Added passive vents (#21796)

Passive vents, as the name suggests, passively interact with the
atmosphere. Basically think of them as an open pipe.

This makes them useful to vent a pipe network to a vacuum, or equalize
the atmospheres of two otherwise unconnected rooms. Being passive
however, they are just as capable of intaking air as they are outputting
air, with no way to control it. If you want to guarantee that air only
goes -out-, use an injector or a pump vent.

code/modules/atmospherics/components/unary/unary_base.dm

@@ -92,15 +92,11 @@
 
 	return null
 
-/obj/machinery/atmospherics/unary/proc/is_welded()
+/obj/machinery/atmospherics/proc/is_welded()
 	return FALSE
 
 /obj/machinery/atmospherics/unary/vent_pump/is_welded()
-	if (welded > 0)
-		return TRUE
-	return FALSE
+	return welded
 
 /obj/machinery/atmospherics/unary/vent_scrubber/is_welded()
-	if (welded > 0)
-		return TRUE
-	return FALSE
+	return welded

code/modules/atmospherics/datum_pipeline.dm

@@ -115,24 +115,28 @@
 	return network
 
 /datum/pipeline/proc/mingle_with_turf(turf/simulated/target, mingle_volume)
+	if(!isturf(target))
+		return
+
 	var/datum/gas_mixture/air_sample = air.remove_ratio(mingle_volume/air.volume)
 	air_sample.volume = mingle_volume
 
-	if(istype(target) && target.zone)
+	if(target.zone)
 		//Have to consider preservation of group statuses
 		var/datum/gas_mixture/turf_copy = new
+		var/datum/gas_mixture/turf_original = new
 
 		turf_copy.copy_from(target.zone.air)
 		turf_copy.volume = target.zone.air.volume //Copy a good representation of the turf from parent group
+		turf_original.copy_from(turf_copy)
 
 		equalize_gases(list(air_sample, turf_copy))
 		air.merge(air_sample)
 
-		turf_copy.subtract(target.zone.air)
-
+		target.zone.air.remove(turf_original.total_moles)
 		target.zone.air.merge(turf_copy)
 
-	else if(target)
+	else
 		var/datum/gas_mixture/turf_air = target.return_air()
 
 		equalize_gases(list(air_sample, turf_air))

