[pdftex] color package in pdfTeX under plain TeX

[Heiko Oberdiek]

On Tue, Aug 02, 2005 at 09:23:55PM +0300, geolsoft at mail.ru wrote:

> Dear list members,
> 
> I am trying to use color package of graphics bundle with
> pdftex and plain TeX.  According to
> 
>   http://pdftex-def.berlios.de/
> 
> `questions regarding the usage of pdftex.def ... should be
> directed to the pdfTeX list', so here it goes.
> 
> Version of pdftex.cfg I use is 0.03m, the latest I could
> find.  pdfTeX is
> 
>   This is pdfTeX, Version 3.14159-1.10b (Web2C 7.4.5)
> 
> 
> Question 1.
> 
> First off, I don't know what is the proper way to select
> pdftex driver, or any other driver different from the
> default `dvips'.  The code I used at the top of the attached
> test file `grfcolor.tex' was adapted from
> $TEXMF/tex/latex/graphics/color.tex.  Is this the way to do
> it?

\input miniltx
\input color.sty

or just

\input color

Assuming an intelligent color.cfg file.
Example for color.cfg (teTeX/TeXLive):

%%% cut %%% color.cfg %%% cut %%%
\ProvidesFile{color.cfg}%
  [2005/02/03 v1.3 color configuration of teTeX/TeXLive]

% Select an appropriate default driver
\begingroup
  \chardef\x=0\relax
  % check pdfTeX
  \@ifundefined{pdfoutput}{}{%
    \ifcase\pdfoutput
    \else
      \chardef\x=1\relax
    \fi
  }%
  % check VTeX
  \@ifundefined{OpMode}{}{%
    \chardef\x=2\relax
  }%
\expandafter\endgroup
\ifcase\x
  % default case
  \def\Gin at driver{dvips.def}%
  \ExecuteOptions{dvips}%
\or
  % pdfTeX is running in pdf mode
  \def\Gin at driver{pdftex.def}%
  \ExecuteOptions{pdftex}%
\else
  % VTeX is running
  \def\Gin at driver{vtex.def}%
  \ExecuteOptions{vtex}%
\fi
\endinput
%%% cut %%% color.cfg %%% cut %%%

Without a color.cfg that detects pdfTeX and sets the
right driver, you can use:

\input miniltx
\input ifpdf
\ifpdf
  \def\Gin at driver{pdftex.def}
\else
  \def\Gin at driver{dvips.def}
\fi
\input color.sty
\resetatcatcode


> Question 2.
> 
> Next, I have the following problem when using \pagecolor
> command.  For every page of output, I get this kind of
> error:
> 
>   ! Output routine didn't use all of \box255.
> 
> and no headline/footline, only main body of a page.  See the
> same test file `grfcolor.tex', compile command is at the
> bottom (compile-command line).
> 
> The patch I send fixes the problem for plain TeX, but I
> don't know whether this solution is compatible with LaTeX,
> most probably not.
> 
> The problem as I see it is as follows:
> 
> \shipout is (re)defined by pdftex.def as
> 
>   \gdef\shipout{%
>     \afterassignment\GPT at shipout
>     \global\setbox\@cclv=%
>   }%
> 
> and plain TeX defines its output routine as
> 
>   \output{\plainoutput}
> 
> where \plainoutput is
> 
>   \def\plainoutput{\shipout\vbox{\makeheadline\pagebody\makefootline}%
>     \advancepageno
>     \ifnum\outputpenalty>-\@MM \else\dosupereject\fi}
> 
> \afterassignment\GPT at shipout in the (re)definition of
> \shipout above causes \GPT at shipout to be expanded after the
> `{' of `\shipout\vbox' in the \plainoutput (and not after
> the `}').  Therefore, the `real' primitive \shipout happens
> at the beginning of that \vbox, shipping out \box255,
> without headline, footline or any insertions.  After that
> \box255 becomes void, and the headline, footline and any
> insertions go into \box255, causing the `Output routine...'
> error message.

\shipout is called as:

  \shipout\vbox{...}

The definition of shipout:
    \gdef\shipout{%
      \afterassignment\GPT at shipout
      \global\setbox\@cclv=%
    }%

Thus you are right, \GPT at shipout is called at the
beginning of \vbox:

    \gdef\GPT at shipout{%
      \ifvoid\@cclv\relax
         \aftergroup\GPT@@shipout
         \GPT at pageliteral
      \else
        \GPTorg at shipout\vbox{%
          \GPT at pageliteral
          \box\@cclv
        }%
      \fi
    }%

But then, the idea of the code was to have a void
box 255. It's true in LaTeX, but not in plain.

> --- pdftex.def.orig	2005-08-02 19:32:15.000000000 +0300
> +++ pdftex.def	2005-08-02 19:35:44.000000000 +0300
> @@ -216,15 +216,18 @@
>           \aftergroup\GPT@@shipout
>           \GPT at pageliteral
>        \else
> -        \GPTorg at shipout\vbox{%
> -          \GPT at pageliteral
> -          \box\@cclv
> -        }%
> +        \aftergroup\GPT@@@shipout

However you cannot use \aftergroup, eg. there is no group:
  \shipout\box255

The solution would be a separate box register to ensure
a void one in order to distinguish between:
  \shipout\vbox{...} and \shipout\box...

Test file:

\input miniltx
\input color.sty

\def\set at page@color{%
  \@ifundefined{GPT at outputbox}{%
    % \newbox is outer in plain
    \csname newbox\endcsname\GPT at outputbox
  }{}%
  \global\let\current at page@color\current at color
  \@ifundefined{GPTorg at shipout}{%
    \global\let\GPTorg at shipout\shipout
    \gdef\shipout{%
      \afterassignment\GPT at shipout  
      \global\setbox\GPT at outputbox=%
    }%
    \gdef\GPT at shipout{%
      \ifvoid\GPT at outputbox\relax
         \aftergroup\GPT@@shipout
         \GPT at pageliteral
      \else
        \GPTorg at shipout\vbox{%
          \GPT at pageliteral  
          \box\GPT at outputbox
        }%
      \fi 
    }%
    \gdef\GPT@@shipout{%
      \GPTorg at shipout\box\GPT at outputbox\relax
    }%
    \gdef\GPT at pageliteral{%
      \pdfliteral direct{%
        q % gsave
        \current at page@color\space
        n % newpath
        0 0 \strip at pt\pdfpagewidth\space
        \strip at pt\pdfpageheight\space re % rectangle
        % there is no need to convert to bp
        f % fill   
        Q% grestore
      }%
    }%  
  }{}%
}
\resetatcatcode

\pagecolor{yellow}

\begingroup
  \color{blue}
  Hello World
\endgroup

\vfill\break

Second page.

\bye

(This would apply to everyshi.sty also.)

If would be nice, if someone could confirm the analysis or
find errors.

Yours sincerely
  Heiko <oberdiek at uni-freiburg.de>
--