src/script/common/c_content.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19 #include "common/c_content.h"
  20 #include "common/c_converter.h"
  21 #include "common/c_types.h"
  22 #include "nodedef.h"
  23 #include "itemdef.h"
  24 #include "object_properties.h"
  25 #include "cpp_api/s_node.h"
  26 #include "lua_api/l_object.h"
  27 #include "lua_api/l_item.h"
  28 #include "common/c_internal.h"
  29 #include "server.h"
  30 #include "log.h"
  31 #include "tool.h"
  32 #include "serverobject.h"
  33 #include "mapgen.h"
  34 #include "json/json.h"
  35
  36 struct EnumString es_TileAnimationType[] =
  37 {
  38         {TAT_NONE, "none"},
  39         {TAT_VERTICAL_FRAMES, "vertical_frames"},
  40         {0, NULL},
  41 };
  42
  43 /******************************************************************************/
  44 ItemDefinition read_item_definition(lua_State* L,int index,
  45                 ItemDefinition default_def)
  46 {
  47         if(index < 0)
  48                 index = lua_gettop(L) + 1 + index;
  49
  50         // Read the item definition
  51         ItemDefinition def = default_def;
  52
  53         def.type = (ItemType)getenumfield(L, index, "type",
  54                         es_ItemType, ITEM_NONE);
  55         getstringfield(L, index, "name", def.name);
  56         getstringfield(L, index, "description", def.description);
  57         getstringfield(L, index, "inventory_image", def.inventory_image);
  58         getstringfield(L, index, "wield_image", def.wield_image);
  59
  60         lua_getfield(L, index, "wield_scale");
  61         if(lua_istable(L, -1)){
  62                 def.wield_scale = check_v3f(L, -1);
  63         }
  64         lua_pop(L, 1);
  65
  66         def.stack_max = getintfield_default(L, index, "stack_max", def.stack_max);
  67         if(def.stack_max == 0)
  68                 def.stack_max = 1;
  69
  70         lua_getfield(L, index, "on_use");
  71         def.usable = lua_isfunction(L, -1);
  72         lua_pop(L, 1);
  73
  74         getboolfield(L, index, "liquids_pointable", def.liquids_pointable);
  75
  76         warn_if_field_exists(L, index, "tool_digging_properties",
  77                         "deprecated: use tool_capabilities");
  78
  79         lua_getfield(L, index, "tool_capabilities");
  80         if(lua_istable(L, -1)){
  81                 def.tool_capabilities = new ToolCapabilities(
  82                                 read_tool_capabilities(L, -1));
  83         }
  84
  85         // If name is "" (hand), ensure there are ToolCapabilities
  86         // because it will be looked up there whenever any other item has
  87         // no ToolCapabilities
  88         if(def.name == "" && def.tool_capabilities == NULL){
  89                 def.tool_capabilities = new ToolCapabilities();
  90         }
  91
  92         lua_getfield(L, index, "groups");
  93         read_groups(L, -1, def.groups);
  94         lua_pop(L, 1);
  95
  96         lua_getfield(L, index, "sounds");
  97         if(lua_istable(L, -1)){
  98                 lua_getfield(L, -1, "place");
  99                 read_soundspec(L, -1, def.sound_place);
 100                 lua_pop(L, 1);
 101         }
 102         lua_pop(L, 1);
 103
 104         def.range = getfloatfield_default(L, index, "range", def.range);
 105
 106         // Client shall immediately place this node when player places the item.
 107         // Server will update the precise end result a moment later.
 108         // "" = no prediction
 109         getstringfield(L, index, "node_placement_prediction",
 110                         def.node_placement_prediction);
 111
 112         return def;
 113 }
 114
 115 /******************************************************************************/
 116 void read_object_properties(lua_State *L, int index,
 117                 ObjectProperties *prop)
 118 {
 119         if(index < 0)
 120                 index = lua_gettop(L) + 1 + index;
 121         if(!lua_istable(L, index))
 122                 return;
 123
 124         prop->hp_max = getintfield_default(L, -1, "hp_max", 10);
 125
 126         getboolfield(L, -1, "physical", prop->physical);
 127         getboolfield(L, -1, "collide_with_objects", prop->collideWithObjects);
 128
 129         getfloatfield(L, -1, "weight", prop->weight);
 130
 131         lua_getfield(L, -1, "collisionbox");
 132         if(lua_istable(L, -1))
 133                 prop->collisionbox = read_aabb3f(L, -1, 1.0);
 134         lua_pop(L, 1);
 135
 136         getstringfield(L, -1, "visual", prop->visual);
 137
 138         getstringfield(L, -1, "mesh", prop->mesh);
 139
 140         lua_getfield(L, -1, "visual_size");
 141         if(lua_istable(L, -1))
 142                 prop->visual_size = read_v2f(L, -1);
 143         lua_pop(L, 1);
 144
 145         lua_getfield(L, -1, "textures");
 146         if(lua_istable(L, -1)){
 147                 prop->textures.clear();
 148                 int table = lua_gettop(L);
 149                 lua_pushnil(L);
 150                 while(lua_next(L, table) != 0){
 151                         // key at index -2 and value at index -1
 152                         if(lua_isstring(L, -1))
 153                                 prop->textures.push_back(lua_tostring(L, -1));
 154                         else
 155                                 prop->textures.push_back("");
 156                         // removes value, keeps key for next iteration
 157                         lua_pop(L, 1);
 158                 }
 159         }
 160         lua_pop(L, 1);
