% Copyright (C) 1994, 1995 Aladdin Enterprises. All rights reserved. % pdf_main.ps % PDF file- and page-level operations. % We don't handle the following PDF elements yet (identified by % page number in the reference manual): % Rotate (53) % We do handle the following as yet undocumented PDF 1.1 extensions: % % - The Dest element of a link or outline entry can be a name, % in which case it is looked up in the (optional) Dests dictionary % that can appear as an element of the Catalog. % % - The page identifier in a link Dest element can be null, meaning % the same page as the link itself appears on. /.setlanguagelevel where { pop 2 .setlanguagelevel } if .currentglobal true .setglobal /pdfdict where { pop } { /pdfdict 100 dict def } ifelse pdfdict begin % For simplicity, we use a single interpretation dictionary for all % PDF graphics execution, even though this is too liberal. /pdfopdict mark objopdict { } forall drawopdict { } forall /endstream { exit } bind (%%EOF) cvn { exit } bind % for filters .dicttomark readonly def % ======================== Main program ======================== % end % pdfdict userdict begin /defaultfontname /Times-Roman def % Make sure the registered encodings are loaded, so we don't run the risk % that some of the indices for their names will overflow the packed % representation. (Yes, this is a hack.) SymbolEncoding pop DingbatsEncoding pop % Redefine 'run' so it recognizes PDF files. systemdict begin /runps /run load def /run { dup type /filetype ne { (r) file } if dup read { dup (%) 0 get eq { pop dup =string readline pop (PDF-) anchorsearch { pop pop runpdf } { pop cvx exec } ifelse } { 2 copy unread pop cvx exec } ifelse } { closefile } ifelse } bind odef /runpdf % runpdf - { userdict begin /PSFile where { pop PSFile (w) file /PSout exch def } if /Page# null def /Page null def /PDFSave null def GS_PDF_ProcSet begin pdfdict begin pdfopen begin Trailer /Root oget /Pages oget /CropBox knownoget { mark /CropBox 3 -1 roll /PAGES pdfmark } if /FirstPage where { pop FirstPage } { 1 } ifelse 1 /LastPage where { pop LastPage } { pdfpagecount } ifelse QUIET not { (Processing pages ) print 2 index =only ( through ) print dup =only (.\n) print flush } if { dup /Page# exch store QUIET not { (Page ) print dup == flush } if [ (%%Page: ) 2 index ( ) 1 index #dsc pdfgetpage /Page exch store save /PDFSave exch store (before exec) VMDEBUG Page pdfshowpage (after exec) VMDEBUG PDFSave restore } for currentdict pdfclose end end end } bind def % Rebind procedures that invoke 'run'. /runlibfile { findlibfile dup pop { exch pop run } { /undefinedfilename signalerror } ifelse } bind def /.runlibfile /runlibfile load def end % systemdict end % userdict pdfdict begin % ======================== File parsing ======================== % % Read the cross-reference and trailer sections. /traileropdict mark (<<) cvn { mark } bind (>>) cvn /.dicttomark load /[ { mark } bind % ditto /] /] load /true true /false false /null null /R { /resolveR cvx 3 packedarray cvx } bind % see Objects below /startxref /exit load .dicttomark readonly def % Because of EOL conversion, lines with fixed contents might be followed % by one or more blanks. /lineeq % lineeq { anchorsearch { pop { ( ) anchorsearch not { () eq exit } if pop } loop } { pop false } ifelse } bind def /linene { lineeq not } bind def % Read (mostly scan) the cross-reference table. /readxref % readxref { PDFfile exch setfileposition PDFfile pdfstring readline pop (xref) linene { /readxref cvx /syntaxerror signalerror } if % Store the xref table entry position for each object. % We only need to read the run headers, not every entry. { PDFfile pdfstring readline pop dup (trailer) lineeq { pop exit } if token pop % first object # exch token pop % entry count exch pop exch % Stack: count obj# PDFfile fileposition 3 -1 roll { Objects 2 index get null eq % later update might have set it { Objects 2 index 2 index cvx put } if exch 1 add exch 20 add } repeat PDFfile exch setfileposition pop } loop PDFfile traileropdict pdfrun } bind def % Open a PDF file and read the trailer and cross-reference. /pdfopen % pdfopen { 10 dict begin cvlit /PDFfile exch def /PDFsource PDFfile def PDFfile dup dup 0 setfileposition bytesavailable setfileposition prevline (%%EOF) linene { /pdfopen cvx /syntaxerror signalerror } if PDFfile exch setfileposition prevline cvi % xref start position exch PDFfile exch setfileposition prevline (startxref) linene { /pdfopen cvx /syntaxerror signalerror } if % Scan backwards for the start of the trailer, % since we have to read the trailer before the first xref section. { PDFfile exch