Map cleanup

Copies some stuff from Spookerton old PR

code/modules/multiz/basic.dm

@@ -42,13 +42,23 @@ var/global/list/z_levels = list()// Each bit re... haha just kidding this is a l
 		return null
 	return HasBelow(turf.z) ? get_step(turf, DOWN) : null
 
-/proc/GetConnectedZlevels(z)
+//[SIERRA-EDIT] - logic for turf/space/open by Spookerton
+/proc/GetAboveZlevels(z)
 	RETURN_TYPE(/list)
-	. = list(z)
-	for(var/level = z, HasBelow(level), level--)
-		. |= level-1
+	. = list()
 	for(var/level = z, HasAbove(level), level++)
-		. |= level+1
+		. |= level + 1
+
+/proc/GetBelowZlevels(z)
+	RETURN_TYPE(/list)
+	. = list()
+	for(var/level = z, HasBelow(level), level--)
+		. |= level - 1
+
+/proc/GetConnectedZlevels(z)
+	RETURN_TYPE(/list)
+	return list(z) + GetAboveZlevels(z) + GetBelowZlevels(z)
+// [/SIERRA-EDIT]
 
 /proc/GetConnectedZlevelsSet(z)
 	RETURN_TYPE(/list)

maps/sierra/sierra_turfs.dm

@@ -22,3 +22,49 @@
 
 /turf/simulated/floor/shuttle_ceiling/sierra/air
 	initial_gas = list("oxygen" = MOLES_O2STANDARD, "nitrogen" = MOLES_N2STANDARD)
+
+/*
+* Z-mimic space turf part
+*/
+
+/turf/space/Initialize()
+	. = ..()
+	update_starlight()
+
+	set_extension(src, /datum/extension/support_lattice)
+
+	if (z_eventually_space)
+		appearance = SSskybox.space_appearance_cache[(((x + y) ^ ~(x * y) + z) % 25) + 1]
+
+	if(!HasBelow(z))
+		return
+	var/turf/below = GetBelow(src)
+
+	if(istype(below, /turf/space))
+		return
+	var/area/A = below.loc
+
+	if(!below.density && (A.area_flags & AREA_FLAG_EXTERNAL))
+		return
+
+	return INITIALIZE_HINT_LATELOAD // oh no! we need to switch to being a different kind of turf!
+
+// Turfs for the non-bottom layers of multi-z space areas
+/turf/space/open
+	icon_state = ""
+	z_flags = ZM_MIMIC_DEFAULTS | ZM_MIMIC_OVERWRITE | ZM_MIMIC_NO_AO
+	z_eventually_space = 0
+
+
+/turf/space/open/Initialize()
+	for (var/level in GetBelowZlevels(z))
+		var/turf/below = locate(x, y, level)
+		if (!istype(below, /turf/space))
+			z_eventually_space = FALSE
+			break
+		if (below.z_eventually_space != 0)
+			z_eventually_space = below.z_eventually_space
+			break
+	if (!z_eventually_space == 0)
+		z_eventually_space = TRUE
+	return ..()