Mainly make collisions and coupling work

Missing: ATC stuff, yaw problems

8 files changed, 201 insertions, 191 deletions

diff --git a/advtrains/atc.lua b/advtrains/atc.lua
index 1d3b04c..480c043 100644
--- a/advtrains/atc.lua
+++ b/advtrains/atc.lua
@@ -30,7 +30,7 @@ function atc.send_command(pos, par_tid)
 	local pts=minetest.pos_to_string(pos)
 	if atc.controllers[pts] then
 		--atprint("Called send_command at "..pts)
-		local train_id = par_tid or advtrains.detector.get(pos) -- TODO: succesively replace those detector calls!
+		local train_id = par_tid or advtrains.get_train_at_pos(pos)
 		if train_id then
 			if advtrains.trains[train_id] then
 				--atprint("send_command inside if: "..sid(train_id))
@@ -131,7 +131,7 @@ advtrains.atc_function = function(def, preset, suffix, rotation)
 						local pts=minetest.pos_to_string(pos)
 						local _, conns=advtrains.get_rail_info_at(pos, advtrains.all_tracktypes)
 						atc.controllers[pts]={command=fields.command}
-						if advtrains.detector.get(pos) then
+						if #advtrains.occ.get_trains_at(pos) > 0 then
 							atc.send_command(pos)
 						end
 					end
diff --git a/advtrains/couple.lua b/advtrains/couple.lua
index b09961f..a4eecf4 100644
--- a/advtrains/couple.lua
+++ b/advtrains/couple.lua
@@ -44,19 +44,19 @@ minetest.register_entity("advtrains:discouple", {
 	end,
 	on_step=function(self, dtime)
 		return advtrains.pcall(function()
-			local t=os.clock()
 			if not self.wagon then
 				self.object:remove()
-				atprint("Discouple: no wagon, destroying")
 				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
-				atprint("Discouple: wagon no longer loaded, destroying")
 				self.object:remove()
 				return
 			end
-			atprintbm("discouple_step", t)
+			if not self.wagon:train() and self.wagon:train().velocity > 0 then
+				self.object:remove()
+				return
+			end
 		end)
 	end,
 })
@@ -102,13 +102,13 @@ minetest.register_entity("advtrains:couple", {
 			advtrains.train_ensure_init(self.train_id_2, train2)
 			
 			local id1, id2=self.train_id_1, self.train_id_2
-			local bp1, bp2 = self.t1_is_backpos, self.t2_is_backpos
-			if not bp1 then
+			local bp1, bp2 = self.t1_is_front, self.t2_is_front
+			if bp1 then
 				if train1.couple_lock_front then
 					lockmarker(self.object)
 					return
 				end
-				if not bp2 then
+				if bp2 then
 					if train2.couple_lock_front then
 						lockmarker(self.object)
 						return
@@ -127,7 +127,7 @@ minetest.register_entity("advtrains:couple", {
 					lockmarker(self.object)
 					return
 				end
-				if not bp2 then
+				if bp2 then
 					if train2.couple_lock_front then
 						lockmarker(self.object)
 						return
@@ -174,13 +174,13 @@ minetest.register_entity("advtrains:couple", {
 			
 			if not self.position_set then
 				local tp1
-				if not self.train1_is_backpos then
+				if self.t1_is_front then
 					tp1=advtrains.path_get_interpolated(train1, train1.index)
 				else
 					tp1=advtrains.path_get_interpolated(train1, train1.end_index)
 				end
 				local tp2
-				if not self.train2_is_backpos then
+				if self.t2_is_front then
 					tp2=advtrains.path_get_interpolated(train2, train2.index)
 				else
 					tp2=advtrains.path_get_interpolated(train2, train2.end_index)
diff --git a/advtrains/occupation.lua b/advtrains/occupation.lua
index 6316bd3..99de521 100644
--- a/advtrains/occupation.lua
+++ b/advtrains/occupation.lua
@@ -56,7 +56,7 @@ Whenever a path gets invalidated or path items are deleted, their index counterp
 When a train needs to know whether a position is blocked by another train, it will (and is permitted to)
 query the train.index and train.end_index and compare them to the blocked position's index.
 
