[HarfBuzz] Some (obsolete) khmer fonts not working (anymore) with harfbuzz

[Olivier Berten]

Well, I did test 255 khmer OpenType fonts and the only ones failing
are the CFC ones and the one attached here, which are all at least
about 10 years old, which is kind of the prehistory of khmer OpenType.

Olivier

2013/5/13 Jonathan Kew <jfkthame at googlemail.com>:
> On 13/5/13 10:58, Olivier Berten wrote:
>>
>> Well... any string with coeng for instance. The string I'm using is:
>> ពុម្ពអក្សរខ្មែរ
>>
>> Here are the results of
>> hb-view --shapers=old Kh-Svayrieng.ttf ពុម្ពអក្សរខ្មែរ
>> hb-view --shapers=ot Kh-Svayrieng.ttf ពុម្ពអក្សរខ្មែរ
>
>
> OK, so the problem is triggered by the fact that these fonts (at least the
> one I looked at) lack a 'pref' feature, and as such, harfbuzz-ng does not
> process them with the Indic shaper (which would rely on this feature for
> correct shaping). Instead, it sends them through the "generic" shaper.
>
> This works "correctly" for fonts that implemented *all* their behavior using
> "generic" features such as 'liga' and 'clig', which people used to do in
> order to get usable results from applications that did not really support
> Indic or Khmer shaping at all.
>
> However, in this case the font is using features such as 'abvs', 'blwf',
> 'pres', etc to do various aspects of the shaping. But these aren't applied
> by the generic shaper.
>
> So I think you'll get the "expected" results if you explicitly tell hb to
> enable these features:
>
>   hb-view --features abvs,blwf,blws,pres,psts Kh-Svayrieng.ttf
> ពុម្ពអក្សរខ្មែរ
>
> Not sure whether we should try to detect this and handle it automatically
> somehow...
>
> JK
>
> _______________________________________________
> HarfBuzz mailing list
> HarfBuzz at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/harfbuzz
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Sankor.ttf
Type: application/x-font-ttf
Size: 255024 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/harfbuzz/attachments/20130513/3eb083ad/attachment.bin>