Opacity refactor (#52881)

Moves all opacity var manipulation to a proc which sends a signal.
    light_blocker element for movable opaque atoms made, which tracks its movement and updates the affected turfs for proper lighting updates.
    has_opaque_atom boolean replaced by the opacity_sources lazylist to keep track of the sources, and a directional_opacity which serves a similar function but also allows for future expansion with on-border opaque objects (not yet implemented).
    Some opacity-related sight procs optimized as a result of this.
    Some variables moved to the object's definition.
    A define or two added into the mix for clarity.
    Some code cleaning, like turning booleans into their defines.
    One file renamed for clarity.

Changelog

cl
balance: Mechs no longer block sight. It's a non-trivial cost for the lighting system with little to no gain.
/cl

code/__DEFINES/dcs/signals.dm

@@ -165,7 +165,9 @@
 ///from base of atom/attack_paw(): (mob/user)
 #define COMSIG_ATOM_ATTACK_PAW "atom_attack_paw"
 	#define COMPONENT_NO_ATTACK_HAND (1<<0)								//works on all 3.
-//This signal return value bitflags can be found in __DEFINES/misc.dm
+///from base of atom/set_opacity(): (new_opacity)
+#define COMSIG_ATOM_SET_OPACITY "atom_set_opacity"
+
 //from base of atom/movable/on_enter_storage(): (datum/component/storage/concrete/master_storage)
 #define COMISG_STORAGE_ENTERED "storage_entered"
 //from base of atom/movable/on_exit_storage(): (datum/component/storage/concrete/master_storage)

code/__DEFINES/flags.dm

@@ -4,9 +4,12 @@
 #define ALL (~0) //For convenience.
 #define NONE 0
 
-
 GLOBAL_LIST_INIT(bitflags, list(1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768))
 
+/* Directions */
+///All the cardinal direction bitflags.
+#define ALL_CARDINALS (NORTH|SOUTH|EAST|WEST)
+
 // for /datum/var/datum_flags
 #define DF_USE_TAG		(1<<0)
 #define DF_VAR_EDITED	(1<<1)

code/__DEFINES/turfs.dm

@@ -4,3 +4,5 @@
 #define CHANGETURF_SKIP				8 // A flag for PlaceOnTop to just instance the new turf instead of calling ChangeTurf. Used for uninitialized turfs NOTHING ELSE
 #define CHANGETURF_INHERIT_AIR 16 // Inherit air from previous turf. Implies CHANGETURF_IGNORE_AIR
 #define CHANGETURF_RECALC_ADJACENT 32 //Immediately recalc adjacent atmos turfs instead of queuing.
+
+#define IS_OPAQUE_TURF(turf) (turf.directional_opacity == ALL_CARDINALS)

code/__HELPERS/game.dm

@@ -262,7 +262,7 @@
 			Y1+=s
 			while(Y1!=Y2)
 				T=locate(X1,Y1,Z)
-				if(T.opacity)
+				if(IS_OPAQUE_TURF(T))
 					return 0
 				Y1+=s
 	else
@@ -278,7 +278,7 @@
 			else
 				X1+=signX //Line exits tile horizontally
 			T=locate(X1,Y1,Z)
-			if(T.opacity)
+			if(IS_OPAQUE_TURF(T))
 				return 0
 	return 1
 #undef SIGNV

code/__HELPERS/unsorted.dm

@@ -461,17 +461,13 @@ Turf and target are separate in case you want to teleport some distance from a t
 		current = get_step_towards(current, target_turf)
 		while(current != target_turf)
 			if(steps > length)
-				return 0
-			if(current.opacity)
-				return 0
-			for(var/thing in current)
-				var/atom/A = thing
-				if(A.opacity)
-					return 0
+				return FALSE
+			if(IS_OPAQUE_TURF(current))
+				return FALSE
 			current = get_step_towards(current, target_turf)
 			steps++
+	return TRUE
 
-	return 1
 
 //Repopulates sortedAreas list
 /proc/repopulate_sorted_areas()

code/datums/components/shrink.dm

@@ -11,7 +11,7 @@
 	olddens = parent_atom.density
 	oldopac = parent_atom.opacity
 	parent_atom.density = 0
-	parent_atom.opacity = 0
+	parent_atom.set_opacity(FALSE)
 	if(isliving(parent_atom))
 		var/mob/living/L = parent_atom
 		L.add_movespeed_modifier(/datum/movespeed_modifier/shrink_ray)
@@ -31,7 +31,7 @@
 	var/atom/parent_atom = parent
 	parent_atom.transform = parent_atom.transform.Scale(2,2)
 	parent_atom.density = olddens
-	parent_atom.opacity = oldopac
+	parent_atom.set_opacity(oldopac)
 	if(isliving(parent_atom))
 		var/mob/living/L = parent_atom
 		L.remove_movespeed_modifier(/datum/movespeed_modifier/shrink_ray)

