% Copyright (C) 2001-2025 Artifex Software, Inc.
% 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.
%
% Refer to licensing information at http://www.artifex.com or contact
% Artifex Software, Inc.,  39 Mesa Street, Suite 108A, San Francisco,
% CA 94129, USA, for further information.
%

% pdf2dsc.ps
% read pdf file and produce DSC "index" file.
%
% Input  file is named PDFname
% Output file is named DSCname
%
% Run using:
%  gs -dNODISPLAY -sPDFname=pdffilename -sDSCname=tempfilename pdf2dsc.ps
% Then display the PDF file with
%  gs tempfilename
%
% This program does not form part of the Ghostscript product, it is a utility which users may find
% useful.
%
% The program uses code based on the original written-in-PostScript PDF interpreter and depends
% heavily on that interpreter for its functioning. Since version 10.x that old PDF interpreter
% has been removed and replaced with a new written-in-C PDF interpreter. Some effort was made to
% ensure that old functionality was preserved, however it is not the same code.
%
% Users may find that some portion of the original functionality no longer works as expected, and
% there is no guarantee that future changes to the interpreter will not cause this program to
% cease working altogether. The code here is not supported by the Ghostscript maintainers.
%
% Modified by Jason McCarty, bug 688071
%       Add PageLabels support.
% Modified by Geoff Keating <geoffk@ozemail.com.au> 21/12/98:
%	Add DocumentMedia, PageMedia comments
%	Use inherited BoundingBox and Orientation
%	Reformat, add new macro 'puts', generally clean up
% Modified by Johannes Plass <plass@dipmza.physik.uni-mainz.de> 1996-11-05:
%	Adds BoundingBox and Orientation if available.
% Modified by rjl/lpd 9/19/96
%	Updates for compatibility with modified pdf_*.ps code for handling
%	  page ranges (i.e., partial files) better.
% Modified by Geoff Keating <Geoff.Keating@anu.edu.au> 7/3/96:
%	include Title and CreationDate DSC comments (these are displayed by
%	  Ghostview);
%	reduce the size of typical output files by a factor of about 3.
% Modified by L. Peter Deutsch 3/18/96:
%	Removes unnecessary and error-prone code duplicated from pdf_main.ps
% Modified by L. Peter Deutsch for GS 3.33
% Originally by Russell Lang  1995-04-26

/PDFfile PDFname (r) file def
/DSCfile DSCname (w) file def
systemdict /.setsafe known { .setsafe } if

/puts { DSCfile exch writestring } bind def
/DSCstring 255 string def
/MediaTypes 10 dict def

   PDFfile runpdfbegin
   /FirstPage where { pop } { /FirstPage 1 def } ifelse
   /LastPage where { pop } { /LastPage pdfpagecount def } ifelse

% scan through for media sizes, keep them in the dictionary
   FirstPage 1 LastPage {
      pdfgetpage /MediaBox pget pop   % MediaBox is a required attribute
      aload pop
      3 -1 roll sub 3 1 roll exch sub exch
      2 array astore
      aload 3 1 roll 10 string cvs exch 10 string cvs
      (x) 3 -1 roll concatstrings concatstrings cvn
      MediaTypes 3 1 roll exch put
   } for

% write header and prolog
   (%!PS-Adobe-3.0\n) puts
   Trailer /Info knownoget
    {
      dup /Title knownoget
       {
         (%%Title: ) puts
         DSCfile exch write==
       }
      if
      /CreationDate knownoget
       {
         (%%CreationDate: ) puts
         DSCfile exch write==
       }
      if
    }
   if
   % This is really supposed to be sorted by frequency of usage...
   (%%DocumentMedia: )
   MediaTypes {
      exch pop
      1 index puts
      (y) puts dup 1 get DSCstring cvs puts
      (x) puts dup 0 get DSCstring cvs puts
      ( ) puts dup 0 get DSCstring cvs puts
      ( ) puts 1 get DSCstring cvs puts
      ( 70 white ()\n) puts
      pop (%%+ )
   } forall
   pop

   (%%Pages: ) puts
   LastPage FirstPage sub 1 add DSCstring cvs puts
   (\n%%EndComments\n) puts
   (%%BeginProlog\n) puts
   (/Page null def\n/Page# 0 def\n/PDFSave null def\n) puts
   (/DSCPageCount 0 def\n) puts
   (/DoPDFPage {dup /Page# exch store dup dopdfpages } def\n) puts
   (%%EndProlog\n) puts
   (%%BeginSetup\n) puts
   DSCfile PDFname write==only
   ( \(r\) file { DELAYSAFER { .setsafe } if } stopped pop\n) puts
   ( runpdfbegin\n) puts
   ( process_trailer_attrs\n) puts
   (%%EndSetup\n) puts

