Replaces /image with /mutable_appearance (#556)

* Replaces /image with /mutable_appearance, where appropriate

* Update miscellaneous.dm

* Delete miscellaneous.dm.rej

* Delete pet.dm.rej

* Update pet.dm

* Update species.dm

* Update miscellaneous.dm

* Update species.dm

* Update miscellaneous.dm

* Delete species.dm.rej

* Update species.dm

pretty sure I got all the indentation correct THIS time, ffs

* Update species.dm

* Update species.dm

fucking tabs man, fucking tabs.

code/game/gamemodes/blob/blobs/blob_mobs.dm

@@ -179,11 +179,11 @@
 		remove_atom_colour(FIXED_COLOUR_PRIORITY)
 	if(is_zombie)
 		copy_overlays(oldguy, TRUE)
-		var/image/I = image('icons/mob/blob.dmi', icon_state = "blob_head")
+		var/mutable_appearance/blob_head_overlay = mutable_appearance('icons/mob/blob.dmi', "blob_head")
 		if(overmind)
-			I.color = overmind.blob_reagent_datum.complementary_color
+			blob_head_overlay.color = overmind.blob_reagent_datum.complementary_color
 		color = initial(color)//looks better.
-		add_overlay(I)
+		add_overlay(blob_head_overlay)
 
 /mob/living/simple_animal/hostile/blob/blobspore/weak
 	name = "fragile blob spore"

code/game/gamemodes/blob/blobs/core.dm

@@ -33,12 +33,11 @@
 /obj/structure/blob/core/update_icon()
 	cut_overlays()
 	color = null
-	var/image/I = new('icons/mob/blob.dmi', "blob")
+	var/mutable_appearance/blob_overlay = mutable_appearance('icons/mob/blob.dmi', "blob")
 	if(overmind)
-		I.color = overmind.blob_reagent_datum.color
-	add_overlay(I)
-	var/image/C = new('icons/mob/blob.dmi', "blob_core_overlay")
-	add_overlay(C)
+		blob_overlay.color = overmind.blob_reagent_datum.color
+	add_overlay(blob_overlay)
+	add_overlay(mutable_appearance('icons/mob/blob.dmi', "blob_core_overlay"))
 
 /obj/structure/blob/core/Destroy()
 	GLOB.blob_cores -= src

code/game/gamemodes/blob/blobs/node.dm

@@ -21,12 +21,11 @@
 /obj/structure/blob/node/update_icon()
 	cut_overlays()
 	color = null
-	var/image/I = new('icons/mob/blob.dmi', "blob")
+	var/mutable_appearance/blob_overlay = mutable_appearance('icons/mob/blob.dmi', "blob")
 	if(overmind)
-		I.color = overmind.blob_reagent_datum.color
-	add_overlay(I)
-	var/image/C = new('icons/mob/blob.dmi', "blob_node_overlay")
-	add_overlay(C)
+		blob_overlay.color = overmind.blob_reagent_datum.color
+	add_overlay(blob_overlay)
+	add_overlay(mutable_appearance('icons/mob/blob.dmi', "blob_node_overlay"))
 
 /obj/structure/blob/node/Destroy()
 	GLOB.blob_nodes -= src

code/game/gamemodes/clock_cult/clock_structures/geis_binding.dm

@@ -42,8 +42,7 @@
 		icon_state = "geisbinding"
 		mob_layer = M.layer
 		layer = M.layer - 0.01
-		var/image/GB = new('icons/effects/clockwork_effects.dmi', src, "geisbinding_top", M.layer + 0.01)
-		add_overlay(GB)
+		add_overlay(mutable_appearance('icons/effects/clockwork_effects.dmi', "geisbinding_top", M.layer + 0.01))
 		for(var/obj/item/I in M.held_items)
 			M.dropItemToGround(I)
 		for(var/i in M.get_empty_held_indexes())

code/game/gamemodes/clock_cult/clock_structures/ratvar_the_clockwork_justicar.dm

@@ -25,7 +25,7 @@
 	START_PROCESSING(SSobj, src)
 	send_to_playing_players("<span class='ratvar'>\"[text2ratvar("ONCE AGAIN MY LIGHT SHALL SHINE ACROSS THIS PATHETIC REALM")]!!\"</span>")
 	send_to_playing_players('sound/effects/ratvar_reveal.ogg')
-	var/image/alert_overlay = image('icons/effects/clockwork_effects.dmi', "ratvar_alert")
+	var/mutable_appearance/alert_overlay = mutable_appearance('icons/effects/clockwork_effects.dmi', "ratvar_alert")
 	var/area/A = get_area(src)
 	notify_ghosts("The Justiciar's light calls to you! Reach out to Ratvar in [A.name] to be granted a shell to spread his glory!", null, source = src, alert_overlay = alert_overlay)
 	INVOKE_ASYNC(SSshuttle.emergency, /obj/docking_port/mobile/emergency..proc/request, null, 0)

code/game/gamemodes/clock_cult/clock_structures/tinkerers_daemon.dm

@@ -14,8 +14,8 @@
 	debris = list(/obj/item/clockwork/alloy_shards/medium = 1, \
 	/obj/item/clockwork/alloy_shards/small = 6, \
 	/obj/item/clockwork/component/replicant_alloy/replication_plate = 1)
-	var/image/daemon_glow
-	var/image/component_glow
+	var/static/mutable_appearance/daemon_glow = mutable_appearance('icons/obj/clockwork_objects.dmi', "tinkerglow")
+	var/static/mutable_appearance/component_glow = mutable_appearance('icons/obj/clockwork_objects.dmi', "t_random_component")
 	var/component_id_to_produce
 	var/production_time = 0 //last time we produced a component
 	var/production_cooldown = 120
@@ -119,14 +119,9 @@
 	. = ..()
 	if(active)
 		var/component_color = get_component_color(component_id_to_produce)
-		if(!daemon_glow)
-			daemon_glow = new('icons/obj/clockwork_objects.dmi', "tinkerglow")
 		daemon_glow.color = component_color
 		add_overlay(daemon_glow)
-		if(!component_glow)
-			component_glow = new('icons/obj/clockwork_objects.dmi', "t_[component_id_to_produce ? component_id_to_produce :"random_component"]")
-		else
-			component_glow.icon_state = "t_[component_id_to_produce ? component_id_to_produce :"random_component"]"
+		component_glow.icon_state = "t_[component_id_to_produce ? component_id_to_produce :"random_component"]"
 		component_glow.color = component_color
 		add_overlay(component_glow)
 		production_time = world.time + production_cooldown //don't immediately produce when turned on after being off

code/game/gamemodes/cult/cult_items.dm

@@ -201,9 +201,9 @@
 	return 0
 
 /obj/item/clothing/suit/hooded/cultrobes/cult_shield/worn_overlays(isinhands)
-    . = list()
-    if(!isinhands && current_charges)
-        . += image(layer = MOB_LAYER+0.01, icon = 'icons/effects/effects.dmi', icon_state = "shield-cult")
+	. = list()
+	if(!isinhands && current_charges)
+		. += mutable_appearance('icons/effects/effects.dmi', "shield-cult", MOB_LAYER + 0.01)
 
