Re: [Freefont-bugs] Anchors

[Denis Jacquerye]

On 10/26/05, Primoz PETERLIN <address@hidden> wrote:
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>
> Hello Denis,
>
> I thank you on your work on adding anchors to characters. They were
> lacking for a long time, and I have to admit that only today I actually
> learned that this craft is not entirely black magic and is actually
> explained on http://fontforge.sourceforge.net/overview.html#Anchors.
>
> As I understand, we have four classes of anchors at the moment:
>
> above, below - for positioning diacritics above or below a letter
> abovemk, belowmk - for stacking diacritics one atop another
>
> Have I got it correctly? I understand that the choice of anchor class
> names is essentially not standardized, i.e. I am just following your
> standard naming convention. :)

I haven't found much documentation on any standardized anchor class
names. I'd love to have something to follow. Right now I'm just
observing the behavior of Doulos SIL or looking at Unicode
documentation to know where diacritics go.

There should be a couple more anchors for Latin script. One for
diacritics that kern left or right of circumflex, one for those
overlayed over the base and one for the horn/hook. We probably need
one for ogonek since it should attached at different positions
depending on the base (in the middle bottom or on the right bottom).
That's it for mark and mkmk features.

The other positioning feature I'll add is kern. For diacritics that
goes between two characters, like the tie bar. I should move up if 
one of the two surrounding characters has an ascender. Another
behaviour could be to substitue the above diacritic for a below one, I
don't know it that's standard, but I could do it.

For the substitution feature, I'm adding ccmp for i and j to be
substituted with their dotless components when followed by a diacritic
above. For example i + circumflex -> dotlessi with circumflex, instead
of and dot with a circumflex above. I'm not sure how to do that for i
with a stroke and j with a loop since there doesn't seem to be any
dotless characters/glyph in the fonts. Where could I add those?
We might want to add ligatures for the contour tones to fully support
IPA, but that's a lot of ligatures.

I'll try to add more IPA characters over time.

If any body knows about documentation on Greek, Cyrillic or even
Hebrew script, I'm willing to add position and substitution features
for those too.

--
Denis Moyogo Jacquerye --- http://home.sus.mcgill.ca/~moyogo