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LuaUtil
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List of utility functions in the Lua API
LuaFunctions
Updated Fri, 19 Apr 2019 23:43:27 +0100 by Wuzzy

Lua API: Utility functions

This page is a list of utility functions in the Lua API and other functions that don't fit anywhere else.

File system functions

HedgewarsScriptLoad(scriptPath [, mustExist])

Loads a script (i.e. a library) from the specified scriptPath . The root directory is here Hedgewars’ data directory. There will be a Lua error if the script does not exist.

If mustExist is false , no Lua error will happen even when the script does not exist.

Returns true if the script was loaded successfully, false otherwise.

Example: HedgewarsScriptLoad("/Scripts/Locale.lua") -- loads locale library

Math functions

div(dividend, divisor)

Performs an integer division and returns the result. The result is an integer and has the value of the first parameter (an integer) divided by the second parameter (another integer), rounded towards zero.

band(value1, value2)

Returns the bitwise logical AND of value1 and value2 .

bor(value1, value2)

Returns the bitwise logical OR of value1 and value2 .

bnot(value)

Returns the bitwise logical NOT of value .

Debugging functions

WriteLnToConsole(string)

Writes string to Logs/game0.log , found in the user data directory.

WriteLnToChat(string) (0.9.24)

Writes string into the chat.

DumpPoint(x, y) (0.9.23)

Converts the whole numbers x and y to strings and writes them to Logs/game0.log , one line each.

StartGhostPoints(count)

Just prints out “GHOST_POINTS” and the argument on the console. This function might change in later versions.

DeclareAchievement(id, teamname, location, value)

Declares an achievement with the identifier id achieved by the team teamname on the map location with an achievement value (e.g. score) of value . value must be an integer. You are supposed to call this function inside an onAchievementsDeclaration callback.

Currently, this actually just triggers a console output, but it might be changed later. The idea is to track multiplayer records.

Example:

DeclareAchievement("height reached", teamname, "ClimbHome", -score) Records a team's best height in ClimbHome.

ParseCommand(string)

Makes the game client parse and execute the specified internal game engine command.

The available commands depend on the current engine protocol version. The engine protocol can (and will) change between releases.

Important: If you use ParseCommand to overcome a shortcoming in our Lua API (e.g. a missing function), please make sure to report the issue.

With your report we can fix the shortcoming in future releases. We will try to remove the reliance on ParseCommand as good as possible. This will allow scripts to use the previously missing feature in a way that won’t break!

There are many available commands, but actual use in scripting is rare, and even then it's discouraged for long-term use. As of 0.9.24, the only command used in official scripts is:

  • "draw <map>" : Draws a hand-drawn map. MapGen must be mgDrawn for this to work. <map> is a string which must follow the format specified in DrawnMapFormat

Moreover, the control action names as listed in ConfigurationFiles (under “Binds”) can be used. Note we will eventually try to remove all ParseCommand s in the official scripts.

EndLuaTest(success)

This function is used by the Hedgewars developers in testing scripts in order to test the game engine. The testing scripts can be found in the Hedgewars source code under tests/lua . This function is useless for anything else.

Calling this function ends an engine test and reports a test result.

success is either one of TEST_SUCCESSFUL to report a successful test or TEST_FAILED for a failed test.

See EngineTestCases to learn more about testing the engine.

Library functions

For more utility functions, you might want to check out the Lua libraries.