summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/source/latex-dev/l3backend/l3backend-color.dtx
diff options
context:
space:
mode:
Diffstat (limited to 'Master/texmf-dist/source/latex-dev/l3backend/l3backend-color.dtx')
-rw-r--r--Master/texmf-dist/source/latex-dev/l3backend/l3backend-color.dtx1356
1 files changed, 1356 insertions, 0 deletions
diff --git a/Master/texmf-dist/source/latex-dev/l3backend/l3backend-color.dtx b/Master/texmf-dist/source/latex-dev/l3backend/l3backend-color.dtx
new file mode 100644
index 00000000000..307432d554f
--- /dev/null
+++ b/Master/texmf-dist/source/latex-dev/l3backend/l3backend-color.dtx
@@ -0,0 +1,1356 @@
+% \iffalse meta-comment
+%
+%% File: l3backend-color.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-color} module\\ Backend color support^^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-color} implementation}
+%
+% \begin{macrocode}
+%<*package>
+%<@@=color>
+% \end{macrocode}
+%
+% Color support is split into parts: collecting data from \LaTeXe{}, the color
+% stack, general color, separations, and color for drawings. We have different
+% approaches in each backend, and have some choices to make about
+% \texttt{dvipdfmx}/\XeTeX{} in particular. Whilst it is in some ways
+% convenient to use the same approach in multiple backends, the fact that
+% \texttt{dvipdfmx}/\XeTeX{} is PDF-based means it (largely) sticks closer to
+% direct PDF output.
+%
+% \subsection{The color stack}
+%
+% For PDF-based engines, we have a color stack available inside the specials.
+% This is used for concepts beyond color itself: it is needed to manage the
+% graphics state generally. Although \texttt{dvipdfmx}/\XeTeX{} have multiple
+% color stacks in recent releases, the way these interact with the original
+% single stack and with other graphic state operations means that currently it
+% is not feasible to use the multiple stacks.
+%
+% \subsubsection{Common code}
+%
+% \begin{macrocode}
+%<*luatex|pdftex>
+% \end{macrocode}
+%
+% \begin{variable}{\l_@@_backend_stack_int}
+% For tracking which stack is in use where multiple stacks are used:
+% currently just \pdfTeX{}/\LuaTeX{} but at some future stage may also cover
+% \texttt{dvipdfmx}/\XeTeX{}.
+% \begin{macrocode}
+\int_new:N \l_@@_backend_stack_int
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macrocode}
+%</luatex|pdftex>
+% \end{macrocode}
+%
+% \subsubsection{\LuaTeX and \pdfTeX{}}
+%
+% \begin{macrocode}
+%<*luatex|pdftex>
+% \end{macrocode}
+%
+% \begin{macro}{\__kernel_color_backend_stack_init:Nnn}
+% \begin{macrocode}
+\cs_new_protected:Npn \__kernel_color_backend_stack_init:Nnn #1#2#3
+ {
+ \int_const:Nn #1
+ {
+%<*luatex>
+ \tex_pdffeedback:D colorstackinit ~
+%</luatex>
+%<*pdftex>
+ \tex_pdfcolorstackinit:D
+%</pdftex>
+ \tl_if_blank:nF {#2} { #2 ~ }
+ {#3}
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\__kernel_color_backend_stack_push:nn}
+% \begin{macro}{\__kernel_color_backend_stack_pop:n}
+% \begin{macrocode}
+\cs_new_protected:Npn \__kernel_color_backend_stack_push:nn #1#2
+ {
+%<*luatex>
+ \tex_pdfextension:D colorstack ~
+%</luatex>
+%<*pdftex>
+ \tex_pdfcolorstack:D
+%</pdftex>
+ \int_eval:n {#1} ~ push ~ {#2}
+ }
+\cs_new_protected:Npn \__kernel_color_backend_stack_pop:n #1
+ {
+%<*luatex>
+ \tex_pdfextension:D colorstack ~
+%</luatex>
+%<*pdftex>
+ \tex_pdfcolorstack:D
+%</pdftex>
+ \int_eval:n {#1} ~ pop \scan_stop:
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macrocode}
+%</luatex|pdftex>
+% \end{macrocode}
+%
+% \subsection{General color}
+%
+% \subsubsection{\texttt{dvips}-style}
+%
+% \begin{macrocode}
+%<*dvips|dvisvgm>
+% \end{macrocode}
+%
+% \begin{macro}
+% {
+% \@@_backend_select_cmyk:n ,
+% \@@_backend_select_gray:n ,
+% \@@_backend_select_named:n ,
+% \@@_backend_select_rgb:n ,
+% \@@_backend_select:n
+% }
+% \begin{macro}{\@@_backend_reset:}
+% Push the data to the stack. In the case of \texttt{dvips} also saves the
+% drawing color in raw PostScript. The |spot| model is for handling data
+% in classical format.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_select_cmyk:n #1
+ { \@@_backend_select:n { cmyk ~ #1 } }
+\cs_new_protected:Npn \@@_backend_select_gray:n #1
+ { \@@_backend_select:n { gray ~ #1 } }
+\cs_new_protected:Npn \@@_backend_select_named:n #1
+ { \@@_backend_select:n { ~ #1 } }
+\cs_new_protected:Npn \@@_backend_select_rgb:n #1
+ { \@@_backend_select:n { rgb ~ #1 } }
+\cs_new_protected:Npn \@@_backend_select:n #1
+ {
+ \__kernel_backend_literal:n { color~push~ #1 }
+%<*dvips>
+ \__kernel_backend_postscript:n { /color.sc ~ { } ~ def }
+%</dvips>
+ }
+\cs_new_protected:Npn \@@_backend_reset:
+ { \__kernel_backend_literal:n { color~pop } }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvips|dvisvgm>
+% \end{macrocode}
+%
+% \subsubsection{\LuaTeX{} and \pdfTeX{}}
+%
+% \begin{macrocode}
+%<*luatex|pdftex>
+% \end{macrocode}
+%
+% \begin{variable}{\l_@@_backend_fill_tl, \l_@@_backend_stroke_tl}
+% \begin{macrocode}
+\tl_new:N \l_@@_backend_fill_tl
+\tl_new:N \l_@@_backend_stroke_tl
+\tl_set:Nn \l_@@_backend_fill_tl { 0 ~ g }
+\tl_set:Nn \l_@@_backend_stroke_tl { 0 ~ G }
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}
+% {
+% \@@_backend_select_cmyk:n ,
+% \@@_backend_select_gray:n ,
+% \@@_backend_select_rgb:n
+% }
+% \begin{macro}{\@@_backend_select:nn}
+% \begin{macro}{\@@_backend_reset:}
+% Store the values then pass to the stack.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_select_cmyk:n #1
