[MIRROR] Adds a preference that disables intensive rendering on different multiz layers [MDB IGNORE] (#17737)

* Adds a preference that disables intensive rendering on different multiz layers (#71218)

## About The Pull Request

It's kinda hacky, but it is nearly the same as just rendering one z
layer.
We allow people to ENTIRELY REMOVE most plane masters from their screen.
This has the side effect of disabling most visual effects (AO is a big
one) which saves a LOT of gpu.

We rely on planes being essentially layers to ensure things render in
the proper order. (outside of some hackyness required to make parallax
work)

I've kept parallax and lighting enabled, so visuals will still look
better then multiz pre plane cube.
It does also mean that things like FOV don't work, but honestly they
didn't work PRE plane cube, and FOV's implementation makes me mad so I
have a hard time caring.

Reduces gpu usage on my machine on tram from 47% to 32%, just above the
27% I get on meta.

I'm happy with this.

Oh also turns out the parallaxing had almost no cost. Need to remove it
as a side effect of what I'm doing but if I could keep it I would.

There's still room for in between performance options, like disabling
things like AO on lower z layers, but I didn't expect it to make a huge
impact, so I left things as is

Also fixes a bug with paper bins not respecting z layer. It came up in
testing and annoyed me

## Why It's Good For The Game

Ensures we can make multiz maps without running into client performance
issues, allows users to customize performance and visual quality.

## Changelog
🆑
add: Adds a new rendering option to the gameplay preferences. You can
now limit the rendering intensity of multiz levels. This will make
things look a bit worse, but run a LOT better. Try it out if your
machine chokes on icebox or somethin.
/🆑

Co-authored-by: Mothblocks <35135081+Mothblocks@ users.noreply.github.com>

* Adds a preference that disables intensive rendering on different multiz layers

Co-authored-by: LemonInTheDark <58055496+LemonInTheDark@users.noreply.github.com>
Co-authored-by: Mothblocks <35135081+Mothblocks@ users.noreply.github.com>

code/__DEFINES/layers.dm

@@ -236,3 +236,21 @@
 ///Plane master controller keys
 #define PLANE_MASTERS_GAME "plane_masters_game"
 #define PLANE_MASTERS_COLORBLIND "plane_masters_colorblind"
+
+//Plane master critical flags
+//Describes how different plane masters behave when they are being culled for performance reasons
+/// This plane master will not go away if its layer is culled. useful for preserving effects
+#define PLANE_CRITICAL_DISPLAY (1<<0)
+/// This plane master will temporarially remove relays to non critical planes if it's layer is culled (and it's critical)
+/// This is VERY hacky, but needed to ensure that some instances of BLEND_MULITPLY work as expected (fuck you god damn parallax)
+/// It also implies that the critical plane has a *'d render target, making it mask itself
+#define PLANE_CRITICAL_NO_EMPTY_RELAY (1<<1)
+
+#define PLANE_CRITICAL_FUCKO_PARALLAX (PLANE_CRITICAL_DISPLAY|PLANE_CRITICAL_NO_EMPTY_RELAY)
+
+/// A value of /datum/preference/numeric/multiz_performance that disables the option
+#define MULTIZ_PERFORMANCE_DISABLE -1
+/// We expect at most 3 layers of multiz
+/// Increment this define if you make a huge map. We unit test for it too just to make it easy for you
+/// If you modify this, you'll need to modify the tsx file too
+#define MAX_EXPECTED_Z_DEPTH 2

code/__HELPERS/_planes.dm

@@ -63,6 +63,8 @@
 #define PLANE_TO_TRUE(plane) ((SSmapping.plane_offset_to_true) ? SSmapping.plane_offset_to_true["[plane]"] : plane)
 /// Takes a plane, returns the offset it uses
 #define PLANE_TO_OFFSET(plane) ((SSmapping.plane_to_offset) ? SSmapping.plane_to_offset["[plane]"] : plane)
+/// Takes a plane, returns TRUE if it is of critical priority, FALSE otherwise
+#define PLANE_IS_CRITICAL(plane) ((SSmapping.plane_to_offset) ? !!SSmapping.critical_planes["[plane]"] : FALSE)
 /// Takes a true plane, returns the offset planes that would canonically represent it
 #define TRUE_PLANE_TO_OFFSETS(plane) ((SSmapping.true_to_offset_planes) ? SSmapping.true_to_offset_planes["[plane]"] : list(plane))
 /// Takes a render target and an offset, returns a canonical render target string for it

