fabric-carpet/docs/scarpet/api/Auxiliary.md

Auxiliary aspects

Collection of other methods that control smaller, yet still important aspects of the game

Sounds

sound(name, pos, volume?, pitch?, mixer?)

Plays a specific sound name, at block or position pos, with optional volume and modified pitch, and under optional mixer. Default values for volume, pitch and mixer are 1.0, 1.0, and master. Valid mixer options are master, music, record, weather, block, hostile,neutral, player, ambient and voice. pos can be either a block, triple of coords, or a list of thee numbers. Uses the same options as a corresponding playsound command.

Particles

particle(name, pos, count?. spread?, speed?, player?)

Renders a cloud of particles name centered around pos position, by default count 10 of them, default speed of 0, and to all players nearby, but these options can be changed via optional arguments. Follow vanilla /particle command on details on those options. Valid particle names are for example 'angry_villager', 'item diamond', 'block stone', 'dust 0.8 0.1 0.1 4'.

particle_line(name, pos, pos2, density?, player?)

Renders a line of particles from point pos to pos2 with supplied density (defaults to 1), which indicates how far apart you would want particles to appear, so 0.1 means one every 10cm. If a player (or player name) is supplied, only that player will receive particles.

particle_box(name, pos, pos2, density?, player?)

particle_rect (deprecated)

Renders a cuboid of particles between points pos and pos2 with supplied density. If a player (or player name) is supplied, only that player will receive particles.

Markers

draw_shape(shape, duration, key?, value?, ... ),

draw_shape(shape, duration, l(key?, value?, ... )),

draw_shape(shape, duration, attribute_map)

draw_shape(shape_list)

Draws a shape in the world that will expire in duration ticks. Other attributes of the shape should be provided as consecutive key - value argument pairs, either as next arguments, or packed in a list, or supplied as a proper key-value map. Arguments may include shared shape attributes, which are all optional, as well as shape-specific attributes, that could be either optional or required. Shapes will draw properly on all carpet clients. Other connected players that don't have carpet installed will still be able to see the required shapes in the form of dust particles. Replacement shapes are not required to follow all attributes precisely, but will allow vanilla clients to receive some experience of your apps. One of the attributes that will definitely not be honored is the duration - particles will be send once per shape and last whatever they typically last in the game.

Shapes can be send one by one, using either of the first three invocations, or batched as a list of shape descriptors. Batching has this benefit that they will be send possibly as one packet, limiting network overhead of sending many small packets to draw several shapes at once.

Shapes will fail to draw and raise a runtime error if not all its required parameters are specified and all available shapes have some parameters that are required, so make sure to have them in place:

On the client, shapes can recognize that they are being redrawn again with the same parameters, disregarding the duration parameter. This updates the expiry on the drawn shape to the new value, instead of adding new shape in its place. This can be used for toggling the shapes on and off that has been send previously with very large durations, or simply refresh the shapes periodically in more dynamic applications.

Optional shared shape attributes:

• color - integer value indicating the main color of the shape in the form of red, green, blue and alpha components in the form of 0xRRGGBBAA, with the default of -1, so white opaque, or 0xFFFFFFFF.
• player - name or player entity to send the shape to. If specified, the shapes will appear only for the specified player, otherwise it will be send to all players in the dimension.
• line - line thickness, defaults to 2.0pt
• fill - color for the faces, defaults to no fill. Use color attribute format
• follow - entity, or player name. Shape will follow an entity instead of being static. Follow attribute requires all positional arguments to be relative to the entity and disallow of using entity or block as position markers. You must specify positions as a triple.
• snap - if follow is present, indicated on which axis the snapping to entity coordinates occurs, and which axis will be treated statically, i.e. the coordinate passed in a coord triple is the actual value in the world. Default value is 'xyz', meaning the shape will be drawn relatively to the entity in all three directions. Using xz for instance makes so that the shape follows the entity, but stays at the same, absolute Y coordinate. Preceeding an axis with d, like dxdydz would make so that entity position is treated discretely (rounded down).

Available shapes:

• 'line' - draws a straight line between two points.

  • Required attributes:
    • from - triple coordinates, entity, or block value indicating one end of the line
    • to - other end of the line, same format as from

• 'label' - draws a text in the world. Default line attribute controls main font color. fill controls the color of the background.

