% \iffalse meta-comment % %% File: l3backend-draw.dtx % % Copyright (C) 2019,2020 The LaTeX3 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} % % \fi % % \title{^^A % The \textsf{l3backend-draw} package\\ Backend drawing support^^A % } % % \author{^^A % The \LaTeX3 Project\thanks % {^^A % E-mail: % \href{mailto:latex-team@latex-project.org} % {latex-team@latex-project.org}^^A % }^^A % } % % \date{Released 2020-06-23} % % \maketitle % % \begin{documentation} % % \end{documentation} % % \begin{implementation} % % \section{\pkg{l3backend-draw} Implementation} % % \begin{macrocode} %<*initex|package> %<@@=draw> % \end{macrocode} % % \subsection{\texttt{dvips} backend} % % \begin{macrocode} %<*dvips> % \end{macrocode} % % \begin{macro}{\@@_backend_literal:n, \@@_backend_literal:x} % The same as literal PostScript: same arguments about positioning apply % her. % \begin{macrocode} \cs_new_eq:NN \@@_backend_literal:n \__kernel_backend_literal_postscript:n \cs_generate_variant:Nn \@@_backend_literal:n { x } % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_begin:, \@@_backend_end:} % \begin{macro}{color.fc} % The |ps::[begin]| special here deals with positioning but allows us to % continue on to a matching |ps::[end]|: contrast with |ps:|, which positions % but where we can't split material between separate calls. The % |@beginspecial|/|@endspecial| pair are from |special.pro| and correct the % scale and $y$-axis direction. The definition of |/color.fc| deals with fill % color in paths. In contrast to \pkg{pgf}, we don't save the current point: % discussion with Tom Rokici suggested a better way to handle the necessary % translations (see \cs{@@_backend_box_use:Nnnnn}). (Note that % |@beginspecial|/|@endspecial| forms a backend scope.) The |[begin]|/^^A % |[end]| lines are handled differently from the rest as they are % conceptually different: not really drawing literals but instructions to % \texttt{dvips} itself. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_begin: { \__kernel_backend_literal:n { ps::[begin] } \@@_backend_literal:n { @beginspecial } \@@_backend_literal:n { SDict ~ begin ~ /color.fc ~ { } ~ def ~ end } } \cs_new_protected:Npn \@@_backend_end: { \@@_backend_literal:n { @endspecial } \__kernel_backend_literal:n { ps::[end] } } % \end{macrocode} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_scope_begin:, \@@_backend_scope_end:} % Scope here may need to contain saved definitions, so the entire memory % rather than just the graphic state has to be sent to the stack. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_scope_begin: { \@@_backend_literal:n { save } } \cs_new_protected:Npn \@@_backend_scope_end: { \@@_backend_literal:n { restore } } % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_moveto:nn, \@@_backend_lineto:nn} % \begin{macro}{\@@_backend_rectangle:nnnn} % \begin{macro}{\@@_backend_curveto:nnnnnn} % Path creation operations mainly resolve directly to PostScript primitive % steps, with only the need to convert to \texttt{bp}. Notice that % \texttt{x}-type expansion is included here to ensure that any variable % values are forced to literals before any possible caching. There is % no native rectangular path command (without also clipping, filling or % stroking), so that task is done using a small amount of PostScript. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_moveto:nn #1#2 { \@@_backend_literal:x { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ moveto } } \cs_new_protected:Npn \@@_backend_lineto:nn #1#2 { \@@_backend_literal:x { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ lineto } } \cs_new_protected:Npn \@@_backend_rectangle:nnnn #1#2#3#4 { \@@_backend_literal:x { \dim_to_decimal_in_bp:n {#4} ~ \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ moveto~dup~0~rlineto~exch~0~exch~rlineto~neg~0~rlineto~closepath } } \cs_new_protected:Npn \@@_backend_curveto:nnnnnn #1#2#3#4#5#6 { \@@_backend_literal:x { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~ \dim_to_decimal_in_bp:n {#5} ~ \dim_to_decimal_in_bp:n {#6} ~ curveto } } % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_evenodd_rule:, \@@_backend_nonzero_rule:} % \begin{variable}{\g_@@_draw_eor_bool} % The even-odd rule here can be implemented as a simply switch. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_evenodd_rule: { \bool_gset_true:N \g_@@_draw_eor_bool } \cs_new_protected:Npn \@@_backend_nonzero_rule: { \bool_gset_false:N \g_@@_draw_eor_bool } \bool_new:N \g_@@_draw_eor_bool % \end{macrocode} % \end{variable} % \end{macro} % % \begin{macro} % { % \@@_backend_closepath: , % \@@_backend_stroke: , % \@@_backend_closestroke: , % \@@_backend_fill: , % \@@_backend_fillstroke: , % \@@_backend_clip: , % \@@_backend_discardpath: % } % \begin{variable}{\g_@@_draw_clip_bool} % Unlike PDF, PostScript doesn't track separate colors for strokes and other % elements. It is also desirable to have the |clip| keyword after a stroke or % fill. To achieve those outcomes, there is some work to do. For color, the % stoke color is simple but the fill one has to be inserted by hand. For % clipping, the required ordering is achieved using a \TeX{} switch. All of % the operations end with a new path instruction as they do not terminate % (again in contrast to PDF). % \begin{macrocode} \cs_new_protected:Npn \@@_backend_closepath: { \@@_backend_literal:n { closepath } } \cs_new_protected:Npn \@@_backend_stroke: { \@@_backend_literal:n { stroke } \bool_if:NT \g_@@_draw_clip_bool { \@@_backend_literal:x { \bool_if:NT \g_@@_draw_eor_bool { eo } clip } } \@@_backend_literal:n { newpath } \bool_gset_false:N \g_@@_draw_clip_bool } \cs_new_protected:Npn \@@_backend_closestroke: { \@@_backend_closepath: \@@_backend_stroke: } \cs_new_protected:Npn \@@_backend_fill: { \@@_backend_literal:n { gsave } \@@_backend_literal:n { color.fc } \@@_backend_literal:x { \bool_if:NT \g_@@_draw_eor_bool { eo } fill } \@@_backend_literal:n { grestore } \bool_if:NT \g_@@_draw_clip_bool { \@@_backend_literal:x { \bool_if:NT \g_@@_draw_eor_bool { eo } clip } } \@@_backend_literal:n { newpath } \bool_gset_false:N \g_@@_draw_clip_bool } \cs_new_protected:Npn \@@_backend_fillstroke: { \@@_backend_literal:n { gsave } \@@_backend_literal:n { color.fc } \@@_backend_literal:x { \bool_if:NT \g_@@_draw_eor_bool { eo } fill } \@@_backend_literal:n { grestore } \@@_backend_literal:n { stroke } \bool_if:NT \g_@@_draw_clip_bool { \@@_backend_literal:x { \bool_if:NT \g_@@_draw_eor_bool { eo } clip } } \@@_backend_literal:n { newpath } \bool_gset_false:N \g_@@_draw_clip_bool } \cs_new_protected:Npn \@@_backend_clip: { \bool_gset_true:N \g_@@_draw_clip_bool } \bool_new:N \g_@@_draw_clip_bool \cs_new_protected:Npn \@@_backend_discardpath: { \bool_if:NT \g_@@_draw_clip_bool { \@@_backend_literal:x { \bool_if:NT \g_@@_draw_eor_bool { eo } clip } } \@@_backend_literal:n { newpath } \bool_gset_false:N \g_@@_draw_clip_bool } % \end{macrocode} % \end{variable} % \end{macro} % % \begin{macro}{\@@_backend_dash_pattern:nn} % \begin{macro}{\@@_backend_dash:n} % \begin{macro}{\@@_backend_linewidth:n} % \begin{macro}{\@@_backend_miterlimit:n} % \begin{macro} % { % \@@_backend_cap_butt:, \@@_backend_cap_round:, \@@_backend_cap_rectangle:, % \@@_backend_join_miter:, \@@_backend_join_round:, \@@_backend_join_bevel: % } % Converting paths to output is again a case of mapping directly to % PostScript operations. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_dash_pattern:nn #1#2 { \@@_backend_literal:x { [ \exp_args:Nf \use:n { \clist_map_function:nN {#1} \@@_backend_dash:n } ] ~ \dim_to_decimal_in_bp:n {#2} ~ setdash } } \cs_new:Npn \@@_backend_dash:n #1 { ~ \dim_to_decimal_in_bp:n {#1} } \cs_new_protected:Npn \@@_backend_linewidth:n #1 { \@@_backend_literal:x { \dim_to_decimal_in_bp:n {#1} ~ setlinewidth } } \cs_new_protected:Npn \@@_backend_miterlimit:n #1 { \@@_backend_literal:n { #1 ~ setmiterlimit } } \cs_new_protected:Npn \@@_backend_cap_butt: { \@@_backend_literal:n { 0 ~ setlinecap } } \cs_new_protected:Npn \@@_backend_cap_round: { \@@_backend_literal:n { 1 ~ setlinecap } } \cs_new_protected:Npn \@@_backend_cap_rectangle: { \@@_backend_literal:n { 2 ~ setlinecap } } \cs_new_protected:Npn \@@_backend_join_miter: { \@@_backend_literal:n { 0 ~ setlinejoin } } \cs_new_protected:Npn \@@_backend_join_round: { \@@_backend_literal:n { 1 ~ setlinejoin } } \cs_new_protected:Npn \@@_backend_join_bevel: { \@@_backend_literal:n { 2 ~ setlinejoin } } % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro} % { % \@@_backend_color_fill_cmyk:n , % \@@_backend_color_stroke_cmyk:n % } % \begin{macro} % { % \@@_backend_color_fill_gray:n , % \@@_backend_color_stroke_gray:n % } % \begin{macro} % { % \@@_backend_color_fill_rgb:n , % \@@_backend_color_stroke_rgb:n % } % \begin{macro}{\@@_backend_color_fill:n, \@@_backend_color_stroke:n} % For \texttt{dvips}, we can use the standard color stack to deal with % stroke color, but for fills have to switch to raw PostScript. This is % thus not handled by the stack, but the context is very restricted. See % also how fills are implemented. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_color_fill_cmyk:n #1 { \@@_backend_color_fill:n { #1 ~ setcmykcolor } } \cs_new_protected:Npn \@@_backend_color_stroke_cmyk:n #1 { \@@_backend_color_stroke:n { cmyk ~ #1 } } \cs_new_protected:Npn \@@_backend_color_stroke_gray:n #1 { \@@_backend_color_fill:n { #1 ~ setgray } } \cs_new_protected:Npn \@@_backend_color_fill_gray:n #1 { \@@_backend_color_stroke:n { gray ~ #1 } } \cs_new_protected:Npn \@@_backend_color_fill_rgb:n #1 { \@@_backend_color_fill:n { #1 ~ setrgbcolor } } \cs_new_protected:Npn \@@_backend_color_stroke_rgb:n #1 { \@@_backend_color_stroke:n { rgb ~ #1 } } \cs_new_protected:Npn \@@_backend_color_fill:n #1 { \__kernel_backend_postscript:n { /color.fc ~ { #1 } ~ def } } \cs_new_protected:Npn \@@_backend_color_stroke:n #1 { \__kernel_backend_literal:n { color~push~#1 } \group_insert_after:N \@@_color_reset: } % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_cm:nnnn} % In \texttt{dvips}, keeping the transformations in line with the engine % is unfortunately not possible for scaling and rotations: even if we % decompose the matrix into those operations, there is still no backend % tracking (\emph{cf.}~\texttt{(x)dvipdfmx}). Thus we take the shortest % path available and simply dump the matrix as given. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_cm:nnnn #1#2#3#4 { \@@_backend_literal:n { [ #1 ~ #2 ~ #3 ~ #4 ~ 0 ~ 0 ] ~ concat } } % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_box_use:Nnnnn} % Inside a picture |@beginspecial|/|@endspecial| are active, which is % normally a good thing but means that the position and scaling would be off % if the box was inserted directly. To deal with that, there are a number of % possible approaches. The implementation here was suggested by Tom Rokici % (author of \texttt{dvips}). We end the current special placement, then % set the current point with a literal |[begin]|. As for general % literals, we then use the stack to store the current point and move to % it. To insert the required transformation, we have to flip the $y$-axis, % once before and once after it. Then we get back to the \TeX{} reference % point to insert our content. The clean up has to happen in the right % places, hence the |[begin]|/|[end]| pair around |restore|. Finally, % we can return to \enquote{normal} drawing mode. Notice that the set up % here is very similar to that in \cs{@@_align_currentpoint_\ldots}, but % the ordering of saving and restoring is different (intermixed). % \begin{macrocode} \cs_new_protected:Npn \@@_backend_box_use:Nnnnn #1#2#3#4#5 { \@@_backend_literal:n { @endspecial } \@@_backend_literal:n { [end] } \@@_backend_literal:n { [begin] } \@@_backend_literal:n { save } \@@_backend_literal:n { currentpoint } \@@_backend_literal:n { currentpoint~translate } \@@_backend_cm:nnnn { 1 } { 0 } { 0 } { -1 } \@@_backend_cm:nnnn {#2} {#3} {#4} {#5} \@@_backend_cm:nnnn { 1 } { 0 } { 0 } { -1 } \@@_backend_literal:n { neg~exch~neg~exch~translate } \@@_backend_literal:n { [end] } \hbox_overlap_right:n { \box_use:N #1 } \@@_backend_literal:n { [begin] } \@@_backend_literal:n { restore } \@@_backend_literal:n { [end] } \@@_backend_literal:n { [begin] } \@@_backend_literal:n { @beginspecial } } % \end{macrocode} % \end{macro} % % \begin{macrocode} % % \end{macrocode} % % \subsection{\texttt{pdfmode} and \texttt{(x)dvipdfmx}} % % Both \texttt{pdfmode} and \texttt{(x)dvipdfmx} directly produce PDF output % and understand a shared set of specials for drawing commands. % % \begin{macrocode} %<*dvipdfmx|pdfmode|xdvipdfmx> % \end{macrocode} % % \subsubsection{Drawing} % % \begin{macro}{\@@_backend_literal:n, \@@_backend_literal:x} % Pass data through using a dedicated interface. % \begin{macrocode} \cs_new_eq:NN \@@_backend_literal:n \__kernel_backend_literal_pdf:n \cs_generate_variant:Nn \@@_backend_literal:n { x } % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_begin:, \@@_backend_end:} % No special requirements here, so simply set up a drawing scope. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_begin: { \@@_backend_scope_begin: } \cs_new_protected:Npn \@@_backend_end: { \@@_backend_scope_end: } % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_scope_begin:, \@@_backend_scope_end:} % Use the backend-level scope mechanisms. % \begin{macrocode} \cs_new_eq:NN \@@_backend_scope_begin: \__kernel_backend_scope_begin: \cs_new_eq:NN \@@_backend_scope_end: \__kernel_backend_scope_end: % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_moveto:nn, \@@_backend_lineto:nn} % \begin{macro}{\@@_backend_curveto:nnnnnn} % \begin{macro}{\@@_backend_rectangle:nnnn} % Path creation operations all resolve directly to PDF primitive steps, with % only the need to convert to \texttt{bp}. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_moveto:nn #1#2 { \@@_backend_literal:x { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ m } } \cs_new_protected:Npn \@@_backend_lineto:nn #1#2 { \@@_backend_literal:x { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ l } } \cs_new_protected:Npn \@@_backend_curveto:nnnnnn #1#2#3#4#5#6 { \@@_backend_literal:x { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~ \dim_to_decimal_in_bp:n {#5} ~ \dim_to_decimal_in_bp:n {#6} ~ c } } \cs_new_protected:Npn \@@_backend_rectangle:nnnn #1#2#3#4 { \@@_backend_literal:x { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~ re } } % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_evenodd_rule:, \@@_backend_nonzero_rule:} % \begin{variable}{\g_@@_draw_eor_bool} % The even-odd rule here can be implemented as a simply switch. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_evenodd_rule: { \bool_gset_true:N \g_@@_draw_eor_bool } \cs_new_protected:Npn \@@_backend_nonzero_rule: { \bool_gset_false:N \g_@@_draw_eor_bool } \bool_new:N \g_@@_draw_eor_bool % \end{macrocode} % \end{variable} % \end{macro} % % \begin{macro} % { % \@@_backend_closepath: , % \@@_backend_stroke: , % \@@_backend_closestroke: , % \@@_backend_fill: , % \@@_backend_fillstroke: , % \@@_backend_clip: , % \@@_backend_discardpath: % } % Converting paths to output is again a case of mapping directly to % PDF operations. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_closepath: { \@@_backend_literal:n { h } } \cs_new_protected:Npn \@@_backend_stroke: { \@@_backend_literal:n { S } } \cs_new_protected:Npn \@@_backend_closestroke: { \@@_backend_literal:n { s } } \cs_new_protected:Npn \@@_backend_fill: { \@@_backend_literal:x { f \bool_if:NT \g_@@_draw_eor_bool * } } \cs_new_protected:Npn \@@_backend_fillstroke: { \@@_backend_literal:x { B \bool_if:NT \g_@@_draw_eor_bool * } } \cs_new_protected:Npn \@@_backend_clip: { \@@_backend_literal:x { W \bool_if:NT \g_@@_draw_eor_bool * } } \cs_new_protected:Npn \@@_backend_discardpath: { \@@_backend_literal:n { n } } % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_dash_pattern:nn} % \begin{macro}{\@@_backend_dash:n} % \begin{macro}{\@@_backend_linewidth:n} % \begin{macro}{\@@_backend_miterlimit:n} % \begin{macro} % { % \@@_backend_cap_butt:, \@@_backend_cap_round:, \@@_backend_cap_rectangle:, % \@@_backend_join_miter:, \@@_backend_join_round:, \@@_backend_join_bevel: % } % Converting paths to output is again a case of mapping directly to % PDF operations. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_dash_pattern:nn #1#2 { \@@_backend_literal:x { [ \exp_args:Nf \use:n { \clist_map_function:nN {#1} \@@_backend_dash:n } ] ~ \dim_to_decimal_in_bp:n {#2} ~ d } } \cs_new:Npn \@@_backend_dash:n #1 { ~ \dim_to_decimal_in_bp:n {#1} } \cs_new_protected:Npn \@@_backend_linewidth:n #1 { \@@_backend_literal:x { \dim_to_decimal_in_bp:n {#1} ~ w } } \cs_new_protected:Npn \@@_backend_miterlimit:n #1 { \@@_backend_literal:x { #1 ~ M } } \cs_new_protected:Npn \@@_backend_cap_butt: { \@@_backend_literal:n { 0 ~ J } } \cs_new_protected:Npn \@@_backend_cap_round: { \@@_backend_literal:n { 1 ~ J } } \cs_new_protected:Npn \@@_backend_cap_rectangle: { \@@_backend_literal:n { 2 ~ J } } \cs_new_protected:Npn \@@_backend_join_miter: { \@@_backend_literal:n { 0 ~ j } } \cs_new_protected:Npn \@@_backend_join_round: { \@@_backend_literal:n { 1 ~ j } } \cs_new_protected:Npn \@@_backend_join_bevel: { \@@_backend_literal:n { 2 ~ j } } % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro} % { % \@@_backend_color_fill_cmyk:n , % \@@_backend_color_stroke_cmyk:n % } % \begin{macro} % { % \@@_backend_color_fill_gray:n , % \@@_backend_color_stroke_gray:n % } % \begin{macro} % { % \@@_backend_color_fill_rgb:n , % \@@_backend_color_stroke_rgb:n % } % \begin{macro}{\@@_backend_color_select:n, \@@_backend_color_select:x} % \begin{macro}{\@@_backend_color_reset:} % Color has to be split between \texttt{(x)dvipdfmx} and the PDF engines % as there is no color stack for fill/stroke separation in the former. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_color_fill_cmyk:n #1 { \@@_backend_color_select:n { #1 ~ k } } \cs_new_protected:Npn \@@_backend_color_stroke_cmyk:n #1 { \@@_backend_color_select:n { #1 ~ K } } \cs_new_protected:Npn \@@_backend_color_fill_gray:n #1 { \@@_backend_color_select:n { #1 ~ g } } \cs_new_protected:Npn \@@_backend_color_stroke_gray:n #1 { \@@_backend_color_select:n { #1 ~ G } } \cs_new_protected:Npn \@@_backend_color_fill_rgb:n #1 { \@@_backend_color_select:n { #1 ~ rg } } \cs_new_protected:Npn \@@_backend_color_stroke_rgb:n #1 { \@@_backend_color_select:n { #1 ~ RG } } %<*pdfmode> \cs_new_protected:Npx \@@_backend_color_select:n #1 { \cs_if_exist:NTF \tex_pdfextension:D { \tex_pdfextension:D colorstack } { \tex_pdfcolorstack:D } \exp_not:N \l__kernel_color_stack_int push {#1} \group_insert_after:N \exp_not:N \@@_backend_color_reset: } \cs_new_protected:Npx \@@_backend_color_reset: { \cs_if_exist:NTF \tex_pdfextension:D { \tex_pdfextension:D colorstack } { \tex_pdfcolorstack:D } \exp_not:N \l__kernel_color_stack_int pop \scan_stop: } % %<*dvipdfmx|xdvipdfmx> \cs_new_eq:NN \@@_backend_color_select:n \__kernel_backend_literal_pdf:n % \cs_generate_variant:Nn \@@_backend_color_select:n { x } % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_cm:nnnn} % \begin{macro}{\@@_backend_cm_aux:nnnn} % Another split here between \texttt{pdfmode} and \texttt{(x)dvipdfmx}. % In the former, we have a direct method to maintain alignment: the backend % can use a matrix itself. For \texttt{(x)dvipdfmx}, we can to decompose the % matrix into rotations and a scaling, then use those operations as they % are handled by the backend. (There is backend support for matrix operations in % \texttt{(x)dvipdfmx}, but as a matched pair so not suitable for the % \enquote{stand alone} transformation set up here.) % \begin{macrocode} \cs_new_protected:Npn \@@_backend_cm:nnnn #1#2#3#4 { %<*pdfmode> \__kernel_backend_matrix:n { #1 ~ #2 ~ #3 ~ #4 } % %<*dvipdfmx|xdvipdfmx> \@@_backend_cm_decompose:nnnnN {#1} {#2} {#3} {#4} \@@_backend_cm_aux:nnnn % } %<*dvipdfmx|xdvipdfmx> \cs_new_protected:Npn \@@_backend_cm_aux:nnnn #1#2#3#4 { \__kernel_backend_literal:x { x:rotate~ \fp_compare:nNnTF {#1} = \c_zero_fp { 0 } { \fp_eval:n { round ( -#1 , 5 ) } } } \__kernel_backend_literal:x { x:scale~ \fp_eval:n { round ( #2 , 5 ) } ~ \fp_eval:n { round ( #3 , 5 ) } } \__kernel_backend_literal:x { x:rotate~ \fp_compare:nNnTF {#4} = \c_zero_fp { 0 } { \fp_eval:n { round ( -#4 , 5 ) } } } } % % \end{macrocode} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_cm_decompose:nnnnN} % \begin{macro} % { % \@@_backend_cm_decompose_auxi:nnnnN, % \@@_backend_cm_decompose_auxii:nnnnN, % \@@_backend_cm_decompose_auxiii:nnnnN, % } % Internally, transformations for drawing are tracked as a matrix. Not all % engines provide a way of dealing with this: if we use a raw matrix, the % engine looses track of positions (for example for hyperlinks), and this is % not desirable. They do, however, allow us to track rotations and scalings. % Luckily, we can decompose any (two-dimensional) matrix into two rotations % and a single scaling: % \[ % \begin{bmatrix} % A & B \\ C & D % \end{bmatrix} % = % \begin{bmatrix} % \cos\beta & \sin\beta \\ -\sin\beta & \cos\beta % \end{bmatrix} % \begin{bmatrix} % w_{1} & 0 \\ 0 & w_{2} % \end{bmatrix} % \begin{bmatrix} % \cos\gamma & \sin\gamma \\ -\sin\gamma & \cos\gamma % \end{bmatrix} % \] % The parent matrix can be converted to % \[ % \begin{bmatrix} % A & B \\ C & D % \end{bmatrix} % = % \begin{bmatrix} % E & H \\-H & E % \end{bmatrix} % + % \begin{bmatrix} % F & G \\ G & -F % \end{bmatrix} % \] % From these, we can find that % \begin{align*} % \frac{w_{1} + w_{2}}{2} &= \sqrt{E^{2} + H^{2}} \\ % \frac{w_{1} - w_{2}}{2} &= \sqrt{F^{2} + G^{2}} \\ % \gamma - \beta &= \tan^{-1}(G/F) \\ % \gamma + \beta &= \tan^{-1}(H/E) % \end{align*} % at which point we just have to do various pieces of re-arrangement to % get all of the values. (See J.~Blinn, \emph{IEEE Comput.\ Graph.\ Appl.