-Callback system for 3rd-party path checkers: TODO
+Callback system for 3rd-party path checkers:
 advtrains.te_register_on_new_path(func(id, train))
 -- Called when a train's path is re-initalized, either when it was invalidated
 -- or the saves were just loaded
@@ -72,6 +72,12 @@ advtrains.te_register_on_update(func(id, train))
 -- It is ensured that on_new_path callbacks are executed prior to these callbacks whenever
 -- an invalidation or a reload occured.
 
+advtrains.te_register_on_create(func(id, train))
+-- Called right after a train is created, right after the initial new_path callback
+advtrains.te_register_on_remove(func(id, train))
+-- Called right before a train is deleted
+
+
 All callbacks are allowed to save certain values inside the train table, but they must ensure that
 those are reinitialized in the on_new_path callback. The on_new_path callback must explicitly
 set ALL OF those values to nil or to a new updated value, and must not rely on their existence.
@@ -162,11 +168,13 @@ function o.check_collision(pos, train_id)
 	if not t then return end
 	local i = 1
 	while t[i] do
-		if t[i]~=train_id then
+		local ti = t[i]
+		if ti~=train_id then
 			local idx = t[i+1]
-			local train = advtrains.trains[train_id]
-			advtrains.train_ensure_init(train_id, train)
+			local train = advtrains.trains[ti]
+			atdebug("checking train",t[i],"index",idx,"<>",train.index,train.end_index)
 			if idx >= train.end_index and idx <= train.index then
+				atdebug("collides.")
 				return true
 			end
 		end
@@ -183,19 +191,39 @@ function o.get_occupations(train, index)
 	local ppos, ontrack = advtrains.path_get(train, index)
 	if not ontrack then
 		atdebug("Train",train.id,"get_occupations requested off-track",index)
-		return {}, pos
+		return {}, ppos
 	end
 	local pos = advtrains.round_vector_floor_y(ppos)
 	local t = occget(pos)
+	if not t then return {} end
 	local r = {}
 	local i = 1
 	local train_id = train.id
 	while t[i] do
 		if t[i]~=train_id then
-			r[train_id] = t[i+1]
+			r[t[i]] = t[i+1]
 		end
 		i = i + 2
 	end
 	return r, pos
 end
+-- Gets a mapping of train id's to indexes of trains that stand or drive over
+-- returns (table with train_id->index), position
+function o.get_trains_at(ppos)
+	local pos = advtrains.round_vector_floor_y(ppos)
+	local t = occget(pos)
+	if not t then return {} end
+	local r = {}
+	local i = 1
+	while t[i] do
+		local train = advtrains.trains[t[i]]
+		local idx = t[i+1]
+		if train.end_index - 0.5 <= idx and idx <= train.index + 0.5 then
+			r[t[i]] = idx
+		end
+		i = i + 2
+	end
+	return r
+end
+
 advtrains.occ = o
diff --git a/advtrains/path.lua b/advtrains/path.lua
index d1d7ad9..d810fd7 100644
--- a/advtrains/path.lua
+++ b/advtrains/path.lua
@@ -137,7 +137,7 @@ function advtrains.path_setrestore(train, invert)
 		idx = train.end_index
 	end
 	
-	local pos, connid, frac = advtrains.path_getrestore(train, idx, invert)
+	local pos, connid, frac = advtrains.path_getrestore(train, idx, invert, true)
 	
 	train.last_pos = pos
 	train.last_connid = connid
@@ -145,23 +145,25 @@ function advtrains.path_setrestore(train, invert)
 end
 -- Get restore position, connid and frac (in this order) for a train that will originate at the passed index
 -- If invert is set, it will return path_cp and multiply frac by -1, in order to reverse the train there.
-function advtrains.path_getrestore(train, index, invert)
-	local idx = train.index
+function advtrains.path_getrestore(train, index, invert, tmp)
+	local idx = index
 	local cns = train.path_cn
 	