 161
 162         lua_getfield(L, -1, "colors");
 163         if(lua_istable(L, -1)){
 164                 prop->colors.clear();
 165                 int table = lua_gettop(L);
 166                 lua_pushnil(L);
 167                 while(lua_next(L, table) != 0){
 168                         // key at index -2 and value at index -1
 169                         if(lua_isstring(L, -1))
 170                                 prop->colors.push_back(readARGB8(L, -1));
 171                         else
 172                                 prop->colors.push_back(video::SColor(255, 255, 255, 255));
 173                         // removes value, keeps key for next iteration
 174                         lua_pop(L, 1);
 175                 }
 176         }
 177         lua_pop(L, 1);
 178
 179         lua_getfield(L, -1, "spritediv");
 180         if(lua_istable(L, -1))
 181                 prop->spritediv = read_v2s16(L, -1);
 182         lua_pop(L, 1);
 183
 184         lua_getfield(L, -1, "initial_sprite_basepos");
 185         if(lua_istable(L, -1))
 186                 prop->initial_sprite_basepos = read_v2s16(L, -1);
 187         lua_pop(L, 1);
 188
 189         getboolfield(L, -1, "is_visible", prop->is_visible);
 190         getboolfield(L, -1, "makes_footstep_sound", prop->makes_footstep_sound);
 191         getfloatfield(L, -1, "automatic_rotate", prop->automatic_rotate);
 192         getfloatfield(L, -1, "stepheight", prop->stepheight);
 193         prop->stepheight*=BS;
 194         lua_getfield(L, -1, "automatic_face_movement_dir");
 195         if (lua_isnumber(L, -1)) {
 196                 prop->automatic_face_movement_dir = true;
 197                 prop->automatic_face_movement_dir_offset = luaL_checknumber(L, -1);
 198         } else if (lua_isboolean(L, -1)) {
 199                 prop->automatic_face_movement_dir = lua_toboolean(L, -1);
 200                 prop->automatic_face_movement_dir_offset = 0.0;
 201         }
 202         lua_pop(L, 1);
 203 }
 204
 205 /******************************************************************************/
 206 TileDef read_tiledef(lua_State *L, int index)
 207 {
 208         if(index < 0)
 209                 index = lua_gettop(L) + 1 + index;
 210
 211         TileDef tiledef;
 212
 213         // key at index -2 and value at index
 214         if(lua_isstring(L, index)){
 215                 // "default_lava.png"
 216                 tiledef.name = lua_tostring(L, index);
 217         }
 218         else if(lua_istable(L, index))
 219         {
 220                 // {name="default_lava.png", animation={}}
 221                 tiledef.name = "";
 222                 getstringfield(L, index, "name", tiledef.name);
 223                 getstringfield(L, index, "image", tiledef.name); // MaterialSpec compat.
 224                 tiledef.backface_culling = getboolfield_default(
 225                                         L, index, "backface_culling", true);
 226                 // animation = {}
 227                 lua_getfield(L, index, "animation");
 228                 if(lua_istable(L, -1)){
 229                         // {type="vertical_frames", aspect_w=16, aspect_h=16, length=2.0}
 230                         tiledef.animation.type = (TileAnimationType)
 231                                         getenumfield(L, -1, "type", es_TileAnimationType,
 232                                         TAT_NONE);
 233                         tiledef.animation.aspect_w =
 234                                         getintfield_default(L, -1, "aspect_w", 16);
 235                         tiledef.animation.aspect_h =
 236                                         getintfield_default(L, -1, "aspect_h", 16);
 237                         tiledef.animation.length =
 238                                         getfloatfield_default(L, -1, "length", 1.0);
 239                 }
 240                 lua_pop(L, 1);
 241         }
 242
 243         return tiledef;
 244 }
 245
 246 /******************************************************************************/
 247 ContentFeatures read_content_features(lua_State *L, int index)
 248 {
 249         if(index < 0)
 250                 index = lua_gettop(L) + 1 + index;
 251
 252         ContentFeatures f;
 253
 254         /* Cache existence of some callbacks */
 255         lua_getfield(L, index, "on_construct");
 256         if(!lua_isnil(L, -1)) f.has_on_construct = true;
 257         lua_pop(L, 1);
 258         lua_getfield(L, index, "on_destruct");
 259         if(!lua_isnil(L, -1)) f.has_on_destruct = true;
 260         lua_pop(L, 1);
 261         lua_getfield(L, index, "after_destruct");
 262         if(!lua_isnil(L, -1)) f.has_after_destruct = true;
 263         lua_pop(L, 1);
 264
 265         lua_getfield(L, index, "on_rightclick");
 266         f.rightclickable = lua_isfunction(L, -1);
 267         lua_pop(L, 1);
 268
 269         /* Name */
 270         getstringfield(L, index, "name", f.name);
 271
 272         /* Groups */
 273         lua_getfield(L, index, "groups");
 274         read_groups(L, -1, f.groups);
 275         lua_pop(L, 1);
 276
 277         /* Visual definition */
 278
 279         f.drawtype = (NodeDrawType)getenumfield(L, index, "drawtype",
 280                         ScriptApiNode::es_DrawType,NDT_NORMAL);
 281         getfloatfield(L, index, "visual_scale", f.visual_scale);
 282
 283         // tiles = {}
 284         lua_getfield(L, index, "tiles");
 285         // If nil, try the deprecated name "tile_images" instead
 286         if(lua_isnil(L, -1)){
 287                 lua_pop(L, 1);
