Assorted atmos performance improvements. (#27966)

code/game/area/areas.dm

@@ -61,8 +61,8 @@
 	var/list/firealarms
 	var/firedoors_last_closed_on = 0
 
-	/// The air alarm to use for atmos_alert consoles
-	var/obj/machinery/alarm/master_air_alarm
+	/// The air alarms present in this area.
+	var/list/air_alarms = list()
 	/// The list of vents in our area.
 	var/list/obj/machinery/atmospherics/unary/vent_pump/vents = list()
 	/// The list of scrubbers in our area.

code/game/machinery/computer/atmos_alert.dm

@@ -19,26 +19,29 @@
 	parent_area_type = machine_area.get_top_parent_type()
 
 /obj/machinery/computer/atmos_alert/process()
-	// This is relatively cheap because the areas list is pretty small
-	for(var/obj/machinery/alarm/air_alarm as anything in GLOB.air_alarms)
-		if(!((get_area(air_alarm)).type in typesof(parent_area_type)) || air_alarm.z != z)
-			continue // Not an area we monitor, or outside our z-level
-		if(!air_alarm.report_danger_level)
+	alarm_cache = list()
+	alarm_cache["priority"] = list()
+	alarm_cache["minor"] = list()
+	alarm_cache["mode"] = list()
+	for(var/area/A in GLOB.all_areas)
+		if(!istype(A, parent_area_type))
 			continue
-		switch(air_alarm.alarm_area.atmosalm)
-			if(ATMOS_ALARM_DANGER)
-				alarm_cache["priority"] |= air_alarm.alarm_area.name
-				alarm_cache["minor"] -= air_alarm.alarm_area.name
-			if(ATMOS_ALARM_WARNING)
-				alarm_cache["priority"] -= air_alarm.alarm_area.name
-				alarm_cache["minor"] |= air_alarm.alarm_area.name
-			else
-				alarm_cache["priority"] -= air_alarm.alarm_area.name
-				alarm_cache["minor"] -= air_alarm.alarm_area.name
-		if(air_alarm.mode == AALARM_MODE_FILTERING)
-			alarm_cache["mode"] -= air_alarm.alarm_area.name
-		else
-			alarm_cache["mode"][air_alarm.alarm_area.name] = GLOB.aalarm_modes["[air_alarm.mode]"]
+		var/alarm_level = null
+		for(var/obj/machinery/alarm/air_alarm in A.air_alarms)
+			if(!istype(air_alarm))
+				continue
+			if(!air_alarm.report_danger_level)
+				continue
+			switch(air_alarm.alarm_area.atmosalm)
+				if(ATMOS_ALARM_DANGER)
+					alarm_level = "priority"
+				if(ATMOS_ALARM_WARNING)
+					if(isnull(alarm_level))
+						alarm_level = "minor"
+			if(!isnull(alarm_level))
+				alarm_cache[alarm_level] += A.name
+			if(air_alarm.mode != AALARM_MODE_FILTERING)
+				alarm_cache["mode"][A.name] = GLOB.aalarm_modes["[air_alarm.mode]"]
 
 	update_icon()
 

code/game/turfs/turf.dm

@@ -85,13 +85,7 @@
 	/// The effect used to render a pressure overlay from this tile.
 	var/obj/effect/pressure_overlay/pressure_overlay
 
-	var/list/milla_atmos_airtight = list(FALSE, FALSE, FALSE, FALSE)
-	var/list/milla_superconductivity = list(
-		OPEN_HEAT_TRANSFER_COEFFICIENT,
-		OPEN_HEAT_TRANSFER_COEFFICIENT,
-		OPEN_HEAT_TRANSFER_COEFFICIENT,
-		OPEN_HEAT_TRANSFER_COEFFICIENT)
-	var/list/milla_data = list()
+	var/list/milla_data = null
 
 	new_attack_chain = TRUE