[cairo] Mac Tiger Core Image

[mental at rydia.net]

Quoting Carl Worth <cworth at cworth.org>:

> I've certainly never seen any other SVG file that was constructed
> in this manner.

It is very common in the output of various bitmap tracing tools that
emit SVG (though for some such tools there may be actual gaps
between the component shapes).

[ In Inkscape, the user may select either that tracing mode or (at
my behest) a saner one in which the image is built up of
overlapping shapes.  Each of the two modes seems to be desired by
some users though. ]

However, in real-world usage I see the "fringing issue" most
commonly with paths that have been "cut out" of one another using
boolean operations.  Graphic artists like to do this a lot,
particularly in conjunction with semi-translucent gradients.  In
those cases the shapes _cannot_ overlap at all, though they are
required to exactly adjoin with no visible gaps.

> If a user has data like this and thinks that dilation is the
> right approach to fix it, then the user is free to do so. Cairo
> certainly won't be making changes like that to the data the user
> provides.

Agreed.  While I used the link to highlight the issue, I wasn't
advocating that particular solution.  Trying to be more clever than
the user is invariably a losing proposition.

-mental