code/_onclick/hud/parallax.dm

@@ -2,9 +2,15 @@
 /datum/hud/proc/create_parallax(mob/viewmob)
 	var/mob/screenmob = viewmob || mymob
 	var/client/C = screenmob.client
+
 	if (!apply_parallax_pref(viewmob)) //don't want shit computers to crash when specing someone with insane parallax, so use the viewer's pref
+		for(var/atom/movable/screen/plane_master/parallax as anything in get_true_plane_masters(PLANE_SPACE_PARALLAX))
+			parallax.hide_plane(screenmob)
 		return
 
+	for(var/atom/movable/screen/plane_master/parallax as anything in get_true_plane_masters(PLANE_SPACE_PARALLAX))
+		parallax.unhide_plane(screenmob)
+
 	if(!length(C.parallax_layers_cached))
 		C.parallax_layers_cached = list()
 		C.parallax_layers_cached += new /atom/movable/screen/parallax_layer/layer_1(null, screenmob)
@@ -23,7 +29,7 @@
 	// We could do not do parallax for anything except the main plane group
 	// This could be changed, but it would require refactoring this whole thing
 	// And adding non client particular hooks for all the inputs, and I do not have the time I'm sorry :(
-	for(var/atom/movable/screen/plane_master/plane_master in screenmob.hud_used.get_true_plane_masters(PLANE_SPACE))
+	for(var/atom/movable/screen/plane_master/plane_master as anything in screenmob.hud_used.get_true_plane_masters(PLANE_SPACE))
 		if(screenmob != mymob)
 			C.screen -= locate(/atom/movable/screen/plane_master/parallax_white) in C.screen
 			C.screen += plane_master
@@ -39,7 +45,7 @@
 	var/mob/screenmob = viewmob || mymob
 	var/client/C = screenmob.client
 	C.screen -= (C.parallax_layers_cached)
-	for(var/atom/movable/screen/plane_master/plane_master in screenmob.hud_used.get_true_plane_masters(PLANE_SPACE))
+	for(var/atom/movable/screen/plane_master/plane_master as anything in screenmob.hud_used.get_true_plane_masters(PLANE_SPACE))
 		if(screenmob != mymob)
 			C.screen -= locate(/atom/movable/screen/plane_master/parallax_white) in C.screen
 			C.screen += plane_master
@@ -50,7 +56,13 @@
 	var/mob/screenmob = viewmob || mymob
 
 	if(SSmapping.level_trait(screenmob.z, ZTRAIT_NOPARALLAX))
+		for(var/atom/movable/screen/plane_master/white_space as anything in get_true_plane_masters(PLANE_SPACE))
+			white_space.hide_plane(screenmob)
 		return FALSE
+
+	for(var/atom/movable/screen/plane_master/white_space as anything in get_true_plane_masters(PLANE_SPACE))
+		white_space.unhide_plane(screenmob)
+
 	if (SSlag_switch.measures[DISABLE_PARALLAX] && !HAS_TRAIT(viewmob, TRAIT_BYPASS_MEASURES))
 		return FALSE
 

code/_onclick/hud/rendering/plane_master.dm

@@ -1,5 +1,6 @@
 // I hate this place
 INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
+
 /atom/movable/screen/plane_master
 	screen_loc = "CENTER"
 	icon_state = "blank"
@@ -51,6 +52,18 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 	/// Planes with this set should NEVER be relay'd into each other, as that will cause visual fuck
 	var/multiz_scaled = TRUE
 
