Version 5.0 The LEDA User Manual

14.11 Rational Segments ( rat segment )
1. Definition
An instance s of the data type rat segment is a directed straight line segment in the twodimensional
plane, i.e., a line segment [p, q] connecting two rational points p and q (cf.
14.10). p is called the source or start point and q is called the target or end point of s. A
segment is called trivial if its source is equal to its target.
#include < LEDA/geo/rat segment.h >
2. Types
rat segment :: coord type
rat segment :: point type
rat segment :: float type
the coordinate type (rational).
the point type (rat point).
the corresponding floatin-point type (segment).
3. Creation
rat segment s;
introduces a variable s of type rat segment. s is initialized to
the empty segment.
rat segment s(const rat point& p, const rat point& q);
introduces a variable s of type rat segment. s is initialized to
the segment [p, q].
rat segment s(const rat point& p, const rat vector& v);
introduces a variable s of type rat segment. s is initialized to
the segment [p, p + v].
Precondition: v.dim() = 2.
rat segment s(const rational& x1 , const rational& y1 , const rational& x2 ,
const rational& y2 );
introduces a variable s of type rat segment. s is initialized to
the segment [(x1, y1), (x2, y2)].
rat segment s(const integer& x1 , const integer& y1 , const integer& w1 ,
const integer& x2 , const integer& y2 , const integer& w2 );
introduces a variable s of type rat segment. s is initialized to
the segment [(x1, y1, w1), (x2, y2, w2)].
rat segment s(const integer& x1 , const integer& y1 , const integer& x2 ,
const integer& y2 );
introduces a variable s of type rat segment. s is initialized to
the segment [(x1, y1), (x2, y2)].