 288                 warn_if_field_exists(L, index, "tile_images",
 289                                 "Deprecated; new name is \"tiles\".");
 290                 lua_getfield(L, index, "tile_images");
 291         }
 292         if(lua_istable(L, -1)){
 293                 int table = lua_gettop(L);
 294                 lua_pushnil(L);
 295                 int i = 0;
 296                 while(lua_next(L, table) != 0){
 297                         // Read tiledef from value
 298                         f.tiledef[i] = read_tiledef(L, -1);
 299                         // removes value, keeps key for next iteration
 300                         lua_pop(L, 1);
 301                         i++;
 302                         if(i==6){
 303                                 lua_pop(L, 1);
 304                                 break;
 305                         }
 306                 }
 307                 // Copy last value to all remaining textures
 308                 if(i >= 1){
 309                         TileDef lasttile = f.tiledef[i-1];
 310                         while(i < 6){
 311                                 f.tiledef[i] = lasttile;
 312                                 i++;
 313                         }
 314                 }
 315         }
 316         lua_pop(L, 1);
 317
 318         // special_tiles = {}
 319         lua_getfield(L, index, "special_tiles");
 320         // If nil, try the deprecated name "special_materials" instead
 321         if(lua_isnil(L, -1)){
 322                 lua_pop(L, 1);
 323                 warn_if_field_exists(L, index, "special_materials",
 324                                 "Deprecated; new name is \"special_tiles\".");
 325                 lua_getfield(L, index, "special_materials");
 326         }
 327         if(lua_istable(L, -1)){
 328                 int table = lua_gettop(L);
 329                 lua_pushnil(L);
 330                 int i = 0;
 331                 while(lua_next(L, table) != 0){
 332                         // Read tiledef from value
 333                         f.tiledef_special[i] = read_tiledef(L, -1);
 334                         // removes value, keeps key for next iteration
 335                         lua_pop(L, 1);
 336                         i++;
 337                         if(i==CF_SPECIAL_COUNT){
 338                                 lua_pop(L, 1);
 339                                 break;
 340                         }
 341                 }
 342         }
 343         lua_pop(L, 1);
 344
 345         f.alpha = getintfield_default(L, index, "alpha", 255);
 346
 347         bool usealpha = getboolfield_default(L, index,
 348                         "use_texture_alpha", false);
 349         if (usealpha)
 350                 f.alpha = 0;
 351
 352         /* Other stuff */
 353
 354         lua_getfield(L, index, "post_effect_color");
 355         if(!lua_isnil(L, -1))
 356                 f.post_effect_color = readARGB8(L, -1);
 357         lua_pop(L, 1);
 358
 359         f.param_type = (ContentParamType)getenumfield(L, index, "paramtype",
 360                         ScriptApiNode::es_ContentParamType, CPT_NONE);
 361         f.param_type_2 = (ContentParamType2)getenumfield(L, index, "paramtype2",
 362                         ScriptApiNode::es_ContentParamType2, CPT2_NONE);
 363
 364         // Warn about some deprecated fields
 365         warn_if_field_exists(L, index, "wall_mounted",
 366                         "deprecated: use paramtype2 = 'wallmounted'");
 367         warn_if_field_exists(L, index, "light_propagates",
 368                         "deprecated: determined from paramtype");
 369         warn_if_field_exists(L, index, "dug_item",
 370                         "deprecated: use 'drop' field");
 371         warn_if_field_exists(L, index, "extra_dug_item",
 372                         "deprecated: use 'drop' field");
 373         warn_if_field_exists(L, index, "extra_dug_item_rarity",
 374                         "deprecated: use 'drop' field");
 375         warn_if_field_exists(L, index, "metadata_name",
 376                         "deprecated: use on_add and metadata callbacks");
 377
 378         // True for all ground-like things like stone and mud, false for eg. trees
 379         getboolfield(L, index, "is_ground_content", f.is_ground_content);
 380         f.light_propagates = (f.param_type == CPT_LIGHT);
 381         getboolfield(L, index, "sunlight_propagates", f.sunlight_propagates);
 382         // This is used for collision detection.
 383         // Also for general solidness queries.
 384         getboolfield(L, index, "walkable", f.walkable);
 385         // Player can point to these
 386         getboolfield(L, index, "pointable", f.pointable);
 387         // Player can dig these
 388         getboolfield(L, index, "diggable", f.diggable);
 389         // Player can climb these
 390         getboolfield(L, index, "climbable", f.climbable);
 391         // Player can build on these
 392         getboolfield(L, index, "buildable_to", f.buildable_to);
 393         // Whether the node is non-liquid, source liquid or flowing liquid
 394         f.liquid_type = (LiquidType)getenumfield(L, index, "liquidtype",
 395                         ScriptApiNode::es_LiquidType, LIQUID_NONE);
 396         // If the content is liquid, this is the flowing version of the liquid.
 397         getstringfield(L, index, "liquid_alternative_flowing",
 398                         f.liquid_alternative_flowing);
 399         // If the content is liquid, this is the source version of the liquid.
