Fix possible crash

mods/CORE/mcl_util/init.lua

@@ -59,6 +59,15 @@ function mcl_util.mcl_log(message, module, bypass_default_logger)
 		minetest.log(selected_module .. " " .. message)
 	end
 end
+function mcl_util.make_mcl_logger(label, option)
+	-- Return dummy function if debug option isn't set
+	if not minetest.settings:get_bool(option,false) then return function() end, false end
+
+	local label_text = "["..tostring(label).."]"
+	return function(message)
+		mcl_util.mcl_log(message, label_text, true)
+	end, true
+end
 
 local player_timers = {}
 
@@ -345,6 +354,33 @@ function mcl_util.hopper_push(pos, dst_pos)
 	return ok
 end
 
+function mcl_util.hopper_pull_to_inventory(hop_inv, hop_list, src_pos, pos)
+	-- TODO: merge together with hopper_pull after https://git.minetest.land/MineClone2/MineClone2/pulls/4190 is merged
+	-- Get node pos' for item transfer
+	local src = minetest.get_node(src_pos)
+	if not minetest.registered_nodes[src.name] then return end
+	local src_type = minetest.get_item_group(src.name, "container")
+	if src_type ~= 2 then return end
+	local src_def = minetest.registered_nodes[src.name]
+
+	local src_list = 'main'
+	local src_inv, stack_id
+
+	if src_def._mcl_hoppers_on_try_pull then
+		src_inv, src_list, stack_id = src_def._mcl_hoppers_on_try_pull(src_pos, pos, hop_inv, hop_list)
+	else
+		local src_meta = minetest.get_meta(src_pos)
+		src_inv = src_meta:get_inventory()
+		stack_id = mcl_util.select_stack(src_inv, src_list, hop_inv, hop_list)
+	end
+
+	if stack_id ~= nil then
+		local ok = mcl_util.move_item(src_inv, src_list, stack_id, hop_inv, hop_list)
+		if src_def._mcl_hoppers_on_after_pull then
+			src_def._mcl_hoppers_on_after_pull(src_pos)
+		end
+	end
+end
 -- Try pulling from source inventory to hopper inventory
 ---@param pos Vector
 ---@param src_pos Vector
@@ -1103,3 +1139,124 @@ function mcl_util.is_it_christmas()
 		return false
 	end
 end
+
+local function table_merge(base, overlay)
+	for k,v in pairs(overlay) do
+		if type(base[k]) == "table" and type(v) == "table" then
+			table_merge(base[k], v)
+		else
+			base[k] = v
+		end
+	end
+	return base
+end
+mcl_util.table_merge = table_merge
+
+function mcl_util.table_keys(t)
+	local keys = {}
+	for k,_ in pairs(t) do
+		keys[#keys + 1] = k
+	end
+	return keys
+end
+
+local uuid_to_aoid_cache = {}
+local function scan_active_objects()
+	-- Update active object ids for all active objects
+	for active_object_id,o in pairs(minetest.luaentities) do
+		o._active_object_id = active_object_id
+		if o._uuid then
+			uuid_to_aoid_cache[o._uuid] = active_object_id
+		end
+	end
+end
+function mcl_util.get_active_object_id(obj)
+	local le = obj:get_luaentity()
+
+	-- If the active object id in the lua entity is correct, return that
+	if le._active_object_id and minetest.luaentities[le._active_object_id] == le then
+		return le._active_object_id
+	end
+
+	scan_active_objects()
+
+	return le._active_object_id
+end
+function mcl_util.get_active_object_id_from_uuid(uuid)
+	return uuid_to_aoid_cache[uuid] or scan_active_objects() or uuid_to_aoid_cache[uuid]
+end
+function mcl_util.get_luaentity_from_uuid(uuid)
+	return minetest.luaentities[ mcl_util.get_active_object_id_from_uuid(uuid) ]
+end
+function mcl_util.gen_uuid()
+	-- Generate a random 128-bit ID that can be assumed to be unique
+	-- To have a 1% chance of a collision, there would have to be 1.6x10^76 IDs generated
+	-- https://en.wikipedia.org/wiki/Birthday_problem#Probability_table
+	local u = {}
+	for i = 1,16 do
+		u[#u + 1] = string.format("%02X",math.random(1,255))
+	end
+	return table.concat(u)
+end
+function mcl_util.assign_uuid(obj)
+	assert(obj)
+
+	local le = obj:get_luaentity()
+	if not le._uuid then
+		le._uuid = mcl_util.gen_uuid()
+	end
+
+	-- Update the cache with this new id
+	local aoid = mcl_util.get_active_object_id(obj)
+	uuid_to_aoid_cache[le._uuid] = aoid
+
+	return le._uuid
+end
+function mcl_util.metadata_last_act(meta, name, delay)
+	local last_act = meta:get_float(name)
+	local now = minetest.get_us_time() * 1e-6
+	if last_act > now + 0.5 then
+		-- Last action was in the future, clock went backwards, so reset
+	elseif last_act >= now - delay then
+		return false
+	end
+
+	meta:set_float(name, now)
+	return true
+end
+
+-- Call a function safely and provide a backtrace on error
+function mcl_util.call_safe(label, func, args)
+	local function caller()
+		return func(unpack(args))
+	end
+
+	local ok,ret = xpcall(caller, debug.traceback)
+	if not ok then
+		minetest.log("error",(label or "")..ret)
+	end
+
+	return ok,ret
+end
+
+function mcl_util.force_get_node(pos)
+	local node = minetest.get_node(pos)
+	if node.name ~= "ignore" then return node end
+
+	local vm = minetest.get_voxel_manip()
+	local emin, emax = vm:read_from_map(pos, pos)
+	local area = VoxelArea:new{
+		MinEdge = emin,
+		MaxEdge = emax,
+	}
+	local data = vm:get_data()
+	local param_data = vm:get_light_data()
+	local param2_data = vm:get_param2_data()
+
+	local vi = area:indexp(pos)
+	return {
+		name = minetest.get_name_from_content_id(data[vi]),
+		param = param_data[vi],
+		param2 = param2_data[vi]
+	}
+end

mods/CORE/vl_scheduler/fifo.lua

@@ -0,0 +1,55 @@
+local mod = vl_scheduler
+
+function Class()
+	local cls = {}
+	cls.mt = { __index = cls }
+	function cls:new(...)
+		local inst = setmetatable({}, cls.mt)
+		local construct = inst.construct
+		if construct then inst:construct(...) end
+		return inst
+	end
+	return cls
+end
+
+-- Amoritized O(1) insert/delete functional First In, First Out (FIFO) queue
+local fifo = Class()
+mod.fifo = fifo
+function fifo:insert(node)
+	if not node then return end
+
+	node.next = self.inbox
+	self.inbox = node
+end
+function fifo:insert_many(nodes)
+	while nodes do
+		local node = nodes
+		nodes = nodes.next
+
+		node.next = self.inbox
+		self.inbox = node.next
+	end
+end
+function fifo:get()
+	if not fifo.outbox then
+		-- reverse inbox
+		local iter = self.inbox
+		self.inbox = nil
+
+		while iter do
+			local i = iter
+			iter = iter.next
+
+			i.next = self.outbox
+			self.outbox = i
+		end
+	end
+
+	local res = self.outbox
+	if res then
+		self.outbox = res.next
+		res.next = nil
+	end
+	return res
+end
+

mods/CORE/vl_scheduler/init.lua

@@ -0,0 +1,164 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+
+vl_scheduler = {}
+local mod = vl_scheduler
+
+-- Imports
+local call_safe = mcl_util.call_safe
+
+dofile(modpath.."/queue.lua")
+dofile(modpath.."/fifo.lua")
+dofile(modpath.."/test.lua")
+
+local run_queues = {}
+for i = 1,4 do
+	run_queues[i] = mod.fifo:new()
+end
+local tasks = 0
+local time = 0
+local priority_queue = mod.queue:new()
+local functions = {}
+local function_id_from_name = {}
+
+local unpack = unpack
+local minetest_get_us_time = minetest.get_us_time
+local queue_add_task = mod.queue.add_task
+local queue_get = mod.queue.get
+local queue_tick = mod.queue.tick
+local fifo_insert = mod.fifo.insert
+local fifo_get = mod.fifo.get
+
+function mod.add_task(time, name, priority, args)
+	if priority then
+		if priority > 4 then priority = 4 end
+		if priority < 1 then priority = 1 end
+	end
+
+	local fid = function_id_from_name[name]
+	if not fid then
+		print("Trying to add task with unknown function "..name)
+		return
+	end
+	local dtime = math.floor(time * 20) + 1
+	local task = {
+		time = dtime, -- Used by scheduler to track how long until this task is dispatched
+		dtime = dtime, -- Original time amount
+		fid = fid,
+		priority = priority,
+		args = args,
+	}
+	queue_add_task(priority_queue, task)
+end
+
+function mod.register_function(name, func, default_time, default_priority)
+	-- Validate module in name
+	local modname = minetest.get_current_modname()
+	if string.sub(name,1,#modname+1) ~= (modname..":") and string.sub(name,1) ~= ":" then
+		error("Module "..modname.." is trying to register function '"..name.."' that doesn't start with either '"..modname..":' or ':'")
+	end
+	if string.sub(name,1) == ":" then
+		name = string.sub(name,2,#name-1)
+	end
+
+	local fid = #functions + 1
+	functions[fid] = {
+		func = func,
+		name = name,
+		fid = fid,
+	}
+	function_id_from_name[name] = fid
+	print("Registering "..name.." as #"..tostring(fid))
+
+	-- Provide a function to easily schedule tasks
+	local dtime = math.floor((default_time or 0) * 20)+1
+	if not default_priority then default_priority = 3 end
+	return function(...)
+		local task = {
+			time = dtime,
+			dtime = dtime,
+			fid = fid,
+			priority = default_priority,
+			args = ...
+		}
+		queue_add_task(priority_queue, task)
+	end
+end
+
+-- Examples of scheduler task:
+if false then
+	-- Register a task that runs ever 0.25 seconds
+	mod.register_function("vl_scheduler:test",function(task)
+		print("game time="..tostring(minetest.get_gametime()))
+
+		-- Reschedule task
+		task.time = 0.25
+		return task
+	end)()
+
+	-- Register a function that runs an action at a fixed time in the future
+	local act = mod.register_function("vl_scheduler:act",function(task,arg1)
+		print(dump(arg1))
+	end, 0.15, 1)
+	act("test")
+end
+
+local function run_scheduler(dtime)
+	if dtime > 0.11 then
+		minetest.log("warning", "Timestep greater than 110ms("..tostring(math.floor(dtime*1000)).." ms), server lag detected")
+	end
+
+	local start_time = minetest_get_us_time()
+	local end_time = start_time + 50000
+	time = time + dtime
+
+	-- Add tasks to the run queues
+	local iter = queue_tick(priority_queue)
+	while iter do
+		local task = iter
+		iter = iter.next
+
+		local priority = task.priority or 3
+
+		fifo_insert(run_queues[priority], task)
+		tasks = tasks + 1
+	end
+	local task_time = minetest_get_us_time()
+	--print("Took "..tostring(task_time-start_time).." us to update task list")
+
+	-- Run tasks until we run out of timeslice
+	if tasks > 0 then
+		local i = 1
+		while i < 4 and minetest_get_us_time() < end_time do
+			local task = fifo_get(run_queues[i])
+			if task then
+				tasks = tasks - 1
+				local func = functions[task.fid]
+				if func then
+					--print("Running task "..dump(task)..",func="..dump(func))
+					local ok,ret = call_safe(
+						"Error while running task "..func.name..": ",
+						func.func, {task, unpack(task.args or {})}
+					)
+
+					-- If the task was returned, reschedule it
+					if ret == task then
+						task.time = math.floor(task.time * 20) + 1
+						task.next = nil
+						queue_add_task(priority_queue, task)
+					end
+					local next_task_time = minetest_get_us_time()
+					print(func.name.." took "..(next_task_time-task_time).." us")
+					task_time = next_task_time
+				end
+			else
+				i = i + 1
+			end
+		end
+	end
+	--print("Total scheduler time: "..tostring(minetest_get_us_time() - start_time).." microseconds")
+	--print("priority_queue="..dump(priority_queue))
+end
+
+minetest.register_globalstep(function(dtime) run_scheduler(dtime) end)
+

mods/CORE/vl_scheduler/mod.conf

@@ -0,0 +1,4 @@
+name = vl_scheduler
+author = teknomunk
+description = Event and Process Scheduler
+depends = mcl_util

mods/CORE/vl_scheduler/queue.lua

@@ -0,0 +1,262 @@
+local mod = vl_scheduler
+local DEBUG = false
+
+--[[
+
+== Radix/Finger queue class
+
+This is a queue based off the concepts behind finger trees (https://en.wikipedia.org/wiki/Finger_tree),
+the radix sort (https://en.wikipedia.org/wiki/Radix_sort) and funnel sort (https://en.wikipedia.org/wiki/Funnelsort)
+
+This algorithm has O(1) deletion and O(k) insertion (k porportional to the time in the future) and uses log_4(n) tree nodes.
+
+At the top level of the queue, there is a 20-element array of linked lists containing tasks that are scheduled to
+start running in the current second. Removing the next linked list of tasks from this array is an O(1) operation.
+
+The queue then has a one-sided finger tree of 20-element lists that are used to replace the initial queue when the
+second rolls over.
+
+]]
+
+function Class()
+	local cls = {}
+	cls.mt = { __index = cls }
+	function cls:new(...)
+		local inst = setmetatable({}, cls.mt)
+		local construct = inst.construct
+		if construct then inst:construct(...) end
+		return inst
+	end
+	return cls
+end
+
+local inner_queue = Class()
+
+-- Imperative forward declarations
+local inner_queue_construct
+local inner_queue_get
+local inner_queue_insert_task
+local inner_queue_add_tasks
+local inner_queue_init_slot_list
+
+function inner_queue:construct(level)
+	self.level = level
+	self.slots = 4
+	--self.items = {}
+	self.unsorted_count = 0
+
+	-- Precompute slot size
+	local slot_size = 20
+	for i = 2,level do
+		slot_size = slot_size * 4
+	end
+	self.slot_size = slot_size
+end
+inner_queue_construct = inner_queue.construct
+
+function inner_queue:get()
+	local slots = self.slots
+	local slot = 5 - slots
+	if not self.items then
+		self.items = inner_queue_init_slot_list(self)
+	end
+	local ret = self.items[slot]
+	self.items[slot] = nil
+
+	-- Take a way a slot, then refill if needed
+	slots = slots - 1
+	if slots == 0 then
+		if self.next_level then
+			local next_level_get = inner_queue_get(self.next_level)
+			if next_level_get then
+				self.items = next_level_get.items
+			else
+				self.items = inner_queue_init_slot_list(self)
+			end
+		else
+			self.items = inner_queue_init_slot_list(self)
+		end
+		slots = 4
+	end
+	self.slots = slots
+
+	return ret
+end
+inner_queue_get = inner_queue.get
+
+function inner_queue:insert_task(task)
+	local slots = self.slots
+	local slot_size = self.slot_size
+	local level = self.level
+
+	local t = task.time
+	if DEBUG then
+		task.log = tostring(t).."(1)<- "..(task.log or "")
+		print("<"..tostring(self.level).."> t="..tostring(t)..",task.time="..tostring(task.time)..",time="..tostring(time))
+	end
+	if not (t >= 1 ) then
+		error("Invalid time: task="..dump(task))
+	end
+
+	if t > slot_size * slots then
+		-- Add to list for next level in the finger tree
+		local count = self.unsorted_count + 1
+		if count > 20 then
+			if not self.next_level then
+				self.next_level = inner_queue:new(self.level + 1)
+			end
+
+			inner_queue_add_tasks( self.next_level, self.first_unsorted, slot_size * slots)
+			self.first_unsorted = nil
+			self.unsorted_count = 0
+			count = 0
+		end
+
+		task.next = self.first_unsorted
+		self.first_unsorted = task
+		self.unsorted_count = count + 1
+		return
+	end
+
+	-- Task belongs in a slot on this level
+	if DEBUG then
+		print("t="..tostring(t)..",slot_size="..tostring(slot_size)..",slots="..tostring(slots))
+	end
+	local slot = math.floor((t-1) / slot_size) + 1 + ( 4 - slots )
+	t = (t - 1) % slot_size + 1
+	if DEBUG then
+		print("slot="..tostring(slot)..",t="..tostring(t)..",slots="..tostring(slots))
+	end
+	task.time = t
+	if DEBUG then
+		task.log = tostring(t).."(2)<- "..(task.log or "")
+	end
+
+	-- Lazily initialize items
+	if not self.items then
+		self.items = inner_queue_init_slot_list(self)
+	end
+
+	-- Get the sublist the item belongs in
+	local list = self.items[slot]
+	if not list then
+		print("self="..dump(self))
+	end
+	if level == 1 then
+		assert(task.time <= 20)
+		task.next = list[t]
+		list[t] = task
+	else
+		inner_queue_insert_task(list, task, 0)
+	end
+end
+inner_queue_insert_task = inner_queue.insert_task
+
+function inner_queue:add_tasks(tasks, time)
+	if DEBUG then
+		print("inner_queue<"..tostring(self.level)..">:add_tasks()")
+	end
+	local task = tasks
+	local slots = self.slots
+	local slot_size = self.slot_size
+
+	if DEBUG then
+		print("This queue handles times 1-"..tostring(slot_size*slots))
+	end
+	while task do
+		local curr_task = task
+		task = task.next
+		curr_task.next = nil
+		curr_task.time = curr_task.time - time
+
+		inner_queue_insert_task(self, curr_task)
+	end
+
+	if DEBUG then
+		print("self="..dump(self))
+	end
+end
+inner_queue_add_tasks = inner_queue.add_tasks
+
+function inner_queue:init_slot_list()
+	local level = self.level
+	if level == 1 then
+		return { {}, {}, {}, {} }
+	else
+		local r = {}
+		for i=1,4 do
+			r[i] = inner_queue:new(level - 1)
+		end
+		return r
+	end
+end
+inner_queue_init_slot_list = inner_queue.init_slot_list
+
+local queue = Class()
+mod.queue = queue
+function queue:construct()
+	self.items = {}
+	self.unsorted_count = 0
+	self.m_tick = 1
+	self.next_level = inner_queue:new(1)
+end
+function queue:add_task(task)
+	-- Adjust time to align with the start of the current second
+	local t = task.time
+	task.original_time = t
+	t = t + self.m_tick
+	if DEBUG then
+		print("add_task({ time="..tostring(t).." })")
+	end
+
+	-- Handle task in current seccond
+	if t <= 20 then
+		task.next = self.items[t]
+		self.items[t] = task
+		return
+	end
+
+	-- Update task time
+	t = t - 20
+	task.time = t
+
+	local count = self.unsorted_count
+	if count > 20 then
+		-- Push to next level
+		self.unsorted_count = 0
+		inner_queue_add_tasks( self.next_level, self.first_unsorted, 0)
+		self.first_unsorted = nil
+		count = 0
+	end
+
+	-- Add to the list of tasks for later time slots
+	task.next = self.first_unsorted
+	task.time = task.time
+	self.first_unsorted = task
+	self.unsorted_count = count + 1
+end
+function queue:tick()
+	-- Get the tasks for this tick
+	local ret = nil
+	if self.items then
+		ret = self.items[self.m_tick]
+		self.items[self.m_tick] = nil
+	end
+	self.m_tick = self.m_tick + 1
+
+	-- Handle second rollover
+	if self.m_tick == 21 then
+		-- Push items to next level
+		if self.first_unsorted then
+			inner_queue_add_tasks(self.next_level, self.first_unsorted, 0)
+			self.first_unsorted = nil
+			self.unsorted_count = 0
+		end
+
+		self.items = inner_queue_get(self.next_level) or {}
+		self.m_tick = 1
+	end
+
+	return ret
+end
+

mods/CORE/vl_scheduler/test.lua

@@ -0,0 +1,34 @@
+local mod = vl_scheduler
+function mod.test()
+	local t = mod.queue.new()
+
+	local pr = PseudoRandom(123456789)
+
+	local start_time = minetest.get_us_time()
+	for i=1,500 do
+		t:add_task({ time = pr:next(1,3600) })
+
+		local stop_time = minetest.get_us_time()
+		print("took "..tostring(stop_time - start_time).."us")
+		start_time = stop_time
+	end
+
+	--print(dump(t:tick()))
+	print(dump(t))
+
+	print("starting ticks")
+
+	local start_time = minetest.get_us_time()
+	for i=1,3600 do
+		local s = t:tick()
+		print("time="..tostring(i+1))
+		--print(dump(s))
+
+		local stop_time = minetest.get_us_time()
+		print("took "..tostring(stop_time - start_time).."us")
+		start_time = stop_time
+	end
+end
+
+--mod.test()
+--error("test failed")

mods/ENTITIES/mcl_entity_invs/init.lua

@@ -35,7 +35,9 @@ function mcl_entity_invs.load_inv(ent,size)
 		mcl_log("load_inv 3")
 		inv =  minetest.create_detached_inventory(ent._inv_id, inv_callbacks)
 		inv:set_size("main", size)
-		if ent._items then
+		if ent._mcl_entity_invs_load_items then
+			inv:set_list("main",ent:_mcl_entity_invs_load_items())
+		elseif ent._items then
 			inv:set_list("main",ent._items)
 		end
 	else
@@ -46,9 +48,14 @@ end
 
 function mcl_entity_invs.save_inv(ent)
 	if ent._inv then
-		ent._items = {}
+		local items = {}
 		for i,it in ipairs(ent._inv:get_list("main")) do
-			ent._items[i] = it:to_string()
+			items[i] = it:to_string()
+		end
+		if ent._mcl_entity_invs_save_items then
+			ent:_mcl_entity_invs_save_items(items)
+		else
+			ent._items = items
 		end
 		minetest.remove_detached_inventory(ent._inv_id)
 		ent._inv = nil

mods/ENTITIES/mcl_item_entity/init.lua

@@ -832,6 +832,7 @@ minetest.register_entity(":__builtin:item", {
 			_insta_collect = self._insta_collect,
 			_flowing = self._flowing,
 			_removed = self._removed,
+			_immortal = self._immortal,
 		})
 		-- sfan5 guessed that the biggest serializable item
 		-- entity would have a size of 65530 bytes. This has
@@ -884,6 +885,7 @@ minetest.register_entity(":__builtin:item", {
 				self._insta_collect = data._insta_collect
 				self._flowing = data._flowing
 				self._removed = data._removed
+				self._immortal = data._immortal
 			end
 		else
 			self.itemstring = staticdata
@@ -976,7 +978,7 @@ minetest.register_entity(":__builtin:item", {
 		if self._collector_timer then
 			self._collector_timer = self._collector_timer + dtime
 		end
-		if time_to_live > 0 and self.age > time_to_live then
+		if time_to_live > 0 and ( self.age > time_to_live and not self._immortal ) then
 			self._removed = true
 			self.object:remove()
 			return

mods/ENTITIES/mcl_minecarts/API.md

@@ -0,0 +1,284 @@
+# Table of Contents
+1. [Useful Constants](#useful-constants)
+2. [Rail](#rail)
+   1. [Constants](#constants)
+   2. [Functions](#functions)
+   3. [Node Definition Options](#node-definition-options)
+3. [Cart Functions](#cart-functions)
+4. [Cart Data Functions](#cart-data-functions)
+5. [Cart-Node Interactions](#cart-node-interactions)
+6. [Train Functions](#train-functions)
+
+## Useful Constants
+
+- `mcl_minecarts.north`
+- `mcl_minecarts.south`
+- `mcl_minecarts.east`
+- `mcl_minecarts.west`
+
+Human-readable names for the cardinal directions.
+
+- `mcl_minecarts.SPEED_MAX`
+
+Maximum speed that minecarts will be accelerated to with powered rails, in blocks per
+second. Defined as 10 blocks/second.
+
+- `mcl_minecarts.CART_BLOCKS_SIZE`
+
+The size of blocks to use when searching for carts to respawn. Defined as is 64 blocks.
+
+- `mcl_minecarts.FRICTION`
+
+Rail friction. Defined as is 0.4 blocks/second^2.
+
+- `mcl_minecarts.MAX_TRAIN_LENGTH`
+
+The maximum number of carts that can be in a single train. Defined as 4 carts.
+
+- `mcl_minecarts.PASSENGER_ATTACH_POSITION`
+
+Where to attach passengers to the minecarts.
+
+## Rail
+
+### Constants
+
+`mcl_minecarts.HORIZONTAL_CURVES_RULES`
+`mcl_minecarts.HORIZONTAL_STANDARD_RULES`
+
+Rail connection rules. Each rule is an table with the following indexes:
+
+1. `node_name_suffix` - The suffix added to a node's `_mcl_minecarts.base_name` to
+   get the name of the node to use for this connection.
+2. `param2_value` - The value of the node's param2. Used to specify rotation.
+
+and the following named options:
+
+- `mask` - Directional connections mask
+- `score` - priority of the rule. If more than one rule matches, the one with the
+  highest store is selected.
+- `can_slope` - true if the result of this rule can be converted into a slope.
+
+`mcl_minecarts.RAIL_GROUPS.STANDARD`
+`mcl_minecarts.RAIL_GROUPS.CURVES`
+
+These constants are used to specify a rail node's `group.rail` value.
+
+### Functions
+
+`mcl_minecarts.get_rail_connections(node_position, options)`
+
+Calculate the rail adjacency information for rail placement. Arguments are:
+
+- `node_position` - the location of the node to calculate adjacency for.
+- `options` - A table containing any of these options:
+  - `legacy`- if true, don't check that a connection proceeds out in a direction
+    a cart can travel. Used for converting legacy rail to newer equivalents.
+  - `ignore_neightbor_connections` - if true, don't check that a cart could leave
+    the neighboring node from this direction.
+
+`mcl_minecarts:is_rail(position, railtype)`
+
+Determines if the node at `position` is a rail. If `railtype` is provided,
+determine if the node at `position` is that type of rail.
+
+`mcl_minecarts.register_rail(itemstring, node_definition)`
+
+Registers a rail with a few sensible defaults and if a craft recipe was specified,
+register that as well.
+
+`mcl_minecarts.register_straight_rail(base_name, tiles, node_definition)`
+
+Registers a rail with only straight and sloped variants.
+
+`mcl_minecarts.register_curves_rail(base_name, tiles, node_definition)`
+
+Registers a rail with straight, sloped, curved, tee and cross variants.
+
+`mcl_minecarts.update_rail_connections(node_position, options)`
+
+Converts the rail at `node_position`, if possible, another variant (curve, etc.)
+and rotates the node as needed so that rails connect together. `options` is
+passed thru to `mcl_minecarts.get_rail_connections()`
+
+`mcl_minecarts:get_rail_direction(rail_position, cart_direction)`
+
+Returns the next direction a cart traveling in the direction specified in `cart_direction`
+will travel from the rail located at `rail_position`.
+
+### Node Definition Options
+
+`_mcl_minecarts.railtype`
+
+This declares the variant type of the rail. This will be one of the following:
+
+- "straight" - two connections opposite each other and no vertical change.
+- "sloped" - two connections opposite each other with one of these connections
+   one block higher.
+- "corner" - two connections at 90 degrees from each other.
+- "tee" - three connections
+- "cross" - four connections allowing only straight-thru movement
+
+#### Hooks
+`_mcl_minecarts.get_next_dir = function(node_position, current_direction, node)`
+
+Called to get the next direction a cart will travel after passing thru this node.
+
+## Cart Functions
+
+`mcl_minecarts.attach_driver(cart, player)`
+
+This attaches (ObjectRef) `player` to the (LuaEntity) `cart`.
+
+`mcl_minecarts.detach_minecart(cart_data)`
+
+This detaches a minecart from any rail it is attached to and makes it start moving
+as an entity affected by gravity. It will keep moving in the same direction and
+at the same speed it was moving at before it detaches.
+
+`mcl_minecarts.get_cart_position(cart_data)`
+
+Compute the location of a minecart from its cart data. This works even when the entity
+is unloaded.
+
+`mcl_minecarts.kill_cart(cart_data)`
+
+Kills a cart and drops it as an item, even if the cart entity is unloaded.
+
+`mcl_minecarts.place_minecart(itemstack, pointed_thing, placer)`
+
+Places a minecart at the location specified by `pointed_thing`
+
+`mcl_minecarts.register_minecart(minecart_definition)`
+
+Registers a minecart. `minecart_definition` defines the entity. All the options supported by
+normal minetest entities are supported, with a few additions:
+
+- `craft` - Crafting recipe for this cart.
+- `drop` - List of items to drop when the cart is killed. (required)
+- `entity_id` - The entity id of the cart. (required)
+- `itemstring` - This is the itemstring to use for this entity. (required)
+
+`mcl_minecarts.reverse_cart_direction(cart_data)`
+
+Force a minecart to start moving in the opposite direction of its current direction.
+
+`mcl_minecarts.snap_direction(direction_vector)`
+
+Returns a valid cart movement direction that has the smallest angle between it and `direction_vector`.
+
+`mcl_minecarts:update_cart_orientation(cart)`
+
+Updates the rotation of a cart entity to match the cart's data.
+
+## Cart Data Functions
+
+`mcl_minecarts.destroy_cart_data(uuid)`
+
+Destroys the data for the cart with the identitfier in `uuid`.
+
+`mcl_minecarts.find_carts_by_block_map(block_map)`
+
+Returns a list of cart data for carts located in the blocks specified in `block_map`. Used
+to respawn carts entering areas around players.
+
+`mcl_minecarts.add_blocks_to_map(block_map, min_pos, max_pos)`
+
+Add blocks that fully contain `min_pos` and `max_pos` to `block_map` for use by
+ `mcl_minecarts.find_cart_by_block_map`.
+
+`mcl_minecarts.get_cart_data(uuid)`
+
+Loads the data for the cart with the identitfier in `uuid`.
+
+`mcl_minecarts.save_cart_data(uuid)`
+
+Saves the data for the cart with the identifier in `uuid`.
+
+`mcl_minecart.update_cart_data(data)`
+
+Replaces the cart data for the cart with the identifier in `data.uuid`, then saves
+the data.
+
+## Cart-Node Interactions
+
+As the cart moves thru the environment, it can interact with the surrounding blocks
+thru a number of handlers in the block definitions. All these handlers are defined
+as:
+
+`function(node_position, cart_luaentity, cart_direction, cart_position)`
+
+Arguments:
+- `node_position` - position of the node the cart is interacting with
+- `cart_luaentity` - The luaentity of the cart that is entering this block. Will
+   be nil for minecarts moving thru unloaded blocks
+- `cart_direction` - The direction the cart is moving
+- `cart_position` - The location of the cart
+- `cart_data` - Information about the cart. This will always be defined.
+
+There are several variants of this handler:
+- `_mcl_minecarts_on_enter` - The cart enters this block
+- `_mcl_minecarts_on_enter_below` - The cart enters above this block
+- `_mcl_minecarts_on_enter_above` - The cart enters below this block
+-  `_mcl_minecarts_on_enter_side` - The cart enters beside this block
+
+Mods can also define global handlers that are called for every node. These
+handlers are defined as:
+
+`function(node_position, cart_luaentity, cart_direction, node_definition, cart_data)`
+
+Arguments:
+- `node_position` - position of the node the cart is interacting with
+- `cart_luaentity` - The luaentity of the cart that is entering this block. Will
+   be nil for minecarts moving thru unloaded blocks
+- `cart_direction` - The direction the cart is moving
+- `cart_position` - The location of the cart
+- `cart_data` - Information about the cart. This will always be defined.
+- `node_definition` - The definition of the node at `node_position`
+
+The available hooks are:
+- `_mcl_minecarts.on_enter` - The cart enters this block
+- `_mcl_minecarts.on_enter_below` - The cart enters above this block
+- `_mcl_minecarts.on_enter_above` - The cart enters below this block
+- `_mcl_minecarts.on_enter_side` - The cart enters beside this block
+
+Only a single function can be installed in each of these handlers. Before installing,
+preserve the existing handler and call it from inside your handler if not `nil`.
+
+## Train Functions
+
+`mcl_minecarts.break_train_at(cart_data)`
+
+Splits a train apart at the specified cart.
+
+`mcl_minecarts.distance_between_cars(cart1_data, cart2_data)`
+
+Returns the distance between two carts even if both entities are unloaded, or nil if either
+cart is not on a rail.
+
+`mcl_minecarts.is_in_same_train(cart1_data, cart2_data)`
+
+Returns true if cart1 and cart2 are a part of the same train and false otherwise.
+
+`mcl_minecarts.link_cart_ahead(cart_data, cart_ahead_data)`
+
+Given two carts, link them together into a train, with the second cart ahead of the first.
+
+`mcl_minecarts.train_cars(cart_data)`
+
+Use to iterate over all carts in a train. Expected usage:
+
+`for cart in mcl_minecarts.train_cars(cart) do --[[ code ]] end`
+
+`mcl_minecarts.reverse_train(cart)`
+
+Make all carts in a train reverse and start moving in the opposite direction.
+
+`mcl_minecarts.train_length(cart_data)`
+
+Compute the current length of the train containing the cart whose data is `cart_data`.
+
+`mcl_minecarts.update_train(cart_data)`
+
+When provided with the rear-most cart of a tain, update speeds of all carts in the train
+so that it holds together and moves as a unit.

