Ventcrawl port from Bay12/VG (#852)

Original code from /vg/, port credit goes to Zuhayr.

baystation12.dme

@@ -1734,6 +1734,9 @@
 #include "code\modules\vehicles\cargo_train.dm"
 #include "code\modules\vehicles\train.dm"
 #include "code\modules\vehicles\vehicle.dm"
+#include "code\modules\ventcrawl\ventcrawl.dm"
+#include "code\modules\ventcrawl\ventcrawl_atmospherics.dm"
+#include "code\modules\ventcrawl\ventcrawl_verb.dm"
 #include "code\modules\virus2\admin.dm"
 #include "code\modules\virus2\analyser.dm"
 #include "code\modules\virus2\antibodies.dm"

code/ATMOSPHERICS/atmospherics.dm

@@ -29,6 +29,8 @@ Pipelines + Other Objects -> Pipe network
 	var/pipe_color
 
 	var/global/datum/pipe_icon_manager/icon_manager
+	var/obj/machinery/atmospherics/node1
+	var/obj/machinery/atmospherics/node2
 
 /obj/machinery/atmospherics/New()
 	if(!icon_manager)

code/ATMOSPHERICS/components/binary_devices/binary_atmos_base.dm

@@ -6,9 +6,6 @@ obj/machinery/atmospherics/binary
 	var/datum/gas_mixture/air1
 	var/datum/gas_mixture/air2
 
-	var/obj/machinery/atmospherics/node1
-	var/obj/machinery/atmospherics/node2
-
 	var/datum/pipe_network/network1
 	var/datum/pipe_network/network2
 

code/ATMOSPHERICS/components/binary_devices/pipeturbine.dm

@@ -17,9 +17,6 @@
 
 	var/dP = 0
 
-	var/obj/machinery/atmospherics/node1
-	var/obj/machinery/atmospherics/node2
-
 	var/datum/pipe_network/network1
 	var/datum/pipe_network/network2
 

code/ATMOSPHERICS/components/trinary_devices/trinary_base.dm

@@ -7,8 +7,6 @@ obj/machinery/atmospherics/trinary
 	var/datum/gas_mixture/air2
 	var/datum/gas_mixture/air3
 
-	var/obj/machinery/atmospherics/node1
-	var/obj/machinery/atmospherics/node2
 	var/obj/machinery/atmospherics/node3
 
 	var/datum/pipe_network/network1

code/ATMOSPHERICS/components/tvalve.dm

@@ -12,8 +12,6 @@
 	var/state = 0 // 0 = go straight, 1 = go to side
 
 	// like a trinary component, node1 is input, node2 is side output, node3 is straight output
-	var/obj/machinery/atmospherics/node1
-	var/obj/machinery/atmospherics/node2
 	var/obj/machinery/atmospherics/node3
 
 	var/datum/pipe_network/network_node1

code/ATMOSPHERICS/components/unary/vent_pump.dm

@@ -378,6 +378,11 @@
 	else
 		..()
 
+/obj/machinery/atmospherics/unary/vent_pump/proc/is_welded()
+	if (welded > 0)
+		return 1
+	return 0
+
 /obj/machinery/atmospherics/unary/vent_pump/examine(mob/user)
 	if(..(user, 1))
 		user << "A small gauge in the corner reads [round(last_flow_rate, 0.1)] L/s; [round(last_power_draw)] W"

code/ATMOSPHERICS/components/valve.dm

@@ -12,9 +12,6 @@
 	var/open = 0
 	var/openDuringInit = 0
 
-	var/obj/machinery/atmospherics/node1
-	var/obj/machinery/atmospherics/node2
-
 	var/datum/pipe_network/network_node1
 	var/datum/pipe_network/network_node2
 

code/ATMOSPHERICS/pipes.dm

@@ -153,9 +153,6 @@
 	dir = SOUTH
 	initialize_directions = SOUTH|NORTH
 
-	var/obj/machinery/atmospherics/node1
-	var/obj/machinery/atmospherics/node2
-
 	var/minimum_temperature_difference = 300
 	var/thermal_conductivity = 0 //WALL_HEAT_TRANSFER_COEFFICIENT No
 
