I'm creating a 2D platformer and I'd like to implement an auto-tiling system. Normally, this wouldn't be particularly difficult. However, I'd like to have tiles like in Yoshi's Island, where the graphics extend past the actual collidable tile's boundaries.
Consider this image:
Although the eggs and the Piranha Plant are clearly resting on the ground, the flower tiles continue behind them, out of the collidable tile.
I know that it would be simple to do by hand, but extremely time consuming. Using an auto-tiling algorithm would save me a lot of time and boredom, but I'm not sure where to start.