From 48cfcb505ab1aa2632eaf1985d2fee72691e21d0 Mon Sep 17 00:00:00 2001
From: Norbert Preining <norbert@preining.info>
Date: Wed, 30 Mar 2022 03:00:41 +0000
Subject: CTAN sync 202203300300

---
 .../annotate-equations/annotate-equations.sty      | 188 +++++++++++++++++++++
 1 file changed, 188 insertions(+)
 create mode 100644 macros/latex/contrib/annotate-equations/annotate-equations.sty

(limited to 'macros/latex/contrib/annotate-equations/annotate-equations.sty')

diff --git a/macros/latex/contrib/annotate-equations/annotate-equations.sty b/macros/latex/contrib/annotate-equations/annotate-equations.sty
new file mode 100644
index 0000000000..a5dbf002f3
--- /dev/null
+++ b/macros/latex/contrib/annotate-equations/annotate-equations.sty
@@ -0,0 +1,188 @@
+% Annotate LaTeX Equations
+% 
+% (c) 2022 by ST John, https://github.com/st--/
+% Licensed under MIT License
+% 
+\NeedsTeXFormat{LaTeX2e}[1994/06/01]
+\ProvidesPackage{annotate-equations}
+  [2022/03/29 v0.1.0 easily annotate equations using TikZ]
+
+%%% lualatex compatibility, from https://tex.stackexchange.com/a/351520/171664
+\RequirePackage{ifluatex}
+\ifluatex
+\RequirePackage{luatex85}
+\RequirePackage{pdftexcmds}
+  \makeatletter
+  \let\pdfstrcmp\pdf@strcmp
+  \let\pdffilemoddate\pdf@filemoddate
+  \makeatother
+\fi
+%%%
+
+\RequirePackage{tikz}
+\RequirePackage{xcolor}
+
+\usetikzlibrary{backgrounds}
+\usetikzlibrary{arrows,shapes}
+\usetikzlibrary{tikzmark} % for \tikzmarknode
+\usetikzlibrary{calc} % for computing the midpoint between two nodes, e.g. at ($(p1.north)!0.5!(p2.north)$) 
+
+
+%%%%% SETTINGS %%%%%
+
+\newcommand{\eqnhighlightheight}{}  % colorbox will shrink to content
+\renewcommand{\eqnhighlightheight}{\mathstrut} % colorbox will always have full height
+
+\newcommand{\eqnhighlightshade}{17}  % light
+%\renewcommand{\eqnhighlightshade}{47}  % dark
+
+\newcommand{\eqnannotationtext}[1]{\sffamily\footnotesize#1\strut} %%% TODO remove textsf/footnotesize/strut?
+
+
+\providecommand\EAmarkanchor{north} % default set to "above"
+\providecommand\EAwesteast{east} % default set to "right"
+\providecommand\EAlabelanchor{south} % default set to "label above"
+% for pgfkeys, see https://tex.stackexchange.com/a/34318/171664
+% for no-value keys, see https://tex.stackexchange.com/a/401848/171664
+\pgfkeys{
+    /eqnannotate/.is family, /eqnannotate,
+    above/.code = {\renewcommand\EAmarkanchor{north}},
+    below/.code = {\renewcommand\EAmarkanchor{south}},
+    left/.code = {\renewcommand\EAwesteast{west}},
+    right/.code = {\renewcommand\EAwesteast{east}},
+    label above/.code = {\renewcommand\EAlabelanchor{south}},
+    label below/.code = {\renewcommand\EAlabelanchor{north}},
+}
+
+%%%%% %%%%%%%% %%%%%
+
+
+\newcommand*{\eqnhighlightcolorbox}[2]{%
+% \colorbox sets the second argument in text mode, so for use within equations we wrap it in $ $ again
+    \mathchoice% to get right font size in each mode:
+        {\colorbox{#1}{$\displaystyle #2$}}%
+        {\colorbox{#1}{$\textstyle #2$}}%
+        {\colorbox{#1}{$\scriptstyle #2$}}%
+        {\colorbox{#1}{$\scriptscriptstyle #2$}}%
+}
+
+%%% the fbox with 0pt rule fixes the height of eqnmark vs eqnmarkbox issue
+\newcommand*{\eqnhighlightfbox}[2]{%
+% \fbox sets the second argument in text mode, so for use within equations we wrap it in $ $ again
+    \mathchoice% to get right font size in each mode:
+        {\begingroup\setlength{\fboxrule}{0pt}\fbox{$\displaystyle\color{#1}#2$}\endgroup}%
+        {\begingroup\setlength{\fboxrule}{0pt}\fbox{$\textstyle\color{#1}#2$}\endgroup}%
+        {\begingroup\setlength{\fboxrule}{0pt}\fbox{$\scriptstyle\color{#1}#2$}\endgroup}%
+        {\begingroup\setlength{\fboxrule}{0pt}\fbox{$\scriptscriptstyle\color{#1}#2$}\endgroup}%
+}
+
+% . is the current color
+
+\newcommand*{\eqnhighlight}[2]{\begingroup\colorlet{currentcolor}{.}\eqnhighlightcolorbox{#1!\eqnhighlightshade}{\eqnhighlightheight #2}\endgroup}
+\newcommand*{\eqncolor}[2]{\begingroup\colorlet{currentcolor}{.}\eqnhighlightfbox{#1}{\eqnhighlightheight #2}\endgroup}
+
+%%% Arguments to \eqnmark[box]: [highlight color]{node name}{term to highlight}
+\newcommand*{\eqnmarkbox}[3][currentcolor]{\addvalue{#2}{#1}\tikzmarknode{#2}{\eqnhighlight{#1}{#3}}}
