Re: [office] Defining Alternative Glyphs

[Thomas Zander <zander@kde.org>]

On Monday 7. July 2008 23:45:05 robert_weir@us.ibm.com wrote:
> I'm reminded of an related set of proposals I heard back in 2006 at a KDE
> conference.
>
> Tim Eves, at SIL International, gave a presentation on the need to add
> "font feature" and "alternative glyph" support to ODF, in order to better
> support minority languages.

The initial proposal for Alternate glyps on this list came from me, so I think 
I should tell you why I suggested it :)

I like explaining things in a usecase, which would help here already.

If I have some text in small-caps (see attached image, second row) you will 
notice that the glyphs used for the digits look different from the full caps 
ones.  The 3 is below the baseline, for example.
Using these old style figures in ODF is currently problematic. They don't have 
unique unicode code points and since the advent of openType and fonts with 
thousands of glyphs, its no longer feasible to use font name.
In the days that a postscript font could hold just 256 glyphs the solution was 
simple; use a different font for the alternate glyphs, but using opentype we 
have to use the same font but specify that we want a specific font-feature 
for this character.

This is all for latin fonts, things get much more complex for minority fonts, 
so I won't explain that here. The simplest is to choose a slashed-zero in 
some cases, which is a user choice for the glyph, but manually forcing the 
usage of a ligature is another good example.

In my opinion this feature is needed for making that last step from nice 
looking text to professional looking text.

-- 
Thomas Zander

20061023_fg1.jpg

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