summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/source/latex-dev/l3backend/l3backend-pdf.dtx
diff options
context:
space:
mode:
Diffstat (limited to 'Master/texmf-dist/source/latex-dev/l3backend/l3backend-pdf.dtx')
-rw-r--r--Master/texmf-dist/source/latex-dev/l3backend/l3backend-pdf.dtx1755
1 files changed, 1755 insertions, 0 deletions
diff --git a/Master/texmf-dist/source/latex-dev/l3backend/l3backend-pdf.dtx b/Master/texmf-dist/source/latex-dev/l3backend/l3backend-pdf.dtx
new file mode 100644
index 00000000000..cf09c0eec22
--- /dev/null
+++ b/Master/texmf-dist/source/latex-dev/l3backend/l3backend-pdf.dtx
@@ -0,0 +1,1755 @@
+% \iffalse meta-comment
+%
+%% File: l3backend-pdf.dtx
+%
+% Copyright (C) 2019-2024 The LaTeX Project
+%
+% It may be distributed and/or modified under the conditions of the
+% LaTeX Project Public License (LPPL), either version 1.3c of this
+% license or (at your option) any later version. The latest version
+% of this license is in the file
+%
+% https://www.latex-project.org/lppl.txt
+%
+% This file is part of the "l3backend bundle" (The Work in LPPL)
+% and all files in that bundle must be distributed together.
+%
+% -----------------------------------------------------------------------
+%
+% The development version of the bundle can be found at
+%
+% https://github.com/latex3/latex3
+%
+% for those people who are interested.
+%
+%<*driver>
+\documentclass[full,kernel]{l3doc}
+\begin{document}
+ \DocInput{\jobname.dtx}
+\end{document}
+%</driver>
+% \fi
+%
+% \title{^^A
+% The \pkg{l3backend-pdf} module\\ Backend PDF features^^A
+% }
+%
+% \author{^^A
+% The \LaTeX{} Project\thanks
+% {^^A
+% E-mail:
+% \href{mailto:latex-team@latex-project.org}
+% {latex-team@latex-project.org}^^A
+% }^^A
+% }
+%
+% \date{Released 2024-04-11}
+%
+% \maketitle
+%
+% \begin{documentation}
+%
+% \end{documentation}
+%
+% \begin{implementation}
+%
+% \section{\pkg{l3backend-pdf} implementation}
+%
+% \begin{macrocode}
+%<*package>
+%<@@=pdf>
+% \end{macrocode}
+%
+% Setting up PDF resources is a complex area with only limited documentation
+% in the engine manuals. The following code builds heavily on existing ideas
+% from \pkg{hyperref} work by Sebastian Rahtz and Heiko Oberdiek, and
+% significant contributions by Alexander Grahn, in addition to the specific
+% code referenced a various points.
+%
+% \subsection{Shared code}
+%
+% A very small number of items that belong at the backend level but which
+% are common to most backends.
+%
+% \begin{macrocode}
+%<*!dvisvgm>
+% \end{macrocode}
+%
+% \begin{variable}{\l_@@_internal_box}
+% \begin{macrocode}
+\box_new:N \l_@@_internal_box
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macrocode}
+%</!dvisvgm>
+% \end{macrocode}
+%
+% \subsection{\texttt{dvips} backend}
+%
+% \begin{macrocode}
+%<*dvips>
+% \end{macrocode}
+%
+% \begin{macro}{\@@_backend_pdfmark:n, \@@_backend_pdfmark:e}
+% Used often enough it should be a separate function.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_pdfmark:n #1
+ { \__kernel_backend_postscript:n { mark #1 ~ pdfmark } }
+\cs_generate_variant:Nn \@@_backend_pdfmark:n { e }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Catalogue entries}
+%
+% \begin{macro}{\@@_backend_catalog_gput:nn, \@@_backend_info_gput:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_catalog_gput:nn #1#2
+ { \@@_backend_pdfmark:n { { Catalog } << /#1 ~ #2 >> /PUT } }
+\cs_new_protected:Npn \@@_backend_info_gput:nn #1#2
+ { \@@_backend_pdfmark:n { /#1 ~ #2 /DOCINFO } }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Objects}
+%
+% \begin{macro}{\@@_backend_object_new:}
+% \begin{macro}[EXP]{\@@_backend_object_ref:n, \@@_backend_object_id:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_object_new:
+ { \int_gincr:N \g_@@_backend_object_int }
+\cs_new:Npn \@@_backend_object_ref:n #1 { { pdf.obj #1 } }
+\cs_new_eq:NN \@@_backend_object_id:n \@@_backend_object_ref:n
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}
+% {
+% \@@_backend_object_write:nnn, \@@_backend_object_write:nne,
+% \@@_backend_object_write_aux:nnn
+% }
+% \begin{macro}
+% {
+% \@@_backend_object_write_array:nn ,
+% \@@_backend_object_write_dict:nn ,
+% \@@_backend_object_write_fstream:nn ,
+% \@@_backend_object_write_stream:nn
+% }
+% \begin{macro}{\@@_backend_object_write_stream:nnn}
+% This is where we choose the actual type: some work to get things
+% right. To allow code sharing with the anonymous version, we use an
+% auxiliary.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_object_write:nnn #1#2#3
+ {
+ \@@_backend_object_write_aux:nnn
+ { \@@_backend_object_ref:n {#1} }
+ {#2} {#3}
+ }
+\cs_generate_variant:Nn \@@_backend_object_write:nnn { nne }
+\cs_new_protected:Npn \@@_backend_object_write_aux:nnn #1#2#3
+ {
+ \@@_backend_pdfmark:e
+ {
+ /_objdef ~ #1
+ /type
+ \str_case:nn {#2}
+ {
+ { array } { /array }
+ { dict } { /dict }
+ { fstream } { /stream }
+ { stream } { /stream }
+ }
+ /OBJ
+ }
+ \use:c { @@_backend_object_write_ #2 :nn } {#1} {#3}
+ }
+\cs_new_protected:Npn \@@_backend_object_write_array:nn #1#2
+ {
+ \@@_backend_pdfmark:e
+ { #1 ~0~ [ ~ \exp_not:n {#2} ~ ] ~ /PUTINTERVAL }
+ }
+\cs_new_protected:Npn \@@_backend_object_write_dict:nn #1#2
+ {
+ \@@_backend_pdfmark:e
+ { #1 << \exp_not:n {#2} >> /PUT }
+ }
+\cs_new_protected:Npn \@@_backend_object_write_fstream:nn #1#2
+ {
+ \exp_args:Ne
+ \@@_backend_object_write_fstream:nnn {#1} #2
+ }
+\cs_new_protected:Npn \@@_backend_object_write_fstream:nnn #1#2#3
+ {
+ \__kernel_backend_postscript:n
+ {
+ SDict ~ begin ~
+ mark ~ #1 ~ << #2 >> /PUT ~ pdfmark ~
+ mark ~ #1 ~ ( #3 )~ ( r )~ file ~ /PUT ~ pdfmark ~
+ end
+ }
+ }
+\cs_new_protected:Npn \@@_backend_object_write_stream:nn #1#2
+ {
+ \exp_args:Ne
+ \@@_backend_object_write_stream:nnn {#1} #2
+ }
+\cs_new_protected:Npn \@@_backend_object_write_stream:nnn #1#2#3
+ {
+ \__kernel_backend_postscript:n
+ {
+ mark ~ #1 ~ ( #3 ) /PUT ~ pdfmark ~
+ mark ~ #1 ~ << #2 >> /PUT ~ pdfmark
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_object_now:nn, \@@_backend_object_now:ne}
+% No anonymous objects, so things are done manually.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_object_now:nn #1#2
+ {
+ \int_gincr:N \g_@@_backend_object_int
+ \@@_backend_object_write_aux:nnn
+ { { pdf.obj \int_use:N \g_@@_backend_object_int } }
+ {#1} {#2}
+ }
+\cs_generate_variant:Nn \@@_backend_object_now:nn { ne }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_object_last:}
+% Much like the annotation version.
