Sidedness

Many geometric objects, such as lines and circles in the plane, or planes and spheres in three-dimensional space, partition the ambient space into two parts. We designate one of the parts as positive and one as negative. The function

	int O.side_of(x);
	
where O is a geometric object and x is a point in ambient space, returns a positive number (zero, a negative number, respectively) if x lies in the positive part (lies on O, lies in the negative part, respectively). Examples are
	int l.side_of(x); //l is line
	int C.side_of(x); //C is circle
	int P.side_of(x); //P is polygon
	
We use the orientation function to define the positive part as follows: The positive part is the region to the left of the object.


Web page created by Thomas Ziegler, Algorithmic Solutions Software GmbH.
Last modified: Tue Mar 20 14:39:34 MET DST 2001