%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% pdfbase.sty
%
% driver independent access to low-level pdf features
%
% Copyright 2015--\today, Alexander Grahn
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% This package implements commands for the creation of PDF Objects,
% Form XObjects, Image XObjects, annotations, links, marked content (BDC/EMC)
% and for manipulating the PDF catalog.
%
% Supported workflows:
%
%   pdflatex, lualatex
%   latex-->dvips-->ps2pdf or Distiller
%   latex-->dvipdfmx
%   xelatex
%
% Package options:
%
%   xetex
%   dvipdfmx
%   dvisvgm  (basic support: \pbs_literal:nn, \pbs_pdfannot:nnnn,
%                            \pbs_pdfxform:nnnnn\pbs_pdfrefxform:n)
%   bigfiles (for embedding large files as stream objects; only relevant for
%     dvips mode, ignored otherwise)
%
% Commands defined:
%
%   \pbs_pdfobj:nnn
%     #1: predefined PDF object ID to be used for the current obj; may be empty
%     #2: type of object ( dict | array | stream | fstream )
%     #3: if #2==
%        `dict' then PDF key-value dictionary
%        `stream' then
%           {stream attributes as PDF key-value dictionary}{content string}
%        `fstream' then
%           {stream attributes as PDF key-value dictionary}{file name}
%
%     if #3 && #1 are both empty, an object reference will be reserved for later
%     use as #1
%
%   \pbs_pdflastobj:
%     inserts object ID of PDF object created/processed during most recent call
%     of \pbs_pdfobj:nnn
%
%   --------
%
%   \pbs_pdfannot:nnnn
%     #1: width, #2: height, #3: depth, #4: dictionary (key-value)
%
%   \pbs_pdflastann:
%     inserts object ID of PDF object created during most recent call of
%     \pbs_pdfannot:nnnn
%
%   --------
%
%   \pbs_appendtofields:n
%     #1 object ID of PDF annotation; annotations of /Subtype/Widget
%     should be appended to the /Fields array of the global /AcroForm dictionary
%
%   --------
%
%   \pbs_pdflink:nn
%     #1: dictionary (key-value), #2: text
%
%   --------
%
%   \pbs_pdfxform:nnnnn
%     #1: add pgf/tikz resources (transparency, shading)? (1|0) %dvipdfmx/xetex
%     #2: used as PDF annotation appearance? (1|0)              %dvips/pdftex
%     #3: additional resources                                  %all BUT dvips
%     #4: additional dictionary entries
%     #5: savebox number
%     creates PDF Form XObject from savebox content
%
%   \pbs_pdflastxform:
%     inserts object ID of PDF Form XObject created during most recent call of
%     \pbs_pdfxform:nnnnn
%
%   \pbs_pdfrefxform:n
%     #1: xform object ID
%     inserts the PDF Form XObject into the current content stream, that is,
%     typsets the PDF Form XObject
%
%   --------
%
%   \pbs_pdfximage:n
%     #1: bitmap image file name
%     creates PDF Image XObject from /bitmap/ file for use as bitmap resource
%     in 3D context
%
%   \pbs_pdflastximage:
%     inserts object ID of PDF Image XObject created during most recent call of
%     \pbs_pdfximage:n
%
%   --------
%
%   \pbs_literal:nn
%     #1: keyword (empty) | direct | page
%     #2: raw PDF/Postscript code
%     implements \pdfliteral{...}, \pdfliteral direct {...},
%     \pdfliteral page {...} from pdfTeX, and
%     \special{" ...} and  \special{ps: ...} from dvips
%
%   --------
%
%   \pbs_pdfcatalog:n
%     #1: dictionary (key-value)
%
%   --------
%
%   marked content BDC/EMC operators
%   \pbs_pdfbdc:nn ...
%   ... \pbs_pdfemc:
%     #1: tag, #2: properties dictionary obj ID
%
%   --------
%
%   alternative \AtEndDvi
%   \pbs_at_end_dvi:n
%     #1: \specials or \write to be inserted on the very last page
%
%   --------
%
%   \pbs_add_form_font: (pdfLaTeX, LuaLaTeX)
%     adds current font as a resource to the global /AcroForm dict, allowing
%     the font to be used in PDF Forms (theoretically, see
%     https://acrobat.uservoice.com/forums/590923-acrobat-for-windows-and-mac/
%       suggestions/33077827-bug-in-text-field-forms-embedded-opentype-font )
%
%   \pbs_last_form_font: (pdfLaTeX, LuaLaTeX)
%     expands to current font's resource name; to be used in the /DA (...)
%     entry of the Form dictionary
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License.
%
% The latest version of this license is in
%   http://mirrors.ctan.org/macros/latex/base/lppl.txt
%
% This work has the LPPL maintenance status `maintained'.
%
% The Current Maintainer of this work is A. Grahn.

\RequirePackage{expl3}
\RequirePackage{l3keys2e}

\def\g@pbs@date@tl{2019/02/21}
\def\g@pbs@version@tl{0.27}

\ProvidesExplPackage{pdfbase}{\g@pbs@date@tl}{\g@pbs@version@tl}
{driver independent access to low-level PDF features}

\int_new:N\g_pbs_page_int %abs. page counter

%creating global definitions
\cs_new:Npn\pbs@newkey#1#2{\tl_gset:cx{#1}{#2}}

\msg_set:nnn{pdfbase}{rerun}{Rerun~to~get~internal~references~right!}

%LaTeX2e wrapper
\cs_new_nopar:Npn\pbs@seq@push@cx#1#2{
  \seq_if_exist:cF{#1}{\seq_new:c{#1}}
  \seq_gput_right:cx{#1}{#2}
}

%wrong image file type for Image XObject generation
\msg_gset:nnn{pdfbase}{wrong~image~resource}{
  Image~resource~file\\~~'#1'\\has~wrong~type.\\\\
  Driver~#2~only~accepts~files~of~type\\#3\\
  as~image~resources.
}

%pdfTeX version check
\sys_if_engine_pdftex:T{
  \int_compare:nT{\pdftexversion<130}{
    \msg_interrupt:nnn{pdfbase~error}{pdfTeX,~version~>=~1.30~required.}{}
  }
}

% page (bop, eop) hooks
\cs_new_protected:Nn\pbs_bop_action:n{\seq_gput_right:Nn\g_pbs_bop_seq{#1}}
\cs_new_protected:Nn\pbs_eop_action:n{\seq_gput_right:Nn\g_pbs_eop_seq{#1}}
\seq_new:N\g_pbs_bop_seq
\seq_new:N\g_pbs_eop_seq

% own AtEndDvi implementation
\cs_new_protected:Nn\pbs_at_end_dvi:n{\seq_gput_right:Nn\g_pbs_eod_seq{#1}}
\seq_new:N\g_pbs_eod_seq
\pbs@newkey{pbs@last@page}{0}