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_object_last:
+ { { pdf.obj \int_use:N \g_@@_backend_object_int } }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_pageobject_ref:n}
+% Page references are easy in \texttt{dvips}.
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_pageobject_ref:n #1
+ { { Page #1 } }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Annotations}
+%
+% In \texttt{dvips}, annotations have to be constructed manually. As such,
+% we need the object code above for some definitions.
+%
+% \begin{variable}{\l_@@_backend_content_box}
+% The content of an annotation.
+% \begin{macrocode}
+\box_new:N \l_@@_backend_content_box
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_backend_model_box}
+% For creating model sizing for links.
+% \begin{macrocode}
+\box_new:N \l_@@_backend_model_box
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_backend_annotation_int}
+% Needed as objects which are not annotations could be created.
+% \begin{macrocode}
+\int_new:N \g_@@_backend_annotation_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}{\@@_backend_annotation:nnnn}
+% Annotations are objects, but we track them separately. Notably, they are
+% not in the object data lists. Here, to get the co-ordinates of the
+% annotation, we need to have the data collected at the PostScript level.
+% That requires a bit of box trickery (effectively a \LaTeXe{} |picture|
+% of zero size). Once the data is collected, use it to set up the annotation
+% border.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_annotation:nnnn #1#2#3#4
+ {
+ \exp_args:Nf \@@_backend_annotation_aux:nnnn
+ { \dim_eval:n {#1} } {#2} {#3} {#4}
+ }
+\cs_new_protected:Npn \@@_backend_annotation_aux:nnnn #1#2#3#4
+ {
+ \box_move_down:nn {#3}
+ { \hbox:n { \__kernel_backend_postscript:n { pdf.save.ll } } }
+ \box_move_up:nn {#2}
+ {
+ \hbox:n
+ {
+ \__kernel_kern:n {#1}
+ \__kernel_backend_postscript:n { pdf.save.ur }
+ \__kernel_kern:n { -#1 }
+ }
+ }
+ \int_gincr:N \g_@@_backend_object_int
+ \int_gset_eq:NN \g_@@_backend_annotation_int \g_@@_backend_object_int
+ \@@_backend_pdfmark:e
+ {
+ /_objdef { pdf.obj \int_use:N \g_@@_backend_object_int }
+ pdf.rect
+ #4 ~
+ /ANN
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_annotation_last:}
+% Provide the last annotation we created: could get tricky of course if
+% other packages are loaded.
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_annotation_last:
+ { { pdf.obj \int_use:N \g_@@_backend_annotation_int } }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{variable}{\g_@@_backend_link_int}
+% To track annotations which are links.
+% \begin{macrocode}
+\int_new:N \g_@@_backend_link_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_backend_link_dict_tl}
+% To pass information to the end-of-link function.
+% \begin{macrocode}
+\tl_new:N \g_@@_backend_link_dict_tl
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_backend_link_sf_int}
+% Needed to save/restore space factor, which is needed to deal with the face
+% we need a box.
+% \begin{macrocode}
+\int_new:N \g_@@_backend_link_sf_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_backend_link_math_bool}
+% Needed to save/restore math mode.
+% \begin{macrocode}
+\bool_new:N \g_@@_backend_link_math_bool
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\g_@@_backend_link_bool}
+% Track link formation: we cannot nest at all.
+% \begin{macrocode}
+\bool_new:N \g_@@_backend_link_bool
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{variable}{\l_@@_breaklink_pdfmark_tl}
+% Swappable content for link breaking.
+% \begin{macrocode}
+\tl_new:N \l_@@_breaklink_pdfmark_tl
+\tl_set:Nn \l_@@_breaklink_pdfmark_tl { pdfmark }
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}{\@@_breaklink_postscript:n}
+% To allow dropping material unless link breaking is active.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_breaklink_postscript:n #1 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_breaklink_usebox:N}
+% Swappable box unpacking or use.
+% \begin{macrocode}
+\cs_new_eq:NN \@@_breaklink_usebox:N \box_use:N
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_link_begin_goto:nnw, \@@_backend_link_begin_user:nnw}
+% \begin{macro}{\@@_backend_link:nw, \@@_backend_link_aux:nw}
+% \begin{macro}{\@@_backend_link_end:, \@@_backend_link_end_aux:}
+% \begin{macro}{\@@_backend_link_minima:}
+% \begin{macro}{\@@_backend_link_outerbox:n}
+% \begin{macro}{\@@_backend_link_sf_save:, \@@_backend_link_sf_restore:}
+% Links are crated like annotations but with dedicated code to allow for
+% adjusting the size of the rectangle. In contrast to \pkg{hyperref}, we
+% grab the link content as a box which can then unbox: this allows the same
+% interface as for \pdfTeX{}.
+%
+% Notice that the link setup here uses |/Action| not |/A|. That is because
+% Distiller \emph{requires} this trigger word, rather than a \enquote{raw}
+% PDF dictionary key (Ghostscript can handle either form).
+%
+% Taking the idea of |evenboxes| from \pkg{hypdvips}, we implement a minimum
+% box height and depth for link placement. This means that \enquote{underlining}
+% with a hyperlink will generally give an even appearance. However, to ensure
+% that the full content is always above the link border, we do not allow
+% this to be negative (contrast \pkg{hypdvips} approach). The result should
+% be similar to \pdfTeX{} in the vast majority of foreseeable cases.
+%
+% The object number for a link is saved separately from the rest of the
+% dictionary as this allows us to insert it just once, at either an
+% unbroken link or only in the first line of a broken one. That makes the
+% code clearer but also avoids a low-level PostScript error with the code
+% as taken from \pkg{hypdvips}.