 /obj/item/clothing/suit/hooded/cultrobes/berserker
 	name = "flagellant's robes"

code/game/gamemodes/cult/runes.dm

@@ -775,11 +775,11 @@ structure_check() searches for nearby cultist structures required for the invoca
 	deltimer(density_timer)
 	air_update_turf(1)
 	if(density)
-		var/image/I = image(layer = ABOVE_MOB_LAYER, icon = 'icons/effects/effects.dmi', icon_state = "barriershimmer")
-		I.appearance_flags = RESET_COLOR
-		I.alpha = 60
-		I.color = "#701414"
-		add_overlay(I)
+		var/mutable_appearance/shimmer = mutable_appearance('icons/effects/effects.dmi', "barriershimmer", ABOVE_MOB_LAYER)
+		shimmer.appearance_flags |= RESET_COLOR
+		shimmer.alpha = 60
+		shimmer.color = "#701414"
+		add_overlay(shimmer)
 		add_atom_colour("#FF0000", FIXED_COLOUR_PRIORITY)
 	else
 		cut_overlays()

code/game/gamemodes/devil/true_devil/inventory.dm

@@ -5,7 +5,7 @@
 	return 0
 
 /mob/living/carbon/true_devil/update_inv_hands()
-	//TODO LORDPIDEY:  Figure out how to make the hands line up properly.  the l/r_hand_image should use the down sprite when facing down, left, or right, and the up sprite when facing up.
+	//TODO LORDPIDEY:  Figure out how to make the hands line up properly.  the l/r_hand_overlay should use the down sprite when facing down, left, or right, and the up sprite when facing up.
 	remove_overlay(DEVIL_HANDS_LAYER)
 	var/list/hands_overlays = list()
 	var/obj/item/l_hand = get_item_for_held_index(1) //hardcoded 2-hands only, for now.
@@ -17,9 +17,9 @@
 		if(!r_state)
 			r_state = r_hand.icon_state
 
-		var/image/r_hand_image = r_hand.build_worn_icon(state = r_state, default_layer = DEVIL_HANDS_LAYER, default_icon_file = r_hand.righthand_file, isinhands = TRUE)
+		var/mutable_appearance/r_hand_overlay = r_hand.build_worn_icon(state = r_state, default_layer = DEVIL_HANDS_LAYER, default_icon_file = r_hand.righthand_file, isinhands = TRUE)
 
-		hands_overlays += r_hand_image
+		hands_overlays += r_hand_overlay
 
 		if(client && hud_used && hud_used.hud_version != HUD_STYLE_NOHUD)
 			r_hand.layer = ABOVE_HUD_LAYER
@@ -33,9 +33,9 @@
 		if(!l_state)
 			l_state = l_hand.icon_state
 
-		var/image/l_hand_image = l_hand.build_worn_icon(state = l_state, default_layer = DEVIL_HANDS_LAYER, default_icon_file = l_hand.lefthand_file, isinhands = TRUE)
+		var/mutable_appearance/l_hand_overlay = l_hand.build_worn_icon(state = l_state, default_layer = DEVIL_HANDS_LAYER, default_icon_file = l_hand.lefthand_file, isinhands = TRUE)
 
-		hands_overlays += l_hand_image
+		hands_overlays += l_hand_overlay
 
 		if(client && hud_used && hud_used.hud_version != HUD_STYLE_NOHUD)
 			l_hand.layer = ABOVE_HUD_LAYER
@@ -54,6 +54,5 @@
 
 
 /mob/living/carbon/true_devil/apply_overlay(cache_index)
-	var/image/I = devil_overlays[cache_index]
-	if(I)
-		add_overlay(I)
+	if((. = devil_overlays[cache_index]))
+		add_overlay(.)

code/game/gamemodes/nuclear/nuclearbomb.dm

@@ -37,8 +37,8 @@
 	var/previous_level = ""
 	var/obj/item/nuke_core/core = null
 	var/deconstruction_state = NUKESTATE_INTACT
-	var/image/lights = null
-	var/image/interior = null
+	var/lights = ""
+	var/interior = ""
 	var/obj/effect/countdown/nuclearbomb/countdown
 	var/static/bomb_set
 
@@ -201,30 +201,32 @@
 	cut_overlay(interior)
 	switch(deconstruction_state)
 		if(NUKESTATE_UNSCREWED)
-			interior = image(icon,"panel-unscrewed")
+			interior = "panel-unscrewed"
 		if(NUKESTATE_PANEL_REMOVED)
-			interior = image(icon,"panel-removed")
+			interior = "panel-removed"
 		if(NUKESTATE_WELDED)
-			interior = image(icon,"plate-welded")
+			interior = "plate-welded"
 		if(NUKESTATE_CORE_EXPOSED)
-			interior = image(icon,"plate-removed")
+			interior = "plate-removed"
 		if(NUKESTATE_CORE_REMOVED)
-			interior = image(icon,"core-removed")
+			interior = "core-removed"
 		if(NUKESTATE_INTACT)
-			interior = null
+			return
 	add_overlay(interior)
 
 /obj/machinery/nuclearbomb/proc/update_icon_lights()
-	cut_overlay(lights)
+	if(lights)
+		cut_overlay(lights)
 	switch(get_nuke_state())
 		if(NUKE_OFF_LOCKED)
-			lights = null
+			lights = ""
+			return
 		if(NUKE_OFF_UNLOCKED)
-			lights = image(icon,"lights-safety")
+			lights = "lights-safety"
 		if(NUKE_ON_TIMING)
-			lights = image(icon,"lights-timing")
+			lights = "lights-timing"
 		if(NUKE_ON_EXPLODING)
-			lights = image(icon,"lights-exploding")
+			lights = "lights-exploding"
 	add_overlay(lights)
 
 /obj/machinery/nuclearbomb/process()

code/game/machinery/computer/apc_control.dm

@@ -96,7 +96,6 @@
 		return
 	if(!usr || !usr.canUseTopic(src) || usr.incapacitated() || stat || QDELETED(src))
 		return
-	var/image/I = image(src) //For feedback message flavor
 	if(href_list["authenticate"])
 		var/obj/item/weapon/card/id/ID = usr.get_active_held_item()
 		if(!istype(ID))
@@ -117,24 +116,24 @@
 		authenticated = FALSE
 		auth_id = "\[NULL\]"
 	if(href_list["restore_logging"])
-		to_chat(usr, "<span class='robot notice'>\icon[I] Logging functionality restored from backup data.</span>")
+		to_chat(usr, "<span class='robot notice'>\icon[src] Logging functionality restored from backup data.</span>")
 		emagged = FALSE
 		LAZYADD(logs, "<b>-=- Logging restored to full functionality at this point -=-</b>")
 	if(href_list["access_apc"])
 		playsound(src, "terminal_type", 50, 0)
 		var/obj/machinery/power/apc/APC = locate(href_list["access_apc"]) in GLOB.apcs_list
 		if(!APC || APC.aidisabled || APC.panel_open || QDELETED(APC))
-			to_chat(usr, "<span class='robot danger'>\icon[I] APC does not return interface request. Remote access may be disabled.</span>")
+			to_chat(usr, "<span class='robot danger'>\icon[src] APC does not return interface request. Remote access may be disabled.</span>")
 			return
 		if(active_apc)
-			to_chat(usr, "<span class='robot danger'>\icon[I] Disconnected from [active_apc].</span>")
+			to_chat(usr, "<span class='robot danger'>\icon[src] Disconnected from [active_apc].</span>")
 			active_apc.say("Remote access canceled. Interface locked.")
 			playsound(active_apc, 'sound/machines/BoltsDown.ogg', 25, 0)
 			playsound(active_apc, 'sound/machines/terminal_alert.ogg', 50, 0)
 			active_apc.locked = TRUE
 			active_apc.update_icon()
 			active_apc = null
-		to_chat(usr, "<span class='robot notice'>\icon[I] Connected to APC in [get_area(APC)]. Interface request sent.</span>")
+		to_chat(usr, "<span class='robot notice'>\icon[src] Connected to APC in [get_area(APC)]. Interface request sent.</span>")
 		log_activity("remotely accessed APC in [get_area(APC)]")
 		APC.interact(usr, GLOB.not_incapacitated_state)
 		playsound(src, 'sound/machines/terminal_prompt_confirm.ogg', 50, 0)

