Base class for GDNative based ARVR interfaces. This class is used as a base class/interface class for implementing GDNative based ARVR interfaces and as a result exposes more of the internals of the ARVR server. Should return the projection 4x4 matrix for the requested eye. Outputs a finished render buffer to the AR/VR device for the given eye. Returns the size at which we should render our scene to get optimal quality on the output device. Get the location and orientation transform used when rendering a specific eye. Return true is an HMD is available. Initialize this interface. Returns true if this interface has been initialized and is active. Returns true if the required middleware is installed. Returns true if we require stereoscopic rendering for this interface. Gets called before rendering each frame so tracking data gets updated in time. Returns true if this interface supports HMDs. Turn this interface off.