compareX method
Compare two collinear segments for left-most ordering. If segs are vertical, use vertical ordering for comparison. If segs are equal, return 0. Segments are assumed to be directed so that the second coordinate is >= to the first (e.g. up and to the right).
@param seg0 a segment to compare @param seg1 a segment to compare @return
Implementation
int compareX(LineSegment seg0, LineSegment seg1) {
int compare0 = seg0.p0.compareTo(seg1.p0);
if (compare0 != 0) return compare0;
return seg0.p1.compareTo(seg1.p1);
}