technic/technic/machines/supply_converter.lua

-- The supply converter is a generic device which can convert from
-- LV to MV and back, and HV to MV and back.
-- The machine is configured by the wiring below and above it.
--
-- It works like this:
--   The top side is setup as the receiver side, the bottom as the producer side.
--   Once the receiver side is powered it will deliver power to the other side.
--   Unused power is wasted just like any other producer!

local S = technic.getter

local function set_supply_converter_formspec(meta)
	local formspec = "size[5,2.25]"..
		"field[0.3,0.5;2,1;power;"..S("Input Power")..";"..meta:get_int("power").."]"
	-- The names for these toggle buttons are explicit about which
	-- state they'll switch to, so that multiple presses (arising
	-- from the ambiguity between lag and a missed press) only make
	-- the single change that the user expects.
	if meta:get_int("mesecon_mode") == 0 then
		formspec = formspec.."button[0,1;5,1;mesecon_mode_1;"..S("Ignoring Mesecon Signal").."]"
	else
		formspec = formspec.."button[0,1;5,1;mesecon_mode_0;"..S("Controlled by Mesecon Signal").."]"
	end
	if meta:get_int("enabled") == 0 then
		formspec = formspec.."button[0,1.75;5,1;enable;"..S("%s Disabled"):format(S("Supply Converter")).."]"
	else
		formspec = formspec.."button[0,1.75;5,1;disable;"..S("%s Enabled"):format(S("Supply Converter")).."]"
	end
	meta:set_string("formspec", formspec)
end

local supply_converter_receive_fields = function(pos, formname, fields, sender)
	local meta = minetest.get_meta(pos)
	local power = nil
	if fields.power then
		power = tonumber(fields.power) or 0
		power = 100 * math.floor(power / 100)
		power = math.max(power, 0)
		power = math.min(power, 10000)
		if power == meta:get_int("power") then power = nil end
	end
	if power then meta:set_int("power", power) end
	if fields.enable then meta:set_int("enabled", 1) end
	if fields.disable then meta:set_int("enabled", 0) end
	if fields.mesecon_mode_0 then meta:set_int("mesecon_mode", 0) end
	if fields.mesecon_mode_1 then meta:set_int("mesecon_mode", 1) end
	set_supply_converter_formspec(meta)
end

local mesecons = {
	effector = {
		action_on = function(pos, node)
			minetest.get_meta(pos):set_int("mesecon_effect", 1)
		end,
		action_off = function(pos, node)
			minetest.get_meta(pos):set_int("mesecon_effect", 0)
		end
	}
}

local run = function(pos, node, run_stage)
	-- run only in producer stage.
	if run_stage == technic.receiver then
		return
	end

	local remain = 0.9
	-- Machine information
	local machine_name  = S("Supply Converter")
	local meta          = minetest.get_meta(pos)
	local enabled       = meta:get_string("enabled")
	if enabled == "" then
		-- Backwards compatibility
		minetest.registered_nodes["technic:supply_converter"].on_construct(pos)
		enabled = true
	else
		enabled = enabled == "1"
	end
	enabled = enabled and (meta:get_int("mesecon_mode") == 0 or meta:get_int("mesecon_effect") ~= 0)
	local demand = enabled and meta:get_int("power") or 0

	local pos_up        = {x=pos.x, y=pos.y+1, z=pos.z}
	local pos_down      = {x=pos.x, y=pos.y-1, z=pos.z}
	local name_up       = minetest.get_node(pos_up).name
	local name_down     = minetest.get_node(pos_down).name

	local from = technic.get_cable_tier(name_up)
	local to   = technic.get_cable_tier(name_down)

	if from and to then
		local input = meta:get_int(from.."_EU_input")
		meta:set_int(from.."_EU_demand", demand)
		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))
	else
		meta:set_string("infotext", S("%s Has Bad Cabling"):format(machine_name))
		if to then
			meta:set_int(to.."_EU_supply", 0)
		end
		if from then
			meta:set_int(from.."_EU_demand", 0)
		end
		return
	end

end

minetest.register_node("technic:supply_converter", {
	description = S("Supply Converter"),
	tiles  = {"technic_supply_converter_top.png", "technic_supply_converter_bottom.png",
	          "technic_supply_converter_side.png", "technic_supply_converter_side.png",
	          "technic_supply_converter_side.png", "technic_supply_converter_side.png"},
	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2,
		technic_machine=1, technic_all_tiers=1},
	connect_sides = {"top", "bottom"},
	sounds = default.node_sound_wood_defaults(),
	on_receive_fields = supply_converter_receive_fields,
	on_construct = function(pos)
		local meta = minetest.get_meta(pos)
		meta:set_string("infotext", S("Supply Converter"))
		meta:set_int("power", 10000)
		meta:set_int("enabled", 1)
		meta:set_int("mesecon_mode", 0)
		meta:set_int("mesecon_effect", 0)
		set_supply_converter_formspec(meta)
	end,
	mesecons = mesecons,
	technic_run = run,
	technic_on_disable = run,
})

minetest.register_craft({
	output = 'technic:supply_converter 1',
	recipe = {
		{'technic:fine_gold_wire', 'technic:rubber',         'technic:doped_silicon_wafer'},
		{'technic:mv_transformer', 'technic:machine_casing', 'technic:lv_transformer'},
		{'technic:mv_cable',       'technic:rubber',         'technic:lv_cable'},
	}
})

for tier, machines in pairs(technic.machines) do
	technic.register_machine(tier, "technic:supply_converter", technic.producer_receiver)
end