Add an extra condition to the visibility check, which is similar to the
previous version of this check, which now guards against the window it
is hosted in not being visible.
Signed-off-by: Christopher Snowhill <kode54@gmail.com>
For legacy systems that do not support Metal. The Metal SceneKit view
does work on even 10.13.6, if a Metal GPU is present in the system.
Signed-off-by: Christopher Snowhill <kode54@gmail.com>