code/datums/elements/light_blocking.dm

@@ -0,0 +1,35 @@
+/**
+  * Attached to movable atoms with opacity. Listens to them move and updates their old and new turf loc's opacity accordingly.
+  */
+/datum/element/light_blocking
+	element_flags = ELEMENT_DETACH
+
+
+/datum/element/light_blocking/Attach(datum/target)
+	. = ..()
+	if(!ismovable(target))
+		return ELEMENT_INCOMPATIBLE
+	RegisterSignal(target, COMSIG_MOVABLE_MOVED, .proc/on_target_move)
+	var/atom/movable/movable_target = target
+	if(isturf(movable_target.loc))
+		var/turf/turf_loc = movable_target.loc
+		turf_loc.add_opacity_source(target)
+
+
+/datum/element/light_blocking/Detach(atom/movable/target)
+	. = ..()
+	UnregisterSignal(target, list(COMSIG_MOVABLE_MOVED))
+	var/atom/movable/movable_target = target
+	if(isturf(movable_target.loc))
+		var/turf/turf_loc = movable_target.loc
+		turf_loc.remove_opacity_source(target)
+
+
+///Updates old and new turf loc opacities.
+/datum/element/light_blocking/proc/on_target_move(atom/movable/source, atom/OldLoc, Dir, Forced = FALSE)
+	if(isturf(OldLoc))
+		var/turf/old_turf = OldLoc
+		old_turf.remove_opacity_source(source)
+	if(isturf(source.loc))
+		var/turf/new_turf = source.loc
+		new_turf.add_opacity_source(source)

code/game/atoms.dm

@@ -204,10 +204,6 @@
 	if (light_power && light_range)
 		update_light()
 
-	if (opacity && isturf(loc))
-		var/turf/T = loc
-		T.has_opaque_atom = TRUE // No need to recalculate it in this case, it's guaranteed to be on afterwards anyways.
-
 	if (length(smoothing_groups))
 		sortTim(smoothing_groups) //In case it's not properly ordered, let's avoid duplicate entries with the same values.
 		SET_BITFLAG_LIST(smoothing_groups)

code/game/atoms_movable.dm

@@ -54,6 +54,7 @@
 	///Used for the calculate_adjacencies proc for icon smoothing.
 	var/can_be_unanchored = FALSE
 
+
 /atom/movable/Initialize(mapload)
 	. = ..()
 	switch(blocks_emissive)
@@ -63,6 +64,8 @@
 			render_target = ref(src)
 			em_block = new(src, render_target)
 			vis_contents += em_block
+	if(opacity)
+		AddElement(/datum/element/light_blocking)
 
 
 /atom/movable/Destroy(force)
@@ -79,13 +82,8 @@
 			air_update_turf(TRUE)
 		loc.handle_atom_del(src)
 
-		// If we have opacity, make sure to tell (potentially) affected light sources.
-		if(opacity && isturf(loc))
-			var/turf/turf_loc = loc
-			var/old_has_opaque_atom = turf_loc.has_opaque_atom
-			turf_loc.recalc_atom_opacity()
-			if(old_has_opaque_atom != turf_loc.has_opaque_atom)
-				turf_loc.reconsider_lights()
+	if(opacity)
+		RemoveElement(/datum/element/light_blocking)
 
 	invisibility = INVISIBILITY_ABSTRACT
 

code/game/machinery/doors/airlock_types.dm

@@ -64,7 +64,7 @@
 */
 
 /obj/machinery/door/airlock/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/glass/incinerator
@@ -82,28 +82,28 @@
 	id_tag = INCINERATOR_SYNDICATELAVA_AIRLOCK_EXTERIOR
 
 /obj/machinery/door/airlock/command/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 	normal_integrity = 400
 
 /obj/machinery/door/airlock/engineering/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/engineering/glass/critical
 	critical_machine = TRUE //stops greytide virus from opening & bolting doors in critical positions, such as the SM chamber.
 
 /obj/machinery/door/airlock/security/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 	normal_integrity = 400
 
 /obj/machinery/door/airlock/medical/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/research/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/research/glass/incinerator
@@ -121,30 +121,30 @@
 	id_tag = INCINERATOR_TOXMIX_AIRLOCK_EXTERIOR
 
 /obj/machinery/door/airlock/mining/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/atmos/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/atmos/glass/critical
 	critical_machine = TRUE //stops greytide virus from opening & bolting doors in critical positions, such as the SM chamber.
 
 /obj/machinery/door/airlock/science/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/virology/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/maintenance/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/maintenance/external/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 	normal_integrity = 200
 
@@ -159,7 +159,7 @@
 	assemblytype = /obj/structure/door_assembly/door_assembly_gold
 
 /obj/machinery/door/airlock/gold/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/silver
@@ -168,7 +168,7 @@
 	assemblytype = /obj/structure/door_assembly/door_assembly_silver
 
 /obj/machinery/door/airlock/silver/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/diamond
@@ -180,7 +180,7 @@
 
 /obj/machinery/door/airlock/diamond/glass
 	normal_integrity = 950
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/uranium
@@ -201,7 +201,7 @@
 	return
 
 /obj/machinery/door/airlock/uranium/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/plasma
@@ -242,7 +242,7 @@
 		return ..()
 
 /obj/machinery/door/airlock/plasma/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/bananium
@@ -253,7 +253,7 @@
 	doorOpen = 'sound/items/bikehorn.ogg'
 
 /obj/machinery/door/airlock/bananium/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/sandstone
@@ -262,7 +262,7 @@
 	assemblytype = /obj/structure/door_assembly/door_assembly_sandstone
 
 /obj/machinery/door/airlock/sandstone/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/wood
@@ -271,7 +271,7 @@
 	assemblytype = /obj/structure/door_assembly/door_assembly_wood
 
 /obj/machinery/door/airlock/wood/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/titanium
@@ -283,7 +283,7 @@
 
 /obj/machinery/door/airlock/titanium/glass
 	normal_integrity = 350
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/bronze
@@ -294,7 +294,7 @@
 
 /obj/machinery/door/airlock/bronze/seethru
 	assemblytype = /obj/structure/door_assembly/door_assembly_bronze/seethru
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 //////////////////////////////////
 /*
@@ -307,7 +307,7 @@
 	assemblytype = /obj/structure/door_assembly/door_assembly_public
 
