Port TG updating appearances (#17943)

* Get pants that match or else you gonna look silly yo

* Posters

* Fix other hud elements

* Rereviewed

* Update shotglass.dm

* Fix for new merged PRs

* Typo

* Coming across other stuff

* Update theblob.dm

* No takebacksies

* smh i forget to leave a comment

* Updated for the detgun and cards

* Should have rerun langserver again

* No longer plastic, more in scope

* Damn you bluespace

* Reverting turret logic, out of scope at this point

* Tweak that part

* Went over energy guns again, and fixed UI White's sprite sheet

* Welding masks, glasses, and JUSTICE

* Update portable_atmospherics.dm

* Cleaning up, clearing things up

* Review and suggestions

* Update valve.dm

* More tweaks

* Missing character

* Not distinct lightmasks, so they can be overlays

* Update generator.dm

* Add parameter so holodeck doesn't try to make a perfect copy

* Update unsorted.dm

* Spiders

* Better fix for spiders, fix vamps too

* Ghosts

* Update telekinesis.dm

* Cleaning up old procs

* It's set up to not copy datums... Unless they're in a list

* Donuts, duct tape, and detgun. D3VR coming to Early Access

* Update procs that interact with doors so they call update_state instead

* Forgot one spot, and actually might as well just force lock

* Cleaning up other things... Sigh, and kitty ears

* oops

* Getting used to how it works

* blinds

* Going back to the suit obscuring thing, so it doesn't update all the time

* Missed that from merging master

* I made this PR and forgot about it

* Fix runtimes in cards

* Make things a bit more unified

* Update update_icons.dm

* yarn, really?

* Update library_equipment.dm

* Update shieldgen.dm

* Every time Charlie merges something, I go back and see if I can improve things further

* what's this? more?

* Update misc_special.dm

* wow, paper

* Review

* More reviews

* To be sure, seems like being broken messed something sometimes

* Brought airlocks closer to how TG works to iron out some stuff

* Pizza and morgue

* Doesn't seem to hurt, tried with holodeck

* Revert "Doesn't seem to hurt, tried with holodeck"

This reverts commit 158529302b.

* Icon conflict

* Fix organ damage

* Don't ask how. Why. It's like that on prod too.

* Cutting down on things and updating from TG.

* More flexible. Just in case the thing you stuck it on didn't destroy.

* Hydro was one the things I touched earlier on, better rework it

* Reviews

* Cleaning up further, also bri'ish

* Undo a change I did, and switch over to a more recent implementation

* Update biogenerator.dm

* Rolling back to old airlocks, but with new duct taped note

* Functionally the same. I'd just rather not have the smoothing happen there

* Went over APCs again

* Fix welding helmet names in species files

* Update airlock.dm

* Update persistent_overlay.dm

* Oh, topic

code/game/objects/structures/bedsheet_bin.dm

@@ -284,7 +284,7 @@ LINEN BINS
 		. += "There are [amount] bed sheets in the bin."
 
 
-/obj/structure/bedsheetbin/update_icon()
+/obj/structure/bedsheetbin/update_icon_state()
 	switch(amount)
 		if(0)
 			icon_state = "linenbin-empty"
@@ -313,6 +313,7 @@ LINEN BINS
 		I.forceMove(src)
 		sheets.Add(I)
 		amount++
+		update_icon(UPDATE_ICON_STATE)
 		to_chat(user, "<span class='notice'>You put [I] in [src].</span>")
 	else if(amount && !hidden && I.w_class < WEIGHT_CLASS_BULKY)	//make sure there's sheets to hide it among, make sure nothing else is hidden in there.
 		if(I.flags & ABSTRACT)
@@ -346,7 +347,7 @@ LINEN BINS
 			hidden.loc = user.loc
 			to_chat(user, "<span class='notice'>[hidden] falls out of [B]!</span>")
 			hidden = null
-
+		update_icon(UPDATE_ICON_STATE)
 
 	add_fingerprint(user)
 
@@ -365,7 +366,7 @@ LINEN BINS
 
 		B.loc = loc
 		to_chat(user, "<span class='notice'>You telekinetically remove [B] from [src].</span>")
-		update_icon()
+		update_icon(UPDATE_ICON_STATE)
 
 		if(hidden)
 			hidden.loc = loc

code/game/objects/structures/coathanger.dm

@@ -9,44 +9,42 @@
 /obj/structure/coatrack/attack_hand(mob/user as mob)
 	user.visible_message("[user] takes [coat] off \the [src].", "You take [coat] off the \the [src]")
 	if(!user.put_in_active_hand(coat))
-		coat.loc = get_turf(user)
+		coat.forceMove(get_turf(user))
 	coat = null
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
 /obj/structure/coatrack/attackby(obj/item/W as obj, mob/user as mob, params)
-	var/can_hang = 0
+	var/can_hang = FALSE
 	for(var/T in allowed)
 		if(istype(W,T))
-			can_hang = 1
+			can_hang = TRUE
 	if(can_hang && !coat)
 		user.visible_message("[user] hangs [W] on \the [src].", "You hang [W] on the \the [src]")
 		coat = W
 		user.drop_item(src)
-		coat.loc = src
-		update_icon()
-	else
-		return ..()
+		coat.forceMove(src)
+		update_icon(UPDATE_OVERLAYS)
+		return
+	return ..()
 
 /obj/structure/coatrack/CanPass(atom/movable/mover, turf/target, height=0)
-	var/can_hang = 0
+	var/can_hang = FALSE
 	for(var/T in allowed)
 		if(istype(mover,T))
-			can_hang = 1
-
+			can_hang = TRUE
 	if(can_hang && !coat)
-		src.visible_message("[mover] lands on \the [src].")
+		visible_message("[mover] lands on \the [src].")
 		coat = mover
-		coat.loc = src
-		update_icon()
-		return 0
-	else
-		return 1
+		coat.forceMove(src)
+		update_icon(UPDATE_OVERLAYS)
+		return
+	return ..()
 
-/obj/structure/coatrack/update_icon()
-	overlays.Cut()
+/obj/structure/coatrack/update_overlays()
+	. = ..()
 	if(istype(coat, /obj/item/clothing/suit/storage/labcoat))
-		overlays += image(icon, icon_state = "coat_lab")
+		. += "coat_lab"
 	if(istype(coat, /obj/item/clothing/suit/storage/labcoat/cmo))
-		overlays += image(icon, icon_state = "coat_cmo")
+		. += "coat_cmo"
 	if(istype(coat, /obj/item/clothing/suit/storage/det_suit))
-		overlays += image(icon, icon_state = "coat_det")
+		. += "coat_det"

code/game/objects/structures/crates_lockers/closets.dm

@@ -24,6 +24,7 @@
 	var/storage_capacity = 30 //This is so that someone can't pack hundreds of items in a locker/crate then open it in a populated area to crash clients.
 	var/material_drop = /obj/item/stack/sheet/metal
 	var/material_drop_amount = 2
+	var/transparent
 
 // Please dont override this unless you absolutely have to
 /obj/structure/closet/Initialize(mapload)
@@ -298,23 +299,22 @@
 		return
 	to_chat(usr, "<span class='warning'>This mob type can't use this verb.</span>")
 
-/obj/structure/closet/update_icon()//Putting the welded stuff in updateicon() so it's easy to overwrite for special cases (Fridges, cabinets, and whatnot)
+/obj/structure/closet/update_icon_state()
 	if(!opened)
-		icon_state = icon_closed
+		icon_state = "[icon_closed][transparent ? "_trans" : ""]"
 	else
-		icon_state = icon_opened
-	update_overlays()
+		icon_state = "[icon_opened][transparent ? "_trans" : ""]"
 