mods/ENTITIES/mcl_minecarts/DOC.md

@@ -0,0 +1,120 @@
+
+## Organization
+- [ init.lua](./init.lua) - module entrypoint. The other files are included from here
+  and several constants are defined here
+
+- [carts.lua](./carts/lua) - This file contains code related to cart entities, cart
+  type registration,  creation, estruction and updating. The global step function
+  responsible for updating attached carts is in this file. The various carts are
+  referenced from this file but actually reside in the subdirectory [carts/](./carts/).
+
+- [functions.lua](./functions.lua) - This file contains various minecart and rail
+  utility functions used by the rest of the code.
+
+- [movement.lua](./movement.lua) - This file contains the code related to cart
+  movement physics.
+
+- [rails.lua](./rails.lua) - This file contains code related to rail registation,
+  placement, connection rules and cart direction selection. This contains the rail
+  behaviors and the LBM code for updating legacy rail nodes to the new versions
+  that don't use the raillike draw type.
+
+- [storage.lua](./storage.lua) - This file contains the code than manages minecart
+  state data to allow processing minecarts while entities are unloaded.
+
+- [train.lua](./train.lua) - This file contains code related to multi-car trains.
+
+## Rail Nodes
+
+Previous versions of mcl\_minecarts used one node type for each rail type (standard,
+powered, detector and activator) using the raillike draw type that minetest provides.
+This version does not use the raillike draw type and instead uses a 1/16th of a block
+high nodebox and uses an additional node definition for each variant. The variants
+present are:
+
+- straight
+- sloped
+- corner
+- tee
+- cross
+
+Of the rail types provided by this module, standard has all of these variants. The
+remaining types only have straight and sloped variants.
+
+Unlike the old rail type, this version will only update connections when placed, and
+will only place a variant that already has connections into the space the rail is
+being placed. Here is how to create the various varients:
+
+- Straight rail is placed when with zero or one adjacent rail nodes. If no rails
+  are adjacent, the rail is placed in line with the direction the player is facing.
+  If there is exactly one adjacent rail present, the straight rail will always rotate
+  to connect to it.
+
+- Sloped rail is placed when there are two rails in a straight line, with one being
+  one block higher. When rail is placed adjacent to a straight rail one block lower
+  and the rail is facing the block the rail is being placed on, the lower rail will
+  convert into a slope.
+
+- A corner rail is placed when there are exactly two adjacent rails that are not in
+  a line and lead into the space the rail is being placed. The corner will be rotated
+  to connect these two rails.
+
+- A tee rail is placed where there are exactly three rails adjact and those existing
+  rails lead into the the space the new rail is being placed.
+
+- A rail cross is placed when there is rail in all four adjacent blocks and they all
+  have a path into the space the new rail is being placed.
+
+The tee variant will interact with redstone and mesecons to switch the curved section.
+
+## On-rail Minecart Movement
+
+Minecart movement is handled in two distinct regimes: on a rail and off. The
+off-rail movement is handled with minetest's builtin entity movement handling.
+The on-rail movement is handled with a custom algorithm. This section details
+the latter.
+
+The data for on-rail minecart movement is stored entirely inside mod storage
+and indexed by a hex-encoded 128-bit universally-unique identifier (uuid). Minecart
+entities store this uuid and a sequence identifier. The code for handling this
+storage is in [storage.lua](./storage.lua). This was done so that minecarts can
+still move while no players are connected or when out of range of players. Inspiration
+for this was the [Advanced Trains mod](http://advtrains.de/). This is a behavior difference
+when compared to minecraft, as carts there will stop movement when out of range of
+players.
+
+Processing for minecart movement is as follows:
+1. In a globalstep handler in [carts.lua](./carts.lua), determine which carts are
+   moving.
+2. Call `do_movement` in [movement.lua](./movement.lua) to update
+   each cart's location and handle interactions with the environment.
+   1. Each movement is broken up into one or more steps that are completely
+      contained inside a block. This prevents carts from ever jumping from
+      one rail to another over a gap or thru solid blocks because of server
+      lag. Each step is processed with `do_movement_step`
+   2. Each step uses physically accurate, timestep-independent physics
+      to move the cart. Calculating the acceleration to apply to a cart
+      is broken out into its own function (`calculate_acceperation`).
+   3. As the cart enters and leaves blocks, handlers in nearby blocks are called
+      to allow the cart to efficiently interact with the environment. Handled by
+      the functions `handle_cart_enter` and `handle_cart_leave`
+   4. The cart checks for nearby carts and collides elastically with these. The
+      calculations for these collisions are in the function `handle_cart_collision`
+   5. If the cart enters a new block, determine the new direction the cart will
+      move with `mcl_minecarts:get_rail_direction` in [functions.lua](./functions.lua).
+      The rail nodes provide a hook `_mcl_minecarts.get_next_direction` that
+      provides this information based on the previous movement direction.
+3. If an entity exists for a given cart, the entity will update its position
+   while loaded in.
+
+Cart movement when on a rail occurs regarless of whether an entity for that
+cart exists or is loaded into memory. As a consequence of this movement, it
+is possible for carts with unloaded entities to enter range of a player.
+To handle this, periodic checks are performed around players and carts that
+are within range but don't have a cart have a new entity spawned.
+
+Every time a cart has a new entity spawned, it increases a sequence number in
+the cart data to allow removing old entities from the minetest engine. Any cart
+entity that does not have the current sequence number for a minecart gets removed
+once processing for that entity resumes.
+

mods/ENTITIES/mcl_minecarts/README.txt

@@ -10,6 +10,7 @@ MIT License
 Copyright (C) 2012-2016 PilzAdam
 Copyright (C) 2014-2016 SmallJoker
 Copyright (C) 2012-2016 Various Minetest developers and contributors
+Copyright (C) 2024 teknomunk
 
 Authors/licenses of media files:
 -----------------------

mods/ENTITIES/mcl_minecarts/carts.lua

@@ -0,0 +1,659 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+
+local mcl_log,DEBUG = mcl_util.make_mcl_logger("mcl_logging_minecarts", "Minecarts")
+
+-- Imports
+local CART_BLOCK_SIZE = mod.CART_BLOCK_SIZE
+local table_merge = mcl_util.table_merge
+local get_cart_data = mod.get_cart_data
+local save_cart_data = mod.save_cart_data
+local update_cart_data = mod.update_cart_data
+local destroy_cart_data = mod.destroy_cart_data
+local find_carts_by_block_map = mod.find_carts_by_block_map
+local do_movement,do_detached_movement,handle_cart_enter = dofile(modpath.."/movement.lua")
+assert(do_movement)
+assert(do_detached_movement)
+assert(handle_cart_enter)
+
+-- Constants
+local max_step_distance = 0.5
+local MINECART_MAX_HP = 4
+local TWO_OVER_PI = 2 / math.pi
+
+local function detach_driver(self)
+	local staticdata = self._staticdata
+
+	if not self._driver then
+		return
+	end
+
+	-- Update player infomation
+	local driver_name = self._driver
+	local playerinfo = mcl_playerinfo[driver_name]
+	if playerinfo then
+		playerinfo.attached_to = nil
+	end
+	mcl_player.player_attached[driver_name] = nil
+
+	minetest.log("action", driver_name.." left a minecart")
+
+	-- Update cart informatino
+	self._driver = nil
+	self._start_pos = nil
+	local player_meta = mcl_playerinfo.get_mod_meta(driver_name, modname)
+	player_meta.attached_to = nil
+
+	-- Detatch the player object from the minecart
+	local player = minetest.get_player_by_name(driver_name)
+	if player then
+		local dir = staticdata.dir or vector.new(1,0,0)
+		local cart_pos = mod.get_cart_position(staticdata) or self.object:get_pos()
+		local new_pos = vector.offset(cart_pos, -dir.z, 0, dir.x)
+		player:set_detach()
+		--print("placing player at "..tostring(new_pos).." from cart at "..tostring(cart_pos)..", old_pos="..tostring(player:get_pos()).."dir="..tostring(dir))
+
+		-- There needs to be a delay here or the player's position won't update
+		minetest.after(0.1,function(driver_name,new_pos)
+			local player = minetest.get_player_by_name(driver_name)
+			player:moveto(new_pos, false)
+		end, driver_name, new_pos)
+
+		player:set_eye_offset(vector.zero(),vector.zero())
+		mcl_player.player_set_animation(player, "stand" , 30)
+	--else
+		--print("No player object found for "..driver_name)
+	end
+end
+
+-- Table for item-to-entity mapping. Keys: itemstring, Values: Corresponding entity ID
+local entity_mapping = {}
+
+local function make_staticdata( _, connected_at, dir )
+	return {
+		connected_at = connected_at,
+		distance = 0,
+		velocity = 0,
+		dir = vector.new(dir),
+		mass = 1,
+		seq = 1,
+	}
+end
+
+local DEFAULT_CART_DEF = {
+	initial_properties = {
+		physical = true,
+		collisionbox = {-10/16., -0.5, -10/16, 10/16, 0.25, 10/16},
+		visual = "mesh",
+		visual_size = {x=1, y=1},
+	},
+
+	hp_max = MINECART_MAX_HP,
+
+	groups = {
+		minecart = 1,
+	},
+
+	_driver = nil, -- player who sits in and controls the minecart (only for minecart!)
+	_passenger = nil, -- for mobs
+	_start_pos = nil, -- Used to calculate distance for “On A Rail” achievement
+	_last_float_check = nil, -- timestamp of last time the cart was checked to be still on a rail
+	_boomtimer = nil, -- how many seconds are left before exploding
+	_blinktimer = nil, -- how many seconds are left before TNT blinking
+	_blink = false, -- is TNT blink texture active?
+	_old_pos = nil,
+	_staticdata = nil,
+}
+function DEFAULT_CART_DEF:on_activate(staticdata, dtime_s)
+	-- Transfer older data
+	local data = minetest.deserialize(staticdata) or {}
+	if not data.uuid then
+		data.uuid  = mcl_util.assign_uuid(self.object)
+	end
+	self._seq = data.seq or 1
+
+	local cd = get_cart_data(data.uuid)
+	if not cd then
+		update_cart_data(data)
+	else
+		if not cd.seq then cd.seq = 1 end
+		data = cd
+	end
+
+	-- Fix up types
+	data.dir = vector.new(data.dir)
+
+	-- Fix mass
+	data.mass = data.mass or 1
+
+	-- Make sure all carts have an ID to isolate them
+	self._uuid = data.uuid
+	self._staticdata = data
+
+	-- Activate cart if on powered activator rail
+	if self.on_activate_by_rail then
+		local pos = self.object:get_pos()
+		local node = minetest.get_node(vector.floor(pos))
+		if node.name == "mcl_minecarts:activator_rail_on" then
+			self:on_activate_by_rail()
+		end
+	end
+end
+function DEFAULT_CART_DEF:get_staticdata()
+	save_cart_data(self._staticdata.uuid)
+	return minetest.serialize({uuid = self._staticdata.uuid, seq=self._seq})
+end
+
+function DEFAULT_CART_DEF:_mcl_entity_invs_load_items()
+	local staticdata = self._staticdata
+	return staticdata.inventory or {}
+end
+function DEFAULT_CART_DEF:_mcl_entity_invs_save_items(items)
+	local staticdata = self._staticdata
+	staticdata.inventory = table.copy(items)
+end
+
+function DEFAULT_CART_DEF:add_node_watch(pos)
+	local staticdata = self._staticdata
+	local watches = staticdata.node_watches or {}
+
+	for i=1,#watches do
+		if watches[i] == pos then return end
+	end
+
+	watches[#watches+1] = pos
+	staticdata.node_watches = watches
+end
+function DEFAULT_CART_DEF:remove_node_watch(pos)
+	local staticdata = self._staticdata
+	local watches = staticdata.node_watches or {}
+
+	local new_watches = {}
+	for i=1,#watches do
+		local node_pos = watches[i]
+		if node_pos ~= pos then
+			new_watches[#new_watches + 1] = node_pos
+		end
+	end
+	staticdata.node_watches = new_watches
+end
+function DEFAULT_CART_DEF:get_cart_position()
+	local staticdata = self._staticdata
+
+	if staticdata.connected_at then
+		return staticdata.connected_at + staticdata.dir * staticdata.distance
+	else
+		return self.object:get_pos()
+	end
+end
+function DEFAULT_CART_DEF:on_punch(puncher, time_from_last_punch, tool_capabilities, dir, damage)
+	if puncher == self._driver then return end
+
+	local staticdata = self._staticdata
+	local controls = staticdata.controls or {}
+
+	local impulse = vector.multiply(dir, damage * 20)
+
+	local accel = vector.dot(staticdata.dir, impulse)
+	if accel < 0 and staticdata.velocity == 0 then
+		mod.reverse_direction(staticdata)
+	end
+
+	controls.impulse = impulse
+	--print("uuid="..self._uuid..", controls="..dump(controls))
+	staticdata.controls = controls
+end
+function DEFAULT_CART_DEF:on_step(dtime)
+	local staticdata = self._staticdata
+	if not staticdata then
+		staticdata = make_staticdata()
+		self._staticdata = staticdata
+	end
+
+	-- Update entity position
+	local pos = mod.get_cart_position(staticdata)
+	if pos then self.object:move_to(pos) end
+
+	-- Repair cart_type
+	if not staticdata.cart_type then
+		staticdata.cart_type = self.name
+	end
+
+	-- Remove superceded entities
+	if self._seq ~= staticdata.seq then
+		--print("removing cart #"..staticdata.uuid.." with sequence number mismatch")
+		self.object:remove()
+		return
+	end
+
+	-- Regen
+	local hp = self.object:get_hp()
+	local time_now = minetest.get_gametime()
+	if hp < MINECART_MAX_HP and (staticdata.last_regen or 0) <= time_now - 1 then
+		staticdata.last_regen = time_now
+		hp = hp + 1
+		self.object:set_hp(hp)
+	end
+
+	-- Cart specific behaviors
+	local hook = self._mcl_minecarts_on_step
+	if hook then hook(self,dtime) end
+
+	if (staticdata.hopper_delay or 0) > 0 then
+		staticdata.hopper_delay = staticdata.hopper_delay - dtime
+	end
+
+	-- Controls
+	local ctrl, player = nil, nil
+	if self._driver then
+		player = minetest.get_player_by_name(self._driver)
+		if player then
+			ctrl = player:get_player_control()
+			-- player detach
+			if ctrl.sneak then
+				detach_driver(self)
+				return
+			end
+
+			-- Experimental controls
+			local now_time = minetest.get_gametime()
+			local controls = {}
+			if ctrl.up then controls.forward = now_time end
+			if ctrl.down then controls.brake = now_time end
+			controls.look = math.round(player:get_look_horizontal() * TWO_OVER_PI) % 4
+			staticdata.controls = controls
+		end
+
+		-- Give achievement when player reached a distance of 1000 nodes from the start position
+		if pos and vector.distance(self._start_pos, pos) >= 1000 then
+			awards.unlock(self._driver, "mcl:onARail")
+		end
+	end
+
+	if not staticdata.connected_at then
+		do_detached_movement(self, dtime)
+	end
+
+	mod.update_cart_orientation(self)
+end
+function mod.kill_cart(staticdata, killer)
+	local pos
+	minetest.log("action", "cart #"..staticdata.uuid.." was killed")
+
+	-- Leave nodes
+	if staticdata.attached_at then
+		handle_cart_leave(self, staticdata.attached_at, staticdata.dir )
+	else
+		--mcl_log("TODO: handle detatched minecart death")
+	end
+
+	-- Handle entity-related items
+	local le = mcl_util.get_luaentity_from_uuid(staticdata.uuid)
+	if le then
+		pos = le.object:get_pos()
+
+		detach_driver(le)
+
+		-- Detach passenger
+		if le._passenger then
+			local mob = le._passenger.object
+			mob:set_detach()
+		end
+
+		-- Remove the entity
+		le.object:remove()
+	else
+		pos = mod.get_cart_position(staticdata)
+	end
+
+	-- Drop items
+	if not staticdata.dropped then
+
+		-- Try to drop the cart
+		local entity_def = minetest.registered_entities[staticdata.cart_type]
+		if entity_def then
+			local drop_cart = true
+			if killer and minetest.is_creative_enabled(killer:get_player_name()) then
+				drop_cart = false
+			end
+
+			if drop_cart then
+				local drop = entity_def.drop
+				for d=1, #drop do
+					minetest.add_item(pos, drop[d])
+				end
+			end
+		end
+
+		-- Drop any items in the inventory
+		local inventory = staticdata.inventory
+		if inventory then
+			for i=1,#inventory do
+				minetest.add_item(pos, inventory[i])
+			end
+		end
+
+		-- Prevent item duplication
+		staticdata.dropped = true
+	end
+
+	-- Remove data
+	destroy_cart_data(staticdata.uuid)
+end
+local kill_cart = mod.kill_cart
+
+function DEFAULT_CART_DEF:on_death(killer)
+	kill_cart(self._staticdata, killer)
+end
+
+-- Create a minecart
+function mod.create_minecart(entity_id, pos, dir)
+	-- Setup cart data
+	local uuid = mcl_util.gen_uuid()
+	local data = make_staticdata( nil, pos, dir )
+	data.uuid = uuid
+	data.cart_type = entity_id
+	update_cart_data(data)
+	save_cart_data(uuid)
+
+	return uuid
+end
+local create_minecart = mod.create_minecart
+
+-- Place a minecart at pointed_thing
+function mod.place_minecart(itemstack, pointed_thing, placer)
+	if not pointed_thing.type == "node" then
+		return
+	end
+
+	local spawn_pos = pointed_thing.above
+	local cart_dir = vector.new(1,0,0)
+
+	local railpos, node
+	if mcl_minecarts:is_rail(pointed_thing.under) then
+		railpos = pointed_thing.under
+	elseif mcl_minecarts:is_rail(pointed_thing.above) then
+		railpos = pointed_thing.above
+	end
+	if railpos then
+		spawn_pos = railpos
+		node = minetest.get_node(railpos)
+		cart_dir = mcl_minecarts:get_rail_direction(railpos, vector.new(1,0,0))
+	end
+
+	local entity_id = entity_mapping[itemstack:get_name()]
+
+	local uuid = create_minecart(entity_id, railpos, cart_dir)
+
+	-- Create the entity with the staticdata already setup
+	local sd = minetest.serialize({ uuid=uuid, seq=1 })
+	local cart = minetest.add_entity(spawn_pos, entity_id, sd)
+	local staticdata = get_cart_data(uuid)
+
+	cart:set_yaw(minetest.dir_to_yaw(cart_dir))
+
+	-- Call placer
+	local le = cart:get_luaentity()
+	if le._mcl_minecarts_on_place then
+		le._mcl_minecarts_on_place(le, placer)
+	end
+
+	if railpos then
+		handle_cart_enter(staticdata, railpos)
+	end
+
+	local pname = placer and placer:get_player_name() or ""
+	if not minetest.is_creative_enabled(pname) then
+		itemstack:take_item()
+	end
+	return itemstack
+end
+
+local function dropper_place_minecart(dropitem, pos)
+	-- Don't try to place the minecart if pos isn't a rail
+	local node = minetest.get_node(pos)
+	if minetest.get_item_group(node.name, "rail") == 0 then return false end
+
+	mod.place_minecart(dropitem, {
+		above = pos,
+		under = vector.offset(pos,0,-1,0)
+	})
+	return true
+end
+
+local function register_minecart_craftitem(itemstring, def)
+	local groups = { minecart = 1, transport = 1 }
+	if def.creative == false then
+		groups.not_in_creative_inventory = 1
+	end
+	local item_def = {
+		stack_max = 1,
+		_mcl_dropper_on_drop = dropper_place_minecart,
+		on_place = function(itemstack, placer, pointed_thing)
+			if not pointed_thing.type == "node" then
+				return
+			end
+
+			-- Call on_rightclick if the pointed node defines it
+			local node = minetest.get_node(pointed_thing.under)
+			if placer and not placer:get_player_control().sneak then
+				if minetest.registered_nodes[node.name] and minetest.registered_nodes[node.name].on_rightclick then
+					return minetest.registered_nodes[node.name].on_rightclick(pointed_thing.under, node, placer, itemstack) or itemstack
+				end
+			end
+
+			return mod.place_minecart(itemstack, pointed_thing, placer)
+		end,
+		_on_dispense = function(stack, pos, droppos, dropnode, dropdir)
+			-- Place minecart as entity on rail. If there's no rail, just drop it.
+			local placed
+			if minetest.get_item_group(dropnode.name, "rail") ~= 0 then
+				-- FIXME: This places minecarts even if the spot is already occupied
+				local pointed_thing = { under = droppos, above = vector.new( droppos.x, droppos.y+1, droppos.z ) }
+				placed = mod.place_minecart(stack, pointed_thing)
+			end
+			if placed == nil then
+				-- Drop item
+				minetest.add_item(droppos, stack)
+			end
+		end,
+		groups = groups,
+	}
+	item_def.description = def.description
+	item_def._tt_help = def.tt_help
+	item_def._doc_items_longdesc = def.longdesc
+	item_def._doc_items_usagehelp = def.usagehelp
+	item_def.inventory_image = def.icon
+	item_def.wield_image = def.icon
+	minetest.register_craftitem(itemstring, item_def)
+end
+
+--[[
+Register a minecart
+* itemstring: Itemstring of minecart item
+* entity_id: ID of minecart entity
+* description: Item name / description
+* longdesc: Long help text
+* usagehelp: Usage help text
+* mesh: Minecart mesh
+* textures: Minecart textures table
+* icon: Item icon
+* drop: Dropped items after destroying minecart
+* on_rightclick: Called after rightclick
+* on_activate_by_rail: Called when above activator rail
+* creative: If false, don't show in Creative Inventory
+]]
+function mod.register_minecart(def)
+	-- Make sure all required parameters are present
+	for _,name in pairs({"drop","itemstring","entity_id"}) do
+		assert( def[name], "def."..name..", a required parameter, is missing")
+	end
+
+	local entity_id = def.entity_id; def.entity_id = nil
+	local craft = def.craft; def.craft = nil
+	local itemstring = def.itemstring; def.itemstring = nil
+
+	-- Build cart definition
+	local cart = table.copy(DEFAULT_CART_DEF)
+	table_merge(cart, def)
+	minetest.register_entity(entity_id, cart)
+
+	-- Register item to entity mapping
+	entity_mapping[itemstring] = entity_id
+
+	register_minecart_craftitem(itemstring, def)
+	if minetest.get_modpath("doc_identifier") then
+		doc.sub.identifier.register_object(entity_id, "craftitems", itemstring)
+	end
+
+	if craft then
+		minetest.register_craft(craft)
+	end
+end
+local register_minecart = mod.register_minecart
+
+dofile(modpath.."/carts/minecart.lua")
+dofile(modpath.."/carts/with_chest.lua")
+dofile(modpath.."/carts/with_commandblock.lua")
+dofile(modpath.."/carts/with_hopper.lua")
+dofile(modpath.."/carts/with_furnace.lua")
+dofile(modpath.."/carts/with_tnt.lua")
+
+if minetest.get_modpath("mcl_wip") then
+	mcl_wip.register_wip_item("mcl_minecarts:chest_minecart")
+	mcl_wip.register_wip_item("mcl_minecarts:furnace_minecart")
+	mcl_wip.register_wip_item("mcl_minecarts:command_block_minecart")
+end
+
+local function respawn_cart(cart)
+	local cart_type = cart.cart_type or "mcl_minecarts:minecart"
+	local pos = mod.get_cart_position(cart)
+
+	local players = minetest.get_connected_players()
+	local distance = nil
+	for _,player in pairs(players) do
+		local d = vector.distance(player:get_pos(), pos)
+		if not distance or d < distance then distance = d end
+	end
+	if not distance or distance > 90 then return end
+
+	mcl_log("Respawning cart #"..cart.uuid.." at "..tostring(pos)..",distance="..distance..",node="..minetest.get_node(pos).name)
+
+	-- Update sequence so that old cart entities get removed
+	cart.seq = (cart.seq or 1) + 1
+	save_cart_data(cart.uuid)
+
+	-- Create the new entity and refresh caches
+	local sd = minetest.serialize({ uuid=cart.uuid, seq=cart.seq })
+	local entity = minetest.add_entity(pos, cart_type, sd)
+	local le = entity:get_luaentity()
+	le._staticdata = cart
+	mcl_util.assign_uuid(entity)
+
+	-- We intentionally don't call the normal hooks because this minecart was already there
+end
+
+-- Try to respawn cart entities for carts that have moved into range of a player
+local function try_respawn_carts()
+	-- Build a map of blocks near players
+	local block_map = {}
+	local players = minetest.get_connected_players()
+	for _,player in pairs(players) do
+		local pos = player:get_pos()
+		mod.add_blocks_to_map(
+			block_map,
+			vector.offset(pos,-CART_BLOCK_SIZE,-CART_BLOCK_SIZE,-CART_BLOCK_SIZE),
+			vector.offset(pos, CART_BLOCK_SIZE, CART_BLOCK_SIZE, CART_BLOCK_SIZE)
+		)
+	end
+
+	-- Find all cart data that are in these blocks
+	local carts = find_carts_by_block_map(block_map)
+
+	-- Check to see if any of these don't have an entity
+	for _,cart in pairs(carts) do
+		local le = mcl_util.get_luaentity_from_uuid(cart.uuid)
+		if not le then
+			respawn_cart(cart)
+		end
+	end
+end
+
+local timer = 0
+minetest.register_globalstep(function(dtime)
+
+	-- Periodically respawn carts that come into range of a player
+	timer = timer - dtime
+	if timer <= 0 then
+		local start_time = minetest.get_us_time()
+		try_respawn_carts()
+		local stop_time = minetest.get_us_time()
+		local duration = (stop_time - start_time) / 1e6
+		timer = duration / 250e-6 -- Schedule 50us per second
+		if timer > 5 then timer = 5 end
+	end
+
+	-- Handle periodically updating out-of-range carts
+	-- TODO: change how often cart positions are updated based on velocity
+	local start_time
+	if DEBUG then start_time = minetest.get_us_time() end
+
+	for uuid,staticdata in mod.carts() do
+		local pos = mod.get_cart_position(staticdata)
+		--[[
+		local le = mcl_util.get_luaentity_from_uuid(staticdata.uuid)
+		print("cart# "..uuid..
+			",velocity="..tostring(staticdata.velocity)..
+			",pos="..tostring(pos)..
+			",le="..tostring(le)..
+			",connected_at="..tostring(staticdata.connected_at)
+		)]]
+
+		--- Non-entity code
+		if staticdata.connected_at then
+			do_movement(staticdata, dtime)
+		end
+	end
+
+	if DEBUG then
+		local stop_time = minetest.get_us_time()
+		print("Update took "..((stop_time-start_time)*1e-6).." seconds")
+	end
+end)
+
+minetest.register_on_joinplayer(function(player)
+	-- Try cart reattachment
+	local player_name = player:get_player_name()
+	local player_meta = mcl_playerinfo.get_mod_meta(player_name, modname)
+	local cart_uuid = player_meta.attached_to
+	if cart_uuid then
+		local cartdata = get_cart_data(cart_uuid)
+
+		-- Can't get into a cart that was destroyed
+		if not cartdata then
+			return
+		end
+
+		-- Don't reattach players if someone else got in the cart
+		if cartdata.last_player ~= player_name then
+			return
+		end
+
+		minetest.after(0.2,function(player_name, cart_uuid)
+			local player = minetest.get_player_by_name(player_name)
+			if not player then
+				return
+			end
+
+			local cart = mcl_util.get_luaentity_from_uuid(cart_uuid)
+			if not cart then
+				return
+			end
+
+			mod.attach_driver(cart, player)
+		end, player_name, cart_uuid)
+	end
+end)
+

mods/ENTITIES/mcl_minecarts/carts/minecart.lua

@@ -0,0 +1,101 @@
+local modname = minetest.get_current_modname()
+local S = minetest.get_translator(modname)
+local mcl_log = mcl_util.make_mcl_logger("mcl_logging_minecarts", "Minecarts")
+local mod = mcl_minecarts
+
+-- Imports
+local PASSENGER_ATTACH_POSITION = mod.PASSENGER_ATTACH_POSITION
+
+local function activate_normal_minecart(self)
+	detach_driver(self)
+
+	-- Detach passenger
+	if self._passenger then
+		local mob = self._passenger.object
+		mob:set_detach()
+	end
+end
+
+function mod.attach_driver(cart, player)
+	local staticdata = cart._staticdata
+
+	-- Make sure we have a player
+	if not player or not player:is_player() then return end
+
+	local player_name = player:get_player_name()
+	if cart._driver or player:get_player_control().sneak then return end
+
+	-- Update cart information
+	cart._driver = player_name
+	cart._start_pos = cart.object:get_pos()
+
+	-- Keep track of player attachment
+	local player_meta = mcl_playerinfo.get_mod_meta(player_name, modname)
+	player_meta.attached_to = cart._uuid
+	staticdata.last_player = player_name
+
+	-- Update player information
+	local uuid = staticdata.uuid
+	mcl_player.player_attached[player_name] = true
+	minetest.log("action", player_name.." entered minecart #"..tostring(uuid).." at "..tostring(cart._start_pos))
+
+	-- Attach the player object to the minecart
+	player:set_attach(cart.object, "", vector.new(1,-1.75,-2), vector.new(0,0,0))
+	minetest.after(0.2, function(name)
+		local player = minetest.get_player_by_name(name)
+		if player then
+			mcl_player.player_set_animation(player, "sit" , 30)
+			player:set_eye_offset(vector.new(0,-5.5,0), vector.new(0,-4,0))
+			mcl_title.set(player, "actionbar", {text=S("Sneak to dismount"), color="white", stay=60})
+		end
+	end, player_name)
+end
+
+mod.register_minecart({
+	itemstring = "mcl_minecarts:minecart",
+	craft = {
+		output = "mcl_minecarts:minecart",
+		recipe = {
+			{"mcl_core:iron_ingot", "", "mcl_core:iron_ingot"},
+			{"mcl_core:iron_ingot", "mcl_core:iron_ingot", "mcl_core:iron_ingot"},
+		},
+	},
+	entity_id = "mcl_minecarts:minecart",
+	description = S("Minecart"),
+	tt_helop = S("Vehicle for fast travel on rails"),
+	long_descp = S("Minecarts can be used for a quick transportion on rails.") .. "\n" ..
+		S("Minecarts only ride on rails and always follow the tracks. At a T-junction with no straight way ahead, they turn left. The speed is affected by the rail type."),
+		S("You can place the minecart on rails. Right-click it to enter it. Punch it to get it moving.") .. "\n" ..
+		S("To obtain the minecart, punch it while holding down the sneak key.") .. "\n" ..
+		S("If it moves over a powered activator rail, you'll get ejected."),
+	initial_properties = {
+		mesh = "mcl_minecarts_minecart.b3d",
+		textures = {"mcl_minecarts_minecart.png"},
+	},
+	icon = "mcl_minecarts_minecart_normal.png",
+	drop = {"mcl_minecarts:minecart"},
+	on_rightclick = mod.attach_driver,
+	on_activate_by_rail = activate_normal_minecart,
+	_mcl_minecarts_on_step = function(self, dtime)
+		-- Grab mob
+		if math.random(1,20) > 15 and not self._passenger then
+			local mobsnear = minetest.get_objects_inside_radius(self.object:get_pos(), 1.3)
+			for n=1, #mobsnear do
+				local mob = mobsnear[n]
+				if mob then
+					local entity = mob:get_luaentity()
+					if entity and entity.is_mob then
+						self._passenger = entity
+						mob:set_attach(self.object, "", PASSENGER_ATTACH_POSITION, vector.zero())
+						break
+					end
+				end
+			end
+		elseif self._passenger then
+			local passenger_pos = self._passenger.object:get_pos()
+			if not passenger_pos then
+				self._passenger = nil
+			end
+		end
+	end
+})

