an_televator/init.lua

-- televator/init.lua

local delay = {}

local itemset
if minetest.get_modpath("default") then
	itemset = {
		steel = "default:steel_ingot",
		gold = "default:gold_ingot",
		copper = "default:copper_ingot",
		glass = "default:glass",
	}
end

---
--- Functions
---

-- [function] Get near elevators
local function get_near_elevators(pos, which)
	for i = 1, 16 do
		local cpos = vector.new(pos)

		if which == "above" then
			cpos.y = cpos.y + i
		elseif which == "below" then
			cpos.y = cpos.y - i
		end

		local name = minetest.get_node(cpos).name
		if (which == "above" and name == "televator:elevator")
				or (which == "below" and i ~= 1 and name == "televator:elevator") then
			cpos.y = cpos.y + 1
			return cpos
		elseif name ~= "air" and name ~= "televator:elevator" then
			return
		end
	end
end

-- [function] Elevator safe
local function is_safe(pos)
	for i = 0, 1 do
		local tpos = vector.new(pos)
		tpos.y = tpos.y + i

		if minetest.get_node(tpos).name ~= "air" then
			return
		end
	end

	return true
end

---
--- Registrations
---

-- [register] Elevator node
minetest.register_node("televator:elevator", {
	description = "Elevator\n"..
			minetest.colorize("grey","Can be placed up to 16 nodes apart\n"
					.."Jump to go up, sneak to go down"),
	tiles = {"televator_elevator.png"},
	groups = {cracky = 2, disable_jump = 1},
	after_place_node = function(pos)
		-- Set infotext
		minetest.get_meta(pos):set_string("infotext", "Elevator")
	end,
})

-- [register] Recipe
if itemset then
	minetest.register_craft({
		output = "televator:elevator 2",
		recipe = {
			{itemset.steel, itemset.glass, itemset.steel},
			{itemset.steel, itemset.gold, itemset.steel},
			{itemset.steel, itemset.copper, itemset.steel,}
		},
	})
end

-- [register] Globalstep
minetest.register_globalstep(function(dtime)
	for _, player in pairs(minetest.get_connected_players()) do
		local pos  = player:get_pos()
		local name = player:get_player_name()

		if not delay[name] then
			delay[name] = 0.5
		else
			delay[name] = delay[name] + dtime
		end

		if not delay[name] or delay[name] > 0.5 then
			if minetest.get_node({x = pos.x, y = pos.y - 1, z = pos.z}).name == "televator:elevator" then
				local where
				local controls = player:get_player_control()
				if controls.jump then
					where = "above"
				elseif controls.sneak then
					where = "below"
				else return end

				local epos = get_near_elevators(pos, where)
				if epos and is_safe(epos) then
					player:set_pos(epos) -- Update player position

					-- Play sound
					minetest.sound_play("televator_whoosh", {
						gain = 0.75,
						pos = epos,
						max_hear_distance = 5,
					})
				elseif epos then
					minetest.chat_send_player(name, "Elevator blocked by obstruction")
				else
					minetest.chat_send_player(name, "Could not find elevator")
				end

				delay[name] = 0 -- Restart delay
			end
		end
	end
end)