-/obj/structure/closet/proc/update_overlays(transparent = FALSE)
-	cut_overlays()
+/obj/structure/closet/update_overlays()
+	. = ..()
 	if(transparent && opened)
-		add_overlay("[open_door_sprite]_trans")
+		. += "[open_door_sprite]_trans"
 		return
 	if(opened)
-		add_overlay(open_door_sprite)
+		. += open_door_sprite
 		return
 	if(welded)
-		add_overlay("welded")
+		. += "welded"
 
 // Objects that try to exit a locker by stepping were doing so successfully,
 // and due to an oversight in turf/Enter() were going through walls.  That
@@ -399,20 +399,17 @@
 	return TRUE
 
 /obj/structure/closet/bluespace/proc/UpdateTransparency(atom/movable/AM, atom/location)
-	var/transparent = FALSE
+	transparent = FALSE
 	for(var/atom/A in location)
 		if(A.density && A != src && A != AM)
 			transparent = TRUE
 			break
-	icon_opened = transparent ? "bluespace_open_trans" : "bluespace_open"
-	icon_closed = transparent ? "bluespace_trans" : "bluespace"
-	icon_state = opened ? icon_opened : icon_closed
-	update_overlays(transparent)
+	update_icon()
 
 /obj/structure/closet/bluespace/Crossed(atom/movable/AM, oldloc)
 	if(AM.density)
-		icon_state = opened ? "bluespace_open_trans" : "bluespace_trans"
-		update_overlays(TRUE)
+		transparent = TRUE
+		update_icon()
 
 /obj/structure/closet/bluespace/Move(NewLoc, direct) // Allows for "phasing" throug objects but doesn't allow you to stuff your EOC homebois in one of these and push them through walls.
 	var/turf/T = get_turf(NewLoc)

code/game/objects/structures/crates_lockers/closets/coffin.dm

@@ -11,12 +11,15 @@
 	open_sound_volume = 25
 	close_sound_volume = 50
 
-/obj/structure/closet/coffin/update_icon()
+/obj/structure/closet/coffin/update_icon_state()
 	if(!opened)
 		icon_state = icon_closed
 	else
 		icon_state = icon_opened
 
+/obj/structure/closet/coffin/update_overlays()
+	return list()
+
 /obj/structure/closet/coffin/sarcophagus
 	name = "sarcophagus"
 	icon_state = "sarc"

code/game/objects/structures/crates_lockers/closets/fireaxe.dm

@@ -20,7 +20,7 @@
 /obj/structure/closet/fireaxecabinet/populate_contents()
 	fireaxe = new/obj/item/twohanded/fireaxe(src)
 	has_axe = "full"
-	update_icon()	// So its initial icon doesn't show it without the fireaxe
+	update_icon(UPDATE_ICON_STATE)	// So its initial icon doesn't show it without the fireaxe
 
 /obj/structure/closet/fireaxecabinet/examine(mob/user)
 	. = ..()
@@ -37,7 +37,7 @@
 			if(do_after(user, 20 * O.toolspeed, target = src))
 				locked = FALSE
 				to_chat(user, "<span class = 'caution'> You disable the locking modules.</span>")
-				update_icon()
+				update_icon(UPDATE_ICON_STATE)
 			return
 		else if(istype(O, /obj/item))
 			user.changeNext_move(CLICK_CD_MELEE)
@@ -58,7 +58,7 @@
 					smashed = TRUE
 					locked = FALSE
 					localopened = TRUE
-			update_icon()
+			update_icon(UPDATE_ICON_STATE)
 		return
 	if(istype(O, /obj/item/twohanded/fireaxe) && localopened)
 		if(!fireaxe)
@@ -73,7 +73,7 @@
 			has_axe = "full"
 			contents += F
 			to_chat(user, "<span class='notice'>You place \the [F] back in the [name].</span>")
-			update_icon()
+			update_icon(UPDATE_ICON_STATE)
 		else
 			if(smashed)
 				return
@@ -107,7 +107,7 @@
 		fireaxe = null
 
 		add_fingerprint(user)
-		update_icon()
+		update_icon(UPDATE_ICON_STATE)
 		return
 	if(smashed)
 		return
@@ -119,7 +119,7 @@
 		to_chat(user, "<span class='notice'>You telekinetically remove \the [fireaxe].</span>")
 		has_axe = "empty"
 		fireaxe = null
-		update_icon()
+		update_icon(UPDATE_ICON_STATE)
 		return
 	attack_hand(user)
 
@@ -153,7 +153,7 @@
 			to_chat(usr, "<span class='notice'>[src] is empty.</span>")
 	else
 		to_chat(usr, "<span class='notice'>[src] is closed.</span>")
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 
 /obj/structure/closet/fireaxecabinet/attack_ai(mob/user as mob)
 	if(smashed)
@@ -180,14 +180,17 @@
 	else
 		flick("fireaxe_[has_axe]_opening", src)
 	sleep(10)
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 
 
-/obj/structure/closet/fireaxecabinet/update_icon()
+/obj/structure/closet/fireaxecabinet/update_icon_state()
 	if(localopened && !smashed)
 		icon_state = "fireaxe_[has_axe]_open"
-		return
-	icon_state = "fireaxe_[has_axe]_[hitstaken]hits"
+	else
+		icon_state = "fireaxe_[has_axe]_[hitstaken]hits"
+
+/obj/structure/closet/fireaxecabinet/update_overlays()
+	return list()
 
 /obj/structure/closet/fireaxecabinet/open()
 	return

code/game/objects/structures/crates_lockers/closets/gimmick.dm

@@ -10,12 +10,15 @@
 	close_sound_volume = 50
 	max_integrity = 70
 
-/obj/structure/closet/cabinet/update_icon()
+/obj/structure/closet/cabinet/update_icon_state()
 	if(!opened)
 		icon_state = icon_closed
 	else
 		icon_state = icon_opened
 
+/obj/structure/closet/cabinet/update_overlays()
+	return list()
+
 /obj/structure/closet/acloset
 	name = "strange closet"
 	desc = "It looks alien!"

code/game/objects/structures/crates_lockers/closets/secure/guncabinet.dm

@@ -21,7 +21,7 @@
 		update_icon()
 
 /obj/structure/closet/secure_closet/guncabinet/update_overlays()
-	cut_overlays()
+	. = list()
 	if(!opened)
 		var/lasers = 0
 		var/ballistics = 0
@@ -43,10 +43,10 @@
 					gun.icon_state = "projectile"
 
 				gun.pixel_x = i*4
-				add_overlay(gun)
+				. += gun
 
-		add_overlay("door")
+		. += "door"
 		if(broken)
-			add_overlay("off")
+			. += "off"
 		else if(locked)
-			add_overlay("locked")
+			. += "locked"

code/game/objects/structures/crates_lockers/closets/secure/secure_closets.dm

@@ -73,7 +73,7 @@
 		locked = FALSE
 		add_overlay("sparking")
 		to_chat(user, "<span class='notice'>You break the lock on [src].</span>")
-		addtimer(CALLBACK(src, .proc/update_icon), 1 SECONDS)
+		addtimer(CALLBACK(src, /atom/.proc/update_icon), 1 SECONDS)
 
 /obj/structure/closet/secure_closet/attack_hand(mob/user)
 	add_fingerprint(user)

code/game/objects/structures/crates_lockers/closets/statue.dm

@@ -105,9 +105,12 @@
 /obj/structure/closet/statue/verb_toggleopen()
 	return
 
-/obj/structure/closet/statue/update_icon()
+/obj/structure/closet/statue/update_icon_state()
 	return
 