% AtEndDvi check
\AtBeginDocument{
  \iow_now:Nx\@mainaux{
    \token_to_str:N\providecommand\token_to_str:N\pbs@newkey[2]{}
  }
  \iow_now:Nx\@mainaux{
    \token_to_str:N\providecommand\token_to_str:N\pbs@seq@push@cx[2]{}
  }
  \iow_now:Nx\@mainaux{
    \token_to_str:N\providecommand\token_to_str:N\pbs@at@end@dvi@check{}
  }
  \iow_now:Nx\@mainaux{\token_to_str:N\pbs@at@end@dvi@check}
  \cs_new_protected:Npn\pbs@at@end@dvi@check{
    \bool_if:nT{
      !\tl_if_exist:NTF\pbs@last@page{
        \int_compare_p:n{\pbs@last@page=\g_pbs_page_int}
      }{
        \c_false_bool
      }
    }{
      \cs_if_exist:NF\g_pbs_rerunwarned_tl{
        \tl_new:N\g_pbs_rerunwarned_tl
        \msg_warning:nn{pdfbase}{rerun}
      }
    }
  }
}

%%%%%%%%%%%%%%%%%
%package options
%%%%%%%%%%%%%%%%%

%unknown package option error message
\msg_gset:nnnn{pdfbase}{unknown~package~option}{Unknown~package~option~`#1'.}{
  Package option~'#1'~is~unknown;\\
  perhaps~it~is~spelled~incorrectly.
}

\bool_new:N\g_pbs_pkgbigfiles_bool
\bool_new:N\g_pbs_dvipdfmx_bool
\bool_new:N\g_pbs_dvisvgm_bool
\bool_new:N\g_pbs_lscape_bool %if we are inside landscape env
\AtBeginDocument{
  \cs_if_exist:NT\landscape{%
    \tl_put_right:Nn\landscape{\bool_gset_true:N\g_pbs_lscape_bool}
    \tl_put_left:Nn\endlandscape{\bool_gset_false:N\g_pbs_lscape_bool}
  }
}

\keys_define:nn{pdfbase}{
  xetex .code:n = {}, %dummy, we use engine test instead

  dvipdfmx .choice:,
  dvipdfmx / true .code:n = {
    \bool_gset_true:N\g_pbs_dvipdfmx_bool
    \bool_gset_false:N\g_pbs_dvisvgm_bool
  },
  dvipdfmx / false .code:n = {\bool_gset_false:N\g_pbs_dvipdfmx_bool},
  dvipdfmx .default:n = {true},

  dvisvgm .choice:,
  dvisvgm / true .code:n = {
    \bool_gset_true:N\g_pbs_dvisvgm_bool
    \bool_gset_false:N\g_pbs_dvipdfmx_bool
  },
  dvisvgm / false .code:n = {\bool_gset_false:N\g_pbs_dvisvgm_bool},
  dvisvgm .default:n = {true},

  bigfiles .bool_gset:N = \g_pbs_pkgbigfiles_bool,

  unknown .code:n = {
    \msg_error:nnx{pdfbase}{unknown~package~option}{\l_keys_key_tl}
  }
}
\ProcessKeysOptions{pdfbase}

\sys_if_output_pdf:T{
  \bool_gset_false:N\g_pbs_dvipdfmx_bool
  \bool_gset_false:N\g_pbs_dvisvgm_bool
}

\sys_if_engine_xetex:T{
  \bool_if:NF\g_pbs_dvisvgm_bool{\bool_gset_true:N\g_pbs_dvipdfmx_bool}
}

\cs_new_nopar:Nn\pbs_first_of_two:nn{#1} %helpers
\cs_new_nopar:Nn\pbs_second_of_two:nn{#2}

\cs_new_nopar:Nn\pbs_insert_properties_entry:{}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%commands for creating PDF objects, annots etc.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\sys_if_output_pdf:TF{
  %in LuaTeX-0.95.0, pdfTeX primitives got new names
  \bool_lazy_and:nnT{
    \sys_if_engine_luatex_p:
  }{
    !\int_compare_p:n{\luatexversion<95}
  }{
    \cs_set_protected:Npn\pdfnames{\pdfextension~names~}
    \cs_set_protected:Npn\pdfobj{\pdfextension~obj~}
    \cs_set_protected:Npn\pdfrefobj{\pdfextension~refobj~}
    \cs_set_protected:Npn\pdfannot{\pdfextension~annot~}
    \cs_set_protected:Npn\pdfstartlink{\pdfextension~startlink~}
    \cs_set_protected:Npn\pdfendlink{\pdfextension~endlink\relax}
    \cs_set_protected:Npn\pdfliteral{\pdfextension~literal~}
    \cs_set_protected:Npn\pdfcatalog{\pdfextension~catalog~}
    \cs_set:Npn\pdflastlink{\numexpr\pdffeedback~lastlink\relax}
    \cs_set:Npn\pdflastobj{\numexpr\pdffeedback~lastobj\relax}
    \cs_set:Npn\pdflastannot{\numexpr\pdffeedback~lastannot\relax}
    \cs_set:Npn\pdfpageref{\numexpr\pdffeedback~pageref\relax}
    \cs_set:Npx\pdfpageresources{\pdfvariable~pageresources}
    \cs_set_eq:NN\pdfximage\saveimageresource
    \cs_set_eq:NN\pdfrefximage\useimageresource
    \cs_set_eq:NN\pdflastximage\lastsavedimageresourceindex
    \cs_set_eq:NN\pdflastximagepages\lastsavedimageresourcepages
    \cs_set_eq:NN\pdfxform\saveboxresource
    \cs_set_eq:NN\pdfrefxform\useboxresource
    \cs_set_eq:NN\pdflastxform\lastsavedboxresourceindex
    \cs_set:Npn\pdffontobjnum{\pdffeedback~fontobjnum}
  }

  %helper func to remove `0 R' part from pdf obj reference
  \cs_new_nopar:Nn\pbs_reftonum:n{\_pbs_reftonum:f{#1}}
  \cs_new_nopar:Nn\_pbs_reftonum:n{\exp_after:wN\_pbs_reftonum:w#1}
  \cs_generate_variant:Nn\_pbs_reftonum:n{f}
  \cs_new_nopar:Npn\_pbs_reftonum:w #1~0~R{#1}

  %literal PDF code into content stream, no saving of graphics state
  \cs_new_protected_nopar:Nn\pbs_literal:nn{ % #1: empty (`'), `direct' or `page'
    \str_case:nnF{#1}{             % #2: raw PDF
      % `direct' inserts raw pdf code without translating origin (0,0) to
      % current position: origin is lower left page corner
      {direct}{\pdfliteral~direct~{#2}}
      % same as above, but closing text object if necessary
      {page}{\pdfliteral~page~{#2}}
    }{
      % closing text object if necessary and setting current
      % location's coordinates to (0,0)
      \pdfliteral{#2}
    }
  }

  \cs_new_protected_nopar:Nn\pbs_pdfobj:nnn{
    \tl_clear:N\l_pbs_usenum_tl
    \tl_if_blank:oF{#1}{
      \tl_set:Nx\l_pbs_usenum_tl{useobjnum~\pbs_reftonum:n{#1}}
    }
    \bool_if:nTF{\tl_if_blank_p:o{#1}&&\tl_if_blank_p:o{#3}}{
      \pdfobj~reserveobjnum
    }{
      \str_case:nn{#2}{
        {dict}{\immediate\pdfobj~\l_pbs_usenum_tl~{<<#3>>}}
        {array}{\immediate\pdfobj~\l_pbs_usenum_tl~{[#3]}}
        {stream}{\immediate\pdfobj~\l_pbs_usenum_tl~stream~
          attr{\pbs_first_of_two:nn#3}~{\pbs_second_of_two:nn#3}
        }
        {fstream}{\immediate\pdfobj~\l_pbs_usenum_tl~stream~
          attr{\pbs_first_of_two:nn#3}~file~{\pbs_second_of_two:nn#3}
        }
      }
    }
    \tl_gset:Nx\g_pbs_pdflastobj_tl{\the\pdflastobj\space 0~R}
  }

