aboutsummaryrefslogtreecommitdiff
path: root/src/script/cpp_api/s_item.cpp
blob: d9a545b4ff9ccea1c68a0a5e07060c140185bcf0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "cpp_api/s_item.h"
#include "cpp_api/s_internal.h"
#include "common/c_converter.h"
#include "common/c_content.h"
#include "lua_api/l_item.h"
#include "lua_api/l_inventory.h"
#include "server.h"
#include "log.h"
#include "util/pointedthing.h"
#include "inventory.h"
#include "inventorymanager.h"

bool ScriptApiItem::item_OnDrop(ItemStack &item,
		ServerActiveObject *dropper, v3f pos)
{
	SCRIPTAPI_PRECHECKHEADER

	int error_handler = PUSH_ERROR_HANDLER(L);

	// Push callback function on stack
	if (!getItemCallback(item.name.c_str(), "on_drop"))
		return false;

	// Call function
	LuaItemStack::create(L, item);
	objectrefGetOrCreate(L, dropper);
	pushFloatPos(L, pos);
	PCALL_RES(lua_pcall(L, 3, 1, error_handler));
	if (!lua_isnil(L, -1)) {
		try {
			item = read_item(L,-1, getServer());
		} catch (LuaError &e) {
			throw LuaError(std::string(e.what()) + ". item=" + item.name);
		}
	}
	lua_pop(L, 2);  // Pop item and error handler
	return true;
}

bool ScriptApiItem::item_OnPlace(ItemStack &item,
		ServerActiveObject *placer, const PointedThing &pointed)
{
	SCRIPTAPI_PRECHECKHEADER

	int error_handler = PUSH_ERROR_HANDLER(L);

	// Push callback function on stack
	if (!getItemCallback(item.name.c_str(), "on_place"))
		return false;

	// Call function
	LuaItemStack::create(L, item);
	objectrefGetOrCreate(L, placer);
	pushPointedThing(pointed);
	PCALL_RES(lua_pcall(L, 3, 1, error_handler));
	if (!lua_isnil(L, -1)) {
		try {
			item = read_item(L,-1, getServer());
		} catch (LuaError &e) {
			throw LuaError(std::string(e.what()) + ". item=" + item.name);
		}
	}
	lua_pop(L, 2);  // Pop item and error handler
	return true;
}

bool ScriptApiItem::item_OnUse(ItemStack &item,
		ServerActiveObject *user, const PointedThing &pointed)
{
	SCRIPTAPI_PRECHECKHEADER

	int error_handler = PUSH_ERROR_HANDLER(L);

	// Push callback function on stack
	if (!getItemCallback(item.name.c_str(), "on_use"))
		return false;

	// Call function
	LuaItemStack::create(L, item);
	objectrefGetOrCreate(L, user);
	pushPointedThing(pointed);
	PCALL_RES(lua_pcall(L, 3, 1, error_handler));
	if(!lua_isnil(L, -1)) {
		try {
			item = read_item(L,-1, getServer());
		} catch (LuaError &e) {
			throw LuaError(std::string(e.what()) + ". item=" + item.name);
		}
	}
	lua_pop(L, 2);  // Pop item and error handler
	return true;
}

bool ScriptApiItem::item_OnCraft(ItemStack &item, ServerActiveObject *user,
		const InventoryList *old_craft_grid, const InventoryLocation &craft_inv)
{
	SCRIPTAPI_PRECHECKHEADER

	int error_handler = PUSH_ERROR_HANDLER(L);

	lua_getglobal(L, "core");
	lua_getfield(L, -1, "on_craft");
	LuaItemStack::create(L, item);
	objectrefGetOrCreate(L, user);

	// Push inventory list
	std::vector<ItemStack> items;
	for (u32 i = 0; i < old_craft_grid->getSize(); i++) {
		items.push_back(old_craft_grid->getItem(i));
	}
	push_items(L, items);

	InvRef::create(L, craft_inv);
	PCALL_RES(lua_pcall(L, 4, 1, error_handler));
	if (!lua_isnil(L, -1)) {
		try {
			item = read_item(L,-1, getServer());
		} catch (LuaError &e) {
			throw LuaError(std::string(e.what()) + ". item=" + item.name);
		}
	}
	lua_pop(L, 2);  // Pop item and error handler
	return true;
}

bool ScriptApiItem::item_CraftPredict(ItemStack &item, ServerActiveObject *user,
		const InventoryList *old_craft_grid, const InventoryLocation &craft_inv)
{
	SCRIPTAPI_PRECHECKHEADER

	int error_handler = PUSH_ERROR_HANDLER(L);

	lua_getglobal(L, "core");
	lua_getfield(L, -1, "craft_predict");
	LuaItemStack::create(L, item);
	objectrefGetOrCreate(L, user);

