The easy stuff like FOV and automap are now in Tile_Map class. There is a class hierarchy confusion with Tile and Tile_Map, because in Tile_Map class sometimes there are simple getters that return Tile information from (x, y) location. It's not always pretty as it happens to be with getters, but I now know better not to spend time trying to create a perfect class hierarchy.
I think the tricky part will be lighting routines, because I'm planning to rewrite them. What I need is a nice line-of-sight routine for lights and a math implementation to light areas. Both can be difficult, at least for a programmer like me. I think I'm not going to use the main FOV routine for lights, but who knows, it may be easy to change it to work with lights. I've been thinking about the wall problem. It's a "bug" where a light source can lit wall from the other side (as if coming through the wall), because walls are usually 1 tile wide. I have some kind of idea how to fix it, but it's too early to tell if it works.
The biggest part will be terrain map routines. I'm trying to avoid Tile_Map becoming a kind of Level class itself and put only low level creation routines in it (things like shape primitives, rooms, etc.).