+\newcommand*{\eqnmark}[3][currentcolor]{\addvalue{#2}{#1}\tikzmarknode{#2}{\eqncolor{#1}{#3}}}
+
+% Store current color in a dictionary (lookup table),
+% from https://tex.stackexchange.com/a/48931/171664 :
+\def\addvalue#1#2{\expandafter\gdef\csname eqnannotate@data@#1\endcsname{#2}}
+\def\usevalue#1{%
+  \ifcsname eqnannotate@data@#1\endcsname
+    \csname eqnannotate@data@#1\expandafter\endcsname
+  \else
+    currentcolor%
+  \fi
+}
+
+
+%%%%% Helpers for swapping north/south / west/east / -/+ depending on above/below / left/right etc.:
+\newcommand*{\swapNorthSouth}[1]{%
+    \ifnum\pdfstrcmp{#1}{south}=0 north\else south\fi
+}
+\newcommand*{\swapWestEast}[1]{%
+    \ifnum\pdfstrcmp{#1}{east}=0 west\else east\fi
+}
+\newcommand*{\EAxshift}[1]{%
+    \ifnum\pdfstrcmp{#1}{east}=0 -0.3ex\else 0.3ex\fi
+}
+%%%%%
+
+
+\newcounter{eqnannotatenode}
+\newcommand*{\eqnannotateCurrentNode}{eqnannotatenode\theeqnannotatenode}
+
+
+\newcommand{\annotatetwo}[5][]{%
+    \begingroup% %%% so we don't leak the \def's below
+    \stepcounter{eqnannotatenode}%
+    %%% #1: (optional) extra args for \node e.g. yshift=...
+    \pgfkeys{/eqnannotate, #2}% %%% all configuration options
+    \def\myEAmarkOne{#3}%
+    \def\myEAmarkTwo{#4}%
+    \colorlet{currentcolor}{.}
+    \def\myEAtext{#5}%
+    \def\myEAcolor{\usevalue{\myEAmarkOne}}%
+    \begin{tikzpicture}[overlay,remember picture,>=stealth,nodes={align=left,inner ysep=1pt},<-]
+        % default anchor is at center
+        \node[anchor=\swapNorthSouth{\EAmarkanchor},color=\myEAcolor!85,#1]  % color blended with white to 85%, any (optional) extra args #1
+            (\eqnannotateCurrentNode)   % use counter-based "local node"
+            at ($(\myEAmarkOne.\EAmarkanchor)!0.5!(\myEAmarkTwo.\EAmarkanchor)$)  % centered between the two nodes
+            {\eqnannotationtext{\myEAtext}};
+        % double arrow to two uses within the equation:
+        \draw [<->,color=\myEAcolor] (\myEAmarkOne.\EAmarkanchor) |- ([yshift=0.1ex] \eqnannotateCurrentNode.\EAlabelanchor) -| (\myEAmarkTwo.\EAmarkanchor);  % from node 1 via annotation to node 2, with anchor #6 each
+    \end{tikzpicture}%
+    \endgroup% %%% close group again
+}
+
+
+%%% \extractfirst from https://tex.stackexchange.com/a/115733/171664
+\RequirePackage{expl3}
+\RequirePackage{xparse}
+\ExplSyntaxOn
+\NewDocumentCommand{\extractfirst}{mm}
+ {
+  \tl_set:Nx #1 {\clist_item:Nn #2 { 1 } }
+ }
+\ExplSyntaxOff
+%%%
+
+\newcommand{\annotate}[4][]{%
+    \begingroup% %%% so we don't leak the \def's below
+    \stepcounter{eqnannotatenode}%
+    %
+    %
+    %
+    % #1: (optional) extra args for \node e.g. yshift=...
+    \pgfkeys{/eqnannotate, #2}
+    \def\myEAmarks{#3}%
+    \extractfirst\myEAmark\myEAmarks% %%% get first node for color and annotation
+    \def\myEAtext{#4}%
+    %
+    %
+    \colorlet{currentcolor}{.}
+    \def\myEAcolor{\usevalue{\myEAmark}}%
+    %
+    %
+    \def\myEAxshift{\EAxshift{\EAwesteast}}%
+    \begin{tikzpicture}[overlay,remember picture,>=stealth,nodes={align=left,inner ysep=1pt},<-]
+        \node[anchor=\swapNorthSouth{\EAmarkanchor} \swapWestEast{\EAwesteast},color=\myEAcolor!85,#1] % TODO for some reason, passing #1 through command doesn't work...
+                % anchor=west: align left edge of text on top of tikzmark in equation
+                % should be north west for below and south west for above ...
+            (\eqnannotateCurrentNode) at (\myEAmark.\EAmarkanchor)  % \EAmarkanchor north: above the equation, south: below
+            {\eqnannotationtext{\myEAtext}};
+        \foreach \EAmark in \myEAmarks
+        \draw [color=\myEAcolor] (\EAmark.\EAmarkanchor)  % arrow from the equation
+                % \EAmarkanchor north: above the equation, south: below
+            |- ([xshift=\myEAxshift,yshift=0.1ex] \eqnannotateCurrentNode.south \EAwesteast);
+                % - south east: we want line to end at bottom right of annotation text;
+                % - negative xshift makes it a little bit shorter;
+                % - yshift for aesthetics (\strut is ever so slightly too tall).
+    \end{tikzpicture}%
+    \endgroup% %%% close group again
+}
+
+\endinput
+%%
+%% End of file
-- 
cgit v1.2.3

