gzdoom-gles/wadsrc/static/zscript/events.txt

class StaticEventHandler : Object native
{
	virtual native void WorldLoaded();
    virtual native void WorldLoadedUnsafe();
	virtual native void WorldUnloading();
    virtual native void WorldUnloadingUnsafe();

	virtual native void RenderFrame();
}

class StaticRenderEventHandler : StaticEventHandler native
{
	// for frame and camera
	native readonly Vector3 ViewPos;
	native readonly double ViewAngle;
	native readonly double ViewPitch;
	native readonly double ViewRoll;
	native readonly double FracTic;
	native readonly Actor Camera;
}

class EventHandler : StaticEventHandler native
{
	static native StaticEventHandler Create(class<StaticEventHandler> type);
	static native StaticEventHandler CreateOnce(class<StaticEventHandler> type);
	static native StaticEventHandler Find(class<StaticEventHandler> type);

	static native bool Register(StaticEventHandler handler);
	static native bool Unregister(StaticEventHandler handler);
}

class RenderEventHandler : StaticRenderEventHandler native { }