signOfDet2x2DD static method
Computes the sign of the determinant of the 2x2 matrix with the given entries.
@return -1 if the determinant is negative, @return 1 if the determinant is positive, @return 0 if the determinant is 0.
Implementation
static int signOfDet2x2DD(DD x1, DD y1, DD x2, DD y2) {
DD det = x1.multiplyDD(y2).selfSubtractDD(y1.multiplyDD(x2));
return det.signum();
}