minetest/doc/client_lua_api.md

Minetest Lua Client Modding API Reference 0.4.15

• More information at http://www.minetest.net/
• Developer Wiki: http://dev.minetest.net/

Introduction

WARNING: The client API is currently unstable, and may break/change without warning.

Content and functionality can be added to Minetest 0.4 by using Lua scripting in run-time loaded mods.

A mod is a self-contained bunch of scripts, textures and other related things that is loaded by and interfaces with Minetest.

Mods are contained and ran solely on the server side. Definitions and media files are automatically transferred to the client.

If you see a deficiency in the API, feel free to attempt to add the functionality in the engine and API. You can send such improvements as source code patches on GitHub (https://github.com/minetest/minetest).

Programming in Lua

If you have any difficulty in understanding this, please read Programming in Lua.

Startup

Mods are loaded during client startup from the mod load paths by running the init.lua scripts in a shared environment.

Paths

• RUN_IN_PLACE=1 (Windows release, local build)
  • $path_user:
    • Linux: <build directory>
    • Windows: <build directory>
  • $path_share
    • Linux: <build directory>
    • Windows: <build directory>
• RUN_IN_PLACE=0: (Linux release)
  • $path_share
    • Linux: /usr/share/minetest
    • Windows: <install directory>/minetest-0.4.x
  • $path_user:
    • Linux: $HOME/.minetest
    • Windows: C:/users/<user>/AppData/minetest (maybe)

Mod load path

Generic:

• $path_share/clientmods/
• $path_user/clientmods/ (User-installed mods)

In a run-in-place version (e.g. the distributed windows version):

• minetest-0.4.x/clientmods/ (User-installed mods)

On an installed version on Linux:

• /usr/share/minetest/clientmods/
• $HOME/.minetest/clientmods/ (User-installed mods)

Modpack support

Mods can be put in a subdirectory, if the parent directory, which otherwise should be a mod, contains a file named modpack.txt. This file shall be empty, except for lines starting with #, which are comments.

Mod directory structure

mods
|-- modname
|   |-- depends.txt
|   |-- screenshot.png
|   |-- description.txt
|   |-- settingtypes.txt
|   |-- init.lua
|   |-- models
|   |-- textures
|   |   |-- modname_stuff.png
|   |   `-- modname_something_else.png
|   |-- sounds
|   |-- media
|   `-- <custom data>
`-- another

modname

The location of this directory can be fetched by using minetest.get_modpath(modname).

depends.txt

List of mods that have to be loaded before loading this mod.

A single line contains a single modname.

Optional dependencies can be defined by appending a question mark to a single modname. Their meaning is that if the specified mod is missing, that does not prevent this mod from being loaded.

screenshot.png

A screenshot shown in the mod manager within the main menu. It should have an aspect ratio of 3:2 and a minimum size of 300×200 pixels.

description.txt

A File containing description to be shown within mainmenu.

settingtypes.txt

A file in the same format as the one in builtin. It will be parsed by the settings menu and the settings will be displayed in the "Mods" category.

init.lua

The main Lua script. Running this script should register everything it wants to register. Subsequent execution depends on minetest calling the registered callbacks.

minetest.setting_get(name) and minetest.setting_getbool(name) can be used to read custom or existing settings at load time, if necessary.

sounds

Media files (sounds) that will be transferred to the client and will be available for use by the mod.

Naming convention for registered textual names

Registered names should generally be in this format:

"modname:<whatever>" (<whatever> can have characters a-zA-Z0-9_)

This is to prevent conflicting names from corrupting maps and is enforced by the mod loader.

Example

In the mod experimental, there is the ideal item/node/entity name tnt. So the name should be experimental:tnt.

Enforcement can be overridden by prefixing the name with :. This can be used for overriding the registrations of some other mod.

Example: Any mod can redefine experimental:tnt by using the name

:experimental:tnt

when registering it. (also that mod is required to have experimental as a dependency)

The : prefix can also be used for maintaining backwards compatibility.

Aliases

Aliases can be added by using minetest.register_alias(name, convert_to) or `minetest.register_alias_force(name, convert_to).

This will make Minetest to convert things called name to things called convert_to.

The only difference between minetest.register_alias and minetest.register_alias_force is that if an item called name exists, minetest.register_alias will do nothing while minetest.register_alias_force will unregister it.

