Too remove potential excessive garbage collection per tick. We will be reusing lists for overlays instead of deleting and creating them.

the .Cut() proc on a list will empty a list by default. This also will set the len to 0.

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@5465 316c924e-a436-60f5-8080-3fe189b3f50e

code/game/gamemodes/changeling/changeling_powers.dm

@@ -216,7 +216,7 @@
 	C.monkeyizing = 1
 	C.canmove = 0
 	C.icon = null
-	C.overlays = null
+	C.overlays.Cut()
 	C.invisibility = 101
 
 	var/atom/movable/overlay/animation = new /atom/movable/overlay( C.loc )
@@ -290,7 +290,7 @@
 	C.monkeyizing = 1
 	C.canmove = 0
 	C.icon = null
-	C.overlays = null
+	C.overlays.Cut()
 	C.invisibility = 101
 	var/atom/movable/overlay/animation = new /atom/movable/overlay( C.loc )
 	animation.icon_state = "blank"

code/game/gamemodes/events/ninja_equipment.dm

@@ -540,7 +540,7 @@ ________________________________________________________________________________
 				playsound(P.loc, 'sound/machines/twobeep.ogg', 50, 1)
 				for (var/mob/O in hearers(3, P.loc))
 					O.show_message(text("\icon[P] *[P.ttone]*"))
-			P.overlays = null
+			P.overlays.Cut()
 			P.overlays += image('icons/obj/pda.dmi', "pda-r")
 
 		if("Inject")

code/game/machinery/bots/mulebot.dm

@@ -510,7 +510,7 @@
 		return
 
 	mode = 1
-	overlays = null
+	overlays.Cut()
 
 	load.loc = src.loc
 	load.pixel_y -= 9

code/game/machinery/cell_charger.dm

@@ -21,12 +21,12 @@
 
 				if(chargelevel != newlevel)
 
-					overlays = null
+					overlays.Cut()
 					overlays += "ccharger-o[newlevel]"
 
 					chargelevel = newlevel
 			else
-				overlays = null
+				overlays.Cut()
 	examine()
 		set src in oview(5)
 		..()

code/game/machinery/computer/ai_core.dm

@@ -249,7 +249,7 @@ That prevents a few funky behaviors.
 							A.loc = T.loc//To replace the terminal.
 							C.icon_state = "aicard"
 							C.name = "inteliCard"
-							C.overlays = null
+							C.overlays.Cut()
 							A.cancel_camera()
 							A << "You have been uploaded to a stationary terminal. Remote device connection restored."
 							U << "\blue <b>Transfer successful</b>: \black [A.name] ([rand(1000,9999)].exe) installed and executed succesfully. Local copy has been removed."
@@ -276,7 +276,7 @@ That prevents a few funky behaviors.
 							else for(var/mob/living/silicon/ai/A in C)
 								C.icon_state = "aicard"
 								C.name = "inteliCard"
-								C.overlays = null
+								C.overlays.Cut()
 								A.loc = T
 								T.occupant = A
 								A.control_disabled = 1
@@ -372,7 +372,7 @@ That prevents a few funky behaviors.
 										A_T.loc = T//Throw them into suit.
 										C.icon_state = "aicard"
 										C.name = "inteliCard"
-										C.overlays = null
+										C.overlays.Cut()
 										T.AI = A_T
 										A_T.cancel_camera()
 										A_T << "You have been uploaded to a mobile storage device."

code/game/machinery/computer/aifixer.dm

@@ -146,7 +146,7 @@
 	..()
 	// Broken / Unpowered
 	if((stat & BROKEN) || (stat & NOPOWER))
-		overlays = null
+		overlays.Cut()
 
