[XeTeX] An OTF feature problem...

[Stephen Moye]

I am writing a series of macros that specialize in the creation of type specimens. I have begun on some using XeTeX, but have come up against a problem. When I specify a feature such as +onum the width of the string and the size of the font are incorrectly calculated. Am I doing something wrong? Thanks for any help.

Here is the plain TeX code showing the problem:

--------------------------------------------

%!TEX TS-program = xetex

%% These macros produce samples of text
%% using OTF fonts that have optical variations
%% Part of the ongoing TypeSpec project

\newdimen\dspsize
\newcount\divisor
\newcount\scratch
\newcount\finsize

\nopagenumbers
%\raggedbottom
\parindent0pt

\def\ABC{ABCDEFGHIJKLMNOPQRSTUVWXYZ}%
\def\abc{abcdefghijklmnopqrstuvwxyz}%
\def\fhabc{abcdefghijklm}
\def\lhabc{nopqrstuvwxyz}
\def\bigsamp{AGHeg12?!\&¶89pyQMT}
\def\subheadsamp{ABCDEFGHIJKLMeg12345\&67890pyNOPQRSTUVWXYZ}
\def\textsamp{\fhabc12345?!\ABC67890\&\lhabc}
\def\captsamp{Quick wafting zephyrs vex bold Jim.
Sphinx of black quartz, judge my vow.
The five boxing wizards jump quickly.
Pack my box with five dozen liquor jugs.}

%% Given the font and the width to be filled
%% find the scaling necessary to sale the
%% font to fit the text to the width
\def\findit{%
\setbox0=\hbox{\dsp\fittext}%
\dspsize=\hsize 
\finsize=\dspsize 
\divisor=\wd0
\divide\finsize by \divisor 
\dspsize=\finsize pt 
\divide\dspsize10
\divide\finsize10}%

\def\makeline#1#2{%
\def\fittext{#1}%
\def\testfont{#2}%
\font\dsp="\testfont/S=14" at .1pt%
\findit
\font\dsp="\testfont/S=\number\finsize" at .1pt%
\findit
\font\dsp="\testfont/S=\number\finsize" at .1pt%
\findit
\message{***\the\finsize:\the\dspsize***}%
\font\fitit="\testfont/S=\number\finsize" at \dspsize
%% The following five lines are optional
%% and can be commented out.
%% This conforms to Adobe's classification
%% of size variants.
\noindent\rm\testfont,
\ifnum\finsize>23 Display%
	\else\ifnum\finsize>15 Subhead%
	\else\ifnum\finsize>9 Text%
	\else Caption\fi\fi\fi,\ \the\dspsize\smallskip
\line{\hss\fitit\fittext\hss}}%

\def\makesample#1{\vbox{%
\makeline{\bigsamp}{#1}%
\medskip
\makeline{\subheadsamp}{#1}%
\medskip
\makeline{\textsamp}{#1}%
\medskip
\makeline{\captsamp}{#1}}}%


%%%%%%%%%%%%%%%%

\makesample{Brioso Pro}

\vskip.5in

\makesample{Brioso Pro:+onum}

\bye