+/obj/structure/closet/statue/update_overlays()
+	return list()
+
 /obj/structure/closet/statue/proc/shatter(mob/user)
 	if(user)
 		user.dust()

code/game/objects/structures/crates_lockers/crates.dm

@@ -15,11 +15,10 @@
 	// A list of beacon names that the crate will announce the arrival of, when delivered.
 	var/list/announce_beacons = list()
 
-/obj/structure/closet/crate/update_icon()
-	..()
-	cut_overlays()
+/obj/structure/closet/crate/update_overlays()
+	. = ..()
 	if(manifest)
-		add_overlay("manifest")
+		. += "manifest"
 
 /obj/structure/closet/crate/can_open()
 	return TRUE
@@ -175,15 +174,15 @@
 	locked = TRUE
 	can_be_emaged = TRUE
 
-/obj/structure/closet/crate/secure/update_icon()
-	..()
+/obj/structure/closet/crate/secure/update_overlays()
+	. = ..()
 	if(broken)
-		add_overlay(emag)
+		. += emag
 		return
 	if(locked)
-		add_overlay(redlight)
+		. += redlight
 	else
-		add_overlay(greenlight)
+		. += greenlight
 
 /obj/structure/closet/crate/secure/take_damage(damage_amount, damage_type = BRUTE, damage_flag = 0, sound_effect = 1)
 	if(prob(tamperproof) && damage_amount >= DAMAGE_PRECISION)

code/game/objects/structures/crates_lockers/largecrate.dm

@@ -10,11 +10,10 @@
 	. = ..()
 	update_icon()
 
-/obj/structure/largecrate/update_icon()
-	..()
-	overlays.Cut()
+/obj/structure/largecrate/update_overlays()
+	. = ..()
 	if(manifest)
-		overlays += "manifest"
+		. += "manifest"
 
 /obj/structure/largecrate/attack_hand(mob/user as mob)
 	if(manifest)

code/game/objects/structures/depot.dm

@@ -86,7 +86,7 @@
 	if(istype(depotarea))
 		if(!depotarea.used_self_destruct)
 			depotarea.used_self_destruct = TRUE // Silences all further alerts from this point onwards.
-			depotarea.updateicon()
+			depotarea.update_state()
 		depotarea.shields_down()
 	else
 		log_debug("[src] at [x],[y],[z] failed depotarea istype check during Initialize()! Either it was spawned outside the depot area (bad idea), or a bug is happening.")
@@ -103,7 +103,7 @@
 		depotarea = get_area(src)
 	if(istype(depotarea))
 		depotarea.destroyed = TRUE
-		depotarea.updateicon()
+		depotarea.update_state()
 
 	for(var/obj/structure/closet/L in range(30, T))
 		for(var/obj/O in L)

code/game/objects/structures/displaycase.dm

@@ -28,7 +28,7 @@
 				trophy_message = showpiece_entry["trophy_message"]
 	if(start_showpiece_type)
 		showpiece = new start_showpiece_type (src)
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
 /obj/structure/displaycase/Destroy()
 	QDEL_NULL(electronics)
@@ -81,7 +81,7 @@
 		open = TRUE
 		new /obj/item/shard(drop_location())
 		playsound(src, "shatter", 70, TRUE)
-		update_icon()
+		update_icon(UPDATE_OVERLAYS)
 		trigger_alarm()
 
 /obj/structure/displaycase/proc/trigger_alarm()
@@ -95,17 +95,17 @@
 			playsound(src, 'sound/machines/burglar_alarm.ogg', 50, 0)
 			sleep(74) // 7.4 seconds long
 
-/obj/structure/displaycase/update_icon()
-	cut_overlays()
+/obj/structure/displaycase/update_overlays()
+	. = ..()
 	if(broken)
-		add_overlay("glassbox_broken")
+		. += "glassbox_broken"
 	if(showpiece)
 		var/mutable_appearance/showpiece_overlay = mutable_appearance(showpiece.icon, showpiece.icon_state)
 		showpiece_overlay.copy_overlays(showpiece)
 		showpiece_overlay.transform *= 0.6
-		add_overlay(showpiece_overlay)
+		. += showpiece_overlay
 	if(!open && !broken)
-		add_overlay("glassbox_closed")
+		. += "glassbox_closed"
 
 /obj/structure/displaycase/attackby(obj/item/I, mob/user, params)
 	if(I.GetID() && !broken && openable)
@@ -131,7 +131,7 @@
 			broken = FALSE
 			open = FALSE
 			obj_integrity = max_integrity
-			update_icon()
+			update_icon(UPDATE_OVERLAYS)
 	else
 		return ..()
 
@@ -174,7 +174,7 @@
 
 /obj/structure/displaycase/proc/toggle_lock()
 	open = !open
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
 /obj/structure/displaycase/attack_hand(mob/user)
 	user.changeNext_move(CLICK_CD_MELEE)
@@ -182,7 +182,7 @@
 		to_chat(user, "<span class='notice'>You deactivate the hover field built into the case.</span>")
 		dump()
 		add_fingerprint(user)
-		update_icon()
+		update_icon(UPDATE_OVERLAYS)
 		return
 	else
 	    //prevents remote "kicks" with TK

code/game/objects/structures/door_assembly.dm

@@ -22,7 +22,7 @@
 
 /obj/structure/door_assembly/Initialize(mapload)
 	. = ..()
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 	update_name()
 
 /obj/structure/door_assembly/Destroy()
@@ -131,7 +131,7 @@
 	else
 		return ..()
 	update_name()
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
 /obj/structure/door_assembly/crowbar_act(mob/user, obj/item/I)
 	if(state != AIRLOCK_ASSEMBLY_NEEDS_SCREWDRIVER )
@@ -152,7 +152,7 @@
 		ae = electronics
 		electronics = null
 		ae.forceMove(loc)
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 	update_name()
 
 /obj/structure/door_assembly/screwdriver_act(mob/user, obj/item/I)
@@ -189,7 +189,7 @@
 	electronics.forceMove(door)
 	electronics = null
 	qdel(src)
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
 /obj/structure/door_assembly/wirecutter_act(mob/user, obj/item/I)
 	if(state != AIRLOCK_ASSEMBLY_NEEDS_ELECTRONICS)
@@ -203,7 +203,7 @@
 	to_chat(user, "<span class='notice'>You cut the wires from the airlock assembly.</span>")
 	new/obj/item/stack/cable_coil(get_turf(user), 1)
 	state = AIRLOCK_ASSEMBLY_NEEDS_WIRES
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
 /obj/structure/door_assembly/wrench_act(mob/user, obj/item/I)
 	if(state != AIRLOCK_ASSEMBLY_NEEDS_WIRES)
@@ -256,17 +256,18 @@
 			return
 		to_chat(user, "<span class='notice'>You disassemble the airlock assembly.</span>")
 		deconstruct(TRUE)
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
-/obj/structure/door_assembly/update_icon()
-	overlays.Cut()
+/obj/structure/door_assembly/update_overlays()
+	. = ..()
 	if(!glass)
-		overlays += get_airlock_overlay("fill_construction", icon)
+		. += get_airlock_overlay("fill_construction", icon)
 	else if(glass)
-		overlays += get_airlock_overlay("glass_construction", overlays_file)
-	overlays += get_airlock_overlay("panel_c[state+1]", overlays_file)
+		. += get_airlock_overlay("glass_construction", overlays_file)
+	. += get_airlock_overlay("panel_c[state+1]", overlays_file)
 
