CGAL 5.1.3 - 2D and 3D Linear Geometry Kernel
CGAL::Ray_2< Kernel > Class Template Reference

#include <CGAL/Ray_2.h>


An object r of the data type Ray_2 is a directed straight ray in the two-dimensional Euclidean plane \( \E^2\).

It starts in a point called the source of r and goes to infinity.

Is Model Of:


 Ray_2 (const Point_2< Kernel > &p, const Point_2< Kernel > &q)
 introduces a ray r with source p and passing through point q.
 Ray_2 (const Point_2< Kernel > &p, const Direction_2< Kernel > &d)
 introduces a ray r starting at source p with direction d.
 Ray_2 (const Point_2< Kernel > &p, const Vector_2< Kernel > &v)
 introduces a ray r starting at source p with the direction of v.
 Ray_2 (const Point_2< Kernel > &p, const Line_2< Kernel > &l)
 introduces a ray r starting at source p with the same direction as l.


bool operator== (const Ray_2< Kernel > &h) const
 Test for equality: two rays are equal, iff they have the same source and the same direction.
bool operator!= (const Ray_2< Kernel > &h) const
 Test for inequality.
Point_2< Kernelsource () const
 returns the source of r.
Point_2< Kernelpoint (const Kernel::FT i) const
 returns a point on r. More...
Direction_2< Kerneldirection () const
 returns the direction of r.
Vector_2< Kernelto_vector () const
 returns a vector giving the direction of r.
Line_2< Kernelsupporting_line () const
 returns the line supporting r which has the same direction.
Ray_2< Kernelopposite () const
 returns the ray with the same source and the opposite direction.


bool is_degenerate () const
 ray r is degenerate, if the source and the second defining point fall together (that is if the direction is degenerate).
bool is_horizontal () const
bool is_vertical () const
bool has_on (const Point_2< Kernel > &p) const
 A point is on r, iff it is equal to the source of r, or if it is in the interior of r.
bool collinear_has_on (const Point_2< Kernel > &p) const
 checks if point p is on r. More...


Ray_2< Kerneltransform (const Aff_transformation_2< Kernel > &t) const
 returns the ray obtained by applying t on the source and on the direction of r.

Member Function Documentation

◆ collinear_has_on()

template<typename Kernel >
bool CGAL::Ray_2< Kernel >::collinear_has_on ( const Point_2< Kernel > &  p) const

checks if point p is on r.

This function is faster than function has_on() if the precondition checking is disabled.

p is on the supporting line of r.

◆ point()

template<typename Kernel >
Point_2<Kernel> CGAL::Ray_2< Kernel >::point ( const Kernel::FT  i) const

returns a point on r.

point(0) is the source, point(i), with i>0, is different from the source.

\( i \geq0\).