[MIRROR] up ports the TG overlays subsystem update (#12222)

Co-authored-by: Kashargul <144968721+Kashargul@users.noreply.github.com>

code/controllers/subsystems/overlays.dm

@@ -1,276 +1,156 @@
-//CHOMPEDIT -- this file is no longer ticked. See overlays_ch.dm for the new overlays subsystem.
-
 SUBSYSTEM_DEF(overlays)
 	name = "Overlay"
-	flags = SS_TICKER
-	wait = 1 // SS_TICKER - Ticks
-	priority = FIRE_PRIORITY_OVERLAYS
-	dependencies = list(
-		/datum/controller/subsystem/atoms
-	)
+	flags = SS_NO_FIRE|SS_NO_INIT
+	var/list/stats
 
-	/// The queue of atoms that need overlay updates.
-	var/static/tmp/list/queue = list()
-
-	/// A list([icon] = list([state] = [appearance], ...), ...) cache of appearances.
-	var/static/tmp/list/state_cache = list()
-
-	/// A list([icon] = [appearance], ...) cache of appearances.
-	var/static/tmp/list/icon_cache = list()
-
-	/// The number of appearances currently cached.
-	var/static/tmp/cache_size = 0
+/datum/controller/subsystem/overlays/PreInit()
+	stats = list()
 
+/datum/controller/subsystem/overlays/Shutdown()
+	WRITE_LOG("[GLOB.log_directory]-overlay.log", render_stats(stats))
 
 /datum/controller/subsystem/overlays/Recover()
-	queue.Cut()
-	state_cache.Cut()
-	icon_cache.Cut()
-	cache_size = 0
-	for (var/atom/atom)
-		atom.flags &= ~OVERLAY_QUEUED
-		CHECK_TICK
+	stats = SSoverlays.stats
 
-/datum/controller/subsystem/overlays/Initialize()
-	fire(FALSE, TRUE)
-	return SS_INIT_SUCCESS
+/// Converts an overlay list into text for debug printing
+/// Of note: overlays aren't actually mutable appearances, they're just appearances
+/// Don't have access to that type tho, so this is the best you're gonna get
+/proc/overlays2text(list/overlays)
+	var/list/unique_overlays = list()
+	// As anything because we're basically doing type coerrsion, rather then actually filtering for mutable apperances
+	for(var/mutable_appearance/overlay as anything in overlays)
+		var/key = "[overlay.icon]-[overlay.icon_state]-[overlay.dir]"
+		unique_overlays[key] += 1
+	var/list/output_text = list()
+	for(var/key in unique_overlays)
+		output_text += "([key]) = [unique_overlays[key]]"
+	return output_text.Join("\n")
 
-/datum/controller/subsystem/overlays/stat_entry(msg)
-	msg = "Queued Atoms: [queue.len], Cache Size: [cache_size]"
-	return ..()
+/proc/iconstate2appearance(icon, iconstate)
+	var/static/image/stringbro = new()
+	stringbro.icon = icon
+	stringbro.icon_state = iconstate
+	return stringbro.appearance
 
-/datum/controller/subsystem/overlays/fire(resumed, no_mc_tick)
-	var/count = 1
-	for (var/atom/atom as anything in queue)
-		++count
-		atom?.UpdateOverlays()
-		if (no_mc_tick)
-			CHECK_TICK
-		else if (MC_TICK_CHECK)
-			queue.Cut(1, count)
-			return
-	queue.Cut()
+/proc/icon2appearance(icon)
+	var/static/image/iconbro = new()
+	iconbro.icon = icon
+	return iconbro.appearance
 