mods/ENTITIES/mcl_minecarts/carts/with_chest.lua

@@ -0,0 +1,35 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+
+-- Minecart with Chest
+mcl_minecarts.register_minecart({
+	itemstring = "mcl_minecarts:chest_minecart",
+	craft = {
+		output = "mcl_minecarts:chest_minecart",
+		recipe = {
+			{"mcl_chests:chest"},
+			{"mcl_minecarts:minecart"},
+		},
+	},
+	entity_id = "mcl_minecarts:chest_minecart",
+	description = S("Minecart with Chest"),
+	tt_help = nil,
+	longdesc = nil,
+	usagehelp = nil,
+	initial_properties = {
+		mesh = "mcl_minecarts_minecart_chest.b3d",
+		textures = {
+			"mcl_chests_normal.png",
+			"mcl_minecarts_minecart.png"
+		},
+	},
+	icon = "mcl_minecarts_minecart_chest.png",
+	drop = {"mcl_minecarts:minecart", "mcl_chests:chest"},
+	groups = { container = 1 },
+	on_rightclick = nil,
+	on_activate_by_rail = nil,
+	creative = true
+})
+mcl_entity_invs.register_inv("mcl_minecarts:chest_minecart","Minecart",27,false,true)

mods/ENTITIES/mcl_minecarts/carts/with_commandblock.lua

@@ -0,0 +1,64 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+
+function table_metadata(table)
+	return {
+		table = table,
+		set_string = function(self, key, value)
+			--print("set_string("..tostring(key)..", "..tostring(value)..")")
+			self.table[key] = tostring(value)
+		end,
+		get_string = function(self, key)
+			if self.table[key] then
+				return tostring(self.table[key])
+			end
+		end
+	}
+end
+
+-- Minecart with Command Block
+mod.register_minecart({
+	itemstring = "mcl_minecarts:command_block_minecart",
+	entity_id = "mcl_minecarts:command_block_minecart",
+	description = S("Minecart with Command Block"),
+	tt_help = nil,
+	loncdesc = nil,
+	usagehelp = nil,
+	initial_properties = {
+		mesh = "mcl_minecarts_minecart_block.b3d",
+		textures = {
+			"jeija_commandblock_off.png^[verticalframe:2:0",
+			"jeija_commandblock_off.png^[verticalframe:2:0",
+			"jeija_commandblock_off.png^[verticalframe:2:0",
+			"jeija_commandblock_off.png^[verticalframe:2:0",
+			"jeija_commandblock_off.png^[verticalframe:2:0",
+			"jeija_commandblock_off.png^[verticalframe:2:0",
+			"mcl_minecarts_minecart.png",
+		},
+	},
+	icon = "mcl_minecarts_minecart_command_block.png",
+	drop = {"mcl_minecarts:minecart"},
+	on_rightclick = function(self, clicker)
+		self._staticdata.meta = self._staticdata.meta or {}
+		local meta = table_metadata(self._staticdata.meta)
+
+		mesecon.commandblock.handle_rightclick(meta, clicker)
+	end,
+	_mcl_minecarts_on_place = function(self, placer)
+		-- Create a fake metadata object that stores into the cart's staticdata
+		self._staticdata.meta = self._staticdata.meta or {}
+		local meta = table_metadata(self._staticdata.meta)
+
+		mesecon.commandblock.initialize(meta)
+		mesecon.commandblock.place(meta, placer)
+	end,
+	on_activate_by_rail = function(self, timer)
+		self._staticdata.meta = self._staticdata.meta or {}
+		local meta = table_metadata(self._staticdata.meta)
+
+		mesecon.commandblock.action_on(meta, self.object:get_pos())
+	end,
+	creative = true
+})

mods/ENTITIES/mcl_minecarts/carts/with_furnace.lua

@@ -0,0 +1,96 @@
+local modname = minetest.get_current_modname()
+local S = minetest.get_translator(modname)
+
+-- Minecart with Furnace
+mcl_minecarts.register_minecart({
+	itemstring = "mcl_minecarts:furnace_minecart",
+	craft = {
+		output = "mcl_minecarts:furnace_minecart",
+		recipe = {
+			{"mcl_furnaces:furnace"},
+			{"mcl_minecarts:minecart"},
+		},
+	},
+	entity_id = "mcl_minecarts:furnace_minecart",
+	description = S("Minecart with Furnace"),
+	tt_help = nil,
+	longdesc = S("A minecart with furnace is a vehicle that travels on rails. It can propel itself with fuel."),
+	usagehelp = S("Place it on rails. If you give it some coal, the furnace will start burning for a long time and the minecart will be able to move itself. Punch it to get it moving.") .. "\n" ..
+		S("To obtain the minecart and furnace, punch them while holding down the sneak key."),
+
+	initial_properties = {
+		mesh = "mcl_minecarts_minecart_block.b3d",
+		textures = {
+			"default_furnace_top.png",
+			"default_furnace_top.png",
+			"default_furnace_front.png",
+			"default_furnace_side.png",
+			"default_furnace_side.png",
+			"default_furnace_side.png",
+			"mcl_minecarts_minecart.png",
+		},
+	},
+	icon = "mcl_minecarts_minecart_furnace.png",
+	drop = {"mcl_minecarts:minecart", "mcl_furnaces:furnace"},
+	on_rightclick = function(self, clicker)
+		local staticdata = self._staticdata
+
+		-- Feed furnace with coal
+		if not clicker or not clicker:is_player() then
+			return
+		end
+		local held = clicker:get_wielded_item()
+		if minetest.get_item_group(held:get_name(), "coal") == 1 then
+			staticdata.fueltime = (staticdata.fueltime or 0) + 180
+
+			-- Trucate to 27 minutes (9 uses)
+			if staticdata.fueltime > 27*60 then
+				staticdata.fuel_time = 27*60
+			end
+
+			if not minetest.is_creative_enabled(clicker:get_player_name()) then
+				held:take_item()
+				local index = clicker:get_wield_index()
+				local inv = clicker:get_inventory()
+				inv:set_stack("main", index, held)
+			end
+			self.object:set_properties({textures =
+			{
+				"default_furnace_top.png",
+				"default_furnace_top.png",
+				"default_furnace_front_active.png",
+				"default_furnace_side.png",
+				"default_furnace_side.png",
+				"default_furnace_side.png",
+				"mcl_minecarts_minecart.png",
+			}})
+		end
+	end,
+	on_activate_by_rail = nil,
+	creative = true,
+	_mcl_minecarts_on_step = function(self, dtime)
+		local staticdata = self._staticdata
+
+		-- Update furnace stuff
+		if (staticdata.fueltime or 0) > 0 then
+			if staticdata.velocity < 0.25 then
+				staticdata.velocity = 0.25
+			end
+
+			staticdata.fueltime = (staticdata.fueltime or dtime) - dtime
+			if staticdata.fueltime <= 0 then
+				self.object:set_properties({textures =
+					{
+					"default_furnace_top.png",
+					"default_furnace_top.png",
+					"default_furnace_front.png",
+					"default_furnace_side.png",
+					"default_furnace_side.png",
+					"default_furnace_side.png",
+					"mcl_minecarts_minecart.png",
+				}})
+				staticdata.fueltime = 0
+			end
+		end
+	end,
+})

mods/ENTITIES/mcl_minecarts/carts/with_hopper.lua

@@ -0,0 +1,178 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+
+local LOGGING_ON = minetest.settings:get_bool("mcl_logging_minecarts", false)
+local function mcl_log(message)
+	if LOGGING_ON then
+		mcl_util.mcl_log(message, "[Minecarts]", true)
+	end
+end
+
+local function hopper_take_item(self, dtime)
+	local pos = self.object:get_pos()
+	if not pos then return end
+
+	if not self or self.name ~= "mcl_minecarts:hopper_minecart" then return end
+
+	if mcl_util.check_dtime_timer(self, dtime, "hoppermc_take", 0.15) then
+		--minetest.log("The check timer was triggered: " .. dump(pos) .. ", name:" .. self.name)
+	else
+		--minetest.log("The check timer was not triggered")
+		return
+	end
+
+
+	local above_pos = vector.offset(pos, 0, 0.9, 0)
+	local objs = minetest.get_objects_inside_radius(above_pos, 1.25)
+
+	if objs then
+		mcl_log("there is an itemstring. Number of objs: ".. #objs)
+
+		for k, v in pairs(objs) do
+			local ent = v:get_luaentity()
+
+			if ent and not ent._removed and ent.itemstring and ent.itemstring ~= "" then
+				local taken_items = false
+
+				mcl_log("ent.name: " .. tostring(ent.name))
+				mcl_log("ent pos: " .. tostring(ent.object:get_pos()))
+
+				local inv = mcl_entity_invs.load_inv(self, 5)
+				if not inv then return false end
+
+				local current_itemstack = ItemStack(ent.itemstring)
+
+				mcl_log("inv. size: " .. self._inv_size)
+				if inv:room_for_item("main", current_itemstack) then
+					mcl_log("Room")
+					inv:add_item("main", current_itemstack)
+					ent.object:get_luaentity().itemstring = ""
+					ent.object:remove()
+					taken_items = true
+				else
+					mcl_log("no Room")
+				end
+
+				if not taken_items then
+					local items_remaining = current_itemstack:get_count()
+
+					-- This will take part of a floating item stack if no slot can hold the full amount
+					for i = 1, self._inv_size, 1 do
+						local stack = inv:get_stack("main", i)
+
+						mcl_log("i: " .. tostring(i))
+						mcl_log("Items remaining: " .. items_remaining)
+						mcl_log("Name: " .. tostring(stack:get_name()))
+
+						if current_itemstack:get_name() == stack:get_name() then
+							mcl_log("We have a match. Name: " .. tostring(stack:get_name()))
+
+							local room_for = stack:get_stack_max() - stack:get_count()
+							mcl_log("Room for: " .. tostring(room_for))
+
+							if room_for == 0 then
+								-- Do nothing
+								mcl_log("No room")
+							elseif room_for < items_remaining then
+								mcl_log("We have more items remaining than space")
+
+								items_remaining = items_remaining - room_for
+								stack:set_count(stack:get_stack_max())
+								inv:set_stack("main", i, stack)
+								taken_items = true
+							else
+								local new_stack_size = stack:get_count() + items_remaining
+								stack:set_count(new_stack_size)
+								mcl_log("We have more than enough space. Now holds: " .. new_stack_size)
+
+								inv:set_stack("main", i, stack)
+								items_remaining = 0
+
+								ent.object:get_luaentity().itemstring = ""
+								ent.object:remove()
+
+								taken_items = true
+								break
+							end
+
+							mcl_log("Count: " .. tostring(stack:get_count()))
+							mcl_log("stack max: " .. tostring(stack:get_stack_max()))
+							--mcl_log("Is it empty: " .. stack:to_string())
+						end
+
+						if i == self._inv_size and taken_items then
+							mcl_log("We are on last item and still have items left. Set final stack size: " .. items_remaining)
+							current_itemstack:set_count(items_remaining)
+							--mcl_log("Itemstack2: " .. current_itemstack:to_string())
+							ent.itemstring = current_itemstack:to_string()
+						end
+					end
+				end
+
+				--Add in, and delete
+				if taken_items then
+					mcl_log("Saving")
+					mcl_entity_invs.save_inv(ent)
+					return taken_items
+				else
+					mcl_log("No need to save")
+				end
+
+			end
+		end
+	end
+
+	return false
+end
+
+-- Minecart with Hopper
+mod.register_minecart({
+	itemstring = "mcl_minecarts:hopper_minecart",
+	craft = {
+		output = "mcl_minecarts:hopper_minecart",
+		recipe = {
+			{"mcl_hoppers:hopper"},
+			{"mcl_minecarts:minecart"},
+		},
+	},
+	entity_id = "mcl_minecarts:hopper_minecart",
+	description = S("Minecart with Hopper"),
+	tt_help = nil,
+	longdesc = nil,
+	usagehelp = nil,
+	initial_properties = {
+		mesh = "mcl_minecarts_minecart_hopper.b3d",
+		textures = {
+			"mcl_hoppers_hopper_inside.png",
+			"mcl_minecarts_minecart.png",
+			"mcl_hoppers_hopper_outside.png",
+			"mcl_hoppers_hopper_top.png",
+		},
+	},
+	icon = "mcl_minecarts_minecart_hopper.png",
+	drop = {"mcl_minecarts:minecart", "mcl_hoppers:hopper"},
+	groups = { container = 1 },
+	on_rightclick = nil,
+	on_activate_by_rail = nil,
+	_mcl_minecarts_on_enter = function(self, pos, staticdata)
+		if (staticdata.hopper_delay or 0) > 0 then
+			return
+		end
+
+		-- try to pull from containers into our inventory
+		if not self then return end
+		local inv = mcl_entity_invs.load_inv(self,5)
+		local above_pos = vector.offset(pos,0,1,0)
+		mcl_util.hopper_pull_to_inventory(inv, 'main', above_pos, pos)
+
+		staticdata.hopper_delay =  (staticdata.hopper_delay or 0) + (1/20)
+	end,
+	_mcl_minecarts_on_step = function(self, dtime)
+		hopper_take_item(self, dtime)
+	end,
+	creative = true
+})
+mcl_entity_invs.register_inv("mcl_minecarts:hopper_minecart", "Hopper Minecart", 5, false, true)
+

mods/ENTITIES/mcl_minecarts/carts/with_tnt.lua

@@ -0,0 +1,133 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+
+local function detonate_tnt_minecart(self)
+	local pos = self.object:get_pos()
+	self.object:remove()
+	mcl_explosions.explode(pos, 6, { drop_chance = 1.0 })
+end
+
+local function activate_tnt_minecart(self, timer)
+	if self._boomtimer then
+		return
+	end
+	if timer then
+		self._boomtimer = timer
+	else
+		self._boomtimer = tnt.BOOMTIMER
+	end
+	self.object:set_properties({textures = {
+		"mcl_tnt_blink.png",
+		"mcl_tnt_blink.png",
+		"mcl_tnt_blink.png",
+		"mcl_tnt_blink.png",
+		"mcl_tnt_blink.png",
+		"mcl_tnt_blink.png",
+		"mcl_minecarts_minecart.png",
+	}})
+	self._blinktimer = tnt.BLINKTIMER
+	minetest.sound_play("tnt_ignite", {pos = self.object:get_pos(), gain = 1.0, max_hear_distance = 15}, true)
+end
+mod.register_minecart({
+	itemstring = "mcl_minecarts:tnt_minecart",
+	craft = {
+		output = "mcl_minecarts:tnt_minecart",
+		recipe = {
+			{"mcl_tnt:tnt"},
+			{"mcl_minecarts:minecart"},
+		},
+	},
+	entity_id = "mcl_minecarts:tnt_minecart",
+	description = S("Minecart with TNT"),
+	tt_help = S("Vehicle for fast travel on rails").."\n"..S("Can be ignited by tools or powered activator rail"),
+	longdesc = S("A minecart with TNT is an explosive vehicle that travels on rail."),
+	usagehelp = S("Place it on rails. Punch it to move it. The TNT is ignited with a flint and steel or when the minecart is on an powered activator rail.") .. "\n" ..
+		S("To obtain the minecart and TNT, punch them while holding down the sneak key. You can't do this if the TNT was ignited."),
+	initial_properties = {
+		mesh = "mcl_minecarts_minecart_block.b3d",
+		textures = {
+			"default_tnt_top.png",
+			"default_tnt_bottom.png",
+			"default_tnt_side.png",
+			"default_tnt_side.png",
+			"default_tnt_side.png",
+			"default_tnt_side.png",
+			"mcl_minecarts_minecart.png",
+		},
+	},
+	icon = "mcl_minecarts_minecart_tnt.png",
+	drop = {"mcl_minecarts:minecart", "mcl_tnt:tnt"},
+	on_rightclick = function(self, clicker)
+		-- Ingite
+		if not clicker or not clicker:is_player() then
+			return
+		end
+		if self._boomtimer then
+			return
+		end
+		local held = clicker:get_wielded_item()
+		if held:get_name() == "mcl_fire:flint_and_steel" then
+			if not minetest.is_creative_enabled(clicker:get_player_name()) then
+				held:add_wear(65535/65) -- 65 uses
+				local index = clicker:get_wield_index()
+				local inv = clicker:get_inventory()
+				inv:set_stack("main", index, held)
+			end
+			activate_tnt_minecart(self)
+		end
+	end,
+	on_activate_by_rail = activate_tnt_minecart,
+	creative = true,
+	_mcl_minecarts_on_step = function(self, dtime)
+		-- Impacts reduce the speed greatly. Use this to trigger explosions
+		local current_speed = vector.length(self.object:get_velocity())
+		if current_speed < (self._old_speed or 0) - 6 then
+			detonate_tnt_minecart(self)
+		end
+		self._old_speed = current_speed
+
+		if self._boomtimer then
+			-- Explode
+			self._boomtimer = self._boomtimer - dtime
+			if self._boomtimer <= 0 then
+				detonate_tnt_minecart(self)
+				return
+			else
+				tnt.smoke_step(pos)
+			end
+		end
+
+		if self._blinktimer then
+			self._blinktimer = self._blinktimer - dtime
+			if self._blinktimer <= 0 then
+				self._blink = not self._blink
+				if self._blink then
+					self.object:set_properties({textures =
+					{
+					"default_tnt_top.png",
+					"default_tnt_bottom.png",
+					"default_tnt_side.png",
+					"default_tnt_side.png",
+					"default_tnt_side.png",
+					"default_tnt_side.png",
+					"mcl_minecarts_minecart.png",
+					}})
+				else
+					self.object:set_properties({textures =
+					{
+					"mcl_tnt_blink.png",
+					"mcl_tnt_blink.png",
+					"mcl_tnt_blink.png",
+					"mcl_tnt_blink.png",
+					"mcl_tnt_blink.png",
+					"mcl_tnt_blink.png",
+					"mcl_minecarts_minecart.png",
+					}})
+				end
+				self._blinktimer = tnt.BLINKTIMER
+			end
+		end
+	end,
+})

mods/ENTITIES/mcl_minecarts/functions.lua

@@ -1,4 +1,13 @@
 local vector = vector
+local mod = mcl_minecarts
+local table_merge = mcl_util.table_merge
+
+function get_path(base, first, ...)
+	if not first then return base end
+	if not base then return end
+	return get_path(base[first], ...)
+end
+local force_get_node = mcl_util.force_get_node
 
 function mcl_minecarts:get_sign(z)
 	if z == 0 then
@@ -10,158 +19,388 @@ end
 
 function mcl_minecarts:velocity_to_dir(v)
 	if math.abs(v.x) > math.abs(v.z) then
-		return {x=mcl_minecarts:get_sign(v.x), y=mcl_minecarts:get_sign(v.y), z=0}
+		return vector.new(
+			mcl_minecarts:get_sign(v.x),
+			mcl_minecarts:get_sign(v.y),
+			0
+		)
 	else
-		return {x=0, y=mcl_minecarts:get_sign(v.y), z=mcl_minecarts:get_sign(v.z)}
+		return vector.new(
+			0,
+			mcl_minecarts:get_sign(v.y),
+			mcl_minecarts:get_sign(v.z)
+		)
 	end
 end
 
 function mcl_minecarts:is_rail(pos, railtype)
-	local node = minetest.get_node(pos).name
-	if node == "ignore" then
-		local vm = minetest.get_voxel_manip()
-		local emin, emax = vm:read_from_map(pos, pos)
-		local area = VoxelArea:new{
-			MinEdge = emin,
-			MaxEdge = emax,
-		}
-		local data = vm:get_data()
-		local vi = area:indexp(pos)
-		node = minetest.get_name_from_content_id(data[vi])
-	end
-	if minetest.get_item_group(node, "rail") == 0 then
+	local node_name = force_get_node(pos).name
+
+	if minetest.get_item_group(node_name, "rail") == 0 then
 		return false
 	end
 	if not railtype then
 		return true
 	end
-	return minetest.get_item_group(node, "connect_to_raillike") == railtype
+	return minetest.get_item_group(node_name, "connect_to_raillike") == railtype
 end
 
-function mcl_minecarts:check_front_up_down(pos, dir_, check_down, railtype)
-	local dir = vector.new(dir_)
-	-- Front
-	dir.y = 0
-	local cur = vector.add(pos, dir)
-	if mcl_minecarts:is_rail(cur, railtype) then
-		return dir
-	end
-	-- Up
-	if check_down then
-		dir.y = 1
-		cur = vector.add(pos, dir)
-		if mcl_minecarts:is_rail(cur, railtype) then
-			return dir
+-- Directional constants
+local north = vector.new( 0, 0, 1); local N = 1 -- 4dir = 0
+local east  = vector.new( 1, 0, 0); local E = 4 -- 4dir = 1
+local south = vector.new( 0, 0,-1); local S = 2 -- 4dir = 2 Note: S is overwritten below with the translator
+local west  = vector.new(-1, 0, 0); local W = 8 -- 4dir = 3
+
+-- Share. Consider moving this to some shared location
+mod.north = north
+mod.south = south
+mod.east = east
+mod.west = west
+
+--[[
+	mcl_minecarts.snap_direction(dir)
+
+	returns a valid cart direction that has the smallest angle difference to `dir'
+]]
+local VALID_DIRECTIONS = {
+	north, vector.offset(north, 0, 1, 0), vector.offset(north, 0, -1, 0),
+	south, vector.offset(south, 0, 1, 0), vector.offset(south, 0, -1, 0),
+	east,  vector.offset(east,  0, 1, 0), vector.offset(east,  0, -1, 0),
+	west,  vector.offset(west,  0, 1, 0), vector.offset(west,  0, -1, 0),
+}
+function mod.snap_direction(dir)
+	dir = vector.normalize(dir)
+	local best = nil
+	local diff = -1
+	for _,d in pairs(VALID_DIRECTIONS) do
+		local dot = vector.dot(dir,d)
+		if dot > diff then
+			best = d
+			diff = dot
 		end
 	end
-	-- Down
-	dir.y = -1
-	cur = vector.add(pos, dir)
-	if mcl_minecarts:is_rail(cur, railtype) then
-		return dir
-	end
-	return nil
+	return best
 end
 
-function mcl_minecarts:get_rail_direction(pos_, dir, ctrl, old_switch, railtype)
-	local pos = vector.round(pos_)
-	local cur
-	local left_check, right_check = true, true
+local CONNECTIONS = { north, south, east, west }
+local HORIZONTAL_STANDARD_RULES = {
+	[N]       = { "", 0, mask = N, score = 1, can_slope = true },
+	[S]       = { "", 0, mask = S, score = 1, can_slope = true },
+	[N+S]     = { "", 0, mask = N+S, score = 2, can_slope = true },
 
-	-- Check left and right
-	local left = {x=0, y=0, z=0}
-	local right = {x=0, y=0, z=0}
-	if dir.z ~= 0 and dir.x == 0 then
-		left.x = -dir.z
-		right.x = dir.z
-	elseif dir.x ~= 0 and dir.z == 0 then
-		left.z = dir.x
-		right.z = -dir.x
-	end
+	[E]       = { "", 1, mask = E, score = 1, can_slope = true },
+	[W]       = { "", 1, mask = W, score = 1, can_slope = true },
+	[E+W]     = { "", 1, mask = E+W, score = 2, can_slope = true },
+}
+mod.HORIZONTAL_STANDARD_RULES = HORIZONTAL_STANDARD_RULES
 
-	if ctrl then
-		if old_switch == 1 then
-			left_check = false
-		elseif old_switch == 2 then
-			right_check = false
-		end
-		if ctrl.left and left_check then
-			cur = mcl_minecarts:check_front_up_down(pos, left, false, railtype)
-			if cur then
-				return cur, 1
-			end
-			left_check = false
-		end
-		if ctrl.right and right_check then
-			cur = mcl_minecarts:check_front_up_down(pos, right, false, railtype)
-			if cur then
-				return cur, 2
-			end
-			right_check = true
-		end
-	end
+local HORIZONTAL_CURVES_RULES = {
+	[N+E]     = { "_corner", 3, name = "ne corner", mask = N+E, score = 3 },
+	[N+W]     = { "_corner", 2, name = "nw corner", mask = N+W, score = 3 },
+	[S+E]     = { "_corner", 0, name = "se corner", mask = S+E, score = 3 },
+	[S+W]     = { "_corner", 1, name = "sw corner", mask = S+W, score = 3 },
 
-	-- Normal
-	cur = mcl_minecarts:check_front_up_down(pos, dir, true, railtype)
-	if cur then
-		return cur
-	end
+	[N+E+W]   = { "_tee_off", 3, mask = N+E+W, score = 4 },
+	[S+E+W]   = { "_tee_off", 1, mask = S+E+W, score = 4 },
+	[N+S+E]   = { "_tee_off", 0, mask = N+S+E, score = 4 },
+	[N+S+W]   = { "_tee_off", 2, mask = N+S+W, score = 4 },
 
-	-- Left, if not already checked
-	if left_check then
-		cur = mcl_minecarts:check_front_up_down(pos, left, false, railtype)
-		if cur then
-			return cur
-		end
-	end
+	[N+S+E+W] = { "_cross", 0, mask = N+S+E+W, score = 5 },
+}
+table_merge(HORIZONTAL_CURVES_RULES, HORIZONTAL_STANDARD_RULES)
+mod.HORIZONTAL_CURVES_RULES = HORIZONTAL_CURVES_RULES
 
-	-- Right, if not already checked
-	if right_check then
-		cur = mcl_minecarts:check_front_up_down(pos, right, false, railtype)
-		if cur then
-			return cur
-		end
-	end
-	-- Backwards
-	if not old_switch then
-		cur = mcl_minecarts:check_front_up_down(pos, {
-				x = -dir.x,
-				y = dir.y,
-				z = -dir.z
-			}, true, railtype)
-		if cur then
-			return cur
-		end
-	end
-	return {x=0, y=0, z=0}
-end
-
-local plane_adjacents = {
-	vector.new(-1,0,0),
-	vector.new(1,0,0),
-	vector.new(0,0,-1),
-	vector.new(0,0,1),
+local HORIZONTAL_RULES_BY_RAIL_GROUP = {
+	[1] = HORIZONTAL_STANDARD_RULES,
+	[2] = HORIZONTAL_CURVES_RULES,
 }
 
-function mcl_minecarts:get_start_direction(pos)
-	local dir
-	local i = 0
-	while (not dir and i < #plane_adjacents) do
-		i = i+1
-		local node = minetest.get_node_or_nil(vector.add(pos, plane_adjacents[i]))
-		if node ~= nil
-		and minetest.get_item_group(node.name, "rail") == 0
-		and minetest.get_item_group(node.name, "solid") == 1
-		and minetest.get_item_group(node.name, "opaque") == 1
-		then
-			dir = mcl_minecarts:check_front_up_down(pos, vector.multiply(plane_adjacents[i], -1), true)
+local function check_connection_rule(pos, connections, rule)
+	-- All bits in the mask must be set for the connection to be possible
+	if bit.band(rule.mask,connections) ~= rule.mask then
+		--print("Mask mismatch ("..tostring(rule.mask)..","..tostring(connections)..")")
+		return false
 	end
+
+	-- If there is an allow filter, that mush also return true
+	if rule.allow and rule.allow(rule, connections, pos) then
+		return false
 	end
-	return dir
+
+	return true
 end
 