 400         getstringfield(L, index, "liquid_alternative_source",
 401                         f.liquid_alternative_source);
 402         // Viscosity for fluid flow, ranging from 1 to 7, with
 403         // 1 giving almost instantaneous propagation and 7 being
 404         // the slowest possible
 405         f.liquid_viscosity = getintfield_default(L, index,
 406                         "liquid_viscosity", f.liquid_viscosity);
 407         f.liquid_range = getintfield_default(L, index,
 408                         "liquid_range", f.liquid_range);
 409         f.leveled = getintfield_default(L, index, "leveled", f.leveled);
 410
 411         getboolfield(L, index, "liquid_renewable", f.liquid_renewable);
 412         getstringfield(L, index, "freezemelt", f.freezemelt);
 413         f.drowning = getintfield_default(L, index,
 414                         "drowning", f.drowning);
 415         // Amount of light the node emits
 416         f.light_source = getintfield_default(L, index,
 417                         "light_source", f.light_source);
 418         f.damage_per_second = getintfield_default(L, index,
 419                         "damage_per_second", f.damage_per_second);
 420
 421         lua_getfield(L, index, "node_box");
 422         if(lua_istable(L, -1))
 423                 f.node_box = read_nodebox(L, -1);
 424         lua_pop(L, 1);
 425
 426         lua_getfield(L, index, "selection_box");
 427         if(lua_istable(L, -1))
 428                 f.selection_box = read_nodebox(L, -1);
 429         lua_pop(L, 1);
 430
 431         f.waving = getintfield_default(L, index,
 432                         "waving", f.waving);
 433
 434         // Set to true if paramtype used to be 'facedir_simple'
 435         getboolfield(L, index, "legacy_facedir_simple", f.legacy_facedir_simple);
 436         // Set to true if wall_mounted used to be set to true
 437         getboolfield(L, index, "legacy_wallmounted", f.legacy_wallmounted);
 438
 439         // Sound table
 440         lua_getfield(L, index, "sounds");
 441         if(lua_istable(L, -1)){
 442                 lua_getfield(L, -1, "footstep");
 443                 read_soundspec(L, -1, f.sound_footstep);
 444                 lua_pop(L, 1);
 445                 lua_getfield(L, -1, "dig");
 446                 read_soundspec(L, -1, f.sound_dig);
 447                 lua_pop(L, 1);
 448                 lua_getfield(L, -1, "dug");
 449                 read_soundspec(L, -1, f.sound_dug);
 450                 lua_pop(L, 1);
 451         }
 452         lua_pop(L, 1);
 453
 454         return f;
 455 }
 456
 457 /******************************************************************************/
 458 void read_server_sound_params(lua_State *L, int index,
 459                 ServerSoundParams &params)
 460 {
 461         if(index < 0)
 462                 index = lua_gettop(L) + 1 + index;
 463         // Clear
 464         params = ServerSoundParams();
 465         if(lua_istable(L, index)){
 466                 getfloatfield(L, index, "gain", params.gain);
 467                 getstringfield(L, index, "to_player", params.to_player);
 468                 lua_getfield(L, index, "pos");
 469                 if(!lua_isnil(L, -1)){
 470                         v3f p = read_v3f(L, -1)*BS;
 471                         params.pos = p;
 472                         params.type = ServerSoundParams::SSP_POSITIONAL;
 473                 }
 474                 lua_pop(L, 1);
 475                 lua_getfield(L, index, "object");
 476                 if(!lua_isnil(L, -1)){
 477                         ObjectRef *ref = ObjectRef::checkobject(L, -1);
 478                         ServerActiveObject *sao = ObjectRef::getobject(ref);
 479                         if(sao){
 480                                 params.object = sao->getId();
 481                                 params.type = ServerSoundParams::SSP_OBJECT;
 482                         }
 483                 }
 484                 lua_pop(L, 1);
 485                 params.max_hear_distance = BS*getfloatfield_default(L, index,
 486                                 "max_hear_distance", params.max_hear_distance/BS);
 487                 getboolfield(L, index, "loop", params.loop);
 488         }
 489 }
 490
 491 /******************************************************************************/
 492 void read_soundspec(lua_State *L, int index, SimpleSoundSpec &spec)
 493 {
 494         if(index < 0)
 495                 index = lua_gettop(L) + 1 + index;
 496         if(lua_isnil(L, index)){
 497         } else if(lua_istable(L, index)){
 498                 getstringfield(L, index, "name", spec.name);
 499                 getfloatfield(L, index, "gain", spec.gain);
 500         } else if(lua_isstring(L, index)){
 501                 spec.name = lua_tostring(L, index);
 502         }
 503 }
 504
 505 /******************************************************************************/
 506 NodeBox read_nodebox(lua_State *L, int index)
 507 {
 508         NodeBox nodebox;
 509         if(lua_istable(L, -1)){
 510                 nodebox.type = (NodeBoxType)getenumfield(L, index, "type",
 511                                 ScriptApiNode::es_NodeBoxType, NODEBOX_REGULAR);
 512
 513                 lua_getfield(L, index, "fixed");
 514                 if(lua_istable(L, -1))
 515                         nodebox.fixed = read_aabb3f_vector(L, -1, BS);
 516                 lua_pop(L, 1);
 517
 518                 lua_getfield(L, index, "wall_top");
 519                 if(lua_istable(L, -1))
 520                         nodebox.wall_top = read_aabb3f(L, -1, BS);
 521                 lua_pop(L, 1);
 522
 523                 lua_getfield(L, index, "wall_bottom");
 524                 if(lua_istable(L, -1))
 525                         nodebox.wall_bottom = read_aabb3f(L, -1, BS);
 526                 lua_pop(L, 1);
 527
 528                 lua_getfield(L, index, "wall_side");
 529                 if(lua_istable(L, -1))
 530                         nodebox.wall_side = read_aabb3f(L, -1, BS);
 531                 lua_pop(L, 1);
 532         }
 533         return nodebox;
 534 }
 535
 536 /******************************************************************************/
 537 MapNode readnode(lua_State *L, int index, INodeDefManager *ndef)
 538 {
 539         lua_getfield(L, index, "name");
 540         const char *name = luaL_checkstring(L, -1);
 541         lua_pop(L, 1);
 542         u8 param1;
 543         lua_getfield(L, index, "param1");
 544         if(lua_isnil(L, -1))
 545                 param1 = 0;
 546         else
 547                 param1 = lua_tonumber(L, -1);
 548         lua_pop(L, 1);
 549         u8 param2;
 550         lua_getfield(L, index, "param2");
 551         if(lua_isnil(L, -1))
 552                 param2 = 0;
 553         else
 554                 param2 = lua_tonumber(L, -1);
 555         lua_pop(L, 1);
 556         return MapNode(ndef, name, param1, param2);
 557 }
 558
 559 /******************************************************************************/