+ { \@@_backend_select:nn { #1 ~ k } { #1 ~ K } }
+\cs_new_protected:Npn \@@_backend_select_gray:n #1
+ { \@@_backend_select:nn { #1 ~ g } { #1 ~ G } }
+\cs_new_protected:Npn \@@_backend_select_rgb:n #1
+ { \@@_backend_select:nn { #1 ~ rg } { #1 ~ RG } }
+\cs_new_protected:Npn \@@_backend_select:nn #1#2
+ {
+ \tl_set:Nn \l_@@_backend_fill_tl {#1}
+ \tl_set:Nn \l_@@_backend_stroke_tl {#2}
+ \__kernel_color_backend_stack_push:nn \l_@@_backend_stack_int { #1 ~ #2 }
+ }
+\cs_new_protected:Npn \@@_backend_reset:
+ { \__kernel_color_backend_stack_pop:n \l_@@_backend_stack_int }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macrocode}
+%</luatex|pdftex>
+% \end{macrocode}
+%
+% \subsubsection{\texttt{dvipmdfx}/\XeTeX{}}
+%
+% These backends have the most possible approaches: it recognises both
+% \texttt{dvips}-based color specials and its own format, plus one can
+% include PDF statements directly. Recent releases also have a color stack
+% approach similar to \pdfTeX{}. Of the stack methods, the dedicated
+% the most versatile is the latter as it can cover all of the use cases
+% we have. However, at present this interacts problematically with any color
+% on the original stack. We therefore stick to a single-stack approach here.
+%
+% \begin{macrocode}
+%<*dvipdfmx|xetex>
+% \end{macrocode}
+%
+% \begin{macro}
+% {
+% \@@_backend_select:n ,
+% \@@_backend_select_cmyk:n ,
+% \@@_backend_select_gray:n ,
+% \@@_backend_select_rgb:n
+% }
+% \begin{macro}{\@@_backend_reset:}
+% Using the single stack is relatively easy as there is only one route.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_select:n #1
+ { \__kernel_backend_literal:n { pdf : bc ~ [ #1 ] } }
+\cs_new_eq:NN \@@_backend_select_cmyk:n \@@_backend_select:n
+\cs_new_eq:NN \@@_backend_select_gray:n \@@_backend_select:n
+\cs_new_eq:NN \@@_backend_select_rgb:n \@@_backend_select:n
+\cs_new_protected:Npn \@@_backend_reset:
+ { \__kernel_backend_literal:n { pdf : ec } }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_select_named:n}
+% For classical named colors, the only value we should get is |Black|.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_select_named:n #1
+ {
+ \str_if_eq:nnTF {#1} { Black }
+ { \@@_backend_select_gray:n { 0 } }
+ { \msg_error:nnn { color } { unknown-named-color } {#1} }
+ }
+\msg_new:nnn { color } { unknown-named-color }
+ { Named~color~'#1'~is~not~known. }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvipdfmx|xetex>
+% \end{macrocode}
+%
+% \subsection{Separations}
+%
+% Here, life gets interesting and we need essentially one approach per
+% backend.
+%
+% \begin{macrocode}
+%<*dvipdfmx|luatex|pdftex|xetex|dvips>
+% \end{macrocode}
+%
+% But we start with some functionality needed for both PostScript and
+% PDF based backends.
+%
+% \begin{variable}{\g_@@_backend_colorant_prop}
+% \begin{macrocode}
+\prop_new:N \g_@@_backend_colorant_prop
+% \end{macrocode}
+% \end{variable}
+%
+% \begin{macro}[EXP]{\@@_backend_devicen_colorants:n}
+% \begin{macro}[EXP]{\@@_backend_devicen_colorants:w}
+% \begin{macrocode}
+\cs_new:Npe \@@_backend_devicen_colorants:n #1
+ {
+ \exp_not:N \tl_if_blank:nF {#1}
+ {
+ \c_space_tl
+ << ~
+ /Colorants ~
+ << ~
+ \exp_not:N \@@_backend_devicen_colorants:w #1 ~
+ \exp_not:N \q_recursion_tail \c_space_tl
+ \exp_not:N \q_recursion_stop
+ >> ~
+ >>
+ }
+ }
+\cs_new:Npn \@@_backend_devicen_colorants:w #1 ~
+ {
+ \quark_if_recursion_tail_stop:n {#1}
+ \prop_if_in:NnT \g_@@_backend_colorant_prop {#1}
+ {
+ #1 ~
+ \prop_item:Nn \g_@@_backend_colorant_prop {#1} ~
+ }
+ \@@_backend_devicen_colorants:w
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvipdfmx|luatex|pdftex|xetex|dvips>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*dvips>
+% \end{macrocode}
+%
+% \begin{macro}{\@@_backend_select_separation:nn, \@@_backend_select_devicen:nn}
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_select_separation:nn #1#2
+ { \@@_backend_select:n { separation ~ #1 ~ #2 } }
+\cs_new_eq:NN \@@_backend_select_devicen:nn \@@_backend_select_separation:nn
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_select_iccbased:nn}
+% No support.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_select_iccbased:nn #1#2 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {
+% \@@_backend_separation_init:nnnnn,
+% \@@_backend_separation_init:neenn
+% }
+% \begin{macro}
+% {\@@_backend_separation_init_aux:nnnnnn}
+% \begin{macro}[EXP]
+% {
+% \@@_backend_separation_init_/DeviceCMYK:nnn ,
+% \@@_backend_separation_init_/DeviceGray:nnn ,
+% \@@_backend_separation_init_/DeviceRGB:nnn
+% }
+% \begin{macro}[EXP]{\@@_backend_separation_init_Device:Nn}
+% \begin{macro}[EXP]{\@@_backend_separation_init:nnn}
+% \begin{macro}[EXP]{\@@_backend_separation_init_count:n}
+% \begin{macro}[EXP]{\@@_backend_separation_init_count:w}
+% \begin{macro}[EXP]{\@@_backend_separation_init:nnnn}
+% \begin{macro}[EXP]{\@@_backend_separation_init:w}
+% \begin{macro}[EXP]{\@@_backend_separation_init:n}
+% \begin{macro}[EXP]{\@@_backend_separation_init:nw}
+% \begin{macro}{\@@_backend_separation_init_CIELAB:nnn}
+% Initialising here means creating a small header set up plus massaging
+% some data. This comes about as we have to deal with PDF-focussed data,
+% which makes most sense \enquote{higher-up}. The approach is based on
+% ideas from \url{https://tex.stackexchange.com/q/560093} plus using
+% the PostScript manual for other aspects.
