From d65c4916ceaeed6eec5fe3f344d4e71b3c96a80b Mon Sep 17 00:00:00 2001
From: rubenwardy <rubenwardy@gmail.com>
Date: Wed, 20 Sep 2017 17:05:04 +0100
Subject: Remove zip release files, move mod to root, exclude assets from
 Makefile (#92)

---
 advtrains/wagons.lua | 900 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 900 insertions(+)
 create mode 100644 advtrains/wagons.lua

(limited to 'advtrains/wagons.lua')

diff --git a/advtrains/wagons.lua b/advtrains/wagons.lua
new file mode 100644
index 0000000..567b560
--- /dev/null
+++ b/advtrains/wagons.lua
@@ -0,0 +1,900 @@
+--atan2 counts angles clockwise, minetest does counterclockwise
+
+minetest.register_privilege("train_place", {
+	description = "Player can place trains on tracks not owned by player",
+	give_to_singleplayer= false,
+});
+minetest.register_privilege("train_remove", {
+	description = "Player can remove trains not owned by player",
+	give_to_singleplayer= false,
+});
+minetest.register_privilege("train_operator", {
+	description = "Player may operate trains and switch signals. Given by default. Revoke to prevent players from griefing automated subway systems.",
+	give_to_singleplayer= true,
+	default= true,
+});
+
+local wagon={
+	collisionbox = {-0.5,-0.5,-0.5, 0.5,0.5,0.5},
+	--physical = true,
+	visual = "mesh",
+	mesh = "wagon.b3d",
+	visual_size = {x=3, y=3},
+	textures = {"black.png"},
+	is_wagon=true,
+	wagon_span=1,--how many index units of space does this wagon consume
+	has_inventory=false,
+}
+
+
+function wagon:train()
+	return advtrains.trains[self.train_id]
+end
+
+--[[about 'initalized':
+	when initialized is false, the entity hasn't got any data yet and should wait for these to be set before doing anything
+	when loading an existing object (with staticdata), it will be set
+	when instanciating a new object via add_entity, it is not set at the time on_activate is called.
+	then, wagon:initialize() will be called
+	
+	wagon will save only uid in staticdata, no serialized table
+]]
+function wagon:on_activate(sd_uid, dtime_s)
+	if sd_uid~="" then
+		--destroy when loaded from static block.
+		self.object:remove()
+		return
+	end
+	self.object:set_armor_groups({immortal=1})
+	self.entity_name=self.name
+end
+
+function wagon:get_staticdata()
+	return advtrains.pcall(function()
+		if not self:ensure_init() then return end
+		atprint("[wagon "..((self.unique_id and self.unique_id~="" and self.unique_id) or "no-id").."]: saving to wagon_save")
+		--serialize inventory, if it has one
+		if self.has_inventory then
+			local inv=minetest.get_inventory({type="detached", name="advtrains_wgn_"..self.unique_id})
+			self.ser_inv=advtrains.serialize_inventory(inv)
+		end
+		--save to table before being unloaded
+		advtrains.wagon_save[self.unique_id]=advtrains.merge_tables(self)
+		advtrains.wagon_save[self.unique_id].entity_name=self.name
+		advtrains.wagon_save[self.unique_id].name=nil
+		advtrains.wagon_save[self.unique_id].object=nil
+		return self.unique_id
+	end)
+end
+--returns: uid of wagon
+function wagon:init_new_instance(train_id, properties)
+	self.unique_id=os.time()..os.clock()
+	self.train_id=train_id
+	for k,v in pairs(properties) do
+		if k~="name" and k~="object" then
+			self[k]=v
+		end
+	end
+	self:init_shared()
+	self.initialized=true
+	atprint("init_new_instance "..self.unique_id.." ("..self.train_id..")")
+	return self.unique_id
+end
+function wagon:init_from_wagon_save(uid)
+	if not advtrains.wagon_save[uid] then
+		self.object:remove()
+		return
+	end
+	self.unique_id=uid
+	for k,v in pairs(advtrains.wagon_save[uid]) do
+		if k~="name" and k~="object" then
+			self[k]=v
+		end
+	end
+	if not self.train_id or not self:train() then
+		self.object:remove()
+		return
+	end
+	self:init_shared()
+	self.initialized=true
+	minetest.after(0.2, function() self:reattach_all() end)
+	atprint("init_from_wagon_save "..self.unique_id.." ("..self.train_id..")")
+end
+function wagon:init_shared()
+	if self.has_inventory then
+		local uid_noptr=self.unique_id..""
