update

mods/advtrains/advtrains/api_doc.txt

@@ -182,9 +182,11 @@ minetest.register_node(nodename, {
 		^- called when a train leaves the rail
 		
 		-- The following function is only in effect when interlocking is enabled:
-		on_train_approach = function(pos, train_id, train, index, lzbdata)
+		on_train_approach = function(pos, train_id, train, index, has_entered, lzbdata)
 		^- called when a train is approaching this position, called exactly once for every path recalculation (which can happen at any time)
 		^- This is called so that if the train would start braking now, it would come to halt about(wide approx) 5 nodes before the rail.
+		^- has_entered: when true, the train is already standing on this node with its front tip, and the enter callback has already been called.
+		   Possibly, some actions need not to be taken in this case. Only set if it's the very first node the train is standing on.
 		^- lzbdata should be ignored and nothing should be assigned to it
 	}
 })

mods/advtrains/advtrains/atc.lua

@@ -72,6 +72,12 @@ function atc.send_command(pos, par_tid)
 			end
 		else
 			atwarn("ATC rail at", pos, ": Sending command failed: There's no train at this position. This seems to be a bug.")
+			-- huch
+			--local train = advtrains.trains[train_id_temp_debug]
+			--atlog("Train speed is",train.velocity,", have moved",train.dist_moved_this_step,", lever",train.lever)
+			--advtrains.path_print(train, atlog)
+			-- TODO track again when ATC bugs occur...
+			
 		end
 	else
 		atwarn("ATC rail at", pos, ": Sending command failed: Entry for controller not found.")
@@ -108,15 +114,12 @@ advtrains.atc_function = function(def, preset, suffix, rotation)
 		return {
 			after_place_node=apn_func,
 			after_dig_node=function(pos)
-				return advtrains.pcall(function()
 				advtrains.invalidate_all_paths(pos)
 				advtrains.ndb.clear(pos)
 				local pts=minetest.pos_to_string(pos)
 				atc.controllers[pts]=nil
-				end)
 			end,
 			on_receive_fields = function(pos, formname, fields, player)
-				return advtrains.pcall(function()
 				if advtrains.is_protected(pos, player:get_player_name()) then
 					minetest.record_protection_violation(pos, player:get_player_name())
 					return
@@ -124,27 +127,27 @@ advtrains.atc_function = function(def, preset, suffix, rotation)
 				local meta=minetest.get_meta(pos)
 				if meta then
 					if not fields.save then 
-							--maybe only the dropdown changed
+						--[[--maybe only the dropdown changed
 						if fields.mode then
 							meta:set_string("mode", idxtrans[fields.mode])
 							if fields.mode=="digiline" then
-									meta:set_string("infotext", attrans("ATC controller, mode @1\nChannel: @2", (fields.mode or "?"), meta:get_string("command")) )
+								meta:set_string("infotext", attrans("ATC controller, mode @1\nChannel: @2", fields.mode, meta:get_string("command")) )
 							else
-									meta:set_string("infotext", attrans("ATC controller, mode @1\nCommand: @2", (fields.mode or "?"), meta:get_string("command")) )
+								meta:set_string("infotext", attrans("ATC controller, mode @1\nCommand: @2", fields.mode, meta:get_string("command")) )
 							end
 							meta:set_string("formspec", atc.get_atc_controller_formspec(pos, meta))
-							end
+						end]]--
 						return
 					end
-						meta:set_string("mode", idxtrans[fields.mode])
+					--meta:set_string("mode", idxtrans[fields.mode])
 					meta:set_string("command", fields.command)
-						meta:set_string("command_on", fields.command_on)
+					--meta:set_string("command_on", fields.command_on)
 					meta:set_string("channel", fields.channel)
-						if fields.mode=="digiline" then
-							meta:set_string("infotext", attrans("ATC controller, mode @1\nChannel: @2", (fields.mode or "?"), meta:get_string("command")) )
-						else
-							meta:set_string("infotext", attrans("ATC controller, mode @1\nCommand: @2", (fields.mode or "?"), meta:get_string("command")) )
-						end
+					--if fields.mode=="digiline" then
+					--	meta:set_string("infotext", attrans("ATC controller, mode @1\nChannel: @2", fields.mode, meta:get_string("command")) )
+					--else
+					meta:set_string("infotext", attrans("ATC controller, mode @1\nCommand: @2", "-", meta:get_string("command")) )
+					--end
 					meta:set_string("formspec", atc.get_atc_controller_formspec(pos, meta))
 					
 					local pts=minetest.pos_to_string(pos)
@@ -154,11 +157,10 @@ advtrains.atc_function = function(def, preset, suffix, rotation)
 						atc.send_command(pos)
 					end
 				end
-				end)
 			end,
 			advtrains = {
 				on_train_enter = function(pos, train_id)
-					atc.send_command(pos)
+					atc.send_command(pos, train_id)
 				end,
 			},
 		}
@@ -256,6 +258,11 @@ local matchptn={
 		end
 		return 1
 	end,
+	["A([01])"]=function(id, train, match)
+		if not advtrains.interlocking then return 2 end
+		advtrains.interlocking.ars_set_disable(train, match=="0")
+		return 2
+	end,
 }
 
 eval_conditional = function(command, arrow, speed)

mods/advtrains/advtrains/copytool.lua

@@ -13,7 +13,6 @@ minetest.register_tool("advtrains:copytool", {
 	-- The front of the train is used as the start of the new train and it proceeds backwards from
 	-- the direction of travel.
 	on_place = function(itemstack, placer, pointed_thing)
-			return advtrains.pcall(function()
 			if ((not pointed_thing.type == "node") or (not placer.get_player_name)) then
 				return
 			end
@@ -82,7 +81,6 @@ minetest.register_tool("advtrains:copytool", {
 			train.line = clipboard.line
 
 			return
-			end)
 		end,
 	-- Copy: Take the pointed-at train and put it on the clipboard
 	on_use = function(itemstack, user, pointed_thing)

mods/advtrains/advtrains/couple.lua

@@ -32,7 +32,6 @@ minetest.register_entity("advtrains:discouple", {
 	end,
 	get_staticdata=function() return "DISCOUPLE" end,
 	on_punch=function(self, player)
-		return advtrains.pcall(function()
 			local pname = player:get_player_name()
 			if pname and pname~="" and self.wagon then
 				if advtrains.safe_decouple_wagon(self.wagon.id, pname) then
@@ -41,16 +40,14 @@ minetest.register_entity("advtrains:discouple", {
 					minetest.add_entity(self.object:getpos(), "advtrains:lockmarker")
 				end
 			end
-		end)
 	end,
 	on_step=function(self, dtime)
-		return advtrains.pcall(function()
 			if not self.wagon then
 				self.object:remove()
 				return
 			end
 			--getyaw seems to be a reliable method to check if an object is loaded...if it returns nil, it is not.
-			if not self.wagon.object:getyaw() then
+			if not self.wagon.object:get_yaw() then
 				self.object:remove()
 				return
 			end
@@ -58,7 +55,6 @@ minetest.register_entity("advtrains:discouple", {
 				self.object:remove()
 				return
 			end
-		end)
 	end,
 })
 
@@ -79,7 +75,6 @@ minetest.register_entity("advtrains:couple", {
 	is_couple=true,
 	static_save = false,
 	on_activate=function(self, staticdata)
-		return advtrains.pcall(function()
 			if staticdata=="COUPLE" then
 				--couple entities have no right to exist further...
 				atprint("Couple loaded from staticdata, destroying")
@@ -87,11 +82,9 @@ minetest.register_entity("advtrains:couple", {
 				return
 			end
 			self.object:set_armor_groups({immmortal=1})
-		end)
 	end,
 	get_staticdata=function(self) return "COUPLE" end,
 	on_rightclick=function(self, clicker)
-		return advtrains.pcall(function()
 			if not self.train_id_1 or not self.train_id_2 then return end
 			
 			local pname=clicker
@@ -102,15 +95,12 @@ minetest.register_entity("advtrains:couple", {
 			else
 				lockmarker(self.object)
 			end
-		end)
 	end,
 	on_step=function(self, dtime)
-		return advtrains.pcall(function()
 			if advtrains.wagon_outside_range(self.object:getpos()) then
 				self.object:remove()
 				return
 			end
-			advtrains.atprint_context_tid=self.train_id_1
 
 			if not self.train_id_1 or not self.train_id_2 then atprint("Couple: train ids not set!") self.object:remove() return end
 			local train1=advtrains.trains[self.train_id_1]
@@ -155,14 +145,12 @@ minetest.register_entity("advtrains:couple", {
 				end
 				local pos_median=advtrains.pos_median(tp1, tp2)
 				if not vector.equals(pos_median, self.object:getpos()) then
-					self.object:setpos(pos_median)
+					self.object:set_pos(pos_median)
 				end
 				self.position_set=true
 			end
 			atprintbm("couple step", t)
 			advtrains.atprint_context_tid=nil
-
-		end)
 	end,
 })
 minetest.register_entity("advtrains:lockmarker", {
@@ -175,7 +163,6 @@ minetest.register_entity("advtrains:lockmarker", {
 	is_lockmarker=true,
 	static_save = false,
 	on_activate=function(self, staticdata)
-		return advtrains.pcall(function()
 			if staticdata=="COUPLE" then
 				--couple entities have no right to exist further...
 				atprint("Couple loaded from staticdata, destroying")
@@ -184,7 +171,6 @@ minetest.register_entity("advtrains:lockmarker", {
 			end
 			self.object:set_armor_groups({immmortal=1})
 			self.life=5
-		end)
 	end,
 	get_staticdata=function(self) return "COUPLE" end,
 	on_step=function(self, dtime)

mods/advtrains/advtrains/debugringbuffer.lua

@@ -24,7 +24,10 @@ function advtrains.drb_dump(tid)
 		return
 	end
 	repeat
-		atdebug(ringbufs[tid][ringbufcnt[tid]])
+		local t = ringbufs[tid][ringbufcnt[tid]]
+		if t then
+			atdebug(t)
+		end
 		ringbufcnt[tid]=ringbufcnt[tid]+1
 		if ringbufcnt[tid] > ringbuflen then
 			ringbufcnt[tid]=0

mods/advtrains/advtrains/init.lua

@@ -26,15 +26,37 @@ minetest.log("action", "[advtrains] Loading...")
 attrans = minetest.get_translator ("advtrains")
 
 --advtrains
+advtrains = {trains={}, player_to_train_mapping={}}
 
-DUMP_DEBUG_SAVE = false
-GENERATE_ATRICIFIAL_LAG = false
+-- =======================Development/debugging settings=====================
+-- DO NOT USE FOR NORMAL OPERATION
+local DUMP_DEBUG_SAVE = false
+-- dump the save files in human-readable format into advtrains_DUMP
+
+local GENERATE_ATRICIFIAL_LAG = false
+local HOW_MANY_LAG = 1.0
+-- Simulate a higher server step interval, as it occurs when the server is on high load
+
+advtrains.IGNORE_WORLD = false
+-- Run advtrains without respecting the world map
+-- - No world collision checks occur
+-- - The NDB forcibly places all nodes stored in it into the world regardless of the world's content.
+-- - Rails do not set the 'attached_node' group
+-- This mode can be useful for debugging/testing a world without the map data available
+-- In this case, choose 'singlenode' as mapgen
+
+local NO_SAVE = false
+-- Do not save any data to advtrains save files
+
+-- ==========================================================================
+
+-- Use a global slowdown factor to slow down train movements. Now a setting
+advtrains.DTIME_LIMIT = tonumber(minetest.settings:get("advtrains_dtime_limit")) or 0.2
+advtrains.SAVE_INTERVAL = tonumber(minetest.settings:get("advtrains_save_interval")) or 60
 
 --Constant for maximum connection value/division of the circle
 AT_CMAX = 16
 
-advtrains = {trains={}, player_to_train_mapping={}}
-
 -- get wagon loading range
 advtrains.wagon_load_range = tonumber(minetest.settings:get("advtrains_wagon_load_range"))
 if not advtrains.wagon_load_range then
@@ -61,25 +83,6 @@ local function reload_saves()
 	end)
 end
 
-function advtrains.pcall(fun)
-	if no_action then return end
-	
-	local succ, return1, return2, return3, return4=xpcall(fun, function(err)
-			atwarn("Lua Error occured: ", err)
-			atwarn(debug.traceback())
-			if advtrains.atprint_context_tid then
-				advtrains.path_print(advtrains.trains[advtrains.atprint_context_tid], atdebug)
-				atwarn(advtrains.trains[advtrains.atprint_context_tid].debug)
-			end
-		end)
-	if not succ then
-		reload_saves()
-	else
-		return return1, return2, return3, return4
-	end
-end
-
-
 advtrains.modpath = minetest.get_modpath("advtrains")
 
 --Advtrains dump (special treatment of pos and sigd)
@@ -464,7 +467,8 @@ advtrains.avt_save = function(remove_players_from_wagons)
 				"trainparts", "recently_collided_with_env",
 				"atc_brake_target", "atc_wait_finish", "atc_command", "atc_delay", "door_open",
 				"text_outside", "text_inside", "line", "routingcode",
-				"il_sections", "speed_restriction", "is_shunt", "points_split", "autocouple"
+				"il_sections", "speed_restriction", "is_shunt",
+				"points_split", "autocouple", "ars_disable",
 			})
 			--then save it
 			tmp_trains[id]=v
@@ -560,14 +564,17 @@ end
 --## MAIN LOOP ##--
 --Calls all subsequent main tasks of both advtrains and atlatc
 local init_load=false
-local save_interval=60
-local save_timer=save_interval
+local save_timer = advtrains.SAVE_INTERVAL
 advtrains.mainloop_runcnt=0
-
+advtrains.global_slowdown = 1
 
 local t = 0
 minetest.register_globalstep(function(dtime_mt)
-	return advtrains.pcall(function()
+		if no_action then
+			-- the advtrains globalstep is skipped by command. Return immediately
+			return
+		end
+
 		advtrains.mainloop_runcnt=advtrains.mainloop_runcnt+1
 		--atprint("Running the main loop, runcnt",advtrains.mainloop_runcnt)
 		--call load once. see advtrains.load() comment
@@ -575,24 +582,30 @@ minetest.register_globalstep(function(dtime_mt)
 			advtrains.load()
 		end
 		
-		local dtime
+		local dtime = dtime_mt * advtrains.global_slowdown
 		if GENERATE_ATRICIFIAL_LAG then
-			dtime = 0.2
+			dtime = HOW_MANY_LAG
 			if os.clock()<t then
 				return
 			end
 			
-			t = os.clock()+0.2
-		else
-			--limit dtime: if trains move too far in one step, automation may cause stuck and wrongly braking trains
-			dtime=dtime_mt
-			if dtime>0.2 then
-				atprint("Limiting dtime to 0.2!")
-				dtime=0.2
+			t = os.clock()+HOW_MANY_LAG
 		end
+		-- if dtime is too high, decrease global slowdown
+		if advtrains.DTIME_LIMIT~=0 then
+			if dtime > advtrains.DTIME_LIMIT then
+				if advtrains.global_slowdown > 0.1 then
+					advtrains.global_slowdown = advtrains.global_slowdown - 0.05
+				else
+					advtrains.global_slowdown = advtrains.global_slowdown / 2
+				end
+				dtime = advtrains.DTIME_LIMIT
+			end
+			-- recover global slowdown slowly over time
+			advtrains.global_slowdown = math.min(advtrains.global_slowdown*1.02, 1)
 		end
 		
-		advtrains.mainloop_trainlogic(dtime)
+		advtrains.mainloop_trainlogic(dtime,advtrains.mainloop_runcnt)
 		if advtrains_itm_mainloop then
 			advtrains_itm_mainloop(dtime)
 		end
@@ -610,10 +623,9 @@ minetest.register_globalstep(function(dtime_mt)
 			local t=os.clock()
 			--save
 			advtrains.save()
-			save_timer=save_interval
+			save_timer = advtrains.SAVE_INTERVAL
 			atprintbm("saving", t)
 		end
-	end)
 end)
 
 --if something goes wrong in these functions, there is no help. no pcall here.
@@ -642,12 +654,27 @@ function advtrains.save(remove_players_from_wagons)
 		atwarn("Instructed to save() but load() was never called!")
 		return
 	end
+	
+	if advtrains.IGNORE_WORLD then
+		advtrains.ndb.restore_all()
+	end
+	
+	if NO_SAVE then
+		return
+	end
+	if no_action then
+		atlog("[save] Saving requested externally, but Advtrains step is disabled. Not saving any data as state may be inconsistent.")
+		return
+	end
+	
+	local t1 = os.clock()
 	advtrains.avt_save(remove_players_from_wagons) --saving advtrains. includes ndb at advtrains.ndb.save_data()
 	if atlatc then
 		atlatc.save()
 	end
-	atprint("[save_all]Saved advtrains save files")
+	atlog("Saved advtrains save files, took",math.floor((os.clock()-t1) * 1000),"ms")
 	
+	-- Cleanup actions
 	--TODO very simple yet hacky workaround for the "green signals" bug
 	advtrains.invalidate_all_paths()
 end
@@ -662,11 +689,9 @@ minetest.register_chatcommand("at_empty_seats",
         description = "Detach all players, especially the offline ones, from all trains. Use only when no one serious is on a train.", -- Full description
         privs = {train_operator=true, server=true}, -- Require the "privs" privilege to run
         func = function(name, param)
-			return advtrains.pcall(function()
 				atwarn("Data is being saved. While saving, advtrains will remove the players from trains. Save files will be reloaded afterwards!")
 				advtrains.save(true)
 				reload_saves()
-			end)
         end,
 })
 -- This chat command solves another problem: Trains getting randomly stuck.
@@ -676,13 +701,36 @@ minetest.register_chatcommand("at_reroute",
         description = "Delete all train routes, force them to recalculate", 
         privs = {train_operator=true}, -- Only train operator is required, since this is relatively safe.
         func = function(name, param)
-			return advtrains.pcall(function()
 				advtrains.invalidate_all_paths()
 				return true, "Successfully invalidated train routes"
-			end)
         end,
 })
 
+minetest.register_chatcommand("at_disable_step",
+	{
+        params = "<yes/no>", 
+        description = "Disable the advtrains globalstep temporarily", 
+        privs = {server=true},
+        func = function(name, param)
+			if minetest.is_yes(param) then
+				-- disable everything, and turn off saving
+				no_action = true;
+				atwarn("The advtrains globalstep has been disabled. Trains are not moving, and no data is saved! Run '/at_disable_step no' to enable again!")
+				return true, "Disabled advtrains successfully"
+			elseif no_action then
+				atwarn("Re-enabling advtrains globalstep...")
+				reload_saves()
+				return true
+			else
+				return false, "Advtrains is already running normally!"
+			end
+        end,
+})
+
+advtrains.is_no_action = function()
+	return no_action
+end
+
 
 local tot=(os.clock()-lot)*1000
 minetest.log("action", "[advtrains] Loaded in "..tot.."ms")

mods/advtrains/advtrains/lzb.lua

@@ -4,20 +4,36 @@
 --[[
 Documentation of train.lzb table
 train.lzb = {
-	trav = Current index that the traverser has advanced so far
-	oncoming = table containing oncoming signals, in order of appearance on the path
+	trav_index = Current index that the traverser has advanced so far
+	checkpoints = table containing oncoming signals, in order of index
 		{
 			pos = position of the point
-			idx = where this is on the path
-			spd = speed allowed to pass
-			fun = function(pos, id, train, index, speed, lzbdata)
+			index = where this is on the path
+			speed = speed allowed to pass. nil = no effect
+			callback = function(pos, id, train, index, speed, lzbdata)
 			-- Function that determines what to do on the train in the moment it drives over that point.
+			-- When spd==0, called instead when train has stopped in front
+			-- nil = no effect
+			lzbdata = {}
+			-- Table of custom data filled in by approach callbacks
+			-- Whenever an approach callback inserts an LZB checkpoint with changed lzbdata,
+			-- all consecutive approach callbacks will see these passed as lzbdata table.
+			
+			udata = arbitrary user data, no official way to retrieve (do not use)
 		}
+	trav_lzbdata = currently active lzbdata table at traverser index
 }
-each step, for every item in "oncoming", we need to determine the location to start braking (+ some safety margin)
-and, if we passed this point for at least one of the items, initiate brake.
-When speed has dropped below, say 3, decrease the margin to zero, so that trains actually stop at the signal IP.
-The spd variable and travsht need to be updated on every aspect change. it's probably best to reset everything when any aspect changes
+The LZB subsystem keeps track of "checkpoints" the train will pass in the future, and has two main tasks:
+1. run approach callbacks, and run callbacks when passing LZB checkpoints
+2. keep track of the permitted speed at checkpoints, and make sure that the train brakes accordingly
+To perform 2, it populates the train.path_speed table which is handled along with the path subsystem.
+This table is used in trainlogic.lua/train_step_b() and applied to the velocity calculations.
+
+Note: in contrast to node enter callbacks, which are called when the train passes the .5 index mark, LZB callbacks are executed on passing the .0 index mark!
+If an LZB checkpoint has speed 0, the train will still enter the node (the enter callback will be called), but will stop at the 0.9 index mark (for details, see SLOW_APPROACH in trainlogic.lua)
+
+The start point for the LZB traverser (and thus the first node that will receive an approach callback) is floor(train.index) + 1. This means, once the LZB checkpoint callback has fired,
+this path node will not receive any further approach callbacks for the same approach situation
 ]]
 
 
@@ -45,42 +61,130 @@ function advtrains.set_lzb_param(par, val)
 	end
 end
 
+local function resolve_latest_lzbdata(ckp, index)
+	local i = #ckp
+	local ckpi
+	while i>0 do
+		ckpi = ckp[i]
+		if ckpi.index <= index and ckpi.lzbdata then
+			return ckpi.lzbdata
+		end
+		i=i-1
+	end
+	return {}
+end
 
 local function look_ahead(id, train)
+	local lzb = train.lzb
+	if lzb.zero_checkpoint then
+		-- if the checkpoints list contains a zero checkpoint, don't look ahead
+		-- in order to not trigger approach callbacks on the wrong path
+		return
+	end
 	
 	local acc = advtrains.get_acceleration(train, 1)
-	local vel = train.velocity
+	-- worst-case: the starting point is maximum speed
+	local vel = train.max_speed or train.velocity
 	local brakedst = ( -(vel*vel) / (2*acc) ) * params.DST_FACTOR
 	
-	local brake_i = advtrains.path_get_index_by_offset(train, train.index, brakedst + params.BRAKE_SPACE)
+	--local brake_i = advtrains.path_get_index_by_offset(train, train.index, brakedst + params.BRAKE_SPACE)
+	-- worst case (don't use index_by_offset)
+	local brake_i = atfloor(train.index + brakedst + params.BRAKE_SPACE)
+	atprint("LZB: looking ahead up to ", brake_i)
+	
 	--local aware_i = advtrains.path_get_index_by_offset(train, brake_i, AWARE_ZONE)
 	
-	local lzb = train.lzb
-	local trav = lzb.trav
+	local trav = lzb.trav_index
+	-- retrieve latest lzbdata
+	if not lzb.trav_lzbdata then
+		lzb.trav_lzbdata = resolve_latest_lzbdata(lzb.checkpoints, trav)
+	end
 	
-	--train.debug = lspd
+	if lzb.trav_lzbdata.off_track then
+		--previous position was off track, do not scan any further
+	end
 	