+%
+% Getting the outer dimensions of the text area may be better using a two-pass
+% approach and |\tex_savepos:D|. That plus generic mode are still to re-examine.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_link_begin_goto:nnw #1#2
+ {
+ \@@_backend_link_begin:nw
+ { #1 /Subtype /Link /Action << /S /GoTo /D ( #2 ) >> }
+ }
+\cs_new_protected:Npn \@@_backend_link_begin_user:nnw #1#2
+ { \@@_backend_link_begin:nw {#1#2} }
+\cs_new_protected:Npn \@@_backend_link_begin:nw #1
+ {
+ \bool_if:NF \g_@@_backend_link_bool
+ { \@@_backend_link_begin_aux:nw {#1} }
+ }
+% \end{macrocode}
+% The definition of |pdf.link.dict| here is needed as there is code in the
+% PostScript headers for breaking links, and that can only work with this
+% available.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_link_begin_aux:nw #1
+ {
+ \bool_gset_true:N \g_@@_backend_link_bool
+ \__kernel_backend_postscript:n
+ { /pdf.link.dict ( #1 ) def }
+ \tl_gset:Nn \g_@@_backend_link_dict_tl {#1}
+ \@@_backend_link_sf_save:
+ \mode_if_math:TF
+ { \bool_gset_true:N \g_@@_backend_link_math_bool }
+ { \bool_gset_false:N \g_@@_backend_link_math_bool }
+ \hbox_set:Nw \l_@@_backend_content_box
+ \@@_backend_link_sf_restore:
+ \bool_if:NT \g_@@_backend_link_math_bool
+ { \c_math_toggle_token }
+ }
+\cs_new_protected:Npn \@@_backend_link_end:
+ {
+ \bool_if:NT \g_@@_backend_link_bool
+ { \@@_backend_link_end_aux: }
+ }
+\cs_new_protected:Npn \@@_backend_link_end_aux:
+ {
+ \bool_if:NT \g_@@_backend_link_math_bool
+ { \c_math_toggle_token }
+ \@@_backend_link_sf_save:
+ \hbox_set_end:
+ \@@_backend_link_minima:
+ \hbox_set:Nn \l_@@_backend_model_box { Gg }
+ \exp_args:Ne \@@_backend_link_outerbox:n
+ {
+ \int_if_odd:nTF { \value { page } }
+ { \oddsidemargin }
+ { \evensidemargin }
+ }
+ \box_move_down:nn { \box_dp:N \l_@@_backend_content_box }
+ { \hbox:n { \__kernel_backend_postscript:n { pdf.save.linkll } } }
+ \@@_breaklink_postscript:n { pdf.bordertracking.begin }
+ \@@_breaklink_usebox:N \l_@@_backend_content_box
+ \@@_breaklink_postscript:n { pdf.bordertracking.end }
+ \box_move_up:nn { \box_ht:N \l_@@_backend_content_box }
+ {
+ \hbox:n
+ { \__kernel_backend_postscript:n { pdf.save.linkur } }
+ }
+ \int_gincr:N \g_@@_backend_object_int
+ \int_gset_eq:NN \g_@@_backend_link_int \g_@@_backend_object_int
+ \__kernel_backend_postscript:e
+ {
+ mark
+ /_objdef { pdf.obj \int_use:N \g_@@_backend_link_int }
+ \g_@@_backend_link_dict_tl \c_space_tl
+ pdf.rect
+ /ANN ~ \l_@@_breaklink_pdfmark_tl
+ }
+ \@@_backend_link_sf_restore:
+ \bool_gset_false:N \g_@@_backend_link_bool
+ }
+\cs_new_protected:Npn \@@_backend_link_minima:
+ {
+ \hbox_set:Nn \l_@@_backend_model_box { Gg }
+ \__kernel_backend_postscript:e
+ {
+ /pdf.linkdp.pad ~
+ \dim_to_decimal:n
+ {
+ \dim_max:nn
+ {
+ \box_dp:N \l_@@_backend_model_box
+ - \box_dp:N \l_@@_backend_content_box
+ }
+ { 0pt }
+ } ~
+ pdf.pt.dvi ~ def
+ /pdf.linkht.pad ~
+ \dim_to_decimal:n
+ {
+ \dim_max:nn
+ {
+ \box_ht:N \l_@@_backend_model_box
+ - \box_ht:N \l_@@_backend_content_box
+ }
+ { 0pt }
+ } ~
+ pdf.pt.dvi ~ def
+ }
+ }
+\cs_new_protected:Npn \@@_backend_link_outerbox:n #1
+ {
+ \__kernel_backend_postscript:e
+ {
+ /pdf.outerbox
+ [
+ \dim_to_decimal:n {#1} ~
+ \dim_to_decimal:n { -\box_dp:N \l_@@_backend_model_box } ~
+ \dim_to_decimal:n { #1 + \textwidth } ~
+ \dim_to_decimal:n { \box_ht:N \l_@@_backend_model_box }
+ ]
+ [ exch { pdf.pt.dvi } forall ] def
+ /pdf.baselineskip ~
+ \dim_to_decimal:n { \tex_baselineskip:D } ~ dup ~ 0 ~ gt
+ { pdf.pt.dvi ~ def }
+ { pop ~ pop }
+ ifelse
+ }
+ }
+\cs_new_protected:Npn \@@_backend_link_sf_save:
+ {
+ \int_gset:Nn \g_@@_backend_link_sf_int
+ {
+ \mode_if_horizontal:TF
+ { \tex_spacefactor:D }
+ { 0 }
+ }
+ }
+\cs_new_protected:Npn \@@_backend_link_sf_restore:
+ {
+ \mode_if_horizontal:T
+ {
+ \int_compare:nNnT \g_@@_backend_link_sf_int > { 0 }
+ { \int_set_eq:NN \tex_spacefactor:D \g_@@_backend_link_sf_int }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% Hooks to allow link breaking: something will be needed in format mode
+% at some stage. At present this code is disabled as there is an open
+% question about the name of the hook: to be resolved at the \LaTeXe{}
+% end.
+% \begin{macrocode}
+\use_none:n
+ {
+ \cs_if_exist:NT \@makecol@hook
+ {
+ \tl_put_right:Nn \@makecol@hook
+ {
+ \box_if_empty:NF \l_shipout_box
+ {
+ \vbox_set:Nn \l_shipout_box
+ {
+ \__kernel_backend_postscript:n
+ {
+ pdf.globaldict /pdf.brokenlink.rect ~ known
+ { pdf.bordertracking.continue }
+ if
+ }
+ \vbox_unpack_drop:N \l_shipout_box
+ \__kernel_backend_postscript:n
+ { pdf.bordertracking.endpage }
+ }
+ }
+ }
+ \tl_set:Nn \l_@@_breaklink_pdfmark_tl { pdf.pdfmark }
+ \cs_set_eq:NN \@@_breaklink_postscript:n \__kernel_backend_postscript:n
+ \cs_set_eq:NN \@@_breaklink_usebox:N \hbox_unpack:N
+ }
+ }
+% \end{macrocode}
+%
+% \begin{macro}{\@@_backend_link_last:}
+% The same as annotations, but with a custom integer.
