Merge pull request #11176 from Very-Soft/ghosties

Allows hiding mobs/areas from observers without completely forbidding

code/game/objects/effects/landmarks.dm

@@ -117,6 +117,15 @@
 	else
 		log_error("[type] mapped in but no using_map")
 
+/obj/effect/landmark/hidden_level
+	delete_me = 1
+/obj/effect/landmark/hidden_level/Initialize()
+	. = ..()
+	if(using_map)
+		using_map.hidden_levels |= z
+	else
+		log_error("[type] mapped in but no using_map")
+
 
 /obj/effect/landmark/virtual_reality
 	name = "virtual_reality"

code/modules/mob/dead/observer/observer.dm

@@ -341,6 +341,8 @@ This is the proc mobs get to turn into a ghost. Forked from ghostize due to comp
 		var/area/A = areas[key]
 		if(A.z in using_map?.secret_levels)
 			areas -= key
+		if(A.z in using_map?.hidden_levels)
+			areas -= key
 
 	return areas
 
@@ -353,7 +355,9 @@ This is the proc mobs get to turn into a ghost. Forked from ghostize due to comp
 		var/mobz = get_z(mobs[key])
 		if(mobz in using_map?.secret_levels)
 			mobs -= key
-	
+		if(mobz in using_map?.hidden_levels)
+			mobs -= key
+
 	return mobs
 
 /mob/observer/dead/verb/dead_tele(areaname as null|anything in jumpable_areas())

maps/~map_system/maps.dm

@@ -35,6 +35,7 @@ var/list/all_maps = list()
 	var/static/list/xenoarch_exempt_levels = list()	//Z-levels exempt from xenoarch finds and digsites spawning.
 	var/static/list/persist_levels = list() // Z-levels where SSpersistence should persist between rounds. Defaults to station_levels if unset.
 	var/static/list/secret_levels = list() // Z-levels that (non-admin) ghosts can't get to
+	var/static/list/hidden_levels = list() // Z-levels who's contents are hidden, but not forbidden (gateways)
 	var/static/list/empty_levels = list()   // Empty Z-levels that may be used for various things
 	var/static/list/mappable_levels = list()// List of levels where mapping or other similar devices might work fully
 	// End Static Lists