[HarfBuzz] HarfBuzz shaping of R2L text

Thu May 30 14:05:32 UTC 2019

> Date: Thu, 30 May 2019 01:18:24 +0100
> From: Richard Wordingham <richard.wordingham at ntlworld.com>
> 
> On Wed, 29 May 2019 22:32:12 +0300
> Eli Zaretskii <eliz at gnu.org> wrote:
> 
> The attached files shows a rendering of <U+1A20 TAI THAM LETTER HIGH
> KA, U+1A6E TAI THAM VOWEL SIGN E, U+1A63 TAI THAM VOWEL SIGN AA>; one
> could equally well use <U+1000 MYANMAR LETTER KA, U+1031, U+102C>.  The
> visual order (in the direction of the script, from left to right) is
> <SIGN E, LETTER...KA, SIGN AA>. 

What font(s) do you use for these scripts?

Also, I'm not sure I understand why you describe some kind of
reordering in this case: AFAICT, all of the characters you mentioned
have string L directionality.  So why would they need to be reordered?