+		--to be used later
+		local inv=minetest.create_detached_inventory("advtrains_wgn_"..self.unique_id, {
+			allow_move = function(inv, from_list, from_index, to_list, to_index, count, player)
+				return count
+			end,
+			allow_put = function(inv, listname, index, stack, player)
+				return stack:get_count()
+			end,
+			allow_take = function(inv, listname, index, stack, player)
+				return stack:get_count()
+			end
+		})
+		if self.ser_inv then
+			advtrains.deserialize_inventory(self.ser_inv, inv)
+		end
+		if self.inventory_list_sizes then
+			for lst, siz in pairs(self.inventory_list_sizes) do
+				inv:set_size(lst, siz)
+			end
+		end
+	end
+	if self.doors then
+		self.door_anim_timer=0
+		self.door_state=0
+	end
+	if self.custom_on_activate then
+		self:custom_on_activate(dtime_s)
+	end
+end
+function wagon:ensure_init()
+	if self.initialized then
+		if self.noninitticks then self.noninitticks=nil end
+		return true
+	end
+	if not self.noninitticks then self.noninitticks=0 end
+	self.noninitticks=self.noninitticks+1
+	if self.noninitticks>20 then
+		self.object:remove()
+	else
+		self.object:setvelocity({x=0,y=0,z=0})
+	end
+	return false
+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
+		if not puncher or not puncher:is_player() then
+			return
+		end
+		if self.owner and puncher:get_player_name()~=self.owner and (not minetest.check_player_privs(puncher, {train_remove = true })) then
+		   minetest.chat_send_player(puncher:get_player_name(), attrans("This wagon is owned by @1, you can't destroy it.", self.owner));
+		   return
+		end
+		
+		if minetest.settings:get_bool("creative_mode") then
+			if not self:destroy() then return end
+			
+			local inv = puncher:get_inventory()
+			if not inv:contains_item("main", self.name) then
+				inv:add_item("main", self.name)
+			end
+		else
+			local pc=puncher:get_player_control()
+			if not pc.sneak then
+				minetest.chat_send_player(puncher:get_player_name(), attrans("Warning: If you destroy this wagon, you only get some steel back! If you are sure, hold Sneak and left-click the wagon."))
+				return
+			end
+
+			if not self:destroy() then return end
+
+			local inv = puncher:get_inventory()
+			for _,item in ipairs(self.drops or {self.name}) do
+				inv:add_item("main", item)
+			end
+		end
+	end)
+end
+function wagon:destroy()
+	--some rules:
+	-- you get only some items back
+	-- single left-click shows warning
+	-- shift leftclick destroys
+	-- not when a driver is inside
+	
+	for _,_ in pairs(self.seatp) do
+		return
+	end
+	
+	if self.custom_may_destroy then
+		if not self.custom_may_destroy(self, puncher, time_from_last_punch, tool_capabilities, direction) then
+			return
+		end
+	end
+	if self.custom_on_destroy then
+		self.custom_on_destroy(self, puncher, time_from_last_punch, tool_capabilities, direction)
+	end
+	
+	atprint("[wagon "..((self.unique_id and self.unique_id~="" and self.unique_id) or "no-id").."]: destroying")
+	
+	self.object:remove()
+
+	table.remove(self:train().trainparts, self.pos_in_trainparts)
+	advtrains.update_trainpart_properties(self.train_id)
+	advtrains.wagon_save[self.unique_id]=nil
+	if self.discouple then self.discouple.object:remove() end--will have no effect on unloaded objects
+	return true
+end
+
+
+function wagon:on_step(dtime)
+	return advtrains.pcall(function()
+		if not self:ensure_init() then return end
+		
+		local t=os.clock()
+		local pos = self.object:getpos()
+		
+		if not pos then
+			atprint("["..self.unique_id.."][fatal] missing position (object:getpos() returned nil)")
+			return
+		end
+
+		self.entity_name=self.name
+		
+		--is my train still here
+		if not self.train_id or not self:train() then
+			atprint("[wagon "..self.unique_id.."] missing train_id, destroying")
+			self.object:remove()
+			return
+		end
+		if not self.seatp then
+			self.seatp={}
+		end
+		if not self.seatpc then
+			self.seatpc={}
+		end
+		
+		--Legacy: remove infotext since it does not work this way anyways
+		self.infotext=nil
+
+		--custom on_step function
+		if self.custom_on_step then
+			self:custom_on_step(self, dtime)
+		end
+
+		--driver control
+		for seatno, seat in ipairs(self.seats) do
+			local driver=self.seatp[seatno] and minetest.get_player_by_name(self.seatp[seatno])
+			local has_driverstand=seat.driving_ctrl_access and self.seatp[seatno] and minetest.check_player_privs(self.seatp[seatno], {train_operator=true})
+			if has_driverstand and driver then
+				advtrains.update_driver_hud(driver:get_player_name(), self:train(), self.wagon_flipped)
+			elseif driver then
+				--only show the inside text
+				local inside=self:train().text_inside or ""
+				advtrains.set_trainhud(driver:get_player_name(), inside)
+			end
+			if driver and driver:get_player_control_bits()~=self.seatpc[seatno] then
+				local pc=driver:get_player_control()
+				self.seatpc[seatno]=driver:get_player_control_bits()
+				
+				if has_driverstand then
+					--regular driver stand controls
+					advtrains.on_control_change(pc, self:train(), self.wagon_flipped)
+				else
+					-- If on a passenger seat and doors are open, get off when W or D pressed.