+% \begin{macrocode}
+\cs_new_protected:Npe \@@_backend_separation_init:nnnnn #1#2#3#4#5
+ {
+ \bool_if:NT \g__kernel_backend_header_bool
+ {
+ \exp_not:N \exp_args:Ne \__kernel_backend_first_shipout:n
+ {
+ \exp_not:N \@@_backend_separation_init_aux:nnnnnn
+ { \exp_not:N \int_use:N \g_@@_model_int }
+ {#1} {#2} {#3} {#4} {#5}
+ }
+ \prop_gput:Nee \exp_not:N \g_@@_backend_colorant_prop
+ { / \exp_not:N \str_convert_pdfname:n {#1} }
+ {
+ << ~
+ /setcolorspace ~ {} ~
+ >> ~ begin ~
+ color \exp_not:N \int_use:N \g_@@_model_int \c_space_tl
+ end
+ }
+ }
+ }
+\cs_generate_variant:Nn \@@_backend_separation_init:nnnnn { nee }
+\cs_new_protected:Npn \@@_backend_separation_init_aux:nnnnnn #1#2#3#4#5#6
+ {
+ \__kernel_backend_literal:e
+ {
+ !
+ TeXDict ~ begin ~
+ /color #1
+ {
+ [ ~
+ /Separation ~ ( \str_convert_pdfname:n {#2} ) ~
+ [ ~ #3 ~ ] ~
+ {
+ \cs_if_exist_use:cF { @@_backend_separation_init_ #3 :nnn }
+ { \@@_backend_separation_init:nnn }
+ {#4} {#5} {#6}
+ }
+ ] ~ setcolorspace
+ } ~ def ~
+ end
+ }
+ }
+\cs_new:cpn { @@_backend_separation_init_ /DeviceCMYK :nnn } #1#2#3
+ { \@@_backend_separation_init_Device:Nn 4 {#3} }
+\cs_new:cpn { @@_backend_separation_init_ /DeviceGray :nnn } #1#2#3
+ { \@@_backend_separation_init_Device:Nn 1 {#3} }
+\cs_new:cpn { @@_backend_separation_init_ /DeviceRGB :nnn } #1#2#3
+ { \@@_backend_separation_init_Device:Nn 2 {#3} }
+\cs_new:Npn \@@_backend_separation_init_Device:Nn #1#2
+ {
+ #2 ~
+ \prg_replicate:nn {#1}
+ { #1 ~ index ~ mul ~ #1 ~ 1 ~ roll ~ }
+ \int_eval:n { #1 + 1 } ~ -1 ~ roll ~ pop
+ }
+% \end{macrocode}
+% For the generic case, we cannot use |/FunctionType 2| unfortunately, so
+% we have to code that idea up in PostScript. Here, we will therefore assume
+% that a range is \emph{always} given. First, we count values in each argument:
+% at the backend level, we can assume there are always well-behaved with
+% spaces present.
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_separation_init:nnn #1#2#3
+ {
+ \exp_args:Ne \@@_backend_separation_init:nnnn
+ { \@@_backend_separation_init_count:n {#2} }
+ {#1} {#2} {#3}
+ }
+\cs_new:Npn \@@_backend_separation_init_count:n #1
+ { \int_eval:n { 0 \@@_backend_separation_init_count:w #1 ~ \s_@@_stop } }
+\cs_new:Npn \@@_backend_separation_init_count:w #1 ~ #2 \s_@@_stop
+ {
+ +1
+ \tl_if_blank:nF {#2}
+ { \@@_backend_separation_init_count:w #2 \s_@@_stop }
+ }
+% \end{macrocode}
+% Now we implement the algorithm. In the terms in the PostScript manual,
+% we have $\mathbf{N} = 1$ and $\mathbf{Domain} = [0~1]$, with
+% $\mathbf{Range}$ as |#2|, $\mathbf{C0}$ as |#3| and $\mathbf{C1}$
+% as |#4|, with the number of output components in |#1|. So all we have
+% to do is implement $y_{i} = \mathbf{C0}_{i} + x(\mathbf{C1}_{i} -
+% \mathbf{C0}_{i})$ with lots of stack manipulation, then check the
+% ranges. That's done by adding everything to the stack first, then using
+% the fact we know all of the offsets. As manipulating the stack is tricky,
+% we start by re-formatting the $\mathbf{C0}$ and $\mathbf{C1}$ arrays to
+% be interleaved, and add a \texttt{0} to each pair: this is used
+% to keep the stack of constant length while we are doing the first pass of
+% mathematics. We then working through that list, calculating from the
+% last to the first value before tidying up by removing all of the input
+% values. We do that by first copying all of the final $y$ values to the
+% end of the stack, then rolling everything so we can pop the now-unneeded
+% material.