 /obj/machinery/door/airlock/public/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/public/glass/incinerator
@@ -337,7 +337,7 @@
 	assemblytype = /obj/structure/door_assembly/door_assembly_ext
 
 /obj/machinery/door/airlock/external/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 //////////////////////////////////
@@ -418,7 +418,7 @@
 	assemblytype = /obj/structure/door_assembly/door_assembly_shuttle
 
 /obj/machinery/door/airlock/shuttle/glass
-	opacity = 0
+	opacity = FALSE
 	glass = TRUE
 
 /obj/machinery/door/airlock/abductor
@@ -515,7 +515,7 @@
 
 /obj/machinery/door/airlock/cult/glass
 	glass = TRUE
-	opacity = 0
+	opacity = FALSE
 
 /obj/machinery/door/airlock/cult/glass/friendly
 	friendly = TRUE
@@ -531,7 +531,7 @@
 
 /obj/machinery/door/airlock/cult/unruned/glass
 	glass = TRUE
-	opacity = 0
+	opacity = FALSE
 
 /obj/machinery/door/airlock/cult/unruned/glass/friendly
 	friendly = TRUE
@@ -552,7 +552,7 @@
 	name = "large glass airlock"
 	icon = 'icons/obj/doors/airlocks/glass_large/glass_large.dmi'
 	overlays_file = 'icons/obj/doors/airlocks/glass_large/overlays.dmi'
-	opacity = 0
+	opacity = FALSE
 	assemblytype = null
 	glass = TRUE
 	bound_width = 64 // 2x1

code/game/machinery/doors/alarmlock.dm

@@ -2,7 +2,7 @@
 	name = "glass alarm airlock"
 	icon = 'icons/obj/doors/airlocks/station2/glass.dmi'
 	overlays_file = 'icons/obj/doors/airlocks/station2/overlays.dmi'
-	opacity = 0
+	opacity = FALSE
 	assemblytype = /obj/structure/door_assembly/door_assembly_public
 	glass = TRUE
 

code/game/machinery/doors/door.dm

@@ -4,7 +4,7 @@
 	desc = "It opens and closes."
 	icon = 'icons/obj/doors/Doorint.dmi'
 	icon_state = "door1"
-	opacity = 1
+	opacity = TRUE
 	density = TRUE
 	move_resist = MOVE_FORCE_VERY_STRONG
 	layer = OPEN_DOOR_LAYER

code/game/machinery/doors/poddoor.dm

@@ -22,7 +22,7 @@
 /obj/machinery/door/poddoor/preopen
 	icon_state = "open"
 	density = FALSE
-	opacity = 0
+	opacity = FALSE
 
 /obj/machinery/door/poddoor/ert
 	name = "hardened blast door"

code/game/machinery/doors/shutters.dm

@@ -10,7 +10,7 @@
 /obj/machinery/door/poddoor/shutters/preopen
 	icon_state = "open"
 	density = FALSE
-	opacity = 0
+	opacity = FALSE
 
 /obj/machinery/door/poddoor/shutters/indestructible
 	name = "hardened shutters"

code/game/machinery/doors/unpowered.dm

@@ -20,6 +20,6 @@
 	icon = 'icons/turf/shuttle.dmi'
 	name = "door"
 	icon_state = "door1"
-	opacity = 1
+	opacity = TRUE
 	density = TRUE
 	explosion_block = 1

code/game/machinery/doors/windowdoor.dm

@@ -12,7 +12,7 @@
 	armor = list("melee" = 20, "bullet" = 50, "laser" = 50, "energy" = 50, "bomb" = 10, "bio" = 100, "rad" = 100, "fire" = 70, "acid" = 100)
 	visible = FALSE
 	flags_1 = ON_BORDER_1
-	opacity = 0
+	opacity = FALSE
 	CanAtmosPass = ATMOS_PASS_PROC
 	interaction_flags_machine = INTERACT_MACHINE_WIRES_IF_OPEN | INTERACT_MACHINE_ALLOW_SILICON | INTERACT_MACHINE_OPEN_SILICON | INTERACT_MACHINE_REQUIRES_SILICON | INTERACT_MACHINE_OPEN
 	var/obj/item/electronics/airlock/electronics = null

code/game/machinery/hypnochair.dm

@@ -5,7 +5,7 @@
 	icon_state = "hypnochair"
 	circuit = /obj/item/circuitboard/machine/hypnochair
 	density = TRUE
-	opacity = 0
+	opacity = FALSE
 
 	var/mob/living/carbon/victim = null ///Keeps track of the victim to apply effects if it teleports away
 	var/interrogating = FALSE ///Is the device currently interrogating someone?

code/game/machinery/shieldgen.dm

@@ -5,7 +5,7 @@
 	icon_state = "shield-old"
 	density = TRUE
 	move_resist = INFINITY
-	opacity = 0
+	opacity = FALSE
 	anchored = TRUE
 	resistance_flags = LAVA_PROOF | FIRE_PROOF | UNACIDABLE | ACID_PROOF
 	max_integrity = 200 //The shield can only take so much beating (prevents perma-prisons)
@@ -107,7 +107,7 @@
 	icon = 'icons/obj/objects.dmi'
 	icon_state = "shieldoff"
 	density = TRUE
-	opacity = 0
+	opacity = FALSE
 	anchored = FALSE
 	pressure_resistance = 2*ONE_ATMOSPHERE
 	req_access = list(ACCESS_ENGINE)

code/game/mecha/combat/reticence.dm

@@ -18,7 +18,7 @@
 	color = "#87878715"
 	stepsound = null
 	turnsound = null
-	opacity = 0
+
 
