Computes the region of the window that is potentially visible. This does not necessarily take into account if the window is obscured by other windows, but no area outside of this region is visible.
a cairo_region_t. This must be freed with cairo_region_destroy() when you are done.
See Implementation
Computes the region of the window that is potentially visible. This does not necessarily take into account if the window is obscured by other windows, but no area outside of this region is visible.