-
-/datum/controller/subsystem/overlays/proc/GetStateAppearance(icon, state)
-	var/list/subcache = state_cache[icon]
-	if (!subcache)
-		subcache = list()
-		state_cache[icon] = subcache
-	if (!subcache[state])
-		var/image/image = new (icon, null, state)
-		subcache[state] = image.appearance
-		++cache_size
-	return subcache[state]
-
-
-/datum/controller/subsystem/overlays/proc/GetIconAppearance(icon)
-	if (!icon_cache[icon])
-		var/image/image = new (icon)
-		icon_cache[icon] = image.appearance
-		++cache_size
-	return icon_cache[icon]
-
-
-/datum/controller/subsystem/overlays/proc/GetAppearanceList(atom/subject, list/sources)
-	if (!sources)
-		return list()
-	if (!islist(sources))
-		sources = list(sources)
-	var/list/result = list()
-	var/icon/icon = subject.icon
-	for (var/atom/entry as anything in sources)
-		AppearanceListEntry(entry, result, icon)
-	return result
-
-//Fixes runtime with overlays present in 515
-/datum/controller/subsystem/overlays/proc/AppearanceListEntry(var/atom/entry,var/list/result,var/icon/icon)
-	if (!entry)
-		return
-	else if(islist(entry))
-		var/list/entry_list = entry
-		for(var/entry_item in entry_list)
-			AppearanceListEntry(entry_item)
-	else if (istext(entry))
-		result += GetStateAppearance(icon, entry)
-	else if (isicon(entry))
-		result += GetIconAppearance(entry)
-	else
-		if (isloc(entry))
-			if (entry.flags & OVERLAY_QUEUED)
-				entry.ImmediateOverlayUpdate()
-		if (!ispath(entry))
-			if(entry.appearance)
-				result += entry.appearance
+/atom/proc/build_appearance_list(list/build_overlays)
+	if (!islist(build_overlays))
+		build_overlays = list(build_overlays)
+	if(priority_overlays)
+		var/list/prio_overlay_temp
+		if(!islist(priority_overlays))
+			prio_overlay_temp = list(priority_overlays)
 		else
-			var/image/image = entry
-			result += image.appearance
+			prio_overlay_temp = priority_overlays.Copy()
+		prio_overlay_temp |= build_overlays
+		build_overlays = prio_overlay_temp
+	for (var/overlay in build_overlays)
+		if(!overlay)
+			build_overlays -= overlay
+			continue
+		if (istext(overlay))
+			// This is too expensive to run normally but running it during CI is a good test
+			/*if (PERFORM_ALL_TESTS(focus_only/invalid_overlays))
+				var/list/icon_states_available = icon_states(icon)
+				if(!(overlay in icon_states_available))
+					var/icon_file = "[icon]" || "Unknown Generated Icon"
+					stack_trace("Invalid overlay: Icon object '[icon_file]' [REF(icon)] used in '[src]' [type] is missing icon state [overlay].")
+					continue*/
 
-/// Enqueues the atom for an overlay update if not already queued
-/atom/proc/QueueOverlayUpdate()
-	if (flags & OVERLAY_QUEUED)
-		return
-	SSoverlays.queue += src
-	flags |= OVERLAY_QUEUED
+			var/index = build_overlays.Find(overlay)
+			build_overlays[index] = iconstate2appearance(icon, overlay)
+		else if(isicon(overlay))
+			var/index = build_overlays.Find(overlay)
+			build_overlays[index] = icon2appearance(overlay)
+	return build_overlays
 
-
-/// Builds the atom's overlay state from caches
-/atom/proc/UpdateOverlays()
-	if (gc_destroyed)
-		if (length(overlays))
-			overlays.Cut()
-		return
-	flags &= ~OVERLAY_QUEUED
-	if (length(priority_overlays))
-		if (length(our_overlays))
-			overlays = priority_overlays + our_overlays
-		else
-			overlays = priority_overlays
-	else if (length(our_overlays))
-		overlays = our_overlays
-	else
-		overlays.Cut()
-
-
-/// Immediately runs an overlay update and dequeues the atom
-/atom/proc/ImmediateOverlayUpdate()
-	SSoverlays.queue -= src
-	UpdateOverlays()
-
-
-/// Clears the atom's overlay cache(s) and queues an update if needed
 /atom/proc/cut_overlays(priority)
-	if (priority)
-		if (!length(priority_overlays))
-			return
-		priority_overlays.Cut()
-		QueueOverlayUpdate()
-	else if (length(our_overlays))
-		our_overlays.Cut()
-		QueueOverlayUpdate()
+	STAT_START_STOPWATCH
+	if(priority)
+		priority_overlays = null
+	overlays = null
+	//POST_OVERLAY_CHANGE(src)
+	STAT_STOP_STOPWATCH
+	STAT_LOG_ENTRY(SSoverlays.stats, type)
 
+/atom/proc/cut_overlay(list/remove_overlays, priority)
+	if(!overlays)
+		return
+	STAT_START_STOPWATCH
+	if(priority)
+		priority_overlays -= remove_overlays
+	if(islist(remove_overlays))
+		remove_overlays = remove_overlays.Copy() //May not be ideal to copy, but as build_appearance_list modifies lists in place which breaks certain things
+	overlays -= build_appearance_list(remove_overlays)
+	//POST_OVERLAY_CHANGE(src)
+	STAT_STOP_STOPWATCH
+	STAT_LOG_ENTRY(SSoverlays.stats, type)
 
