Re: [Freefont-bugs] Anchors

[Denis Jacquerye]

On 10/26/05, Denis Jacquerye <address@hidden> wrote:
> On 10/26/05, Primoz PETERLIN <address@hidden> wrote:
> > -----BEGIN PGP SIGNED MESSAGE-----
> >
> > 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

Actually, there seems to be a bug with Fontforge and mkmk. They need
to be added in a specific order for them to work on a character. First
add the base-mark and then add the mark-mark. This is the only way
I've managed to get them piled up.

> > 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
>