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_link_last:
+ { { pdf.obj \int_use:N \g_@@_backend_link_int } }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_link_margin:n}
+% Convert to big points and pass to PostScript.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_link_margin:n #1
+ {
+ \__kernel_backend_postscript:e
+ {
+ /pdf.linkmargin { \dim_to_decimal:n {#1} ~ pdf.pt.dvi } def
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_destination:nn}
+% \begin{macro}{\@@_backend_destination:nnnn, \@@_backend_destination_aux:nnnn}
+% Here, we need to turn the zoom into a scale. We also need to know where
+% the current anchor point actually is: worked out in PostScript. For the
+% rectangle version, we have a bit more PostScript: we need two points.
+% fitr without rule spec doesn't work, so it falls back to \texttt{/Fit} here.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_destination:nn #1#2
+ {
+ \__kernel_backend_postscript:n { pdf.dest.anchor }
+ \@@_backend_pdfmark:e
+ {
+ /View
+ [
+ \str_case:nnF {#2}
+ {
+ { xyz } { /XYZ ~ pdf.dest.point ~ null }
+ { fit } { /Fit }
+ { fitb } { /FitB }
+ { fitbh } { /FitBH ~ pdf.dest.y }
+ { fitbv } { /FitBV ~ pdf.dest.x }
+ { fith } { /FitH ~ pdf.dest.y }
+ { fitv } { /FitV ~ pdf.dest.x }
+ { fitr } { /Fit }
+ }
+ {
+ /XYZ ~ pdf.dest.point ~ \fp_eval:n { (#2) / 100 }
+ }
+ ]
+ /Dest ( \exp_not:n {#1} ) cvn
+ /DEST
+ }
+ }
+\cs_new_protected:Npn \@@_backend_destination:nnnn #1#2#3#4
+ {
+ \exp_args:Ne \@@_backend_destination_aux:nnnn
+ { \dim_eval:n {#2} } {#1} {#3} {#4}
+ }
+\cs_new_protected:Npn \@@_backend_destination_aux:nnnn #1#2#3#4
+ {
+ \vbox_to_zero:n
+ {
+ \__kernel_kern:n {#4}
+ \hbox:n { \__kernel_backend_postscript:n { pdf.save.ll } }
+ \tex_vss:D
+ }
+ \__kernel_kern:n {#1}
+ \vbox_to_zero:n
+ {
+ \__kernel_kern:n { -#3 }
+ \hbox:n { \__kernel_backend_postscript:n { pdf.save.ur } }
+ \tex_vss:D
+ }
+ \__kernel_kern:n { -#1 }
+ \@@_backend_pdfmark:n
+ {
+ /View
+ [
+ /FitR ~
+ pdf.llx ~ pdf.lly ~ pdf.dest2device ~
+ pdf.urx ~ pdf.ury ~ pdf.dest2device
+ ]
+ /Dest ( #2 ) cvn
+ /DEST
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Structure}
+%
+% \begin{macro}{\@@_backend_compresslevel:n}
+% \begin{macro}{\@@_backend_compress_objects:n}
+% Doable for the usual \texttt{ps2pdf} method.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_compresslevel:n #1
+ {
+ \int_compare:nNnT {#1} = 0
+ {
+ \__kernel_backend_literal_postscript:n
+ {
+ /setdistillerparams ~ where
+ { pop << /CompressPages ~ false >> setdistillerparams }
+ if
+ }
+ }
+ }
+\cs_new_protected:Npn \@@_backend_compress_objects:n #1
+ {
+ \bool_if:nF {#1}
+ {
+ \__kernel_backend_literal_postscript:n
+ {
+ /setdistillerparams ~ where
+ { pop << /CompressStreams ~ false >> setdistillerparams }
+ if
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}
+% {\@@_backend_version_major_gset:n, \@@_backend_version_minor_gset:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_version_major_gset:n #1
+ {
+ \cs_gset:Npe \@@_backend_version_major: { \int_eval:n {#1} }
+ }
+\cs_new_protected:Npn \@@_backend_version_minor_gset:n #1
+ {
+ \cs_gset:Npe \@@_backend_version_minor: { \int_eval:n {#1} }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_version_major:, \@@_backend_version_minor:}
+% Data not available!
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_version_major: { -1 }
+\cs_new:Npn \@@_backend_version_minor: { -1 }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Marked content}
+%
+% \begin{macro}{\@@_backend_bdc:nn}
+% \begin{macro}{\@@_backend_emc:}
+% Simple wrappers.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_bdc:nn #1#2
+ { \@@_backend_pdfmark:n { /#1 ~ #2 /BDC } }
+\cs_new_protected:Npn \@@_backend_emc:
+ { \@@_backend_pdfmark:n { /EMC } }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvips>
+% \end{macrocode}
+%
+% \subsection{\LuaTeX{} and \pdfTeX{} backend}
+%
+% \begin{macrocode}
+%<*luatex|pdftex>
+% \end{macrocode}
+%
+% \subsubsection{Annotations}
+%
+% \begin{macro}{\@@_backend_annotation:nnnn}
+% Simply pass the raw data through, just dealing with evaluation of dimensions.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_annotation:nnnn #1#2#3#4
+ {
+%<*luatex>
+ \tex_pdfextension:D annot ~
+%</luatex>
+%<*pdftex>
+ \tex_pdfannot:D
+%</pdftex>
+ width ~ \dim_eval:n {#1} ~
+ height ~ \dim_eval:n {#2} ~
+ depth ~ \dim_eval:n {#3} ~
+ {#4}
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_annotation_last:}
+% A tiny amount of extra data gets added here; we use \texttt{x}-type
+% expansion to get the space in the right place and form. The \enquote{extra}
+% space in the \LuaTeX{} version is \emph{required} as it is consumed in
+% finding the end of the keyword.
+% \begin{macrocode}
+\cs_new:Npe \@@_backend_annotation_last:
+ {
+ \exp_not:N \int_value:w
+%<*luatex>
+ \exp_not:N \tex_pdffeedback:D lastannot ~
+%</luatex>
+%<*pdftex>
+ \exp_not:N \tex_pdflastannot:D
+%</pdftex>
+ \c_space_tl 0 ~ R
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {\@@_backend_link_begin_goto:nnw, \@@_backend_link_begin_user:nnw}
+% \begin{macro}{\@@_backend_link_begin:nnnw}
+% \begin{macro}{\@@_backend_link_end:}
+% Links are all created using the same internals.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_link_begin_goto:nnw #1#2
+ { \@@_backend_link_begin:nnnw {#1} { goto~name } {#2} }
+\cs_new_protected:Npn \@@_backend_link_begin_user:nnw #1#2
+ { \@@_backend_link_begin:nnnw {#1} { user } {#2} }
+\cs_new_protected:Npn \@@_backend_link_begin:nnnw #1#2#3
+ {
+%<*luatex>
+ \tex_pdfextension:D startlink ~
+%</luatex>
+%<*pdftex>
+ \tex_pdfstartlink:D
+%</pdftex>
+ attr {#1}
+ #2 {#3}
+ }
+\cs_new_protected:Npn \@@_backend_link_end:
+ {
+%<*luatex>
+ \tex_pdfextension:D endlink \scan_stop:
+%</luatex>
+%<*pdftex>
+ \tex_pdfendlink:D
+%</pdftex>
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_link_last:}
+% Formatted for direct use.
