition: p, q and r are collinear.
bool	collinear_are_ordered_along_line ( Point_3<Kernel> p, Point_3<Kernel> q, Point_3<Kernel> r)
		returns true, iff q lies between p and r. Precondition: p, q and r are collinear.

See Also