 	// Working / Powered
 	else

code/game/machinery/computer/message.dm

@@ -452,7 +452,7 @@
 									var/mob/living/carbon/human/H = customrecepient.loc
 									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] (PDA: [customsender]) sent \"[custommessage]\" to [customrecepient.owner]")
-								customrecepient.overlays = null
+								customrecepient.overlays.Cut()
 								customrecepient.overlays += image('icons/obj/pda.dmi', "pda-r")
 						//Sender is faking as someone who exists
 						else
@@ -466,7 +466,7 @@
 									var/mob/living/carbon/human/H = customrecepient.loc
 									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] (PDA: [PDARec.owner]) sent \"[custommessage]\" to [customrecepient.owner]")
-								customrecepient.overlays = null
+								customrecepient.overlays.Cut()
 								customrecepient.overlays += image('icons/obj/pda.dmi', "pda-r")
 						//Finally..
 						ResetMessage()

code/game/machinery/doors/airlock.dm

@@ -641,7 +641,7 @@ About the new airlock wires panel:
 			source.thermal_conductivity = initial(source.thermal_conductivity)
 
 /obj/machinery/door/airlock/update_icon()
-	if(overlays) overlays = null
+	if(overlays) overlays.Cut()
 	if(density)
 		if(locked && lights)
 			icon_state = "door_locked"
@@ -661,14 +661,14 @@ About the new airlock wires panel:
 /obj/machinery/door/airlock/animate(animation)
 	switch(animation)
 		if("opening")
-			if(overlays) overlays = null
+			if(overlays) overlays.Cut()
 			if(p_open)
 				spawn(2) // The only work around that works. Downside is that the door will be gone for a millisecond.
 					flick("o_door_opening", src)  //can not use flick due to BYOND bug updating overlays right before flicking
 			else
 				flick("door_opening", src)
 		if("closing")
-			if(overlays) overlays = null
+			if(overlays) overlays.Cut()
 			if(p_open)
 				flick("o_door_closing", src)
 			else

code/game/machinery/doors/brigdoors.dm

@@ -219,7 +219,7 @@
 // Adds an icon in case the screen is broken/off, stolen from status_display.dm
 	proc/set_picture(var/state)
 		picture_state = state
-		overlays = null
+		overlays.Cut()
 		overlays += image('icons/obj/status_display.dmi', icon_state=picture_state)
 
 
@@ -227,10 +227,10 @@
 // Stolen from status_display
 	proc/update_display(var/line1, var/line2)
 		if(line2 == null)		// single line display
-			overlays = null
+			overlays.Cut()
 			overlays += texticon(line1, 23, -13)
 		else					// dual line display
-			overlays = null
+			overlays.Cut()
 			overlays += texticon(line1, 23, -9)
 			overlays += texticon(line2, 23, -17)
 		// return an icon of a time text string (tn)

code/game/machinery/doors/firedoor.dm

@@ -71,7 +71,7 @@
 
 
 	update_icon()
-		overlays = null
+		overlays.Cut()
 		if(density)
 			icon_state = "door_closed"
 			if(blocked)

code/game/machinery/flasher.dm

@@ -112,7 +112,7 @@
 
 		if (!src.anchored)
 			user.show_message(text("\red [src] can now be moved."))
-			src.overlays = null
+			src.overlays.Cut()
 
 		else if (src.anchored)
 			user.show_message(text("\red [src] is now secured."))

code/game/machinery/hydroponics.dm

@@ -151,7 +151,7 @@ obj/machinery/hydroponics/process()
 
 obj/machinery/hydroponics/proc/updateicon()
 	//Refreshes the icon and sets the luminosity
-	overlays = null
+	overlays.Cut()
 	if(planted)
 		if(dead)
 			overlays += image('icons/obj/hydroponics.dmi', icon_state="[myseed.species]-dead")
@@ -1017,7 +1017,7 @@ obj/machinery/hydroponics/attackby(var/obj/item/O as obj, var/mob/user as mob)
 	use_power = 0
 
 	updateicon() // Same as normal but with the overlays removed - Cheridan.
-		overlays = null
+		overlays.Cut()
 		if(planted)
 			if(dead)
 				overlays += image('icons/obj/hydroponics.dmi', icon_state="[myseed.species]-dead")

code/game/machinery/kitchen/gibber.dm

@@ -50,7 +50,7 @@
 	src.overlays += image('icons/obj/kitchen.dmi', "grjam")
 