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_separation_init:nnnn #1#2#3#4
+ {
+ \@@_backend_separation_init:w #3 ~ \s_@@_stop #4 ~ \s_@@_stop
+ \prg_replicate:nn {#1}
+ {
+ pop ~ 1 ~ index ~ neg ~ 1 ~ index ~ add ~
+ \int_eval:n { 3 * #1 } ~ index ~ mul ~
+ 2 ~ index ~ add ~
+ \int_eval:n { 3 * #1 } ~ #1 ~ roll ~
+ }
+ \int_step_function:nnnN {#1} { -1 } { 1 }
+ \@@_backend_separation_init:n
+ \int_eval:n { 4 * #1 + 1 } ~ #1 ~ roll ~
+ \prg_replicate:nn { 3 * #1 + 1 } { pop ~ }
+ \tl_if_blank:nF {#2}
+ { \@@_backend_separation_init:nw {#1} #2 ~ \s_@@_stop }
+ }
+\cs_new:Npn \@@_backend_separation_init:w
+ #1 ~ #2 \s_@@_stop #3 ~ #4 \s_@@_stop
+ {
+ #1 ~ #3 ~ 0 ~
+ \tl_if_blank:nF {#2}
+ { \@@_backend_separation_init:w #2 \s_@@_stop #4 \s_@@_stop }
+ }
+\cs_new:Npn \@@_backend_separation_init:n #1
+ { \int_eval:n { #1 * 2 } ~ index ~ }
+% \end{macrocode}
+% Finally, we deal with the range limit if required. This is handled
+% by splitting the range into pairs. It's then just a question of doing
+% the comparisons, this time dropping everything except the desired
+% result.
+% \begin{macrocode}
+\cs_new:Npn \@@_backend_separation_init:nw #1#2 ~ #3 ~ #4 \s_@@_stop
+ {
+ #2 ~ #3 ~
+ 2 ~ index ~ 2 ~ index ~ lt ~
+ { ~ pop ~ exch ~ pop ~ } ~
+ { ~
+ 2 ~ index ~ 1 ~ index ~ gt ~
+ { ~ exch ~ pop ~ exch ~ pop ~ } ~
+ { ~ pop ~ pop ~ } ~
+ ifelse ~
+ }
+ ifelse ~
+ #1 ~ 1 ~ roll ~
+ \tl_if_blank:nF {#4}
+ { \@@_backend_separation_init:nw {#1} #4 \s_@@_stop }
+ }
+% \end{macrocode}
+% CIELAB support uses the detail from the PostScript reference, page 227;
+% other than that block of PostScript, this is the same as for PDF-based
+% routes.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_separation_init_CIELAB:nnn #1#2#3
+ {
+ \@@_backend_separation_init:neenn
+ {#2}
+ {
+ /CIEBasedABC ~
+ << ~
+ /RangeABC ~ [ ~ \c_@@_model_range_CIELAB_tl \c_space_tl ] ~
+ /DecodeABC ~
+ [ ~
+ { ~ 16 ~ add ~ 116 ~ div ~ } ~ bind ~
+ { ~ 500 ~ div ~ } ~ bind ~
+ { ~ 200 ~ div ~ } ~ bind ~
+ ] ~
+ /MatrixABC ~ [ ~ 1 ~ 1 ~ 1 ~ 1 ~ 0 ~ 0 ~ 0 ~ 0 ~ -1 ~ ] ~
+ /DecodeLMN ~
+ [ ~
+ { ~
+ dup ~ 6 ~ 29 ~ div ~ ge ~
+ { ~ dup ~ dup ~ mul ~ mul ~ ~ } ~
+ { ~ 4 ~ 29 ~ div ~ sub ~ 108 ~ 841 ~ div ~ mul ~ } ~
+ ifelse ~
+ 0.9505 ~ mul ~
+ } ~ bind ~
+ { ~
+ dup ~ 6 ~ 29 ~ div ~ ge ~
+ { ~ dup ~ dup ~ mul ~ mul ~ } ~
+ { ~ 4 ~ 29 ~ div ~ sub ~ 108 ~ 841 ~ div ~ mul ~ } ~
+ ifelse ~
+ } ~ bind ~
+ { ~
+ dup ~ 6 ~ 29 ~ div ~ ge ~
+ { ~ dup ~ dup ~ mul ~ mul ~ } ~
+ { ~ 4 ~ 29 ~ div ~ sub ~ 108 ~ 841 ~ div ~ mul ~ } ~
+ ifelse ~
+ 1.0890 ~ mul ~
+ } ~ bind
+ ] ~
+ /WhitePoint ~
+ [ ~ \tl_use:c { c_@@_model_whitepoint_CIELAB_ #1 _tl } ~ ] ~
+ >>
+ }
+ { \c_@@_model_range_CIELAB_tl }
+ { 100 ~ 0 ~ 0 }
+ {#3}
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_devicen_init:nnn}
+% Trivial as almost all of the work occurs in the shared code.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_devicen_init:nnn #1#2#3
+ {
+ \__kernel_backend_literal:e
+ {
+ !