-	while trav <= brake_i do
-		trav = trav + 1
+	while trav <= brake_i and not lzb.zero_checkpoint do
 		local pos = advtrains.path_get(train, trav)
 		-- check offtrack
-		if trav > train.path_trk_f then
-			table.insert(lzb.oncoming, {
-				pos = pos,
-				idx = trav-1,
-				spd = 0,
-			})
+		if trav - 1 == train.path_trk_f then
+			lzb.trav_lzbdata.off_track = true
+			advtrains.lzb_add_checkpoint(train, trav - 1, 0, nil, lzb.trav_lzbdata)
 		else
 			-- run callbacks
 			-- Note: those callbacks are defined in trainlogic.lua for consistency with the other node callbacks
-			advtrains.tnc_call_approach_callback(pos, id, train, trav, lzb.data)
+			advtrains.tnc_call_approach_callback(pos, id, train, trav, lzb.trav_lzbdata)
 			
 		end
+		trav = trav + 1
+		
 	end
 	
-	lzb.trav = trav
+	lzb.trav_index = trav
 	
 end
+advtrains.lzb_look_ahead = look_ahead
+
+
+local function call_runover_callbacks(id, train)
+	if not train.lzb then return end
+	
+	local i = 1
+	local idx = atfloor(train.index)
+	local ckp = train.lzb.checkpoints
+	while ckp[i] do
+		if ckp[i].index <= idx then
+			atprint("LZB: checkpoint run over: i=",ckp[i].index,"s=",ckp[i].speed)
+			-- call callback
+			local it = ckp[i]
+			if it.callback then
+				it.callback(it.pos, id, train, it.index, it.speed, train.lzb.lzbdata)
+			end
+			-- note: lzbdata is always defined as look_ahead was called before
+			table.remove(ckp, i)
+		else
+			i = i + 1
+		end
+	end
+end
+
+-- Flood-fills train.path_speed, based on this checkpoint 
+local function apply_checkpoint_to_path(train, checkpoint)
+	if not checkpoint.speed then
+		return
+	end
+	atprint("LZB: applying checkpoint: i=",checkpoint.index,"s=",checkpoint.speed)
+	
+	if checkpoint.speed == 0 then
+		train.lzb.zero_checkpoint = true
+	end
+	
+	-- make sure path exists until checkpoint
+	local pos = advtrains.path_get(train, checkpoint.index)
+	
+	local brake_accel = advtrains.get_acceleration(train, 11)
+	
+	-- start with the checkpoint index at specified speed
+	local index = checkpoint.index
+	local p_speed -- speed in path_speed
+	local c_speed = checkpoint.speed -- calculated speed at current index
+	while true do
+		p_speed = train.path_speed[index]
+		if (p_speed and p_speed <= c_speed) or index < train.index then
+			--we're done. train already slower than wanted at this position
+			return
+		end
+		-- insert calculated target speed
+		train.path_speed[index] = c_speed
+		-- calculate c_speed at previous index
+		advtrains.path_get(train, index-1)
+		local eldist = train.path_dist[index] - train.path_dist[index-1]
+		-- Calculate the start velocity the train would have if it had a end velocity of c_speed and accelerating with brake_accel, after a distance of eldist:
+		-- v0² = v1² - 2*a*s
+		c_speed = math.sqrt( (c_speed * c_speed) - (2 * brake_accel * eldist) )
+		index = index - 1
+	end
+end
 
 --[[
 Distance needed to accelerate from v0 to v1 with constant acceleration a:
@@ -90,95 +194,74 @@ s = v0 * -------  +  - * | ------- |    =  -----------
             a        2   \    a    /           2*a
 ]]
 
-local function apply_control(id, train)
-	local lzb = train.lzb
-	
-	local i = 1
-	while i<=#lzb.oncoming do
-		if lzb.oncoming[i].idx < train.index then
-			local ent = lzb.oncoming[i]
-			if ent.fun then
-				ent.fun(ent.pos, id, train, ent.idx, ent.spd, lzb.data)
-			end
-			
-			table.remove(lzb.oncoming, i)
-		else
-			i = i + 1
-		end
-	end
-	
-	for i, it in ipairs(lzb.oncoming) do
-		local a = advtrains.get_acceleration(train, 1) --should be negative
-		local v0 = train.velocity
-		local v1 = it.spd
-		if v1 and v1 <= v0 then
-			local s = (v1*v1 - v0*v0) / (2*a)
-			
-			local st = s + params.ADD_SLOW
-			if v0 > 3 then
-				st = s + params.ADD_FAST
-			end
-			if v0<=0 then
-				st = s + params.ADD_STAND
-			end
-			
-			local i = advtrains.path_get_index_by_offset(train, it.idx, -st)
-			
-			--train.debug = dump({v0f=v0*f, aff=a*f*f,v0=v0, v1=v1, f=f, a=a, s=s, st=st, i=i, idx=train.index})
-			if i <= train.index then
-				-- Gotcha! Braking...
-				train.ctrl.lzb = 1
-				--train.debug = train.debug .. "BRAKE!!!"
-				return
-			end
-			
-			i = advtrains.path_get_index_by_offset(train, i, -params.ZONE_ROLL)
-			if i <= train.index and v0>1 then
-				-- roll control
-				train.ctrl.lzb = 2
-				return
-			end
-			i = advtrains.path_get_index_by_offset(train, i, -params.ZONE_HOLD)
-			if i <= train.index and v0>1 then
-				-- hold speed
-				train.ctrl.lzb = 3
-				return
-			end
-		end
-	end
-	train.ctrl.lzb = nil
-end
-
-local function invalidate(train)
+-- Removes all LZB checkpoints and restarts the traverser at the current train index
+function advtrains.lzb_invalidate(train)
 	train.lzb = {
-		trav = atfloor(train.index),
-		data = {},
-		oncoming = {},
+		trav_index = atfloor(train.index) + 1,
+		checkpoints = {},
 	}
 end
 
-function advtrains.lzb_invalidate(train)
-	invalidate(train)
+-- LZB part of path_invalidate_ahead. Clears all checkpoints that are ahead of start_idx
+-- in contrast to path_inv_ahead, doesn't complain if start_idx is behind train.index, clears everything then
+function advtrains.lzb_invalidate_ahead(train, start_idx)
+	if train.lzb then
+		local idx = atfloor(start_idx)
+		local i = 1
+		while train.lzb.checkpoints[i] do
+			if train.lzb.checkpoints[i].index >= idx then
+				table.remove(train.lzb.checkpoints, i)
+			else
+				i=i+1
+			end
+		end
+		train.lzb.trav_index = idx
+		-- FIX reset trav_lzbdata (look_ahead fetches these when required)
+		train.lzb.trav_lzbdata = nil
+		-- re-apply all checkpoints to path_speed
+		train.path_speed = {}
+		train.lzb.zero_checkpoint = false
+		for _,ckp in ipairs(train.lzb.checkpoints) do
+			apply_checkpoint_to_path(train, ckp)
+		end
+	end
 end
 
 -- Add LZB control point
--- udata: User-defined additional data
-function advtrains.lzb_add_checkpoint(train, index, speed, callback, udata)
+-- lzbdata: If you modify lzbdata in an approach callback, you MUST add a checkpoint AND pass the (modified) lzbdata into it.
+-- If you DON'T modify lzbdata, you MUST pass nil as lzbdata. Always modify the lzbdata table in place, never overwrite it!
+-- udata: user-defined data, do not use externally
+function advtrains.lzb_add_checkpoint(train, index, speed, callback, lzbdata, udata)
 	local lzb = train.lzb
 	local pos = advtrains.path_get(train, index)
-	table.insert(lzb.oncoming, {
+	local lzbdata_c = nil
+	if lzbdata then
+		-- make a shallow copy of lzbdata
+		lzbdata_c = {}
+		for k,v in pairs(lzbdata) do lzbdata_c[k] = v end
+	end
+	local ckp = {
 		pos = pos,
-		idx = index,
-		spd = speed,
-		fun = callback,
+		index = index,
+		speed = speed,
+		callback = callback,
+		lzbdata = lzbdata_c,
 		udata = udata,
-	})
+	}
+	table.insert(lzb.checkpoints, ckp)
+	
+	apply_checkpoint_to_path(train, ckp)
 end
 
 
 advtrains.te_register_on_new_path(function(id, train)
-	invalidate(train)
-	look_ahead(id, train)
+	advtrains.lzb_invalidate(train)
+	-- Taken care of in pre-move hook (see train_step_b)
+	--look_ahead(id, train)
+end)
+
+advtrains.te_register_on_invalidate_ahead(function(id, train, start_idx)
+	advtrains.lzb_invalidate_ahead(train, start_idx)
 end)
 
 advtrains.te_register_on_update(function(id, train)
@@ -186,6 +269,8 @@ advtrains.te_register_on_update(function(id, train)
 		atprint("LZB run: no path on train, skip step")
 		return
 	end
-	look_ahead(id, train)
-	apply_control(id, train)
+	-- Note: look_ahead called from train_step_b before applying movement
+	-- TODO: if more pre-move hooks are added, make a separate callback hook
+	--look_ahead(id, train)
+	call_runover_callbacks(id, train)
 end, true)

mods/advtrains/advtrains/nodedb.lua

@@ -246,7 +246,7 @@ function ndb.update(pos, pnode)
 		local resid = (nid * 4) + (l2b(node.param2 or 0))
 		ndbset(pos.x, pos.y, pos.z, resid )
 		--atdebug("nodedb: updating node", pos, "stored nid",nid,"assigned",ndb_nodeids[nid],"resulting cid",resid)
-		minetest.after(0, advtrains.invalidate_all_paths, pos)
+		advtrains.invalidate_all_paths_ahead(pos)
 	else
 		--at this position there is no longer a node that needs to be tracked.
 		--atdebug("nodedb: updating node", pos, "cleared")
@@ -281,8 +281,9 @@ function advtrains.get_rail_info_at(pos, drives_on)
 	return true, conns, railheight
 end
 
+local IGNORE_WORLD = advtrains.IGNORE_WORLD
+
 ndb.run_lbm = function(pos, node)
-	return advtrains.pcall(function()
 		local cid=ndbget(pos.x, pos.y, pos.z)
 		if cid then
 			--if in database, detect changes and apply.
@@ -310,7 +311,6 @@ ndb.run_lbm = function(pos, node)
 			ndb.update(pos, node)
 		end
 		return false
-	end)
 end
 
 
@@ -327,6 +327,7 @@ minetest.register_lbm({
 --used when restoring stuff after a crash
 ndb.restore_all = function()
 	--atlog("Updating the map from the nodedb, this may take a while")
+	local t1 = os.clock()
 	local cnt=0
 	local dcnt=0
 	for y, ny in pairs(ndb_nodes) do
@@ -337,7 +338,7 @@ ndb.restore_all = function()
 				if node then
 					local ori_ndef=minetest.registered_nodes[node.name]
 					local ndbnode=ndb.get_node_raw(pos)
-					if ori_ndef and ori_ndef.groups.save_in_at_nodedb then --check if this node has been worldedited, and don't replace then
+					if (ori_ndef and ori_ndef.groups.save_in_at_nodedb) or IGNORE_WORLD then --check if this node has been worldedited, and don't replace then
 						if (ndbnode.name~=node.name or ndbnode.param2~=node.param2) then
 							minetest.swap_node(pos, ndbnode)
 							--atlog("Replaced",node.name,"@",pos,"with",ndbnode.name)
@@ -352,15 +353,13 @@ ndb.restore_all = function()
 			end
 		end
 	end
-	local text="Restore node database: Replaced "..cnt.." nodes, removed "..dcnt.." ghost nodes."
+	local text="Restore node database: Replaced "..cnt.." nodes, removed "..dcnt.." ghost nodes. (took "..math.floor((os.clock()-t1) * 1000).."ms)"
 	atlog(text)
 	return text
 end
     
 minetest.register_on_dignode(function(pos, oldnode, digger)
-	return advtrains.pcall(function()
 		ndb.clear(pos)
-	end)
 end)
 
 function ndb.get_nodes()
@@ -381,14 +380,12 @@ minetest.register_chatcommand("at_sync_ndb",
         description = "Write node db back to map and find ghost nodes", -- Full description
         privs = {train_operator=true}, 
         func = function(name, param)
-			return advtrains.pcall(function()
-				if os.time() < ptime+30 then
+				if os.time() < ptime+30 and not minetest.get_player_privs(name, "server") then
 					return false, "Please wait at least 30s from the previous execution of /at_restore_ndb!"
 				end
 				local text = ndb.restore_all()
 				ptime=os.time()
 				return true, text
-			end)
         end,
     })
 

mods/advtrains/advtrains/occupation.lua

@@ -196,7 +196,6 @@ function o.get_trains_over(ppos)
 	local r = {}
 	local i = 1
 	while t[i] do
-		local train = advtrains.trains[t[i]]
 		local idx = t[i+1]
 		r[t[i]] = idx
 		i = i + 2

mods/advtrains/advtrains/path.lua

@@ -19,6 +19,8 @@
 --     When the day comes on that path!=node, these will only be set if this index represents a transition between rail nodes
 -- path_dist - The total distance of this path element from path element 0
 -- path_dir  - The direction of this path item's transition to the next path item, which is the angle of conns[path_cn[i]].c
+-- path_speed- Populated by the LZB system. The maximum speed (velocity) permitted in the moment this path item is passed.
+--             (this saves brake distance calculations every step to determine LZB control). nil means no limit.
 --Variables:
 -- path_ext_f/b - how far path[i] is set
 -- path_trk_f/b - how far the path extends along a track. beyond those values, paths are generated in a straight line.
@@ -52,6 +54,8 @@ function advtrains.path_create(train, pos, connid, rel_index)
 		[0] = advtrains.conn_angle_median(conns[mconnid].c, conns[connid].c)
 	}
 	
+	train.path_speed = { }
+	
 	train.path_ext_f=0
 	train.path_ext_b=0
 	train.path_trk_f=0
@@ -123,6 +127,7 @@ function advtrains.path_invalidate(train, ignore_lock)
 	train.path_cp = nil
 	train.path_cn = nil
 	train.path_dir = nil
+	train.path_speed = nil
 	train.path_ext_f=0
 	train.path_ext_b=0
 	train.path_trk_f=0
@@ -131,6 +136,40 @@ function advtrains.path_invalidate(train, ignore_lock)
 	train.path_req_b=0
 	
 	train.dirty = true
+	--atdebug(train.id, "Path invalidated")
+end
+
+-- Keeps the path intact, but invalidates all path nodes from the specified index (inclusive)
+-- onwards. This has the advantage that we don't need to recalculate the whole path, and we can do it synchronously.
+function advtrains.path_invalidate_ahead(train, start_idx, ignore_when_passed)
+	if not train.path then
+		-- the path wasn't even initialized. Nothing to do
+		return
+	end
+
+	local idx = atfloor(start_idx)
+	--atdebug("Invalidate_ahead:",train.id,"start_index",start_idx,"cur_idx",train.index)
+	
+	if(idx <= train.index - 0.5) then
+		if ignore_when_passed then
+			--atdebug("ignored passed")
+			return
+		end
+		advtrains.path_print(train, atwarn)
+		error("Train "+train.id+": Cannot path_invalidate_ahead start_idx="+idx+" as train has already passed!")
+	end
+	
+	-- leave current node in path, it won't change. What might change is the path onward from here (e.g. switch)
+	local i = idx + 1
+	while train.path[i] do
+		advtrains.occ.clear_item(train.id, advtrains.round_vector_floor_y(train.path[i]))
+		i = i+1
+	end
+	train.path_ext_f=idx
+	train.path_trk_f=math.min(idx, train.path_trk_f)
+	
+	-- callbacks called anyway for current node, because of LZB
+	advtrains.run_callbacks_invahead(train.id, train, idx)
 end
 
 -- Prints a path using the passed print function
@@ -141,12 +180,12 @@ function advtrains.path_print(train, printf)
 		printf("path_print: Path is invalidated/inexistant.")
 		return
 	end
-	printf("i:	CP	Position	Dir	CN		Dist")
+	printf("i:	CP	Position	Dir				CN		Dist		Speed")
 	for i = train.path_ext_b, train.path_ext_f do
 		if i==train.path_trk_b then
 			printf("--Back on-track border here--")
 		end
-		printf(i,":	",train.path_cp[i],"	",train.path[i],"	",train.path_dir[i],"	",train.path_cn[i],"		",train.path_dist[i],"")
+		printf(i,":	",train.path_cp[i],"	",train.path[i],"	",train.path_dir[i],"	",train.path_cn[i],"		",train.path_dist[i],"		",train.path_speed[i])
 		if i==train.path_trk_f then
 			printf("--Front on-track border here--")		
 		end
@@ -350,6 +389,7 @@ function advtrains.path_clear_unused(train)
 		train.path_ext_b = i + 1
 	end
 	
+	--[[ Why exactly are we clearing path from the front? This doesn't make sense!
 	for i = train.path_ext_f,train.path_req_f + PATH_CLEAR_KEEP,-1 do
 		advtrains.occ.clear_item(train.id, advtrains.round_vector_floor_y(train.path[i]))
 		train.path[i] = nil
@@ -358,14 +398,16 @@ function advtrains.path_clear_unused(train)
 		train.path_cn[i] = nil
 		train.path_dir[i+1] = nil
 		train.path_ext_f = i - 1
-	end
+	end ]]
 	train.path_trk_b = math.max(train.path_trk_b, train.path_ext_b)
-	train.path_trk_f = math.min(train.path_trk_f, train.path_ext_f)
+	--train.path_trk_f = math.min(train.path_trk_f, train.path_ext_f)
 	
 	train.path_req_f = math.ceil(train.index)
 	train.path_req_b = math.floor(train.end_index or train.index)
 end
 
+-- Scan the path of the train for position, without querying the occupation table
+-- returns index, or nil if pos is not on the path
 function advtrains.path_lookup(train, pos)
 	local cp = advtrains.round_vector_floor_y(pos)
 	for i = train.path_ext_b, train.path_ext_f do

mods/advtrains/advtrains/settingtypes.txt

@@ -45,3 +45,14 @@ advtrains_overrun_mode (Overrun mode) enum drop none,drop,normal
 #    When a wagon leaves this range + 32 nodes, it is unloaded
 #    If unset, defaults to active_block_range*16
 advtrains_wagon_load_range (Wagon Entity Load/Unload Range) int 96 32 512
+
+#    Simulation DTime Limit after which slow-down becomes effective
+#    When the dtime value (time since last server step) is higher than this value,
+#    advtrains applies a global slow-down factor to the dtime and to the velocity and
+#    acceleration of wagons to decrease server load.
+#    A value of 0 (default) disables this behavior.
+advtrains_dtime_limit (DTime Limit for slow-down) float 0.2 0 5
+
+#    Time interval in seconds in which advtrains stores its save data to disk
+#    Nevertheless, advtrains saves all data when shutting down the server.
+advtrains_save_interval (Save Interval) int 60 20 3600

mods/advtrains/advtrains/signals.lua

@@ -12,22 +12,26 @@ end
 
 local function aspect(b)
 return {
-	main = {
-		free = b,
-		speed = -1,
-	},
-	shunt = {
-		free = false,
-		proceed_as_main = true
-	},
-	dst = {
-		free = true,
-		speed = -1,
-	},
+	main = (not b) and 0, -- b ? false : 0
+	shunt = false,
+	proceed_as_main = true,
+	dst = false,
 	info = {}
 }
 end
 
+local suppasp = {
+		main = {0, false},
+		dst = {false},
+		shunt = nil,
+		proceed_as_main = true,
+		info = {
+			call_on = false,
+			dead_end = false,
+			w_speed = nil,
+		}
+}
+
 for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red", als="green"}}) do
 
 	advtrains.trackplacer.register_tracktype("advtrains:retrosignal", "")
@@ -63,6 +67,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 				rules=advtrains.meseconrules,
 				["action_"..f.as] = function (pos, node)
 					advtrains.ndb.swap_node(pos, {name = "advtrains:retrosignal_"..f.as..rotation, param2 = node.param2}, true)
+					advtrains.interlocking.signal_on_aspect_changed(pos)
 				end
 			}},
 			on_rightclick=function(pos, node, player)
@@ -74,12 +79,13 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 					advtrains.interlocking.show_ip_form(pos, pname)
 				elseif advtrains.check_turnout_signal_protection(pos, player:get_player_name()) then
 					advtrains.ndb.swap_node(pos, {name = "advtrains:retrosignal_"..f.as..rotation, param2 = node.param2}, true)
+					advtrains.interlocking.signal_on_aspect_changed(pos)
 				end
 			end,
 			-- new signal API
 			advtrains = {
 				set_aspect = function(pos, node, asp)
-					if asp.main.free then
+					if asp.main ~= 0 then
 						advtrains.ndb.swap_node(pos, {name = "advtrains:retrosignal_on"..rotation, param2 = node.param2}, true)
 					else
 						advtrains.ndb.swap_node(pos, {name = "advtrains:retrosignal_off"..rotation, param2 = node.param2}, true)
@@ -87,7 +93,8 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 				end,
 				get_aspect = function(pos, node)
 					return aspect(r=="on")
-				end
+				end,
+				supported_aspects = suppasp,
 			},
 			can_dig = can_dig_func,
 		})
@@ -120,6 +127,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 				rules=advtrains.meseconrules,
 				["action_"..f.as] = function (pos, node)
 					advtrains.setstate(pos, f.als, node)
+					advtrains.interlocking.signal_on_aspect_changed(pos)
 				end
 			}},
 			on_rightclick=function(pos, node, player)
@@ -131,12 +139,13 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 					advtrains.interlocking.show_ip_form(pos, pname)
 				elseif advtrains.check_turnout_signal_protection(pos, player:get_player_name()) then
 					advtrains.setstate(pos, f.als, node)
+					advtrains.interlocking.signal_on_aspect_changed(pos)
 				end
 			end,
 			-- new signal API
 			advtrains = {
 				set_aspect = function(pos, node, asp)
-					if asp.main.free then
+					if asp.main ~= 0 then
 						advtrains.ndb.swap_node(pos, {name = "advtrains:signal_on"..rotation, param2 = node.param2}, true)
 					else
 						advtrains.ndb.swap_node(pos, {name = "advtrains:signal_off"..rotation, param2 = node.param2}, true)
@@ -145,6 +154,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 				get_aspect = function(pos, node)
 					return aspect(r=="on")
 				end,
+				supported_aspects = suppasp,
 				getstate = f.ls,
 				setstate = function(pos, node, newstate)
 					if newstate == f.als then
@@ -204,7 +214,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 			-- new signal API
 			advtrains = {
 				set_aspect = function(pos, node, asp)
-					if asp.main.free then
+					if asp.main ~= 0 then
 						advtrains.ndb.swap_node(pos, {name = "advtrains:signal_wall_"..loc.."_on", param2 = node.param2}, true)
 					else
 						advtrains.ndb.swap_node(pos, {name = "advtrains:signal_wall_"..loc.."_off", param2 = node.param2}, true)
@@ -213,6 +223,7 @@ for r,f in pairs({on={as="off", ls="green", als="red"}, off={as="on", ls="red",
 				get_aspect = function(pos, node)
 					return aspect(r=="on")
 				end,
+				supported_aspects = suppasp,
 				getstate = f.ls,
 				setstate = function(pos, node, newstate)
 					if newstate == f.als then

