aboutsummaryrefslogtreecommitdiff
path: root/src/serialization.cpp
blob: 36ddb467cbbc5a7fa82fac1f51fff8e6acba225a (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
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
/*
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 "serialization.h"

#include "util/serialize.h"

#include "zlib.h"

/* report a zlib or i/o error */
void zerr(int ret)
{
    dstream<<"zerr: ";
    switch (ret) {
    case Z_ERRNO:
        if (ferror(stdin))
            dstream<<"error reading stdin"<<std::endl;
        if (ferror(stdout))
            dstream<<"error writing stdout"<<std::endl;
        break;
    case Z_STREAM_ERROR:
        dstream<<"invalid compression level"<<std::endl;
        break;
    case Z_DATA_ERROR:
        dstream<<"invalid or incomplete deflate data"<<std::endl;
        break;
    case Z_MEM_ERROR:
        dstream<<"out of memory"<<std::endl;
        break;
    case Z_VERSION_ERROR:
        dstream<<"zlib version mismatch!"<<std::endl;
		break;
	default:
		dstream<<"return value = "<<ret<<std::endl;
    }
}

void compressZlib(const u8 *data, size_t data_size, std::ostream &os, int level)
{
	z_stream z;
	const s32 bufsize = 16384;
	char output_buffer[bufsize];
	int status = 0;
	int ret;

	z.zalloc = Z_NULL;
	z.zfree = Z_NULL;
	z.opaque = Z_NULL;

	ret = deflateInit(&z, level);
	if(ret != Z_OK)
		throw SerializationError("compressZlib: deflateInit failed");

	// Point zlib to our input buffer
	z.next_in = (Bytef*)&data[0];
	z.avail_in = data_size;
	// And get all output
	for(;;)
	{
		z.next_out = (Bytef*)output_buffer;
		z.avail_out = bufsize;

		status = deflate(&z, Z_FINISH);
		if(status == Z_NEED_DICT || status == Z_DATA_ERROR
				|| status == Z_MEM_ERROR)
		{
			zerr(status);
			throw SerializationError("compressZlib: deflate failed");
		}
		int count = bufsize - z.avail_out;
		if(count)
			os.write(output_buffer, count);
		// This determines zlib has given all output
		if(status == Z_STREAM_END)
			break;
	}

	deflateEnd(&z);
}

void compressZlib(const std::string &data, std::ostream &os, int level)
{
	compressZlib((u8*)data.c_str(), data.size(), os, level);
}

void decompressZlib(std::istream &is, std::ostream &os)
{
	z_stream z;
	const s32 bufsize = 16384;
	char input_buffer[bufsize];
	char output_buffer[bufsize];
	int status = 0;
	int ret;
	int bytes_read = 0;
	int input_buffer_len = 0;

	z.zalloc = Z_NULL;
	z.zfree = Z_NULL;
	z.opaque = Z_NULL;

	ret = inflateInit(&z);
	if(ret != Z_OK)
		throw SerializationError("dcompressZlib: inflateInit failed");

	z.avail_in = 0;

	//dstream<<"initial fail="<<is.fail()<<" bad="<<is.bad()<<std::endl;

	for(;;)
	{
		z.next_out = (Bytef*)output_buffer;
		z.avail_out = bufsize;

		if(z.avail_in == 0)
		{
			z.next_in = (Bytef*)input_buffer;
			is.read(input_buffer, bufsize);
			input_buffer_len = is.gcount();
			z.avail_in = input_buffer_len;
			//dstream<<"read fail="<<is.fail()<<" bad="<<is.bad()<<std::endl;
		}
		if(z.avail_in == 0)
		{
			//dstream<<"z.avail_in == 0"<<std::endl;
			break;
		}

		//dstream<<"1 z.avail_in="<<z.avail_in<<std::endl;
		status = inflate(&z, Z_NO_FLUSH);
		//dstream<<"2 z.avail_in="<<z.avail_in<<std::endl;
		bytes_read += is.gcount() - z.avail_in;
		//dstream<<"bytes_read="<<bytes_read<<std::endl;

		if(status == Z_NEED_DICT || status == Z_DATA_ERROR
				|| status == Z_MEM_ERROR)
		{
			zerr(status);
			throw SerializationError("decompressZlib: inflate failed");
		}
		int count = bufsize - z.avail_out;
		//dstream<<"count="<<count<<std::endl;
		if(count)
			os.write(output_buffer, count);
		if(status == Z_STREAM_END)
		{
			//dstream<<"Z_STREAM_END"<<std::endl;

			//dstream<<"z.avail_in="<<z.avail_in<<std::endl;
			//dstream<<"fail="<<is.fail()<<" bad="<<is.bad()<<std::endl;
			// Unget all the data that inflate didn't take
			is.clear(); // Just in case EOF is set
			for(u32 i=0; i < z.avail_in; i++)
			{
				is.unget();
				if(is.fail() || is.bad())
				{
					dstream<<"unget #"<<i<<" failed"<<std::endl;
					dstream<<"fail="<<is.fail()<<" bad="<<is.bad()<<std::endl;
					throw SerializationError("decompressZlib: unget failed");
				}
			}

			break;
		}
	}

	inflateEnd(&z);
}

void compress(const SharedBuffer<u8> &data, std::ostream &os, u8 version)
{
	if(version >= 11)
	{
		compressZlib(*data ,data.getSize(), os);
		return;
	}

	if(data.getSize() == 0)
		return;

	// Write length (u32)

	u8 tmp[4];
	writeU32(tmp, data.getSize());
	os.write((char*)tmp, 4);

	// We will be writing 8-bit pairs of more_count and byte
	u8 more_count = 0;
	u8 current_byte = data[0];
	for(u32 i=1; i<data.getSize(); i++)
	{
		if(
			data[i] != current_byte
			|| more_count == 255
		)
		{
			// write count and byte
			os.write((char*)&more_count, 1);
			os.write((char*)&current_byte, 1);
			more_count = 0;
			current_byte = data[i];
		}
		else
		{
			more_count++;
		}
	}
	// write count and byte
	os.write((char*)&more_count, 1);
	os.write((char*)&current_byte, 1);
}

void decompress(std::istream &is, std::ostream &os, u8 version)
{
	if(version >= 11)
	{
		decompressZlib(is, os);
		return;
	}

