LevelScripts
Contents
Overview
Level scripts allow you to set up level-wide code that will get run, regardless of what characters, items, and hotspots exist in that level.
Generally you should prefer to put your script logic in hotspots or character controller scripts.
However, sometimes a level script is the right tool for the job. This is especially true when you need to intercept messages that are only passed to level scripts, and that are not (by default) sent to smaller objects in the scene.
Script Tiers
The order that the engine calls into level scripts is as follows:
Global level script
This script file is located in ../Overgrowth/Data/Scripts/level.as.
Only one of these scripts is ever active at a time, since it is either defined by the base game, or by a mod, and only one mod is allowed to be active at the same time that changes this file. The game will tell you "File Collision" if you try to activate a second mod that overrides the file.
The engine will call into this script for every level in the game. You can override this script in mods, but it is best to only do this as a last resort, since this can make your mod incompatible with other script mods that also override the same file.
Per-level script
Only one of these scripts is ever active at a time, since it is defined per-level, and you cannot have more than one level running at the same time.
The specific path for this script is found in the <script> XML tag inside each level XML file. This can be changed in the top bar in the editor under Edit -> Set Level Script....
You can override this script in your mods, but that requires you to override it for each individual level. Only one such script can be active for a given level, so this is another place where mod collisions might occur.
Per-mod Level Script
Many of these scripts can be active at the same time, but each mod can only have one.
To use this script file you have to manually add the following XML tag the mod.xml that you make for your mod: <LevelHookFile>some_dir/something.as</LevelHookFile>
Functions in this script are run for every level in the game, and every mod can add their own level hook script.
The disadvantage to it is that you can't as easily override default level script behavior. For the most part, changes in this file are limited to adding on additional behavior, rather than altering existing behavior in the base level script.
Which level scripts to use in mods, and where to put files
In mods, you should always strive to do the least impacting change possible. Prefer modifying level scripts in this order:
If you're creating a per-mod level script, then you have the most flexibility of where to put your script files. Still, it is best to follow a standard convention so that it is easier to find the scripts in other people's mods. The recommended location is ../Overgrowth/Data/Mods/your_mod_name/Data/Scripts/your_mod_name/level_hook.as.
If you're trying to alter existing script files, then you'll need to place your modified script files in more specific locations.
To override a per-level script you must put your script file in ../Overgrowth/Data/Mods/your_mod_dir/Data/Scripts/, as this is the root directory for the <script> tag. To avoid accidentally overshadowing another mod's or one of the main game's script files, it is recommended that you create a directory in the Scripts directory with the name of your mod, and then put the script file in there.
To overshadow the Global level script, create your script file with the following directory and name: ../Overgrowth/Data/Mods/your_mod_dir/Data/Scripts/level.as.
Documentation
Documentation of the functions, classes, and object instances that you can access inside a level script are available in an automatically generated file on your hard drive after starting the game for the first time. Find the location for your operating system just below.
- Windows:
My Documents\Wolfire\Overgrowth\aslevel_docs.h - Mac:
~/Library/Application Support/Overgrowth/aslevel_docs.h - Linux:
~/.local/share/Overgrowth/aslevel_docs.h
The list of available functions, classes, and object instances can change with each version of the game, so keep checking back on this aslevel_docs.h file to see the most up to date information.
List of hook functions for global level file
Required global functions
These functions are required, and must be present in level.as. If you override that file in your mod, you must include all of these functions.
void Init(string level_name) { }
// Called when the level is first loaded.
// Be careful, this may be called before some objects or script params are present in the level.
// It is most useful for setting initial values for file-scope angelscript state.
void Update(int is_paused) { }
// Called regularly by the engine so you can perform work, or detect that the game is paused.
// It may be useful to do initialization once in this function, if you need objects or level script params to be present.
void ReceiveMessage(string message) { }
// Called when level-wide messages have been sent by the engine, or by objects in levels.
// Objects in levels (such as characters or hotspots) can send this using '''level.SendMessage("some message string");'''.
