If you call this during a paint (e.g. between Window.beginPaintRegion
and Window.endPaint then GDK will mark the current clip region of the
window as being drawn. This is required when mixing GL rendering via
Cairo.drawFromGl and cairo rendering, as otherwise GDK has no way
of knowing when something paints over the GL-drawn regions.
This is typically called automatically by GTK+ and you don't need
to care about this.
If you call this during a paint (e.g. between Window.beginPaintRegion and Window.endPaint then GDK will mark the current clip region of the window as being drawn. This is required when mixing GL rendering via Cairo.drawFromGl and cairo rendering, as otherwise GDK has no way of knowing when something paints over the GL-drawn regions.
This is typically called automatically by GTK+ and you don't need to care about this.