+					local pass = self.seatp[seatno] and minetest.get_player_by_name(self.seatp[seatno])
+					if pass and self:train().door_open~=0 then
+					local pc=pass:get_player_control()
+						if pc.up or pc.down then
+							self:get_off(seatno)
+						end
+					end		      
+				end
+				if pc.aux1 and pc.sneak then
+					self:get_off(seatno)
+				end
+			end
+		end
+		
+		--check infotext
+		local outside=self:train().text_outside or ""
+		if self.object:get_properties().infotext~=outside  then
+			self.object:set_properties({infotext=outside})
+		end
+		
+		local gp=self:train()
+		local fct=self.wagon_flipped and -1 or 1
+		--door animation
+		if self.doors then
+			if (self.door_anim_timer or 0)<=0 then
+				local dstate = (gp.door_open or 0) * fct
+				if dstate ~= self.door_state then
+					local at
+					--meaning of the train.door_open field:
+					-- -1: left doors (rel. to train orientation)
+					--  0: closed
+					--  1: right doors
+					--this code produces the following behavior:
+					-- if changed from 0 to +-1, play open anim. if changed from +-1 to 0, play close.
+					-- if changed from +-1 to -+1, first close and set 0, then it will detect state change again and run open.
+					if self.door_state == 0 then
+						at=self.doors.open[dstate]
+						self.object:set_animation(at.frames, at.speed or 15, at.blend or 0, false)
+						self.door_state = dstate
+					else
+						at=self.doors.close[self.door_state or 1]--in case it has not been set yet
+						self.object:set_animation(at.frames, at.speed or 15, at.blend or 0, false)
+						self.door_state = 0
+					end
+					self.door_anim_timer = at.time
+				end
+			else
+				self.door_anim_timer = (self.door_anim_timer or 0) - dtime
+			end
+		end
+		
+		--DisCouple
+		if self.pos_in_trainparts and self.pos_in_trainparts>1 then
+			if gp.velocity==0 and not self.lock_couples then
+				if not self.discouple or not self.discouple.object:getyaw() then
+					local object=minetest.add_entity(pos, "advtrains:discouple")
+					if object then
+						local le=object:get_luaentity()
+						le.wagon=self
+						--box is hidden when attached, so unuseful.
+						--object:set_attach(self.object, "", {x=0, y=0, z=self.wagon_span*10}, {x=0, y=0, z=0})
+						self.discouple=le
+					else
+						atprint("Couldn't spawn DisCouple")
+					end
+				end
+			else
+				if self.discouple and self.discouple.object:getyaw() then
+					self.discouple.object:remove()
+				end
+			end
+		end
+		--for path to be available. if not, skip step
+		if not gp.path then
+			self.object:setvelocity({x=0, y=0, z=0})
+			return
+		end
+		if not self.pos_in_train then
+			--why ever. but better continue next step...