	//Push inventory list
	std::vector<ItemStack> items;
	for (u32 i = 0; i < old_craft_grid->getSize(); i++) {
		items.push_back(old_craft_grid->getItem(i));
	}
	push_items(L, items);

	InvRef::create(L, craft_inv);
	PCALL_RES(lua_pcall(L, 4, 1, error_handler));
	if (!lua_isnil(L, -1)) {
		try {
			item = read_item(L,-1, getServer());
		} catch (LuaError &e) {
			throw LuaError(std::string(e.what()) + ". item=" + item.name);
		}
	}
	lua_pop(L, 2);  // Pop item and error handler
	return true;
}

// Retrieves core.registered_items[name][callbackname]
// If that is nil or on error, return false and stack is unchanged
// If that is a function, returns true and pushes the
// function onto the stack
// If core.registered_items[name] doesn't exist, core.nodedef_default
// is tried instead so unknown items can still be manipulated to some degree
bool ScriptApiItem::getItemCallback(const char *name, const char *callbackname)
{
	lua_State* L = getStack();

	lua_getglobal(L, "core");
	lua_getfield(L, -1, "registered_items");
	lua_remove(L, -2); // Remove core
	luaL_checktype(L, -1, LUA_TTABLE);
	lua_getfield(L, -1, name);
	lua_remove(L, -2); // Remove registered_items
	// Should be a table
	if(lua_type(L, -1) != LUA_TTABLE)
	{
		// Report error and clean up
		errorstream << "Item \"" << name << "\" not defined" << std::endl;
		lua_pop(L, 1);

		// Try core.nodedef_default instead
		lua_getglobal(L, "core");
		lua_getfield(L, -1, "nodedef_default");
		lua_remove(L, -2);
		luaL_checktype(L, -1, LUA_TTABLE);
	}

	setOriginFromTable(-1);

	lua_getfield(L, -1, callbackname);
	lua_remove(L, -2); // Remove item def
	// Should be a function or nil
	if (lua_type(L, -1) == LUA_TFUNCTION) {
		return true;
	} else if (!lua_isnil(L, -1)) {
		errorstream << "Item \"" << name << "\" callback \""
			<< callbackname << "\" is not a function" << std::endl;
	}
	lua_pop(L, 1);
	return false;
}

void ScriptApiItem::pushPointedThing(const PointedThing& pointed)
{
	lua_State* L = getStack();

	lua_newtable(L);
	if(pointed.type == POINTEDTHING_NODE)
	{
		lua_pushstring(L, "node");
		lua_setfield(L, -2, "type");
		push_v3s16(L, pointed.node_undersurface);
		lua_setfield(L, -2, "under");
		push_v3s16(L, pointed.node_abovesurface);
		lua_setfield(L, -2, "above");
	}
	else if(pointed.type == POINTEDTHING_OBJECT)
	{
		lua_pushstring(L, "object");
		lua_setfield(L, -2, "type");
		objectrefGet(L, pointed.object_id);
		lua_setfield(L, -2, "ref");
	}
	else
	{
		lua_pushstring(L, "nothing");
		lua_setfield(L, -2, "type");
	}
}

2' href='#n1212'>1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447
-- wagon.lua
-- Holds all logic related to wagons
-- From now on, wagons are, just like trains, just entries in a table
-- All data that is static is stored in the entity prototype (self).
--   A copy of the entity prototype is always available inside wagon_prototypes
-- All dynamic data is stored in the (new) wagons table
-- An entity is ONLY spawned by update_trainpart_properties when it finds it useful.
-- Only data that are only important to the entity itself are stored in the luaentity

-- TP delay when getting off wagon
local GETOFF_TP_DELAY = 0.5

advtrains.wagons = {}
advtrains.wagon_prototypes = {}
advtrains.wagon_objects = {}

local unload_wgn_range = advtrains.wagon_load_range + 32
function advtrains.wagon_outside_range(pos) -- returns true if the object is outside of unload_wgn_range of any player
	return not advtrains.position_in_range(pos, unload_wgn_range)
end

local setting_show_ids = minetest.settings:get_bool("advtrains_show_ids")

