move filter_data to atoms def, add get_overlays

code/_helpers/visual_filters.dm

@@ -1,8 +1,5 @@
 // These involve BYOND's built in filters that do visual effects, and not stuff that distinguishes between things.
 
-// All of this ported from TG.
-/atom/movable
-	var/list/filter_data // For handling persistent filters
 
 /proc/cmp_filter_data_priority(list/A, list/B)
 	return A["priority"] - B["priority"]

code/controllers/subsystems/overlays.dm

@@ -222,6 +222,32 @@ var/global/image/appearance_bro = new() // Temporarily super-global because of B
 	else if(cut_old)
 		cut_overlays()
 
+/**
+ * Returns a list of overlays that the target atom has
+ *
+ * @param priority If true, returns priority overlays as well
+ * @param special If true, returns special overlays like emissives and em_blockers
+ */
+/proc/get_overlays(atom/other, priority, special)
+	var/list/including = list()
+	if(!other)
+		return including
+
+	for(var/image/I as anything in other.our_overlays)
+		if(!special && I.plane > 0)
+			continue
+		including += I
+
+	if(!priority)
+		return including
+
+	for(var/image/I as anything in other.priority_overlays)
+		if(!special && I.plane > 0)
+			continue
+		including += I
+
+	return including
+
 #undef NOT_QUEUED_ALREADY
 #undef QUEUE_FOR_COMPILE
 

code/game/atoms.dm

@@ -26,8 +26,15 @@
 	///Chemistry.
 
 	// Overlays
-	var/list/our_overlays	//our local copy of (non-priority) overlays without byond magic. Use procs in SSoverlays to manipulate
-	var/list/priority_overlays	//overlays that should remain on top and not normally removed when using cut_overlay functions, like c4.
+	///Our local copy of (non-priority) overlays without byond magic. Use procs in SSoverlays to manipulate
+	var/list/our_overlays
+	///Overlays that should remain on top and not normally removed when using cut_overlay functions, like c4.
+	var/list/priority_overlays
+	///vis overlays managed by SSvis_overlays to automaticaly turn them like other overlays
+	var/list/managed_vis_overlays
+
+	///Our local copy of filter data so we can add/remove it
+	var/list/filter_data
 
 	//Detective Work, used for the duplicate data points kept in the scanners
 	var/list/original_atom