This can be used for maintaining backwards compatibility.

This can be also used for setting quick access names for things, e.g. if you have an item called epiclylongmodname:stuff, you could do

minetest.register_alias("stuff", "epiclylongmodname:stuff")

and be able to use /giveme stuff.

Sounds

Only Ogg Vorbis files are supported.

For positional playing of sounds, only single-channel (mono) files are supported. Otherwise OpenAL will play them non-positionally.

Mods should generally prefix their sounds with modname_, e.g. given the mod name "foomod", a sound could be called:

foomod_foosound.ogg

Sounds are referred to by their name with a dot, a single digit and the file extension stripped out. When a sound is played, the actual sound file is chosen randomly from the matching sounds.

When playing the sound foomod_foosound, the sound is chosen randomly from the available ones of the following files:

• foomod_foosound.ogg
• foomod_foosound.0.ogg
• foomod_foosound.1.ogg
• (...)
• foomod_foosound.9.ogg

Examples of sound parameter tables:

-- Play locationless on all clients
{
    gain = 1.0, -- default
}
-- Play locationless to one player
{
    to_player = name,
    gain = 1.0, -- default
}
-- Play locationless to one player, looped
{
    to_player = name,
    gain = 1.0, -- default
    loop = true,
}
-- Play in a location
{
    pos = {x = 1, y = 2, z = 3},
    gain = 1.0, -- default
    max_hear_distance = 32, -- default, uses an euclidean metric
}
-- Play connected to an object, looped
{
    object = <an ObjectRef>,
    gain = 1.0, -- default
    max_hear_distance = 32, -- default, uses an euclidean metric
    loop = true,
}

Looped sounds must either be connected to an object or played locationless to one player using to_player = name,

SimpleSoundSpec

• e.g. ""
• e.g. "default_place_node"
• e.g. {}
• e.g. {name = "default_place_node"}
• e.g. {name = "default_place_node", gain = 1.0}

Representations of simple things

Position/vector

{x=num, y=num, z=num}

For helper functions see "Vector helpers".

pointed_thing

• {type="nothing"}
• {type="node", under=pos, above=pos}
• {type="object", ref=ObjectRef}

Flag Specifier Format

Flags using the standardized flag specifier format can be specified in either of two ways, by string or table.

The string format is a comma-delimited set of flag names; whitespace and unrecognized flag fields are ignored. Specifying a flag in the string sets the flag, and specifying a flag prefixed by the string "no" explicitly clears the flag from whatever the default may be.

In addition to the standard string flag format, the schematic flags field can also be a table of flag names to boolean values representing whether or not the flag is set. Additionally, if a field with the flag name prefixed with "no" is present, mapped to a boolean of any value, the specified flag is unset.

E.g. A flag field of value

{place_center_x = true, place_center_y=false, place_center_z=true}

is equivalent to

{place_center_x = true, noplace_center_y=true, place_center_z=true}

which is equivalent to

"place_center_x, noplace_center_y, place_center_z"

or even

"place_center_x, place_center_z"

since, by default, no schematic attributes are set.

Formspec

Formspec defines a menu. Currently not much else than inventories are supported. It is a string, with a somewhat strange format.

Spaces and newlines can be inserted between the blocks, as is used in the examples.

Examples

Chest

size[8,9]
list[context;main;0,0;8,4;]
list[current_player;main;0,5;8,4;]

Furnace

size[8,9]
list[context;fuel;2,3;1,1;]
list[context;src;2,1;1,1;]
list[context;dst;5,1;2,2;]
list[current_player;main;0,5;8,4;]

Minecraft-like player inventory

size[8,7.5]
image[1,0.6;1,2;player.png]
list[current_player;main;0,3.5;8,4;]
list[current_player;craft;3,0;3,3;]
list[current_player;craftpreview;7,1;1,1;]

Elements

size[<W>,<H>,<fixed_size>]

• Define the size of the menu in inventory slots
• fixed_size: true/false (optional)
• deprecated: invsize[<W>,<H>;]

container[<X>,<Y>]

• Start of a container block, moves all physical elements in the container by (X, Y)
• Must have matching container_end
• Containers can be nested, in which case the offsets are added (child containers are relative to parent containers)

container_end[]

• End of a container, following elements are no longer relative to this container

list[<inventory location>;<list name>;<X>,<Y>;<W>,<H>;]

