XeLaTeX, xy, and dejavu-otf

Question

The following document renders fine with XeLaTeX...

\documentclass[12pt]{standalone}

%\usepackage{dejavu-otf}

\usepackage[all]{xy}

\newcommand*{\point}[1]{*+[F.]{\makebox[2.8em]{$#1\mathstrut$}}}
\newcommand*{\dotsitem}{*+[F.]{\makebox[2em]{\ldots\mathstrut}}}

\begin{document}
\xy
\xymatrix @C=0pt @R=0pt{
  *++{\textbf{mz\mathstrut}} &
  \point{0} & \point{1} & \dotsitem & \point{n - 1} &
  \point{n} & \point{n + 1} &  \dotsitem & \point{2n - 1} &
  \dotsitem & \dotsitem & \point{l - 2} & \point{l - 1}\\
  *++{\textbf{scan\mathstrut}} &
  \point{0} & \point{1} & \dotsitem & \point{n - 1} &
  \point{n} & \point{n + 1} &  \dotsitem & \point{2n - 1} &
  \dotsitem & \dotsitem & \point{l - 2} & \point{l - 1}\\
  *++{\textbf{intens\mathstrut}} &
  \point{0} & \point{1} & \dotsitem & \point{n - 1} &
  \point{n} & \point{n + 1} &  \dotsitem & \point{2n - 1} &
  \dotsitem & \dotsitem & \point{l - 2} & \point{l - 1}}
\save "1,2"."3,5"="chunk1" \restore
\save "1,6"."3,9"="chunk2" \restore
\save "1,11"."3,13"="chunkN" \restore
\POS"chunk1"!CD!<0pt,-2\jot>*\frm{_\}} *++!U\txt<6em>{Chunk $1$}
\POS"chunk2"!CD!<0pt,-2\jot>*\frm{_\}} *++!U\txt<6em>{Chunk $2$}
\POS"chunkN"!CD!<0pt,-2\jot>*\frm{_\}} *++!U\txt<6em>{Chunk $N$}
\save "chunk1"*\frm{-} \restore
\save "chunk2"*\frm{-} \restore
\save "chunkN"*\frm{-} \restore
\endxy
\end{document}

... unless I uncomment the

\usepackage{dejavu-otf}

line (I do want DejaVu fonts):

Is it a problem with xy or dejavu-otf, and can it be somehow worked around?

Answer 1

This happens as soon as you load unicode-math, which dejavu-otf does internally.

You have to restore some legacy symbols, namely those for the underbraces and overbraces, otherwise the commands point to the wrong symbol in the Unicode math font.

\documentclass[12pt]{standalone}

\usepackage{dejavu-otf}

\usepackage[all]{xy}

% restore the legacy brace pieces using cmex
\DeclareSymbolFont{oldlargesymbols}{OMX}{cmex}{m}{n}
% for horizontal braces
\DeclareMathSymbol{\braceld}{\mathord}{oldlargesymbols}{"7A}
\DeclareMathSymbol{\bracerd}{\mathord}{oldlargesymbols}{"7B}
\DeclareMathSymbol{\bracelu}{\mathord}{oldlargesymbols}{"7C}
\DeclareMathSymbol{\braceru}{\mathord}{oldlargesymbols}{"7D}
% for vertical braces
\DeclareMathSymbol{\braceur}{\mathord}{oldlargesymbols}{"38}
\DeclareMathSymbol{\braceul}{\mathord}{oldlargesymbols}{"39}
\DeclareMathSymbol{\bracedr}{\mathord}{oldlargesymbols}{"3A}
\DeclareMathSymbol{\bracedl}{\mathord}{oldlargesymbols}{"3B}
\DeclareMathSymbol{\bracecl}{\mathord}{oldlargesymbols}{"3C}
\DeclareMathSymbol{\bracecr}{\mathord}{oldlargesymbols}{"3D}
\DeclareMathSymbol{\bracec}{\mathord}{oldlargesymbols}{"3E}
%%% end of fix

\newcommand*{\point}[1]{*+[F.]{\makebox[2.8em]{$#1\mathstrut$}}}
\newcommand*{\dotsitem}{*+[F.]{\makebox[2em]{\ldots\mathstrut}}}    

\begin{document}

\begin{xy}
\xymatrix @C=0pt @R=0pt{
  *++{\textbf{mz\mathstrut}} &
  \point{0} & \point{1} & \dotsitem & \point{n - 1} &
  \point{n} & \point{n + 1} &  \dotsitem & \point{2n - 1} &
  \dotsitem & \dotsitem & \point{l - 2} & \point{l - 1}\\
  *++{\textbf{scan\mathstrut}} &
  \point{0} & \point{1} & \dotsitem & \point{n - 1} &
  \point{n} & \point{n + 1} &  \dotsitem & \point{2n - 1} &
  \dotsitem & \dotsitem & \point{l - 2} & \point{l - 1}\\
  *++{\textbf{intens\mathstrut}} &
  \point{0} & \point{1} & \dotsitem & \point{n - 1} &
  \point{n} & \point{n + 1} &  \dotsitem & \point{2n - 1} &
  \dotsitem & \dotsitem & \point{l - 2} & \point{l - 1}}
\save "1,2"."3,5"="chunk1" \restore
\save "1,6"."3,9"="chunk2" \restore
\save "1,11"."3,13"="chunkN" \restore
\POS"chunk1"!CD!<0pt,-2\jot>*\frm{_\}} *++!U\txt<6em>{Chunk $1$}
\POS"chunk2"!CD!<0pt,-2\jot>*\frm{_\}} *++!U\txt<6em>{Chunk $2$}
\POS"chunkN"!CD!<0pt,-2\jot>*\frm{_\}} *++!U\txt<6em>{Chunk $N$}
\save "chunk1"*\frm{-} \restore
\save "chunk2"*\frm{-} \restore
\save "chunkN"*\frm{-} \restore
\end{xy}

\end{document}

What's the problem? Xy-pic needs the \braceld command and the companions one for drawing the braces and it uses glyphs in the standard OMX encoded font for math extensions. Unfortunately, when unicode-math is loaded, the font used for the math extensions is the same as the main math font and this has different glyphs at the slots shown above. For instance, "7A is z, which is why you see a “z” in your picture. Those pieces the braces are made do not exist in Unicode, but we can easily use the ones in the standard math extension font, with the definitions above.

This might be a feature request for Xy-pic.