 /obj/mecha/combat/reticence/loaded/Initialize()
 	. = ..()

code/game/mecha/mecha.dm

@@ -3,7 +3,6 @@
 	desc = "Exosuit"
 	icon = 'icons/mecha/mecha.dmi'
 	density = TRUE //Dense. To raise the heat.
-	opacity = TRUE //opaque. Menacing.
 	move_force = MOVE_FORCE_VERY_STRONG
 	move_resist = MOVE_FORCE_EXTREMELY_STRONG
 	resistance_flags = FIRE_PROOF | ACID_PROOF

code/game/mecha/mecha_wreckage.dm

@@ -9,7 +9,7 @@
 	icon = 'icons/mecha/mecha.dmi'
 	density = TRUE
 	anchored = FALSE
-	opacity = 0
+	opacity = FALSE
 	var/list/welder_salvage = list(/obj/item/stack/sheet/plasteel, /obj/item/stack/sheet/metal, /obj/item/stack/rods)
 	var/salvage_num = 5
 	var/list/crowbar_salvage = list()

code/game/mecha/working/ripley.dm

@@ -19,7 +19,6 @@
 	enclosed = FALSE //Normal ripley has an open cockpit design
 	enter_delay = 10 //can enter in a quarter of the time of other mechs
 	exit_delay = 10
-	opacity = FALSE //Ripley has a window
 	/// Amount of Goliath hides attached to the mech
 	var/hides = 0
 	/// List of all things in Ripley's Cargo Compartment

code/game/objects/effects/alien_acid.dm

@@ -4,7 +4,7 @@
 	desc = "Burbling corrosive stuff."
 	icon_state = "acid"
 	density = FALSE
-	opacity = 0
+	opacity = FALSE
 	anchored = TRUE
 	resistance_flags = FIRE_PROOF | UNACIDABLE | ACID_PROOF
 	layer = ABOVE_NORMAL_TURF_LAYER

code/game/objects/effects/bump_teleporter.dm

@@ -7,7 +7,7 @@
 	invisibility = INVISIBILITY_ABSTRACT 		//nope, can't see this
 	anchored = TRUE
 	density = TRUE
-	opacity = 0
+	opacity = FALSE
 
 	var/static/list/AllTeleporters
 

code/game/objects/effects/effect_system/effects_explosion.dm

@@ -1,7 +1,7 @@
 /obj/effect/particle_effect/expl_particles
 	name = "fire"
 	icon_state = "explosion_particle"
-	opacity = 1
+	opacity = TRUE
 	anchored = TRUE
 
 /obj/effect/particle_effect/expl_particles/Initialize()
@@ -27,7 +27,7 @@
 	name = "fire"
 	icon = 'icons/effects/96x96.dmi'
 	icon_state = "explosion"
-	opacity = 1
+	opacity = TRUE
 	anchored = TRUE
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
 	pixel_x = -32

code/game/objects/effects/effect_system/effects_foam.dm

@@ -8,7 +8,7 @@
 /obj/effect/particle_effect/foam
 	name = "foam"
 	icon_state = "foam"
-	opacity = 0
+	opacity = FALSE
 	anchored = TRUE
 	density = FALSE
 	layer = EDGED_TURF_LAYER
@@ -257,7 +257,7 @@
 	icon = 'icons/effects/effects.dmi'
 	icon_state = "metalfoam"
 	density = TRUE
-	opacity = 1 	// changed in New()
+	opacity = TRUE 	// changed in New()
 	anchored = TRUE
 	layer = EDGED_TURF_LAYER
 	resistance_flags = FIRE_PROOF | ACID_PROOF

code/game/objects/effects/effect_system/effects_smoke.dm

@@ -8,7 +8,7 @@
 	icon_state = "smoke"
 	pixel_x = -32
 	pixel_y = -32
-	opacity = 0
+	opacity = FALSE
 	layer = FLY_LAYER
 	anchored = TRUE
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT

code/game/objects/effects/forcefields.dm

@@ -3,7 +3,7 @@
 	name = "FORCEWALL"
 	icon_state = "m_shield"
 	anchored = TRUE
-	opacity = 0
+	opacity = FALSE
 	density = TRUE
 	CanAtmosPass = ATMOS_PASS_DENSITY
 	var/timeleft = 300 //Set to 0 for permanent forcefields (ugh)

code/game/objects/effects/glowshroom.dm

@@ -4,7 +4,7 @@
 	name = "glowshroom"
 	desc = "Mycena Bregprox, a species of mushroom that glows in the dark."
 	anchored = TRUE
-	opacity = 0
+	opacity = FALSE
 	density = FALSE
 	icon = 'icons/obj/lighting.dmi'
 	icon_state = "glowshroom" //replaced in New

code/game/objects/items/RCD.dm

@@ -12,7 +12,7 @@ RLD
 /obj/item/construction
 	name = "not for ingame use"
 	desc = "A device used to rapidly build and deconstruct. Reload with metal, plasteel, glass or compressed matter cartridges."
-	opacity = 0
+	opacity = FALSE
 	density = FALSE
 	anchored = FALSE
 	flags_1 = CONDUCT_1

code/game/objects/items/RSF.dm

@@ -14,7 +14,7 @@ RSF
 	var/spent_icon_state = "rsf_empty"
 	lefthand_file = 'icons/mob/inhands/equipment/tools_lefthand.dmi'
 	righthand_file = 'icons/mob/inhands/equipment/tools_righthand.dmi'
-	opacity = 0
+	opacity = FALSE
 	density = FALSE
 	anchored = FALSE
 	item_flags = NOBLUDGEON

code/game/objects/items/implants/implantchair.dm

@@ -4,7 +4,7 @@
 	icon = 'icons/obj/machines/implantchair.dmi'
 	icon_state = "implantchair"
 	density = TRUE
-	opacity = 0
+	opacity = FALSE
 
