1 Minetest Lua Modding API Reference 0.4.dev
2 ==========================================
3 More information at http://c55.me/minetest/
7 Content and functionality can be added to Minetest 0.4 by using Lua
8 scripting in run-time loaded mods.
10 A mod is a self-contained bunch of scripts, textures and other related
11 things that is loaded by and interfaces with Minetest.
13 Mods are contained and ran solely on the server side. Definitions and media
14 files are automatically transferred to the client.
16 If you see a deficiency in the API, feel free to attempt to add the
17 functionality in the engine and API. You can send such improvements as
18 source code patches to <celeron55@gmail.com>.
22 If you have any difficulty in understanding this, please read:
23 http://www.lua.org/pil/
27 Mods are loaded during server startup from the mod load paths by running
33 $path_share/games/gameid/mods/
34 $path_share/mods/gameid/
35 $path_user/games/gameid/mods/
36 $path_user/mods/gameid/ <-- User-installed mods
39 In a run-in-place version (eg. the distributed windows version):
40 minetest-0.4.x/games/gameid/mods/
41 minetest-0.4.x/mods/gameid/ <-- User-installed mods
42 minetest-0.4.x/worlds/worldname/worldmods/
44 On an installed version on linux:
45 /usr/share/minetest/games/gameid/mods/
46 ~/.minetest/mods/gameid/ <-- User-installed mods
47 ~/.minetest/worlds/worldname/worldmods
49 Mod directory structure
50 ------------------------
56 | | |-- modname_stuff.png
57 | | `-- modname_something_else.png
62 The location of this directory can be fetched by using
63 minetest.get_modpath(modname)
66 List of mods that have to be loaded before loading this mod.
67 A single line contains a single modname.
70 The main Lua script. Running this script should register everything it
71 wants to register. Subsequent execution depends on minetest calling the
74 minetest.setting_get(name) and minetest.setting_getbool(name) can be used
75 to read custom or existing settings at load time, if necessary.
78 These textures will be transferred to the client and can be referred to
81 Naming convention for registered textual names
82 ----------------------------------------------
83 Registered names should generally be in this format:
84 "modname:<whatever>" (<whatever> can have characters a-zA-Z0-9_)
86 This is to prevent conflicting names from corrupting maps and is
87 enforced by the mod loader.
89 Example: mod "experimental", ideal item/node/entity name "tnt":
90 -> the name should be "experimental:tnt".
92 Enforcement can be overridden by prefixing the name with ":". This can
93 be used for overriding the registrations of some other mod.
95 Example: Any mod can redefine experimental:tnt by using the name
96 ":experimental:tnt" when registering it.
97 (also that mod is required to have "experimental" as a dependency)
99 The ":" prefix can also be used for maintaining backwards compatibility.
103 Aliases can be added by using minetest.register_alias(name, convert_to)
105 This will make Minetest to convert things called name to things called
108 This can be used for maintaining backwards compatibility.
110 This can be also used for setting quick access names for things, eg. if
111 you have an item called epiclylongmodname:stuff, you could do
112 minetest.register_alias("stuff", "epiclylongmodname:stuff")
113 and be able to use "/giveme stuff".
117 Mods should generally prefix their textures with modname_, eg. given
118 the mod name "foomod", a texture could be called
119 "foomod_foothing.png"
121 Representations of simple things
122 --------------------------------
123 MapNode representation:
124 {name="name", param1=num, param2=num}
126 MapNodes do not directly have any other data associated with them.
127 If you want to access the definition of the node, you access
128 minetest.registered_nodes[node.name]
130 param1 and param2 are 8 bit and 4 bit integers, respectively. They
131 are reserved for certain automated functions. If you don't use these
132 functions, you can use them to store arbitrary values.
134 param1 is reserved for the engine when:
136 param2 is reserved for the engine when any of these are used:
137 liquidtype == "flowing"
138 drawtype == "flowingliquid"
139 drawtype == "torchlike"
140 drawtype == "signlike"
143 {x=num, y=num, z=num}
144 Currently the API does not provide any helper functions for addition,
145 subtraction and whatever; you can define those that you need yourself.
147 stackstring/itemstring: A stack of items in serialized format.
