CGAL 5.1.3  2D and 3D Linear Geometry Kernel

AdaptableFunctor
(with four arguments)CGAL::side_of_oriented_circle()
Operations  
Oriented_side  operator() (const Kernel::Point_2 &p, const Kernel::Point_2 &q, const Kernel::Point_2 &r, const Kernel::Point_2 &t) 
returns the relative position of point t to the oriented circle defined by p , q and r . More...  
Oriented_side Kernel::SideOfOrientedCircle_2::operator()  (  const Kernel::Point_2 &  p, 
const Kernel::Point_2 &  q,  
const Kernel::Point_2 &  r,  
const Kernel::Point_2 &  t  
) 
returns the relative position of point t
to the oriented circle defined by p
, q
and r
.
The order of the points p
, q
and r
is important, since it determines the orientation of the implicitly constructed circle.
If p
, q
and r
are collinear, the circle degenerates in a line. CGAL::ON_ORIENTED_BOUNDARY is returned if t
is also collinear or if two points are identical, otherwise, side_of_oriented_circle(r, q, t, p)
is returned.