public static XMVector InverseRotate(XMVector v, XMVector rotationQuaternion)
{
//// Transform a vector using the inverse of a rotation expressed as a unit quaternion
XMVector a = XMVector.Select(XMGlobalConstants.Select1110, v, XMGlobalConstants.Select1110);
XMVector result = XMQuaternion.Multiply(rotationQuaternion, a);
XMVector q = XMQuaternion.Conjugate(rotationQuaternion);
return(XMQuaternion.Multiply(result, q));
}
public static XMVector Inverse(XMVector q)
{
XMVector zero = XMVector.Zero;
XMVector l = XMVector4.LengthSquare(q);
XMVector conjugate = XMQuaternion.Conjugate(q);
XMVector control = XMVector.LessOrEqual(l, XMGlobalConstants.Epsilon);
XMVector result = XMVector.Divide(conjugate, l);
result = XMVector.Select(result, zero, control);
return(result);
}
