[XeTeX] problem rendering unicode Devanagari dependent vowel signs and ligatures

[Leo Brouwer]

I've run Richard's sample (with devamt.ttf, the IBM version of Devanagari
MT---apparently not an exact equivalent, as it doesn't render "trya"
correctly), and it appears to me that it's not the fonts, but the lack
of* *Script=Devanagari
in the font options that's causing the difference. Using velthuis-sanskrit
mapping *without *Script=Devanagari displays visarga & dependent vowels
without the circle for *all *fonts I've tried. It also doesn't form
conjuncts correctly, however. Strangely enough, leaving out the script
option doesn't seem to make a difference when using Romdev mapping, or when
inputting Devanagari directly.

\documentclass{article}

 \usepackage{fontspec}

\usepackage{xltxtra}

\usepackage{xunicode}


 \newfontfamily{\DMTAFont}[Mapping=velthuis-sanskrit]{Devanagari MT for IBM}

\newfontfamily{\DMTBFont}[Mapping=velthuis-sanskrit,
Script=Devanagari]{Devanagari MT for IBM}

 \newfontfamily{\NakulaAFont}[Mapping=velthuis-sanskrit]{Nakula}

\newfontfamily{\NakulaBFont}[Mapping=velthuis-sanskrit,
Script=Devanagari]{Nakula}


 \begin{document}


 Devanagari MT without Script=Devanagari: {\DMTAFont .h .m atrya \char"0903
\char"093E}


 Devanagari MT: {\DMTBFont .h .m atrya \char"0903 \char"093E}


 Nakula without Script=Devanagari: {\NakulaAFont .h .m atrya \char"0903
\char"093E}


 Nakula: {\NakulaBFont .h .m atrya \char"0903 \char"093E}


 \end{document}

Thank you for bringing this to my attention; for now, I'll just make some
macros with velthuis mapping & script turned off for the characters I need.

I wonder how much of this is XeTeX and how much of this is an issue of font
> encoding and design, although I know very little about the internals of
> either.


Yes, I've wondered about this also. Most of the fonts that don't work in
XeTex display correct conjuncts in word processors, web browsers, etc., so
it does seem to be something specific about Xetex that's causing the fonts
to malfunction.

Sincerely,

Leo Brouwer
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