mods/advtrains/advtrains/trackplacer.lua

@@ -275,7 +275,6 @@ function tp.register_track_placer(nnprefix, imgprefix, dispname, def)
 		groups={advtrains_trackplacer=1, digtron_on_place=1},
 		liquids_pointable = def.liquids_pointable,
 		on_place = function(itemstack, placer, pointed_thing)
-			return advtrains.pcall(function()
 				local name = placer:get_player_name()
 				if not name then
 				   return itemstack, false
@@ -303,7 +302,6 @@ function tp.register_track_placer(nnprefix, imgprefix, dispname, def)
 					end
 				end
 				return itemstack, true
-			end)
 		end,
 	})
 end
@@ -317,7 +315,6 @@ minetest.register_craftitem("advtrains:trackworker",{
 	wield_image = "advtrains_trackworker.png",
 	stack_max = 1,
 	on_place = function(itemstack, placer, pointed_thing)
-		return advtrains.pcall(function()
 			local name = placer:get_player_name()
 			if not name then
 				return
@@ -382,10 +379,8 @@ minetest.register_craftitem("advtrains:trackworker",{
 					advtrains.ndb.swap_node(pos, {name=nnprefix.."_"..suffix..modext[modpos+1], param2=node.param2})
 				end
 			end
-		end)
 	end,
 	on_use=function(itemstack, user, pointed_thing)
-		return advtrains.pcall(function()
 				local name = user:get_player_name()
 			if not name then
 			   return
@@ -430,7 +425,6 @@ minetest.register_craftitem("advtrains:trackworker",{
 			else
 				atprint(name, dump(tp.tracks))
 			end
-		end)
 	end,
 })
 

mods/advtrains/advtrains/tracks.lua

@@ -469,7 +469,7 @@ function advtrains.register_tracks(tracktype, def, preset)
 					tiles = {def.shared_texture or (def.texture_prefix.."_"..img_suffix..".png"), def.second_texture},
 					
 					groups = {
-						attached_node=1,
+						attached_node = advtrains.IGNORE_WORLD and 0 or 1,
 						advtrains_track=1,
 						["advtrains_track_"..tracktype]=1,
 						save_in_at_nodedb=1,

mods/advtrains/advtrains/trainhud.lua

@@ -43,7 +43,7 @@ function advtrains.on_control_change(pc, train, flip)
 	else
 		local act=false
 		if pc.jump then
-			train.ctrl.user = 1
+			train.ctrl_user = 1
 			act=true
 		end
 		-- If atc command set, only "Jump" key can clear command. To prevent accidental control.
@@ -51,15 +51,15 @@ function advtrains.on_control_change(pc, train, flip)
 			return
 		end
 		if pc.up then
-		   train.ctrl.user=4
+		   train.ctrl_user=4
 		   act=true
 		end
 		if pc.down then
 			if train.velocity>0 then
 				if pc.jump then
-					train.ctrl.user = 0
+					train.ctrl_user = 0
 				else
-					train.ctrl.user = 2
+					train.ctrl_user = 2
 				end
 				act=true
 			else
@@ -82,7 +82,7 @@ function advtrains.on_control_change(pc, train, flip)
 			end
 		end
 		if not act then
-			train.ctrl.user = nil
+			train.ctrl_user = nil
 		end
 	end
 end
@@ -186,6 +186,9 @@ function advtrains.hud_train_format(train, flip)
 	
 	local tlev=train.lever or 1
 	if train.velocity==0 and not train.active_control then tlev=1 end
+	if train.hud_lzb_effect_tmr then
+		tlev=1
+	end
 	
 	local ht = {"[combine:440x110:0,0=(advtrains_hud_bg.png^[resize\\:440x110)"}
 	local st = {}
@@ -245,7 +248,7 @@ function advtrains.hud_train_format(train, flip)
 	if train.tarvelocity or train.atc_command then
 		ht[#ht+1] = "10,10=(advtrains_hud_atc.png^[resize\\:30x30^[multiply\\:cyan)"
 	end
-	if train.ctrl.lzb then
+	if train.hud_lzb_effect_tmr then
 		ht[#ht+1] = "50,10=(advtrains_hud_lzb.png^[resize\\:30x30^[multiply\\:red)"
 	end
 	if train.is_shunt then
@@ -274,10 +277,10 @@ function advtrains.hud_train_format(train, flip)
 		ht[#ht+1] = sformat("%d,85=(advtrains_hud_arrow.png^[multiply\\:cyan^[transformFY^[makealpha\\:#000000)", 1+train.tarvelocity*11)
 	end
 	local lzb = train.lzb
-	if lzb and lzb.oncoming then
-		local oc = lzb.oncoming
+	if lzb and lzb.checkpoints then
+		local oc = lzb.checkpoints
 		for i = 1, #oc do
-			local spd = oc[i].spd
+			local spd = oc[i].speed
 			local c = not spd and "lime" or (type(spd) == "number" and (spd == 0) and "red" or "orange") or nil
 			if c then
 				ht[#ht+1] = sformat("130,10=(advtrains_hud_bg.png^[resize\\:30x5^[colorize\\:%s)",c)
@@ -286,7 +289,7 @@ function advtrains.hud_train_format(train, flip)
 					ht[#ht+1] = sformat("%d,50=(advtrains_hud_arrow.png^[multiply\\:red^[makealpha\\:#000000)", 1+spd*11) 
 				end
 				local floor = math.floor
-				local dist = floor(((oc[i].idx or train.index)-train.index))
+				local dist = floor(((oc[i].index or train.index)-train.index))
 				dist = math.max(0, math.min(999, dist))
 				for j = 1, 3, 1 do
 					sevenseg(floor((dist/10^(3-j))%10), 119+j*11, 18, 4, 2, "[colorize\\:"..c)

mods/advtrains/advtrains/trainlogic.lua

@@ -36,6 +36,7 @@ end
 local t_accel_all={
 	[0] = -10,
 	[1] = -3,
+	[11] = -2, -- calculation base for LZB
 	[2] = -0.5,
 	[4] = 0.5,
 }
@@ -43,19 +44,35 @@ local t_accel_all={
 local t_accel_eng={
 	[0] = 0,
 	[1] = 0,
+	[11] = 0,
 	[2] = 0,
 	[4] = 1.5,
 }
 
+local VLEVER_EMERG = 0
+local VLEVER_BRAKE = 1
+local VLEVER_LZBCALC = 11
+local VLEVER_ROLL = 2
+local VLEVER_HOLD = 3
+local VLEVER_ACCEL = 4
+
+-- How far in front of a whole index with LZB 0 restriction the train should come to a halt
+-- value must be between 0 and 0.5, exclusively
+local LZB_ZERO_APPROACH_DIST = 0.1
+-- Speed the train temporarily approaches the stop point with
+local LZB_ZERO_APPROACH_SPEED = 0.2
+
+
+
 tp_player_tmr = 0
 
-advtrains.mainloop_trainlogic=function(dtime)
+advtrains.mainloop_trainlogic=function(dtime, stepno)
 	--build a table of all players indexed by pts. used by damage and door system.
 	advtrains.playersbypts={}
 	for _, player in pairs(minetest.get_connected_players()) do
 		if not advtrains.player_to_train_mapping[player:get_player_name()] then
 			--players in train are not subject to damage
-			local ptspos=minetest.pos_to_string(vector.round(player:getpos()))
+			local ptspos=minetest.pos_to_string(vector.round(player:get_pos()))
 			advtrains.playersbypts[ptspos]=player
 		end
 	end
@@ -81,6 +98,7 @@ advtrains.mainloop_trainlogic=function(dtime)
 	
 	for k,v in pairs(advtrains.trains) do
 		advtrains.atprint_context_tid=k
+		--atprint("=== Step",stepno,"===")
 		advtrains.train_ensure_init(k, v)
 	end
 	
@@ -113,11 +131,10 @@ function advtrains.tp_player_to_train(player)
 		--set the player to the train position.
 		--minetest will emerge the area and load the objects, which then will call reattach_all().
 		--because player is in mapping, it will not be subject to dying.
-		player:setpos(train.last_pos)
+		player:set_pos(train.last_pos)
 	end
 end
 minetest.register_on_joinplayer(function(player)
-	return advtrains.pcall(function()
 		advtrains.hud[player:get_player_name()] = nil
 		advtrains.hhud[player:get_player_name()] = nil
 		--independent of this, cause all wagons of the train which are loaded to reattach their players
@@ -127,12 +144,10 @@ minetest.register_on_joinplayer(function(player)
 				wagon:reattach_all()
 			end
 		end
-	end)
 end)
 
 
 minetest.register_on_dieplayer(function(player)
-	return advtrains.pcall(function()
 		local pname=player:get_player_name()
 		local id=advtrains.player_to_train_mapping[pname]
 		if id then
@@ -146,7 +161,6 @@ minetest.register_on_dieplayer(function(player)
 				end
 			end
 		end
-	end)
 end)
 
 --[[
@@ -190,6 +204,8 @@ end
 
 function advtrains.get_acceleration(train, lever)
 	local acc_all = t_accel_all[lever]
+	if not acc_all then return 0 end
+	
 	local acc_eng = t_accel_eng[lever]
 	local nwagons = #train.trainparts
 	if nwagons == 0 then
@@ -215,14 +231,16 @@ local function mkcallback(name)
 		assertt(func, "function")
 		table.insert(callt, func)
 	end
-	return callt, function(id, train)
+	return callt, function(id, train, param1, param2, param3)
 		for _,f in ipairs(callt) do
-			f(id, train)
+			f(id, train, param1, param2, param3)
 		end
 	end
 end
 
 local callbacks_new_path, run_callbacks_new_path = mkcallback("new_path")
+local callbacks_invahead
+callbacks_invahead, advtrains.run_callbacks_invahead = mkcallback("invalidate_ahead") -- (id, train, start_idx)
 local callbacks_update, run_callbacks_update = mkcallback("update")
 local callbacks_create, run_callbacks_create = mkcallback("create")
 local callbacks_remove, run_callbacks_remove = mkcallback("remove")
@@ -240,21 +258,25 @@ function advtrains.train_ensure_init(id, train)
 	end
 	
 	train.dirty = true
-	if train.no_step then return nil end
+	if train.no_step then
+		--atprint("in ensure_init: no_step set, train step ignored!")
+		return nil
+	end
 
 	assertdef(train, "velocity", 0)
 	--assertdef(train, "tarvelocity", 0)
 	assertdef(train, "acceleration", 0)
 	assertdef(train, "id", id)
-	assertdef(train, "ctrl", {})
 	
 	
 	if not train.drives_on or not train.max_speed then
+		--atprint("in ensure_init: missing properties, updating!")
 		advtrains.update_trainpart_properties(id)
 	end
 	
 	--restore path
 	if not train.path then
+		--atprint("in ensure_init: Needs restoring path...")
 		if not train.last_pos then
 			atlog("Train",id,": Restoring path failed, no last_pos set! Train will be disabled. You can try to fix the issue in the save file.")
 			train.no_step = true
@@ -277,6 +299,8 @@ function advtrains.train_ensure_init(id, train)
 		
 		local result = advtrains.path_create(train, train.last_pos, train.last_connid or 1, train.last_frac or 0)
 		
+		--atprint("in ensure_init: path_create result ",result)
+		
 		if result==false then
 			atlog("Train",id,": Restoring path failed, node at",train.last_pos,"is gone! Train will be disabled. You can try to place a rail at this position and restart the server.")
 			train.no_step = true
@@ -304,6 +328,10 @@ function advtrains.train_ensure_init(id, train)
 	return true
 end
 
+local function v_target_apply(v_targets, lever, vel)
+	v_targets[lever] = v_targets[lever] and math.min(v_targets[lever], vel) or vel
+end
+
 function advtrains.train_step_b(id, train, dtime)
 	if train.no_step or train.wait_for_path or not train.path then return end
 	
@@ -311,25 +339,49 @@ function advtrains.train_step_b(id, train, dtime)
 	advtrains.path_get(train, atfloor(train.index + 2))
 	advtrains.path_get(train, atfloor(train.end_index - 1))
 	
+	-- run pre-move hooks
+	-- TODO: if more pre-move hooks are added, make a separate callback hook
+	advtrains.lzb_look_ahead(id, train)
+	
+	--[[ again, new velocity control:
+	There are two heterogenous means of control:
+	-> set a fixed acceleration and ignore speed (user)
+	-> steer towards a target speed, distance doesn't matter
+		-> needs to specify the maximum acceleration/deceleration values they are willing to accelerate/brake with
+	-> Reach a target speed after a certain distance (LZB, handled specially)
+	
+	]]--
+	
 	--- 3. handle velocity influences ---
-	local train_moves=(train.velocity~=0)
-	local tarvel_cap = train.speed_restriction
+	
+	local v0 = train.velocity
+	local sit_v_cap = train.max_speed -- Maximum speed in current situation (multiple limit factors)
+	-- The desired speed change issued by the active control (user or atc)
+	local ctrl_v_tar -- desired speed which should not be crossed by braking or accelerating
+	local ctrl_accelerating = false -- whether the train should accelerate
+	local ctrl_braking = false -- whether the train should brake
+	local ctrl_lever -- the lever value to use to calculate the acceleration
+	-- the final speed change after applying LZB
+	local v_cap -- absolute maximum speed
+	local v_tar -- desired speed which should not be crossed by braking or accelerating
+	local accelerating = false-- whether the train should accelerate
+	local braking = false -- whether the train should brake
+	local lever -- the lever value to use to calculate the acceleration
+	local train_moves = (v0 > 0)
 	
 	if train.recently_collided_with_env then
-		tarvel_cap=0
 		if not train_moves then
 			train.recently_collided_with_env=nil--reset status when stopped
 		end
-	end
-	if train.locomotives_in_train==0 then
-		tarvel_cap=0
-	end
-	
-	--- 3a. this can be useful for debugs/warnings and is used for check_trainpartload ---
-	local t_info, train_pos=sid(id), advtrains.path_get(train, atfloor(train.index))
-	if train_pos then
-		t_info=t_info.." @"..minetest.pos_to_string(train_pos)
-		--atprint("train_pos:",train_pos)
+		--atprint("in train_step_b: applying collided_with_env")
+		sit_v_cap = 0
+	elseif train.locomotives_in_train==0 then
+		--atprint("in train_step_b: applying no_locomotives")
+		sit_v_cap = 0
+	-- interlocking speed restriction
+	elseif train.speed_restriction then
+		--atprint("in train_step_b: applying interlocking speed restriction",train.speed_restriction)
+		sit_v_cap = train.speed_restriction
 	end
 	
 	--apply off-track handling:
@@ -337,38 +389,47 @@ function advtrains.train_step_b(id, train, dtime)
 	local back_off_track=train.end_index<train.path_trk_b
 	train.off_track = front_off_track or back_off_track
 	
-	if front_off_track then
-		tarvel_cap=0
-	end
-	if back_off_track then -- eventually overrides front_off_track restriction
-		tarvel_cap=1
+	if back_off_track and (not v_cap or v_cap > 1) then
+		--atprint("in train_step_b: applying back_off_track")
+		sit_v_cap = 1
+	elseif front_off_track then
+		--atprint("in train_step_b: applying front_off_track")
+		sit_v_cap = 0
 	end
 	
-	-- Driving control rework:
-	--[[
-	Items are only defined when something is controlling them.
-	In order of precedence.
-	train.ctrl = {
-		lzb  = restrictive override from LZB
-		user = User input from driverstand
-		atc  = ATC command override (determined here)
-	}
-	The code here determines the precedence and writes the final control into train.lever
-	]]
 	
 	--interpret ATC command and apply auto-lever control when not actively controlled
-	local trainvelocity = train.velocity
-	
-	if train.ctrl.user then
+	local userc = train.ctrl_user
+	if userc then
+		--atprint("in train_step_b: ctrl_user active",userc)
 		advtrains.atc.train_reset_command(train)
+		
+		if userc >= VLEVER_ACCEL then
+			ctrl_accelerating = true
 		else
+			ctrl_braking = true
+		end
+		ctrl_lever = userc
+	else
+		if train.atc_command then
+			if (not train.atc_delay or train.atc_delay<=0) and not train.atc_wait_finish then
+				advtrains.atc.execute_atc_command(id, train)
+			else
+				train.atc_delay=train.atc_delay-dtime
+			end
+		elseif train.atc_delay then
+			train.atc_delay = nil
+		end
+	
 		local braketar = train.atc_brake_target
 		local emerg = false -- atc_brake_target==-1 means emergency brake (BB command)
 		if braketar == -1 then
 			braketar = 0
 			emerg = true
 		end
-		if braketar and braketar>=trainvelocity then
+		--atprint("in train_step_b: ATC: brake state braketar=",braketar,"emerg=",emerg)
+		if braketar and braketar>=v0 then
+			--atprint("in train_step_b: ATC: brake target cleared")
 			train.atc_brake_target=nil
 			braketar = nil
 		end
@@ -380,111 +441,175 @@ function advtrains.train_step_b(id, train, dtime)
 				train.atc_wait_finish=nil
 			end
 		end
-		if train.atc_command then
-			if (not train.atc_delay or train.atc_delay<=0) and not train.atc_wait_finish then
-				advtrains.atc.execute_atc_command(id, train)
-			else
-				train.atc_delay=train.atc_delay-dtime
-			end
-		elseif train.atc_delay then
-			train.atc_delay = nil
-		end
 		
-		train.ctrl.atc = nil
-		if train.tarvelocity and train.tarvelocity>trainvelocity then
-			train.ctrl.atc=4
-		end
-		if train.tarvelocity and train.tarvelocity<trainvelocity then
-			if (braketar and braketar<trainvelocity) then
+		if train.tarvelocity and train.tarvelocity>v0 then
+			--atprint("in train_step_b: applying ATC ACCEL", train.tarvelocity)
+			ctrl_accelerating = true
+			ctrl_lever = VLEVER_ACCEL
+		elseif train.tarvelocity and train.tarvelocity<v0 then
+			ctrl_braking = true
+			
+			if (braketar and braketar<v0) then
 				if emerg then
-					train.ctrl.atc = 0
+					--atprint("in train_step_b: applying ATC EMERG", train.tarvelocity)
+					ctrl_lever = VLEVER_EMERG
 				else
-					train.ctrl.atc=1
+					--atprint("in train_step_b: applying ATC BRAKE", train.tarvelocity)
+					ctrl_v_tar = braketar
+					ctrl_lever = VLEVER_BRAKE
 				end
 			else
-				train.ctrl.atc=2
+				--atprint("in train_step_b: applying ATC ROLL", train.tarvelocity)
+				ctrl_v_tar = train.tarvelocity
+				ctrl_lever = VLEVER_ROLL
 			end
 		end
 	end
 	
-	--if tarvel_cap and train.tarvelocity and tarvel_cap<train.tarvelocity then
-	--	train.tarvelocity=tarvel_cap
-	--end
+	--- 2b. look at v_target, determine the effective v_target and desired acceleration ---
+	--atprint("in train_step_b: Resulting control before LZB: accelerating",ctrl_accelerating,"braking",ctrl_braking,"lever", ctrl_lever, "target", ctrl_v_tar)
+	--train.debug = dump({tv_target,tv_lever})
 	
-	local tmp_lever
+	--atprint("in train_step_b: Current index",train.index,"end",train.end_index,"vel",v0)
+	--- 3a. calculate the acceleration required to reach the speed restriction in path_speed (LZB) ---
+	-- Iterates over the path nodes we WOULD pass if we were continuing with the current speed
+	-- and determines the MINIMUM of path_speed in this range.
+	-- Then, determines acceleration so that we can reach this 'overridden' target speed in this step (but short-circuited)
+	local lzb_next_zero_barrier -- if defined, train should not pass this point as it's a 0-LZB
+	local new_index_curr_tv -- pre-calculated new train index in lzb check
+	local lzb_v_cap -- the maximum speed that LZB dictates
 	
-	for _, lev in pairs(train.ctrl) do
-		-- use the most restrictive of all control overrides
-		tmp_lever = math.min(tmp_lever or 4, lev)
-	end
-	
-	if not tmp_lever then
-		-- if there was no control at all, default to 3
-		tmp_lever = 3
-	end
-	
-	if tarvel_cap and trainvelocity>tarvel_cap then
-		tmp_lever = 0
-	end
-	
-	train.lever = tmp_lever
-	
-	--- 3a. actually calculate new velocity ---
-	if tmp_lever~=3 then
-		local accel = advtrains.get_acceleration(train, tmp_lever)
-		local vdiff = accel*dtime
-		
-		-- This should only be executed when we are accelerating
-		-- I suspect that this causes the braking bugs
-		if tmp_lever == 4 then
-		
-			-- ATC control exception: don't cross tarvelocity if
-			-- atc provided a target_vel
-			if train.tarvelocity then
-				local tvdiff = train.tarvelocity - trainvelocity
-				if tvdiff~=0 and math.abs(vdiff) > math.abs(tvdiff) then
-					--applying this change would cross tarvelocity
-					--atdebug("In Tvdiff condition, clipping",vdiff,"to",tvdiff)
-					--atdebug("vel=",trainvelocity,"tvel=",train.tarvelocity)
-					vdiff=tvdiff
+	local dst_curr_v = v0 * dtime
+	new_index_curr_tv = advtrains.path_get_index_by_offset(train, train.index, dst_curr_v)
+	local i = atfloor(train.index)
+	local psp
+	while true do
+		psp = train.path_speed[i]
+		if psp then
+			lzb_v_cap = lzb_v_cap and math.min(lzb_v_cap, psp) or psp
+			if psp == 0 and not lzb_next_zero_barrier then
+				--atprint("in train_step_b: Found zero barrier: ",i)
+				lzb_next_zero_barrier = i - LZB_ZERO_APPROACH_DIST
 			end
 		end
-			if tarvel_cap and trainvelocity<=tarvel_cap and trainvelocity+vdiff>tarvel_cap then
-				vdiff = tarvel_cap - train.velocity
-			end
-			local mspeed = (train.max_speed or 10)
-			if trainvelocity+vdiff > mspeed then
-				vdiff = mspeed - trainvelocity
+		if i > new_index_curr_tv then
+			break
 		end
+		i = i + 1
 	end
 	
-		if trainvelocity+vdiff < 0 then
-			vdiff = - trainvelocity
+	if lzb_next_zero_barrier and train.index < lzb_next_zero_barrier then
+		lzb_v_cap = LZB_ZERO_APPROACH_SPEED
 	end
 	
+	--atprint("in train_step_b: LZB calculation yields newindex=",new_index_curr_tv,"lzbtarget=",lzb_v_cap,"zero_barr=",lzb_next_zero_barrier,"")
 	
-		train.acceleration=vdiff
-		train.velocity=train.velocity+vdiff
-		--if train.ctrl.user then
-		--	train.tarvelocity = train.velocity
-		--end
+	-- LZB HUD: decrement timer and delete when 0
+	if train.hud_lzb_effect_tmr then
+		if train.hud_lzb_effect_tmr <=0 then
+			train.hud_lzb_effect_tmr = nil
 		else
+			train.hud_lzb_effect_tmr = train.hud_lzb_effect_tmr - 1
+		end
+	end
+	
+	-- We now need to bring ctrl_*, sit_v_cap and lzb_v_cap together to determine the final controls.
+	local v_cap = sit_v_cap -- always defined, by default train.max_speed
+	if lzb_v_cap and lzb_v_cap < v_cap then
+		v_cap = lzb_v_cap
+		lever = VLEVER_BRAKE -- actually irrelevant, acceleration is not considered anyway unless v_tar is also set.
+		-- display LZB control override in the HUD
+		if lzb_v_cap <= v0 then
+			train.hud_lzb_effect_tmr = 1
+			-- This is to signal the HUD that LZB is active. This works as a timer to avoid HUD blinking
+		end
+	end
+	
+	v_tar = ctrl_v_tar
+	-- if v_cap is smaller than the current speed, we need to brake in all cases.
+	if v_cap < v0 then
+		braking = true
+		lever = VLEVER_BRAKE
+		-- set v_tar to v_cap to not slow down any further than required.
+		-- unless control wants us to brake too, then we use control's v_tar.
+		if not ctrl_v_tar or ctrl_v_tar > v_cap then
+			v_tar = v_cap
+		end
+	else -- else, use what the ctrl says
+		braking = ctrl_braking
+		accelerating = ctrl_accelerating and not braking
+		lever = ctrl_lever
+	end
+	train.lever = lever
+	
+	--atprint("in train_step_b: final control: accelerating",accelerating,"braking",braking,"lever", lever, "target", v_tar)
+	
+	-- reset train acceleration when holding speed
+	if not braking and not accelerating then
 		train.acceleration = 0
 	end
 	