 560 void pushnode(lua_State *L, const MapNode &n, INodeDefManager *ndef)
 561 {
 562         lua_newtable(L);
 563         lua_pushstring(L, ndef->get(n).name.c_str());
 564         lua_setfield(L, -2, "name");
 565         lua_pushnumber(L, n.getParam1());
 566         lua_setfield(L, -2, "param1");
 567         lua_pushnumber(L, n.getParam2());
 568         lua_setfield(L, -2, "param2");
 569 }
 570
 571 /******************************************************************************/
 572 void warn_if_field_exists(lua_State *L, int table,
 573                 const char *fieldname, const std::string &message)
 574 {
 575         lua_getfield(L, table, fieldname);
 576         if(!lua_isnil(L, -1)){
 577 //TODO find way to access backtrace fct from here
 578                 //              infostream<<script_get_backtrace(L)<<std::endl;
 579                 infostream<<"WARNING: field \""<<fieldname<<"\": "
 580                                 <<message<<std::endl;
 581         }
 582         lua_pop(L, 1);
 583 }
 584
 585 /******************************************************************************/
 586 int getenumfield(lua_State *L, int table,
 587                 const char *fieldname, const EnumString *spec, int default_)
 588 {
 589         int result = default_;
 590         string_to_enum(spec, result,
 591                         getstringfield_default(L, table, fieldname, ""));
 592         return result;
 593 }
 594
 595 /******************************************************************************/
 596 bool string_to_enum(const EnumString *spec, int &result,
 597                 const std::string &str)
 598 {
 599         const EnumString *esp = spec;
 600         while(esp->str){
 601                 if(str == std::string(esp->str)){
 602                         result = esp->num;
 603                         return true;
 604                 }
 605                 esp++;
 606         }
 607         return false;
 608 }
 609
 610 /******************************************************************************/
 611 ItemStack read_item(lua_State* L, int index,Server* srv)
 612 {
 613         if(index < 0)
 614                 index = lua_gettop(L) + 1 + index;
 615
 616         if(lua_isnil(L, index))
 617         {
 618                 return ItemStack();
 619         }
 620         else if(lua_isuserdata(L, index))
 621         {
 622                 // Convert from LuaItemStack
 623                 LuaItemStack *o = LuaItemStack::checkobject(L, index);
 624                 return o->getItem();
 625         }
 626         else if(lua_isstring(L, index))
 627         {
 628                 // Convert from itemstring
 629                 std::string itemstring = lua_tostring(L, index);
 630                 IItemDefManager *idef = srv->idef();
 631                 try
 632                 {
 633                         ItemStack item;
 634                         item.deSerialize(itemstring, idef);
 635                         return item;
 636                 }
 637                 catch(SerializationError &e)
 638                 {
 639                         infostream<<"WARNING: unable to create item from itemstring"
 640                                         <<": "<<itemstring<<std::endl;
 641                         return ItemStack();
 642                 }
 643         }
 644         else if(lua_istable(L, index))
 645         {
 646                 // Convert from table
 647                 IItemDefManager *idef = srv->idef();
 648                 std::string name = getstringfield_default(L, index, "name", "");
 649                 int count = getintfield_default(L, index, "count", 1);
 650                 int wear = getintfield_default(L, index, "wear", 0);
 651                 std::string metadata = getstringfield_default(L, index, "metadata", "");
 652                 return ItemStack(name, count, wear, metadata, idef);
 653         }
 654         else
 655         {
 656                 throw LuaError(NULL, "Expecting itemstack, itemstring, table or nil");
 657         }
 658 }
 659
 660 /******************************************************************************/
 661 void push_tool_capabilities(lua_State *L,
 662                 const ToolCapabilities &toolcap)
 663 {
 664         lua_newtable(L);
 665         setfloatfield(L, -1, "full_punch_interval", toolcap.full_punch_interval);
 666                 setintfield(L, -1, "max_drop_level", toolcap.max_drop_level);
 667                 // Create groupcaps table
 668                 lua_newtable(L);
 669                 // For each groupcap
 670                 for(std::map<std::string, ToolGroupCap>::const_iterator
 671                                 i = toolcap.groupcaps.begin(); i != toolcap.groupcaps.end(); i++){
 672                         // Create groupcap table
 673                         lua_newtable(L);
 674                         const std::string &name = i->first;
 675                         const ToolGroupCap &groupcap = i->second;
 676                         // Create subtable "times"
 677                         lua_newtable(L);
 678                         for(std::map<int, float>::const_iterator
 679                                         i = groupcap.times.begin(); i != groupcap.times.end(); i++){
 680                                 int rating = i->first;
 681                                 float time = i->second;
 682                                 lua_pushinteger(L, rating);
 683                                 lua_pushnumber(L, time);
 684                                 lua_settable(L, -3);
 685                         }
 686                         // Set subtable "times"
 687                         lua_setfield(L, -2, "times");
 688                         // Set simple parameters
 689                         setintfield(L, -1, "maxlevel", groupcap.maxlevel);
 690                         setintfield(L, -1, "uses", groupcap.uses);
 691                         // Insert groupcap table into groupcaps table
 692                         lua_setfield(L, -2, name.c_str());
 693                 }
 694                 // Set groupcaps table
 695                 lua_setfield(L, -2, "groupcaps");
 696                 //Create damage_groups table
 697                 lua_newtable(L);
 698                 // For each damage group
 699                 for(std::map<std::string, s16>::const_iterator
 700                                 i = toolcap.damageGroups.begin(); i != toolcap.damageGroups.end(); i++){
 701                         // Create damage group table
 702                         lua_pushinteger(L, i->second);
 703                         lua_setfield(L, -2, i->first.c_str());
 704                 }
 705                 lua_setfield(L, -2, "damage_groups");
 706 }
 707
 708 /******************************************************************************/
 709 void push_inventory_list(lua_State *L, Inventory *inv, const char *name)
 710 {
 711         InventoryList *invlist = inv->getList(name);
 712         if(invlist == NULL){
 713                 lua_pushnil(L);