  \cs_new_protected_nopar:Nn\pbs_pdfannot:nnnn{
    %dumb dummy Widget, workaround for AR bug;
    %see https://forums.adobe.com/message/5787612#5787612
    \str_if_eq_x:nnF{\cs_if_exist_use:N\ocgbase_insert_oc:}{}{
      \immediate\pdfannot~width~3pt~height~3pt~depth~\c_zero_dim {
        /Ff~65537/FT/Btn/Subtype/Widget
      }
    }
    \immediate\pdfannot~width~#1~height~#2~depth~#3 {
      \cs_if_exist_use:N\ocgbase_insert_oc:~#4}
    \tl_gset:Nx\g_pbs_pdflastann_tl{\the\pdflastannot\space 0~R}
  }

  \cs_new_protected:Nn\pbs_pdflink:nn{
    %dumb dummy Widget, workaround for AR bug;
    %see https://forums.adobe.com/message/5787612#5787612
    \str_if_eq_x:nnF{\cs_if_exist_use:N\ocgbase_insert_oc:}{}{
      \immediate\pdfannot~width~3pt~height~3pt~depth~\c_zero_dim {
        /Ff~65537/FT/Btn/Subtype/Widget
      }
    }
    \immediate\pdfstartlink~user~{
      \cs_if_exist_use:N\ocgbase_insert_oc:~#1}#2\pdfendlink
  }

  \cs_new_protected_nopar:Nn\pbs_pdfxform:nnnnn{ % #1 not used
    %additional resources
    \tl_set:Nx\l_tmpa_tl{\the\pdfpageresources~#3}\tl_trim_spaces:N\l_tmpa_tl
    %additional dict entries
    \tl_set:Nx\l_tmpb_tl{#4}
    \tl_trim_spaces:N\l_tmpb_tl
    \int_compare:nT{#2>\c_zero}{\immediate}
    \pdfxform~
      \str_if_eq_x:nnF{\l_tmpb_tl}{}{attr~{\l_tmpb_tl}~}
      \str_if_eq_x:nnF{\l_tmpa_tl}{}{resources~{\l_tmpa_tl}~}#5
    \tl_gset:Nx\g_pbs_pdflastxform_tl{\the\pdflastxform\space 0~R}
  }

  \cs_new_protected_nopar:Nn\pbs_pdfrefxform:n{% #1: xform obj ID
    \hbox_overlap_right:n{\smash{\pdfrefxform\pbs_reftonum:n{#1}}}
  }

  \cs_new_protected_nopar:Nn\pbs_pdfximage:n{
    \filename@parse{#1}
    \tl_set:Nx\l_pbs_ext_tl{\tl_lower_case:n{\filename@ext}}
    \bool_if:nTF{
      \str_if_eq_p:Vn\l_pbs_ext_tl{png}
      ||\str_if_eq_p:Vn\l_pbs_ext_tl{jpg}
      ||\str_if_eq_p:Vn\l_pbs_ext_tl{jpeg}
      ||\str_if_eq_p:Vn\l_pbs_ext_tl{jbig2}
      ||\str_if_eq_p:Vn\l_pbs_ext_tl{jb2}
    }{
      \immediate\pdfximage{#1}
      \tl_gset:Nx\g_pbs_pdflastximage_tl{\the\pdflastximage\space 0~R}
    }{
      \msg_error:nnnnn{pdfbase}{wrong~image~resource}{#1}{pdftex}{
        png,~jpeg~and~jbig2
      }
    }
  }

  \cs_new_protected_nopar:Nn\pbs_pdfcatalog:n{\pdfcatalog{#1}}

  \int_new:N\g_pbs_oc_int %object ID for marked content Properties

  \cs_new_protected_nopar:Nn\pbs_zap_properties:{ %strip /Properties dict from
    \group_begin:                       %/pdfpageresources
    \tl_set:Nx\l_pbs_temp_tl{\group_end:
      \global\pdfpageresources{
        \exp_after:wN\_pbs_zap_properties:w\the\pdfpageresources/Properties<<>>.
      }
    }\l_pbs_temp_tl
  }
  \cs_new_nopar:Npn\_pbs_zap_properties:w#1/Properties<<#2>>#3{
    \bool_if:nTF{\tl_if_empty_p:n{#2}&&\str_if_eq_p:nn{#3}{.}}{#1}{
      #1\_pbs_zap_properties:w#3
    }
  }

  \cs_new_protected_nopar:Nn\pbs_pdfbdc:nn{
    \pdfliteral~page~{#1/rm@oc\int_use:N\g_pbs_oc_int\space BDC}
    %decide whether the current property is to be written to the page
    %resources or to the xobject resources, depending on whether marked content
    %is written to a page stream or to an xobject stream (for compatibility with
    %`xsavebox' package)
    \bool_if:nTF{
      \cs_if_exist:NTF\xsb_count_props:{
        \int_compare_p:n{\xsb_count_props:>\c_zero}
      }{
        \c_false_bool
      }
    }{
      \xsb_addto_props:n{/rm@oc\int_use:N\g_pbs_oc_int\space#2}
    }{
      \iow_shipout_x:Nx\@mainaux{\token_to_str:N\pbs@seq@push@cx{
          pbs@props@\exp_not:N\int_use:N\g_pbs_page_int
      }{/rm@oc\int_use:N\g_pbs_oc_int\space#2}}
    }
    \int_gincr:N\g_pbs_oc_int
  }

  \cs_new_protected_nopar:Nn\pbs_pdfemc:{\pdfliteral~page~{EMC}}

  %inserts /Properties <<...>> entry into page resources
  \cs_gset:Nn\pbs_insert_properties_entry:{
    \pbs_zap_properties: %purge those from previous page
    \tl_set:Nx\l_tmpa_tl{\seq_if_exist:cT{pbs@props@\int_use:N\g_pbs_page_int}{
      \seq_use:cn{pbs@props@\int_use:N\g_pbs_page_int}{~}}}
    \tl_trim_spaces:N\l_tmpa_tl
    \str_if_eq_x:nnF{\l_tmpa_tl}{}{
      \group_begin:
      \tl_set:Nx\l_pbs_temp_tl{\group_end:
        \global\pdfpageresources{
          \the\pdfpageresources
          /Properties<<\seq_if_exist:cT{pbs@props@\int_use:N\g_pbs_page_int}{
            \seq_use:cn{pbs@props@\int_use:N\g_pbs_page_int}{~}
          }>>
        }
      }\l_pbs_temp_tl
    }
  }