149 eg. 'default:pick_wood 21323'
152 item: A stack of items in Lua table format.
153 eg. {name="default:dirt", count=5, wear=0, metadata=""}
155 eg. {name="default:pick_wood", count=1, wear=21323, metadata=""}
156 ^ a wooden pick about 1/3 weared out
157 eg. {name="default:apple", count=1, wear=0, metadata=""}
160 Any time an item must be passed to a function, it can be an
161 ItemStack (see below), an itemstring or a table in the above format.
165 eg. "default_place_node"
167 eg. {name="default_place_node"}
168 eg. {name="default_place_node", gain=1.0}
172 Node (register_node):
173 A node from the world
174 Tool (register_tool):
175 A tool/weapon that can dig and damage things according to tool_capabilities
176 Craftitem (register_craftitem):
181 In a number of places, there is a group table. Groups define the
182 properties of a thing (item, node, armor of entity, capabilities of
183 tool) in such a way that the engine and other mods can can interact with
184 the thing without actually knowing what the thing is.
187 - Groups are stored in a table, having the group names with keys and the
188 group ratings as values. For example:
189 groups = {crumbly=3, soil=1}
190 ^ Default dirt (soil group actually currently not defined; TODO)
191 groups = {crumbly=2, soil=1, level=2, outerspace=1}
192 ^ A more special dirt-kind of thing
193 - Groups always have a rating associated with them. If there is no
194 useful meaning for a rating for an enabled group, it shall be 1.
195 - When not defined, the rating of a group defaults to 0. Thus when you
196 read groups, you must interpret nil and 0 as the same value, 0.
200 Groups of items can define what kind of an item it is (eg. wool).
204 In addition to the general item things, whether a node is diggable and how
205 long it takes is defined by using groups.
209 For entities, groups are, as of now, used only for calculating damage.
211 object.get_armor_groups() -> a group-rating table (eg. {fleshy=3})
212 object.set_armor_groups({level=2, fleshy=2, cracky=2})
216 Groups in tools define which groups of nodes and entities they are
219 Groups in crafting recipes
220 ---------------------------
221 - Not implemented yet. (TODO)
222 - Will probably look like this:
224 output = 'food:meat_soup_raw',
230 preserve = {'group:bowl'},
235 - immortal: Disables the group damage system for an entity
236 - level: Can be used to give an additional sense of progression in the game.
237 - A larger level will cause eg. a weapon of a lower level make much less
238 damage, and get weared out much faster, or not be able to get drops
239 from destroyed nodes.
240 - 0 is something that is directly accessible at the start of gameplay
241 - dig_immediate: (player can always pick up node without tool wear)
242 - 2: node is removed without tool wear after 0.5 seconds or so
244 - 3: node is removed without tool wear immediately (torch)
246 Known damage and digging time defining groups
247 ----------------------------------------------
248 - crumbly: dirt, sand
249 - cracky: tough but crackable stuff like stone.
250 - snappy: something that can be cut using fine tools; eg. leaves, small
251 plants, wire, sheets of metal
252 - choppy: something that can be cut using force; eg. trees, wooden planks
253 - fleshy: Living things like animals and the player. This could imply
254 some blood effects when hitting.
255 - explody: Especially prone to explosions
256 - oddly_breakable_by_hand:
257 Can be added to nodes that shouldn't logically be breakable by the
258 hand but are. Somewhat similar to dig_immediate, but times are more
259 like {[1]=3.50,[2]=2.00,[3]=0.70} and this does not override the
260 speed of a tool if the tool can dig at a larger speed than this
261 suggests for the hand.
263 Examples of custom groups
264 --------------------------
265 Item groups are often used for defining, well, //groups of items//.
266 - meat: any meat-kind of a thing (rating might define the size or healing
267 ability or be irrelevant - it is not defined as of yet)
268 - eatable: anything that can be eaten. Rating might define HP gain in half
270 - flammable: can be set on fire. Rating might define the intensity of the
271 fire, affecting eg. the speed of the spreading of an open fire.
