[HarfBuzz] Hangul Shaper (was Re: an issue regarding discrepancy between Korean and Unicode standards

[Dohyun Kim]

2013/4/15 Dohyun Kim <nomosnomos at gmail.com>:
>
> The behavior of new Uniscribe is quote confusing and seems to be
> inconsistant on some points.  I cannot describe concisely what it
> does.  But it is evident that it renders correctly only those input
> sequence which is compliant to KS X 1026-1.
>

OK.  My guess about the behavior of new Uniscribe:

1.  demarcate syllable blocks according to KS X 1026-1

   - between L and L, V and V, T and T, or L and T (these are illegal string)
   - between V and L, T and L, or M and L (these are legal break point)
   - between Jamo and non-Jamo character including Hangul syllables
   - but not between L and V, V and T, T and M, V and M, LVT and M, LV and M.

where LVT and LV are Hangul syllables; L, V, and T are Jamos; M means
Hangul tone marks (U+302E or U+302F)

2.  reorder Hangul tone marks

    - if syllable block is well-formed, move M from the last to the
first of the cluster.
    - if syllable is not well-formed, Uniscribe does not move M.
Instead, U+25CC is inserted after M.

where "well-formed" means <LVT>, <LV>, <L V T>, or <L V>.

Regards,
--
Dohyun Kim
College of Law, Dongguk University
Seoul, Republic of Korea