+ TeXDict ~ begin ~
+ /color \int_use:N \g_@@_model_int
+ {
+ [ ~
+ /DeviceN ~
+ [ ~ #1 ~ ] ~
+ #2 ~
+ { ~ #3 ~ } ~
+ \@@_backend_devicen_colorants:n {#1}
+ ] ~ setcolorspace
+ } ~ def ~
+ end
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_iccbased_init:nnn}
+% No support at present.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_iccbased_init:nnn #1#2#3 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvips>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*dvisvgm>
+% \end{macrocode}
+%
+% \begin{macro}
+% {
+% \@@_backend_select_separation:nn,
+% \@@_backend_select_devicen:nn
+% }
+% No support at present.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_select_separation:nn #1#2 { }
+\cs_new_eq:NN \@@_backend_select_devicen:nn \@@_backend_select_separation:nn
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {\@@_backend_separation_init:nnnnn, \@@_backend_separation_init_CIELAB:nnn}
+% No support at present.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_separation_init:nnnnn #1#2#3#4#5 { }
+\cs_new_protected:Npn \@@_backend_separation_init_CIELAB:nnnnnn #1#2#3 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_select_iccbased:nn}
+% As detailed in \url{https://www.w3.org/TR/css-color-4/#at-profile},
+% we can apply a color profile using CSS. As we have a local file, we use
+% a relative URL.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_select_iccbased:nn #1#2
+ {
+ \__kernel_backend_literal_svg:e
+ {
+ <style>
+ @color-profile ~
+ \str_if_eq:nnTF {#2} { cmyk }
+ { device-cmyk }
+ { --color \int_use:N \g_@@_model_int }
+ \c_space_tl
+ {
+ src:("#1")
+ }
+ </style>
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvisvgm>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*dvipdfmx|luatex|pdftex|xetex>
+% \end{macrocode}
+%
+% \begin{macro}
+% {
+% \@@_backend_select_separation:nn,
+% \@@_backend_select_devicen:nn ,
+% \@@_backend_select_iccbased:nn
+% }
+% \begin{macrocode}
+%<*dvipdfmx|xetex>
+\cs_new_protected:Npn \@@_backend_select_separation:nn #1#2
+ { \__kernel_backend_literal:e { pdf : bc ~ \pdf_object_ref:n {#1} ~ [ #2 ] } }
+%</dvipdfmx|xetex>
+%<*luatex|pdftex>
+\cs_new_protected:Npn \@@_backend_select_separation:nn #1#2
+ { \@@_backend_select:nn { /#1 ~ cs ~ #2 ~ scn } { /#1 ~ CS ~ #2 ~ SCN } }
+%</luatex|pdftex>
+\cs_new_eq:NN \@@_backend_select_devicen:nn \@@_backend_select_separation:nn
+\cs_new_eq:NN \@@_backend_select_iccbased:nn \@@_backend_select_separation:nn
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_init_resource:n}
+% Resource initiation comes up a few times. For \texttt{dvipdfmx}/\XeTeX{},
+% we skip this as at present it's handled by the backend.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_init_resource:n #1
+ {
+%<*luatex|pdftex>
+ \bool_lazy_and:nnT
+ { \cs_if_exist_p:N \pdfmanagement_if_active_p: }
+ { \pdfmanagement_if_active_p: }
+ {
+ \use:e
+ {
+ \pdfmanagement_add:nnn
+ { Page / Resources / ColorSpace }
+ { #1 }
+ { \pdf_object_ref_last: }
+ }
+ }
+%</luatex|pdftex>
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_separation_init:nnnnn}
+% \begin{macro}{\@@_backend_separation_init:nn}
+% \begin{macro}{\@@_backend_separation_init_CIELAB:nnn}
+% Initialising the PDF structures needs two parts: creating an object
+% containing the \enquote{real} name of the Separation, then adding a reference
+% to that to each page. We use a separate object for the tint transformation
+% following the model in the PDF reference. The object here for the color
+% needs to be named as that way it's accessible to
+% \texttt{dvipdfmx}/\XeTeX{}.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_separation_init:nnnnn #1#2#3#4#5
+ {
+ \pdf_object_unnamed_write:ne { dict }
+ {
+ /FunctionType ~ 2
+ /Domain ~ [0 ~ 1]
+ \tl_if_blank:nF {#3} { /Range ~ [#3] }
+ /C0 ~ [#4] ~
+ /C1 ~ [#5] /N ~ 1
+ }
+ \exp_args:Ne \@@_backend_separation_init:nn
+ { \str_convert_pdfname:n {#1} } {#2}
+ \@@_backend_init_resource:n { color \int_use:N \g_@@_model_int }
+ }
+\cs_new_protected:Npn \@@_backend_separation_init:nn #1#2
+ {
+ \use:e
+ {
+ \pdf_object_new:n { color \int_use:N \g_@@_model_int }
+ \pdf_object_write:nnn { color \int_use:N \g_@@_model_int } { array }
+ { /Separation /#1 ~ #2 ~ \pdf_object_ref_last: }
+ }
+ \prop_gput:Nne \g_@@_backend_colorant_prop { /#1 }
+ { \pdf_object_ref_last: }
+ }
+% \end{macrocode}
+% For CIELAB colors, we need one object per document for the illuminant,
+% plus initialisation of the color space referencing that object.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_separation_init_CIELAB:nnn #1#2#3
+ {
+ \pdf_object_if_exist:nF { @@_illuminant_CIELAB_ #1 }
+ {
+ \pdf_object_new:n { @@_illuminant_CIELAB_ #1 }
+ \pdf_object_write:nne { @@_illuminant_CIELAB_ #1 } { array }
+ {
+ /Lab ~
+ <<
+ /WhitePoint ~
+ [ \tl_use:c { c_@@_model_whitepoint_CIELAB_ #1 _tl } ]
+ /Range ~ [ \c_@@_model_range_CIELAB_tl ]
+ >>
+ }
+ }
+ \@@_backend_separation_init:nnnnn
+ {#2}
+ { \pdf_object_ref:n { @@_illuminant_CIELAB_ #1 } }
+ { \c_@@_model_range_CIELAB_tl }
+ { 100 ~ 0 ~ 0 }
+ {#3}
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_devicen_init:nnn}
+% \begin{macro}[EXP]{\@@_backend_devicen_init:w}
+% Similar to the Separations case, but with an arbitrary function for
