arena_lib/DOCS.md

Arena_lib docs

Table of Contents

• 1. Minigame configuration
  • 1.1 Per server configuration
  • 1.2 Privileges
  • 1.3 Commands
    • 1.3.1 Admins only
  • 1.4 Callbacks
    • 1.4.1 Minigame callbacks
    • 1.4.2 Global callbacks
  • 1.5 Additional properties
    • 1.5.1 Arena properties
      • 1.5.1.1 Updating non temporary properties via code
      • 1.5.1.2 Updating properties for old arenas
    • 1.5.2 Player properties
    • 1.5.3 Team properties
  • 1.6 HUD
  • 1.7 Extendable editor
  • 1.8 Utils
  • 1.9 Getters
  • 1.10 Things you don't want to do with a light heart
  • 1.11 Example file
• 2. Arenas
  • 2.1 Storing arenas
  • 2.2 Setting up an arena
    • 2.2.1 Editor
    • 2.2.2 CLI
      • 2.2.2.1 Creating and removing arenas
      • 2.2.2.2 Renaming an arena
      • 2.2.2.3 Players management
      • 2.2.2.4 Enabling/Disabling teams
      • 2.2.2.5 Spawners
      • 2.2.2.6 Signs
      • 2.2.2.7 Enabling/Disabling an arena
      • 2.2.2.8 Arena properties
      • 2.2.2.9 Timers
      • 2.2.2.10 Music
      • 2.2.2.11 Celestial vault
      • 2.2.2.12 Lighting
  • 2.3 Arena phases
  • 2.4 Spectate mode
• 3. About the author(s)

1. Minigame configuration

First of all download the mod and put it in your mods folder.

Now you need to register your minigame, possibly inside the init.lua of your mod, via:

arena_lib.register_minigame("yourmod", {parameter1, parameter2 etc})

"yourmod" is how arena_lib will store your mod inside its storage, and it's also what it needs in order to understand you're referring to that specific minigame (that's why almost every arena_lib function contains "mod" as a parameter). You'll need it when calling for commands and callbacks. Use the same name you used in mod.conf or some features won't be available.
The second field, on the contrary, is a table of optional parameters: they define the very features of your minigame. They are:

• name: (string) the name of your minigame. If not specified, it takes the name used to register the minigame
• prefix: (string) what's going to appear in most of the lines printed by your mod. Default is [<mg name>] , where <mg name> is the name of your minigame
• icon: (string) optional icon to represent your minigame. Currently unused by default (nil), it comes in handy for external mods
• teams: (table) contains team names. If not declared, your minigame won't have teams and the table will be equal to {-1}. You can add as many teams as you like, as the number of spawners (and players) will be multiplied by the number of teams (so max_players = 4 * 3 teams = max_players = 12)
• teams_color_overlay: (table) color strings. It applies a color overlay onto the players' skin according to their team, to better distinguish them. It requires teams. Default is nil
• is_team_chat_default: (bool) whether players messages in a game should be sent to their teammates only. It requires teams, default is false
• chat_all_prefix: (string) prefix for every message sent in arena, team chat aside. Default is [arena] (geolocalised)
• chat_team_prefix: (string) prefix for every message sent in the team chat. Default is [team] (geolocalised)
• chat_spectate_prefix: (string) prefix for every message sent in the spectate chat. Default is [spectator] (geolocalised)
• chat_all_color: (string) color for every message sent in arena, team chat aside. Default is white ("#ffffff")
• chat_team_color: (string) color for every message sent in the team chat. Default is light sky blue ("#ddfdff")
• chat_spectate_color: color for every message sent in the spectate chat. Default is gray ("#dddddd")
• fov: (int) changes the fov of every player
• camera_offset: (table) changes the offset of the camera for every player. It's structured as such: {1st_person, 3rd_person}, e.g. {nil, {x=5, y=3, z=-4}}
• hotbar: (table) overrides the server hotbar while inside an arena. Its fields are:
  • slots =: (int) the number of slots
  • background_image =: (string) the background image
  • selected_image =: (string) the image to show when a slot is selected
    If a field is not declared, it'll keep the server defaults
• join_while_in_progress: (bool) whether the minigame allows to join an ongoing match. Default is false
• spectate_mode: (bool) whether the minigame features the spectator mode. Default is true
• keep_inventory: (bool) whether to keep players inventories when joining an arena. Default is false. Check out also STORE_INVENTORY_MODE in SETTINGS.lua, to choose whether and how to store players' inventory
• show_nametags: (bool) whether to show the players nametags while in game. Default is false
• show_minimap: (bool) whether to allow players to use the builtin minimap function. Default is false
• time_mode: (string) whether arenas will keep track of the time or not.
  • "none": no time tracking at all (default)
  • "incremental": incremental time (0, 1, 2, ...)
  • "decremental": decremental time, as in a timer (3, 2, 1, 0). The timer value is 300 seconds by default, but it can be changed per arena
• load_time: (int) the time in seconds between the loading state and the start of the match. Default is 5
• celebration_time: (int) the time in seconds between the celebration state and the end of the match. Default is 5
• in_game_physics: (table) a physical override to set to each player when they enter an arena, following the Minetest physics_override parameters
• disabled_damage_types: (table) contains which damage types will be disabled once in a game. Damage types are strings, the same as in reason.type in the minetest API
• properties: see 1.5 Additional properties
• temp_properties: ^
• player_properties: ^
• team_properties: ^ (it won't work if teams hasn't been declared)

