public static void Multiply(ref SphericalDirectionF d, ref QuaternionF q, out SphericalDirectionF result)
{
Vector3F vector;
d.GetVector(out vector);
Vector3F vector2;
QuaternionF.Multiply(ref vector, ref q, out vector2);
SphericalDirectionF.FromVector(ref vector2, out result);
}
public static void Slerp(ref QuaternionF from, ref QuaternionF to, float t, out QuaternionF result)
{
QuaternionF temp;
float omega, cosom, sinom, scale0, scale1;
if (t <= 0.0f)
{
result = from;
}
if (t >= 1.0f)
{
result = to;
}
if (from == to)
{
result = to;
}
cosom = from.X * to.X + from.Y * to.Y + from.Z * to.Z + from.W * to.W;
if (cosom < 0.0f)
{
temp = -to;
cosom = -cosom;
}
else
{
temp = to;
}
if ((1.0f - cosom) > MathEx.Epsilon)
{
scale0 = 1.0f - cosom * cosom;
sinom = MathEx.InvSqrt(scale0);
omega = MathEx.Atan2(scale0 * sinom, cosom);
scale0 = MathEx.Sin((1.0f - t) * omega) * sinom;
scale1 = MathEx.Sin(t * omega) * sinom;
}
else
{
scale0 = 1.0f - t;
scale1 = t;
}
QuaternionF s1, s2;
QuaternionF.Multiply(scale0, ref from, out s1);
QuaternionF.Multiply(scale1, ref temp, out s2);
QuaternionF.Add(ref s1, ref s2, out result);
//return ( scale0 * from ) + ( scale1 * temp );
}