@@ -423,8 +420,6 @@
 	dir = SOUTH
 	initialize_directions = EAST|NORTH|WEST
 
-	var/obj/machinery/atmospherics/node1
-	var/obj/machinery/atmospherics/node2
 	var/obj/machinery/atmospherics/node3
 
 	level = 1
@@ -679,8 +674,6 @@
 	dir = SOUTH
 	initialize_directions = NORTH|SOUTH|EAST|WEST
 
-	var/obj/machinery/atmospherics/node1
-	var/obj/machinery/atmospherics/node2
 	var/obj/machinery/atmospherics/node3
 	var/obj/machinery/atmospherics/node4
 
@@ -1061,8 +1054,6 @@
 	initialize_directions = SOUTH
 	density = 1
 
-	var/obj/machinery/atmospherics/node1
-
 /obj/machinery/atmospherics/pipe/tank/New()
 	icon_state = "air"
 	initialize_directions = dir
@@ -1237,8 +1228,6 @@
 
 	var/build_killswitch = 1
 
-	var/obj/machinery/atmospherics/node1
-
 /obj/machinery/atmospherics/pipe/vent/New()
 	initialize_directions = dir
 	..()

code/TriDimension/Pipes.dm

@@ -13,9 +13,6 @@ obj/machinery/atmospherics/pipe/zpipe
 		dir = SOUTH
 		initialize_directions = SOUTH
 
-		var/obj/machinery/atmospherics/node1	//connection on the same Z
-		var/obj/machinery/atmospherics/node2	//connection on the other Z
-
 		var/minimum_temperature_difference = 300
 		var/thermal_conductivity = 0 //WALL_HEAT_TRANSFER_COEFFICIENT No
 

code/modules/mob/living/carbon/alien/life.dm

@@ -116,6 +116,9 @@
 
 /mob/living/carbon/alien/proc/handle_regular_hud_updates()
 
+	if(is_ventcrawling == 0) // Stops sight returning to normal if inside a vent
+		sight = species.vision_flags
+
 	if (stat == 2 || (XRAY in src.mutations))
 		sight |= SEE_TURFS
 		sight |= SEE_MOBS

code/modules/mob/living/carbon/human/life.dm

@@ -1248,9 +1248,10 @@
 					*/
 
 		else
-			sight = species.vision_flags
-			see_in_dark = species.darksight
-			see_invisible = see_in_dark>2 ? SEE_INVISIBLE_LEVEL_ONE : SEE_INVISIBLE_LIVING
+			if(is_ventcrawling == 0) // Stops sight returning to normal if inside a vent
+				sight = species.vision_flags
+				see_in_dark = species.darksight
+				see_invisible = see_in_dark>2 ? SEE_INVISIBLE_LEVEL_ONE : SEE_INVISIBLE_LIVING
 
 			if(XRAY in mutations)
 				sight |= SEE_TURFS|SEE_MOBS|SEE_OBJS

code/modules/mob/living/carbon/metroid/life.dm

@@ -11,6 +11,9 @@
 		handle_chemicals_in_body()
 		handle_nutrition()
 
+		if(is_ventcrawling == 0) // Stops sight returning to normal if inside a vent
+			sight = SEE_SELF
+
 		if (!client)
 			handle_targets()
 			if (!AIproc)
@@ -58,7 +61,7 @@
 				adjustToxLoss(200)
 			else
 				adjustToxLoss(30)
-				
+
 	updatehealth()
 
 	return //TODO: DEFERRED

code/modules/mob/living/carbon/metroid/metroid.dm

@@ -410,9 +410,4 @@
 		if(powerlevel > 10)
 			powerlevel = 10
 			adjustToxLoss(-10)
-	nutrition = max(nutrition, get_max_nutrition())
-
-/mob/living/carbon/slime/cannot_use_vents()
-	if(Victim)
-		return "You cannot ventcrawl while feeding."
-	..()
+	nutrition = max(nutrition, get_max_nutrition())

code/modules/mob/living/living.dm

@@ -664,114 +664,6 @@ default behaviour is:
 	resting = !resting
 	src << "<span class='notice'>You are now [resting ? "resting" : "getting up"]</span>"
 