• Show an inventory list

list[<inventory location>;<list name>;<X>,<Y>;<W>,<H>;<starting item index>]

• Show an inventory list

listring[<inventory location>;<list name>]

• Allows to create a ring of inventory lists
• Shift-clicking on items in one element of the ring will send them to the next inventory list inside the ring
• The first occurrence of an element inside the ring will determine the inventory where items will be sent to

listring[]

• Shorthand for doing listring[<inventory location>;<list name>] for the last two inventory lists added by list[...]

listcolors[<slot_bg_normal>;<slot_bg_hover>]

• Sets background color of slots as ColorString
• Sets background color of slots on mouse hovering

listcolors[<slot_bg_normal>;<slot_bg_hover>;<slot_border>]

• Sets background color of slots as ColorString
• Sets background color of slots on mouse hovering
• Sets color of slots border

listcolors[<slot_bg_normal>;<slot_bg_hover>;<slot_border>;<tooltip_bgcolor>;<tooltip_fontcolor>]

• Sets background color of slots as ColorString
• Sets background color of slots on mouse hovering
• Sets color of slots border
• Sets default background color of tooltips
• Sets default font color of tooltips

tooltip[<gui_element_name>;<tooltip_text>;<bgcolor>,<fontcolor>]

• Adds tooltip for an element
• <bgcolor> tooltip background color as ColorString (optional)
• <fontcolor> tooltip font color as ColorString (optional)

image[<X>,<Y>;<W>,<H>;<texture name>]

• Show an image
• Position and size units are inventory slots

item_image[<X>,<Y>;<W>,<H>;<item name>]

• Show an inventory image of registered item/node
• Position and size units are inventory slots

bgcolor[<color>;<fullscreen>]

• Sets background color of formspec as ColorString
• If true, the background color is drawn fullscreen (does not effect the size of the formspec)

background[<X>,<Y>;<W>,<H>;<texture name>]

• Use a background. Inventory rectangles are not drawn then.
• Position and size units are inventory slots
• Example for formspec 8x4 in 16x resolution: image shall be sized 8 times 16px times 4 times 16px.

background[<X>,<Y>;<W>,<H>;<texture name>;<auto_clip>]

• Use a background. Inventory rectangles are not drawn then.
• Position and size units are inventory slots
• Example for formspec 8x4 in 16x resolution: image shall be sized 8 times 16px times 4 times 16px
• If true the background is clipped to formspec size (x and y are used as offset values, w and h are ignored)

pwdfield[<X>,<Y>;<W>,<H>;<name>;<label>]

• Textual password style field; will be sent to server when a button is clicked
• When enter is pressed in field, fields.key_enter_field will be sent with the name of this field.
• x and y position the field relative to the top left of the menu
• w and h are the size of the field
• Fields are a set height, but will be vertically centred on h
• Position and size units are inventory slots
• name is the name of the field as returned in fields to on_receive_fields
• label, if not blank, will be text printed on the top left above the field
• See field_close_on_enter to stop enter closing the formspec

field[<X>,<Y>;<W>,<H>;<name>;<label>;<default>]

• Textual field; will be sent to server when a button is clicked
• When enter is pressed in field, fields.key_enter_field will be sent with the name of this field.
• x and y position the field relative to the top left of the menu
• w and h are the size of the field
• Fields are a set height, but will be vertically centred on h
• Position and size units are inventory slots
• name is the name of the field as returned in fields to on_receive_fields
• label, if not blank, will be text printed on the top left above the field
• default is the default value of the field
  • default may contain variable references such as ${text}' which will fill the value from the metadata value text
  • Note: no extra text or more than a single variable is supported ATM.
• See field_close_on_enter to stop enter closing the formspec

field[<name>;<label>;<default>]

• As above, but without position/size units
• When enter is pressed in field, fields.key_enter_field will be sent with the name of this field.
• Special field for creating simple forms, such as sign text input
• Must be used without a size[] element
• A "Proceed" button will be added automatically
• See field_close_on_enter to stop enter closing the formspec

field_close_on_enter[<name>;<close_on_enter>]

• is the name of the field
• if <close_on_enter> is false, pressing enter in the field will submit the form but not close it
• defaults to true when not specified (ie: no tag for a field)

textarea[<X>,<Y>;<W>,<H>;<name>;<label>;<default>]

