触摸板例程CapTouchBoosterPack_UserExperience中 这个函数是什么意思~求大神指导

if(wheel_position != ILLEGAL_SLIDER_WHEEL_POSITION)
{
centerButtonTouched = 0;

/* Adjust wheel position based: rotate CCW by 2 positions */
if (wheel_position < 0x08)
{
wheel_position += 0x40 - 0x08;
}
else
{
wheel_position -= 0x08;
/* Adjust wheel position based: rotate CCW by 2 positions */
}

wheel_position = wheel_position >>2; // divide by four