%!PS

% Temporary PostScript Transparency Demo forGuruGram #9A
% ======================================================
% by  Don Lancaster

%  Copyright c 2002 by Don Lancaster & Synergetics, Box 809, Thatcher, AZ, 85552
%  (928) 428-4073 Email: don@tinaja.com Website: http://www.tinaja.com
%  Consulting services available http://www.tinaja.com/info01.html
 
%  All commercial rights and all electronic media rights ~fully~ reserved.
%  Linking usually welcome. Reposting expressly forbidden. Version 1.5 

%  Shows an initial attempt at PostScript to Distiller transparency for
%  Acrobat 5.0. See http://www.tinaja.com/glib/pstrans.pdf for details. 


/transoverlay {

   % make a new graphics state
   [ /_objdef {newgsstate} /type /dict /OBJ pdfmark 

   % fill the new overlay graphics state - See PDF manual for details 
   [  {newgsstate}
          <<
            /Type /ExtGState 
            /ca 0.5                % fill transparency is 0.5
            /CA 0.5                % stroke transparency is 0.5
            /BM /Normal 
            /AIS false 
            /OP false 
            /OPM 1 
            /op true 
           >> /PUT

           pdfmark

    % start a Begin Picture graphics overlay subroutine...
    [ /BBox [0 0 1000 1000 ] /_objdef {overlaypix} /BP pdfmark

    % fill the Begin Picture graphics overlay Xobject subroutine...

          0 0.5 1 setrgbcolor     % on the aqua side of blue
          4 4 6 6 rectfill

    % complete the Begin Picture graphics overlay Xobject...
    [ /EP pdfmark

     } def


% Write a two squares program...

  /twosquares { gsave translate
                1 0.5 0 setrgbcolor            % red side of orange
                2 2 6 6 rectfill               % do background opaque box

                [ {overlaypix} /SP pdfmark     % show foreground transparent box

                grestore} def


%  Distill the two squares program. Initially use a BARE Distiller Job
%  Options that has no compression, no embedded fonts, and little else 

  gsave 50 50 translate 10 dup scale
  transoverlay                          % create new objects
  0 0 twosquares
  grestore

  showpage

%  IMPORTANT: Manual patching is now required per GuruGream 9a...

%    (0) Distill this file in Acrobat 5 using BARE job options.

%    (1) IN WORDPAD, make a copy of g8demox.pdf Rename it g8demo.pdf.
%    (2) Change the "/GS1 gs" in XObject object 2 to "/GS2 gs".
%    (3) Change "/GS1 6 0 R" in Resource object 8 to "/GS2 1 0 R"
%    (4) Save and view as PDF 5. Rebuild is expected but should work.
%    (5) Do a self SAVE AS to g8demo.pdf to preserve new file for use.

% Step (2) selects a transparent overlay graphics state for the top square.
% Step (3) links the transparent graphic state for the top square

%  A finished example is  http://www.tinaja.com/glair/g9ademo.pdf

% EOF