	// Read length (u32)

	u8 tmp[4];
	is.read((char*)tmp, 4);
	u32 len = readU32(tmp);

	// We will be reading 8-bit pairs of more_count and byte
	u32 count = 0;
	for(;;)
	{
		u8 more_count=0;
		u8 byte=0;

		is.read((char*)&more_count, 1);

		is.read((char*)&byte, 1);

		if(is.eof())
			throw SerializationError("decompress: stream ended halfway");

		for(s32 i=0; i<(u16)more_count+1; i++)
			os.write((char*)&byte, 1);

		count += (u16)more_count+1;

		if(count == len)
			break;
	}
}


1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 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
/*
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 "common/c_content.h"
#include "common/c_converter.h"
#include "common/c_types.h"
#include "nodedef.h"
#include "object_properties.h"
#include "cpp_api/s_node.h"
#include "lua_api/l_object.h"
#include "lua_api/l_item.h"
#include "common/c_internal.h"
#include "server.h"
#include "log.h"
#include "tool.h"
#include "serverobject.h"
#include "porting.h"
#include "mg_schematic.h"
#include "noise.h"
#include <json/json.h>

struct EnumString es_TileAnimationType[] =
{
	{TAT_NONE, "none"},
	{TAT_VERTICAL_FRAMES, "vertical_frames"},
	{TAT_SHEET_2D, "sheet_2d"},
	{0, NULL},
};

/******************************************************************************/
ItemDefinition read_item_definition(lua_State* L,int index,
		ItemDefinition default_def)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	// Read the item definition
	ItemDefinition def = default_def;

	def.type = (ItemType)getenumfield(L, index, "type",
			es_ItemType, ITEM_NONE);
	getstringfield(L, index, "name", def.name);
	getstringfield(L, index, "description", def.description);
	getstringfield(L, index, "inventory_image", def.inventory_image);
	getstringfield(L, index, "wield_image", def.wield_image);

	lua_getfield(L, index, "wield_scale");
	if(lua_istable(L, -1)){
		def.wield_scale = check_v3f(L, -1);
	}
	lua_pop(L, 1);

	int stack_max = getintfield_default(L, index, "stack_max", def.stack_max);
	def.stack_max = rangelim(stack_max, 1, U16_MAX);

	lua_getfield(L, index, "on_use");
	def.usable = lua_isfunction(L, -1);
	lua_pop(L, 1);

	getboolfield(L, index, "liquids_pointable", def.liquids_pointable);

	warn_if_field_exists(L, index, "tool_digging_properties",
			"Deprecated; use tool_capabilities");

	lua_getfield(L, index, "tool_capabilities");
	if(lua_istable(L, -1)){
		def.tool_capabilities = new ToolCapabilities(
				read_tool_capabilities(L, -1));
	}

	// If name is "" (hand), ensure there are ToolCapabilities
	// because it will be looked up there whenever any other item has
	// no ToolCapabilities
	if(def.name == "" && def.tool_capabilities == NULL){
		def.tool_capabilities = new ToolCapabilities();
	}

	lua_getfield(L, index, "groups");
	read_groups(L, -1, def.groups);
	lua_pop(L, 1);

	lua_getfield(L, index, "sounds");
	if(lua_istable(L, -1)){
		lua_getfield(L, -1, "place");
		read_soundspec(L, -1, def.sound_place);
		lua_pop(L, 1);
		lua_getfield(L, -1, "place_failed");
		read_soundspec(L, -1, def.sound_place_failed);
		lua_pop(L, 1);
	}
	lua_pop(L, 1);

	def.range = getfloatfield_default(L, index, "range", def.range);

	// Client shall immediately place this node when player places the item.
	// Server will update the precise end result a moment later.
	// "" = no prediction
	getstringfield(L, index, "node_placement_prediction",
			def.node_placement_prediction);

	return def;
}

/******************************************************************************/
void read_object_properties(lua_State *L, int index,
		ObjectProperties *prop)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;
	if(!lua_istable(L, index))
		return;

	prop->hp_max = getintfield_default(L, -1, "hp_max", 10);

	getboolfield(L, -1, "physical", prop->physical);
	getboolfield(L, -1, "collide_with_objects", prop->collideWithObjects);

	getfloatfield(L, -1, "weight", prop->weight);

	lua_getfield(L, -1, "collisionbox");
	if(lua_istable(L, -1))
		prop->collisionbox = read_aabb3f(L, -1, 1.0);
	lua_pop(L, 1);

	getstringfield(L, -1, "visual", prop->visual);

	getstringfield(L, -1, "mesh", prop->mesh);

	lua_getfield(L, -1, "visual_size");
	if(lua_istable(L, -1))
		prop->visual_size = read_v2f(L, -1);
	lua_pop(L, 1);

	lua_getfield(L, -1, "textures");
	if(lua_istable(L, -1)){
		prop->textures.clear();
		int table = lua_gettop(L);
		lua_pushnil(L);
		while(lua_next(L, table) != 0){
			// key at index -2 and value at index -1
			if(lua_isstring(L, -1))
				prop->textures.push_back(lua_tostring(L, -1));
			else
				prop->textures.push_back("");
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
		}
	}
	lua_pop(L, 1);

	lua_getfield(L, -1, "colors");
	if (lua_istable(L, -1)) {
		int table = lua_gettop(L);
		prop->colors.clear();
		for (lua_pushnil(L); lua_next(L, table); lua_pop(L, 1)) {
			video::SColor color(255, 255, 255, 255);
			read_color(L, -1, &color);
			prop->colors.push_back(color);
		}
	}
	lua_pop(L, 1);

	lua_getfield(L, -1, "spritediv");
	if(lua_istable(L, -1))
		prop->spritediv = read_v2s16(L, -1);
	lua_pop(L, 1);

	lua_getfield(L, -1, "initial_sprite_basepos");
	if(lua_istable(L, -1))
		prop->initial_sprite_basepos = read_v2s16(L, -1);
	lua_pop(L, 1);