code/modules/atmospherics/vent_passive.dm

@@ -0,0 +1,178 @@
+/obj/machinery/atmospherics/pipe/vent_passive
+	name = "passive vent"
+	desc = ""
+	icon = 'icons/atmos/vent_passive.dmi'
+	icon_state = "map_vent"
+
+	connect_types = CONNECT_TYPE_REGULAR|CONNECT_TYPE_SUPPLY|CONNECT_TYPE_SCRUBBER|CONNECT_TYPE_AUX|CONNECT_TYPE_FUEL //connects to all pipes except HE
+
+	level = 1
+
+	volume = 250
+
+	dir = SOUTH
+	initialize_directions = SOUTH
+
+	var/obj/machinery/atmospherics/node
+	var/welded = FALSE
+
+/obj/machinery/atmospherics/pipe/vent_passive/Initialize()
+	initialize_directions = dir
+	. = ..()
+
+/obj/machinery/atmospherics/pipe/vent_passive/hide(var/i)
+	if(istype(loc, /turf/simulated))
+		set_invisibility(i ? 101 : 0)
+	queue_icon_update()
+
+/obj/machinery/atmospherics/pipe/vent_passive/mechanics_hints(mob/user, distance, is_adjacent)
+	. = ..()
+	. += "This passively outputs the contents of the attached pipe out into the atmosphere."
+
+/obj/machinery/atmospherics/pipe/vent_passive/feedback_hints(mob/user, distance, is_adjacent)
+	. = list()
+	if(welded)
+		. += "It seems welded shut."
+
+/obj/machinery/atmospherics/pipe/vent_passive/update_icon(safety = 0)
+
+	var/vent_icon = ""
+
+	if(welded)
+		vent_icon += "weld"
+	else
+		vent_icon += "vent"
+
+	icon_state = vent_icon
+
+	update_underlays()
+
+/obj/machinery/atmospherics/pipe/vent_passive/update_underlays()
+	if(..())
+		underlays.Cut()
+		var/turf/T = get_turf(src)
+		if(!istype(T))
+			return
+		if(!T.is_plating() && node && node.level == 1 && istype(node, /obj/machinery/atmospherics/pipe))
+			return
+		else
+			if(node)
+				add_underlay(T, node, dir, node.icon_connect_type)
+			else
+				add_underlay(T,, dir)
+			underlays += "frame"
+
+/obj/machinery/atmospherics/pipe/vent_passive/process(seconds_per_tick)
+	if(!parent)
+		..()
+	else
+		parent.mingle_with_turf(loc, volume)
+
+/obj/machinery/atmospherics/pipe/vent_passive/Destroy()
+	if(node)
+		node.disconnect(src)
+
+	node = null
+
+	return ..()
+
+/obj/machinery/atmospherics/pipe/vent_passive/pipeline_expansion()
+	return list(node)
+
+/obj/machinery/atmospherics/pipe/vent_passive/atmos_init()
+	for(var/obj/machinery/atmospherics/target in get_step(src, dir))
+		if(target.initialize_directions & get_dir(target,src))
+			if (check_connect_types(target,src))
+				node = target
+				break
+
+	atmos_initialised = TRUE
+	SSicon_update.add_to_queue(src)
+
+/obj/machinery/atmospherics/pipe/vent_passive/disconnect(obj/machinery/atmospherics/reference)
+	if(reference == node)
+		if(istype(node, /obj/machinery/atmospherics/pipe))
+			qdel(parent)
+		node = null
+
+	update_icon()
+
+	return null
+
+/obj/machinery/atmospherics/pipe/vent_passive/attackby(obj/item/attacking_item, mob/user)
+
+	if(attacking_item.tool_behaviour == TOOL_WELDER)
+		var/obj/item/weldingtool/WT = attacking_item
+		if (!WT.welding)
+			to_chat(user, SPAN_DANGER("\The [WT] must be turned on!"))
+		else if (WT.use(0,user))
+			to_chat(user, SPAN_NOTICE("Now welding the vent."))
+			if(attacking_item.use_tool(src, user, 30, volume = 50))
+				if(!src || !WT.isOn())
+					return TRUE
+				welded = !welded
+				update_icon()
+				playsound(src, 'sound/items/welder_pry.ogg', 50, 1)
+				user.visible_message(SPAN_NOTICE("\The [user] [welded ? "welds \the [src] shut" : "unwelds \the [src]"]."), \
+										SPAN_NOTICE("You [welded ? "weld \the [src] shut" : "unweld \the [src]"]."), \
+										"You hear welding.")
+			else
+				to_chat(user, SPAN_NOTICE("You fail to complete the welding."))
+		else
+			to_chat(user, SPAN_WARNING("You need more welding fuel to complete this task."))
+		return TRUE
+
+
+	else if(istype(attacking_item, /obj/item/melee/arm_blade))
+		if(!welded)
+			to_chat(user, SPAN_WARNING("\The [attacking_item] can only be used to tear open welded air vents!"))
+			return TRUE
+		user.visible_message(SPAN_WARNING("\The [user] starts using \the [attacking_item] to hack open \the [src]!"), SPAN_NOTICE("You start hacking open \the [src] with \the [attacking_item]..."))
+		user.do_attack_animation(src, attacking_item)
+		playsound(loc, 'sound/weapons/smash.ogg', 60, TRUE)
+		var/cut_amount = 3
+		for(var/i = 0; i <= cut_amount; i++)
+			if(!attacking_item || !do_after(user, 30, src))
+				return TRUE
+			user.do_attack_animation(src, attacking_item)
+			user.visible_message(SPAN_WARNING("\The [user] smashes \the [attacking_item] into \the [src]!"), SPAN_NOTICE("You smash \the [attacking_item] into \the [src]."))
+			playsound(loc, 'sound/weapons/smash.ogg', 60, TRUE)
+			if(i == cut_amount)
+				welded = FALSE
+				spark(get_turf(src), 3, GLOB.alldirs)
+				playsound(loc, 'sound/items/welder_pry.ogg', 50, TRUE)
+				update_icon()
+
+	else if(attacking_item.tool_behaviour == TOOL_WRENCH)
+		var/turf/T = src.loc
+
+		if(level==1 && isturf(T) && !T.is_plating())
+			to_chat(user, SPAN_WARNING("You must remove the plating first."))
+
+		else if(loc)
+			var/datum/gas_mixture/int_air = return_air()
+			var/datum/gas_mixture/env_air = loc.return_air()
+
+			if((int_air.return_pressure()-env_air.return_pressure()) > PRESSURE_EXERTED)
+				to_chat(user, SPAN_WARNING("You cannot unwrench \the [src], it is too exerted due to internal pressure."))
+				add_fingerprint(user)
+
+			else
+				to_chat(user, SPAN_NOTICE("You begin to unfasten \the [src]..."))
+
+				if(attacking_item.use_tool(src, user, istype(attacking_item, /obj/item/pipewrench) ? 80 : 40, volume = 50))
+					user.visible_message(SPAN_NOTICE("\The [user] unfastens \the [src]."), \
+											SPAN_NOTICE("You have unfastened \the [src]."), \
+											"You hear a ratchet.")
+					new /obj/item/pipe(loc, make_from=src)
+					qdel(src)
+
+	else if(istype(attacking_item, /obj/item/analyzer) && in_range(user, src))
+		var/obj/item/analyzer/A = attacking_item
+		A.analyze_gases(src, user)
+		return TRUE
+
+	return ..()
+
+/obj/machinery/atmospherics/pipe/vent_passive/is_welded()
+	return welded