sp_range

Prototypeint sp_range(int active_sprite, int range[-1])

sp_range() gets or sets the range value for the active_sprite.

For an active_sprite that is playing an animation sequence with a special damage frame (i.e. attack sequences), the range value is used to temporarily deform the hardbox of all other sprites according to the current direction of the active_sprite. The active_sprite will hit any of the active_sprites that it overlaps.

If range is 0 (default), the range will be 28 for left and right, and 36 for up and down.

Direction	Left	Top	Right	Bottom
2	-10 - (range / 8)	-range	+10 + (range / 8)	0
4	0	-10 - (range / 8)	+range	+10 + (range / 8)
6	-range	-10 - (range / 8)	0	+10 + (range / 8)
8	-10	0	+10	+range

So, the range value essentially extends the hardboxes so that they're easier to hit based on the active_sprite's current direction. If the active_sprite is facing right and attacks, the hardboxes of all sprites are temporarily extended left range pixels (among other changes).

For sp_brain() 11 and 17 (missiles), range pixels are added around the missile's hardbox to make it more likely to hit enemies.

It is possible to see sp_range deformed hardboxes in debug mode.