+	/// Bitfield that describes how this plane master will render if its z layer is being "optimized"
+	/// If a plane master is NOT critical, it will be completely dropped if we start to render outside a client's multiz boundary prefs
+	/// Of note: most of the time we will relay renders to non critical planes in this stage. so the plane master will end up drawing roughly "in order" with its friends
+	/// This is NOT done for parallax and other problem children, because the rules of BLEND_MULTIPLY appear to not behave as expected :(
+	/// This will also just make debugging harder, because we do fragile things in order to ensure things operate as epected. I'm sorry
+	/// Compile time
+	/// See [code\__DEFINES\layers.dm] for our bitflags
+	var/critical = NONE
+
+	/// If this plane master is outside of our visual bounds right now
+	var/is_outside_bounds = FALSE
+
 /atom/movable/screen/plane_master/Initialize(mapload, datum/plane_master_group/home, offset = 0)
 	. = ..()
 	src.offset = offset
@@ -116,7 +129,7 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 /// Returns TRUE if the call is allowed, FALSE otherwise
 /atom/movable/screen/plane_master/proc/show_to(mob/mymob)
 	SHOULD_CALL_PARENT(TRUE)
-	if(force_hidden)
+	if(force_hidden || is_outside_bounds)
 		return FALSE
 
 	var/client/our_client = mymob?.client
@@ -166,6 +179,45 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 	else
 		unhide_plane(our_mob)
 
+/atom/movable/screen/plane_master/proc/outside_bounds(mob/relevant)
+	if(force_hidden || is_outside_bounds)
+		return
+	is_outside_bounds = TRUE
+	// If we're of critical importance, AND we're below the rendering layer
+	if(critical & PLANE_CRITICAL_DISPLAY)
+		if(!(critical & PLANE_CRITICAL_NO_EMPTY_RELAY))
+			return
+		var/client/our_client = relevant.client
+		if(!our_client)
+			return
+		for(var/atom/movable/render_plane_relay/relay as anything in relays)
+			if(!relay.critical_target)
+				our_client.screen -= relay
+
+		// We here assume that your render target starts with *
+		if(render_target)
+			render_target = copytext_char(render_target, 2)
+		return
+	hide_from(relevant)
+
+/atom/movable/screen/plane_master/proc/inside_bounds(mob/relevant)
+	is_outside_bounds = FALSE
+	if(critical & PLANE_CRITICAL_DISPLAY)
+		if(!(critical & PLANE_CRITICAL_NO_EMPTY_RELAY))
+			return
+		var/client/our_client = relevant.client
+		if(!our_client)
+			return
+		for(var/atom/movable/render_plane_relay/relay as anything in relays)
+			if(!relay.critical_target)
+				our_client.screen += relay
+
+		// We here assume that your render target starts with *
+		if(render_target)
+			render_target = "*[render_target]"
+		return
+	show_to(relevant)
+
 /atom/movable/screen/plane_master/clickcatcher
 	name = "Click Catcher"
 	documentation = "Contains the screen object we use as a backdrop to catch clicks on portions of the screen that would otherwise contain nothing else. \
@@ -173,6 +225,7 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 	plane = CLICKCATCHER_PLANE
 	appearance_flags = PLANE_MASTER|NO_CLIENT_COLOR
 	multiz_scaled = FALSE
+	critical = PLANE_CRITICAL_DISPLAY
 
 /atom/movable/screen/plane_master/clickcatcher/Initialize(mapload, datum/plane_master_group/home, offset)
 	. = ..()
@@ -192,6 +245,7 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 		<br>If you want something to look as if it has parallax on it, draw it to this plane."
 	plane = PLANE_SPACE
 	appearance_flags = PLANE_MASTER|NO_CLIENT_COLOR
+	critical = PLANE_CRITICAL_FUCKO_PARALLAX // goes funny when touched. no idea why I don't trust byond
 
 ///Contains space parallax
 /atom/movable/screen/plane_master/parallax
@@ -205,6 +259,7 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 	blend_mode = BLEND_MULTIPLY
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
 	multiz_scaled = FALSE
+	critical = PLANE_CRITICAL_FUCKO_PARALLAX
 