+	--- 3b. if braking, modify the velocity BEFORE the movement
+	if braking then
+		local dv = advtrains.get_acceleration(train, lever) * dtime
+		local v1 = v0 + dv
+		if v_tar and v1 < v_tar then
+			--atprint("in train_step_b: Braking: Hit v_tar!")
+			v1 = v_tar
+		end
+		if v1 > v_cap then
+			--atprint("in train_step_b: Braking: Hit v_cap!")
+			v1 = v_cap
+		end
+		if v1 < 0 then
+			--atprint("in train_step_b: Braking: Hit 0!")
+			v1 = 0
+		end
+		
+		train.acceleration = (v1 - v0) / dtime
+		train.velocity = v1
+		--atprint("in train_step_b: Braking: New velocity",v1," (yields acceleration",train.acceleration,")")
+		-- make saved new_index_curr_tv invalid because speed has changed
+		new_index_curr_tv = nil
+	end
+	
 	--- 4. move train ---
+	-- if we have calculated the new end index before, don't do that again
+	if not new_index_curr_tv then
+		local dst_curr_v = train.velocity * dtime
+		new_index_curr_tv = advtrains.path_get_index_by_offset(train, train.index, dst_curr_v)
+		--atprint("in train_step_b: movement calculation (re)done, yields newindex=",new_index_curr_tv)
+	else
+		--atprint("in train_step_b: movement calculation reusing from LZB newindex=",new_index_curr_tv)
+	end
 	
-	local idx_floor = math.floor(train.index)
-	local pdist = (train.path_dist[idx_floor+1] - train.path_dist[idx_floor])
-	local distance = (train.velocity*dtime) / pdist
-	
-	--debugging code
-	--train.debug = atdump(train.ctrl).."step_dist: "..math.floor(distance*1000)
-	
-	train.index=train.index+distance
+	-- if the zeroappr mechanism has hit, go no further than zeroappr index
+	if lzb_next_zero_barrier and new_index_curr_tv > lzb_next_zero_barrier then
+		--atprint("in train_step_b: Zero barrier hit, clipping to newidx_tv=",new_index_curr_tv, "zb_idx=",lzb_next_zero_barrier)
+		new_index_curr_tv = lzb_next_zero_barrier
+	end
+	train.index = new_index_curr_tv
 	
 	recalc_end_index(train)
+	--atprint("in train_step_b: New index",train.index,"end",train.end_index,"vel",train.velocity)
 	
+	--- 4a. if accelerating, modify the velocity AFTER the movement
+	if accelerating then
+		local dv = advtrains.get_acceleration(train, lever) * dtime
+		local v1 = v0 + dv
+		if v_tar and v1 > v_tar then
+			--atprint("in train_step_b: Accelerating: Hit v_tar!")
+			v1 = v_tar
+		end
+		if v1 > v_cap then
+			--atprint("in train_step_b: Accelerating: Hit v_cap!")
+			v1 = v_cap
+		end
+		
+		train.acceleration = (v1 - v0) / dtime
+		train.velocity = v1
+		--atprint("in train_step_b: Accelerating: New velocity",v1," (yields acceleration",train.acceleration,")")
+	end
 end
 
 function advtrains.train_step_c(id, train, dtime)
@@ -609,8 +734,9 @@ local callbacks_enter_node, run_callbacks_enter_node = mknodecallback("enter")
 local callbacks_leave_node, run_callbacks_leave_node = mknodecallback("leave")
 
 -- Node callback for approaching
--- Might be called multiple times, whenever path is recalculated
--- signature is function(pos, id, train, index, lzbdata)
+-- Might be called multiple times, whenever path is recalculated. Also called for the first node the train is standing on, then has_entered is true.
+-- signature is function(pos, id, train, index, has_entered, lzbdata)
+-- has_entered: true if the "enter" callback has already been executed for this train in this location
 -- lzbdata: arbitrary data (shared between all callbacks), deleted when LZB is restarted.
 -- These callbacks are called in order of distance as train progresses along tracks, so lzbdata can be used to
 -- keep track of a train's state once it passes this point
@@ -666,16 +792,19 @@ end
 
 function advtrains.tnc_call_approach_callback(pos, train_id, train, index, lzbdata)
 	--atdebug("tnc approach",pos,train_id, lzbdata)
+	local has_entered = atround(train.index) == index
+	
 	local node = advtrains.ndb.get_node(pos) --this spares the check if node is nil, it has a name in any case
 	local mregnode=minetest.registered_nodes[node.name]
 	if mregnode and mregnode.advtrains and mregnode.advtrains.on_train_approach then
-		mregnode.advtrains.on_train_approach(pos, train_id, train, index, lzbdata)
+		mregnode.advtrains.on_train_approach(pos, train_id, train, index, has_entered, lzbdata)
 	end
 	
 	-- call other registered callbacks
-	run_callbacks_approach_node(pos, train_id, train, index, lzbdata)
+	run_callbacks_approach_node(pos, train_id, train, index, has_entered, lzbdata)
 end
 
+-- === te callback definition for tnc node callbacks ===
 
 advtrains.te_register_on_new_path(function(id, train)
 	train.tnc = {
@@ -865,7 +994,7 @@ function advtrains.spawn_wagons(train_id)
 				atwarn("Train",train_id,"Wagon #",i,": Saved train ID",data.train_id,"did not match!")
 				data.train_id = train_id
 			end
-			if not advtrains.wagon_objects[w_id] or not advtrains.wagon_objects[w_id]:getyaw() then
+			if not advtrains.wagon_objects[w_id] or not advtrains.wagon_objects[w_id]:get_yaw() then
 				-- eventually need to spawn new object. check if position is loaded.
 				local index = advtrains.path_get_index_by_offset(train, train.index, -data.pos_in_train)
 				local pos   = advtrains.path_get(train, atfloor(index))
@@ -1017,7 +1146,7 @@ end
 function advtrains.train_check_couples(train)
 	--atdebug("rechecking couples")
 	if train.cpl_front then
-		if not train.cpl_front:getyaw() then
+		if not train.cpl_front:get_yaw() then
 			-- objectref is no longer valid. reset.
 			train.cpl_front = nil
 		end
@@ -1047,7 +1176,7 @@ function advtrains.train_check_couples(train)
 		end
 	end
 	if train.cpl_back then
-		if not train.cpl_back:getyaw() then
+		if not train.cpl_back:get_yaw() then
 			-- objectref is no longer valid. reset.
 			train.cpl_back = nil
 		end
@@ -1195,6 +1324,18 @@ function advtrains.invalidate_all_paths(pos)
 		advtrains.invalidate_path(id)
 	end
 end
+
+-- Calls invalidate_path_ahead on all trains occupying (having paths over) this node
+-- Can be called during train step.
+function advtrains.invalidate_all_paths_ahead(pos)
+	local tab = advtrains.occ.get_trains_over(pos)
+	
+	for id,index in pairs(tab) do
+		local train = advtrains.trains[id]
+		advtrains.path_invalidate_ahead(train, index, true)
+	end
+end
+
 function advtrains.invalidate_path(id)
 	--atdebug("Path invalidate:",id)
 	local v=advtrains.trains[id]

mods/advtrains/advtrains/wagons.lua

@@ -10,6 +10,8 @@
 -- TP delay when getting off wagon
 local GETOFF_TP_DELAY = 0.5
 
+local IGNORE_WORLD = advtrains.IGNORE_WORLD
+
 advtrains.wagons = {}
 advtrains.wagon_prototypes = {}
 advtrains.wagon_objects = {}
@@ -154,7 +156,7 @@ function wagon:ensure_init()
 		atwarn("wagon",self.id,"uninitialized, removing")
 		self:destroy()
 	else
-		self.object:setvelocity({x=0,y=0,z=0})
+		self.object:set_velocity({x=0,y=0,z=0})
 	end
 	return false
 end
@@ -166,7 +168,6 @@ end
 
 -- Remove the wagon
 function wagon:on_punch(puncher, time_from_last_punch, tool_capabilities, direction)
-	return advtrains.pcall(function()
 		if not self:ensure_init() then return end
 		
 		local data = advtrains.wagons[self.id]
@@ -223,7 +224,6 @@ function wagon:on_punch(puncher, time_from_last_punch, tool_capabilities, direct
 		for _,item in ipairs(self.drops or {self.name}) do
 			inv:add_item("main", item)
 		end
-	end)
 end
 function wagon:destroy()
 	--some rules:
@@ -268,11 +268,15 @@ function wagon:is_driver_stand(seat)
 end
 
 function wagon:on_step(dtime)
-	return advtrains.pcall(function()
 		if not self:ensure_init() then return end
 		
+		if advtrains.is_no_action() then
+			self.object:remove()
+			return
+		end
+		
 		local t=os.clock()
-		local pos = self.object:getpos()
+		local pos = self.object:get_pos()
 		local data = advtrains.wagons[self.id]
 		
 		if not pos then
@@ -400,8 +404,8 @@ function wagon:on_step(dtime)
 		
 		--for path to be available. if not, skip step
 		if not train.path or train.no_step then
-			self.object:setvelocity({x=0, y=0, z=0})
-			self.object:setacceleration({x=0, y=0, z=0})
+			self.object:set_velocity({x=0, y=0, z=0})
+			self.object:set_acceleration({x=0, y=0, z=0})
 			return
 		end
 		if not data.pos_in_train then
@@ -444,7 +448,7 @@ function wagon:on_step(dtime)
 		end
 		
 		--checking for environment collisions(a 3x3 cube around the center)
-		if is_in_loaded_area and not train.recently_collided_with_env then
+		if not IGNORE_WORLD and is_in_loaded_area and not train.recently_collided_with_env then
 			local collides=false
 			local exh = self.extent_h or 1
 			local exv = self.extent_v or 2
@@ -470,7 +474,7 @@ function wagon:on_step(dtime)
 		-- FIX: Need to do this after the yaw calculation
 		if is_in_loaded_area and data.pos_in_trainparts and data.pos_in_trainparts>1 then
 			if train.velocity==0 then
-				if not self.discouple or not self.discouple.object:getyaw() then
+				if not self.discouple or not self.discouple.object:get_yaw() then
 					atprint(self.id,"trying to spawn discouple")
 					local dcpl_pos = vector.add(pos, {y=0, x=-math.sin(yaw)*self.wagon_span, z=math.cos(yaw)*self.wagon_span})
 					local object=minetest.add_entity(dcpl_pos, "advtrains:discouple")
@@ -483,7 +487,7 @@ function wagon:on_step(dtime)
 					end
 				end
 			else
-				if self.discouple and self.discouple.object:getyaw() then
+				if self.discouple and self.discouple.object:get_yaw() then
 					self.discouple.object:remove()
 					atprint(self.id," removing discouple")
 				end
@@ -491,8 +495,8 @@ function wagon:on_step(dtime)
 		end
 		
 		--FIX: use index of the wagon, not of the train.
-		local velocity = train.velocity
-		local acceleration = (train.acceleration or 0)
+		local velocity = train.velocity * advtrains.global_slowdown
+		local acceleration = (train.acceleration or 0) * (advtrains.global_slowdown*advtrains.global_slowdown)
 		local velocityvec = vector.multiply(vdir, velocity)
 		local accelerationvec = vector.multiply(vdir, acceleration)
 		
@@ -539,9 +543,9 @@ function wagon:on_step(dtime)
 				or self.old_yaw~=yaw
 				or updatepct_timer_elapsed then--only send update packet if something changed
 			
-			self.object:setpos(pos)
-			self.object:setvelocity(velocityvec)
-			self.object:setacceleration(accelerationvec)
+			self.object:set_pos(pos)
+			self.object:set_velocity(velocityvec)
+			self.object:set_acceleration(accelerationvec)
 			
 			if #self.seats > 0 and self.old_yaw ~= yaw then
 				if not self.player_yaw then
@@ -574,7 +578,7 @@ function wagon:on_step(dtime)
                 end
                 self.object:set_rotation({x=pitch, y=yaw, z=0})
             else
-                self.object:setyaw(yaw)
+                self.object:set_yaw(yaw)
             end
 			
 			if self.update_animation then
@@ -595,11 +599,9 @@ function wagon:on_step(dtime)
 		self.old_acceleration_vector=accelerationvec
 		self.old_yaw=yaw
 		atprintbm("wagon step", t)
-	end)
 end
 
 function wagon:on_rightclick(clicker)
-	return advtrains.pcall(function()
 		if not self:ensure_init() then return end
 		if not clicker or not clicker:is_player() then
 			return
@@ -687,7 +689,6 @@ function wagon:on_rightclick(clicker)
 				self:show_get_on_form(pname)
 			end
 		end
-	end)
 end
 
 function wagon:get_on(clicker, seatno)
@@ -770,7 +771,7 @@ function wagon:get_off(seatno)
 				
 				--atdebug("platpos:", platpos, "offpos:", offpos)
 				if minetest.get_item_group(minetest.get_node(platpos).name, "platform")>0 then
-					minetest.after(GETOFF_TP_DELAY, function() clicker:setpos(offpos) end)
+					minetest.after(GETOFF_TP_DELAY, function() clicker:set_pos(offpos) end)
 					--atdebug("tp",offpos)
 					return
 				end
@@ -790,7 +791,7 @@ function wagon:get_off(seatno)
 			offp=vector.add({x=isx and r*2 or 0, y=1, z=not isx and r*2 or 0}, objpos)
 			--atdebug("platpos:", p, "offpos:", offp)
 			if minetest.get_item_group(minetest.get_node(p).name, "platform")>0 then
-				minetest.after(GETOFF_TP_DELAY, function() clicker:setpos(offp) end)
+				minetest.after(GETOFF_TP_DELAY, function() clicker:set_pos(offp) end)
 				--atdebug("tp",offp)
 				return
 			end
@@ -987,10 +988,10 @@ function wagon:show_bordcom(pname)
 	
 	-- Interlocking functionality: If the interlocking module is loaded, you can set the signal aspect
 	-- from inside the train
-	if advtrains.interlocking and train.lzb and #train.lzb.oncoming > 0 then
+	if advtrains.interlocking and train.lzb and #train.lzb.checkpoints > 0 then
 		local i=1
-		while train.lzb.oncoming[i] do
-			local oci = train.lzb.oncoming[i]
+		while train.lzb.checkpoints[i] do
+			local oci = train.lzb.checkpoints[i]
 			if oci.udata and oci.udata.signal_pos then
 				if advtrains.interlocking.db.get_sigd_for_signal(oci.udata.signal_pos) then
 					form = form .. "button[4.5,8;5,1;ilrs;Remote Routesetting]"
@@ -999,6 +1000,9 @@ function wagon:show_bordcom(pname)
 			end
 			i=i+1
 		end
+		if train.ars_disable then
+			form = form .. "button[4.5,7;5,1;ilarsenable;Clear 'Disable ARS' flag]"
+		end
 	end
 	
 	minetest.show_formspec(pname, "advtrains_bordcom_"..self.id, form)
@@ -1071,10 +1075,11 @@ function wagon:handle_bordcom_fields(pname, formname, fields)
 	
 	-- Interlocking functionality: If the interlocking module is loaded, you can set the signal aspect
 	-- from inside the train
-	if fields.ilrs and advtrains.interlocking and train.lzb and #train.lzb.oncoming > 0 then
+	if advtrains.interlocking then
+		if fields.ilrs and train.lzb and #train.lzb.checkpoints > 0 then
 			local i=1
-		while train.lzb.oncoming[i] do
-			local oci = train.lzb.oncoming[i]
+			while train.lzb.checkpoints[i] do
+				local oci = train.lzb.checkpoints[i]
 				if oci.udata and oci.udata.signal_pos then
 					local sigd = advtrains.interlocking.db.get_sigd_for_signal(oci.udata.signal_pos)
 					if sigd then
@@ -1085,6 +1090,10 @@ function wagon:handle_bordcom_fields(pname, formname, fields)
 				i=i+1
 			end
 		end
+		if fields.ilarsenable then
+			advtrains.interlocking.ars_set_disable(train, false)
+		end
+	end
 	
 	
 	if not fields.quit then
@@ -1093,7 +1102,6 @@ function wagon:handle_bordcom_fields(pname, formname, fields)
 end
 
 minetest.register_on_player_receive_fields(function(player, formname, fields)
-	return advtrains.pcall(function()
 		local uid=string.match(formname, "^advtrains_geton_(.+)$")
 		if uid then
 			for _,wagon in pairs(minetest.luaentities) do
@@ -1177,7 +1185,6 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 				end
 			end
 		end
-	end)
 end)
 function wagon:seating_from_key_helper(pname, fields, no)
 	local data = advtrains.wagons[self.id]
@@ -1381,7 +1388,6 @@ function advtrains.register_wagon(sysname_p, prototype, desc, inv_img, nincreati
 		groups = { not_in_creative_inventory = nincreative and 1 or 0},
 		
 		on_place = function(itemstack, placer, pointed_thing)
-			return advtrains.pcall(function()
 				if not pointed_thing.type == "node" then
 					return
 				end
@@ -1419,8 +1425,6 @@ function advtrains.register_wagon(sysname_p, prototype, desc, inv_img, nincreati
 					itemstack:take_item()
 				end
 				return itemstack
-				
-			end)
 		end,
 	})
 end

mods/advtrains/advtrains_interlocking/approach.lua

@@ -19,38 +19,50 @@ local function get_over_function(speed, shunt)
 		if speed == 0 and minetest.settings:get_bool("at_il_force_lzb_halt") then
 			atwarn(id,"overrun LZB 0 restriction (red signal) ",pos)
 			-- Set train 1 index backward. Hope this does not lead to bugs...
-			train.index = index - 0.5
-			train.velocity = 0
-			train.ctrl.lzb = 0
-			minetest.after(0, advtrains.invalidate_path, id)
+			--train.index = index - 0.5
+			train.speed_restriction = 0
+			
+			--TODO temporary
+			--advtrains.drb_dump(id)
+			--error("Debug: "..id.." triggered LZB-0")
 		else
 			train.speed_restriction = speed
 			train.is_shunt = shunt
 		end
+		--atdebug("train drove over IP: speed=",speed,"shunt=",shunt)
 	end
 end
 
-advtrains.tnc_register_on_approach(function(pos, id, train, index, lzbdata)
+advtrains.tnc_register_on_approach(function(pos, id, train, index, has_entered, lzbdata)
 
 	--atdebug(id,"IL ApprC",pos,index,lzbdata)
 	--train.debug = advtrains.print_concat_table({train.is_shunt,"|",index,"|",lzbdata})
 
 	local pts = advtrains.roundfloorpts(pos)
 	local cn  = train.path_cn[index]
-	local travsht = lzbdata.travsht
+	local travsht = lzbdata.il_shunt
+	
+	local travspd = lzbdata.il_speed
 	
 	if travsht==nil then
-		travsht = train.is_shunt
+		-- lzbdata has reset
+		travspd = train.speed_restriction
+		travsht = train.is_shunt or false
 	end
 	
-	local travspd = lzbdata.travspd
-	local travwspd = lzbdata.travwspd
+	
 	
 	-- check for signal
 	local asp, spos = il.db.get_ip_signal_asp(pts, cn)
 	
 	-- do ARS if needed
-	if spos then
+	local ars_enabled = not train.ars_disable
+	-- Note on ars_disable:
+	-- Theoretically, the ars_disable flag would need to behave like the speed restriction field: it should be
+	-- stored in lzbdata and updated once the train drives over. However, for the sake of simplicity, it is simply
+	-- a value in the train. In this case, this is sufficient because once a train triggers ARS for the first time,
+	-- resetting the path does not matter to the set route and ARS doesn't need to be called again.
+	if spos and ars_enabled then
 		--atdebug(id,"IL Spos (ARS)",spos,asp)
 		local sigd = il.db.get_sigd_for_signal(spos)
 		if sigd then
@@ -60,22 +72,22 @@ advtrains.tnc_register_on_approach(function(pos, id, train, index, lzbdata)
 	--atdebug("trav: ",pos, cn, asp, spos, "travsht=", lzb.travsht)
 	local lspd
 	if asp then
-		--atdebug(id,"IL Signal",spos,asp)
+		--atdebug(id,"IL Signal",spos, asp, lzbdata, "trainstate", train.speed_restriction, train.is_shunt)
 		local nspd = 0
 		--interpreting aspect and determining speed to proceed
 		if travsht then
 			--shunt move
-			if asp.shunt.free then
+			if asp.shunt then
 				nspd = SHUNT_SPEED_MAX
-			elseif asp.shunt.proceed_as_main and asp.main.free then
-				nspd = asp.main.speed
+			elseif asp.proceed_as_main and asp.main ~= 0 then
+				nspd = asp.main
 				travsht = false
 			end
 		else
 			--train move
-			if asp.main.free then
-				nspd = asp.main.speed
-			elseif asp.shunt.free then
+			if asp.main ~= 0 then
+				nspd = asp.main
+			elseif asp.shunt then
 				nspd = SHUNT_SPEED_MAX
 				travsht = true
 			end
@@ -89,25 +101,26 @@ advtrains.tnc_register_on_approach(function(pos, id, train, index, lzbdata)
 			end
 		end
 		