-function mcl_minecarts:set_velocity(obj, dir, factor)
-	obj._velocity = vector.multiply(dir, factor or 3)
-	obj._old_pos = nil
-	obj._punched = true
+local function make_sloped_if_straight(pos, dir)
+	local node = minetest.get_node(pos)
+	local nodedef = minetest.registered_nodes[node.name]
+
+	local param2 = 0
+	if dir == east then
+		param2 = 3
+	elseif dir == west then
+		param2 = 1
+	elseif dir == north then
+		param2 = 2
+	elseif dir == south then
+		param2 = 0
+	end
+
+	if get_path( nodedef, "_mcl_minecarts", "railtype" ) == "straight" then
+		minetest.swap_node(pos, {name = nodedef._mcl_minecarts.base_name .. "_sloped", param2 = param2})
+	end
 end
+
+local function is_connection(pos, dir)
+	local node = force_get_node(pos)
+	local nodedef = minetest.registered_nodes[node.name]
+
+	local get_next_dir = get_path(nodedef, "_mcl_minecarts", "get_next_dir")
+	if not get_next_dir then return end
+
+	local next_dir = get_next_dir(pos, dir, node)
+	next_dir.y = 0
+	return vector.equals(next_dir, dir)
+end
+
+local function get_rail_connections(pos, opt)
+	local legacy = opt and opt.legacy
+	local ignore_neighbor_connections = opt and opt.ignore_neighbor_connections
+
+	local connections = 0
+	for i = 1,#CONNECTIONS do
+		dir = CONNECTIONS[i]
+		local neighbor = vector.add(pos, dir)
+		local node = force_get_node(neighbor)
+		local nodedef = minetest.registered_nodes[node.name]
+
+		-- Only allow connections to the open ends of rails, as decribed by get_next_dir
+		if mcl_minecarts:is_rail(neighbor) and ( legacy or get_path(nodedef, "_mcl_minecarts", "get_next_dir" ) ) then
+			local rev_dir = vector.direction(dir,vector.zero())
+			if ignore_neighbor_connections or is_connection(neighbor, rev_dir) then
+				connections = bit.bor(connections, bit.lshift(1,i - 1))
+			end
+		end
+
+		-- Check for sloped rail one block down
+		local below_neighbor = vector.offset(neighbor, 0, -1, 0)
+		local node = force_get_node(below_neighbor)
+		local nodedef = minetest.registered_nodes[node.name]
+		if mcl_minecarts:is_rail(below_neighbor) and ( legacy or get_path(nodedef, "_mcl_minecarts", "get_next_dir" ) ) then
+			local rev_dir = vector.direction(dir, vector.zero())
+			if ignore_neighbor_connections or is_connection(below_neighbor, rev_dir) then
+				connections = bit.bor(connections, bit.lshift(1,i - 1))
+			end
+		end
+	end
+	return connections
+end
+mod.get_rail_connections = get_rail_connections
+
+local function update_rail_connections(pos, opt)
+	local ignore_neighbor_connections = opt and opt.ignore_neighbor_connections
+
+	local node = minetest.get_node(pos)
+	local nodedef = minetest.registered_nodes[node.name]
+	if not nodedef or not nodedef._mcl_minecarts then return end
+
+	-- Get the mappings to use
+	local rules = HORIZONTAL_RULES_BY_RAIL_GROUP[nodedef.groups.rail]
+	if nodedef._mcl_minecarts and nodedef._mcl_minecarts.connection_rules then -- Custom connection rules
+		rules = nodedef._mcl_minecarts.connection_rules
+	end
+	if not rules then return end
+
+	-- Horizontal rules, Check for rails on each neighbor
+	local connections = get_rail_connections(pos, opt)
+
+	-- Check for rasing rails to slopes
+	for i = 1,#CONNECTIONS do
+		local dir = CONNECTIONS[i]
+		local neighbor = vector.add(pos, dir)
+		make_sloped_if_straight( vector.offset(neighbor, 0, -1, 0), dir )
+	end
+
+	-- Select the best allowed connection
+	local rule = nil
+	local score = 0
+	for k,r in pairs(rules) do
+		if check_connection_rule(pos, connections, r) then
+			if r.score > score then
+				--print("Best rule so far is "..dump(r))
+				score = r.score
+				rule = r
+			end
+		end
+	end
+
+	if rule then
+		-- Apply the mapping
+		local new_name = nodedef._mcl_minecarts.base_name..rule[1]
+		if new_name ~= node.name or node.param2 ~= rule[2] then
+			--print("swapping "..node.name.." for "..new_name..","..tostring(rule[2]).." at "..tostring(pos))
+			node.name = new_name
+			node.param2 = rule[2]
+			minetest.swap_node(pos, node)
+		end
+
+		if rule.after then
+			rule.after(rule, pos, connections)
+		end
+	end
+
+	local node_def = minetest.registered_nodes[node.name]
+	if get_path(node_def, "_mcl_minecarts", "can_slope") then
+		for i=1,#CONNECTIONS do
+			local dir = CONNECTIONS[i]
+			local higher_rail_pos = vector.offset(pos,dir.x,1,dir.z)
+			local rev_dir = vector.direction(dir,vector.zero())
+			if mcl_minecarts:is_rail(higher_rail_pos) and is_connection(higher_rail_pos, rev_dir) then
+				make_sloped_if_straight(pos, rev_dir)
+			end
+		end
+	end
+
+end
+mod.update_rail_connections = update_rail_connections
+
+local north = vector.new(0,0,1)
+local south = vector.new(0,0,-1)
+local east  = vector.new(1,0,0)
+local west = vector.new(-1,0,0)
+
+local function is_ahead_slope(pos, dir)
+	local ahead = vector.add(pos,dir)
+	if mcl_minecarts:is_rail(ahead) then return false end
+
+	local below = vector.offset(ahead,0,-1,0)
+	if not mcl_minecarts:is_rail(below) then return false end
+
+	local node_name = force_get_node(below).name
+	return minetest.get_item_group(node_name, "rail_slope") ~= 0
+end
+
+local function get_rail_direction_inner(pos, dir)
+	-- Handle new track types that have track-specific direction handler
+	local node = minetest.get_node(pos)
+	local node_def = minetest.registered_nodes[node.name]
+	local get_next_dir = get_path(node_def,"_mcl_minecarts","get_next_dir")
+	if not get_next_dir then return dir end
+
+	dir = node_def._mcl_minecarts.get_next_dir(pos, dir, node)
+
+	-- Handle reversing if there is a solid block in the next position
+	local next_pos = vector.add(pos, dir)
+	local next_node = minetest.get_node(next_pos)
+	local node_def = minetest.registered_nodes[next_node.name]
+	if node_def and node_def.groups and ( node_def.groups.solid or node_def.groups.stair ) then
+		-- Reverse the direction without giving -0 members
+		dir = vector.direction(next_pos, pos)
+	end
+
+	-- Handle going downhill
+	if is_ahead_slope(pos,dir) then
+		dir = vector.offset(dir,0,-1,0)
+	end
+
+	return dir
+end
+function mcl_minecarts:get_rail_direction(pos_, dir)
+	local pos = vector.round(pos_)
+
+	-- diagonal direction handling
+	if dir.x ~= 0 and dir.z ~= 0 then
+		-- Check both possible diagonal movements
+		local dir_a = vector.new(dir.x,0,0)
+		local dir_b = vector.new(0,0,dir.z)
+		local new_dir_a = mcl_minecarts:get_rail_direction(pos, dir_a)
+		local new_dir_b = mcl_minecarts:get_rail_direction(pos, dir_b)
+
+		-- If either is the same diagonal direction, continue as you were
+		if vector.equals(dir,new_dir_a) or vector.equals(dir,new_dir_b) then
+			return dir
+
+		-- Otherwise, if either would try to move in the same direction as
+		-- what tried, move that direction
+		elseif vector.equals(dir_a, new_dir_a) then
+			return new_dir_a
+		elseif vector.equals(dir_b, new_dir_b) then
+			return new_dir_b
+		end
+
+		 -- And if none of these were true, fall thru into standard behavior
+	end
+
+	local new_dir = get_rail_direction_inner(pos, dir)
+
+	-- Check four 45 degree movement
+	local next_rails_dir = get_rail_direction_inner(vector.add(pos, new_dir), new_dir)
+	if vector.equals(next_rails_dir, dir) and not vector.equals(new_dir, next_rails_dir) then
+		return vector.add(new_dir, next_rails_dir)
+	else
+		return new_dir
+	end
+end
+function mod.update_cart_orientation(self)
+	local staticdata = self._staticdata
+
+	-- constants
+	local _2_pi = math.pi * 2
+	local pi = math.pi
+	local dir = staticdata.dir
+
+	-- Calculate an angle from the x,z direction components
+	local rot_y = math.atan2( dir.x, dir.z ) + ( staticdata.rot_adjust or 0 )
+	if rot_y < 0 then
+		rot_y = rot_y + _2_pi
+	end
+
+	-- Check if the rotation is a 180 flip and don't change if so
+	local rot = self.object:get_rotation()
+	local diff = math.abs((rot_y - ( rot.y + pi ) % _2_pi) )
+	if diff < 0.001 or diff > _2_pi - 0.001 then
+		-- Update rotation adjust and recalculate the rotation
+		staticdata.rot_adjust = ( ( staticdata.rot_adjust or 0 ) + pi ) % _2_pi
+		rot.y = math.atan2( dir.x, dir.z ) + ( staticdata.rot_adjust or 0 )
+	else
+		rot.y = rot_y
+	end
+
+	-- Forward/backwards tilt (pitch)
+	if dir.y < 0 then
+		rot.x = -0.25 * pi
+	elseif dir.y > 0 then
+		rot.x = 0.25 * pi
+	else
+		rot.x = 0
+	end
+
+	if ( staticdata.rot_adjust or 0 ) < 0.01 then
+		rot.x = -rot.x
+	end
+	if dir.z ~= 0 then
+		rot.x = -rot.x
+	end
+
+	self.object:set_rotation(rot)
+end
+
+function mod.get_cart_position(cart_staticdata)
+	local data = cart_staticdata
+	if not data then return nil end
+	if not data.connected_at then return nil end
+
+	return vector.add(data.connected_at, vector.multiply(data.dir or vector.zero(), data.distance or 0))
+end
+
+function mod.reverse_cart_direction(staticdata)
+
+	-- Complete moving thru this block into the next, reverse direction, and put us back at the same position we were at
+	local next_dir = -staticdata.dir
+	staticdata.connected_at = staticdata.connected_at + staticdata.dir
+	staticdata.distance = 1 - (staticdata.distance or 0)
+
+	-- recalculate direction
+	local next_dir,_ = mod:get_rail_direction(staticdata.connected_at, next_dir)
+	staticdata.dir = next_dir
+end
+

mods/ENTITIES/mcl_minecarts/mod.conf

@@ -1,5 +1,5 @@
 name = mcl_minecarts
 author = Krock
 description = Minecarts are vehicles to move players quickly on rails.
-depends = mcl_title, mcl_explosions, mcl_core, mcl_sounds, mcl_player, mcl_achievements, mcl_chests, mcl_furnaces, mesecons_commandblock, mcl_hoppers, mcl_tnt, mesecons, mcl_entity_invs
-optional_depends = doc_identifier, mcl_wip
+depends = mcl_title, mcl_explosions, mcl_core, mcl_util, mcl_sounds, mcl_player, mcl_playerinfo, mcl_achievements, mcl_chests, mcl_furnaces, mesecons_commandblock, mcl_hoppers, mcl_tnt, mesecons, mcl_entity_invs
+optional_depends = doc_identifier, mcl_wip, mcl_physics, vl_physics

mods/ENTITIES/mcl_minecarts/models/flat_track.obj

@@ -0,0 +1,15 @@
+# hand-made Wavefront .OBJ file for sloped rail
+mtllib mcl_minecarts_rail.mtl
+o flat_track.001
+v -0.500000 -0.437500 -0.500000
+v -0.500000 -0.437500  0.500000
+v  0.500000 -0.437500  0.500000
+v  0.500000 -0.437500 -0.500000
+vt 1.000000 0.000000
+vt 1.000000 1.000000
+vt 0.000000 1.000000
+vt 0.000000 0.000000
+vn 0.000000 1.000000 0.000000
+usemtl None
+s off
+f 1/1/1 2/2/1 3/3/1 4/4/1

mods/ENTITIES/mcl_minecarts/models/sloped_track.obj

@@ -0,0 +1,15 @@
+# hand-made Wavefront .OBJ file for sloped rail
+mtllib mcl_minecarts_rail.mtl
+o sloped_rail.001
+v -0.500000 -0.437500 -0.500000
+v -0.500000  0.562500  0.500000
+v  0.500000  0.562500  0.500000
+v  0.500000 -0.437500 -0.500000
+vt 1.000000 0.000000
+vt 1.000000 1.000000
+vt 0.000000 1.000000
+vt 0.000000 0.000000
+vn 0.707106 0.707106 0.000000
+usemtl None
+s off
+f 1/1/1 2/2/1 3/3/1 4/4/1

mods/ENTITIES/mcl_minecarts/movement.lua

@@ -0,0 +1,564 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+
+-- Constants
+local mcl_debug,DEBUG = mcl_util.make_mcl_logger("mcl_logging_minecart_debug", "Minecart Debug")
+--DEBUG = false
+--mcl_debug = function(msg) print(msg) end
+
+-- Imports
+local env_physics
+if minetest.get_modpath("mcl_physics") then
+	env_physics = mcl_physics
+elseif minetest.get_modpath("vl_physics") then
+	env_physics = vl_physics
+end
+local FRICTION = mcl_minecarts.FRICTION
+local MAX_TRAIN_LENGTH = mod.MAX_TRAIN_LENGTH
+local SPEED_MAX = mod.SPEED_MAX
+local train_length = mod.train_length
+local update_train = mod.update_train
+local reverse_train = mod.reverse_train
+local link_cart_ahead = mod.link_cart_ahead
+local update_cart_orientation = mod.update_cart_orientation
+local get_cart_data = mod.get_cart_data
+local get_cart_position = mod.get_cart_position
+
+
+local function reverse_direction(staticdata)
+	if staticdata.behind or staticdata.ahead then
+		reverse_train(staticdata)
+		return
+	end
+
+	mod.reverse_cart_direction(staticdata)
+end
+mod.reverse_direction = reverse_direction
+
+
+--[[
+	Array of hooks { {u,v,w}, name }
+	Actual position is pos + u * dir + v * right + w * up
+]]
+local enter_exit_checks = {
+	{ 0, 0, 0, "" },
+	{ 0, 0, 1, "_above" },
+	{ 0, 0,-1, "_below" },
+	{ 0, 1, 0, "_side" },
+	{ 0,-1, 0, "_side" },
+}
+
+local function handle_cart_enter_exit(staticdata, pos, next_dir, event)
+	local luaentity = mcl_util.get_luaentity_from_uuid(staticdata.uuid)
+	local dir = staticdata.dir
+	local right = vector.new( dir.z, dir.y, -dir.x)
+	local up = vector.new(0,1,0)
+	for i=1,#enter_exit_checks do
+		local check = enter_exit_checks[i]
+
+		local check_pos = pos + dir * check[1] + right * check[2] + up * check[3]
+		local node = minetest.get_node(check_pos)
+		local node_def = minetest.registered_nodes[node.name]
+		if node_def then
+			-- node-specific hook
+			local hook_name = "_mcl_minecarts_"..event..check[4]
+			local hook = node_def[hook_name]
+			if hook then hook(check_pos, luaentity, next_dir, pos, staticdata) end
+
+			-- global minecart hook
+			hook = mcl_minecarts[event..check[4]]
+			if hook then hook(check_pos, luaentity, next_dir, pos, staticdata, node_def) end
+		end
+	end
+
+	-- Handle cart-specific behaviors
+	if luaentity then
+		local hook = luaentity["_mcl_minecarts_"..event]
+		if hook then hook(luaentity, pos, staticdata) end
+	else
+		--minetest.log("warning", "TODO: change _mcl_minecarts_"..event.." calling so it is not dependent on the existence of a luaentity")
+	end
+end
+local function set_metadata_cart_status(pos, uuid, state)
+	local meta = minetest.get_meta(pos)
+	local carts = minetest.deserialize(meta:get_string("_mcl_minecarts_carts")) or {}
+	carts[uuid] = state
+	meta:set_string("_mcl_minecarts_carts", minetest.serialize(carts))
+end
+local function handle_cart_enter(staticdata, pos, next_dir)
+	--print("entering "..tostring(pos))
+	set_metadata_cart_status(pos, staticdata.uuid, 1)
+	handle_cart_enter_exit(staticdata, pos, next_dir, "on_enter" )
+end
+local function handle_cart_leave(staticdata, pos, next_dir)
+	--print("leaving "..tostring(pos))
+	set_metadata_cart_status(pos, staticdata.uuid, nil)
+	handle_cart_enter_exit(staticdata, pos, next_dir, "on_leave" )
+end
+local function handle_cart_node_watches(staticdata, dtime)
+	local watches = staticdata.node_watches or {}
+	local new_watches = {}
+	local luaentity = mcl_util.get_luaentity_from_uuid(staticdata.uuid)
+	for i=1,#watches do
+		local node_pos = watches[i]
+		local node = minetest.get_node(node_pos)
+		local node_def = minetest.registered_nodes[node.name]
+		if node_def then
+			local hook = node_def._mcl_minecarts_node_on_step
+			if hook and hook(node_pos, luaentity, dtime, staticdata) then
+				new_watches[#new_watches+1] = node_pos
+			end
+		end
+	end
+
+	staticdata.node_watches = new_watches
+end
+
+local function detach_minecart(staticdata)
+	handle_cart_leave(staticdata, staticdata.connected_at, staticdata.dir)
+	staticdata.connected_at = nil
+
+	local luaentity = mcl_util.get_luaentity_from_uuid(staticdata.uuid)
+	if luaentity then
+		luaentity.object:set_velocity(staticdata.dir * staticdata.velocity)
+	end
+end
+mod.detach_minecart = detach_minecart
+
+local function try_detach_minecart(staticdata)
+	if not staticdata or not staticdata.connected_at then return end
+	if not mod:is_rail(staticdata.connected_at) then
+		mcl_debug("Detaching minecart #"..tostring(staticdata.uuid))
+		detach_minecart(staticdata)
+	end
+end
+
+local function handle_cart_collision(cart1_staticdata, prev_pos, next_dir)
+	if not cart1_staticdata then return end
+
+	-- Look ahead one block
+	local pos = vector.add(prev_pos, next_dir)
+
+	local meta = minetest.get_meta(pos)
+	local carts = minetest.deserialize(meta:get_string("_mcl_minecarts_carts")) or {}
+	local cart_uuid = nil
+	local dirty = false
+	for uuid,v in pairs(carts) do
+		-- Clean up dead carts
+		local data = get_cart_data(uuid)
+		if not data or not data.connected_at then
+			carts[uuid] = nil
+			dirty = true
+			uuid = nil
+		end
+
+		if uuid and uuid ~= cart1_staticdata.uuid then cart_uuid = uuid end
+	end
+	if dirty then
+		meta:set_string("_mcl_minecarts_carts",minetest.serialize(carts))
+	end
+
+	local meta = minetest.get_meta(vector.add(pos,next_dir))
+	if not cart_uuid then return end
+
+	-- Don't collide with the train car in front of you
+	if cart1_staticdata.ahead == cart_uuid then return end
+
+	minetest.log("action","cart #"..cart1_staticdata.uuid.." collided with cart #"..cart_uuid.." at "..tostring(pos))
+
+	-- Standard Collision Handling
+	local cart2_staticdata = get_cart_data(cart_uuid)
+
+	local u1 = cart1_staticdata.velocity
+	local u2 = cart2_staticdata.velocity
+	local m1 = cart1_staticdata.mass
+	local m2 = cart2_staticdata.mass
+
+	--print("u1="..tostring(u1)..",u2="..tostring(u2))
+	if u2 == 0 and u1 < 4 and train_length(cart1_staticdata) < MAX_TRAIN_LENGTH then
+		link_cart_ahead(cart1_staticdata, cart2_staticdata)
+		cart2_staticdata.dir = mcl_minecarts:get_rail_direction(cart2_staticdata.connected_at, cart1_staticdata.dir)
+		cart2_staticdata.velocity = cart1_staticdata.velocity
+		return
+	end
+
+	-- Calculate new velocities according to https://en.wikipedia.org/wiki/Elastic_collision#One-dimensional_Newtonian
+	local c1 = m1 + m2
+	local d = m1 - m2
+	local v1 = (      d * u1 + 2 * m2 * u2 ) / c1
+	local v2 = ( 2 * m1 * u1 +      d * u2 ) / c1
+
+	cart1_staticdata.velocity = v1
+	cart2_staticdata.velocity = v2
+
+	-- Force the other cart to move the same direction this one was
+	cart2_staticdata.dir = mcl_minecarts:get_rail_direction(cart2_staticdata.connected_at, cart1_staticdata.dir)
+end
+
+local function vector_away_from_players(cart, staticdata)
+	local function player_repel(obj)
+		-- Only repel from players
+		local player_name = obj:get_player_name()
+		if not player_name or player_name == "" then return false end
+
+		-- Don't repel away from players in minecarts
+		local player_meta = mcl_playerinfo.get_mod_meta(player_name, modname)
+		if player_meta.attached_to then return false end
+
+		return true
+	end
+
+	-- Get the cart position
+	local cart_pos = mod.get_cart_position(staticdata)
+	if cart then cart_pos = cart.object:get_pos() end
+	if not cart_pos then return nil end
+
+	for _,obj in pairs(minetest.get_objects_inside_radius(cart_pos, 1.1)) do
+		if player_repel(obj) then
+			return obj:get_pos() - cart_pos
+		end
+	end
+
+	return nil
+end
+
+local function direction_away_from_players(staticdata)
+	local diff = vector_away_from_players(nil,staticdata)
+	if not diff then return 0 end
+
+	local length = vector.distance(vector.zero(),diff)
+	local vec = diff / length
+	local force = vector.dot( vec, vector.normalize(staticdata.dir) )
+
+	-- Check if this would push past the end of the track and don't move it it would
+	-- This prevents an oscillation that would otherwise occur
+	local dir = staticdata.dir
+	if force > 0 then
+		dir = -dir
+	end
+	if mcl_minecarts:is_rail( staticdata.connected_at + dir ) then
+		if force > 0.5 then
+			return -length * 4
+		elseif force < -0.5 then
+			return length * 4
+		end
+	end
+	return 0
+end
+
+local function calculate_acceleration(staticdata)
+	local acceleration = 0
+
+	-- Fix up movement data
+	staticdata.velocity = staticdata.velocity or 0
+
+	-- Apply friction if moving
+	if staticdata.velocity > 0 then
+		acceleration = -FRICTION
+	end
+
+	local pos = staticdata.connected_at
+	local node_name = minetest.get_node(pos).name
+	local node_def = minetest.registered_nodes[node_name]
+
+	local ctrl = staticdata.controls or {}
+	local time_active = minetest.get_gametime() - 0.25
+
+	if (ctrl.forward or 0) > time_active then
+		if staticdata.velocity == 0 then
+			local look_dir = minetest.facedir_to_dir(ctrl.look or 0)
+			local dot = vector.dot(staticdata.dir, look_dir)
+			if dot < 0 then
+				reverse_direction(staticdata)
+			end
+		end
+		acceleration = 4
+	elseif (ctrl.brake or 0) > time_active then
+		acceleration = -1.5
+	elseif ctrl.impulse then
+		acceleration = vector.dot(staticdata.dir, ctrl.impulse)
+		ctrl.impulse = nil
+	elseif (staticdata.fueltime or 0) > 0 and staticdata.velocity <= 4 then
+		acceleration = 0.6
+	elseif staticdata.velocity >= ( node_def._max_acceleration_velocity or SPEED_MAX ) then
+		-- Standard friction
+	elseif node_def and node_def._rail_acceleration then
+		acceleration = node_def._rail_acceleration * 4
+	end
+
+	-- Factor in gravity after everything else
+	local gravity_strength = 2.45 --friction * 5
+	if staticdata.dir.y < 0 then
+		acceleration = gravity_strength - FRICTION
+	elseif staticdata.dir.y > 0 then
+		acceleration = -gravity_strength + FRICTION
+	end
+
+	return acceleration
+end
+
+local function do_movement_step(staticdata, dtime)
+	if not staticdata.connected_at then return 0 end
+
+	-- Calculate timestep remaiing in this block
+	local x_0 = staticdata.distance or 0
+	local remaining_in_block = 1 - x_0
+	local a = calculate_acceleration(staticdata)
+	local v_0 = staticdata.velocity
+
+	-- Repel minecarts
+	local away = direction_away_from_players(staticdata)
+	if away > 0 then
+		v_0 = away
+	elseif away < 0 then
+		reverse_direction(staticdata)
+		v_0 = -away
+	end
+
+	if DEBUG and ( v_0 > 0 or a ~= 0 ) then
+		mcl_debug("    cart "..tostring(staticdata.uuid)..
+		       ": a="..tostring(a)..
+		        ",v_0="..tostring(v_0)..
+		        ",x_0="..tostring(x_0)..
+			",dtime="..tostring(dtime)..
+		        ",dir="..tostring(staticdata.dir)..
+			",connected_at="..tostring(staticdata.connected_at)..
+			",distance="..tostring(staticdata.distance)
+		)
+	end
+
+	-- Not moving
+	if a == 0 and v_0 == 0 then return 0 end
+
+	-- Movement equation with acceleration: x_1 = x_0 + v_0 * t + 0.5 * a * t*t
+	local timestep
+	local stops_in_block = false
+	local inside = v_0 * v_0 + 2 * a * remaining_in_block
+	if inside < 0 then
+		-- Would stop or reverse direction inside this block, calculate time to v_1 = 0
+		timestep = -v_0 / a
+		stops_in_block = true
+	elseif a ~= 0 then
+		-- Setting x_1 = x_0 + remaining_in_block, and solving for t gives:
+		timestep = ( math.sqrt( v_0 * v_0 + 2 * a * remaining_in_block) - v_0 ) / a
+	else
+		timestep = remaining_in_block / v_0
+	end
+
+	-- Truncate timestep to remaining time delta
+	if timestep > dtime then
+		timestep = dtime
+	end
+
+	-- Truncate timestep to prevent v_1 from being larger that speed_max
+	local v_max = SPEED_MAX
+	if (v_0 < v_max) and ( v_0 + a * timestep > v_max) then
+		timestep = ( v_max - v_0 ) / a
+	end
+
+	-- Prevent infinite loops
+	if timestep <= 0 then return 0 end
+
+	-- Calculate v_1 taking v_max into account
+	local v_1 = v_0 + a * timestep
+	if v_1 > v_max then
+		v_1 = v_max
+	elseif v_1 < FRICTION / 5 then
+		v_1 = 0
+	end
+
+	-- Calculate x_1
+	local x_1 = x_0 + timestep * v_0 + 0.5 * a * timestep * timestep
+
+	-- Update position and velocity of the minecart
+	staticdata.velocity = v_1
+	staticdata.distance = x_1
+
+	if DEBUG and (1==0) and ( v_0 > 0 or a ~= 0 ) then
+		mcl_debug( "-   cart #"..tostring(staticdata.uuid)..
+		       ": a="..tostring(a)..
+		        ",v_0="..tostring(v_0)..
+		        ",v_1="..tostring(v_1)..
+		        ",x_0="..tostring(x_0)..
+		        ",x_1="..tostring(x_1)..
+		        ",timestep="..tostring(timestep)..
+		        ",dir="..tostring(staticdata.dir)..
+			",connected_at="..tostring(staticdata.connected_at)..
+			",distance="..tostring(staticdata.distance)
+		)
+	end
+
+	-- Entity movement
+	local pos = staticdata.connected_at
+
+	-- Handle movement to next block, account for loss of precision in calculations
+	if x_1 >= 0.99 then
+		staticdata.distance = 0
+
+		-- Anchor at the next node
+		local old_pos = pos
+		pos = pos + staticdata.dir
+		staticdata.connected_at = pos
+
+		-- Get the next direction
+		local next_dir,_ = mcl_minecarts:get_rail_direction(pos, staticdata.dir, nil, nil, staticdata.railtype)
+		if DEBUG and next_dir ~= staticdata.dir then
+			mcl_debug( "Changing direction from "..tostring(staticdata.dir).." to "..tostring(next_dir))
+		end
+
+		-- Handle cart collisions
+		handle_cart_collision(staticdata, pos, next_dir)
+
+		-- Leave the old node
+		handle_cart_leave(staticdata, old_pos, next_dir )
+
+		-- Enter the new node
+		handle_cart_enter(staticdata, pos, next_dir)
+
+		-- Handle end of track
+		if next_dir == staticdata.dir * -1 and next_dir.y == 0 then
+			if DEBUG then mcl_debug("Stopping cart at end of track at "..tostring(pos)) end
+			staticdata.velocity = 0
+		end
+
+		-- Update cart direction
+		staticdata.dir = next_dir
+	elseif stops_in_block and v_1 < (FRICTION/5) and a <= 0 and staticdata.dir.y > 0 then
+		-- Handle direction flip due to gravity
+		if DEBUG then mcl_debug("Gravity flipped direction") end
+
+		-- Velocity should be zero at this point
+		staticdata.velocity = 0
+
+		reverse_direction(staticdata)
+
+		-- Intermediate movement
+		pos = staticdata.connected_at + staticdata.dir * staticdata.distance
+	else
+		-- Intermediate movement
+		pos = pos + staticdata.dir * staticdata.distance
+	end
+
+	-- Debug reporting
+	if DEBUG and ( v_0 > 0 or v_1 > 0 ) then
+		mcl_debug( "    cart #"..tostring(staticdata.uuid)..
+		       ": a="..tostring(a)..
+		        ",v_0="..tostring(v_0)..
+		        ",v_1="..tostring(v_1)..
+		        ",x_0="..tostring(x_0)..
+		        ",x_1="..tostring(x_1)..
+		        ",timestep="..tostring(timestep)..
+		        ",dir="..tostring(staticdata.dir)..
+			",pos="..tostring(pos)..
+			",connected_at="..tostring(staticdata.connected_at)..
+			",distance="..tostring(staticdata.distance)
+		)
+	end
+
+	-- Report the amount of time processed
+	return dtime - timestep
+end
+
+local function do_movement( staticdata, dtime )
+	assert(staticdata)
+
+	-- Allow the carts to be delay for the rest of the world to react before moving again
+	--[[
+	if ( staticdata.delay or 0 ) > dtime then
+		staticdata.delay = staticdata.delay - dtime
+		return
+	else
+		staticdata.delay = 0
+	end]]
+
+	-- Break long movements at block boundaries to make it
+	-- it impossible to jump across gaps due to server lag
+	-- causing large timesteps
+	while dtime > 0 do
+		local new_dtime = do_movement_step(staticdata, dtime)
+		try_detach_minecart(staticdata)
+
+		update_train(staticdata)
+
+		-- Handle node watches here in steps to prevent server lag from changing behavior
+		handle_cart_node_watches(staticdata, dtime - new_dtime)
+
+		dtime = new_dtime
+	end
+end
+
+local function do_detached_movement(self, dtime)
+	local staticdata = self._staticdata
+
+	-- Make sure the object is still valid before trying to move it
+	if not self.object or not self.object:get_pos() then return end
+
+	-- Apply physics
+	if env_physics then
+		env_physics.apply_entity_environmental_physics(self)
+	else
+		-- Simple physics
+		local friction = self.object:get_velocity() or vector.zero()
+		friction.y = 0
+
+		local accel = vector.new(0,-9.81,0) -- gravity
+
+		-- Don't apply friction in the air
+		local pos_rounded = vector.round(self.object:get_pos())
+		if minetest.get_node(vector.offset(pos_rounded,0,-1,0)).name ~= "air" then
+			accel = vector.add(accel, vector.multiply(friction,-0.9))
+		end
+
+		self.object:set_acceleration(accel)
+	end
+
+	local away = vector_away_from_players(self, staticdata)
+	if away then
+		local v = self.object:get_velocity()
+		self.object:set_velocity(v - away)
+
+		-- Boost the minecart vertically a bit to get over the edge of rails and things like carpets
+		local boost = vector.offset(vector.multiply(vector.normalize(away), 0.1), 0, 0.07, 0) -- 1/16th + 0.0075
+		local pos = self.object:get_pos()
+		self.object:set_pos(vector.add(pos,boost))
+	end
+
+	-- Try to reconnect to rail
+	local pos = self.object:get_pos()
+	local yaw = self.object:get_yaw()
+	local yaw_dir = minetest.yaw_to_dir(yaw)
+	local test_positions = {
+		pos,
+		vector.offset(vector.add(pos, vector.multiply(yaw_dir, 0.5)),0,-0.55,0),
+		vector.offset(vector.add(pos, vector.multiply(yaw_dir,-0.5)),0,-0.55,0),
+	}
+
+	for i=1,#test_positions do
+		local test_pos = test_positions[i]
+		local pos_r = vector.round(test_pos)
+		local node = minetest.get_node(pos_r)
+		if minetest.get_item_group(node.name, "rail") ~= 0 then
+			staticdata.connected_at = pos_r
+			staticdata.railtype = node.name
+
+			local freebody_velocity = self.object:get_velocity()
+			staticdata.dir = mod:get_rail_direction(pos_r, mod.snap_direction(freebody_velocity))
+
+			-- Use vector projection to only keep the velocity in the new direction of movement on the rail
+			-- https://en.wikipedia.org/wiki/Vector_projection
+			staticdata.velocity = vector.dot(staticdata.dir,freebody_velocity)
+			print("Reattached velocity="..tostring(staticdata.velocity)..", freebody_velocity="..tostring(freebody_velocity))
+
+			-- Clear freebody movement
+			self.object:set_velocity(vector.zero())
+			self.object:set_acceleration(vector.zero())
+			return
+		end
+	end
+end
+
+--return do_movement, do_detatched_movement
+return do_movement,do_detached_movement,handle_cart_enter
+

mods/ENTITIES/mcl_minecarts/rails.lua

@@ -1,53 +1,349 @@
-local S = minetest.get_translator(minetest.get_current_modname())
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+mod.RAIL_GROUPS = {
+	STANDARD = 1,
+	CURVES = 2,
+}
 