272 - wool: any wool (any origin, any color)
275 - heavy: anything considerably heavy
277 Digging time calculation specifics
278 -----------------------------------
279 Groups such as **crumbly**, **cracky** and **snappy** are used for this
280 purpose. Rating is 1, 2 or 3. A higher rating for such a group implies
283 Also, the **level** group is used.
285 Tools define their properties by a list of parameters for groups. They
286 cannot dig other groups; thus it is important to use a standard bunch of
287 groups to enable interaction with tools.
289 **Example definition of the digging capabilities of a tool:**
290 tool_capabilities = {
291 full_punch_interval=1.5,
294 crumbly={maxwear=0.01, maxlevel=2, times={[1]=0.80, [2]=0.60, [3]=0.40}}
299 * Full punch interval Maximum drop level For an arbitrary list of groups:
300 * Maximum level (usually 0, 1, 2 or 3) Maximum wear (0...1) Digging times
302 **Full punch interval**: When used as a weapon, the tool will do full
303 damage if this time is spent between punches. If eg. half the time is
304 spent, the tool will do half damage.
306 **Maximum drop level** suggests the maximum level of node, when dug with
307 the tool, that will drop it's useful item. (eg. iron ore to drop a lump of
310 **Maximum level** tells what is the maximum level of a node of this group
311 that the tool will be able to dig.
313 **Maximum wear** determines how much the tool wears out when it is used for
314 digging a node, of this group, of the maximum level. For lower leveled
315 tools, the wear is divided by //4// to the exponent //level difference//.
316 This means for a maximum wear of 0.1, a level difference 1 will result in
317 wear=0.1/4=0.025, and a level difference of 2 will result in
318 wear=0.1/(4*4)=0.00625.
320 **Digging times** is basically a list of digging times for different
321 ratings of the group. It also determines the damage done to entities, based
322 on their "armor groups".
323 * For example, as a lua table, ''times={2=2.00, 3=0.70}''. This would
324 * result the tool to be able to dig nodes that have a rating of 2 or 3
325 * for this group, and unable to dig the rating 1, which is the toughest.
326 * Unless there is a matching group that enables digging otherwise. For
327 * entities, damage equals the amount of nodes dug in the time spent
328 * between hits, with a maximum of ''full_punch_interval''.
330 Entity damage mechanism
331 ------------------------
332 Client predicts damage based on damage groups. Because of this, it is able to
333 give an immediate response when an entity is damaged or dies; the response is
334 pre-defined somehow (eg. by defining a sprite animation) (not implemented;
337 The group **immortal** will completely disable normal damage.
339 Entities can define a special armor group, which is **punch_operable**. This
340 group will disable the regular damage mechanism for players punching it by hand
343 On the Lua side, every punch calls ''entity:on_punch(puncher,
344 time_from_last_punch, tool_capabilities, direction)''. This should never be
345 called directly, because damage is usually not handled by the entity itself.
346 * ''puncher'' is the object performing the punch. Can be nil. Should never be
347 accessed unless absolutely required.
348 * ''time_from_last_punch'' is time from last punch (by puncher) or nil.
349 * ''tool_capabilities'' can be nil.
350 * ''direction'' is a unit vector, pointing from the source of the punch to
353 To punch an entity/object in Lua, call ''object:punch(puncher, time_from_last_punch, tool_capabilities, direction)''.
354 * Return value is tool wear.
355 * Parameters are equal to the above callback.
356 * If ''direction'' is nil and ''puncher'' is not nil, ''direction'' will be
357 automatically filled in based on the location of ''puncher''.