 	if invert then
-		idx = train.end_index
 		cns = train.path_cp
 	end
 	
-	fli = atfloor(train.index)
+	fli = atfloor(index)
+	advtrains.path_get(train, fli)
 	if fli > train.path_trk_f then
 		fli = train.path_trk_f
 	end
 	if fli < train.path_trk_b then
 		fli = train.path_trk_b
 	end
-	
+	if not tmp then
+	atdebug ("getrestore ",atround(train.index),"calc",atround(index),fli)
+	end
 	return advtrains.path_get(train, fli),
 			cns[fli],
 			(idx - fli) * (invert and -1 or 1)
@@ -359,7 +361,7 @@ function advtrains.path_clear_unused(train)
 		train.path_cp[i] = nil
 		train.path_cn[i] = nil
 		train.path_dir[i+1] = nil
-		train.path_ext_b = i - 1
+		train.path_ext_f = i - 1
 	end
 	
 	train.path_req_f = math.ceil(train.index)
diff --git a/advtrains/tracks.lua b/advtrains/tracks.lua
index f31fef6..eefff66 100644
--- a/advtrains/tracks.lua
+++ b/advtrains/tracks.lua
@@ -389,100 +389,6 @@ function advtrains.get_track_connections(name, param2)
 	return advtrains.rotate_conn_by(nodedef.at_conns, noderot*AT_CMAX/4), (nodedef.at_rail_y or 0), tracktype

 end

 

---detector code

---holds a table with nodes on which trains are on.

-

-advtrains.detector = {}

-advtrains.detector.on_node = {}

-

---Returns true when position is occupied by a train other than train_id, false when occupied by the same train as train_id and nil in case there's no train at all

-function advtrains.detector.occupied(pos, train_id)

-	local ppos=advtrains.round_vector_floor_y(pos)

-	local pts=minetest.pos_to_string(ppos)

-	local s=advtrains.detector.on_node[pts]

-	if not s then return nil end

-	if s==train_id then return false end

-	--in case s is a table, it's always occupied by another train

-	return true

-end

--- If given a train id as second argument, this is considered as 'not there'.

--- Returns the train id of (one of, nondeterministic) the trains at this position

-function advtrains.detector.get(pos, train_id)

-	local ppos=advtrains.round_vector_floor_y(pos)

-	local pts=minetest.pos_to_string(ppos)

-	local s=advtrains.detector.on_node[pts]

-	if not s then return nil end

-	if type(s)=="table" then 

-		for _,t in ipairs(s) do

-			if t~=train_id then return t end

-		end

-		return nil

-	end

-	return s

-end

-

-function advtrains.detector.enter_node(pos, train_id)

-	advtrains.detector.stay_node(pos, train_id)

-	local ppos=advtrains.round_vector_floor_y(pos)

-	advtrains.detector.call_enter_callback(ppos, train_id)

-end

-function advtrains.detector.leave_node(pos, train_id)

-	local ppos=advtrains.round_vector_floor_y(pos)

-	local pts=minetest.pos_to_string(ppos)

-	local s=advtrains.detector.on_node[pts]

-	if type(s)=="table" then

-		local i

-		for j,t in ipairs(s) do

-			if t==train_id then i=j end

-		end

-		if not i then return end

-		s=table.remove(s,i)

-		if #s==0 then

-			s=nil

-		elseif #s==1 then

-			s=s[1]

-		end

-		advtrains.detector.on_node[pts]=s

-	else

-		advtrains.detector.on_node[pts]=nil

-	end

-	advtrains.detector.call_leave_callback(ppos, train_id)

-end

-function advtrains.detector.stay_node(pos, train_id)

-	local ppos=advtrains.round_vector_floor_y(pos)

-	local pts=minetest.pos_to_string(ppos)

-	

-	local s=advtrains.detector.on_node[pts]

-	if not s then

-		advtrains.detector.on_node[pts]=train_id

-	elseif type(s)=="string" then

-		advtrains.detector.on_node[pts]={s, train_id}

-	elseif type(s)=="table" then

-		advtrains.detector.on_node[pts]=table.insert(s, train_id)

-	end

-end

-

-

-

-function advtrains.detector.call_enter_callback(pos, train_id)

-	--atprint("instructed to call enter calback")

-

-	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_enter then

-		mregnode.advtrains.on_train_enter(pos, train_id)

-	end

-end

-function advtrains.detector.call_leave_callback(pos, train_id)

-	--atprint("instructed to call leave calback")

-

-	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_leave then

-		mregnode.advtrains.on_train_leave(pos, train_id)

-	end 

-end

-

 -- slope placer. Defined in register_tracks.

