MCU does not support custom easing curves

 qreal static inline _cbrt(qreal d)
    {
        qreal sign = 1;
        if (d < 0)
            sign = -1;
        d = d * sign;

        qreal t = _fast_cbrt(d);

        //one step of Halley's Method to get a better approximation
        const qreal t_cubic = t * t * t;
        const qreal f = t_cubic + t_cubic + d;
        if (f != qreal(0.0))
            t = t * (t_cubic + d + d) / f;

        //another step
        /*qreal t_i = t;
         t_i_cubic = pow(t_i, 3);
         t = t_i * (t_i_cubic + d + d) / (t_i_cubic + t_i_cubic + d);*/

        return t * sign;
    }

    float static inline _fast_cbrt(float x)
    {
        union {
            float f;
            quint32 i;
        } ux;

        const unsigned int B1 = 709921077;

        ux.f = x;
        ux.i = (ux.i / 3 + B1);

        return ux.f;
    }

    double static inline _fast_cbrt(double d)
    {
        union {
            double d;
            quint32 pt[2];
        } ut, ux;

        const unsigned int B1 = 715094163;

#if Q_BYTE_ORDER == Q_LITTLE_ENDIAN
        const int h0 = 1;
#else
        const int h0 = 0;
#endif
        ut.d = 0.0;
        ux.d = d;

        quint32 hx = ux.pt[h0]; //high word of d
        ut.pt[h0] = hx / 3 + B1;

        return ut.d;
    }

    qreal static inline _acos(qreal x)
    {
        return std::sqrt(1-x)*(1.5707963267948966192313216916398f + x*(-0.213300989f + x*(0.077980478f + x*-0.02164095f)));
    }

    qreal static inline _cos(qreal x) //super fast _cos
    {
        const qreal pi_times2 = 2 * M_PI;
        const qreal pi_neg = -1 * M_PI;
        const qreal pi_by2 = M_PI / 2.0;

        x += pi_by2; //the polynom is for sin

        if (x < pi_neg)
            x += pi_times2;
        else if (x > M_PI)
            x -= pi_times2;

        const qreal a = 0.405284735;
        const qreal b = 1.27323954;

        const qreal x_squared = x * x;

        if (x < 0) {
            qreal cos = b * x + a * x_squared;

            if (cos < 0)
                return 0.225 * (cos * -1 * cos - cos) + cos;
            return 0.225 * (cos * cos - cos) + cos;
        } //else

        qreal cos = b * x - a * x_squared;

        if (cos < 0)
            return 0.225 * (cos * 1 *-cos - cos) + cos;
        return 0.225 * (cos * cos - cos) + cos;
    }

    bool static inline inRange(qreal f)
    {
        return (f >= -0.01 && f <= 1.01);
    }

    void static inline cosacos(qreal x, qreal &s1, qreal &s2, qreal &s3 )
    {
        //This function has no proper algebraic representation in real numbers.
        //We use approximations instead

        const qreal x_squared = x * x;
        const qreal x_plus_one_sqrt = qSqrt(1.0 + x);
        const qreal one_minus_x_sqrt = qSqrt(1.0 - x);

        //cos(acos(x) / 3)
        //s1 = _cos(_acos(x) / 3);
        s1 = 0.463614 - 0.0347815 * x + 0.00218245 * x_squared +  0.402421 * x_plus_one_sqrt;

        //cos(acos((x) -  M_PI) / 3)
        //s3 = _cos((_acos(x) - M_PI) / 3);
        s3 = 0.463614 + 0.402421 * one_minus_x_sqrt + 0.0347815 * x + 0.00218245 * x_squared;

        //cos((acos(x) +  M_PI) / 3)
        //s2 = _cos((_acos(x) + M_PI) / 3);
        s2 = -0.401644 * one_minus_x_sqrt - 0.0686804  * x + 0.401644 * x_plus_one_sqrt;
    }

    qreal static inline singleRealSolutionForCubic(qreal a, qreal b, qreal c)
    {
        //returns the real solutiuon in [0..1]
        //We use the Cardano formula

        //substituiton: x = z - a/3
        // z^3+pz+q=0

        if (c < 0.000001 && c > -0.000001)
            return 0;

        const qreal a_by3 = a / 3.0;

        const qreal a_cubic = a * a * a;

        const qreal p = b - a * a_by3;
        const qreal q = 2.0 * a_cubic / 27.0 - a * b / 3.0 + c;

        const qreal q_squared = q * q;
        const qreal p_cubic = p * p * p;
        const qreal D = 0.25 * q_squared + p_cubic / 27.0;

        if (D >= 0) {
            const qreal D_sqrt = qSqrt(D);
            qreal u = _cbrt( -q * 0.5 + D_sqrt);
            qreal v = _cbrt( -q * 0.5 - D_sqrt);
            qreal z1 = u + v;

            qreal t1 = z1 - a_by3;

            if (inRange(t1))
                return t1;
            qreal z2 = -1 *u;
            qreal t2 = z2 - a_by3;
            return t2;
        }

        //casus irreducibilis
        const qreal p_minus_sqrt = qSqrt(-p);

        //const qreal f = sqrt(4.0 / 3.0 * -p);
        const qreal f = qSqrt(4.0 / 3.0) * p_minus_sqrt;

        //const qreal sqrtP = sqrt(27.0 / -p_cubic);
        const qreal sqrtP = -3.0*qSqrt(3.0) / (p_minus_sqrt * p);


        const qreal g = -q * 0.5 * sqrtP;

        qreal s1;
        qreal s2;
        qreal s3;

        cosacos(g, s1, s2, s3);

        qreal z1 = -1* f * s2;
        qreal t1 = z1 - a_by3;
        if (inRange(t1))
            return t1;

        qreal z2 = f * s1;
        qreal t2 = z2 - a_by3;
        if (inRange(t2))
            return t2;

        qreal z3 = -1 * f * s3;
        qreal t3 = z3 - a_by3;
        return t3;
    }