1.1 Per server configuration

There are also a couple of settings that can only be set in game via /minigamesettings. This because different servers might need different parameters. They are:

• hub_spawn_point: where players will be teleported when a match in your mod ends. Default is { x = 0, y = 20, z = 0 }. A bit of noise is applied on the x and z axis, ranging between -1.5 and 1.5.
• queue_waiting_time: the time to wait before the loading phase starts. It gets triggered when the minimum amount of players has been reached to start the queue. Default is 10

BEWARE: as you noticed, the hub spawn point is bound to the very minigame. In fact, there is no global spawn point as arena_lib could be used even in a survival server that wants to feature just a couple minigames. If you're looking for a hub manager because your goal is to create a full minigame server, have a look at my other mod Hub Manager. Also, if you want to be sure to join the same arena/team with your friends, you need to install my other mod Parties

1.2 Privileges

• arenalib_admin: allows to use a few more commands

1.3 Commands

A couple of general commands are already declared inside arena_lib, them being:

• /quit: quits a game
• /all: writes in the arena global chat
• /t: writes in the arena team chat (if teams are enabled)

1.3.1 Admins only

A couple more are available for players having the arenalib_admin privilege:

• /minigamesettings mod: change mod settings
• /arenakick player_name: kicks a player out of an ongoing game, no matter the mod
• /forceend mod arena_name: forcibly ends an ongoing game
• /flusharena mod arena_name: restores a broken arena (when not in progress)

Those aside, you need to connect a few functions with your mod in order to use them. The best way is with commands and I suggest you ChatCmdBuilder by rubenwardy. This is what I came up with in my Block League minigame, which relies on arena_lib. As you can see, I declared a local mod = "block_league" at the beginning, because it's how I stored my mod inside the library. Also, I created the support for both the editor and the chat commands.

1.4 Callbacks

Callbacks are divided in two types: minigame callbacks and global callbacks. The former allow you to customise your mod even more, whilst the latter are great for external mods that want to customise the experience outside of a specific minigame (e.g. a server giving players some currency when winning, a HUD telling players what game is in progress).

1.4.1 Minigame callbacks

• arena_lib.on_enable(mod, function(arena, p_name): run more checks before enabling an arena. Must return true or the arena won't be enabled
• arena_lib.on_disable(mod, function(arena, p_name): run more checks before disabling an arena. Must return true or the arena won't be disabled
• arena_lib.on_prejoin_queue(mod, function(arena, p_name): run more checks when entering a queue. Must return true or the player won't be added
• arena_lib.on_join_queue(mod, function(arena, p_name): additional actions to perform after a player has successfully joined a queue
• arena_lib.on_leave_queue(mod, function(arena, p_name): same as above, but for when they leave
• arena_lib.on_load(mod, function(arena): see 2.3 Arena phases
• arena_lib.on_start(mod, function(arena)): same as above
• arena_lib.on_celebration(mod, function(arena, winners): same as above. winners can be either a string, an integer or a table of string/integers. If you want to have a single winner, return their name (string). If you want to have a whole team, return the team ID (integer). If you want to have more single winners, a table of strings, and more teams, a table of integers.
• arena_lib.on_end(mod, function(arena, players, winners, spectators, is_forced)): same as above. Players and spectators are given here because end_arena has already deleted them - hence these are a copy. is_forced returns true when the match has been forcibly terminated (via force_arena_ending)
• arena_lib.on_join(mod, function(p_name, arena, as_spectator)): called when a player joins an ongoing match. If as_spectator is true, they'll be added as such
• arena_lib.on_death(mod, function(arena, p_name, reason)): called when a player dies
• arena_lib.on_respawn(mod, function(arena, p_name)): called when a player respawns
• arena_lib.on_change_spectated_target(mod, function(arena, sp_name, t_type, t_name, prev_type, prev_spectated)): called when a spectator (sp_name) changes who or what they're spectating, including when they get assigned someone to spectate at entering the arena.
  • t_type represents the type of the target (either "player", "entity" or "area")
  • t_name its name. If it's an entity or an area, it'll be the name used to register it through the arena_lib.add_spectate... functions
  • if they were following someone/something else earlier, prev_type and prev_spectated follow the same logic of the aforementioned parameters
  • Beware: as this gets called also when entering, keep in mind that it gets called before the on_join callback
• arena_lib.on_time_tick(mod, function(arena)): called every second if time_mode is different from "none"
• arena_lib.on_timeout(mod, function(arena)): called when the timer of an arena, if exists (time_mode = "decremental"), reaches 0. Not declaring it will make the server crash when time runs out
• arena_lib.on_eliminate(mod, function(arena, p_name)): called when a player is eliminated (see arena_lib.remove_player_from_arena(...))
• arena_lib.on_quit(mod, function(arena, p_name, is_spectator, reason)): called when a player/spectator quits from a match. See arena_lib.remove_player_from_arena(...) to learn about the reason parameter
• arena_lib.on_prequit(mod, function(arena, p_name)): called when a player tries to quit with /quit. If it returns false, quit is cancelled. Useful to ask confirmation first, or simply to impede a player to quit