	getboolfield(L, -1, "is_visible", prop->is_visible);
	getboolfield(L, -1, "makes_footstep_sound", prop->makes_footstep_sound);
	getfloatfield(L, -1, "automatic_rotate", prop->automatic_rotate);
	if (getfloatfield(L, -1, "stepheight", prop->stepheight))
		prop->stepheight *= BS;
	lua_getfield(L, -1, "automatic_face_movement_dir");
	if (lua_isnumber(L, -1)) {
		prop->automatic_face_movement_dir = true;
		prop->automatic_face_movement_dir_offset = luaL_checknumber(L, -1);
	} else if (lua_isboolean(L, -1)) {
		prop->automatic_face_movement_dir = lua_toboolean(L, -1);
		prop->automatic_face_movement_dir_offset = 0.0;
	}
	lua_pop(L, 1);
	getboolfield(L, -1, "backface_culling", prop->backface_culling);

	getstringfield(L, -1, "nametag", prop->nametag);
	lua_getfield(L, -1, "nametag_color");
	if (!lua_isnil(L, -1)) {
		video::SColor color = prop->nametag_color;
		if (read_color(L, -1, &color))
			prop->nametag_color = color;
	}
	lua_pop(L, 1);

	lua_getfield(L, -1, "automatic_face_movement_max_rotation_per_sec");
	if (lua_isnumber(L, -1)) {
		prop->automatic_face_movement_max_rotation_per_sec = luaL_checknumber(L, -1);
	}
	lua_pop(L, 1);
	getstringfield(L, -1, "infotext", prop->infotext);
}

/******************************************************************************/
void push_object_properties(lua_State *L, ObjectProperties *prop)
{
	lua_newtable(L);
	lua_pushnumber(L, prop->hp_max);
	lua_setfield(L, -2, "hp_max");
	lua_pushboolean(L, prop->physical);
	lua_setfield(L, -2, "physical");
	lua_pushboolean(L, prop->collideWithObjects);
	lua_setfield(L, -2, "collide_with_objects");
	lua_pushnumber(L, prop->weight);
	lua_setfield(L, -2, "weight");
	push_aabb3f(L, prop->collisionbox);
	lua_setfield(L, -2, "collisionbox");
	lua_pushlstring(L, prop->visual.c_str(), prop->visual.size());
	lua_setfield(L, -2, "visual");
	lua_pushlstring(L, prop->mesh.c_str(), prop->mesh.size());
	lua_setfield(L, -2, "mesh");
	push_v2f(L, prop->visual_size);
	lua_setfield(L, -2, "visual_size");

	lua_newtable(L);
	u16 i = 1;
	for (std::vector<std::string>::iterator it = prop->textures.begin();
			it != prop->textures.end(); ++it) {
		lua_pushlstring(L, it->c_str(), it->size());
		lua_rawseti(L, -2, i);
	}
	lua_setfield(L, -2, "textures");

	lua_newtable(L);
	i = 1;
	for (std::vector<video::SColor>::iterator it = prop->colors.begin();
			it != prop->colors.end(); ++it) {
		push_ARGB8(L, *it);
		lua_rawseti(L, -2, i);
	}
	lua_setfield(L, -2, "colors");

	push_v2s16(L, prop->spritediv);
	lua_setfield(L, -2, "spritediv");
	push_v2s16(L, prop->initial_sprite_basepos);
	lua_setfield(L, -2, "initial_sprite_basepos");
	lua_pushboolean(L, prop->is_visible);
	lua_setfield(L, -2, "is_visible");
	lua_pushboolean(L, prop->makes_footstep_sound);
	lua_setfield(L, -2, "makes_footstep_sound");
	lua_pushnumber(L, prop->automatic_rotate);
	lua_setfield(L, -2, "automatic_rotate");
	lua_pushnumber(L, prop->stepheight / BS);
	lua_setfield(L, -2, "stepheight");
	if (prop->automatic_face_movement_dir)
		lua_pushnumber(L, prop->automatic_face_movement_dir_offset);
	else
		lua_pushboolean(L, false);
	lua_setfield(L, -2, "automatic_face_movement_dir");
	lua_pushboolean(L, prop->backface_culling);
	lua_setfield(L, -2, "backface_culling");
	lua_pushlstring(L, prop->nametag.c_str(), prop->nametag.size());
	lua_setfield(L, -2, "nametag");
	push_ARGB8(L, prop->nametag_color);
	lua_setfield(L, -2, "nametag_color");
	lua_pushnumber(L, prop->automatic_face_movement_max_rotation_per_sec);
	lua_setfield(L, -2, "automatic_face_movement_max_rotation_per_sec");
	lua_pushlstring(L, prop->infotext.c_str(), prop->infotext.size());
	lua_setfield(L, -2, "infotext");
}

/******************************************************************************/
TileDef read_tiledef(lua_State *L, int index, u8 drawtype)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	TileDef tiledef;

	bool default_tiling = true;
	bool default_culling = true;
	switch (drawtype) {
		case NDT_PLANTLIKE:
		case NDT_FIRELIKE:
			default_tiling = false;
			// "break" is omitted here intentionaly, as PLANTLIKE
			// FIRELIKE drawtype both should default to having
			// backface_culling to false.
		case NDT_MESH:
		case NDT_LIQUID:
			default_culling = false;
			break;
		default:
			break;
	}

	// key at index -2 and value at index
	if(lua_isstring(L, index)){
		// "default_lava.png"
		tiledef.name = lua_tostring(L, index);
		tiledef.tileable_vertical = default_tiling;
		tiledef.tileable_horizontal = default_tiling;
		tiledef.backface_culling = default_culling;
	}
	else if(lua_istable(L, index))
	{
		// name="default_lava.png"
		tiledef.name = "";
		getstringfield(L, index, "name", tiledef.name);
		getstringfield(L, index, "image", tiledef.name); // MaterialSpec compat.
		tiledef.backface_culling = getboolfield_default(
			L, index, "backface_culling", default_culling);
		tiledef.tileable_horizontal = getboolfield_default(
			L, index, "tileable_horizontal", default_tiling);
		tiledef.tileable_vertical = getboolfield_default(
			L, index, "tileable_vertical", default_tiling);
		// color = ...
		lua_getfield(L, index, "color");
		tiledef.has_color = read_color(L, -1, &tiledef.color);
		lua_pop(L, 1);
		// animation = {}
		lua_getfield(L, index, "animation");
		tiledef.animation = read_animation_definition(L, -1);
		lua_pop(L, 1);
	}

	return tiledef;
}

/******************************************************************************/
ContentFeatures read_content_features(lua_State *L, int index)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	ContentFeatures f;