 	var/ready = TRUE
 	var/replenishing = FALSE

code/game/objects/structures/aliens.dm

@@ -55,7 +55,7 @@
 	icon = 'icons/obj/smooth_structures/alien/resin_wall.dmi'
 	icon_state = "smooth"
 	density = TRUE
-	opacity = 1
+	opacity = TRUE
 	anchored = TRUE
 	smoothing_flags = SMOOTH_CORNERS
 	smoothing_groups = list(SMOOTH_GROUP_ALIEN_RESIN)
@@ -91,7 +91,7 @@
 	desc = "Resin just thin enough to let light pass through."
 	icon = 'icons/obj/smooth_structures/alien/resin_membrane.dmi'
 	icon_state = "smooth"
-	opacity = 0
+	opacity = FALSE
 	max_integrity = 160
 	resintype = "membrane"
 	smoothing_groups = list(SMOOTH_GROUP_ALIEN_RESIN, SMOOTH_GROUP_ALIEN_WALLS)

code/game/objects/structures/false_walls.dm

@@ -9,7 +9,7 @@
 	icon_state = "wall"
 	layer = LOW_OBJ_LAYER
 	density = TRUE
-	opacity = 1
+	opacity = TRUE
 	max_integrity = 100
 	smoothing_flags = SMOOTH_CORNERS
 	smoothing_groups = list(SMOOTH_GROUP_CLOSED_TURFS, SMOOTH_GROUP_WALLS)

code/game/objects/structures/fluff.dm

@@ -7,7 +7,7 @@
 	icon_state = "minibar"
 	anchored = TRUE
 	density = FALSE
-	opacity = 0
+	opacity = FALSE
 	var/deconstructible = TRUE
 
 /obj/structure/fluff/attackby(obj/item/I, mob/living/user, params)
@@ -261,4 +261,4 @@
 	deconstructible = FALSE
 
 /obj/structure/fluff/hedge/opaque //useful for mazes and such
-	opacity = 1
+	opacity = TRUE

code/game/objects/structures/guncase.dm

@@ -6,7 +6,7 @@
 	icon_state = "shotguncase"
 	anchored = FALSE
 	density = TRUE
-	opacity = 0
+	opacity = FALSE
 	var/case_type = ""
 	var/gun_category = /obj/item/gun
 	var/open = TRUE

code/game/objects/structures/signs/_signs.dm

@@ -1,7 +1,7 @@
 /obj/structure/sign
 	icon = 'icons/obj/decals.dmi'
 	anchored = TRUE
-	opacity = 0
+	opacity = FALSE
 	density = FALSE
 	layer = SIGN_LAYER
 	custom_materials = list(/datum/material/plastic = 2000)

code/game/objects/structures/watercloset.dm

@@ -441,13 +441,13 @@
 		density = TRUE
 		open = FALSE
 		if(opaque_closed)
-			opacity = TRUE
+			set_opacity(TRUE)
 	else
 		icon_state = "[icon_type]-open"
 		layer = SIGN_LAYER
 		density = FALSE
 		open = TRUE
-		opacity = FALSE
+		set_opacity(FALSE)
 
 /obj/structure/curtain/attackby(obj/item/W, mob/user)
 	if (istype(W, /obj/item/toy/crayon))

code/game/objects/structures/window.dm

@@ -576,7 +576,7 @@
 /obj/structure/window/reinforced/tinted
 	name = "tinted window"
 	icon_state = "twindow"
-	opacity = 1
+	opacity = TRUE
 /obj/structure/window/reinforced/tinted/frosted
 	name = "frosted window"
 	icon_state = "fwindow"

code/game/shuttle_engines.dm

@@ -103,7 +103,7 @@
 	name = "propulsion engine"
 	icon_state = "propulsion"
 	desc = "A standard reliable bluespace engine used by many forms of shuttles."
-	opacity = 1
+	opacity = TRUE
 
 /obj/structure/shuttle/engine/propulsion/left
 	name = "left propulsion engine"
@@ -136,7 +136,7 @@
 
 /obj/structure/shuttle/engine/large
 	name = "engine"
-	opacity = 1
+	opacity = TRUE
 	icon = 'icons/obj/2x2.dmi'
 	icon_state = "large_engine"
 	desc = "A very large bluespace engine used to propel very large ships."
@@ -146,7 +146,7 @@
 
 /obj/structure/shuttle/engine/huge
 	name = "engine"
-	opacity = 1
+	opacity = TRUE
 	icon = 'icons/obj/3x3.dmi'
 	icon_state = "huge_engine"
 	desc = "An extremely large bluespace engine used to propel extremely large ships."

code/game/turfs/change_turf.dm

@@ -77,11 +77,11 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 	if(flags & CHANGETURF_SKIP)
 		return new path(src)
 
