Interface API

the plugins system now use source interfaces.

The launcher exposes almost everything required by plugins in interfaces that allow for backwards compatibility. The only thing that’s passed to a plugin directly is the northstar dll HWND and a struct of data that’s different for each plugin.

Plugins are required to expose a void* CreateInterface(const char* name, int* status) function to share their own interfaces. The launcher loads the PluginId interface from the plugin to query info such as it’s name.

Plugins can use the CreateInterface function exposed by the northstarDll to use northstar interfaces such as for logging. An interface is just an abstract class to force all functions into a vftable.

Northstar Interfaces

NSSys001

Exposes some system functionality to plugins

// 32 bit
enum LogLevel {
  INFO,
  WARN,
  ERR,
};

// handle: handle of the plugin. Passed to the plugin on init.
void Log(HMODULE handle, LogLevel level, char* msg); // logs a message with the plugin's log name
void Unload(HMODULE handle); // unloads the plugin
void Reload(HMODULE handle);

Required Plugin Interfaces

Interfaces that have to be exposed for the plugin to be loaded.

PluginId001

// strings of data about the plugin itself. may be extended in the future
// 32 bit
enum PluginString {
  NAME, // the name of the plugin
  LOG_NAME, // the name used for logging
  DEPENDENCY_NAME, // the name used for squirrel dependency constants created. The value returned for this has to be a valid squirrel identifier or the plugin will fail to load
}

// bitfields about the plugin
// 32 bit
enum PluginField {
  CONTEXT // 0x1 if the plugin is allowed to run on dedicated servers and 0x2 if the plugin is allowed to run on clients (is this even needed seems useless to me)
}

char* GetString(PluginString prop);
i64 GetField(PluginField prop);

PluginCallbacks001

struct PluginNorthstarData { HMODULE handle; };

// COPY THE initData IT MAY BE MOVED AT RUNTIME
void Init(HMODULE nsModule, const PluginNorthstarData* initData, bool reloaded); // called after the plugin has been validated. The nsmodule allows northstar plugins to work for the ronin client as well (assuming they update their fork lmao)
void Finalize(); // called after all plugins have been loaded. Useful for dependencies
void Unload(); // called just before the plugin is getting unloaded
void OnSqvmCreated(CSquirrelVM* sqvm); // the context of the sqvm is contained in the instance
void OnSqvmDestroying(CSquirrelVM* sqvm); // callback with the sqvm instance that's about to be destroyed (for UI, CLIENT is destroyed for some reason??)
void OnLibraryLoaded(HMODULE module, const char* libraryName); // called for any library loaded by the game (for example engine.dll)
void RunFrame(); // just runs on every frame of the game I think

What’s an interface anyways?

Interfaces are just abstract classes. So make sure the first parameter is always a pointer to the instance of the interface you’re using.

an example what NSSys001 looks like in C:

typedef enum {
  LOG_INFO,
  LOG_WARN,
  LOG_ERR,
};

typedef struct CSys {
  struct {
    void (*log)(struct CSys* self, HMODULE handle, LogLevel level, char* msg);
    void (*unload)(struct CSys* self, HMODULE handle);
  }* vftable;
} CSys;

// use like this
g_c_sys->vftable->log(g_c_sys, g_handle, LOG_INFO, "my balls are itching");

Interfaces are created with CreateInterface that’s exposed in another dll.