code/game/machinery/computer/message.dm

@@ -419,7 +419,7 @@
 									to_chat(H, "\icon[customrecepient] <b>Message from [customsender] ([customjob]), </b>\"[custommessage]\" (<a href='byond://?src=\ref[src];choice=Message;skiprefresh=1;target=\ref[src]'>Reply</a>)")
 								log_pda("[usr]/([usr.ckey]) (PDA: [customsender]) sent \"[custommessage]\" to [customrecepient.owner]")
 								customrecepient.cut_overlays()
-								customrecepient.add_overlay(image('icons/obj/pda.dmi', "pda-r"))
+								customrecepient.add_overlay(mutable_appearance('icons/obj/pda.dmi', "pda-r"))
 						//Sender is faking as someone who exists
 						else
 							src.linkedServer.send_pda_message("[customrecepient.owner]", "[PDARec.owner]","[custommessage]")
@@ -432,7 +432,7 @@
 									to_chat(H, "\icon[customrecepient] <b>Message from [PDARec.owner] ([customjob]), </b>\"[custommessage]\" (<a href='byond://?src=\ref[customrecepient];choice=Message;skiprefresh=1;target=\ref[PDARec]'>Reply</a>)")
 								log_pda("[usr]/([usr.ckey]) (PDA: [PDARec.owner]) sent \"[custommessage]\" to [customrecepient.owner]")
 								customrecepient.cut_overlays()
-								customrecepient.add_overlay(image('icons/obj/pda.dmi', "pda-r"))
+								customrecepient.add_overlay(mutable_appearance('icons/obj/pda.dmi', "pda-r"))
 						//Finally..
 						ResetMessage()
 

code/game/machinery/doors/airlock.dm

@@ -366,13 +366,13 @@
 	set_airlock_overlays(state)
 
 /obj/machinery/door/airlock/proc/set_airlock_overlays(state)
-	var/image/frame_overlay
-	var/image/filling_overlay
-	var/image/lights_overlay
-	var/image/panel_overlay
-	var/image/weld_overlay
-	var/image/damag_overlay
-	var/image/sparks_overlay
+	var/mutable_appearance/frame_overlay
+	var/mutable_appearance/filling_overlay
+	var/mutable_appearance/lights_overlay
+	var/mutable_appearance/panel_overlay
+	var/mutable_appearance/weld_overlay
+	var/mutable_appearance/damag_overlay
+	var/mutable_appearance/sparks_overlay
 
 	switch(state)
 		if(AIRLOCK_CLOSED)
@@ -494,10 +494,8 @@
 	pass(A)	//suppress unused warning
 	var/list/airlock_overlays = A.airlock_overlays
 	var/iconkey = "[icon_state][icon_file]"
-	if(airlock_overlays[iconkey])
-		return airlock_overlays[iconkey]
-	airlock_overlays[iconkey] = image(icon_file, icon_state)
-	return airlock_overlays[iconkey]
+	if((!(. = airlock_overlays[iconkey])))
+		. = airlock_overlays[iconkey] = mutable_appearance(icon_file, icon_state)
 
 /obj/machinery/door/airlock/do_animate(animation)
 	switch(animation)

code/game/machinery/doors/brigdoors.dm

@@ -184,7 +184,7 @@
 	if(maptext)
 		maptext = ""
 	cut_overlays()
-	add_overlay(image('icons/obj/status_display.dmi', icon_state=state))
+	add_overlay(mutable_appearance('icons/obj/status_display.dmi', state))
 
 
 //Checks to see if there's 1 line or 2, adds text-icons-numbers/letters over display

code/game/machinery/iv_drip.dm

@@ -36,27 +36,27 @@
 		else
 			add_overlay("beakeridle")
 		if(beaker.reagents.total_volume)
-			var/image/filling = image('icons/obj/iv_drip.dmi', src, "reagent")
+			var/mutable_appearance/filling_overlay = mutable_appearance('icons/obj/iv_drip.dmi', "reagent")
 
 			var/percent = round((beaker.reagents.total_volume / beaker.volume) * 100)
 			switch(percent)
 				if(0 to 9)
-					filling.icon_state = "reagent0"
+					filling_overlay.icon_state = "reagent0"
 				if(10 to 24)
-					filling.icon_state = "reagent10"
+					filling_overlay.icon_state = "reagent10"
 				if(25 to 49)
-					filling.icon_state = "reagent25"
+					filling_overlay.icon_state = "reagent25"
 				if(50 to 74)
-					filling.icon_state = "reagent50"
+					filling_overlay.icon_state = "reagent50"
 				if(75 to 79)
-					filling.icon_state = "reagent75"
+					filling_overlay.icon_state = "reagent75"
 				if(80 to 90)
-					filling.icon_state = "reagent80"
+					filling_overlay.icon_state = "reagent80"
 				if(91 to INFINITY)
-					filling.icon_state = "reagent100"
+					filling_overlay.icon_state = "reagent100"
 
-			filling.icon += mix_color_from_reagents(beaker.reagents.reagent_list)
-			add_overlay(filling)
+			filling_overlay.color = list("#0000", "#0000", "#0000", "#000f", mix_color_from_reagents(beaker.reagents.reagent_list))
+			add_overlay(filling_overlay)
 
 /obj/machinery/iv_drip/MouseDrop(mob/living/target)
 	if(!ishuman(usr) || !usr.canUseTopic(src,BE_CLOSE) || !isliving(target))

code/game/machinery/status_display.dm

@@ -146,7 +146,7 @@
 /obj/machinery/status_display/proc/set_picture(state)
 	picture_state = state
 	remove_display()
-	add_overlay(image('icons/obj/status_display.dmi', icon_state=picture_state))
+	add_overlay(picture_state)
 
 /obj/machinery/status_display/proc/update_display(line1, line2)
 	var/new_text = {"<div style="font-size:[FONT_SIZE];color:[FONT_COLOR];font:'[FONT_STYLE]';text-align:center;" valign="top">[line1]<br>[line2]</div>"}
@@ -278,7 +278,7 @@
 /obj/machinery/ai_status_display/proc/set_picture(state)
 	picture_state = state
 	cut_overlays()
-	add_overlay(image('icons/obj/status_display.dmi', icon_state=picture_state))
+	add_overlay(picture_state)
 
 #undef CHARS_PER_LINE
 #undef FOND_SIZE

code/game/machinery/vending.dm

@@ -297,7 +297,7 @@
 			to_chat(user, "<span class='notice'>You [panel_open ? "open" : "close"] the maintenance panel.</span>")
 			cut_overlays()
 			if(panel_open)
-				add_overlay(image(icon, "[initial(icon_state)]-panel"))
+				add_overlay("[initial(icon_state)]-panel")
 			playsound(src.loc, W.usesound, 50, 1)
 			updateUsrDialog()
 		else

code/game/machinery/washing_machine.dm

@@ -186,7 +186,7 @@
 		var/full = contents.len ? 1 : 0
 		icon_state = "wm_[state_open]_[full]"
 	if(panel_open)
-		add_overlay(image(icon, icon_state = "wm_panel"))
+		add_overlay("wm_panel")
 