-	var/old_opacity = opacity
 	var/old_dynamic_lighting = dynamic_lighting
 	var/old_affecting_lights = affecting_lights
 	var/old_lighting_object = lighting_object
 	var/old_corners = corners
+	var/old_directional_opacity = directional_opacity
 
 	var/old_exl = explosion_level
 	var/old_exi = explosion_id
@@ -117,12 +117,11 @@ GLOBAL_LIST_INIT(blacklisted_automated_baseturfs, typecacheof(list(
 	W.blueprint_data = old_bp
 
 	if(SSlighting.initialized)
-		recalc_atom_opacity()
 		lighting_object = old_lighting_object
 		affecting_lights = old_affecting_lights
 		corners = old_corners
-		if (old_opacity != opacity || dynamic_lighting != old_dynamic_lighting)
-			reconsider_lights()
+		directional_opacity = old_directional_opacity
+		recalculate_directional_opacity()
 
 		if (dynamic_lighting != old_dynamic_lighting)
 			if (IS_DYNAMIC_LIGHTING(src))

code/game/turfs/closed/_closed.dm

@@ -1,6 +1,6 @@
 /turf/closed
 	layer = CLOSED_TURF_LAYER
-	opacity = 1
+	opacity = TRUE
 	density = TRUE
 	blocks_air = TRUE
 	flags_1 = RAD_PROTECT_CONTENTS_1 | RAD_NO_CONTAMINATE_1
@@ -114,7 +114,7 @@
 /turf/closed/indestructible/fakeglass
 	name = "window"
 	icon_state = "fake_window"
-	opacity = 0
+	opacity = FALSE
 	smoothing_flags = SMOOTH_CORNERS
 	icon = 'icons/obj/smooth_structures/reinforced_window.dmi'
 
@@ -127,7 +127,7 @@
 /turf/closed/indestructible/opsglass
 	name = "window"
 	icon_state = "plastitanium_window"
-	opacity = 0
+	opacity = FALSE
 	smoothing_flags = SMOOTH_CORNERS
 	icon = 'icons/obj/smooth_structures/plastitanium_window.dmi'
 

code/game/turfs/closed/minerals.dm

@@ -10,7 +10,7 @@
 	canSmoothWith = list(SMOOTH_GROUP_MINERAL_WALLS)
 	baseturfs = /turf/open/floor/plating/asteroid/airless
 	initial_gas_mix = AIRLESS_ATMOS
-	opacity = 1
+	opacity = TRUE
 	density = TRUE
 	layer = EDGED_TURF_LAYER
 	temperature = TCMB

code/game/turfs/closed/wall/reinf_walls.dm

@@ -3,7 +3,7 @@
 	desc = "A huge chunk of reinforced metal used to separate rooms."
 	icon = 'icons/turf/walls/reinforced_wall.dmi'
 	icon_state = "r_wall"
-	opacity = 1
+	opacity = TRUE
 	density = TRUE
 
 	var/d_state = INTACT

code/game/turfs/open/space/space.dm

@@ -61,7 +61,7 @@
 		update_light()
 
 	if (opacity)
-		has_opaque_atom = TRUE
+		directional_opacity = ALL_CARDINALS
 
 	ComponentInitialize()
 

code/game/turfs/turf.dm

@@ -3,6 +3,7 @@ GLOBAL_LIST_EMPTY(station_turfs)
 	icon = 'icons/turf/floors.dmi'
 	flags_1 = CAN_BE_DIRTY_1
 	vis_flags = VIS_INHERIT_ID|VIS_INHERIT_PLANE // Important for interaction with and visualization of openspace.
+	luminosity = 1
 
 	var/intact = 1
 
@@ -37,6 +38,21 @@ GLOBAL_LIST_EMPTY(station_turfs)
 	///Icon-smoothing variable to map a diagonal wall corner with a fixed underlay.
 	var/list/fixed_underlay = null
 
+	var/dynamic_lighting = TRUE
+
+	var/tmp/lighting_corners_initialised = FALSE
+
+	///List of light sources affecting this turf.
+	var/tmp/list/datum/light_source/affecting_lights
+	///Our lighting object.
+	var/tmp/atom/movable/lighting_object/lighting_object
+	var/tmp/list/datum/lighting_corner/corners
+
+	///Which directions does this turf block the vision of, taking into account both the turf's opacity and the movable opacity_sources.
+	var/directional_opacity = NONE
+	///Lazylist of movable atoms providing opacity sources.
+	var/list/atom/movable/opacity_sources
+
 
 /turf/vv_edit_var(var_name, new_value)
 	var/static/list/banned_edits = list("x", "y", "z")
@@ -99,7 +115,7 @@ GLOBAL_LIST_EMPTY(station_turfs)
 		SEND_SIGNAL(T, COMSIG_TURF_MULTIZ_NEW, src, UP)
 
 	if (opacity)
-		has_opaque_atom = TRUE
+		directional_opacity = ALL_CARDINALS
 
 	// apply materials properly from the default custom_materials value
 	set_custom_materials(custom_materials)
@@ -288,13 +304,6 @@ GLOBAL_LIST_EMPTY(station_turfs)
 		if(QDELETED(mover))
 			return FALSE		//We were deleted.
 
-/turf/Entered(atom/movable/AM)
-	..()
-
-	// If an opaque movable atom moves around we need to potentially update visibility.
-	if (AM.opacity)
-		has_opaque_atom = TRUE // Make sure to do this before reconsider_lights(), incase we're on instant updates. Guaranteed to be on in this case.
-		reconsider_lights()
 
 /turf/open/Entered(atom/movable/AM)
 	..()

code/modules/antagonists/blob/structures/_blob.dm

@@ -5,7 +5,7 @@
 	light_range = 2
 	desc = "A thick wall of writhing tendrils."
 	density = FALSE //this being false causes two bugs, being able to attack blob tiles behind other blobs and being unable to move on blob tiles in no gravity, but turning it to 1 causes the blob mobs to be unable to path through blobs, which is probably worse.
-	opacity = 0
+	opacity = FALSE
 	anchored = TRUE
 	layer = BELOW_MOB_LAYER
 	CanAtmosPass = ATMOS_PASS_PROC

code/modules/atmospherics/environmental/LINDA_turf_tile.dm

@@ -419,7 +419,7 @@
 /turf/proc/conductivity_directions()
 	if(archived_cycle < SSair.times_fired)
 		archive()
-	return NORTH|SOUTH|EAST|WEST
+	return ALL_CARDINALS
 