-/**
- * Adds specific overlay(s) to the atom.
- * It is designed so any of the types allowed to be added to /atom/overlays can be added here too. More details below.
- *
- * @param add The overlay(s) to add.  These may be
- *	- A string: In which case it is treated as an icon_state of the atom's icon.
- *	- An icon: It is treated as an icon.
- *	- An atom: Its own overlays are compiled and then it's appearance is added. (Meaning its current apperance is frozen).
- *	- An image: Image's apperance is added (i.e. subsequently editing the image will not edit the overlay)
- *	- A type path: Added to overlays as is.  Does whatever it is BYOND does when you add paths to overlays.
- *	- Or a list containing any of the above.
- * @param priority The overlays are added to the "priority" list istead of the normal one.
- */
-/atom/proc/add_overlay(list/add, priority)
-	if (!add)
+/atom/proc/add_overlay(list/add_overlays, priority)
+	if(!overlays)
 		return
-	add = SSoverlays.GetAppearanceList(src, add)
-	if (!length(add))
+	STAT_START_STOPWATCH
+	if(islist(add_overlays))
+		if(priority)
+			if (priority_overlays)
+				priority_overlays += add_overlays
+			else
+				priority_overlays = add_overlays
+		add_overlays = add_overlays.Copy() //May not be ideal to copy, but as build_appearance_list modifies lists in place which breaks certain things
+	overlays += build_appearance_list(add_overlays) //May not be ideal to copy, but as build_appearance_list modifies lists in place which breaks certain things
+	VALIDATE_OVERLAY_LIMIT(src)
+	//POST_OVERLAY_CHANGE(src)
+	STAT_STOP_STOPWATCH
+	STAT_LOG_ENTRY(SSoverlays.stats, type)
+
+/atom/proc/copy_overlays(atom/other, cut_old) //copys our_overlays from another atom
+	if(!other)
+		if(cut_old)
+			cut_overlays()
 		return
-	if (priority)
-		if (priority_overlays)
-			priority_overlays += add
+
+	STAT_START_STOPWATCH
+	var/list/cached_other = other.overlays.Copy()
+	if(cut_old)
+		if(cached_other)
+			overlays = cached_other
 		else
-			priority_overlays = add
-	else if (our_overlays)
-		our_overlays += add
-	else
-		our_overlays = add
-	QueueOverlayUpdate()
-
-
-/**
- * Removes specific overlay(s) from the atom.  Usually does not remove them from "priority" overlays.
- *
- * @param overlays The overlays to removed, type can be anything that is allowed for add_overlay().
- * @param priority If true, also will remove them from the "priority" overlays.
- */
-/atom/proc/cut_overlay(list/cut, priority)
-	if (!cut)
-		return
-	cut = SSoverlays.GetAppearanceList(src, cut)
-	if (!length(cut))
-		return
-	var/update
-	if (priority && length(priority_overlays))
-		priority_overlays -= cut
-		update = TRUE
-	if (length(our_overlays))
-		our_overlays -= cut
-		update = TRUE
-	if (update)
-		QueueOverlayUpdate()
-
-
-/**
- * Copy the overlays from another atom, either replacing all of ours or appending to our existing overlays.
- * Note: This copies only the normal overlays, not the "priority" overlays.
- *
- * @param other The atom to copy overlays from.
- * @param cut_old If true, all of our overlays will be *replaced* by the other's. If other is null, that means cutting all ours.
- */
-/atom/proc/copy_overlays(atom/other, cut)
-	if (!other)
-		if (cut)
-			cut_overlays()
-		return
-	if (!length(other.our_overlays))
-		if (cut)
-			cut_overlays()
-		return
-	if (cut || !length(our_overlays))
-		our_overlays = other.our_overlays.Copy()
-	else
-		our_overlays |= other.our_overlays
-	QueueOverlayUpdate()
-
-
-/**
- * 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
+			overlays = null
+		VALIDATE_OVERLAY_LIMIT(src)
+		//POST_OVERLAY_CHANGE(src)
+		STAT_STOP_STOPWATCH
+		STAT_LOG_ENTRY(SSoverlays.stats, type)
+	else if(cached_other)
+		overlays += cached_other
+		VALIDATE_OVERLAY_LIMIT(src)
+		//POST_OVERLAY_CHANGE(src)
+		STAT_STOP_STOPWATCH
+		STAT_LOG_ENTRY(SSoverlays.stats, type)
 
