Difference between revisions of "Lua Mod API"

Revision as of 08:13, 13 February 2007

ETPro now supports server-side mods via the Lua scripting language. For more information about Lua, visit the Reference manual, the online edition of the book Programming in Lua or the lua-users wiki.

ETPro has an embedded Lua 5.0.2 interpreter, and if present will load user-defined scripts from the ETPro directory. It also provides an "et" library of function calls for Lua that allow access to the server engine, and provides callbacks so a server side mod may trigger on specific server events.

The following standard Lua libraries are initialized by default and available to ETPro Lua scripts: basic, table, i/o, os (available features vary depending on your OS), string, math.

A list of ETPro mods can be found here.

A tutorial about ETPro Lua scripting can be found here.

API requests can be discussed at the Lua Mod API talk page.

client commands

lua_status

lists all currently loaded lua modules.

lua mods cannot override this client command.

server commands

lua_status

lists all currently loaded lua modules.

cvars

lua_modules

(default "", disabled)

space separated list of lua modules for ETPro to load. modules will be run in the order listed.

lua_allowedmodules

(default "", disabled)

if set, only lua modules with the matching sha1 signatures listed in this cvar will be allowed to load.

changing either cvar will cause all currently loaded modules to :quit and be unloaded until the next map_restart.

et library calls

modules

et.RegisterModname( modname )

Registers a descriptive string modname for this mod.

vmnumber = et.FindSelf()

Returns a number indicating the VM slot the current mod is loaded into.

modname, signature = et.FindMod( vmnumber )

Returns the modname and sha1 signature for the mod loaded in the VM slot vmnumber. Returns nil, nil if the VM slot is invalid.

success = et.IPCSend( vmnumber, message )

Sends the string message to the mod in the VM slot indicated by vmnumber. The mod receiving message must have an et_IPCReceive() callback. If the message is successfully sent, success will be 1. On failure it will be 0. See the Lua IPC page for a simple example.

printing

et.G_Print( text )

Prints the string text to the server console.

et.G_LogPrint( text )

Prints the string text to the server console and writes it to the server log.

argument handling

These functions are to be used within the command callback functions.
args = et.ConcatArgs( index )

Returns all arguments beginning from index concatenated into a single string args

argcount = et.trap_Argc()

Returns a number indicating the number of command line arguments in the command buffer.

arg = et.trap_Argv( argnum )

Returns the contents of the command line argument argnum.

cvars

cvarvalue = et.trap_Cvar_Get( cvarname )

Returns the value of the cvar cvarname as a string. If there is no cvar named cvarname, returns a zero length string.

et.trap_Cvar_Set( cvarname, cvarvalue )

Sets the cvar cvarname to cvarvalue

configstrings

configstringvalue = et.trap_GetConfigstring( index )

Returns the string configstringvalue containing the contents of the configstring index

et.trap_SetConfigstring( index, configstringvalue )

Sets the configstring index to the string configstringvalue

server

et.trap_SendConsoleCommand( when, command )

Sends the command command to the server console, to be executed when (see et.EXEC_* constants)

clients

et.trap_DropClient( clientnum, reason, ban_time )

Disconnects clientnum from the server, with descriptive string reason reported to clients. ban_time is the time in seconds to ban the client from the server. ban_time is optional and may be entirely omitted, in which case the ban time defaults to the cvar b_defaultbantime

et.trap_SendServerCommand( clientnum, command )

Sends the command command to the client clientnum. If clientnum is -1, the command is broadcast to all connected clients.

et.G_Say( clientNum, mode, text )

Sends a chat command on behalf of client clientNum with the mode mode (see et.SAY_* constants) and chat text text.

et.ClientUserinfoChanged( clientNum )

Loads the new Userinfo of clientNum and stores it in the configstring and client variables

userinfo

userinfo = et.trap_GetUserinfo( clientnum )

Returns the contents of the Userinfo string for the client clientnum

et.trap_SetUserinfo( clientnum, userinfo )

Sets the Userinfo string for the client clientnum to userinfo

string utility functions

infostring = et.Info_RemoveKey( infostring, key )

Removes key key from infostring infostring and returns the modified infostring.

infostring = et.Info_SetValueForKey( infostring, key, value )

Sets the key key in the infostring infostring to value and returns the modified infostring. If value is an empty string, key is removed from the string.

keyvalue = et.Info_ValueForKey( infostring, key )

