Merge pull request #10568 from r4d6/Passive-Vents

Add passive vents

code/game/objects/items/RPD.dm

@@ -35,6 +35,7 @@ GLOBAL_LIST_INIT(atmos_pipe_recipes, list(
 		new /datum/pipe_info/meter("Meter"),
 		new /datum/pipe_info/pipe("Gas Filter",			/obj/machinery/atmospherics/components/trinary/filter),
 		new /datum/pipe_info/pipe("Gas Mixer",			/obj/machinery/atmospherics/components/trinary/mixer),
+		new /datum/pipe_info/pipe("Passive Vent",		/obj/machinery/atmospherics/components/unary/passive_vent),
 	),
 	"Heat Exchange" = list(
 		new /datum/pipe_info/pipe("Pipe",				/obj/machinery/atmospherics/pipe/heat_exchanging/simple),

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

@@ -0,0 +1,55 @@
+/obj/machinery/atmospherics/components/unary/passive_vent
+	icon_state = "passive_vent_map-2"
+
+	name = "passive vent"
+	desc = "It is an open vent."
+	can_unwrench = TRUE
+
+	level = 1
+	layer = GAS_SCRUBBER_LAYER
+
+	pipe_state = "pvent"
+
+/obj/machinery/atmospherics/components/unary/passive_vent/update_icon_nopipes()
+	cut_overlays()
+	if(showpipe)
+		var/image/cap = getpipeimage(icon, "vent_cap", initialize_directions)
+		add_overlay(cap)
+	icon_state = "passive_vent"
+
+/obj/machinery/atmospherics/components/unary/passive_vent/process_atmos()
+	..()
+
+	var/datum/gas_mixture/environment = loc.return_air()
+	var/environment_pressure = environment.return_pressure()
+	var/pressure_delta = abs(environment_pressure - airs[1].return_pressure())
+
+	if((environment.temperature || airs[1].temperature) && pressure_delta > 0.5)
+		if(environment_pressure < airs[1].return_pressure())
+			var/air_temperature = (environment.temperature > 0) ? environment.temperature : airs[1].temperature
+			var/transfer_moles = (pressure_delta * environment.volume) / (air_temperature * R_IDEAL_GAS_EQUATION)
+			var/datum/gas_mixture/removed = airs[1].remove(transfer_moles)
+			loc.assume_air(removed)
+			air_update_turf()
+		else
+			var/air_temperature = (airs[1].temperature > 0) ? airs[1].temperature : environment.temperature
+			var/output_volume = airs[1].volume
+			var/transfer_moles = (pressure_delta * output_volume) / (air_temperature * R_IDEAL_GAS_EQUATION)
+			transfer_moles = min(transfer_moles, environment.total_moles()*airs[1].volume/environment.volume)
+			var/datum/gas_mixture/removed = loc.remove_air(transfer_moles)
+			if(isnull(removed))
+				return
+			airs[1].merge(removed)
+			air_update_turf()
+	update_parents()
+
+/obj/machinery/atmospherics/components/unary/passive_vent/can_crawl_through()
+	return TRUE
+
+/obj/machinery/atmospherics/components/unary/passive_vent/layer1
+	piping_layer = PIPING_LAYER_MIN
+	icon_state = "passive_vent_map-1"
+
+/obj/machinery/atmospherics/components/unary/passive_vent/layer3
+	piping_layer = PIPING_LAYER_MAX
+	icon_state = "passive_vent_map-3"

tgstation.dme

@@ -1480,6 +1480,7 @@
 #include "code\modules\atmospherics\machinery\components\unary_devices\cryo.dm"
 #include "code\modules\atmospherics\machinery\components\unary_devices\heat_exchanger.dm"
 #include "code\modules\atmospherics\machinery\components\unary_devices\outlet_injector.dm"
+#include "code\modules\atmospherics\machinery\components\unary_devices\passive_vent.dm"
 #include "code\modules\atmospherics\machinery\components\unary_devices\portables_connector.dm"
 #include "code\modules\atmospherics\machinery\components\unary_devices\relief_valve.dm"
 #include "code\modules\atmospherics\machinery\components\unary_devices\tank.dm"