361 dump2(obj, name="_", dumped={})
362 ^ Return object serialized as a string, handles reference loops
364 ^ Return object serialized as a string
366 minetest namespace reference
367 -----------------------------
368 minetest.register_entity(name, prototype table)
369 minetest.register_abm(abm definition)
370 minetest.register_node(name, node definition)
371 minetest.register_tool(name, item definition)
372 minetest.register_craftitem(name, item definition)
373 minetest.register_alias(name, convert_to)
374 minetest.register_craft(recipe)
375 minetest.register_globalstep(func(dtime))
376 minetest.register_on_placenode(func(pos, newnode, placer))
377 minetest.register_on_dignode(func(pos, oldnode, digger))
378 minetest.register_on_punchnode(func(pos, node, puncher))
379 minetest.register_on_generated(func(minp, maxp))
380 minetest.register_on_newplayer(func(ObjectRef))
381 minetest.register_on_dieplayer(func(ObjectRef))
382 minetest.register_on_respawnplayer(func(ObjectRef))
383 ^ return true in func to disable regular player placement
384 ^ currently called _before_ repositioning of player occurs
385 minetest.register_on_chat_message(func(name, message))
386 minetest.add_to_creative_inventory(itemstring)
387 minetest.setting_get(name) -> string or nil
388 minetest.setting_getbool(name) -> boolean value or nil
389 minetest.chat_send_all(text)
390 minetest.chat_send_player(name, text)
391 minetest.get_player_privs(name) -> set of privs
392 minetest.get_inventory(location) -> InvRef
393 ^ location = eg. {type="player", name="celeron55"}
394 {type="node", pos={x=, y=, z=}}
395 minetest.get_current_modname() -> string
396 minetest.get_modpath(modname) -> eg. "/home/user/.minetest/usermods/modname"
397 ^ Useful for loading additional .lua modules or static data from mod
398 minetest.get_worldpath(modname) -> eg. "/home/user/.minetest/world"
399 ^ Useful for storing custom data
404 minetest.log(loglevel, line)
405 ^ loglevel one of "error", "action", "info", "verbose"
408 minetest.env - environment reference
411 minetest.registered_items
412 ^ List of registered items, indexed by name
413 minetest.registered_nodes
414 ^ List of registered node definitions, indexed by name
415 minetest.registered_craftitems
416 ^ List of registered craft item definitions, indexed by name
417 minetest.registered_tools
418 ^ List of registered tool definitions, indexed by name
419 minetest.registered_entities
420 ^ List of registered entity prototypes, indexed by name
422 ^ List of object references, indexed by active object id
424 ^ List of lua entities, indexed by active object id
426 Deprecated but defined for backwards compatibility:
427 minetest.digprop_constanttime(time)
428 minetest.digprop_stonelike(toughness)
429 minetest.digprop_dirtlike(toughness)
430 minetest.digprop_gravellike(toughness)
431 minetest.digprop_woodlike(toughness)
432 minetest.digprop_leaveslike(toughness)
433 minetest.digprop_glasslike(toughness)
437 EnvRef: basically ServerEnvironment and ServerMap combined.
439 - add_node(pos, node)
442 ^ Returns {name="ignore", ...} for unloaded area
443 - get_node_or_nil(pos)
444 ^ Returns nil for unloaded area
445 - get_node_light(pos, timeofday) -> 0...15 or nil
446 ^ timeofday: nil = current time, 0 = night, 0.5 = day
447 - add_entity(pos, name): Returns ObjectRef or nil if failed
448 - add_item(pos, itemstring)
451 - get_meta(pos) -- Get a NodeMetaRef at that position
452 - get_player_by_name(name) -- Get an ObjectRef to a player
453 - get_objects_inside_radius(pos, radius)
454 - set_timeofday(val): val: 0...1; 0 = midnight, 0.5 = midday
457 NodeMetaRef (this stuff is subject to change in a future version)
460 - allows_text_input()
461 - set_text(text) -- eg. set the text of a sign
465 Generic node metadata specific:
466 - set_infotext(infotext)
467 - get_inventory() -> InvRef
468 - set_inventory_draw_spec(string)
469 - set_allow_text_input(bool)
470 - set_allow_removal(bool)
471 - set_enforce_owner(bool)
472 - is_inventory_modified()
473 - reset_inventory_modified()
475 - reset_text_modified()
476 - set_string(name, value)
479 ObjectRef: Moving things in the game are generally these
480 (basically reference to a C++ ServerActiveObject)
482 - remove(): remove object (after returning from Lua)
483 - getpos() -> {x=num, y=num, z=num}
484 - setpos(pos); pos={x=num, y=num, z=num}
485 - moveto(pos, continuous=false): interpolated move
486 - punch(puncher, time_from_last_punch, tool_capabilities, direction)
487 ^ puncher = an another ObjectRef,