BEWARE: there is a default behaviour already for most of these situations: for instance when a player dies, their deaths increase by 1. These callbacks exist just in case you want to add some extra behaviour to arena_lib's.

So for instance, if we want to add an object in the first slot when a player joins the pre-match, we can simply do:

arena_lib.on_load("mymod", function(arena)

  local item = ItemStack("default:dirt")

  for pl_name, stats in pairs(arena.players) do
    pl_name:get_inventory():set_stack("main", 1, item)
  end

end)

1.4.2 Global callbacks

Global callbacks act in the same way of minigame callbacks with the same name. Keep in mind that not every minigame callback has a global counterpart.

• arena_lib.register_on_enable(function(mod_ref, arena, p_name))
• arena_lib.register_on_disable(function(mod_ref, arena, p_name))
• arena_lib.register_on_prejoin_queue(function(mod_ref, arena, p_name))
• arena_lib.register_on_join_queue(function(mod_ref, arena, p_name, has_queue_status_changed)): has_queue_status_changed is a boolean, returning true when the arena goes from in queue -> not in queue, and viceversa
• arena_lib.register_on_leave_queue(function(mod_ref, arena, p_name, has_queue_status_changed)): check the previous callback for has_queue_status_changed
• arena_lib.register_on_load(function(mod_ref, arena))
• arena_lib.register_on_start(function(mod_ref, arena))
• arena_lib.register_on_join(function(mod_ref, arena, p_name, as_spectator))
• arena_lib.register_on_celebration(function(mod_ref, arena, winners))
• arena_lib.register_on_end(function(mod_ref, arena, players, winners, spectators, is_forced))
• arena_lib.register_on_eliminate(function(mod_ref, arena, p_name))
• arena_lib.register_on_quit(function(mod_ref, arena, p_name, is_spectator, reason))

Let's say we want to stop people to enter minigames when there is an event on our server. We can simply do:

arena_lib.register_on_prejoin_queue(function(mod_ref, arena, p_name)

  if myservermod.is_event_active() then
	minetest.chat_send_player(p_name, "There is a special event in progress, minigames will be back once it ends!")
	return
  end
  
  return true
end)

1.5 Additional properties

Let's say you want to add a kill leader parameter. Arena_lib doesn't provide specific parameters, as its role is to be generic. Instead, you can create your own kill leader parameter by using the four tables properties, temp_properties, player_properties and team_properties. The first two are for the arena, the third is for players and the fourth for teams.
No matter the type of property, they're all shared between arenas. Better said, their values can change, but there can't be an arena with more or less properties than another.

1.5.1 Arena properties

The difference between properties and temp/player/team's is that the former will be stored by the the mod so that when the server reboots it'll still be there, while the others won't and they reset every time a match ends. Everything but properties is temporary. In our case, for instance, we don't want the kill leader to be preserved outside of a match, thus we go to our arena_lib.register_minigame(...) and write:

arena_lib.register_minigame("mymod", {
  --whatever stuff we already have
  temp_properties = {
    kill_leader = ""
  }
}

in doing so, we can easily access the kill_leader field whenever we want from every arena we have, via ourarena.kill_leader. E.g. when creating a function calculating the arena kill leader

BEWARE: you DO need to initialise your properties (whatever type) or it'll return an error

1.5.1.1 Updating non temporary properties via code

Let's say you want to change a property from your mod. A naive approach would be doing yourarena.property = something. This, though, won't update it in the storage, so when you restart the server it'll still have the old value.
Instead, the right way to permanently update a property for an arena is calling arena_lib.change_arena_property(<sender>, mod, arena_name, property, new_value). If sender is nil, the output message will be printed in the log.

