public static int GetFretInputMask(this GamepadInput gamepad)
        {
            int inputMask = 0;

            foreach (Note.GuitarFret fret in System.Enum.GetValues(typeof(Note.GuitarFret)))
            {
                if (gamepad.GetFretInput(fret))
                {
                    inputMask |= 1 << (int)fret;
                }
            }

            return(inputMask);
        }