488 ^ time_from_last_punch = time since last punch action of the puncher
489 - right_click(clicker); clicker = an another ObjectRef
490 - get_hp(): returns number of hitpoints (2 * number of hearts)
491 - set_hp(hp): set number of hitpoints (2 * number of hearts)
492 - get_inventory() -> InvRef
493 - get_wield_list(): returns the name of the inventory list the wielded item is in
494 - get_wield_index(): returns the index of the wielded item
495 - get_wielded_item() -> ItemStack
496 - set_wielded_item(item): replaces the wielded item, returns true if successful
497 LuaEntitySAO-only: (no-op for other objects)
498 - setvelocity({x=num, y=num, z=num})
499 - getvelocity() -> {x=num, y=num, z=num}
500 - setacceleration({x=num, y=num, z=num})
501 - getacceleration() -> {x=num, y=num, z=num}
503 - getyaw() -> radians
505 - setsprite(p={x=0,y=0}, num_frames=1, framelength=0.2,
506 - select_horiz_by_yawpitch=false)
507 - ^ Select sprite from spritesheet with optional animation and DM-style
508 - texture selection based on yaw relative to camera
509 - set_armor_groups({group1=rating, group2=rating, ...})
510 - get_entity_name() (DEPRECATED: Will be removed in a future version)
512 Player-only: (no-op for other objects)
513 - get_player_name(): will return nil if is not a player
514 - get_look_dir(): get camera direction as a unit vector
515 - get_look_pitch(): pitch in radians
516 - get_look_yaw(): yaw in radians (wraps around pretty randomly as of now)
518 InvRef: Reference to an inventory
520 - get_size(listname): get size of a list
521 - set_size(listname, size): set size of a list
522 - get_stack(listname, i): get a copy of stack index i in list
523 - set_stack(listname, i, stack): copy stack to index i in list
524 - get_list(listname): return full list
525 - set_list(listname, list): set full list (size will not change)
526 - add_item(listname, stack): add item somewhere in list, returns leftover ItemStack
527 - room_for_item(listname, stack): returns true if the stack of items
528 can be fully added to the list
529 - contains_item(listname, stack): returns true if the stack of items
530 can be fully taken from the list
531 remove_item(listname, stack): take as many items as specified from the list,
532 returns the items that were actually removed (as an ItemStack)
534 ItemStack: A stack of items.
536 - is_empty(): return true if stack is empty
537 - get_name(): returns item name (e.g. "default:stone")
538 - get_count(): returns number of items on the stack
539 - get_wear(): returns tool wear (0-65535), 0 for non-tools
540 - get_metadata(): returns metadata (a string attached to an item stack)
541 - clear(): removes all items from the stack, making it empty
542 - replace(item): replace the contents of this stack (item can also
543 be an itemstring or table)
544 - to_string(): returns the stack in itemstring form
545 - to_table(): returns the stack in Lua table form
546 - get_stack_max(): returns the maximum size of the stack (depends on the item)
547 - get_free_space(): returns get_stack_max() - get_count()
548 - is_known(): returns true if the item name refers to a defined item type
549 - get_definition(): returns the item definition table
550 - get_tool_capabilities(): returns the digging properties of the item,
551 ^ or those of the hand if none are defined for this item type
552 - add_wear(amount): increases wear by amount if the item is a tool
553 - add_item(item): put some item or stack onto this stack,
554 ^ returns leftover ItemStack
555 - item_fits(item): returns true if item or stack can be fully added to this one
556 - take_item(n): take (and remove) up to n items from this stack
557 ^ returns taken ItemStack
558 ^ if n is omitted, n=1 is used
559 - peek_item(n): copy (don't remove) up to n items from this stack
560 ^ returns copied ItemStack
561 ^ if n is omitted, n=1 is used
565 - Functions receive a "luaentity" as self:
566 - It has the member .name, which is the registered name ("mod:thing")
567 - It has the member .object, which is an ObjectRef pointing to the object
568 - The original prototype stuff is visible directly via a metatable
570 - on_activate(self, staticdata)
571 ^ Called when the object is instantiated.
572 - on_step(self, dtime)
573 ^ Called on every server tick (dtime is usually 0.05 seconds)
574 - on_punch(self, puncher, time_from_last_punch, tool_capabilities, dir)
575 ^ Called when somebody punches the object.
576 ^ Note that you probably want to handle most punches using the
577 automatic armor group system.
