[XeTeX] diacritics stacking using anchor points

[Jonathan Kew]

On 23/10/2021 14:37, Antonis Tsolomitis wrote:
> 
> It is a long time now that NewComputerModern has build-in information 
> for diacritics stacking.
> I have heard  that xetex supports this but I can not make it work. The 
> font is developed
> with fontforge and as you can see in the attached screenshot, fontforge 
> shows stacking working.
> 
> However xelatex just places, say the grave (uni0300) next and not above 
> the character, say uni2C9B
> (as in screenshot).
> 
> So I guess I have something wrong in the font that xetex does not like(?)


Do any other diacritics such as the acute (U+0301) or dieresis (U+0308) 
work? From a quick look at the GPOS table in the font -- if I'm reading 
it correctly -- it appears that uni0300 may have the wrong attachment 
point class (whereas in uni0301 and uni0308, it looks correct).

JK



> 
> The font currently develops the coptic block for academic needs this is 
> why I use uni2C9B.
> 
> A sample file is
> 
> \documentclass{article}
> \usepackage{fontspec}
> \setmainfont{NewCM10-Regular.otf}
> \begin{document}
> ⲛ̀
> \end{document}
> 
> However the font that contains this character (since it is under 
> development) is here:
> https://myria.math.aegean.gr/~atsol/tmp/NewCM10-Regular.sfd 
> <https://myria.math.aegean.gr/~atsol/tmp/NewCM10-Regular.sfd>
> https://myria.math.aegean.gr/~atsol/tmp/NewCM10-Regular.otf 
> <https://myria.math.aegean.gr/~atsol/tmp/NewCM10-Regular.otf>
> 
> thanks for any help,
> 
> Antonis.
>