-/obj/structure/door_assembly/proc/update_name()
+/obj/structure/door_assembly/update_name()
+	. = ..()
 	name = ""
 	switch(state)
 		if(AIRLOCK_ASSEMBLY_NEEDS_WIRES)
@@ -289,7 +290,7 @@
 	if(electronics)
 		target.electronics = source.electronics
 		source.electronics.forceMove(target)
-	target.update_icon()
+	target.update_icon(UPDATE_OVERLAYS)
 	target.update_name()
 	qdel(source)
 

code/game/objects/structures/electricchair.dm

@@ -6,10 +6,11 @@
 	var/obj/item/assembly/shock_kit/part = null
 	var/last_time = 1.0
 	var/delay_time = 50
+	var/shocking = FALSE
 
 /obj/structure/chair/e_chair/Initialize(mapload, obj/item/assembly/shock_kit/sk)
 	. = ..()
-	overlays += image('icons/obj/chairs.dmi', src, "echair_over", MOB_LAYER + 1, dir)
+	update_icon(UPDATE_OVERLAYS)
 
 	if(sk)
 		part = sk
@@ -50,17 +51,25 @@
 
 /obj/structure/chair/e_chair/rotate()
 	..()
-	overlays.Cut()
-	overlays += image('icons/obj/chairs.dmi', src, "echair_over", MOB_LAYER + 1, dir)	//there's probably a better way of handling this, but eh. -Pete
+	update_icon(UPDATE_OVERLAYS)
+
+/obj/structure/chair/e_chair/update_icon_state()
+	icon_state = "echair[shocking]"
+
+/obj/structure/chair/e_chair/update_overlays()
+	. = ..()
+	. += image('icons/obj/chairs.dmi', src, "echair_over", MOB_LAYER + 1, dir)
 
 /obj/structure/chair/e_chair/proc/shock()
 	if(last_time + delay_time > world.time)
 		return
 	last_time = world.time
 
-	icon_state = "echair1"
+	shocking = TRUE
+	update_icon(UPDATE_ICON_STATE)
 	spawn(delay_time)
-		icon_state = "echair0"
+		shocking = FALSE
+		update_icon(UPDATE_ICON_STATE)
 
 	// special power handling
 	var/area/A = get_area(src)
@@ -70,7 +79,7 @@
 		return
 	A.use_power(5000, EQUIP)
 	var/light = A.power_light
-	A.updateicon()
+	A.update_icon(UPDATE_ICON_STATE)
 
 	flick("echair_shock", src)
 	do_sparks(12, 1, src)
@@ -83,4 +92,4 @@
 			spawn(1)
 				buckled_mob.electrocute_act(110, src, 1)
 	A.power_light = light
-	A.updateicon()
+	A.update_icon(UPDATE_ICON_STATE)

code/game/objects/structures/engicart.dm

@@ -37,49 +37,49 @@
 			if(!myglass)
 				put_in_cart(I, user)
 				myglass=I
-				update_icon()
+				update_icon(UPDATE_OVERLAYS)
 			else
 				to_chat(user, fail_msg)
 		else if(istype(I, /obj/item/stack/sheet/metal))
 			if(!mymetal)
 				put_in_cart(I, user)
 				mymetal=I
-				update_icon()
+				update_icon(UPDATE_OVERLAYS)
 			else
 				to_chat(user, fail_msg)
 		else if(istype(I, /obj/item/stack/sheet/plasteel))
 			if(!myplasteel)
 				put_in_cart(I, user)
 				myplasteel=I
-				update_icon()
+				update_icon(UPDATE_OVERLAYS)
 			else
 				to_chat(user, fail_msg)
 		else if(istype(I, /obj/item/flashlight))
 			if(!myflashlight)
 				put_in_cart(I, user)
 				myflashlight=I
-				update_icon()
+				update_icon(UPDATE_OVERLAYS)
 			else
 				to_chat(user, fail_msg)
 		else if(istype(I, /obj/item/storage/toolbox/mechanical))
 			if(!mybluetoolbox)
 				put_in_cart(I, user)
 				mybluetoolbox=I
-				update_icon()
+				update_icon(UPDATE_OVERLAYS)
 			else
 				to_chat(user, fail_msg)
 		else if(istype(I, /obj/item/storage/toolbox/electrical))
 			if(!myyellowtoolbox)
 				put_in_cart(I, user)
 				myyellowtoolbox=I
-				update_icon()
+				update_icon(UPDATE_OVERLAYS)
 			else
 				to_chat(user, fail_msg)
 		else if(istype(I, /obj/item/storage/toolbox))
 			if(!myredtoolbox)
 				put_in_cart(I, user)
 				myredtoolbox=I
-				update_icon()
+				update_icon(UPDATE_OVERLAYS)
 			else
 				to_chat(user, fail_msg)
 		else if(istype(I, /obj/item/wrench))
@@ -120,6 +120,7 @@
 	var/datum/browser/popup = new(user, "engicart", name, 240, 160)
 	popup.set_content(dat)
 	popup.open()
+
 /obj/structure/engineeringcart/Topic(href, href_list)
 	if(!in_range(src, usr))
 		return
@@ -162,22 +163,22 @@
 			to_chat(user, "<span class='notice'>You take [myyellowtoolbox] from [src].</span>")
 			myyellowtoolbox = null
 
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 	updateUsrDialog()
 
-/obj/structure/engineeringcart/update_icon()
-	overlays.Cut()
+/obj/structure/engineeringcart/update_overlays()
+	. = ..()
 	if(myglass)
-		overlays += "cart_glass"
+		. += "cart_glass"
 	if(mymetal)
-		overlays += "cart_metal"
+		. += "cart_metal"
 	if(myplasteel)
-		overlays += "cart_plasteel"
+		. += "cart_plasteel"
 	if(myflashlight)
-		overlays += "cart_flashlight"
+		. += "cart_flashlight"
 	if(mybluetoolbox)
-		overlays += "cart_bluetoolbox"
+		. += "cart_bluetoolbox"
 	if(myredtoolbox)
-		overlays += "cart_redtoolbox"
+		. += "cart_redtoolbox"
 	if(myyellowtoolbox)
-		overlays += "cart_yellowtoolbox"
+		. += "cart_yellowtoolbox"

code/game/objects/structures/extinguisher.dm

@@ -45,7 +45,7 @@
 		return
 	playsound(loc, 'sound/machines/click.ogg', 15, TRUE, -3)
 	opened = !opened
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 
 /obj/structure/extinguisher_cabinet/Destroy()
 	QDEL_NULL(has_extinguisher)
@@ -59,7 +59,7 @@
 /obj/structure/extinguisher_cabinet/handle_atom_del(atom/A)
 	if(A == has_extinguisher)
 		has_extinguisher = null
-		update_icon()
+		update_icon(UPDATE_ICON_STATE)
 
 /obj/structure/extinguisher_cabinet/attackby(obj/item/O, mob/user, params)
 	if(isrobot(user) || isalien(user))
@@ -71,17 +71,17 @@
 			user.drop_item(O)
 			contents += O
 			has_extinguisher = O
-			update_icon()
+			update_icon(UPDATE_ICON_STATE)
 			to_chat(user, "<span class='notice'>You place [O] in [src].</span>")
 			return TRUE
 		else
 			playsound(loc, 'sound/machines/click.ogg', 15, TRUE, -3)
 			opened = !opened
-		update_icon()
+		update_icon(UPDATE_ICON_STATE)
 	else if(user.a_intent != INTENT_HARM)
 		playsound(loc, 'sound/machines/click.ogg', 15, TRUE, -3)
 		opened = !opened
-		update_icon()
+		update_icon(UPDATE_ICON_STATE)
 	else
 		return ..()
 
