cairo_path_t to GdkRegion?

["Brian J. Tarricone" <bjt23 cornell edu>]

Hi all,

I'm writing a semi-transparent window widget that uses cairo for
drawing.  I'm using an ARGB window, and the window itself isn't
necessarily rectangular (sometimes it'll have rounded corners of
arbitrary radius, and other non-regular shapes are possible).

Since I'm using cairo to do the drawing, I can of course very easily
get a cairo_path_t for the visible outline of the window.

I want to be able to draw this at least passably well for users not
running a compositing manager (and it would be nice to set an input
shape as well).  Anybody know of a way to munge a cairo_path_t into at
least an approximate GdkRegion (i.e. suitable for
gdk_window_shape_combine_region())?  Or is there a better way to do
this?

Thanks,
Brian