  • Required attributes:
    • pos - position
    • text - string or formatted text to display
  • Optional attributes
    • value - string or formatted text to display instead of the main text. value unlike text is not used to determine uniqueness of the drawn text so can be used to display smoothly dynamic elements where value of an element is constantly changing and updates to it are being sent from the server.
    • size - float. Default font size is 10.
    • facing - text direction, where its facing. Possible options are: player (default, text always rotates to face the player), north, south, east, west, up, down
    • doublesided - if true it will make the text visible from the back as well. Default is false (1.16+)
    • align - text alignment with regards to pos. Default is center (displayed text is centered with respect to pos), left (pos indicates beginning of text), and right (pos indicates the end of text).
    • tilt - additional rotation of the text on the canvas
    • indent, height, raise - offsets for text rendering on X (indent), Y (height), and Z axis (raise) with regards to the plane of the text. One unit of these corresponds to 1 line spacing, which can be used to display multiple lines of text bound to the same pos

• 'box' - draws a box with corners in specified points

  • Required attributes:
    • from - triple coordinates, entity, or block value indicating one corner of the box
    • to - other corner, same format as from

• 'sphere':

  • Required attributes:
    • center - center of the sphere
    • radius - radius of the sphere
  • Optional attributes:
    • level - level of details, or grid size. The more the denser your sphere. Default level of 0, means that the level of detail will be selected automatically based on radius.

• 'cylinder':

  • Required attributes:
    • center - center of the base
    • radius - radius of the base circle
  • Optional attributes:
    • axis - cylinder direction, one of 'x', 'y', 'z' defaults to 'y'
    • height - height of the cyllinder, defaults to 0, so flat disk. Can be negative.
    • level - level of details, see 'sphere'.

create_marker(text, pos, rotation?, block?, interactive?)

Spawns a (permanent) marker entity with text or block at position. Returns that entity for further manipulations. Unloading the app that spawned them will cause all the markers from the loaded portion of the world to be removed. Also, if the game loads that marker in the future and the app is not loaded, it will be removed as well.

If interactive (true by default) is false, the armorstand will be a marker and would not be interactive in any gamemode. But blocks can be placed inside markers and will not catch any interaction events.

Y Position of a marker text or block will be adjusted to make blocks or text appear at the specified position. This makes so that actual armorstand position may be offset on Y axis. You would need to adjust your entity locations if you plan to move the armorstand around after the fact. If both text and block are specified - one of them will be aligned (armorstand type markers text shows up at their feet, while for regular armorstands - above the head, while block on the head always render in the same position regardless if its a marker or not).

remove_all_markers()

Removes all scarpet markers from the loaded portion of the world created by this app, in case you didn't want to do the proper cleanup.

System function

nbt(expr)

Treats the argument as a nbt serializable string and returns its nbt value. In case nbt is not in a correct nbt compound tag format, it will return null value.

Consult section about container operations in Expression to learn about possible operations on nbt values.

escape_nbt(expr)

Excapes all the special characters in the string or nbt tag and returns a string that can be stored in nbt directly as a string value.

tag_matches(daddy_tag, baby_tag, match_lists?)

Utility returning true if baby_tag is fully contained in daddy_tag. Anything matches null baby tag, and Nothing is contained in a null daddy tag. If match_lists is specified and false, content of nested lists is ignored. Default behaviour is to match them.

parse_nbt(tag)

Converts NBT tag to a scarpet value, which you can navigate through much better.

Converts:

• Compound tags into maps with string keys
• List tags into list values
• Numbers (Ints, Floats, Doubles, Longs) into a number
• Rest is converted to strings.

encode_nbt(expr, force?)

Encodes value of the expression as an NBT tag. By default (or when force is false), it will only allow to encode values that are guaranteed to return the same value when applied the resulting tag to parse_nbt(). Supported types that can reliably convert back and forth to and from NBT values are:

• Maps with string keywords
• Lists of items of the same type (scarpet will take care of unifying value types if possible)
• Numbers (encoded as Ints -> Longs -> Doubles, as needed)
• Strings

Other value types will only be converted to tags (including NBT tags) if force is true. They would require extra treatment when loading them back from NBT, but using force true will always produce output / never produce an exception.

print(expr)

Displays the result of the expression to the chat. Overrides default scarpet behaviour of sending everyting to stderr.

format(components, ...), format(l(components, ...))

