docs: protected final int isLeft(double[] a, double[] b, double[] o) {
      final double cross = getRX(a, o) * getRY(b, o) - getRY(a, o) * getRX(b, o);
      if(cross == 0) {
        // Compare manhattan distances - same angle!
        final double dista = Math.abs(getRX(a, o)) + Math.abs(getRY(a, o));
        final double distb = Math.abs(getRX(b, o)) + Math.abs(getRY(b, o));
        return Double.compare(dista, distb);
      }
      return Double.compare(cross, 0);
    }