Version 5.0 The LEDA User Manual

at circle C(const circle& c, int prec = rat point :: default precision);
4. Operations
introduces a variable C of type rat circle. C is initialized to
the circle obtained by approximating three defining points of
c.
circle C.to float( ) returns a floating point approximation of C.
void C.normalize( ) simplifies the homogenous representation by normalizing
p 1 , p 2 , and p 3 .
int C.orientation( ) returns the orientation of C.
rat point C.center( ) returns the center of C.
Precondition: C has a center, i.e., is not a line.
rat point C.point1( ) returns p 1 .
rat point C.point2( ) returns p 2 .
rat point C.point3( ) returns p 3 .
rational C.sqr radius( ) returns the square of the radius of C.
rat point
C.point on circle(double alpha, double epsilon)
returns a point p on C such that the angle of p
differs from alpha by at most epsilon.
bool C.is degenerate( ) returns true if the defining points are collinear.
bool C.is trivial( ) returns true if C has radius zero.
bool C.is line( ) returns true if C is a line.
int C.side of(const rat point& p)
bool C.inside(const rat point& p)
bool C.outside(const rat point& p)
bool C.contains(const rat point& p)
returns −1, +1, or 0 if p lies right of, left of, or on
C respectively.
returns true iff p lies inside of C.
returns true iff p lies outside of C.
returns true iff p lies on C.
rat circle
C.translate(const rational& dx, const rational& dy)
returns C translated by vector (dx, dy).