accents not working in context

[adityam]

Only the \hat accent works with euler-otf. \vec gives a broken vector, and other accents are simply ignored. I think that this may be due to the implementation differences between unicode-math and context.

Here is a minimal example.

\starttypescript    [math]     [euler][name]
  \definefontsynonym[MathRoman][name:Neo Euler] [features=math]
\stoptypescript

\definetypeface [mainface] [rm] [serif] [palatino] [default] [features=oldstyle]
\definetypeface [mainface] [mm] [math]  [euler] [default]  

\setupbodyfont[mainface,12pt]
\starttext
\startlines
acute       $\acute a$
grave       $\grave a$
ddot        $\ddot a$
tilde       $\tilde a$
mathring    $\mathring a$
bar         $\bar a$
breve       $\breve a$
check       $\check a$
hat         $\hat a$
vec         $\vec a$
dot         $\dot a$
widetilde   $\widetilde a$
widehat     $\widehat a$
\stoplines
\stoptext

[khaledhosny]

Unicode-math uses the combining accents, U+0300 etc. which sounds reasonable to me, however ConTeXt is using the spacing accents, U+0060 etc. which IMO is wrong; those are spacing characters and IMO shouldn't be used as accents. I don't mind duplicating few glyphs, be we need to settle which code points are correct.

[adityam]

hmm...in context we went back and forth between using combining accents and spacing accents. If I remember correctly, someone suggested that using spacing accents is the right thing to do. Personally, I do not understand unicode well, so I will ask Taco and Hans what they think.

For the moment, I will just adapt char-def to work with combining accents.

[khaledhosny]

Add some spacing accents

ConTeXt is using spacing accents instead of combining ones, though this is IMO wrong approach, I just duplicated the said glyphs.

Also fix a gap in combining arrows (\vec et al).

closed by 132a2f61eafcef59719fba2c6510c2c4c043bdc9

[adityam]

Thanks.

I will send out a detailed email to discuss this with everyone involved in two weeks, so that we can settle on a common standard.

[khaledhosny]

For the mean time, I duplicated the combing accents. Context seems to treat \vec as a "wide accent" (building it from its various parts), but it was broken and fixed now, though ConTeXt behavior seems to differ from plain TeX and should be revised. The wide hat and tilde is a different issue, please open an new issue for it, I'll try to debug it later.