  \cs_new_protected_nopar:Nn\pbs_add_form_font:{
    \cs_if_exist:cF{pbs_form_font_\pdffontobjnum\font}{
      \tl_new:c{pbs_form_font_\pdffontobjnum\font}
      \tl_gput_right:Nx\g_pbs_form_fonts_tl{
        ~/FormFont\pdffontobjnum\font\space\pdffontobjnum\font\space 0~R
      }
    }
    \tl_gset:Nx\g_pbs_last_form_font_tl{/FormFont\pdffontobjnum\font}
  }
  \cs_new_nopar:Nn\pbs_last_form_font:{\g_pbs_last_form_font_tl}
}{
  %pgf + transparency related settings
  \bool_new:N\g_pbs_pgfloaded_bool
  \bool_gset_false:N\g_pbs_pgfloaded_bool
  \AtBeginDocument{
    \@ifpackageloaded{pgf}{\bool_gset_true:N\g_pbs_pgfloaded_bool}{}
  }
  \int_new:N\g_pbs_obj_int %object ID
  \bool_if:NTF\g_pbs_dvipdfmx_bool{ %dvipdfmx/XeTeX
    %suppress any annotation growth through (x)dvipdfmx option/config var `g'
    \AtBeginDocument{\special{dvipdfmx:config~g~0}}

    %literal PDF code into content stream; open text objects are always closed
    \cs_new_protected_nopar:Nn\pbs_literal:nn{ % #1: empty (`'), `direct' or `page'
      \str_if_eq:nnTF{#1}{}{         % #2: raw PDF
        % set current location's coordinates to (0,0), while saving graphics
        % state before and re-instating after insertion (this is different from
        % \pdfliteral{...}
        \special{pdf:content~#2}
      }{
        % `direct' works the same as `page': no origin translation,
        % no gs saving, but closing open text objects
        \special{pdf:code~#2}
      }
    }

    \cs_new_protected_nopar:Nn\pbs_pdfobj:nnn{
      \tl_if_blank:oTF{#1}{
        \tl_set:Nx\l_pbs_usenum_tl{@pbs@obj\int_use:N\g_pbs_obj_int}
        \int_gincr:N\g_pbs_obj_int
      }{
        \tl_set:Nx\l_pbs_usenum_tl{#1}
      }
      \tl_if_blank:oF{#3}{
        \str_case:nn{#2}{
          {dict}{\special{pdf:obj~\l_pbs_usenum_tl\space<<#3>>}}
          {array}{\special{pdf:obj~\l_pbs_usenum_tl\space[#3]}}
          {stream}{\special{pdf:stream~\l_pbs_usenum_tl\space
            (\pbs_second_of_two:nn#3)<<\pbs_first_of_two:nn#3>>
          }}
          {fstream}{
            \message{<\pbs_second_of_two:nn#3>}
            \special{pdf:fstream~\l_pbs_usenum_tl\space
              (\pbs_second_of_two:nn#3)<<\pbs_first_of_two:nn#3>>
            }
          }
        }
      }
      \tl_gset_eq:NN\g_pbs_pdflastobj_tl\l_pbs_usenum_tl
    }

    \cs_new_protected_nopar:Nn\pbs_pdfannot:nnnn{
      \bool_if:NTF\g_pbs_lscape_bool{
        %fix missing annotation rotation of (x)dvipdfmx on landscape pages
        \box_move_up:nn{\dim_eval:n{#2}}{\vbox:n{
          %dumb dummy Widget, workaround for AR bug;
          %see https://forums.adobe.com/message/5787612#5787612
          \str_if_eq_x:nnF{\cs_if_exist_use:N\ocgbase_insert_oc:}{}{
            \special{pdf:ann~
              width~3pt~height~3pt~depth~0pt~<</Ff~65537/FT/Btn/Subtype/Widget>>
            }
          }
          \special{pdf:ann~@pbs@obj\int_use:N\g_pbs_obj_int\space
            width~\dim_eval:n{#2+#3}\space
            height~\dim_eval:n{#1}\space
            depth~\dim_eval:n{\c_zero_dim}~<<
              \cs_if_exist_use:N\ocgbase_insert_oc:~#4>>
          }
        }}
      }{
        %dumb dummy Widget, workaround for AR bug;
        %see https://forums.adobe.com/message/5787612#5787612
        \str_if_eq_x:nnF{\cs_if_exist_use:N\ocgbase_insert_oc:}{}{
          \special{pdf:ann~
            width~3pt~height~3pt~depth~0pt~<</Ff~65537/FT/Btn/Subtype/Widget>>
          }
        }
        \special{pdf:ann~@pbs@obj\int_use:N\g_pbs_obj_int\space
          width~\dim_eval:n{#1}\space
          height~\dim_eval:n{#2}\space
          depth~\dim_eval:n{#3}~<<\cs_if_exist_use:N\ocgbase_insert_oc:~#4>>
        }
      }
      \tl_gset:Nx\g_pbs_pdflastann_tl{@pbs@obj\int_use:N\g_pbs_obj_int}
      \int_gincr:N\g_pbs_obj_int
    }

    \cs_new_protected:Nn\pbs_pdflink:nn{
      %dumb dummy Widget, workaround for AR bug;
      %see https://forums.adobe.com/message/5787612#5787612
      \str_if_eq_x:nnF{\cs_if_exist_use:N\ocgbase_insert_oc:}{}{
        \special{pdf:ann~
          width~3pt~height~3pt~depth~0pt~<</Ff~65537/FT/Btn/Subtype/Widget>>
        }
      }
      \special{pdf:bann~<<\cs_if_exist_use:N\ocgbase_insert_oc:~#1>>}#2
      \special{pdf:eann}
    }

    \cs_new_protected_nopar:Nn\pbs_pdfxform:nnnnn{ % #2 not used
      \begin{picture}(0,0)
        \put(0,0){
          \special{pdf:bxobj~@pbs@obj\int_use:N\g_pbs_obj_int\space
            width\space \dim_use:N\box_wd:N#5\space
            height\space\dim_use:N\box_ht:N#5\space
            depth\space \dim_use:N\box_dp:N#5
          }
          \box_use:N#5
          \tl_clear:N\l_tmpa_tl{}
          %transparency et al. for PGF
          \bool_if:nT{\int_compare_p:n{#1>\c_zero} && \g_pbs_pgfloaded_bool}{
            \ifpgf@sys@pdf@extgs@exists
              \tl_set:Nn\l_tmpa_tl{/ExtGState~@pgfextgs}
            \fi
            \ifpgf@sys@pdf@patterns@exists
              \tl_put_right:Nn\l_tmpa_tl{/Pattern~@pgfpatterns}
            \fi
            \ifpgf@sys@pdf@colorspaces@exists
              \tl_put_right:Nn\l_tmpa_tl{/ColorSpace~@pgfcolorspaces}
            \fi
          }
          %additional resources
          \tl_put_right:Nx\l_tmpa_tl{~#3}\tl_trim_spaces:N\l_tmpa_tl
          \str_if_eq_x:nnF{\l_tmpa_tl}{}{
            \special{pdf:put~@resources~<<\l_tmpa_tl>>}
          }
          %additional dict entries
          \tl_set:Nx\l_tmpa_tl{#4}
          \tl_trim_spaces:N\l_tmpa_tl
          \special{pdf:exobj %close form xobject
            \str_if_eq_x:nnF{\l_tmpa_tl}{}{<<\l_tmpa_tl>>}
          }
        }
      \end{picture}
      \tl_gset:Nx\g_pbs_pdflastxform_tl{@pbs@obj\int_use:N\g_pbs_obj_int}
      \int_gincr:N\g_pbs_obj_int
    }