 --crafted with rail and gravel

 local sl={}

diff --git a/advtrains/trainlogic.lua b/advtrains/trainlogic.lua
index 129722a..feb35b5 100644
--- a/advtrains/trainlogic.lua
+++ b/advtrains/trainlogic.lua
@@ -176,29 +176,24 @@ end
 -- Occupation Callback system
 -- see occupation.lua
 
-local callbacks_new_path = {}
-local callbacks_update = {}
-
-function advtrains.te_register_on_new_path(func)
-	assertt(func, "function")
-	table.insert(callbacks_new_path, func)
-end
-function advtrains.te_register_on_update(func)
-	assertt(func, "function")
-	table.insert(callbacks_update, func)
-end
-
-local function run_callbacks_new_path(id, train)
-	for _,f in ipairs(callbacks_new_path) do
-		f(id, train)
-	end
-end
-local function run_callbacks_update(id, train)
-	for _,f in ipairs(callbacks_new_path) do
-		f(id, train)
+local function mkcallback(name)
+	local callt = {}
+	advtrains["te_register_on_"..name] = function(func)
+		assertt(func, "function")
+		table.insert(callt, func)
+	end
+	return callt, function(id, train)
+		for _,f in ipairs(callt) do
+			f(id, train)
+		end
 	end
 end
 
+local callbacks_new_path, run_callbacks_new_path = mkcallback("new_path")
+local callbacks_update, run_callbacks_update = mkcallback("update")
+local callbacks_create, run_callbacks_create = mkcallback("create")
+local callbacks_remove, run_callbacks_remove = mkcallback("remove")
+
 
 -- train_ensure_init: responsible for creating a state that we can work on, after one of the following events has happened:
 -- - the train's path got cleared
@@ -385,7 +380,7 @@ function advtrains.train_step_b(id, train, dtime)
 	--- 4. move train ---
 	
 	train.index=train.index and train.index+((train.velocity/(train.path_dist[math.floor(train.index)] or 1))*dtime) or 0
-	recalc_end_index()
+	recalc_end_index(train)
 
