Version 5.0 The LEDA User Manual

4. Operations
real point l.point1( ) returns a point on l.
real point l.point2( ) returns a second point on l.
real segment l.seg( ) returns a segment on l.
bool l.is vertical( ) returns true iff l is vertical.
bool l.is horizontal( ) returns true iff l is horizontal.
real l.sqr dist(const real point& q)
real l.distance(const real point& q)
int l.orientation(const real point& p)
returns the square of the distance between l and
q.
returns the distance between l and q.
returns orientation(l.point1(), l.point2(), p).
real l.slope( ) returns the slope of l.
Precondition: l is not vertical.
real l.y proj(real x) returns p.ycoord(), where p ∈ l with p.xcoord() =
x.
Precondition: l is not vertical.
real l.x proj(real y) returns p.xcoord(), where p ∈ l with p.ycoord() =
y.
Precondition: l is not horizontal.
real l.y abs( ) returns the y-abscissa of l (l.y proj(0)).
Precondition: l is not vertical.
bool l.intersection(const real line& g, real 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 real segment& s, real 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 real segment& s)
returns true, if l and s intersect, false otherwise.
real line
l.translate(real dx, real dy)
returns l translated by vector (dx, dy).