-		local nwspd = asp.info.w_speed
-		if nwspd then
-			if nwspd == -1 then
-				travwspd = nil
-			else
-				travwspd = nwspd
-			end
-		end
-		--atdebug("ns,wns,ts,wts", nspd, nwspd, travspd, travwspd)
+		--atdebug("ns,ts", nspd, travspd)
+
 		lspd = travspd
-		if travwspd and (not lspd or lspd>travwspd) then
-			lspd = travwspd
-		end
 		
 		local udata = {signal_pos = spos}
 		local callback = get_over_function(lspd, travsht)
-		advtrains.lzb_add_checkpoint(train, index, lspd, callback, udata)
+		lzbdata.il_shunt = travsht
+		lzbdata.il_speed = travspd
+		--atdebug("new lzbdata",lzbdata)
+		advtrains.lzb_add_checkpoint(train, index, lspd, callback, lzbdata, udata)
 	end
-	lzbdata.travsht = travsht
-	lzbdata.travspd = travspd
-	lzbdata.travwspd = travwspd
 end)
+
+-- Set the ars_disable flag to the value passed
+-- Triggers a path invalidation if set to false
+function advtrains.interlocking.ars_set_disable(train, value)
+	if value then
+		train.ars_disable = true
+	else
+		train.ars_disable = nil
+		minetest.after(0, advtrains.path_invalidate, train)
+	end
+end

mods/advtrains/advtrains_interlocking/database.lua

@@ -131,6 +131,37 @@ function ildb.load(data)
 	if data.npr_rails then
 		advtrains.interlocking.npr_rails = data.npr_rails
 	end
+	
+	--COMPATIBILITY to Signal aspect format
+	-- TODO remove in time...
+	for pts,tcb in pairs(track_circuit_breaks) do
+		for connid, tcbs in ipairs(tcb) do
+			if tcbs.routes then
+				for _,route in ipairs(tcbs.routes) do
+					if route.aspect then
+						-- transform the signal aspect format
+						local asp = route.aspect
+						if type(asp.main) == "table" then
+							atwarn("Transforming route aspect of signal",pts,"/",connid,"")
+							if asp.main.free then
+								asp.main = asp.main.speed
+							else
+								asp.main = 0
+							end
+							if asp.dst.free then
+								asp.dst = asp.dst.speed
+							else
+								asp.dst = 0
+							end
+							asp.proceed_as_main = asp.shunt.proceed_as_main
+							asp.shunt = asp.shunt.free
+							-- Note: info table not transferred, it's not used right now
+						end
+					end
+				end
+			end
+		end
+	end
 end
 
 function ildb.save()
@@ -149,6 +180,7 @@ end
 --[[
 TCB data structure
 {
+-- This is the "A" side of the TCB
 [1] = { -- Variant: with adjacent TCs.
 	ts_id = <id> -- ID of the assigned track section
 	signal = <pos> -- optional: when set, routes can be set from this tcb/direction and signal
@@ -164,6 +196,7 @@ TCB data structure
 	routes = { <route definition> } -- a collection of routes from this signal
 	route_auto = <boolean> -- When set, we will automatically re-set the route (designated by routeset)
 },
+-- This is the "B" side of the TCB
 [2] = { -- Variant: end of track-circuited area (initial state of TC)
 	ts_id = nil, -- this is the indication for end_of_interlocking
 	section_free = <boolean>, --this can be set by an exit node via mesecons or atlatc, 

mods/advtrains/advtrains_interlocking/demosignals.lua

@@ -6,10 +6,10 @@
 
 
 local setaspect = function(pos, node, asp)
-	if not asp.main.free then
+	if asp.main == 0 then
 		advtrains.ndb.swap_node(pos, {name="advtrains_interlocking:ds_danger"})
 	else
-		if asp.dst.free and asp.main.speed == -1 then
+		if asp.dst ~= 0 and asp.main == -1 then
 			advtrains.ndb.swap_node(pos, {name="advtrains_interlocking:ds_free"})
 		else
 			advtrains.ndb.swap_node(pos, {name="advtrains_interlocking:ds_slow"})
@@ -22,18 +22,10 @@ local setaspect = function(pos, node, asp)
 end
 
 local suppasp = {
-		main = {
-			free = nil,
-			speed = {6, -1},
-		},
-		dst = {
-			free = nil,
-			speed = nil,
-		},
-		shunt = {
-			free = false,
+		main = {0, 6, -1},
+		dst = {0, false},
+		shunt = false,
 		proceed_as_main = true,
-		},
 		info = {
 			call_on = false,
 			dead_end = false,
@@ -74,10 +66,7 @@ minetest.register_node("advtrains_interlocking:ds_free", {
 		supported_aspects = suppasp,
 		get_aspect = function(pos, node)
 			return {
-				main = {
-					free = true,
-					speed = -1,
-				}
+				main = -1,
 			}
 		end,
 	},
@@ -98,10 +87,7 @@ minetest.register_node("advtrains_interlocking:ds_slow", {
 		supported_aspects = suppasp,
 		get_aspect = function(pos, node)
 			return {
-				main = {
-					free = true,
-					speed = 6,
-				}
+				main = 6,
 			}
 		end,
 	},

mods/advtrains/advtrains_interlocking/route_prog.lua

@@ -112,7 +112,8 @@ route = {
 		next = <sigd>, -- of the next (note: next) TCB on the route
 		locks = {<pts> = "state"} -- route locks of this route segment
 	}
-	terminal = 
+	terminal = <sigd>,
+	aspect = <signal aspect>,--note, might change in future
 }
 The first item in the TCB path (namely i=0) is always the start signal of this route,
 so this is left out.

mods/advtrains/advtrains_interlocking/route_ui.lua

@@ -129,7 +129,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 				advtrains.interlocking.show_route_edit_form(pname, sigd, routeid)
 			end
 			
-			advtrains.interlocking.show_signal_aspect_selector(pname, suppasp, route.name, callback, route.aspect)
+			advtrains.interlocking.show_signal_aspect_selector(pname, suppasp, route.name, callback, route.aspect or advtrains.interlocking.GENERIC_FREE)
 			return
 		end
 		if fields.delete then

mods/advtrains/advtrains_interlocking/routesetting.lua

@@ -6,21 +6,6 @@ local function sigd_to_string(sigd)
 	return minetest.pos_to_string(sigd.p).." / "..lntrans[sigd.s]
 end
 
-local asp_generic_free = {
-	main = {
-		free = true,
-		speed = -1,
-	},
-	shunt = {
-		free = false,
-	},
-	dst = {
-		free = true,
-		speed = -1,
-	},
-	info = {}
-}
-
 local ildb = advtrains.interlocking.db
 local ilrs = {}
 
@@ -127,7 +112,7 @@ function ilrs.set_route(signal, route, try)
 			}
 			if c_tcbs.signal then
 				c_tcbs.route_committed = true
-				c_tcbs.aspect = route.aspect or asp_generic_free
+				c_tcbs.aspect = route.aspect or advtrains.interlocking.GENERIC_FREE
 				c_tcbs.route_origin = signal
 				advtrains.interlocking.update_signal_aspect(c_tcbs)
 			end

mods/advtrains/advtrains_interlocking/signal_api.lua

@@ -3,29 +3,39 @@
 
 --[[
 Signal aspect table:
+Note: All speeds are measured in m/s, aka the number of + signs in the HUD.
 asp = {
-	main = {
-		free = <boolean>,
-		speed = <int km/h>,
-	},
-	shunt = {
-		free = <boolean>,
+	main = <int speed>,
+		-- Main signal aspect, tells state and permitted speed of next section
+		-- 0 = section is blocked
+		-- >0 = section is free, speed limit is this value
+		-- -1 = section is free, maximum speed permitted
+		-- false/nil = Signal doesn't provide main signal information, retain current speed limit.
+	shunt = <boolean>,
 		-- Whether train may proceed as shunt move, on sight
 		-- main aspect takes precedence over this
+		-- When main==0, train switches to shunt move and is restricted to speed 6
 	proceed_as_main = <boolean>,
-		-- If an approaching train is a shunt move and "main.free" is set,
+		-- If an approaching train is a shunt move and 'shunt' is false,
 		-- the train may proceed as a train move under the "main" aspect
+		-- if the main aspect permits it (i.e. main!=0)
 		-- If this is not set, shunt moves are NOT allowed to switch to
-		-- a train move, and must stop even if "main.free" is set.
+		-- a train move, and must stop even if "main" would permit passing.
 		-- This is intended to be used for "Halt for shunt moves" signs.
-	}
-	dst = {
-		free = <boolean>,
-		speed = <int km/h>,
-	}
-	info = {
+	
+	dst = <int speed>,
+		-- Distant signal aspect, tells state and permitted speed of the section after next section
+		-- The character of these information is purely informational
+		-- At this time, this field is not actively used
+		-- 0 = section is blocked
+		-- >0 = section is free, speed limit is this value
+		-- -1 = section is free, maximum speed permitted
+		-- false/nil = Signal doesn't provide distant signal information.
+	
+	-- the character of call_on and dead_end is purely informative
 	call_on = <boolean>, -- Call-on route, expect train in track ahead (not implemented yet)
 	dead_end = <boolean>, -- Route ends on a dead end (e.g. bumper) (not implemented yet)
+
 	w_speed = <integer>,
 	-- "Warning speed restriction". Supposed for short-term speed
 	-- restrictions which always override any other restrictions
@@ -33,12 +43,6 @@ asp = {
 	-- (Example: german Langsamfahrstellen-Signale)
 	}
 }
--- For "speed" and "w_speed" fields, a value of -1 means that the
--- restriction is lifted. If they are omitted, the value imposed at
--- the last aspect received remains valid.
--- The "dst" subtable can be completely omitted when no explicit dst
--- aspect should be signalled to the train. In this case, the last
--- signalled dst aspect remains valid.
 
 == How signals actually work in here ==
 Each signal (in the advtrains universe) is some node that has at least the
@@ -60,10 +64,16 @@ advtrains = {
 		-- This function gets called whenever the signal should display
 		-- a new or changed signal aspect. It is not required that
 		-- the signal actually displays the exact same aspect, since
-		-- some signals can not do this by design.
-		-- Example: pure shunt signals can not display a "main" aspect
+		-- some signals can not do this by design. However, it must
+		-- display an aspect that is at least as restrictive as the passed
+		-- aspect as far as it is capable of doing so.
+		-- Examples:
+		-- - pure shunt signals can not display a "main" aspect
 		--   and have no effect on train moves, so they will only ever
 		--   honor the shunt.free field for their aspect.
+		-- - the german Hl system can only signal speeds of 40, 60
+		--   and 100 km/h, a speed of 80km/h should then be signalled
+		--   as 60 km/h instead.
 		-- In turn, it is not guaranteed that the aspect will fulfill the
 		-- criteria put down in supported_aspects.
 		-- If set_aspect is present, supported_aspects should also be declared.
@@ -87,51 +97,52 @@ advtrains = {
 				false: always shows "blocked", unchangable
 				true: always shows "free", unchangable
 		-- Any of the "speed" fields should contain a list of possible values
-		--  to be set as restriction. If omitted, this signal should never
-		--  set the corresponding "speed" field in the aspect, which means
-		--  that the previous speed limit stays valid
+		--  to be set as restriction. If omitted, the value of the described
+		--  field is always assumed to be false (no information)
+		-- A speed of 0 means that the signal can show a "blocked" aspect
+		--  (which is probably the case for most signals)
+		-- If the signal can signal "no information" on one of the fields
+		--  (thus false is an acceptable value), include false in the list
 		-- If your signal can only display a single speed (may it be -1),
 		--  always enclose that single value into a list. (such as {-1})
-		main = {
-			free = <boolean/nil>,
-			speed = {<speed1>, ..., <speedn>} or nil,
-		},
-		dst = {
-			free = <boolean/nil>,
-			speed = {<speed1>, ..., <speedn>} or nil,
-		},
-		shunt = {
-			free = <boolean/nil>,
-		},
-		info = {
+		main = {<speed1>, ..., <speedn>} or nil,
+		dst = {<speed1>, ..., <speedn>} or nil,
+		shunt = <boolean/nil>,
+		
 		call_on = <boolean/nil>,
 		dead_end = <boolean/nil>,
 		w_speed = {<speed1>, ..., <speedn>} or nil,
-		}
 		
 	},
+	Example for supported_aspects:
+	supported_aspects = {
+		main = {0, 6, -1}, -- can show either "Section blocked", "Proceed at speed 6" or "Proceed at maximum speed"
+		dst = {0, false}, -- can show only if next signal shows "blocked", no other information.
+		shunt = false, -- shunting by this signal is never allowed.
+		
+		call_on = false,
+		dead_end = false,
+		w_speed = nil,
+		-- none of the information can be shown by the signal
+		
+	},
+	
 	get_aspect = function(pos, node)
 		-- This function gets called by the train safety system. It
 		should return the aspect that this signal actually displays,
 		not preferably the input of set_aspect.
 		-- For regular, full-featured light signals, they will probably
 		honor all entries in the original aspect, however, e.g.
-		simple shunt signals always return main.free=true regardless of
+		simple shunt signals always return main=false regardless of
 		the set_aspect input because they can not signal "Halt" to
 		train moves.
 		-- advtrains.interlocking.DANGER contains a default "all-danger" aspect.
 		-- If your signal does not cover certain sub-tables of the aspect,
 		the following reasonable defaults are automatically assumed:
-		main = {
-			free = true,
-		}
-		dst = {
-			free = true,
-		}
-		shunt = {
-			free = false,
-			proceed_as_main = false,
-		}
+		main = false (unchanged)
+		dst = false (unchanged)
+		shunt = false (shunting not allowed)
+		info = {} (no further information)
 	end,
 }
 on_rightclick = advtrains.interlocking.signal_rc_handler
@@ -155,51 +166,37 @@ This function will query get_aspect to retrieve the new aspect.
 ]]--
 
 local DANGER = {
-	main = {
-		free = false,
-		speed = 0,
-	},
-	shunt = {
-		free = false,
-	},
-	dst = {
-		free = false,
-		speed = 0,
-	},
-	info = {}
+	main = 0,
+	dst = false,
+	shunt = false,
 }
 advtrains.interlocking.DANGER = DANGER
 
-local function fillout_aspect(asp)
-	if not asp.main then
-		asp.main = {
-			free = true,
-		}
-	elseif type(asp.main) ~= "table" then
-		asp.main = {
-			free = asp.main~=0,
-			speed = asp.main,
-		}
+advtrains.interlocking.GENERIC_FREE = {
+	main = -1,
+	shunt = false,
+	dst = false,
+}
+
+local function convert_aspect_if_necessary(asp)
+	if type(asp.main) == "table" then
+		local newasp = {} 
+		if asp.main.free then
+			newasp.main = asp.main.speed
+		else
+			newasp.main = 0
 		end
-	if not asp.dst then
-		asp.dst = {
-			free = true,
-		}
+		if asp.dst and asp.dst.free then
+			newasp.dst = asp.dst.speed
+		else
+			newasp.dst = 0
 		end
-	if not asp.shunt then
-		asp.shunt = {
-			free = false,
-			proceed_as_main = false,
-		}
-	elseif type(asp.shunt) ~= "table" then
-		asp.shunt = {
-			free = asp.shunt,
-			proceed_as_main = asp.proceed_as_main,
-		}
-	end
-	if not asp.info then
-		asp.info = {}
+		newasp.proceed_as_main = asp.shunt.proceed_as_main
+		newasp.shunt = asp.shunt.free
+		-- Note: info table not transferred, it's not used right now
+		return newasp
 	end
+	return asp
 end
 
 function advtrains.interlocking.update_signal_aspect(tcbs)
@@ -219,7 +216,7 @@ function advtrains.interlocking.signal_after_dig(pos)
 end
 
 function advtrains.interlocking.signal_set_aspect(pos, asp)
-	fillout_aspect(asp)
+	asp = convert_aspect_if_necessary(asp)
 	local node=advtrains.ndb.get_node(pos)
 	local ndef=minetest.registered_nodes[node.name]
 	if ndef and ndef.advtrains and ndef.advtrains.set_aspect then
@@ -234,17 +231,17 @@ function advtrains.interlocking.signal_on_aspect_changed(pos)
 	if not ipts then return end
 	local ipos = minetest.string_to_pos(ipts)
 	
-	local tns = advtrains.occ.get_trains_over(ipos)
-	for id, sidx in pairs(tns) do
---		local train = advtrains.trains[id]
-		--if train.index <= sidx then
-		minetest.after(0, advtrains.invalidate_path, id)
-		--end
-	end
+	advtrains.invalidate_all_paths_ahead(ipos)
 end
 
 function advtrains.interlocking.signal_rc_handler(pos, node, player, itemstack, pointed_thing)
 	local pname = player:get_player_name()
+	local control = player:get_player_control()
+	if control.aux1 then
+		advtrains.interlocking.show_ip_form(pos, pname)
+		return
+	end
+	
 	local sigd = advtrains.interlocking.db.get_sigd_for_signal(pos)
 	if sigd then
 		advtrains.interlocking.show_signalling_form(sigd, pname)
@@ -252,7 +249,16 @@ function advtrains.interlocking.signal_rc_handler(pos, node, player, itemstack,
 		local ndef = minetest.registered_nodes[node.name]
 		if ndef.advtrains and ndef.advtrains.set_aspect then
 			-- permit to set aspect manually
-			minetest.show_formspec(pname, "at_il_sigasp_"..minetest.pos_to_string(pos), "field[aspect;Set Aspect ('A' to assign IP);D0D0D]")
+			local function callback(pname, aspect)
+				advtrains.interlocking.signal_set_aspect(pos, aspect)
+			end
+			local isasp = ndef.advtrains.get_aspect(pos, node)
+			
+			advtrains.interlocking.show_signal_aspect_selector(
+				pname,
+				ndef.advtrains.supported_aspects,
+				"Set aspect manually", callback,
+				isasp)
 		else
 			--static signal - only IP
 			advtrains.interlocking.show_ip_form(pos, pname)
@@ -260,45 +266,13 @@ function advtrains.interlocking.signal_rc_handler(pos, node, player, itemstack,
 	end
 end
 
-minetest.register_on_player_receive_fields(function(player, formname, fields)
-	local pname = player:get_player_name()
-	local pts = string.match(formname, "^at_il_sigasp_(.+)$")
-	local pos
-	if pts then pos = minetest.string_to_pos(pts) end
-	if pos and fields.aspect then
-		if fields.aspect == "A" then
-			advtrains.interlocking.show_ip_form(pos, pname)
-			return
-		end
-		local mfs, msps, dfs, dsps, shs = string.match(fields.aspect, "^([FD])([-0-9]+)([FD])([-0-9]+)([FD])$")
-		local asp = {
-			main = {
-				free = mfs=="F",
-				speed = tonumber(msps),
-			},
-			shunt = {
-				free = shs=="F",
-			},
-			dst = {
-				free = dfs=="F",
-				speed = tonumber(dsps),
-			},
-			info = {
-				call_on = false, -- Call-on route, expect train in track ahead
-				dead_end = false, -- Route ends on a dead end (e.g. bumper)
-			}
-		}
-		advtrains.interlocking.signal_set_aspect(pos, asp)
-	end
-end)
-
 -- Returns the aspect the signal at pos is supposed to show
 function advtrains.interlocking.signal_get_supposed_aspect(pos)
 	local sigd = advtrains.interlocking.db.get_sigd_for_signal(pos)
 	if sigd then
 		local tcbs = advtrains.interlocking.db.get_tcbs(sigd)
 		if tcbs.aspect then
-			return tcbs.aspect
+			return convert_aspect_if_necessary(tcbs.aspect)
 		end
 	end
 	return DANGER;
@@ -312,8 +286,7 @@ function advtrains.interlocking.signal_get_aspect(pos)
 	if ndef and ndef.advtrains and ndef.advtrains.get_aspect then
 		local asp = ndef.advtrains.get_aspect(pos, node)
 		if not asp then asp = DANGER end
-		fillout_aspect(asp)
-		return asp
+		return convert_aspect_if_necessary(asp)
 	end
 	return nil
 end
@@ -447,42 +420,45 @@ local players_aspsel = {}
 suppasp: "supported_aspects" table
 purpose: form title string
 callback: func(pname, aspect) called on form submit
+isasp: aspect currently set
 ]]
-function advtrains.interlocking.show_signal_aspect_selector(pname, p_suppasp, p_purpose, callback, p_isasp)
+function advtrains.interlocking.show_signal_aspect_selector(pname, p_suppasp, p_purpose, callback, isasp)
 	local suppasp = p_suppasp or {
-		main = {}, dst = {}, shunt = {}, info = {},
+		main = {0, -1}, dst = {false}, shunt = false, info = {},
 	}
 	local purpose = p_purpose or ""
-	local isasp = p_isasp and fillout_aspect(p_isasp)
 	
 	local form = "size[7,5]label[0.5,0.5;Select Signal Aspect:]"
 	form = form.."label[0.5,1;"..purpose.."]"
 	
 	form = form.."label[0.5,1.5;== Main Signal ==]"
-	if suppasp.main.free == nil then
-		local st = 2
-		if isasp and not isasp.main.free then st=1 end
-		form = form.."dropdown[0.5,2;2;main_free;danger,free;"..st.."]"
-	end
-	if suppasp.main.speed then
 	local selid = 1
-		if isasp and isasp.main.speed then
-			for idx, spv in ipairs(suppasp.main.speed) do
-				if spv == isasp.main.speed then
+	local entries = {}
+	for idx, spv in ipairs(suppasp.main) do
+		local entry
+		if spv == 0 then
+			entry = "Halt"
+		elseif spv == -1 then
+			entry = "Continue at maximum speed"
+		elseif not spv then
+			entry = "Continue\\, speed limit unchanged (no info)"
+		else
+			entry = "Continue at speed of "..spv				
+		end
+		-- hack: the crappy formspec system returns the label, not the index. save the index in it.
+		entries[idx] = idx.."| "..entry
+		if isasp and spv == (isasp.main or false) then
 			selid = idx
-					break
 		end
 	end
-		end
-		form = form.."label[2.3,1;Speed:]"
-		form = form.."dropdown[3,2;2;main_speed;"..table.concat(suppasp.main.speed, ",")..";"..selid.."]"
-	end
+	form = form.."dropdown[0.5,2;6;main;"..table.concat(entries, ",")..";"..selid.."]"
+
 	
 	form = form.."label[0.5,3;== Shunting ==]"
-	if suppasp.shunt.free == nil then
+	if suppasp.shunt == nil then
 		local st = 1
-		if isasp and isasp.shunt.free then st=2 end
-		form = form.."dropdown[0.5,3.5;2;shunt_free;---,allowed;"..st.."]"
+		if isasp and isasp.shunt then st=2 end
+		form = form.."dropdown[0.5,3.5;6;shunt_free;---,allowed;"..st.."]"
 	end
 		
 	form = form.."button_exit[0.5,4.5;  5,1;save;OK]"
@@ -507,12 +483,10 @@ local function usebool(sup, val, free)
 		return sup
 	end
 end
-local function usespeed(sup, val)
-	if sup then
-		return tonumber(val)
-	else
-		return nil
-	end
+
+-- other side of hack: extract the index
+local function ddindex(val)
+	return tonumber(string.match(val, "^(%d+)|"))
 end
 
 -- TODO use non-hacky way to parse outputs
@@ -523,17 +497,12 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 	if psl then
 		if formname == "at_il_sigaspdia_"..psl.token then
 			if fields.save then
+				local maini = ddindex(fields.main)
+				if not maini then return end
 				local asp = {
-					main = {
-						free = usebool(psl.suppasp.main.free, fields.main_free, "free"),
-						speed = usespeed(psl.suppasp.main.speed, fields.main_speed),
-					},
-					dst = {
-						free = true, speed = -1,
-					},
-					shunt = {
-						free = usebool(psl.suppasp.shunt.free, fields.shunt_free, "allowed"),
-					},
+					main = psl.suppasp.main[maini],
+					dst = false,
+					shunt = usebool(psl.suppasp.shunt, fields.shunt_free, "allowed"),
 					info = {}
 				}
 				psl.callback(pname, asp)

mods/advtrains/advtrains_interlocking/tcb_ts_ui.lua

@@ -558,7 +558,7 @@ local sig_pselidx = {}
 -- Players having a signalling form open
 local p_open_sig_form = {}
 
-function advtrains.interlocking.show_signalling_form(sigd, pname, sel_rte)
+function advtrains.interlocking.show_signalling_form(sigd, pname, sel_rte, called_from_form_update)
 	if not minetest.check_player_privs(pname, "train_operator") then
 		minetest.chat_send_player(pname, "Insufficient privileges to use this!")
 		return
@@ -651,7 +651,10 @@ function advtrains.interlocking.show_signalling_form(sigd, pname, sel_rte)
 	p_open_sig_form[pname] = sigd
 	