--- Template rail function
-local function register_rail(itemstring, tiles, def_extras, creative)
-	local groups = {handy=1,pickaxey=1, attached_node=1,rail=1,connect_to_raillike=minetest.raillike_group("rail"),dig_by_water=0,destroy_by_lava_flow=0, transport=1}
-	if creative == false then
-		groups.not_in_creative_inventory = 1
+-- Inport functions and constants from elsewhere
+local table_merge = mcl_util.table_merge
+local check_connection_rules = mod.check_connection_rules
+local update_rail_connections = mod.update_rail_connections
+local minetest_fourdir_to_dir = minetest.fourdir_to_dir
+local minetest_dir_to_fourdir = minetest.dir_to_fourdir
+local vector_offset = vector.offset
+local vector_equals = vector.equals
+local north = mod.north
+local south = mod.south
+local east = mod.east
+local west = mod.west
+
+--- Rail direction Handleres
+local function rail_dir_straight(pos, dir, node)
+	dir = vector.new(dir)
+	dir.y = 0
+
+	if node.param2 == 0 or node.param2 == 2 then
+		if vector_equals(dir, north) then
+			return north
+		else
+			return south
 		end
-	local ndef = {
-		drawtype = "raillike",
-		tiles = tiles,
-		is_ground_content = false,
-		inventory_image = tiles[1],
-		wield_image = tiles[1],
+	else
+		if vector_equals(dir,east) then
+			return east
+		else
+			return west
+		end
+	end
+end
+local function rail_dir_sloped(pos, dir, node)
+	local uphill = minetest_fourdir_to_dir(node.param2)
+	local downhill = minetest_fourdir_to_dir((node.param2+2)%4)
+	local up_uphill = vector_offset(uphill,0,1,0)
+
+	if vector_equals(dir, uphill) or vector_equals(dir, up_uphill) then
+		return up_uphill
+	else
+		return downhill
+	end
+end
+-- Fourdir to cardinal direction
+-- 0 = north
+-- 1 = east
+-- 2 = south
+-- 3 = west
+
+-- This takes a table `dirs` that has one element for each cardinal direction
+-- and which specifies the direction for a cart to continue in when entering
+-- a rail node in the direction of the cardinal. This function takes node
+-- rotations into account.
+local function rail_dir_from_table(pos, dir, node, dirs)
+	dir = vector.new(dir)
+	dir.y = 0
+	local dir_fourdir = (minetest_dir_to_fourdir(dir) - node.param2 + 4) % 4
+	local new_fourdir = (dirs[dir_fourdir] + node.param2) % 4
+	return minetest_fourdir_to_dir(new_fourdir)
+end
+
+local CURVE_RAIL_DIRS = { [0] = 1, 1, 2, 2, }
+local function rail_dir_curve(pos, dir, node)
+	return rail_dir_from_table(pos, dir, node, CURVE_RAIL_DIRS)
+end
+local function rail_dir_tee_off(pos, dir, node)
+	return rail_dir_from_table(pos, dir, node, CURVE_RAIL_DIRS)
+end
+
+local TEE_RAIL_ON_DIRS = { [0] = 0, 1, 1, 0 }
+local function rail_dir_tee_on(pos, dir, node)
+	return rail_dir_from_table(pos, dir, node, TEE_RAIL_ON_DIRS)
+end
+
+local function rail_dir_cross(pos, dir, node)
+	dir = vector.new(dir)
+	dir.y = 0
+
+	-- Always continue in the same direction. No direction changes allowed
+	return dir
+end
+
+-- Setup shared text
+local railuse = S(
+	"Place them on the ground to build your railway, the rails will automatically connect to each other and will"..
+	" turn into curves, T-junctions, crossings and slopes as needed."
+)
+mod.text = mod.text or {}
+mod.text.railuse = railuse
+local BASE_DEF = {
+	drawtype = "mesh",
+	mesh = "flat_track.obj",
 	paramtype = "light",
-		walkable = false,
+	paramtype2 = "4dir",
+	stack_max = 64,
+	sounds = mcl_sounds.node_sound_metal_defaults(),
+	is_ground_content = true,
+	paramtype = "light",
+	use_texture_alpha = "clip",
+	collision_box = {
+		type = "fixed",
+		fixed = { -8/16, -8/16, -8/16, 8/16, -7/16, 8/15 }
+	},
 	selection_box = {
 		type = "fixed",
 		fixed = {-1/2, -1/2, -1/2, 1/2, -1/2+1/16, 1/2},
 	},
-		stack_max = 64,
-		groups = groups,
-		sounds = mcl_sounds.node_sound_metal_defaults(),
-		_mcl_blast_resistance = 0.7,
-		_mcl_hardness = 0.7,
-		after_destruct = function(pos)
-			-- Scan for minecarts in this pos and force them to execute their "floating" check.
-			-- Normally, this will make them drop.
-			local objs = minetest.get_objects_inside_radius(pos, 1)
-			for o=1, #objs do
-				local le = objs[o]:get_luaentity()
-				if le then
-					-- All entities in this mod are minecarts, so this works
-					if string.sub(le.name, 1, 14) == "mcl_minecarts:" then
-						le._last_float_check = mcl_minecarts.check_float_time
-					end
-				end
+	groups = {
+		handy=1, pickaxey=1,
+		attached_node=1,
+		rail=1,
+		connect_to_raillike=minetest.raillike_group("rail"),
+		dig_by_water=0,destroy_by_lava_flow=0,
+		transport=1
+	},
+	description = S("New Rail"), -- Temporary name to make debugging easier
+	_tt_help = S("Track for minecarts"),
+	_doc_items_usagehelp = railuse,
+	_doc_items_longdesc = S("Rails can be used to build transport tracks for minecarts. Normal rails slightly slow down minecarts due to friction."),
+	on_place = function(itemstack, placer, pointed_thing)
+		local node_name = minetest.get_node(pointed_thing.under).name
+		-- Don't allow placing rail above rail
+		if minetest.get_item_group(node_name,"rail") == 0 then
+			return minetest.item_place_node(itemstack, placer, pointed_thing)
+		else
+			return itemstack
 		end
 	end,
+	after_place_node = function(pos, placer, itemstack, pointed_thing)
+		update_rail_connections(pos)
+	end,
+	_mcl_minecarts = {
+		get_next_dir = rail_dir_straight,
+	},
+	_mcl_blast_resistance = 0.7,
+	_mcl_hardness = 0.7,
+}
+
+local SLOPED_RAIL_DEF = table.copy(BASE_DEF)
+table_merge(SLOPED_RAIL_DEF,{
+	drawtype = "mesh",
+	mesh = "sloped_track.obj",
+	groups = {
+		rail_slope = 1,
+		not_in_creative_inventory = 1,
+	},
+	collision_box = {
+		type = "fixed",
+		fixed = {
+			{ -0.5, -0.5, -0.5,  0.5,  0.0,  0.5 },
+			{ -0.5,  0.0,  0.0,  0.5,  0.5,  0.5 }
 		}
-	if def_extras then
-		for k,v in pairs(def_extras) do
-			ndef[k] = v
-		end
-	end
+	},
+	selection_box = {
+		type = "fixed",
+		fixed = {
+			{ -0.5, -0.5, -0.5,  0.5,  0.0,  0.5 },
+			{ -0.5,  0.0,  0.0,  0.5,  0.5,  0.5 }
+		}
+	},
+	_mcl_minecarts = {
+		get_next_dir = rail_dir_sloped,
+	},
+})
+
+function mod.register_rail(itemstring, ndef)
+	assert(ndef.tiles)
+
+	-- Extract out the craft recipe
+	local craft = ndef.craft
+	ndef.craft = nil
+
+	-- Add sensible defaults
+	if not ndef.inventory_image then ndef.inventory_image = ndef.tiles[1] end
+	if not ndef.wield_image then ndef.wield_image = ndef.tiles[1] end
+
+	--print("registering rail "..itemstring.." with definition: "..dump(ndef))
+
+	-- Make registrations
+	minetest.register_node(itemstring, ndef)
+	if craft then minetest.register_craft(craft) end
+end
+
+function mod.register_straight_rail(base_name, tiles, def)
+	def = def or {}
+	local base_def = table.copy(BASE_DEF)
+	local sloped_def = table.copy(SLOPED_RAIL_DEF)
+	local add = {
+		tiles = { tiles[1] },
+		drop = base_name,
+		groups = {
+			rail = mod.RAIL_GROUPS.STANDARD,
+		},
+		_mcl_minecarts = {
+			base_name = base_name,
+			can_slope = true,
+		},
+	}
+	table_merge(base_def, add); table_merge(sloped_def, add)
+	table_merge(base_def, def); table_merge(sloped_def, def)
+
+	-- Register the base node
+	mod.register_rail(base_name, base_def)
+	base_def.craft = nil; sloped_def.craft = nil
+	table_merge(base_def,{
+		_mcl_minecarts = {
+			railtype = "straight",
+		},
+	})
+
+	-- Sloped variant
+	mod.register_rail_sloped(base_name.."_sloped", table_merge(table.copy(sloped_def),{
+		_mcl_minecarts = {
+			get_next_dir = rail_dir_sloped,
+		},
+		mesecons = def.mesecons_sloped,
+		tiles = { tiles[1] },
+		_mcl_minecarts = {
+			railtype = "sloped",
+		},
+	}))
+end
+
+function mod.register_curves_rail(base_name, tiles, def)
+	def = def or {}
+	local base_def = table.copy(BASE_DEF)
+	local sloped_def = table.copy(SLOPED_RAIL_DEF)
+	local add = {
+		_mcl_minecarts = { base_name = base_name },
+		groups = {
+			rail = mod.RAIL_GROUPS.CURVES
+		},
+		drop = base_name,
+	}
+	table_merge(base_def, add); table_merge(sloped_def, add)
+	table_merge(base_def, def); table_merge(sloped_def, def)
+
+	-- Register the base node
+	mod.register_rail(base_name, table_merge(table.copy(base_def),{
+		tiles = { tiles[1] },
+		_mcl_minecarts = {
+			get_next_dir = rail_dir_straight,
+			railtype = "straight",
+			can_slope = true,
+		},
+	}))
+
+	-- Update for other variants
+	base_def.craft = nil
+	table_merge(base_def, {
+		groups = {
+			not_in_creative_inventory = 1
+		}
+	})
+
+	-- Corner variants
+	mod.register_rail(base_name.."_corner", table_merge(table.copy(base_def),{
+		tiles = { tiles[2] },
+		_mcl_minecarts = {
+			get_next_dir = rail_dir_curve,
+			railtype = "corner",
+		},
+	}))
+
+	-- Tee variants
+	mod.register_rail(base_name.."_tee_off", table_merge(table.copy(base_def),{
+		tiles = { tiles[3] },
+		mesecons = {
+			effector = {
+				action_on = function(pos, node)
+					local new_node = {name = base_name.."_tee_on", param2 = node.param2}
+					minetest.swap_node(pos, new_node)
+				end,
+				rules = mesecon.rules.alldirs,
+			}
+		},
+		_mcl_minecarts = {
+			get_next_dir = rail_dir_tee_off,
+			railtype = "tee",
+		},
+	}))
+	mod.register_rail(base_name.."_tee_on", table_merge(table.copy(base_def),{
+		tiles = { tiles[4] },
+		_mcl_minecarts = {
+			get_next_dir = rail_dir_tee_on,
+			railtype = "tee",
+		},
+		mesecons = {
+			effector = {
+				action_off = function(pos, node)
+					local new_node = {name = base_name.."_tee_off", param2 = node.param2}
+					minetest.swap_node(pos, new_node)
+				end,
+				rules = mesecon.rules.alldirs,
+			}
+		}
+	}))
+
+	-- Sloped variant
+	mod.register_rail_sloped(base_name.."_sloped", table_merge(table.copy(sloped_def),{
+		description = S("Sloped Rail"), -- Temporary name to make debugging easier
+		_mcl_minecarts = {
+			get_next_dir = rail_dir_sloped,
+			railtype = "tee",
+		},
+		tiles = { tiles[1] },
+	}))
+
+	-- Cross variant
+	mod.register_rail(base_name.."_cross", table_merge(table.copy(base_def),{
+		tiles = { tiles[5] },
+		_mcl_minecarts = {
+			get_next_dir = rail_dir_cross,
+			railtype = "cross",
+		},
+	}))
+end
+
+function mod.register_rail_sloped(itemstring, def)
+	assert(def.tiles)
+
+	-- Build the node definition
+	local ndef = table.copy(SLOPED_RAIL_DEF)
+	table_merge(ndef, def)
+
+	-- Add sensible defaults
+	if not ndef.inventory_image then ndef.inventory_image = ndef.tiles[1] end
+	if not ndef.wield_image then ndef.wield_image = ndef.tiles[1] end
+
+	--print("registering sloped rail "..itemstring.." with definition: "..dump(ndef))
+
+	-- Make registrations
 	minetest.register_node(itemstring, ndef)
 end
 
 -- Redstone rules
-local rail_rules_long =
+mod.rail_rules_long =
 {{x=-1,  y= 0, z= 0, spread=true},
  {x= 1,  y= 0, z= 0, spread=true},
  {x= 0,  y=-1, z= 0, spread=true},
@@ -64,202 +360,96 @@ local rail_rules_long =
  {x= 0, y= 1, z=-1},
  {x= 0, y=-1, z=-1}}
 
-local rail_rules_short = mesecon.rules.pplate
-
-local railuse = S("Place them on the ground to build your railway, the rails will automatically connect to each other and will turn into curves, T-junctions, crossings and slopes as needed.")
-
--- Normal rail
-register_rail("mcl_minecarts:rail",
-	{"default_rail.png", "default_rail_curved.png", "default_rail_t_junction.png", "default_rail_crossing.png"},
-	{
-		description = S("Rail"),
-		_tt_help = S("Track for minecarts"),
-		_doc_items_longdesc = S("Rails can be used to build transport tracks for minecarts. Normal rails slightly slow down minecarts due to friction."),
-		_doc_items_usagehelp = railuse,
-	}
-)
-
--- Powered rail (off = brake mode)
-register_rail("mcl_minecarts:golden_rail",
-	{"mcl_minecarts_rail_golden.png", "mcl_minecarts_rail_golden_curved.png", "mcl_minecarts_rail_golden_t_junction.png", "mcl_minecarts_rail_golden_crossing.png"},
-	{
-		description = S("Powered Rail"),
-		_tt_help = S("Track for minecarts").."\n"..S("Speed up when powered, slow down when not powered"),
-		_doc_items_longdesc = S("Rails can be used to build transport tracks for minecarts. Powered rails are able to accelerate and brake minecarts."),
-		_doc_items_usagehelp = railuse .. "\n" .. S("Without redstone power, the rail will brake minecarts. To make this rail accelerate minecarts, power it with redstone power."),
-		_rail_acceleration = -3,
-		mesecons = {
-			conductor = {
-				state = mesecon.state.off,
-				offstate = "mcl_minecarts:golden_rail",
-				onstate = "mcl_minecarts:golden_rail_on",
-				rules = rail_rules_long,
-			},
-		},
-	}
-)
-
--- Powered rail (on = acceleration mode)
-register_rail("mcl_minecarts:golden_rail_on",
-	{"mcl_minecarts_rail_golden_powered.png", "mcl_minecarts_rail_golden_curved_powered.png", "mcl_minecarts_rail_golden_t_junction_powered.png", "mcl_minecarts_rail_golden_crossing_powered.png"},
-	{
-		_doc_items_create_entry = false,
-		_rail_acceleration = 4,
-		mesecons = {
-			conductor = {
-				state = mesecon.state.on,
-				offstate = "mcl_minecarts:golden_rail",
-				onstate = "mcl_minecarts:golden_rail_on",
-				rules = rail_rules_long,
-			},
-			effector = {
-				action_on = function(pos, node)
-					local dir = mcl_minecarts:get_start_direction(pos)
-					if not dir then return end
-					local objs = minetest.get_objects_inside_radius(pos, 1)
-					for _, o in pairs(objs) do
-						local l = o:get_luaentity()
-						local v = o:get_velocity()
-						if l and string.sub(l.name, 1, 14) == "mcl_minecarts:"
-						and v and vector.equals(v, vector.zero())
-						then
-							mcl_minecarts:set_velocity(l, dir)
-						end
-					end
-end,
-			},
-		},
-		drop = "mcl_minecarts:golden_rail",
-	},
-	false
-)
-
--- Activator rail (off)
-register_rail("mcl_minecarts:activator_rail",
-	{"mcl_minecarts_rail_activator.png", "mcl_minecarts_rail_activator_curved.png", "mcl_minecarts_rail_activator_t_junction.png", "mcl_minecarts_rail_activator_crossing.png"},
-	{
-		description = S("Activator Rail"),
-		_tt_help = S("Track for minecarts").."\n"..S("Activates minecarts when powered"),
-		_doc_items_longdesc = S("Rails can be used to build transport tracks for minecarts. Activator rails are used to activate special minecarts."),
-		_doc_items_usagehelp = railuse .. "\n" .. S("To make this rail activate minecarts, power it with redstone power and send a minecart over this piece of rail."),
-		mesecons = {
-			conductor = {
-				state = mesecon.state.off,
-				offstate = "mcl_minecarts:activator_rail",
-				onstate = "mcl_minecarts:activator_rail_on",
-				rules = rail_rules_long,
-
-			},
-		},
-	}
-)
-
--- Activator rail (on)
-register_rail("mcl_minecarts:activator_rail_on",
-	{"mcl_minecarts_rail_activator_powered.png", "mcl_minecarts_rail_activator_curved_powered.png", "mcl_minecarts_rail_activator_t_junction_powered.png", "mcl_minecarts_rail_activator_crossing_powered.png"},
-	{
-		_doc_items_create_entry = false,
-		mesecons = {
-			conductor = {
-				state = mesecon.state.on,
-				offstate = "mcl_minecarts:activator_rail",
-				onstate = "mcl_minecarts:activator_rail_on",
-				rules = rail_rules_long,
-			},
-			effector = {
-				-- Activate minecarts
-				action_on = function(pos, node)
-					local pos2 = { x = pos.x, y =pos.y + 1, z = pos.z }
-					local objs = minetest.get_objects_inside_radius(pos2, 1)
-					for _, o in pairs(objs) do
-						local l = o:get_luaentity()
-						if l and string.sub(l.name, 1, 14) == "mcl_minecarts:" and l.on_activate_by_rail then
-							l:on_activate_by_rail()
-						end
-					end
-				end,
-			},
-
-		},
-		drop = "mcl_minecarts:activator_rail",
-	},
-	false
-)
-
--- Detector rail (off)
-register_rail("mcl_minecarts:detector_rail",
-	{"mcl_minecarts_rail_detector.png", "mcl_minecarts_rail_detector_curved.png", "mcl_minecarts_rail_detector_t_junction.png", "mcl_minecarts_rail_detector_crossing.png"},
-	{
-		description = S("Detector Rail"),
-		_tt_help = S("Track for minecarts").."\n"..S("Emits redstone power when a minecart is detected"),
-		_doc_items_longdesc = S("Rails can be used to build transport tracks for minecarts. A detector rail is able to detect a minecart above it and powers redstone mechanisms."),
-		_doc_items_usagehelp = railuse .. "\n" .. S("To detect a minecart and provide redstone power, connect it to redstone trails or redstone mechanisms and send any minecart over the rail."),
-		mesecons = {
-			receptor = {
-				state = mesecon.state.off,
-				rules = rail_rules_short,
-			},
-		},
-	}
-)
-
--- Detector rail (on)
-register_rail("mcl_minecarts:detector_rail_on",
-	{"mcl_minecarts_rail_detector_powered.png", "mcl_minecarts_rail_detector_curved_powered.png", "mcl_minecarts_rail_detector_t_junction_powered.png", "mcl_minecarts_rail_detector_crossing_powered.png"},
-	{
-		_doc_items_create_entry = false,
-		mesecons = {
-			receptor = {
-				state = mesecon.state.on,
-				rules = rail_rules_short,
-			},
-		},
-		drop = "mcl_minecarts:detector_rail",
-	},
-	false
-)
-
-
--- Crafting
-minetest.register_craft({
-	output = "mcl_minecarts:rail 16",
-	recipe = {
-		{"mcl_core:iron_ingot", "", "mcl_core:iron_ingot"},
-		{"mcl_core:iron_ingot", "mcl_core:stick", "mcl_core:iron_ingot"},
-		{"mcl_core:iron_ingot", "", "mcl_core:iron_ingot"},
-	}
-})
-
-minetest.register_craft({
-	output = "mcl_minecarts:golden_rail 6",
-	recipe = {
-		{"mcl_core:gold_ingot", "", "mcl_core:gold_ingot"},
-		{"mcl_core:gold_ingot", "mcl_core:stick", "mcl_core:gold_ingot"},
-		{"mcl_core:gold_ingot", "mesecons:redstone", "mcl_core:gold_ingot"},
-	}
-})
-
-minetest.register_craft({
-	output = "mcl_minecarts:activator_rail 6",
-	recipe = {
-		{"mcl_core:iron_ingot", "mcl_core:stick", "mcl_core:iron_ingot"},
-		{"mcl_core:iron_ingot", "mesecons_torch:mesecon_torch_on", "mcl_core:iron_ingot"},
-		{"mcl_core:iron_ingot", "mcl_core:stick", "mcl_core:iron_ingot"},
-	}
-})
-
-minetest.register_craft({
-	output = "mcl_minecarts:detector_rail 6",
-	recipe = {
-		{"mcl_core:iron_ingot", "", "mcl_core:iron_ingot"},
-		{"mcl_core:iron_ingot", "mesecons_pressureplates:pressure_plate_stone_off", "mcl_core:iron_ingot"},
-		{"mcl_core:iron_ingot", "mesecons:redstone", "mcl_core:iron_ingot"},
-	}
-})
-
+dofile(modpath.."/rails/normal.lua")
+dofile(modpath.."/rails/activator.lua")
+dofile(modpath.."/rails/detector.lua")
+dofile(modpath.."/rails/powered.lua")
 
 -- Aliases
 if minetest.get_modpath("doc") then
 	doc.add_entry_alias("nodes", "mcl_minecarts:golden_rail", "nodes", "mcl_minecarts:golden_rail_on")
 end
 
+local CURVY_RAILS_MAP = {
+	["mcl_minecarts:rail"] = "mcl_minecarts:rail_v2",
+}
+for old,new in pairs(CURVY_RAILS_MAP) do
+	nodenames = mcl_util.table_keys(STRAIGHT_RAILS_MAP),
+	minetest.register_node(old, {
+		drawtype = "raillike",
+		inventory_image = new_def.inventory_image,
+		groups = { rail = 1 },
+		tiles = { new_def.tiles[1], new_def.tiles[1], new_def.tiles[1], new_def.tiles[1] },
+	})
+end
+minetest.register_lbm({
+	name = "mcl_minecarts:update_legacy_curvy_rails",
+	nodenames = mcl_util.table_keys(CURVY_RAILS_MAP),
+	action = function(pos, node)
+		node.name = CURVY_RAILS_MAP[node.name]
+		if node.name then
+			minetest.swap_node(pos, node)
+			mod.update_rail_connections(pos, { legacy = true, ignore_neighbor_connections = true })
+		end
+	end
+})
+local STRAIGHT_RAILS_MAP ={
+	["mcl_minecarts:golden_rail"] = "mcl_minecarts:golden_rail_v2",
+	["mcl_minecarts:golden_rail_on"] = "mcl_minecarts:golden_rail_v2_on",
+	["mcl_minecarts:activator_rail"] = "mcl_minecarts:activator_rail_v2",
+	["mcl_minecarts:activator_rail_on"] = "mcl_minecarts:activator_rail_v2_on",
+	["mcl_minecarts:detector_rail"] = "mcl_minecarts:detector_rail_v2",
+	["mcl_minecarts:detector_rail_on"] = "mcl_minecarts:detector_rail_v2_on",
+}
+for old,new in pairs(STRAIGHT_RAILS_MAP) do
+	local new_def = minetest.registered_nodes[new]
+	minetest.register_node(old, {
+		drawtype = "raillike",
+		inventory_image = new_def.inventory_image,
+		groups = { rail = 1 },
+		tiles = { new_def.tiles[1], new_def.tiles[1], new_def.tiles[1], new_def.tiles[1] },
+	})
+end
+local TRANSLATE_RAILS_MAP = table.copy(STRAIGHT_RAILS_MAP)
+table_merge(TRANSLATE_RAILS_MAP, CURVY_RAILS_MAP)
+
+minetest.register_lbm({
+	name = "mcl_minecarts:update_legacy_straight_rails",
+	nodenames = mcl_util.table_keys(STRAIGHT_RAILS_MAP),
+	run_at_every_load = true,
+	action = function(pos, node)
+		node.name = STRAIGHT_RAILS_MAP[node.name]
+		if node.name then
+			local connections = mod.get_rail_connections(pos, { legacy = true, ignore_neighbor_connections = true })
+			if not mod.HORIZONTAL_STANDARD_RULES[connections] then
+				-- Drop an immortal object at this location
+				local item_entity = minetest.add_item(pos, ItemStack(node.name))
+				if item_entity then
+					item_entity:get_luaentity()._immortal = true
+				end
+
+				-- This is a configuration that doesn't exist in the new rail
+				-- Replace with a standard rail
+				node.name = "mcl_minecarts:rail_v2"
+			end
+			minetest.swap_node(pos, node)
+			mod.update_rail_connections(pos, { legacy = true, ignore_neighbor_connections = true })
+		end
+	end
+})
+
+-- Convert old rail in the player's inventory to new rail
+minetest.register_on_joinplayer(function(player)
+	local inv = player:get_inventory()
+	local size = inv:get_size("main")
+	for i=1,size do
+		local stack = inv:get_stack("main", i)
+
+		local new_name = TRANSLATE_RAILS_MAP[stack:get_name()]
+		if new_name then
+			stack:set_name(new_name)
+			inv:set_stack("main", i, stack)
+		end
+	end
+end)
+

mods/ENTITIES/mcl_minecarts/rails/activator.lua

@@ -0,0 +1,87 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+
+-- Activator rail (off)
+mod.register_straight_rail("mcl_minecarts:activator_rail_v2", {"mcl_minecarts_rail_activator.png"},{
+	description = S("Activator Rail"),
+	_tt_help = S("Track for minecarts").."\n"..S("Activates minecarts when powered"),
+	_doc_items_longdesc = S("Rails can be used to build transport tracks for minecarts. Activator rails are used to activate special minecarts."),
+	_doc_items_usagehelp = mod.text.railuse .. "\n" .. S("To make this rail activate minecarts, power it with redstone power and send a minecart over this piece of rail."),
+	mesecons = {
+		conductor = {
+			state = mesecon.state.off,
+			offstate = "mcl_minecarts:activator_rail_v2",
+			onstate  = "mcl_minecarts:activator_rail_v2_on",
+			rules = mod.rail_rules_long,
+		},
+	},
+	mesecons_sloped = {
+		conductor = {
+			state = mesecon.state.off,
+			offstate = "mcl_minecarts:activator_rail_v2_sloped",
+			onstate  = "mcl_minecarts:activator_rail_v2_on_sloped",
+			rules = mod.rail_rules_long,
+		},
+	},
+	craft = {
+		output = "mcl_minecarts:activator_rail_v2 6",
+		recipe = {
+			{"mcl_core:iron_ingot", "mcl_core:stick", "mcl_core:iron_ingot"},
+			{"mcl_core:iron_ingot", "mesecons_torch:mesecon_torch_on", "mcl_core:iron_ingot"},
+			{"mcl_core:iron_ingot", "mcl_core:stick", "mcl_core:iron_ingot"},
+		}
+	},
+})
+
+-- Activator rail (on)
+local function activator_rail_action_on(pos, node)
+	local pos2 = { x = pos.x, y =pos.y + 1, z = pos.z }
+	local objs = minetest.get_objects_inside_radius(pos2, 1)
+	for _, o in pairs(objs) do
+		local l = o:get_luaentity()
+		if l and string.sub(l.name, 1, 14) == "mcl_minecarts:" and l.on_activate_by_rail then
+			l:on_activate_by_rail()
+		end
+	end
+end
+mod.register_straight_rail("mcl_minecarts:activator_rail_v2_on", {"mcl_minecarts_rail_activator_powered.png"},{
+	_doc_items_create_entry = false,
+	groups = {
+		not_in_creative_inventory = 1,
+	},
+	mesecons = {
+		conductor = {
+			state = mesecon.state.on,
+			offstate = "mcl_minecarts:activator_rail_v2",
+			onstate  = "mcl_minecarts:activator_rail_v2_on",
+			rules = mod.rail_rules_long,
+		},
+		effector = {
+			-- Activate minecarts
+			action_on = activator_rail_action_on,
+		},
+
+	},
+	mesecons_sloped = {
+		conductor = {
+			state = mesecon.state.on,
+			offstate = "mcl_minecarts:activator_rail_v2_sloped",
+			onstate  = "mcl_minecarts:activator_rail_v2_on_sloped",
+			rules = mod.rail_rules_long,
+		},
+		effector = {
+			-- Activate minecarts
+			action_on = activator_rail_action_on,
+		},
+
+	},
+	_mcl_minecarts_on_enter = function(pos, cart)
+		if cart.on_activate_by_rail then
+			cart:on_activate_by_rail()
+		end
+	end,
+	drop = "mcl_minecarts:activator_rail_v2",
+})
+

mods/ENTITIES/mcl_minecarts/rails/detector.lua

@@ -0,0 +1,64 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+
+local rail_rules_short = mesecon.rules.pplate
+
+-- Detector rail (off)
+mod.register_straight_rail("mcl_minecarts:detector_rail_v2",{"mcl_minecarts_rail_detector.png"},{
+	description = S("Detector Rail"),
+	_tt_help = S("Track for minecarts").."\n"..S("Emits redstone power when a minecart is detected"),
+	_doc_items_longdesc = S("Rails can be used to build transport tracks for minecarts. A detector rail is able to detect a minecart above it and powers redstone mechanisms."),
+	_doc_items_usagehelp = mod.text.railuse .. "\n" .. S("To detect a minecart and provide redstone power, connect it to redstone trails or redstone mechanisms and send any minecart over the rail."),
+	mesecons = {
+		receptor = {
+			state = mesecon.state.off,
+			rules = rail_rules_short,
+		},
+	},
+	_mcl_minecarts_on_enter = function(pos, cart)
+		local node = minetest.get_node(pos)
+
+		local newnode = {
+			name = "mcl_minecarts:detector_rail_v2_on",
+			param2 = node.param2
+		}
+		minetest.swap_node( pos, newnode )
+		mesecon.receptor_on(pos)
+	end,
+	craft = {
+		output = "mcl_minecarts:detector_rail_v2 6",
+		recipe = {
+			{"mcl_core:iron_ingot", "", "mcl_core:iron_ingot"},
+			{"mcl_core:iron_ingot", "mesecons_pressureplates:pressure_plate_stone_off", "mcl_core:iron_ingot"},
+			{"mcl_core:iron_ingot", "mesecons:redstone", "mcl_core:iron_ingot"},
+		}
+	}
+})
+
+-- Detector rail (on)
+mod.register_straight_rail("mcl_minecarts:detector_rail_v2_on",{"mcl_minecarts_rail_detector_powered.png"},{
+	groups = {
+		not_in_creative_inventory = 1,
+	},
+	_doc_items_create_entry = false,
+	mesecons = {
+		receptor = {
+			state = mesecon.state.on,
+			rules = rail_rules_short,
+		},
+	},
+	_mcl_minecarts_on_leave = function(pos, cart)
+		local node = minetest.get_node(pos)
+
+		local newnode = {
+			name = "mcl_minecarts:detector_rail",
+			param2 = node.param2
+		}
+		minetest.swap_node( pos, newnode )
+		mesecon.receptor_off(pos)
+	end,
+	drop = "mcl_minecarts:detector_rail_v2",
+})
+

mods/ENTITIES/mcl_minecarts/rails/normal.lua

@@ -0,0 +1,27 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+
+-- Normal rail
+mod.register_curves_rail("mcl_minecarts:rail_v2", {
+	"default_rail.png", 
+	"default_rail_curved.png",
+	"default_rail_t_junction.png",
+	"default_rail_t_junction_on.png",
+	"default_rail_crossing.png"
+},{
+	description = S("Rail"),
+	_tt_help = S("Track for minecarts"),
+	_doc_items_longdesc = S("Rails can be used to build transport tracks for minecarts. Normal rails slightly slow down minecarts due to friction."),
+	_doc_items_usagehelp = mod.text.railuse,
+	craft = {
+		output = "mcl_minecarts:rail_v2 16",
+		recipe = {
+			{"mcl_core:iron_ingot", "", "mcl_core:iron_ingot"},
+			{"mcl_core:iron_ingot", "mcl_core:stick", "mcl_core:iron_ingot"},
+			{"mcl_core:iron_ingot", "", "mcl_core:iron_ingot"},
+		}
+	},
+})
+

mods/ENTITIES/mcl_minecarts/rails/powered.lua

@@ -0,0 +1,69 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+local S = minetest.get_translator(modname)
+
+-- Powered rail (off = brake mode)
+mod.register_straight_rail("mcl_minecarts:golden_rail_v2",{ "mcl_minecarts_rail_golden.png" },{
+	description = S("Powered Rail"),
+	_tt_help = S("Track for minecarts").."\n"..S("Speed up when powered, slow down when not powered"),
+	_doc_items_longdesc = S("Rails can be used to build transport tracks for minecarts. Powered rails are able to accelerate and brake minecarts."),
+	_doc_items_usagehelp = mod.text.railuse .. "\n" .. S("Without redstone power, the rail will brake minecarts. To make this rail accelerate"..
+		" minecarts, power it with redstone power."),
+	_doc_items_create_entry = false,
+	_rail_acceleration = -3,
+	_max_acceleration_velocity = 8,
+	mesecons = {
+		conductor = {
+			state = mesecon.state.off,
+			offstate = "mcl_minecarts:golden_rail_v2",
+			onstate  = "mcl_minecarts:golden_rail_v2_on",
+			rules = mod.rail_rules_long,
+		},
+	},
+	mesecons_sloped = {
+		conductor = {
+			state = mesecon.state.off,
+			offstate = "mcl_minecarts:golden_rail_v2_sloepd",
+			onstate  = "mcl_minecarts:golden_rail_v2_on_sloped",
+			rules = mod.rail_rules_long,
+		},
+	},
+	drop = "mcl_minecarts:golden_rail_v2",
+	craft = {
+		output = "mcl_minecarts:golden_rail_v2 6",
+		recipe = {
+			{"mcl_core:gold_ingot", "", "mcl_core:gold_ingot"},
+			{"mcl_core:gold_ingot", "mcl_core:stick", "mcl_core:gold_ingot"},
+			{"mcl_core:gold_ingot", "mesecons:redstone", "mcl_core:gold_ingot"},
+		}
+	}
+})
+
+-- Powered rail (on = acceleration mode)
+mod.register_straight_rail("mcl_minecarts:golden_rail_v2_on",{ "mcl_minecarts_rail_golden_powered.png" },{
+	_doc_items_create_entry = false,
+	_rail_acceleration = 4,
+	_max_acceleration_velocity = 8,
+	groups = {
+		not_in_creative_inventory = 1,
+	},
+	mesecons = {
+		conductor = {
+			state = mesecon.state.on,
+			offstate = "mcl_minecarts:golden_rail_v2",
+			onstate  = "mcl_minecarts:golden_rail_v2_on",
+			rules = mod.rail_rules_long,
+		},
+	},
+	mesecons_sloped = {
+		conductor = {
+			state = mesecon.state.on,
+			offstate = "mcl_minecarts:golden_rail_v2_sloped",
+			onstate  = "mcl_minecarts:golden_rail_v2_on_sloped",
+			rules = mod.rail_rules_long,
+		},
+	},
+	drop = "mcl_minecarts:golden_rail_v2",
+})
+

