[luatex] Misplaced letter

[Hans Hagen]

On 12/17/2017 7:45 AM, Javier Bezos wrote:
> Hans,
> 
>>> Javier (just dreaming of a merge of xetex and luatex...)
>> that dream will not come true ... the wole idea of luatex is not to hard
>> code things but to permit whatever solutions
> 
> I guess you are tired (understandably) of hearing things like
> this. Actually I was thinking of projects/attempts to use harfbuzz
> with luatex. Just to have the possibility to choose.
You can hook whatever library in via lua but in practice that doesn't 
mean you get better results.

Concerning hb: here i can hook that into context already for a while 
using plug mode but (1) users will loose quite some functionality that 
we have now with fonts as it's one or the other (per font), and i'm not 
eager to deal with discussions about that and support interferences; (2) 
performance on latin is in most cases much slower, on complex arabic it 
can be somewhat faster (also due to some dropped featurses in context 
node mode) and on the average performance is worse; (3) the main reason 
why we sometimes use it is in comparing output with uniscribe (which is 
an option) as that is the de facto standard for rendering opentype and 
there are curious border cases where the three methods (node node, plug 
mode hb-native, plug mode hb-uniscribe) disagree with each other which 
we then (read: idris in his font project) tries to work around, (4) 
libraries create a dependency that can be a pain (esp when one has 
different versions) and the less the better (ok, there's then a 
dependency on lua but that is visible code that one can patch without 
compilation)

Anyway, there's pdftex, xetex and luatex and each has its advantages 
(speed, integration, flexibility) which is good i think. Just like i use 
different operating systems and editors, i can also use different engines.

Hans

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