 714                 return;
 715         }
 716         std::vector<ItemStack> items;
 717         for(u32 i=0; i<invlist->getSize(); i++)
 718                 items.push_back(invlist->getItem(i));
 719         push_items(L, items);
 720 }
 721
 722 /******************************************************************************/
 723 void read_inventory_list(lua_State *L, int tableindex,
 724                 Inventory *inv, const char *name, Server* srv, int forcesize)
 725 {
 726         if(tableindex < 0)
 727                 tableindex = lua_gettop(L) + 1 + tableindex;
 728         // If nil, delete list
 729         if(lua_isnil(L, tableindex)){
 730                 inv->deleteList(name);
 731                 return;
 732         }
 733         // Otherwise set list
 734         std::vector<ItemStack> items = read_items(L, tableindex,srv);
 735         int listsize = (forcesize != -1) ? forcesize : items.size();
 736         InventoryList *invlist = inv->addList(name, listsize);
 737         int index = 0;
 738         for(std::vector<ItemStack>::const_iterator
 739                         i = items.begin(); i != items.end(); i++){
 740                 if(forcesize != -1 && index == forcesize)
 741                         break;
 742                 invlist->changeItem(index, *i);
 743                 index++;
 744         }
 745         while(forcesize != -1 && index < forcesize){
 746                 invlist->deleteItem(index);
 747                 index++;
 748         }
 749 }
 750
 751 /******************************************************************************/
 752 ToolCapabilities read_tool_capabilities(
 753                 lua_State *L, int table)
 754 {
 755         ToolCapabilities toolcap;
 756         getfloatfield(L, table, "full_punch_interval", toolcap.full_punch_interval);
 757         getintfield(L, table, "max_drop_level", toolcap.max_drop_level);
 758         lua_getfield(L, table, "groupcaps");
 759         if(lua_istable(L, -1)){
 760                 int table_groupcaps = lua_gettop(L);
 761                 lua_pushnil(L);
 762                 while(lua_next(L, table_groupcaps) != 0){
 763                         // key at index -2 and value at index -1
 764                         std::string groupname = luaL_checkstring(L, -2);
 765                         if(lua_istable(L, -1)){
 766                                 int table_groupcap = lua_gettop(L);
 767                                 // This will be created
 768                                 ToolGroupCap groupcap;
 769                                 // Read simple parameters
 770                                 getintfield(L, table_groupcap, "maxlevel", groupcap.maxlevel);
 771                                 getintfield(L, table_groupcap, "uses", groupcap.uses);
 772                                 // DEPRECATED: maxwear
 773                                 float maxwear = 0;
 774                                 if(getfloatfield(L, table_groupcap, "maxwear", maxwear)){
 775                                         if(maxwear != 0)
 776                                                 groupcap.uses = 1.0/maxwear;
 777                                         else
 778                                                 groupcap.uses = 0;
 779                                         infostream<<script_get_backtrace(L)<<std::endl;
 780                                         infostream<<"WARNING: field \"maxwear\" is deprecated; "
 781                                                         <<"should replace with uses=1/maxwear"<<std::endl;
 782                                 }
 783                                 // Read "times" table
 784                                 lua_getfield(L, table_groupcap, "times");
 785                                 if(lua_istable(L, -1)){
 786                                         int table_times = lua_gettop(L);
 787                                         lua_pushnil(L);
 788                                         while(lua_next(L, table_times) != 0){
 789                                                 // key at index -2 and value at index -1
 790                                                 int rating = luaL_checkinteger(L, -2);
 791                                                 float time = luaL_checknumber(L, -1);
 792                                                 groupcap.times[rating] = time;
 793                                                 // removes value, keeps key for next iteration
 794                                                 lua_pop(L, 1);
 795                                         }
 796                                 }
 797                                 lua_pop(L, 1);
 798                                 // Insert groupcap into toolcap
 799                                 toolcap.groupcaps[groupname] = groupcap;
 800                         }
 801                         // removes value, keeps key for next iteration
 802                         lua_pop(L, 1);
 803                 }
 804         }
 805         lua_pop(L, 1);
 806
 807         lua_getfield(L, table, "damage_groups");
 808         if(lua_istable(L, -1)){
 809                 int table_damage_groups = lua_gettop(L);
 810                 lua_pushnil(L);
 811                 while(lua_next(L, table_damage_groups) != 0){
 812                         // key at index -2 and value at index -1
 813                         std::string groupname = luaL_checkstring(L, -2);
 814                         u16 value = luaL_checkinteger(L, -1);
 815                         toolcap.damageGroups[groupname] = value;
 816                         // removes value, keeps key for next iteration
 817                         lua_pop(L, 1);
 818                 }
 819         }
 820         lua_pop(L, 1);
 821         return toolcap;
 822 }
 823
 824 /******************************************************************************/
 825 void push_dig_params(lua_State *L,const DigParams &params)
 826 {
 827         lua_newtable(L);
 828         setboolfield(L, -1, "diggable", params.diggable);
 829         setfloatfield(L, -1, "time", params.time);
 830         setintfield(L, -1, "wear", params.wear);
 831 }
 832
 833 /******************************************************************************/
 834 void push_hit_params(lua_State *L,const HitParams &params)
 835 {
 836         lua_newtable(L);
 837         setintfield(L, -1, "hp", params.hp);
 838         setintfield(L, -1, "wear", params.wear);
 839 }
 840
 841 /******************************************************************************/
 842 u32 getflagsfield(lua_State *L, int table,
 843         const char *fieldname, FlagDesc *flagdesc) {
 844         std::string flagstring;
 845
 846         flagstring = getstringfield_default(L, table, fieldname, "");
 847         return readFlagString(flagstring, flagdesc);
 848 }
 849
 850 /******************************************************************************/
 851 /* Lua Stored data!                                                           */