+% \begin{macrocode}
+\cs_new:Npe \@@_backend_link_last:
+ {
+ \exp_not:N \int_value:w
+%<*luatex>
+ \exp_not:N \tex_pdffeedback:D lastlink ~
+%</luatex>
+%<*pdftex>
+ \exp_not:N \tex_pdflastlink:D
+%</pdftex>
+ \c_space_tl 0 ~ R
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_link_margin:n}
+% A simple task: pass the data to the primitive.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_link_margin:n #1
+ {
+%<*luatex>
+ \tex_pdfvariable:D linkmargin
+%</luatex>
+%<*pdftex>
+ \tex_pdflinkmargin:D
+%</pdftex>
+ \dim_eval:n {#1} \scan_stop:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_destination:nn}
+% \begin{macro}{\@@_backend_destination:nnnn}
+% A simple task: pass the data to the primitive. The |\scan_stop:| deals
+% with the danger of an unterminated keyword. The zoom given here is a
+% percentage, but we need to pass it as \emph{per mille}. The rectangle
+% version is also easy as everything is build in.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_destination:nn #1#2
+ {
+%<*luatex>
+ \tex_pdfextension:D dest ~
+%</luatex>
+%<*pdftex>
+ \tex_pdfdest:D
+%</pdftex>
+ name {#1}
+ \str_case:nnF {#2}
+ {
+ { xyz } { xyz }
+ { fit } { fit }
+ { fitb } { fitb }
+ { fitbh } { fitbh }
+ { fitbv } { fitbv }
+ { fith } { fith }
+ { fitv } { fitv }
+ { fitr } { fitr }
+ }
+ { xyz ~ zoom \fp_eval:n { #2 * 10 } }
+ \scan_stop:
+ }
+\cs_new_protected:Npn \@@_backend_destination:nnnn #1#2#3#4
+ {
+%<*luatex>
+ \tex_pdfextension:D dest ~
+%</luatex>
+%<*pdftex>
+ \tex_pdfdest:D
+%</pdftex>
+ name {#1}
+ fitr ~
+ width \dim_eval:n {#2} ~
+ height \dim_eval:n {#3} ~
+ depth \dim_eval:n {#4} \scan_stop:
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Catalogue entries}
+%
+% \begin{macro}{\@@_backend_catalog_gput:nn, \@@_backend_info_gput:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_catalog_gput:nn #1#2
+ {
+%<*luatex>
+ \tex_pdfextension:D catalog
+%</luatex>
+%<*pdftex>
+ \tex_pdfcatalog:D
+%</pdftex>
+ { / #1 ~ #2 }
+ }
+\cs_new_protected:Npn \@@_backend_info_gput:nn #1#2
+ {
+%<*luatex>
+ \tex_pdfextension:D info
+%</luatex>
+%<*pdftex>
+ \tex_pdfinfo:D
+%</pdftex>
+ { / #1 ~ #2 }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Objects}
+%
+% \begin{variable}{\g_@@_backend_object_prop}
+% For tracking objects to allow finalisation.
+% \begin{macrocode}
+\prop_new:N \g_@@_backend_object_prop
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}{\@@_backend_object_new:}
+% \begin{macro}[EXP]{\@@_backend_object_ref:n, \@@_backend_object_id:n}
+% Declaring objects means reserving at the PDF level plus starting
+% tracking.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_object_new:
+ {
+%<*luatex>
+ \tex_pdfextension:D obj ~
+%</luatex>
+%<*pdftex>
+ \tex_pdfobj:D
+%</pdftex>
+ reserveobjnum ~
+ \int_gset:Nn \g_@@_backend_object_int
+%<*luatex>
+ { \tex_pdffeedback:D lastobj }
+%</luatex>
+%<*pdftex>
+ { \tex_pdflastobj:D }
+%</pdftex>
+ }
+\cs_new:Npn \@@_backend_object_ref:n #1 { #1 ~ 0 ~ R }
+\cs_new:Npn \@@_backend_object_id:n #1 {#1}
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_object_write:nnn, \@@_backend_object_write:nne}
+% \begin{macro}[EXP]{\@@_backend_object_write:nn}
+% \begin{macro}[EXP]{\@@_exp_not_i:nn, \@@_exp_not_ii:nn}
+% Writing the data needs a little information about the structure of the
+% object.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_object_write:nnn #1#2#3
+ {
+%<*luatex>
+ \tex_immediate:D \tex_pdfextension:D obj ~
+%</luatex>
+%<*pdftex>
+ \tex_immediate:D \tex_pdfobj:D
+%</pdftex>
+ useobjnum ~ #1
+ \@@_backend_object_write:nn {#2} {#3}
+ }
+\cs_new:Npn \@@_backend_object_write:nn #1#2
+ {
+ \str_case:nn {#1}
+ {
+ { array } { { [ ~ \exp_not:n {#2} ~ ] } }
+ { dict } { { << ~ \exp_not:n {#2} ~ >> } }
+ { fstream }
+ {
+ stream ~ attr ~ { \@@_exp_not_i:nn #2 } ~
+ file ~ { \@@_exp_not_ii:nn #2 }
+ }
+ { stream }
+ {
+ stream ~ attr ~ { \@@_exp_not_i:nn #2 } ~
+ { \@@_exp_not_ii:nn #2 }
+ }
+ }
+ }
+\cs_generate_variant:Nn \@@_backend_object_write:nnn { nne }
+\cs_new:Npn \@@_exp_not_i:nn #1#2 { \exp_not:n {#1} }
+\cs_new:Npn \@@_exp_not_ii:nn #1#2 { \exp_not:n {#2} }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_object_now:nn, \@@_backend_object_now:ne}
+% Much like writing, but direct creation.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_object_now:nn #1#2
+ {
+%<*luatex>
+ \tex_immediate:D \tex_pdfextension:D obj ~
+%</luatex>
+%<*pdftex>
+ \tex_immediate:D \tex_pdfobj:D
+%</pdftex>
+ \@@_backend_object_write:nn {#1} {#2}
+ }
+\cs_generate_variant:Nn \@@_backend_object_now:nn { ne }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_object_last:}
+% Much like annotation.
+% \begin{macrocode}
+\cs_new:Npe \@@_backend_object_last:
+ {
+ \exp_not:N \int_value:w
+%<*luatex>
+ \exp_not:N \tex_pdffeedback:D lastobj ~
+%</luatex>
+%<*pdftex>
+ \exp_not:N \tex_pdflastobj:D
+%</pdftex>
+ \c_space_tl 0 ~ R
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_pageobject_ref:n}
+% The usual wrapper situation; the three spaces here are essential.