setfileposition prevline (trailer) lineeq { exit } if } loop pop PDFfile traileropdict pdfrun % Stack: xrefpos trailerdict /Trailer exch def Trailer /Size get /Objects 1 index array def /Generations exch string def % Read the last cross-reference table. readxref pop % Read any previous cross-reference tables. Trailer { /Prev .knownget not { exit } if readxref } loop % Create and initialize some caches. /PageCount pdfpagecount def /PageNumbers PageCount dict def % Write the DSC header if appropriate. [ (%!PS-Adobe-1.0) #dsc [ (%%Pages: ) pdfpagecount #dsc [ (%%EndComments) #dsc [ (%%BeginProlog) #dsc [ (\(gs_pdf.ps\) /runlibfile where { pop runlibfile } { run } ifelse) #dsc [ (GS_PDF_ProcSet begin) #dsc [ (%%EndProlog) #dsc % Copy bookmarks (outline) to the output. Trailer /Root oget /Outlines knownoget { /First knownoget { { dup writeoutline /Next knownoget not { exit } if } loop } if } if currentdict end } bind def % Write the outline structure for a file. Uses linkdest (below). /writeoutline % writeoutline - { mark 0 2 index /First knownoget { { exch 1 add exch /Next knownoget not { exit } if } loop } if % stack: dict mark count dup 0 eq { pop 1 index } { 2 index /Count knownoget { 0 lt { neg } if } if /Count exch 3 index } ifelse linkdest /Title oget /Title exch /OUT pdfmark /First knownoget { { dup writeoutline /Next knownoget not { exit } if } loop } if } bind def % Close a PDF file. /pdfclose % pdfclose - { begin /PSout where { pop [ (%%Trailer) #dsc PSout closefile } if PDFfile closefile end } bind def % ======================== Page accessing ======================== % % Get a (possibly inherited) attribute of a page. /pget % pget -true- % pget -false- { 2 copy knownoget { exch pop exch pop true } { exch /Parent knownoget { exch pget } { pop false } ifelse } ifelse } bind def % Get the total number of pages in the document. /pdfpagecount % - pdfpagecount { Trailer /Root oget /Pages oget /Count oget } bind def % Get the N'th page of the document. % The first page is numbered 1. /pdfgetpage % pdfgetpage { dup Trailer /Root oget /Pages oget { % We should be able to tell when we reach a leaf % by finding a Type unequal to /Pages. Unfortunately, % some files distributed by Adobe lack the Type key % in some of the Pages nodes! Instead, we check for Kids. dup /Kids knownoget not { exit } if exch pop null 0 1 3 index length 1 sub { 2 index exch oget dup /Kids known { dup /Count oget } { 1 } ifelse % Stack: index kids null node count dup 5 index ge { pop exch pop exit } if 5 -1 roll exch sub 4 1 roll pop } for exch pop dup null eq { pop pop 1 null exit } if } loop 1 index 1 ne { pop pop /pdfgetpage cvx /rangecheck signalerror } if exch pop exch pop } bind def % Find the page number of a page object (inverse of pdfgetpage). /pdfpagenumber % pdfpagenumber { % We use the simplest and stupidest of all possible algorithms.... PageNumbers 1 index .knownget { exch pop } { 1 1 PageCount 1 add % will give a rangecheck if not found { dup pdfgetpage oforce 2 index eq { exit } if pop } for PageNumbers 3 -1 roll 2 index put } ifelse } bind def % Display a given page. /boxrect % [ ] boxrect { aload pop exch 3 index sub exch 2 index sub } bind def /linkdest % linkdest % ([/Page ] /View | ) { dup /Dest knownoget { % Check for a name, to be looked up in Dests. dup type /nametype eq { Trailer /Root oget /Dests oget exch oget /D get } if dup 0 oget dup null eq { pop } { pdfpagenumber 1 add /Page exch 4 -2 roll } ifelse dup length 1 sub 1 exch getinterval /View exch 3 -1 roll } if } bind def /annottypes 5 dict dup begin /Text { mark exch { /Rect /Open /Contents } { 2 copy knownoget { 3 -1 roll } { pop } ifelse } forall pop /ANN pdfmark } bind def /Link { mark exch { /Rect /Border } { 2 copy knownoget { 3 -1 roll } { pop } ifelse } forall linkdest pop /LNK pdfmark } bind def end def /pdfshowpage % pdfshowpage - { dup /Contents knownoget not { 0 array } if dup type /arraytype ne { 1 array astore } if gsave 1 index /MediaBox pget { % We should really use setpagedevice to set the page size, % but it doesn't work reliably yet. boxrect statusdict /.setpagesize get exec exch neg exch neg translate } { initmatrix initclip } ifelse 1 index /CropBox pget { boxrect rectclip 1 index /CropBox knownoget { mark /CropBox 3 -1 roll /PAGE pdfmark } if } if % Copy annotations and links. 1 index /Annots knownoget { 0 1 2 index length 1 sub { 1 index exch oget dup /Subtype oget annottypes exch .knownget { exec } { pop } ifelse } for pop } if exch pop beginpage { oforce false resolvestream pdfopdict pdfrun } forall endpage grestore /showpage 0 # } bind def end % pdfdict .setglobal