Vector Dir Slerp VEX two methods

// axis angle

float angle (vector a, b){
    return acos(dot(normalize(a),normalize(b))) ;
}

vector mtCross (vector a, b){
    matrix3 mt = lookat(0, -b, a) ;
    return {1,0,0} * mt ;
}

vector dirLerp (vector a, b; float blend){
    vector4 quat = quaternion(angle(a,b) * blend, mtCross(a,b)) ;
    return qrotate(quat, a) ;
}

// dihedral slerp

vector dirLerp (vector a, b; float blend; matrix3 rot){
    vector4 quat = quaternion(dihedral(a,b)) ;
    quat = slerp({0,0,0,1}, quat, blend) ;
    rot = qconvert(quat) ;
    return qrotate(quat, a) ;
}