 /obj/machinery/gibber/update_icon()
-	overlays = null
+	overlays.Cut()
 	if (dirty)
 		src.overlays += image('icons/obj/kitchen.dmi', "grbloody")
 	if(stat & (NOPOWER|BROKEN))

code/game/machinery/newscaster.dm

@@ -114,11 +114,11 @@ var/list/obj/machinery/newscaster/allCasters = list() //Global list that will co
 	if(!ispowered || isbroken)
 		icon_state = "newscaster_off"
 		if(isbroken) //If the thing is smashed, add crack overlay on top of the unpowered sprite.
-			src.overlays = null
+			src.overlays.Cut()
 			src.overlays += image(src.icon, "crack3")
 		return
 
-	src.overlays = null //reset overlays
+	src.overlays.Cut() //reset overlays
 
 	if(news_network.wanted_issue) //wanted icon state, there can be no overlays on it as it's a priority message
 		icon_state = "newscaster_wanted"

code/game/machinery/spaceheater.dm

@@ -23,7 +23,7 @@
 		return
 
 	update_icon()
-		overlays = null
+		overlays.Cut()
 		icon_state = "sheater[on]"
 		if(open)
 			overlays  += "sheater-open"

code/game/machinery/status_display.dm

@@ -47,7 +47,7 @@
 
 	process()
 		if(stat & NOPOWER)
-			overlays = null
+			overlays.Cut()
 			return
 
 		update()
@@ -68,7 +68,7 @@
 			return
 
 		if(mode==0)
-			overlays = null
+			overlays.Cut()
 			return
 
 		if(mode==3)	// alert picture, no change
@@ -89,7 +89,7 @@
 				update_display(displayloc, displaytime)
 				return
 			else
-				overlays = null
+				overlays.Cut()
 				return
 
 		if(mode==4)		// supply shuttle timer
@@ -160,7 +160,7 @@
 
 	proc/set_picture(var/state)
 		picture_state = state
-		overlays = null
+		overlays.Cut()
 		overlays += image('icons/obj/status_display.dmi', icon_state=picture_state)
 
 	proc/update_display(var/line1, var/line2)
@@ -172,11 +172,11 @@
 		lastdisplayline2 = line2
 
 		if(line2 == null)		// single line display
-			overlays = null
+			overlays.Cut()
 			overlays += texticon(line1, 23, -13)
 		else					// dual line display
 
-			overlays = null
+			overlays.Cut()
 			overlays += texticon(line1, 23, -9)
 			overlays += texticon(line2, 23, -17)
 
@@ -272,7 +272,7 @@
 
 	process()
 		if(stat & NOPOWER)
-			overlays = null
+			overlays.Cut()
 			return
 
 		update()
@@ -287,7 +287,7 @@
 	proc/update()
 
 		if(mode==0) //Blank
-			overlays = null
+			overlays.Cut()
 			return
 
 		if(mode==1)	// AI emoticon
@@ -328,5 +328,5 @@
 
 	proc/set_picture(var/state)
 		picture_state = state
-		overlays = null
+		overlays.Cut()
 		overlays += image('icons/obj/status_display.dmi', icon_state=picture_state)

code/game/machinery/vending.dm

@@ -143,7 +143,7 @@
 	else if(istype(W, /obj/item/weapon/screwdriver))
 		src.panel_open = !src.panel_open
 		user << "You [src.panel_open ? "open" : "close"] the maintenance panel."
-		src.overlays = null
+		src.overlays.Cut()
 		if(src.panel_open)
 			src.overlays += image(src.icon, "[initial(icon_state)]-panel")
 		src.updateUsrDialog()

code/game/objects/items/bodybag.dm

@@ -61,7 +61,7 @@
 		else if(istype(W, /obj/item/weapon/wirecutters))
 			user << "You cut the tag off the bodybag"
 			src.name = "body bag"
-			src.overlays = null
+			src.overlays.Cut()
 			return
 
 

