Update SSOverlays (ported from Baystation) (#19051)

Our SSOverlays system is outdated, and is likely the cause of many of
the issues seen in #18895. It has also been linked to a massive server
performance decrease.

This brings an updated system from Baystation, hopefully with speed
increases.

Should be testmerged, ideally with #18895.

---------

Co-authored-by: Cody Brittain <cbrittain10@live.com>

code/game/objects/items/airbubble.dm

@@ -492,15 +492,15 @@
 	return contains_body
 
 /obj/structure/closet/airbubble/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(ripped)
 		name = "ripped air bubble"
 		icon_state = "[icon_state]_ripped"
 	else
 		icon_state = "[initial(icon_state)][opened ? "_open" : ""]"
 	if(zipped)
-		add_overlay("[icon_state]_restrained")
-	add_overlay("pressure_[(use_internal_tank) ?("on") : ("off") ]")
+		AddOverlays("[icon_state]_restrained")
+	AddOverlays("pressure_[(use_internal_tank) ?("on") : ("off") ]")
 
 // Process transfer of air from the tank. Handle if it is ripped open.
 /obj/structure/closet/airbubble/proc/process_tank_give_air()

code/game/objects/items/crayons.dm

@@ -92,10 +92,10 @@
 	update_icon()
 
 /obj/item/pen/crayon/augment/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	var/image/crayon_tip = image('icons/obj/crayons.dmi', "crayonaugment_tip")
 	crayon_tip.color = colour
-	add_overlay(crayon_tip)
+	AddOverlays(crayon_tip)
 
 /obj/item/pen/crayon/augment/throw_at(atom/target, range, speed, mob/user)
 	user.drop_from_inventory(src)

code/game/objects/items/devices/aicard.dm

@@ -104,10 +104,10 @@
 			. = TRUE
 
 /obj/item/aicard/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(carded_ai)
 		if (!carded_ai.control_disabled)
-			add_overlay("aicard-on")
+			AddOverlays("aicard-on")
 		if(carded_ai.stat)
 			icon_state = "aicard-404"
 		else

code/game/objects/items/devices/auto_cpr.dm

@@ -65,35 +65,35 @@
 		var/c_state = "battery[battery_level][contained_sprite ? slot_str_to_contained_flag(slot) : ""]"
 		var/image/battery_overlay = image(c_icon, c_state)
 		battery_overlay.appearance_flags = RESET_ALPHA
-		I.add_overlay(battery_overlay)
+		I.AddOverlays(battery_overlay)
 	if(breath_mask)
 		var/c_state = "mask_[mask_on ? "worn" : "idle"][contained_sprite ? slot_str_to_contained_flag(slot) : ""]"
 		var/image/mask_overlay = image(c_icon, c_state)
 		mask_overlay.appearance_flags = RESET_ALPHA
-		I.add_overlay(mask_overlay)
+		I.AddOverlays(mask_overlay)
 	if(tank)
 		if(tank_level)
 			var/c_state = "tank_indicator[tank_level][contained_sprite ? slot_str_to_contained_flag(slot) : ""]"
 			var/image/tank_level_overlay = image(c_icon, c_state)
 			tank_level_overlay.appearance_flags = RESET_ALPHA
-			I.add_overlay(tank_level_overlay)
+			I.AddOverlays(tank_level_overlay)
 		var/c_state = "tank_[tank_type][contained_sprite ? slot_str_to_contained_flag(slot) : ""]"
 		var/image/tank_overlay = image(c_icon, c_state)
 		tank_overlay.appearance_flags = RESET_ALPHA
-		I.add_overlay(tank_overlay)
+		I.AddOverlays(tank_overlay)
 	if(epp_active)
 		var/c_state = "epp_active[cpr_mode ? "_cpr" : ""][contained_sprite ? slot_str_to_contained_flag(slot) : ""]"
 		var/image/epp_overlay = image(c_icon, c_state)
 		epp_overlay.appearance_flags = RESET_ALPHA
-		I.add_overlay(epp_overlay)
+		I.AddOverlays(epp_overlay)
 	return I
 
 /obj/item/auto_cpr/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	item_state = "[cpr_mode ? "med_harness_cpr" : "[initial(item_state)]"]"
 
 	if(breath_mask)
-		add_overlay("mask_[mask_on ? "worn" : "idle"]")
+		AddOverlays("mask_[mask_on ? "worn" : "idle"]")
 	if(battery)
 		switch(battery.percent())
 			if(90 to INFINITY)	battery_level = 6
@@ -103,7 +103,7 @@
 			if(20 to 39)		battery_level = 2
 			if(05 to 19)		battery_level = 1
 			if(-INFINITY to 4)	battery_level = 0
-		add_overlay("battery[battery_level]")
+		AddOverlays("battery[battery_level]")
 	if(tank)
 		switch(tank.percent())
 			if(90 to INFINITY)	tank_level = 6
@@ -113,7 +113,7 @@
 			if(20 to 39)		tank_level = 2
 			if(05 to 19)		tank_level = 1
 			if(-INFINITY to 4)	tank_level = 0
-		add_overlay("tank_indicator[tank_level]")
+		AddOverlays("tank_indicator[tank_level]")
 
 		if(istype(tank, /obj/item/tank/emergency_oxygen/engi))
 			tank_type = "engi"
@@ -121,11 +121,11 @@
 			tank_type = "oxy"
 		else
 			tank_type = "other"
-		add_overlay("tank_[tank_type]")
+		AddOverlays("tank_[tank_type]")
 	if(epp_active)
-		add_overlay("epp_active")
+		AddOverlays("epp_active")
 	if(panel_open)
-		add_overlay("panel_open[battery ? "_battery" : ""]")
+		AddOverlays("panel_open[battery ? "_battery" : ""]")
 
 /obj/item/auto_cpr/mob_can_equip(mob/living/carbon/human/H, slot, disable_warning = 0, force = 0)
 	. = ..()

code/game/objects/items/devices/lighting/glowstick.dm

@@ -34,7 +34,7 @@
 	else if(on)
 		var/image/I = overlay_image(icon, "glowstick-overlay", color)
 		I.blend_mode = BLEND_ADD
-		add_overlay(I)
+		AddOverlays(I)
 		icon_state = "[initial(icon_state)]-on"
 		item_state = "[initial(icon_state)]-on"
 		set_light(brightness_on, flashlight_power, light_color)

code/game/objects/items/devices/lighting/lamp.dm

@@ -52,10 +52,10 @@
 		set_light(brightness_on, flashlight_power, light_color)
 	else
 		set_light(0)
-	cut_overlays()
+	ClearOverlays()
 	var/image/I = image(icon = icon, icon_state = "lavalamp-[on ? "on" : "off"]")
 	I.color = light_color
-	add_overlay(I)
+	AddOverlays(I)
 