 end
 
@@ -420,22 +415,21 @@ if train.no_step or train.wait_for_path then return end
 	
 	if train_moves then
 		
-		local collpos
+		local collided = false
 		local coll_grace=1
-		local collindex = advtrains.path_get_index_by_offset(train, train.index, coll_grace)
-		collpos = advtrains.path_get(train, atround(collindex))
+		local collindex = advtrains.path_get_index_by_offset(train, train.index, -coll_grace)
+		local collpos = advtrains.path_get(train, atround(collindex))
 		if collpos then
 			local rcollpos=advtrains.round_vector_floor_y(collpos)
 			for x=-train.extent_h,train.extent_h do
 				for z=-train.extent_h,train.extent_h do
 					local testpos=vector.add(rcollpos, {x=x, y=0, z=z})
 					--- 8a Check collision ---
-					if advtrains.occ.check_collision(testpos, id) then
+					if not collided and advtrains.occ.check_collision(testpos, id) then
 						--collides
-						--advtrains.collide_and_spawn_couple(id, testpos, advtrains.detector.get(testpos, id), train.movedir==-1)
 						train.velocity = 0
 						train.tarvelocity = 0
-						atwarn("Train",id,"collided!")
+						collided = true
 					end
 					--- 8b damage players ---
 					if not minetest.settings:get_bool("creative_mode") then
@@ -499,7 +493,9 @@ advtrains.te_register_on_new_path(function(id, train)
 		old_index = atround(train.index),
 		old_end_index = atround(train.end_index),
 	}
+	atdebug(id,"tnc init",train.index,train.end_index)
 end)
+
 advtrains.te_register_on_update(function(id, train)
 	local new_index = atround(train.index)
 	local new_end_index = atround(train.end_index)
@@ -507,14 +503,38 @@ advtrains.te_register_on_update(function(id, train)
 	local old_end_index = train.tnc.old_end_index
 	while old_index < new_index do
 		old_index = old_index + 1
-		local pos = advtrains.round_vector_floor_y(advtrains.path_get(old_index))
+		local pos = advtrains.round_vector_floor_y(advtrains.path_get(train,old_index))
 		tnc_call_enter_callback(pos, id)
 	end
-	while old_end_index > new_end_index do
-		local pos = advtrains.round_vector_floor_y(advtrains.path_get(old_end_index))
+	while old_end_index < new_end_index do
+		local pos = advtrains.round_vector_floor_y(advtrains.path_get(train,old_end_index))
 		tnc_call_leave_callback(pos, id)
-		old_end_index = old_end_index - 1
+		old_end_index = old_end_index + 1
 	end
+	train.tnc.old_index = new_index
+	train.tnc.old_end_index = new_end_index
+end)
+
+advtrains.te_register_on_create(function(id, train)
+	local index = atround(train.index)
+	local end_index = atround(train.end_index)
+	while end_index <= index do
+		local pos = advtrains.round_vector_floor_y(advtrains.path_get(train,end_index))
+		tnc_call_enter_callback(pos, id)
+		end_index = end_index + 1
+	end
+	atdebug(id,"tnc create",train.index,train.end_index)
+end)
+
+advtrains.te_register_on_remove(function(id, train)
+	local index = atround(train.index)
+	local end_index = atround(train.end_index)
+	while end_index <= index do
+		local pos = advtrains.round_vector_floor_y(advtrains.path_get(train,end_index))
+		tnc_call_leave_callback(pos, id)
+		end_index = end_index + 1
+	end
+	atdebug(id,"tnc remove",train.index,train.end_index)
 end)
 
 -- Calculates the indices where the window borders of the occupation windows are.
@@ -572,9 +592,10 @@ function advtrains.create_new_train_at(pos, connid, ioff, trainparts)
 	advtrains.trains[new_id] = t
 	atdebug("Created new train:",t)
 	
-	
 	advtrains.train_ensure_init(new_id, advtrains.trains[new_id])
 	
+	run_callbacks_create(new_id, advtrains.trains[new_id])
+	
 	return new_id
 end
 
@@ -583,9 +604,13 @@ function advtrains.remove_train(id)
 	
 	advtrains.train_ensure_init(id, train)
 	
+	run_callbacks_remove(id, train)
+	
 	advtrains.path_invalidate(train)
+	advtrains.couple_invalidate(train)
 	
 	local tp = train.trainparts
+	atdebug("Removing train",id,"leftover trainparts:",tp)
 	
 	advtrains.trains[id] = nil
 	
@@ -661,6 +686,8 @@ function advtrains.update_trainpart_properties(train_id, invert_flipstate)
 	train.locomotives_in_train = count_l
 end
 
+
+local ablkrng = minetest.settings:get("active_block_range")*16
 -- This function checks whether entities need to be spawned for certain wagons, and spawns them.
 function advtrains.spawn_wagons(train_id)
 	local train = advtrains.trains[train_id]
@@ -668,12 +695,23 @@ function advtrains.spawn_wagons(train_id)
 	for i, w_id in ipairs(train.trainparts) do
 		local data = advtrains.wagons[w_id]
 		if data then
+			if data.train_id ~= train_id then
+				atwarn("Train",train_id,"Wagon #",1,": Saved train ID",data.train_id,"did not match!")
+				data.train_id = train_id
+			end
 			if not data.object or not data.object:getyaw() 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))
 				
-				if minetest.get_node_or_nil(pos) then
+				local spawn = false
+				for _,p in pairs(minetest.get_connected_players()) do
+					if vector.distance(p:get_pos(),pos)<=ablkrng then
+						spawn = true
+					end
+				end
+				
+				if spawn then
 					local wt = advtrains.get_wagon_prototype(data)
 					local wagon = minetest.add_entity(pos, wt):get_luaentity()
 					wagon:set_id(w_id)
@@ -693,16 +731,15 @@ function advtrains.split_train_at_wagon(wagon_id)
 	
 	advtrains.train_ensure_init(old_id, train)
 	
