DummyLoader: Skip registering the interfaces as part of the loader

[forderud]

Done to prevent the loader from "hijacking" the registration of the IImage3dSource and IImage3dFileLoader interfaces that should really be the responsibility of the "host" SW to register.

How SW implementation suggestion

Host SW that already registers COM classes can just add the IImage3dSource and IImage3dFileLoader to the library section of their IDL file to auto-register the interfaces.

Host SW that is not registering any COM classes can instead add the following C++ code:

// load and register type library
// only works out-of-proc if running as admin
CComPtr<ITypeLib> pTypeLib;
HRESULT hr = LoadTypeLibEx(L"Image3dAPI.tlb", REGKIND_REGISTER, &pTypeLib);
CHECK(hr);

[jogerh]

This makes quite a lot of sense. I agree that it should be the responsibility of the host to register the interfaces that it provides. But do you see this as a change that we would implement for all loaders, or just for the dummy loader?

[forderud]

This makes quite a lot of sense. I agree that it should be the responsibility of the host to register the interfaces that it provides. But do you see this as a change that we would implement for all loaders, or just for the dummy loader?

All loaders will likely need to be updated the same or in a similar way. Hosts may also need to be updated to ensure that they're instead registering the interfaces if not done by the loaders any more.