 /obj/machinery/washing_machine/attackby(obj/item/weapon/W, mob/user, params)
 	if(default_deconstruction_screwdriver(user, null, null, W))

code/game/mecha/mecha_wreckage.dm

@@ -23,7 +23,7 @@
 		AI.apply_damage(150, BURN) //Give the AI a bit of damage from the "shock" of being suddenly shut down
 		AI.death() //The damage is not enough to kill the AI, but to be 'corrupted files' in need of repair.
 		AI.forceMove(src) //Put the dead AI inside the wreckage for recovery
-		add_overlay(image('icons/obj/projectiles.dmi', icon_state = "green_laser")) //Overlay for the recovery beacon
+		add_overlay(mutable_appearance('icons/obj/projectiles.dmi', "green_laser")) //Overlay for the recovery beacon
 		AI.controlled_mech = null
 		AI.remote_control = null
 

code/game/mecha/working/ripley.dm

@@ -48,9 +48,9 @@
 	if (hides)
 		cut_overlays()
 		if(hides < 3)
-			add_overlay(image("icon" = "mecha.dmi", "icon_state" = occupant ? "ripley-g" : "ripley-g-open"))
+			add_overlay(occupant ? "ripley-g" : "ripley-g-open")
 		else
-			add_overlay(image("icon" = "mecha.dmi", "icon_state" = occupant ? "ripley-g-full" : "ripley-g-full-open"))
+			add_overlay(occupant ? "ripley-g-full" : "ripley-g-full-open")
 
 
 /obj/mecha/working/ripley/firefighter

code/game/objects/effects/decals/cleanable/humans.dm

@@ -161,23 +161,15 @@
 
 	for(var/Ddir in GLOB.cardinal)
 		if(entered_dirs & Ddir)
-			var/image/I
-			if(GLOB.bloody_footprints_cache["entered-[blood_state]-[Ddir]"])
-				I = GLOB.bloody_footprints_cache["entered-[blood_state]-[Ddir]"]
-			else
-				I =  image(icon,"[blood_state]1",dir = Ddir)
-				GLOB.bloody_footprints_cache["entered-[blood_state]-[Ddir]"] = I
-			if(I)
-				add_overlay(I)
+			var/image/bloodstep_overlay = GLOB.bloody_footprints_cache["entered-[blood_state]-[Ddir]"]
+			if(!bloodstep_overlay)
+				GLOB.bloody_footprints_cache["entered-[blood_state]-[Ddir]"] = bloodstep_overlay = image(icon, "[blood_state]1", dir = Ddir)
+			add_overlay(bloodstep_overlay)
 		if(exited_dirs & Ddir)
-			var/image/I
-			if(GLOB.bloody_footprints_cache["exited-[blood_state]-[Ddir]"])
-				I = GLOB.bloody_footprints_cache["exited-[blood_state]-[Ddir]"]
-			else
-				I = image(icon,"[blood_state]2",dir = Ddir)
-				GLOB.bloody_footprints_cache["exited-[blood_state]-[Ddir]"] = I
-			if(I)
-				add_overlay(I)
+			var/image/bloodstep_overlay = GLOB.bloody_footprints_cache["exited-[blood_state]-[Ddir]"]
+			if(!bloodstep_overlay)
+				GLOB.bloody_footprints_cache["exited-[blood_state]-[Ddir]"] = bloodstep_overlay = image(icon, "[blood_state]2", dir = Ddir)
+			add_overlay(bloodstep_overlay)
 
 	alpha = BLOODY_FOOTPRINT_BASE_ALPHA+bloodiness
 

code/game/objects/items.dm

@@ -1,4 +1,4 @@
-GLOBAL_DATUM_INIT(fire_overlay, /image, image("icon" = 'icons/effects/fire.dmi', "icon_state" = "fire"))
+GLOBAL_DATUM_INIT(fire_overlay, /mutable_appearance, mutable_appearance('icons/effects/fire.dmi', "fire"))
 
 GLOBAL_VAR_INIT(rpg_loot_items, FALSE)
 // if true, everyone item when created will have its name changed to be

code/game/objects/items/crayons.dm

@@ -521,7 +521,7 @@
 /obj/item/weapon/storage/crayons/update_icon()
 	cut_overlays()
 	for(var/obj/item/toy/crayon/crayon in contents)
-		add_overlay(image('icons/obj/crayons.dmi',crayon.item_color))
+		add_overlay(mutable_appearance('icons/obj/crayons.dmi', crayon.item_color))
 
 /obj/item/weapon/storage/crayons/attackby(obj/item/W, mob/user, params)
 	if(istype(W, /obj/item/toy/crayon))
@@ -667,10 +667,9 @@
 	icon_state = is_capped ? icon_capped : icon_uncapped
 	if(use_overlays)
 		cut_overlays()
-		var/image/I = image('icons/obj/crayons.dmi',
-			icon_state = "[is_capped ? "spraycan_cap_colors" : "spraycan_colors"]")
-		I.color = paint_color
-		add_overlay(I)
+		var/mutable_appearance/spray_overlay = mutable_appearance('icons/obj/crayons.dmi', "[is_capped ? "spraycan_cap_colors" : "spraycan_colors"]")
+		spray_overlay.color = paint_color
+		add_overlay(spray_overlay)
 
 /obj/item/toy/crayon/spraycan/gang
 	//desc = "A modified container containing suspicious paint."

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

@@ -51,7 +51,7 @@ GLOBAL_LIST_EMPTY(PDAs)
 
 	var/obj/item/device/paicard/pai = null	// A slot for a personal AI device
 
-	var/image/photo = null //Scanned photo
+	var/icon/photo //Scanned photo
 
 	var/list/contained_item = list(/obj/item/weapon/pen, /obj/item/toy/crayon, /obj/item/weapon/lipstick, /obj/item/device/flashlight/pen, /obj/item/clothing/mask/cigarette)
 	var/obj/item/inserted_item //Used for pen, crayon, and lipstick insertion or removal. Same as above.
@@ -82,22 +82,24 @@ GLOBAL_LIST_EMPTY(PDAs)
 
 /obj/item/device/pda/update_icon()
 	cut_overlays()
+	var/mutable_appearance/overlay = new()
+	overlay.pixel_x = overlays_x_offset
 	if(id)
-		var/image/I = image(icon_state = "id_overlay", pixel_x = overlays_x_offset)
-		add_overlay(I)
+		overlay.icon_state = "id_overlay"
+		add_overlay(new /mutable_appearance(overlay))
 	if(inserted_item)
-		var/image/I = image(icon_state = "insert_overlay", pixel_x = overlays_x_offset)
-		add_overlay(I)
+		overlay.icon_state = "insert_overlay"
+		add_overlay(new /mutable_appearance(overlay))
 	if(fon)
-		var/image/I = image(icon_state = "light_overlay", pixel_x = overlays_x_offset)
-		add_overlay(I)
+		overlay.icon_state = "light_overlay"
+		add_overlay(new /mutable_appearance(overlay))
 	if(pai)
 		if(pai.pai)
-			var/image/I = image(icon_state = "pai_overlay", pixel_x = overlays_x_offset)
-			add_overlay(I)
+			overlay.icon_state = "pai_overlay"
+			add_overlay(new /mutable_appearance(overlay))
 		else
-			var/image/I = image(icon_state = "pai_off_overlay", pixel_x = overlays_x_offset)
-			add_overlay(I)
+			overlay.icon_state = "pai_off_overlay"
+			add_overlay(new /mutable_appearance(overlay))
 