 /obj/item/device/flashlight/lamp/lava/red
 	light_color = COLOR_RED

code/game/objects/items/devices/lightreplacer.dm

@@ -173,7 +173,7 @@
 
 /obj/item/device/lightreplacer/update_icon()
 	if(emagged)
-		add_overlay("emagged")
+		AddOverlays("emagged")
 
 
 /obj/item/device/lightreplacer/proc/Use(var/mob/user)

code/game/objects/items/devices/magnetic_lock.dm

@@ -167,15 +167,15 @@
 				if (WT.use(2, user))
 					user.visible_message(SPAN_NOTICE("[user] starts welding the metal shell of [src]."), SPAN_NOTICE("You start [hacked ? "repairing" : "welding open"] the metal covering of [src]."))
 					playsound(loc, 'sound/items/Welder.ogg', 50, 1)
-					add_overlay("overlay_welding")
+					AddOverlays("overlay_welding")
 					if(WT.use_tool(src, user, 25, volume = 50))
 						to_chat(user, SPAN_NOTICE("You are able to [hacked ? "repair" : "weld through"] the metal shell of [src]."))
 						if (hacked) locked = 1
 						else locked = 0
 						hacked = !hacked
-						cut_overlay("overlay_welding")
+						CutOverlays("overlay_welding")
 					else
-						cut_overlay("overlay_welding")
+						CutOverlays("overlay_welding")
 					update_icon()
 				return TRUE
 
@@ -402,7 +402,7 @@
 	update_overlays()
 
 /obj/item/device/magnetic_lock/proc/update_overlays()
-	cut_overlays()
+	ClearOverlays()
 	switch (status)
 		if (STATUS_BROKEN)
 			icon_state = "broken"
@@ -410,16 +410,16 @@
 
 		if (STATUS_INACTIVE to STATUS_ACTIVE)
 			if (hacked)
-				add_overlay("overlay_hacked")
+				AddOverlays("overlay_hacked")
 			else if (locked)
-				add_overlay("overlay_locked")
+				AddOverlays("overlay_locked")
 			else
-				add_overlay("overlay_unlocked")
+				AddOverlays("overlay_unlocked")
 			switch (constructionstate)
 				if (0)
 					return
 				if (1 to 4)
-					add_overlay("overlay_deconstruct_[constructionstate]")
+					AddOverlays("overlay_deconstruct_[constructionstate]")
 
 /obj/item/device/magnetic_lock/proc/takedamage(var/damage)
 	if(invincible)
@@ -453,7 +453,7 @@
 	switch (status)
 		if (STATUS_INACTIVE to STATUS_ACTIVE)
 			if(istype(src, /obj/item/device/magnetic_lock/keypad))
-				add_overlay("overlay_keypad")
+				AddOverlays("overlay_keypad")
 
 /obj/item/device/magnetic_lock/keypad/ui_interact(mob/user, datum/tgui/ui)
 	ui = SStgui.try_update_ui(user, src, ui)

code/game/objects/items/devices/memorywiper.dm

@@ -35,13 +35,13 @@
 	update_icon()
 
 /obj/item/device/memorywiper/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(anchored)
 		icon_state = "[initial(icon_state)]_opened"
 		if(attached)
-			add_overlay("wireout")
+			AddOverlays("wireout")
 		if(wiping)
-			add_overlay("screen")
+			AddOverlays("screen")
 	else
 		icon_state = initial(icon_state)
 

code/game/objects/items/devices/multitool.dm

@@ -121,7 +121,7 @@
 			if(tracking_apc)
 				START_PROCESSING(SSprocessing, src)
 				apc_indicator = mutable_appearance(icon, "lost")
-				add_overlay(apc_indicator)
+				AddOverlays(apc_indicator)
 			else
 				STOP_PROCESSING(SSprocessing, src)
 				QDEL_NULL(apc_indicator)
@@ -169,7 +169,7 @@
 				apc_indicator.icon_state = "medium"
 			if(16 to INFINITY)
 				apc_indicator.icon_state = "far"
-	set_overlays(apc_indicator)
+	SetOverlays(apc_indicator)
 
 /obj/item/device/multitool/proc/wire(datum/integrated_io/io, mob/user)
 	if(!io.holder.assembly)

code/game/objects/items/devices/paicard.dm

@@ -34,7 +34,7 @@
 
 /obj/item/device/paicard/Initialize()
 	. = ..()
-	add_overlay("pai_off")
+	AddOverlays("pai_off")
 	SSpai.all_pai_devices += src
 	update_light()
 
@@ -389,19 +389,19 @@
 
 /obj/item/device/paicard/proc/setPersonality(mob/living/silicon/pai/personality)
 	src.pai = personality
-	add_overlay("pai-happy")
+	AddOverlays("pai-happy")
 	playsound(src, 'sound/effects/pai/pai_restore.ogg', 75)
 
 /obj/item/device/paicard/proc/removePersonality()
 	src.pai = null
-	cut_overlays()
-	add_overlay("pai-off")
+	ClearOverlays()
+	AddOverlays("pai-off")
 
 /obj/item/device/paicard
 	var/current_emotion = 1
 /obj/item/device/paicard/proc/setEmotion(var/emotion)
 	if(pai)
-		cut_overlays()
+		ClearOverlays()
 		var/new_state
 		switch(emotion)
 			if(1) new_state = "pai-happy"
@@ -420,7 +420,7 @@
 			if(14) new_state = "pai-exclamation"
 			if(15) new_state = "pai-question"
 		if (new_state)
-			add_overlay(new_state)
+			AddOverlays(new_state)
 		current_emotion = emotion
 
 /obj/item/device/paicard/proc/alertUpdate()

code/game/objects/items/devices/radio/intercom.dm

@@ -431,19 +431,19 @@ pixel_x = 8;
 	..(dest)
 
 /obj/item/device/radio/intercom/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(!on)
 		icon_state = initial(icon_state)
 		set_light(FALSE)
 		return
 	else
-		add_overlay(screen_overlays["intercom_screen"])
-		add_overlay(screen_overlays["intercom_scanline"])
+		AddOverlays(screen_overlays["intercom_screen"])
+		AddOverlays(screen_overlays["intercom_scanline"])
 		set_light(1.4, 1.3, COLOR_CYAN)
 		if(broadcasting)
-			add_overlay(screen_overlays["intercom_b"])
+			AddOverlays(screen_overlays["intercom_b"])
 		if(listening)
-			add_overlay(screen_overlays["intercom_l"])
+			AddOverlays(screen_overlays["intercom_l"])
 