    \cs_new_protected_nopar:Nn\pbs_pdfrefxform:n{\special{pdf:uxobj~#1}}% #1: xform obj ID

    \cs_new_protected_nopar:Nn\pbs_pdfximage:n{
      \filename@parse{#1}
      \tl_set:Nx\l_pbs_ext_tl{\tl_lower_case:n{\filename@ext}}
      \bool_if:nTF{
          \str_if_eq_p:Vn\l_pbs_ext_tl{png}
        ||\str_if_eq_p:Vn\l_pbs_ext_tl{jpg}
        ||\str_if_eq_p:Vn\l_pbs_ext_tl{jpeg}
      }{
        \special{pdf:image~@pbs@obj\int_use:N\g_pbs_obj_int\space
          %move initial display off the page
          matrix~0.000001~0~0~0.000001~-1000000~-1000000~(#1)}
        \tl_gset:Nx\g_pbs_pdflastximage_tl{@pbs@obj\int_use:N\g_pbs_obj_int}
        \int_gincr:N\g_pbs_obj_int
      }{
        \msg_error:nnnnn{pdfbase}{wrong~image~resource}{#1}{dvipdfmx/xetex}{
          png~and~jpeg
        }
      }
    }

    \cs_new_protected_nopar:Nn\pbs_pdfcatalog:n{\special{pdf:put~@catalog~<<#1>>}}

    \int_new:N\g_pbs_oc_int %object ID
    \cs_new_protected_nopar:Nn\pbs_pdfbdc:nn{
      \special{pdf:code~#1/rm@oc\int_use:N\g_pbs_oc_int\space BDC}
      \special{pdf:put~@resources~<<
        /Properties~<</rm@oc\int_use:N\g_pbs_oc_int\space#2>>>>}
      \int_gincr:N\g_pbs_oc_int
    }
    \cs_new_nopar:Nn\pbs_pdfemc:{\special{pdf:code~EMC}}
  }{
    \bool_if:NTF\g_pbs_dvisvgm_bool{
      \tl_gset:Nx\g_pbs_hash_tl{\token_to_str:N#}
      %insert literal Postscript code
      \cs_new_protected_nopar:Nn\pbs_literal:nn{ % #1: empty (`'), `direct' or `page'
        \str_if_eq:nnTF{#1}{}{         % #2: raw Postscript
          % set current location's coordinates to (0,0) and set unit vectors to
          % 1bp right and 1bp upwards; graphics state is saved before and
          % re-instated after insertion
          \special{"~#2}
        }{
          % `direct' does the same as `page': no origin translation,
          % no gs saving
          \special{ps::~#2}
        }
      }

      \cs_new_protected_nopar:Nn\pbs_pdfannot:nnnn{
        \special{dvisvgm:raw~{?nl}<path~d=}
        \group_begin:\dim_set:Nn\unitlength{1pt}
        \begin{picture}(0,0)% mark annotation rectangle
          \put(0,-\dim_to_decimal:n{#3}){% ll
            \special{dvisvgm:raw~'M{?x}~{?y}}
          }
          \put(\dim_to_decimal:n{#1},-\dim_to_decimal:n{#3}){% lr
            \special{dvisvgm:raw~{?nl}L{?x}~{?y}}
          }
          \put(\dim_to_decimal:n{#1},\dim_to_decimal:n{#2}){% ur
            \special{dvisvgm:raw~{?nl}L{?x}~{?y}}
          }
          \put(0,\dim_to_decimal:n{#2}){% ul
            \special{dvisvgm:raw~{?nl}L{?x}~{?y}~Z'}
          }
        \end{picture}
        \group_end:
        \special{dvisvgm:raw~{?nl}opacity='0'~#4~class='annot'/>}
      }

      \cs_new_protected_nopar:Nn\pbs_pdfxform:nnnnn{
        \makebox[\c_zero_dim][l]{
          \raisebox{\c_zero_dim}[\c_zero_dim][\c_zero_dim]{
            \special{dvisvgm:raw~{?nl}<defs>{?nl}
              <
                g~transform='translate(-{?x},-{?y})'~#4~
                id='pbs@obj\int_use:N\g_pbs_obj_int'~class='xform'
              >
            }
            \box_use_drop:N#5
            \special{dvisvgm:raw~{?nl}</g>{?nl}</defs>}
          }
        }
        \tl_gset:Nx\g_pbs_pdflastxform_tl{\g_pbs_hash_tl pbs@obj\int_use:N\g_pbs_obj_int}
        \int_gincr:N\g_pbs_obj_int
      }

      \cs_new_protected_nopar:Nn\pbs_pdfrefxform:n{
        \special{dvisvgm:raw~{?nl}<use~x='{?x}'~y='{?y}'~xlink:href='#1'/>}
      }
    }{
      %dvips
      \bool_new:N\g_pbs_powerdot_bool %to cope with some powerdot oddity
      \@ifclassloaded{powerdot}{\bool_gset_true:N\g_pbs_powerdot_bool}{}

      \sys_if_engine_pdftex:TF{
        \cs_new_nopar:Nn\pbs_filesize:n{\pdffilesize{#1}}
        \cs_new_nopar:Nn\pbs_filedump:nnn{\pdffiledump~offset~#1~length~#2~{#3}}
      }{
        \sys_if_engine_luatex:T{
          \RequirePackage{pdftexcmds}
          \cs_new_nopar:Nn\pbs_filesize:n{\pdf@filesize{#1}}
          \cs_new_nopar:Nn\pbs_filedump:nnn{\pdf@filedump{#1}{#2}{#3}}
        }
      }

      \AtBeginDocument{
        \@ifpackageloaded{hyperref}{}{
          %define `?pdfmark' operator as in file pdfmark.def from package `hyperref'
          \special{!~
            systemdict~/pdfmark~known
            {
              userdict~/?pdfmark~systemdict~/exec~get~put
            }{
              userdict~/?pdfmark~systemdict~/pop~get~put~
              userdict~/pdfmark~systemdict~/cleartomark~get~put
            }
            ifelse
          }
        }
        \special{!~
          %keeping track of xform nesting level
          true~setglobal~globaldict~/pbs@xform@level~0~put~false~setglobal
        }
      }

      \bool_if:NT\g_pbs_pkgbigfiles_bool{
        \special{psfile=\jobname.pbsdat}
        %open auxiliary file \jobname.pbsdat for writing hex encoded streams of
        %the files to be embedded. This file is inserted into PS during dvips run
        \iow_new:N\g_pbs_mstreams_stream
        \iow_open:Nn\g_pbs_mstreams_stream{\jobname.pbsdat}
        \iow_now:Nn\g_pbs_mstreams_stream{
          /M9D~1~dict~def~M9D~begin
          /o{mark/_objdef}bind~def/O{/type/stream/OBJ~pdfmark}bind~def
          /m~systemdict/mark~get~def
          /P{/ASCIIHexDecode~filter/PUT~pdfmark}bind~def
          /PP{/PUT~pdfmark}bind~def
          /C{/CLOSE~pdfmark}bind~def~end
        }
      }