	/* Cache existence of some callbacks */
	lua_getfield(L, index, "on_construct");
	if(!lua_isnil(L, -1)) f.has_on_construct = true;
	lua_pop(L, 1);
	lua_getfield(L, index, "on_destruct");
	if(!lua_isnil(L, -1)) f.has_on_destruct = true;
	lua_pop(L, 1);
	lua_getfield(L, index, "after_destruct");
	if(!lua_isnil(L, -1)) f.has_after_destruct = true;
	lua_pop(L, 1);

	lua_getfield(L, index, "on_rightclick");
	f.rightclickable = lua_isfunction(L, -1);
	lua_pop(L, 1);

	/* Name */
	getstringfield(L, index, "name", f.name);

	/* Groups */
	lua_getfield(L, index, "groups");
	read_groups(L, -1, f.groups);
	lua_pop(L, 1);

	/* Visual definition */

	f.drawtype = (NodeDrawType)getenumfield(L, index, "drawtype",
			ScriptApiNode::es_DrawType,NDT_NORMAL);
	getfloatfield(L, index, "visual_scale", f.visual_scale);

	/* Meshnode model filename */
	getstringfield(L, index, "mesh", f.mesh);

	// tiles = {}
	lua_getfield(L, index, "tiles");
	// If nil, try the deprecated name "tile_images" instead
	if(lua_isnil(L, -1)){
		lua_pop(L, 1);
		warn_if_field_exists(L, index, "tile_images",
				"Deprecated; new name is \"tiles\".");
		lua_getfield(L, index, "tile_images");
	}
	if(lua_istable(L, -1)){
		int table = lua_gettop(L);
		lua_pushnil(L);
		int i = 0;
		while(lua_next(L, table) != 0){
			// Read tiledef from value
			f.tiledef[i] = read_tiledef(L, -1, f.drawtype);
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
			i++;
			if(i==6){
				lua_pop(L, 1);
				break;
			}
		}
		// Copy last value to all remaining textures
		if(i >= 1){
			TileDef lasttile = f.tiledef[i-1];
			while(i < 6){
				f.tiledef[i] = lasttile;
				i++;
			}
		}
	}
	lua_pop(L, 1);

	// special_tiles = {}
	lua_getfield(L, index, "special_tiles");
	// If nil, try the deprecated name "special_materials" instead
	if(lua_isnil(L, -1)){
		lua_pop(L, 1);
		warn_if_field_exists(L, index, "special_materials",
				"Deprecated; new name is \"special_tiles\".");
		lua_getfield(L, index, "special_materials");
	}
	if(lua_istable(L, -1)){
		int table = lua_gettop(L);
		lua_pushnil(L);
		int i = 0;
		while(lua_next(L, table) != 0){
			// Read tiledef from value
			f.tiledef_special[i] = read_tiledef(L, -1, f.drawtype);
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
			i++;
			if(i==CF_SPECIAL_COUNT){
				lua_pop(L, 1);
				break;
			}
		}
	}
	lua_pop(L, 1);

	f.alpha = getintfield_default(L, index, "alpha", 255);

	bool usealpha = getboolfield_default(L, index,
			"use_texture_alpha", false);
	if (usealpha)
		f.alpha = 0;

	// Read node color.
	lua_getfield(L, index, "color");
	read_color(L, -1, &f.color);
	lua_pop(L, 1);

	getstringfield(L, index, "palette", f.palette_name);

	/* Other stuff */

	lua_getfield(L, index, "post_effect_color");
	read_color(L, -1, &f.post_effect_color);
	lua_pop(L, 1);

	f.param_type = (ContentParamType)getenumfield(L, index, "paramtype",
			ScriptApiNode::es_ContentParamType, CPT_NONE);
	f.param_type_2 = (ContentParamType2)getenumfield(L, index, "paramtype2",
			ScriptApiNode::es_ContentParamType2, CPT2_NONE);

	if (f.palette_name != "" &&
			!(f.param_type_2 == CPT2_COLOR ||
			f.param_type_2 == CPT2_COLORED_FACEDIR ||
			f.param_type_2 == CPT2_COLORED_WALLMOUNTED))
		warningstream << "Node " << f.name.c_str()
			<< " has a palette, but not a suitable paramtype2." << std::endl;

	// Warn about some deprecated fields
	warn_if_field_exists(L, index, "wall_mounted",
			"Deprecated; use paramtype2 = 'wallmounted'");
	warn_if_field_exists(L, index, "light_propagates",
			"Deprecated; determined from paramtype");
	warn_if_field_exists(L, index, "dug_item",
			"Deprecated; use 'drop' field");
	warn_if_field_exists(L, index, "extra_dug_item",
			"Deprecated; use 'drop' field");
	warn_if_field_exists(L, index, "extra_dug_item_rarity",
			"Deprecated; use 'drop' field");
	warn_if_field_exists(L, index, "metadata_name",
			"Deprecated; use on_add and metadata callbacks");

	// True for all ground-like things like stone and mud, false for eg. trees
	getboolfield(L, index, "is_ground_content", f.is_ground_content);
	f.light_propagates = (f.param_type == CPT_LIGHT);
	getboolfield(L, index, "sunlight_propagates", f.sunlight_propagates);
	// This is used for collision detection.
	// Also for general solidness queries.
	getboolfield(L, index, "walkable", f.walkable);
	// Player can point to these
	getboolfield(L, index, "pointable", f.pointable);
	// Player can dig these
	getboolfield(L, index, "diggable", f.diggable);
	// Player can climb these
	getboolfield(L, index, "climbable", f.climbable);
	// Player can build on these
	getboolfield(L, index, "buildable_to", f.buildable_to);
	// Liquids flow into and replace node
	getboolfield(L, index, "floodable", f.floodable);
	// Whether the node is non-liquid, source liquid or flowing liquid
	f.liquid_type = (LiquidType)getenumfield(L, index, "liquidtype",
			ScriptApiNode::es_LiquidType, LIQUID_NONE);
	// If the content is liquid, this is the flowing version of the liquid.
	getstringfield(L, index, "liquid_alternative_flowing",
			f.liquid_alternative_flowing);
	// If the content is liquid, this is the source version of the liquid.
	getstringfield(L, index, "liquid_alternative_source",
			f.liquid_alternative_source);
	// Viscosity for fluid flow, ranging from 1 to 7, with
	// 1 giving almost instantaneous propagation and 7 being
	// the slowest possible
	f.liquid_viscosity = getintfield_default(L, index,
			"liquid_viscosity", f.liquid_viscosity);
	f.liquid_range = getintfield_default(L, index,
			"liquid_range", f.liquid_range);
	f.leveled = getintfield_default(L, index, "leveled", f.leveled);

