Ring of fire now expands outwards (#17177)

code/__HELPERS/maths.dm

@@ -27,6 +27,14 @@ proc/arctan(x)
 /proc/Ceiling(x, y = 1)
 	. = -round(-x / y) * y
 
+/proc/sgn(const/i)
+	if(i > 0)
+		return 1
+	else if(i < 0)
+		return -1
+	else
+		return 0
+
 //Moved to macros.dm to reduce pure calling overhead, this was being called shitloads, like, most calls of all procs.
 /*
 /proc/Clamp(const/val, const/min, const/max)

code/datums/locking_category.dm

@@ -33,6 +33,10 @@
 	update_lock(AM)
 	AM.change_dir(owner.dir, owner)
 
+/datum/locking_category/proc/update_locks()
+	for(var/atom/A in locked)
+		update_lock(A)
+
 // Updates the position for AM.
 /datum/locking_category/proc/update_lock(var/atom/movable/AM)
 	var/new_loc = owner.loc

code/game/atoms_movable.dm

@@ -320,6 +320,7 @@
 	C.name = id
 	locking_categories_name[id] = C
 	locking_categories += C
+	return C
 
 /atom/movable/proc/get_lock_cat(var/category = /datum/locking_category)
 	locking_init()

code/modules/spells/general/ring_of_fire.dm

@@ -75,13 +75,36 @@
 /obj/effect/ring_of_fire/New(loc, list/locations, duration)
 	..()
 
+	var/list/processing_locking_cats = list()
+
 	for(var/turf/T in locations)
+		//Create the flames at their intended location
 		var/obj/effect/fire_blast/ring_of_fire/F = new /obj/effect/fire_blast/ring_of_fire(T, fire_duration = duration)
 
 		var/lock_id = "\ref[F]"
-		add_lock_cat(/datum/locking_category/ring_of_fire, lock_id)
+		var/datum/locking_category/ring_of_fire/locking_cat = add_lock_cat(/datum/locking_category/ring_of_fire, lock_id)
+		//Lock_atom notes their intended location, and moves all of them to the caster's turf
 		lock_atom(F, lock_id)
 
+		processing_locking_cats.Add(locking_cat)
+
+	//This subprocess moves all flames to their intended location
+	spawn()
+		while(processing_locking_cats.len)
+			for(var/datum/locking_category/ring_of_fire/ROF in processing_locking_cats)
+				if(ROF.x_offset == ROF.target_x_offset && ROF.y_offset == ROF.target_y_offset)
+					processing_locking_cats.Remove(ROF)
+					continue
+				if(!ROF.locked || !ROF.locked.len || !ROF.owner || !ROF.owner.loc)
+					processing_locking_cats.Remove(ROF)
+					continue
+
+				ROF.x_offset += sgn(ROF.target_x_offset - ROF.x_offset)
+				ROF.y_offset += sgn(ROF.target_y_offset - ROF.y_offset)
+				ROF.update_locks()
+
+			sleep(5)
+
 	spawn(duration)
 		qdel(src)
 
@@ -90,9 +113,13 @@
 	spread = 0
 
 /datum/locking_category/ring_of_fire
+	var/target_x_offset
+	var/target_y_offset
 
 /datum/locking_category/ring_of_fire/lock(atom/movable/AM)
-	x_offset = AM.x - owner.x
-	y_offset = AM.y - owner.y
+	target_x_offset = AM.x - owner.x
+	target_y_offset = AM.y - owner.y
+	x_offset = 0
+	y_offset = 0
 
 	..()