[AUCTeX-devel] Preview FAQ: colors

[Julien Rioux]

How to customize foreground and background colors in previews, 
compatible with the tightpage option, and both dvips and pdflatex backends?

--

Ideally, with a preamble such as

\usepackage{color}
\pagecolor{blue}
\color{red}
\usepackage[active,tightpage]{preview}

the output would have red text on blue background on each page, and the 
correct tight bounding box. But this is not the case: only the 
\pagecolor is understood and only by pdflatex.

We can add hooks to each preview to add the foreground color.

address@hidden@macro\preview{\color{red}}

It works. Well, what about adding the \pagecolor there as well? The 
problem is that the special postscript code from \pagecolor interferes 
with the postscript code generated by the tightpage option (the bounding 
box info appears after the color info in the generated postscript, but 
it should appear before). Nevermind, we'll generate our own. The 
relevant code is

\color{blue}\special{ps::clippath fill}

In order to avoid warning messages about special postscript code in the 
output file when executing pdflatex, we wrap this with a check for the 
dvips option.

Another problem is that space is introduced within the shipout box. So 
instead of redefining \preview, we'll redefine address@hidden@end. This is a 
shipout hook allowing us to manipulate the preview box without changing 
its size.

Complete minimal example attached. Process through latex, dvips and 
ghostcript, using
gs -sDEVICE=png16m -dTextAlphaBits=4 -r300 -dGraphicsAlphaBits=4 -dSAFER 
-q -dNOPAUSE -sOutputFile="eta%d.png" "minimal.ps" -dBATCH

The same for pdflatex and ghostscript.

Cheers.

--
Julien

minimal.tex
Description: TeX document

eta1.png
Description: PNG image