	getboolfield(L, index, "liquid_renewable", f.liquid_renewable);
	f.drowning = getintfield_default(L, index,
			"drowning", f.drowning);
	// Amount of light the node emits
	f.light_source = getintfield_default(L, index,
			"light_source", f.light_source);
	if (f.light_source > LIGHT_MAX) {
		warningstream << "Node " << f.name.c_str()
			<< " had greater light_source than " << LIGHT_MAX
			<< ", it was reduced." << std::endl;
		f.light_source = LIGHT_MAX;
	}
	f.damage_per_second = getintfield_default(L, index,
			"damage_per_second", f.damage_per_second);

	lua_getfield(L, index, "node_box");
	if(lua_istable(L, -1))
		f.node_box = read_nodebox(L, -1);
	lua_pop(L, 1);

	lua_getfield(L, index, "connects_to");
	if (lua_istable(L, -1)) {
		int table = lua_gettop(L);
		lua_pushnil(L);
		while (lua_next(L, table) != 0) {
			// Value at -1
			f.connects_to.push_back(lua_tostring(L, -1));
			lua_pop(L, 1);
		}
	}
	lua_pop(L, 1);

	lua_getfield(L, index, "connect_sides");
	if (lua_istable(L, -1)) {
		int table = lua_gettop(L);
		lua_pushnil(L);
		while (lua_next(L, table) != 0) {
			// Value at -1
			std::string side(lua_tostring(L, -1));
			// Note faces are flipped to make checking easier
			if (side == "top")
				f.connect_sides |= 2;
			else if (side == "bottom")
				f.connect_sides |= 1;
			else if (side == "front")
				f.connect_sides |= 16;
			else if (side == "left")
				f.connect_sides |= 32;
			else if (side == "back")
				f.connect_sides |= 4;
			else if (side == "right")
				f.connect_sides |= 8;
			else
				warningstream << "Unknown value for \"connect_sides\": "
					<< side << std::endl;
			lua_pop(L, 1);
		}
	}
	lua_pop(L, 1);

	lua_getfield(L, index, "selection_box");
	if(lua_istable(L, -1))
		f.selection_box = read_nodebox(L, -1);
 	lua_pop(L, 1);

	lua_getfield(L, index, "collision_box");
	if(lua_istable(L, -1))
		f.collision_box = read_nodebox(L, -1);
	lua_pop(L, 1);

	f.waving = getintfield_default(L, index,
			"waving", f.waving);

	// Set to true if paramtype used to be 'facedir_simple'
	getboolfield(L, index, "legacy_facedir_simple", f.legacy_facedir_simple);
	// Set to true if wall_mounted used to be set to true
	getboolfield(L, index, "legacy_wallmounted", f.legacy_wallmounted);

	// Sound table
	lua_getfield(L, index, "sounds");
	if(lua_istable(L, -1)){
		lua_getfield(L, -1, "footstep");
		read_soundspec(L, -1, f.sound_footstep);
		lua_pop(L, 1);
		lua_getfield(L, -1, "dig");
		read_soundspec(L, -1, f.sound_dig);
		lua_pop(L, 1);
		lua_getfield(L, -1, "dug");
		read_soundspec(L, -1, f.sound_dug);
		lua_pop(L, 1);
	}
	lua_pop(L, 1);

	return f;
}

/******************************************************************************/
void read_server_sound_params(lua_State *L, int index,
		ServerSoundParams &params)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;
	// Clear
	params = ServerSoundParams();
	if(lua_istable(L, index)){
		getfloatfield(L, index, "gain", params.gain);
		getstringfield(L, index, "to_player", params.to_player);
		lua_getfield(L, index, "pos");
		if(!lua_isnil(L, -1)){
			v3f p = read_v3f(L, -1)*BS;
			params.pos = p;
			params.type = ServerSoundParams::SSP_POSITIONAL;
		}
		lua_pop(L, 1);
		lua_getfield(L, index, "object");
		if(!lua_isnil(L, -1)){
			ObjectRef *ref = ObjectRef::checkobject(L, -1);
			ServerActiveObject *sao = ObjectRef::getobject(ref);
			if(sao){
				params.object = sao->getId();
				params.type = ServerSoundParams::SSP_OBJECT;
			}
		}
		lua_pop(L, 1);
		params.max_hear_distance = BS*getfloatfield_default(L, index,
				"max_hear_distance", params.max_hear_distance/BS);
		getboolfield(L, index, "loop", params.loop);
	}
}

/******************************************************************************/
void read_soundspec(lua_State *L, int index, SimpleSoundSpec &spec)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;
	if(lua_isnil(L, index)){
	} else if(lua_istable(L, index)){
		getstringfield(L, index, "name", spec.name);
		getfloatfield(L, index, "gain", spec.gain);
	} else if(lua_isstring(L, index)){
		spec.name = lua_tostring(L, index);
	}
}

/******************************************************************************/
NodeBox read_nodebox(lua_State *L, int index)
{
	NodeBox nodebox;
	if(lua_istable(L, -1)){
		nodebox.type = (NodeBoxType)getenumfield(L, index, "type",
				ScriptApiNode::es_NodeBoxType, NODEBOX_REGULAR);

#define NODEBOXREAD(n, s) \
	do { \
		lua_getfield(L, index, (s)); \
		if (lua_istable(L, -1)) \
			(n) = read_aabb3f(L, -1, BS); \
		lua_pop(L, 1); \
	} while (0)