--
function advtrains.create_wagon(wtype, owner)
	local new_id=advtrains.random_id()
	while advtrains.wagons[new_id] do new_id=advtrains.random_id() end
	local wgn = {}
	wgn.type = wtype
	wgn.seatp = {}
	wgn.owner = owner
	wgn.id = new_id
	---wgn.train_id = train_id   --- will get this via update_trainpart_properties
	advtrains.wagons[new_id] = wgn
	--atdebug("Created new wagon:",wgn)
	return new_id
end

local function make_inv_name(uid)
	return "detached:advtrains_wgn_"..uid
end


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=1, y=1},
	textures = {"black.png"},
	is_wagon=true,
	wagon_span=1,--how many index units of space does this wagon consume
	wagon_width=3, -- Wagon width in meters
	has_inventory=false,
	static_save=false,
}


function wagon:train()
	local data = advtrains.wagons[self.id]
	return advtrains.trains[data.train_id]
end


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})
end

local function invcallback(id, pname, rtallow, rtfail)
	local data = advtrains.wagons[id]
	if data and advtrains.check_driving_couple_protection(pname, data.owner, data.whitelist) then
		return rtallow
	end
	return rtfail
end

function wagon:set_id(wid)
	self.id = wid
	self.initialized = true
	
	local data = advtrains.wagons[self.id]
	advtrains.wagon_objects[self.id] = self.object
	
	--atdebug("Created wagon entity:",self.name," w_id",wid," t_id",data.train_id)
	
	if self.has_inventory then
		--to be used later
		local inv=minetest.get_inventory({type="detached", name="advtrains_wgn_"..self.id})
		-- create inventory, if not yet created
		if not inv then	
			inv=minetest.create_detached_inventory("advtrains_wgn_"..self.id, {
				allow_move = function(inv, from_list, from_index, to_list, to_index, count, player)
					return invcallback(wid, player:get_player_name(), count, 0)
				end,
				allow_put = function(inv, listname, index, stack, player)
					return invcallback(wid, player:get_player_name(), stack:get_count(), 0)
				end,
				allow_take = function(inv, listname, index, stack, player)
					return invcallback(wid, player:get_player_name(), stack:get_count(), 0)
				end
			})
			if data.ser_inv then
				advtrains.deserialize_inventory(data.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
	end
	self.door_anim_timer=0
	self.door_state=0
	
	minetest.after(0.2, function() self:reattach_all() end)
	
	
	
	if self.set_textures then
		self:set_textures(data)
	end
	
	if self.custom_on_activate then
		self:custom_on_activate()
	end
end

function wagon:get_staticdata()
	return "STATIC"
end

function wagon:ensure_init()
			-- Note: A wagon entity won't exist when there's no train, because the train is
			-- the thing that actually creates the entity
			-- 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 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
		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})
	end
	return false
end

function wagon:train()
	local data = advtrains.wagons[self.id]
	return advtrains.trains[data.train_id]
end

-- Remove the wagon
function wagon:on_punch(puncher, time_from_last_punch, tool_capabilities, direction)
		if not self:ensure_init() then return end
		
		local data = advtrains.wagons[self.id]
	
		if not puncher or not puncher:is_player() then
			return
		end
		if data.owner and puncher:get_player_name()~=data.owner and (not minetest.check_player_privs(puncher, {train_admin = true })) then
		   minetest.chat_send_player(puncher:get_player_name(), attrans("This wagon is owned by @1, you can't destroy it.", data.owner));
		   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
		local itemstack = puncher:get_wielded_item()
		-- WARNING: This part of the API is guaranteed to change! DO NOT USE!
		if self.set_livery and itemstack:get_name() == "bike:painter" then
			self:set_livery(puncher, itemstack, data)
			return
		end
		-- check whether wagon has an inventory. Is is empty?
		if self.has_inventory then
			local inv=minetest.get_inventory({type="detached", name="advtrains_wgn_"..self.id})
			if not inv then -- inventory is not initialized when wagon was never loaded - should never happen
				atwarn("Destroying wagon with inventory, but inventory is not found? Shouldn't happen!")
				return
			end
			for listname, _ in pairs(inv:get_lists()) do
				if not inv:is_empty(listname) then
					minetest.chat_send_player(puncher:get_player_name(), attrans("The wagon's inventory is not empty!"));
					return
				end
			end
		end
		
		if #(self:train().trainparts)>1 then
		   minetest.chat_send_player(puncher:get_player_name(), attrans("Wagon needs to be decoupled from other wagons in order to destroy it."));
		   return
		end

