Peter B. West wrote:
If a user renders a given .fo file on two different systems, using the same renderer (say, PDF), and specifies a font family (say, Baskerville) that does not exist on the first system, but does on the second, what result should be expected?
If the user specified a fallback, it is tried, otherwise I'd expect an error abort. What should be the alternative to the latter? Guessing the font characteristics and using a substitute font?
Although not mandated in XSL-FO, CSS2 offers a number of methods of font matching, only some of which preserve metrics. The FO User Agent is free to make implementation-specific decisions about this, I assume. My main interest here is in whether we want to try to separate out the font handling so that we try to guarantee identical layout on any renderer, or whether we state up front that such universality is *not* on offer. The latter course is certainly easier. The former seems to involve a metrics-preserving font matching front-end to every renderer. But fonts is an area I'm not familiar with.
I would assume that the most useful response to the above situation is to issue a warning and do one's best to match the font. The user has access to a number of mechanisms for narrowing font choice, and in the worst case we use a fall-back font.
Peter -- Peter B. West <http://www.powerup.com.au/~pbwest/resume.html>