• Same as fields above, but with multi-line input

label[<X>,<Y>;<label>]

• x and y work as per field
• label is the text on the label
• Position and size units are inventory slots

vertlabel[<X>,<Y>;<label>]

• Textual label drawn vertically
• x and y work as per field
• label is the text on the label
• Position and size units are inventory slots

button[<X>,<Y>;<W>,<H>;<name>;<label>]

• Clickable button. When clicked, fields will be sent.
• x, y and name work as per field
• w and h are the size of the button
• label is the text on the button
• Position and size units are inventory slots

image_button[<X>,<Y>;<W>,<H>;<texture name>;<name>;<label>]

• x, y, w, h, and name work as per button
• texture name is the filename of an image
• Position and size units are inventory slots

image_button[<X>,<Y>;<W>,<H>;<texture name>;<name>;<label>;<noclip>;<drawborder>;<pressed texture name>]

• x, y, w, h, and name work as per button
• texture name is the filename of an image
• Position and size units are inventory slots
• noclip=true means the image button doesn't need to be within specified formsize
• drawborder: draw button border or not
• pressed texture name is the filename of an image on pressed state

item_image_button[<X>,<Y>;<W>,<H>;<item name>;<name>;<label>]

• x, y, w, h, name and label work as per button
• item name is the registered name of an item/node, tooltip will be made out of its description to override it use tooltip element
• Position and size units are inventory slots

button_exit[<X>,<Y>;<W>,<H>;<name>;<label>]

• When clicked, fields will be sent and the form will quit.

image_button_exit[<X>,<Y>;<W>,<H>;<texture name>;<name>;<label>]

• When clicked, fields will be sent and the form will quit.

textlist[<X>,<Y>;<W>,<H>;<name>;<listelem 1>,<listelem 2>,...,<listelem n>]

• Scrollable item list showing arbitrary text elements
• x and y position the itemlist relative to the top left of the menu
• w and h are the size of the itemlist
• name fieldname sent to server on doubleclick value is current selected element
• listelements can be prepended by #color in hexadecimal format RRGGBB (only),
  • if you want a listelement to start with "#" write "##".

textlist[<X>,<Y>;<W>,<H>;<name>;<listelem 1>,<listelem 2>,...,<listelem n>;<selected idx>;<transparent>]

• Scrollable itemlist showing arbitrary text elements
• x and y position the item list relative to the top left of the menu
• w and h are the size of the item list
• name fieldname sent to server on doubleclick value is current selected element
• listelements can be prepended by #RRGGBB (only) in hexadecimal format
  • if you want a listelement to start with "#" write "##"
• Index to be selected within textlist
• true/false: draw transparent background
• See also minetest.explode_textlist_event (main menu: engine.explode_textlist_event)

tabheader[<X>,<Y>;<name>;<caption 1>,<caption 2>,...,<caption n>;<current_tab>;<transparent>;<draw_border>]

• Show a tabheader at specific position (ignores formsize)
• x and y position the itemlist relative to the top left of the menu
• name fieldname data is transferred to Lua
• caption 1...: name shown on top of tab
• current_tab: index of selected tab 1...
• transparent (optional): show transparent
• draw_border (optional): draw border

box[<X>,<Y>;<W>,<H>;<color>]

• Simple colored semitransparent box
• x and y position the box relative to the top left of the menu
• w and h are the size of box
• color is color specified as a ColorString

dropdown[<X>,<Y>;<W>;<name>;<item 1>,<item 2>, ...,<item n>;<selected idx>]

• Show a dropdown field
• Important note: There are two different operation modes:
  1. handle directly on change (only changed dropdown is submitted)
  2. read the value on pressing a button (all dropdown values are available)
• x and y position of dropdown
• Width of dropdown
• Fieldname data is transferred to Lua
• Items to be shown in dropdown
• Index of currently selected dropdown item

checkbox[<X>,<Y>;<name>;<label>;<selected>]

• Show a checkbox
• x and y: position of checkbox
• name fieldname data is transferred to Lua
• label to be shown left of checkbox
• selected (optional): true/false

scrollbar[<X>,<Y>;<W>,<H>;<orientation>;<name>;<value>]