@@ -122,7 +122,7 @@
 	else
 		playsound(loc, 'sound/machines/click.ogg', 15, TRUE, -3)
 		opened = !opened
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 
 /obj/structure/extinguisher_cabinet/attack_tk(mob/user)
 	if(has_extinguisher)
@@ -135,7 +135,7 @@
 	else
 		playsound(loc, 'sound/machines/click.ogg', 15, TRUE, -3)
 		opened = !opened
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 
 /obj/structure/extinguisher_cabinet/obj_break(damage_flag)
 	if(!broken && !(flags & NODECONSTRUCT))
@@ -144,7 +144,7 @@
 		if(has_extinguisher)
 			has_extinguisher.forceMove(loc)
 			has_extinguisher = null
-		update_icon()
+		update_icon(UPDATE_ICON_STATE)
 
 /obj/structure/extinguisher_cabinet/deconstruct(disassembled = TRUE)
 	if(!(flags & NODECONSTRUCT))
@@ -154,7 +154,7 @@
 			has_extinguisher = null
 	qdel(src)
 
-/obj/structure/extinguisher_cabinet/update_icon()
+/obj/structure/extinguisher_cabinet/update_icon_state()
 	if(!opened)
 		icon_state = "extinguisher_closed"
 		return

code/game/objects/structures/false_walls.dm

@@ -84,7 +84,7 @@
 	opening = FALSE
 	update_icon()
 
-/obj/structure/falsewall/update_icon()
+/obj/structure/falsewall/update_icon_state()
 	if(opening)
 		smoothing_flags = NONE
 		clear_smooth_overlays()

code/game/objects/structures/grille.dm

@@ -50,9 +50,9 @@
 
 /obj/structure/grille/take_damage(damage_amount, damage_type = BRUTE, damage_flag = 0, sound_effect = 1, attack_dir)
 	. = ..()
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 
-/obj/structure/grille/update_icon()
+/obj/structure/grille/update_icon_state()
 	if(QDELETED(src) || broken)
 		return
 

code/game/objects/structures/inflatable.dm

@@ -41,7 +41,7 @@
 	T.air_update_turf(TRUE)
 
 /obj/structure/inflatable/CanPass(atom/movable/mover, turf/target, height=0)
-	return 0
+	return
 
 /obj/structure/inflatable/CanAtmosPass(turf/T)
 	return !density
@@ -105,14 +105,12 @@
 
 /obj/structure/inflatable/door //Based on mineral door code
 	name = "inflatable door"
-
-	icon = 'icons/obj/inflatable.dmi'
 	icon_state = "door_closed"
 	torn = /obj/item/inflatable/door/torn
 	intact = /obj/item/inflatable/door
 
 	var/state_open = FALSE
-	var/isSwitchingStates = FALSE
+	var/is_operating = FALSE
 
 /obj/structure/inflatable/door/detailed_examine()
 	return "Click the door to open or close it. It only stops air while closed.<br>\
@@ -123,10 +121,10 @@
 		return
 	else if(isrobot(user)) //but cyborgs can
 		if(get_dist(user,src) <= 1) //not remotely though
-			return TryToSwitchState(user)
+			return try_to_operate(user)
 
 /obj/structure/inflatable/door/attack_hand(mob/user as mob)
-	return TryToSwitchState(user)
+	return try_to_operate(user)
 
 /obj/structure/inflatable/door/CanPass(atom/movable/mover, turf/target, height=0)
 	if(istype(mover, /obj/effect/beam))
@@ -136,8 +134,8 @@
 /obj/structure/inflatable/door/CanAtmosPass(turf/T)
 	return !density
 
-/obj/structure/inflatable/door/proc/TryToSwitchState(atom/user)
-	if(isSwitchingStates)
+/obj/structure/inflatable/door/proc/try_to_operate(atom/user)
+	if(is_operating)
 		return
 	if(ismob(user))
 		var/mob/M = user
@@ -147,42 +145,28 @@
 			if(iscarbon(M))
 				var/mob/living/carbon/C = M
 				if(!C.handcuffed)
-					SwitchState()
+					operate()
 			else
-				SwitchState()
+				operate()
 	else if(istype(user, /obj/mecha))
-		SwitchState()
+		operate()
 
-/obj/structure/inflatable/door/proc/SwitchState()
-	if(state_open)
-		Close()
+/obj/structure/inflatable/door/proc/operate()
+	is_operating = TRUE
+	//playsound(loc, 'sound/effects/stonedoor_openclose.ogg', 100, 1)
+	if(!state_open)
+		flick("door_opening",src)
 	else
-		Open()
+		flick("door_closing",src)
+	sleep(10)
+	density = !density
+	opacity = !opacity
+	state_open = !state_open
+	update_icon(UPDATE_ICON_STATE)
+	is_operating = FALSE
 	air_update_turf(1)
 
-/obj/structure/inflatable/door/proc/Open()
-	isSwitchingStates = TRUE
-	//playsound(loc, 'sound/effects/stonedoor_openclose.ogg', 100, 1)
-	flick("door_opening",src)
-	sleep(10)
-	density = FALSE
-	opacity = FALSE
-	state_open = TRUE
-	update_icon()
-	isSwitchingStates = FALSE
-
-/obj/structure/inflatable/door/proc/Close()
-	isSwitchingStates = TRUE
-	//playsound(loc, 'sound/effects/stonedoor_openclose.ogg', 100, 1)
-	flick("door_closing",src)
-	sleep(10)
-	density = TRUE
-	opacity = FALSE
-	state_open = FALSE
-	update_icon()
-	isSwitchingStates = FALSE
-
-/obj/structure/inflatable/door/update_icon()
+/obj/structure/inflatable/door/update_icon_state()
 	if(state_open)
 		icon_state = "door_open"
 	else

code/game/objects/structures/janicart.dm

@@ -40,7 +40,7 @@
 	return
 
 /obj/structure/janitorialcart/on_reagent_change()
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
 /obj/structure/janitorialcart/attackby(obj/item/I, mob/user, params)
 	var/fail_msg = "<span class='notice'>There is already one of those in [src].</span>"
@@ -66,7 +66,7 @@
 			if(!myspray)
 				put_in_cart(I, user)
 				myspray=I
-				update_icon()
+				update_icon(UPDATE_OVERLAYS)
 			else
 				to_chat(user, fail_msg)
 		else if(istype(I, /obj/item/lightreplacer))
@@ -79,7 +79,7 @@
 			if(signs < max_signs)
 				put_in_cart(I, user)
 				signs++
-				update_icon()
+				update_icon(UPDATE_OVERLAYS)
 			else
 				to_chat(user, "<span class='notice'>[src] can't hold any more signs.</span>")
 		else if(istype(I, /obj/item/crowbar))
@@ -163,22 +163,22 @@
 				WARNING("Signs ([signs]) didn't match contents")
 				signs = 0
 
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 	updateUsrDialog()
 
 
-/obj/structure/janitorialcart/update_icon()
-	overlays = null
+/obj/structure/janitorialcart/update_overlays()
+	. = ..()
 	if(mybag)
-		overlays += "cart_garbage"
+		. += "cart_garbage"
 	if(mymop)
-		overlays += "cart_mop"
+		. += "cart_mop"
 	if(myspray)
-		overlays += "cart_spray"
+		. += "cart_spray"
 	if(myreplacer)
-		overlays += "cart_replacer"
+		. += "cart_replacer"
 	if(signs)
-		overlays += "cart_sign[signs]"
+		. += "cart_sign[signs]"
 	if(reagents.total_volume > 0)
 		var/image/reagentsImage = image(icon,src,"cart_reagents0")
 		reagentsImage.alpha = 150
@@ -192,4 +192,4 @@
 			if(76 to 100)
 				reagentsImage.icon_state = "cart_reagents4"
 		reagentsImage.icon += mix_color_from_reagents(reagents.reagent_list)
-		add_overlay(reagentsImage)
+		. += reagentsImage

code/game/objects/structures/ladders.dm

@@ -55,7 +55,7 @@
 		down.update_icon()
 	up = down = null
 
-/obj/structure/ladder/update_icon()
+/obj/structure/ladder/update_icon_state()
 	if(up && down)
 		icon_state = "ladder11"
 