+//TODO: Better solution for these?
 /image/proc/add_overlay(x)
-	overlays += x
-
+	overlays |= x
 
 /image/proc/cut_overlay(x)
 	overlays -= x
 
-
 /image/proc/cut_overlays(x)
 	overlays.Cut()
 
-
 /image/proc/copy_overlays(atom/other, cut_old)
 	if(!other)
 		if(cut_old)
 			cut_overlays()
 		return
 
-	var/list/cached_other = other.our_overlays
+	var/list/cached_other = other.overlays.Copy()
 	if(cached_other)
 		if(cut_old || !overlays.len)
-			overlays = cached_other.Copy()
+			overlays = cached_other
 		else
 			overlays |= cached_other
 	else if(cut_old)
@@ -372,3 +252,10 @@ SUBSYSTEM_DEF(overlays)
 	message_admins(text)
 	log_world(text)
 	return diff_found
+
+//Legacy, does basically nothing
+/atom/proc/ImmediateOverlayUpdate()
+	if (gc_destroyed)
+		if (length(overlays))
+			overlays.Cut()
+		return

code/controllers/subsystems/overlays_ch.dm

@@ -1,244 +0,0 @@
-SUBSYSTEM_DEF(overlays)
-	name = "Overlay"
-	flags = SS_NO_FIRE|SS_NO_INIT
-	var/list/stats
-
-/datum/controller/subsystem/overlays/PreInit()
-	stats = list()
-
-/datum/controller/subsystem/overlays/Shutdown()
-	WRITE_LOG("[GLOB.log_directory]-overlay.log", render_stats(stats))
-
-/datum/controller/subsystem/overlays/Recover()
-	stats = SSoverlays.stats
-
-/// Converts an overlay list into text for debug printing
-/// Of note: overlays aren't actually mutable appearances, they're just appearances
-/// Don't have access to that type tho, so this is the best you're gonna get
-/proc/overlays2text(list/overlays)
-	var/list/unique_overlays = list()
-	// As anything because we're basically doing type coerrsion, rather then actually filtering for mutable apperances
-	for(var/mutable_appearance/overlay as anything in overlays)
-		var/key = "[overlay.icon]-[overlay.icon_state]-[overlay.dir]"
-		unique_overlays[key] += 1
-	var/list/output_text = list()
-	for(var/key in unique_overlays)
-		output_text += "([key]) = [unique_overlays[key]]"
-	return output_text.Join("\n")
-
-/proc/iconstate2appearance(icon, iconstate)
-	var/static/image/stringbro = new()
-	stringbro.icon = icon
-	stringbro.icon_state = iconstate
-	return stringbro.appearance
-
-/proc/icon2appearance(icon)
-	var/static/image/iconbro = new()
-	iconbro.icon = icon
-	return iconbro.appearance
-
-/atom/proc/build_appearance_list(list/build_overlays)
-	if (!islist(build_overlays))
-		build_overlays = list(build_overlays)
-	for (var/overlay in build_overlays)
-		if(!overlay)
-			build_overlays -= overlay
-			continue
-		if (istext(overlay))
-			// This is too expensive to run normally but running it during CI is a good test
-			/*if (PERFORM_ALL_TESTS(focus_only/invalid_overlays))
-				var/list/icon_states_available = icon_states(icon)
-				if(!(overlay in icon_states_available))
-					var/icon_file = "[icon]" || "Unknown Generated Icon"
-					stack_trace("Invalid overlay: Icon object '[icon_file]' [REF(icon)] used in '[src]' [type] is missing icon state [overlay].")
-					continue*/
-
-			var/index = build_overlays.Find(overlay)
-			build_overlays[index] = iconstate2appearance(icon, overlay)
-		else if(isicon(overlay))
-			var/index = build_overlays.Find(overlay)
-			build_overlays[index] = icon2appearance(overlay)
-	return build_overlays
-
-/atom/proc/cut_overlays()
-	STAT_START_STOPWATCH
-	overlays = null
-	//POST_OVERLAY_CHANGE(src)
-	STAT_STOP_STOPWATCH
-	STAT_LOG_ENTRY(SSoverlays.stats, type)
-
-/atom/proc/cut_overlay(list/remove_overlays)
-	if(!overlays)
-		return
-	STAT_START_STOPWATCH
-	if(islist(remove_overlays))
-		remove_overlays = remove_overlays.Copy() //May not be ideal to copy, but as build_appearance_list modifies lists in place which breaks certain things
-	overlays -= build_appearance_list(remove_overlays)
-	//POST_OVERLAY_CHANGE(src)
-	STAT_STOP_STOPWATCH
-	STAT_LOG_ENTRY(SSoverlays.stats, type)
-
-/atom/proc/add_overlay(list/add_overlays)
-	if(!overlays)
-		return
-	STAT_START_STOPWATCH
-	if(islist(add_overlays))
-		add_overlays = add_overlays.Copy() //May not be ideal to copy, but as build_appearance_list modifies lists in place which breaks certain things
-	overlays += build_appearance_list(add_overlays) //May not be ideal to copy, but as build_appearance_list modifies lists in place which breaks certain things
-	VALIDATE_OVERLAY_LIMIT(src)
-	//POST_OVERLAY_CHANGE(src)
-	STAT_STOP_STOPWATCH
-	STAT_LOG_ENTRY(SSoverlays.stats, type)
-
-/atom/proc/copy_overlays(atom/other, cut_old) //copys our_overlays from another atom
-	if(!other)
-		if(cut_old)
-			cut_overlays()
-		return
-
-	STAT_START_STOPWATCH
-	var/list/cached_other = other.overlays.Copy()
-	if(cut_old)
-		if(cached_other)
-			overlays = cached_other
-		else
-			overlays = null
-		VALIDATE_OVERLAY_LIMIT(src)
-		//POST_OVERLAY_CHANGE(src)
-		STAT_STOP_STOPWATCH
