* @param t0            domain of axial shading, limit 1
     * @param t1            domain of axial shading, limit 2
     * @param extended      2 element vector, indicating line extension along domain
     * @return parametric value.
     */
    private float parametrixValue(float linearMapping, float t0, float t1,
                                  Vector extended) {

        if (linearMapping < 0 && ((Boolean) extended.get(0))) {
            return t0;
        } else if (linearMapping > 1 && ((Boolean) extended.get(1))) {
            return t1;
        } else {
            return t0 + ((t1 - t0) * linearMapping);
        }
    }