Implements pump power draw

code/ATMOSPHERICS/components/binary_devices/pump.dm

@@ -22,6 +22,10 @@ obj/machinery/atmospherics/binary/pump
 	var/on = 0
 	var/target_pressure = ONE_ATMOSPHERE
 	var/power_rating = 7500		//A measure of how powerful the pump is, in Watts. 7500 W ~ 10 HP
+	
+	//The maximum amount of volume in Liters the pump can transfer in 1 second. 
+	//This is limited by how fast the pump can spin without breaking, and means you can't instantly fill up the distro even when it's empty (at 10000, it will take about 15 seconds)
+	var/max_volume_transfer = 10000
 
 	use_power = 1
 	idle_power_usage = 10	//10 W for internal circuitry and stuff
@@ -29,12 +33,17 @@ obj/machinery/atmospherics/binary/pump
 	var/frequency = 0
 	var/id = null
 	var/datum/radio_frequency/radio_connection
+	
+	New()
+		..()
+		active_power_usage = power_rating	//make sure this is equal to the max power rating so that auto use power works correctly
 
 	highcap
 		name = "High capacity gas pump"
 		desc = "A high capacity pump"
 
-		target_pressure = 15000000
+		target_pressure = 15000000	//15 GPa? Really?
+		power_rating = 112500	//150 Horsepower
 
 	on
 		on = 1
@@ -62,46 +71,65 @@ obj/machinery/atmospherics/binary/pump
 			return 0
 
 		var/output_starting_pressure = air2.return_pressure()
-
 		if( (target_pressure - output_starting_pressure) < 0.01)
 			//No need to pump gas if target is already reached!
+			if (use_power >= 2)
+				update_use_power(1)
 			return 1
+		
+		var/output_volume = air2.volume
+		if (network2 && network2.air_transient)
+			output_volume = network2.air_transient.volume
+		output_volume = min(output_volume, max_volume_transfer)
 
 		//Calculate necessary moles to transfer using PV=nRT
 		if((air1.total_moles() > 0) && (air1.temperature > 0 || air2.temperature > 0))
 			var/air_temperature = (air2.temperature > 0)? air2.temperature : air1.temperature
 			var/pressure_delta = target_pressure - output_starting_pressure
-			var/transfer_moles = pressure_delta*air2.volume/(air_temperature * R_IDEAL_GAS_EQUATION)	//The number of moles that would have to be transfered to bring air2 to the target pressure
+			var/transfer_moles = pressure_delta*output_volume/(air_temperature * R_IDEAL_GAS_EQUATION)	//The number of moles that would have to be transfered to bring air2 to the target pressure
 			
 			//estimate the amount of energy required
 			var/specific_entropy = air2.specific_entropy() - air1.specific_entropy()	//air2 is gaining moles, air1 is loosing
 			var/specific_power = 0
 			
-			src.visible_message("DEBUG: [src] >>> terminal pressures: sink = [air2.return_pressure()] kPa, source = [air1.return_pressure()] kPa")
+			//src.visible_message("DEBUG: [src] >>> terminal pressures: sink = [air2.return_pressure()] kPa, source = [air1.return_pressure()] kPa")
-			src.visible_message("DEBUG: [src] >>> specific entropy = [air2.specific_entropy()] - [air1.specific_entropy()] = [specific_entropy] J/K")
+			//src.visible_message("DEBUG: [src] >>> specific entropy = [air2.specific_entropy()] - [air1.specific_entropy()] = [specific_entropy] J/K")
 			
 			//if specific_entropy >= 0 then gas just flows naturally and we are not limited by how powerful the pump is.
 			if (specific_entropy < 0)
 				specific_power = -specific_entropy*air_temperature		//how much power we need per mole
 				
-				src.visible_message("DEBUG: [src] >>> limiting transfer_moles to [power_rating / (air_temperature * -specific_entropy)] mol")
+				//src.visible_message("DEBUG: [src] >>> limiting transfer_moles to [power_rating / (air_temperature * -specific_entropy)] mol")
 				transfer_moles = min(transfer_moles, power_rating / specific_power)
 			
 			//Actually transfer the gas		
 			var/datum/gas_mixture/removed = air1.remove(transfer_moles)
 			air2.merge(removed)
 			
-			src.visible_message("DEBUG: [src] >>> entropy_change = [specific_entropy*transfer_moles] J/K")
+			//src.visible_message("DEBUG: [src] >>> entropy_change = [specific_entropy*transfer_moles] J/K")
 			
 			//if specific_entropy >= 0 then gas is flowing naturally and we don't need to use extra power
 			if (specific_entropy < 0)
 				//pump draws power and heats gas according to 2nd law of thermodynamics
-				
+				var/power_draw = round(transfer_moles*specific_power)
-				var/power_draw = transfer_moles*specific_power
 				air2.add_thermal_energy(power_draw)
-				use_power(power_draw)
+			
+				if (power_draw >= power_rating - 5)	//if we are close enough to max power just active_power_usage
+					if (use_power < 2)
+						update_use_power(2)
+				else
+					if (use_power >= 2)
+						update_use_power(1)
+						//src.visible_message("DEBUG: [src] >>> Forcing area power update: use_power changed to [use_power]")
+					
+					if (power_draw > idle_power_usage)
+						use_power(power_draw)
+			else
+				if (use_power >= 2)
+					update_use_power(1)
+					//src.visible_message("DEBUG: [src] >>> Forcing area power update: use_power changed to [use_power]")
 				
-				src.visible_message("DEBUG: [src] >>> drawing [power_draw] W of power.")
+				//src.visible_message("DEBUG: [src] >>> drawing [power_draw] W of power.")
 
 			if(network1)
 				network1.update = 1
@@ -163,6 +191,7 @@ obj/machinery/atmospherics/binary/pump
 
 		if("power_toggle" in signal.data)
 			on = !on
+			update_use_power(on)
 
 		if("set_output_pressure" in signal.data)
 			target_pressure = between(

code/game/machinery/machinery.dm

@@ -157,6 +157,11 @@ Class Procs:
 	if(prob(50))
 		del(src)
 
+//sets the use_power var and then forces an area power update
+/obj/machinery/proc/update_use_power(var/new_use_power)
+	use_power = new_use_power
+	use_power(0) //force area power update
+
 /obj/machinery/proc/auto_use_power()
 	if(!powered(power_channel))
 		return 0