Utility functions for working with quadrants, which are numbered as follows:
1 | 0 --+-- 2 | 3 <pre>
Returns the right-hand quadrant of the halfplane defined by the two quadrants, or -1 if the quadrants are opposite, or the quadrant if they are identical.
Returns whether the given quadrant lies within the given halfplane (specified by its right-hand quadrant).
Returns true if the given quadrant is 0 or 1.
Returns true if the quadrants are 1 and 3, or 2 and 4
Returns the quadrant of a directed line segment (specified as x and y displacements, which cannot both be 0).
IllegalArgumentException if the displacements are both 0
Returns the quadrant of a directed line segment from p0 to p1.
IllegalArgumentException if the points are equal