@@ -198,5 +198,5 @@
 	. = ..()
 	set_light(light_range, light_power)		//magical glowing anchor
 
-/obj/structure/ladder/unbreakable/dive_point/update_icon()
+/obj/structure/ladder/unbreakable/dive_point/update_icon_state()
 	return

code/game/objects/structures/mineral_doors.dm

@@ -13,7 +13,7 @@
 	rad_insulation = RAD_MEDIUM_INSULATION
 	var/initial_state
 	var/state_open = FALSE
-	var/isSwitchingStates = FALSE
+	var/is_operating = FALSE
 	var/close_delay = -1 //-1 if does not auto close.
 
 	var/hardness = 1
@@ -41,20 +41,20 @@
 /obj/structure/mineral_door/Bumped(atom/user)
 	..()
 	if(!state_open)
-		return TryToSwitchState(user)
+		return try_to_operate(user)
 
 /obj/structure/mineral_door/attack_ai(mob/user) //those aren't machinery, they're just big fucking slabs of a mineral
 	if(isAI(user)) //so the AI can't open it
 		return
 	else if(isrobot(user) && Adjacent(user)) //but cyborgs can, but not remotely
-		return TryToSwitchState(user)
+		return try_to_operate(user)
 
 /obj/structure/mineral_door/attack_hand(mob/user)
-	return TryToSwitchState(user)
+	return try_to_operate(user)
 
 /obj/structure/mineral_door/attack_ghost(mob/user)
 	if(user.can_advanced_admin_interact())
-		SwitchState()
+		operate()
 
 /obj/structure/mineral_door/CanPass(atom/movable/mover, turf/target, height = 0)
 	if(istype(mover, /obj/effect/beam))
@@ -64,8 +64,8 @@
 /obj/structure/mineral_door/CanAtmosPass(turf/T)
 	return !density
 
-/obj/structure/mineral_door/proc/TryToSwitchState(atom/user)
-	if(isSwitchingStates)
+/obj/structure/mineral_door/proc/try_to_operate(atom/user)
+	if(is_operating)
 		return
 	if(isliving(user))
 		var/mob/living/M = user
@@ -75,52 +75,35 @@
 			if(iscarbon(M))
 				var/mob/living/carbon/C = M
 				if(!C.handcuffed)
-					SwitchState()
+					operate()
 			else
-				SwitchState()
+				operate()
 	else if(istype(user, /obj/mecha))
-		SwitchState()
+		operate()
 
-/obj/structure/mineral_door/proc/SwitchState()
-	if(state_open)
-		Close()
+/obj/structure/mineral_door/proc/operate()
+	is_operating = TRUE
+	if(!state_open)
+		playsound(loc, openSound, 100, 1)
+		flick("[initial_state]opening",src)
 	else
-		Open()
-
-/obj/structure/mineral_door/proc/Open()
-	isSwitchingStates = TRUE
-	playsound(loc, openSound, 100, 1)
-	flick("[initial_state]opening",src)
+		var/turf/T = get_turf(src)
+		for(var/mob/living/L in T)
+			return
+		playsound(loc, closeSound, 100, 1)
+		flick("[initial_state]closing",src)
 	sleep(10)
-	density = FALSE
-	opacity = FALSE
-	state_open = TRUE
+	density = !density
+	opacity = !opacity
+	state_open = !state_open
 	air_update_turf(1)
-	update_icon()
-	isSwitchingStates = FALSE
+	update_icon(UPDATE_ICON_STATE)
+	is_operating = FALSE
 
-	if(close_delay != -1)
-		spawn(close_delay)
-			Close()
+	if(state_open && close_delay != -1)
+		addtimer(CALLBACK(src, .proc/operate), close_delay)
 
-/obj/structure/mineral_door/proc/Close()
-	if(isSwitchingStates || !state_open)
-		return
-	var/turf/T = get_turf(src)
-	for(var/mob/living/L in T)
-		return
-	isSwitchingStates = TRUE
-	playsound(loc, closeSound, 100, 1)
-	flick("[initial_state]closing",src)
-	sleep(10)
-	density = TRUE
-	opacity = TRUE
-	state_open = FALSE
-	air_update_turf(1)
-	update_icon()
-	isSwitchingStates = FALSE
-
-/obj/structure/mineral_door/update_icon()
+/obj/structure/mineral_door/update_icon_state()
 	if(state_open)
 		icon_state = "[initial_state]open"
 	else
@@ -180,7 +163,7 @@
 	opacity = FALSE
 	rad_insulation = RAD_VERY_LIGHT_INSULATION
 
-/obj/structure/mineral_door/transparent/Close()
+/obj/structure/mineral_door/transparent/operate()
 	..()
 	set_opacity(0)
 
@@ -235,6 +218,6 @@
 	damageSound = 'sound/effects/attackblob.ogg'
 	sheetType = null
 
-/obj/structure/mineral_door/resin/TryToSwitchState(atom/user)
+/obj/structure/mineral_door/resin/try_to_operate(atom/user)
 	if(isalien(user))
 		return ..()

code/game/objects/structures/mop_bucket.dm

@@ -6,7 +6,7 @@
 	density = TRUE
 	container_type = OPENCONTAINER
 	face_while_pulling = FALSE
-	var/obj/item/mop/mymop = null
+	var/obj/item/mop/stored_mop = null
 	var/amount_per_transfer_from_this = 5 //shit I dunno, adding this so syringes stop runtime erroring. --NeoFite
 
 /obj/structure/mopbucket/Initialize(mapload)
@@ -29,12 +29,12 @@
 
 /obj/structure/mopbucket/attackby(obj/item/W as obj, mob/user as mob, params)
 	if(istype(W, /obj/item/mop))
-		var/obj/item/mop/m = W
-		if(m.reagents.total_volume < m.reagents.maximum_volume)
-			m.wet_mop(src, user)
+		var/obj/item/mop/M = W
+		if(M.reagents.total_volume < M.reagents.maximum_volume)
+			M.wet_mop(src, user)
 			return
-		if(!mymop)
-			m.janicart_insert(user, src)
+		if(!stored_mop)
+			M.janicart_insert(user, src)
 			return
 		to_chat(user, "<span class='notice'>Theres already a mop in the mopbucket.</span>")
 		return
@@ -47,12 +47,12 @@
 	return
 
 /obj/structure/mopbucket/on_reagent_change()
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
-/obj/structure/mopbucket/update_icon()
-	overlays.Cut()
-	if(mymop)
-		overlays += image(icon,"mopbucket_mop")
+/obj/structure/mopbucket/update_overlays()
+	. = ..()
+	if(stored_mop)
+		. += "mopbucket_mop"
 	if(reagents.total_volume > 0)
 		var/image/reagentsImage = image(icon, src, "mopbucket_reagents0")
 		reagentsImage.alpha = 150
@@ -66,15 +66,15 @@
 			if(76 to 100)
 				reagentsImage.icon_state = "mopbucket_reagents4"
 		reagentsImage.icon += mix_color_from_reagents(reagents.reagent_list)
-		add_overlay(reagentsImage)
+		. += reagentsImage
 
 /obj/structure/mopbucket/attack_hand(mob/living/user)
 	. = ..()
-	if(mymop)
-		user.put_in_hands(mymop)
-		to_chat(user, "<span class='notice'>You take [mymop] from [src].</span>")
-		mymop = null
-		update_icon()
+	if(stored_mop)
+		user.put_in_hands(stored_mop)
+		to_chat(user, "<span class='notice'>You take [stored_mop] from [src].</span>")
+		stored_mop = null
+		update_icon(UPDATE_OVERLAYS)
 		return
 
