pointsCompare method
Implementation
int pointsCompare(JTS.Coordinate p1, JTS.Coordinate p2) {
// returns -1 if p1 is smaller, 1 if p2 is smaller, 0 if equal
if (pointsSameX(p1, p2))
return pointsSameY(p1, p2) ? 0 : (p1.y < p2.y ? -1 : 1);
return p1.x < p2.x ? -1 : 1;
}