[HarfBuzz] A problem in thai shaper

Behdad Esfahbod behdad at behdad.org
Mon Apr 16 18:08:49 PDT 2012


Thanks for the email. My comments inline.

On 04/13/2012 09:41 AM, datao zhang wrote
> So I think for the new Thai shaper, the valid composition of “consonant [1
> mandatory]+ diacritic vowel [1 optional] + tone mark [1 optional] “ should be
> set as same cluster.

I would guess that our generic layer will already take care of this based on
canonical combining categories?  Do you have a test case that you want to see

> Problem 2:
> When there is no consonant exist, the dotted circle should be inserted as base
> character.  The logic should be the first step for the shaping engine to find
> the invalid combing marks. Refer to
> http://www.microsoft.com/typography/otfntdev/thaiot/shaping.aspx#comb

Right.  We do not handle invalid combining marks yet.  That's something I want
to do at some point but it's not high priority.


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