1.5.1.2 Updating properties for old arenas

This is done automatically by arena_lib every time you change the properties declaration in register_minigame, so don't worry. Just, keep in mind that when a property is removed, it'll be removed from every arena; so if you're not sure about what you're doing, do a backup first.

1.5.2 Player properties

These are a particular type of temporary properties, as they're attached to every player in the arena. Let's say you now want to keep track of how many kills a player does in a streak without dying. You just need to create a killstreak parameter, declaring it like so

arena_lib.register_minigame("mymod", {
  --stuff
  temp_properties = {
    kill_leader = ""
  },
  player_properties = {
    killstreak = 0
  }
}

Now you can easily access the killstreak parameter by retrieving the player inside an arena via ourarena.players[p_name].killstreak. Also, don't forget to reset it when a player dies via the on_death callback we saw earlier:

arena_lib.on_death("mymod", function(arena, p_name, reason)
  arena.players[p_name].killstreak = 0
end)

1.5.3 Team properties

Same as above, but for teams. For instance, you could count how many rounds of a single match has been won by a specific team, and then call a load_celebration when one of them reaches 3 wins.

1.6 HUD

arena_lib also comes with a triple practical HUD: title, broadcast and hotbar. These HUDs only appear when a message is sent to them and they can be easily used via the following functions:

• arena_lib.HUD_send_msg(HUD_type, p_name, msg, <duration>, <sound>, <color>): sends a message to the specified player/spectator in the specified HUD type ("title", "broadcast" or "hotbar"). If no duration is declared, it won't disappear by itself. If a sound is declared, it'll be played at the very showing of the HUD. color must be in a hexadecimal format and, if not specified, it defaults to white (0xFFFFFF).
• arena_lib.HUD_send_msg_all(HUD_type, arena, msg, <duration>, <sound>, <color>): same as above, but for all the players and spectators inside the arena
• arena_lib.HUD_hide(HUD_type, player_or_arena): makes the specified HUD disappear; it can take both a player/spectator and a whole arena. Also, a special parameter all can be used in HUD_type to make all the HUDs disappear

1.7 Extendable editor

Since 4.0, every minigame can extend the editor with an additional custom section on the 5th slot. To do that, the function is

arena_lib.register_editor_section("yourmod", {parameter1, parameter2 etc})

On the contrary of when an arena is registered, every parameter here is mandatory. They are:

• name: the name of the item that will represent the section
• icon: the icon of the item that will represent the section
• hotbar_message: the message that will appear in the hotbar HUD once the section has been opened
• give_items = function(itemstack, user, arena): this function must return the list of items to give to the player once the section has been opened, or nil if we want to deny the access. Having a function instead of a list is useful as it allows to run whatever check inside of it, and to give different items accordingly

When a player is inside the editor, they have 2 string metadata containing the name of the mod and the name of the arena that's currently being modified. These are necessary to do whatever arena operation with items passed via give_items, as they allow to obtain the arena ID and the arena itself via arena_lib.get_arena_by_name(mod, arena_name). To better understand this, have a look at how arena_lib does

1.8 Utils

There are also some other functions which might turn useful. They are:

• arena_lib.is_player_in_queue(p_name, <mod>): returns a boolean. If a mod is specified, returns true only if it's inside a queue of that specific mod
• arena_lib.is_player_in_arena(p_name, <mod>): returns a boolean. Same as above
• arena_lib.is_player_in_same_team(arena, p_name, t_name): compares two players teams by the players names. Returns true if on the same team, false if not
• arena_lib.is_team_declared(mod_ref, team_name): returns true if there is a team called team_name. Otherwise it returns false
• arena_lib.force_arena_ending(mod, arena, <sender>): forcibly ends an ongoing game. It's usually called by /forceend, but it can be used, for instance, to annul a game. sender will inform players about who called the function. It returns true if successfully executed
• arena_lib.join_queue(mod, arena, p_name): adds p_name to the queue of arena. Returns true if successful. If the player is already in a different queue, they'll be removed from the one they're currently in and automatically added to the new one
• arena_lib.remove_player_from_queue(p_name): removes the player from the queue is in, if any. Returns true if successful
• arena_lib.remove_player_from_arena(p_name, reason, <executioner>): removes the player from the arena and it brings back the player to the game world if still online. This is already extensively used within arena_lib, but modders can use it to customise their gameplay (e.g. to eliminate a player or to automatically kick a user who went AFK). This is not called when an arena is forcibly terminated
  • reason is an integer, and it equals to...
    • 0: player disconnected. Default used when: players disconnect
    • 1: player eliminated. Default used when: ---
    • 2: player kicked. Default used when: players are kicked through /arenakick
    • 3: player quits. Default used when: players do /quit or when they leave the spectator mode
    • All these reasons call on_quit, with the only exception of 1, that calls on_eliminate if declared, and that only calls on_quit if there is no spectator mode
  • executioner can be passed to tell who removed the player. By default, this happens when someone uses /arenakick and /forceend, so that these commands can't be abused without consequences for the admin
• arena_lib.send_message_in_arena(arena, channel, msg, <teamID>, <except_teamID>): sends a message to all the players/spectators in that specific arena, according to what channel is: "players", "spectators" or "both". If teamID is specified, it'll be only sent to the players inside that very team. On the contrary, if except_teamID is true, it'll be sent to every player BUT the ones in the specified team. These last two fields are pointless if channel is equal to "spectators"
• arena_lib.add_spectate_entity(mod, arena, e_name, entity): adds to the current ongoing match a spectatable entity, allowing spectators to spectate more than just players. e_name is the name that will appear in the spectator info hotbar, and entity the luaentity table. When the entity is removed/unloaded, automatically calls remove_spectate_entity(...)
• arena_lib.add_spectate_area(mod, arena, pos_name, pos): same as add_spectate_entity, but it adds an area instead. pos is a table containing the coordinates of the area to spectate
• arena_lib.remove_spectate_entity(mod, arena, e_name): removes an entity from the spectatable entities of an ongoing match
• arena_lib.remove_spectate_area(mod, arena, pos_name): removes an area from the spectatable areas of an ongoing match
• arena_lib.is_player_spectating(sp_name): returns whether a player is spectating a match, as a boolean
• arena_lib.is_player_spectated(p_name): returns whether a player is being spectated
• arena_lib.is_entity_spectated(mod, arena_name, e_name): returns whether an entity is being spectated
• arena_lib.is_area_spectated(mod, arena_name, pos_name): returns whether an area is being spectated
• arena_lib.is_arena_in_edit_mode(arena_name): returns whether the arena is in edit mode or not, as a boolean
• arena_lib.is_player_in_edit_mode(p_name): returns whether a player is editing an arena, as a boolean

1.9 Getters

• arena_lib.get_arena_by_name(mod, arena_name): returns the ID and the whole arena (so a table)
• arena_lib.get_mod_by_player(p_name): returns the minigame a player's in (game or queue)
• arena_lib.get_arena_by_player(p_name): returns the arena the player's in, (game or queue)
• arena_lib.get_arenaID_by_player(p_name): returns the ID of the arena the player's playing in
• arena_lib.get_queueID_by_player(p_name): returns the ID of the arena the player's queueing for
• arena_lib.get_arena_spawners_count(arena, <team_ID>): returns the total amount of spawners declared in the specified arena. If team_ID is specified, it only counts the ones belonging to that team
• arena_lib.get_random_spawner(arena, <team_ID>): returns a random spawner declared in the specified arena. If team_ID is specified, it only considers the ones belonging to that team
• arena_lib.get_players_amount_left_to_start_queue(arena): returns the amount of player still needed to make a queue start, or nil if the arena is already in game
• arena_lib.get_players_in_game(): returns all the players playing in whatever arena of whatever minigame
• arena_lib.get_players_in_minigame(mod, <to_player>): returns a table containing as index either the names of all the players inside the specified minigame (mod) or, if to_player is true, the players themselves
• arena_lib.get_players_in_team(arena, team_ID, <to_player>): returns a table containing as index either the names of the players inside the specified team or, if to_player is true, the players themselves
• arena_lib.get_active_teams(arena): returns an ordered table having as values the ID of teams that are not empty
• arena_lib.get_player_spectators(p_name): returns a list containing all the people currently spectating p_name. Format {sp_name = true}
• arena_lib.get_player_spectated(sp_name): returns the player sp_name is currently spectating, if any
• arena_lib.get_spectate_entities(mod, arena_name): returns a table containing all the spectatable entities of arena_name, if any. Format {e_name = entity}, where e_name is the name used to register the entity in add_spectate_entity(...) and entity the luaentity table
• arena_lib.get_spectate_areas(mod, arena_name): same as in get_spectate_entities(...) but for areas. Entities returned in the table are the dummy ObjectRef entities put at the area coordinates
• arena_lib.get_player_in_edit_mode(arena_name): returns the name of the player who's editing arena_name, if any

1.10 Things you don't want to do with a light heart

• Changing the number of the teams: it'll delete your spawners (this has to be done in order to avoid further problems)
• Any action in the "Players" section of the editor, except changing their minimum amount: it'll delete your spawners (same as above)
• Removing properties in the minigame declaration: it'll delete them from every arena, without any possibility to get them back. Always do a backup first
• Disabling timers (time_mode = "decremental" to something else) when arenas have custom timer values: it'll reset every custom value, so you have to put them again manually if/when you decide to turning timers back up