 852 /******************************************************************************/
 853
 854 /******************************************************************************/
 855 void read_groups(lua_State *L, int index,
 856                 std::map<std::string, int> &result)
 857 {
 858         if (!lua_istable(L,index))
 859                 return;
 860         result.clear();
 861         lua_pushnil(L);
 862         if(index < 0)
 863                 index -= 1;
 864         while(lua_next(L, index) != 0){
 865                 // key at index -2 and value at index -1
 866                 std::string name = luaL_checkstring(L, -2);
 867                 int rating = luaL_checkinteger(L, -1);
 868                 result[name] = rating;
 869                 // removes value, keeps key for next iteration
 870                 lua_pop(L, 1);
 871         }
 872 }
 873
 874 /******************************************************************************/
 875 void push_items(lua_State *L, const std::vector<ItemStack> &items)
 876 {
 877         // Create and fill table
 878         lua_createtable(L, items.size(), 0);
 879         std::vector<ItemStack>::const_iterator iter = items.begin();
 880         for (u32 i = 0; iter != items.end(); iter++) {
 881                 LuaItemStack::create(L, *iter);
 882                 lua_rawseti(L, -2, ++i);
 883         }
 884 }
 885
 886 /******************************************************************************/
 887 std::vector<ItemStack> read_items(lua_State *L, int index, Server *srv)
 888 {
 889         if(index < 0)
 890                 index = lua_gettop(L) + 1 + index;
 891
 892         std::vector<ItemStack> items;
 893         luaL_checktype(L, index, LUA_TTABLE);
 894         lua_pushnil(L);
 895         while (lua_next(L, index)) {
 896                 s32 key = luaL_checkinteger(L, -2);
 897                 if (key < 1) {
 898                         throw LuaError(NULL, "Invalid inventory list index");
 899                 }
 900                 if (items.size() < (u32) key) {
 901                         items.resize(key);
 902                 }
 903                 items[key - 1] = read_item(L, -1, srv);
 904                 lua_pop(L, 1);
 905         }
 906         return items;
 907 }
 908
 909 /******************************************************************************/
 910 void luaentity_get(lua_State *L, u16 id)
 911 {
 912         // Get minetest.luaentities[i]
 913         lua_getglobal(L, "minetest");
 914         lua_getfield(L, -1, "luaentities");
 915         luaL_checktype(L, -1, LUA_TTABLE);
 916         lua_pushnumber(L, id);
 917         lua_gettable(L, -2);
 918         lua_remove(L, -2); // luaentities
 919         lua_remove(L, -2); // minetest
 920 }
 921
 922 /******************************************************************************/
 923 NoiseParams *read_noiseparams(lua_State *L, int index)
 924 {
 925         if (index < 0)
 926                 index = lua_gettop(L) + 1 + index;
 927
 928         if (!lua_istable(L, index))
 929                 return NULL;
 930
 931         NoiseParams *np = new NoiseParams;
 932
 933         np->offset  = getfloatfield_default(L, index, "offset", 0.0);
 934         np->scale   = getfloatfield_default(L, index, "scale", 0.0);
 935         lua_getfield(L, index, "spread");
 936         np->spread  = read_v3f(L, -1);
 937         lua_pop(L, 1);
 938         np->seed    = getintfield_default(L, index, "seed", 0);
 939         np->octaves = getintfield_default(L, index, "octaves", 0);
 940         np->persist = getfloatfield_default(L, index, "persist", 0.0);
 941
 942         return np;
 943 }
 944
 945 /******************************************************************************/
 946 bool read_schematic(lua_State *L, int index, DecoSchematic *dschem, Server *server) {
 947         if (index < 0)
 948                 index = lua_gettop(L) + 1 + index;
 949
 950         INodeDefManager *ndef = server->getNodeDefManager();
 951
 952         if (lua_istable(L, index)) {
 953                 lua_getfield(L, index, "size");
 954                 v3s16 size = read_v3s16(L, -1);
 955                 lua_pop(L, 1);
 956
 957                 int numnodes = size.X * size.Y * size.Z;
 958                 MapNode *schemdata = new MapNode[numnodes];
 959                 int i = 0;
 960
 961                 // Get schematic data
 962                 lua_getfield(L, index, "data");
 963                 luaL_checktype(L, -1, LUA_TTABLE);
 964
 965                 lua_pushnil(L);
 966                 while (lua_next(L, -2)) {
 967                         if (i < numnodes) {
 968                                 // same as readnode, except param1 default is MTSCHEM_PROB_CONST
 969                                 lua_getfield(L, -1, "name");
 970                                 const char *name = luaL_checkstring(L, -1);
 971                                 lua_pop(L, 1);
 972
 973                                 u8 param1;
 974                                 lua_getfield(L, -1, "param1");
 975                                 param1 = !lua_isnil(L, -1) ? lua_tonumber(L, -1) : MTSCHEM_PROB_ALWAYS;
 976                                 lua_pop(L, 1);
 977
 978                                 u8 param2;
 979                                 lua_getfield(L, -1, "param2");
 980                                 param2 = !lua_isnil(L, -1) ? lua_tonumber(L, -1) : 0;
 981                                 lua_pop(L, 1);
 982
 983                                 schemdata[i] = MapNode(ndef, name, param1, param2);
 984                         }
 985
 986                         i++;
 987                         lua_pop(L, 1);
 988                 }
 989
 990                 if (i != numnodes) {
 991                         errorstream << "read_schematic: incorrect number of "
 992                                 "nodes provided in raw schematic data (got " << i <<
 993                                 ", expected " << numnodes << ")." << std::endl;
 994                         return false;
 995                 }
 996
 997                 u8 *sliceprobs = new u8[size.Y];
 998                 for (i = 0; i != size.Y; i++)
 999                         sliceprobs[i] = MTSCHEM_PROB_ALWAYS;
1000
1001                 // Get Y-slice probability values (if present)
1002                 lua_getfield(L, index, "yslice_prob");
1003                 if (lua_istable(L, -1)) {
1004                         lua_pushnil(L);
1005                         while (lua_next(L, -2)) {
1006                                 if (getintfield(L, -1, "ypos", i) && i >= 0 && i < size.Y) {
1007                                         sliceprobs[i] = getintfield_default(L, -1,
1008                                                 "prob", MTSCHEM_PROB_ALWAYS);
1009                                 }
1010                                 lua_pop(L, 1);
1011                         }
1012                 }
1013
1014                 dschem->size        = size;
1015                 dschem->schematic   = schemdata;
1016                 dschem->slice_probs = sliceprobs;