-/mob/living/proc/is_allowed_vent_crawl_item(var/obj/item/carried_item)
-	return isnull(get_inventory_slot(carried_item))
-
-/mob/living/simple_animal/spiderbot/is_allowed_vent_crawl_item(var/obj/item/carried_item)
-	if(carried_item == held_item)
-		return 0
-	return ..()
-
-/mob/living/proc/handle_ventcrawl(var/obj/machinery/atmospherics/unary/vent_pump/vent_found = null, var/ignore_items = 0) // -- TLE -- Merged by Carn
-	if(stat)
-		src << "You must be conscious to do this!"
-		return
-	if(lying)
-		src << "You can't vent crawl while you're stunned!"
-		return
-
-	var/special_fail_msg = cannot_use_vents()
-	if(special_fail_msg)
-		src << "<span class='warning'>[special_fail_msg]</span>"
-		return
-
-	if(vent_found) // one was passed in, probably from vent/AltClick()
-		if(vent_found.welded)
-			src << "That vent is welded shut."
-			return
-		if(!vent_found.Adjacent(src))
-			return // don't even acknowledge that
-	else
-		for(var/obj/machinery/atmospherics/unary/vent_pump/v in range(1,src))
-			if(!v.welded)
-				if(v.Adjacent(src))
-					vent_found = v
-	if(!vent_found)
-		src << "You'll need a non-welded vent to crawl into!"
-		return
-
-	if(!vent_found.network || !vent_found.network.normal_members.len)
-		src << "This vent is not connected to anything."
-		return
-
-	var/list/vents = list()
-	for(var/obj/machinery/atmospherics/unary/vent_pump/temp_vent in vent_found.network.normal_members)
-		if(temp_vent.welded)
-			continue
-		if(temp_vent in loc)
-			continue
-		var/turf/T = get_turf(temp_vent)
-
-		if(!T || T.z != loc.z)
-			continue
-
-		var/i = 1
-		var/index = "[T.loc.name]\[[i]\]"
-		while(index in vents)
-			i++
-			index = "[T.loc.name]\[[i]\]"
-		vents[index] = temp_vent
-	if(!vents.len)
-		src << "\red There are no available vents to travel to, they could be welded."
-		return
-
-	var/obj/selection = input("Select a destination.", "Duct System") as null|anything in sortAssoc(vents)
-	if(!selection)	return
-
-	if(!vent_found.Adjacent(src))
-		src << "Never mind, you left."
-		return
-
-	if(!ignore_items)
-		for(var/obj/item/carried_item in contents)//If the monkey got on objects.
-			if(is_allowed_vent_crawl_item(carried_item))
-				continue
-			src << "<span class='warning'>You can't be carrying items or have items equipped when vent crawling!</span>"
-			return
-
-	if(isslime(src))
-		var/mob/living/carbon/slime/S = src
-		if(S.Victim)
-			src << "\red You'll have to let [S.Victim] go or finish eating \him first."
-			return
-
-	var/obj/machinery/atmospherics/unary/vent_pump/target_vent = vents[selection]
-	if(!target_vent)
-		return
-
-	for(var/mob/O in viewers(src, null))
-		O.show_message(text("<B>[src] scrambles into the ventillation ducts!</B>"), 1)
-	loc = target_vent
-
-	var/travel_time = round(get_dist(loc, target_vent.loc) / 2)
-
-	spawn(travel_time)
-
-		if(!target_vent)	return
-		for(var/mob/O in hearers(target_vent,null))
-			O.show_message("You hear something squeezing through the ventilation ducts.",2)
-
-		sleep(travel_time)
-
-		if(!target_vent)	return
-		if(target_vent.welded)			//the vent can be welded while alien scrolled through the list or travelled.
-			target_vent = vent_found 	//travel back. No additional time required.
-			src << "\red The vent you were heading to appears to be welded."
-		loc = target_vent.loc
-		var/area/new_area = get_area(loc)
-		if(new_area)
-			new_area.Entered(src)
-
 /mob/living/proc/cannot_use_vents()
 	return "You can't fit into that vent."
 