 /obj/item/device/pda/MouseDrop(obj/over_object, src_location, over_location)
 	var/mob/M = usr
@@ -633,7 +635,7 @@ GLOBAL_LIST_EMPTY(PDAs)
 		to_chat(L, "\icon[src] <b>Message from [source.owner] ([source.ownjob]), </b>\"[msg.message]\"[msg.get_photo_ref()] (<a href='byond://?src=\ref[src];choice=Message;skiprefresh=1;target=\ref[source]'>Reply</a>)")
 
 	update_icon()
-	add_overlay(image(icon, icon_alert))
+	add_overlay(icon_alert)
 
 /obj/item/device/pda/proc/show_to_ghosts(mob/living/user, datum/data_pda_msg/msg,multiple = 0)
 	for(var/mob/M in GLOB.player_list)

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

@@ -23,6 +23,7 @@
 	update_icon() //Whatever happened, update the card's state (icon, name) to match.
 
 /obj/item/device/aicard/update_icon()
+	cut_overlays()
 	if(AI)
 		name = "[initial(name)]- [AI.name]"
 		if(AI.stat == DEAD)
@@ -30,12 +31,11 @@
 		else
 			icon_state = "aicard-full"
 		if(!AI.control_disabled)
-			add_overlay(image('icons/obj/aicards.dmi', "aicard-on"))
+			add_overlay("aicard-on")
 		AI.cancel_camera()
 	else
 		name = initial(name)
 		icon_state = initial(icon_state)
-		cut_overlays()
 
 /obj/item/device/aicard/ui_interact(mob/user, ui_key = "main", datum/tgui/ui = null, force_open = 0, \
 									datum/tgui/master_ui = null, datum/ui_state/state = GLOB.hands_state)

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

@@ -344,8 +344,9 @@
 		cut_overlays()
 		set_light(0)
 	else if(on)
-		var/image/I = image(icon,"glowstick-glow",color)
-		add_overlay(I)
+		var/mutable_appearance/glowstick_overlay = mutable_appearance(icon, "glowstick-glow")
+		glowstick_overlay.color = color
+		add_overlay(glowstick_overlay)
 		item_state = "glowstick-on"
 		set_light(brightness_on)
 	else

code/game/objects/items/robot/robot_items.dm

@@ -493,7 +493,7 @@
 /obj/item/projectile/bullet/reusable/lollipop/New()
 	var/obj/item/weapon/reagent_containers/food/snacks/lollipop/S = new ammo_type(src)
 	color2 = S.headcolor
-	var/image/head = image(icon = 'icons/obj/projectiles.dmi', icon_state = "lollipop_2")
+	var/mutable_appearance/head = mutable_appearance('icons/obj/projectiles.dmi', "lollipop_2")
 	head.color = color2
 	add_overlay(head)
 

code/game/objects/items/shooting_range.dm

@@ -73,18 +73,18 @@
 		if(hp <= 0)
 			visible_message("<span class='danger'>[src] breaks into tiny pieces and collapses!</span>")
 			qdel(src)
-		var/image/I = image("icon"='icons/effects/effects.dmi', "icon_state"="scorch", "layer"=OBJ_LAYER+0.5)
-		I.pixel_x = p_x - 1 //offset correction
-		I.pixel_y = p_y - 1
+		var/image/bullet_hole = image('icons/effects/effects.dmi', "scorch", OBJ_LAYER + 0.5)
+		bullet_hole.pixel_x = p_x - 1 //offset correction
+		bullet_hole.pixel_y = p_y - 1
 		if(decaltype == DECALTYPE_SCORCH)
-			I.setDir(pick(NORTH,SOUTH,EAST,WEST))// random scorch design
+			bullet_hole.setDir(pick(NORTH,SOUTH,EAST,WEST))// random scorch design
 			if(P.damage >= 20 || istype(P, /obj/item/projectile/beam/practice))
-				I.setDir(pick(NORTH,SOUTH,EAST,WEST))
+				bullet_hole.setDir(pick(NORTH,SOUTH,EAST,WEST))
 			else
-				I.icon_state = "light_scorch"
+				bullet_hole.icon_state = "light_scorch"
 		else
-			I.icon_state = "dent"
-		add_overlay(I)
+			bullet_hole.icon_state = "dent"
+		add_overlay(bullet_hole)
 		return
 	return -1
 

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

@@ -155,7 +155,7 @@
 	var/mob/living/captured = null
 	var/obj/item/weapon/gun/energy/chrono_gun/gun = null
 	var/tickstokill = 15
-	var/image/mob_underlay = null
+	var/mutable_appearance/mob_underlay
 	var/preloaded = 0
 	var/RPpos = null
 
@@ -172,7 +172,7 @@
 			mob_icon.Blend(removing_frame, ICON_MULTIPLY)
 			cached_icon.Insert(mob_icon, "frame[i]")
 
-		mob_underlay = new(cached_icon, "frame1")
+		mob_underlay = mutable_appearance(cached_icon, "frame1")
 		update_icon()
 
 		desc = initial(desc) + "<br><span class='info'>It appears to contain [target.name].</span>"

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

@@ -496,11 +496,11 @@ CIGARETTE PACKETS ARE IN FANCY.DM
 
 /obj/item/weapon/lighter/greyscale/update_icon()
 	cut_overlays()
-	var/image/I = image(icon,"[initial(icon_state)]_base")
-	I.appearance_flags = RESET_COLOR //the edging doesn't change color
+	var/mutable_appearance/base_overlay = mutable_appearance(icon,"[initial(icon_state)]_base")
+	base_overlay.appearance_flags = RESET_COLOR //the edging doesn't change color
 	if(lit)
-		I.icon_state = "[initial(icon_state)]_on"
-	add_overlay(I)
+		base_overlay.icon_state = "[initial(icon_state)]_on"
+	add_overlay(base_overlay)
 
 /obj/item/weapon/lighter/greyscale/ignition_effect(atom/A, mob/user)
 	. = "<span class='notice'>After some fiddling, [user] manages to light [A] with [src].</span>"
@@ -651,9 +651,9 @@ CIGARETTE PACKETS ARE IN FANCY.DM
 			screw = 1
 			to_chat(user, "<span class='notice'>You open the cap on the [src]</span>")
 			if(super)
-				add_overlay(image(icon, "vapeopen_med"))
+				add_overlay("vapeopen_med")
 			else
-				add_overlay(image(icon, "vapeopen_low"))
+				add_overlay("vapeopen_low")
 		else
 			screw = 0
 			to_chat(user, "<span class='notice'>You close the cap on the [src]</span>")
@@ -665,12 +665,12 @@ CIGARETTE PACKETS ARE IN FANCY.DM
 				cut_overlays()
 				super = 1
 				to_chat(user, "<span class='notice'>You increase the voltage in the [src]</span>")
-				add_overlay(image(icon, "vapeopen_med"))
+				add_overlay("vapeopen_med")
 			else
 				cut_overlays()
 				super = 0
 				to_chat(user, "<span class='notice'>You decrease the voltage in the [src]</span>")
-				add_overlay(image(icon, "vapeopen_low"))
+				add_overlay("vapeopen_low")
 
 		if(screw && emagged)
 			to_chat(user, "<span class='notice'>The [name] can't be modified!</span>")
@@ -683,7 +683,7 @@ CIGARETTE PACKETS ARE IN FANCY.DM
 			emagged = 1
 			super = 0
 			to_chat(user, "<span class='warning'>You maximize the voltage in the [src]</span>")
-			add_overlay(image(icon, "vapeopen_high"))
+			add_overlay("vapeopen_high")
 			var/datum/effect_system/spark_spread/sp = new /datum/effect_system/spark_spread //for effect
 			sp.set_up(5, 1, src)
 			sp.start()

