This is an extension of my previous question How can I highlight part of an equation with TikZ but without extra space around the highlighted part?. The new question is, how do I make the hilite command work over a page break? It was suggested that the \iftikzmarkoncurrentpage mechanism might work, but I'm having difficulty with the required logic. I also found Tikz picture with tikzmark across page boundary won't print if inside environment, Leaving Whitespace for Hidden Text, Math, and Figures, and some other posts that may be relevant.
I understand the difference between \AddToShipoutPictureBG and \AddToShipoutPictureBG* and with the former, every highlight background is shipped out to every page rather than just the current page. I am obviously am not doing something correctly.
This MWE is the closest I've come to getting a working solution.
% !TEX TS-program = lualatexmk
%
\documentclass[10pt]{article}
\usepackage{amsmath}
\usepackage{tikz}
\usepackage{eso-pic}
\usetikzlibrary{shapes,fit,tikzmark}
% This original works, except over pagebreaks!
%\newcounter{tikzhighlightnode}
%\NewDocumentCommand{\hilite}{ O{magenta!60} m O{rectangle} }{%
% % Code by anonymous user abcdefg
% % See https://texample.net/tikz/examples/beamer-arrows/
% % See also https://tex.stackexchange.com/a/406084/218142
% % See also https://tex.stackexchange.com/a/570858/218142
% % See also https://tex.stackexchange.com/a/570789/218142
% % See also https://tex.stackexchange.com/a/79659/218142
% % See also https://tex.stackexchange.com/q/375032/218142
% \stepcounter{tikzhighlightnode}%
% \tikzmarknode{highlighted-node-\number\value{tikzhighlightnode}}{#2}%
% \edef\temp{\noexpand\AddToShipoutPictureBG*{\noexpand\begin{tikzpicture}[overlay,remember picture]
% \noexpand\node[inner sep=1.0pt,fill=#1,#3,fit=(highlighted-node-\number\value{tikzhighlightnode})]{};%
% \noexpand\end{tikzpicture}}}%
% \temp%
%}%
\newcounter{tikzhighlightnode}
\NewDocumentCommand{\hilite}{ O{magenta!60} m O{rectangle} }{%
% Modified by me.
% See https://texample.net/tikz/examples/beamer-arrows/
% See also https://tex.stackexchange.com/a/406084/218142
% See also https://tex.stackexchange.com/a/570858/218142
% See also https://tex.stackexchange.com/a/570789/218142
% See also https://tex.stackexchange.com/a/79659/218142
% See also https://tex.stackexchange.com/q/375032/218142
\stepcounter{tikzhighlightnode}%
\tikzmarknode{highlighted-node-\number\value{tikzhighlightnode}}{#2}%
\iftikzmarkoncurrentpage{\thetikzhighlightnode}%
\else
\edef\temp{%
\noexpand\AddToShipoutPictureBG{%
\noexpand\begin{tikzpicture}[overlay,remember picture]%
\noexpand\node[inner sep=1.0pt,fill=#1,#3,fit=(highlighted-node-\number\value{tikzhighlightnode})]{};%
\noexpand\end{tikzpicture}%
}%
}%
\temp%
\fi
}%
\begin{document}
\begin{align}
(\Delta s)^2 &= -(\Delta t)^2 + (\Delta x)^2 + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite{-(\Delta t)^2 + (\Delta x)^2} + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite[brown]{-(\Delta t)^2 + (\Delta x)^2}[ellipse] + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite[cyan!50]{-(\Delta t)^2 + (\Delta x)^2}[rounded rectangle] + (\Delta y)^2 + (\Delta z)^2
\end{align}
\begin{align}
(\Delta s)^2 &= -(\Delta t)^2 + (\Delta x)^2 + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite{-(\Delta t)^2 + (\Delta x)^2}[rounded rectangle] + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite{-(\Delta t)^2 + (\Delta x)^2}[rectangle] + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite{-(\Delta t)^2 + (\Delta x)^2}[ellipse] + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^{\hilite{2}[circle]} &= \hilite[green]{-}[circle](\Delta t)^{\hilite[cyan]{2}[circle]}+
(\Delta x)^{\hilite[orange]{2}[circle]} + (\Delta y)^{\hilite[blue!50]{2}[circle]} +
(\Delta z)^{\hilite[violet!45]{2}[circle]}
\end{align}
\begin{align}
(\Delta s)^2 &= -(\Delta t)^2 + (\Delta x)^2 + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite[blue!50]{-(\Delta t)^2 + (\Delta x)^2}[rounded rectangle] + (\Delta y)^2 +
(\Delta z)^2 \
(\Delta s)^2 &= \hilite[green!50]{-(\Delta t)^2 + (\Delta x)^2}[rectangle] + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite[magenta!70]{-(\Delta t)^2 + (\Delta x)^2}[ellipse] + (\Delta y)^2 + (\Delta z)^2
\end{align}
\begin{align}
(\Delta s)^2 &= -(\Delta t)^2 + (\Delta x)^2 + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite[violet!50]{-(\Delta t)^2+(\Delta x)^2}[rounded rectangle]+(\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite[darkgray!50]{-(\Delta t)^2 + (\Delta x)^2}[rectangle] + (\Delta y)^2 + (\Delta z)^2 \
(\Delta s)^2 &= \hilite[purple!50]{-(\Delta t)^2 + (\Delta x)^2}[ellipse] + (\Delta y)^2 + (\Delta z)^2
\end{align}
\begin{align}
\Delta\mathbf{p} &= \mathbf{F}{\textnormal{net}},\Delta t \
\hilite[orange]{\Delta\mathbf{p}}[circle] &= \mathbf{F}{\textnormal{net}},\Delta t \
\Delta\mathbf{p} &= \hilite[yellow!50]{\mathbf{F}{\textnormal{net}}}[rounded rectangle],\Delta t \
\Delta\mathbf{p} &= \mathbf{F}{\textnormal{net}},\hilite[olive!50]{\Delta t}[rectangle] \
\Delta\mathbf{p} &= \hilite[cyan!50]{\mathbf{F}{\textnormal{net}},\Delta t}[ellipse] \
\hilite{\Delta\mathbf{p}}[rectangle] &= \mathbf{F}{\textnormal{net}},\Delta t
\end{align}
\begin{align}
\Delta\mathbf{p} &= \mathbf{F}{\textnormal{net}},\Delta t \
\hilite[orange]{\Delta\mathbf{p}}[circle] &= \mathbf{F}{\textnormal{net}},\Delta t \
\Delta\mathbf{p} &= \hilite[yellow!50]{\mathbf{F}{\textnormal{net}}}[rounded rectangle],\Delta t \
\Delta\mathbf{p} &= \mathbf{F}{\textnormal{net}},\hilite[olive!50]{\Delta t}[rectangle] \
\Delta\mathbf{p} &= \hilite[cyan!50]{\mathbf{F}{\textnormal{net}},\Delta t}[ellipse] \
\hilite{\Delta\mathbf{p}}[rectangle] &= \mathbf{F}{\textnormal{net}},\Delta t
\end{align}
\end{document}
convert -density 300 -delay 164 -loop 0 -alpha remove file.pdf file.gifto create an animated gif. See the end of this post. – Nov 21 '20 at 04:38\makealetterand\makeatotherdon't seem to be needed. – LaTeXereXeTaL Nov 21 '20 at 05:38\ifmeasuring@but this seems not to be needed.) – Nov 21 '20 at 05:40