plan9fox/sys/lib/ghostscript/viewpcx.ps

%    Copyright (C) 1996, 1999 Aladdin Enterprises.  All rights reserved.
% 
% This software is provided AS-IS with no warranty, either express or
% implied.
% 
% This software is distributed under license and may not be copied,
% modified or distributed except as expressly authorized under the terms
% of the license contained in the file LICENSE in this distribution.
% 
% For more information about licensing, please refer to
% http://www.ghostscript.com/licensing/. For information on
% commercial licensing, go to http://www.artifex.com/licensing/ or
% contact Artifex Software, Inc., 101 Lucas Valley Road #110,
% San Rafael, CA  94903, U.S.A., +1(415)492-9861.

% $Id: viewpcx.ps,v 1.5 2002/06/02 12:03:28 mpsuzuki Exp $
% viewpcx.ps
% Display a PCX file.
% Requires the Level 2 `image' operator (to handle variable pixel widths).
% If SCALE is defined, maps input pixels to output pixels with that scale;
% if SCALE is undefined, scales the image to fit the page.
% ****NOTE: does not handle multi-plane images with palette.

/pcxbytes [
  0 1 255 {
    64 string exch 0 1 63 {
      3 copy exch put pop
    } for pop
  } for
] readonly def
/readpcx {			% - readpcx <str>
  f				% gets replaced
  dup read not {
    pop ()
  } {
    dup 192 lt {
      ( ) dup 0 4 -1 roll put exch pop
    } {
      192 sub //pcxbytes 3 -1 roll read pop get exch 0 exch getinterval
    } ifelse
  } ifelse
} def
/get2				% <string> <index> get2 <int>
 { 2 copy get 3 1 roll 1 add get 8 bitshift add
 } bind def
/dsproc
 { df s readstring pop		% s gets filled in
   s1 () ne { df s1 readstring pop pop } if % discard padding bytes
 } def				% don't bind, must be writable
/viewpcx			% <filename> viewpcx -
 { 100 dict begin
   /fname 1 index def
   /f exch (r) file def
		% Read and unpack the header.
   /header f 128 string readstring pop def
   /version header 1 get def
   /bpp header 3 get def
   /w header 8 get2 header 4 get2 sub 1 add def
   /h header 10 get2 header 6 get2 sub 1 add def
   /nplanes header 65 get def
   /bpl header 66 get2 def
   /palinfo header 68 get2 def
   /nbits bpp nplanes mul def
   version 5 eq
    { nbits 8 le
       { /cspace
	   [/Indexed   /DeviceRGB   1 bpp bitshift 1 sub
	 f fileposition
	 1 nbits bitshift 3 mul string
	 fname status pop pop pop exch pop
	 1 index length sub f exch setfileposition
	 f exch readstring pop
	 exch f exch setfileposition
	   ] def
	 /decode [0 cspace 2 get] def
       }
       { /cspace /DeviceRGB def
	 /decode [0 1 0 1 0 1] def
       }
      ifelse
    }
    { /cspace
	[/Indexed   /DeviceRGB   1 bpp bitshift 1 sub
	 header 16 1 nbits bitshift 16 .min 3 mul getinterval
	] def
      /decode [0 cspace 2 get] def
    }
   ifelse
		% Set up scaling.
   /SCALE where
    { pop
	% Map pixels SCALE-for-1.  Assume orthogonal transformation.
      w 1 0 dtransform add abs div SCALE mul
      h 0 1 dtransform add abs div SCALE mul
    }
    {	% Scale the image (uniformly) to fit the page.
      clippath pathbbox pop pop translate
      pathbbox .min exch pop exch pop ceiling
      dup h w gt { w mul h div exch } { h mul w div } ifelse
    }
   ifelse scale
		% Since the number of bytes per line is always even,
		% it may not match the width specification.
   /wbpl w bpp mul 7 add 8 idiv def
		% Define the data source procedure.
   /s1 bpl wbpl sub string def
   /df /readpcx load copyarray dup 0 f put cvx bind readonly
     0 () /SubFileDecode filter def
   /dsource [ nplanes
    { /dsproc load copyarray
      dup 1 wbpl string put
      cvx bind readonly
    }
   repeat ] def
		% Construct the image dictionary.
   20 dict begin		% image dictionary
     /ImageType 1 def
     /Width w def
     /Height h def
     /ImageMatrix [w 0 0 h neg 0 h] def
     /BitsPerComponent bpp def
     /Decode decode def
     /DataSource dsource dup length 1 gt
      { /MultipleDataSources true def }
      { 0 get }
     ifelse def
   currentdict end
		% Finally, display the image.
   cspace setcolorspace
   image
   showpage
   df closefile
   f closefile
   end
 } bind def

% If the program was invoked from the command line, run it now.
[ shellarguments
 { counttomark 1 ge
    { ] { viewpcx } forall
    }
    { cleartomark
      (Usage: gs -- viewpcx.ps filename.pcx ...\n) print
      ( e.g.: gs -- viewpcx.ps my.pcx another.pcx\n) print flush
    }
   ifelse
 }
 { pop
 }
ifelse