      %insert literal Postscript code
      \cs_new_protected_nopar:Nn\pbs_literal:nn{ % #1: empty (`'), `direct' or `page'
        \str_if_eq:nnTF{#1}{}{         % #2: raw Postscript
          % set current location's coordinates to (0,0) and set unit vectors to
          % 1bp right and 1bp upwards; graphics state is saved before and
          % re-instated after insertion
          \special{"~#2}
        }{
          % `direct' does the same as `page': no origin translation,
          % no gs saving
          \special{ps::~#2}
        }
      }

      \cs_new_protected_nopar:Nn\pbs_pdfobj:nnn{
        \tl_clear:N\l_pbs_usenum_tl
        \tl_if_blank:oTF{#1}{
          \tl_set:Nx\l_pbs_usenum_tl{{pbs@obj\int_use:N\g_pbs_obj_int}}
          \int_gincr:N\g_pbs_obj_int
        }{
          \tl_set:Nx\l_pbs_usenum_tl{#1}
        }
        \tl_if_blank:oF{#3}{
          \bool_if:nTF{
            \g_pbs_pkgbigfiles_bool &&
            \str_if_eq_p:nn{#2}{fstream}
          }{
            \iow_now:Nx\g_pbs_mstreams_stream{
              M9D~begin~o\l_pbs_usenum_tl O
            }
          }{
            \special{ps:~mark~/_objdef~\l_pbs_usenum_tl\space/type
              \str_case:nn{#2}{
                {dict}{/dict}
                {array}{/array}
                {stream}{/stream}
                {fstream}{/stream}
              }~
              /OBJ~pdfmark
            }
          }
          \str_case:nn{#2}{
            {dict}{\special{ps:~mark~\l_pbs_usenum_tl~<<#3>>/PUT~pdfmark}}
            {array}{
              \special{ps:~mark~\l_pbs_usenum_tl~0~[#3]/PUTINTERVAL~pdfmark}
            }
            {stream}{\special{ps::[nobreak]
              ~mark~\l_pbs_usenum_tl~(\pbs_second_of_two:nn#3)/PUT~pdfmark~
              ~mark~\l_pbs_usenum_tl~<<\pbs_first_of_two:nn#3>>/PUT~pdfmark
            }}
            {fstream}{
              \tl_set:Nn\l_pbs_offset_tl{0}
              \tl_set:Nx\l_pbs_fsize_tl{\pbs_filesize:n{\pbs_second_of_two:nn#3}}
              \message{<\pbs_second_of_two:nn#3}
              %embed file in chunks of 32768 Bytes into PS as chunks of
              %65536 Bytes of HEX code
              \bool_while_do:nn{
                \int_compare_p:n{\l_pbs_offset_tl<\l_pbs_fsize_tl}
              }{
                \bool_if:NTF\g_pbs_pkgbigfiles_bool{
                  \iow_now:Nx\g_pbs_mstreams_stream{
                    m\l_pbs_usenum_tl
                    (\pbs_filedump:nnn{\l_pbs_offset_tl}{32767}{
                      \pbs_second_of_two:nn#3
                    })P
                  }
                }{
                  \special{ps:
                    mark~
                      \l_pbs_usenum_tl~
                      (\pbs_filedump:nnn{\l_pbs_offset_tl}{32767}{
                        \pbs_second_of_two:nn#3
                      })~
                      /ASCIIHexDecode~filter~/PUT~
                    pdfmark
                  }
                }
                \tl_set:Nx\l_pbs_offset_tl{\int_eval:n{\l_pbs_offset_tl+32767}}
                \message{.}
              }
              \bool_if:NTF\g_pbs_pkgbigfiles_bool{
                \iow_now:Nx\g_pbs_mstreams_stream{
                  m\l_pbs_usenum_tl<<\pbs_first_of_two:nn#3>>PP~
                  m\l_pbs_usenum_tl~C~end
                }
              }{
                \special{ps:
                  mark~\l_pbs_usenum_tl~<<\pbs_first_of_two:nn#3>>~/PUT~pdfmark~
                  mark~\l_pbs_usenum_tl~/CLOSE~pdfmark
                }
              }
              \message{>}
            }
          }
        }
        \tl_gset_eq:NN\g_pbs_pdflastobj_tl\l_pbs_usenum_tl
      }

      \cs_new_protected_nopar:Nn\pbs_pdfannot:nnnn{
        \group_begin:
          \dim_set:Nn\unitlength{1pt}
          \begin{picture}(0,0)% mark annotation rectangle
          \put(0,-\dim_to_decimal:n{#3}){
            \special{ps:~currentpoint~/pbs@lly~exch~def~/pbs@llx~exch~def}
          }
          \put(\dim_to_decimal:n{#1},\dim_to_decimal:n{#2}){
            \special{ps:~currentpoint~/pbs@ury~exch~def~/pbs@urx~exch~def}
          }
          \end{picture}
        \group_end:
        %dumb dummy Widget, workaround for AR bug;
        %see https://forums.adobe.com/message/5787612#5787612
        \str_if_eq_x:nnF{\cs_if_exist_use:N\ocgbase_insert_oc:}{}{
          \special{ps:
            mark~
              /_objdef~{pbs@obj\int_use:N\g_pbs_obj_int}
              /Rect~[pbs@llx~pbs@lly~pbs@urx~pbs@ury]
              /Ff~65537/FT/Btn/Subtype/Widget
            /ANN~pdfmark
          }
          \int_gincr:N\g_pbs_obj_int
        }
        %the actual annotation
        \str_if_eq_x:nnF{#4}{}{
          \special{ps:
            mark~
              /_objdef~{pbs@obj\int_use:N\g_pbs_obj_int}
              /Rect~[pbs@llx~pbs@lly~pbs@urx~pbs@ury]
              \cs_if_exist_use:N\ocgbase_insert_oc:~#4
            /ANN~pdfmark
          }
          \tl_gset:Nx\g_pbs_pdflastann_tl{{pbs@obj\int_use:N\g_pbs_obj_int}}
          \int_gincr:N\g_pbs_obj_int
        }
      }

      \cs_new_protected:Nn\pbs_pdflink:nn{
        %dumb dummy Widget, workaround for AR bug;
        %see https://forums.adobe.com/message/5787612#5787612
        \pbs_pdfannot:nnnn{3pt}{3pt}{0pt}{}
        \cs_if_exist:NTF\pdfmark{
          \pdfmark[#2]{pdfmark=/ANN,Raw={
            \cs_if_exist_use:N\ocgbase_insert_oc:~#1}}
        }{
          \hbox_set:Nn\l_tmpb_box{#2}
          \pbs_pdfannot:nnnn{
            \dim_use:N\box_wd:N\l_tmpb_box}{
            \dim_use:N\box_ht:N\l_tmpb_box}{
            \dim_use:N\box_dp:N\l_tmpb_box
          }{#1}
          \box_use_drop:N\l_tmpb_box
        }
      }

