public static XMVector NormalizeEst(XMVector v)
{
//// XMVector2NormalizeEst uses a reciprocal estimate and
//// returns QNaN on zero and infinite vectors.
XMVector result;
result = XMVector2.ReciprocalLength(v);
result = XMVector.Multiply(v, result);
return(result);
}
public static XMVector AngleBetweenVectors(XMVector v1, XMVector v2)
{
XMVector l1 = XMVector2.ReciprocalLength(v1);
XMVector l2 = XMVector2.ReciprocalLength(v2);
XMVector dot = XMVector2.Dot(v1, v2);
l1 = XMVector.Multiply(l1, l2);
return(XMVector.Multiply(dot, l1)
.Clamp(XMGlobalConstants.NegativeOne, XMGlobalConstants.One)
.ACos());
}