 	-- always a good idea to update the signal aspect
+	if not called_from_form_update then
+	-- FIX prevent a callback loop
 		advtrains.interlocking.update_signal_aspect(tcbs)
+	end
 end
 
 function advtrains.interlocking.update_player_forms(sigd)
@@ -763,7 +766,7 @@ minetest.register_on_player_receive_fields(function(player, formname, fields)
 			tcbs.route_auto = false
 		end
 		
-		advtrains.interlocking.show_signalling_form(sigd, pname, sel_rte)
+		advtrains.interlocking.show_signalling_form(sigd, pname, sel_rte, true)
 		return
 	end
 	

mods/advtrains/advtrains_line_automation/stoprail.lua

@@ -169,7 +169,8 @@ local adefunc = function(def, preset, suffix, rotation)
 				show_stoprailform(pos, player)
 			end,
 			advtrains = {
-				on_train_approach = function(pos,train_id, train, index)
+				on_train_approach = function(pos,train_id, train, index, has_entered)
+					if has_entered then return end -- do not stop again!
 					if train.path_cn[index] == 1 then
 						local pe = advtrains.encode_pos(pos)
 						local stdata = advtrains.lines.stops[pe]
@@ -184,6 +185,7 @@ local adefunc = function(def, preset, suffix, rotation)
 								local stn = advtrains.lines.stations[stdata.stn]
 								local stnname = stn and stn.name or "Unknown Station"
 								train.text_inside = "Next Stop:\n"..stnname
+								advtrains.interlocking.ars_set_disable(train, true)
 							end
 						end
 					end
@@ -201,7 +203,7 @@ local adefunc = function(def, preset, suffix, rotation)
 							local stnname = stn and stn.name or "Unknown Station"
 							
 							-- Send ATC command and set text
-							advtrains.atc.train_set_command(train, "B0 W O"..stdata.doors..(stdata.kick and "K" or "").." D"..stdata.wait.." OC "..(stdata.reverse and "R" or "").."D"..(stdata.ddelay or 1) .. "S" ..(stdata.speed or "M"), true)
+							advtrains.atc.train_set_command(train, "B0 W O"..stdata.doors..(stdata.kick and "K" or "").." D"..stdata.wait.." OC "..(stdata.reverse and "R" or "").."D"..(stdata.ddelay or 1) .. " A1 S" ..(stdata.speed or "M"), true)
 							train.text_inside = stnname
 							if tonumber(stdata.wait) then
 								minetest.after(tonumber(stdata.wait), function() train.text_inside = "" end)

mods/advtrains/advtrains_luaautomation/README.md

@@ -1,7 +1,9 @@
 
 # Advtrains - Lua Automation features
 
-This mod offers components that run LUA code and interface with each other through a global environment. It makes complex automated railway systems possible. The mod is sometimes abbreviated as 'atlatc'. This stands for AdvTrainsLuaATC. This short name has been chosen for user convenience, since the name of this mod ('advtrains_luaautomation') is very long.
+This mod offers components that run LUA code and interface with each other through a global environment. It makes complex automated railway systems possible. The mod is sometimes abbreviated as 'LuaATC' or 'atlatc'. This stands for AdvTrainsLuaATC. This short name has been chosen for user convenience, since the name of this mod ('advtrains_luaautomation') is very long.
+
+A probably more complete documentation of LuaATC is found on the [Advtrains Wiki](http://advtrains.de/wiki/doku.php?id=usage:atlatc:start)
 
 ## Privileges
 To perform any operations using this mod (except executing operation panels), players need the "atlatc" privilege.
@@ -18,6 +20,13 @@ Create environment with the given name. To be able to do anything, you first nee
  - `/env_setup <env_name>`:
 Invoke the form to edit the environment's initialization code. For more information, see the section on active components. You can also delete an environment from here.
 
+ - `/env_subscribe <env_name>`, `/env_unsubscribe <env_name>`:
+Subscribe or unsubscribe from log/error messages originating from this environment
+
+ - `/env_subscriptions [env_name]`:
+List your subscriptions or players subscribed to an environment.
+
+
 ## Functions and variables
 ### General Functions and Variables
 The following standard Lua libraries are available:
@@ -40,41 +49,6 @@ The following standard Lua functions are available:
 
 Any attempt to overwrite the predefined values results in an error.
 
-## Components and Events
-
-### Components
-Atlac components introduce automation-capable components that fall within two categories:
- - Active Components are components that are able to run Lua code, triggered by specific events.
- - Passive Components can't perform actions themselves. Their state can be read and set by active components or manually by the player.
- 
-
-
-## Functions and Variables
-
-### Events
-The event table is a variable created locally by the component being triggered. It is a table with the following format:
-```lua
-event = {
-	type = "<event type>",
-	<event type> = true,
-	--additional event-specific content
-}
-```
-You can check the event type by using the following:
-```lua 
-if event.type == "wanted" then
-	--do stuff
-end
-```
-or
-```lua
-if event.wanted then
-	--do stuff
-end
-````
-where `wanted` is the event type to check for.  
-See the "Active Components" section below for details on the various event types as not all of them are applicable to all components.
-
 ### LuaAutomation Global Variables
  - `S`
 The variable 'S' contains a table which is shared between all components of the environment. Its contents are persistent over server restarts. May not contain functions, every other value is allowed.
@@ -104,11 +78,17 @@ Set the state of the passive component at position `pos`.
 Checks whether there is a passive component at the position pos (and/or whether a passive component with this name exists)
 
  - `interrupt(time, message)`
-Cause LuaAutomation to trigger an `int` event on this component after the given time in seconds with the specified `message` field. `message` can be of any Lua data type. *Not available in init code.*
+Cause LuaAutomation to trigger an `int` event on this component after the given time in seconds with the specified `message` field. `message` can be of any Lua data type. Returns true. *Not available in init code.*
+
+ - `interrupt_safe(time, message)`
+Like `interrupt()`, but does not add an interrupt and returns false when an interrupt (of any type) is already present for this component. Returns true when interrupt was successfully added.
 
  - `interrupt_pos(pos, message)`
 Immediately trigger an `ext_int` event on the active component at position pos. `message` is like in interrupt(). Use with care, or better **_don't use_**! Incorrect use can result in **_expotential growth of interrupts_**.
 
+ - `clear_interrupts()`
+Removes any pending interrupts of this node.
+
  - `digiline_send(channel, message)`
 Make this active component send a digiline message on the specified channel.
 Not available in init code.
@@ -128,52 +108,105 @@ Cancels the route that is set from the signal at pos. Has the same effect as cli
  - `get_aspect(pos)`
 Returns the signal aspect of the signal at pos. A signal aspect has the following format:
 ```lua
-{
-	main = { -- the next track section in line. Shows blocked for shunt routes
-		free = <boolean>,
-		speed = <int km/h>,
-	},
-	shunt = { -- whether a "shunting allowed" aspect should be shown
-		free = <boolean>,
-	},
-	dst = { -- the aspect of the next main signal on (at end of) route
-		free = <boolean>,
-		speed = <int km/h>,
-	},
-	info = {
-		call_on = <boolean>, -- Call-on route, expect train in track ahead
-		dead_end = <boolean>, -- Route ends on a dead end (e.g. bumper)
-	}
+asp = {
+	main = <int speed>,
+		-- Main signal aspect, tells state and permitted speed of next section
+		-- 0 = section is blocked
+		-- >0 = section is free, speed limit is this value
+		-- -1 = section is free, maximum speed permitted
+		-- false = Signal doesn't provide main signal information, retain current speed limit.
+	shunt = <boolean>,
+		-- Whether train may proceed as shunt move, on sight
+		-- main aspect takes precedence over this
+		-- When main==0, train switches to shunt move and is restricted to speed 8
+	proceed_as_main = <boolean>,
+		-- If an approaching train is a shunt move and 'shunt' is false,
+		-- the train may proceed as a train move under the "main" aspect
+		-- if the main aspect permits it (i.e. main!=0)
+		-- If this is not set, shunt moves are NOT allowed to switch to
+		-- a train move, and must stop even if "main" would permit passing.
+		-- This is intended to be used for "Halt for shunt moves" signs.
+	
+	dst = <int speed>,
+		-- Distant signal aspect, tells state and permitted speed of the section after next section
+		-- The character of these information is purely informational
+		-- At this time, this field is not actively used
+		-- 0 = section is blocked
+		-- >0 = section is free, speed limit is this value
+		-- -1 = section is free, maximum speed permitted
+		-- false = Signal doesn't provide distant signal information.
+	
+	-- the character of call_on and dead_end is purely informative
+	call_on = <boolean>, -- Call-on route, expect train in track ahead (not implemented yet)
+	dead_end = <boolean>, -- Route ends on a dead end (e.g. bumper) (not implemented yet)
+
+	w_speed = <integer>,
+	-- "Warning speed restriction". Supposed for short-term speed
+	-- restrictions which always override any other restrictions
+	-- imposed by "speed" fields, until lifted by a value of -1
+	-- (Example: german Langsamfahrstellen-Signale)
 }
 ```
-As of August 2018 (git commit d837e7e), only the aspect.main.free field is ever used by the interlocking system.
+As of January 2020, the 'dst', 'call_on' and 'dead_end' fields are not used.
 
-### Active Component
-#### Lua ATC Rails
-Lua ATC rails are the only components that can actually interface with trains. The following event types are available to the Lua ATC rails:
- - ```lua
-{type="train", train=true, id="<train_id>"}
+#### Lines
+
+The advtrains_line_automation component adds a few contraptions that should make creating timeable systems easier.
+Part of its functionality is also available in LuaATC:
+
+- `rwt.*` - all Railway Time functions are included as documented in [the wiki](https://advtrains.de/wiki/doku.php?id=dev:lines:rwt)
+
+ - `schedule(rw_time, msg)`, `schedule_in(rw_dtime, msg)`
+Schedules an event of type {type="schedule", schedule=true, msg=msg} at (resp. after) the specified railway time (which can be in any format). You can only schedule one event this way. (uses the new lines-internal scheduler)
+
+Note: Using the lines scheduler is preferred over using `interrupt()`, as it's more performant and safer to use.
+
+## Events
+The event table is a variable created locally by the component being triggered. It is a table with the following format:
+```lua
+event = {
+	type = "<event type>",
+	<event type> = true,
+	--additional event-specific content
+}
 ```
+You can check the event type by using the following:
+```lua 
+if event.type == "wanted" then
+	--do stuff
+end
+```
+or
+```lua
+if event.wanted then
+	--do stuff
+end
+```
+where `wanted` is the event type to check for.  
+See the "Active Components" section below for details on the various event types as not all of them are applicable to all components.
+
+## Components
+Atlac components introduce automation-capable components that fall within two categories:
+ - Active Components are components that are able to run Lua code, triggered by specific events.
+ - Passive Components can't perform actions themselves. Their state can be read and set by active components or manually by the player.
+
+### Lua ATC Rails
+Lua ATC rails are the only components that can actually interface with trains. The following event types are available to the Lua ATC rails:
+ - `{type="train", train=true, id="<train_id>"}`
 	* This event is fired when a train enters the rail. The field `id` is the unique train ID, which is 6-digit random numerical string.
 	* If the world contains trains from an older advtrains version, this string may be longer and contain a dot `.`
 
- - ```lua
-{type="int", int=true, msg=<message>}
-```
+ - `{type="int", int=true, msg=<message>}`
 	* Fired when an interrupt set by the `interrupt` function runs out. `<message>` is the message passed to the interrupt function.
 	* For backwards compatiblity reasons, `<message>` is also contained in an `event.message` variable.
 
- - ```lua
-{type="ext_int", ext_int=true, message=<message>}
-```
+ - `{type="ext_int", ext_int=true, message=<message>}`
 	* Fired when another node called `interrupt_pos` on this position. `message` is the message passed to the interrupt_pos function.
 
- - ```lua
-{type="digiline", digiline=true, channel=<channel>, msg=<message>}
-```
+ - `{type="digiline", digiline=true, channel=<channel>, msg=<message>}`
 	* Fired when the controller receives a digiline message.
 
-##### Basic Lua Rail Functions and Variables
+#### Basic Lua Rail Functions and Variables
 In addition to the above environment functions, the following functions are available to whilst the train is in contact with the LuaATC rail:
 
  - `atc_send(<atc_command>)`
@@ -215,7 +248,7 @@ In addition to the above environment functions, the following functions are avai
 	Sets the "Routingcode" property of the train (a string).
 	The interlocking system uses this property for Automatic Routesetting.
 
-##### Shunting Functions and Variables
+#### Shunting Functions and Variables
 There are several functions available especially for shunting operations. Some of these functions make use of Freight Codes (FC) set in the Wagon Properties of each wagon and/or locomotive:
 
  - `split_at_index(index, atc_command)`
@@ -241,8 +274,6 @@ There are several functions available especially for shunting operations. Some o
 	Result: `"foo" "foo" "foo"` and `"foo" "bar" "bar"`  
 	The function returns `"foo"` in this case.
 
-	
-
  - `split_off_locomotive(command, len)`
 	Splits off the locomotives at the front of the train, which are
 	identified by an empty FC. `command` specifies the ATC command to be
@@ -269,10 +300,56 @@ There are several functions available especially for shunting operations. Some o
 	Unsets autocouple mode
 
 Deprecated:
+
  - `set_shunt()`, `unset_shunt()`
 	deprecated aliases for set_autocouple() and unset_autocouple(), will be removed from a later release.
 
-##### Timetable Automation
+
+#### Interlocking
+This additional function is available when advtrains_interlocking is enabled:
+
+ - `atc_set_disable_ars(boolean)`
+	Disables (true) or enables (false) the use of ARS for this train. The train will not trigger ARS (automatic route setting) on signals then.
+	
+	Note: If you want to disable ARS from an approach callback, the call to `atc_set_disable_ars(true)` *must* happen during the approach callback, and may not be deferred to an interrupt(). Else the train might trigger an ARS before the interrupt fires.
+
+#### Approach callbacks
+The LuaATC interface provides a way to hook into the approach callback system, which is for example used in the TSR rails (provided by advtrains_interlocking) or the station tracks (provided by advtrains_lines). However, for compatibility reasons, this behavior needs to be explicitly enabled.
+
+Enabling the receiving of approach events works by setting a variable in the local environment of the ATC rail, by inserting the following code:
+
+```lua
+__approach_callback_mode = 1
+-- to receive approach callbacks only in arrow direction
+-- or alternatively
+__approach_callback_mode = 2
+-- to receive approach callbacks in both directions
+```
+
+The following event will be emitted when a train approaches:
+```lua
+{type="approach", approach=true, id="<train_id>"}
+```
+
+Please note these important considerations when using approach callbacks:
+
+ - Approach events might be generated multiple times for the same approaching train. If you are using atc_set_lzb_tsr(), you need to call this function on every run of the approach callback, even if you issued it before for the same train.
+ - A reference to the train is available while executing this event, so that functions such as atc_send() or atc_set_text_outside() can be called. On any consecutive interrupts, that reference will no longer be available until the train enters the track ("train" event)
+ - Unlike all other callbacks, approach callbacks are executed synchronous during the train step. This may cause unexpected side effects when performing certain actions (such as switching turnouts, setting signals/routes) from inside such a callback. I strongly encourage you to only run things that are absolutely necessary at this point in time, and defer anything else to an interrupt(). Be aware that certain things might trigger unexpected behavior.
+
+Operations that are safe to execute in approach callbacks:
+
+ - anything related only to the global environment (setting things in S)
+ - digiline_send()
+ - atc_set_text_*()
+ - atc_set_lzb_tsr() (see below)
+
+In the context of approach callbacks, one more function is available:
+
+ - `atc_set_lzb_tsr(speed)`
+Impose a Temporary Speed Restriction at the location of this rail, making the train pass this rail at the specified speed. (Causes the same behavior as the TSR rail)
+
+#### Timetable Automation
 
 The advtrains_line_automation component adds a few contraptions that should make creating timeable systems easier.
 Part of its functionality is also available in LuaATC:
@@ -284,12 +361,12 @@ All Railway Time functions are included as documented in https://advtrains.de/wi
 - `schedule_in(rw_dtime, msg)`
 Schedules the following event `{type="schedule", schedule=true, msg=msg}` at (resp. after) the specified railway time (which can be in any format). You can only schedule one event this way. Uses the new lines-internal scheduler.
 
-#### Operator panel
+### Operator panel
 This simple node executes its actions when punched. It can be used to change a switch and update the corresponding signals or similar applications. It can also be connected to by the`digilines` mod.
 
 The event fired is `{type="punch", punch=true}` by default. In case of an interrupt or a digiline message, the events are similar to the ones of the ATC rail.
 
-#### Init code
+### Init code
 The initialization code is not a component as such, but rather a part of the whole environment. It can (and should) be used to make definitions that other components can refer to.  
 A basic example function to define behavior for trains in stations:
 ```lua
@@ -304,12 +381,12 @@ function F.station(station_name)
 		atc_send("OCD1SM")
 	end
 end
-````
+```
 
 The corresponding Lua ATC Rail(s) would then contain the following or similar:  
-````lua
+```lua
 F.station("Main Station")
-````
+```
 
 The init code is run whenever the F table needs to be refilled with data. This is the case on server startup and whenever the init code is changed and you choose to run it.
 The event table of the init code is always `{type="init", init=true}` and can not be anything else.  
@@ -322,15 +399,18 @@ Each node below has been mapped to specific "states":
 
 #### Signals
 The red/green light signals `advtrains:signal_on/off` are interfaceable. Others such as `advtrains:retrosignal_on/off` are not. If advtrains_interlocking is enabled, trains will obey the signal if the influence point is set.
+
  - "green" - Signal shows green light
  - "red" - Signal shows red light
 
 #### Switches/Turnouts
 All default rail switches are interfaceable, independent of orientation.
+
  - "cr" The switch is set in the direction that is not straight.
  - "st" The switch is set in the direction that is straight.
 
 The "Y" and "3-Way" switches have custom states. Looking from the convergence point:
+
  - "l" The switch is set towards the left.
  - "c" The switch is set towards the center (3-way only).
  - "r" The switch is set towards the right.
@@ -338,10 +418,12 @@ The "Y" and "3-Way" switches have custom states. Looking from the convergence po
 
 #### Mesecon Switch
 The Mesecon switch can be switched using LuaAutomation. Note that this is not possible on levers or protected mesecon switches, only the unprotected full-node 'Switch' block `mesecons_switch:mesecon_switch_on/off`.
+
  - "on" - the switch is switched on.
  - "off" - the switch is switched off.
 
 #### Andrew's Cross
+
  - "on" - it blinks.
  - "off" - it does not blink.
 
@@ -356,4 +438,3 @@ Use `setstate("Stn_P1_out", "green")` instead of `setstate(POS(1,2,3), "green")`
 If `advtrains_interlocking` is enabled, PC-Naming can also be used to name interlocking signals for route setting via the `set_route()` functions.  
 **Important**: The "Signal Name" field in the signalling formspec is completely independent from PC-Naming and can't be used to look up the position. You need to explicitly use the PC-Naming tool.
 
---TODO: Ein paar mehr Codebeispiele wären schön, insbesondere mit os.date und so...

mods/advtrains/advtrains_luaautomation/active_common.lua

@@ -109,8 +109,9 @@ function ac.run_in_env(pos, evtdata, customfct_p)
 		atwarn("LuaAutomation component at",ph,": Not an existing environment: "..(nodetbl.env or "<nil>"))
 		return false
 	end
+	local env = atlatc.envs[nodetbl.env]
 	if not nodetbl.code or nodetbl.code=="" then
-		atwarn("LuaAutomation component at",ph,": No code to run! (insert -- to suppress warning)")
+		env:log("warning", "LuaAutomation component at",ph,": No code to run! (insert -- to suppress warning)")
 		return false
 	end
 	
@@ -121,6 +122,18 @@ function ac.run_in_env(pos, evtdata, customfct_p)
 		assert(t >= 0)
 		atlatc.interrupt.add(t, pos, {type="int", int=true, message=imesg, msg=imesg}) --Compatiblity "message" field.
 	end
+	customfct.interrupt_safe=function(t, imesg)
+		assertt(t, "number")
+		assert(t >= 0)
+		if atlatc.interrupt.has_at_pos(pos) then
+			return false
+		end
+		atlatc.interrupt.add(t, pos, {type="int", int=true, message=imesg, msg=imesg}) --Compatiblity "message" field.
+		return true
+	end
+	customfct.clear_interrupts=function()
+		atlatc.interrupt.clear_ints_at_pos(pos)
+	end
 	-- add digiline_send function, if digiline is loaded
 	if minetest.global_exists("digiline") then
 		customfct.digiline_send=function(channel, msg)
@@ -141,15 +154,20 @@ function ac.run_in_env(pos, evtdata, customfct_p)
 	end
 	
 	local datain=nodetbl.data or {}
-	local succ, dataout = atlatc.envs[nodetbl.env]:execute_code(datain, nodetbl.code, evtdata, customfct)
+	local succ, dataout = env:execute_code(datain, nodetbl.code, evtdata, customfct)
 	if succ then
 		atlatc.active.nodes[ph].data=atlatc.remove_invalid_data(dataout)
 	else
 		atlatc.active.nodes[ph].err=dataout
-		atwarn("LuaAutomation ATC interface rail at",ph,": LUA Error:",dataout)
+		env:log("error", "LuaATC component at",ph,": LUA Error:",dataout)
 		if meta then
-			meta:set_string("infotext", "LuaAutomation ATC interface rail, ERROR:"..dataout)
+			meta:set_string("infotext", "LuaATC component, ERROR:"..dataout)
 		end
+		--TODO temporary
+		--if customfct.atc_id then
+		--	advtrains.drb_dump(customfct.atc_id)
+		--	error("Debug: LuaATC error hit!")
+		--end
 	end
 	if meta then
 		meta:set_string("formspec", ac.getform(pos, meta))

mods/advtrains/advtrains_luaautomation/atc_rail.lua

@@ -5,7 +5,10 @@
 --Using subtable
 local r={}
 
-function r.fire_event(pos, evtdata)
+-- Note on appr_internal:
+-- The Approach callback is a special corner case: the train is not on the node, and it is executed synchronized 
+-- (in the train step right during LZB traversal). We therefore need access to the train id and the lzbdata table
+function r.fire_event(pos, evtdata, appr_internal)
 	
 	local ph=minetest.pos_to_string(pos)
 	local railtbl = atlatc.active.nodes[ph]
@@ -15,37 +18,34 @@ function r.fire_event(pos, evtdata)
 		return
 	end
 	
-	
-	local arrowconn = railtbl.arrowconn
-	if not arrowconn then
-		atwarn("LuaAutomation ATC interface rail at",ph,": Incomplete Data! Please visit position and click 'Save'!")
-		return
-	end
-	
 	--prepare ingame API for ATC. Regenerate each time since pos needs to be known
 	--If no train, then return false.
-	local train_id=advtrains.get_train_at_pos(pos)
-	local train, atc_arrow, tvel
-	if train_id then train=advtrains.trains[train_id] end
-	if train then 
-		if not train.path then
-			--we happened to get in between an invalidation step
-			--delay
-			atlatc.interrupt.add(0,pos,evtdata)
-			return
-		end
-		local index = advtrains.path_lookup(train, pos)
 	