 /turf/open/conductivity_directions()
 	if(blocks_air)

code/modules/atmospherics/machinery/pipes/heat_exchange/manifold.dm

@@ -23,7 +23,7 @@
 	return ..()
 
 /obj/machinery/atmospherics/pipe/heat_exchanging/manifold/SetInitDirections()
-	initialize_directions = NORTH|SOUTH|EAST|WEST
+	initialize_directions = ALL_CARDINALS
 	initialize_directions &= ~dir
 
 /obj/machinery/atmospherics/pipe/heat_exchanging/manifold/update_icon()

code/modules/atmospherics/machinery/pipes/heat_exchange/manifold4w.dm

@@ -7,7 +7,7 @@
 	name = "4-way pipe manifold"
 	desc = "A manifold composed of heat-exchanging pipes."
 
-	initialize_directions = NORTH|SOUTH|EAST|WEST
+	initialize_directions = ALL_CARDINALS
 
 	device_type = QUATERNARY
 

code/modules/atmospherics/machinery/pipes/manifold.dm

@@ -27,7 +27,7 @@
 	return ..()
 
 /obj/machinery/atmospherics/pipe/manifold/SetInitDirections()
-	initialize_directions = NORTH|SOUTH|EAST|WEST
+	initialize_directions = ALL_CARDINALS
 	initialize_directions &= ~dir
 
 /obj/machinery/atmospherics/pipe/manifold/update_icon()

code/modules/atmospherics/machinery/pipes/manifold4w.dm

@@ -7,7 +7,7 @@
 	name = "4-way pipe manifold"
 	desc = "A manifold composed of regular pipes."
 
-	initialize_directions = NORTH|SOUTH|EAST|WEST
+	initialize_directions = ALL_CARDINALS
 
 	device_type = QUATERNARY
 

code/modules/clothing/spacesuits/chronosuit.dm

@@ -246,7 +246,7 @@
 	density = FALSE
 	anchored = TRUE
 	invisibility = INVISIBILITY_ABSTRACT
-	opacity = 0
+	opacity = FALSE
 	mouse_opacity = MOUSE_OPACITY_TRANSPARENT
 	var/mob/holder
 	var/phase_time = 0

code/modules/library/lib_items.dm

@@ -21,7 +21,7 @@
 	desc = "A great place for storing knowledge."
 	anchored = FALSE
 	density = TRUE
-	opacity = 0
+	opacity = FALSE
 	resistance_flags = FLAMMABLE
 	max_integrity = 200
 	armor = list("melee" = 0, "bullet" = 0, "laser" = 0, "energy" = 0, "bomb" = 0, "bio" = 0, "rad" = 0, "fire" = 50, "acid" = 0)

code/modules/lighting/lighting_atom.dm

@@ -41,25 +41,36 @@
 			light = new/datum/light_source(src, .)
 
 
-// Should always be used to change the opacity of an atom.
-// It notifies (potentially) affected light sources so they can update (if needed).
+/**
+  * Updates the atom's opacity value.
+  *
+  * This exists to act as a hook for associated behavior.
+  * It notifies (potentially) affected light sources so they can update (if needed).
+  */
 /atom/proc/set_opacity(new_opacity)
 	if (new_opacity == opacity)
 		return
-
+	SEND_SIGNAL(src, COMSIG_ATOM_SET_OPACITY, new_opacity)
+	. = opacity
 	opacity = new_opacity
-	var/turf/T = loc
-	if (!isturf(T))
+
+
+/atom/movable/set_opacity(new_opacity)
+	. = ..()
+	if(isnull(.) || !isturf(loc))
 		return
 
-	if (new_opacity == TRUE)
-		T.has_opaque_atom = TRUE
-		T.reconsider_lights()
+	if(opacity)
+		AddElement(/datum/element/light_blocking)
 	else
-		var/old_has_opaque_atom = T.has_opaque_atom
-		T.recalc_atom_opacity()
-		if (old_has_opaque_atom != T.has_opaque_atom)
-			T.reconsider_lights()
+		RemoveElement(/datum/element/light_blocking)
+
+
+/turf/set_opacity(new_opacity)
+	. = ..()
+	if(isnull(.))
+		return
+	recalculate_directional_opacity()
 
 
 /atom/movable/Moved(atom/OldLoc, Dir)

code/modules/lighting/lighting_source.dm

@@ -224,7 +224,7 @@
 		for(T in view(CEILING(light_range, 1), source_turf))
 			if((!IS_DYNAMIC_LIGHTING(T) && !T.light_sources))
 				continue
-			if(!T.has_opaque_atom)
+			if(!IS_OPAQUE_TURF(T))
 				if (!T.lighting_corners_initialised)
 					T.generate_missing_corners()
 				for (thing in T.corners)

code/modules/lighting/lighting_turf.dm

@@ -1,14 +1,3 @@
-/turf
-	var/dynamic_lighting = TRUE
-	luminosity           = 1
-
-	var/tmp/lighting_corners_initialised = FALSE
-
-	var/tmp/list/datum/light_source/affecting_lights       // List of light sources affecting this turf.
-	var/tmp/atom/movable/lighting_object/lighting_object // Our lighting object.
-	var/tmp/list/datum/lighting_corner/corners
-	var/tmp/has_opaque_atom = FALSE // Not to be confused with opacity, this will be TRUE if there's any opaque atom on the tile.
-
 // Causes any affecting light sources to be queued for a visibility update, for example a door got opened.
 /turf/proc/reconsider_lights()
 	var/datum/light_source/L
@@ -86,21 +75,42 @@
 
 	return !lighting_object.luminosity
 
-// Can't think of a good name, this proc will recalculate the has_opaque_atom variable.
-/turf/proc/recalc_atom_opacity()
-	has_opaque_atom = opacity
-	if (!has_opaque_atom)
-		for (var/atom/A in src.contents) // Loop through every movable atom on our tile PLUS ourselves (we matter too...)
-			if (A.opacity)
-				has_opaque_atom = TRUE
-				break
 
