#!/usr/bin/perl -w

## This perl script converts the X11 rgb.txt file into latex commands
## suitable for use with the \color command from pstricks.  Make sure
## that the value of $rgbfile is correct and run the script.  It takes
## no arguments and writes out rgb.tex, which is to be \input-ed in
## your latex document, and colors.tex, which is a latex documents
## using rgb.tex and demonstarting each color defined.  Don't forget
## to put \usepackage{pstricks, pstcol} in the preamble of your
## document.

$rgbfile = '/usr/X11R6/lib/X11/rgb.txt';
$styfile = 'rgb.tex';
$texfile = 'colors.tex';

open(RGB, $rgbfile)     || die "could not find $rgbfile\n";
open(STY, ">".$styfile) || die "could not find $styfile for writing\n";
open(TEX, ">".$texfile) || die "could not find $styfile for writing\n";

				# headers
print TEX "\\documentclass{article}\n",
  "\\usepackage{pstricks, pstcol}\n",
  "\\begin{document}\n\n",
  "\\twocolumn\n\n",
  "\\input{rgb.tex}\n\n";

print STY '
%% rgb.tex
%% this file defines the X11 rgb color names for use with pstricks
%% put \usepackage{pstricks, pstcol} in the preamble of your document
%% the put \input{rgb.tex} in the body of your document.
%% Color in pstricks works like a switch.  If you enter
%%    The text will become \color{red}red.
%% Then all text after the \color command will printed in red in the
%% postscript file.  You can restrict the range of the red text in this
%% manner
%%    One {\color{red}some text} will be red.
%% The color will NOT show up in the dvi file, only in the .ps file!
%%
%% this file was created by rgb2tex.pl
%% rgb2tex.pl is by Bruce Ravel <bruce.ravel@nist.gov>
%% --------------------------------------------------------------------------

';

while (<RGB>) {			# convert rgb.tex
    next if (/^!/) ;
    next if (/^[ \t]*$/) ;
    chomp;
    @line = split;
    next if ($#line >= 4);	# only keep colors with one-word names
    $line[3] =~ tr/[A-Z]/[a-z]/; # canonicalize to lower case
    $key = $line[0] . $line[1] . $line[2];
    next if ($name{$key});	# no repeats!
    $name{$key} = $line[3];
    $r = $line[0]/255.0;	# the rgb values to 2 sig figs
    $g = $line[1]/255.0;
    $b = $line[2]/255.0;
    $color = $line[3].'}';
				# one entry for each color in each file
    printf STY "\\definecolor {%-20s {rgb}{%4.2f,%4.2f,%4.2f}\n",
      $color, $r, $g, $b;
    print TEX "{\\color{$color This is {$color }\n\n";
}
print TEX '\end{document}', "\n";
				# all done!