+			advtrains.update_trainpart_properties(self.train_id)
+			return
+		end
+		
+		local index=advtrains.get_real_path_index(self:train(), self.pos_in_train)
+		--atprint("trainindex "..gp.index.." wagonindex "..index)
+		
+		--automatic get_on
+		--needs to know index and path
+		if self.door_entry and gp.door_open and gp.door_open~=0 and gp.velocity==0 then
+			--using the mapping created by the trainlogic globalstep
+			for i, ino in ipairs(self.door_entry) do
+				--fct is the flipstate flag from door animation above
+				local aci = index + ino*fct
+				local ix1=gp.path[math.floor(aci)]
+				local ix2=gp.path[math.floor(aci+1)]
+				-- the two wanted positions are ix1 and ix2 + (2nd-1st rotated by 90deg)
+				-- (x z) rotated by 90deg is (-z x)  (http://stackoverflow.com/a/4780141)
+				local add = { x = (ix2.z-ix1.z)*gp.door_open, y = 0, z = (ix1.x-ix2.x)*gp.door_open }
+				local pts1=vector.round(vector.add(ix1, add))
+				local pts2=vector.round(vector.add(ix2, add))
+				if minetest.get_item_group(minetest.get_node(pts1).name, "platform")>0 then
+					local ckpts={
+						pts1,
+						pts2,
+						vector.add(pts1, {x=0, y=1, z=0}),
+						vector.add(pts2, {x=0, y=1, z=0}),
+					}
+					for _,ckpos in ipairs(ckpts) do
+						local cpp=minetest.pos_to_string(ckpos)
+						if advtrains.playersbypts[cpp] then
+							self:on_rightclick(advtrains.playersbypts[cpp])
+						end
+					end
+				end
+			end
+		end
+		
+		--position recalculation
+		local first_pos=gp.path[math.floor(index)]
+		local second_pos=gp.path[math.floor(index)+1]
+		if not first_pos or not second_pos then
+			--atprint(" object "..self.unique_id.." path end reached!")
+			self.object:setvelocity({x=0,y=0,z=0})
+			return
+		end
+		
+		--checking for environment collisions(a 3x3 cube around the center)
+		if not gp.recently_collided_with_env then
+			local collides=false
+			for x=-1,1 do
+				for y=0,2 do
+					for z=-1,1 do
+						local node=minetest.get_node_or_nil(vector.add(first_pos, {x=x, y=y, z=z}))
+						if (advtrains.train_collides(node)) then
+							collides=true
+						end
+					end
+				end
+			end
+			if collides then
+				if self.collision_count and self.collision_count>10 then
+					--enable collision mercy to get trains stuck in walls out of walls
+					--actually do nothing except limiting the velocity to 1
+					gp.velocity=math.min(gp.velocity, 1)
+					gp.tarvelocity=math.min(gp.tarvelocity, 1)
+				else
+					gp.recently_collided_with_env=true
+					gp.velocity=2*gp.velocity
+					gp.movedir=-gp.movedir
+					gp.tarvelocity=0
+					self.collision_count=(self.collision_count or 0)+1
+				end
+			else
+				self.collision_count=nil
+			end
+		end
+		
+		--FIX: use index of the wagon, not of the train.
+		local velocity=(gp.velocity*gp.movedir)/(gp.path_dist[math.floor(index)] or 1)
+		local acceleration=(gp.last_accel or 0)/(gp.path_dist[math.floor(index)] or 1)
+		local factor=index-math.floor(index)
+		local actual_pos={x=first_pos.x-(first_pos.x-second_pos.x)*factor, y=first_pos.y-(first_pos.y-second_pos.y)*factor, z=first_pos.z-(first_pos.z-second_pos.z)*factor,}
+		local velocityvec={x=(first_pos.x-second_pos.x)*velocity*-1, z=(first_pos.z-second_pos.z)*velocity*-1, y=(first_pos.y-second_pos.y)*velocity*-1}
+		local accelerationvec={x=(first_pos.x-second_pos.x)*acceleration*-1, z=(first_pos.z-second_pos.z)*acceleration*-1, y=(first_pos.y-second_pos.y)*acceleration*-1}
+		
+		--some additional positions to determine orientation
+		local aposfwd=gp.path[math.floor(index+2)]
+		local aposbwd=gp.path[math.floor(index-1)]
+		
+		local yaw
+		if aposfwd and aposbwd then
+			yaw=advtrains.get_wagon_yaw(aposfwd, second_pos, first_pos, aposbwd, factor)+math.pi--TODO remove when cleaning up
+		else
+			yaw=math.atan2((first_pos.x-second_pos.x), (second_pos.z-first_pos.z))
+		end
+		if self.wagon_flipped then
+			yaw=yaw+math.pi
+		end
+		
+		self.updatepct_timer=(self.updatepct_timer or 0)-dtime
+		if not self.old_velocity_vector 
+				or not vector.equals(velocityvec, self.old_velocity_vector)