Creates a line of formatted text. Each component is either a string indicating formatting and text it corresponds to or a decorator affecting the component preceding it.

Regular formatting components is a string that have the structure of: '<format> <text>', like 'gi Hi', which in this case indicates a grey, italicised word 'Hi'. The space to separate the format and the text is mandatory. The format can be empty, but the space still needs to be there otherwise the first word of the text will be used as format, which nobody wants.

Format is a list of formatting symbols indicating the format. They can be mixed and matched although color will only be applied once. Available symbols include:

• i - italic
• b - bold
• s - strikethrough
• u - underline
• o - obfuscated

And colors:

• w - White (default)
• y - Yellow
• m - Magenta (light purple)
• r - Red
• c - Cyan (aqua)
• l - Lime
• t - lighT blue
• f - dark grayF (weird Flex, but ok)
• g - Gray
• d - golD
• p - PurPle
• n - browN (dark red)
• q - turQuoise (dark aqua)
• e - grEEn
• v - naVy blue
• k - blaK
• #FFAACC - arbitrary RGB color (1.16+), hex notation. Use uppercase for A-F symbols

Decorators (listed as extra argument after the component they would affect):

• '^<format> <text>' - hover over tooltip text, appearing when hovering with your mouse over the text below.
• '?<suggestion> - command suggestion - a message that will be pasted to chat when text below it is clicked.
• '!<message>' - a chat message that will be executed when the text below it is clicked.

Both suggestions and messages can contain a command, which will be executed as a player that clicks it.

So far the only usecase for formatted texts is with a print command. Otherwise it functions like a normal string value representing what is actually displayed on screen.

Example usages:

 print(format('rbu Error: ', 'r Stuff happened!'))
 print(format('w Click ','tb [HERE]', '^di Awesome!', '!/kill', 'w \ button to win $1000'))
  // the reason why I backslash the second space is that otherwise command parser may contract consecutive spaces
  // not a problem in apps

display_title(players, type, title?, fadeInTicks?, stayTicks?, fadeOutTicks),

Sends the player (or players if players is a list) a title of a specific type, with optionally some times.

• players is either an online player or a list of players. When sending a single player, it will throw if the player is invalid or offline.
• type is either 'title', 'subtitle', actionbar or clear. Note: subtitle will only be displayed if there is a title being displayed (can be an empty one)
• title is what title to send to the player. It is required except for clear type. Can be a text formatted using format()
• ...Ticks are the number of ticks the title will stay in that state. If not specified, it will use current defaults (those defaults may have changed from a previous /title times execution). Executing with those will set the times to the specified ones. Note that actionbar type doesn't support changing times (vanilla bug, see MC-106167).

logger(msg), logger(type, msg)

Prints the message to system logs, and not to chat. By default prints an info, unless you specify otherwise in the type parameter.

Available output types:

'debug', 'warn', 'fatal', 'info' and 'error'

read_file(resource, type)

delete_file(resource, type)

write_file(resource, type, data, ...)

With the specified resource in the scripts folder, of a specific type, writes/appends data to it, reads its content, or deletes the resource.

Resource is identified by a path to the file.
A path can contain letters, numbers, characters -, +, or _, and a folder separator: '/'. Any other characters are stripped from the name. Empty descriptors are invalid. Do not add file extensions to the descriptor - extensions are inferred based on the type of the file.

Resources can be located in the app specific space, or a shared space for all the apps. Accessing of app-specific resources is guaranteed to be isolated from other apps. Shared resources are... well, shared across all apes, meaning they can eat of each others file, however all access to files is synchronized, and files are never left open, so this should not lead to any access problems.

If the app's name is 'foo', the script location would be world/scripts/foo.sc, app specific data directory is under world/scripts/foo.data/..., and shared data space is under world/scripts/shared/....

The default no-name app, via /script run command can only save/load/read files from the shared space.

Functions return null if an error is encounter or no file is present (for read and delete operations). Returns true for success writes and deletes, and requested data, based on the file type, for read operations.

NBT files can be written once as they an store one tag at a time. Consecutive writes will overwrite previous data.