• Show a scrollbar
• There are two ways to use it:
  1. handle the changed event (only changed scrollbar is available)
  2. read the value on pressing a button (all scrollbars are available)
• x and y: position of trackbar
• w and h: width and height
• orientation: vertical/horizontal
• Fieldname data is transferred to Lua
• Value this trackbar is set to (0-1000)
• See also minetest.explode_scrollbar_event (main menu: engine.explode_scrollbar_event)

table[<X>,<Y>;<W>,<H>;<name>;<cell 1>,<cell 2>,...,<cell n>;<selected idx>]

• Show scrollable table using options defined by the previous tableoptions[]
• Displays cells as defined by the previous tablecolumns[]
• x and y: position the itemlist relative to the top left of the menu
• w and h are the size of the itemlist
• name: fieldname sent to server on row select or doubleclick
• cell 1...cell n: cell contents given in row-major order
• selected idx: index of row to be selected within table (first row = 1)
• See also minetest.explode_table_event (main menu: engine.explode_table_event)

tableoptions[<opt 1>;<opt 2>;...]

• Sets options for table[]
• color=#RRGGBB
  • default text color (ColorString), defaults to #FFFFFF
• background=#RRGGBB
  • table background color (ColorString), defaults to #000000
• border=<true/false>
  • should the table be drawn with a border? (default: true)
• highlight=#RRGGBB
  • highlight background color (ColorString), defaults to #466432
• highlight_text=#RRGGBB
  • highlight text color (ColorString), defaults to #FFFFFF
• opendepth=<value>
  • all subtrees up to depth < value are open (default value = 0)
  • only useful when there is a column of type "tree"

tablecolumns[<type 1>,<opt 1a>,<opt 1b>,...;<type 2>,<opt 2a>,<opt 2b>;...]

• Sets columns for table[]
• Types: text, image, color, indent, tree
  • text: show cell contents as text
  • image: cell contents are an image index, use column options to define images
  • color: cell contents are a ColorString and define color of following cell
  • indent: cell contents are a number and define indentation of following cell
  • tree: same as indent, but user can open and close subtrees (treeview-like)
• Column options:
  • align=<value>
    • for text and image: content alignment within cells. Available values: left (default), center, right, inline
  • width=<value>
    • for text and image: minimum width in em (default: 0)
    • for indent and tree: indent width in em (default: 1.5)
  • padding=<value>: padding left of the column, in em (default 0.5). Exception: defaults to 0 for indent columns
  • tooltip=<value>: tooltip text (default: empty)
  • image column options:
    • 0=<value> sets image for image index 0
    • 1=<value> sets image for image index 1
    • 2=<value> sets image for image index 2
    • and so on; defined indices need not be contiguous empty or non-numeric cells are treated as 0.
  • color column options:
    • span=<value>: number of following columns to affect (default: infinite)

Note: do not use a element name starting with key_; those names are reserved to pass key press events to formspec!

Spatial Vectors

• vector.new(a[, b, c]): returns a vector:
  • A copy of a if a is a vector.
  • {x = a, y = b, z = c}, if all a, b, c are defined
• vector.direction(p1, p2): returns a vector
• vector.distance(p1, p2): returns a number
• vector.length(v): returns a number
• vector.normalize(v): returns a vector
• vector.floor(v): returns a vector, each dimension rounded down
• vector.round(v): returns a vector, each dimension rounded to nearest int
• vector.apply(v, func): returns a vector
• vector.equals(v1, v2): returns a boolean

For the following functions x can be either a vector or a number:

• vector.add(v, x): returns a vector
• vector.subtract(v, x): returns a vector
• vector.multiply(v, x): returns a scaled vector or Schur product
• vector.divide(v, x): returns a scaled vector or Schur quotient

Helper functions

• dump2(obj, name="_", dumped={})
  • Return object serialized as a string, handles reference loops
• dump(obj, dumped={})
  • Return object serialized as a string
• math.hypot(x, y)
  • Get the hypotenuse of a triangle with legs x and y. Useful for distance calculation.
• math.sign(x, tolerance)
  • Get the sign of a number. Optional: Also returns 0 when the absolute value is within the tolerance (default: 0)
• `string.split(str, separator=",", include_empty=false, max_splits=-1,
• sep_is_pattern=false)`
  • If max_splits is negative, do not limit splits.
  • sep_is_pattern specifies if separator is a plain string or a pattern (regex).
  • e.g. string:split("a,b", ",") == {"a","b"}
• string:trim()
  • e.g. string.trim("\n \t\tfoo bar\t ") == "foo bar"
• minetest.is_yes(arg)
  • returns whether arg can be interpreted as yes
• minetest.get_us_time()
  • returns time with microsecond precision. May not return wall time.
• table.copy(table): returns a table
  • returns a deep copy of table

