Function quaternion_core::scale_add_vec

pub fn scale_add_vec<T>(s: T, a: Vector3<T>, b: Vector3<T>) -> Vector3<T> where
    T: Float, 

s*a + b

If the fma feature is enabled, the FMA calculation is performed using the mul_add method. If not enabled, it’s computed by unfused multiply-add (s*a + b).