[cairo] cairo-1.13 finally opens

[Bill Spitzak]

Krzysztof Kosiński wrote:

>> Inset shadow

> Why not:
> cairo_fill_preserve(cr);
> cairo_clip_preserve(cr);
> cairo_set_blur(...);
> cairo_set_source(...); // change shadow color
> cairo_fill(cr);

The path/mask has to be inverted as well so the color is put against the 
edges, not in the middle. This can be done either before or after the blur.

> This also allows patterned shadows, which are not possible under your approach.

But I think you have the right approach.