 /obj/item/device/radio/intercom/broadcasting/Initialize()
 	SHOULD_CALL_PARENT(FALSE)

code/game/objects/items/devices/scanners.dm

@@ -472,10 +472,10 @@ BREATH ANALYZER
 	origin_tech = list(TECH_MAGNET = 4, TECH_BIO = 2)
 
 /obj/item/device/mass_spectrometer/adv/clear_blood_overlay()
-	cut_overlays()
+	ClearOverlays()
 
 /obj/item/device/mass_spectrometer/adv/add_blood_overlay(var/image/I)
-	add_overlay(I)
+	AddOverlays(I)
 
 /obj/item/device/reagent_scanner
 	name = "reagent scanner"

code/game/objects/items/devices/slide_projector.dm

@@ -157,7 +157,7 @@
 	if(!istype(I))
 		qdel(src)
 		return
-	cut_overlays()
+	ClearOverlays()
 	var/mutable_appearance/MA = new(I)
 	MA.plane = EFFECTS_ABOVE_LIGHTING_PLANE
 	MA.appearance_flags = RESET_ALPHA
@@ -202,6 +202,6 @@
 	if(!istype(P))
 		qdel(src)
 		return
-	cut_overlays()
+	ClearOverlays()
 	if(P.info)
 		icon_state = "text[rand(1,3)]"

code/game/objects/items/devices/suit_cooling.dm

@@ -175,7 +175,7 @@
 	return ..()
 
 /obj/item/device/suit_cooling_unit/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(cover_open)
 		if(cell)
 			icon_state = "suitcooler1"
@@ -202,7 +202,7 @@
 			if(-INFINITY to 17)
 				battery_level = 5
 
-		add_overlay("battery-[battery_level]")
+		AddOverlays("battery-[battery_level]")
 		item_state = "coolingpack[battery_level]"
 
 	if(ismob(loc))

code/game/objects/items/devices/transfer_valve.dm

@@ -117,7 +117,7 @@
 			toggle = 1
 
 /obj/item/device/transfer_valve/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	underlays = null
 
 	if(!tank_one && !tank_two && !attached_device)
@@ -126,13 +126,13 @@
 	icon_state = "valve"
 
 	if(tank_one)
-		add_overlay("[tank_one.icon_state]")
+		AddOverlays("[tank_one.icon_state]")
 	if(tank_two)
 		var/icon/J = new(icon, icon_state = "[tank_two.icon_state]")
 		J.Shift(WEST, 13)
 		underlays += J
 	if(attached_device)
-		add_overlay("device")
+		AddOverlays("device")
 
 /obj/item/device/transfer_valve/proc/remove_tank(obj/item/tank/T, mob/user)
 	if(tank_one == T)

code/game/objects/items/draftingchalk.dm

@@ -114,6 +114,6 @@
 	update_icon()
 
 /obj/item/storage/box/fancy/crayons/chalkbox/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	for(var/obj/item/pen/drafting/chalk in contents)
-		add_overlay("[chalk.colorName]")
+		AddOverlays("[chalk.colorName]")

code/game/objects/items/glassjar.dm

@@ -145,7 +145,7 @@
 
 /obj/item/glass_jar/update_icon() // Also updates name and desc
 	underlays.Cut()
-	cut_overlays()
+	ClearOverlays()
 	switch(contains)
 		if(JAR_NOTHING)
 			name = initial(name)

code/game/objects/items/holomenu.dm

@@ -34,7 +34,7 @@
 	update_icon()
 
 /obj/item/holomenu/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(anchored)
 		set_light(2)
 		if(rave_mode)
@@ -46,11 +46,11 @@
 			holo_lights.color = null
 			holo_text.color = null
 			holo_border.color = null
-		add_overlay(holo_lights)
+		AddOverlays(holo_lights)
 		if(length(menu_text))
-			add_overlay(holo_text)
+			AddOverlays(holo_text)
 		if(border_on)
-			add_overlay(holo_border)
+			AddOverlays(holo_border)
 	else
 		set_light(0)
 

code/game/objects/items/ipc_overloaders.dm

@@ -284,12 +284,12 @@
 
 /obj/item/storage/overloader/update_icon()
 	. = ..()
-	cut_overlays()
+	ClearOverlays()
 	var/obj/item/ipc_overloader/overloader = locate() in contents
 	if(overloader)
-		add_overlay(image(overloader.icon, null, overloader.icon_state, sealed ? layer - 0.01 : layer + 0.01))
+		AddOverlays(image(overloader.icon, null, overloader.icon_state, sealed ? layer - 0.01 : layer + 0.01))
 		if(!sealed)
-			add_overlay(image(icon, null, "box-overlay", layer + 0.02))
+			AddOverlays(image(icon, null, "box-overlay", layer + 0.02))
 	if(!sealed)
 		icon_state = "box-open"
 

code/game/objects/items/items_icon.dm

@@ -46,9 +46,9 @@ var/list/mob_icon_icon_states = list()
 		I = overlay_image(mob_overlay_icon, color = color, flags = RESET_COLOR|RESET_ALPHA)
 	var/image/additional_parts = build_additional_parts(H, mob_icon, slot)
 	if(additional_parts)
-		I.add_overlay(additional_parts)
+		I.AddOverlays(additional_parts)
 	if(has_accents)
-		I.add_overlay(overlay_image(icon, "[UNDERSCORE_OR_NULL(src.icon_species_tag)][item_state][contained_sprite ? slot_str_to_contained_flag(slot) : ""]_acc", accent_color, accent_flags))
+		I.AddOverlays(overlay_image(icon, "[UNDERSCORE_OR_NULL(src.icon_species_tag)][item_state][contained_sprite ? slot_str_to_contained_flag(slot) : ""]_acc", accent_color, accent_flags))
 	var/offset_x = worn_x_dimension
 	var/offset_y = worn_y_dimension
 	center_image(I, offset_x, offset_y)

code/game/objects/items/knitting.dm

@@ -59,9 +59,9 @@
 			yarn_overlay.color = ball.color
 		else
 			yarn_overlay.appearance_flags = RESET_COLOR
-		add_overlay(yarn_overlay)
+		AddOverlays(yarn_overlay)
 	else
-		cut_overlays()
+		ClearOverlays()
 	update_held_icon()
 
