whipping up a simple puzzle chest to give a clue about ancient numbering

The coding is done, but UI and a node mesh need to be done

df_underworld_items/init.lua

@@ -13,6 +13,7 @@ dofile(modpath.."/hunter_statue.lua")
 dofile(modpath.."/glowing_pit_plasma.lua")
 
 dofile(modpath.."/puzzle_seal.lua")
+dofile(modpath.."/puzzle_chest.lua")
 dofile(modpath.."/ancient_lanterns.lua")
 if df_underworld_items.config.enable_slade_drill then
 	dofile(modpath.."/slade_drill.lua")

df_underworld_items/puzzle_chest.lua

@@ -0,0 +1,121 @@
+local S = minetest.get_translator(minetest.get_current_modname())
+
+local initialize = function(pos, meta)
+	if not meta:contains("key") then
+		local inv = meta:get_inventory()
+		inv:set_size("main", 8)
+		local next_seed = math.random() * 2^21
+		math.randomseed(pos.x + pos.y^8 + pos.z^16)
+		-- Key is consistent with location
+		local key = {math.random(0,7), math.random(0,7), math.random(0,7), math.random(0,7)}
+		math.randomseed(next_seed)
+		local state = {math.random(0,7), math.random(0,7), math.random(0,7), math.random(0,7)}
+		meta:set_string("key", minetest.serialize(key))
+		meta:set_string("state", minetest.serialize(state))
+		meta:mark_as_private("key")
+		meta:mark_as_private("state") -- not really necessary, but for consistency
+	end
+end
+
+-- 1 2
+-- 3 4
+
+local sum_square = function(input)
+	return {input[1] + input[2], input[3] + input[4], input[1] + input[3], input[2] + input[4]}
+end
+
+local formspec_dial = function(identifier, state)
+	return "label[0.5,0;"..tostring(state).."]"
+		.. "button[0,0.25;0.5,0.5;"..identifier.."-;←]"
+		.. "button[1.5,0.25;0.5,0.5;"..identifier.."+;→]"
+end
+
+local formspec_bar = function(horizontal, state, key)
+	--return "label[0,0;" .. tostring(state) .. "/" .. tostring(key) .. "]"
+	if horizontal then
+		return "box[0,0;".. tostring(key/14 * 2) ..",1;#222222ff]box[0,0.1;".. tostring(state/14 * 2)..",0.8;#ff00ffff]"
+	end
+	return "box[0,0;1,".. tostring(key/14 * 2) ..";#222222ff]box[0.1,0;0.8,".. tostring(state/14 * 2)..";#ff00ffff]"
+end
+
+local prefix = "df_underworld_items:puzzle_chest"
+local prefix_len = string.len("df_underworld_items:puzzle_chest")
+
+local show_formspec = function(pos, node, clicker, itemstack, pointed_thing)
+	local meta = minetest.get_meta(pos)
+	initialize(pos, meta)
+	local key = minetest.deserialize(meta:get_string("key"))
+	local state = minetest.deserialize(meta:get_string("state"))
+	local key_sum = sum_square(key)
+	local state_sum = sum_square(state)
+	local solved = key_sum[1] == state_sum[1] and key_sum[2] == state_sum[2] and key_sum[3] == state_sum[3] and key_sum[4] == state_sum[4]
+	local playername = clicker:get_player_name()
+	local formname = prefix .. minetest.pos_to_string(pos)
+	local formspec = "formspec_version[6]"
+		.. "size[11,11.5]"
+		.. "container[3.5,1]"
+		.. "container[0,0]" .. formspec_dial("dial1", state[1]) .. "container_end[]"
+		.. "container[2,0]" .. formspec_dial("dial2", state[2]) .. "container_end[]"
+		.. "container[0,1]" .. formspec_dial("dial3", state[3]) .. "container_end[]"
+		.. "container[2,1]" .. formspec_dial("dial4", state[4]) .. "container_end[]"
+		.. "container[4.1,0]" .. formspec_bar(true, state_sum[1], key_sum[1]) .. "container_end[]"		
+		.. "container[4.1,1]" .. formspec_bar(true, state_sum[2], key_sum[2]) .. "container_end[]"		
+		.. "container[0.5,2.1]" .. formspec_bar(false, state_sum[3], key_sum[3]) .. "container_end[]"		
+		.. "container[2.5,2.1]" .. formspec_bar(false, state_sum[4], key_sum[4]) .. "container_end[]"
+		.. "container_end[]"
+		.. "list[current_player;main;0.6,6.2;8,4;]"
+	if solved then
+		local nodemeta = "nodemeta:"..pos.x..","..pos.y..","..pos.z
+		formspec = formspec
+			.. "list["..nodemeta..";main;0.6,4.7;8,1;]"
+	end
+
+	minetest.show_formspec(playername, formname, formspec)
+end
+
+minetest.register_on_player_receive_fields(function(player, formname, fields)
+	if string.sub(formname, 1, prefix_len) ~= prefix then return end
+	--minetest.debug(dump(fields))
+	if fields.quit then return end
+	local pos = minetest.string_to_pos(string.sub(formname, prefix_len+1, -1))
+	local meta = minetest.get_meta(pos)
+	local state = minetest.deserialize(meta:get_string("state"))
+	for i = 1,4 do
+		if fields["dial"..tostring(i).."+"] then
+			state[i] = (state[i] + 1) % 8
+			break
+		elseif fields["dial"..tostring(i).."-"] then
+			state[i] = (state[i] - 1) % 8
+			break
+		end
+	end
+	meta:set_string("state", minetest.serialize(state))
+	show_formspec(pos, nil, player)
+end)
+
+
+minetest.register_node("df_underworld_items:puzzle_chest", {
+	description = S("Puzzle Chest"),
+	_doc_items_longdesc = df_underworld_items.doc.puzzle_chest_desc,
+	_doc_items_usagehelp = df_underworld_items.doc.puzzle_chest_usage,
+	tiles = {"dfcaverns_glow_amethyst.png"},
+	is_ground_content = false,
+	groups = {cracky=3, pit_plasma_resistant=1, pickaxey = 4, building_block = 1,}, -- deliberately not in material_stone group to keep pit plasma ABM efficient
+	sounds = df_dependencies.sound_glass(),
+	light_source = 6,
+	paramtype = "light",
+	use_texture_alpha = "blend",
+	drawtype = "glasslike",
+	sunlight_propagates = true,
+	_mcl_blast_resistance = 6,
+	_mcl_hardness = 2,
+	
+	on_rightclick = show_formspec,
+	can_dig = function(pos, player)
+		local meta = minetest.get_meta(pos)
+		initialize(pos, meta)
+		local inv = meta:get_inventory()
+		return inv:is_empty("main")
+	end,
+})
+