\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)
CGAL 4.12.1 - 2D and 3D Linear Geometry Kernel

See also
CGAL::coplanar()
CGAL::coplanar_side_of_bounded_circle()
CGAL::orientation()

Functions

template<typename Kernel >
Orientation CGAL::coplanar_orientation (const CGAL::Point_3< Kernel > &p, const CGAL::Point_3< Kernel > &q, const CGAL::Point_3< Kernel > &r, const CGAL::Point_3< Kernel > &s)
 Let P be the plane defined by the points p, q, and r. More...
 
template<typename Kernel >
Orientation CGAL::coplanar_orientation (const CGAL::Point_3< Kernel > &p, const CGAL::Point_3< Kernel > &q, const CGAL::Point_3< Kernel > &r)
 If p,q,r are collinear, then CGAL::COLLINEAR is returned. More...
 

Function Documentation

◆ coplanar_orientation() [1/2]

template<typename Kernel >
Orientation CGAL::coplanar_orientation ( const CGAL::Point_3< Kernel > &  p,
const CGAL::Point_3< Kernel > &  q,
const CGAL::Point_3< Kernel > &  r,
const CGAL::Point_3< Kernel > &  s 
)

#include <CGAL/Kernel/global_functions.h>

Let P be the plane defined by the points p, q, and r.

Note that the order defines the orientation of P. The function computes the orientation of points p, q, and s in P: Iff p, q, s are collinear, CGAL::COLLINEAR is returned. Iff P and the plane defined by p, q, and s have the same orientation, 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.

◆ coplanar_orientation() [2/2]

template<typename Kernel >
Orientation CGAL::coplanar_orientation ( const CGAL::Point_3< Kernel > &  p,
const CGAL::Point_3< Kernel > &  q,
const CGAL::Point_3< Kernel > &  r 
)

#include <CGAL/Kernel/global_functions.h>

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

If not, then p,q,r define a plane p. 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 a 2D orientation in p.