code/modules/mob/living/living_powers.dm

@@ -1,13 +1,3 @@
-/mob/living/proc/ventcrawl()
-	set name = "Crawl through Vent"
-	set desc = "Enter an air vent and crawl through the pipe system."
-	set category = "Abilities"
-
-	if(stat == DEAD || paralysis || weakened || stunned || restrained())
-		return
-
-	handle_ventcrawl()
-
 /mob/living/proc/hide()
 	set name = "Hide"
 	set desc = "Allows to hide beneath tables or certain items. Toggled on or off."

code/modules/ventcrawl/ventcrawl.dm

@@ -0,0 +1,223 @@
+var/list/ventcrawl_machinery = list(
+	/obj/machinery/atmospherics/unary/vent_pump,
+	/obj/machinery/atmospherics/unary/vent_scrubber
+	)
+
+// Vent crawling whitelisted items, whoo
+/mob/living/var/list/can_enter_vent_with = list(
+	/obj/item/weapon/implant,
+	/obj/item/device/radio/borg,
+	/obj/item/weapon/holder,
+	/obj/machinery/camera,
+	/mob/living/simple_animal/borer
+	)
+
+/mob/living/var/list/icon/pipes_shown = list()
+/mob/living/var/last_played_vent
+/mob/living/var/is_ventcrawling = 0
+/mob/living/var/next_play_vent = 0
+
+/mob/living/proc/can_ventcrawl()
+	return 0
+
+/mob/living/Login()
+	. = ..()
+	//login during ventcrawl
+	if(is_ventcrawling && istype(loc, /obj/machinery/atmospherics)) //attach us back into the pipes
+		remove_ventcrawl()
+		add_ventcrawl(loc)
+
+/mob/living/carbon/slime/can_ventcrawl()
+	if(Victim)
+		src << "<span class='warning'>You cannot ventcrawl while feeding.</span>"
+		return 0
+	return 1
+
+/mob/living/proc/is_allowed_vent_crawl_item(var/obj/item/carried_item)
+	for(var/type in can_enter_vent_with)
+		if(istype(carried_item, can_enter_vent_with))
+			return get_inventory_slot(carried_item) == 0
+	return 0
+
+/mob/living/carbon/is_allowed_vent_crawl_item(var/obj/item/carried_item)
+	if(carried_item in internal_organs)
+		return 1
+	return ..()
+
+/mob/living/carbon/human/is_allowed_vent_crawl_item(var/obj/item/carried_item)
+	if(carried_item in organs)
+		return 1
+	return ..()
+
+/mob/living/simple_animal/spiderbot/is_allowed_vent_crawl_item(var/obj/item/carried_item)
+	if(carried_item == held_item)
+		return 1
+	return ..()
+
+/mob/living/proc/ventcrawl_carry()
+	for(var/atom/A in src.contents)
+		if(!is_allowed_vent_crawl_item(A))
+			src << "<span class='warning'>You can't be carrying that when vent crawling!</span>"
+			return 0
+	return 1
+
+/obj/machinery/atmospherics/AltClick(mob/living/user)
+	if(is_type_in_list(src,ventcrawl_machinery) && user.can_ventcrawl())
+		user.handle_ventcrawl()
+		return 1
+	return ..()
+
+/mob/living/carbon/human/can_ventcrawl()
+	return issmall(src)
+
+/mob/proc/start_ventcrawl()
+	var/atom/pipe
+	var/list/pipes = list()
