function compare(Point1, Point2) {
if (Point1->X != Point2->X) {
return Point1->X - Point2->X;
}
if (Point1->Y != Point2->Y) {
return Point1->Y - Point2->Y;
}
return Point1->Z - Point2->Z;
}
if (compare(edge.Point1, edge,Point2) > 0) {
// перевернуть отрезок
}