mods/ENTITIES/mcl_minecarts/storage.lua

@@ -0,0 +1,92 @@
+local storage = minetest.get_mod_storage()
+local mod = mcl_minecarts
+
+-- Imports
+local CART_BLOCK_SIZE = mod.CART_BLOCK_SIZE
+assert(CART_BLOCK_SIZE)
+
+local cart_data = {}
+local cart_data_fail_cache = {}
+local cart_ids = storage:get_keys()
+
+local function get_cart_data(uuid)
+	if cart_data[uuid] then return cart_data[uuid] end
+	if cart_data_fail_cache[uuid] then return nil end
+
+	local data = minetest.deserialize(storage:get_string("cart-"..uuid))
+	if not data then
+		cart_data_fail_cache[uuid] = true
+		return nil
+	else
+		-- Repair broken data
+		if not data.distance then data.distance = 0 end
+		if data.distance == 0/0 then data.distance = 0 end
+		if data.distance == -0/0 then data.distance = 0 end
+		data.dir = vector.new(data.dir)
+		data.connected_at = vector.new(data.connected_at)
+	end
+
+	cart_data[uuid] = data
+	return data
+end
+mod.get_cart_data = get_cart_data
+
+-- Preload all cart data into memory
+for _,id in pairs(cart_ids) do
+	local uuid = string.sub(id,6)
+	get_cart_data(uuid)
+end
+
+local function save_cart_data(uuid)
+	if not cart_data[uuid] then return end
+	storage:set_string("cart-"..uuid,minetest.serialize(cart_data[uuid]))
+end
+mod.save_cart_data = save_cart_data
+
+function mod.update_cart_data(data)
+	local uuid = data.uuid
+	cart_data[uuid] = data
+	cart_data_fail_cache[uuid] = nil
+	save_cart_data(uuid)
+end
+function mod.destroy_cart_data(uuid)
+	storage:set_string("cart-"..uuid,"")
+	cart_data[uuid] = nil
+	cart_data_fail_cache[uuid] = true
+end
+
+function mod.carts()
+	return pairs(cart_data)
+end
+
+function mod.find_carts_by_block_map(block_map)
+	local cart_list = {}
+	for _,data in pairs(cart_data) do
+		if data and data.connected_at then
+			local pos = mod.get_cart_position(data)
+			local block = vector.floor(vector.divide(pos,CART_BLOCK_SIZE))
+			if block_map[vector.to_string(block)] then
+				cart_list[#cart_list + 1] = data
+			end
+		end
+	end
+	return cart_list
+end
+
+function mod.add_blocks_to_map(block_map, min_pos, max_pos)
+	local min = vector.floor(vector.divide(min_pos, CART_BLOCK_SIZE))
+	local max = vector.floor(vector.divide(max_pos, CART_BLOCK_SIZE)) + vector.new(1,1,1)
+	for z = min.z,max.z do
+		for y = min.y,max.y do
+			for x = min.x,max.x do
+				block_map[ vector.to_string(vector.new(x,y,z)) ] = true
+			end
+		end
+	end
+end
+
+minetest.register_on_shutdown(function()
+	for uuid,_ in pairs(cart_data) do
+		save_cart_data(uuid)
+	end
+end)

mods/ENTITIES/mcl_minecarts/train.lua

@@ -0,0 +1,155 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+local mod = mcl_minecarts
+
+-- Imports
+local get_cart_data = mod.get_cart_data
+local save_cart_data = mod.save_cart_data
+local MAX_TRAIN_LENGTH = mod.MAX_TRAIN_LENGTH
+
+-- Follow .behind to the back end of a train
+local function find_back(start)
+	assert(start)
+
+	while start.behind do
+		local nxt = get_cart_data(start.behind)
+		if not nxt then return start end
+		start = nxt
+	end
+	return start
+end
+
+-- Iterate across all the cars in a train
+local function train_cars(staticdata)
+	assert(staticdata)
+
+	local back = find_back(staticdata)
+	local limit = MAX_TRAIN_LENGTH
+	return function()
+		if not back or limit <= 0 then return end
+		limit = limit - 1
+
+		local ret = back
+		if back.ahead then
+			back = get_cart_data(back.ahead)
+		else
+			back = nil
+		end
+		return ret
+	end
+end
+function mod.train_length(cart)
+	local count = 0
+	for cart in train_cars(cart) do
+		count = count + 1
+	end
+	return count
+end
+
+function mod.is_in_same_train(anchor, other)
+	for cart in train_cars(anchor) do
+		if cart.uuid == other.uuid then return true end
+	end
+	return false
+end
+
+function mod.distance_between_cars(car1, car2)
+	if not car1.connected_at then return nil end
+	if not car2.connected_at then return nil end
+
+	if not car1.dir then car1.dir = vector.zero() end
+	if not car2.dir then car2.dir = vector.zero() end
+
+	local pos1 = vector.add(car1.connected_at, vector.multiply(car1.dir, car1.distance))
+	local pos2 = vector.add(car2.connected_at, vector.multiply(car2.dir, car2.distance))
+
+	return vector.distance(pos1, pos2)
+end
+local distance_between_cars = mod.distance_between_cars
+
+local function break_train_at(cart)
+	if cart.ahead then
+		local ahead = get_cart_data(cart.ahead)
+		if ahead then
+			ahead.behind = nil
+			cart.ahead = nil
+			save_cart_data(ahead.uuid)
+		end
+	end
+	if cart.behind then
+		local behind = get_cart_data(cart.behind)
+		if behind then
+			behind.ahead = nil
+			cart.behind = nil
+			save_cart_data(behind.uuid)
+		end
+	end
+	save_cart_data(cart.uuid)
+end
+mod.break_train_at = break_train_at
+
+function mod.update_train(staticdata)
+	--local staticdata = cart._staticdata
+
+	-- Only update from the back
+	if staticdata.behind or not staticdata.ahead then return end
+	--print("\nUpdating train")
+
+	-- Do no special processing if the cart is not part of a train
+	if not staticdata.ahead and not staticdata.behind then return end
+
+	-- Calculate the maximum velocity of all train cars
+	local velocity = 0
+	local count = 0
+	for cart in train_cars(staticdata) do
+		velocity = velocity + (cart.velocity or 0)
+		count = count + 1
+	end
+	velocity = velocity / count
+	--print("Using velocity "..tostring(velocity))
+
+	-- Set the entire train to the average velocity
+	local behind = nil
+	for c in train_cars(staticdata) do
+		local e = 0
+		local separation
+		local cart_velocity = velocity
+		if not c.connected_at then
+			break_train_at(c)
+		elseif behind then
+			separation = distance_between_cars(behind, c)
+			local e = 0
+			if not separation then
+				break_train_at(c)
+			elseif separation > 1.6 then
+				cart_velocity = velocity * 0.9
+			elseif separation > 2.5 then
+				break_train_at(c)
+			elseif separation < 1.15 then
+				cart_velocity = velocity * 1.1
+			end
+		end
+		--[[
+		print(tostring(c.behind).."->"..c.uuid.."->"..tostring(c.ahead).."("..tostring(separation)..")  setting cart #"..
+			c.uuid.." velocity from "..tostring(c.velocity).." to "..tostring(cart_velocity))
+		]]
+		c.velocity = cart_velocity
+
+		behind = c
+	end
+end
+
+function mod.link_cart_ahead(staticdata, ca_staticdata)
+	minetest.log("action","Linking cart #"..staticdata.uuid.." to cart #"..ca_staticdata.uuid)
+
+	staticdata.ahead = ca_staticdata.uuid
+	ca_staticdata.behind = staticdata.uuid
+end
+
+function mod.reverse_train(cart)
+	for c in train_cars(cart) do
+		mod.reverse_cart_direction(c)
+		c.behind,c.ahead = c.ahead,c.behind
+	end
+end
+

mods/HUD/mcl_inventory/creative.lua

@@ -386,7 +386,7 @@ local tab_icon = {
 	blocks = "mcl_core:brick_block",
 	deco = "mcl_flowers:peony",
 	redstone = "mesecons:redstone",
-	rail = "mcl_minecarts:golden_rail",
+	rail = "mcl_minecarts:golden_rail_v2",
 	misc = "mcl_buckets:bucket_lava",
 	nix = "mcl_compass:compass",
 	food = "mcl_core:apple",

mods/ITEMS/REDSTONE/mcl_comparators/init.lua

@@ -1,4 +1,6 @@
 local S = minetest.get_translator(minetest.get_current_modname())
+mcl_comparators = {}
+local mod = mcl_comparators
 
 -- Functions that get the input/output rules of the comparator
 
@@ -10,7 +12,6 @@ local function comparator_get_output_rules(node)
 	return rules
 end
 
-
 local function comparator_get_input_rules(node)
 	local rules = {
 		-- we rely on this order in update_self below
@@ -24,117 +25,105 @@ local function comparator_get_input_rules(node)
 	return rules
 end
 
-
--- Functions that are called after the delay time
-
-local function comparator_turnon(params)
-	local rules = comparator_get_output_rules(params.node)
-	mesecon.receptor_on(params.pos, rules)
-end
-
-
-local function comparator_turnoff(params)
-	local rules = comparator_get_output_rules(params.node)
-	mesecon.receptor_off(params.pos, rules)
-end
-
-
--- Functions that set the correct node type an schedule a turnon/off
-
-local function comparator_activate(pos, node)
-	local def = minetest.registered_nodes[node.name]
-	local onstate = def.comparator_onstate
-	if onstate then
-		minetest.swap_node(pos, { name = onstate, param2 = node.param2 })
-	end
-	minetest.after(0.1, comparator_turnon , {pos = pos, node = node})
-end
-
-
-local function comparator_deactivate(pos, node)
-	local def = minetest.registered_nodes[node.name]
-	local offstate = def.comparator_offstate
-	if offstate then
-		minetest.swap_node(pos, { name = offstate, param2 = node.param2 })
-	end
-	minetest.after(0.1, comparator_turnoff, {pos = pos, node = node})
-end
-
-
--- weather pos has an inventory that contains at least one item
-local function container_inventory_nonempty(pos)
-	local invnode = minetest.get_node(pos)
-	local invnodedef = minetest.registered_nodes[invnode.name]
-	-- Ignore stale nodes
-	if not invnodedef then return false end
-
-	-- Only accept containers. When a container is dug, it's inventory
-	-- seems to stay. and we don't want to accept the inventory of an air
-	-- block
-	if not invnodedef.groups.container then return false end
-
-	local inv = minetest.get_inventory({type="node", pos=pos})
-	if not inv then return false end
-
-	for listname, _ in pairs(inv:get_lists()) do
-		if not inv:is_empty(listname) then return true end
-	end
-
-	return false
-end
-
--- weather pos has an constant signal output for the comparator
-local function static_signal_output(pos)
-	local node = minetest.get_node(pos)
-	local g = minetest.get_item_group(node.name, "comparator_signal")
-	return g > 0
-end
-
--- whether the comparator should be on according to its inputs
-local function comparator_desired_on(pos, node)
-	local my_input_rules = comparator_get_input_rules(node);
-	local back_rule = my_input_rules[1]
-	local state
-	if back_rule then
-		local back_pos = vector.add(pos, back_rule)
-		state = mesecon.is_power_on(back_pos) or container_inventory_nonempty(back_pos) or static_signal_output(back_pos)
-	end
-
-	-- if back input if off, we don't need to check side inputs
-	if not state then return false end
-
-	-- without power levels, side inputs have no influence on output in compare
-	-- mode
-	local mode = minetest.registered_nodes[node.name].comparator_mode
-	if mode == "comp" then return state end
-
-	-- subtract mode, subtract max(side_inputs) from back input
-	local side_state = false
-	for ri = 2,3 do
-		if my_input_rules[ri] then
-			side_state = mesecon.is_power_on(vector.add(pos, my_input_rules[ri]))
-		end
-		if side_state then break end
-	end
-	-- state is known to be true
-	return not side_state
-end
-
-
+local POSSIBLE_COMPARATOR_POSITIONS = {
+	vector.new( 1,0, 0),
+	vector.new(-1,0, 0),
+	vector.new( 0,0, 1),
+	vector.new( 0,0,-1),
+}
 -- update comparator state, if needed
 local function update_self(pos, node)
+	print("Updating comparator at "..vector.to_string(pos))
 	node = node or minetest.get_node(pos)
-	local old_state = mesecon.is_receptor_on(node.name)
-	local new_state = comparator_desired_on(pos, node)
-	if new_state ~= old_state then
-		if new_state then
-			comparator_activate(pos, node)
+	local nodedef = minetest.registered_nodes[node.name]
+
+	-- Find the node we are pointing at
+	local input_rules = comparator_get_input_rules(node);
+	local back_rule = input_rules[1]
+	local back_pos = vector.add(pos, back_rule)
+	local back_node = minetest.get_node(back_pos)
+	local back_nodedef = minetest.registered_nodes[back_node.name]
+
+	-- Get the comparator mode
+	local mode = nodedef.comparator_mode
+
+	-- Get a comparator reading from the block at the back of the comparator
+	local power_level = 0
+	if back_nodedef and back_nodedef._mcl_comparators_get_reading then
+		power_level = back_nodedef._mcl_comparators_get_reading(back_pos)
 	else
-			comparator_deactivate(pos, node)
+		power_level = vl_redstone.get_power(back_pos)
+	end
+
+	-- Get the maximum side power level
+	local side_power_level = 0
+	for i=2,3 do
+		local pl = vl_redstone.get_power(vector.add(pos,input_rules[i]))
+		if pl > side_power_level then
+			side_power_level = pl
+		end
+	end
+
+	-- Apply subtraction or comparison
+	if mode == "sub" then
+		power_level = power_level - side_power_level
+		if power_level < 0 then power_level = 0 end
+	elseif mode == "comp" then
+		if side_power_level > power_level then
+			power_level = 0
+		end
+	end
+
+	-- Update output power level
+	vl_redstone.set_power(pos, power_level)
+
+	-- Update node
+	if power_level ~= 0 then
+		node.name = nodedef.comparator_onstate
+		minetest.swap_node(pos, node)
+	else
+		node.name = nodedef.comparator_offstate
+		minetest.swap_node(pos, node)
+	end
+end
+
+local node_readings = {}
+function mod.trigger_update(pos, node)
+	local node = node or minetest.get_node(pos)
+	local nodedef = minetest.registered_nodes[node.name] or {}
+
+	-- If this position can't provide a comparator reading, we should
+	-- never trigger a comparator update
+	local get_reading = nodedef._mcl_comparators_get_reading
+	if not get_reading then return end
+
+	-- Only update if the reading has changed
+	local pos_hash = minetest.hash_node_position(pos)
+	local old_reading = node_readings[pos_hash]
+	local new_reading = get_reading(pos)
+	if old_reading == new_reading then return end
+	node_readings[pos_hash] = new_reading
+
+	-- try to find a comparator with the back rule leading to pos
+	for i = 1,#POSSIBLE_COMPARATOR_POSITIONS do
+		local candidate = vector.add(pos, POSSIBLE_COMPARATOR_POSITIONS[i])
+		local node = minetest.get_node(candidate)
+		if minetest.get_item_group(node.name,"mcl_comparator") ~= 0 then
+			update_self(candidate, node)
 		end
 	end
 end
 
+function mod.read_inventory(inv, inv_name)
+	local stacks = inv:get_list(inv_name)
+	if not stacks then return 0 end
+
+	local count = 0
+	for i=1,#stacks do
+		count = count + ( stacks[i]:get_count() / stacks[i]:get_stack_max() )
+	end
+	return math.floor(count * 16 / #stacks)
+end
 
 -- compute tile depending on state and mode
 local function get_tiles(state, mode)
@@ -215,6 +204,7 @@ local groups = {
 	destroy_by_lava_flow = 1,
 	dig_by_piston = 1,
 	attached_node = 1,
+	mcl_comparator = 1,
 }
 
 local on_rotate
@@ -309,7 +299,7 @@ for _, mode in pairs{"comp", "sub"} do
 		end
 
 		minetest.register_node(nodename, nodedef)
-		mcl_wip.register_wip_item(nodename)
+		--mcl_wip.register_wip_item(nodename)
 	end
 end
 
@@ -327,6 +317,7 @@ minetest.register_craft({
 	}
 })
 
+--[[
 -- Register active block handlers
 minetest.register_abm({
 	label = "Comparator signal input check (comparator is off)",
@@ -352,7 +343,7 @@ minetest.register_abm({
 	chance = 1,
 	action = update_self,
 })
-
+]]
 
 -- Add entry aliases for the Help
 if minetest.get_modpath("doc") then

mods/ITEMS/REDSTONE/mcl_comparators/mod.conf

@@ -1,3 +1,3 @@
 name = mcl_comparators
-depends = mcl_wip, mesecons, mcl_sounds
+depends = mesecons, mcl_sounds, vl_redstone
 optional_depends = doc, screwdriver

mods/ITEMS/REDSTONE/mcl_droppers/init.lua

@@ -129,9 +129,9 @@ local dropperdef = {
 				-- If they are containers - double down as hopper
 				mcl_util.hopper_push(pos, droppos)
 			end
-			if dropnodedef.walkable then
-				return
-			end
+			if dropnodedef.walkable then return end
+
+			-- Build a list of items in the dropper
 			local stacks = {}
 			for i = 1, inv:get_size("main") do
 				local stack = inv:get_stack("main", i)
@@ -139,12 +139,32 @@ local dropperdef = {
 					table.insert(stacks, { stack = stack, stackpos = i })
 				end
 			end
+
+			-- Pick an item to drop
+			local dropitem = nil
+			local stack = nil
+			local r = nil
 			if #stacks >= 1 then
-				local r = math.random(1, #stacks)
-				local stack = stacks[r].stack
-				local dropitem = ItemStack(stack)
+				r = math.random(1, #stacks)
+				stack = stacks[r].stack
+				dropitem = ItemStack(stack)
 				dropitem:set_count(1)
-				local stack_id = stacks[r].stackpos
+			end
+			if not dropitem then return end
+
+			-- Flag for if the item was dropped. If true the item will be removed from
+			-- the inventory after dropping
+			local item_dropped = false
+
+			-- Check if the drop item has a custom handler
+			local itemdef = minetest.registered_craftitems[dropitem:get_name()]
+			if itemdef._mcl_dropper_on_drop then
+				item_dropped = itemdef._mcl_dropper_on_drop(dropitem, droppos)
+			end
+
+			-- If a custom handler wasn't successful then drop the item as an entity
+			if not item_dropped then
+				-- Drop as entity
 				local pos_variation = 100
 				droppos = vector.offset(droppos,
 					math.random(-pos_variation, pos_variation) / 1000,
@@ -156,6 +176,12 @@ local dropperdef = {
 				local speed = 3
 				item_entity:set_velocity(vector.multiply(drop_vel, speed))
 				stack:take_item()
+				item_dropped = trie
+			end
+
+			-- Remove dropped items from inventory
+			if item_dropped then
+				local stack_id = stacks[r].stackpos
 				inv:set_stack("main", stack_id, stack)
 			end
 		end,

mods/ITEMS/REDSTONE/mesecons/actionqueue.lua

@@ -58,9 +58,11 @@ local function get_highest_priority(actions)
 	return highesti
 end
 
+--[[
 local m_time = 0
 local resumetime = mesecon.setting("resumetime", 4)
 minetest.register_globalstep(function (dtime)
+
 	m_time = m_time + dtime
 	-- don't even try if server has not been running for XY seconds; resumetime = time to wait
 	-- after starting the server before processing the ActionQueue, don't set this too low
@@ -87,6 +89,7 @@ minetest.register_globalstep(function (dtime)
 		table.remove(actions_now, hp)
 	end
 end)
+]]
 
 function mesecon.queue:execute(action)
 	if not action.pos then return end

mods/ITEMS/REDSTONE/mesecons/init.lua

@@ -87,7 +87,9 @@ mesecon.queue:add_function("receptor_on", function (pos, rules)
 end)
 
 function mesecon.receptor_on(pos, rules)
-	mesecon.queue:add_action(pos, "receptor_on", {rules}, nil, rules)
+	print("receptor_on(pos="..vector.to_string(pos)..",rules="..dump(rules))
+	print(debug.traceback())
+	--mesecon.queue:add_action(pos, "receptor_on", {rules}, nil, rules)
 end
 
 mesecon.queue:add_function("receptor_off", function (pos, rules)
@@ -114,7 +116,9 @@ mesecon.queue:add_function("receptor_off", function (pos, rules)
 end)
 
 function mesecon.receptor_off(pos, rules)
-	mesecon.queue:add_action(pos, "receptor_off", {rules}, nil, rules)
+	print("receptor_off(pos="..vector.to_string(pos)..",rules="..dump(rules))
+	print(debug.traceback())
+	--mesecon.queue:add_action(pos, "receptor_off", {rules}, nil, rules)
 end
 
 --Services like turnoff receptor on dignode and so on

mods/ITEMS/REDSTONE/mesecons/services.lua

@@ -2,6 +2,7 @@
 
 function mesecon.on_placenode(pos, node)
 	mesecon.execute_autoconnect_hooks_now(pos, node)
+	--[[
 
 	-- Receptors: Send on signal when active
 	if mesecon.is_receptor_on(node.name) then
@@ -68,6 +69,7 @@ function mesecon.on_placenode(pos, node)
 			end
 		end
 	end
+	]]
 end
 
 function mesecon.on_dignode(pos, node)
@@ -103,7 +105,7 @@ function mesecon.on_blastnode(pos, node)
 end
 
 minetest.register_on_placenode(mesecon.on_placenode)
-minetest.register_on_dignode(mesecon.on_dignode)
+--minetest.register_on_dignode(mesecon.on_dignode)
 
 -- Overheating service for fast circuits
 local OVERHEAT_MAX = mesecon.setting("overheat_max", 8)

mods/ITEMS/REDSTONE/mesecons_commandblock/api.lua

@@ -0,0 +1,227 @@
+mesecon = mesecon or {}
+local mod = {}
+mesecon.commandblock = mod
+
+local S = minetest.get_translator(minetest.get_current_modname())
+local F = minetest.formspec_escape
+local color_red = mcl_colors.RED
+
+mod.initialize = function(meta)
+	meta:set_string("commands", "")
+	meta:set_string("commander", "")
+end
+
+mod.place = function(meta, placer)	
+	if not placer then return end
+
+	meta:set_string("commander", placer:get_player_name())
+end
+
+mod.resolve_commands = function(commands, meta, pos)
+	local players = minetest.get_connected_players()
+	local commander = meta:get_string("commander")
+
+	-- A non-printable character used while replacing “@@”.
+	local SUBSTITUTE_CHARACTER = "\26" -- ASCII SUB
+
+	-- No players online: remove all commands containing
+	-- problematic placeholders.
+	if #players == 0 then
+		commands = commands:gsub("[^\r\n]+", function (line)
+			line = line:gsub("@@", SUBSTITUTE_CHARACTER)
+			if line:find("@n") then return "" end
+			if line:find("@p") then return "" end
+			if line:find("@f") then return "" end
+			if line:find("@r") then return "" end
+			line = line:gsub("@c", commander)
+			line = line:gsub(SUBSTITUTE_CHARACTER, "@")
+			return line
+		end)
+		return commands
+	end
+
+	local nearest, farthest = nil, nil
+	local min_distance, max_distance = math.huge, -1
+	for index, player in pairs(players) do
+		local distance = vector.distance(pos, player:get_pos())
+		if distance < min_distance then
+			min_distance = distance
+			nearest = player:get_player_name()
+		end
+		if distance > max_distance then
+			max_distance = distance
+			farthest = player:get_player_name()
+		end
+	end
+	local random = players[math.random(#players)]:get_player_name()
+	commands = commands:gsub("@@", SUBSTITUTE_CHARACTER)
+	commands = commands:gsub("@p", nearest)
+	commands = commands:gsub("@n", nearest)
+	commands = commands:gsub("@f", farthest)
+	commands = commands:gsub("@r", random)
+	commands = commands:gsub("@c", commander)
+	commands = commands:gsub(SUBSTITUTE_CHARACTER, "@")
+	return commands
+end
+local resolve_commands = mod.resolve_commands
+
+mod.check_commands = function(commands, player_name)
+	for _, command in pairs(commands:split("\n")) do
+		local pos = command:find(" ")
+		local cmd = command
+		if pos then
+			cmd = command:sub(1, pos - 1)
+		end
+		local cmddef = minetest.chatcommands[cmd]
+		if not cmddef then
+			-- Invalid chat command
+			local msg = S("Error: The command “@1” does not exist; your command block has not been changed. Use the “help” chat command for a list of available commands.", cmd)
+			if string.sub(cmd, 1, 1) == "/" then
+				msg = S("Error: The command “@1” does not exist; your command block has not been changed. Use the “help” chat command for a list of available commands. Hint: Try to remove the leading slash.", cmd)
+			end
+			return false, minetest.colorize(color_red, msg)
+		end
+		if player_name then
+			local player_privs = minetest.get_player_privs(player_name)
+
+			for cmd_priv, _ in pairs(cmddef.privs) do
+				if player_privs[cmd_priv] ~= true then
+					local msg = S("Error: You have insufficient privileges to use the command “@1” (missing privilege: @2)! The command block has not been changed.", cmd, cmd_priv)
+					return false, minetest.colorize(color_red, msg)
+				end
+			end
+		end
+	end
+	return true
+end
+local check_commands = mod.check_commands
+
+mod.action_on = function(meta, pos)
+	local commander = meta:get_string("commander")
+	local commands = resolve_commands(meta:get_string("commands"), meta, pos)
+	for _, command in pairs(commands:split("\n")) do
+		local cpos = command:find(" ")
+		local cmd, param = command, ""
+		if cpos then
+			cmd = command:sub(1, cpos - 1)
+			param = command:sub(cpos + 1)
+		end
+		local cmddef = minetest.chatcommands[cmd]
+		if not cmddef then
+			-- Invalid chat command
+			return
+		end
+		-- Execute command in the name of commander
+		cmddef.func(commander, param)
+	end
+end
+
+local formspec_metas = {}
+
+mod.handle_rightclick = function(meta, player)
+	local can_edit = true
+	-- Only allow write access in Creative Mode
+	if not minetest.is_creative_enabled(player:get_player_name()) then
+		can_edit = false
+	end
+	local pname = player:get_player_name()
+	if minetest.is_protected(pos, pname) then
+		can_edit = false
+	end
+	local privs = minetest.get_player_privs(pname)
+	if not privs.maphack then
+		can_edit = false
+	end
+
+	local commands = meta:get_string("commands")
+	if not commands then
+		commands = ""
+	end
+	local commander = meta:get_string("commander")
+	local commanderstr
+	if commander == "" or commander == nil then
+		commanderstr = S("Error: No commander! Block must be replaced.")
+	else
+		commanderstr = S("Commander: @1", commander)
+	end
+	local textarea_name, submit, textarea
+	-- If editing is not allowed, only allow read-only access.
+	-- Player can still view the contents of the command block.
+	if can_edit then
+		textarea_name = "commands"
+		submit = "button_exit[3.3,4.4;2,1;submit;"..F(S("Submit")).."]"
+	else
+		textarea_name = ""
+		submit = ""
+	end
+	if not can_edit and commands == "" then
+		textarea = "label[0.5,0.5;"..F(S("No commands.")).."]"
+	else
+		textarea = "textarea[0.5,0.5;8.5,4;"..textarea_name..";"..F(S("Commands:"))..";"..F(commands).."]"
+	end
+	local formspec = "size[9,5;]" ..
+	textarea ..
+	submit ..
+	"image_button[8,4.4;1,1;doc_button_icon_lores.png;doc;]" ..
+	"tooltip[doc;"..F(S("Help")).."]" ..
+	"label[0,4;"..F(commanderstr).."]"
+
+	-- Store the metadata object for later use
+	local fs_id = #formspec_metas + 1
+	formspec_metas[fs_id] = meta
+	print("using fs_id="..tostring(fs_id)..",meta="..tostring(meta)..",formspec_metas[fs_id]="..tostring(formspec_metas[fs_id]))
+
+	minetest.show_formspec(pname, "commandblock_"..tostring(fs_id), formspec)
+end
+
+minetest.register_on_player_receive_fields(function(player, formname, fields)
+	if string.sub(formname, 1, 13) == "commandblock_" then
+		-- Show documentation
+		if fields.doc and minetest.get_modpath("doc") then
+			doc.show_entry(player:get_player_name(), "nodes", "mesecons_commandblock:commandblock_off", true)
+			return
+		end
+
+		-- Validate form fields
+		if (not fields.submit and not fields.key_enter) or (not fields.commands) then
+			return
+		end
+
+		-- Check privileges
+		local privs = minetest.get_player_privs(player:get_player_name())
+		if not privs.maphack then
+			minetest.chat_send_player(player:get_player_name(), S("Access denied. You need the “maphack” privilege to edit command blocks."))
+			return
+		end
+
+		-- Check game mode
+		if not minetest.is_creative_enabled(player:get_player_name()) then
+			minetest.chat_send_player(player:get_player_name(),
+				S("Editing the command block has failed! You can only change the command block in Creative Mode!")
+			)
+			return
+		end
+
+		-- Retrieve the metadata object this formspec data belongs to
+		local index, _, fs_id = string.find(formname, "commandblock_(-?%d+)")
+		fs_id = tonumber(fs_id)
+		if not index or not fs_id or not formspec_metas[fs_id] then 
+			print("index="..tostring(index)..", fs_id="..tostring(fs_id).."formspec_metas[fs_id]="..tostring(formspec_metas[fs_id]))
+			minetest.chat_send_player(player:get_player_name(), S("Editing the command block has failed! The command block is gone."))
+			return
+		end
+		local meta = formspec_metas[fs_id]
+		formspec_metas[fs_id] = nil
+
+		-- Verify the command
+		local check, error_message = check_commands(fields.commands, player:get_player_name())
+		if check == false then
+			-- Command block rejected
+			minetest.chat_send_player(player:get_player_name(), error_message)
+			return
+		end
+
+		-- Update the command in the metadata
+		meta:set_string("commands", fields.commands)
+	end
+end)

mods/ITEMS/REDSTONE/mesecons_commandblock/init.lua

@@ -1,104 +1,27 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
 local S = minetest.get_translator(minetest.get_current_modname())
-local F = minetest.formspec_escape
 