 /atom/movable/screen/plane_master/parallax/Initialize(mapload, datum/plane_master_group/home, offset)
 	. = ..()
@@ -225,6 +280,21 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 			// Overlay so we don't multiply twice, and thus fuck up our rendering
 			add_relay_to(GET_NEW_PLANE(plane, offset), BLEND_OVERLAY)
 
+// Hacky shit to ensure parallax works in perf mode
+/atom/movable/screen/plane_master/parallax/outside_bounds(mob/relevant)
+	if(offset == 0)
+		remove_relay_from(GET_NEW_PLANE(RENDER_PLANE_GAME, 0))
+		is_outside_bounds = TRUE // I'm sorry :(
+		return
+	return ..()
+
+/atom/movable/screen/plane_master/parallax/inside_bounds(mob/relevant)
+	if(offset == 0)
+		add_relay_to(GET_NEW_PLANE(RENDER_PLANE_GAME, 0))
+		is_outside_bounds = FALSE
+		return
+	return ..()
+
 /atom/movable/screen/plane_master/gravpulse
 	name = "Gravpulse"
 	documentation = "Ok so this one's fun. Basically, we want to be able to distort the game plane when a grav annom is around.\
@@ -407,6 +477,7 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 	render_relay_planes = list(RENDER_PLANE_LIGHTING)
 	blend_mode_override = BLEND_ADD
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
+	critical = PLANE_CRITICAL_DISPLAY
 
 /// This will not work through multiz, because of a byond bug with BLEND_MULTIPLY
 /// Bug report is up, waiting on a fix
@@ -420,6 +491,7 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 	render_target = O_LIGHTING_VISUAL_RENDER_TARGET
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
 	blend_mode = BLEND_MULTIPLY
+	critical = PLANE_CRITICAL_DISPLAY
 
 /atom/movable/screen/plane_master/above_lighting
 	name = "Above lighting"
@@ -444,6 +516,7 @@ INITIALIZE_IMMEDIATE(/atom/movable/screen/plane_master)
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
 	render_target = EMISSIVE_RENDER_TARGET
 	render_relay_planes = list()
+	critical = PLANE_CRITICAL_DISPLAY
 
 /atom/movable/screen/plane_master/emissive/Initialize(mapload)
 	. = ..()

code/_onclick/hud/rendering/plane_master_group.dm

@@ -11,7 +11,6 @@
 	var/list/atom/movable/screen/plane_master/plane_masters = list()
 	/// The visual offset we are currently using
 	var/active_offset = 0
-
 	/// What, if any, submap we render onto
 	var/map = ""
 
@@ -94,7 +93,8 @@
 // It's hard, and potentially expensive. be careful
 /datum/plane_master_group/proc/transform_lower_turfs(datum/hud/source, new_offset, use_scale = TRUE)
 	// Check if this feature is disabled for the client, in which case don't use scale.
-	if(!our_hud?.mymob?.client?.prefs?.read_preference(/datum/preference/toggle/multiz_parallax))
+	var/mob/our_mob = our_hud?.mymob
+	if(!our_mob?.client?.prefs?.read_preference(/datum/preference/toggle/multiz_parallax))
 		use_scale = FALSE
 
 	// No offset? piss off
@@ -115,8 +115,15 @@
 		scale_by = 1
 
 	var/list/offsets = list()
+	var/multiz_boundary = our_mob?.client?.prefs?.read_preference(/datum/preference/numeric/multiz_performance)
+
 	// We accept negatives so going down "zooms" away the drop above as it goes
 	for(var/offset in -SSmapping.max_plane_offset to SSmapping.max_plane_offset)
+		// Multiz boundaries disable transforms
+		if(multiz_boundary != MULTIZ_PERFORMANCE_DISABLE && (multiz_boundary < abs(offset)))
+			offsets += null
+			continue
+
 		// No transformations if we're landing ON you
 		if(offset == 0)
 			offsets += null
@@ -132,11 +139,23 @@
 