Write operations to text files always result in appending to the existing file, so consecutive writes will increase the size of the file and add data to it. Since files are closed after each write, sending multiple lines of data to write is beneficial for writing speed. To send multiple packs of data, either provide them flat or as a list in the third argument.

• write_file('temp', 'text', 'foo', 'bar', 'baz') or
• write_file('temp', 'text', l('foo', 'bar', 'baz'))

To log a single line of string

Supported values for resource type is:

• nbt - NBT tag
• text - text resource with automatic newlines added
• raw - text resource without implied newlines
• shared_nbt, shared_text, shared_raw - shared versions of the above

NBT files have extension .nbt, store one NBT tag, and return a NBT type value. Text files have .txt extension, stores multiple lines of text and returns lists of all lines from the file. With write_file, multiple lines can be sent to the file at once. The only difference between raw and text types are automatic newlines added after each record to the file.

write_file('foo', 'shared_text, l('one', 'two'));
write_file('foo', 'shared_text', 'three\n', 'four\n');
write_file('foo', 'shared_raw', 'five\n', 'six\n');

read_file('foo', 'shared_text')     => ['one', 'two', 'three', '', 'four', '', 'five', 'six']

run(expr)

Runs a vanilla command from the string result of the expr and returns a triple of success count, intercepted list of output messages, and error message if the command resulted in a failure. Successful commands return null as their error.

run('fill 1 1 1 10 10 10 air') -> [123, ["Successfully filled 123 blocks"], null] // 123 block were filled, this operation was successful 123 times out of a possible 1000 block volume
run('give @s stone 4') -> [1, ["Gave 4 [Stone] to gnembon"], null] // this operation was successful once
run('seed') -> [-170661413, ["Seed: [4031384495743822299]"], null]
run('sed') -> [0, [], "sed<--[HERE]"] // wrong command

save()

Performs autosave, saves all chunks, player data, etc. Useful for programs where autosave is disabled due to performance reasons and saves the world only on demand.

load_app_data()

NOTE: usages with arguments, so load_app_data(file) and load_app_data(file, shared?) are deprecated. Use read_file instead.

Loads the app data associated with the app from the world /scripts folder. Without argument returns the memory managed and buffered / throttled NBT tag. With a file name, reads explicitly a file with that name from the scripts folder that belongs exclusively to the app. if shared is true, the file location is not exclusive to the app anymore, but located in a shared app space.

File descriptor can contain letters, numbers and folder separator: '/'. Any other characters are stripped from the name before saving/loading. Empty descriptors are invalid. Do not add file extensions to the descriptor

Function returns nbt value with the file content, or null if the file is missing or there were problems with retrieving the data.

The default no-name app, via /script run command can only save/load file from the shared data location.

If the app's name is 'foo', the script location would be world/scripts/foo.sc, system-managed default app data storage is in world/scripts/foo.data.nbt, app specific data directory is under world/scripts/foo.data/bar/../baz.nbt, and shared data space is under world/scripts/shared/bar/../baz.nbt.

You can use app data to save non-vanilla information separately from the world and other scripts.

store_app_data(tag)

Note: store_app_data(tag, file) and store_app_data(tag, file, shared?) usages deprecated. Use write_file instead.

Stores the app data associated with the app from the world /scripts folder. With the file parameter saves immediately and with every call to a specific file defined by the file, either in app space, or in the scripts shared space if shared is true. Without file parameter, it may take up to 10 seconds for the output file to sync preventing flickering in case this tag changes frequently. It will be synced when server closes.

Returns true if the file was saved successfully, false otherwise.

Uses the same file structure for exclusive app data, and shared data folder as load_app_data.

tick_time()

Returns server tick counter. Can be used to run certain operations every n-th ticks, or to count in-game time.

world_time()

Returns dimension-specific tick counter.

day_time(new_time?)

Returns current daytime clock value. If new_time is specified, sets a new clock to that value. Daytime clocks are shared between all dimensions.

last_tick_times()

Returns a 100-long array of recent tick times, in milliseconds. First item on the list is the most recent tick If called outside of the main tick (either throgh scheduled tasks, or async execution), then the first item on the list may refer to the previous tick performance. In this case the last entry (tick 100) would refer to the most current tick. For all intent and purpose, last_tick_times():0 should be used as last tick execution time, but individual tick times may vary greatly, and these need to be taken with the little grain of averaging.

game_tick(mstime?)

