// TODO: untested
public Quaternion Interpolate(Quaternion to, float dt)
{
Float4 v0 = ToFloat4();
Float4 v1 = to.ToFloat4();
float dot = v0.Dot(v1);
if (dot < 0.0f)
{
v1 = new Float4(-v1.X, -v1.Y, -v1.Z, -v1.W);
dot = -dot;
}
if (dot > 0.9995f)
{
return(to);
//// If the inputs are too close for comfort, linearly interpolate and normalize the result
//Float4 result = v0 + dt * (v1 - v0);
//result.Normalize();
//return new Quaternion(result);
}
float theta = RyneMath.Acos(dot);
float deltaTheta = theta * dt;
float sinTheta = RyneMath.Sin(theta);
float sinDeltaTheta = RyneMath.Sin(deltaTheta);
float s0 = RyneMath.Cos(deltaTheta) - dot * sinDeltaTheta / sinTheta;
float s1 = sinDeltaTheta / sinTheta;
return(new Quaternion((s0 * v0) + (s1 * v1)));
}
public float RotationAngle(bool degrees = true)
{
return(RyneMath.RadiansToDegrees(2.0f * RyneMath.Acos(W)));
}