 	for(var/plane_key in plane_masters)
 		var/atom/movable/screen/plane_master/plane = plane_masters[plane_key]
-		if(!plane.multiz_scaled || !plane.allows_offsetting)
+		if(!plane.allows_offsetting)
 			continue
 
 		var/visual_offset = plane.offset - new_offset
-		if(plane.force_hidden || visual_offset < 0)
+		// we get like 47 -> 42 from just no AO/displace on lower levels. 39 with no FOV blocking
+		// 31 with only barebones lower planes
+
+		// Basically uh, if we're showing something down X amount of levels, or up any amount of levels
+		if(multiz_boundary != MULTIZ_PERFORMANCE_DISABLE && (visual_offset > multiz_boundary || visual_offset < 0))
+			plane.outside_bounds(our_mob)
+		else if(plane.is_outside_bounds)
+			plane.inside_bounds(our_mob)
+
+		if(!plane.multiz_scaled)
+			continue
+
+		if(plane.force_hidden || plane.is_outside_bounds || visual_offset < 0)
 			// We don't animate here because it should be invisble, but we do mark because it'll look nice
 			plane.transform = offsets[visual_offset + offset_offset]
 			continue

code/_onclick/hud/rendering/render_plate.dm

@@ -13,6 +13,8 @@
 	layer = -1
 	plane = 0
 	appearance_flags = PASS_MOUSE | NO_CLIENT_COLOR | KEEP_TOGETHER
+	/// If we render into a critical plane master, or not
+	var/critical_target = FALSE
 
 /**
  * ## Rendering plate
@@ -119,6 +121,7 @@
 	plane = RENDER_PLANE_LIGHTING
 	blend_mode_override = BLEND_MULTIPLY
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
+	critical = PLANE_CRITICAL_DISPLAY
 
 /atom/movable/screen/plane_master/rendering_plate/lighting/show_to(mob/mymob)
 	. = ..()
@@ -251,6 +254,7 @@
 	relay.blend_mode = blend_to_use
 	relay.mouse_opacity = mouse_opacity
 	relay.name = render_target
+	relay.critical_target = PLANE_IS_CRITICAL(target_plane)
 	relays += relay
 	// Relays are sometimes generated early, before huds have a mob to display stuff to
 	// That's what this is for

code/controllers/subsystem/mapping.dm

@@ -47,6 +47,8 @@ SUBSYSTEM_DEF(mapping)
 	var/list/plane_offset_blacklist
 	/// List of render targets that do not allow for offsetting
 	var/list/render_offset_blacklist
+	/// List of plane masters that are of critical priority
+	var/list/critical_planes
 	/// The largest plane offset we've generated so far
 	var/max_plane_offset = 0
 
@@ -111,6 +113,7 @@ SUBSYSTEM_DEF(mapping)
 	plane_to_offset["[FLOAT_PLANE]"] = 0
 	plane_offset_blacklist = list()
 	render_offset_blacklist = list()
+	critical_planes = list()
 	create_plane_offsets(0, 0)
 	initialize_biomes()
 	loadWorld()
@@ -802,6 +805,9 @@ GLOBAL_LIST_EMPTY(the_station_areas)
 
 	generate_offset_lists(old_max + 1, max_plane_offset)
 	SEND_SIGNAL(src, COMSIG_PLANE_OFFSET_INCREASE, old_max, max_plane_offset)
+	// Sanity check
+	if(max_plane_offset > MAX_EXPECTED_Z_DEPTH)
+		stack_trace("We've loaded a map deeper then the max expected z depth. Preferences won't cover visually disabling all of it!")
 