// Parameters can be sent by separating them with spaces, and putting quotes around parameters that might contain spaces,
// then using the '''TokenIterator''' object.
void HotspotExit(string str, MovementObject @mo) { }
// Triggered when any hotspot is exited by a movement object
void HotspotEnter(string str, MovementObject @mo) { }
// Triggered when any hotspot is entered by a movement object
void DrawGUI() { }
// Serves as an update function for script-defined GUIs
void SetWindowDimensions(int width, int height) { }
// Allows a script-defined GUI to resize itself when the window gets resized
void SaveHistoryState(SavedChunk@ chunk) { }
// Allows the level script to save extra undo state
void ReadChunk(SavedChunk@ chunk) { }
// Allows the level script to retrieve extra redo state
bool HasFocus() { return false; }
// Old unused function.
// Reserved, though, so be careful to just make this function return false, and not use it for anything
Optional global functions
These functions are optional, but will be called if they are present in level.as.
void IncomingTCPData(uint socket, array<uint8>@ data) { }
// Optional - Networking hook for when network data comes in over a socket you've created
void DrawGUI2() { }
// Optional - A second pass for updating script-defined GUIs, in case you need to do something with two passes (e.g. layout)
List of per-level script hook functions
Note that the specific path and filename of each of these scripts is defined in each level's XML file, and there can only be one such script defined per level.
Required per-level functions
These functions are required, and must be present in a per-level script file. If you have that script file in your mod you must include all of the following functions.
void Init(string level_name) { }
// Called when the level is first loaded.
// Be careful, this may be called before some objects or script params are present in the level.
// It is most useful for setting initial values for file-scope angelscript state.
void Update() { }
// Called regularly by the engine so you can perform work.
// This function '''will not be called''' if the game is paused.
// It may be useful to do initialization once in this function, if you need objects or level script params to be present.
void DrawGUI() { }
// Serves as an update function for script-defined GUIs
bool HasFocus() { return false; }
// Old unused function.
// Reserved, though, so be careful to just make this function return false, and not use it for anything
Optional per-level functions
These functions are optional, but will be called if they are present in a per-level script file.
void ReceiveMessage(string message) { }
// Called when level-wide messages have been sent by the engine, or by objects in levels.
// Objects in levels (such as characters or hotspots) can send this using '''level.SendMessage("some message string");'''.
// Parameters can be sent by separating them with spaces, and putting quotes around parameters that might contain spaces,
// then using the '''TokenIterator''' object.
void IncomingTCPData(uint socket, array<uint8>@ data) { }
// Optional - Networking hook for when network data comes in over a socket you've created
void DrawGUI2() { }
// Optional - A second pass for updating script-defined GUIs, in case you need to do something with two passes (e.g. layout)
List of per-mod hook functions
Note that the specific path and filename of each of these scripts is defined in each mod's mod.xml file, and there can only be one such script defined per mod.
Required per-mod functions
These functions are required, and must be present in a per-mod script file. If you add this level hook script in your mod, you must include all of these functions.
void Init(string level_name) { }
// Called when the level is first loaded.
// Be careful, this may be called before some objects or script params are present in the level.
// It is most useful for setting initial values for file-scope angelscript state.
void Update(int is_paused) { }
// Called regularly by the engine so you can perform work, or detect that the game is paused.
// It may be useful to do initialization once in this function, if you need objects or level script params to be present.
void DrawGUI() { }
// Serves as an update function for script-defined GUIs
void SetWindowDimensions(int width, int height) { }
// Allows a script-defined GUI to resize itself when the window gets resized
Optional per-mod functions
These functions are optional, but will be called if they are present in a per-mod level script hook file.
void ReceiveMessage(string message) { }
// Called when level-wide messages have been sent by the engine, or by objects in levels.
// Objects in levels (such as characters or hotspots) can send this using '''level.SendMessage("some message string");'''.
// Parameters can be sent by separating them with spaces, and putting quotes around parameters that might contain spaces,
// then using the '''TokenIterator''' object.
void IncomingTCPData(uint socket, array<uint8>@ data) { }
// Optional - Networking hook for when network data comes in over a socket you've created
void DrawGUI2() { }
// Optional - A second pass for updating script-defined GUIs, in case you need to do something with two passes (e.g. layout)