Returns the value of the key key in the infostring infostring. If key is not present in the string, an empty string is returned.

cleanstring = et.Q_CleanStr( string )

Returns string stripped of all color codes

ET filesystem

fd, len = et.trap_FS_FOpenFile( filename, mode )

Attempts to open the file filename with the access mode mode (see et.FS_ constants). Returns the filedescriptor fd and file length len. On error, len returns -1.

filedata = et.trap_FS_Read( fd, count )

Reads count bytes from filedescriptor fd.

count = et.trap_FS_Write( filedata, count, fd )

Attempts to write count bytes of filedata to filedescriptor fd. Returns number of bytes successfully written.

et.trap_FS_Rename( oldname, newname )

Renames file oldname to newname.

et.trap_FS_FCloseFile( fd )

Closes filedescriptor fd

indexes

soundindex = et.G_SoundIndex( filename )

Returns an index to the soundfile indicated by filename

modelindex = et.G_ModelIndex( filename )

Returns an index to the model indicated by filename

sound

et.G_globalSound( sound )

Plays the global sound indicated by the filename sound.

et.G_Sound( entnum, soundindex )

Plays the sound soundindex at the location of entity entnum

miscellaneous

milliseconds = et.trap_Milliseconds()

Returns a number indicating the current server time in milliseconds.

et.G_Damage( target, inflictor, attacker, damage, dflags, mod )

Does damage amount of damage on target inflicted by inflictor and cased by attacker

target, inflictor, attacker are entity numbers

dflags is a bitflag number to decide how the damage is inflickted, see dflags flaglist

mod is a number from 0 up to 64 o set the type of damage, see mod list

entities

entnum = et.G_Spawn()

Spawns a new entity and returns the new entity number.

entnum = et.G_TempEntity( origin, event )

Spawns a new TempEntity of event type event and places it at origin in the world.

Warning: up to and including ETPro 3.2.4 the signature of the method is broken and expects four instead of two parameters. To successfully call it, you need to prepend the parameter list with two dummy parameters like et.G_TempEntity( 0, 0, origin, event ). Use this method with care, because in future ETPro versions it will probably be corrected to the one stated above and might break your script.

et.G_FreeEntity( entnum )

Frees the entity entnum

spawnval = et.G_GetSpawnVar( entnum, key )

Returns the value of spawnvar key for entity entnum

et.G_SetSpawnVar( entnum, key, value )

Sets the spawnvar key to value for entity entnum

integer entnum = et.G_SpawnGEntityFromSpawnVars( string spawnvar, string spawnvalue, ... )

This function can only be called inside the et_InitGame callback

et.trap_LinkEntity( entnum )

Links the entity entnum

et.trap_UnlinkEntity( entnum )

Unlinks the entity entnum

(variable) = et.gentity_get ( entnum, Fieldname ,arrayindex )

Gets the value of Fieldname from entity entnum out of the g_entity struct. For NULL entities or clients, nil is returned.

arrayindex is used to specify which element of an array entity field to get. It is required when accessing array type fields. Entity field array indexes start at 0.

et.gentity_set( entnum, Fieldname, arrayindex, (value) )

Sets the value of Fieldname from entity entnum in the g_entity struct to (value)

arrayindex is used to specify which element of an array entity field to set.

et.G_AddEvent( ent, event, eventparm' )

Adds event event whit eventparameter eventparm' to entity ent

callbacks

qagame execution

et_InitGame( levelTime, randomSeed, restart )

Called when qagame initializes. levelTime is the current level time in milliseconds. randomSeed is a number that can be used to seed random number generators. restart indicates if et_InitGame() is being called due to a map restart (1) or not (0).

et_ShutdownGame( restart )

Called when qagame shuts down. restart indicates if the shutdown is being called due to a map_restart (1) or not (0).

et_RunFrame( levelTime )

Called when qagame runs a server frame. levelTime is the current level time in milliseconds.

et_Quit()

Called when ETPro unloads the mod. The mod should close all open filedescriptors and perform all cleanup.

client management

rejectreason = et_ClientConnect( clientNum, firstTime, isBot )

Called when a client attempts to connect to the server. clientNum is the client slot id, firstTime indicates if this is a new connection (1) or a reconnection (0). isBot indicates if the client is a bot (1) or not (0). If the mod accepts the connection, it should return nil. Otherwise, the mod should return a string describing the reason the client connection was rejected.