 /// Takes an offset to generate misc lists to, and a base to start from
 /// Use this to react globally to maintain parity with plane offsets
@@ -833,6 +839,9 @@ GLOBAL_LIST_EMPTY(the_station_areas)
 				if(plane_offset != 0)
 					continue
 
+			if(initial(master_type.critical) & PLANE_CRITICAL_DISPLAY)
+				critical_planes[string_plane] = TRUE
+
 			plane_offset_to_true[string_plane] = plane_to_use
 			plane_to_offset[string_plane] = plane_offset
 

code/datums/components/fov_handler.dm

@@ -22,7 +22,7 @@
 		qdel(src) //no QDEL hint for components, and we dont want this to print a warning regarding bad component application
 		return
 
-	for(var/atom/movable/screen/plane_master/plane_master in mob_parent.hud_used.get_true_plane_masters(FIELD_OF_VISION_BLOCKER_PLANE))
+	for(var/atom/movable/screen/plane_master/plane_master as anything in mob_parent.hud_used.get_true_plane_masters(FIELD_OF_VISION_BLOCKER_PLANE))
 		plane_master.unhide_plane(mob_parent)
 
 	blocker_mask = new
@@ -36,7 +36,7 @@
 
 /datum/component/fov_handler/Destroy()
 	var/mob/living/mob_parent = parent
-	for(var/atom/movable/screen/plane_master/plane_master in mob_parent.hud_used.get_true_plane_masters(FIELD_OF_VISION_BLOCKER_PLANE))
+	for(var/atom/movable/screen/plane_master/plane_master as anything in mob_parent.hud_used.get_true_plane_masters(FIELD_OF_VISION_BLOCKER_PLANE))
 		plane_master.hide_plane(mob_parent)
 
 	if(applied_mask)

code/modules/cargo/centcom_podlauncher.dm

@@ -105,7 +105,7 @@
 	var/datum/plane_master_group/planes = cam_screen.display_to(holder.mob)
 
 	if(!renderLighting)
-		for(var/atom/movable/screen/plane_master/instance in holder.mob.hud_used.get_true_plane_masters(LIGHTING_PLANE, planes.key))
+		for(var/atom/movable/screen/plane_master/instance as anything in holder.mob.hud_used.get_true_plane_masters(LIGHTING_PLANE, planes.key))
 			instance.set_alpha(100)
 
 	cam_background = new

code/modules/client/preferences/ambient_occlusion.dm

@@ -6,5 +6,5 @@
 
 /datum/preference/toggle/ambient_occlusion/apply_to_client(client/client, value)
 	/// Backdrop for the game world plane.
-	for(var/atom/movable/screen/plane_master/rendering_plate/game_world/plane_master in client.mob?.hud_used?.get_true_plane_masters(GAME_PLANE))
+	for(var/atom/movable/screen/plane_master/plane_master as anything in client.mob?.hud_used?.get_true_plane_masters(GAME_PLANE))
 		plane_master.show_to(client.mob)

code/modules/client/preferences/multiz_performance.dm

@@ -0,0 +1,21 @@
+/// Boundary for how many z levels down to render properly before we start going cheapo mode
+/datum/preference/numeric/multiz_performance
+	category = PREFERENCE_CATEGORY_GAME_PREFERENCES
+	savefile_key = "multiz_performance"
+	savefile_identifier = PREFERENCE_PLAYER
+
+	minimum = MULTIZ_PERFORMANCE_DISABLE
+	maximum = MAX_EXPECTED_Z_DEPTH - 1
+
+/datum/preference/numeric/multiz_performance/create_default_value()
+	return -1
+
+/datum/preference/numeric/multiz_performance/apply_to_client(client/client, value)
+	// Update the plane master group's layering
+	var/datum/hud/my_hud = client.mob?.hud_used
+	if(!my_hud)
+		return
+
+	for(var/group_key as anything in my_hud.master_groups)
+		var/datum/plane_master_group/group = my_hud.master_groups[group_key]
+		group.transform_lower_turfs(my_hud, my_hud.current_plane_offset)

code/modules/mob/living/ventcrawling.dm

@@ -110,18 +110,18 @@
 			client.images -= current_image
 		pipes_shown.len = 0
 		pipetracker = null
-		for(var/atom/movable/screen/plane_master/lighting in hud_used.get_true_plane_masters(LIGHTING_PLANE))
+		for(var/atom/movable/screen/plane_master/lighting as anything in hud_used.get_true_plane_masters(LIGHTING_PLANE))
 			lighting.remove_atom_colour(TEMPORARY_COLOUR_PRIORITY, "#4d4d4d")
-		for(var/atom/movable/screen/plane_master/pipecrawl in hud_used.get_true_plane_masters(PIPECRAWL_IMAGES_PLANE))
+		for(var/atom/movable/screen/plane_master/pipecrawl as anything in hud_used.get_true_plane_masters(PIPECRAWL_IMAGES_PLANE))
 			pipecrawl.hide_plane(src)
 		return
 
