Until the first call to gtk.snapshot.Snapshot.pop, the mask image for the mask operation will be recorded.
After that call, the source image will be recorded until the second call to gtk.snapshot.Snapshot.pop.
Calling this function requires 2 subsequent calls to gtk.snapshot.Snapshot.pop.
mask mode to use
Until the first call to gtk.snapshot.Snapshot.pop, the mask image for the mask operation will be recorded.
After that call, the source image will be recorded until the second call to gtk.snapshot.Snapshot.pop.
Calling this function requires 2 subsequent calls to gtk.snapshot.Snapshot.pop.