}, % 1996, \textbf{16}, 82--88.) There is one wrinkle: the PostScript (and PDF) % way of specifying a transformation matrix exchanges where one would % normally expect $B$ and $C$ to be. % \begin{macrocode} %<*dvipdfmx|xdvipdfmx> \cs_new_protected:Npn \@@_backend_cm_decompose:nnnnN #1#2#3#4#5 { \use:x { \@@_backend_cm_decompose_auxi:nnnnN { \fp_eval:n { (#1 + #4) / 2 } } { \fp_eval:n { (#1 - #4) / 2 } } { \fp_eval:n { (#3 + #2) / 2 } } { \fp_eval:n { (#3 - #2) / 2 } } } #5 } \cs_new_protected:Npn \@@_backend_cm_decompose_auxi:nnnnN #1#2#3#4#5 { \use:x { \@@_backend_cm_decompose_auxii:nnnnN { \fp_eval:n { 2 * sqrt ( #1 * #1 + #4 * #4 ) } } { \fp_eval:n { 2 * sqrt ( #2 * #2 + #3 * #3 ) } } { \fp_eval:n { atand ( #3 , #2 ) } } { \fp_eval:n { atand ( #4 , #1 ) } } } #5 } \cs_new_protected:Npn \@@_backend_cm_decompose_auxii:nnnnN #1#2#3#4#5 { \use:x { \@@_backend_cm_decompose_auxiii:nnnnN { \fp_eval:n { ( #4 - #3 ) / 2 } } { \fp_eval:n { ( #1 + #2 ) / 2 } } { \fp_eval:n { ( #1 - #2 ) / 2 } } { \fp_eval:n { ( #4 + #3 ) / 2 } } } #5 } \cs_new_protected:Npn \@@_backend_cm_decompose_auxiii:nnnnN #1#2#3#4#5 { \fp_compare:nNnTF { abs( #2 ) } > { abs ( #3 ) } { #5 {#1} {#2} {#3} {#4} } { #5 {#1} {#3} {#2} {#4} } } % % \end{macrocode} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_box_use:Nnnnn} % Inserting a \TeX{} box transformed to the requested position and using % the current matrix is done using a mixture of \TeX{} and low-level % manipulation. The offset can be handled by \TeX{}, so only any rotation/^^A % skew/scaling component needs to be done using the matrix operation. As this % operation can never be cached, the scope is set directly not using the % \texttt{draw} version. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_box_use:Nnnnn #1#2#3#4#5 { \__kernel_backend_scope_begin: %<*pdfmode> \@@_backend_cm:nnnn {#2} {#3} {#4} {#5} % %<*dvipdfmx|xdvipdfmx> \__kernel_backend_literal:n { pdf:btrans~matrix~ #2 ~ #3 ~ #4 ~ #5 ~ 0 ~ 0 } % \hbox_overlap_right:n { \box_use:N #1 } %<*dvipdfmx|xdvipdfmx> \__kernel_backend_literal:n { pdf:etrans } % \__kernel_backend_scope_end: } % \end{macrocode} % \end{macro} % % \begin{macrocode} % % \end{macrocode} % % \subsection{\texttt{dvisvgm} backend} % % \begin{macrocode} %<*dvisvgm> % \end{macrocode} % % \begin{macro}{\@@_backend_literal:n, \@@_backend_literal:x} % The same as the more general literal call. % \begin{macrocode} \cs_new_eq:NN \@@_backend_literal:n \__kernel_backend_literal_svg:n \cs_generate_variant:Nn \@@_backend_literal:n { x } % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_begin:, \@@_backend_end:} % A drawing needs to be set up such that the co-ordinate system is % translated. That is done inside a scope, which as described below % \begin{macrocode} \cs_new_protected:Npn \@@_backend_begin: { \@@_backend_scope_begin: \@@_backend_scope:n { transform="translate({?x},{?y})~scale(1,-1)" } } \cs_new_protected:Npn \@@_backend_end: { \@@_backend_scope_end: } % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_scope_begin:, \@@_backend_scope_end:} % \begin{macro}{\@@_backend_scope:n, \@@_backend_scope:x} % \begin{variable}{\g_@@_draw_scope_int, \l_@@_draw_scope_int} % Several settings that with other backends are \enquote{stand alone} have % to be given as part of a scope in SVG. As a result, there is a need to % provide a mechanism to automatically close these extra scopes. That is % done using a dedicated function and a pair of tracking variables. Within % each graphics scope we use a global variable to do the work, with a group % used to save the value between scopes. The result is that no direct action % is needed when creating a scope. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_scope_begin: { \int_set_eq:NN \l_@@_draw_scope_int \g_@@_draw_scope_int \group_begin: \int_gzero:N \g_@@_draw_scope_int } \cs_new_protected:Npn \@@_backend_scope_end: { \prg_replicate:nn { \g_@@_draw_scope_int } { \@@_backend_literal:n { } } \group_end: \int_gset_eq:NN \g_@@_draw_scope_int \l_@@_draw_scope_int } \cs_new_protected:Npn \@@_backend_scope:n #1 { \@@_backend_literal:n { } \int_gincr:N \g_@@_draw_scope_int } \cs_generate_variant:Nn \@@_backend_scope:n { x } \int_new:N \g_@@_draw_scope_int \int_new:N \l_@@_draw_scope_int % \end{macrocode} % \end{variable} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_moveto:nn, \@@_backend_lineto:nn} % \begin{macro}{\@@_backend_rectangle:nnnn} % \begin{macro}{\@@_backend_curveto:nnnnnn} % \begin{macro}{\@@_backend_add_to_path:n} % \begin{variable}{\g_@@_draw_path_tl} % Once again, some work is needed to get path constructs correct. Rather % then write the values as they are given, the entire path needs to be % collected up before being output in one go. For that we use a dedicated % storage routine, which adds spaces as required. Since paths should % be fully expanded there is no need to worry about the internal % \texttt{x}-type expansion. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_moveto:nn #1#2 { \@@_backend_add_to_path:n { M ~ \dim_to_decimal:n {#1} ~ \dim_to_decimal:n {#2} } } \cs_new_protected:Npn \@@_backend_lineto:nn #1#2 { \@@_backend_add_to_path:n { L ~ \dim_to_decimal:n {#1} ~ \dim_to_decimal:n {#2} } } \cs_new_protected:Npn \@@_backend_rectangle:nnnn #1#2#3#4 { \@@_backend_add_to_path:n { M ~ \dim_to_decimal:n {#1} ~ \dim_to_decimal:n {#2} h ~ \dim_to_decimal:n {#3} ~ v ~ \dim_to_decimal:n {#4} ~ h ~ \dim_to_decimal:n { -#3 } ~ Z } } \cs_new_protected:Npn \@@_backend_curveto:nnnnnn #1#2#3#4#5#6 { \@@_backend_add_to_path:n { C ~ \dim_to_decimal:n {#1} ~ \dim_to_decimal:n {#2} ~ \dim_to_decimal:n {#3} ~ \dim_to_decimal:n {#4} ~ \dim_to_decimal:n {#5} ~ \dim_to_decimal:n {#6} } } \cs_new_protected:Npn \@@_backend_add_to_path:n #1 { \tl_gset:Nx \g_@@_draw_path_tl { \g_@@_draw_path_tl \tl_if_empty:NF \g_@@_draw_path_tl { \c_space_tl } #1 } } \tl_new:N \g_@@_draw_path_tl % \end{macrocode} % \end{variable} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_evenodd_rule:, \@@_backend_nonzero_rule:} % The fill rules here have to be handled as scopes. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_evenodd_rule: { \@@_backend_scope:n { fill-rule="evenodd" } } \cs_new_protected:Npn \@@_backend_nonzero_rule: { \@@_backend_scope:n { fill-rule="nonzero" } } % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_path:n} % \begin{macro} % { % \@@_backend_closepath: , % \@@_backend_stroke: , % \@@_backend_closestroke: , % \@@_backend_fill: , % \@@_backend_fillstroke: , % \@@_backend_clip: , % \@@_backend_discardpath: % } % \begin{variable}{\g_@@_draw_clip_bool} % \begin{variable}{\g_@@_draw_path_int} % Setting fill and stroke effects and doing clipping all has to be done using % scopes. This means setting up the various requirements in a shared % auxiliary which deals with the bits and pieces. Clipping paths are reused % for path drawing: not essential but avoids constructing them twice. % Discarding a path needs a separate function as it's not quite the same. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_closepath: { \@@_backend_add_to_path:n { Z } } \cs_new_protected:Npn \@@_backend_path:n #1 { \bool_if:NTF \g_@@_draw_clip_bool { \int_gincr:N \g_@@_clip_path_int \@@_backend_literal:x { < clipPath~id = " l3cp \int_use:N \g_@@_clip_path_int " > { ?nl } { ?nl } < /clipPath > { ? nl } < use~xlink:href = "\c_hash_str l3path \int_use:N \g_@@_path_int " ~ #1 /> } \@@_backend_scope:x { clip-path = "url( \c_hash_str l3cp \int_use:N \g_@@_clip_path_int)" } } { \@@_backend_literal:x { } } \tl_gclear:N \g_@@_draw_path_tl \bool_gset_false:N \g_@@_draw_clip_bool } \int_new:N \g_@@_path_int \cs_new_protected:Npn \@@_backend_stroke: { \@@_backend_path:n { style="fill:none" } } \cs_new_protected:Npn \@@_backend_closestroke: { \@@_backend_closepath: \@@_backend_stroke: } \cs_new_protected:Npn \@@_backend_fill: { \@@_backend_path:n { style="stroke:none" } } \cs_new_protected:Npn \@@_backend_fillstroke: { \@@_backend_path:n { } } \cs_new_protected:Npn \@@_backend_clip: { \bool_gset_true:N \g_@@_draw_clip_bool } \bool_new:N \g_@@_draw_clip_bool \cs_new_protected:Npn \@@_backend_discardpath: { \bool_if:NT \g_@@_draw_clip_bool { \int_gincr:N \g_@@_clip_path_int \@@_backend_literal:x { < clipPath~id = " l3cp \int_use:N \g_@@_clip_path_int " > { ?nl } { ?nl } < /clipPath > } \@@_backend_scope:x { clip-path = "url( \c_hash_str l3cp \int_use:N \g_@@_clip_path_int)" } } \tl_gclear:N \g_@@_draw_path_tl \bool_gset_false:N \g_@@_draw_clip_bool } % \end{macrocode} % \end{variable} % \end{variable} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_dash_pattern:nn} % \begin{macro}{\@@_backend_dash:n} % \begin{macro}{\@@_backend_dash_aux:nn} % \begin{macro}{\@@_backend_linewidth:n} % \begin{macro}{\@@_backend_miterlimit:n} % \begin{macro} % { % \@@_backend_cap_butt:, \@@_backend_cap_round:, \@@_backend_cap_rectangle:, % \@@_backend_join_miter:, \@@_backend_join_round:, \@@_backend_join_bevel: % } % All of these ideas are properties of scopes in SVG. The only slight % complexity is converting the dash array properly (doing any required % maths). % \begin{macrocode} \cs_new_protected:Npn \@@_backend_dash_pattern:nn #1#2 { \use:x { \@@_backend_dash_aux:nn { \clist_map_function:nn {#1} \@@_backend_dash:n } { \dim_to_decimal:n {#2} } } } \cs_new:Npn \@@_backend_dash:n #1 { , \dim_to_decimal_in_bp:n {#1} } \cs_new_protected:Npn \@@_backend_dash_aux:nn #1#2 { \@@_backend_scope:x { stroke-dasharray = " \tl_if_empty:oTF { \use_none:n #1 } { none } { \use_none:n #1 } " ~ stroke-offset=" #2 " } } \cs_new_protected:Npn \@@_backend_linewidth:n #1 { \@@_backend_scope:x { stroke-width=" \dim_to_decimal:n {#1} " } } \cs_new_protected:Npn \@@_backend_miterlimit:n #1 { \@@_backend_scope:x { stroke-miterlimit=" #1 " } } \cs_new_protected:Npn \@@_backend_cap_butt: { \@@_backend_scope:n { stroke-linecap="butt" } } \cs_new_protected:Npn \@@_backend_cap_round: { \@@_backend_scope:n { stroke-linecap="round" } } \cs_new_protected:Npn \@@_backend_cap_rectangle: { \@@_backend_scope:n { stroke-linecap="square" } } \cs_new_protected:Npn \@@_backend_join_miter: { \@@_backend_scope:n { stroke-linejoin="miter" } } \cs_new_protected:Npn \@@_backend_join_round: { \@@_backend_scope:n { stroke-linejoin="round" } } \cs_new_protected:Npn \@@_backend_join_bevel: { \@@_backend_scope:n { stroke-linejoin="bevel" } } % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro} % { % \@@_backend_color_fill_cmyk:n , % \@@_backend_color_stroke_cmyk:n % } % \begin{macro}{\@@_backend_color_cmyk:nw} % \begin{macro} % { % \@@_backend_color_fill_gray:n , % \@@_backend_color_stroke_gray:n % } % \begin{macro}{\@@_backend_color_gray:nn, \@@_backend_color_gray_aux:n} % \begin{macro} % { % \@@_backend_color_fill_rgb:n , % \@@_backend_color_stroke_rgb:n % } % \begin{macro}{\@@_backend_color_rgb:nw} % \begin{macro}{\@@_backend_color:nnnn} % For drawings in SVG, we use scopes for all 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_color_fill_cmyk:n #1 { \@@_backend_color_cmyk:nw { fill } #1 \s_@@_stop } \cs_new_protected:Npn \@@_backend_color_stroke_cmyk:n #1 { \@@_backend_color_cmyk:nw { stroke } #1 \s_@@_stop } \cs_new_protected:Npn \@@_backend_color_cmyk:nw #1#2 ~ #3 ~ #4 ~ #5 \s_@@_stop { \use:x { \@@_backend_color:nnnn {#1} { \fp_eval:n { -100 * ( 1 - min ( 1 , #2 + #5 ) ) } } { \fp_eval:n { -100 * ( 1 - min ( 1 , #3 + #5 ) ) } } { \fp_eval:n { -100 * ( 1 - min ( 1 , #4 + #5 ) ) } } } } \cs_new_protected:Npn \@@_backend_color_fill_gray:n #1 { \@@_backend_color_grab:nn { fill } {#1} } \cs_new_protected:Npn \@@_backend_color_stroke_gray:n #1 { \@@_backend_color_grab:nn { stroke } {#1} } \cs_new_protected:Npn \@@_backend_color_gray:nn #1#2 { \use:x { \@@_backend_color_gray_aux:nn {#1} { \fp_eval:n { 100 * (#2) } } } } \cs_new_protected:Npn \@@_backend_color_gray_aux:nn #1#2 { \@@_backend_color:nnn {#1} {#2} {#2} {#2} } \cs_new_protected:Npn \@@_backend_color_rgb_cmyk:n #1 { \@@_backend_color_rgb:nw { fill } #1 \s_@@_stop } \cs_new_protected:Npn \@@_backend_color_rgb_cmyk:n #1 { \@@_backend_color_rgb:nw { stroke } #1 \s_@@_stop } \cs_new_protected:Npn \@@_backend_color_rgb:nw #1#2 ~ #3 ~ #4\s_@@_stop { \use:x { \@@_backend_color:nnnn { fill } { \fp_eval:n { 100 * (#2) } } { \fp_eval:n { 100 * (#3) } } { \fp_eval:n { 100 * (#4) } } } } \cs_new_protected:Npx \@@_backend_color:nnnn #1#2#3#4 { \@@_backend_scope:n { #1 = " rgb ( #2 \c_percent_str , #3 \c_percent_str , #4 \c_percent_str ) " } } % \end{macrocode} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % \end{macro} % % \begin{macro}{\@@_backend_cm:nnnn} % The four arguments here are floats (the affine matrix), the last % two are a displacement vector. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_cm:nnnn #1#2#3#4 { \@@_backend_scope:n { transform = " matrix ( #1 , #2 , #3 , #4 , 0pt , 0pt ) " } } % \end{macrocode} % \end{macro} % % \begin{macro}{\@@_backend_box_use:Nnnnn} % No special savings can be made here: simply displace the box inside % a scope. As there is nothing to re-box, just make the box passed of % zero size. % \begin{macrocode} \cs_new_protected:Npn \@@_backend_box_use:Nnnnn #1#2#3#4#5#6#7 { \__kernel_backend_scope_begin: \@@_backend_cm:nnnn {#2} {#3} {#4} {#5} \__kernel_backend_literal_svg:n { < g~ stroke="none"~ transform="scale(-1,1)~translate({?x},{?y})~scale(-1,-1)" > } \box_set_wd:Nn #1 { 0pt } \box_set_ht:Nn #1 { 0pt } \box_set_dp:Nn #1 { 0pt } \box_use:N #1 \__kernel_backend_literal_svg:n { } \__kernel_backend_scope_end: } % \end{macrocode} % \end{macro} % % \begin{macrocode} % % \end{macrocode} % % \begin{macrocode} % % \end{macrocode} % % \end{implementation} % % \PrintIndex