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

@@ -38,10 +38,10 @@
 	to_chat(user, "<span class='notice'>You twist \the [src] [open ? "closed" : "open"].</span>")
 	open = !open
 	if(open)
-		var/image/colored = image("icon"='icons/obj/items.dmi', "icon_state"="lipstick_uncap_color")
-		colored.color = colour
+		var/mutable_appearance/colored_overlay = mutable_appearance(icon, "lipstick_uncap_color")
+		colored_overlay.color = colour
 		icon_state = "lipstick_uncap"
-		add_overlay(colored)
+		add_overlay(colored_overlay)
 	else
 		icon_state = "lipstick"
 

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

@@ -16,7 +16,7 @@
 
 /obj/item/weapon/c4/New()
 	wires = new /datum/wires/explosive/c4(src)
-	image_overlay = image('icons/obj/grenade.dmi', "plastic-explosive2")
+	plastic_overlay = mutable_appearance(icon, "plastic-explosive2")
 	..()
 
 /obj/item/weapon/c4/Destroy()
@@ -92,7 +92,7 @@
 		message_admins(message,0,1)
 		log_game("[key_name(user)] planted [name] on [target.name] at [COORD(target)] with [timer] second fuse")
 
-		target.add_overlay(image_overlay, 1)
+		target.add_overlay(plastic_overlay, 1)
 		to_chat(user, "<span class='notice'>You plant the bomb. Timer counting down from [timer].</span>")
 		addtimer(CALLBACK(src, .proc/explode), timer * 10)
 
@@ -103,7 +103,7 @@
 	if(target)
 		if(!QDELETED(target))
 			location = get_turf(target)
-			target.cut_overlay(image_overlay, TRUE)
+			target.cut_overlay(plastic_overlay, TRUE)
 	else
 		location = get_turf(src)
 	if(location)

code/game/objects/items/weapons/grenades/ghettobomb.dm

@@ -19,8 +19,8 @@
 
 /obj/item/weapon/grenade/iedcasing/New(loc)
 	..()
-	add_overlay(image('icons/obj/grenade.dmi', icon_state = "improvised_grenade_filled"))
-	add_overlay(image('icons/obj/grenade.dmi', icon_state = "improvised_grenade_wired"))
+	add_overlay("improvised_grenade_filled")
+	add_overlay("improvised_grenade_wired")
 	times = list("5" = 10, "-1" = 20, "[rand(30,80)]" = 50, "[rand(65,180)]" = 20)// "Premature, Dud, Short Fuse, Long Fuse"=[weighting value]
 	det_time = text2num(pickweight(times))
 	if(det_time < 0) //checking for 'duds'
@@ -33,13 +33,10 @@
 	..()
 	var/obj/item/weapon/reagent_containers/food/drinks/soda_cans/can = locate() in contents
 	if(can)
-		var/muh_layer = can.layer
-		var/muh_plane = can.plane
-		can.layer = FLOAT_LAYER
-		can.plane = FLOAT_PLANE
-		underlays += can
-		can.layer = muh_layer
-		can.plane = muh_plane
+		var/mutable_appearance/can_underlay = new(can)
+		can_underlay.layer = FLOAT_LAYER
+		can_underlay.plane = FLOAT_PLANE
+		underlays += can_underlay
 
 
 /obj/item/weapon/grenade/iedcasing/attack_self(mob/user) //
@@ -47,7 +44,7 @@
 		if(clown_check(user))
 			to_chat(user, "<span class='warning'>You light the [name]!</span>")
 			active = 1
-			cut_overlay(image('icons/obj/grenade.dmi', icon_state = "improvised_grenade_filled"), TRUE)	//this line make no sense
+			cut_overlay("improvised_grenade_filled")
 			icon_state = initial(icon_state) + "_active"
 			add_fingerprint(user)
 			var/turf/bombturf = get_turf(src)

code/game/objects/items/weapons/grenades/plastic.dm

@@ -7,7 +7,7 @@
 	det_time = 10
 	display_timer = 0
 	var/atom/target = null
-	var/image_overlay = null
+	var/mutable_appearance/plastic_overlay
 	var/obj/item/device/assembly_holder/nadeassembly = null
 	var/assemblyattacher
 	var/directional = FALSE
@@ -15,7 +15,7 @@
 	var/boom_sizes = list(0, 0, 3)
 
 /obj/item/weapon/grenade/plastic/New()
-	image_overlay = image('icons/obj/grenade.dmi', "[item_state]2")
+	plastic_overlay = mutable_appearance(icon, "[item_state]2")
 	..()
 
 /obj/item/weapon/grenade/plastic/Destroy()
@@ -50,7 +50,7 @@
 	if(target)
 		if(!QDELETED(target))
 			location = get_turf(target)
-			target.cut_overlay(image_overlay, TRUE)
+			target.cut_overlay(plastic_overlay, TRUE)
 	else
 		location = get_turf(src)
 	if(location)
@@ -111,7 +111,7 @@
 		message_admins("[ADMIN_LOOKUPFLW(user)] planted [name] on [target.name] at [ADMIN_COORDJMP(target)] with [det_time] second fuse",0,1)
 		log_game("[key_name(user)] planted [name] on [target.name] at [COORD(src)] with [det_time] second fuse")
 
-		target.add_overlay(image_overlay, 1)
+		target.add_overlay(plastic_overlay, 1)
 		if(!nadeassembly)
 			to_chat(user, "<span class='notice'>You plant the bomb. Timer counting down from [det_time].</span>")
 			addtimer(CALLBACK(src, .proc/prime), det_time*10)

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

@@ -71,7 +71,7 @@
 /obj/item/weapon/nullrod/staff/worn_overlays(isinhands)
 	. = list()
 	if(isinhands)
-		. += image(layer = MOB_LAYER+0.01, icon = 'icons/effects/effects.dmi', icon_state = "[shield_icon]")
+		. += mutable_appearance('icons/effects/effects.dmi', shield_icon, MOB_LAYER + 0.01)
 
 /obj/item/weapon/nullrod/staff/blue
 	name = "blue holy staff"

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

@@ -162,5 +162,5 @@
 	src.cut_overlays()
 	if(!tank)
 		return
-	src.add_overlay(image('icons/obj/pneumaticCannon.dmi', "[tank.icon_state]"))
+	add_overlay(tank.icon_state)
 	src.update_icon()

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

@@ -334,14 +334,14 @@
 /obj/item/weapon/storage/bag/tray/proc/rebuild_overlays()
 	cut_overlays()
 	for(var/obj/item/I in contents)
-		add_overlay(image("icon" = I.icon, "icon_state" = I.icon_state, "layer" = -1))
+		add_overlay(mutable_appearance(I.icon, I.icon_state))
 