578 ^ puncher: ObjectRef (can be nil)
579 ^ time_from_last_punch: Meant for disallowing spamming of clicks (can be nil)
580 ^ tool_capabilities: capability table of used tool (can be nil)
581 ^ dir: unit vector of direction of punch. Always defined. Points from
582 the puncher to the punched.
583 - on_rightclick(self, clicker)
584 - get_staticdata(self)
585 ^ Should return a string that will be passed to on_activate when
586 the object is instantiated the next time.
591 Entity definition (register_entity)
594 collisionbox = {-0.5,-0.5,-0.5, 0.5,0.5,0.5},
595 visual = "cube"/"sprite",
596 visual_size = {x=1, y=1},
597 textures = {texture,texture,texture,texture,texture,texture},
598 spritediv = {x=1, y=1},
599 initial_sprite_basepos = {x=0, y=0},
600 on_activate = function(self, staticdata),
601 on_step = function(self, dtime),
602 on_punch = function(self, hitter),
603 on_rightclick = function(self, clicker),
604 get_staticdata = function(self),
605 # Also you can define arbitrary member variables here
606 myvariable = whatever,
609 ABM (ActiveBlockModifier) definition (register_abm)
611 nodenames = {"default:lava_source"},
612 neighbors = {"default:water_source", "default:water_flowing"}, -- (any of these)
613 ^ If left out or empty, any neighbor will do
614 interval = 1.0, -- (operation interval)
615 chance = 1, -- (chance of trigger is 1.0/this)
616 action = func(pos, node, active_object_count, active_object_count_wider),
619 Item definition (register_node, register_craftitem, register_tool)
621 description = "Steel Axe",
622 groups = {}, -- key=name, value=rating; rating=1..3.
623 if rating not applicable, use 1.
624 eg. {wool=1, fluffy=3}
625 {soil=2, outerspace=1, crumbly=1}
627 {hard=1, metal=1, spikes=1}
628 inventory_image = "default_tool_steelaxe.png",
630 wield_scale = {x=1,y=1,z=1},
632 liquids_pointable = false,
633 tool_capabilities = {
634 full_punch_interval = 1.0,
638 fleshy={times={[2]=0.80, [3]=0.40}, maxwear=0.05, maxlevel=1},
639 snappy={times={[2]=0.80, [3]=0.40}, maxwear=0.05, maxlevel=1},
640 choppy={times={[3]=0.90}, maxwear=0.05, maxlevel=0}
643 on_drop = func(item, dropper, pos),
644 on_place = func(item, placer, pointed_thing),
645 on_use = func(item, user, pointed_thing),
648 Node definition (register_node)
650 <all fields allowed in item definitions>,
654 tile_images = {"default_unknown_block.png"},
655 special_materials = {
656 {image="", backface_culling=true},
657 {image="", backface_culling=true},
660 post_effect_color = {a=0, r=0, g=0, b=0},
663 is_ground_content = false,
664 sunlight_propagates = false,
669 buildable_to = false,
671 -- alternatively drop = { max_items = ..., items = { ... } }
674 liquid_alternative_flowing = "",
675 liquid_alternative_source = "",
676 liquid_viscosity = 0,
678 damage_per_second = 0,
679 selection_box = {type="regular"},
680 legacy_facedir_simple = false, -- Support maps made in and before January 2012
681 legacy_wallmounted = false, -- Support maps made in and before January 2012
683 footstep = <SimpleSoundSpec>,
684 dug = <SimpleSoundSpec>,
688 Recipe: (register_craft)
690 output = 'default:pick_stone',
692 {'default:cobble', 'default:cobble', 'default:cobble'},
693 {'', 'default:stick', ''},
694 {'', 'default:stick', ''},
696 replacements = <optional list of item pairs,
697 replace one input item with another item on crafting>
703 output = 'mushrooms:mushroom_stew',
706 "mushrooms:mushroom_brown",
707 "mushrooms:mushroom_red",
709 replacements = <optional list of item pairs,
710 replace one input item with another item on crafting>
713 Recipe (tool repair):
716 additional_wear = -0.02,
722 output = "default:glass",
723 recipe = "default:sand",
727 Recipe (furnace fuel):
730 recipe = "default:leaves",