[Web4lib] RSS and diacritics

[Bob Rasmussen]

On Thu, 29 Nov 2007, Thomas Dowling wrote:

> The more adept browsers out there figured this out quite a while ago.  If the
> font they're using doesn't have a glyph for the character requested, they pull
> the correct glyph from a font that does have it.  Awkwardly, there's a less
> adept browser that fails to do this, that has about 80% market share...
> 
> CSS2 requires that browsers work their way down the list of specified fonts to
> find the right glyph, not just find a matching font name.  IIRC, Gecko-based
> browsers and Opera go beyond that to find any system font with the right
> glyph.

As an aside, that is precisely the approach taken by Anzio, our terminal 
emulation package, and Print Wizard, our printing utility. These programs 
also take many steps to handle combining diacritics well, including 
raising the "above" diacritics where necessary to avoid collision with the 
base character.

My perception of the most common issues in regards to library systems 
displaying (and printing) diacritics and non-Latin characters:

1) Very few fonts have the combining double tilde and combining double 
ligature marks, used mostly with transliterated Russian.

2) Software does not correctly combine combining diacritics. 

3) Fonts are inconsistent in the way they specify the X-location of 
combining diacritics.

4) Library software I have worked with does not give the browsers 
information about the language contained in a particular section of text. 
Thus the browser can not take advantage of the user's language-specific 
font preferences. This is especially a problem in rendering Han 
characters, which could be part of a Japanese, Korean, Simplified Chinese, 
or Traditional Chinese title, for instance. With IE, this seems to force 
the user to use one super-font, which inevitably has shortcomings.

Finally, Andrew Cunningham mentioned Font Linking. According to MS's 
documentation, this should make it possible to define a large virtual font 
by linking together multiple fonts, without physically combining the 
files. So theoretically I could create a font with the missing ligature 
marks (see 1 above), and link it to Arial Unicode, for instance. However, 
I have never succeeded in this in regards to IE. Has anyone succeeded in 
doing this?

Regards,
....Bob Rasmussen,   President,   Rasmussen Software, Inc.

personal e-mail: ras at anzio.com
 company e-mail: rsi at anzio.com
          voice: (US) 503-624-0360 (9:00-6:00 Pacific Time)
            fax: (US) 503-624-0760
            web: http://www.anzio.com