+% the alternative space work.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_devicen_init:nnn #1#2#3
+ {
+ \pdf_object_unnamed_write:ne { stream }
+ {
+ {
+ /FunctionType ~ 4 ~
+ /Domain ~
+ [ ~
+ \prg_replicate:nn
+ { 0 \@@_backend_devicen_init:w #1 ~ \s_@@_stop }
+ { 0 ~ 1 ~ }
+ ] ~
+ /Range ~
+ [ ~
+ \str_case:nn {#2}
+ {
+ { /DeviceCMYK } { 0 ~ 1 ~ 0 ~ 1 ~ 0 ~ 1 ~ 0 ~ 1 }
+ { /DeviceGray } { 0 ~ 1 }
+ { /DeviceRGB } { 0 ~ 1 ~ 0 ~ 1 ~ 0 ~ 1 }
+ } ~
+ ]
+ }
+ { {#3} }
+ }
+ \use:e
+ {
+ \pdf_object_new:n { color \int_use:N \g_@@_model_int }
+ \pdf_object_write:nnn { color \int_use:N \g_@@_model_int } { array }
+ {
+ /DeviceN ~
+ [ ~ #1 ~ ] ~
+ #2 ~
+ \pdf_object_ref_last:
+ \@@_backend_devicen_colorants:n {#1}
+ }
+ }
+ \@@_backend_init_resource:n { color \int_use:N \g_@@_model_int }
+ }
+\cs_new:Npn \@@_backend_devicen_init:w #1 ~ #2 \s_@@_stop
+ {
+ + 1
+ \tl_if_blank:nF {#2}
+ { \@@_backend_devicen_init:w #2 \s_@@_stop }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_iccbased_init:nnn}
+% Lots of data to save here: we only want to do that once per file,
+% so track it by name.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_iccbased_init:nnn #1#2#3
+ {
+ \pdf_object_if_exist:nF { @@_icc_ #1 }
+ {
+ \pdf_object_new:n { @@_icc_ #1 }
+ \pdf_object_write:nne { @@_icc_ #1 } { fstream }
+ {
+ {
+ /N ~ \exp_not:n { #2 } ~
+ \tl_if_empty:nF { #3 } { /Range~[ #3 ] }
+ }
+ {#1}
+ }
+ }
+ \pdf_object_unnamed_write:ne { array }
+ { /ICCBased ~ \pdf_object_ref:n { @@_icc_ #1 } }
+ \@@_backend_init_resource:n { color \int_use:N \g_@@_model_int }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_iccbased_device:nnn}
+% This is very similar to setting up a color space: the only part we
+% add to the page resources differently.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_iccbased_device:nnn #1#2#3
+ {
+ \pdf_object_if_exist:nF { @@_icc_ #1 }
+ {
+ \pdf_object_new:n { @@_icc_ #1 }
+ \pdf_object_write:nnn { @@_icc_ #1 } { fstream }
+ {
+ { /N ~ #3 }
+ {#1}
+ }
+ }
+ \pdf_object_unnamed_write:ne { array }
+ { /ICCBased ~ \pdf_object_ref:n { @@_icc_ #1 } }
+ \@@_backend_init_resource:n { Default #2 }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvipdfmx|luatex|pdftex|xetex>
+% \end{macrocode}
+%
+% \subsection{Fill and stroke color}
+%
+% Here, \texttt{dvipdfmx}/\XeTeX{} we write direct PDF specials for the fill,
+% and only use the stack for the stroke color (see above for comments on why
+% we cannot use multiple stacks with these backends). \LuaTeX{} and \pdfTeX{}
+% have mutiple stacks that can deal with fill and stroke. For \texttt{dvips}
+% we have to manage fill and stroke color ourselves. We also handle
+% \texttt{dvisvgm} independently, as there we can create SVG directly.
+%
+% \begin{macrocode}
+%<*dvipdfmx|xetex>
+% \end{macrocode}
+%
+% \begin{macro}
+% {
+% \@@_backend_fill:n ,
+% \@@_backend_fill_cmyk:n ,
+% \@@_backend_fill_gray:n ,
+% \@@_backend_fill_rgb:n ,
+% \@@_backend_stroke:n ,
+% \@@_backend_stroke_cmyk:n ,
+% \@@_backend_stroke_gray:n ,
+% \@@_backend_stroke_rgb:n
+% }
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_fill:n #1
+ { \__kernel_backend_literal:n { pdf : bc ~ fill ~ [ #1 ] } }
+\cs_new_eq:NN \@@_backend_fill_cmyk:n \@@_backend_fill:n
+\cs_new_eq:NN \@@_backend_fill_gray:n \@@_backend_fill:n
+\cs_new_eq:NN \@@_backend_fill_rgb:n \@@_backend_fill:n
+\cs_new_protected:Npn \@@_backend_stroke:n #1
+ { \__kernel_backend_literal:n { pdf : bc ~ stroke ~ [ #1 ] } }
+\cs_new_eq:NN \@@_backend_stroke_cmyk:n \@@_backend_stroke:n
+\cs_new_eq:NN \@@_backend_stroke_gray:n \@@_backend_stroke:n
+\cs_new_eq:NN \@@_backend_stroke_rgb:n \@@_backend_stroke:n
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {
+% \@@_backend_fill_separation:nn,
+% \@@_backend_stroke_separation:nn,
+% \@@_backend_fill_devicen:nn,
+% \@@_backend_stroke_devicen:nn
+% }
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_fill_separation:nn #1#2
+ {
+ \__kernel_backend_literal:e
+ { pdf : bc ~ fill ~ \pdf_object_ref:n {#1} ~ [ #2 ] }
+ }
+\cs_new_protected:Npn \@@_backend_stroke_separation:nn #1#2
+ {
+ \__kernel_backend_literal:e
+ { pdf : bc ~ stroke ~ \pdf_object_ref:n {#1} ~ [ #2 ] }
+ }
+\cs_new_eq:NN \@@_backend_fill_devicen:nn \@@_backend_fill_separation:nn
+\cs_new_eq:NN \@@_backend_stroke_devicen:nn \@@_backend_stroke_separation:nn
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_fill_reset:, \@@_backend_stroke_reset:}
+% \begin{macrocode}
+\cs_new_eq:NN \@@_backend_fill_reset: \@@_backend_reset:
+\cs_new_eq:NN \@@_backend_stroke_reset: \@@_backend_reset:
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvipdfmx|xetex>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*luatex|pdftex>
+% \end{macrocode}
+%
+% \begin{macro}
+% {
+% \@@_backend_fill_cmyk:n ,
+% \@@_backend_fill_gray:n ,
+% \@@_backend_fill_rgb:n ,
+% \@@_backend_fill:n ,
+% \@@_backend_stroke_cmyk:n ,
+% \@@_backend_stroke_gray:n ,
+% \@@_backend_stroke_rgb:n ,
+% \@@_backend_stroke:n
+% }
+% Drawing (fill/stroke) color is handled in \texttt{dvipdfmx}/\XeTeX{} in the
+% same way as \LuaTeX{}/\pdfTeX{}. We use the same approach as earlier, except the
+% color stack is not involved so the generic direct PDF operation is used.