-	local index=advtrains.path_get_index_by_offset(train, train.index, -(data.pos_in_train + wagon.wagon_span))
+	local index=advtrains.path_get_index_by_offset(train, train.index, - data.pos_in_train + wagon.wagon_span)
 	
 	-- find new initial path position for this train
 	local pos, connid, frac = advtrains.path_getrestore(train, index)
-		
 	
 	-- build trainparts table, passing it directly to the train constructor
 	local tp = {}
 	for k,v in ipairs(train.trainparts) do
-		if k>=wagon.pos_in_trainparts then
+		if k >= data.pos_in_trainparts then
 			table.insert(tp, v)
 			train.trainparts[k]=nil
 		end
@@ -728,7 +765,7 @@ function advtrains.split_train_at_wagon(wagon_id)
 end
 
 -- coupling
-local CPL_CHK_DST = 1
+local CPL_CHK_DST = -1
 local CPL_ZONE = 2
 
 -- train.couple_* contain references to ObjectRefs of couple objects, which contain all relevant information
@@ -739,11 +776,24 @@ local function createcouple(pos, train1, t1_is_front, train2, t2_is_front)
 	local le=obj:get_luaentity()
 	le.train_id_1=train1.id
 	le.train_id_2=train2.id
-	le.train1_is_backpos=not t1_is_front
-	le.train2_is_backpos=not t2_is_front
+	le.t1_is_front=t1_is_front
+	le.t2_is_front=t2_is_front
+	atdebug("created couple between",train1.id,t1_is_front,train2.id,t2_is_front)
+	if t1_is_front then
+		train1.cpl_front = obj
+	else
+		train1.cpl_back = obj
+	end
+	if t2_is_front then
+		train2.cpl_front = obj
+	else
+		train2.cpl_back = obj
+	end
+	
 end
 
 function advtrains.train_check_couples(train)
+	atdebug("rechecking couples")
 	if train.cpl_front then
 		if not train.cpl_front:getyaw() then
 			-- objectref is no longer valid. reset.
@@ -756,6 +806,7 @@ function advtrains.train_check_couples(train)
 		for tid, idx in pairs(front_trains) do
 			local other_train = advtrains.trains[tid]
 			advtrains.train_ensure_init(tid, other_train)
+			atdebug(train.id,"front: ",idx,"on",tid,atround(other_train.index),atround(other_train.end_index))
 			if other_train.velocity == 0 then
 				if idx>=other_train.index and idx<=other_train.index + CPL_ZONE then
 					createcouple(pos, train, true, other_train, true)
@@ -794,7 +845,17 @@ function advtrains.train_check_couples(train)
 	end
 end
 
-
+function advtrains.couple_invalidate(train)
+	if train.cpl_back then
+		train.cpl_back:remove()
+		train.cpl_back = nil
+	end
+	if train.cpl_front then
+		train.cpl_front:remove()
+		train.cpl_front = nil
+	end
+	train.was_standing = nil
+end
 
 -- relevant code for this comment is in couple.lua
 
@@ -833,6 +894,9 @@ function advtrains.do_connect_trains(first_id, second_id)
 	first.velocity=0
 	first.tarvelocity=0
 	first.couple_lck_back=tmp_cpl_lck
+	
+	advtrains.update_trainpart_properties(first_id)
+	advtrains.couple_invalidate(first)
 	return true
 end
 
@@ -845,8 +909,12 @@ function advtrains.invert_train(train_id)
 	