+% \begin{macrocode}
+\cs_new:Npe \@@_backend_pageobject_ref:n #1
+ {
+ \exp_not:N \int_value:w
+%<*luatex>
+ \exp_not:N \tex_pdffeedback:D pageref
+%</luatex>
+%<*pdftex>
+ \exp_not:N \tex_pdfpageref:D
+%</pdftex>
+ \c_space_tl #1 \c_space_tl \c_space_tl \c_space_tl 0 ~ R
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Structure}
+%
+% \begin{macro}{\@@_backend_compresslevel:n}
+% \begin{macro}{\@@_backend_compress_objects:n}
+% \begin{macro}{\@@_backend_objcompresslevel:n}
+% Simply pass data to the engine.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_compresslevel:n #1
+ {
+ \tex_global:D
+%<*luatex>
+ \tex_pdfvariable:D compresslevel
+%</luatex>
+%<*pdftex>
+ \tex_pdfcompresslevel:D
+%</pdftex>
+ \int_value:w \int_eval:n {#1} \scan_stop:
+ }
+\cs_new_protected:Npn \@@_backend_compress_objects:n #1
+ {
+ \bool_if:nTF {#1}
+ { \@@_backend_objcompresslevel:n { 2 } }
+ { \@@_backend_objcompresslevel:n { 0 } }
+ }
+\cs_new_protected:Npn \@@_backend_objcompresslevel:n #1
+ {
+ \tex_global:D
+%<*luatex>
+ \tex_pdfvariable:D objcompresslevel
+%</luatex>
+%<*pdftex>
+ \tex_pdfobjcompresslevel:D
+%</pdftex>
+ #1 \scan_stop:
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}
+% {\@@_backend_version_major_gset:n, \@@_backend_version_minor_gset:n}
+% The availability of the primitive is not universal, so we have to test
+% at load time.
+% \begin{macrocode}
+\cs_new_protected:Npe \@@_backend_version_major_gset:n #1
+ {
+%<*luatex>
+ \int_compare:nNnT \tex_luatexversion:D > { 106 }
+ {
+ \exp_not:N \tex_global:D \tex_pdfvariable:D majorversion
+ \exp_not:N \int_eval:n {#1} \scan_stop:
+ }
+%</luatex>
+%<*pdftex>
+ \cs_if_exist:NT \tex_pdfmajorversion:D
+ {
+ \exp_not:N \tex_global:D \tex_pdfmajorversion:D
+ \exp_not:N \int_eval:n {#1} \scan_stop:
+ }
+%</pdftex>
+ }
+\cs_new_protected:Npn \@@_backend_version_minor_gset:n #1
+ {
+ \tex_global:D
+%<*luatex>
+ \tex_pdfvariable:D minorversion
+%</luatex>
+%<*pdftex>
+ \tex_pdfminorversion:D
+%</pdftex>
+ \int_eval:n {#1} \scan_stop:
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_version_major:, \@@_backend_version_minor:}
+% As above.
+% \begin{macrocode}
+\cs_new:Npe \@@_backend_version_major:
+ {
+%<*luatex>
+ \int_compare:nNnTF \tex_luatexversion:D > { 106 }
+ { \exp_not:N \tex_the:D \tex_pdfvariable:D majorversion }
+ { 1 }
+%</luatex>
+%<*pdftex>
+ \cs_if_exist:NTF \tex_pdfmajorversion:D
+ { \exp_not:N \tex_the:D \tex_pdfmajorversion:D }
+ { 1 }
+%</pdftex>
+ }
+\cs_new:Npn \@@_backend_version_minor:
+ {
+ \tex_the:D
+%<*luatex>
+ \tex_pdfvariable:D minorversion
+%</luatex>
+%<*pdftex>
+ \tex_pdfminorversion:D
+%</pdftex>
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Marked content}
+%
+% \begin{macro}{\@@_backend_bdc:nn}
+% \begin{macro}{\@@_backend_emc:}
+% Simple wrappers. May need refinement: see
+% \url{https://chat.stackexchange.com/transcript/message/49970158#49970158}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_bdc:nn #1#2
+ { \__kernel_backend_literal_page:n { /#1 ~ #2 ~ BDC } }
+\cs_new_protected:Npn \@@_backend_emc:
+ { \__kernel_backend_literal_page:n { EMC } }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macrocode}
+%</luatex|pdftex>
+% \end{macrocode}
+%
+% \subsection{\texttt{dvipdfmx} backend}
+%
+% \begin{macrocode}
+%<*dvipdfmx|xetex>
+% \end{macrocode}
+%
+% \begin{macro}{\@@_backend:n, \@@_backend:e}
+% A generic function for the backend PDF specials: used where we can.
+% \begin{macrocode}
+\cs_new_protected:Npe \@@_backend:n #1
+ { \__kernel_backend_literal:n { pdf: #1 } }
+\cs_generate_variant:Nn \@@_backend:n { e }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Catalogue entries}
+%
+% \begin{macro}{\@@_backend_catalog_gput:nn, \@@_backend_info_gput:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_catalog_gput:nn #1#2
+ { \@@_backend:n { put ~ @catalog << /#1 ~ #2 >> } }
+\cs_new_protected:Npn \@@_backend_info_gput:nn #1#2
+ { \@@_backend:n { docinfo << /#1 ~ #2 >> } }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Objects}
+%
+% \begin{variable}{\g_@@_backend_object_prop}
+% For tracking objects to allow finalisation.
+% \begin{macrocode}
+\prop_new:N \g_@@_backend_object_prop
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}{\@@_backend_object_new:}
+% \begin{macro}[EXP]{\@@_backend_object_ref:n, \@@_backend_object_id:n}
+% Objects are tracked at the macro level, but we don't have to do anything
+% at this stage.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_object_new:
+ { \int_gincr:N \g_@@_backend_object_int }
+\cs_new:Npn \@@_backend_object_ref:n #1 { @pdf.obj #1 }
+\cs_new_eq:NN \@@_backend_object_id:n \@@_backend_object_ref:n
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_object_write:nnn, \@@_backend_object_write:nne}
+% \begin{macro}
+% {
+% \@@_backend_object_write_array:nn ,
+% \@@_backend_object_write_dict:nn ,
+% \@@_backend_object_write_fstream:nn ,
+% \@@_backend_object_write_stream:nn
+% }
+% \begin{macro}{\@@_backend_object_write_stream:nnnn}
+% This is where we choose the actual type.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_object_write:nnn #1#2#3
+ {
+ \use:c { @@_backend_object_write_ #2 :nn }
+ { \@@_backend_object_ref:n {#1} } {#3}
+ }
+\cs_generate_variant:Nn \@@_backend_object_write:nnn { nne }
+\cs_new_protected:Npn \@@_backend_object_write_array:nn #1#2
+ {
+ \@@_backend:e
+ { obj ~ #1 ~ [ ~ \exp_not:n {#2} ~ ] }
+ }
+\cs_new_protected:Npn \@@_backend_object_write_dict:nn #1#2
+ {
+ \@@_backend:e
+ { obj ~ #1 ~ << ~ \exp_not:n {#2} ~ >> }
+ }
+\cs_new_protected:Npn \@@_backend_object_write_fstream:nn #1#2
+ { \@@_backend_object_write_stream:nnnn { f } {#1} #2 }
+\cs_new_protected:Npn \@@_backend_object_write_stream:nn #1#2
+ { \@@_backend_object_write_stream:nnnn { } {#1} #2 }
+\cs_new_protected:Npn \@@_backend_object_write_stream:nnnn #1#2#3#4
+ {
+ \@@_backend:e
+ {
+ #1 stream ~ #2 ~
+ ( \exp_not:n {#4} ) ~ << \exp_not:n {#3} >>
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_object_now:nn, \@@_backend_object_now:ne}
+% No anonymous objects with \texttt{dvipdfmx} so we have to give an
+% object name.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_object_now:nn #1#2
+ {
+ \int_gincr:N \g_@@_backend_object_int
+ \exp_args:Nne \use:c { @@_backend_object_write_ #1 :nn }
+ { @pdf.obj \int_use:N \g_@@_backend_object_int }
+ {#2}
+ }
+\cs_generate_variant:Nn \@@_backend_object_now:nn { ne }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_object_last:}
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_object_last:
+ { @pdf.obj \int_use:N \g_@@_backend_object_int }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_pageobject_ref:n}
+% Page references are easy in \texttt{dvipdfmx}/\XeTeX{}.
