After the brief discussion of other ways of nicer ways to show hostiles on levels above you DarklingWolf suggested I dig out the old z-level stuff I started for pre DDA Cataclysm. As I had some free time this weekend here it is mostly merged in and stuck in github.
This is not under mods right now because it’s not even working well enough to count as a mod, it’s very broken and crashy, even by my standards ;D
There are also a few ‘issues’ with how it displays things, first up in that item highlights are showing even for floors we aren’t on. Notice just above the look around cursor there is things in the wall, really they are in the door way on the ground floor where I broke in.
Next up we can see me trying to jump out the window, here I just copied the standard trap messages but tell you the number of floors.
Jumping down one story is boring though so…
Up we go 
Notice that the view looks the same as my tower blocks are generated empty other than the stair well and there is no way of showing how far down the outside world is. I made it grey (which could have also meant night 
but that is the best I could think of. If anyone has any ideas please let me know.
Turns out jumping that far was fatal, I may have overdone the damages somewhat. Also I notice there is no windows on the ground floor, would suck to live in those flats…
I’m fairly sure you can get melee attacked through floors too but I’ve not managed to get that to reproduce yet. Also if your high up and save sometimes the game crashes and destroys your world, it’s just a issue with the way I hacked in the submap support but haven’t gotten around to fixing it yet.
Really I think we need to rewrite the map code for this to work nicely, also sorry about the size of the images.
Things to do:
- stop it crashing
- make tower blocks generate sensible flats and only in cities (currently they replace all houses just so I can test it)
- look around doesn’t report sensible on open spaces
- items and traps are broken with reporting
- path finding between levels does not work
- think of a way to show how far down the ground is
- make lighting support z-levels
- should not be able to see into ground floor buildings from high up
- look up / down scrolling in look around
- display for hostiles on higher / lower ground
- better fall damage
- walkways
- bridges actually using z-levels so you can sail/swim under them
- see roofs of lower buildings (rather than the inside floor)