Interface Querying

When navigating a scene, a plug-in reference will often be retrieved without knowing the concrete type of the plug-in. There are two mechanisms used for querying run-time type information from a plug-in. Each mechanism uses a function named GetInterface(). The first one is InterfaceServer::GetInterface() and the second one is Animatable:: GetInterface(). These functions both return an abstract base class (interface) using an interface identifier.

InterfaceServer::GetInterface()

The function InterfaceServer::GetInterface()uses the type Interface_ID to identify interfaces. An Interface_ID for a given interface can usually be found as a macro in the same file as the interface definition. For example, IDX8PixelShader has its interface ID defined in the same header file d3dx8.h.

Plug-ins should correctly handle the requests for interfaces in their implementation of InterfaceServer::GetInterface(), or they may not be displayed correctly in the Nitrous viewport. Developers are encouraged to read the Handling Requests for Interfaces best practices to find more information on this issue.

Animatable::GetInterface()

The function Animatable::GetInterface() uses integers to identify the interface IDs. Consult the C++ Reference's "Modules > List of interface IDs supported by different plugin types" for the list of pre-defined constants used to identify interfaces. To determine if an animatable can be used as the type a certain interface is representing, it is recommended to see if that animatable implements that interface or not, rather than to perform casts using dynamic_cast or static_cast.

NOTE:Animatable derives from InterfaceServer, so objects deriving from Animatable will need to support both InterfaceServer::GetInterface() and Animatable::GetInterface().