[HarfBuzz] 'mark' feature in myanmar

[Behdad Esfahbod]

On 13-07-18 02:19 PM, Jonathan Kew wrote:
> Hey Behdad,
> 
> In hb-ot-shape-complex-myanmar.cc, we have the code fragment
> 
>   /*
>    * Note:
>    *
>    * Spec says 'mark' is used, and the mmrtext.ttf font from
>    * Windows 8 has lookups for it.  But testing suggests that
>    * Windows 8 Uniscribe is NOT applying it.  It *is* applying
>    * 'mkmk' however.
>    */
>   if (hb_options ().uniscribe_bug_compatible)
>     plan->map.add_feature (HB_TAG('m','a','r','k'), 0, F_GLOBAL);
> 
> which disables the 'mark' feature in Uniscribe-compatible mode.
> 
> However, AFAICT from my current testing, it looks like Uniscribe on Win8 *is*
> applying the 'mark' feature, and so this is resulting in tons of unwanted
> discrepancies when I try to compare stuff. (This is when testing with the
> mmrtext.ttf font from Windows 8.)

Interesting.  IIRC we were getting 100% parity in February with that same
font, right?


> Could you re-test and see whether you agree that 'mark' is now being applied
> by Uniscribe? (I wonder if there's been a fix in a Win8 update of some kind
> since we originally worked on this?) If so, we should remove this hack.

I will.  I haven't opened my Windows laptop since the February hackfest.  Will
see if an update changes it.  Got a sample sequence with expected / current
output?

Also, feel like asking MS people on the OpenType list?

> JK
> 

-- 
behdad
http://behdad.org/