-/turf/Exited(atom/movable/Obj, atom/newloc)
-	. = ..()
+///Proc to add movable sources of opacity on the turf and let it handle lighting code.
+/turf/proc/add_opacity_source(atom/movable/new_source)
+	LAZYADD(opacity_sources, new_source)
+	if(opacity)
+		return
+	recalculate_directional_opacity()
+
+
+///Proc to remove movable sources of opacity on the turf and let it handle lighting code.
+/turf/proc/remove_opacity_source(atom/movable/old_source)
+	LAZYREMOVE(opacity_sources, old_source)
+	if(opacity) //Still opaque, no need to worry on updating.
+		return
+	recalculate_directional_opacity()
+
+
+///Calculate on which directions this turfs block view.
+/turf/proc/recalculate_directional_opacity()
+	. = directional_opacity
+	if(opacity)
+		directional_opacity = ALL_CARDINALS
+		if(. != directional_opacity)
+			reconsider_lights()
+		return
+	directional_opacity = NONE
+	for(var/am in opacity_sources)
+		var/atom/movable/opacity_source = am
+		if(opacity_source.flags_1 & ON_BORDER_1)
+			directional_opacity |= opacity_source.dir
+		else //If fulltile and opaque, then the whole tile blocks view, no need to continue checking.
+			directional_opacity = ALL_CARDINALS
+			break
+	if(. != directional_opacity && (. == ALL_CARDINALS || directional_opacity == ALL_CARDINALS))
+		reconsider_lights() //The lighting system only cares whether the tile is fully concealed from all directions or not.
 
-	if (Obj && Obj.opacity)
-		recalc_atom_opacity() // Make sure to do this before reconsider_lights(), incase we're on instant updates.
-		reconsider_lights()
 
 /turf/proc/change_area(area/old_area, area/new_area)
 	if(SSlighting.initialized)

code/modules/mob/living/simple_animal/hostile/megafauna/drake.dm

@@ -460,7 +460,7 @@ Difficulty: Medium
 	icon = 'icons/effects/fire.dmi'
 	icon_state = "1"
 	anchored = TRUE
-	opacity = 0
+	opacity = FALSE
 	density = TRUE
 	CanAtmosPass = ATMOS_PASS_DENSITY
 	duration = 82

code/modules/ninja/suit/n_suit_verbs/energy_net_nets.dm

@@ -10,7 +10,7 @@ It is possible to destroy the net by the occupant or someone else.
 	icon_state = "energynet"
 
 	density = TRUE//Can't pass through.
-	opacity = 0//Can see through.
+	opacity = FALSE //Can see through.
 	mouse_opacity = MOUSE_OPACITY_ICON//So you can hit it with stuff.
 	anchored = TRUE//Can't drag/grab the net.
 	layer = ABOVE_ALL_MOB_LAYER

code/modules/power/solar.dm

@@ -145,7 +145,7 @@
 		x_hit += target_x
 		y_hit += target_y
 		hit = locate(round(x_hit, 1), round(y_hit, 1), z)
-		if(hit.opacity)
+		if(IS_OPAQUE_TURF(hit))
 			return
 		if(hit.x == 1 || hit.x == world.maxx || hit.y == 1 || hit.y == world.maxy) //edge of the map
 			break

code/modules/spells/spell.dm

@@ -97,7 +97,7 @@ GLOBAL_LIST_INIT(spells, typesof(/obj/effect/proc_holder/spell)) //needed for th
 	anchored = TRUE // Crap like fireball projectiles are proc_holders, this is needed so fireballs don't get blown back into your face via atmos etc.
 	pass_flags = PASSTABLE
 	density = FALSE
-	opacity = 0
+	opacity = FALSE
 
 	var/school = "evocation" //not relevant at now, but may be important later if there are changes to how spells work. the ones I used for now will probably be changed... maybe spell presets? lacking flexibility but with some other benefit?
 

code/modules/surgery/organs/eyes.dm

@@ -322,7 +322,7 @@
 	on_mob.forceMove(scanning)
 	for(var/i in 1 to light_beam_distance)
 		scanning = get_step(scanning, scandir)
-		if(scanning.opacity || scanning.has_opaque_atom)
+		if(IS_OPAQUE_TURF(scanning))
 			stop = TRUE
 		var/obj/effect/abstract/eye_lighting/L = LAZYACCESS(eye_lighting, i)
 		if(stop)

tgstation.dme

@@ -114,7 +114,7 @@
 #include "code\__DEFINES\time.dm"
 #include "code\__DEFINES\tools.dm"
 #include "code\__DEFINES\traits.dm"
-#include "code\__DEFINES\turf_flags.dm"
+#include "code\__DEFINES\turfs.dm"
 #include "code\__DEFINES\typeids.dm"
 #include "code\__DEFINES\vehicles.dm"
 #include "code\__DEFINES\vv.dm"
@@ -563,6 +563,7 @@
 #include "code\datums\elements\embed.dm"
 #include "code\datums\elements\firestacker.dm"
 #include "code\datums\elements\forced_gravity.dm"
+#include "code\datums\elements\light_blocking.dm"
 #include "code\datums\elements\selfknockback.dm"
 #include "code\datums\elements\snail_crawl.dm"
 #include "code\datums\elements\squish.dm"