Version 5.0 The LEDA User Manual

14.3 Straight Rays ( ray )
1. Definition
An instance r of the data type ray is a directed straight ray in the two-dimensional plane.
The angle between a right oriented horizontal ray and r is called the direction of r.
#include < LEDA/geo/ray.h >
2. Types
ray :: coord type
ray :: point type
the coordinate type (double).
the point type (point).
3. Creation
ray r(const point& p, const point& q);
introduces a variable r of type ray. r is initialized to the ray
starting at point p and passing through point q.
ray r(const segment& s); introduces a variable r of type ray.
ray(s.source(), s.target()).
r is initialized to
ray r(const point& p, const vector& v);
ray r(const point& p, double alpha);
introduces a variable r of type ray. r is initialized to ray(p, p+
v).
introduces a variable r of type ray. r is initialized to the ray
starting at point p with direction alpha.
ray r;
introduces a variable r of type ray. r is initialized to the ray
starting at the origin with direction 0.
ray r(const ray& r1 , int);
introduces a variable r of type ray. r is initialized to a copy
of r 1 . The second argument is for compatibility with rat ray.
4. Operations
point r.source( ) returns the source of r.
point r.point1( ) returns the source of r.
point r.point2( ) returns a point on r different from r.source( ).