Version 5.0 The LEDA User Manual

double l.direction( ) returns the direction of l.
double l.angle( ) returns l.direction().
bool l.is vertical( ) returns true iff l is vertical.
bool l.is horizontal( ) returns true iff l is horizontal.
double l.sqr dist(const point& q) returns the square of the distance between l and
q.
double l.distance(const point& q) returns the distance between l and q.
int l.orientation(const point& p)
returns orientation(l.point1(), l.point2(), p).
double l.slope( ) returns the slope of l.
Precondition: l is not vertical.
double l.y proj(double x) returns p.ycoord(), where p ∈ l with p.xcoord() =
x.
Precondition: l is not vertical.
double l.x proj(double y) returns p.xcoord(), where p ∈ l with p.ycoord() =
y.
Precondition: l is not horizontal.
double l.y abs( ) returns the y-abscissa of l (l.y proj(0)).
Precondition: l is not vertical.
bool l.intersection(const line& g, point& p)
if l and g intersect in a single point this point is
assigned to p and the result is true, otherwise the
result is false.
bool
l.intersection(const segment& s, point& inter)
if l and s intersect in a single point this point is
assigned to p and the result is true, otherwise the
result is false.
bool l.intersection(const segment& s)
returns true, if l and s intersect, false otherwise.
line l.translate by angle(double a, double d)
returns l translated in direction a by distance d.
line
l.translate(double dx, double dy)
returns l translated by vector (dx, dy).