Show EU power values more readable (#424)

Add the EU_string helper function
In comparison to pretty_num it uses SI prefixes, adds "EU" (e.g. kEU) and rounds the number for readability
Add a constant_digit_count boolean setting

technic/machines/LV/solar_panel.lua

@@ -35,7 +35,8 @@ local run = function(pos, node)
 		local charge_to_give = math.floor((light + pos1.y) * 3)
 		charge_to_give = math.max(charge_to_give, 0)
 		charge_to_give = math.min(charge_to_give, 200)
-		meta:set_string("infotext", S("@1 Active (@2 EU)", machine_name, technic.pretty_num(charge_to_give)))
+		meta:set_string("infotext", S("@1 Active (@2)", machine_name,
+			technic.EU_string(charge_to_give)))
 		meta:set_int("LV_EU_supply", charge_to_give)
 	else
 		meta:set_string("infotext", S("%s Idle"):format(machine_name))
@@ -54,7 +55,7 @@ minetest.register_node("technic:solar_panel", {
 	active = false,
 	drawtype = "nodebox",
 	paramtype = "light",
-	is_ground_content = true,	
+	is_ground_content = true,
 	node_box = {
 		type = "fixed",
 		fixed = {-0.5, -0.5, -0.5, 0.5, 0, 0.5},

technic/machines/MV/wind_mill.lua

@@ -60,7 +60,8 @@ local run = function(pos, node)
 	elseif check == true then
 		local power = math.min(pos.y * 100, 5000)
 		meta:set_int("MV_EU_supply", power)
-		meta:set_string("infotext", S("@1 (@2 EU)", machine_name, technic.pretty_num(power)))
+		meta:set_string("infotext", S("@1 (@2)", machine_name,
+			technic.EU_string(power)))
 	end
 	-- check == nil: assume nothing has changed
 end

technic/machines/power_monitor.lua

@@ -55,7 +55,7 @@ minetest.register_abm({
 			local demand = sw_meta:get_int("demand")
 			meta:set_string("infotext",
 					S("Power Monitor. Supply: @1 Demand: @2",
-					technic.pretty_num(supply), technic.pretty_num(demand)))
+					technic.EU_string(supply), technic.EU_string(demand)))
 		else
 			meta:set_string("infotext",S("Power Monitor Has No Network"))
 		end

technic/machines/register/battery_box.lua

@@ -255,8 +255,9 @@ function technic.register_battery_box(data)
 
 		local charge_percent = math.floor(current_charge / max_charge * 100)
 		meta:set_string("formspec", formspec..add_on_off_buttons(meta, ltier, charge_percent))
-		local infotext = S("@1 Battery Box: @2/@3", tier,
-				technic.pretty_num(current_charge), technic.pretty_num(max_charge))
+		local infotext = S("@1 Battery Box: @2 / @3", tier,
+				technic.EU_string(current_charge),
+				technic.EU_string(max_charge))
 		if eu_input == 0 then
 			infotext = S("%s Idle"):format(infotext)
 		end

technic/machines/register/solar_array.lua

@@ -30,14 +30,15 @@ function technic.register_solar_array(data)
 			local charge_to_give = math.floor((light + pos.y) * data.power)
 			charge_to_give = math.max(charge_to_give, 0)
 			charge_to_give = math.min(charge_to_give, data.power * 50)
-			meta:set_string("infotext", S("@1 Active (@2 EU)", machine_name, technic.pretty_num(charge_to_give)))
+			meta:set_string("infotext", S("@1 Active (@2)", machine_name,
+				technic.EU_string(charge_to_give)))
 			meta:set_int(tier.."_EU_supply", charge_to_give)
 		else
 			meta:set_string("infotext", S("%s Idle"):format(machine_name))
 			meta:set_int(tier.."_EU_supply", 0)
 		end
 	end
-	
+
 	minetest.register_node("technic:solar_array_"..ltier, {
 		tiles = {"technic_"..ltier.."_solar_array_top.png",  "technic_"..ltier.."_solar_array_bottom.png",
 			 "technic_"..ltier.."_solar_array_side.png", "technic_"..ltier.."_solar_array_side.png",

technic/machines/supply_converter.lua

@@ -149,7 +149,9 @@ local run = function(pos, node, run_stage)
 		meta:set_int(from.."_EU_supply", 0)
 		meta:set_int(to.."_EU_demand", 0)
 		meta:set_int(to.."_EU_supply", input * remain)
-		meta:set_string("infotext", S("@1 (@2 @3 -> @4 @5)", machine_name, technic.pretty_num(input), from, technic.pretty_num(input * remain), to))
+		meta:set_string("infotext", S("@1 (@2 @3 -> @4 @5)", machine_name,
+			technic.EU_string(input), from,
+			technic.EU_string(input * remain), to))
 	else
 		meta:set_string("infotext", S("%s Has Bad Cabling"):format(machine_name))
 		if to then

technic/machines/switching_station.lua

@@ -361,9 +361,9 @@ minetest.register_abm({
 		end
 		--dprint("Total BA demand:"..BA_eu_demand)
 
-		meta:set_string("infotext",
-				S("@1. Supply: @2 Demand: @3",
-				machine_name, technic.pretty_num(PR_eu_supply), technic.pretty_num(RE_eu_demand)))
+		meta:set_string("infotext", S("@1. Supply: @2 Demand: @3",
+				machine_name, technic.EU_string(PR_eu_supply),
+				technic.EU_string(RE_eu_demand)))
 
 		-- If mesecon signal and power supply or demand changed then
 		-- send them via digilines.