Using urw-garamond fonts in plain TeX

Question

I am struggling with a font problem that I can't solve by myself. I almost always write my files with pdfLaTeX and the urw-garamond fonts from mathdesign. However I would like to produce the same output with plain TeX or plain XeTeX, but with no success. I tried to read the mathdesign.sty file, and yet I can't really understand what is going on. The point of my question is about mathematical formulae, since I think I could use Garamond with XeTeX with little effort. Can you give me some hints?

Answer 1

The fonts used by mathdesign are encoded just like the normal Plain TeX fonts, so it's just a matter of reassigning the font names:

% redefine the font descriptors
\font\tenrm=mdugmr7t at 10pt % roman text
\font\sevenrm=mdugmr7t at 7pt
\font\fiverm=mdugmr7t at 5pt

\font\teni=mdugmri7m at 10pt % math italic
\font\seveni=mdugmri7m at 7pt
\font\fivei=mdugmri7m at 5pt

\font\tensy=mdugmr7y at 10pt % math symbols
\font\sevensy=mdugmr7y at 7pt
\font\fivesy=mdugmr7y at 5pt

\font\tenex=mdugmr7v at 10pt % math extension

\font\tenbf=mdugmm7t at 10pt % boldface extended
\font\sevenbf=mdugmm7t at 7pt
\font\fivebf=mdugmm7t at 5pt

\font\tensl=mdugmro7t at 10pt % slanted roman

\font\tenit=mdugmmi7t at 10pt % text italic

% reassign the math font families
\textfont0=\tenrm \scriptfont0=\sevenrm \scriptscriptfont0=\fiverm
\textfont1=\teni \scriptfont1=\seveni \scriptscriptfont1=\fivei
\textfont2=\tensy \scriptfont2=\sevensy \scriptscriptfont2=\fivesy
\textfont3=\tenex \scriptfont3=\tenex \scriptscriptfont3=\tenex
\textfont\itfam=\tenit
\textfont\slfam=\tensl
\textfont\bffam=\tenbf \scriptfont\bffam=\sevenbf
\scriptscriptfont\bffam=\fivebf
\textfont\ttfam=\tentt

% initialize the roman font
\rm

% start the document

The following facts are {\it well\/} known:
$$
\int_{-\infty}^{\infty}e^{-x^2}\,dx=
\sqrt{\displaystyle 6\sum_{k\ge1}{1\over k^2}}
=\sqrt{\pi}
$$

\bye