 	-- rotate some other stuff
 	train.couple_lck_back, train.couple_lck_front = train.couple_lck_front, train.couple_lck_back
+	if train.door_open then
+		train.door_open = - train.door_open
+	end
 	
 	advtrains.path_invalidate(train)
+	advtrains.couple_invalidate(train)
 	
 	local old_trainparts=train.trainparts
 	train.trainparts={}
@@ -857,7 +925,7 @@ function advtrains.invert_train(train_id)
 end
 
 function advtrains.get_train_at_pos(pos)
-	return advtrains.detector.get(pos)
+	return advtrains.occ.get_trains_at(pos)[1]
 end
 
 function advtrains.invalidate_all_paths(pos)
@@ -883,6 +951,7 @@ function advtrains.invalidate_path(id)
 	local v=advtrains.trains[id]
 	if not v then return end
 	advtrains.path_invalidate(v)
+	advtrains.couple_invalidate(v)
 	v.dirty = true
 end
 
diff --git a/advtrains/wagons.lua b/advtrains/wagons.lua
index 38c551e..254e6a8 100644
--- a/advtrains/wagons.lua
+++ b/advtrains/wagons.lua
@@ -10,6 +10,7 @@
 advtrains.wagons = {}

 advtrains.wagon_prototypes = {}

 

+-- TODO: That yaw thing is still not fixed. seems like minetest itself obeys the counterclockwise system...

 

 --

 function advtrains.create_wagon(wtype, owner)

@@ -107,14 +108,18 @@ function wagon:ensure_init()
 			-- Train not being set just means that this will happen as soon as the train calls update_trainpart_properties.

 	if self.initialized and self.id then

 		local data = advtrains.wagons[self.id]

-		if data.train_id then

+		if data and data.train_id and self:train() then

 			if self.noninitticks then self.noninitticks=nil end

 			return true

 		end

 	end

-	if not self.noninitticks then self.noninitticks=0 end

+	if not self.noninitticks then

+		atwarn("wagon",self.id,"uninitialized init=",self.initialized)

+		self.noninitticks=0

+	end

 	self.noninitticks=self.noninitticks+1

 	if self.noninitticks>20 then

+		atwarn("wagon",self.id,"uninitialized, removing")

 		self:destroy()

 	else

 		self.object:setvelocity({x=0,y=0,z=0})

@@ -174,6 +179,10 @@ function wagon:destroy()
 	-- not when a driver is inside

 	if self.id then

 		local data = advtrains.wagons[self.id]

+		if not data then

+			atwarn("wagon:destroy(): data is not set!")

+			return

+		end

 		

 		if self.custom_on_destroy then

 			self.custom_on_destroy(self)

@@ -184,14 +193,12 @@ function wagon:destroy()
 		end

 		

 		if data.train_id and self:train() then

-			table.remove(self:train().trainparts, data.pos_in_trainparts)

-			advtrains.update_trainpart_properties(data.train_id)

+			advtrains.remove_train(data.train_id)

 			advtrains.wagons[self.id]=nil

 			if self.discouple then self.discouple.object:remove() end--will have no effect on unloaded objects

-			return true

 		end

 	end

-	atprint("[wagon ", self.id, "]: destroying")

+	atdebug("[wagon ", self.id, "]: destroying")

 	

 	self.object:remove()

 end

@@ -247,7 +254,7 @@ function wagon:on_step(dtime)
 					advtrains.on_control_change(pc, self:train(), data.wagon_flipped)

 					--bordcom

 					if pc.sneak and pc.jump then

-						self:show_bordcom(self.seatp[seatno])

+						self:show_bordcom(data.seatp[seatno])

 					end

 					--sound horn when required

 					if self.horn_sound and pc.aux1 and not pc.sneak and not self.horn_handle then

@@ -458,6 +465,7 @@ function wagon:on_step(dtime)
 				or not vector.equals(accelerationvec, self.old_acceleration_vector)

 				or self.old_yaw~=yaw

 				or self.updatepct_timer<=0 then--only send update packet if something changed

+			

 			self.object:setpos(pos)

 			self.object:setvelocity(velocityvec)

 			self.object:setacceleration(accelerationvec)

@@ -494,6 +502,10 @@ function wagon:on_step(dtime)
 			if self.custom_on_velocity_change then

 				self:custom_on_velocity_change(train.velocity, self.old_velocity or 0, dtime)

 			end

+			-- remove discouple object, because it will be in a wrong location

+			if self.discouple then

+				self.discouple.object:remove()

+			end

 		end

 		

 		

@@ -529,7 +541,7 @@ function wagon:on_rightclick(clicker)
 					poss[#poss+1]={name=attrans("Show Inventory"), key="inv"}

 				end

 				if self.seat_groups[sgr].driving_ctrl_access and advtrains.check_driving_couple_protection(pname, data.owner, data.whitelist) then

