Merge pull request #7009 from atlantiscze/2020_04_17_EPRFix

Fixes supermatter monitoring EPR indicator showing Undefined

code/modules/modular_computers/file_system/programs/engineering/supermatter_monitor.dm

@@ -77,6 +77,7 @@
 		data["SM_power"] = active.power
 		data["SM_ambienttemp"] = air.temperature
 		data["SM_ambientpressure"] = air.return_pressure()
+		data["SM_EPR"] = active.get_epr()
 		//data["SM_EPR"] = active.get_epr()
 		if(air.total_moles)
 			data["SM_gas_O2"] = round(100*air.gas["oxygen"]/air.total_moles,0.01)

code/modules/power/supermatter/supermatter.dm

@@ -131,6 +131,16 @@
 	return SUPERMATTER_INACTIVE
 
 
+/obj/machinery/power/supermatter/proc/get_epr()
+	var/turf/T = get_turf(src)
+	if(!istype(T))
+		return
+	var/datum/gas_mixture/air = T.return_air()
+	if(!air)
+		return 0
+	return round((air.total_moles / air.group_multiplier) / 23.1, 0.01)
+
+
 /obj/machinery/power/supermatter/proc/explode()
 	message_admins("Supermatter exploded at ([x],[y],[z] - <A HREF='?_src_=holder;adminplayerobservecoodjump=1;X=[x];Y=[y];Z=[z]'>JMP</a>)",0,1)
 	log_game("SUPERMATTER([x],[y],[z]) Exploded. Power:[power], Oxygen:[oxygen], Damage:[damage], Integrity:[get_integrity()]")