 /obj/item/knittingneedles/attackby(obj/item/attacking_item, mob/user)

code/game/objects/items/shooting_range.dm

@@ -24,7 +24,7 @@
 			return TRUE
 		var/obj/item/weldingtool/WT = attacking_item
 		if(WT.use(0, user))
-			cut_overlays()
+			ClearOverlays()
 			LAZYCLEARLIST(bullet_holes)
 			icon = initial(icon)
 			hp = initial(hp)
@@ -97,7 +97,7 @@
 			virtual_icon.DrawBox(null, B.b2x, B.b2y1,  B.b2x, B.b2y2) // vertical line, top to bottom
 
 
-		add_overlay(bmark) // add the decal
+		AddOverlays(bmark) // add the decal
 		icon = virtual_icon // apply bullet_holes over decals
 		return
 

code/game/objects/items/skrell.dm

@@ -61,7 +61,7 @@
 	. = ..()
 	if(!glow_state)
 		glow_state = make_screen_overlay(icon, icon_state)
-	add_overlay(glow_state)
+	AddOverlays(glow_state)
 
 /obj/effect/temp_visual/constellation/attackby(obj/item/attacking_item, mob/user)
 	visible_message("<span class='notice'>\The [src] vanishes!</span>")
@@ -151,10 +151,10 @@
 	update_icon()
 
 /obj/item/skrell_projector/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(working)
 		var/image/overlay = overlay_image(icon, "projector_light", light_color, RESET_COLOR)
-		add_overlay(overlay)
+		AddOverlays(overlay)
 
 /obj/item/skrell_projector/process()
 	if(!selected_world)

code/game/objects/items/stacks/medical.dm

@@ -106,7 +106,7 @@ Contains:
 	if(!automatic_charge_overlays)	//Checks if the item has this feature enabled
 		return	//If it does not, do nothing
 	var/ratio = CEILING(clamp(amount / max_amount, 0, 1) * charge_sections, 1)
-	cut_overlays()
+	ClearOverlays()
 	var/iconState = "[icon_state]_charge"
 	if(!amount)	//Checks if there are still charges left in the item
 		return //If it does not, do nothing, as the overlays have been cut before this already.
@@ -114,7 +114,7 @@ Contains:
 		var/mutable_appearance/charge_overlay = mutable_appearance(icon, iconState)
 		for(var/i = ratio, i >= 1, i--)
 			charge_overlay.pixel_x = charge_x_offset * (i - 1)
-			add_overlay(charge_overlay)
+			AddOverlays(charge_overlay)
 
 // Bruise Pack.
 /obj/item/stack/medical/bruise_pack

code/game/objects/items/toys.dm

@@ -256,9 +256,9 @@
 	..()
 	if(status == BALLOON_BURST)
 		worn_overlay = null
-	cut_overlay()
+	CutOverlays()
 	if(worn_overlay)
-		add_overlay(overlay_image(icon, "[initial(icon_state)]_[worn_overlay]", flags=RESET_COLOR))
+		AddOverlays(overlay_image(icon, "[initial(icon_state)]_[worn_overlay]", flags=RESET_COLOR))
 
 #undef BALLOON_NORMAL
 #undef BALLOON_BLOW

code/game/objects/items/vaurca.dm

@@ -115,10 +115,10 @@
 	update_icon()
 
 /obj/item/skrell_projector/vaurca_projector/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(working)
 		var/image/overlay = overlay_image(icon, "zora_projector_light", light_color, RESET_COLOR)
-		add_overlay(overlay)
+		AddOverlays(overlay)
 
 /obj/item/skrell_projector/vaurca_projector/process()
 	if(!selected_world || !possible_messages)

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

@@ -112,10 +112,10 @@
 	check_obfuscation()
 
 /obj/item/card/id/syndicate/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(electronic_warfare)
 		var/mutable_appearance/electro_overlay = mutable_appearance(icon, "electronic_warfare")
-		add_overlay(electro_overlay)
+		AddOverlays(electro_overlay)
 
 /obj/item/card/id/syndicate/proc/check_obfuscation()
 	if(electronic_warfare)

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

@@ -23,11 +23,11 @@
 		update_icon()
 
 /obj/item/clothing/mask/chewable/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(wrapped)
 		var/mutable_appearance/base_overlay = mutable_appearance(icon, "[initial(icon_state)]_wrapper")
 		base_overlay.appearance_flags = RESET_COLOR
-		add_overlay(base_overlay)
+		AddOverlays(base_overlay)
 
 /obj/item/clothing/mask/chewable/Initialize()
 	create_reagents(chem_volume) // making the cigarrete a chemical holder with a maximum volume of 15
@@ -236,12 +236,12 @@
 		spitout(0)
 
 /obj/item/clothing/mask/chewable/candy/lolli/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	var/mutable_appearance/base_overlay = mutable_appearance(icon, "[initial(icon_state)]_stick")
 	base_overlay.appearance_flags = RESET_COLOR
-	add_overlay(base_overlay)
+	AddOverlays(base_overlay)
 	if(wrapped)
-		add_overlay("[initial(icon_state)]_wrapper")
+		AddOverlays("[initial(icon_state)]_wrapper")
 
 /obj/item/clothing/mask/chewable/candy/lolli/Initialize()
 	. = ..()

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

@@ -16,14 +16,14 @@
 	pickup_sound = 'sound/items/pickup/screwdriver.ogg'
 
 /obj/item/lipstick/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(open)
 		worn_overlay = "open_overlay"
 		worn_overlay_color = lipstick_color
 		icon_state = "[initial(icon_state)]_open"
 		var/image/stick_overlay = image('icons/obj/cosmetics.dmi', null, "[initial(icon_state)]_open_overlay")
 		stick_overlay.color = lipstick_color
-		add_overlay(stick_overlay)
+		AddOverlays(stick_overlay)
 	else
 		icon_state = initial(icon_state)
 		worn_overlay = initial(worn_overlay)

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

@@ -65,19 +65,19 @@
 		location.hotspot_expose(700, 2)
 
 /obj/item/flamethrower/update_icon()
-	cut_overlays()
-	add_overlay("+[initial(welding_tool.icon_state)]")
+	ClearOverlays()
+	AddOverlays("+[initial(welding_tool.icon_state)]")
 
 	if(igniter)
-		add_overlay("+igniter[secured]")
+		AddOverlays("+igniter[secured]")
 
 	if(istype(gas_tank, /obj/item/tank/phoron))
-		add_overlay("+phoron_tank")
+		AddOverlays("+phoron_tank")
 	else if(istype(gas_tank, /obj/item/tank/hydrogen))
-		add_overlay("+hydro_tank")
+		AddOverlays("+hydro_tank")
 
 	if(lit)
-		add_overlay("+lit")
+		AddOverlays("+lit")
 		set_light(1.4, 2)
 		item_state = "flamethrower_1"
 	else