+				or not self.old_acceleration_vector 
+				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(actual_pos)
+			self.object:setvelocity(velocityvec)
+			self.object:setacceleration(accelerationvec)
+			self.object:setyaw(yaw)
+			self.updatepct_timer=2
+			if self.update_animation then
+				self:update_animation(gp.velocity)
+			end
+		end
+		
+		
+		self.old_velocity_vector=velocityvec
+		self.old_acceleration_vector=accelerationvec
+		self.old_yaw=yaw
+		atprintbm("wagon step", t)
+	end)
+end
+
+function advtrains.get_real_path_index(train, pit)
+	local pos_in_train_left=pit
+	local index=train.index
+	if pos_in_train_left>(index-math.floor(index))*(train.path_dist[math.floor(index)] or 1) then
+		pos_in_train_left=pos_in_train_left - (index-math.floor(index))*(train.path_dist[math.floor(index)] or 1)
+		index=math.floor(index)
+		while pos_in_train_left>(train.path_dist[index-1] or 1) do
+			pos_in_train_left=pos_in_train_left - (train.path_dist[index-1] or 1)
+			index=index-1
+		end
+		index=index-(pos_in_train_left/(train.path_dist[index-1] or 1))
+	else
+		index=index-(pos_in_train_left/(train.path_dist[math.floor(index-1)] or 1))
+	end
+	return index
+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
+		end
+		if clicker:get_player_control().aux1 then
+			--advtrains.dumppath(self:train().path)
+			--minetest.chat_send_all("at index "..(self:train().index or "nil"))
+			--advtrains.invert_train(self.train_id)
+			atprint(dump(self))
+			return
+		end	
+		local pname=clicker:get_player_name()
+		local no=self:get_seatno(pname)
+		if no then
+			if self.seat_groups then
+				local poss={}
+				local sgr=self.seats[no].group
+				for _,access in ipairs(self.seat_groups[sgr].access_to) do
+					if self:check_seat_group_access(pname, access) then
+						poss[#poss+1]={name=self.seat_groups[access].name, key="sgr_"..access}
+					end
+				end
+				if self.has_inventory and self.get_inventory_formspec then
+					poss[#poss+1]={name=attrans("Show Inventory"), key="inv"}
+				end
+				if self.owner==pname then
+					poss[#poss+1]={name=attrans("Wagon properties"), key="prop"}
+				end
+				if not self.seat_groups[sgr].require_doors_open or self:train().door_open~=0 then
+					poss[#poss+1]={name=attrans("Get off"), key="off"}
+				else
+					if clicker:get_player_control().sneak then
+						poss[#poss+1]={name=attrans("Get off (forced)"), key="off"}
+					else
+						poss[#poss+1]={name=attrans("(Doors closed)"), key="dcwarn"}
+					end
+				end
+				if #poss==0 then
+					--can't do anything.
+				elseif #poss==1 then
+					self:seating_from_key_helper(pname, {[poss[1].key]=true}, no)
+				else
+					local form = "size[5,"..1+(#poss).."]"
+					for pos,ent in ipairs(poss) do
+						form = form .. "button_exit[0.5,"..(pos-0.5)..";4,1;"..ent.key..";"..ent.name.."]"
+					end
+					minetest.show_formspec(pname, "advtrains_seating_"..self.unique_id, form)
+				end
+			else
+				self:get_off(no)
+			end
+		else
+			--do not attach if already on a train
+			if advtrains.player_to_train_mapping[pname] then return end
+			if self.seat_groups then
+				if #self.seats==0 then
+					if self.has_inventory and self.get_inventory_formspec then
+						minetest.show_formspec(pname, "advtrains_inv_"..self.unique_id, self:get_inventory_formspec(pname))
+					end
+					return
+				end
+				
+				local doors_open = self:train().door_open~=0 or clicker:get_player_control().sneak
+				for _,sgr in ipairs(self.assign_to_seat_group) do
+					if self:check_seat_group_access(pname, sgr) then
+						for seatid, seatdef in ipairs(self.seats) do
+							if seatdef.group==sgr and not self.seatp[seatid] and (not self.seat_groups[sgr].require_doors_open or doors_open) then
+								self:get_on(clicker, seatid)
+								return
+							end
+						end
+					end
+				end
+				minetest.chat_send_player(pname, attrans("Can't get on: wagon full or doors closed!"))
+				minetest.chat_send_player(pname, attrans("Use Sneak+rightclick to bypass closed doors!"))
+			else
+				self:show_get_on_form(pname)
+			end
+		end
+	end)
+end
+
+function wagon:get_on(clicker, seatno)
+	if not self.seatp then self.seatp={}end
+	if not self.seatpc then self.seatpc={}end--player controls in driver stands
+	
+	if not self.seats[seatno] then return end
+	local oldno=self:get_seatno(clicker:get_player_name())
+	if oldno then
+		atprint("get_on: clearing oldno",seatno)
+		advtrains.player_to_train_mapping[clicker:get_player_name()]=nil
+		advtrains.clear_driver_hud(clicker:get_player_name())
+		self.seatp[oldno]=nil
+	end
+	if self.seatp[seatno] and self.seatp[seatno]~=clicker:get_player_name() then
+		atprint("get_on: throwing off",self.seatp[seatno],"from seat",seatno)
+		self:get_off(seatno)
+	end
+	atprint("get_on: attaching",clicker:get_player_name())
+	self.seatp[seatno] = clicker:get_player_name()
+	self.seatpc[seatno] = clicker:get_player_control_bits()
+	advtrains.player_to_train_mapping[clicker:get_player_name()]=self.train_id
+	clicker:set_attach(self.object, "", self.seats[seatno].attach_offset, {x=0,y=0,z=0})
+	clicker:set_eye_offset(self.seats[seatno].view_offset, self.seats[seatno].view_offset)
+end
+function wagon:get_off_plr(pname)
+	local no=self:get_seatno(pname)
+	if no then
+		self:get_off(no)
+	end
+end
+function wagon:get_seatno(pname)
+	for no, cont in pairs(self.seatp) do
+		if cont==pname then
+			return no
+		end
+	end
+	return nil
+end
+function wagon:get_off(seatno)
+	if not self.seatp[seatno] then return end
+	local pname = self.seatp[seatno]
+	local clicker = minetest.get_player_by_name(pname)
+	advtrains.player_to_train_mapping[pname]=nil
+	advtrains.clear_driver_hud(pname)
+	self.seatp[seatno]=nil
+	self.seatpc[seatno]=nil
+	if clicker then
+		atprint("get_off: detaching",clicker:get_player_name())
+		clicker:set_detach()
+		clicker:set_eye_offset({x=0,y=0,z=0}, {x=0,y=0,z=0})
+		local gp=self:train()
+		--code as in step - automatic get on
+		if self.door_entry and gp.door_open and gp.door_open~=0 and gp.velocity==0 and gp.index and gp.path then
+			local index=advtrains.get_real_path_index(gp, self.pos_in_train)
+			--using the mapping created by the trainlogic globalstep
+			for i, ino in ipairs(self.door_entry) do
+				local aci = index + ino*(self.wagon_flipped and -1 or 1)
+				local ix1=gp.path[math.floor(aci)]
+				local ix2=gp.path[math.floor(aci+1)]
+				-- the two wanted positions are ix1 and ix2 + (2nd-1st rotated by 90deg)
+				-- (x z) rotated by 90deg is (-z x)  (http://stackoverflow.com/a/4780141)
+				-- multiplied by 2 here, to place off on platform, y of add is 1.
+				local add = { x = (ix2.z-ix1.z)*gp.door_open, y = 0, z = (ix1.x-ix2.x)*gp.door_open}
+				local oadd = { x = (ix2.z-ix1.z)*gp.door_open*2, y = 1, z = (ix1.x-ix2.x)*gp.door_open*2}
+				local platpos=vector.round(vector.add(ix1, add))
+				local offpos=vector.round(vector.add(ix1, oadd))
+				atprint("platpos:", platpos, "offpos:", offpos)
+				if minetest.get_item_group(minetest.get_node(platpos).name, "platform")>0 then
+					minetest.after(0.2, function() clicker:setpos(offpos) end)
+					return
+				end
+			end
+		else--if not door_entry, or paths missing, fall back to old method
+			local objpos=advtrains.round_vector_floor_y(self.object:getpos())
+			local yaw=self.object:getyaw()
+			local isx=(yaw < math.pi/4) or (yaw > 3*math.pi/4 and yaw < 5*math.pi/4) or (yaw > 7*math.pi/4)
+			--abuse helper function
+			for _,r in ipairs({-1, 1}) do
+				local p=vector.add({x=isx and r or 0, y=0, z=not isx and r or 0}, objpos)
+				local offp=vector.add({x=isx and r*2 or 0, y=1, z=not isx and r*2 or 0}, objpos)
+				if minetest.get_item_group(minetest.get_node(p).name, "platform")>0 then
+					minetest.after(0.2, function() clicker:setpos(offp) end)
+					return
+				end
+			end
+		end
+	end
+end
+function wagon:show_get_on_form(pname)
+	if not self.initialized then return end
+	if #self.seats==0 then
+		if self.has_inventory and self.get_inventory_formspec then
+			minetest.show_formspec(pname, "advtrains_inv_"..self.unique_id, self:get_inventory_formspec(pname))
+		end
+		return
+	end
+	local form, comma="size[5,8]label[0.5,0.5;"..attrans("Select seat:").."]textlist[0.5,1;4,6;seat;", ""
+	for seatno, seattbl in ipairs(self.seats) do
+		local addtext, colorcode="", ""
+		if self.seatp and self.seatp[seatno] then
+			colorcode="#FF0000"
+			addtext=" ("..self.seatp[seatno]..")"
