Be aware - since stoppers are easily skippable, these hitboxes don't mean much due to the fact that one can easily skip several units through a stopper with speed.
1-way stoppers (assumed to be pointing upwards) will prevent further downwards motion starting a distance 34 units upwards from the center but 16 units leftwards, rightwards, and downwards from the center.
2-way stoppers (assumed to be pointing up and down) will prevent inwards motion starting a distance 34 units upwards and downwards from the center but 16 units left and right from the center.
4-way stoppers will prevent inwards motion starting a distance 34 units in all directions from the center. Keep in mind that the hitbox is "+" shaped rather than square shaped.