		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
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
	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)
		end
		
		for seat,_ in pairs(data.seatp) do
			self:get_off(seat)
		end
		
		if data.train_id and self:train() then
			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
		end
	end
	--atdebug("[wagon ", self.id, "]: destroying")
	
	self.object:remove()
	return true
end

function wagon:is_driver_stand(seat)
	if self.seat_groups then
		return (seat.driving_ctrl_access or self.seat_groups[seat.group].driving_ctrl_access)
	else
		return seat.driving_ctrl_access
	end
	
end

function wagon:on_step(dtime)
		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 data = advtrains.wagons[self.id]
		
		if not pos then
			--atdebug("["..self.id.."][fatal] missing position (object:getpos() returned nil)")
			return
		end
		
		if not data.seatp then
			data.seatp={}
		end
		if not self.seatpc then
			self.seatpc={}
		end
		
		local train=self:train()
		
		local is_in_loaded_area = advtrains.is_node_loaded(pos)

		--custom on_step function
		if self.custom_on_step then
			self:custom_on_step(dtime, data, train)
		end

		--driver control
		for seatno, seat in ipairs(self.seats) do
			local pname=data.seatp[seatno]
			local driver=pname and minetest.get_player_by_name(pname)
			local has_driverstand = pname and advtrains.check_driving_couple_protection(pname, data.owner, data.whitelist)
			has_driverstand = has_driverstand and self:is_driver_stand(seat)
			if has_driverstand and driver then
				advtrains.update_driver_hud(driver:get_player_name(), self:train(), data.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(), data.wagon_flipped)
					--bordcom
					if pc.sneak and pc.jump then
						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
						self.horn_handle = minetest.sound_play(self.horn_sound, {
							object = self.object,
							gain = 1.0, -- default
							max_hear_distance = 128, -- default, uses an euclidean metric
							loop = true,
						})
					elseif not pc.aux1 and self.horn_handle then
						minetest.sound_stop(self.horn_handle)
						self.horn_handle = nil
					end
				else
					-- If on a passenger seat and doors are open, get off when W or D pressed.
					local pass = data.seatp[seatno] and minetest.get_player_by_name(data.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=train.text_outside or ""
		if setting_show_ids then
			outside = outside .. "\nT:" .. data.train_id .. " W:" .. self.id .. " O:" .. data.owner
		end
		
		
		--show off-track information in outside text instead of notifying the whole server about this
		if train.off_track then
			outside = outside .."\n!!! Train off track !!!"
		end
		
		if self.infotext_cache~=outside  then
			self.object:set_properties({infotext=outside})
			self.infotext_cache=outside
		end
		
		local fct=data.wagon_flipped and -1 or 1
		
		--door animation
		if self.doors then
			if (self.door_anim_timer or 0)<=0 then
				local dstate = (train.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
						if self.doors.open.sound then minetest.sound_play(self.doors.open.sound, {object = self.object}) end
						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
						if self.doors.close.sound then minetest.sound_play(self.doors.close.sound, {object = self.object}) end
						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
		
		--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})
			return
		end
		if not data.pos_in_train then
			return
		end
		
		-- Calculate new position, yaw and direction vector
		local index = advtrains.path_get_index_by_offset(train, train.index, -data.pos_in_train)
		local pos, yaw, npos, npos2 = advtrains.path_get_interpolated(train, index)
		local vdir = vector.normalize(vector.subtract(npos2, npos))
		
		--automatic get_on
		--needs to know index and path
		if self.door_entry and train.door_open and train.door_open~=0 and train.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 = advtrains.path_get_index_by_offset(train, index, ino*fct)
				local ix1, ix2 = advtrains.path_get_adjacent(train, aci)
				-- 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)*train.door_open, y = 0, z = (ix1.x-ix2.x)*train.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
		
		--checking for environment collisions(a 3x3 cube around the center)
		if 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
			for x=-exh,exh do
				for y=0,exv do
					for z=-exh,exh do
						local node=minetest.get_node_or_nil(vector.add(npos, {x=x, y=y, z=z}))
						if (advtrains.train_collides(node)) then
							collides=true
						end
					end
				end
			end
			if collides then
				-- screw collision mercy
				train.recently_collided_with_env=true
				train.velocity=0
				advtrains.atc.train_reset_command(train)
			end
		end
		
		--DisCouple
		-- 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
					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")
					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
					end
				end
			else
				if self.discouple and self.discouple.object:getyaw() then
					self.discouple.object:remove()
					atprint(self.id," removing discouple")
				end
			end
		end
		