 	// We're gonna color the lighting plane to make it darker while ventcrawling, so things look nicer
 	// This is a bit hacky but it makes the background darker, which has a nice effect
-	for(var/atom/movable/screen/plane_master/lighting in hud_used.get_true_plane_masters(LIGHTING_PLANE))
+	for(var/atom/movable/screen/plane_master/lighting as anything in hud_used.get_true_plane_masters(LIGHTING_PLANE))
 		lighting.add_atom_colour("#4d4d4d", TEMPORARY_COLOUR_PRIORITY)
 
-	for(var/atom/movable/screen/plane_master/pipecrawl in hud_used.get_true_plane_masters(PIPECRAWL_IMAGES_PLANE))
+	for(var/atom/movable/screen/plane_master/pipecrawl as anything in hud_used.get_true_plane_masters(PIPECRAWL_IMAGES_PLANE))
 		pipecrawl.unhide_plane(src)
 
 	var/obj/machinery/atmospherics/current_location = loc

code/modules/mob/mob.dm

@@ -1142,7 +1142,7 @@
 /mob/proc/sync_lighting_plane_alpha()
 	if(!hud_used)
 		return
-	for(var/atom/movable/screen/plane_master/rendering_plate/lighting/light_plane in hud_used.get_true_plane_masters(RENDER_PLANE_LIGHTING))
+	for(var/atom/movable/screen/plane_master/light_plane as anything in hud_used.get_true_plane_masters(RENDER_PLANE_LIGHTING))
 		light_plane.set_alpha(lighting_alpha)
 
 ///Update the mouse pointer of the attached client in this mob

code/modules/paperwork/paperbin.dm

@@ -152,7 +152,7 @@
 /obj/item/paper_bin/update_overlays()
 	. = ..()
 
-	var/static/reference_paper
+	var/static/obj/item/paper/reference_paper
 	if (isnull(reference_paper))
 		reference_paper = new /obj/item/paper
 
@@ -163,6 +163,9 @@
 		bin_overlay = mutable_appearance(icon, bin_overlay_string)
 
 	if(total_paper > 0)
+		if(total_paper > length(paper_stack))
+			SET_PLANE_EXPLICIT(reference_paper, initial(reference_paper.plane), src)
+			reference_paper.update_appearance() // Ensures all our overlays are on the right plane
 		for(var/paper_number in 1 to total_paper)
 			if(paper_number != total_paper && paper_number % PAPERS_PER_OVERLAY != 0) //only top paper and every nth paper get overlays
 				continue

tgstation.dme

@@ -2830,6 +2830,7 @@
 #include "code\modules\client\preferences\jobless_role.dm"
 #include "code\modules\client\preferences\mod_select.dm"
 #include "code\modules\client\preferences\multiz_parallax.dm"
+#include "code\modules\client\preferences\multiz_performance.dm"
 #include "code\modules\client\preferences\names.dm"
 #include "code\modules\client\preferences\ooc.dm"
 #include "code\modules\client\preferences\parallax.dm"

tgui/packages/tgui/interfaces/PreferencesMenu/preferences/features/game_preferences/multiz_performance.tsx

@@ -0,0 +1,12 @@
+import { createDropdownInput, Feature } from '../base';
+
+export const multiz_performance: Feature<number> = {
+  name: 'Multi-Z Detail',
+  category: 'GAMEPLAY',
+  description: 'How detailed multi-z is. Lower this to improve performance',
+  component: createDropdownInput({
+    [-1]: 'Standard',
+    1: 'Medium',
+    0: 'Low',
+  }),
+};