+% There is no worry about the nature of strokes: everything is handled
+% automatically.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_fill_cmyk:n #1
+ { \@@_backend_fill:n { #1 ~ k } }
+\cs_new_protected:Npn \@@_backend_fill_gray:n #1
+ { \@@_backend_fill:n { #1 ~ g } }
+\cs_new_protected:Npn \@@_backend_fill_rgb:n #1
+ { \@@_backend_fill:n { #1 ~ rg } }
+\cs_new_protected:Npn \@@_backend_fill:n #1
+ {
+ \tl_set:Nn \l_@@_backend_fill_tl {#1}
+ \__kernel_color_backend_stack_push:nn \l_@@_backend_stack_int
+ { #1 ~ \l_@@_backend_stroke_tl }
+ }
+\cs_new_protected:Npn \@@_backend_stroke_cmyk:n #1
+ { \@@_backend_stroke:n { #1 ~ K } }
+\cs_new_protected:Npn \@@_backend_stroke_gray:n #1
+ { \@@_backend_stroke:n { #1 ~ G } }
+\cs_new_protected:Npn \@@_backend_stroke_rgb:n #1
+ { \@@_backend_stroke:n { #1 ~ RG } }
+\cs_new_protected:Npn \@@_backend_stroke:n #1
+ {
+ \tl_set:Nn \l_@@_backend_stroke_tl {#1}
+ \__kernel_color_backend_stack_push:nn \l_@@_backend_stack_int
+ { \l_@@_backend_fill_tl \c_space_tl #1 }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {
+% \@@_backend_fill_separation:nn,
+% \@@_backend_stroke_separation:nn,
+% \@@_backend_fill_devicen:nn,
+% \@@_backend_stroke_devicen:nn
+% }
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_fill_separation:nn #1#2
+ { \@@_backend_fill:n { /#1 ~ cs ~ #2 ~ scn } }
+\cs_new_protected:Npn \@@_backend_stroke_separation:nn #1#2
+ { \@@_backend_stroke:n { /#1 ~ CS ~ #2 ~ SCN } }
+\cs_new_eq:NN \@@_backend_fill_devicen:nn \@@_backend_fill_separation:nn
+\cs_new_eq:NN \@@_backend_stroke_devicen:nn \@@_backend_stroke_separation:nn
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_fill_reset:, \@@_backend_stroke_reset:}
+% \begin{macrocode}
+\cs_new_eq:NN \@@_backend_fill_reset: \@@_backend_reset:
+\cs_new_eq:NN \@@_backend_stroke_reset: \@@_backend_reset:
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</luatex|pdftex>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*dvips>
+% \end{macrocode}
+%
+% \begin{macro}
+% {
+% \@@_backend_fill_cmyk:n ,
+% \@@_backend_fill_gray:n ,
+% \@@_backend_fill_rgb:n ,
+% \@@_backend_fill:n ,
+% \@@_backend_stroke_cmyk:n ,
+% \@@_backend_stroke_gray:n ,
+% \@@_backend_stroke_rgb:n
+% }
+% Fill color here is the same as general color \emph{except} we skip the
+% stroke part.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_fill_cmyk:n #1
+ { \@@_backend_fill:n { cmyk ~ #1 } }
+\cs_new_protected:Npn \@@_backend_fill_gray:n #1
+ { \@@_backend_fill:n { gray ~ #1 } }
+\cs_new_protected:Npn \@@_backend_fill_rgb:n #1
+ { \@@_backend_fill:n { rgb ~ #1 } }
+\cs_new_protected:Npn \@@_backend_fill:n #1
+ {
+ \__kernel_backend_literal:n { color~push~ #1 }
+ }
+\cs_new_protected:Npn \@@_backend_stroke_cmyk:n #1
+ { \__kernel_backend_postscript:n { /color.sc { #1 ~ setcmykcolor } def } }
+\cs_new_protected:Npn \@@_backend_stroke_gray:n #1
+ { \__kernel_backend_postscript:n { /color.sc { #1 ~ setgray } def } }
+\cs_new_protected:Npn \@@_backend_stroke_rgb:n #1
+ { \__kernel_backend_postscript:n { /color.sc { #1 ~ setrgbcolor } def } }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}
+% {
+% \@@_backend_fill_separation:nn,
+% \@@_backend_stroke_separation:nn,
+% \@@_backend_fill_devicen:nn,
+% \@@_backend_stroke_devicen:nn
+% }
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_fill_separation:nn #1#2
+ { \@@_backend_fill:n { separation ~ #1 ~ #2 } }
+\cs_new_protected:Npn \@@_backend_stroke_separation:nn #1#2
+ { \__kernel_backend_postscript:n { /color.sc { separation ~ #1 ~ #2 } def } }
+\cs_new_eq:NN \@@_backend_fill_devicen:nn \@@_backend_fill_separation:nn
+\cs_new_eq:NN \@@_backend_stroke_devicen:nn \@@_backend_stroke_separation:nn
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_fill_reset:, \@@_backend_stroke_reset:}
+% \begin{macrocode}
+\cs_new_eq:NN \@@_backend_fill_reset: \@@_backend_reset:
+\cs_new_protected:Npn \@@_backend_stroke_reset: { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvips>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*dvisvgm>
+% \end{macrocode}
+%
+% \begin{macro}
+% {
+% \@@_backend_fill_cmyk:n ,
+% \@@_backend_fill_gray:n ,
+% \@@_backend_fill_rgb:n ,
+% \@@_backend_fill:n
+% }
+% Fill color here is the same as general color \emph{except} we skip the
+% stroke part.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_fill_cmyk:n #1
+ { \@@_backend_fill:n { cmyk ~ #1 } }
+\cs_new_protected:Npn \@@_backend_fill_gray:n #1
+ { \@@_backend_fill:n { gray ~ #1 } }
+\cs_new_protected:Npn \@@_backend_fill_rgb:n #1
+ { \@@_backend_fill:n { rgb ~ #1 } }
+\cs_new_protected:Npn \@@_backend_fill:n #1
+ {
+ \__kernel_backend_literal:n { color~push~ #1 }
+ }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_stroke_cmyk:n}
+% \begin{macro}{\@@_backend_stroke_cmyk:w}
+% \begin{macro}{\@@_backend_stroke_gray:n, \@@_backend_stroke_gray_aux:n}
+% \begin{macro}{\@@_backend_stroke_rgb:n}
+% \begin{macro}{\@@_backend_stroke_rgb:w}
+% \begin{macro}{\@@_backend:nnn}
+% For drawings in SVG, we use scopes for all stroke colors. That
+% requires using \texttt{RGB} values, which luckily are easy to
+% convert here (|cmyk| to |RGB| is a fixed function).