1.11 Example file

Check this out for a full configuration file

2. Arenas

It all starts with a table called arena_lib.mods = {}. This table allows arena_lib to be subdivided per mod and it has different parameters, one being arena_lib.mods[yourmod].arenas. Here is where every new arena created gets put.
An arena is a table having as a key an ID and as a value its parameters. They are:

• name: (string) the name of the arena, declared when creating it
• author: (string) the name of the one who built/designed the map. Default is "???". It appears in the signs infobox (right-click an arena sign)
• sign: (pos) the position of the sign associated with the arena
• players: (table) where to store players information, such as their team ID (teamID) and player_properties. Format {[p_name] = {stuff}, [p_name2] = {stuff}, ...}
• spectators: (table) where to store spectators information. Format {[sp_name] = true}
• players_and_spectators: (table) where to store both players and spectators names. Format {[psp_name] = true}
• past_present_players: (table) keeps track of every player who took part to the match, even if they are spectators now or they left. Contrary to players and players_and_spectators, this is created when the arena loads, so it doesn't consider people who joined and left during the queue. Format {[ppp_name] = true}
• past_present_players_inside: (table) same as past_present_players but without keeping track of the ones who left
• teams: (table) where to store teams information, such as their name (name) and team_properties. If there are no teams, it's {-1}. If there are, format is {[teamID] = {stuff}, [teamID2] = {stuff}, ...}
• teams_enabled: (boolean) whether teams are enabled in the arena. Requires teams
• players_amount: (int) separately stores how many players are inside the arena/queue
• players_amount_per_team: (table) separately stores how many players currently are in a given team. Format {[teamID] = amount}. If teams are disabled, it's nil
• spectators_amount: (int) separately stores how many spectators are inside the arena
• spectators_amount_per_team: (table) like players_amount_per_team, but for spectators
• spectate_entities_amount: (int) the amount of entities that can be currently spectated in an ongoing game. If spectate mode is disabled, it's nil. Outside of ongoing games is always nil
• spectate_areas_amount: (int) like spectate_entities_amount but for areas
• spawn_points: (table) contains information about the spawn points. Format {[spawnID] = {pos = coords, teamID = team ID}}. If teams are disabled, teamID is nil
• max_players: (string) default is 4. When this value is reached, queue time decreases to 5 if it's not lower already
• min_players: (string) default is 2. When this value is reached, a queue starts
• initial_time: (int) in seconds. It's nil when the mod doesn't keep track of time, it's 0 when the mod does it incrementally and it's inherited by the mod if the mod has a timer. In this case, every arena can have its specific value. By default time tracking is disabled, hence it's nil
• current_time: (int) in seconds. It requires initial_time and it exists only when a game is in progress, keeping track of the current time
• celestial_vault: (table) if present, contains the information about the celestial vault to display to each player whilst in game, overriding the default one. Default is nil.
• lighting: (table) if present, contains the information about the lighting settings of the arena, overriding players' default ones. Default is nil.
• bgm: (table) if present, contains the information about the audio track to play whilst in game. Audio tracks must be placed in the minigame /sounds path (not arena_lib's) in order to be found. Default is nil. In-depth fields, all empty by default, are:
  • track: (string) the audio file, without .ogg. Mandatory. If no track is specified, all the other fields will be consequently empty
  • title: (string) the title to display in the infobox (right-clicking a sign)
  • author: (string) the author to display in the infobox (right-clicking a sign)
  • gain: (int) the volume of the track
  • pitch: (int) the pitch of the track
• in_queue: (bool) about phases, look at "Arena phases" down below
• in_loading: (bool)
• in_game: (bool)
• in_celebration: (bool)
• enabled: (bool) by default an arena is disabled, to avoid any unwanted damage

BEWARE: don't edit these parameters manually! Each one of them can be set through some arena_lib function, which runs the required checks in order to avoid any collateral damage

Being arenas stored by ID, they can be easily retrieved by arena_libs.mods[yourmod].arenas[THEARENAID].

There are two ways to know an arena ID: the first is in-game via the two debug utilities:

• arena_lib.print_arenas(sender, mod): concise
• arena_lib.print_arena_info(sender, mod, arena_name): extended with much more information (this one is implemented in the editor by default)

The second is via code by the functions:

• arena_lib.get_arenaID_by_player(p_name): the player must be queueing for the arena, or playing it
• arena_lib.get_arena_by_name(mod, arena_name): it returns both the ID and the arena (so, the table)

2.1 Storing arenas

Arenas and their settings are stored inside the mod storage. What is not stored are players, their stats and such.
Better said, these kind of parameters are emptied every time the server starts. And not when it ends, because handling situations like crashes is simply not possible.

2.2 Setting up an arena

In order for an arena to be playable, three conditions must be satisfied: the arena has to exist, spawners have to be set, and an arena sign must be placed (to allow players to enter the minigame).

