[FIX] Ventcrawling overlay fixes (#27013)

* Vent images update while ventcrawling

* Add some comments

* Autodoc for a variable

* Get rid of this useless timer

* Update code/modules/atmospherics/machinery/atmospherics.dm

Co-authored-by: Nathan Winters <100448493+CinnamonSnowball@users.noreply.github.com>
Signed-off-by: Chap <erwin@lombok.demon.nl>

* Move update pipe image to unary base

* We're doing signals now

* Added a comment to the signal

* Trailing newline

---------

Signed-off-by: Chap <erwin@lombok.demon.nl>
Co-authored-by: Adrer <adrermail@gmail.com>
Co-authored-by: Nathan Winters <100448493+CinnamonSnowball@users.noreply.github.com>

code/modules/atmospherics/machinery/atmospherics.dm

@@ -101,8 +101,8 @@ Pipelines + Other Objects -> Pipe network
 			plane = GAME_PLANE
 			layer = GAS_PIPE_VISIBLE_LAYER + layer_offset
 
-/obj/machinery/atmospherics/proc/update_pipe_image()
-	pipe_image = image(src, loc, layer = ABOVE_HUD_LAYER, dir = dir) //the 20 puts it above Byond's darkness (not its opacity view)
+/obj/machinery/atmospherics/proc/update_pipe_image(overlay = src)
+	pipe_image = image(overlay, loc, layer = ABOVE_HUD_LAYER, dir = dir) //the 20 puts it above Byond's darkness (not its opacity view)
 	pipe_image.plane = HUD_PLANE
 
 /obj/machinery/atmospherics/proc/check_icon_cache()
@@ -322,6 +322,7 @@ Pipelines + Other Objects -> Pipe network
 // Ventcrawling
 #define VENT_SOUND_DELAY 30
 /obj/machinery/atmospherics/relaymove(mob/living/user, direction)
+	var/datum/pipeline/current_pipenet = returnPipenet(src)
 	direction &= initialize_directions
 	if(!direction || !(direction in GLOB.cardinal)) //cant go this way.
 		return
@@ -332,6 +333,7 @@ Pipelines + Other Objects -> Pipe network
 	var/obj/machinery/atmospherics/target_move = findConnecting(direction)
 	if(target_move)
 		if(is_type_in_list(target_move, GLOB.ventcrawl_machinery) && target_move.can_crawl_through())
+			current_pipenet.crawlers -= user
 			user.remove_ventcrawl()
 			user.forceMove(target_move.loc) //handles entering and so on
 			user.visible_message("You hear something squeezing through the ducts.", "You climb out of the ventilation system.")
@@ -344,6 +346,7 @@ Pipelines + Other Objects -> Pipe network
 				playsound(src, 'sound/machines/ventcrawl.ogg', 50, TRUE, -3)
 	else
 		if((direction & initialize_directions) || is_type_in_list(src, GLOB.ventcrawl_machinery)) //if we move in a way the pipe can connect, but doesn't - or we're in a vent
+			current_pipenet.crawlers -= user
 			user.remove_ventcrawl()
 			user.forceMove(loc)
 			user.visible_message("You hear something squeezing through the pipes.", "You climb out of the ventilation system.")

code/modules/atmospherics/machinery/components/unary_devices/unary_base.dm

@@ -50,6 +50,13 @@
 		build_network()
 		. = 1
 
+/obj/machinery/atmospherics/unary/update_pipe_image()
+	. = ..()
+	if(parent)
+		for(var/mob/crawler in parent.crawlers)
+			var/mob/living/current_crawler = crawler
+			current_crawler.update_pipe_vision(src)
+
 /obj/machinery/atmospherics/unary/build_network(remove_deferral = FALSE)
 	if(!parent)
 		parent = new /datum/pipeline()

code/modules/atmospherics/machinery/components/unary_devices/vent_pump.dm

@@ -88,8 +88,7 @@
 		vent_icon += "[on ? "[releasing ? "out" : "in"]" : "off"]"
 
 	. += GLOB.pipe_icon_manager.get_atmos_icon("device", state = vent_icon)
-
-	update_pipe_image()
+	update_pipe_image(.)
 
 /obj/machinery/atmospherics/unary/vent_pump/update_underlays()
 	if(..())

code/modules/atmospherics/machinery/components/unary_devices/vent_scrubber.dm

@@ -83,7 +83,7 @@
 		scrubber_icon = "scrubberweld"
 
 	. += GLOB.pipe_icon_manager.get_atmos_icon("device", state = scrubber_icon)
-	update_pipe_image()
+	update_pipe_image(.)
 
 /obj/machinery/atmospherics/unary/vent_scrubber/update_underlays()
 	if(..())

code/modules/atmospherics/machinery/datum_pipeline.dm

@@ -7,6 +7,8 @@
 
 	var/update = TRUE
 
+	var/list/crawlers = list()
+
 /datum/pipeline/New()
 	SSair.pipenets += src
 
@@ -220,3 +222,12 @@
 				GL += C.portableConnectorReturnAir()
 
 	share_many_airs(GL)
+
+/datum/pipeline/proc/add_ventcrawler(mob/living/crawler)
+	if(!(crawler in crawlers))
+		RegisterSignal(crawler, COMSIG_LIVING_EXIT_VENTCRAWL, PROC_REF(remove_ventcrawler), crawler)
+		crawlers += crawler
+
+/datum/pipeline/proc/remove_ventcrawler(mob/living/crawler)
+	UnregisterSignal(crawler, COMSIG_LIVING_EXIT_VENTCRAWL)
+	crawlers -= crawler