WOW! Thanks for the hints/tips/info Jeremy

If it helps (and you hadn't noticed from earlier posts), I am doing an article on colliding 2d boxes with a 2d regular tile grid that has solid tiles.

I WAS going to explain about the type of 2d grid being used + the 3 classes I am using to do the collisions:

TTileGrid class - contains the 2d grid, tile info like solid edges, and finding what grid location a x,y coordinate is in.
TCollider class - can collide with, and not move through solid tile edges defined in the TTileGrid class.
TCollidableObject class - has TCollider objects inside itself and won't move through solid tiles because of this.

I'm not really sure yet how I am going to break it down into separate bits if I have to go that way...

PS. Is this magazine going to be down-loadable, or as hard-copy (print), or both?
cheers,
Paul