Retrieves the currently set vertex shader.
- ppShader [out, retval]
Pointer to a vertex shader interface.
If the method succeeds, the return value is D3D_OK. If ppShader is invalid, D3DERR_INVALIDCALL is returned.
Typically, methods that return state will not work on a device that is created using D3DCREATE_PUREDEVICE. This method however, will work even on a pure device because it returns an interface.