+	for(var/obj/machinery/atmospherics/unary/U in range(1))
+		if(is_type_in_list(U,ventcrawl_machinery) && Adjacent(U))
+			pipes |= U
+	if(!pipes || !pipes.len)
+		usr << "<span class='notice'>There are no pipes that you can ventcrawl into within range!</span>"
+		return
+	if(pipes.len == 1)
+		pipe = pipes[1]
+	else
+		pipe = input("Crawl Through Vent", "Pick a pipe") as null|anything in pipes
+	if(canmove && pipe)
+		return pipe
+
+/mob/living/carbon/slime/can_ventcrawl()
+	return 1
+
+/mob/living/simple_animal/borer/can_ventcrawl()
+	return 1
+
+/mob/living/simple_animal/borer/ventcrawl_carry()
+	return 1
+
+/mob/living/simple_animal/mouse/can_ventcrawl()
+	return 1
+
+/mob/living/simple_animal/spiderbot/can_ventcrawl()
+	return 1
+
+/mob/living/carbon/alien/can_ventcrawl()
+	return 1
+
+/mob/living/carbon/alien/ventcrawl_carry()
+	return 1
+
+/mob/living/proc/size_to_crawldelay(var/size)
+	var/delayticks = size * 3
+	return delayticks >= 3 ? delayticks : 3
+
+/mob/living/var/ventcrawl_layer = 3
+
+/mob/living/proc/handle_ventcrawl(var/atom/clicked_on)
+
+	if(!stat)
+		if(!lying)
+
+			var/obj/machinery/atmospherics/unary/vent_found
+
+			if(clicked_on && Adjacent(clicked_on))
+				vent_found = clicked_on
+				if(!istype(vent_found) || !vent_found.can_crawl_through())
+					vent_found = null
+
+			if(!vent_found)
+				for(var/obj/machinery/atmospherics/machine in range(1,src))
+					if(is_type_in_list(machine, ventcrawl_machinery))
+						vent_found = machine
+
+					if(!vent_found || !vent_found.can_crawl_through())
+						vent_found = null
+
+					if(vent_found)
+						break
+
+			if(istype(vent_found, /obj/machinery/atmospherics/unary/vent_pump/) && vent_found:is_welded()) // welded check
+				src << "<span class='warning'>You can't crawl into a welded vent!</span>"
+				return
+
+			if(vent_found)
+				if(vent_found.network && (vent_found.network.normal_members.len || vent_found.network.line_members.len))
+
+					visible_message("<span class='warning'>[src] begins to climb into the ventilation system!","<span class='notice'>You begin climbing into the ventilation system...</span>")
+					if(vent_found.air_contents && !issilicon(src))
+
+						switch(vent_found.air_contents.temperature)
+							if(0 to BODYTEMP_COLD_DAMAGE_LIMIT)
+								src << "<span class='danger'>You feel a painful freeze coming from the vent!</span>"
+							if(BODYTEMP_COLD_DAMAGE_LIMIT to T0C)
+								src << "<span class='warning'>You feel an icy chill coming from the vent.</span>"
+							if(T0C + 40 to BODYTEMP_HEAT_DAMAGE_LIMIT)
+								src << "<span class='warning'>You feel a hot wash coming from the vent.</span>"