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

@@ -167,7 +167,7 @@
 	if(build_from_parts) //random colors!
 		if(!color)
 			color = pick(COLOR_RED, COLOR_BLUE, COLOR_LIME, COLOR_ORANGE, COLOR_WHITE, COLOR_PINK, COLOR_YELLOW, COLOR_CYAN)
-		add_overlay(overlay_image(icon, "[initial(icon_state)]_end", flags=RESET_COLOR))
+		AddOverlays(overlay_image(icon, "[initial(icon_state)]_end", flags=RESET_COLOR))
 
 /obj/item/handcuffs/cable/attack_self(mob/user)
 	legcuff = !legcuff

code/game/objects/items/weapons/implants/implantcase.dm

@@ -30,11 +30,11 @@
 
 
 /obj/item/implantcase/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if (imp)
 		var/overlay_icon_state = "implantstorage_[imp.implant_icon]"
 		var/mutable_appearance/overlay_implant_icon = mutable_appearance(icon, overlay_icon_state)
-		add_overlay(overlay_implant_icon)
+		AddOverlays(overlay_implant_icon)
 
 /obj/item/implantcase/attackby(obj/item/attacking_item, mob/user)
 	if (attacking_item.ispen())

code/game/objects/items/weapons/implants/implanter.dm

@@ -16,12 +16,12 @@
 	update_icon()
 
 /obj/item/implanter/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	icon_state = "implanter-[imp ? "1" : "0"]"
 	if (imp)
 		var/mutable_appearance/overlay_implant_icon = mutable_appearance(icon, "implanter-overlay")
 		overlay_implant_icon.color = imp.implant_color
-		add_overlay(overlay_implant_icon)
+		AddOverlays(overlay_implant_icon)
 
 /obj/item/implanter/attackby(obj/item/attacking_item, mob/user)
 	if(!imp && istype(attacking_item, /obj/item/implant) && user.unEquip(attacking_item, src))

code/game/objects/items/weapons/implants/implantpad.dm

@@ -12,13 +12,13 @@
 	var/listening = TRUE
 
 /obj/item/implantpad/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	icon_state = "implantpad-[case ? "1" : "0"]"
 	if(case?.imp)
 		var/obj/item/implant/caseimplant = case.imp
 		var/implant_overlay_icon_state = "implantstorage_[caseimplant.implant_icon]"
 		var/mutable_appearance/implant_case_implant_overlay = mutable_appearance(icon, implant_overlay_icon_state)
-		add_overlay(implant_case_implant_overlay)
+		AddOverlays(implant_case_implant_overlay)
 
 
 /obj/item/implantpad/attack_hand(mob/user)

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

@@ -62,7 +62,7 @@
 	var/image/I = image(icon, null, "wiredrod_cable")
 	I.appearance_flags = RESET_COLOR
 	I.color = cable_color
-	add_overlay(I)
+	AddOverlays(I)
 
 /obj/item/material/wirerod/attackby(obj/item/attacking_item, mob/user)
 	..()

code/game/objects/items/weapons/material/ashtray.dm

@@ -39,20 +39,20 @@
 
 /obj/item/material/ashtray/update_icon()
 	color = null
-	cut_overlays()
+	ClearOverlays()
 	var/list/ashtray_cache = SSicon_cache.ashtray_cache
 	var/cache_key = "base-[material.name]"
 	if(!ashtray_cache[cache_key])
 		var/image/I = image('icons/obj/ashtray.dmi',"ashtray")
 		I.color = material.icon_colour
 		ashtray_cache[cache_key] = I
-	add_overlay(ashtray_cache[cache_key])
+	AddOverlays(ashtray_cache[cache_key])
 
 	if (contents.len == max_butts)
-		add_overlay("ashtray_full")
+		AddOverlays("ashtray_full")
 		desc = "It's stuffed full."
 	else if (contents.len > max_butts/2)
-		add_overlay("ashtray_half")
+		AddOverlays("ashtray_half")
 		desc = "It's half-filled."
 	else
 		desc = "An ashtray made of [material.display_name]."

code/game/objects/items/weapons/material/kitchen.dm

@@ -58,7 +58,7 @@
 			is_liquid = FALSE
 		else
 			playsound(user.loc, 'sound/items/eatfood.ogg', rand(10, 50), 1)
-		cut_overlays()
+		ClearOverlays()
 		return
 	else
 		to_chat(user, SPAN_WARNING("You don't have anything on \the [src].")) 	//if we have help intent and no food scooped up DON'T STAB OURSELVES WITH THE FORK)
@@ -70,7 +70,7 @@
 		reagents.clear_reagents()
 		is_liquid = FALSE
 		loaded = null
-		cut_overlays()
+		ClearOverlays()
 	return
 
 /obj/item/material/kitchen/utensil/verb/bite_size()

code/game/objects/items/weapons/material/misc.dm

@@ -102,7 +102,7 @@
 	if(build_from_parts)
 		var/image/I = image(icon, icon_state = "machete_handle")
 		I.color = pick(COLOR_BLUE, COLOR_RED, COLOR_CYAN, COLOR_BLACK, COLOR_AMBER, COLOR_GREEN, COLOR_OLIVE, COLOR_GUNMETAL, COLOR_DARK_BLUE_GRAY)
-		add_overlay(I)
+		AddOverlays(I)
 
 /obj/item/material/hatchet/machete/unbreakable
 	unbreakable = TRUE

code/game/objects/items/weapons/material/twohanded.dm

@@ -277,7 +277,7 @@
 		usr.drop_from_inventory(attacking_item, HS)
 		var/mutable_appearance/MA = new(attacking_item)
 		MA.layer = FLOAT_LAYER
-		HS.add_overlay(MA)
+		HS.AddOverlays(MA)
 		HS.name = "[attacking_item.name] on a spear"
 		HS.material = material.name
 		qdel(src)

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

@@ -30,13 +30,13 @@
 	update_icon()
 
 /obj/item/reagent_containers/glass/paint/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(!is_open_container())
-		add_overlay("paint_lid")
+		AddOverlays("paint_lid")
 	else if(reagents.total_volume)
 		var/image/I = image(icon, "paint_full")
 		I.color = reagents.get_color()
-		add_overlay(I)
+		AddOverlays(I)
 
 /obj/item/reagent_containers/glass/paint/on_reagent_change()
 	update_icon()

