Why x y coordinates in BRUSH Collision?

[amyren]

I have a feeling this might be a silly question and I'm missing somethings obvious, but I still ask..
Why do you need to enter x y in the collision argument for brushes?

I mean for sprite collision its just the id arguments. It may be the same png file loaded as a brush or as a sprite, with or without transparent areas, what is the difference in the collision detection.

[plouf]

a brush can be displayed with the same id several times in screen while sprites only once so

[amyren]

That makes sense, thanks