Causes game to run for one tick. By default runs it and returns control to the program, but can optionally accept expected tick length, in milliseconds. You can't use it to permanently change the game speed, but setting longer commands with custom tick speeds can be interrupted via /script stop command

loop(1000,game_tick())  // runs the game as fast as it can for 1000 ticks
loop(1000,game_tick(100)) // runs the game twice as slow for 1000 ticks

seed() deprecated

Returns current world seed. Function is deprecated, use system_info('world_seed') insteads.

current_dimension()

Returns current dimension that the script runs in.

in_dimension(smth, expr)

Evaluates the expression expr with different dimension execution context. smth can be an entity, world-localized block, so not block('stone'), or a string representing a dimension like: 'nether', 'the_nether', 'end' or 'overworld', etc.

view_distance()

Returns the view distance of the server.

get_mob_counts(), get_mob_counts(category) 1.16+

Returns either a map of mob categories with its respective counts and capacities (a.k.a. mobcaps) or just a tuple of count and limit for a specific category. If a category was not spawning for whatever reason it may not be returned from get_mob_counts(), but could be retrieved for get_mob_counts(category). Returned counts is what spawning algorithm has taken in to account last time mobs spawned.

schedule(delay, function, args...)

Schedules a user defined function to run with a specified delay ticks of delay. Scheduled functions run at the end of the tick, and they will run in order they were scheduled.

statistic(player, category, entry)

Queries in-game statistics for certain values. Categories include:

• mined: blocks mined
• crafted: items crafted
• used: items used
• broken: items broken
• picked_up: items picked up
• dropped: items dropped
• killed: mobs killed
• killed_by: mobs killed by
• custom: various random stats

For the options of entry, consult your statistics page, or give it a guess.

The call will return null if the statistics options are incorrect, or player doesn't have them in their history. If the player encountered the statistic, or game created for him empty one, it will return a number. Scarpet will not affect the entries of the statistics, even if it is just creating empty ones. With null response it could either mean your input is wrong, or statistic effectively has a value of 0.

system_info(), system_info(property)

Fetches the value of a system property or returns all inforation as a map when called without any arguments. It can be used to fetch various information, mostly not changing, or only available via low level system calls. In all cirumstances, these are only provided as read-only.

Available options in the scarpet app space:

• app_name - current app name or null if its a default app
• app_list - list of all loaded apps excluding default commandline app
• app_scope - scope of the global variables and function. Available options is player and global
• app_player - returns a player list that have app run under them. For global apps, the list is always empty

Relevant world related properties

• world_name - name of the world
• world_seed - a numeric seed of the world
• world_path - full path to the world saves folder
• world_folder - name of the direct folder in the saves that holds world files
• world_carpet_rules - returns all Carpet rules in a map form (rule->value). Note that the values are always returned as strings, so you can't do boolean comparisons directly. Includes rules from extensions with their namespace (namespace:rule->value). You can later listen to rule changes with the on_carpet_rule_changes(rule, newValue) event.

Relevant gameplay related properties

• game_difficulty - current difficulty of the game: 'peacefu', 'easy', 'normal', or 'hard'
• game_hardcore - boolean whether the game is in hardcore mode
• game_storage_format - format of the world save files, either 'McRegion' or 'Anvil'
• game_default_gamemode - default gamemode for new players
• game_max_players - max allowed players when joining the world
• game_view_distance - the view distance
• game_mod_name - the name of the base mod. Expect 'fabric'
• game_version - base version of the game

Server related properties

• server_motd - the motd of the server visible when joining
• server_ip - IP adress of the game hosted
• server_whitelisted - boolean indicating whether the access to the server is only for whitelisted players
• server_whitelist - list of players allowed to log in
• server_banned_players - list of banned player names
• server_banned_ips - list of banned IP addresses

System related properties

• java_max_memory - maximum allowed memory accessible by JVM
• java_allocated_memory - currently allocated memory by JVM
• java_used_memory - currently used memory by JVM
• java_cpu_count - number of processors
• java_version - version of Java
• java_bits - number indicating how many bits the Java has, 32 or 64
• java_system_cpu_load - current percentage of CPU used by the system
• java_process_cpu_load - current percentage of CPU used by JVM