-		STAT_LOG_ENTRY(SSoverlays.stats, type)
-	else if(cached_other)
-		overlays += cached_other
-		VALIDATE_OVERLAY_LIMIT(src)
-		//POST_OVERLAY_CHANGE(src)
-		STAT_STOP_STOPWATCH
-		STAT_LOG_ENTRY(SSoverlays.stats, type)
-
-//TODO: Better solution for these?
-/image/proc/add_overlay(x)
-	overlays |= x
-
-/image/proc/cut_overlay(x)
-	overlays -= x
-
-/image/proc/cut_overlays(x)
-	overlays.Cut()
-
-/image/proc/copy_overlays(atom/other, cut_old)
-	if(!other)
-		if(cut_old)
-			cut_overlays()
-		return
-
-	var/list/cached_other = other.overlays.Copy()
-	if(cached_other)
-		if(cut_old || !overlays.len)
-			overlays = cached_other
-		else
-			overlays |= cached_other
-	else if(cut_old)
-		cut_overlays()
-
-// Debug procs
-
-/atom
-	/// List of overlay "keys" (info about the appearance) -> mutable versions of static appearances
-	/// Drawn from the overlays list
-	var/list/realized_overlays
-	/// List of underlay "keys" (info about the appearance) -> mutable versions of static appearances
-	/// Drawn from the underlays list
-	var/list/realized_underlays
-
-/image
-	/// List of overlay "keys" (info about the appearance) -> mutable versions of static appearances
-	/// Drawn from the overlays list
-	var/list/realized_overlays
-	/// List of underlay "keys" (info about the appearance) -> mutable versions of static appearances
-	/// Drawn from the underlays list
-	var/list/realized_underlays
-
-/// Takes the atoms's existing overlays and underlays, and makes them mutable so they can be properly vv'd in the realized_overlays/underlays list
-/atom/proc/realize_overlays()
-	realized_overlays = realize_appearance_queue(overlays)
-	realized_underlays = realize_appearance_queue(underlays)
-
-/// Takes the image's existing overlays, and makes them mutable so they can be properly vv'd in the realized_overlays list
-/image/proc/realize_overlays()
-	realized_overlays = realize_appearance_queue(overlays)
-	realized_underlays = realize_appearance_queue(underlays)
-
-/// Takes a list of appearnces, makes them mutable so they can be properly vv'd and inspected
-/proc/realize_appearance_queue(list/appearances)
-	var/list/real_appearances = list()
-	var/list/queue = appearances.Copy()
-	var/queue_index = 0
-	while(queue_index < length(queue))
-		queue_index++
-		// If it's not a command, we assert that it's an appearance
-		var/mutable_appearance/appearance = queue[queue_index]
-		if(!appearance) // Who fucking adds nulls to their sublists god you people are the worst
-			continue
-
-		var/mutable_appearance/new_appearance = new /mutable_appearance()
-		new_appearance.appearance = appearance
-		var/key = "[appearance.icon]-[appearance.icon_state]-[appearance.plane]-[appearance.layer]-[appearance.dir]-[appearance.color]"
-		var/tmp_key = key
-		var/appearance_indx = 1
-		while(real_appearances[tmp_key])
-			tmp_key = "[key]-[appearance_indx]"
-			appearance_indx++
-
-		real_appearances[tmp_key] = new_appearance
-		var/add_index = queue_index
-		// Now check its children
-		for(var/mutable_appearance/child_appearance as anything in appearance.overlays)
-			add_index++
-			queue.Insert(add_index, child_appearance)
-		for(var/mutable_appearance/child_appearance as anything in appearance.underlays)
-			add_index++
-			queue.Insert(add_index, child_appearance)
-	return real_appearances
-
-/// Takes two appearances as args, prints out, logs, and returns a text representation of their differences
-/// Including suboverlays
-/proc/diff_appearances(mutable_appearance/first, mutable_appearance/second, iter = 0)
-	var/list/diffs = list()
-	var/list/firstdeet = first.vars
-	var/list/seconddeet = second.vars
-	var/diff_found = FALSE
-	for(var/name in first.vars)
-		var/firstv = firstdeet[name]
-		var/secondv = seconddeet[name]
-		if(firstv ~= secondv)
-			continue
-		if((islist(firstv) || islist(secondv)) && length(firstv) == 0 && length(secondv) == 0)
-			continue
-		if(name == "vars") // Go away
-			continue
-		if(name == "_listen_lookup") // This is just gonna happen with marked datums, don't care
-			continue
-		if(name == "overlays")
-			first.realize_overlays()
-			second.realize_overlays()
-			var/overlays_differ = FALSE
-			for(var/i in 1 to length(first.realized_overlays))
-				if(diff_appearances(first.realized_overlays[i], second.realized_overlays[i], iter + 1))
-					overlays_differ = TRUE
-
-			if(!overlays_differ)
-				continue
-
-		diff_found = TRUE
-		diffs += "Diffs detected at [name]: First ([firstv]), Second ([secondv])"
-
-	var/text = "Depth of: [iter]\n\t[diffs.Join("\n\t")]"
-	message_admins(text)
-	log_world(text)
-	return diff_found
-
-//Legacy, does basically nothing
-/atom/proc/ImmediateOverlayUpdate()
-	if (gc_destroyed)
-		if (length(overlays))
-			overlays.Cut()
-		return