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_pageobject_ref:n #1
+ { @page #1 }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Annotations}
+%
+% \begin{variable}{\g_@@_backend_annotation_int}
+% Needed as objects which are not annotations could be created.
+% \begin{macrocode}
+\int_new:N \g_@@_backend_annotation_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}{\@@_backend_annotation:nnnn}
+% Simply pass the raw data through, just dealing with evaluation of dimensions.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_annotation:nnnn #1#2#3#4
+ {
+ \int_gincr:N \g_@@_backend_object_int
+ \int_gset_eq:NN \g_@@_backend_annotation_int \g_@@_backend_object_int
+ \@@_backend:e
+ {
+ ann ~ @pdf.obj \int_use:N \g_@@_backend_object_int \c_space_tl
+ width ~ \dim_eval:n {#1} ~
+ height ~ \dim_eval:n {#2} ~
+ depth ~ \dim_eval:n {#3} ~
+ << /Type /Annot #4 >>
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_annotation_last:}
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_annotation_last:
+ { @pdf.obj \int_use:N \g_@@_backend_annotation_int }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{variable}{\g_@@_backend_link_int}
+% To track annotations which are links.
+% \begin{macrocode}
+\int_new:N \g_@@_backend_link_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}
+% {\@@_backend_link_begin_goto:nnw, \@@_backend_link_begin_user:nnw}
+% \begin{macro}{\@@_backend_link_begin:n}
+% \begin{macro}{\@@_backend_link_end:}
+% All created using the same internals.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_link_begin_goto:nnw #1#2
+ { \@@_backend_link_begin:n { #1 /Subtype /Link /A << /S /GoTo /D ( #2 ) >> } }
+\cs_new_protected:Npn \@@_backend_link_begin_user:nnw #1#2
+ { \@@_backend_link_begin:n {#1#2} }
+\cs_new_protected:Npe \@@_backend_link_begin:n #1
+ {
+ \exp_not:N \int_gincr:N \exp_not:N \g_@@_backend_link_int
+ \@@_backend:e
+ {
+ bann ~
+ @pdf.lnk
+ \exp_not:N \int_use:N \exp_not:N \g_@@_backend_link_int
+ \c_space_tl
+ <<
+ /Type /Annot
+ #1
+ >>
+ }
+ }
+\cs_new_protected:Npn \@@_backend_link_end:
+ { \@@_backend:n { eann } }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_link_last:}
+% Available using the backend mechanism with a suitably-recent
+% version.
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_link_last:
+ { @pdf.lnk \int_use:N \g_@@_backend_link_int }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_link_margin:n}
+% Pass to \texttt{dvipdfmx}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_link_margin:n #1
+ { \__kernel_backend_literal:e { dvipdfmx:config~g~ \dim_eval:n {#1} } }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_destination:nn}
+% \begin{macro}{\@@_backend_destination:nnnn,\@@_backend_destination_aux:nnnn}
+% Here, we need to turn the zoom into a scale. The method for \texttt{FitR}
+% is from Alexander Grahn: the idea is to avoid needing to do any calculations
+% in \TeX{} by using the backend data for \texttt{@xpos} and \texttt{@ypos}.
+% \texttt{/FitR} without rule spec doesn't work, so it falls back to
+% \texttt{/Fit} here.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_destination:nn #1#2
+ {
+ \@@_backend:e
+ {
+ dest ~ ( \exp_not:n {#1} )
+ [
+ @thispage
+ \str_case:nnF {#2}
+ {
+ { xyz } { /XYZ ~ @xpos ~ @ypos ~ null }
+ { fit } { /Fit }
+ { fitb } { /FitB }
+ { fitbh } { /FitBH }
+ { fitbv } { /FitBV ~ @xpos }
+ { fith } { /FitH ~ @ypos }
+ { fitv } { /FitV ~ @xpos }
+ { fitr } { /Fit }
+ }
+ { /XYZ ~ @xpos ~ @ypos ~ \fp_eval:n { (#2) / 100 } }
+ ]
+ }
+ }
+\cs_new_protected:Npn \@@_backend_destination:nnnn #1#2#3#4
+ {
+ \exp_args:Ne \@@_backend_destination_aux:nnnn
+ { \dim_eval:n {#2} } {#1} {#3} {#4}
+ }
+\cs_new_protected:Npn \@@_backend_destination_aux:nnnn #1#2#3#4
+ {
+ \vbox_to_zero:n
+ {
+ \__kernel_kern:n {#4}
+ \hbox:n
+ {
+ \@@_backend:n { obj ~ @pdf_ #2 _llx ~ @xpos }
+ \@@_backend:n { obj ~ @pdf_ #2 _lly ~ @ypos }
+ }
+ \tex_vss:D
+ }
+ \__kernel_kern:n {#1}
+ \vbox_to_zero:n
+ {
+ \__kernel_kern:n { -#3 }
+ \hbox:n
+ {
+ \@@_backend:n
+ {
+ dest ~ (#2)
+ [
+ @thispage
+ /FitR ~
+ @pdf_ #2 _llx ~ @pdf_ #2 _lly ~
+ @xpos ~ @ypos
+ ]
+ }
+ }
+ \tex_vss:D
+ }
+ \__kernel_kern:n { -#1 }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Structure}
+%
+% \begin{macro}{\@@_backend_compresslevel:n}
+% \begin{macro}{\@@_backend_compress_objects:n}
+% Pass data to the backend: these are a one-shot.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_compresslevel:n #1
+ { \__kernel_backend_literal:e { dvipdfmx:config~z~ \int_eval:n {#1} } }
+\cs_new_protected:Npn \@@_backend_compress_objects:n #1
+ {
+ \bool_if:nF {#1}
+ { \__kernel_backend_literal:n { dvipdfmx:config~C~0x40 } }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}
+% {\@@_backend_version_major_gset:n, \@@_backend_version_minor_gset:n}
+% We start with the assumption that the default is active.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_version_major_gset:n #1
+ {
+ \cs_gset:Npe \@@_backend_version_major: { \int_eval:n {#1} }
+ \__kernel_backend_literal:e { pdf:majorversion~ \@@_backend_version_major: }
+ }
+\cs_new_protected:Npn \@@_backend_version_minor_gset:n #1
+ {
+ \cs_gset:Npe \@@_backend_version_minor: { \int_eval:n {#1} }
+ \__kernel_backend_literal:e { pdf:minorversion~ \@@_backend_version_minor: }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_version_major:, \@@_backend_version_minor:}
+% We start with the assumption that the default is active.
