Check if a window context associated to the identifier windowID exists. A window context exists if it has previously been created by TwSetCurrentWindow.

Window context identifier.

The window context identifier 0 always exist, this is the default context created when AntTweakBar is initialized through TwInit.

• 0 if the window context does not exist
• 1 if the window context exists

TwSetCurrentWindow, TwGetCurrentWindow