code/game/atoms_movable.dm

@@ -44,10 +44,12 @@
 			gen_emissive_blocker.color = GLOB.em_block_color
 			gen_emissive_blocker.dir = dir
 			gen_emissive_blocker.appearance_flags |= appearance_flags
+			// Note, this should be refactored to drop priority overlays
 			add_overlay(list(gen_emissive_blocker), TRUE)
 		if(EMISSIVE_BLOCK_UNIQUE)
 			render_target = ref(src)
 			em_block = new(src, render_target)
+			// Note, this should be refactored to drop priority overlays
 			add_overlay(list(em_block), TRUE)
 			RegisterSignal(em_block, COMSIG_QDELETING, PROC_REF(emblocker_gc))
 	if(opacity)

code/game/gamemodes/technomancer/spells/control.dm

@@ -41,6 +41,7 @@
 		var/mob/living/simple_mob/SM = L
 		SM.friends |= src.owner
 
+	// Note, this should be refactored to drop priority overlays
 	L.add_overlay(control_overlay, TRUE)
 	controlled_mobs |= L
 

code/game/objects/items/weapons/explosives.dm

@@ -68,7 +68,7 @@
 			message_admins("[key_name(user, user.client)](<A href='byond://?_src_=holder;[HrefToken()];adminmoreinfo=\ref[user]'>?</A>) planted [src.name] on [target.name] at ([target.x],[target.y],[target.z] - <A href='byond://?_src_=holder;[HrefToken()];adminplayerobservecoodjump=1;X=[target.x];Y=[target.y];Z=[target.z]'>JMP</a>) with [timer] second fuse",0,1)
 			log_game("[key_name(user)] planted [src.name] on [target.name] at ([target.x],[target.y],[target.z]) with [timer] second fuse")
 
-		target.add_overlay(image_overlay, TRUE)
+		target.add_overlay(image_overlay)
 		to_chat(user, "Bomb has been planted. Timer counting down from [timer].")
 		spawn(timer*10)
 			explode(get_turf(target))
@@ -90,7 +90,7 @@
 		else
 			target.ex_act(1)
 	if(target)
-		target.cut_overlay(image_overlay, TRUE)
+		target.cut_overlay(image_overlay)
 	qdel(src)
 
