Each plug-in has to provide a single implementation of the Cry::IEnginePlugin interface. In our case, one was automatically created along with our project; see GamePlugin.cpp and GamePlugin.h.

Before we take a look at the default implementation, let's have a look at the bare minimum implementation of an engine plug-in:

Plug-in Breakdown

class CGamePlugin final : public Cry::IEnginePlugin
{
  CRYINTERFACE_SIMPLE(Cry::IEnginePlugin)
  CRYGENERATE_SINGLETONCLASS_GUID(CGamePlugin, "Blank", "f01244b0-a4e7-4dc6-91e1-0ed18906fe7c"_cry_guid)
 
  virtual bool Initialize(SSystemGlobalEnvironment& env, const SSystemInitParams& initParams) override
  {
  }
};
 
CRYREGISTER_SINGLETON_CLASS(CGamePlugin)

Let's dissect this into parts:

Inheritance

class CGamePlugin final : public Cry::IEnginePlugin

Here we declare our game plug-in implementation as CGamePlugin, and inherit from Cry::IEnginePlugin. On startup, the engine parses the Game.cryproject file in your project directory, which in turn contains a path to our game plug-in DLL. Once the plug-in is loaded, an instance of our plug-in is created, invoking the CGamePlugin constructor.

Extension Framework

CRYINTERFACE_SIMPLE(Cry::IEnginePlugin)

Plug-ins utilize the engine's extension framework. This is a form of reflection allowing us to query implementations based on a specific interface. In this case, we indicate that our implementation implements Cry::IEnginePlugin.

CRYGENERATE_SINGLETONCLASS_GUID(CGamePlugin, "Blank", "f01244b0-a4e7-4dc6-91e1-0ed18906fe7c"_cry_guid)

In the next section, we need to provide our plug-in with a name and a GUID.