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_version_major: { 1 }
+\cs_new:Npn \@@_backend_version_minor: { 5 }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Marked content}
+%
+% \begin{macro}{\@@_backend_bdc:nn}
+% \begin{macro}{\@@_backend_emc:}
+% Simple wrappers. May need refinement: see
+% \url{https://chat.stackexchange.com/transcript/message/49970158#49970158}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_bdc:nn #1#2
+ { \__kernel_backend_literal_page:n { /#1 ~ #2 ~ BDC } }
+\cs_new_protected:Npn \@@_backend_emc:
+ { \__kernel_backend_literal_page:n { EMC } }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvipdfmx|xetex>
+% \end{macrocode}
+%
+% \subsection{\texttt{dvisvgm} backend}
+%
+% \begin{macrocode}
+%<*dvisvgm>
+% \end{macrocode}
+%
+% \subsubsection{Annotations}
+%
+% \begin{macro}{\@@_backend_annotation:nnnn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_annotation:nnnn #1#2#3#4 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_annotation_last:}
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_annotation_last: { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {\@@_backend_link_begin_goto:nnw, \@@_backend_link_begin_user:nnw}
+% \begin{macro}{\@@_backend_link_begin:nnnw}
+% \begin{macro}{\@@_backend_link_end:}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_link_begin_goto:nnw #1#2 { }
+\cs_new_protected:Npn \@@_backend_link_begin_user:nnw #1#2 { }
+\cs_new_protected:Npn \@@_backend_link_begin:nnnw #1#2#3 { }
+\cs_new_protected:Npn \@@_backend_link_end: { }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_link_last:}
+% \begin{macrocode}
+\cs_new:Npe \@@_backend_link_last: { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_link_margin:n}
+% A simple task: pass the data to the primitive.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_link_margin:n #1 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_destination:nn}
+% \begin{macro}{\@@_backend_destination:nnnn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_destination:nn #1#2 { }
+\cs_new_protected:Npn \@@_backend_destination:nnnn #1#2#3#4 { }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Catalogue entries}
+%
+% \begin{macro}{\@@_backend_catalog_gput:nn, \@@_backend_info_gput:nn}
+% No-op.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_catalog_gput:nn #1#2 { }
+\cs_new_protected:Npn \@@_backend_info_gput:nn #1#2 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \subsubsection{Objects}
+%
+% \begin{macro}{\@@_backend_object_new:}
+% \begin{macro}[EXP]{\@@_backend_object_ref:n, \@@_backend_object_id:n}
+% \begin{macro}{\@@_backend_object_write:nnn, \@@_backend_object_write:ne}
+% \begin{macro}{\@@_backend_object_now:nn, , \@@_backend_object_now:ne}
+% \begin{macro}{\@@_backend_object_last:}
+% \begin{macro}[EXP]{\@@_backend_pageobject_ref:n}
+% All no-ops here.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_object_new: { }
+\cs_new:Npn \@@_backend_object_ref:n #1 { }
+\cs_new:Npn \@@_backend_object_id:n #1 { }
+\cs_new_protected:Npn \@@_backend_object_write:nnn #1#2#3 { }
+\cs_new_protected:Npn \@@_backend_object_write:nne #1#2#3 { }
+\cs_new_protected:Npn \@@_backend_object_now:nn #1#2 { }
+\cs_new_protected:Npn \@@_backend_object_now:ne #1#2 { }
+\cs_new:Npn \@@_backend_object_last: { }
+\cs_new:Npn \@@_backend_pageobject_ref:n #1 { }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \subsubsection{Structure}
+%
+% \begin{macro}{\@@_backend_compresslevel:n}
+% \begin{macro}{\@@_backend_compress_objects:n}
+% These are all no-ops.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_compresslevel:n #1 { }
+\cs_new_protected:Npn \@@_backend_compress_objects:n #1 { }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}
+% {\@@_backend_version_major_gset:n, \@@_backend_version_minor_gset:n}
+% Data not available!
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_version_major_gset:n #1 { }
+\cs_new_protected:Npn \@@_backend_version_minor_gset:n #1 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}[EXP]{\@@_backend_version_major:, \@@_backend_version_minor:}
+% Data not available!
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_version_major: { -1 }
+\cs_new:Npn \@@_backend_version_minor: { -1 }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_bdc:nn}
+% \begin{macro}{\@@_backend_emc:}
+% More no-ops.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_bdc:nn #1#2 { }
+\cs_new_protected:Npn \@@_backend_emc: { }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvisvgm>
+% \end{macrocode}
+%
+% \subsection{PDF Page size (media box)}
+%
+% For setting the media box, the split between backends is somewhat different
+% to other areas, thus we approach this separately. The code here assumes a
+% recent \LaTeXe{}: that is ensured at the level above.
+%
+% \begin{macrocode}
+%<*dvipdfmx|dvips>
+% \end{macrocode}
+%
+% \begin{macro}{\@@_backend_pagesize_gset:nn}
+% This is done as a backend literal, so we deal with it using the shipout
+% hook.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_pagesize_gset:nn #1#2
+ {
+ \__kernel_backend_first_shipout:n
+ {
+ \__kernel_backend_literal:e
+ {
+%<*dvipdfmx>
+ pdf:pagesize ~
+ width ~ \dim_eval:n {#1} ~
+ height ~ \dim_eval:n {#2}
+%</dvipdfmx>
+%<*dvips>
+ papersize = \dim_eval:n {#1} , \dim_eval:n {#2}
+%</dvips>
+ }
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvipdfmx|dvips>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*luatex|pdftex|xetex>
+% \end{macrocode}
+%
+% \begin{macro}{\@@_backend_pagesize_gset:nn}
+% Pass to the primitives.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_pagesize_gset:nn #1#2
+ {
+ \dim_gset:Nn \tex_pagewidth:D {#1}
+ \dim_gset:Nn \tex_pageheight:D {#2}
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</luatex|pdftex|xetex>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*dvisvgm>
+% \end{macrocode}
+%
+% \begin{macro}{\@@_backend_pagesize_gset:nn}
+% A no-op.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_pagesize_gset:nn #1#2 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvisvgm>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%</package>
+% \end{macrocode}
+%
+% \end{implementation}
+%
+% \PrintIndex