-local tonumber = tonumber
-
-local color_red = mcl_colors.RED
+-- Initialize API
+dofile(modpath.."/api.lua")
+local api = mesecon.commandblock
 
 local command_blocks_activated = minetest.settings:get_bool("mcl_enable_commandblocks", true)
 local msg_not_activated = S("Command blocks are not enabled on this server")
 
 local function construct(pos)
 	local meta = minetest.get_meta(pos)
-
-	meta:set_string("commands", "")
-	meta:set_string("commander", "")
+	api.initialize(meta)
 end
 
 local function after_place(pos, placer)
-	if placer then
 	local meta = minetest.get_meta(pos)
-		meta:set_string("commander", placer:get_player_name())
-	end
+	api.place(meta, placer)
 end
 
 local function resolve_commands(commands, pos)
-	local players = minetest.get_connected_players()
-
 	local meta = minetest.get_meta(pos)
-	local commander = meta:get_string("commander")
-
-	-- A non-printable character used while replacing “@@”.
-	local SUBSTITUTE_CHARACTER = "\26" -- ASCII SUB
-
-	-- No players online: remove all commands containing
-	-- problematic placeholders.
-	if #players == 0 then
-		commands = commands:gsub("[^\r\n]+", function (line)
-			line = line:gsub("@@", SUBSTITUTE_CHARACTER)
-			if line:find("@n") then return "" end
-			if line:find("@p") then return "" end
-			if line:find("@f") then return "" end
-			if line:find("@r") then return "" end
-			line = line:gsub("@c", commander)
-			line = line:gsub(SUBSTITUTE_CHARACTER, "@")
-			return line
-		end)
-		return commands
-	end
-
-	local nearest, farthest = nil, nil
-	local min_distance, max_distance = math.huge, -1
-	for index, player in pairs(players) do
-		local distance = vector.distance(pos, player:get_pos())
-		if distance < min_distance then
-			min_distance = distance
-			nearest = player:get_player_name()
-		end
-		if distance > max_distance then
-			max_distance = distance
-			farthest = player:get_player_name()
-		end
-	end
-	local random = players[math.random(#players)]:get_player_name()
-	commands = commands:gsub("@@", SUBSTITUTE_CHARACTER)
-	commands = commands:gsub("@p", nearest)
-	commands = commands:gsub("@n", nearest)
-	commands = commands:gsub("@f", farthest)
-	commands = commands:gsub("@r", random)
-	commands = commands:gsub("@c", commander)
-	commands = commands:gsub(SUBSTITUTE_CHARACTER, "@")
-	return commands
-end
-
-local function check_commands(commands, player_name)
-	for _, command in pairs(commands:split("\n")) do
-		local pos = command:find(" ")
-		local cmd = command
-		if pos then
-			cmd = command:sub(1, pos - 1)
-		end
-		local cmddef = minetest.chatcommands[cmd]
-		if not cmddef then
-			-- Invalid chat command
-			local msg = S("Error: The command “@1” does not exist; your command block has not been changed. Use the “help” chat command for a list of available commands.", cmd)
-			if string.sub(cmd, 1, 1) == "/" then
-				msg = S("Error: The command “@1” does not exist; your command block has not been changed. Use the “help” chat command for a list of available commands. Hint: Try to remove the leading slash.", cmd)
-			end
-			return false, minetest.colorize(color_red, msg)
-		end
-		if player_name then
-			local player_privs = minetest.get_player_privs(player_name)
-
-			for cmd_priv, _ in pairs(cmddef.privs) do
-				if player_privs[cmd_priv] ~= true then
-					local msg = S("Error: You have insufficient privileges to use the command “@1” (missing privilege: @2)! The command block has not been changed.", cmd, cmd_priv)
-					return false, minetest.colorize(color_red, msg)
-				end
-			end
-		end
-	end
-	return true
+	return api.resolve_commands(commands, meta)
 end
 
 local function commandblock_action_on(pos, node)
@@ -107,7 +30,6 @@ local function commandblock_action_on(pos, node)
 	end
 
 	local meta = minetest.get_meta(pos)
-	local commander = meta:get_string("commander")
 
 	if not command_blocks_activated then
 		--minetest.chat_send_player(commander, msg_not_activated)
@@ -115,22 +37,7 @@ local function commandblock_action_on(pos, node)
 	end
 	minetest.swap_node(pos, {name = "mesecons_commandblock:commandblock_on"})
 
-	local commands = resolve_commands(meta:get_string("commands"), pos)
-	for _, command in pairs(commands:split("\n")) do
-		local cpos = command:find(" ")
-		local cmd, param = command, ""
-		if cpos then
-			cmd = command:sub(1, cpos - 1)
-			param = command:sub(cpos + 1)
-		end
-		local cmddef = minetest.chatcommands[cmd]
-		if not cmddef then
-			-- Invalid chat command
-			return
-		end
-		-- Execute command in the name of commander
-		cmddef.func(commander, param)
-	end
+	api.action_on(meta, pos)
 end
 
 local function commandblock_action_off(pos, node)
@@ -144,54 +51,10 @@ local function on_rightclick(pos, node, player, itemstack, pointed_thing)
 		minetest.chat_send_player(player:get_player_name(), msg_not_activated)
 		return
 	end
-	local can_edit = true
-	-- Only allow write access in Creative Mode
-	if not minetest.is_creative_enabled(player:get_player_name()) then
-		can_edit = false
-	end
-	local pname = player:get_player_name()
-	if minetest.is_protected(pos, pname) then
-		can_edit = false
-	end
-	local privs = minetest.get_player_privs(pname)
-	if not privs.maphack then
-		can_edit = false
-	end
 
 	local meta = minetest.get_meta(pos)
-	local commands = meta:get_string("commands")
-	if not commands then
-		commands = ""
-	end
-	local commander = meta:get_string("commander")
-	local commanderstr
-	if commander == "" or commander == nil then
-		commanderstr = S("Error: No commander! Block must be replaced.")
-	else
-		commanderstr = S("Commander: @1", commander)
-	end
-	local textarea_name, submit, textarea
-	-- If editing is not allowed, only allow read-only access.
-	-- Player can still view the contents of the command block.
-	if can_edit then
-		textarea_name = "commands"
-		submit = "button_exit[3.3,4.4;2,1;submit;"..F(S("Submit")).."]"
-	else
-		textarea_name = ""
-		submit = ""
-	end
-	if not can_edit and commands == "" then
-		textarea = "label[0.5,0.5;"..F(S("No commands.")).."]"
-	else
-		textarea = "textarea[0.5,0.5;8.5,4;"..textarea_name..";"..F(S("Commands:"))..";"..F(commands).."]"
-	end
-	local formspec = "size[9,5;]" ..
-	textarea ..
-	submit ..
-	"image_button[8,4.4;1,1;doc_button_icon_lores.png;doc;]" ..
-	"tooltip[doc;"..F(S("Help")).."]" ..
-	"label[0,4;"..F(commanderstr).."]"
-	minetest.show_formspec(pname, "commandblock_"..pos.x.."_"..pos.y.."_"..pos.z, formspec)
+	api.handle_rightclick(meta, player)
+
 end
 
 local function on_place(itemstack, placer, pointed_thing)
@@ -205,8 +68,6 @@ local function on_place(itemstack, placer, pointed_thing)
 		return new_stack
 	end
 
-	--local node = minetest.get_node(pointed_thing.under)
-
 	local privs = minetest.get_player_privs(placer:get_player_name())
 	if not privs.maphack then
 		minetest.chat_send_player(placer:get_player_name(), S("Placement denied. You need the “maphack” privilege to place command blocks."))
@@ -280,44 +141,6 @@ minetest.register_node("mesecons_commandblock:commandblock_on", {
 	_mcl_hardness = -1,
 })
 
-minetest.register_on_player_receive_fields(function(player, formname, fields)
-	if string.sub(formname, 1, 13) == "commandblock_" then
-		if fields.doc and minetest.get_modpath("doc") then
-			doc.show_entry(player:get_player_name(), "nodes", "mesecons_commandblock:commandblock_off", true)
-			return
-		end
-		if (not fields.submit and not fields.key_enter) or (not fields.commands) then
-			return
-		end
-
-		local privs = minetest.get_player_privs(player:get_player_name())
-		if not privs.maphack then
-			minetest.chat_send_player(player:get_player_name(), S("Access denied. You need the “maphack” privilege to edit command blocks."))
-			return
-		end
-
-		local index, _, x, y, z = string.find(formname, "commandblock_(-?%d+)_(-?%d+)_(-?%d+)")
-		if index and x and y and z then
-			local pos = {x = tonumber(x), y = tonumber(y), z = tonumber(z)}
-			local meta = minetest.get_meta(pos)
-			if not minetest.is_creative_enabled(player:get_player_name()) then
-				minetest.chat_send_player(player:get_player_name(), S("Editing the command block has failed! You can only change the command block in Creative Mode!"))
-				return
-			end
-			local check, error_message = check_commands(fields.commands, player:get_player_name())
-			if check == false then
-				-- Command block rejected
-				minetest.chat_send_player(player:get_player_name(), error_message)
-				return
-			else
-				meta:set_string("commands", fields.commands)
-			end
-		else
-			minetest.chat_send_player(player:get_player_name(), S("Editing the command block has failed! The command block is gone."))
-		end
-	end
-end)
-
 -- Add entry alias for the Help
 if minetest.get_modpath("doc") then
 	doc.add_entry_alias("nodes", "mesecons_commandblock:commandblock_off", "nodes", "mesecons_commandblock:commandblock_on")

mods/ITEMS/REDSTONE/mesecons_delayer/init.lua

@@ -108,10 +108,10 @@ local function check_unlock_repeater(pos, node)
 		end
 		if mesecon.is_powered(lpos, delayer_get_input_rules(lnode)[1]) then
 			minetest.set_node(lpos, {name="mesecons_delayer:delayer_on_"..ldelay, param2=lnode.param2})
-			mesecon.queue:add_action(lpos, "receptor_on", {delayer_get_output_rules(lnode)}, ldef.delayer_time, nil)
+			vl_redstone.set_power(lpos, 15, ldef.delayer_time)
 		else
 			minetest.set_node(lpos, {name="mesecons_delayer:delayer_off_"..ldelay, param2=lnode.param2})
-			mesecon.queue:add_action(lpos, "receptor_off", {delayer_get_output_rules(lnode)}, ldef.delayer_time, nil)
+			vl_redstone.set_power(lpos,  0, ldef.delayer_time)
 		end
 		return true
 	end
@@ -123,7 +123,7 @@ local function delayer_activate(pos, node)
 	local def = minetest.registered_nodes[node.name]
 	local time = def.delayer_time
 	minetest.set_node(pos, {name=def.delayer_onstate, param2=node.param2})
-	mesecon.queue:add_action(pos, "receptor_on", {delayer_get_output_rules(node)}, time, nil)
+	vl_redstone.set_power(pos, 15, time)
 	check_lock_repeater(pos, node)
 end
 
@@ -131,7 +131,7 @@ local function delayer_deactivate(pos, node)
 	local def = minetest.registered_nodes[node.name]
 	local time = def.delayer_time
 	minetest.set_node(pos, {name=def.delayer_offstate, param2=node.param2})
-	mesecon.queue:add_action(pos, "receptor_off", {delayer_get_output_rules(node)}, time, nil)
+	vl_redstone.set_power(pos, 0, time)
 	check_unlock_repeater(pos, node)
 end
 
@@ -207,7 +207,7 @@ for i = 1, 4 do
 						if mesecon.is_powered(pos, delayer_get_input_rules(node)[1]) ~= false then
 							local newnode = {name="mesecons_delayer:delayer_on_locked", param2 = node.param2}
 							minetest.set_node(pos, newnode)
-							mesecon.queue:add_action(pos, "receptor_on", {delayer_get_output_rules(newnode)}, DEFAULT_DELAY, nil)
+							vl_redstone.set_power(pos, 15, DEFAULT_DELAY)
 						else
 							minetest.set_node(pos, {name="mesecons_delayer:delayer_off_locked", param2 = node.param2})
 						end

mods/ITEMS/REDSTONE/mesecons_delayer/mod.conf

@@ -1,3 +1,3 @@
 name = mesecons_delayer
-depends = mesecons
+depends = mesecons, vl_redstone
 optional_depends = doc, screwdriver

mods/ITEMS/REDSTONE/mesecons_torch/init.lua

@@ -62,51 +62,47 @@ local function torch_overheated(pos)
 	timer:start(TORCH_COOLOFF)
 end
 
-local function torch_action_on(pos, node)
-	local overheat
-	if node.name == "mesecons_torch:mesecon_torch_on" then
-		overheat = mesecon.do_overheat(pos)
-		if overheat then
-			minetest.swap_node(pos, {name="mesecons_torch:mesecon_torch_overheated", param2=node.param2})
-		else
-			minetest.swap_node(pos, {name="mesecons_torch:mesecon_torch_off", param2=node.param2})
-		end
-		mesecon.receptor_off(pos, torch_get_output_rules(node))
-	elseif node.name == "mesecons_torch:mesecon_torch_on_wall" then
-		overheat = mesecon.do_overheat(pos)
-		if overheat then
-			minetest.swap_node(pos, {name="mesecons_torch:mesecon_torch_overheated_wall", param2=node.param2})
-		else
-			minetest.swap_node(pos, {name="mesecons_torch:mesecon_torch_off_wall", param2=node.param2})
-		end
-		mesecon.receptor_off(pos, torch_get_output_rules(node))
-	end
-	if overheat then
-		torch_overheated(pos)
-	end
-end
+local TORCH_STATE_ON = {
+	["mesecons_torch:mesecon_torch_off"] = "mesecons_torch:mesecon_torch_on",
+	["mesecons_torch:mesecon_torch_off_wall"] = "mesecons_torch:mesecon_torch_on_wall",
+}
+local TORCH_STATE_OFF = {
+	["mesecons_torch:mesecon_torch_on"] = "mesecons_torch:mesecon_torch_off",
+	["mesecons_torch:mesecon_torch_on_wall"] = "mesecons_torch:mesecon_torch_off_wall",
+}
+local TORCH_STATE_OVERHEAT = {
+	["mesecons_torch:mesecon_torch_on"] = "mesecons_torch:mesecon_torch_overheated",
+	["mesecons_torch:mesecon_torch_on_wall"] = "mesecons_torch:mesecon_torch_overheated_wall",
+	["mesecons_torch:mesecon_torch_off"] = "mesecons_torch:mesecon_torch_overheated",
+	["mesecons_torch:mesecon_torch_off_wall"] = "mesecons_torch:mesecon_torch_overheated_wall",
+}
 
-local function torch_action_off(pos, node)
-	local overheat
-	if node.name == "mesecons_torch:mesecon_torch_off" or node.name == "mesecons_torch:mesecon_torch_overheated" then
+local function torch_action_change(pos, node, rule, strength)
+	local nodedef = minetest.registered_nodes[node.name]
+	--local effector_state = ((nodedef.mesecons or {}).effector or {}).state
+	--local is_on = ( effector_state == mesecon.state.on )
+	local overheat = false
+	local original_name = node.name
+
+	if strength == 0 then
+		-- Turn on
+		node.name = TORCH_STATE_ON[node.name] or node.name
+		vl_redstone.set_power(pos, 15, 0.1)
 		overheat = mesecon.do_overheat(pos)
-		if overheat then
-			minetest.swap_node(pos, {name="mesecons_torch:mesecon_torch_overheated", param2=node.param2})
 	else
-			minetest.swap_node(pos, {name="mesecons_torch:mesecon_torch_on", param2=node.param2})
-			mesecon.receptor_on(pos, torch_get_output_rules(node))
-		end
-	elseif node.name == "mesecons_torch:mesecon_torch_off_wall" or node.name == "mesecons_torch:mesecon_torch_overheated_wall" then
-		overheat = mesecon.do_overheat(pos)
-		if overheat then
-			minetest.swap_node(pos, {name="mesecons_torch:mesecon_torch_overheated_wall", param2=node.param2})
-		else
-			minetest.swap_node(pos, {name="mesecons_torch:mesecon_torch_on_wall", param2=node.param2})
-			mesecon.receptor_on(pos, torch_get_output_rules(node))
-		end
+		-- Turn off
+		node.name = TORCH_STATE_OFF[node.name] or node.name
+		vl_redstone.set_power(pos, 0, 0.1)
 	end
+
 	if overheat then
+		print("overheat")
 		torch_overheated(pos)
+		node.name = TORCH_STATE_OVERHEAT[node.name] or node.name
+	end
+
+	if node.name ~= original_name then
+		minetest.swap_node(pos, node)
 	end
 end
 
@@ -140,9 +136,9 @@ local off_override = {
 		effector = {
 			state = mesecon.state.on,
 			rules = torch_get_input_rules,
-			action_off = torch_action_off,
+			action_change = torch_action_change,
+		},
 	},
-	}
 }
 
 minetest.override_item("mesecons_torch:mesecon_torch_off", off_override)
@@ -158,7 +154,7 @@ local overheated_override = {
 	on_timer = function(pos, elapsed)
 		if not mesecon.is_powered(pos) then
 			local node = minetest.get_node(pos)
-			torch_action_off(pos, node)
+			torch_action_change(pos, node, nil, 0)
 		end
 	end
 }
@@ -183,7 +179,7 @@ mcl_torches.register_torch(on_def)
 local on_override = {
 	on_destruct = function(pos, oldnode)
 		local node = minetest.get_node(pos)
-		torch_action_on(pos, node)
+		torch_action_change(pos, node, nil, 0)
 	end,
 	mesecons = {
 		receptor = {
@@ -193,7 +189,7 @@ local on_override = {
 		effector = {
 			state = mesecon.state.off,
 			rules = torch_get_input_rules,
-			action_on = torch_action_on,
+			action_change = torch_action_change,
 		},
 	},
 	_tt_help = S("Provides redstone power when it's not powered itself"),

mods/ITEMS/REDSTONE/mesecons_torch/mod.conf

@@ -1,3 +1,3 @@
 name = mesecons_torch
-depends = mesecons, mcl_torches
+depends = mesecons, mcl_torches, vl_redstone
 optional_depends = doc

mods/ITEMS/REDSTONE/mesecons_walllever/init.lua

@@ -52,7 +52,7 @@ minetest.register_node("mesecons_walllever:wall_lever_off", {
 	_doc_items_usagehelp = S("Use the lever to flip it on or off."),
 	on_rightclick = function(pos, node)
 		minetest.swap_node(pos, {name="mesecons_walllever:wall_lever_on", param2=node.param2})
-		mesecon.receptor_on(pos, lever_get_output_rules(node))
+		vl_redstone.set_power(pos, 16)
 		minetest.sound_play("mesecons_button_push", {pos=pos, max_hear_distance=16}, true)
 	end,
 	node_placement_prediction = "",
@@ -152,7 +152,7 @@ minetest.register_node("mesecons_walllever:wall_lever_on", {
 	_doc_items_create_entry = false,
 	on_rightclick = function(pos, node)
 		minetest.swap_node(pos, {name="mesecons_walllever:wall_lever_off", param2=node.param2})
-		mesecon.receptor_off(pos, lever_get_output_rules(node))
+		vl_redstone.set_power(pos, 0)
 		minetest.sound_play("mesecons_button_push", {pos=pos, max_hear_distance=16, pitch=0.9}, true)
 	end,
 	sounds = mcl_sounds.node_sound_stone_defaults(),

mods/ITEMS/REDSTONE/mesecons_walllever/mod.conf

@@ -1,3 +1,3 @@
 name = mesecons_walllever
-depends = mesecons
+depends = mesecons, vl_redstone
 optional_depends = doc

mods/ITEMS/REDSTONE/mesecons_wires/init.lua

@@ -214,6 +214,11 @@ local function register_wires()
 		local dot_off = "redstone_redstone_dust_dot.png^[colorize:#FF0000:"..ratio_off
 		local dot_on = "redstone_redstone_dust_dot.png^[colorize:#FF0000:"..ratio_on
 
+		local crossing = "(redstone_redstone_dust_dot.png^redstone_redstone_dust_line0.png^(redstone_redstone_dust_line1.png^[transformR90))"
+		local straight0 = "redstone_redstone_dust_line0.png"
+		local straight1 = "redstone_redstone_dust_line0.png"
+		local dot = "redstone_redstone_dust_dot.png"
+
 		local tiles_off, tiles_on
 
 		local wirehelp, tt, longdesc, usagehelp, img, desc_off, desc_on
@@ -221,8 +226,8 @@ local function register_wires()
 			-- Non-connected redstone wire
 			nodebox.fixed = {-8/16, -.5, -8/16, 8/16, -.5+1/64, 8/16}
 			-- “Dot” texture
-			tiles_off = { dot_off, dot_off, "blank.png", "blank.png", "blank.png", "blank.png" }
-			tiles_on = { dot_on, dot_on, "blank.png", "blank.png", "blank.png", "blank.png" }
+			tiles_off = { dot, dot, "blank.png", "blank.png", "blank.png", "blank.png" }
+			tiles_on = { dot, dot, "blank.png", "blank.png", "blank.png", "blank.png" }
 
 			tt = S("Transmits redstone power, powers mechanisms")
 			longdesc = S("Redstone is a versatile conductive mineral which transmits redstone power. It can be placed on the ground as a trail.").."\n"..
@@ -237,8 +242,8 @@ S("Read the help entries on the other redstone components to learn how redstone
 		else
 			-- Connected redstone wire
 			table.insert(nodebox, box_center)
-			tiles_off = { crossing_off, crossing_off, straight0_off, straight1_off, straight0_off, straight1_off }
-			tiles_on = { crossing_on, crossing_on, straight0_on, straight1_on, straight0_on, straight1_on }
+			tiles_off = { crossing, crossing, straight0, straight1, straight0, straight1 }
+			tiles_on = { crossing, crossing, straight0, straight1, straight0, straight1 }
 			wirehelp = false
 			desc_off = S("Redstone Trail (@1)", nodeid)
 			desc_on = S("Powered Redstone Trail (@1)", nodeid)
@@ -247,6 +252,8 @@ S("Read the help entries on the other redstone components to learn how redstone
 		mesecon.register_node(":mesecons:wire_"..nodeid, {
 			drawtype = "nodebox",
 			paramtype = "light",
+			paramtype2 = "color4dir",
+			palette = "redstone-palette.png",
 			use_texture_alpha = minetest.features.use_texture_alpha_string_modes and "clip" or true,
 			sunlight_propagates = true,
 			selection_box = selectionbox,

mods/ITEMS/REDSTONE/vl_redstone/init.lua

@@ -0,0 +1,435 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+vl_redstone = {}
+local mod = vl_redstone
+
+-- Imports
+local mcl_util_force_get_node = mcl_util.force_get_node
+local mcl_util_call_safe = mcl_util.call_safe
+local minetest_get_item_group = minetest.get_item_group
+local minetest_get_meta = minetest.get_meta
+local minetest_hash_node_pos = minetest.hash_node_position
+local minetest_get_position_from_hash = minetest.get_position_from_hash
+local minetest_serialize = minetest.serialize
+local minetest_deserialize = minetest.deserialize
+local minetest_swap_node = minetest.swap_node
+local vector_add = vector.add
+local vector_to_string = vector.to_string
+local vector_from_string = vector.from_string
+local math_floor = math.floor
+
+-- Constants
+local REDSTONE_POWER_META = modname .. ".power"
+local REDSTONE_POWER_META_SOURCE = REDSTONE_POWER_META.."."
+
+local multipower_cache = {}
+
+local function hash_from_direction(dir)
+	return 9 * (dir.x + 1) + 3 * (dir.y + 1) + dir.z + 1
+end
+local function direction_from_hash(dir_hash)
+	local x = math_floor(dir_hash / 9) - 1
+	local y = math_floor((dir_hash % 9) / 3 ) - 1
+	local z = dir_hash % 3 - 1
+	return vector.new(x,y,z)
+end
+local HASH_REVERSES = {}
+for i=0,27 do
+	local dir = direction_from_hash(i)
+	local dir_rev = vector.subtract(vector.zero(), dir)
+	local dir_rev_hash = hash_from_direction(dir_rev)
+	HASH_REVERSES[dir_rev_hash] = i
+	--print("hash["..tostring(i).."] = "..vector_to_string(direction_from_hash(i))..", rev="..tostring(dir_rev_hash))
+end
+
+local DIR_HASH_ZERO = hash_from_direction(vector.zero())
+print("DIR_HASH_ZERO="..tostring(DIR_HASH_ZERO))
+
+local function get_input_rules_hash(mesecons, input_rules)
+	-- Skip build if already built
+	local redstone = mesecons._vl_redtone or {}
+	mesecons._vl_redstone = redstone
+	if redstone.input_rules_hash then return redstone.input_rules_hash end
+
+	-- Build the rules
+	local input_rules_hash = {}
+	redstone.input_rules_hash = input_rules_hash
+	if input_rules then
+		for i=1,#input_rules do
+			input_rules_hash[hash_from_direction(input_rules[i])] = true
+		end
+	end
+
+	return input_rules_hash
+end
+
+local function get_node_multipower_data(pos, no_create)
+	local hash = minetest_hash_node_pos(pos)
+	local node_multipower = multipower_cache[hash]
+	if not node_multipower then
+		local meta = minetest_get_meta(pos)
+		node_multipower = minetest_deserialize(meta:get_string("vl_redstone.multipower"))
+		if not no_create and ( not node_multipower or node_multipower.version ~= 1 ) then
+			node_multipower = {
+				version = 1,
+				sources={}
+			}
+		end
+		multipower_cache[hash] = node_multipower
+	end
+	return node_multipower
+end
+
+local function calculate_driven_strength(pos, input_rules_hash, dir)
+	local dir_hash = dir and hash_from_direction(dir)
+	local node_multipower = get_node_multipower_data(pos)
+	local strength = 0
+	local strongest_direction_hash = nil
+	local sources = node_multipower.sources
+	input_rules_hash = input_rules_hash or {}
+
+	--print("in update_node(pos="..vector_to_string(pos)..") node_multipower("..tostring(node_multipower)..")="..dump(node_multipower))
+	for pos_hash,data in pairs(sources) do
+		local source_strength = data[1]
+		local dirs = data[2]
+		--print("data="..dump(data))
+		--print("\t"..vector_to_string(pos)..".source["..vector_to_string(minetest_get_position_from_hash(pos_hash)).."] = "..tostring(strength))
+
+		-- Filter by specified direction
+		local match = false
+		if not dir_hash then
+			match = true
+		else
+			for i=1,#dirs do
+				match = match or input_rules_hash[dirs[i]]
+			end
+		end
+
+		--print("match="..tostring(match)..",source_strength="..tostring(source_strength))
+
+		-- Update strength and track which direction the strongest power is coming from
+		if match and source_strength >= strength then
+			strength = source_strength
+			if #dirs ~= 0 then
+				strongest_direction_hash = dirs[1]
+			end
+		end
+	end
+
+	return strength,HASH_REVERSES[strongest_direction_hash]
+end
+
+local function update_node(pos, node)
+	local node = node or mcl_util_force_get_node(pos)
+	local nodedef = minetest.registered_nodes[node.name]
+
+	-- Only do this processing of signal sinks and conductors
+	local nodedef_mesecons = nodedef.mesecons
+	if not nodedef_mesecons then return end
+
+	--print("Running update_node(pos="..vector_to_string(pos)..", node.name="..node.name..")")
+
+	-- Get input rules
+	local input_rules = nil
+	if nodedef_mesecons.conductor then
+		input_rules = nodedef_mesecons.conductor.rules
+	elseif nodedef_mesecons.effector then
+		input_rules = nodedef_mesecons.effector.rules
+	else
+		-- No input rules, can't act
+		--print("Unable to find input rules for "..node.name..": mesecons="..dump(nodedef_mesecons))
+		return
+	end
+	if type(input_rules) == "function" then
+		input_rules = input_rules(node)
+	end
+
+	-- Calculate the maximum power feeding into this node
+	local input_rules_hash = get_input_rules_hash(nodedef_mesecons, input_rules)
+	--print("input_rules_hash="..dump(input_rules_hash)..", input_rules="..dump(input_rules))
+	local strength,dir_hash = calculate_driven_strength(pos, input_rules_hash)
+	--print("strength="..tostring(strength)..",dir_hash="..tostring(dir_hash))
+
+	-- Don't do any processing inf the actual strength at this node has changed
+	local node_multipower = get_node_multipower_data(pos)
+	local last_strength = node_multipower.strength or 0
+
+	--[[
+	print("At "..vector_to_string(pos).."("..node.name..") strength="..tostring(strength)..",last_strength="..tostring(last_strength))
+	if last_strength == strength then
+		print("No strength change")
+		return
+	end
+	--]]
+
+	-- Determine the input rule that the strength is coming from (for mesecons compatibility; there are mods that depend on it)
+	local rule = nil
+	--print("input_rules="..dump(input_rules))
+	--print("input_rules_hash="..dump(input_rules_hash))
+	--print("dir_hash="..tostring(dir_hash))
+	for i = 1,#input_rules do
+		local input_rule = input_rules[i]
+		local input_rule_hash = hash_from_direction(input_rule)
+		if dir_hash == input_rule_hash then
+			rule = input_rule
+			break
+		end
+	end
+	if not rule then
+		--print("No rule found")
+		return
+	end
+
+	-- Update the state
+	node_multipower.strength = strength
+
+	local sink = nodedef_mesecons.effector
+	if sink then
+		local new_node_name = nil
+		--print("Updating "..node.name.." at "..vector_to_string(pos).."("..tostring(last_strength).."->"..tostring(strength)..")")
+		-- Inform the node of changes
+		if strength ~= 0 and last_strength == 0 then
+			-- Handle activation
+			local hook = sink.action_on
+			if hook then
+				mcl_util_call_safe(nil, hook, {pos, node, rule, strength})
+			end
+			if sink.onstate then
+				new_node_name = sink.onstate
+			end
+		elseif strength == 0 and last_strength ~= 0 then
+			-- Handle deactivation
+			local hook = sink.action_off
+			if hook then
+				mcl_util_call_safe(nil, hook, {pos, node, rule, strength})
+			end
+			if sink.offstate then
+				new_node_name = sink.offstate
+			end
+		end
+
+		-- handle signal level change notification
+		local hook = sink.action_change
+		if hook then
+			mcl_util_call_safe(nil, hook, {pos, node, rule, strength})
+		end
+		if sink.strength_state then
+			new_node_name = sink.strength_state[strength]
+		end
+
+		-- Update the node
+		if new_node_name and new_node_name ~= node.name then
+			node.name = new_node_name
+			minetest_swap_node(pos, node)
+		end
+		return
+	end
+
+	local conductor = nodedef_mesecons.conductor
+	if conductor then
+		-- Figure out if the node name changes based on the new state
+		local new_node_name = nil
+		if conductor.strength_state then
+			new_node_name = conductor.strength_state[strength]
+		elseif strength > 0 and conductor.onstate then
+			new_node_name = conductor.onstate
+		elseif strength == 0 and conductor.offstate then
+			new_node_name = conductor.offstate
+		end
+
+		-- Update the node
+		if new_node_name and new_node_name ~= node.name then
+			--[[
+			print("Changing "..vector_to_string(pos).." from "..node.name.." to "..new_node_name..
+			    ", strength="..tostring(strength)..",last_strength="..tostring(last_strength))
+			print("node.name="..node.name..
+			     ",conductor.onstate="..tostring(conductor.onstate)..
+			     ",conductor.offstate="..tostring(conductor.offstate)
+			)
+			--]]
+			node.param2 = strength * 4
+			node.name = new_node_name
+			minetest_swap_node(pos, node)
+		end
+	end
+end
+
+local POWERED_BLOCK_RULES = {
+	vector.new( 1, 0, 0),
+	vector.new(-1, 0, 0),
+	vector.new( 0, 1, 0),
+	vector.new( 0,-1, 0),
+	vector.new( 0, 0, 1),
+	vector.new( 0, 0,-1),
+}
+
+local function get_positions_from_node_rules(pos, rules_type, list, powered)
+	list = list or {}
+
+	local node = mcl_util_force_get_node(pos)
+	local nodedef = minetest.registered_nodes[node.name]
+	local rules
+	if nodedef.mesecons then
+		-- Get mesecons rules
+		if not nodedef.mesecons[rules_type] then
+			minetest.log("info","Node "..node.name.." has no mesecons."..rules_type.." rules")
+			return list
+		end
+		rules = nodedef.mesecons[rules_type].rules
+		if type(rules) == "function" then rules = rules(node) end
+	else
+		-- The only blocks that don't support mesecon that propagate power are solid blocks that
+		-- are powered by another device. Mesecons calls this 'spread'
+		if not powered[minetest_hash_node_pos(pos)] then return list end
+		if minetest_get_item_group(node.name,"solid") == 0 then return list end
+
+		rules = POWERED_BLOCK_RULES
+	end
+
+	--print("rules="..dump(rules))
+
+	-- Convert to absolute positions
+	for i=1,#rules do
+		local rule = rules[i]
+		local next_pos = vector_add(pos, rule)
+		local next_pos_hash = minetest_hash_node_pos(next_pos)
+		--print("\tnext: "..next_pos_str..", prev="..tostring(list[next_pos_str]))
+		local dirs = list[next_pos_hash] or {}
+		list[next_pos_hash] = dirs
+		dirs[hash_from_direction(rule)] = true
+
+		-- Power solid blocks
+		if rules[i].spread then
+			powered[next_pos_hash] = true
+			--print("powering "..vector_to_string(next_pos)
+		end
+	end
+
+	return list
+end
+
+vl_scheduler.register_function("vl_redstone:flow_power",function(task, source_pos, source_strength, distance)
+	--print("Flowing lv"..tostring(source_strength).." power from "..vector_to_string(source_pos).." for "..tostring(distance).." blocks")
+	local processed = {}
+	local powered = {}
+	local source_pos_hash = minetest_hash_node_pos(source_pos)
+	processed[source_pos_hash] = true
+
+	-- Update the source node's redstone power
+	local node_multipower = get_node_multipower_data(source_pos)
+	node_multipower.strength = source_strength
+	node_multipower.drive_strength = source_strength
+
+	-- Get rules
+	local list = {}
+	get_positions_from_node_rules(source_pos, "receptor", list, powered)
+	--print("initial list="..dump(list))
+
+	for i=1,distance do
+		local next_list = {}
+		local strength = source_strength - (i - 1)
+		if strength < 0 then strength = 0 end
+
+		for pos_hash,dir_list in pairs(list) do
+			--print("Processing "..pos_str)
+
+			if not processed[pos_hash] then
+				processed[pos_hash] = true
+
+				local pos = minetest_get_position_from_hash(pos_hash)
+
+				-- Update node power directly
+				local node_multipower = get_node_multipower_data(pos)
+				--local old_data = node_multipower.sources[source_pos_hash]
+				--local old_strength = old_data and old_data[1] or 0
+				--print("Changing "..vector.to_string(pos)..".source["..vector_to_string(source_pos).."] from "..tostring(old_strength).." to "..tostring(strength))
+				--print("\tBefore node_multipower("..tostring(node_multipower)..")="..dump(node_multipower))
+				--print("\tdir_list="..dump(dir_list))
+				local dirs = {}
+				for k,_ in pairs(dir_list) do
+					dirs[#dirs+1] = k
+				end
+				node_multipower.sources[source_pos_hash] = {strength,dirs}
+				--print("\tAfter  node_multipower("..tostring(node_multipower)..")="..dump(node_multipower))
+
+				-- handle spread
+				get_positions_from_node_rules(pos, "conductor", next_list, powered)
+
+				-- Update the position
+				update_node(pos)
+			end
+		end
+
+		-- Continue onto the next set of nodes to process
+		list = next_list
+	end
+end)
+
+function vl_redstone.set_power(pos, strength, delay, node)
+	-- Get existing multipower data, but don't create the data if the strength is zero
+	local no_create
+	if strength == 0 then no_create = true end
+	local node_multipower = get_node_multipower_data(pos, no_create)
+	if not node_multipower then
+		print("No node multipower, no_create="..tostring(no_create))
+		return
+	end
+
+	-- Determine how far we need to trace conductors
+	local distance = node_multipower.drive_strength or 0
+
+	-- Don't perform an update if the power level is the same as before
+	if distance == strength then
+		print("Don't perform update distance="..tostring(distance)..",strength="..tostring(strength))
+		return
+	end
+
+	--print("previous="..tostring(distance)..", new="..tostring(strength))
+
+	-- Make the update distance the maximum of the new strength and the old strength
+	if distance < strength then
+		distance = strength
+	end
+
+	-- Schedule an update
+	vl_scheduler.add_task(delay or 0, "vl_redstone:flow_power", 2, {pos, strength, distance + 1, node})
+end
+
+function vl_redstone.get_power(pos)
+	local node_multipower = get_node_multipower_data(pos)
+	return node_multipower.strength or 0
+end
+
+function vl_redstone.on_placenode(pos, node)
+	local nodedef = minetest.registered_nodes[node.name]
+	if not nodedef then return end
+	if not nodedef.mesecons then return end
+	local receptor = nodedef.mesecons.receptor
+	if not receptor then return end
+
+	if receptor.state == mesecon.state.on then
+		vl_redstone.set_power(pos, 15)
+	else
+		vl_redstone.set_power(pos, 0)
+	end
+end
+function vl_redstone.on_dignode(pos, node)
+	print("Dug node at "..vector.to_string(pos))
+
+	-- Node was dug, can't power anything
+	-- This doesn't work because the node is gone and we don't know what we were powering
+	-- TODO: get the rules here and use that for the first step
+	vl_redstone.set_power(pos, 0, nil, node)
+end
+
+-- Persist multipower data
+minetest.register_on_shutdown(function()
+	for pos_hash,node_multipower in pairs(multipower_cache) do
+		local pos = minetest_get_position_from_hash(pos_hash)
+		local meta = minetest_get_meta(pos)
+		meta:set_string("vl_redstone.multipower", minetest_serialize(node_multipower))
+	end
+end)
+minetest.register_on_placenode(vl_redstone.on_placenode)
+minetest.register_on_dignode(vl_redstone.on_dignode)
+