1017
1018         } else if (lua_isstring(L, index)) {
1019                 dschem->filename = std::string(lua_tostring(L, index));
1020         } else {
1021                 errorstream << "read_schematic: missing schematic "
1022                         "filename or raw schematic data" << std::endl;
1023                 return false;
1024         }
1025
1026         return true;
1027 }
1028
1029 /******************************************************************************/
1030 // Returns depth of json value tree
1031 static int push_json_value_getdepth(const Json::Value &value)
1032 {
1033         if (!value.isArray() && !value.isObject())
1034                 return 1;
1035
1036         int maxdepth = 0;
1037         for (Json::Value::const_iterator it = value.begin();
1038                         it != value.end(); ++it) {
1039                 int elemdepth = push_json_value_getdepth(*it);
1040                 if (elemdepth > maxdepth)
1041                         maxdepth = elemdepth;
1042         }
1043         return maxdepth + 1;
1044 }
1045 // Recursive function to convert JSON --> Lua table
1046 static bool push_json_value_helper(lua_State *L, const Json::Value &value,
1047                 int nullindex)
1048 {
1049         switch(value.type()) {
1050                 case Json::nullValue:
1051                 default:
1052                         lua_pushvalue(L, nullindex);
1053                         break;
1054                 case Json::intValue:
1055                         lua_pushinteger(L, value.asInt());
1056                         break;
1057                 case Json::uintValue:
1058                         lua_pushinteger(L, value.asUInt());
1059                         break;
1060                 case Json::realValue:
1061                         lua_pushnumber(L, value.asDouble());
1062                         break;
1063                 case Json::stringValue:
1064                         {
1065                                 const char *str = value.asCString();
1066                                 lua_pushstring(L, str ? str : "");
1067                         }
1068                         break;
1069                 case Json::booleanValue:
1070                         lua_pushboolean(L, value.asInt());
1071                         break;
1072                 case Json::arrayValue:
1073                         lua_newtable(L);
1074                         for (Json::Value::const_iterator it = value.begin();
1075                                         it != value.end(); ++it) {
1076                                 push_json_value_helper(L, *it, nullindex);
1077                                 lua_rawseti(L, -2, it.index() + 1);
1078                         }
1079                         break;
1080                 case Json::objectValue:
1081                         lua_newtable(L);
1082                         for (Json::Value::const_iterator it = value.begin();
1083                                         it != value.end(); ++it) {
1084                                 const char *str = it.memberName();
1085                                 lua_pushstring(L, str ? str : "");
1086                                 push_json_value_helper(L, *it, nullindex);
1087                                 lua_rawset(L, -3);
1088                         }
1089                         break;
1090         }
1091         return true;
1092 }
1093 // converts JSON --> Lua table; returns false if lua stack limit exceeded
1094 // nullindex: Lua stack index of value to use in place of JSON null
1095 bool push_json_value(lua_State *L, const Json::Value &value, int nullindex)
1096 {
1097         if(nullindex < 0)
1098                 nullindex = lua_gettop(L) + 1 + nullindex;
1099
1100         int depth = push_json_value_getdepth(value);
1101
1102         // The maximum number of Lua stack slots used at each recursion level
1103         // of push_json_value_helper is 2, so make sure there a depth * 2 slots
1104         if (lua_checkstack(L, depth * 2))
1105                 return push_json_value_helper(L, value, nullindex);
1106         else
1107                 return false;
1108 }
1109
1110 // Converts Lua table --> JSON
1111 void read_json_value(lua_State *L, Json::Value &root, int index, u8 recursion)
1112 {
1113         if (recursion > 16) {
1114                 throw SerializationError("Maximum recursion depth exceeded");
1115         }
1116         int type = lua_type(L, index);
1117         if (type == LUA_TBOOLEAN) {
1118                 root = (bool) lua_toboolean(L, index);
1119         } else if (type == LUA_TNUMBER) {
1120                 root = lua_tonumber(L, index);
1121         } else if (type == LUA_TSTRING) {
1122                 size_t len;
1123                 const char *str = lua_tolstring(L, index, &len);
1124                 root = std::string(str, len);
1125         } else if (type == LUA_TTABLE) {
1126                 lua_pushnil(L);
1127                 while (lua_next(L, index)) {
1128                         // Key is at -2 and value is at -1
1129                         Json::Value value;
1130                         read_json_value(L, value, lua_gettop(L), recursion + 1);
1131
1132                         Json::ValueType roottype = root.type();
1133                         int keytype = lua_type(L, -1);
1134                         if (keytype == LUA_TNUMBER) {
1135                                 lua_Number key = lua_tonumber(L, -1);
1136                                 if (roottype != Json::nullValue && roottype != Json::arrayValue) {
1137                                         throw SerializationError("Can't mix array and object values in JSON");
1138                                 } else if (key < 1) {
1139                                         throw SerializationError("Can't use zero-based or negative indexes in JSON");
1140                                 } else if (floor(key) != key) {
1141                                         throw SerializationError("Can't use indexes with a fractional part in JSON");
1142                                 }
1143                                 root[(Json::ArrayIndex) key - 1] = value;
1144                         } else if (keytype == LUA_TSTRING) {
1145                                 if (roottype != Json::nullValue && roottype != Json::objectValue) {
1146                                         throw SerializationError("Can't mix array and object values in JSON");
1147                                 }
1148                                 root[lua_tostring(L, -1)] = value;
1149                         } else {
1150                                 throw SerializationError("Lua key to convert to JSON is not a string or number");
1151                         }
1152                 }
1153         } else if (type == LUA_TNIL) {
1154                 root = Json::nullValue;
1155         } else {
1156                 throw SerializationError("Can only store booleans, numbers, strings, objects, arrays, and null in JSON");
1157         }
1158         lua_pop(L, 1); // Pop value
1159 }
1160