public class MonotoneChainIndexer
extends Object

MonotoneChains are a way of partitioning the segments of an edge to allow for fast searching of intersections. Specifically, a sequence of contiguous line segments is a monotone chain iff all the vectors defined by the oriented segments lies in the same quadrant.

Monotone Chains have the following useful properties:

1. the segments within a monotone chain will never intersect each other
2. the envelope of any contiguous subset of the segments in a monotone chain is simply the envelope of the endpoints of the subset.

Property 1 means that there is no need to test pairs of segments from within the same monotone chain for intersection. Property 2 allows binary search to be used to find the intersection points of two monotone chains. For many types of real-world data, these properties eliminate a large number of segment comparisons, producing substantial speed gains.