+							if(BODYTEMP_HEAT_DAMAGE_LIMIT to INFINITY)
+								src << "<span class='danger'>You feel a searing heat coming from the vent!</span>"
+
+						switch(vent_found.air_contents.return_pressure())
+							if(0 to HAZARD_LOW_PRESSURE)
+								src << "<span class='danger'>You feel a rushing draw pulling you into the vent!</span>"
+							if(HAZARD_LOW_PRESSURE to WARNING_LOW_PRESSURE)
+								src << "<span class='warning'>You feel a strong drag pulling you into the vent.</span>"
+							if(WARNING_HIGH_PRESSURE to HAZARD_HIGH_PRESSURE)
+								src << "<span class='warning'>You feel a strong current pushing you away from the vent.</span>"
+							if(HAZARD_HIGH_PRESSURE to INFINITY)
+								src << "<span class='danger'>You feel a roaring wind pushing you away from the vent!</span>"
+
+					if(!do_mob(src, vent_found, mob_size ? size_to_crawldelay(mob_size) : size_to_crawldelay(15), 1, 1))
+						return
+
+					if(!client)
+						return
+
+					if(!ventcrawl_carry())
+						return
+
+					visible_message("<B>[src] scrambles into the ventilation ducts!</B>", "You climb into the ventilation system.")
+
+					forceMove(vent_found)
+					add_ventcrawl(vent_found)
+					sight = (SEE_TURFS|BLIND)
+
+				else
+					src << "<span class='notice'>This vent is not connected to anything."
+
+			else
+				src << "<span class='notice'>You must be standing on or beside an air vent to enter it."
+
+		else
+			src << "<span class='notice'>You can't vent crawl while you're stunned!"
+
+	else
+		src << "<span class='notice'>You must be conscious to do this!"
+	return
+
+/mob/living/proc/add_ventcrawl(obj/machinery/atmospherics/starting_machine)
+	is_ventcrawling = 1
+	//candrop = 0
+	var/datum/pipe_network/network = starting_machine.return_network(starting_machine)
+	if(!network)
+		return
+	for(var/datum/pipeline/pipeline in network.line_members)
+		for(var/obj/machinery/atmospherics/A in (pipeline.members || pipeline.edges)) // Adds pipe and manifold images
+			if(!A.pipe_image)
+				A.pipe_image = image(A, A.loc, layer = 20, dir = A.dir)
+			pipes_shown += A.pipe_image
+			client.images += A.pipe_image
+	for (var/obj/machinery/atmospherics/V in network.normal_members) // Adds vent and scrubber images
+		if (!V.pipe_image || istype(V, /obj/machinery/atmospherics/unary/vent_pump/))
+			V.pipe_image = image(V, V.loc, layer = 20, dir = V.dir)
+		pipes_shown += V.pipe_image
+		client.images += V.pipe_image
+
+/mob/living/proc/remove_ventcrawl()
+	is_ventcrawling = 0
+	//candrop = 1
+	if(client)
+		for(var/image/current_image in pipes_shown)
+			client.images -= current_image
+		client.eye = src
+
+	pipes_shown.len = 0