et_ClientDisconnect( clientNum )

Called when a client disconnects. clientNum is the client slot id.

et_ClientBegin( clientNum )

Called when a client begins (becomes active, and enters the gameworld). clientNum is the client slot id.

et_ClientUserinfoChanged( clientNum )

Called when a client's Userinfo string has changed. clientNum is the client slot id.

et_ClientSpawn( clientNum, revived )

Called when a client is spawned. clientNum is the client slot id. revived is 1 if the client was spawned by beeying revived.

commands

intercepted = et_ClientCommand( clientNum, command )

Called when a command is received from a client. clientNum is the client slot id. command is the command. The mod should return 1 if the command was intercepted by the mod, and 0 if the command was ignored by the mod and should be passed through to the server (and other mods in the chain).

The actual command can be accessed through the argument handling functions, as seen in the ETPro:Lua Sample Code.

intercepted = et_ConsoleCommand()

Called when a command is entered on the server console. The mod should return 1 if the command was intercepted by the mod, and 0 if the command was ignored by the mod and should be passed through to the server (and other mods in the chain).

The actual command can be accessed through the argument handling functions, as seen in the ETPro:Lua Sample Code.

xp

et_UpgradeSkill( cno, skill )

Called when client on slot cno gets an upgrade on skill skill. Return -1 to override (abort) the qagame function, anything else to "passthrough". Callback may modify skills (or do anything else it wants) during passthrough.

et_SetPlayerSkill( cno, skill )

Called when clients (on slot cno) skill level skill is set. Return -1 to override (abort) the qagame function, anything else to "passthrough". Callback may modify skills (or do anything else it wants) during passthrough.

miscellaneous

et_IPCReceive( vmnumber, message )

Called when another mod sends an et.IPCSend() message to this mod. vmnumber is the VM slot number of the sender, and message is the message.

et_Print( text )

Called whenever the server or qagame prints a string to the console.

et_Obituary( victim, killer, meansOfDeath )

Called whenever a player is killed.

predefined constants

et.EXEC_NOW
et.EXEC_INSERT
et.EXEC_APPEND
et.FS_READ
et.FS_WRITE
et.FS_APPEND
et.FS_APPEND_SYNC
et.SAY_ALL
et.SAY_TEAM
et.SAY_BUDDY
et.SAY_TEAMNL

et.HOSTARCH

set to WIN32 or UNIX depending on the host architecture qagame is running on.

LUA_PATH

set to fs_homepath/fs_game/?.lua in order to ease use of the require function.

configs

If a config is loaded, all modules are shutdown and reloaded. If a certified config is loaded, all modules are shutdown and reloaded, and additionally the following functions are disabled: require(), loadfile(), loadlib(), loadstring(), dofile()

caveats

Like qagame, lua modules are unloaded and reloaded on map_restart and map changes. This means that all global variables and other information is lost. Mods may choose to store persistent data in cvars or external files.

FAQ

Q: OMG I hate the libary prefix et.* on everything!!11!1oneone
A: table.foreach(et, function (func, value) _G[func] = value; end)

Q: How do a reload my lua file without restarting the whole server?
A: Use map_restart, reset_match or simply change the map.

Q: Can I see some sample code?
A: Lua sample code

Q: Is there a list of ETPro Lua mods?
A: Yes, here.

Q: OMG my mod doesn't work!
A: Make sure you added your mod's filename to the lua_modules cvar (e.g. set lua_modules mymod.lua).

Q: OMG why has et_ClientSay been removed?
A: That's a secret but, to keep the function as it was, just add the following code to your et_ClientCommand() function

	-- et_ClientSay had to be removed in order to intercept all commands 
	-- so here's a wrapper for that
		arg0 = et.trap_Argv(0) -- get the main command
		
		if arg0 == "say" then
			return et_ClientSay( clientNum, et.SAY_ALL, et.ConcatArgs(1))
		elseif arg0 == "say_team" then
			return et_ClientSay( clientNum, et.SAY_TEAM, et.ConcatArgs(1))
		elseif arg0 == "say_buddy" then
			return et_ClientSay( clientNum, et.SAY_BUDDY, et.ConcatArgs(1))
		elseif arg0 == "say_teamnl" then
			return et_ClientSay( clientNum, et.SAY_TEAMNL, et.ConcatArgs(1))
		end
	-- et_ClientSay wrapper end