 /obj/item/plastique/attack(mob/M as mob, mob/user as mob, def_zone)

code/game/objects/items/weapons/explosives_vr.dm

@@ -10,7 +10,7 @@
 	var/turf/T = get_turf(target)
 	if((T.z in using_map.station_levels) || (T.z in using_map.admin_levels))
 		target.visible_message(span_danger("\The [src] lets out a loud beep as safeties trigger, before imploding and falling apart."))
-		target.cut_overlay(image_overlay, TRUE)
+		target.cut_overlay(image_overlay)
 		qdel(src)
 		return 0
 	else

code/game/turfs/simulated/dungeon/wall.dm

@@ -66,7 +66,7 @@
 	return mining_overlay_cache["[cache_id]_[direction]"]
 
 /turf/simulated/wall/solidrock/update_icon(var/update_neighbors)
-	cut_overlays() //ChompEDIT
+	cut_overlays()
 	if(density)
 		var/image/I
 		for(var/i = 1 to 4)

code/game/turfs/simulated/floor_types.dm

@@ -23,7 +23,7 @@
 /obj/landed_holder/proc/land_on(var/turf/T)
 	//Gather destination information
 	var/obj/landed_holder/new_holder = new(null)
-	T.lighting_clear_overlay() //CHOMP Add
+	T.lighting_clear_overlay()
 	new_holder.turf_type = T.type
 	new_holder.dir = T.dir
 	new_holder.icon = T.icon
@@ -34,12 +34,12 @@
 
 	//Set the destination to be like us
 	var/turf/simulated/shuttle/new_dest = T.ChangeTurf(my_turf.type,,1)
-	my_turf.lighting_clear_overlay() //CHOMP Add
+	my_turf.lighting_clear_overlay()
 	new_dest.set_dir(my_turf.dir)
 	new_dest.icon_state = my_turf.icon_state
 	new_dest.icon = my_turf.icon
 	new_dest.copy_overlays(my_turf, TRUE)
-	new_dest.underlays = my_turf.underlays.Copy() //CHOMP Edit
+	new_dest.underlays = my_turf.underlays.Copy()
 	new_dest.decals = my_turf.decals
 	//Shuttle specific stuff
 	new_dest.interior_corner = my_turf.interior_corner
@@ -47,7 +47,7 @@
 	new_dest.under_turf = my_turf.under_turf
 	new_dest.join_flags = my_turf.join_flags
 	new_dest.join_group = my_turf.join_group
-	new_dest.lighting_build_overlay() //CHOMP Add
+	new_dest.lighting_build_overlay()
 
 	// Associate the holder with the new turf.
 	new_holder.my_turf = new_dest
@@ -64,14 +64,14 @@
 	//Change our source to whatever it was before
 	if(turf_type)
 		new_source = my_turf.ChangeTurf(turf_type,,1)
-		new_source.lighting_clear_overlay() //CHOMP Add
+		new_source.lighting_clear_overlay()
 		new_source.set_dir(dir)
 		new_source.icon_state = icon_state
 		new_source.icon = icon
 		new_source.copy_overlays(src, TRUE)
-		new_source.underlays = underlays.Copy() //CHOMP Edit
+		new_source.underlays = underlays.Copy()
 		new_source.decals = decals
-		new_source.lighting_build_overlay() //CHOMP Add
+		new_source.lighting_build_overlay()
 	else
 		new_source = my_turf.ChangeTurf(base_turf ? base_turf : get_base_turf_by_area(my_turf),,1)
 
@@ -110,13 +110,13 @@
 
 // For joined corners touching static lighting turfs, add an overlay to cancel out that part of our lighting overlay.
 /turf/simulated/shuttle/proc/update_breaklights()
-	cut_overlay(antilight_cache["[join_flags]"], TRUE)
+	cut_overlay(antilight_cache["[join_flags]"])
 	if(!(join_flags in GLOB.cornerdirs)) //We're not joined at an angle
 		return
 	//Dynamic lighting dissolver
 	var/turf/T = get_step(src, turn(join_flags,180))
 	if(!T || !T.dynamic_lighting || !get_area(T).dynamic_lighting)
-		add_overlay(antilight_cache["[join_flags]"], TRUE)
+		add_overlay(antilight_cache["[join_flags]"])
 