code/modules/ventcrawl/ventcrawl_atmospherics.dm

@@ -0,0 +1,90 @@
+/obj/machinery/atmospherics/var/image/pipe_image
+
+/obj/machinery/atmospherics/Destroy()
+	for(var/mob/living/M in src) //ventcrawling is serious business
+		M.remove_ventcrawl()
+		M.forceMove(get_turf(src))
+	if(pipe_image)
+		for(var/mob/living/M in player_list)
+			if(M.client)
+				M.client.images -= pipe_image
+				M.pipes_shown -= pipe_image
+		pipe_image = null
+	. = ..()
+
+/obj/machinery/atmospherics/ex_act(severity)
+	for(var/atom/movable/A in src) //ventcrawling is serious business
+		A.ex_act(severity)
+	. = ..()
+
+/obj/machinery/atmospherics/Entered(atom/movable/Obj)
+	if(istype(Obj, /mob/living))
+		var/mob/living/L = Obj
+		L.ventcrawl_layer = layer
+	. = ..()
+
+/obj/machinery/atmospherics/relaymove(mob/living/user, direction)
+	if(!(direction & initialize_directions)) //can't go in a way we aren't connecting to
+		return
+	ventcrawl_to(user,findConnecting(direction, user.ventcrawl_layer),direction)
+
+/obj/machinery/atmospherics/proc/ventcrawl_to(var/mob/living/user, var/obj/machinery/atmospherics/target_move, var/direction)
+	if(target_move)
+		if(is_type_in_list(target_move, ventcrawl_machinery) && target_move.can_crawl_through())
+			if(istype(target_move, /obj/machinery/atmospherics/unary/vent_pump/) && target_move:is_welded())
+				user.visible_message("<span class='warning'You hear something banging on \the [target_move.name]!</span>", "<span class='notice'>You can't escape from a welded vent.</span>")
+			else
+				user.remove_ventcrawl()
+				user.forceMove(target_move.loc) //handles entering and so on
+				user.sight &= ~(SEE_TURFS|BLIND)
+				user.visible_message("<span class='warning'>You hear something squeezing through the ducts.</span>", "You climb out the ventilation system.")
+		else if(target_move.can_crawl_through())
+			if(target_move.return_network(target_move) != return_network(src))
+				user.remove_ventcrawl()
+				user.add_ventcrawl(target_move)
+			user.forceMove(target_move)
+			user.client.eye = target_move //if we don't do this, Byond only updates the eye every tick - required for smooth movement
+			if(world.time > user.next_play_vent)
+				user.next_play_vent = world.time+30
+				playsound(src, 'sound/machines/ventcrawl.ogg', 50, 1, -3)
+	else
+		if((direction & initialize_directions) || is_type_in_list(src, ventcrawl_machinery) && src.can_crawl_through()) //if we move in a way the pipe can connect, but doesn't - or we're in a vent
+			user.remove_ventcrawl()
+			user.forceMove(src.loc)
+			user.visible_message("<span class='warning'>You hear something squeezing through the pipes.</span>", "You climb out the ventilation system.")
+	user.canmove = 0
+	spawn(1)
+		user.canmove = 1
+
+/obj/machinery/atmospherics/proc/can_crawl_through()
+	return 1
+
+/obj/machinery/atmospherics/proc/findConnecting(var/direction)
+	for(var/obj/machinery/atmospherics/target in get_step(src,direction))
+		if(target.initialize_directions & get_dir(target,src))
+			if(isConnectable(target) && target.isConnectable(src))
+				return target
+
+/obj/machinery/atmospherics/proc/isConnectable(var/obj/machinery/atmospherics/target)
+	return (target == node1 || target == node2)
+
+/obj/machinery/atmospherics/pipe/manifold/isConnectable(var/obj/machinery/atmospherics/target)
+	return (target == node3 || ..())
+
+obj/machinery/atmospherics/trinary/isConnectable(var/obj/machinery/atmospherics/target)
+	return (target == node3 || ..())
+
+/obj/machinery/atmospherics/pipe/manifold4w/isConnectable(var/obj/machinery/atmospherics/target)
+	return (target == node3 || target == node4 || ..())
+
+/obj/machinery/atmospherics/tvalve/isConnectable(var/obj/machinery/atmospherics/target)
+	return (target == node3 || ..())
+
+/obj/machinery/atmospherics/pipe/cap/isConnectable(var/obj/machinery/atmospherics/target)
+	return (target == node || ..())
+
+/obj/machinery/atmospherics/portables_connector/isConnectable(var/obj/machinery/atmospherics/target)
+	return (target == node || ..())
+
+/obj/machinery/atmospherics/unary/isConnectable(var/obj/machinery/atmospherics/target)
+	return (target == node || ..())

code/modules/ventcrawl/ventcrawl_verb.dm

@@ -0,0 +1,9 @@
+/mob/living/proc/ventcrawl()
+	set name = "Crawl through Vent"
+	set desc = "Enter an air vent and crawl through the pipe system."
+	set category = "Abilities"
+	if(paralysis || restrained())
+		return
+	var/pipe = start_ventcrawl()
+	if(pipe)
+		handle_ventcrawl()

html/changelogs/Bedshaped-PR-852.yml

@@ -0,0 +1,6 @@
+author: Bedshaped
+
+delete-after: True
+
+changes: 
+  - rscadd: "Ported Bay12's ventcrawling by Zuhayr, originally from vg."