If you love yourself, there is a built-in editor that allows you to easily make these things and many many more. Or, if you don't love yourself, you can connect every setup function to your custom CLI. Either way, both the approaches require you to connect at least the arena_lib.create_arena function inside your mod. It follows an example using ChatCmdBuilder:

local yourmod = "mymod"

ChatCmdBuilder.new("NAMEOFYOURCOMMAND", function(cmd)

	cmd:sub("create :arena", function(name, arena_name)
		arena_lib.create_arena(name, yourmod, arena_name)
	end)

end, {})

Now do /NAMEOFYOURCOMMAND create foo and you'll have your first arena called "foo": 🎉

2.2.1 Editor

arena_lib comes with a fancy editor via hotbar so you don't have to configure and memorise a lot of commands.
In order to use the editor, no other players shall be editing the same arena and there shall not be any ongoing game. When entering, the arena is disabled automatically. The rest is pretty straightforward :D if you're not sure of what something does, just open the inventory and read its name.

The function calling the editor is arena_lib.enter_editor(sender, mod, arena_name), so we just need to add the following code into the previous snippet

	-- right after the first cmd:sub function

	cmd:sub("edit :arena", function(sender, arena)
		arena_lib.enter_editor(sender, yourmod, arena)
	end)

To enter our "foo" arena, we can just simply do /NAMEOFYOURCOMMAND edit foo. Feel now free to skip to 2.3 Arena phases.

2.2.2 CLI

If you don't want to rely on the hotbar, or you want both the editor and the commands via chat, here's how the commands work. Note that there actually is another parameter at the end of each of these functions named in_editor but, since it's solely used by the editor itself in order to run less checks, I've chosen to omit it.

2.2.2.1 Creating and removing arenas

• arena_lib.create_arena(sender, mod, arena_name, <min_players>, <max_players>): arena_name must be unique. Sender is a string, fields between < > are optional
• arena_lib.remove_arena(mod, arena_name)

2.2.2.2 Renaming an arena

Being arenas stored by ID, changing their names is no big deal. An arena can be renamed via
arena_lib.rename_arena(sender, mod, arena_name, new_name) In order to do so, it must be disabled.

2.2.2.3 Players management

arena_lib.change_players_amount(sender, mod, arena_name, min_players, max_players) changes the amount of players in a specific arena. It also works by specifying only one field (such as ([...] myarena, 3) or ([...] myarena, nil, 6)). It returns true if it succeeded.

2.2.2.4 Enabling/Disabling teams

arena_lib.toggle_teams_per_arena(sender, mod, arena_name, enable) enables/disables teams per single arena. enable is an int, where 0 disables teams and 1 enables them.

2.2.2.5 Spawners

arena_lib.set_spawner(sender, mod, arena_name, <teamID_or_name>, <param>, <ID>) creates a spawner where the sender is standing, so be sure to stand where you want the spawn point to be. Spawners can't exceed the maximum players of an arena and, more specifically, they must be the same number. A spawner is a table with pos and team_ID as values.

• teamID_or_name can be both a string and a number. It must be specified if your arena uses teams
• param is a string, specifically "overwrite", "delete" or "deleteall". "deleteall" aside, the other ones need an ID after them. Also, if a team is specified with "deleteall", it will only delete the spawners belonging to that team
• ID is the spawner ID, for param

Back on ChatCmdBuilder, here are few set_spawner examples:

	-- whatever previous subcommand

	-- for creating spawners without teams
	cmd:sub("setspawn :arena", function(sender, arena)
	  arena_lib.set_spawner(sender, yourmod, arena)
	end)

	-- for creating spawners with teams
	cmd:sub("setspawn :arena :team:word", function(sender, arena, team)
          arena_lib.set_spawner(sender, yourmod, arena, team)
      	end)

	-- for using 'param' (just pass a random number for deleteall as it won't matter)
	cmd:sub("setspawn :arena :param:word :ID:int", function(sender, arena, param, ID)
	  arena_lib.set_spawner(sender, yourmod, arena, nil, param, ID)
	end)

	-- for using 'param' with teams
	cmd:sub("setspawn :arena :team:word :param:word :ID:int", function(sender, arena, team, param, ID)
	  arena_lib.set_spawner(sender, yourmod, arena, team, param, ID)
	end)

   -- etc.

