[XeTeX] Re: Unicode/font mixing

[Jonathan Kew]

On 25 Jan 2005, at 3:12 pm, Adam Lindsay wrote:

> Simon Spiegel said this at Tue, 25 Jan 2005 16:00:24 +0100:
>
>>> There have been requests in the past for a way to, in effect, declare
>>> several "current fonts" each covering a different Unicode range, so
>>> that mixed-script text wouldn't require explicit font changes. This 
>>> is
>>> an interesting possibility, but coming up with a design that would
>>> reliably do "the right thing", especially with characters such as
>>> punctuation or numerals that may be "shared" between scripts, is not 
>>> a
>>> trivial thing.
>
> True, but one solution is to point back to Apple. It might not be "the
> right thing," but it's the "Apple approach," and is probably worth
> entertaining. And as Apple provide four strategies for fallback 
> methods,
> it seems like users can somehow contort into what's needed, no?
> <http://developer.apple.com/documentation/Carbon/Reference/
> ATSUI_Reference/atsu_reference_Reference/function_group_9.html#//
> apple_ref/doc/uid/TP30000309/F17528>

Seems tempting, but inadequate (even if I could get it to work.... I 
tried, a little while back, but couldn't get it to co-operate; need to 
investigate again sometime).

The font fallback mechanism is, in principle, sufficient to make sure 
that all the characters in your text get rendered with some font that 
at least makes them visible (if available at all). But if you're 
wanting to set mixed-script text using several fonts, and actually get 
a typographically good result, you'll almost certainly need to specify 
some kind of relative scaling for the various fonts you provide, so 
that they match visually. (Just like when you load a font with 
fontspec.sty and specify [scale=...] to make it match the rest of your 
text better. Apologies for the reference to LaTeX rather than ConTeXt, 
Adam!)

If I can get font fallbacks to work, I'll probably permit that as an 
option (on the basis that seeing the Last Resort font would be much 
better than getting blanks or box glyphs), but I don't think it really 
addresses the general issue of setting mixed-script text without 
explicitly changing fonts.

JK