 /turf/simulated/shuttle/proc/underlay_update()
 	if(!takes_underlays)

code/modules/mob/living/living.dm

@@ -3,6 +3,7 @@
 
 	//Prime this list if we need it.
 	if(has_huds)
+		// Note, this should be refactored to drop priority overlays
 		add_overlay(backplane,TRUE) //Strap this on here, to block HUDs from appearing in rightclick menus: http://www.byond.com/forum/?post=2336679
 		hud_list = list()
 		hud_list.len = TOTAL_HUDS

code/modules/mob/living/simple_mob/subtypes/blob/spore.dm

@@ -94,7 +94,7 @@
 		if(overmind)
 			blob_head_overlay.color = overmind.blob_type.complementary_color
 		color = initial(color)//looks better.
-		add_overlay(blob_head_overlay, TRUE)
+		add_overlay(blob_head_overlay)
 
 /mob/living/simple_mob/blob/spore/handle_special()
 	..()

code/modules/multiz/turf.dm

@@ -67,7 +67,7 @@ GLOBAL_DATUM_INIT(openspace_backdrop_one_for_all, /atom/movable/openspace_backdr
 /turf/simulated/open/Initialize(mapload)
 	. = ..()
 	ASSERT(HasBelow(z))
-	add_overlay(GLOB.openspace_backdrop_one_for_all, TRUE) //Special grey square for projecting backdrop darkness filter on it.
+	add_overlay(GLOB.openspace_backdrop_one_for_all) //Special grey square for projecting backdrop darkness filter on it.
 	return INITIALIZE_HINT_LATELOAD
 
 /turf/simulated/open/LateInitialize()
@@ -99,7 +99,7 @@ GLOBAL_DATUM_INIT(openspace_backdrop_one_for_all, /atom/movable/openspace_backdr
 /turf/simulated/open/update_icon()
 	cut_overlays()
 	update_icon_edge()
-	add_overlay(GLOB.openspace_backdrop_one_for_all, TRUE) //Special grey square for projecting backdrop darkness filter on it. //ChompEDIT - add this on icon update.
+	add_overlay(GLOB.openspace_backdrop_one_for_all) //Special grey square for projecting backdrop darkness filter on it.
 
 // Straight copy from space.
 /turf/simulated/open/attackby(obj/item/C as obj, mob/user as mob)

code/modules/shieldgen/energy_shield.dm

@@ -32,8 +32,8 @@
 		overlays.Cut() // Snowflake handling, avoiding SSoverlays
 	else
 		icon_state = enabled_icon_state
-		//flags |= OVERLAY_QUEUED //Trick SSoverlays //CHOMPEdit
-		//SSoverlays.queue += src //CHOMPEdit
+		//flags |= OVERLAY_QUEUED //Trick SSoverlays
+		//SSoverlays.queue += src
 
 /obj/effect/shield/proc/update_color()
 	if(disabled_for || diffused_for)

code/modules/vore/eating/belly_obj_vr.dm

@@ -661,6 +661,7 @@
 			temp.filters += filter(type = "alpha", icon = icon(I.icon, I.icon_state))
 			I.d_stage_overlay = temp
 			for(var/count in I.d_mult to 1 step 0.25)
+				// Note, this should be refactored to drop priority overlays
 				I.add_overlay(I.d_stage_overlay, TRUE)
 
 // SEND_SIGNAL(COMSIG_BELLY_UPDATE_VORE_FX) is sometimes used when calling vore_fx() to send belly visuals

vorestation.dme

@@ -142,7 +142,7 @@
 #include "code\__defines\ores.dm"
 #include "code\__defines\organ_external.dm"
 #include "code\__defines\organ_internal.dm"
-#include "code\__defines\overlay_ch.dm"
+#include "code\__defines\overlay.dm"
 #include "code\__defines\overmap.dm"
 #include "code\__defines\paicard.dm"
 #include "code\__defines\particles.dm"
@@ -604,7 +604,7 @@
 #include "code\controllers\subsystems\motion_tracker.dm"
 #include "code\controllers\subsystems\nerdle.dm"
 #include "code\controllers\subsystems\nightshift.dm"
-#include "code\controllers\subsystems\overlays_ch.dm"
+#include "code\controllers\subsystems\overlays.dm"
 #include "code\controllers\subsystems\overmap_renamer_vr.dm"
 #include "code\controllers\subsystems\pathfinder_ch.dm"
 #include "code\controllers\subsystems\persist_vr.dm"