Brilliant Stuff! Exactly what I was looking for! Finally, projectiles can collide with walls! My topdown action adventure couldn't exist without it. THANK YOU!
Just a small note though - there is a slight inconsistency with tile collisions. My 16x16 bullet does not register collision when passing directly below or directly to the right of collision tile, but it registers when directly above or directly to the left. (When I'm standing at 8px half-tile position). Changing bullet's collision box doesn't seem do do anything, only 1px offsets at bullet launch but then this inconsistency only gets reversed. Perhaps take a look at it?