minetest namespace reference

Utilities

• minetest.get_current_modname(): returns the currently loading mod's name, when we are loading a mod
• minetest.get_version(): returns a table containing components of the engine version. Components:
  • project: Name of the project, eg, "Minetest"
  • string: Simple version, eg, "1.2.3-dev"
  • hash: Full git version (only set if available), eg, "1.2.3-dev-01234567-dirty" Use this for informational purposes only. The information in the returned table does not represent the capabilities of the engine, nor is it reliable or verifyable. Compatible forks will have a different name and version entirely. To check for the presence of engine features, test whether the functions exported by the wanted features exist. For example: if core.nodeupdate then ... end.

Logging

• minetest.debug(...)
  • Equivalent to minetest.log(table.concat({...}, "\t"))
• minetest.log([level,] text)
  • level is one of "none", "error", "warning", "action", "info", or "verbose". Default is "none".

Global callback registration functions

Call these functions only at load time!

• minetest.register_globalstep(func(dtime))
  • Called every client environment step, usually interval of 0.1s
• minetest.register_on_shutdown(func())
  • Called before client shutdown
  • Warning: If the client terminates abnormally (i.e. crashes), the registered callbacks will likely not be run. Data should be saved at semi-frequent intervals as well as on server shutdown.
• minetest.register_on_receiving_chat_message(func(name, message))
  • Called always when a client receive a message
  • Return true to mark the message as handled, which means that it will not be shown to chat
• minetest.register_on_sending_chat_message(func(name, message))
  • Called always when a client send a message from chat
  • Return true to mark the message as handled, which means that it will not be sent to server
• minetest.register_chatcommand(cmd, chatcommand definition)
  • Adds definition to minetest.registered_chatcommands
• minetest.register_on_death(func())
  • Called when the local player dies
• minetest.register_on_hp_modification(func(hp))
  • Called when server modified player's HP
• minetest.register_on_damage_taken(func(hp))
  • Called when the local player take damages
• minetest.register_on_formspec_input(func(formname, fields))
  • Called when a button is pressed in the local player's inventory form
  • Newest functions are called first
  • If function returns true, remaining functions are not called
• minetest.register_on_dignode(func(pos, node))
  • Called when the local player digs a node
  • Newest functions are called first
  • If any function returns true, the node isn't dug
• minetest.register_on_punchnode(func(pos, node))
  • Called when the local player punches a node
  • Newest functions are called first
  • If any function returns true, the punch is ignored

Sounds

• minetest.sound_play(spec, parameters): returns a handle
  • spec is a SimpleSoundSpec
  • parameters is a sound parameter table
• minetest.sound_stop(handle)

Timing

• minetest.after(time, func, ...)
  • Call the function func after time seconds, may be fractional
  • Optional: Variable number of arguments that are passed to func

Map

• minetest.get_node(pos)
  • Returns the node at the given position as table in the format {name="node_name", param1=0, param2=0}, returns {name="ignore", param1=0, param2=0} for unloaded areas.
• minetest.get_node_or_nil(pos)
  • Same as get_node but returns nil for unloaded areas.

Player

• minetest.get_wielded_item()
  • Returns the itemstack the local player is holding

Client Environment

• minetest.get_player_names()
  • Returns list of player names on server

Misc.