#define NODEBOXREADVEC(n, s) \
	do { \
		lua_getfield(L, index, (s)); \
		if (lua_istable(L, -1)) \
			(n) = read_aabb3f_vector(L, -1, BS); \
		lua_pop(L, 1); \
	} while (0)
		NODEBOXREADVEC(nodebox.fixed, "fixed");
		NODEBOXREAD(nodebox.wall_top, "wall_top");
		NODEBOXREAD(nodebox.wall_bottom, "wall_bottom");
		NODEBOXREAD(nodebox.wall_side, "wall_side");
		NODEBOXREADVEC(nodebox.connect_top, "connect_top");
		NODEBOXREADVEC(nodebox.connect_bottom, "connect_bottom");
		NODEBOXREADVEC(nodebox.connect_front, "connect_front");
		NODEBOXREADVEC(nodebox.connect_left, "connect_left");
		NODEBOXREADVEC(nodebox.connect_back, "connect_back");
		NODEBOXREADVEC(nodebox.connect_right, "connect_right");
	}
	return nodebox;
}

/******************************************************************************/
MapNode readnode(lua_State *L, int index, INodeDefManager *ndef)
{
	lua_getfield(L, index, "name");
	if (!lua_isstring(L, -1))
		throw LuaError("Node name is not set or is not a string!");
	const char *name = lua_tostring(L, -1);
	lua_pop(L, 1);

	u8 param1 = 0;
	lua_getfield(L, index, "param1");
	if (!lua_isnil(L, -1))
		param1 = lua_tonumber(L, -1);
	lua_pop(L, 1);

	u8 param2 = 0;
	lua_getfield(L, index, "param2");
	if (!lua_isnil(L, -1))
		param2 = lua_tonumber(L, -1);
	lua_pop(L, 1);

	return MapNode(ndef, name, param1, param2);
}

/******************************************************************************/
void pushnode(lua_State *L, const MapNode &n, INodeDefManager *ndef)
{
	lua_newtable(L);
	lua_pushstring(L, ndef->get(n).name.c_str());
	lua_setfield(L, -2, "name");
	lua_pushnumber(L, n.getParam1());
	lua_setfield(L, -2, "param1");
	lua_pushnumber(L, n.getParam2());
	lua_setfield(L, -2, "param2");
}

/******************************************************************************/
void warn_if_field_exists(lua_State *L, int table,
		const char *name, const std::string &message)
{
	lua_getfield(L, table, name);
	if (!lua_isnil(L, -1)) {
		warningstream << "Field \"" << name << "\": "
				<< message << std::endl;
		infostream << script_get_backtrace(L) << std::endl;
	}
	lua_pop(L, 1);
}

/******************************************************************************/
int getenumfield(lua_State *L, int table,
		const char *fieldname, const EnumString *spec, int default_)
{
	int result = default_;
	string_to_enum(spec, result,
			getstringfield_default(L, table, fieldname, ""));
	return result;
}

/******************************************************************************/
bool string_to_enum(const EnumString *spec, int &result,
		const std::string &str)
{
	const EnumString *esp = spec;
	while(esp->str){
		if(str == std::string(esp->str)){
			result = esp->num;
			return true;
		}
		esp++;
	}
	return false;
}

/******************************************************************************/
ItemStack read_item(lua_State* L, int index, IItemDefManager *idef)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	if(lua_isnil(L, index))
	{
		return ItemStack();
	}
	else if(lua_isuserdata(L, index))
	{
		// Convert from LuaItemStack
		LuaItemStack *o = LuaItemStack::checkobject(L, index);
		return o->getItem();
	}
	else if(lua_isstring(L, index))
	{
		// Convert from itemstring
		std::string itemstring = lua_tostring(L, index);
		try
		{
			ItemStack item;
			item.deSerialize(itemstring, idef);
			return item;
		}
		catch(SerializationError &e)
		{
			warningstream<<"unable to create item from itemstring"
					<<": "<<itemstring<<std::endl;
			return ItemStack();
		}
	}
	else if(lua_istable(L, index))
	{
		// Convert from table
		std::string name = getstringfield_default(L, index, "name", "");
		int count = getintfield_default(L, index, "count", 1);
		int wear = getintfield_default(L, index, "wear", 0);

		ItemStack istack(name, count, wear, idef);

		// BACKWARDS COMPATIBLITY
		std::string value = getstringfield_default(L, index, "metadata", "");
		istack.metadata.setString("", value);

		// Get meta
		lua_getfield(L, index, "meta");
		int fieldstable = lua_gettop(L);
		if (lua_istable(L, fieldstable)) {
			lua_pushnil(L);
			while (lua_next(L, fieldstable) != 0) {
				// key at index -2 and value at index -1
				std::string key = lua_tostring(L, -2);
				size_t value_len;
				const char *value_cs = lua_tolstring(L, -1, &value_len);
				std::string value(value_cs, value_len);
				istack.metadata.setString(key, value);
				lua_pop(L, 1); // removes value, keeps key for next iteration
			}
		}

		return istack;
	} else {
		throw LuaError("Expecting itemstack, itemstring, table or nil");
	}
}

/******************************************************************************/
void push_tool_capabilities(lua_State *L,
		const ToolCapabilities &toolcap)
{
	lua_newtable(L);
	setfloatfield(L, -1, "full_punch_interval", toolcap.full_punch_interval);
		setintfield(L, -1, "max_drop_level", toolcap.max_drop_level);
		// Create groupcaps table
		lua_newtable(L);
		// For each groupcap
		for (ToolGCMap::const_iterator i = toolcap.groupcaps.begin();
			i != toolcap.groupcaps.end(); i++) {
			// Create groupcap table
			lua_newtable(L);
			const std::string &name = i->first;
			const ToolGroupCap &groupcap = i->second;
			// Create subtable "times"
			lua_newtable(L);
			for (UNORDERED_MAP<int, float>::const_iterator
					i = groupcap.times.begin(); i != groupcap.times.end(); i++) {
				lua_pushinteger(L, i->first);
				lua_pushnumber(L, i->second);
				lua_settable(L, -3);
			}
			// Set subtable "times"
			lua_setfield(L, -2, "times");
			// Set simple parameters
			setintfield(L, -1, "maxlevel", groupcap.maxlevel);
			setintfield(L, -1, "uses", groupcap.uses);
			// Insert groupcap table into groupcaps table
			lua_setfield(L, -2, name.c_str());
		}
		// Set groupcaps table
		lua_setfield(L, -2, "groupcaps");
		//Create damage_groups table
		lua_newtable(L);
		// For each damage group
		for (DamageGroup::const_iterator i = toolcap.damageGroups.begin();
			i != toolcap.damageGroups.end(); i++) {
			// Create damage group table
			lua_pushinteger(L, i->second);
			lua_setfield(L, -2, i->first.c_str());
		}
		lua_setfield(L, -2, "damage_groups");
}