      \msg_set:nnn{pdfbase}{content~too~large}{
        Line~\msg_line_number: :\\
        Content~exceeds~paper~size~(width~and/or~height)\\
        of~the~document~and~may~be~clipped~in~the~final\\
        output.
      }

      \cs_new_protected_nopar:Nn\pbs_pdfxform:nnnnn{ % #1, #3 not used (resources are
        %this allows nesting \pbs_pdfxform:nnnnn{...}      %  managed by pdfmarks)
        \special{ps:
          gsave~
          pbs@xform@level~0~eq~{/pbs@ctm@0~matrix~currentmatrix~def}~if~
          pbs@ctm@0~setmatrix~
          true~setglobal~
          globaldict~/pbs@xform@level~pbs@xform@level~1~add~put~
          false~setglobal
        }
        %rescale box to fit within the papersize while distilling
        \tl_gset:cx{scale_{pbs@obj\int_use:N\g_pbs_obj_int}}{\fp_eval:n{min(1.0,
          \dim_ratio:nn{\paperwidth}{\box_wd:N#5},
          \dim_ratio:nn{\paperheight}{\box_ht:N#5+\box_dp:N#5}
        )}}
        \box_scale:Nnn#5{
          \tl_use:c{scale_{pbs@obj\int_use:N\g_pbs_obj_int}}
        }{
          \tl_use:c{scale_{pbs@obj\int_use:N\g_pbs_obj_int}}
        }
        \group_begin:
          %mark bbox of box#5
          \dim_set:Nn\unitlength{1pt}
          \begin{picture}(0,0)
          \put(0,-\dim_to_decimal:n{\box_dp:N#5}){
            \special{ps:
              currentpoint~/pbs@lly~exch~def~/pbs@llx~exch~def
            }
          }
          \put(
            \dim_to_decimal:n{\box_wd:N#5},
            \dim_to_decimal:n{\box_ht:N#5}
          ){
            \special{ps:
              currentpoint~/pbs@ury~exch~def~/pbs@urx~exch~def
            }
          }
          \end{picture}
        \group_end:
        %additional dict entries
        \tl_set:Nx\l_tmpa_tl{#4} \tl_trim_spaces:N\l_tmpa_tl
        \special{ps:
          gsave~
          currentpoint~/pbs@cury~exch~def~/pbs@curx~exch~def~
          %translate graphics to upper left page corner
          \bool_if:nF{\g_pbs_powerdot_bool||\g_pbs_lscape_bool}{
            {
              pbs@llx~neg~pbs@ury~neg~translate~
              Resolution~neg~VResolution~neg~translate %one inch left, one inch up
            }?pdfmark~
          }
          %distill graphics into XObject
          gsave~pbs@curx~pbs@cury~translate~ %move origin (0,0) to the current
          mark~                              %position
            /_objdef~{pbs@obj\int_use:N\g_pbs_obj_int}
            /BBox~[
              pbs@llx~pbs@curx~sub~pbs@lly~pbs@cury~sub~
              pbs@urx~pbs@curx~sub~pbs@ury~pbs@cury~sub
            ]
            %insert additional dict entries (the Distiller way)
            \str_if_eq_x:nnF{\l_tmpa_tl}{}{
              product~(Distiller)~search~{pop~pop~pop~\l_tmpa_tl}{pop}ifelse
            }
          /BP~pdfmark~grestore~
          \int_compare:nT{#2>\c_zero}{
            %operations needed if used as annotation appearance
            {
              isls{%landscape mode (powerdot, geometry /w landscape option)
                /pbs@dxdy~{
                  pbs@urx~pbs@llx~sub~abs~
                  pbs@ury~pbs@lly~sub~abs~div
                }~bind~def
                /pbs@dydx~{1~pbs@dxdy~div}~bind~def
                /pbs@cx~{pbs@urx~pbs@llx~add~2~div}~bind~def
                /pbs@cy~{pbs@ury~pbs@lly~add~2~div}~bind~def
                %graphics needs to be rescaled for some reason ...
                [pbs@dxdy~0~0~pbs@dydx~1~pbs@dxdy~sub~pbs@cx~mul~
                  1~pbs@dydx~sub~pbs@cy~mul]~concat
                %... rotated by 270 degrees ...
                [0~-1~1~0~pbs@cx~pbs@cy~sub~pbs@cx~pbs@cy~add]~concat
                %... and flipped around vertical axis
                [-1~0~0~1~pbs@llx~pbs@urx~add~0]~concat
              }{%flip around horizontal axis in portrait mode
                [1~0~0~-1~0~pbs@lly~pbs@ury~add]~concat
              }ifelse
            }?pdfmark
          }
        }
        \begin{picture}(0,0)\put(0,0){\box_use:N#5}\end{picture}
        \special{ps:~mark~/EP~pdfmark~grestore}
        %insert additional dict entries (the Ghostscript way)
        \str_if_eq_x:nnF{\l_tmpa_tl}{}{
          \special{ps:
            product~(Ghostscript)~search~{
              pop~pop~pop~
              mark~{pbs@obj\int_use:N\g_pbs_obj_int}~<<\l_tmpa_tl>>~/PUT~pdfmark
            }{pop}ifelse
          }
        }
        \tl_gset:Nx\g_pbs_pdflastxform_tl{{pbs@obj\int_use:N\g_pbs_obj_int}}
        \int_gincr:N\g_pbs_obj_int
        \int_compare:nT{#2>\c_zero}{
          %Form XObjects for use as annotation appearances require that
          %dvips generated PostScript to be further processed with ps2pdf
          %must not have the exaggerated dpi resolution resulting from dvips
          %option `-Ppdf'.
          \tl_if_exist:NF\g_pbs_dpiwarned_tl{
            \tl_new:N\g_pbs_dpiwarned_tl
            \pbs_at_end_dvi:n{\special{ps::[nobreak]\pbs_dpiwarning:}}
          }
        }
        \special{ps:
          true~setglobal~
          globaldict~/pbs@xform@level~pbs@xform@level~1~sub~put~
          false~setglobal~
          grestore
        }
      }

      \cs_new_protected_nopar:Nn\pbs_pdfrefxform:n{% #1: xform obj ID
        %The /SP pdfmark for placement of Form XObjects works reliably only
        %since gs-9.14. As gs-9.14 had some other TeX-related issues, we
        %require 9.15.
        \tl_if_exist:NF\g_pbs_gsoldwarned_tl{
          \tl_new:N\g_pbs_gsoldwarned_tl
          \pbs_at_end_dvi:n{\special{ps::[nobreak]\pbs_gsoldwarning:}}
        }
        \special{ps:
          gsave~currentpoint~translate~1~\tl_use:c{scale_#1}~div~dup~scale~
          mark~#1~/SP~pdfmark~grestore
        }
      }