+		end
+		form=form..comma..colorcode..seattbl.name..addtext
+		comma=","
+	end
+	form=form..";0,false]"
+	if self.has_inventory and self.get_inventory_formspec then
+		form=form.."button_exit[1,7;3,1;inv;"..attrans("Show Inventory").."]"
+	end
+	minetest.show_formspec(pname, "advtrains_geton_"..self.unique_id, form)
+end
+function wagon:show_wagon_properties(pname)
+	local numsgr=0
+	if self.seat_groups then
+		numsgr=#self.seat_groups
+	end
+	if not self.seat_access then
+		self.seat_access={}
+	end
+	--[[
+	fields: seat access: empty: everyone
+	checkbox: lock couples
+	button: save
+	]]
+	local form="size[5,"..(numsgr*1.5+7).."]"
+	local at=0
+	if self.seat_groups then
+		for sgr,sgrdef in pairs(self.seat_groups) do
+			local text = attrans("Access to @1",sgrdef.name)
+			form=form.."field[0.5,"..(0.5+at*1.5)..";4,1;sgr_"..sgr..";"..text..";"..(self.seat_access[sgr] or "").."]"
+			at=at+1
+		end
+	end
+	form=form.."checkbox[0,"..(at*1.5)..";lock_couples;"..attrans("Lock couples")..";"..(self.lock_couples and "true" or "false").."]"
+	if self:train() then --just in case
+		form=form.."field[0.5,"..(1.5+at*1.5)..";4,1;text_outside;"..attrans("Text displayed outside on train")..";"..(self:train().text_outside or "").."]"
+		form=form.."field[0.5,"..(2.5+at*1.5)..";4,1;text_inside;"..attrans("Text displayed inside train")..";"..(self:train().text_inside or "").."]"
+	end
+	form=form.."button_exit[0.5,"..(3+at*1.5)..";4,1;save;"..attrans("Save wagon properties").."]"
+	minetest.show_formspec(pname, "advtrains_prop_"..self.unique_id, form)
+end
+minetest.register_on_player_receive_fields(function(player, formname, fields)
+	return advtrains.pcall(function()
+		local uid=string.match(formname, "^advtrains_geton_(.+)$")
+		if uid then
+			for _,wagon in pairs(minetest.luaentities) do
+				if wagon.is_wagon and wagon.initialized and wagon.unique_id==uid then
+					if fields.inv then
+						if wagon.has_inventory and wagon.get_inventory_formspec then
+							minetest.show_formspec(player:get_player_name(), "advtrains_inv_"..uid, wagon:get_inventory_formspec(player:get_player_name()))
+						end
+					elseif fields.seat then
+						local val=minetest.explode_textlist_event(fields.seat)
+						if val and val.type~="INV" and not wagon.seatp[player:get_player_name()] then
+						--get on
+							wagon:get_on(player, val.index)
+							--will work with the new close_formspec functionality. close exactly this formspec.
+							minetest.show_formspec(player:get_player_name(), formname, "")
+						end
+					end
+				end
+			end
+		end
+		uid=string.match(formname, "^advtrains_seating_(.+)$")
+		if uid then
+			for _,wagon in pairs(minetest.luaentities) do
+				if wagon.is_wagon and wagon.initialized and wagon.unique_id==uid then
+					local pname=player:get_player_name()
+					local no=wagon:get_seatno(pname)
+					if no then
+						if wagon.seat_groups then
+							wagon:seating_from_key_helper(pname, fields, no)
+						end
+					end
+				end
+			end
+		end
+		uid=string.match(formname, "^advtrains_prop_(.+)$")
+		if uid then
+			for _,wagon in pairs(minetest.luaentities) do
+				if wagon.is_wagon and wagon.initialized and wagon.unique_id==uid then
+					local pname=player:get_player_name()
+					if pname~=wagon.owner then
+						return true
+					end
+					if fields.save or not fields.quit then
+						for sgr,sgrdef in pairs(wagon.seat_groups) do
+							if fields["sgr_"..sgr] then
+								local fcont = fields["sgr_"..sgr]
+								wagon.seat_access[sgr] = fcont~="" and fcont or nil
+							end
+						end
+						if fields.lock_couples then
+							wagon.lock_couples = fields.lock_couples == "true"
+						end
+						if fields.text_outside then
+							if fields.text_outside~="" then
+								wagon:train().text_outside=fields.text_outside
+							else
+								wagon:train().text_outside=nil
+							end
+						end
+						if fields.text_inside then
+							if fields.text_inside~="" then
+								wagon:train().text_inside=fields.text_inside
+							else
+								wagon:train().text_inside=nil
+							end
+						end
+						
+					end
+				end
+			end
+		end
+	end)
+end)
+function wagon:seating_from_key_helper(pname, fields, no)
+	local sgr=self.seats[no].group
+	for _,access in ipairs(self.seat_groups[sgr].access_to) do
+		if fields["sgr_"..access] and self:check_seat_group_access(pname, access) then
+			for seatid, seatdef in ipairs(self.seats) do
+				if seatdef.group==access and not self.seatp[seatid] then
+					self:get_on(minetest.get_player_by_name(pname), seatid)
+					return
+				end
+			end
+		end
+	end
+	if fields.inv and self.has_inventory and self.get_inventory_formspec then
+		minetest.show_formspec(player:get_player_name(), "advtrains_inv_"..self.unique_id, wagon:get_inventory_formspec(player:get_player_name()))
+	end
+	if fields.prop and self.owner==pname then
+		self:show_wagon_properties(pname)
+	end
+	if fields.dcwarn then
+		minetest.chat_send_player(pname, attrans("Doors are closed! Use Sneak+rightclick to ignore the closed doors and get off!"))
+	end
+	if fields.off then
+		self:get_off(no)
+	end
+end
+function wagon:check_seat_group_access(pname, sgr)
+	if not self.seat_access then
+		return true
+	end
+	local sae=self.seat_access[sgr]
+	if not sae or sae=="" then
+		return true
+	end
+	for name in string.gmatch(sae, "%S+") do
+		if name==pname then
+			return true
+		end
+	end
+	return false
+end
+function wagon:reattach_all()
+	if not self.seatp then self.seatp={} end
+	for seatno, pname in pairs(self.seatp) do
+		local p=minetest.get_player_by_name(pname)
+		if p then
+			self:get_on(p ,seatno)
+		end
+	end
+end
+
+function advtrains.register_wagon(sysname, prototype, desc, inv_img)
+	setmetatable(prototype, {__index=wagon})
+	minetest.register_entity(":advtrains:"..sysname,prototype)
+	
+	minetest.register_craftitem(":advtrains:"..sysname, {
+		description = desc,
+		inventory_image = inv_img,
+		wield_image = inv_img,
+		stack_max = 1,
+		
+		on_place = function(itemstack, placer, pointed_thing)
+			return advtrains.pcall(function()
+				if not pointed_thing.type == "node" then
+					return
+				end
+				
+
+				local node=minetest.get_node_or_nil(pointed_thing.under)
+				if not node then atprint("[advtrains]Ignore at placer position") return itemstack end
+				local nodename=node.name
+				if(not advtrains.is_track_and_drives_on(nodename, prototype.drives_on)) then
+					atprint("no track here, not placing.")
+					return itemstack
+				end
+				if not minetest.check_player_privs(placer, {train_place = true }) and minetest.is_protected(pointed_thing.under, placer:get_player_name()) then
+					minetest.record_protection_violation(pointed_thing.under, placer:get_player_name())
+					return
+				end
+				local conn1=advtrains.get_track_connections(node.name, node.param2)
+				local id=advtrains.create_new_train_at(pointed_thing.under, advtrains.dirCoordSet(pointed_thing.under, conn1))
+				
+				local ob=minetest.add_entity(pointed_thing.under, "advtrains:"..sysname)
+				if not ob then
+					atprint("couldn't add_entity, aborting")
+				end
+				local le=ob:get_luaentity()
+				
+				le.owner=placer:get_player_name()
+				
+				local wagon_uid=le:init_new_instance(id, {})
+				
+				advtrains.add_wagon_to_train(le, id)
+				if not minetest.settings:get_bool("creative_mode") then
+					itemstack:take_item()
+				end
+				return itemstack
+				
+			end)
+		end,
+	})
+end
+
+--[[
+	wagons can define update_animation(self, velocity) if they have a speed-dependent animation
+	this function will be called when the velocity vector changes or every 2 seconds.
+]]
+
+
-- 
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