Add the air currents system. (faster atmospheric spread)

code/LINDA/LINDA_system.dm

@@ -128,6 +128,7 @@ turf/CanPass(atom/movable/mover, turf/target, height=1.5,air_group=0)
 		CalculateAdjacentTurfs()
 	if(air_master)
 		air_master.add_to_active(src,command)
+	InvalidateAtmoPassCache()
 
 /atom/movable/proc/move_update_air(var/turf/T)
     if(istype(T,/turf))

code/LINDA/LINDA_turf_tile.dm

@@ -281,6 +281,7 @@
 /turf/simulated/proc/share_air(var/turf/simulated/T)
 	if(T.current_cycle < current_cycle)
 		var/difference
+		air_currents_master.onGasExchange(src, air.return_pressure(),T.air.return_pressure())
 		difference = air.share(T.air, atmos_adjacent_turfs_amount)
 		if(difference)
 			if(difference > 0)

code/controllers/Processes/air.dm

@@ -1,16 +1,19 @@
 var/kill_air = 0
 
 var/global/datum/controller/process/air_system/air_master
-
+/turf/var/activeturf_airmastercycle = 0
+/datum/excited_group/var/excitedturf_airmastercycle = 0
 /datum/controller/process/air_system
 	var/list/excited_groups = list()
 	var/list/active_turfs = list()
 	var/list/hotspots = list()
 
+
 	//Special functions lists
 	var/list/turf/simulated/active_super_conductivity = list()
 	var/list/turf/simulated/high_pressure_delta = list()
 
+	var/sub_cycle = 0
 	var/current_cycle = 0
 	var/failed_ticks = 0
 	var/tick_progress = 0
@@ -24,7 +27,7 @@ var/global/datum/controller/process/air_system/air_master
 
 /datum/controller/process/air_system/setup()
 	name = "air"
-	schedule_interval = 20 // every 2 seconds
+	schedule_interval = 5 // every 2 seconds
 	start_delay = 4
 	air_master = src
 
@@ -37,7 +40,10 @@ var/global/datum/controller/process/air_system/air_master
 /datum/controller/process/air_system/doWork()
 	if(kill_air)
 		return 1
-	current_cycle++
+	if (sub_cycle >= 4)
+		current_cycle++
+		sub_cycle = 0
+	sub_cycle++
 	process_active_turfs()
 	process_excited_groups()
 	process_high_pressure_delta()
@@ -52,13 +58,13 @@ var/global/datum/controller/process/air_system/air_master
 
 /datum/controller/process/air_system/proc/process_hotspots()
 	last_hotspots = hotspots.len
-	for(var/obj/effect/hotspot/H in hotspots)
+	for(var/obj/effect/hotspot/H in hotspots) //we could split it as well, but at the same time it never represented much load in any profile i saw, so maybe we could just let it be faster
 		H.process()
 		SCHECK
 
 /datum/controller/process/air_system/proc/process_super_conductivity()
 	last_asc = active_super_conductivity.len
-	for(var/turf/simulated/T in active_super_conductivity)
+	for(var/turf/simulated/T in active_super_conductivity) //we could split it as well, but at the same time it never represented much load in any profile i saw, so maybe we could just let it be faster
 		T.super_conduct()
 		SCHECK
 
@@ -72,8 +78,16 @@ var/global/datum/controller/process/air_system/air_master
 
 /datum/controller/process/air_system/proc/process_active_turfs()
 	last_active = active_turfs.len
+	var/count = 0
 	for(var/turf/simulated/T in active_turfs)
+		if (T.activeturf_airmastercycle == current_cycle)
+			continue
+		if (count > last_active/4 && sub_cycle < 4) //do at most 1/4 every subcycle, unless its the last one, then do whatever is left (to cover those added etc)
+			break
+		count++
+		T.activeturf_airmastercycle = current_cycle
 		T.process_cell()
+
 		SCHECK
 
 /datum/controller/process/air_system/proc/remove_from_active(var/turf/simulated/T)
@@ -119,7 +133,14 @@ var/global/datum/controller/process/air_system/air_master
 
 /datum/controller/process/air_system/proc/process_excited_groups()
 	last_excited = excited_groups.len
+	var/count = 0
 	for(var/datum/excited_group/EG in excited_groups)
+		if (EG.excitedturf_airmastercycle == current_cycle)
+			continue
+		if (count > last_excited/4 && sub_cycle < 4) //do at most 1/4 every subcycle, unless its the last one, then do whatever is left (to cover those added etc)
+			break
+		count++
+		EG.excitedturf_airmastercycle = current_cycle
 		EG.breakdown_cooldown++
 		if(EG.breakdown_cooldown == 10)
 			EG.self_breakdown()