Lua implementation of furnace with visible active state

games/minimal/mods/default/init.lua

@@ -1269,6 +1269,135 @@ minetest.register_node("default:furnace", {
 	end,
 })
 
+minetest.register_node("default:furnace_active", {
+	description = "Furnace",
+	tile_images = {"default_furnace_side.png", "default_furnace_side.png", "default_furnace_side.png",
+		"default_furnace_side.png", "default_furnace_side.png", "default_furnace_front_active.png"},
+	paramtype2 = "facedir",
+	light_source = 8,
+	drop = "default:furnace",
+	groups = {cracky=2},
+	legacy_facedir_simple = true,
+	sounds = default.node_sound_stone_defaults(),
+	on_construct = function(pos)
+		local meta = minetest.env:get_meta(pos)
+		meta:set_string("formspec",
+			"invsize[8,9;]"..
+			"list[current_name;fuel;2,3;1,1;]"..
+			"list[current_name;src;2,1;1,1;]"..
+			"list[current_name;dst;5,1;2,2;]"..
+			"list[current_player;main;0,5;8,4;]")
+		meta:set_string("infotext", "Furnace");
+		local inv = meta:get_inventory()
+		inv:set_size("fuel", 1)
+		inv:set_size("src", 1)
+		inv:set_size("dst", 4)
+	end,
+})
+
+function hacky_swap_node(pos,name)
+	local node = minetest.env:get_node(pos)
+	local meta = minetest.env:get_meta(pos)
+	local meta0 = meta:to_table()
+	if node.name == name then
+		return
+	end
+	node.name = name
+	local meta0 = meta:to_table()
+	minetest.env:set_node(pos,node)
+	meta = minetest.env:get_meta(pos)
+	meta:from_table(meta0)
+end
+
+minetest.register_abm({
+	nodenames = {"default:furnace","default:furnace_active"},
+	interval = 1.0,
+	chance = 1,
+	action = function(pos, node, active_object_count, active_object_count_wider)
+		local meta = minetest.env:get_meta(pos)
+		for i, name in ipairs({
+				"fuel_totaltime",
+				"fuel_time",
+				"src_totaltime",
+				"src_time"
+		}) do
+			if meta:get_string(name) == "" then
+				meta:set_float(name, 0.0)
+			end
+		end
+
+		local inv = meta:get_inventory()
+
+		local srclist = inv:get_list("src")
+		local cooked = nil
+		
+		if srclist then
+			cooked = minetest.get_craft_result({method = "cooking", width = 1, items = srclist})
+		end
+		
+		local was_active = false
+		
+		if meta:get_float("fuel_time") < meta:get_float("fuel_totaltime") then
+			was_active = true
+			meta:set_float("fuel_time", meta:get_float("fuel_time") + 1)
+			meta:set_float("src_time", meta:get_float("src_time") + 1)
+			if cooked and cooked.item and meta:get_float("src_time") >= 3 then
+				-- check if there's room for output in "dst" list
+				if inv:room_for_item("dst",cooked.item) then
+					-- Put result in "dst" list
+					inv:add_item("dst", cooked.item)
+					-- take stuff from "src" list
+					srcstack = inv:get_stack("src", 1)
+					srcstack:take_item()
+					inv:set_stack("src", 1, srcstack)
+				else
+					print("Could not insert '"..cooked.item.."'")
+				end
+				meta:set_string("src_time", 0)
+			end
+		end
+		
+		if meta:get_float("fuel_time") < meta:get_float("fuel_totaltime") then
+			meta:set_string("infotext","Furnace active: "..(meta:get_float("fuel_time")/meta:get_float("fuel_totaltime")*100).."%")
+			hacky_swap_node(pos,"default:furnace_active")
+			return
+		end
+
+		local fuel = nil
+		local cooked = nil
+		local fuellist = inv:get_list("fuel")
+		local srclist = inv:get_list("src")
+		
+		if srclist then
+			cooked = minetest.get_craft_result({method = "cooking", width = 1, items = srclist})
+		end
+		if fuellist then
+			fuel = minetest.get_craft_result({method = "fuel", width = 1, items = fuellist})
+		end
+
+		if fuel.time <= 0 then
+			meta:set_string("infotext","Furnace out of fuel")
+			hacky_swap_node(pos,"default:furnace")
+			return
+		end
+
+		if cooked.item:is_empty() then
+			if was_active then
+				meta:set_string("infotext","Furnace is empty")
+				hacky_swap_node(pos,"default:furnace")
+			end
+			return
+		end
+
+		meta:set_string("fuel_totaltime", fuel.time)
+		meta:set_string("fuel_time", 0)
+		
+		local stack = inv:get_stack("fuel", 1)
+		stack:take_item()
+		inv:set_stack("fuel", 1, stack)
+	end,
+})
+
 minetest.register_node("default:cobble", {
 	description = "Cobble",
 	tile_images = {"default_cobble.png"},