		--FIX: use index of the wagon, not of the train.
		local velocity = train.velocity
		local acceleration = (train.acceleration or 0)
		local velocityvec = vector.multiply(vdir, velocity)
		local accelerationvec = vector.multiply(vdir, acceleration)
		
		if data.wagon_flipped then
			yaw=yaw+math.pi
		end
		
		-- this timer runs off every 2 seconds.
		self.updatepct_timer=(self.updatepct_timer or 0)-dtime
		local updatepct_timer_elapsed = self.updatepct_timer<=0
		
		if updatepct_timer_elapsed then
			--restart timer
			self.updatepct_timer=2
			-- perform checks that are not frequently needed
			
			-- unload entity if out of range (because relevant pr won't be merged in engine)
			-- This is a WORKAROUND!
			local players_in = false
			for sno,pname in pairs(data.seatp) do
				if minetest.get_player_by_name(pname) then
					-- Fix: If the RTT is too high, a wagon might be recognized out of range even if a player sits in it
					-- (client updates position not fast enough)
					players_in = true
					break
				end
			end
			if not players_in then
				if advtrains.wagon_outside_range(pos) then
					--atdebug("wagon",self.id,"unloading (too far away)")
                    -- Workaround until minetest engine deletes attached sounds
                    if self.sound_loop_handle then
                        minetest.sound_stop(self.sound_loop_handle)
                    end
					self.object:remove()
				end
			end
		end
		
		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 updatepct_timer_elapsed then--only send update packet if something changed
			
			self.object:setpos(pos)
			self.object:setvelocity(velocityvec)
			self.object:setacceleration(accelerationvec)
			
			if #self.seats > 0 and self.old_yaw ~= yaw then
				if not self.player_yaw then
					self.player_yaw = {}
				end
				if not self.old_yaw then
					self.old_yaw=yaw
				end
				for _,name in pairs(data.seatp) do
					local p = minetest.get_player_by_name(name)
					if p then
						if not self.turning then
							-- save player looking direction offset
							self.player_yaw[name] = p:get_look_horizontal()-self.old_yaw
						end
						-- set player looking direction using calculated offset
						p:set_look_horizontal((self.player_yaw[name] or 0)+yaw)
					end
				end
				self.turning = true							 
			elseif self.old_yaw == yaw then
				-- train is no longer turning
				self.turning = false
			end
			
			if self.object.set_rotation then
                local pitch = math.atan2(vdir.y, math.hypot(vdir.x, vdir.z))
                if data.wagon_flipped then
                    pitch = -pitch
                end
                self.object:set_rotation({x=pitch, y=yaw, z=0})
            else
                self.object:setyaw(yaw)
            end
			
			if self.update_animation then
				self:update_animation(train.velocity, self.old_velocity)
			end
			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 not updatepct_timer_elapsed and self.discouple then
				self.discouple.object:remove()
			end
		end
		
		
		self.old_velocity_vector=velocityvec
		self.old_velocity = train.velocity
		self.old_acceleration_vector=accelerationvec
		self.old_yaw=yaw
		atprintbm("wagon step", t)
end

function wagon:on_rightclick(clicker)
		if not self:ensure_init() then return end
		if not clicker or not clicker:is_player() then
			return
		end
		
		local data = advtrains.wagons[self.id]
		
		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 and advtrains.check_driving_couple_protection(pname, data.owner, data.whitelist) then
					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("Onboard Computer"), key="bordcom"}
				end
				if data.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.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 and advtrains.check_driving_couple_protection(pname, data.owner, data.whitelist) then
						minetest.show_formspec(pname, "advtrains_inv_"..self.id, self:get_inventory_formspec(pname, make_inv_name(self.id)))
					end
					return
				end
				
				local doors_open = self:train().door_open~=0 or clicker:get_player_control().sneak
				local allow, rsn=false, "Wagon has no seats!"
				for _,sgr in ipairs(self.assign_to_seat_group) do
					allow, rsn = self:check_seat_group_access(pname, sgr)
					if allow then
						for seatid, seatdef in ipairs(self.seats) do
							if seatdef.group==sgr then
								if (not self.seat_groups[sgr].require_doors_open or doors_open) then
									if not data.seatp[seatid] then
										self:get_on(clicker, seatid)
										return
									else
										rsn="Wagon is full."
									end
								else
									rsn="Doors are closed! (try holding sneak key!)"
								end
							end
						end
					end
				end
				minetest.chat_send_player(pname, attrans("Can't get on: "..rsn))
			else
				self:show_get_on_form(pname)
			end
		end
end

