%    Copyright (C) 1989, 1992, 1993, 1998 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: viewgif.ps,v 1.5 2003/04/12 18:08:18 ray Exp $% viewgif.ps% Display a GIF file. /read1			% <file> read1 <int> { read pop } bind def/read2			% <file> read2 <int> { dup read1 exch read1 8 bitshift add } bind def /readGIFheader		% <file> readGIFheader <dict> { 20 dict begin   dup 6 string readstring pop   dup (GIF87a) eq exch (GIF89a) eq or not    { (Not a GIF file.\n) print cleartomark stop    } if   dup read2 /Width exch def   dup read2 /Height exch def   dup read1   dup 128 ge /GlobalColor exch def   dup -4 bitshift 7 and 1 add /BitsPerPixel exch def	%***BOGUS?***   dup 8 and 0 ne /PaletteSorted exch def   7 and 1 add dup /BitsPerPixel exch def     1 exch bitshift /PaletteSize exch def   dup read1 /BackgroundIndex exch def   dup read1 15 add 64 div /AspectRatio exch def   GlobalColor    { PaletteSize 3 mul string readstring pop      /GlobalPalette exch def    } if   currentdict end } bind def /readGIFimageHeader	% <file> readGIFimageHeader <dict>			% Note: GIF header must be on dict stack { 10 dict begin    { dup read1      dup (!) 0 get ne { exit } if pop		% extension      dup read1 pop       { dup read1 dup 0 eq { pop exit } if { dup read1 pop } repeat       } loop    } loop   (,) 0 get ne    { (Not a GIF image.\n) print stop    } if   dup read2 /Left exch def   dup read2 /Top exch def   dup read2 /Width exch def   dup read2 /Height exch def   dup read1   dup 128 ge /LocalColor exch def   dup 64 and 0 ne /Interlaced exch def   LocalColor    { 7 and 1 add /BitsPerPixel exch def      1 BitsPerPixel bitshift 3 mul string readstring pop      /Palette exch def    }    { pop pop /Palette GlobalPalette def    }   ifelse   currentdict end } bind def /imageGIF		% <imagedict> imageGIF { /ImageOut where    { pop		% We know BitsPerComponent = 8, Decode = [0 255].		% and there is only a single data source which is		% either a filter or a string whose size is exactly		% the width of the row.      dup /DataSource get dup type /stringtype eq       { ImageOut exch writestring       }       { pop dup /Width get string	 1 index /Height get	  { 1 index /DataSource get 1 index readstring pop	    ImageOut exch writestring	  }	 repeat pop pop       }      ifelse     }    { image    }   ifelse } bind def /viewGIF		% <file|string> viewGIF - { save 20 dict begin   /saved exch def   dup type /stringtype eq { (r) file } if   /F exch def   /ImageOutFile where { /ImageOut ImageOutFile (w) file def } if   F readGIFheader /Header exch def     currentdict Header end begin begin   VGIFDEBUG { Header { exch == == } forall (----------------\n) print flush } if   F readGIFimageHeader /ImageHeader exch def     currentdict ImageHeader end begin begin   VGIFDEBUG { ImageHeader { exch == == } forall (----------------\n) print flush } if   /D F   <<	/InitialCodeLength F read1	/FirstBitLowOrder true	/BlockData true	/EarlyChange 0   >> /LZWDecode filter def    [/Indexed /DeviceRGB 1 BitsPerPixel bitshift 1 sub Palette] setcolorspace   matrix currentmatrix   0 1 3 { 2 copy get dup 0 ne { dup abs div } if 3 copy put pop pop } for   setmatrix   <<	/ImageType 1	/ImageMatrix [1 0 0 -1 0 Height]	/BitsPerComponent 8	/Decode [0 255]   Interlaced    {	/Width Width   /Height 1	/row Width string def	/DataSource row      >> /I exch def      /inter		% <num> <denom> inter -       { /denom exch def   /num exch def         gsave	 /lines Height denom 1 sub add num sub denom idiv def	 0 1 lines 1 sub {	   Height exch denom mul num add sub	   I /ImageMatrix get 5 3 -1 roll put	   D row readstring pop pop	   I imageGIF	 } for	 grestore       }      bind def      0 8 inter      4 8 inter      2 4 inter      1 2 inter    }    {	/Width Width   /Height Height	/DataSource D      >> imageGIF    }   ifelse   saved end end end restore } bind def