[MIRROR] Opacity refactor (#405)

* 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

* Opacity refactor

Co-authored-by: Rohesie <rohesie@gmail.com>

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"