[cairo] Tangential glyph enlargement

[Tobias Hoffmann]

Maarten Bosmans wrote:
> The quick-n-dirty way is to just use a stroke. Let's say you want the
> text enlarged by 10px and a stroke (outside of the enlarged glyphs) of
> 4px, then you draw a stroke of 28px in the stroke color, followed by a
> stroke of 20px in the fill color and finally a fill.
Hmm, it can probably work very well in practice.
I do wonder about the performance penalty for overpainting a pixel 
multiple times (when composing more than one or two sizes [and colors]).
OTOH, it's not as general, e.g. when transparency comes into play.

I think I have to play around with these options a little bit, to get a 
feeling of what is really necessary and worth the effort.
  Tobias