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

@@ -682,7 +682,7 @@ var/global/list/obj/item/device/pda/PDAs = list()
 //EXTRA FUNCTIONS===================================
 
 	if (mode == 2||mode == 21)//To clear message overlays.
-		overlays = null
+		overlays.Cut()
 
 	if ((honkamt > 0) && (prob(60)))//For clown virus.
 		honkamt--
@@ -781,7 +781,7 @@ var/global/list/obj/item/device/pda/PDAs = list()
 			L << "\icon[P] <b>Message from [src.owner] ([ownjob]), </b>\"[t]\" (<a href='byond://?src=\ref[P];choice=Message;skiprefresh=1;target=\ref[src]'>Reply</a>)"
 
 		log_pda("[usr] (PDA: [src.name]) sent \"[t]\" to [P.name]")
-		P.overlays = null
+		P.overlays.Cut()
 		P.overlays += image('icons/obj/pda.dmi', "pda-r")
 	else
 		U << "<span class='notice'>ERROR: Server isn't responding.</span>"

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

@@ -110,12 +110,12 @@
 
 /obj/item/device/paicard/proc/removePersonality()
 	src.pai = null
-	src.overlays = null
+	src.overlays.Cut()
 	src.overlays += "pai-off"
 
 /obj/item/device/paicard/proc/setEmotion(var/emotion)
 	if(pai)
-		src.overlays = null
+		src.overlays.Cut()
 		switch(emotion)
 			if(1) src.overlays += "pai-happy"
 			if(2) src.overlays += "pai-cat"

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

@@ -115,7 +115,7 @@
 			toggle = 1
 
 /obj/item/device/transfer_valve/update_icon()
-	overlays = null
+	overlays.Cut()
 	underlays = null
 
 	if(!tank_one && !tank_two && !attached_device)

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

@@ -73,7 +73,7 @@
 	src.updateicon()
 
 /obj/item/robot_parts/robot_suit/proc/updateicon()
-	src.overlays = null
+	src.overlays.Cut()
 	if(src.l_arm)
 		src.overlays += "l_arm+o"
 	if(src.r_arm)

code/game/objects/items/shooting_range.dm

@@ -36,7 +36,7 @@
 		if (istype(W, /obj/item/weapon/weldingtool))
 			var/obj/item/weapon/weldingtool/WT = W
 			if(WT.remove_fuel(0, user))
-				overlays = null
+				overlays.Cut()
 				usr << "You slice off [src]'s uneven chunks of aluminum and scorch marks."
 				return
 

code/game/objects/items/tk_grab.dm

@@ -97,7 +97,7 @@
 
 
 	update_icon()
-		overlays = null
+		overlays.Cut()
 		if(focus && focus.icon && focus.icon_state)
 			overlays += icon(focus.icon,focus.icon_state)
 		return

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

@@ -48,7 +48,7 @@
 
 
 /obj/item/weapon/flamethrower/update_icon()
-	overlays = null
+	overlays.Cut()
 	if(igniter)
 		overlays += "+igniter[status]"
 	if(ptank)

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

@@ -222,7 +222,7 @@
 /obj/item/weapon/tray/attack(mob/living/carbon/M as mob, mob/living/carbon/user as mob)
 
 	// Drop all the things. All of them.
-	overlays = null
+	overlays.Cut()
 	for(var/obj/item/I in carrying)
 		I.loc = M.loc
 		carrying.Remove(I)
@@ -391,7 +391,7 @@
 		foundtable = 1
 		break
 
-	overlays = null
+	overlays.Cut()
 
 	for(var/obj/item/I in carrying)
 		I.loc = loc

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

@@ -106,7 +106,7 @@
 		emagged = 1
 		src.overlays += image('icons/obj/storage.dmi', icon_sparking)
 		sleep(6)
-		src.overlays = null
+		src.overlays.Cut()
 		overlays += image('icons/obj/storage.dmi', icon_locking)
 		locked = 0
 		if(istype(W, /obj/item/weapon/melee/energy/blade))
@@ -225,7 +225,7 @@
 				src.l_set = 1
 			else if ((src.code == src.l_code) && (src.emagged == 0) && (src.l_set == 1))
 				src.locked = 0
-				src.overlays = null
+				src.overlays.Cut()
 				overlays += image('icons/obj/storage.dmi', icon_opened)
 				src.code = null
 			else
@@ -233,7 +233,7 @@
 		else
 			if ((href_list["type"] == "R") && (src.emagged == 0) && (!src.l_setshort))
 				src.locked = 1
-				src.overlays = null
+				src.overlays.Cut()
 				src.code = null
 				src.close(usr)
 			else