-		local iconnid = 1
-		if index then
-			iconnid = train.path_cn[index]
+	-- try to get the train from the event data
+	-- This workaround is required because the callback is one step delayed, and a fast train may have already left the node.
+	-- Also used for approach callback
+	local train_id = evtdata._train_id
+	local atc_arrow = evtdata._train_arrow
+	local train, tvel
+	
+	if train_id then
+		train=advtrains.trains[train_id]
+		-- speed
+		tvel=train.velocity
+	-- if still no train_id available, try to get the train at my position
 	else
-			atwarn("ATC rail at", pos, ": Rail not on train's path! Can't determine arrow direction. Assuming +!")
-		end
-		atc_arrow = iconnid == 1
-		
+		train_id=advtrains.get_train_at_pos(pos)
+		if train_id then
+			train=advtrains.trains[train_id]
+			advtrains.train_ensure_init(train_id, train)
+			-- look up atc_arrow
+			local index = advtrains.path_lookup(train, pos)
+			atc_arrow = (train.path_cn[index] == 1)
+			-- speed
 			tvel=train.velocity
 		end
+	end
+	
 	local customfct={
 		atc_send = function(cmd)
 			if not train_id then return false end
@@ -92,12 +92,13 @@ function r.fire_event(pos, evtdata)
 			advtrains.train_step_fc(train)
 		end,
 		set_shunt = function()
+			-- enable shunting mode
 			if not train_id then return false end
-			train.autocouple = true
+			train.is_shunt = true
 		end,
 		unset_shunt = function()
 			if not train_id then return false end
-			train.autocouple = nil
+			train.is_shunt = nil
 		end,
 		set_autocouple = function ()
 			if not train_id then return false end
@@ -150,14 +151,30 @@ function r.fire_event(pos, evtdata)
 			advtrains.trains[train_id].text_inside=text
 			return true
 		end,
+		atc_set_lzb_tsr = function(speed)
+			if not appr_internal then
+				error("atc_set_lzb_tsr() can only be used during 'approach' events!")
+			end
+			assert(tonumber(speed), "Number expected!")
+			
+			local index = appr_internal.index
+			advtrains.lzb_add_checkpoint(train, index, speed, nil)
+			
+			return true
+		end,
 	}
+	-- interlocking specific
+	if advtrains.interlocking then
+		customfct.atc_set_ars_disable = function(value)
+			advtrains.interlocking.ars_set_disable(train, value)
+		end
+	end
 	
 	atlatc.active.run_in_env(pos, evtdata, customfct)
 	
 end
 
-if minetest.get_modpath("advtrains_train_track") ~= nil then
-	advtrains.register_tracks("default", {
+advtrains.register_tracks("default", {
 	nodename_prefix="advtrains_luaautomation:dtrack",
 	texture_prefix="advtrains_dtrack_atc",
 	models_prefix="advtrains_dtrack",
@@ -169,14 +186,42 @@ if minetest.get_modpath("advtrains_train_track") ~= nil then
 		return {
 			after_place_node = atlatc.active.after_place_node,
 			after_dig_node = atlatc.active.after_dig_node,
+
 			on_receive_fields = function(pos, ...)
 				atlatc.active.on_receive_fields(pos, ...)
+				
 				--set arrowconn (for ATC)
 				local ph=minetest.pos_to_string(pos)
 				local _, conns=advtrains.get_rail_info_at(pos, advtrains.all_tracktypes)
 				atlatc.active.nodes[ph].arrowconn=conns[1].c
 			end,
-				advtrains = atlatc.active.trackdef_advtrains_defs,
+
+			advtrains = {
+				on_train_enter = function(pos, train_id, train, index)
+					--do async. Event is fired in train steps
+					atlatc.interrupt.add(0, pos, {type="train", train=true, id=train_id,
+							_train_id = train_id, _train_arrow = (train.path_cn[index] == 1)})
+				end,
+				on_train_approach = function(pos, train_id, train, index, has_entered, lzbdata)
+					-- Insert an event only if the rail indicated that it supports approach callbacks
+					local ph=minetest.pos_to_string(pos)
+					local railtbl = atlatc.active.nodes[ph]
+					-- uses a "magic variable" in the local environment of the node
+					-- This hack is necessary because code might not be prepared to get approach events...
+					if railtbl and railtbl.data and railtbl.data.__approach_callback_mode then
+						local acm = railtbl.data.__approach_callback_mode
+						local in_arrow = (train.path_cn[index] == 1)
+						if acm==2 or (acm==1 and in_arrow) then
+							local evtdata = {type="approach", approach=true, id=train_id, has_entered = has_entered,
+									_train_id = train_id, _train_arrow = in_arrow} -- reuses code from train_enter
+							-- This event is *required* to run synchronously, because it might set the ars_disable flag on the train and add LZB checkpoints,
+							-- although this is generally discouraged because this happens right in a train step
+							-- At this moment, I am not aware whether this may cause side effects, and I must encourage users not to do expensive calculations here.
+							r.fire_event(pos, evtdata, {train_id = train_id, train = train, index = index, lzbdata = lzbdata})
+						end
+					end
+				end,
+			},
 			luaautomation = {
 				fire_event=r.fire_event
 			},
@@ -188,7 +233,7 @@ if minetest.get_modpath("advtrains_train_track") ~= nil then
 			},
 		}
 	end,
-	}, advtrains.trackpresets.t_30deg_straightonly)
-end
+}, advtrains.trackpresets.t_30deg_straightonly)
+
 
 atlatc.rail = r

mods/advtrains/advtrains_luaautomation/chatcmds.lua

@@ -43,12 +43,78 @@ core.register_chatcommand("env_create", {
 	privs = {atlatc=true},
 	func = function(name, param)
 		if not param or param=="" then return false, "Name required!" end
+		if string.find(param, "[^a-zA-Z0-9-_]") then return false, "Invalid name (only common characters)" end
 		if atlatc.envs[param] then return false, "Environment already exists!" end
 		atlatc.envs[param] = atlatc.env_new(param)
+		atlatc.envs[param].subscribers = {name}
 		return true, "Created environment '"..param.."'. Use '/env_setup "..param.."' to define global initialization code, or start building LuaATC components!"
 	end,
 })
-
+core.register_chatcommand("env_subscribe", {
+	params = "<environment name>",
+	description = "Subscribe to the log of an Advtrains LuaATC environment",
+	privs = {atlatc=true},
+	func = function(name, param)
+		local env=atlatc.envs[param]
+		if not env then return false,"Invalid environment name!" end
+		for _,pname in ipairs(env.subscribers) do
+			if pname==name then
+				return false, "Already subscribed!"
+			end
+		end
+		table.insert(env.subscribers, name)
+		return true, "Subscribed to environment '"..param.."'."
+	end,
+})
+core.register_chatcommand("env_unsubscribe", {
+	params = "<environment name>",
+	description = "Unubscribe to the log of an Advtrains LuaATC environment",
+	privs = {atlatc=true},
+	func = function(name, param)
+		local env=atlatc.envs[param]
+		if not env then return false,"Invalid environment name!" end
+		for index,pname in ipairs(env.subscribers) do
+			if pname==name then
+				table.remove(env.subscribers, index)
+				return true, "Successfully unsubscribed!"
+			end
+		end
+		return false, "Not subscribed to environment '"..param.."'."
+	end,	
+})
+core.register_chatcommand("env_subscriptions", {
+	params = "[environment name]",
+	description = "List Advtrains LuaATC environments you are subscribed to (no parameters) or subscribers of an environment (giving an env name).",
+	privs = {atlatc=true},
+	func = function(name, param)
+		if not param or param=="" then
+			local none=true
+			for envname, env in pairs(atlatc.envs) do
+				for _,pname in ipairs(env.subscribers) do
+					if pname==name then
+						none=false
+						minetest.chat_send_player(name, envname)
+					end
+				end
+			end
+			if none then
+				return false, "Not subscribed to any!"
+			end
+			return true
+		end
+		local env=atlatc.envs[param]
+		if not env then return false,"Invalid environment name!" end
+		local none=true
+		for index,pname in ipairs(env.subscribers) do
+			none=false
+			minetest.chat_send_player(name, pname)
+		end
+		if none then
+			return false, "No subscribers!"
+		end
+		return true
+	end,
+})
 
 minetest.register_on_player_receive_fields(function(player, formname, fields)
 	

mods/advtrains/advtrains_luaautomation/environment.lua

@@ -33,12 +33,12 @@ local env_proto={
 		self.sdata=data.sdata and atlatc.remove_invalid_data(data.sdata) or {}
 		self.fdata={}
 		self.init_code=data.init_code or ""
-		self.step_code=data.step_code or ""
+		self.subscribers=data.subscribers or {}
 	end,
 	save = function(self)
 		-- throw any function values out of the sdata table
 		self.sdata = atlatc.remove_invalid_data(self.sdata)
-		return {sdata = self.sdata, init_code=self.init_code, step_code=self.step_code}
+		return {sdata = self.sdata, init_code=self.init_code, subscribers=self.subscribers}
 	end,
 }
 
@@ -50,14 +50,6 @@ local safe_globals = {
 	"tonumber", "tostring", "type", "unpack", "_VERSION"
 }
 
---print is actually minetest.chat_send_all()
---using advtrains.print_concat_table because it's cool
-local function safe_print(t, ...)
-	local str=advtrains.print_concat_table({t, ...})
-	minetest.log("action", "[atlatc] "..str)
-	minetest.chat_send_all(str)
-end
-
 local function safe_date(f, t)
 	if not f then
 		-- fall back to old behavior
@@ -95,7 +87,6 @@ local mp=minetest.get_modpath("advtrains_luaautomation")
 
 local static_env = {
 	--core LUA functions
-	print = safe_print,
 	string = {
 		byte = string.byte,
 		char = string.char,
@@ -252,7 +243,6 @@ for _, name in pairs(safe_globals) do
 	static_env[name] = _G[name]
 end
 
-
 --The environment all code calls get is a table that has set static_env as metatable.
 --In general, every variable is local to a single code chunk, but kept persistent over code re-runs. Data is also saved, but functions and userdata and circular references are removed
 --Init code and step code's environments are not saved
@@ -265,6 +255,14 @@ local proxy_env={}
 
 -- returns: true, fenv if successful; nil, error if error 
 function env_proto:execute_code(localenv, code, evtdata, customfct)
+	-- create us a print function specific for this environment
+	if not self.safe_print_func then
+		local myenv = self
+		self.safe_print_func = function(...)
+			myenv:log("info", ...)
+		end
+	end
+	
 	local metatbl ={
 		__index = function(t, i)
 			if i=="S" then
@@ -277,6 +275,8 @@ function env_proto:execute_code(localenv, code, evtdata, customfct)
 				return customfct[i]
 			elseif localenv and localenv[i] then
 				return localenv[i]
+			elseif i=="print" then
+				return self.safe_print_func
 			end
 			return static_env[i]
 		end,
@@ -306,35 +306,39 @@ function env_proto:run_initcode()
 	if self.init_code and self.init_code~="" then
 		local old_fdata=self.fdata
 		self.fdata = {}
-		atprint("[atlatc]Running initialization code for environment '"..self.name.."'")
+		--atprint("[atlatc]Running initialization code for environment '"..self.name.."'")
 		local succ, err = self:execute_code({}, self.init_code, {type="init", init=true})
 		if not succ then
-			atwarn("[atlatc]Executing InitCode for '"..self.name.."' failed:"..err)
+			self:log("error", "Executing InitCode for '"..self.name.."' failed:"..err)
 			self.init_err=err
 			if old_fdata then
 				self.fdata=old_fdata
-				atwarn("[atlatc]The 'F' table has been restored to the previous state.")
+				self:log("warning", "The 'F' table has been restored to the previous state.")
 			end
 		end
 	end
 end
-function env_proto:run_stepcode()
-	if self.step_code and self.step_code~="" then
-		local succ, err = self:execute_code({}, self.step_code, nil, {})
-		if not succ then
-			--TODO
-		end
+
+-- log to environment subscribers. severity can be "error", "warning" or "info" (used by internal print)
+function env_proto:log(severity, ...)
+	local text=advtrains.print_concat_table({"[atlatc "..self.name.." "..severity.."]", ...})
+	minetest.log("action", text)
+	for _, pname in ipairs(self.subscribers) do
+		minetest.chat_send_player(pname, text)
 	end
 end
 
+-- env.subscribers table may be directly altered by callers.
+
+
 --- class interface
 
 function atlatc.env_new(name)
 	local newenv={
 		name=name,
 		init_code="",
-		step_code="",
-		sdata={}
+		sdata={},
+		subscribers={},
 	}
 	setmetatable(newenv, {__index=env_proto})
 	return newenv
@@ -351,11 +355,6 @@ function atlatc.run_initcode()
 		env:run_initcode()
 	end
 end
-function atlatc.run_stepcode()
-	for envname, env in pairs(atlatc.envs) do
-		env:run_stepcode()
-	end
-end
 
 
 

mods/advtrains/advtrains_luaautomation/interrupt.lua

@@ -16,6 +16,30 @@ function iq.save()
 	return {queue = queue, timer=timer}
 end
 
+function iq.has_at_pos(pos)
+	for i=1,#queue do
+		local qe=queue[i]
+		if vector.equals(pos, qe.p) then
+			return true
+		end
+	end
+	return false
+end
+
+function iq.clear_ints_at_pos(pos)
+	local i=1
+	while i<=#queue do
+		local qe=queue[i]
+		if not qe then
+			table.remove(queue, i)
+		elseif vector.equals(pos, qe.p) and (qe.e.int or qe.e.ext_int) then
+			table.remove(queue, i)
+		else
+			i=i+1
+		end
+	end
+end
+
 function iq.add(t, pos, evtdata)
 	queue[#queue+1]={t=t+timer, p=pos, e=evtdata}
 	run=true
@@ -23,13 +47,14 @@ end
 
 function iq.mainloop(dtime)
 	timer=timer + math.min(dtime, 0.2)
-	for i=1,#queue do
+	local i=1
+	while i<=#queue do
 		local qe=queue[i]
 		if not qe then
 			table.remove(queue, i)
-			i=i-1
 		elseif timer>qe.t then
-			local pos, evtdata=queue[i].p, queue[i].e
+			table.remove(queue, i)
+			local pos, evtdata=qe.p, qe.e
 			local node=advtrains.ndb.get_node(pos)
 			local ndef=minetest.registered_nodes[node.name]
 			if ndef and ndef.luaautomation and ndef.luaautomation.fire_event then
@@ -37,8 +62,8 @@ function iq.mainloop(dtime)
 			else
 				atwarn("[atlatc][interrupt] Couldn't run event",evtdata.type,"on",pos,", something wrong with the node",node)
 			end
-			table.remove(queue, i)
-			i=i-1
+		else
+			i=i+1
 		end
 	end
 end

mods/advtrains/advtrains_luaautomation/passive_api.txt

@@ -7,7 +7,7 @@ Displays
 Mesecon Transmitter
 Those passive components can also be used inside interlocking systems.
 
-All passive components have a table called 'advtrains' in their node definition and have the group 'save_in_nodedb' set, so they work in unloaded chunks.
+All passive components have a table called 'advtrains' in their node definition and have the group 'save_in_at_nodedb' set, so they work in unloaded chunks.
 Example for a switch:
 advtrains = {
 	getstate = function(pos, node)

mods/advtrains/advtrains_signals_ks/init.lua

@@ -6,14 +6,14 @@
 
 local setaspectf = function(rot)
  return function(pos, node, asp)
-	if not asp.main.free then
-		if asp.shunt.free then
+	if asp.main == 0 then
+		if asp.shunt then
 			advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:hs_shunt_"..rot, param2 = node.param2})
 		else
 			advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:hs_danger_"..rot, param2 = node.param2})
 		end
 	else
-		if asp.dst.free and asp.main.speed == -1 then
+		if asp.dst ~= 0 and asp.main == -1 then
 			advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:hs_free_"..rot, param2 = node.param2})
 		else
 			advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:hs_slow_"..rot, param2 = node.param2})
@@ -22,19 +22,12 @@ local setaspectf = function(rot)
  end
 end
 
+
 local suppasp = {
-		main = {
-			free = nil,
-			speed = {6, -1},
-		},
-		dst = {
-			free = nil,
-			speed = nil,
-		},
-		shunt = {
-			free = nil,
+		main = {0, 6, -1},
+		dst = {0, false},
+		shunt = nil,
 		proceed_as_main = true,
-		},
 		info = {
 			call_on = false,
 			dead_end = false,
@@ -45,7 +38,7 @@ local suppasp = {
 --Rangiersignal
 local setaspectf_ra = function(rot)
  return function(pos, node, asp)
-	if asp.shunt.free then
+	if asp.shunt then
 		advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:ra_shuntd_"..rot, param2 = node.param2})
 	else
 		advtrains.ndb.swap_node(pos, {name="advtrains_signals_ks:ra_danger_"..rot, param2 = node.param2})
@@ -58,17 +51,11 @@ local setaspectf_ra = function(rot)
 end
 
 local suppasp_ra = {
-		main = {
-			free = true,
-		},
-		dst = {
-			free = nil,
-			speed = nil,
-		},
-		shunt = {
-			free = nil,
+		main = { false },
+		dst = { false },
+		shunt = nil,
 		proceed_as_main = false,
-		},
+		
 		info = {
 			call_on = false,
 			dead_end = false,
@@ -90,9 +77,9 @@ for _, rtab in ipairs({
 	local rot = rtab.rot
 	for typ, prts in pairs({
 			danger = {asp = advtrains.interlocking.DANGER, n = "slow", ici=true},
-			slow   = {asp = { main = { free = true, speed = 6 }, shunt = {proceed_as_main = true}} , n = "free"},
-			free   = {asp = { main = { free = true, speed = -1 }, shunt = {proceed_as_main = true}} , n = "shunt"},
-			shunt  = {asp = { main = {free = false}, shunt = {free = true} } , n = "danger"},
+			slow   = {asp = { main =  6, proceed_as_main = true} , n = "free"},
+			free   = {asp = { main = -1, proceed_as_main = true} , n = "shunt"},
+			shunt  = {asp = { main =  0, shunt = true} , n = "danger"},
 		}) do
 		minetest.register_node("advtrains_signals_ks:hs_"..typ.."_"..rot, {
 			description = "Ks Main Signal",
@@ -136,8 +123,8 @@ for _, rtab in ipairs({
 	
 	--Rangiersignale:
 	for typ, prts in pairs({
-			danger = {asp = { main = {free = true}, shunt = {free = false} }, n = "shuntd", ici=true},
-			shuntd = {asp = { main = {free = true}, shunt = {free = true} } , n = "danger"},
+			danger = {asp = { main = false, shunt = false }, n = "shuntd", ici=true},
+			shuntd = {asp = { main = false, shunt = true } , n = "danger"},
 		}) do
 		minetest.register_node("advtrains_signals_ks:ra_"..typ.."_"..rot, {
 			description = "Ks Shunting Signal",
@@ -181,13 +168,14 @@ for _, rtab in ipairs({
 	--Schilder:
 	for typ, prts in pairs({
 			-- Speed restrictions:
-			["8"] = {asp = { main = {free = true, speed = 8}, shunt = {free = true} }, n = "12", ici=true},
-			["12"] = {asp = { main = {free = true, speed = 12}, shunt = {free = true} }, n = "16"},
-			["16"] = {asp = { main = {free = true, speed = 16}, shunt = {free = true} }, n = "e"},
+			["8"] = {asp = { main = 8, shunt = true }, n = "12", ici=true},
+			["12"] = {asp = { main = 12, shunt = true }, n = "16"},
+			["16"] = {asp = { main = 16, shunt = true }, n = "e"},
 			-- Speed restriction lifted
-			["e"] = {asp = { main = {free = true, speed = -1}, shunt = {free = true} }, n = "hfs"},
+			["e"] = {asp = { main = -1, shunt = true }, n = "hfs"},
 			-- Halt for shunt moves:
-			["hfs"] = {asp = { main = {free = true}, shunt = {free = false} }, n = "8"},
+			["hfs"] = {asp = { main = false, shunt = false }, n = "pam"},
+			["pam"] = {asp = { main = -1, shunt = false, proceed_as_main = true}, n = "8"},
 		}) do
 		minetest.register_node("advtrains_signals_ks:sign_"..typ.."_"..rot, {
 			description = "Signal Sign",

mods/advtrains/advtrains_signals_ks/init_degrotate_nodes.lua

@@ -1,5 +1,5 @@
 -- Ks Signals for advtrains
--- will implement the advtrains signal API (which does not exist yet)
+-- will implement the advtrains signal API
 
 local function place_degrotate(pos, placer, itemstack, pointed_thing)
 	local yaw = placer:get_look_horizontal()

mods/advtrains/atc_command.txt

@@ -72,12 +72,15 @@ If the train drives in the 'wrong' direction, stop and reverse; independently ac
 I<8 S8 ;
 If the train is slower than 8, accelerate to 8.
 
-# ATC controller operation modes
-static: Only give 1 static command.
+# Interlocking
 
-mesecon: Give 2 different commands depending on if the controller is mesecon-powered or not
-digiline: Don't give any commands by itself. When a train passes, a digiline message in the form of "[+/-][speed]" is sent on the set channel (where +/- means the same as with conditions). Any digiline message sent to the controller will be interpreted as ATC command and sent to the train.
-** the latter two are not yet implemented.
+With advtrains_interlocking, there's one more available command:
+
+A0
+Disable ARS on the train.
+A1
+Enable ARS on the train.
+When disabled, the train will not trigger automatic route setting on signals based on ARS.
 