mods/ITEMS/REDSTONE/vl_redstone/mod.conf

@@ -0,0 +1,4 @@
+description = Redstone implementation
+name = vl_redstone
+depends = mcl_sounds, mcl_core, vl_scheduler
+optional_depends = doc

mods/ITEMS/mcl_core/nodes_cactuscane.lua

@@ -48,6 +48,11 @@ minetest.register_node("mcl_core:cactus", {
 	end),
 	_mcl_blast_resistance = 0.4,
 	_mcl_hardness = 0.4,
+	_mcl_minecarts_on_enter_side = function(pos, _, _, _, cart_data)
+		if mcl_minecarts then
+			mcl_minecarts.kill_cart(cart_data)
+		end
+	end,
 })
 
 minetest.register_node("mcl_core:reeds", {

mods/ITEMS/mcl_hoppers/init.lua

@@ -9,6 +9,8 @@ local function mcl_log(message)
 	end
 end
 
+mcl_hoppers = {}
+
 --[[ BEGIN OF NODE DEFINITIONS ]]
 
 local mcl_hoppers_formspec = table.concat({
@@ -32,6 +34,12 @@ local mcl_hoppers_formspec = table.concat({
 	"listring[current_player;main]",
 })
 
+local function get_reading(pos)
+	local meta = minetest.get_meta(pos)
+	local inv = meta:get_inventory()
+	return mcl_comparators.read_inventory(inv, "main")
+end
+
 local function straight_hopper_act(pos, node, active_object_count, active_count_wider)
 	local timer = minetest.get_node_timer(pos)
 	if timer:is_started() then
@@ -50,9 +58,15 @@ local function straight_hopper_act(pos, node, active_object_count, active_count_
 		dst_def._mcl_hopper_act( dst_pos, dst_node, active_object_count, active_count_wider )
 	end
 
-	mcl_util.hopper_push(pos, dst_pos)
+	local pushed = mcl_util.hopper_push(pos, dst_pos)
+
 	local src_pos = vector.offset(pos, 0, 1, 0)
-	mcl_util.hopper_pull(pos, src_pos)
+	local pulled = mcl_util.hopper_pull(pos, src_pos)
+
+	if pushed or pulled then mcl_comparators.trigger_update(pos) end
+
+	-- Update comparators
+	mcl_comparators.trigger_update(pos, node)
 end
 
 local function bent_hopper_act(pos, node, active_object_count, active_object_count_wider)
@@ -92,8 +106,103 @@ local function bent_hopper_act(pos, node, active_object_count, active_object_cou
 
 	local src_pos = vector.offset(pos, 0, 1, 0)
 	mcl_util.hopper_pull(pos, src_pos)
+
+	-- Update comparators
+	mcl_comparators.trigger_update(pos, node)
 end
 
+--[[
+  Returns true if an item was pushed to the minecart
+]]
+local function hopper_push_to_mc(mc_ent, dest_pos, inv_size)
+	if not mcl_util.metadata_last_act(minetest.get_meta(dest_pos), "hopper_push_timer", 1) then return false end
+
+	local dest_inv = mcl_entity_invs.load_inv(mc_ent, inv_size)
+	if not dest_inv then
+		mcl_log("No inv")
+		return false
+	end
+
+	local meta = minetest.get_meta(dest_pos)
+	local inv = meta:get_inventory()
+	if not inv then
+		mcl_log("No dest inv")
+		return
+	end
+
+	mcl_log("inv. size: " .. mc_ent._inv_size)
+	for i = 1, mc_ent._inv_size, 1 do
+		local stack = inv:get_stack("main", i)
+
+		mcl_log("i: " .. tostring(i))
+		mcl_log("Name: [" .. tostring(stack:get_name()) .. "]")
+		mcl_log("Count: " .. tostring(stack:get_count()))
+		mcl_log("stack max: " .. tostring(stack:get_stack_max()))
+
+		if not stack:get_name() or stack:get_name() ~= "" then
+			if dest_inv:room_for_item("main", stack:peek_item()) then
+				mcl_log("Room so unload")
+				dest_inv:add_item("main", stack:take_item())
+				inv:set_stack("main", i, stack)
+
+				-- Take one item and stop until next time
+				return
+			else
+				mcl_log("no Room")
+			end
+
+		else
+			mcl_log("nothing there")
+		end
+	end
+end
+--[[
+  Returns true if an item was pulled from the minecart
+]]
+local function hopper_pull_from_mc(mc_ent, dest_pos, inv_size)
+	if not mcl_util.metadata_last_act(minetest.get_meta(dest_pos), "hopper_pull_timer", 1) then return false end
+
+	local inv = mcl_entity_invs.load_inv(mc_ent, inv_size)
+	if not inv then
+		mcl_log("No inv")
+		return false
+	end
+
+	local dest_meta = minetest.get_meta(dest_pos)
+	local dest_inv = dest_meta:get_inventory()
+	if not dest_inv then
+		mcl_log("No dest inv")
+		return false
+	end
+
+	mcl_log("inv. size: " .. mc_ent._inv_size)
+	for i = 1, mc_ent._inv_size, 1 do
+		local stack = inv:get_stack("main", i)
+
+		mcl_log("i: " .. tostring(i))
+		mcl_log("Name: [" .. tostring(stack:get_name()) .. "]")
+		mcl_log("Count: " .. tostring(stack:get_count()))
+		mcl_log("stack max: " .. tostring(stack:get_stack_max()))
+
+		if not stack:get_name() or stack:get_name() ~= "" then
+			if dest_inv:room_for_item("main", stack:peek_item()) then
+				mcl_log("Room so unload")
+				dest_inv:add_item("main", stack:take_item())
+				inv:set_stack("main", i, stack)
+
+				-- Take one item and stop until next time, report that we took something
+				return true
+			else
+				mcl_log("no Room")
+			end
+
+		else
+			mcl_log("nothing there")
+		end
+	end
+end
+mcl_hoppers.pull_from_minecart = hopper_pull_from_mc
+
 -- Downwards hopper (base definition)
 
 ---@type node_definition
@@ -188,17 +297,61 @@ local def_hopper = {
 		end
 	end,
 	on_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
+		mcl_comparators.trigger_update(pos)
 		minetest.log("action", player:get_player_name() ..
 			" moves stuff in mcl_hoppers at " .. minetest.pos_to_string(pos))
 	end,
 	on_metadata_inventory_put = function(pos, listname, index, stack, player)
+		mcl_comparators.trigger_update(pos)
 		minetest.log("action", player:get_player_name() ..
 			" moves stuff to mcl_hoppers at " .. minetest.pos_to_string(pos))
 	end,
 	on_metadata_inventory_take = function(pos, listname, index, stack, player)
+		mcl_comparators.trigger_update(pos)
 		minetest.log("action", player:get_player_name() ..
 			" takes stuff from mcl_hoppers at " .. minetest.pos_to_string(pos))
 	end,
+	_mcl_minecarts_on_enter_below = function(pos, cart, next_dir)
+		-- Only pull to containers
+		if cart and cart.groups and (cart.groups.container or 0) ~= 0 then
+			cart:add_node_watch(pos)
+			hopper_push_to_mc(cart, pos, 5)
+		end
+	end,
+	_mcl_minecarts_on_enter_above = function(pos, cart, next_dir)
+		-- Only push to containers
+		if cart and cart.groups and (cart.groups.container or 0) ~= 0 then
+			cart:add_node_watch(pos)
+			hopper_pull_from_mc(cart, pos, 5)
+		end
+	end,
+	_mcl_minecarts_on_leave_above = function(pos, cart, next_dir)
+		if not cart then return end
+
+		cart:remove_node_watch(pos)
+	end,
+	_mcl_minecarts_node_on_step = function(pos, cart, dtime, cartdata)
+		if not cart then
+			minetest.log("warning", "trying to process hopper-to-minecart movement without luaentity")
+			return
+		end
+
+		local cart_pos = mcl_minecarts.get_cart_position(cartdata)
+		if not cart_pos then return false end
+		if vector.distance(cart_pos, pos) > 1.5 then
+			cart:remove_node_watch(pos)
+			return
+		end
+		if vector.direction(pos,cart_pos).y > 0 then
+			-- The cart is above us, pull from minecart
+			hopper_pull_from_mc(cart, pos, 5)
+		else
+			hopper_push_to_mc(cart, pos, 5)
+		end
+
+		return true
+	end,
+	_mcl_comparators_get_reading = get_reading,
 	sounds = mcl_sounds.node_sound_metal_defaults(),
 
 	_mcl_blast_resistance = 4.8,
@@ -390,20 +543,83 @@ local def_hopper_side = {
 		end
 	end,
 	on_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
+		mcl_comparators.trigger_update(pos)
 		minetest.log("action", player:get_player_name() ..
-			" moves stuff in mcl_hoppers at " .. minetest.pos_to_string(pos))
+			" moves stuff in mcl_hoppers at (1) " .. minetest.pos_to_string(pos))
 	end,
 	on_metadata_inventory_put = function(pos, listname, index, stack, player)
+		mcl_comparators.trigger_update(pos)
 		minetest.log("action", player:get_player_name() ..
-			" moves stuff to mcl_hoppers at " .. minetest.pos_to_string(pos))
+			" moves stuff to mcl_hoppers at (2) " .. minetest.pos_to_string(pos))
 	end,
 	on_metadata_inventory_take = function(pos, listname, index, stack, player)
+		mcl_comparators.trigger_update(pos)
 		minetest.log("action", player:get_player_name() ..
-			" takes stuff from mcl_hoppers at " .. minetest.pos_to_string(pos))
+			" takes stuff from mcl_hoppers at (3) " .. minetest.pos_to_string(pos))
 	end,
 	on_rotate = on_rotate,
 	sounds = mcl_sounds.node_sound_metal_defaults(),
 
+	_mcl_minecarts_on_enter_below = function(pos, cart, next_dir)
+		-- Only push to containers
+		if cart and cart.groups and (cart.groups.container or 0) ~= 0 then
+			cart:add_node_watch(pos)
+			hopper_pull_from_mc(cart, pos, 5)
+		end
+	end,
+	_mcl_minecarts_on_leave_below = function(pos, cart, next_dir)
+		if not cart then return end
+
+		cart:remove_node_watch(pos)
+	end,
+	_mcl_minecarts_on_enter_side = function(pos, cart, next_dir, rail_pos)
+		if not cart then return end
+
+		-- Only try to push to minecarts when the spout position is pointed at the rail
+		local face = minetest.get_node(pos).param2
+		local dst_pos = {}
+		if face == 0 then
+			dst_pos = vector.offset(pos, -1, 0, 0)
+		elseif face == 1 then
+			dst_pos = vector.offset(pos, 0, 0, 1)
+		elseif face == 2 then
+			dst_pos = vector.offset(pos, 1, 0, 0)
+		elseif face == 3 then
+			dst_pos = vector.offset(pos, 0, 0, -1)
+		end
+		if dst_pos ~= rail_pos then return end
+
+		-- Only push to containers
+		if cart.groups and (cart.groups.container or 0) ~= 0 then
+			cart:add_node_watch(pos)
+		end
+
+		hopper_push_to_mc(cart, pos, 5)
+	end,
+	_mcl_minecarts_on_leave_side = function(pos, cart, next_dir)
+		if not cart then return end
+
+		cart:remove_node_watch(pos)
+	end,
+	_mcl_minecarts_node_on_step = function(pos, cart, dtime, cartdata)
+		if not cart then return end
+
+		local cart_pos = mcl_minecarts.get_cart_position(cartdata)
+		if not cart_pos then return false end
+		if vector.distance(cart_pos, pos) > 1.5 then
+			cart:remove_node_watch(pos)
+			return false
+		end
+
+		if cart_pos.y == pos.y then
+			hopper_push_to_mc(cart, pos, 5)
+		elseif cart_pos.y > pos.y then
+			hopper_pull_from_mc(cart, pos, 5)
+		end
+
+		return true
+	end,
+
 	_mcl_blast_resistance = 4.8,
 	_mcl_hardness = 3,
 }
@@ -435,87 +651,6 @@ minetest.register_node("mcl_hoppers:hopper_side_disabled", def_hopper_side_disab
 
 --[[ END OF NODE DEFINITIONS ]]
 
-local function hopper_pull_from_mc(mc_ent, dest_pos, inv_size)
-	local inv = mcl_entity_invs.load_inv(mc_ent, inv_size)
-	if not inv then
-		mcl_log("No inv")
-		return false
-	end
-
-	local dest_meta = minetest.get_meta(dest_pos)
-	local dest_inv = dest_meta:get_inventory()
-	if not dest_inv then
-		mcl_log("No dest inv")
-		return
-	end
-
-	mcl_log("inv. size: " .. mc_ent._inv_size)
-	for i = 1, mc_ent._inv_size, 1 do
-		local stack = inv:get_stack("main", i)
-
-		mcl_log("i: " .. tostring(i))
-		mcl_log("Name: [" .. tostring(stack:get_name()) .. "]")
-		mcl_log("Count: " .. tostring(stack:get_count()))
-		mcl_log("stack max: " .. tostring(stack:get_stack_max()))
-
-		if not stack:get_name() or stack:get_name() ~= "" then
-			if dest_inv:room_for_item("main", stack:peek_item()) then
-				mcl_log("Room so unload")
-				dest_inv:add_item("main", stack:take_item())
-				inv:set_stack("main", i, stack)
-
-				-- Take one item and stop until next time
-				return
-			else
-				mcl_log("no Room")
-			end
-
-		else
-			mcl_log("nothing there")
-		end
-	end
-end
-
-local function hopper_push_to_mc(mc_ent, dest_pos, inv_size)
-	local dest_inv = mcl_entity_invs.load_inv(mc_ent, inv_size)
-	if not dest_inv then
-		mcl_log("No inv")
-		return false
-	end
-
-	local meta = minetest.get_meta(dest_pos)
-	local inv = meta:get_inventory()
-	if not inv then
-		mcl_log("No dest inv")
-		return
-	end
-
-	mcl_log("inv. size: " .. mc_ent._inv_size)
-	for i = 1, mc_ent._inv_size, 1 do
-		local stack = inv:get_stack("main", i)
-
-		mcl_log("i: " .. tostring(i))
-		mcl_log("Name: [" .. tostring(stack:get_name()) .. "]")
-		mcl_log("Count: " .. tostring(stack:get_count()))
-		mcl_log("stack max: " .. tostring(stack:get_stack_max()))
-
-		if not stack:get_name() or stack:get_name() ~= "" then
-			if dest_inv:room_for_item("main", stack:peek_item()) then
-				mcl_log("Room so unload")
-				dest_inv:add_item("main", stack:take_item())
-				inv:set_stack("main", i, stack)
-
-				-- Take one item and stop until next time
-				return
-			else
-				mcl_log("no Room")
-			end
-
-		else
-			mcl_log("nothing there")
-		end
-	end
-end
 
 --[[ BEGIN OF ABM DEFINITONS ]]
 
@@ -555,7 +690,7 @@ minetest.register_abm({
 							and (hm_pos.z >= pos.z - DIST_FROM_MC and hm_pos.z <= pos.z + DIST_FROM_MC) then
 							mcl_log("Minecart close enough")
 							if entity.name == "mcl_minecarts:hopper_minecart" then
-								hopper_pull_from_mc(entity, pos, 5)
+								--hopper_pull_from_mc(entity, pos, 5)
 							elseif entity.name == "mcl_minecarts:chest_minecart" or entity.name == "mcl_boats:chest_boat" then
 								hopper_pull_from_mc(entity, pos, 27)
 							end
@@ -564,7 +699,7 @@ minetest.register_abm({
 							and (hm_pos.z >= pos.z - DIST_FROM_MC and hm_pos.z <= pos.z + DIST_FROM_MC) then
 							mcl_log("Minecart close enough")
 							if entity.name == "mcl_minecarts:hopper_minecart" then
-								hopper_push_to_mc(entity, pos, 5)
+								--hopper_push_to_mc(entity, pos, 5)
 							elseif entity.name == "mcl_minecarts:chest_minecart" or entity.name == "mcl_boats:chest_boat" then
 								hopper_push_to_mc(entity, pos, 27)
 							end

mods/ITEMS/mcl_hoppers/mod.conf

@@ -1,4 +1,4 @@
 name = mcl_hoppers
 description = It's just a clone of Minecraft hoppers, functions nearly identical to them minus mesecons making them stop and the way they're placed.
-depends = mcl_core, mcl_formspec, mcl_sounds, mcl_util, mcl_dye
+depends = mcl_core, mcl_formspec, mcl_sounds, mcl_util, mcl_dye, mcl_comparators
 optional_depends = doc, screwdriver

mods/MAPGEN/tsm_railcorridors/gameconfig.lua

@@ -3,17 +3,38 @@
 
 -- Adapted for MineClone 2!
 
+-- Imports
+local create_minecart = mcl_minecarts.create_minecart
+local get_cart_data = mcl_minecarts.get_cart_data
+local save_cart_data = mcl_minecarts.save_cart_data
+
 -- Node names (Don't use aliases!)
 tsm_railcorridors.nodes = {
 	dirt = "mcl_core:dirt",
 	chest = "mcl_chests:chest",
-	rail = "mcl_minecarts:rail",
+	rail = "mcl_minecarts:rail_v2",
 	torch_floor = "mcl_torches:torch",
 	torch_wall = "mcl_torches:torch_wall",
 	cobweb = "mcl_core:cobweb",
 	spawner = "mcl_mobspawners:spawner",
 }
 
+local update_rail_connections = mcl_minecarts.update_rail_connections
+local rails_to_update = {}
+tsm_railcorridors.on_place_node = {
+	[tsm_railcorridors.nodes.rail] = function(pos, node)
+		rails_to_update[#rails_to_update + 1] = pos
+	end,
+}
+tsm_railcorridors.on_start = function()
+	rails_to_update = {}
+end
+tsm_railcorridors.on_finish = function()
+	for _,pos in pairs(rails_to_update) do
+		update_rail_connections(pos, {legacy = true, ignore_neighbor_connections = true})
+	end
+end
+
 local mg_name = minetest.get_mapgen_setting("mg_name")
 
 if mg_name == "v6" then
@@ -37,19 +58,31 @@ else
 end
 
 
--- TODO: Use minecart with chest instead of normal minecart
-tsm_railcorridors.carts = { "mcl_minecarts:minecart" }
+tsm_railcorridors.carts = { "mcl_minecarts:chest_minecart", "mcl_minecarts:hopper_minecart", "mcl_minecarts:minecart" }
+local has_loot = {
+	["mcl_minecarts:chest_minecart"] = true,
+	["mcl_minecarts:hopper_minceart"] = true,
+}
 
-function tsm_railcorridors.on_construct_cart(pos, cart)
-	-- TODO: Fill cart with treasures
+function tsm_railcorridors.create_cart_staticdata(entity_id,pos, pr)
+	local uuid = create_minecart(entity_id, pos, vector.new(1,0,0))
 
-	-- This is it? There's this giant hack announced in
-	-- the other file and I grep for the function and it's
-	-- a stub? :)
+	-- Fill the cart with loot
+	local cartdata = get_cart_data(uuid)
+	if cartdata and has_loot[entity_id] then
+		local items = tsm_railcorridors.get_treasures(pr)
 
-	-- The path here using some minetest.after hackery was
-	-- deactivated in init.lua - reactivate when this does
-	-- something the function is called RecheckCartHack.
+		-- Convert from ItemStack to itemstrings
+		for k,item in pairs(items) do
+			items[k] = item:to_string()
+		end
+		cartdata.inventory = items
+
+		print("cartdata = "..dump(cartdata))
+		save_cart_data(uuid)
+	end
+
+	return minetest.serialize({ uuid=uuid, seq=1 })
 end
 
 -- Fallback function. Returns a random treasure. This function is called for chests
@@ -102,11 +135,11 @@ function tsm_railcorridors.get_treasures(pr)
 		stacks_min = 3,
 		stacks_max = 3,
 		items = {
-			{ itemstring = "mcl_minecarts:rail", weight = 20, amount_min = 4, amount_max = 8 },
+			{ itemstring = "mcl_minecarts:rail_v2", weight = 20, amount_min = 4, amount_max = 8 },
 			{ itemstring = "mcl_torches:torch", weight = 15, amount_min = 1, amount_max = 16 },
-			{ itemstring = "mcl_minecarts:activator_rail", weight = 5, amount_min = 1, amount_max = 4 },
-			{ itemstring = "mcl_minecarts:detector_rail", weight = 5, amount_min = 1, amount_max = 4 },
-			{ itemstring = "mcl_minecarts:golden_rail", weight = 5, amount_min = 1, amount_max = 4 },
+			{ itemstring = "mcl_minecarts:activator_rail_v2", weight = 5, amount_min = 1, amount_max = 4 },
+			{ itemstring = "mcl_minecarts:detector_rail_v2", weight = 5, amount_min = 1, amount_max = 4 },
+			{ itemstring = "mcl_minecarts:golden_rail_v2", weight = 5, amount_min = 1, amount_max = 4 },
 		}
 	},
 	-- non-MC loot: 50% chance to add a minecart, offered as alternative to spawning minecarts on rails.

mods/MAPGEN/tsm_railcorridors/init.lua

@@ -1,7 +1,9 @@
 local pairs = pairs
 local tonumber = tonumber
 
-tsm_railcorridors = {}
+tsm_railcorridors = {
+	after = {},
+}
 
 -- Load node names
 dofile(minetest.get_modpath(minetest.get_current_modname()).."/gameconfig.lua")
@@ -170,6 +172,10 @@ local function SetNodeIfCanBuild(pos, node, check_above, can_replace_rail)
 			(can_replace_rail and name == tsm_railcorridors.nodes.rail)
 			) then
 		minetest.set_node(pos, node)
+		local after = tsm_railcorridors.on_place_node[node.name]
+		if after then
+			after(pos, node)
+		end
 		return true
 	else
 		return false
@@ -394,34 +400,6 @@ local function PlaceChest(pos, param2)
 	end
 end
 
-
--- This function checks if a cart has ACTUALLY been spawned.
--- To be calld by minetest.after.
--- This is a workaround thanks to the fact that minetest.add_entity is unreliable as fuck
--- See: https://github.com/minetest/minetest/issues/4759
--- FIXME: Kill this horrible hack with fire as soon you can.
-
--- Why did anyone activate it in the first place? It doesn't
--- have a function seeing as there are no chest minecarts yet.
---[[
-local function RecheckCartHack(params)
-	local pos = params[1]
-	local cart_id = params[2]
-	-- Find cart
-	for _, obj in pairs(minetest.get_objects_inside_radius(pos, 1)) do
-		if obj and obj:get_luaentity().name == cart_id then
-			-- Cart found! We can now safely call the callback func.
-			-- (calling it earlier has the danger of failing)
-			minetest.log("info", "[tsm_railcorridors] Cart spawn succeeded: "..minetest.pos_to_string(pos))
-			tsm_railcorridors.on_construct_cart(pos, obj)
-			return
-		end
-	end
-	minetest.log("info", "[tsm_railcorridors] Cart spawn FAILED: "..minetest.pos_to_string(pos))
-end
---]]
-
-
 -- Try to place a cobweb.
 -- pos: Position of cobweb
 -- needs_check: If true, checks if any of the nodes above, below or to the side of the cobweb.
@@ -944,16 +922,13 @@ local function spawn_carts()
 			-- See <https://github.com/minetest/minetest/issues/4759>
 			local cart_id = tsm_railcorridors.carts[cart_type]
 			minetest.log("info", "[tsm_railcorridors] Cart spawn attempt: "..minetest.pos_to_string(cpos))
-			minetest.add_entity(cpos, cart_id)
+			local cart_staticdata = nil
 
-			-- This checks if the cart is actually spawned, it's a giant hack!
-			-- Note that the callback function is also called there.
-			-- TODO: Move callback function to this position when the
-			-- minetest.add_entity bug has been fixed.
+			-- Try to create cart staticdata
+			local hook = tsm_railcorridors.create_cart_staticdata
+			if hook then cart_staticdata = hook(cart_id, cpos, pr) end
 
-			-- minetest.after(3, RecheckCartHack, {cpos, cart_id})
-			-- This whole recheck logic leads to a stub right now
-			-- it can be reenabled when chest carts are a thing.
+			minetest.add_entity(cpos, cart_id, cart_staticdata)
 		end
 	end
 	carts_table = {}
@@ -1123,7 +1098,15 @@ mcl_structures.register_structure("mineshaft",{
 		end
 		if p.y > -10 then return true end
 		InitRandomizer(blockseed)
+
+		local hook = tsm_railcorridors.on_start
+		if hook then hook() end
+
 		create_corridor_system(p, pr)
+
+		local hook = tsm_railcorridors.on_finish
+		if hook then hook() end
+
 		return true
 	end,
 

mods/MAPGEN/tsm_railcorridors/settingtypes.txt

@@ -25,7 +25,7 @@ tsm_railcorridors_probability_chest (Chest probability) float 0.05 0.0 1.0
 #of finding a cart in rail corridors with high rail damage will be lower.
 #NOTE: Due to a bug in Minetest <https://github.com/minetest/minetest/issues/4759>
 #carts often fail to spawn even if they should.
-tsm_railcorridors_probability_cart (Cart probability) float 0.0 0.0 1.0
+tsm_railcorridors_probability_cart (Cart probability) float 0.05 0.0 1.0
 
 #If enabled, cobwebs may be placed in some corridors.
 #Currently, cobwebs are only supported with the Mobs Redo mod.

mods/PLAYER/mcl_playerinfo/init.lua

@@ -1,7 +1,10 @@
 local table = table
 
+local storage = minetest.get_mod_storage()
+
 -- Player state for public API
 mcl_playerinfo = {}
+local player_mod_metadata = {}
 
 -- Get node but use fallback for nil or unknown
 local function node_ok(pos, fallback)
@@ -21,8 +24,6 @@ local function node_ok(pos, fallback)
 	return fallback
 end
 
-local time = 0
-
 local function get_player_nodes(player_pos)
 	local work_pos = table.copy(player_pos)
 
@@ -43,11 +44,10 @@ local function get_player_nodes(player_pos)
 	return node_stand, node_stand_below, node_head, node_feet, node_head_top
 end
 
+local time = 0
 minetest.register_globalstep(function(dtime)
-
-	time = time + dtime
-
 	-- Run the rest of the code every 0.5 seconds
+	time = time + dtime
 	if time < 0.5 then
 		return
 	end
@@ -76,6 +76,23 @@ minetest.register_globalstep(function(dtime)
 
 end)
 
+function mcl_playerinfo.get_mod_meta(player_name, modname)
+	-- Load the player's metadata
+	local meta = player_mod_metadata[player_name]
+	if not meta then
+		meta = minetest.deserialize(storage:get_string(player_name))
+	end
+	if not meta then
+		meta = {}
+	end
+	player_mod_metadata[player_name] = meta
+
+	-- Get the requested module's section of the metadata
+	local mod_meta = meta[modname] or {}
+	meta[modname] = mod_meta
+	return mod_meta
+end
+
 -- set to blank on join (for 3rd party mods)
 minetest.register_on_joinplayer(function(player)
 	local name = player:get_player_name()
@@ -87,7 +104,6 @@ minetest.register_on_joinplayer(function(player)
 		node_stand_below = "",
 		node_head_top = "",
 	}
-
 end)
 
 -- clear when player leaves
@@ -96,3 +112,9 @@ minetest.register_on_leaveplayer(function(player)
 
 	mcl_playerinfo[name] = nil
 end)
+
+minetest.register_on_shutdown(function()
+	for name,data in pairs(player_mod_metadata) do
+		storage:set_string(name, minetest.serialize(data))
+	end
+end)