 /obj/item/weapon/storage/bag/tray/remove_from_storage(obj/item/W as obj, atom/new_location)
 	..()
 	rebuild_overlays()
 
 /obj/item/weapon/storage/bag/tray/handle_item_insertion(obj/item/I, prevent_warning = 0)
-	add_overlay(image("icon" = I.icon, "icon_state" = I.icon_state, "layer" = -1))
+	add_overlay(mutable_appearance(I.icon, I.icon_state))
 	. = ..()
 
 

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

@@ -38,7 +38,7 @@
 	. = ..()
 	if(illustration)
 		cut_overlays()
-		add_overlay(image('icons/obj/storage.dmi', "[illustration]"))
+		add_overlay(illustration)
 
 /obj/item/weapon/storage/box/attack_self(mob/user)
 	..()

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

@@ -141,12 +141,15 @@
 			add_overlay("[icon_state]_open")
 			var/i = contents.len
 			for(var/C in contents)
+				var/mutable_appearance/inserted_overlay = mutable_appearance(icon)
+				inserted_overlay.pixel_x = 1 * (i - 1)
 				if(istype(C, /obj/item/weapon/lighter/greyscale))
-					add_overlay(image(icon = src.icon, icon_state = "lighter_in", pixel_x = 1 * (i -1)))
+					inserted_overlay.icon_state = "lighter_in"
 				else if(istype(C, /obj/item/weapon/lighter))
-					add_overlay(image(icon = src.icon, icon_state = "zippo_in", pixel_x = 1 * (i -1)))
+					inserted_overlay.icon_state = "zippo_in"
 				else
-					add_overlay(image(icon = src.icon, icon_state = "cigarette", pixel_x = 1 * (i -1)))
+					inserted_overlay.icon_state = "cigarette"
+				add_overlay(inserted_overlay)
 				i--
 	else
 		cut_overlays()
@@ -247,13 +250,14 @@
 	spawn_type = /obj/item/clothing/mask/cigarette/cigar
 
 /obj/item/weapon/storage/fancy/cigarettes/cigars/update_icon()
+	cut_overlays()
 	if(fancy_open)
-		cut_overlays()
 		add_overlay("[icon_state]_open")
+		var/mutable_appearance/cigar_overlay = mutable_appearance(icon, icon_type)
 		for(var/c = contents.len, c >= 1, c--)
-			add_overlay(image(icon = src.icon, icon_state = icon_type, pixel_x = 4 * (c -1)))
+			cigar_overlay.pixel_x = 4 * (c - 1)
+			add_overlay(cigar_overlay)
 	else
-		cut_overlays()
 		icon_state = "cigarcase"
 
 /obj/item/weapon/storage/fancy/cigarettes/cigars/cohiba

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

@@ -94,7 +94,7 @@
 			else if ((src.code == src.l_code) && (src.l_set == 1))
 				src.locked = 0
 				cut_overlays()
-				add_overlay(image('icons/obj/storage.dmi', icon_opened))
+				add_overlay(icon_opened)
 				src.code = null
 			else
 				src.code = "ERROR"

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

@@ -29,7 +29,7 @@
 	..()
 	cut_overlays()
 	if(has_latches)
-		add_overlay(image('icons/obj/storage.dmi', "[latches]"))
+		add_overlay(latches)
 
 
 /obj/item/weapon/storage/toolbox/suicide_act(mob/user)

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

@@ -370,7 +370,7 @@
 	cut_overlays()
 
 	if(reagents.total_volume)
-		var/image/filling = image('icons/obj/reagentfillings.dmi',icon_state = "backpack-10")
+		var/mutable_appearance/filling = mutable_appearance('icons/obj/reagentfillings.dmi', "backpack-10")
 
 		var/percent = round((reagents.total_volume / volume) * 100)
 		switch(percent)
@@ -388,7 +388,7 @@
 	. = list()
 	//inhands + reagent_filling
 	if(!isinhands && reagents.total_volume)
-		var/image/filling = image('icons/obj/reagentfillings.dmi',icon_state = "backpackmob-10")
+		var/mutable_appearance/filling = mutable_appearance('icons/obj/reagentfillings.dmi', "backpackmob-10")
 
 		var/percent = round((reagents.total_volume / volume) * 100)
 		switch(percent)

code/game/objects/obj_defense.dm

@@ -148,7 +148,7 @@
 
 ///// ACID
 
-GLOBAL_DATUM_INIT(acid_overlay, /image, image("icon" = 'icons/effects/effects.dmi', "icon_state" = "acid"))
+GLOBAL_DATUM_INIT(acid_overlay, /mutable_appearance, mutable_appearance('icons/effects/effects.dmi', "acid"))
 
 //the obj's reaction when touched by acid
 /obj/acid_act(acidpwr, acid_volume)

code/game/objects/structures/beds_chairs/alien_nest.dm

@@ -12,11 +12,7 @@
 	canSmoothWith = null
 	buildstacktype = null
 	flags = NODECONSTRUCT
-	var/image/nest_overlay
-
-/obj/structure/bed/nest/New()
-	nest_overlay = image('icons/mob/alien.dmi', "nestoverlay", layer=LYING_MOB_LAYER)
-	return ..()
+	var/static/mutable_appearance/nest_overlay = mutable_appearance('icons/mob/alien.dmi', "nestoverlay", LYING_MOB_LAYER)
 
 /obj/structure/bed/nest/user_unbuckle_mob(mob/living/buckled_mob, mob/living/user)
 	if(has_buckled_mobs())

code/game/objects/structures/beds_chairs/chair.dm

@@ -145,11 +145,11 @@
 	obj_integrity = 70
 	max_integrity = 70
 	buildstackamount = 2
-	var/image/armrest = null
+	var/mutable_appearance/armrest
 	item_chair = null
 
 /obj/structure/chair/comfy/Initialize()
-	armrest = image("icons/obj/chairs.dmi", "comfychair_armrest")
+	armrest = mutable_appearance('icons/obj/chairs.dmi', "comfychair_armrest")
 	armrest.layer = ABOVE_MOB_LAYER
 	return ..()
 

code/game/objects/structures/electricchair.dm

@@ -8,7 +8,7 @@
 
 /obj/structure/chair/e_chair/New()
 	..()
-	add_overlay(image('icons/obj/chairs.dmi', src, "echair_over", MOB_LAYER + 1))
+	add_overlay(mutable_appearance('icons/obj/chairs.dmi', "echair_over", MOB_LAYER + 1))
 