 # Persistence
 ATC controllers that are configured as 'static' or 'mesecon' are persistent over mapblock unloads and will even command the train when the mapblock is unloaded. This is not possible with digilines since these do not work in unloaded mapchunks.

mods/builtin_item/README.md

@@ -4,7 +4,7 @@ edited by TenPlus1
 
 Features:
 - Items are destroyed by lava
-- Items are pushed along by flowing water (thanks to QwertyMine3)
+- Items are pushed along by flowing water (thanks to QwertyMine3 and Gustavo6046)
 - Items are removed after 900 seconds or the time that is specified by
    remove_items in minetest.conf (-1 disables it)
 - Particle effects added

mods/builtin_item/init.lua

@@ -1,8 +1,10 @@
 -- Minetest: builtin/item_entity.lua
 
 -- override ice to make slippery for 0.4.16
-minetest.override_item("default:ice", {
+if not minetest.raycast then
+	minetest.override_item("default:ice", {
 		groups = {cracky = 3, puts_out_fire = 1, cools_lava = 1, slippery = 3}})
+end
 
 
 function core.spawn_item(pos, item)
@@ -27,23 +29,28 @@ local destroy_item = core.settings:get_bool("destroy_item") ~= false
 
 
 -- water flow functions by QwertyMine3, edited by TenPlus1
+local inv_roots = {
+	[0] = 1
+}
+
 local function to_unit_vector(dir_vector)
 
-	local inv_roots = {
-		[0] = 1,
-		[1] = 1,
-		[2] = 0.70710678118655,
-		[4] = 0.5,
-		[5] = 0.44721359549996,
-		[8] = 0.35355339059327
-	}
-
 	local sum = dir_vector.x * dir_vector.x + dir_vector.z * dir_vector.z
+	local invr_sum = 0
+
+	-- find inverse square root if possible
+	if inv_roots[sum] ~= nil then
+		invr_sum = inv_roots[sum]
+	else
+		-- not found, compute and save the inverse square root
+		invr_sum = 1.0 / math.sqrt(sum)
+		inv_roots[sum] = invr_sum
+	end
 
 	return {
-		x = dir_vector.x * inv_roots[sum],
+		x = dir_vector.x * invr_sum,
 		y = dir_vector.y,
-		z = dir_vector.z * inv_roots[sum]
+		z = dir_vector.z * invr_sum
 	}
 end
 
@@ -63,6 +70,11 @@ end
 local function quick_flow_logic(node, pos_testing, direction)
 
 	local node_testing = node_ok(pos_testing)
+	local param2 = node.param2
+
+	if not minetest.registered_nodes[node.name].groups.liquid then
+		param2 = 0
+	end
 
 	if minetest.registered_nodes[node_testing.name].liquidtype ~= "flowing"
 	and minetest.registered_nodes[node_testing.name].liquidtype ~= "source" then
@@ -71,17 +83,17 @@ local function quick_flow_logic(node, pos_testing, direction)
 
 	local param2_testing = node_testing.param2
 
-	if param2_testing < node.param2 then
+	if param2_testing < param2 then
 
-		if (node.param2 - param2_testing) > 6 then
+		if (param2 - param2_testing) > 6 then
 			return -direction
 		else
 			return direction
 		end
 
-	elseif param2_testing > node.param2 then
+	elseif param2_testing > param2 then
 
-		if (param2_testing - node.param2) > 6 then
+		if (param2_testing - param2) > 6 then
 			return direction
 		else
 			return -direction
@@ -92,13 +104,12 @@ local function quick_flow_logic(node, pos_testing, direction)
 end
 
 
+-- reciprocal of the length of an unit square's diagonal
+local DIAG_WEIGHT = 2 / math.sqrt(2)
+
 local function quick_flow(pos, node)
 
-	if not minetest.registered_nodes[node.name].groups.liquid then
-		return {x = 0, y = 0, z = 0}
-	end
-
-	local x, z = 0, 0
+	local x, z = 0.0, 0.0
 
 	x = x + quick_flow_logic(node, {x = pos.x - 1, y = pos.y, z = pos.z},-1)
 	x = x + quick_flow_logic(node, {x = pos.x + 1, y = pos.y, z = pos.z}, 1)
@@ -131,6 +142,10 @@ local function add_effects(pos)
 end
 
 
+local water_force = 0.8
+local water_friction = 0.8
+local dry_friction = 2.5
+
 core.register_entity(":__builtin:item", {
 
 	initial_properties = {
@@ -270,7 +285,7 @@ core.register_entity(":__builtin:item", {
 		return true
 	end,
 
-	on_step = function(self, dtime)
+	on_step = function(self, dtime, moveresult)
 
 		local pos = self.object:get_pos()
 
@@ -295,11 +310,22 @@ core.register_entity(":__builtin:item", {
 			self.def_inside = self.node_inside
 					and core.registered_nodes[self.node_inside.name]
 
-			self.node_under = minetest.get_node_or_nil({
-				x = pos.x,
-				y = pos.y + self.object:get_properties().collisionbox[2] - 0.05,
-				z = pos.z
-			})
+			-- get ground node for collision
+			self.node_under = nil
+
+			if moveresult.touching_ground then
+
+				for _, info in ipairs(moveresult.collisions) do
+
+					if info.axis == "y" then
+
+						self.node_under = core.get_node(info.node_pos)
+
+						break
+					end
+				end
+			end
+
 			self.def_under = self.node_under
 					and core.registered_nodes[self.node_under.name]
 
@@ -352,10 +378,39 @@ core.register_entity(":__builtin:item", {
 		-- water flowing
 		if def and def.liquidtype == "flowing" then
 
+			-- force applies on acceleration over time, thus multiply
+			local force = water_force * dtime
+			-- friction applies on velocity over time,     thus exponentiate
+			local friction = (1.0 + water_friction) ^ dtime
+
+			-- get flow velocity and current vel/acc state
 			local vec = quick_flow(pos, node)
+			local a = self.object:get_acceleration()
+
+			self.object:set_acceleration({
+				x = a.x + vec.x * force,
+				y = a.y,
+				z = a.z + vec.z * force
+			})
+
+			-- apply friction to prevent items going too fast, and also to make
+			-- water flow override previous horizontal momentum more quickly
+
 			local v = self.object:get_velocity()
 
-			self.object:set_velocity({x = vec.x, y = v.y, z = vec.z})
+			-- adjust friction for going against the current
+			local v_horz = { x = v.x, y = 0, z = v.z }
+			local v_dir = to_unit_vector(v_horz)
+			local flow_dot = v_dir.x * vec.x + v_dir.y * vec.y
+
+			-- also maps flow_dot from [-1,0] to [0.5,2.5]
+			friction = 1.0 + ((friction - 1.0) * (flow_dot + 1.5))
+
+			self.object:set_velocity({
+				x = v.x / friction,
+				y = v.y / friction,
+				z = v.z / friction
+			})
 
 			return
 		end
@@ -412,11 +467,26 @@ core.register_entity(":__builtin:item", {
 		self.moving_state = is_moving
 		self.slippery_state = is_slippery
 
+		local a_curr = self.object:get_acceleration()
+		local v_curr = self.object:get_velocity()
+
 		if is_moving then
-			self.object:set_acceleration({x = 0, y = -gravity, z = 0})
+
+			self.object:set_acceleration({
+				x = a_curr.x,
+				y = a_curr.y - gravity,
+				z = a_curr.z
+			})
 		else
 			self.object:set_acceleration({x = 0, y = 0, z = 0})
-			self.object:set_velocity({x = 0, y = 0, z = 0})
+
+			-- preserve *some* velocity so items don't get stuck on the very ledges
+			-- of nodes once they move just enough to leave the hitbox of flowing water
+			self.object:set_velocity({
+				x = v_curr.x / dry_friction,
+				y = v_curr.y / dry_friction,
+				z = v_curr.z / dry_friction
+			})
 		end
 
 		--Only collect items if not moving

mods/farming/README.md

@@ -13,7 +13,7 @@ This mod works by adding your new plant to the {growing=1} group and numbering t
 
 ### Changelog:
 
-- 1.46 - Added min/max default light settings, added lettuce and blackberries with food items (thanks OgelGames), added soya and vanilla (thanks Felfa), added tofu
+- 1.46 - Added min/max default light settings, added lettuce and blackberries with food items (thanks OgelGames), added soya and vanilla (thanks Felfa), added tofu, added salt crystals (thanks gorlock)
 - 1.45 - Dirt and Hoes are more in line with default by using dry/wet/base, added cactus juice, added pasta, spaghetti, cabbage, korean bibimbap, code tidy
 options, onion soup added (thanks edcrypt), Added apple pie, added wild cotton to savanna
 - 1.44 - Added 'farming_stage_length' in mod settings for speed of crop growth, also thanks to TheDarkTiger for translation updates

mods/farming/food.lua

@@ -33,7 +33,48 @@ minetest.register_node("farming:salt", {
 	selection_box = {
 		type = "fixed",
 		fixed = {-0.25, -0.5, -0.25, 0.25, 0.3, 0.25}
-	}
+	},
+	-- special function to make salt crystals form inside water
+	dropped_step = function(self, pos, dtime)
+
+		self.ctimer = (self.ctimer or 0) + dtime
+		if self.ctimer < 15.0 then return end
+		self.ctimer = 0
+
+		local needed
+
+		if self.node_inside
+		and self.node_inside.name == "default:water_source" then
+			needed = 8
+
+		elseif self.node_inside
+		and self.node_inside.name == "default:river_water_source" then
+			needed = 9
+		end
+
+		if not needed then return end
+
+		local objs = core.get_objects_inside_radius(pos, 0.5)
+
+		if not objs or #objs ~= 1 then return end
+
+		local salt, ent = nil, nil
+
+		for k, obj in pairs(objs) do
+
+			ent = obj:get_luaentity()
+
+			if ent and ent.name == "__builtin:item"
+			and ent.itemstring == "farming:salt " .. needed then
+
+				obj:remove()
+
+				core.add_item(pos, "farming:salt_crystal")
+
+				return false -- return with no further action
+			end
+		end
+	end
 })
 
 minetest.register_craft({
@@ -44,6 +85,40 @@ minetest.register_craft({
 	replacements = {{"bucket:bucket_water", "bucket:bucket_empty"}}
 })
 
+--= Salt Crystal
+
+minetest.register_node("farming:salt_crystal", {
+	description = ("Salt crystal"),
+	inventory_image = "farming_salt_crystal.png",
+	wield_image = "farming_salt_crystal.png",
+	drawtype = "plantlike",
+	visual_scale = 0.8,
+	paramtype = "light",
+	light_source = 1,
+	tiles = {"farming_salt_crystal.png"},
+	groups = { dig_immediate = 3, attached_node = 1},
+	sounds = default.node_sound_defaults(),
+	selection_box = {
+		type = "fixed",
+		fixed = {-0.25, -0.5, -0.25, 0.25, 0.3, 0.25}
+	},
+})
+minetest.register_craft({
+	type = "shapeless",
+	output = "farming:salt 9",
+	recipe = {"farming:salt_crystal", "farming:mortar_pestle"},
+	replacements = {{"farming:mortar_pestle", "farming:mortar_pestle"}}
+})
+
+minetest.register_craft({
+	output = "farming:salt_crystal",
+	recipe = {
+		{"farming:salt", "farming:salt", "farming:salt"},
+		{"farming:salt", "farming:salt", "farming:salt"},
+		{"farming:salt", "farming:salt", "farming:salt"}
+	}
+})
+
 --= Rose Water
 
 minetest.register_node("farming:rose_water", {

mods/farming/license.txt

@@ -155,3 +155,6 @@ Created by Felfa (CC0)
   farming_burger.png
   farming_soy*.png
   farming_vanilla*.png
+
+Created by gorlock (CC0)
+  farming_salt_crystal.png

mods/gloopblocks/crafts.lua

@@ -298,6 +298,21 @@ minetest.register_craft({
 	}
 })
 
+minetest.register_craft({
+	type = "shapeless",
+	output = "default:cobble 8",
+	recipe = {
+		"gloopblocks:pumice",
+		"gloopblocks:pumice",
+		"gloopblocks:pumice",
+		"gloopblocks:pumice",
+		"gloopblocks:basalt",
+		"gloopblocks:basalt",
+		"gloopblocks:basalt",
+		"gloopblocks:basalt"
+	}
+})
+
 minetest.register_craft({
 	output = "gloopblocks:fence_steel 1",
 	recipe = {

mods/playerplus/init.lua

@@ -245,7 +245,7 @@ minetest.register_privilege("no_knockback", {
 		give_to_singleplayer = false})
 
 -- is player knock-back effect enabled?
-if minetest.settings:get_bool("player_knockback") ~= false then
+if minetest.settings:get_bool("player_knockback") == true then
 
 minetest.register_entity("playerplus:temp", {
 	physical = true,

mods/playerplus/settingtypes.txt

@@ -1,4 +1,4 @@
 #    If enabled players are knocked back when hit by mobs or other players
-player_knockback (Player knockback) bool true
+player_knockback (Player knockback) bool false
 #    If enabled the players use the old sneak glitch and movements
 old_sneak (Use old sneak glitch) bool false

mods/signs_lib/api.lua

@@ -155,6 +155,7 @@ signs_lib.flip_walldir = {
 
 -- Initialize character texture cache
 local ctexcache = {}
+local ctexcache_wide = {}
 
 -- entity handling
 
@@ -251,7 +252,10 @@ function signs_lib.set_obj_text(pos, text)
 	local text_ansi = Utf8ToAnsi(text)
 	local n = minetest.registered_nodes[minetest.get_node(pos).name]
 	signs_lib.delete_objects(pos)
+	-- only create sign entity for actual text
+	if text_ansi and text_ansi ~= "" then
 		signs_lib.spawn_entity(pos, signs_lib.make_sign_texture(split(text_ansi), pos) )
+	end
 end
 
 -- rotation
@@ -330,8 +334,10 @@ end
 local TP = signs_lib.path .. "/textures"
 -- Font file formatter
 local CHAR_FILE = "%s_%02x.png"
+local CHAR_FILE_WIDE = "%s_%s.png"
 -- Fonts path
 local CHAR_PATH = TP .. "/" .. CHAR_FILE
+local CHAR_PATH_WIDE = TP .. "/" .. CHAR_FILE_WIDE
 
 -- Lots of overkill here. KISS advocates, go away, shoo! ;) -- kaeza
 
@@ -391,6 +397,7 @@ end
 local function build_char_db(font_size)
 
 	local cw = {}
+	local cw_wide = {}
 
 	-- To calculate average char width.
 	local total_width = 0
@@ -406,20 +413,32 @@ local function build_char_db(font_size)
 		end
 	end
 
+	for i = 1, #signs_lib.wide_character_codes do
+		local ch = signs_lib.wide_character_codes[i]
+		local w, h = signs_lib.read_image_size(CHAR_PATH_WIDE:format("signs_lib_font_"..font_size.."px", ch))
+		if w and h then
+			cw_wide[ch] = w
+			total_width = total_width + w
+			char_count = char_count + 1
+		end
+	end
+
 	local cbw, cbh = signs_lib.read_image_size(TP.."/signs_lib_color_"..font_size.."px_n.png")
 	assert(cbw and cbh, "error reading bg dimensions")
-	return cw, cbw, cbh, (total_width / char_count)
+	return cw, cbw, cbh, (total_width / char_count), cw_wide
 end
 
 signs_lib.charwidth15,
 signs_lib.colorbgw15,
 signs_lib.lineheight15,
-signs_lib.avgwidth15 = build_char_db(15)
+signs_lib.avgwidth15,
+signs_lib.charwidth_wide15 = build_char_db(15)
 
 signs_lib.charwidth31,
 signs_lib.colorbgw31,
 signs_lib.lineheight31,
-signs_lib.avgwidth31 = build_char_db(31)
+signs_lib.avgwidth31,
+signs_lib.charwidth_wide31 = build_char_db(31)
 
 local sign_groups = {choppy=2, dig_immediate=2}
 local fences_with_sign = { }
@@ -455,7 +474,22 @@ local function char_tex(font_name, ch)
 	end
 end
 
-local function make_line_texture(line, lineno, pos, line_width, line_height, cwidth_tab, font_size, colorbgw)
+local function char_tex_wide(font_name, ch)
+	if ctexcache_wide[font_name..ch] then
+		return ctexcache_wide[font_name..ch], true
+	else
+		local exists, tex = file_exists(CHAR_PATH_WIDE:format(font_name, ch))
+		if exists then
+			tex = CHAR_FILE_WIDE:format(font_name, ch)
+		else
+			tex = CHAR_FILE:format(font_name, 0x5f)
+		end
+		ctexcache_wide[font_name..ch] = tex
+		return tex, exists
+	end
+end
+
+local function make_line_texture(line, lineno, pos, line_width, line_height, cwidth_tab, font_size, colorbgw, cwidth_tab_wide)
 	local width = 0
 	local maxw = 0
 	local font_name = "signs_lib_font_"..font_size.."px"
@@ -492,6 +526,27 @@ local function make_line_texture(line, lineno, pos, line_width, line_height, cwi
 		local word_l = #word
 		local i = 1
 		while i <= word_l  do
+			local wide_c
+			if "&#x" == word:sub(i, i + 2) then
+				local j = i + 3
+				local collected = ""
+				while j <= word_l do
+					local c = word:sub(j, j)
+					if c == ";" then
+						wide_c = collected
+						break
+					elseif c < "0" then
+						break
+					elseif "f" < c then
+						break
+					elseif ("9" < c) and (c < "a") then
+						break
+					else
+						collected = collected .. c
+						j = j + 1
+					end
+				end
+			end
 			local c = word:sub(i, i)
 			if c == "#" then
 				local cc = tonumber(word:sub(i+1, i+1), 16)
@@ -499,6 +554,25 @@ local function make_line_texture(line, lineno, pos, line_width, line_height, cwi
 					i = i + 1
 					cur_color = cc
 				end
+			elseif wide_c then
+				local w = cwidth_tab_wide[wide_c]
+				if w then
+					width = width + w + 1
+					if width >= (line_width - cwidth_tab[" "]) then
+						width = 0
+					else
+						maxw = math_max(width, maxw)
+					end
+					if #chars < MAX_INPUT_CHARS then
+						table.insert(chars, {
+							off = ch_offs,
+							tex = char_tex_wide(font_name, wide_c),
+							col = ("%X"):format(cur_color),
+						})
+					end
+					ch_offs = ch_offs + w
+				end
+				i = i + #wide_c + 3
 			else
 				local w = cwidth_tab[c]
 				if w then
@@ -578,6 +652,7 @@ function signs_lib.make_sign_texture(lines, pos)
 	local line_width
 	local line_height
 	local char_width
+	local char_width_wide
 	local colorbgw
 	local widemult = 1
 
@@ -590,12 +665,14 @@ function signs_lib.make_sign_texture(lines, pos)
 		line_width = math.floor(signs_lib.avgwidth31 * def.chars_per_line) * (def.horiz_scaling * widemult)
 		line_height = signs_lib.lineheight31
 		char_width = signs_lib.charwidth31
+		char_width_wide = signs_lib.charwidth_wide31
 		colorbgw = signs_lib.colorbgw31
 	else
 		font_size = 15
 		line_width = math.floor(signs_lib.avgwidth15 * def.chars_per_line) * (def.horiz_scaling * widemult)
 		line_height = signs_lib.lineheight15
 		char_width = signs_lib.charwidth15
+		char_width_wide = signs_lib.charwidth_wide15
 		colorbgw = signs_lib.colorbgw15
 	end
 
@@ -604,7 +681,7 @@ function signs_lib.make_sign_texture(lines, pos)
 	local lineno = 0
 	for i = 1, #lines do
 		if lineno >= def.number_of_lines then break end
-		local linetex, ln = make_line_texture(lines[i], lineno, pos, line_width, line_height, char_width, font_size, colorbgw)
+		local linetex, ln = make_line_texture(lines[i], lineno, pos, line_width, line_height, char_width, font_size, colorbgw, char_width_wide)
 		table.insert(texture, linetex)
 		lineno = ln + 1
 	end

mods/signs_lib/encoding.lua

@@ -203,6 +203,32 @@ local utf8_decode = {
 	[210] = {[144] = "\165", [145] = "\180"}
 }
 
+local wide_character_codes = {
+}
+
+signs_lib.unicode_install = function(
+	numbers
+)
+	local scope = utf8_decode
+	for i = 1,#numbers-2 do
+		if not scope[numbers[i]] then
+			scope[numbers[i]] = {}
+		end
+		scope = scope[numbers[i]]
+	end
+	scope[numbers[#numbers-1]] = "&#x" .. numbers[#numbers] .. ";"
+	table.insert(
+		wide_character_codes,
+		numbers[#numbers]
+	)
+end
+
+signs_lib.unicode_install({38,"26"})
+
+dofile(signs_lib.path.."/nonascii-de.lua")
+dofile(signs_lib.path.."/nonascii-fr.lua")
+dofile(signs_lib.path.."/nonascii-pl.lua")
+
 local nmdc = {
 	[36] = "$",
 	[124] = "|"
@@ -230,36 +256,33 @@ function AnsiToUtf8(s)
 end
 
 function Utf8ToAnsi(s)
-	local a, j, r, b = 0, 0, ""
+	local a, j, r, b, scope = 0, 0, ""
 	for i = 1, s and s:len() or 0 do
 		b = s:byte(i)
-		if b < 128 then
+		if b == 0x26 then
+			r = r .. "&#x26;"
+		elseif b < 128 then
 			if nmdc[b] then
 				r = r .. nmdc[b]
 			else
 				r = r .. string.char(b)
 			end
-		elseif a == 2 then
-			a, j = a - 1, b
-		elseif a == 1 then
-			--if j == nil or b == nil then return r end
-			--print(j)
-			--print(b)
-			--local ansi = utf8_decode[j]
-			--if ansi == nil then return r end
-			--if ansi[b] == nil then return r end
-			if utf8_decode[j] then
-				if utf8_decode[j][b] then
-					a, r = a - 1, r .. utf8_decode[j][b]
+		elseif scope then
+			if scope[b] then
+				scope = scope[b]
+				if "string" == type(scope) then
+					r, scope = r .. scope
 				end
+			else
+				r, scope = r .. "_"
 			end
-		elseif b == 226 then
-			a = 2
-		elseif b == 194 or b == 208 or b == 209 or b == 210 then
-			j, a = b, 1
+		elseif utf8_decode[b] then
+			scope = utf8_decode[b]
 		else
 			r = r .. "_"
 		end
 	end
 	return r
 end
+
+signs_lib.wide_character_codes = wide_character_codes

mods/signs_lib/init.lua

@@ -10,7 +10,7 @@ signs_lib.path = minetest.get_modpath(minetest.get_current_modname())
 local S, NS = dofile(signs_lib.path .. "/intllib.lua")
 signs_lib.gettext = S
 
-dofile(signs_lib.path.."/api.lua")
 dofile(signs_lib.path.."/encoding.lua")
+dofile(signs_lib.path.."/api.lua")
 dofile(signs_lib.path.."/standard_signs.lua")
 dofile(signs_lib.path.."/compat.lua")

mods/signs_lib/nonascii-de.lua

@@ -0,0 +1,7 @@
+signs_lib.unicode_install({195,132,"00c4"})
+signs_lib.unicode_install({195,150,"00d6"})
+signs_lib.unicode_install({195,156,"00dc"})
+signs_lib.unicode_install({195,159,"00df"})
+signs_lib.unicode_install({195,164,"00e4"})
+signs_lib.unicode_install({195,182,"00f6"})
+signs_lib.unicode_install({195,188,"00fc"})

mods/signs_lib/nonascii-fr.lua

@@ -0,0 +1,16 @@
+signs_lib.unicode_install({195,128,"00c0"})
+signs_lib.unicode_install({195,134,"00c6"})
+signs_lib.unicode_install({195,135,"00c7"})
+signs_lib.unicode_install({195,136,"00c8"})
+signs_lib.unicode_install({195,137,"00c9"})
+signs_lib.unicode_install({195,138,"00ca"})
+signs_lib.unicode_install({195,148,"00d4"})
+signs_lib.unicode_install({195,153,"00d9"})
+signs_lib.unicode_install({195,160,"00e0"})
+signs_lib.unicode_install({195,166,"00e6"})
+signs_lib.unicode_install({195,167,"00e7"})
+signs_lib.unicode_install({195,168,"00e8"})
+signs_lib.unicode_install({195,169,"00e9"})
+signs_lib.unicode_install({195,170,"00ea"})
+signs_lib.unicode_install({195,180,"00f4"})
+signs_lib.unicode_install({195,185,"00f9"})

mods/signs_lib/nonascii-pl.lua

@@ -0,0 +1,16 @@
+signs_lib.unicode_install({195,147,"00d3"})
+signs_lib.unicode_install({195,179,"00f3"})
+signs_lib.unicode_install({196,132,"0104"})
+signs_lib.unicode_install({196,133,"0105"})
+signs_lib.unicode_install({196,134,"0106"})
+signs_lib.unicode_install({196,135,"0107"})
+signs_lib.unicode_install({196,152,"0118"})
+signs_lib.unicode_install({196,153,"0119"})
+signs_lib.unicode_install({197,129,"0141"})
+signs_lib.unicode_install({197,130,"0142"})
+signs_lib.unicode_install({197,154,"015a"})
+signs_lib.unicode_install({197,155,"015b"})
+signs_lib.unicode_install({197,185,"0179"})
+signs_lib.unicode_install({197,186,"017a"})
+signs_lib.unicode_install({197,187,"017b"})
+signs_lib.unicode_install({197,188,"017c"})