• minetest.parse_json(string[, nullvalue]): returns something
  • Convert a string containing JSON data into the Lua equivalent
  • nullvalue: returned in place of the JSON null; defaults to nil
  • On success returns a table, a string, a number, a boolean or nullvalue
  • On failure outputs an error message and returns nil
  • Example: parse_json("[10, {\"a\":false}]"), returns {10, {a = false}}
• minetest.write_json(data[, styled]): returns a string or nil and an error message
  • Convert a Lua table into a JSON string
  • styled: Outputs in a human-readable format if this is set, defaults to false
  • Unserializable things like functions and userdata are saved as null.
  • Warning: JSON is more strict than the Lua table format.
    1. You can only use strings and positive integers of at least one as keys.
    2. You can not mix string and integer keys. This is due to the fact that JSON has two distinct array and object values.
  • Example: write_json({10, {a = false}}), returns "[10, {\"a\": false}]"
• minetest.serialize(table): returns a string
  • Convert a table containing tables, strings, numbers, booleans and nils into string form readable by minetest.deserialize
  • Example: serialize({foo='bar'}), returns 'return { ["foo"] = "bar" }'
• minetest.deserialize(string): returns a table
  • Convert a string returned by minetest.deserialize into a table
  • string is loaded in an empty sandbox environment.
  • Will load functions, but they cannot access the global environment.
  • Example: deserialize('return { ["foo"] = "bar" }'), returns {foo='bar'}
  • Example: deserialize('print("foo")'), returns nil (function call fails)
    • error:[string "print("foo")"]:1: attempt to call global 'print' (a nil value)
• minetest.compress(data, method, ...): returns compressed_data
  • Compress a string of data.
  • method is a string identifying the compression method to be used.
  • Supported compression methods:

  • Deflate (zlib): `"deflate"`
    

  • ... indicates method-specific arguments. Currently defined arguments are:

  • Deflate: `level` - Compression level, `0`-`9` or `nil`.
    

• minetest.decompress(compressed_data, method, ...): returns data
  • Decompress a string of data (using ZLib).
  • See documentation on minetest.compress() for supported compression methods.
  • currently supported.
  • ... indicates method-specific arguments. Currently, no methods use this.
• minetest.encode_base64(string): returns string encoded in base64
  • Encodes a string in base64.
• minetest.decode_base64(string): returns string
  • Decodes a string encoded in base64.
• `core.gettext(string) : returns string
  • look up the translation of a string in the gettext message catalog
• fgettext_ne(string, ...)
  • call core.gettext(string), replace "$1"..."$9" with the given extra arguments and return the result
• fgettext(string, ...) : returns string
  • same as fgettext_ne(), but calls core.formspec_escape before returning result

UI

• minetest.ui.minimap
  • Reference to the minimap object. See Minimap class reference for methods.
• show_formspec(formname, formspec) : returns true on success
  • Shows a formspec to the player

Class reference

Minimap

An interface to manipulate minimap on client UI

• show(): shows the minimap (if not disabled by server)
• hide(): hides the minimap
• set_pos(pos): sets the minimap position on screen
• get_pos(): returns the minimap current position
• set_angle(deg): sets the minimap angle in degrees
• get_angle(): returns the current minimap angle in degrees
• set_mode(mode): sets the minimap mode (0 to 6)
• get_mode(): returns the current minimap mode
• toggle_shape(): toggles minimap shape to round or square.

Settings

An interface to read config files in the format of minetest.conf.

It can be created via Settings(filename).

Methods

• get(key): returns a value
• get_bool(key): returns a boolean
• set(key, value)
• remove(key): returns a boolean (true for success)
• get_names(): returns {key1,...}
• write(): returns a boolean (true for success)
  • write changes to file
• to_table(): returns {[key1]=value1,...}

Definition tables

Chat command definition (register_chatcommand)

{
    params = "<name> <privilege>", -- Short parameter description
    description = "Remove privilege from player", -- Full description
    privs = {privs=true}, -- Require the "privs" privilege to run
    func = function(name, param), -- Called when command is run.
                                  -- Returns boolean success and text output.
}

Escape sequences

Most text can contain escape sequences, that can for example color the text. There are a few exceptions: tab headers, dropdowns and vertical labels can't. The following functions provide escape sequences:

• core.get_color_escape_sequence(color):
  • color is a ColorString
  • The escape sequence sets the text color to color
• core.colorize(color, message):
  • Equivalent to: core.get_color_escape_sequence(color) .. message .. core.get_color_escape_sequence("#ffffff")
• color.get_background_escape_sequence(color)
  • color is a ColorString
  • The escape sequence sets the background of the whole text element to color. Only defined for item descriptions and tooltips.

ColorString

#RGB defines a color in hexadecimal format.

#RGBA defines a color in hexadecimal format and alpha channel.

#RRGGBB defines a color in hexadecimal format.

#RRGGBBAA defines a color in hexadecimal format and alpha channel.

Named colors are also supported and are equivalent to CSS Color Module Level 4. To specify the value of the alpha channel, append #AA to the end of the color name (e.g. colorname#08). For named colors the hexadecimal string representing the alpha value must (always) be two hexadecima