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

@@ -275,7 +275,7 @@
 		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)
-	overlays = null
+	overlays.Cut()
 	if(!opened)
 		icon_state = icon_closed
 		if(welded)

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

@@ -151,7 +151,7 @@
 		usr << "<span class='warning'>This mob type can't use this verb.</span>"
 
 /obj/structure/closet/secure_closet/update_icon()//Putting the welded stuff in updateicon() so it's easy to overwrite for special cases (Fridges, cabinets, and whatnot)
-	overlays = null
+	overlays.Cut()
 	if(!opened)
 		if(locked)
 			icon_state = icon_locked

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

@@ -211,10 +211,10 @@
 /obj/structure/closet/crate/secure/New()
 	..()
 	if(locked)
-		overlays = null
+		overlays.Cut()
 		overlays += redlight
 	else
-		overlays = null
+		overlays.Cut()
 		overlays += greenlight
 
 /obj/structure/closet/crate/rcd/New()
@@ -287,7 +287,7 @@
 		if (allowed(user))
 			user << "<span class='notice'>You unlock [src].</span>"
 			src.locked = 0
-			overlays = null
+			overlays.Cut()
 			overlays += greenlight
 			return
 		else
@@ -300,11 +300,11 @@
 	if(istype(W, /obj/item/weapon/card) && src.allowed(user) && !locked && !opened && !broken)
 		user << "<span class='notice'>You lock \the [src].</span>"
 		src.locked = 1
-		overlays = null
+		overlays.Cut()
 		overlays += redlight
 		return
 	else if ( (istype(W, /obj/item/weapon/card/emag)||istype(W, /obj/item/weapon/melee/energy/blade)) && locked &&!broken)
-		overlays = null
+		overlays.Cut()
 		overlays += emag
 		overlays += sparks
 		spawn(6) overlays -= sparks //Tried lots of stuff but nothing works right. so i have to use this *sadface*
@@ -357,10 +357,10 @@
 	if(!broken && !opened  && prob(50/severity))
 		if(!locked)
 			src.locked = 1
-			overlays = null
+			overlays.Cut()
 			overlays += redlight
 		else
-			overlays = null
+			overlays.Cut()
 			overlays += emag
 			overlays += sparks
 			spawn(6) overlays -= sparks //Tried lots of stuff but nothing works right. so i have to use this *sadface*

code/game/objects/structures/electricchair.dm

@@ -39,7 +39,7 @@
 
 /obj/structure/stool/bed/chair/e_chair/rotate()
 	..()
-	overlays = null
+	overlays.Cut()
 	overlays += image('icons/obj/objects.dmi', src, "echair_over", MOB_LAYER + 1, dir)	//there's probably a better way of handling this, but eh. -Pete
 	return
 

code/game/objects/structures/tank_dispenser.dm

@@ -23,7 +23,7 @@
 
 
 /obj/structure/dispenser/update_icon()
-	overlays = null
+	overlays.Cut()
 	switch(oxygentanks)
 		if(1 to 3)	overlays += "oxygen-[oxygentanks]"
 		if(4 to INFINITY) overlays += "oxygen-4"

code/game/objects/structures/watercloset.dm

@@ -165,7 +165,7 @@
 			user.visible_message("<span class='notice'>[user] adjusts the shower with the [I].</span>", "<span class='notice'>You adjust the shower with the [I].</span>")
 
 /obj/machinery/shower/update_icon()	//this is terribly unreadable, but basically it makes the shower mist up
-	overlays = null					//once it's been on for a while, in addition to handling the water overlay.
+	overlays.Cut()					//once it's been on for a while, in addition to handling the water overlay.
 	if(mymist)
 		del(mymist)