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

@@ -193,11 +193,11 @@ var/list/tape_roll_applications = list()
 
 		if(tape_roll_applications[F] & direction) // hazard_overlay in F.overlays wouldn't work.
 			user.visible_message("[user] uses the adhesive of \the [src] to remove area markings from \the [F].", "You use the adhesive of \the [src] to remove area markings from \the [F].")
-			F.cut_overlay(hazard_overlay, TRUE)
+			F.CutOverlays(hazard_overlay, ATOM_ICON_CACHE_PROTECTED)
 			tape_roll_applications[F] &= ~direction
 		else
 			user.visible_message("[user] applied \the [src] on \the [F] to create area markings.", "You apply \the [src] on \the [F] to create area markings.")
-			F.add_overlay(hazard_overlay, TRUE)
+			F.AddOverlays(hazard_overlay, ATOM_ICON_CACHE_PROTECTED)
 			tape_roll_applications[F] |= direction
 		return
 

code/game/objects/items/weapons/storage/backpack.dm

@@ -947,7 +947,7 @@
 /obj/item/storage/backpack/cloak/get_mob_overlay(var/mob/living/carbon/human/human, var/mob_icon, var/mob_state, var/slot)
 	var/image/I = ..()
 	var/image/cape_backing = image(mob_icon, null, "[icon_state]_backing", MOB_SHADOW_LAYER)
-	I.add_overlay(cape_backing)
+	I.AddOverlays(cape_backing)
 	return I
 
 /obj/item/storage/backpack/cloak/sedantis

code/game/objects/items/weapons/storage/belt.dm

@@ -22,10 +22,10 @@
 		M.update_inv_belt()
 
 /obj/item/storage/belt/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(content_overlays)
 		for(var/obj/item/I in contents)
-			add_overlay(I.get_belt_overlay())
+			AddOverlays(I.get_belt_overlay())
 	..()
 
 /obj/item/storage/belt/build_additional_parts(H, mob_icon, slot)
@@ -44,7 +44,7 @@
 		var/image/belt_item_image = image(c_icon, c_state)
 		belt_item_image.color = i.color
 		belt_item_image.appearance_flags = RESET_ALPHA
-		I.add_overlay(belt_item_image)
+		I.AddOverlays(belt_item_image)
 	return I
 
 /obj/item/storage/belt/verb/toggle_layer()

code/game/objects/items/weapons/storage/boxes.dm

@@ -50,7 +50,7 @@
 	if(ispath(src.trash))
 		desc_info += "This can be crumpled up into a trash item when empty, or forcibly crumpled on harm intent. "
 	if(illustration)
-		add_overlay(illustration)
+		AddOverlays(illustration)
 
 /obj/item/storage/box/proc/damage(var/severity)
 	health -= severity

code/game/objects/items/weapons/storage/business_card.dm

@@ -9,7 +9,7 @@
 	can_hold = list(/obj/item/paper/business_card)
 
 /obj/item/storage/business_card_holder/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	var/overlay_type
 	if(length(contents))
 		var/obj/O = contents[1]
@@ -22,7 +22,7 @@
 			card_overlay.color = O.color
 		else
 			card_overlay.appearance_flags = RESET_COLOR
-		add_overlay(card_overlay)
+		AddOverlays(card_overlay)
 
 /obj/item/storage/business_card_holder/wood
 	icon_state = "holder_wood"
@@ -44,8 +44,8 @@
 /obj/item/paper/business_card/update_icon()
 	. = ..()
 	if(worn_overlay)
-		cut_overlays()
-		add_overlay(overlay_image(icon, worn_overlay, flags=RESET_COLOR))
+		ClearOverlays()
+		AddOverlays(overlay_image(icon, worn_overlay, flags=RESET_COLOR))
 
 /obj/item/paper/business_card/attack_self(mob/living/user)
 	if(last_flash <= world.time - 20)

code/game/objects/items/weapons/storage/fancy.dm

@@ -63,7 +63,7 @@
 			icon_state = "[initial(icon_state)][src.opened]"
 			..()
 	else
-		cut_overlays()
+		ClearOverlays()
 		icon_state = "[initial(icon_state)]" // closed
 	..()
 
@@ -102,10 +102,10 @@
 /obj/item/storage/box/fancy/donut/update_icon() // One of the few unique update_icon()s, due to having to store both regular and sprinkled donuts.
 	. = ..()
 	if(opened)
-		cut_overlays()
+		ClearOverlays()
 		var/i = 0
 		for(var/obj/item/reagent_containers/food/snacks/donut/D in contents)
-			add_overlay("[i][D.overlay_state]")
+			AddOverlays("[i][D.overlay_state]")
 			i++
 
 /obj/item/storage/box/fancy/donut/empty
@@ -221,10 +221,10 @@
 
 /obj/item/storage/box/fancy/crayons/update_icon()
 	. = ..()
-	cut_overlays()
-	add_overlay("crayonbox")
+	ClearOverlays()
+	AddOverlays("crayonbox")
 	for(var/obj/item/pen/crayon/crayon in contents)
-		add_overlay("[crayon.colourName]")
+		AddOverlays("[crayon.colourName]")
 
 /obj/item/storage/box/fancy/crayons/attackby(obj/item/attacking_item, mob/user)
 	if(istype(attacking_item, /obj/item/pen/crayon))
@@ -467,13 +467,13 @@
 	. = ..()
 	var/total_contents = src.contents.len - itemremoved
 	src.icon_state = "vialbox[total_contents]"
-	cut_overlays()
+	ClearOverlays()
 	if (!broken)
-		add_overlay("led[locked]")
+		AddOverlays("led[locked]")
 		if(locked)
-			add_overlay("cover")
+			AddOverlays("cover")
 	else
-		add_overlay("ledb")
+		AddOverlays("ledb")
 
 /obj/item/storage/lockbox/vials/attackby(attacking_item, mob/user)
 	..()
@@ -527,7 +527,7 @@
 	update_icon()
 
 /obj/item/pizzabox/update_icon()
-	cut_overlays()
+	ClearOverlays()
 
