Vostok Mods

This is an experimental mod loader for Road to Vostok.
RTV doesn't natively support mods, so we need to inject a script that loads other PCKs and runs other scripts.
The mod loader can be injected using one of the 2 options:

• (Currently used) Modifying the user://Preferences.tres save file to reference a subresource script.
• (Not implemented) Injecting a custom main loop using GodotPckTool and running it with --script

Mod PCKs (or ZIPs) will overwrite existing game files at runtime. Partial patches are not supported.

Installation

• Go to the releases page
• Download the Injector.pck file from the latest release
• Right click Road to Vostok in your Steam library and select "Manage>Browse local files"
• Move the downloaded file into the folder
• Right click Road to Vostok again and select "Properties..."
• In the "General" tab, set the launch options to --main-pack Injector.pck
• The mod loader is now installed

To install mods, move the mod .ZIPs into the mods folder in the game directory.

Creating mods

Download GodotPckTool to extract the game PCK.
All the extracted resources will be in a binary form, you can use Godot RE Tools to convert them back to usable formats.
Decompiling the GDScript scripts requires v0.7.0 or newer.
To create a mod, create a new folder with a file called mod.txt and fill it out with information.
mod.txt uses the ConfigFile format and requires the following fields:

[mod]
name="Human-readable mod name"
id="internal-mod-id"
version="0.0.1"

To modify a script or asset, extract it and decompile it.
If a script has a class_name, it needs to be removed.
Files must be in the same relative directory to your mod folder as in the PCK (e.g. res://Scripts/Character.gd -> mod_src/MyMod/Character.gd).
To run the mod, ZIP the contents of your mod so that mod.txt is in the root of the ZIP and put it in the mods folder next to the game executable.

Autoloads

Mod autoloads let you run scripts when the mod is loaded. They can be defined in the [autoload] section in mod.txt.
The value of a field must be a path to a script inhereting Node or a path to a PackedScene. The autoload will be added as a child of /root/ and it's name will be set to the field key.
Example autoload section:

[autoload]
MyModMain="res://MyMod/Main.gd"

Modifying assets

Dynamically

This method is prefered for modifying scripts, scenes and custom resources as it allows multiple mods to make changes on a single resource. For textures and audio, the static approach might be better but this approach works too.
To modify a script, create a script in your mod and extend it using the path to the script you want to modify, instead of it's class name. Then in your mod autoload script, load and compile the script and call take_over_path() on your new script with the path of the original script, for example:

extends "res://Scripts/Weapon.gd"

func PlayFireAudio():
	base()
	print("Pew!")

Autoload script:

func _ready():
	var script = load("res://MyMod/Weapon.gd")
	script.reload() # compile the script
	var parentScript = script.get_base_script()
	script.take_over_path(parentScript.resource_path)
	queue_free()

Important

Due to an issue with Godot, scripts can be overriden ONLY ONCE.
See godot#83542 and godot-mod-loader#338
We might switch to a hook-based system, which adds PRE and POST function hooks in the future if the issue isn't resolved. (godot-mod-loader#408)

This process also works for any other asset.

Statically

You can replace assets by having a file with the same path in your mod as the file you want to replace. A lot of assets will have a .remap file, which acts like a symlink. .remap files have the following format:

[remap]
path="res://path/to/target.file"

If you want to replace a file with a .remap file, you must create your own .remap file, which points to a different path.

Sample mods

These mods are included in the sample_mods directory

LightlyWeathered

Time, weather and music changes when entering a new zone.

SimpleControls

Simplifies the controls.
Weapon is always ready when not sprinting, arm stamina is only consumed while aiming. Bolt- and pump- action weapons automatically chamber next round and reload automatically with a single reload button press.