/******************************************************************************/
void push_inventory_list(lua_State *L, Inventory *inv, const char *name)
{
	InventoryList *invlist = inv->getList(name);
	if(invlist == NULL){
		lua_pushnil(L);
		return;
	}
	std::vector<ItemStack> items;
	for(u32 i=0; i<invlist->getSize(); i++)
		items.push_back(invlist->getItem(i));
	push_items(L, items);
}

/******************************************************************************/
void read_inventory_list(lua_State *L, int tableindex,
		Inventory *inv, const char *name, Server* srv, int forcesize)
{
	if(tableindex < 0)
		tableindex = lua_gettop(L) + 1 + tableindex;
	// If nil, delete list
	if(lua_isnil(L, tableindex)){
		inv->deleteList(name);
		return;
	}
	// Otherwise set list
	std::vector<ItemStack> items = read_items(L, tableindex,srv);
	int listsize = (forcesize != -1) ? forcesize : items.size();
	InventoryList *invlist = inv->addList(name, listsize);
	int index = 0;
	for(std::vector<ItemStack>::const_iterator
			i = items.begin(); i != items.end(); i++){
		if(forcesize != -1 && index == forcesize)
			break;
		invlist->changeItem(index, *i);
		index++;
	}
	while(forcesize != -1 && index < forcesize){
		invlist->deleteItem(index);
		index++;
	}
}

/******************************************************************************/
struct TileAnimationParams read_animation_definition(lua_State *L, int index)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	struct TileAnimationParams anim;
	anim.type = TAT_NONE;
	if (!lua_istable(L, index))
		return anim;

	anim.type = (TileAnimationType)
		getenumfield(L, index, "type", es_TileAnimationType,
		TAT_NONE);
	if (anim.type == TAT_VERTICAL_FRAMES) {
		// {type="vertical_frames", aspect_w=16, aspect_h=16, length=2.0}
		anim.vertical_frames.aspect_w =
			getintfield_default(L, index, "aspect_w", 16);
		anim.vertical_frames.aspect_h =
			getintfield_default(L, index, "aspect_h", 16);
		anim.vertical_frames.length =
			getfloatfield_default(L, index, "length", 1.0);
	} else if (anim.type == TAT_SHEET_2D) {
		// {type="sheet_2d", frames_w=5, frames_h=3, frame_length=0.5}
		getintfield(L, index, "frames_w",
			anim.sheet_2d.frames_w);
		getintfield(L, index, "frames_h",
			anim.sheet_2d.frames_h);
		getfloatfield(L, index, "frame_length",
			anim.sheet_2d.frame_length);
	}

	return anim;
}

/******************************************************************************/
ToolCapabilities read_tool_capabilities(
		lua_State *L, int table)
{
	ToolCapabilities toolcap;
	getfloatfield(L, table, "full_punch_interval", toolcap.full_punch_interval);
	getintfield(L, table, "max_drop_level", toolcap.max_drop_level);
	lua_getfield(L, table, "groupcaps");
	if(lua_istable(L, -1)){
		int table_groupcaps = lua_gettop(L);
		lua_pushnil(L);
		while(lua_next(L, table_groupcaps) != 0){
			// key at index -2 and value at index -1
			std::string groupname = luaL_checkstring(L, -2);
			if(lua_istable(L, -1)){
				int table_groupcap = lua_gettop(L);
				// This will be created
				ToolGroupCap groupcap;
				// Read simple parameters
				getintfield(L, table_groupcap, "maxlevel", groupcap.maxlevel);
				getintfield(L, table_groupcap, "uses", groupcap.uses);
				// DEPRECATED: maxwear
				float maxwear = 0;
				if (getfloatfield(L, table_groupcap, "maxwear", maxwear)){
					if (maxwear != 0)
						groupcap.uses = 1.0/maxwear;
					else
						groupcap.uses = 0;
					warningstream << "Field \"maxwear\" is deprecated; "
							<< "replace with uses=1/maxwear" << std::endl;
					infostream << script_get_backtrace(L) << std::endl;
				}
				// Read "times" table
				lua_getfield(L, table_groupcap, "times");
				if(lua_istable(L, -1)){
					int table_times = lua_gettop(L);
					lua_pushnil(L);
					while(lua_next(L, table_times) != 0){
						// key at index -2 and value at index -1
						int rating = luaL_checkinteger(L, -2);
						float time = luaL_checknumber(L, -1);
						groupcap.times[rating] = time;
						// removes value, keeps key for next iteration
						lua_pop(L, 1);
					}
				}
				lua_pop(L, 1);
				// Insert groupcap into toolcap
				toolcap.groupcaps[groupname] = groupcap;
			}
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
		}
	}
	lua_pop(L, 1);

	lua_getfield(L, table, "damage_groups");
	if(lua_istable(L, -1)){
		int table_damage_groups = lua_gettop(L);
		lua_pushnil(L);
		while(lua_next(L, table_damage_groups) != 0){
			// key at index -2 and value at index -1
			std::string groupname = luaL_checkstring(L, -2);
			u16 value = luaL_checkinteger(L, -1);
			toolcap.damageGroups[groupname] = value;
			// removes value, keeps key for next iteration
			lua_pop(L, 1);
		}
	}
	lua_pop(L, 1);
	return toolcap;
}

/******************************************************************************/
void push_dig_params(lua_State *L,const DigParams &params)
{
	lua_newtable(L);
	setboolfield(L, -1, "diggable", params.diggable);
	setfloatfield(L, -1, "time", params.time);
	setintfield(L, -1, "wear", params.wear);
}

