On 13-04-23 05:29 PM, Khaled Hosny wrote: > On Tue, Apr 23, 2013 at 03:59:32PM -0400, Ed Trager wrote: >> Hi, Behdad and OpenType Experts-at-Large! >> >> I'm trying to find a good OpenType solution to a problem in the Tai Tham >> font that I am developing. >> >> The problem, as illustrated in (1) in the attached image, is that the >> subjoined form of consonant u1A36 TAI THAM LETTER NA or subjoined form of >> consonant u1A3E TAI THAM LETTER MA may commonly be followed by a subjoined >> dependent vowel u1A69 TAI THAM VOWEL SIGN U or u1A6A TAI THAM VOWEL SIGN UU >> and we don't want these to overlap. >> >> The solution that I thought would work quite well is to create ligature >> glyphs with the correct spacing, as shown in (2) in the attached figure. >> Note that these "ligature" glyphs are "mark" glyphs >> >> The lookup table, as one would expect it to be, is shown in (3). >> >> However, this apparently does not work! > > Ligatures should work for mark glyphs (I had used them few times, though > I generally prefer positioning with ‘mkmk’ anchors), so you have to > elaborate on how you are making your ligatures.
Correct. > Another possibility is > that ‘liga’ features or not activated for Thai shaping by default (I > don’t know), so may be using another tag would help. Correct. For Tai *Tham* (ie. in the SEA shaper) we force disable 'liga'. This is to allow developers to use liga to get the font working on systems without a dedicated Tai Tham shaper. You can use, eg. the 'blws' feature to do what you want to do. It can even reference the same lookups that 'liga' does. behdad > Regards, > Khaled > _______________________________________________ > HarfBuzz mailing list > [email protected] > http://lists.freedesktop.org/mailman/listinfo/harfbuzz > -- behdad http://behdad.org/ _______________________________________________ HarfBuzz mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/harfbuzz