 	// Set appropriate description
 	if( open && pizza )
@@ -555,7 +555,7 @@
 		if( pizza )
 			var/image/pizzaimg = image(pizza.icon, pizza.icon_state)
 			pizzaimg.pixel_y = -2
-			add_overlay(pizzaimg)
+			AddOverlays(pizzaimg)
 
 		return
 	else
@@ -572,7 +572,7 @@
 		if( doimgtag )
 			var/image/tagimg = image(icon, icon_state = "pizzabox_tag")
 			tagimg.pixel_y = boxes.len * 3
-			add_overlay(tagimg)
+			AddOverlays(tagimg)
 
 	icon_state = "pizzabox[boxes.len+1]"
 

code/game/objects/items/weapons/storage/secure.dm

@@ -105,15 +105,15 @@
 				src.l_set = 1
 			else if ((src.code == src.l_code) && (src.emagged == 0) && (src.l_set == 1))
 				src.locked = 0
-				cut_overlays()
-				add_overlay(icon_opened)
+				ClearOverlays()
+				AddOverlays(icon_opened)
 				src.code = null
 			else
 				src.code = "ERROR"
 		else
 			if ((href_list["type"] == "R") && (src.emagged == 0) && (!src.l_setshort))
 				src.locked = 1
-				cut_overlays()
+				ClearOverlays()
 				src.code = null
 				src.close(usr)
 			else
@@ -130,10 +130,10 @@
 /obj/item/storage/secure/emag_act(var/remaining_charges, var/mob/user, var/feedback)
 	if(!emagged)
 		emagged = 1
-		add_overlay(icon_sparking)
+		AddOverlays(icon_sparking)
 		sleep(6)
-		cut_overlays()
-		add_overlay(icon_locking)
+		ClearOverlays()
+		AddOverlays(icon_locking)
 		locked = 0
 		to_chat(user, (feedback ? feedback : "You short out the lock of \the [src]."))
 		return 1

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

@@ -360,12 +360,12 @@
 			ND.sample_object.maptext = SMALL_FONTS(7, "[(ND.number > 1)? "[ND.number]" : ""]")
 			ND.sample_object.hud_layerise()
 			if(display_contents_initials)
-				ND.sample_object.cut_overlays() // a limitation of this code is that overlays get blasted off the item, since we need to add one to add the second maptext. woe is me
+				ND.sample_object.ClearOverlays() // a limitation of this code is that overlays get blasted off the item, since we need to add one to add the second maptext. woe is me
 				var/object_initials = handle_name_initials(ND.sample_object.name)
 				var/image/name_overlay = image(null)
 				name_overlay.maptext = SMALL_FONTS(7, object_initials)
 				name_overlay.maptext_x = 22 - ((length(object_initials) - 1) * 6)
-				ND.sample_object.add_overlay(name_overlay)
+				ND.sample_object.AddOverlays(name_overlay)
 			cx++
 			if (cx > (4+cols))
 				cx = 4
@@ -395,7 +395,7 @@
 	var/stored_cap_width = 4 //length of sprite for start and end of the box representing the stored item
 	var/storage_width = min( round( 224 * max_storage_space/baseline_max_storage_space ,1) ,284) //length of sprite for the box representing total storage space
 
-	storage_start.cut_overlays()
+	storage_start.ClearOverlays()
 
 	var/matrix/M = matrix()
 	M.Scale((storage_width-storage_cap_width*2+3)/32,1)
@@ -439,7 +439,7 @@
 		O.hud_layerise()
 
 	if (!defer_overlays)
-		storage_start.compile_overlays()
+		storage_start.UpdateOverlays()
 
 	closer.screen_loc = "4:[storage_width+19],2:16"
 	return
@@ -654,7 +654,7 @@
 	if(W.maptext)
 		W.maptext = ""
 	if(display_contents_initials)
-		W.cut_overlays()
+		W.ClearOverlays()
 	W.on_exit_storage(src)
 	update_icon()
 	return TRUE

code/game/objects/items/weapons/storage/wallets.dm

@@ -79,7 +79,7 @@
 			update_icon()
 
 /obj/item/storage/wallet/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	worn_overlay = "fasteners"
 	if(front_id)
 		if(("[icon_state]-open") in icon_states(icon))
@@ -89,10 +89,10 @@
 		if(("[initial(icon_state)]-[front_id.icon_state]") in icon_states(icon))
 			tiny_state = "[initial(icon_state)]-[front_id.icon_state]"
 		var/image/tiny_image = overlay_image(icon, icon_state = tiny_state, flags = RESET_COLOR)
-		add_overlay(tiny_image)
+		AddOverlays(tiny_image)
 		if(("[initial(icon_state)]-film") in icon_states(icon))
 			var/image/film_image = overlay_image(icon, "[initial(icon_state)]-film", flags = RESET_COLOR)
-			add_overlay(film_image)
+			AddOverlays(film_image)
 	else
 		icon_state = "[initial(icon_state)]"
 		. = ..()
@@ -205,16 +205,16 @@
 	. = ..()
 	if(("[initial(icon_state)]-film") in icon_states(icon))
 		var/image/film_image = overlay_image(icon, "[initial(icon_state)]-film", flags = RESET_COLOR)
-		add_overlay(film_image)
+		AddOverlays(film_image)
 
 /obj/item/storage/wallet/lanyard/get_mob_overlay(mob/living/carbon/human/H, mob_icon, mob_state, slot)
 	var/image/I = ..()
 	if(front_id)
-		I.add_overlay(image('icons/mob/lanyard_overlays.dmi', icon_state = "lanyard-[front_id_overlay_state]"))
+		I.AddOverlays(image('icons/mob/lanyard_overlays.dmi', icon_state = "lanyard-[front_id_overlay_state]"))
 	else
 		if(!plastic_film)
 			plastic_film = image('icons/mob/lanyard_overlays.dmi', icon_state = "[plastic_film_overlay_state]")
-		I.add_overlay(plastic_film)
+		I.AddOverlays(plastic_film)
 	return I
 
 // wallet subtypes

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

@@ -254,7 +254,7 @@
 	if(!cable_color)
 		cable_color = COLOR_RED
 	I.color = cable_color
-	add_overlay(I)
+	AddOverlays(I)
 
 /obj/item/melee/baton/stunrod
 	name = "stunrod"

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

@@ -226,7 +226,7 @@
 	)
 
 /obj/item/storage/box/fancy/tray/update_icon()
-	cut_overlays()
+	ClearOverlays()
 
 	var/list/types_and_overlays = list(
 		/obj/item/surgery/bonesetter = "tray_bonesetter",
@@ -248,7 +248,7 @@
 	)
 	for (var/obj/item/W in contents)
 		if (types_and_overlays[W.type])
-			add_overlay(types_and_overlays[W.type])
+			AddOverlays(types_and_overlays[W.type])
 			types_and_overlays -= W.type
 
 /obj/item/storage/box/fancy/tray/fill()

