An object r of the data type Ray_2<Kernel> is a directed straight ray in the two-dimensional Euclidean plane 2. It starts in a point called the source of r and goes to infinity.


Ray_2<Kernel> r ( Point_2<Kernel> p, Point_2<Kernel> q);
introduces a ray r with source p and passing through point q.

Ray_2<Kernel> r ( Point_2<Kernel> p, Direction_2<Kernel> d);
introduces a ray r starting at source p with direction d.

Ray_2<Kernel> r ( Point_2<Kernel> p, Vector_2<Kernel> v);
introduces a ray r starting at source p with the direction of v.

Ray_2<Kernel> r ( Point_2<Kernel> p, Line_2<Kernel> l);
introduces a ray r starting at source p with the same direction as l.


bool r.operator== ( h)
Test for equality: two rays are equal, iff they have the same source and the same direction.

bool r.operator!= ( h)
Test for inequality.

Point_2<Kernel> r.source () returns the source of r.

Point_2<Kernel> r.point ( int i) returns a point on r. point(0) is the source, point(i), with i>0, is different from the source.
Precondition: i 0.

r.direction () returns the direction of r.

Vector_2<Kernel> r.to_vector () returns a vector giving the direction of r.

Line_2<Kernel> r.supporting_line ()
returns the line supporting r which has the same direction.

Ray_2<Kernel> r.opposite () returns the ray with the same source and the opposite direction.


bool r.is_degenerate () ray r is degenerate, if the source and the second defining point fall together (that is if the direction is degenerate).

bool r.is_horizontal ()
bool r.is_vertical ()

bool r.has_on ( Point_2<Kernel> p)
A point is on r, iff it is equal to the source of r, or if it is in the interior of r.

bool r.collinear_has_on ( Point_2<Kernel> p)
checks if point p is on r. This function is faster than function has_on() if the precondition checking is disabled.
Precondition: p is on the supporting line of r.


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

See Also