New MV hydro with upgraded power

The LV hydro is easy to make giving lot of power. The New hydro MV will put a tier system to it; thereby giving more incentive to player to pursue MV hydro plus a little survival aspect. This is a result of [Detailed discussion which is here](minetest-mods#411). Thanks to VanessaE for a good talk and support :)

technic/machines/MV/hydro_turbine.lua

@@ -0,0 +1,109 @@
+-- A Hydro Turbine produces MV EUs by exploiting flowing water across it
+-- It is a MV EU supplyer and fairly high yield (max 1750EUs)
+
+local S = technic.getter
+
+local cable_entry = "^technic_cable_connection_overlay.png"
+
+minetest.register_alias("hydro_turbine", "technic:hydro_turbine")
+
+minetest.register_craft({
+	output = 'technic:hydro_turbine',
+	recipe = {
+		{'technic:stainless_steel_ingot', 'technic:water_mill',        'technic:stainless_steel_ingot'},
+		{'default:diamond',     'technic:mv_transformer', 'default:diamond'},
+		{'technic:stainless_steel_ingot', 'technic:mv_cable',       'technic:stainless_steel_ingot'},
+	}
+})
+
+local function check_node_around_mill(pos)
+	local node = minetest.get_node(pos)
+	if node.name == "default:water_flowing"
+	  or node.name == "default:river_water_flowing" then
+		return node.param2 -- returns approx. water flow, if any
+	end
+	return false
+end
+
+local run = function(pos, node)
+	local meta             = minetest.get_meta(pos)
+	local water_flow       = 0
+	local lava_nodes       = 0
+	local production_level = 0
+	local eu_supply        = 0
+	local max_output       = 35 * 50 -- 10 times better than LV hydro because of 2 diamonds extra and 4 stainless steel, a transformer and whatnot ;P. If 2 extra diamonds feels too hard to get; change it to mese may be. But i don't think that's a good idea. I would rather go for mese block or something if changing. Man hydro turbines are strong and long lasting. So, give it some value :)
+
+	local positions = {
+		{x=pos.x+1, y=pos.y, z=pos.z},
+		{x=pos.x-1, y=pos.y, z=pos.z},
+		{x=pos.x,   y=pos.y, z=pos.z+1},
+		{x=pos.x,   y=pos.y, z=pos.z-1},
+	}
+
+	for _, p in pairs(positions) do
+		local check = check_node_around_mill(p)
+		if check then
+			water_flow = water_flow + check
+		end
+	end
+
+	eu_supply = math.min(35 * water_flow, max_output)
+	production_level = math.floor(100 * eu_supply / max_output)
+
+	meta:set_int("MV_EU_supply", eu_supply)
+
+	meta:set_string("infotext",
+		S("Hydro %s Generator"):format("MV").." ("..production_level.."%)")
+
+	if production_level > 0 and
+	   minetest.get_node(pos).name == "technic:hydro_turbine" then
+		technic.swap_node (pos, "technic:hydro_turbine_active")
+		meta:set_int("MV_EU_supply", 0)
+		return
+	end
+	if production_level == 0 then
+		technic.swap_node(pos, "technic:hydro_turbine")
+	end
+end
+
+minetest.register_node("technic:hydro_turbine", {
+	description = S("Hydro %s Generator"):format("MV"),
+	tiles = {
+		"technic_hydro_turbine_top.png",
+		"technic_machine_bottom.png"..cable_entry,
+		"technic_hydro_turbine_side.png",
+		"technic_hydro_turbine_side.png",
+		"technic_hydro_turbine_side.png",
+		"technic_hydro_turbine_side.png"
+	},
+	paramtype2 = "facedir",
+	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2,
+		technic_machine=1, technic_mv=1},
+	legacy_facedir_simple = true,
+	sounds = default.node_sound_wood_defaults(),
+	on_construct = function(pos)
+		local meta = minetest.get_meta(pos)
+		meta:set_string("infotext", S("Hydro %s Generator"):format("MV"))
+		meta:set_int("MV_EU_supply", 0)
+	end,
+	technic_run = run,
+})
+
+minetest.register_node("technic:hydro_turbine_active", {
+	description = S("Hydro %s Generator"):format("MV"),
+	tiles = {"technic_hydro_turbine_top_active.png", "technic_machine_bottom.png",
+	         "technic_hydro_turbine_side.png",       "technic_hydro_turbine_side.png",
+	         "technic_hydro_turbine_side.png",       "technic_hydro_turbine_side.png"},
+	paramtype2 = "facedir",
+	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2,
+		technic_machine=1, technic_mv=1, not_in_creative_inventory=1},
+	legacy_facedir_simple = true,
+	sounds = default.node_sound_wood_defaults(),
+	drop = "technic:hydro_turbine",
+	technic_run = run,
+	technic_disabled_machine_name = "technic:hydro_turbine",
+})
+
+technic.register_machine("MV", "technic:hydro_turbine",        technic.producer)
+technic.register_machine("MV", "technic:hydro_turbine_active", technic.producer)
+

technic/machines/MV/init.lua

@@ -13,7 +13,7 @@ if technic.config:get_bool("enable_wind_mill") then
 end
 dofile(path.."/generator.lua")
 dofile(path.."/solar_array.lua")
-
+dofile(path.."/hydro_turbine.lua")
 -- Machines
 dofile(path.."/alloy_furnace.lua")
 dofile(path.."/electric_furnace.lua")