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

@@ -77,13 +77,13 @@
 	add_fingerprint(user)
 
 	if(blood_overlay && blood_DNA && (blood_DNA.len >= 1)) //updates blood overlay, if any
-		cut_overlay(blood_overlay, TRUE)
+		CutOverlays(blood_overlay, ATOM_ICON_CACHE_PROTECTED)
 		var/icon/I = new /icon(src.icon, src.icon_state)
 		I.Blend(new /icon('icons/effects/blood.dmi', rgb(255,255,255)),ICON_ADD)
 		I.Blend(new /icon('icons/effects/blood.dmi', "itemblood"),ICON_MULTIPLY)
 		blood_overlay = image(I)
 		blood_overlay.color = blood_color
-		add_overlay(blood_overlay, TRUE)
+		AddOverlays(blood_overlay, ATOM_ICON_CACHE_PROTECTED)
 		update_icon()
 
 	return

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

@@ -226,9 +226,9 @@
 		return
 
 	last_gauge_pressure = gauge_pressure
-	cut_overlays()
+	ClearOverlays()
 	// SSoverlay will handle icon caching.
-	add_overlay("[gauge_icon][(gauge_pressure == -1) ? "overload" : gauge_pressure]")
+	AddOverlays("[gauge_icon][(gauge_pressure == -1) ? "overload" : gauge_pressure]")
 
 /obj/item/tank/proc/percent()
 	var/gauge_pressure = 0

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

@@ -75,7 +75,7 @@
 	. = ..()
 	if(build_from_parts) //random colors!
 		color = pick(COLOR_BLUE, COLOR_RED, COLOR_PURPLE, COLOR_BROWN, COLOR_GREEN, COLOR_CYAN, COLOR_YELLOW)
-		add_overlay(overlay_image(icon, "[initial(icon_state)]_[worn_overlay]", flags=RESET_COLOR))
+		AddOverlays(overlay_image(icon, "[initial(icon_state)]_[worn_overlay]", flags=RESET_COLOR))
 
 /obj/item/screwdriver/update_icon()
 	var/matrix/tf = matrix()
@@ -88,7 +88,7 @@
 	var/mutable_appearance/body = mutable_appearance('icons/obj/clothing/belt_overlays.dmi', "screwdriver")
 	var/mutable_appearance/head = mutable_appearance('icons/obj/clothing/belt_overlays.dmi', "screwdriver_head")
 	body.color = color
-	head.add_overlay(body)
+	head.AddOverlays(body)
 	return head
 
 /obj/item/screwdriver/pickup(mob/user)
@@ -153,7 +153,7 @@
 	. = ..()
 	if(build_from_parts)
 		color = pick(color_options)
-		add_overlay(overlay_image(icon, "[initial(icon_state)]_[worn_overlay]", flags=RESET_COLOR))
+		AddOverlays(overlay_image(icon, "[initial(icon_state)]_[worn_overlay]", flags=RESET_COLOR))
 
 /obj/item/wirecutters/update_icon()
 	var/matrix/tf = matrix()
@@ -166,7 +166,7 @@
 	var/mutable_appearance/body = mutable_appearance('icons/obj/clothing/belt_overlays.dmi', "wirecutters")
 	var/mutable_appearance/head = mutable_appearance('icons/obj/clothing/belt_overlays.dmi', "wirecutters_head")
 	body.color = color
-	head.add_overlay(body)
+	head.AddOverlays(body)
 	return head
 
 /obj/item/wirecutters/pickup(mob/user)
@@ -306,13 +306,13 @@
 /obj/item/weldingtool/use_tool(atom/target, mob/living/user, delay, amount, volume, datum/callback/extra_checks)
 	var/image/welding_sparks = image('icons/effects/effects.dmi', welding_state)
 	welding_sparks.plane = EFFECTS_ABOVE_LIGHTING_PLANE
-	target.add_overlay(welding_sparks)
+	target.AddOverlays(welding_sparks)
 	. = ..()
-	target.cut_overlay(welding_sparks)
+	target.CutOverlays(welding_sparks)
 
 /obj/item/weldingtool/proc/update_torch()
 	if(welding)
-		add_overlay("[initial(icon_state)]-on")
+		AddOverlays("[initial(icon_state)]-on")
 		item_state = "[initial(item_state)]1"
 	else
 		item_state = "[initial(item_state)]"
@@ -325,11 +325,11 @@
 		set_light(0)
 
 /obj/item/weldingtool/update_icon()
-	cut_overlays()
+	ClearOverlays()
 	if(change_icons)
 		var/ratio = get_fuel() / max_fuel
 		ratio = CEILING(ratio*4, 1) * 25
-		add_overlay("[initial(icon_state)][ratio]")
+		AddOverlays("[initial(icon_state)][ratio]")
 	update_torch()
 	var/mob/M = loc
 	if(istype(M))
@@ -582,7 +582,7 @@
 		to_chat(user, SPAN_NOTICE("You install \the [attacking_item] into \the [src]."))
 		eyeshield = attacking_item
 		produces_flash = FALSE
-		add_overlay("eyeshield_attached", TRUE)
+		AddOverlays("eyeshield_attached", ATOM_ICON_CACHE_PROTECTED)
 		return TRUE
 	if(istype(attacking_item, /obj/item/overcapacitor))
 		if(overcap)
@@ -591,7 +591,7 @@
 		user.drop_from_inventory(attacking_item, src)
 		to_chat(user, SPAN_NOTICE("You install \the [attacking_item] into \the [src]."))
 		overcap = attacking_item
-		add_overlay("overcap_attached", TRUE)
+		AddOverlays("overcap_attached", ATOM_ICON_CACHE_PROTECTED)
 		toolspeed *= 2
 		return TRUE
 	if(attacking_item.isscrewdriver())
@@ -619,7 +619,7 @@
 			return TRUE
 		user.put_in_hands(remove_accessory)
 		to_chat(user, SPAN_NOTICE("You remove \the [remove_accessory] into \the [src]."))
-		cut_overlay("[remove_accessory.icon_state]_attached", TRUE)
+		CutOverlays("[remove_accessory.icon_state]_attached", ATOM_ICON_CACHE_PROTECTED)
 		return TRUE
 	return ..()
 
@@ -1005,7 +1005,7 @@
 	. = ..()
 	var/mutable_appearance/handle = mutable_appearance('icons/obj/tools.dmi', "hammer_handle")
 	handle.color = pick(COLOR_BLUE, COLOR_RED, COLOR_PURPLE, COLOR_BROWN, COLOR_GREEN, COLOR_CYAN, COLOR_YELLOW)
-	add_overlay(handle)
+	AddOverlays(handle)
 
 /obj/item/hammer/ishammer()
 	return TRUE