/******************************************************************************/
void push_hit_params(lua_State *L,const HitParams &params)
{
	lua_newtable(L);
	setintfield(L, -1, "hp", params.hp);
	setintfield(L, -1, "wear", params.wear);
}

/******************************************************************************/

bool getflagsfield(lua_State *L, int table, const char *fieldname,
	FlagDesc *flagdesc, u32 *flags, u32 *flagmask)
{
	lua_getfield(L, table, fieldname);

	bool success = read_flags(L, -1, flagdesc, flags, flagmask);

	lua_pop(L, 1);

	return success;
}

bool read_flags(lua_State *L, int index, FlagDesc *flagdesc,
	u32 *flags, u32 *flagmask)
{
	if (lua_isstring(L, index)) {
		std::string flagstr = lua_tostring(L, index);
		*flags = readFlagString(flagstr, flagdesc, flagmask);
	} else if (lua_istable(L, index)) {
		*flags = read_flags_table(L, index, flagdesc, flagmask);
	} else {
		return false;
	}

	return true;
}

u32 read_flags_table(lua_State *L, int table, FlagDesc *flagdesc, u32 *flagmask)
{
	u32 flags = 0, mask = 0;
	char fnamebuf[64] = "no";

	for (int i = 0; flagdesc[i].name; i++) {
		bool result;

		if (getboolfield(L, table, flagdesc[i].name, result)) {
			mask |= flagdesc[i].flag;
			if (result)
				flags |= flagdesc[i].flag;
		}

		strlcpy(fnamebuf + 2, flagdesc[i].name, sizeof(fnamebuf) - 2);
		if (getboolfield(L, table, fnamebuf, result))
			mask |= flagdesc[i].flag;
	}

	if (flagmask)
		*flagmask = mask;

	return flags;
}

void push_flags_string(lua_State *L, FlagDesc *flagdesc, u32 flags, u32 flagmask)
{
	std::string flagstring = writeFlagString(flags, flagdesc, flagmask);
	lua_pushlstring(L, flagstring.c_str(), flagstring.size());
}

/******************************************************************************/
/* Lua Stored data!                                                           */
/******************************************************************************/

/******************************************************************************/
void read_groups(lua_State *L, int index, ItemGroupList &result)
{
	if (!lua_istable(L,index))
		return;
	result.clear();
	lua_pushnil(L);
	if(index < 0)
		index -= 1;
	while(lua_next(L, index) != 0){
		// key at index -2 and value at index -1
		std::string name = luaL_checkstring(L, -2);
		int rating = luaL_checkinteger(L, -1);
		result[name] = rating;
		// removes value, keeps key for next iteration
		lua_pop(L, 1);
	}
}

/******************************************************************************/
void push_groups(lua_State *L, const ItemGroupList &groups)
{
	lua_newtable(L);
	for (ItemGroupList::const_iterator it = groups.begin(); it != groups.end(); ++it) {
		lua_pushnumber(L, it->second);
		lua_setfield(L, -2, it->first.c_str());
	}
}

/******************************************************************************/
void push_items(lua_State *L, const std::vector<ItemStack> &items)
{
	lua_createtable(L, items.size(), 0);
	for (u32 i = 0; i != items.size(); i++) {
		LuaItemStack::create(L, items[i]);
		lua_rawseti(L, -2, i + 1);
	}
}

/******************************************************************************/
std::vector<ItemStack> read_items(lua_State *L, int index, Server *srv)
{
	if(index < 0)
		index = lua_gettop(L) + 1 + index;

	std::vector<ItemStack> items;
	luaL_checktype(L, index, LUA_TTABLE);
	lua_pushnil(L);
	while (lua_next(L, index)) {
		s32 key = luaL_checkinteger(L, -2);
		if (key < 1) {
			throw LuaError("Invalid inventory list index");
		}
		if (items.size() < (u32) key) {
			items.resize(key);
		}
		items[key - 1] = read_item(L, -1, srv->idef());
		lua_pop(L, 1);
	}
	return items;
}

/******************************************************************************/
void luaentity_get(lua_State *L, u16 id)
{
	// Get luaentities[i]
	lua_getglobal(L, "core");
	lua_getfield(L, -1, "luaentities");
	luaL_checktype(L, -1, LUA_TTABLE);
	lua_pushnumber(L, id);
	lua_gettable(L, -2);
	lua_remove(L, -2); // Remove luaentities
	lua_remove(L, -2); // Remove core
}

/******************************************************************************/
bool read_noiseparams(lua_State *L, int index, NoiseParams *np)
{
	if (index < 0)
		index = lua_gettop(L) + 1 + index;

	if (!lua_istable(L, index))
		return false;

	getfloatfield(L, index, "offset",      np->offset);
	getfloatfield(L, index, "scale",       np->scale);
	getfloatfield(L, index, "persist",     np->persist);
	getfloatfield(L, index, "persistence", np->persist);
	getfloatfield(L, index, "lacunarity",  np->lacunarity);
	getintfield(L,   index, "seed",        np->seed);
	getintfield(L,   index, "octaves",     np->octaves);

	u32 flags    = 0;
	u32 flagmask = 0;
	np->flags = getflagsfield(L, index, "flags", flagdesc_noiseparams,
		&flags, &flagmask) ? flags : NOISE_FLAG_DEFAULTS;

	lua_getfield(L, index, "spread");
	np->spread  = read_v3f(L, -1);
	lua_pop(L, 1);

	return true;
}

void push_noiseparams(lua_State *L, NoiseParams *np)
{
	lua_newtable(L);
	lua_pushnumber(L, np->offset);
	lua_setfield(L, -2, "offset");
	lua_pushnumber(L, np->scale);
	lua_setfield(L, -2, "scale");
	lua_pushnumber(L, np->persist);
	lua_setfield(L, -2, "persistence");
	lua_pushnumber(L, np->lacunarity);
	lua_setfield(L, -2, "lacunarity");
	lua_pushnumber(L, np->seed);
	lua_setfield(L, -2, "seed");
	lua_pushnumber(L, np->octaves);
	lua_setfield(L, -2, "octaves");

	push_flags_string(L, flagdesc_noiseparams, np->flags,
		np->flags);
	lua_setfield(L, -2, "flags");

	push_v3f(L, np->spread);
	lua_setfield(L, -2, "spread");
}

/******************************************************************************/