Merge pull request #9867 from RemieRichards/PipePressureLethality

Pipe Pressure Panic

code/ATMOSPHERICS/atmospherics.dm

@@ -103,28 +103,56 @@ Pipelines + Other Objects -> Pipe network
 
 /obj/machinery/atmospherics/attackby(var/obj/item/weapon/W as obj, var/mob/user as mob, params)
 	if(can_unwrench && istype(W, /obj/item/weapon/wrench))
-		var/turf/T = src.loc
+		var/turf/T = get_turf(src)
 		if (level==1 && isturf(T) && T.intact)
 			user << "<span class='warning'>You must remove the plating first!</span>"
 			return 1
 		var/datum/gas_mixture/int_air = return_air()
 		var/datum/gas_mixture/env_air = loc.return_air()
 		add_fingerprint(user)
-		if ((int_air.return_pressure()-env_air.return_pressure()) > 2*ONE_ATMOSPHERE)
-			user << "<span class='warning'>You cannot unwrench this [src], it is too exerted due to internal pressure!</span>"
-			return 1
+
+		var/unsafe_wrenching = FALSE
+		var/internal_pressure = int_air.return_pressure()-env_air.return_pressure()
+
 		playsound(src.loc, 'sound/items/Ratchet.ogg', 50, 1)
 		user << "<span class='notice'>You begin to unfasten \the [src]...</span>"
+		if (internal_pressure > 2*ONE_ATMOSPHERE)
+			user << "<span class='warning'>As you begin unwrenching \the [src] a gush of air blows in your face... maybe you should reconsider?</span>"
+			unsafe_wrenching = TRUE //Oh dear oh dear
+
 		if (do_after(user, 40) && !gc_destroyed)
 			user.visible_message( \
 				"[user] unfastens \the [src].", \
 				"<span class='notice'>You unfasten \the [src].</span>", \
 				"<span class='italics'>You hear ratchet.</span>")
 			investigate_log("was <span class='warning'>REMOVED</span> by [key_name(usr)]", "atmos")
+
+			//You unwrenched a pipe full of pressure? let's splat you into the wall silly.
+			if(unsafe_wrenching)
+				unsafe_pressure_release(user,internal_pressure)
 			Deconstruct()
+
 	else
 		return ..()
 
+
+//Called when an atmospherics object is unwrenched while having a large pressure difference
+//with it's locs air contents.
+/obj/machinery/atmospherics/proc/unsafe_pressure_release(var/mob/user,var/pressures)
+	if(!user)
+		return
+
+	if(!pressures)
+		var/datum/gas_mixture/int_air = return_air()
+		var/datum/gas_mixture/env_air = loc.return_air()
+		pressures = int_air.return_pressure()-env_air.return_pressure()
+
+	var/fuck_you_dir = get_dir(src,user)
+	var/turf/general_direction = get_edge_target_turf(user,fuck_you_dir)
+	user.visible_message("<span class='danger'>[user] is sent flying by pressure!</span>","<span class='userdanger'>The pressure sends you flying!</span>")
+	//Values based on 2*ONE_ATMOS (the unsafe pressure), resulting in 20 range and 4 speed
+	user.throw_at(general_direction,pressures/10,pressures/50)
+
 /obj/machinery/atmospherics/Deconstruct()
 	if(can_unwrench)
 		var/turf/T = loc

code/ATMOSPHERICS/components/binary_devices/binary_atmos_base.dm

@@ -160,4 +160,21 @@
 	if(Old == parent1)
 		parent1 = New
 	else if(Old == parent2)
-		parent2 = New
+		parent2 = New
+
+
+/obj/machinery/atmospherics/binary/unsafe_pressure_release(var/mob/user,var/pressures)
+	..()
+
+	var/turf/T = get_turf(src)
+	if(T)
+		//Remove the gas from air1+air2 and assume it
+		var/datum/gas_mixture/environment = T.return_air()
+		var/lost = pressures*environment.volume/(air1.temperature * R_IDEAL_GAS_EQUATION)
+		lost += pressures*environment.volume/(air2.temperature * R_IDEAL_GAS_EQUATION)
+		var/shared_loss = lost/2
+
+		var/datum/gas_mixture/to_release = air1.remove(shared_loss)
+		to_release.merge(air2.remove(shared_loss))
+		T.assume_air(to_release)
+		air_update_turf(1)

code/ATMOSPHERICS/components/trinary_devices/trinary_base.dm

@@ -219,4 +219,23 @@ Housekeeping and pipe network stuff below
 	else if(Old == parent2)
 		parent2 = New
 	else if(Old == parent3)
-		parent3 = New
+		parent3 = New
+
+
+/obj/machinery/atmospherics/trinary/unsafe_pressure_release(var/mob/user,var/pressures)
+	..()
+
+	var/turf/T = get_turf(src)
+	if(T)
+		//Remove the gas from air1+air2+air3 and assume it
+		var/datum/gas_mixture/environment = T.return_air()
+		var/lost = pressures*environment.volume/(air1.temperature * R_IDEAL_GAS_EQUATION)
+		lost += pressures*environment.volume/(air2.temperature * R_IDEAL_GAS_EQUATION)
+		lost += pressures*environment.volume/(air3.temperature * R_IDEAL_GAS_EQUATION)
+		var/shared_loss = lost/3
+
+		var/datum/gas_mixture/to_release = air1.remove(shared_loss)
+		to_release.merge(air2.remove(shared_loss))
+		to_release.merge(air3.remove(shared_loss))
+		T.assume_air(to_release)
+		air_update_turf(1)

code/ATMOSPHERICS/components/unary_devices/unary_base.dm

@@ -117,4 +117,20 @@ Housekeeping and pipe network stuff below
 
 /obj/machinery/atmospherics/unary/replacePipenet(datum/pipeline/Old, datum/pipeline/New)
 	if(Old == parent)
-		parent = New
+		parent = New
+
+
+/obj/machinery/atmospherics/unary/unsafe_pressure_release(var/mob/user,var/pressures)
+	..()
+
+	var/turf/T = get_turf(src)
+	if(T)
+		//Remove the gas from air_contents and assume it
+		var/datum/gas_mixture/environment = T.return_air()
+		var/lost = pressures*environment.volume/(air_contents.temperature * R_IDEAL_GAS_EQUATION)
+
+		var/datum/gas_mixture/to_release = air_contents.remove(lost)
+		T.assume_air(to_release)
+		air_update_turf(1)
+
+

html/changelogs/RemieRichards-PipePressureLethality.yml

@@ -0,0 +1,8 @@
+
+author: RemieRichards
+
+delete-after: True
+
+changes: 
+  - tweak: "You can now unwrench pipes who's internal pressures are greater than that of their environment..."
+  - rscadd: "However it will throw you away from the pipe at extreme speed! (You are warned beforehand if the pipe will do this, allowing you to cancel)"