-					poss[#poss+1]={name=attrans("Bord Computer"), key="bordcom"}

+					poss[#poss+1]={name=attrans("Board Computer"), key="bordcom"}

 				end

 				if data.owner==pname then

 					poss[#poss+1]={name=attrans("Wagon properties"), key="prop"}

@@ -706,7 +718,7 @@ function wagon:show_get_on_form(pname)
 		local addtext, colorcode="", ""

 		if data.seatp and data.seatp[seatno] then

 			colorcode="#FF0000"

-			addtext=" ("..self.seatp[seatno]..")"

+			addtext=" ("..data.seatp[seatno]..")"

 		end

 		form=form..comma..colorcode..seattbl.name..addtext

 		comma=","

@@ -732,16 +744,12 @@ function wagon:show_wagon_properties(pname)
 end

 

 --BordCom

-local function checkcouple(eid)

-	if not eid then return nil end

-	local ent=minetest.object_refs[eid]

+local function checkcouple(ent)

 	if not ent or not ent:getyaw() then

-		eid=nil

 		return nil

 	end

 	local le = ent:get_luaentity()

 	if not le or not le.is_couple then

-		eid=nil

 		return nil

 	end

 	return le

@@ -793,8 +801,8 @@ function wagon:show_bordcom(pname)
 			form = form .. "label[0.5,"..(linhei)..";<--]"

 		end

 		--check cpl_eid_front and _back of train

-		local couple_front = checkcouple(train.couple_eid_front)

-		local couple_back = checkcouple(train.couple_eid_back)

+		local couple_front = checkcouple(train.cpl_front)

+		local couple_back = checkcouple(train.cpl_back)

 		if couple_front then

 			form = form .. "image_button[0.5,"..(linhei+1)..";1,1;advtrains_couple.png;cpl_f;]"

 		end

@@ -872,8 +880,8 @@ function wagon:handle_bordcom_fields(pname, formname, fields)
 		end

 	end

 	--check cpl_eid_front and _back of train

-	local couple_front = checkcouple(train.couple_eid_front)

-	local couple_back = checkcouple(train.couple_eid_back)

+	local couple_front = checkcouple(train.cpl_front)

+	local couple_back = checkcouple(train.cpl_back)

 	

 	if fields.cpl_f and couple_front then

 		couple_front:on_rightclick(pname)

diff --git a/advtrains_luaautomation/atc_rail.lua b/advtrains_luaautomation/atc_rail.lua
index 88c9ee9..d001d88 100644
--- a/advtrains_luaautomation/atc_rail.lua
+++ b/advtrains_luaautomation/atc_rail.lua
@@ -24,7 +24,7 @@ function r.fire_event(pos, evtdata)
 	
 	--prepare ingame API for ATC. Regenerate each time since pos needs to be known
 	--If no train, then return false.
-	local train_id=advtrains.detector.get(pos)
+	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 
@@ -34,19 +34,16 @@ function r.fire_event(pos, evtdata)
 			atlatc.interrupt.add(0,pos,evtdata)
 			return
 		end
-		for index, ppos in pairs(train.path) do
-			if vector.equals(advtrains.round_vector_floor_y(ppos), pos) then
-				atc_arrow =
-						vector.equals(
-								advtrains.dirCoordSet(pos, arrowconn),
-								advtrains.round_vector_floor_y(train.path[index+train.movedir])
-						)
-			end
-		end
-		if atc_arrow==nil then
-			atwarn("LuaAutomation ATC rail at", pos, ": Rail not on train's path! Can't determine arrow direction. Assuming +!")
-			atc_arrow=true
+		local index = advtrains.path_lookup(train, pos)
+				
+		local iconnid = 1
+		if index then
+			iconnid = train.path_cn[index]
+		else
+			atwarn("ATC rail at", pos, ": Rail not on train's path! Can't determine arrow direction. Assuming +!")
 		end
+		atc_arrow = iconnid == 1
+		
 		tvel=train.velocity
 	end
 	local customfct={