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_stroke_cmyk:n #1
+ { \@@_backend_cmyk:w #1 \s_@@_stop }
+\cs_new_protected:Npn \@@_backend_stroke_cmyk:w
+ #1 ~ #2 ~ #3 ~ #4 \s_@@_stop
+ {
+ \use:e
+ {
+ \@@_backend:nnn
+ { \fp_eval:n { -100 * ( 1 - min ( 1 , #1 + #4 ) ) } }
+ { \fp_eval:n { -100 * ( 1 - min ( 1 , #2 + #4 ) ) } }
+ { \fp_eval:n { -100 * ( 1 - min ( 1 , #3 + #4 ) ) } }
+ }
+ }
+\cs_new_protected:Npn \@@_backend_stroke_gray:n #1
+ {
+ \use:e
+ {
+ \@@_backend_stroke_gray_aux:n
+ { \fp_eval:n { 100 * (#1) } }
+ }
+ }
+\cs_new_protected:Npn \@@_backend_stroke_gray_aux:n #1
+ { \@@_backend:nnn {#1} {#1} {#1} }
+\cs_new_protected:Npn \@@_backend_stroke_rgb:n #1
+ { \@@_backend_rgb:w #1 \s_@@_stop }
+\cs_new_protected:Npn \@@_backend_stroke_rgb:w
+ #1 ~ #2 ~ #3 \s_@@_stop
+ {
+ \use:e
+ {
+ \@@_backend:nnn
+ { \fp_eval:n { 100 * (#1) } }
+ { \fp_eval:n { 100 * (#2) } }
+ { \fp_eval:n { 100 * (#3) } }
+ }
+ }
+\cs_new_protected:Npe \@@_backend:nnn #1#2#3
+ {
+ \__kernel_backend_scope:n
+ {
+ stroke =
+ "
+ rgb
+ (
+ #1 \c_percent_str ,
+ #2 \c_percent_str ,
+ #3 \c_percent_str
+ )
+ "
+ }
+ }
+% \end{macrocode}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+% \end{macro}
+%
+% \begin{macro}
+% {
+% \@@_backend_fill_separation:nn,
+% \@@_backend_stroke_separation:nn,
+% \@@_backend_fill_devicen:nn,
+% \@@_backend_stroke_devicen:nn
+% }
+% At present, these are no-ops.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_fill_separation:nn #1#2 { }
+\cs_new_protected:Npn \@@_backend_stroke_separation:nn #1#2 { }
+\cs_new_eq:NN \@@_backend_fill_devicen:nn \@@_backend_fill_separation:nn
+\cs_new_eq:NN \@@_backend_stroke_devicen:nn \@@_backend_stroke_separation:nn
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_fill_reset:, \@@_backend_stroke_reset:}
+% \begin{macrocode}
+\cs_new_eq:NN \@@_backend_fill_reset: \@@_backend_reset:
+\cs_new_protected:Npn \@@_backend_stroke_reset: { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\@@_backend_devicen_init:nnn, \@@_backend_iccbased_init:nnn}
+% No support at present.
+% \begin{macrocode}
+\cs_new_protected:Npn \@@_backend_devicen_init:nnn #1#2#3 { }
+\cs_new_protected:Npn \@@_backend_iccbased_init:nnn #1#2#3 { }
+% \end{macrocode}
+% \end{macro}
+%
+% \begin{macrocode}
+%</dvisvgm>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%</package>
+% \end{macrocode}
+%
+% \subsection{Font handling integration}
+%
+% In \LuaTeX{} these colors should also be usable to color fonts, so
+% \texttt{luaotfload} color handling is extended to include these.
+%
+% \begin{macrocode}
+%<*lua>
+% \end{macrocode}
+%
+% \begin{macrocode}
+local l = lpeg
+local spaces = l.P' '^0
+local digit16 = l.R('09', 'af', 'AF')
+
+local octet = digit16 * digit16 / function(s)
+ return string.format('%.3g ', tonumber(s, 16) / 255)
+end
+
+if luaotfload and luaotfload.set_transparent_colorstack then
+ local htmlcolor = l.Cs(octet * octet * octet * -1 * l.Cc'rg')
+ local color_export = {
+ token.create'tex_endlocalcontrol:D',
+ token.create'tex_hpack:D',
+ token.new(0, 1),
+ token.create'color_export:nnN',
+ token.new(0, 1),
+ '',
+ token.new(0, 2),
+ token.new(0, 1),
+ 'backend',
+ token.new(0, 2),
+ token.create'l_tmpa_tl',
+ token.create'exp_after:wN',
+ token.create'@@_select:nn',
+ token.create'l_tmpa_tl',
+ token.new(0, 2),
+ }
+ local group_end = token.create'group_end:'
+ local value = (1 - l.P'}')^0
+ luatexbase.add_to_callback('luaotfload.parse_color', function (value)
+% Also allow HTML colors to preserve compatibility
+ local html = htmlcolor:match(value)
+ if html then return html end
+
+% If no l3color named color with this name is known, check for defined xcolor colors
+ local l3color_prop = token.get_macro(string.format('l_@@_named_%s_prop', value))
+ if l3color_prop == nil or l3color_prop == '' then
+ local legacy_color_macro = token.create(string.format('\\color@%s', value))
+ if legacy_color_macro.cmdname ~= 'undefined_cs' then
+ token.put_next(legacy_color_macro)
+ return token.scan_argument()
+ end
+ end
+
+ tex.runtoks(function()
+ token.get_next()
+ color_export[6] = value
+ tex.sprint(-2, color_export)
+ end)
+ local list = token.scan_list()
+ if not list.head or list.head.next
+ or list.head.subtype ~= node.subtype'pdf_colorstack' then
+ error'Unexpected backend behavior'
+ end
+ local cmd = list.head.data
+ node.free(list)
+ return cmd
+ end, 'l3color')
+end
+% \end{macrocode}
+%
+% \begin{macrocode}
+%</lua>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*luatex>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%<*package>
+\lua_load_module:n {l3backend-luatex}
+%</package>
+% \end{macrocode}
+%
+% \begin{macrocode}
+%</luatex>
+% \end{macrocode}
+%
+% \end{implementation}
+%
+% \PrintIndex