      \cs_new_protected_nopar:Nn\pbs_pdfximage:n{
        \filename@parse{#1}
        \tl_set:Nx\l_pbs_ext_tl{\tl_lower_case:n{\filename@ext}}
        \bool_if:nTF{
            \str_if_eq_p:Vn\l_pbs_ext_tl{ps}
          ||\str_if_eq_p:Vn\l_pbs_ext_tl{eps}
        }{
          \special{ps:
            mark~/_objdef~{pbs@obj\int_use:N\g_pbs_obj_int}~/NI~pdfmark
          }
          \special{psfile=#1~hsize=0~vsize=0}
          \special{ps:
            {
              0~0~1~[1~0~0~1~0~0]~{}~image~%empty dummy, in case #1 is not
            }?pdfmark                      %a valid raster image file
          }
          \tl_gset:Nx\g_pbs_pdflastximage_tl{{pbs@obj\int_use:N\g_pbs_obj_int}}
          \int_gincr:N\g_pbs_obj_int
        }{
          \msg_error:nnxxx{pdfbase}{wrong~image~resource}{#1}{dvips}{
            Postscript~(ps/eps)~with~bitmapped~content
          }
        }
      }

      \cs_new_protected_nopar:Nn\pbs_pdfcatalog:n{
        \special{ps:~mark~{Catalog}~<<#1>>~/PUT~pdfmark}
      }

      %marked content BDC/EMC operators
      %require Ghostscript v. >= 9.15
      \cs_new_protected_nopar:Nn\pbs_pdfbdc:nn{
        \special{ps:~mark~#1~#2~/BDC~pdfmark}
        \tl_if_exist:NF\g_pbs_gsoldwarned_tl{
          \tl_new:N\g_pbs_gsoldwarned_tl
          \pbs_at_end_dvi:n{\special{ps::[nobreak]\pbs_gsoldwarning:}}
        }
      }
      \cs_new_nopar:Nn\pbs_pdfemc:{\special{ps:~mark~/EMC~pdfmark}}
    }  
  }
}

\cs_new_nopar:Nn\pbs_pdflastobj:{\g_pbs_pdflastobj_tl}
\cs_new_nopar:Nn\pbs_pdflastann:{\g_pbs_pdflastann_tl}
\cs_new_nopar:Nn\pbs_pdflastxform:{\g_pbs_pdflastxform_tl}
\cs_new_nopar:Nn\pbs_pdflastximage:{\g_pbs_pdflastximage_tl}

%adding AcroForm dict to PDF Catalog
\tl_new:N\g_pbs_fields_tl %takes object IDs of Fields (aka annots with
\tl_new:N\g_pbs_form_fonts_tl %name tree of font resources used in text fields
\pbs_at_end_dvi:n{
  \tl_if_empty:NF\g_pbs_fields_tl{
    \pbs_pdfobj:nnn{}{array}{\g_pbs_fields_tl}
    \pbs_pdfcatalog:n{
      /AcroForm~<<
        /Fields~\pbs_pdflastobj:/NeedAppearances~false~
        \tl_if_empty:NF\g_pbs_form_fonts_tl{
          /DR~<</Font~<<\g_pbs_form_fonts_tl>> >>
        }
      >>
    }
  }
}
\cs_new_protected_nopar:Nn\pbs_appendtofields:n{
  \tl_gput_left:Nx\g_pbs_fields_tl{#1\space}
}

%modify output routine for output box insertions
\bool_new:N\l_pbs_is_vertical_bool
\cs_set_eq:NN\pbs_outputpage_orig:\@outputpage
\cs_set_nopar:Npn\@outputpage{
  \int_gincr:N\g_pbs_page_int
  \iow_now:Nx\@mainaux{
    \token_to_str:N\pbs@newkey{pbs@last@page}{\int_use:N\g_pbs_page_int}
  }
  \box_if_vertical:cTF{@outputbox}{
    \bool_set_true:N\l_pbs_is_vertical_bool
  }{
    \bool_set_false:N\l_pbs_is_vertical_bool
  }
  \hbox_set:Nn\@outputbox{
    %begin of page
    \hbox_overlap_right:n{\seq_map_inline:Nn\g_pbs_bop_seq{##1}}
    \box_use_drop:N\@outputbox
    %end of page
    \hbox_overlap_right:n{\seq_map_inline:Nn\g_pbs_eop_seq{##1}}
  }
  \bool_if:NT\l_pbs_is_vertical_bool{
    \vbox_set:Nn\@outputbox{\box_use_drop:N\@outputbox}
  }
  \pbs_outputpage_orig:
}

\RequirePackage{atbegshi}
\AtBeginDocument{
  \AtBeginShipout{
    \AtBeginShipoutAddToBoxForeground{
      %insert /Properties into current page's resources
      \pbs_insert_properties_entry:
      %end of dvi (last page)
      \int_compare:nT{\pbs@last@page=\g_pbs_page_int}{
        \seq_map_variable:NNn\g_pbs_eod_seq\l_tmpa_tl{\l_tmpa_tl}
      }
    }
  }
}

\group_begin:
\char_set_catcode_active:N\+\let+\space
\cs_new_nopar:Nx\pbs_gsoldwarning:{
  {product~(Ghostscript)~search~{pop~pop~pop~true}{pop~false}ifelse~
   revision~915~lt~and~{
  (\token_to_str:N\n
  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\token_to_str:N\n
  @@++++++++++++Warning:+Ghostscript+too+old!++++++++++++@@\token_to_str:N\n
  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\token_to_str:N\n
  @@+++++++++++++++++++++++++++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@+Ghostscript+version+>=+9.15.+required!++++++++++++++@@\token_to_str:N\n
  @@+++++++++++++++++++++++++++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@+Various+advanced+PDF+features+such+as+Layers+(OCGs)+@@\token_to_str:N\n
  @@+and+animations+may+not+work.++++++++++++++++++++++++@@\token_to_str:N\n
  @@+++++++++++++++++++++++++++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@+Get+current+version+from++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@+http://www.ghostscript.com/download+++++++++++++++++@@\token_to_str:N\n
  @@+++++++++++++++++++++++++++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\token_to_str:N\n)
  print}~if}~?pdfmark
}

\cs_new_nopar:Nx\pbs_dpiwarning:{
  {Resolution~1200~gt~VResolution~1200~gt~or~product~(Ghostscript)~
  search~{pop~pop~pop~true}{pop~false}ifelse~and~{
  (\token_to_str:N\n
  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\token_to_str:N\n
  @@+++++Warning:+DVI+resolution+greater+than+1200+dpi!+++++@@\token_to_str:N\n
  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\token_to_str:N\n
  @@++++++++++++++++++++++++++++++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@+PDF+Annotation+appearances+(buttons,+animation+frames)+@@\token_to_str:N\n
  @@+may+be+poorly+scaled,+clipped+or+invisible.++++++++++++@@\token_to_str:N\n
  @@++++++++++++++++++++++++++++++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@+Dvips+should+be+called+either+without+option+`-Ppdf':++@@\token_to_str:N\n
  @@++++++++++++++++++++++++++++++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@+++dvips+\jobname\token_to_str:N\n
  @@++++++++++++++++++++++++++++++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@+or+with+a+different+resolution+setting,+e.g.:++++++++++@@\token_to_str:N\n
  @@++++++++++++++++++++++++++++++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@+++dvips+-Ppdf+-D1200+\jobname\token_to_str:N\n
  @@++++++++++++++++++++++++++++++++++++++++++++++++++++++++@@\token_to_str:N\n
  @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@\token_to_str:N\n)
  print}~if}~?pdfmark
}
\group_end: