inverse method
void
inverse()
Invert this.
Implementation
void inverse() {
final l = 1.0 / length2;
_qStorage[3] = _qStorage[3] * l;
_qStorage[2] = -_qStorage[2] * l;
_qStorage[1] = -_qStorage[1] * l;
_qStorage[0] = -_qStorage[0] * l;
}