AkiKurisu / HybridCLR_IL2CPP_Modding

Modding support for HybridCLR IL2CPP Plus

HybridCLR IL2CPP Plus Modding Support

Modify engine assemblies table deserialized from ScriptingAssemblies.json by replacing dummy assembly name, so you can load other assembly dynamically without need to add them in json before build.

This repo is target to game programmer who want to use IL2CPP while supporting mod.

Dependency

HybridCLR

How to use

Since support C# modding for IL2CPP is not HybridCLR designed for, you should do some work to make it come true:

1. Replace Editor\BuildProcessors\PatchScriptingAssemblyList.cs of HybridCLR unity package to pre-add mod assembly place holders
2. Hardcode external assemblies info path in il2cpp-api.cpp (eg. {PersistentDataPath}/external.txt)
3. Write your mod assemblies name to info file (eg. Kurisu.Mod.Test, do not add suffix which should be .dll.bytes)

Support platform

Currently it can support modding for Windows and Android.

Else you should do

1. Do aot pre-process in your game source code for preventing generic stripping problem in mod assemblies (also providing mod interface access to game api is better than let modder use reflection since it may cause problem above)
2. Mod assembly's name should smaller than placeholder's name (currently maximum is 36, can be changed in PatchScriptingAssemblyList.cs)
3. Assembly not contained Monobehaviour, ScriptableObject and ManagedReference do not need to be added to external.txt.
4. If new mod is added or removed, external.txt should be modified before game loading. You can make a re-launch dialog box after user loads mod for first time.

#if IL2CPP_TARGET_ANDROID
void loadExternalAndroid()
{
    //It's your game's persistent data path in android: com.{CompanyName}.{ProjectName}.
    std::ifstream file("/storage/emulated/0/Android/data/com.AkiKurisu.IL2CPP_Mod/files/external.txt");
    loadExternalFromStream(file);
}
#endif // IL2CPP_TARGET_ANDROID

void loadExternalWin(const char *data_path)
{
    //Since engine send {GamePath}/il2cpp_data path to il2cpp, you can use it directly in Windows.
    const char *filePath = hybridclr::ConcatNewString(data_path, "/external.txt");
    std::ifstream file(filePath);
    loadExternalFromStream(file);
}

Safe Modding Method for MonoBehaviour

See https://github.com/AkiKurisu/MonoReference