Ports over Fires to Subsystems

code/controllers/subsystem/fire_burning.dm

@@ -0,0 +1,37 @@
+SUBSYSTEM_DEF(fire_burning)
+	name = "Fire Burning"
+	priority = FIRE_PRIOTITY_BURNING
+	flags = SS_NO_INIT|SS_BACKGROUND
+	runlevels = RUNLEVEL_GAME | RUNLEVEL_POSTGAME
+
+	var/list/currentrun = list()
+	var/list/processing = list()
+
+/datum/controller/subsystem/fire_burning/stat_entry()
+	..("P:[processing.len]")
+
+
+/datum/controller/subsystem/fire_burning/fire(resumed = 0)
+	if(!resumed)
+		src.currentrun = processing.Copy()
+
+	//cache for sanic speed (lists are references anyways)
+	var/list/currentrun = src.currentrun
+
+	while(currentrun.len)
+		var/obj/O = currentrun[currentrun.len]
+		currentrun.len--
+		if(!O || qdeleted(O))
+			processing -= O
+			if(MC_TICK_CHECK)
+				return
+			continue
+
+		if(O.burn_state == ON_FIRE)
+			if(O.burn_world_time < world.time)
+				O.burn()
+		else
+			processing -= O
+
+		if(MC_TICK_CHECK)
+			return