2.2.2.6 Signs

arena_lib.set_sign(sender, mod, arena_name, <pos, remove>) allows to either set or remove the sign of that specific arena. pos is a table, and it must correspond to an arena_lib sign to be set. remove is a boolean, and if true, pos will be ignored, as it'll erase the current arena sign (if exists)

2.2.2.7 Enabling/Disabling an arena

When a sign has been set, it won't work. This because an arena must be enabled manually via arena_lib.enable_arena(sender, mod, arena_name). If all the conditions are met, it'll return true and you'll receive a confirmation. If not, you'll receive the reason why it didn't through and the arena will remain disabled. Conditions are:

• all spawn points set
• sign placed
• potential custom checks through arena_lib.on_enable callback

Arenas can be disabled too, via arena_lib.disable_arena(sender, mod, arena_name).
In order to do that, no game must be taking place in that specific arena. If successful, it'll return true and any potential player in queue will be removed. It acts like enable_arena (with arena_lib.on_disable as callback)

2.2.2.8 Arena properties

Arena properties allow you to create additional persistent attributes specifically suited for what you have in mind (e.g. a score to reach to win the game). arena_lib.change_arena_property(sender, mod, arena_name, property, new_value) changes the specified arena property with new_value. Keep in mind you can't change a property type (a number must remain a number, a string a string etc), and strings need quotes surrounding them - so false is a boolean, but "false" is a string. Also, as the title suggests, this works for arena properties only. Not for temporary, players, nor team ones.

2.2.2.9 Timers

arena_lib.set_timer(sender, mod, arena_name, timer) changes the timer of the arena. It only works if timers are enabled (time_mode = "decremental").

2.2.2.10 Music

arena_lib.set_bgm(sender, mod, arena_name, track, title, author, volume, pitch) sets the background music of the arena. The audio file (track) must be inside the sounds folder of the minigame mod (NOT arena_lib's), and .ogg shall be omitted from the string. If track is nil, arena.bgm will be set to nil too

2.2.2.11 Celestial vault

By default, the arena's celestial vault reflects the celestial vault of the player before entering the match (meaning there are no default values inside arena_lib).
arena_lib.set_celestial_vault(sender, mod, arena_name, element, params) allows you to change parts of the vault, forcing it to players entering the arena. element is a string representing the part of the vault to be changed ("sky", "sun", "moon", "stars", "clouds", or the explained later "all"), and params a table with the new values. This table is the same as the one used in the Minetest API set_sky(...), set_sun(...) etc. functions, so for instance doing

	local sun_params = {
		scale = 2.5,
		sunrise_visible = false
	}
	arena_lib.set_celestial_vault(sender, mod, arena, "sun", sun_params)

will increase the size of the sun inside the arena and hide the sunrise texture. params can also be nil, and in that case will remove any custom setting previously set.
Last but not least, the special element "all" allows you to change everything, and it needs a table with the following optional parameters: {sky={...}, sun={...}, moon={...}, stars={...}, clouds={...}}. If params is nil, it'll reset the whole celestial vault.

2.2.2.12 Lighting

NOTE: EXPERIMENTAL FEATURE. EXPECT BREAKAGE IN THE FUTURE (according to the direction Minetest will choose to go with lighting) By default, the arena's lighting settings reflect the lighting settings of the player before entering the match (meaning there are no default values inside arena_lib).
arena_lib.set_lighting(sender, mod, arena_name, light_table) allows you to override those settings. As for now, light_table only takes one field, light, a float between 0 and 1 that changes the intensity of the global lighting. If light_table is nil, it'll reset the whole lighting settings.

2.3 Arena phases

An arena comes in 4 phases:

• waiting phase: the queuing process. People hit a sign waiting for other players to play with
• loading phase: the pre-match. By default players get teleported in the arena, waiting for the game to start. Relevant callback: on_load
• fighting phase: the actual game. Relevant callbacks: on_start, on_join
• celebration phase: the after-match. By default people stroll around for the arena knowing who won, waiting to be teleported. Relevant callbacks: on_celebration, on_end

2.4 Spectate mode

Every minigame has this mode enabled by default. As the name suggests, it allows people to spectate a match, and there are two ways to enter this mode: the first is by getting eliminated (remove_player_from_arena with 1 as a reason), while the other is through the very sign of the arena. In this last case, users just need to right-click the sign and press the "eye" button to be turned into spectators (a game must be in progress). While in this state, they can't interact in any way with the actual match: neither by hitting entities/blocks, nor by writing in chat. The latter, more precisely, is a separated chat that spectators and spectators only are able to read. Vice versa, they're not able to read the players one.
By default, spectate mode allows to follow players, but it also allows modders to expand it to entities and areas. To do that, have a look at arena_lib.add_spectate_entity(...) and arena_lib.add_spectate_area(...)

3. About the author(s)

I'm Zughy (Marco), a professional Italian pixel artist who fights for FOSS and digital ethics. If this library spared you a lot of time and you want to support me somehow, please consider donating on Liberapay. Also, this project wouldn't have been possible if it hadn't been for some friends who helped me testing through: Giov4, SonoMichele, _Zaizen_ and Xx_Crazyminer_xX