If you download and run the “Interaction_Interactors_101” and “Interaction_Interactors_102” programs, we demonstrate the creation of a console based gaze aware windows with no WPF or Winforms loaded.. I think this should help you out?
When you do not work with WPF or WindowsForms, the Tobii Core SDK has UnboundInteractorAgent, which you can use to control everything related to interactors.
To help you manage interactors, the Tobii Core SDK provides another concept – InteractorAgents.
Although the syntax is still C#, the documentation related to the underlying class “virtualinteractor” is further explained @ https://tobii.github.io/CoreSDK/api/Tobii.Interaction.VirtualInteractor.html
You should ideally be able to adapt the “currentWindowHandle” to a rectangle, although you didn’t mention upon which graphical system this rectangle is being drawn. In any event, please try these out and let us know how you get on.