 /obj/structure/chair/e_chair/attackby(obj/item/weapon/W, mob/user, params)
 	if(istype(W, /obj/item/weapon/wrench))

code/game/objects/structures/guncase.dm

@@ -7,7 +7,7 @@
 	anchored = 0
 	density = 1
 	opacity = 0
-	var/case_type = null
+	var/case_type = ""
 	var/gun_category = /obj/item/weapon/gun
 	var/open = 1
 	var/capacity = 4
@@ -25,8 +25,10 @@
 /obj/structure/guncase/update_icon()
 	cut_overlays()
 	if(case_type && LAZYLEN(contents))
+		var/mutable_appearance/gun_overlay = mutable_appearance(icon, case_type)
 		for(var/i in 1 to contents.len)
-			add_overlay(image(icon = src.icon, icon_state = "[case_type]", pixel_x = 3 * (i - 1) ))
+			gun_overlay.pixel_x = 3 * (i - 1)
+			add_overlay(gun_overlay)
 	if(open)
 		add_overlay("[icon_state]_open")
 	else

code/game/objects/structures/transit_tubes/transit_tube.dm

@@ -143,21 +143,21 @@
 
 
 /obj/structure/transit_tube/proc/create_tube_overlay(direction, shift_dir)
-	var/image/I
+	var/image/tube_overlay = new(dir = direction)
 	if(shift_dir)
-		I = image(loc = src, icon_state = "decorative_diag", dir = direction)
+		tube_overlay.icon_state = "decorative_diag"
 		switch(shift_dir)
 			if(NORTH)
-				I.pixel_y = 32
+				tube_overlay.pixel_y = 32
 			if(SOUTH)
-				I.pixel_y = -32
+				tube_overlay.pixel_y = -32
 			if(EAST)
-				I.pixel_x = 32
+				tube_overlay.pixel_x = 32
 			if(WEST)
-				I.pixel_x = -32
+				tube_overlay.pixel_x = -32
 	else
-		I = image(loc = src, icon_state = "decorative", dir = direction)
-	add_overlay(I)
+		tube_overlay.icon_state = "decorative"
+	add_overlay(tube_overlay)
 
 
 

code/game/objects/structures/watercloset.dm

@@ -239,7 +239,7 @@
 		qdel(mymist)
 
 	if(on)
-		add_overlay(image('icons/obj/watercloset.dmi', src, "water", MOB_LAYER + 1, dir))
+		add_overlay(mutable_appearance('icons/obj/watercloset.dmi', "water", MOB_LAYER + 1))
 		if(watertemp == "freezing")
 			return
 		if(!ismist)

code/game/objects/structures/window.dm

@@ -18,7 +18,7 @@
 	var/fulltile = 0
 	var/glass_type = /obj/item/stack/sheet/glass
 	var/glass_amount = 1
-	var/image/crack_overlay
+	var/static/mutable_appearance/crack_overlay = mutable_appearance('icons/obj/structures.dmi')
 	var/list/debris = list()
 	can_be_unanchored = 1
 	resistance_flags = ACID_PROOF
@@ -377,10 +377,10 @@
 		if(smooth)
 			queue_smooth(src)
 
-		cut_overlay(crack_overlay)
+		cut_overlays()
 		if(ratio > 75)
 			return
-		crack_overlay = image('icons/obj/structures.dmi',"damage[ratio]",-(layer+0.1))
+		crack_overlay.icon_state = "damage[ratio]"
 		add_overlay(crack_overlay)
 
 /obj/structure/window/temperature_expose(datum/gas_mixture/air, exposed_temperature, exposed_volume)

code/game/turfs/closed.dm

@@ -71,10 +71,8 @@
 /turf/closed/indestructible/fakeglass/Initialize()
 	..()
 	icon_state = null //set the icon state to null, so our base state isn't visible
-	var/image/I = image('icons/obj/structures.dmi', loc = src, icon_state = "grille")
-	underlays += I //add a grille underlay
-	I = image('icons/turf/floors.dmi', loc = src, icon_state = "plating")
-	underlays += I //add the plating underlay, below the grille
+	underlays += mutable_appearance('icons/obj/structures.dmi', "grille") //add a grille underlay
+	underlays += mutable_appearance('icons/turf/floors.dmi', "plating") //add the plating underlay, below the grille
 
 /turf/closed/indestructible/fakedoor
 	name = "Centcom Access"

code/game/turfs/open.dm

@@ -3,7 +3,7 @@
 
 	var/wet = 0
 	var/wet_time = 0 // Time in seconds that this floor will be wet for.
-	var/image/wet_overlay = null
+	var/mutable_appearance/wet_overlay
 
 /turf/open/indestructible
 	name = "floor"
@@ -183,17 +183,22 @@
 	if(wet_setting != TURF_DRY)
 		if(wet_overlay)
 			cut_overlay(wet_overlay)
-			wet_overlay = null
+		else
+			wet_overlay = mutable_appearance()
 		var/turf/open/floor/F = src
 		if(istype(F))
 			if(wet_setting == TURF_WET_PERMAFROST)
-				wet_overlay = image('icons/effects/water.dmi', src, "ice_floor")
+				wet_overlay.icon = 'icons/effects/water.dmi'
+				wet_overlay.icon_state = "ice_floor"
 			else if(wet_setting == TURF_WET_ICE)
-				wet_overlay = image('icons/turf/overlays.dmi', src, "snowfloor")
+				wet_overlay.icon = 'icons/turf/overlays.dmi'
+				wet_overlay.icon_state = "snowfloor"
 			else
-				wet_overlay = image('icons/effects/water.dmi', src, "wet_floor_static")
+				wet_overlay.icon = 'icons/effects/water.dmi'
+				wet_overlay.icon_state = "wet_floor_static"
 		else
-			wet_overlay = image('icons/effects/water.dmi', src, "wet_static")
+			wet_overlay.icon = 'icons/effects/water.dmi'
+			wet_overlay.icon_state = "wet_static"
 		add_overlay(wet_overlay)
 	HandleWet()
 

code/game/turfs/simulated/minerals.dm

@@ -21,7 +21,7 @@
 	var/spread = 0 //will the seam spread?
 	var/spreadChance = 0 //the percentual chance of an ore spreading to the neighbouring tiles
 	var/last_act = 0
-	var/scan_state = null //Holder for the image we display when we're pinged by a mining scanner
+	var/scan_state = "" //Holder for the image we display when we're pinged by a mining scanner
 	var/defer_change = 0
 
 /turf/closed/mineral/Initialize()
@@ -380,7 +380,7 @@
 	var/stage = 0 //How far into the lifecycle of gibtonite we are, 0 is untouched, 1 is active and attempting to detonate, 2 is benign and ready for extraction
 	var/activated_ckey = null //These are to track who triggered the gibtonite deposit for logging purposes
 	var/activated_name = null
-	var/activated_image = null
+	var/mutable_appearance/activated_overlay
 
 /turf/closed/mineral/gibtonite/Initialize()
 	det_time = rand(8,10) //So you don't know exactly when the hot potato will explode
@@ -394,9 +394,8 @@
 
 /turf/closed/mineral/gibtonite/proc/explosive_reaction(mob/user = null, triggered_by_explosion = 0)
 	if(stage == 0)
-		var/image/I = image('icons/turf/smoothrocks.dmi', loc = src, icon_state = "rock_Gibtonite_active", layer = ON_EDGED_TURF_LAYER)
-		add_overlay(I)
-		activated_image = I
+		activated_overlay = mutable_appearance('icons/turf/smoothrocks.dmi', "rock_Gibtonite_active", ON_EDGED_TURF_LAYER)
+		add_overlay(activated_overlay)
 		name = "gibtonite deposit"
 		desc = "An active gibtonite reserve. Run!"
 		stage = 1
@@ -433,9 +432,9 @@
 
 /turf/closed/mineral/gibtonite/proc/defuse()
 	if(stage == 1)
-		cut_overlay(activated_image)
-		var/image/I = image('icons/turf/smoothrocks.dmi', loc = src, icon_state = "rock_Gibtonite_inactive", layer = ON_EDGED_TURF_LAYER)
-		add_overlay(I)
+		cut_overlay(activated_overlay)
+		activated_overlay.icon_state = "rock_Gibtonite_inactive"
+		add_overlay(activated_overlay)
 		desc = "An inactive gibtonite reserve. The ore can be extracted."
 		stage = 2
 		if(det_time < 0)