   /.hasPageLabels false def % see "Page Labels" in the PDF Reference
   Trailer /Root knownoget {
     /PageLabels knownoget {
       /PageLabels exch def
       /.pageCounter 1 def
       /.pageCounterType /D def
       /.pagePrefix () def

       % (TEXT)  .ToLower  (text)  -- convert text to lowercase -- only letters!
       /.ToLower {
         dup length 1 sub  -1 0 {
           1 index exch 2 copy get 2#00100000 or put
         } for
       } def

       % int  .CvAlpha  (int in alphabetic base 26)  -- convert a positive
       % integer to base 26 in capital letters, with 1=A; i.e. A..Z, AA..AZ, ...
       /.CvAlpha { % using cvrs seems futile since this isn't zero-based ...
         [ exch % construct an array of ASCII values, in reverse
         { % the remainder stays on the top of stack
           dup 0 eq { pop exit } if % quit if the value is zero
           dup 26 mod dup 0 eq { 26 add } if % so that the division is correct
           dup 64 add 3 1 roll sub 26 idiv % save the ASCII value and iterate
         } loop ]
         dup length dup string 3 1 roll
         dup -1 1 { % put the letters in a string
           4 copy sub exch 4 -1 roll 1 sub get put
         } for pop pop
       } def

       % int  .CvRoman  (int in capital Roman numerals)
       % convert a positive integer to capital Roman numerals
       % return a decimal string if >= 4000
       /.CvRoman {
         dup DSCstring cvs % start with the decimal representation
         exch 4000 lt { % convert only if Roman numerals can represent this
           dup length
           [ [ () (I) (II) (III) (IV) (V) (VI) (VII) (VIII) (IX) ]
             [ () (X) (XX) (XXX) (XL) (L) (LX) (LXX) (LXXX) (XC) ]
             [ () (C) (CC) (CCC) (CD) (D) (DC) (DCC) (DCCC) (CM) ]
             [ () (M) (MM) (MMM) ] ] % Roman equivalents
           () % append the Roman equivalent of each decimal digit to this string
           2 index  -1 1 {
             2 index 1 index 1 sub get
             5 index 5 index 4 -1 roll sub get
             48 sub get concatstrings
           } for
           4 1 roll pop pop pop
         } if
       } def

       /PageToString <<
         /D { DSCstring cvs }
         /R { .CvRoman }
         /r { .CvRoman .ToLower }
         /A { .CvAlpha }
         /a { .CvAlpha .ToLower }
       >> def
       /.hasPageLabels true def
     } if
   } if

   % process each page
   FirstPage 1 LastPage {
       (%%Page: ) puts

       .hasPageLabels {
         dup 1 sub PageLabels exch numoget dup null ne {
           % page labels changed at this page, reset the values
           dup /S known { dup /S get } { null } ifelse
           /.pageCounterType exch def

           dup /P known { dup /P get } { () } ifelse
           /.pagePrefix exch def

           dup /St known { /St get } { pop 1 } ifelse
           /.pageCounter exch def
         } { pop } ifelse

         % output the page label
         (\() .pagePrefix
         .pageCounterType //null ne dup {
           PageToString .pageCounterType known and
         } if { % format the page number
           .pageCounter dup 0 gt { % don't try to format nonpositive numbers
             PageToString .pageCounterType get exec
           } {
             DSCstring cvs
          } ifelse
         } { () } ifelse
         (\)) concatstrings concatstrings concatstrings puts

         /.pageCounter .pageCounter 1 add def
       } {
         dup DSCstring cvs puts
       } ifelse
       ( ) puts
       dup DSCstring cvs puts
       (\n) puts

       dup pdfgetpage
       dup /MediaBox pget pop
         (%%PageMedia: y) puts
         aload pop 3 -1 roll sub DSCstring cvs puts
         (x) puts exch sub DSCstring cvs puts
         (\n) puts
       dup /CropBox pget {
         (%%PageBoundingBox: ) puts
         {DSCfile exch write=only ( ) puts} forall
         (\n) puts
       } if
       /Rotate pget {
         (%%PageOrientation: ) puts
         90 div cvi 4 mod dup 0 lt {4 add} if
         [(Portrait) (Landscape) (UpsideDown) (Seascape)] exch get puts
         (\n) puts
       } if

       DSCfile exch DSCstring cvs writestring
       ( DoPDFPage\n) puts
    } for
    runpdfend
% write trailer
(%%Trailer\n) puts
(runpdfend\n) puts
(%%EOF\n) puts
% close output file and exit
DSCfile closefile
quit
% end of pdf2dsc.ps