 

code/game/objects/structures/morgue.dm

@@ -40,36 +40,39 @@
 
 /obj/structure/morgue/Initialize()
 	. = ..()
-	update()
+	update_icon(update_state())
 
-/obj/structure/morgue/proc/update()
-	cut_overlays()
-	if(!connected)
-		if(contents.len)
-			var/mob/living/M = locate() in contents
-			var/obj/structure/closet/body_bag/B = locate() in contents
-			if(M==null) M = locate() in B
-
-			if(M)
-				var/mob/dead/observer/G = M.get_ghost()
-				if(M.mind && !M.mind.suicided)
-					if(M.client)
-						status = REVIVABLE
-					else if(G && G.client) //There is a ghost and it is connected to the server
-						status = GHOST_CONNECTED
-					else
-						status = UNREVIVABLE
-				else
-					status = UNREVIVABLE
-			else
-				status = NOT_BODY
-		else
-			status = EMPTY_MORGUE
-		add_overlay("morgue_[status]")
-	else
+/obj/structure/morgue/proc/update_state()
+	. = UPDATE_OVERLAYS
+	if(connected)
 		status = EXTENDED_TRAY
+		return
+	if(!length(contents))
+		status = EMPTY_MORGUE
+		return
+	var/mob/living/M = locate() in contents
+	var/obj/structure/closet/body_bag/B = locate() in contents
+	if(!M)
+		M = locate() in B
+	if(!M)
+		status = NOT_BODY
+		return
+	var/mob/dead/observer/G = M.get_ghost()
+	if(M.mind && !M.mind.suicided)
+		if(M.client)
+			status = REVIVABLE
+			return
+		if(G && G.client) //There is a ghost and it is connected to the server
+			status = GHOST_CONNECTED
+			return
+	status = UNREVIVABLE
+
+/obj/structure/morgue/update_overlays()
+	. = ..()
+	if(!connected)
+		. += "morgue_[status]"
 	if(name != initial(name))
-		add_overlay("morgue_label")
+		. += "morgue_label"
 
 /obj/structure/morgue/examine(mob/user)
 	. = ..()
@@ -110,7 +113,7 @@
 		playsound(loc, open_sound, 50, 1)
 		connect()
 	add_fingerprint(user)
-	update()
+	update_icon(update_state())
 	return
 
 /obj/structure/morgue/attackby(P as obj, mob/user as mob, params)
@@ -118,7 +121,7 @@
 		var/t = rename_interactive(user, P)
 		if(isnull(t))
 			return
-		update()
+		update_icon(UPDATE_OVERLAYS)
 		add_fingerprint(user)
 		return
 	return ..()
@@ -127,7 +130,7 @@
 	if(name != initial(name))
 		to_chat(user, "<span class='notice'>You cut the tag off the morgue.</span>")
 		name = initial(name)
-		update()
+		update_icon(UPDATE_OVERLAYS)
 		return TRUE
 
 /obj/structure/morgue/relaymove(mob/user as mob)
@@ -196,7 +199,7 @@
 			if(!( A.anchored ))
 				A.forceMove(connected)
 		connected.connected = null
-		connected.update()
+		connected.update_icon(UPDATE_OVERLAYS)
 		add_fingerprint(user)
 		qdel(src)
 		return
@@ -256,17 +259,18 @@
 
 /obj/structure/crematorium/Initialize(mapload)
 	. = ..()
-	update()
+	update_icon(UPDATE_OVERLAYS)
 
-/obj/structure/crematorium/proc/update()
-	cut_overlays()
-	if(!connected)
-		add_overlay("crema_closed")
-		if(cremating)
-			add_overlay("crema_active")
-			return
-		if(contents.len)
-			add_overlay("crema_full")
+/obj/structure/crematorium/update_overlays()
+	. = ..()
+	if(connected)
+		return
+	. += "crema_closed"
+	if(cremating)
+		. += "crema_active"
+		return
+	if(length(contents))
+		. += "crema_full"
 
 /obj/structure/crematorium/ex_act(severity)
 	switch(severity)
@@ -306,7 +310,7 @@
 		playsound(loc, open_sound, 50, 1)
 		connect()
 	add_fingerprint(user)
-	update()
+	update_icon(UPDATE_OVERLAYS)
 
 /obj/structure/crematorium/attackby(P as obj, mob/user as mob, params)
 	if(istype(P, /obj/item/pen))
@@ -327,7 +331,7 @@
 	var/turf/T = get_step(src, SOUTH)
 	if(T.contents.Find(connected))
 		connected.connected = src
-		update()
+		update_icon(UPDATE_OVERLAYS)
 		for(var/atom/movable/A in src)
 			A.forceMove(connected.loc)
 		connected.icon_state = "crema_tray"
@@ -349,7 +353,7 @@
 
 		cremating = TRUE
 		locked = TRUE
-		update()
+		update_icon(UPDATE_OVERLAYS)
 
 		for(var/mob/living/M in search_contents_for(/mob/living))
 			if(QDELETED(M))
@@ -371,7 +375,7 @@
 		sleep(30)
 		cremating = FALSE
 		locked = FALSE
-		update()
+		update_icon(UPDATE_OVERLAYS)
 		playsound(loc, 'sound/machines/ding.ogg', 50, 1)
 	return
 
@@ -419,7 +423,7 @@
 				A.forceMove(connected)
 			//Foreach goto(26)
 		connected.connected = null
-		connected.update()
+		connected.update_icon(UPDATE_OVERLAYS)
 		add_fingerprint(user)
 		qdel(src)
 		return
@@ -488,7 +492,7 @@
 		if(istype(C)) //We found our corpse, is it inside a morgue?
 			morgue = get(C.loc, /obj/structure/morgue)
 			if(morgue)
-				morgue.update()
+				morgue.update_icon(UPDATE_OVERLAYS)
 
 #undef EXTENDED_TRAY
 #undef EMPTY_MORGUE

code/game/objects/structures/safe.dm

@@ -112,7 +112,7 @@ GLOBAL_LIST_EMPTY(safes)
 /obj/structure/safe/examine_status(mob/user)
 	return
 
-/obj/structure/safe/update_icon()
+/obj/structure/safe/update_icon_state()
 	if(open)
 		if(broken)
 			icon_state = "[initial(icon_state)]-open-broken"
@@ -124,17 +124,13 @@ GLOBAL_LIST_EMPTY(safes)
 		else
 			icon_state = initial(icon_state)
 
-	var/list/overlays_to_cut = list(drill_overlay)
-	if(!drill_timer)
-		overlays_to_cut += progress_bar
-
-	cut_overlay(overlays_to_cut)
-
+/obj/structure/safe/update_overlays()
+	. = ..()
 	if(istype(drill, /obj/item/thermal_drill))
 		var/drill_icon = istype(drill, /obj/item/thermal_drill/diamond_drill) ? "d" : "h"
 		var/state = "[initial(icon_state)]_[drill_icon]-drill-[drill_timer ? "on" : "off"]"
 		drill_overlay = image(icon = 'icons/effects/drill.dmi', icon_state = state, pixel_x = drill_x_offset, pixel_y = drill_y_offset)
-		add_overlay(drill_overlay)
+		. += drill_overlay
 
 /obj/structure/safe/attack_ghost(mob/user)
 	if(..() || drill)

code/game/objects/structures/tables_racks.dm

@@ -49,15 +49,15 @@
 /obj/structure/table/proc/deconstruction_hints(mob/user)
 	return "<span class='notice'>The top is <b>screwed</b> on, but the main <b>bolts</b> are also visible.</span>"
 
