Kernel::CoplanarOrientation_3 Concept Reference

Definition

Refines

AdaptableQuaternaryFunction

See also

CGAL::coplanar_orientation()

Operations
A model of this concept must provide:
Orientation	operator() (const Kernel::Point_3 &p, const Kernel::Point_3 &q, const Kernel::Point_3 &r, const Kernel::Point_3 &s)
	If p, q, and s are collinear, then CGAL::COLLINEAR is returned.
Orientation	operator() (const Kernel::Point_3 &p, const Kernel::Point_3 &q, const Kernel::Point_3 &r)
	If p, q, and r are collinear, then CGAL::COLLINEAR is returned.

Member Function Documentation

operator()() [1/2]

Orientation Kernel::CoplanarOrientation_3::operator()	(	const Kernel::Point_3 &	p,
		const Kernel::Point_3 &	q,
		const Kernel::Point_3 &	r
	)

If p, q, and r are collinear, then CGAL::COLLINEAR is returned.

If not, let P be the plane defined by the points p, q, and r. The return value in this case is either CGAL::POSITIVE or CGAL::NEGATIVE, but we don't specify it explicitly. However, we guarantee that all calls to this predicate over 3 points in P will return a coherent orientation if considered as a 2D orientation in P.

operator()() [2/2]

Orientation Kernel::CoplanarOrientation_3::operator()	(	const Kernel::Point_3 &	p,
		const Kernel::Point_3 &	q,
		const Kernel::Point_3 &	r,
		const Kernel::Point_3 &	s
	)

If p, q, and s are collinear, then CGAL::COLLINEAR is returned.

If not, let P be the plane defined by the points p, q, and r. Note that the order defines the orientation of P. If P and the plane defined by p, q, and s have the same orientation, then CGAL::POSITIVE is returned; otherwise CGAL::NEGATIVE is returned.

Precondition

p, q, r, and s are coplanar and p, q, and r are not collinear.