function wagon:get_on(clicker, seatno)
	
	local data = advtrains.wagons[self.id]
		
	if not data.seatp then data.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())
		data.seatp[oldno]=nil
	end
	if data.seatp[seatno] and data.seatp[seatno]~=clicker:get_player_name() then
		atprint("get_on: throwing off",data.seatp[seatno],"from seat",seatno)
		self:get_off(seatno)
	end
	atprint("get_on: attaching",clicker:get_player_name())
	data.seatp[seatno] = clicker:get_player_name()
	self.seatpc[seatno] = clicker:get_player_control_bits()
	advtrains.player_to_train_mapping[clicker:get_player_name()]=data.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)
	
	local data = advtrains.wagons[self.id]
	
	for no, cont in pairs(data.seatp) do
		if cont==pname then
			return no
		end
	end
	return nil
end
function wagon:get_off(seatno)
	
	local data = advtrains.wagons[self.id]
	
	if not data.seatp[seatno] then return end
	local pname = data.seatp[seatno]
	local clicker = minetest.get_player_by_name(pname)
	advtrains.player_to_train_mapping[pname]=nil
	advtrains.clear_driver_hud(pname)
	data.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 train=self:train()
		--code as in step - automatic get on
		if self.door_entry and train.door_open and train.door_open~=0 and train.velocity==0 and train.index and train.path then
			local index = advtrains.path_get_index_by_offset(train, train.index, -data.pos_in_train)
			for i, ino in ipairs(self.door_entry) do
				--atdebug("using door-based",i,ino)
				local fct=data.wagon_flipped and -1 or 1
				local aci = advtrains.path_get_index_by_offset(train, index, ino*fct)
				local ix1, ix2 = advtrains.path_get_adjacent(train, aci)
				local d = train.door_open
				if self.wagon_width then
					d = d * math.floor(self.wagon_width/2)
				end
				-- 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)*d, y = 0, z = (ix1.x-ix2.x)*d }
				local oadd = { x = (ix2.z-ix1.z)*(d+train.door_open), y = 1, z = (ix1.x-ix2.x)*(d+train.door_open)}
				local platpos=vector.round(vector.add(ix1, add))
				local offpos=vector.round(vector.add(ix1, oadd))
				
				--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)
					--atdebug("tp",offpos)
					return
				end
				--atdebug("nope")
			end
		end
		--if not door_entry, or paths missing, fall back to old method
		--atdebug("using fallback")
		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)
		local offp
		--abuse helper function
		for _,r in ipairs({-1, 1}) do
			--atdebug("offset",r)
			local p=vector.add({x=isx and r or 0, y=0, z=not isx and r or 0}, objpos)
			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)
				--atdebug("tp",offp)
				return
			end
		end
		--atdebug("nope")
		
	end
end
function wagon:show_get_on_form(pname)
	if not self.initialized then return end
	
	local data = advtrains.wagons[self.id]
	if #self.seats==0 then
		if self.has_inventory and self.get_inventory_formspec and advtrains.check_driving_couple_protection(pname, data.owner, data.whitelist) then
			minetest.show_formspec(pname, "advtrains_inv_"..self.id, self:get_inventory_formspec(pname, make_inv_name(self.id)))
		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 data.seatp and data.seatp[seatno] then
			colorcode="#FF0000"
			addtext=" ("..data.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.id, form)
end
function wagon:show_wagon_properties(pname)
	--[[
	fields: 
	field: driving/couple whitelist
	button: save
	]]
	local data = advtrains.wagons[self.id]
	local form="size[5,5]"
	form = form .. "field[0.5,1;4.5,1;whitelist;Allow these players to access your wagon:;"..minetest.formspec_escape(data.whitelist or "").."]"
	form = form .. "field[0.5,2;4.5,1;roadnumber;Wagon road number:;"..minetest.formspec_escape(data.roadnumber or "").."]"
	local fc = ""
	if data.fc then
		fc = table.concat(data.fc, "!")
	end
	form = form .. "field[0.5,3;4.5,1;fc;Freight Code:;"..fc.."]"
	if data.fc then
		if not data.fcind then data.fcind = 1 end
		if data.fcind > 1 then
			form=form.."button[0.5,3.5;1,1;fcp;prev FC]"
		end
		form=form.."label[1.5,3.5;Current FC:]"

		local cur = data.fc[data.fcind] or ""
		form=form.."label[1.5,3.75;"..minetest.formspec_escape(cur).."]"