-/obj/structure/table/update_icon()
+/obj/structure/table/update_icon(updates=ALL)
+	. = ..()
+	update_smoothing()
+
+/obj/structure/table/update_icon_state()
 	if((smoothing_flags & (SMOOTH_CORNERS|SMOOTH_BITMASK)) && !flipped)
 		icon_state = ""
-		QUEUE_SMOOTH(src)
-		QUEUE_SMOOTH_NEIGHBORS(src)
 
 	if(flipped)
-		clear_smooth_overlays()
-
 		var/type = 0
 		var/subtype = null
 		for(var/direction in list(turn(dir,90), turn(dir,-90)) )
@@ -80,7 +80,13 @@
 
 		icon_state = "[base]flip[type][type == 1 ? subtype : ""]"
 
-		return 1
+/obj/structure/table/proc/update_smoothing()
+	if((smoothing_flags & (SMOOTH_CORNERS|SMOOTH_BITMASK)) && !flipped)
+		QUEUE_SMOOTH(src)
+		QUEUE_SMOOTH_NEIGHBORS(src)
+
+	if(flipped)
+		clear_smooth_overlays()
 
 /obj/structure/table/narsie_act()
 	new /obj/structure/table/wood(loc)

code/game/objects/structures/tank_dispenser.dm

@@ -21,7 +21,7 @@
 /obj/structure/dispenser/Initialize(mapload)
 	. = ..()
 	initialize_tanks()
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
 /obj/structure/dispenser/Destroy()
 	QDEL_LIST(stored_plasma_tanks)
@@ -37,21 +37,21 @@
 		var/obj/item/tank/internals/oxygen/O = new(src)
 		stored_oxygen_tanks.Add(O)
 
-/obj/structure/dispenser/update_icon()
-	cut_overlays()
+/obj/structure/dispenser/update_overlays()
+	. = ..()
 	var/oxy_tank_amount = LAZYLEN(stored_oxygen_tanks)
 	switch(oxy_tank_amount)
 		if(1 to 3)
-			overlays += "oxygen-[oxy_tank_amount]"
+			. += "oxygen-[oxy_tank_amount]"
 		if(4 to INFINITY)
-			overlays += "oxygen-4"
+			. += "oxygen-4"
 
 	var/pla_tank_amount = LAZYLEN(stored_plasma_tanks)
 	switch(pla_tank_amount)
 		if(1 to 4)
-			overlays += "plasma-[pla_tank_amount]"
+			. += "plasma-[pla_tank_amount]"
 		if(5 to INFINITY)
-			overlays += "plasma-5"
+			. += "plasma-5"
 
 /obj/structure/dispenser/attack_hand(mob/user)
 	if(..())
@@ -119,7 +119,7 @@
 		T.forceMove(loc) // If the user's hands are full, place it on the tile of the dispenser.
 
 	to_chat(user, "<span class='notice'>You take [T] out of [src].</span>")
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 
 /// Called when the user clicks on the dispenser with a tank. Tries to insert the tank into the dispenser, and updates the UI if successful.
 /obj/structure/dispenser/proc/try_insert_tank(mob/living/user, list/tank_list, obj/item/tank/T)
@@ -133,7 +133,7 @@
 
 	T.forceMove(src)
 	tank_list.Add(T)
-	update_icon()
+	update_icon(UPDATE_OVERLAYS)
 	to_chat(user, "<span class='notice'>You put [T] in [src].</span>")
 	SStgui.update_uis(src)
 

code/game/objects/structures/watercloset.dm

@@ -47,7 +47,7 @@
 	open = !open
 	update_icon()
 
-/obj/structure/toilet/update_icon()
+/obj/structure/toilet/update_icon_state()
 	icon_state = "toilet[open][cistern]"
 	if(!anchored)
 		pixel_x = 0
@@ -340,11 +340,11 @@
 		transfer_prints_to(S, TRUE)
 		qdel(src)
 
-/obj/machinery/shower/update_icon()
-	cut_overlays()
+/obj/machinery/shower/update_overlays()
+	. = ..()
 	if(on)
 		var/mutable_appearance/water_falling = mutable_appearance('icons/obj/watercloset.dmi', "water", ABOVE_MOB_LAYER)
-		add_overlay(water_falling)
+		. += water_falling
 
 /obj/machinery/shower/proc/handle_mist()
 	// If there is no mist, and the shower was turned on (on a non-freezing temp): make mist in 5 seconds
@@ -565,8 +565,7 @@
 			dir = dir_choices[selected]
 	update_icon()	//is this necessary? probably not
 
-/obj/structure/sink/update_icon()
-	..()
+/obj/structure/sink/update_icon_state()
 	layer = OBJ_LAYER
 	if(!anchored)
 		pixel_x = 0

code/game/objects/structures/windoor_assembly.dm

@@ -50,7 +50,7 @@
 	setDir(ini_dir)
 	move_update_air(T)
 
-/obj/structure/windoor_assembly/update_icon()
+/obj/structure/windoor_assembly/update_icon_state()
 	icon_state = "[facing]_[secure ? "secure_" : ""]windoor_assembly[state]"
 
 /obj/structure/windoor_assembly/CanPass(atom/movable/mover, turf/target, height=0)
@@ -156,7 +156,7 @@
 				return ..()
 
 	//Update to reflect changes(if applicable)
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 
 /obj/structure/windoor_assembly/crowbar_act(mob/user, obj/item/I)	//Crowbar to complete the assembly, Step 7 complete.
 	if(state != "02")
@@ -244,7 +244,7 @@
 		name = "secure anchored windoor assembly"
 	else
 		name = "anchored windoor assembly"
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 
 /obj/structure/windoor_assembly/wrench_act(mob/user, obj/item/I)
 	if(state != "01")
@@ -282,7 +282,7 @@
 			name = "secure windoor assembly"
 		else
 			name = "windoor assembly"
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 
 /obj/structure/windoor_assembly/welder_act(mob/user, obj/item/I)
 	if(state != "01")
@@ -320,7 +320,7 @@
 	setDir(target_dir)
 
 	ini_dir = dir
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 	return TRUE
 
 /obj/structure/windoor_assembly/AltClick(mob/user)
@@ -348,5 +348,5 @@
 		facing = "l"
 		to_chat(usr, "The windoor will now slide to the left.")
 
-	update_icon()
+	update_icon(UPDATE_ICON_STATE)
 	return

code/game/objects/structures/window.dm

@@ -454,7 +454,8 @@
 	if(smoothing_flags & (SMOOTH_CORNERS|SMOOTH_BITMASK))
 		QUEUE_SMOOTH_NEIGHBORS(src)
 
-/obj/structure/window/update_icon()
+/obj/structure/window/update_overlays()
+	. = ..()
 	if(!QDELETED(src))
 		if(!fulltile)
 			return
@@ -464,11 +465,10 @@
 		if(smoothing_flags & (SMOOTH_CORNERS|SMOOTH_BITMASK))
 			QUEUE_SMOOTH(src)
 
-		cut_overlay(crack_overlay)
 		if(ratio > 75)
 			return
 		crack_overlay = mutable_appearance('icons/obj/structures.dmi', "damage[ratio]", -(layer+0.1))
-		add_overlay(crack_overlay)
+		. += crack_overlay
 
 /obj/structure/window/temperature_expose(datum/gas_mixture/air, exposed_temperature, exposed_volume)
 	..()
@@ -569,7 +569,7 @@
 	if(active && !powered(power_channel))
 		toggle_tint()
 
-/obj/machinery/button/windowtint/update_icon()
+/obj/machinery/button/windowtint/update_icon_state()
 	icon_state = "light[active]"
 
 /obj/structure/window/plasmabasic