Patches TikZ's foreach to remember more information between iterations

This commit adds more information to what TikZ remembers between foreach iterations, and does so in a way that makes it easier to add other macros and dimensions to the list of things it remembers, both at the code level and via keys. Fixes pgf-tikz#356, pgf-tikz#1047, pgf-tikz#1303, pgf-tikz#1313 Signed-off-by: Andrew Stacey <[email protected]>
loopspace · Apr 12, 2024 · 33aff2d · 33aff2d
1 parent 20d9027
commit 33aff2d
Show file tree

Hide file tree

Showing 2 changed files with 63 additions and 16 deletions.
diff --git a/doc/generic/pgf/CHANGELOG.md b/doc/generic/pgf/CHANGELOG.md
@@ -12,6 +12,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ### Fixed
 
+- Foreach in path remembers nodes between iterations #356, #1047, #1303, #1313
 - Typo in animations `end on` key #1273
 - Output bounding box adjustment in pgfsys-dvisvgm.def #1275
 - Fix shadings under LuaMetaTeX

diff --git a/tex/generic/pgf/frontendlayer/tikz/tikz.code.tex b/tex/generic/pgf/frontendlayer/tikz/tikz.code.tex
@@ -2580,28 +2580,77 @@
 
 \def\tikz@fchar oreach{\tikz@foreach}%
 
+%
+% These are to allow \foreach to remember macros and dimensions between iterations
+%
+
+\def\tikzforeach@smugglers@cove{}
+\let\tikztostart=\relax
+
+\def\tikzforeach@smuggle@macro#1{%
+ \pgfutil@ifx#1\relax{}{%
+ \expandafter
+ \pgfutil@g@addto@macro
+ \expandafter
+ \tikzforeach@smugglers@cove
+ \expandafter
+ {%
+ \expandafter\def\expandafter#1\expandafter{#1}%
+ }%
+ }%
+}
+
+\def\tikzforeach@smuggle@dimen#1{%
+ \pgfutil@ifx#1\relax{}{%
+ \expandafter
+ \pgfutil@g@addto@macro
+ \expandafter
+ \tikzforeach@smugglers@cove
+ \expandafter
+ {%
+ \expandafter#1\expandafter=\the#1\relax%
+ }%
+ }%
+}
+
+\def\tikzforeach@smugglers@loot{%
+ %
+ \tikzforeach@smuggle@macro\tikz@moveto@waiting%
+ \tikzforeach@smuggle@macro\tikztostart%
+ \tikzforeach@smuggle@macro\tikz@tangent%
+ %
+ \tikzforeach@smuggle@dimen\tikz@lastx%
+ \tikzforeach@smuggle@dimen\tikz@lasty%
+ \tikzforeach@smuggle@dimen\tikz@lastxsaved%
+ \tikzforeach@smuggle@dimen\tikz@lastysaved%
+ %
+}
+
+\tikzset{
+ remember macro/.code={
+ \tikzforeach@smuggle@macro#1
+ },
+ remember dimension/.code={
+ \tikzforeach@smuggle@dimen#1
+ }
+}
+
+
 \def\tikz@foreach{%
  \def\pgffor@beginhook{%
- \tikz@lastx=\tikz@foreach@save@lastx%
- \tikz@lasty=\tikz@foreach@save@lasty%
- \tikz@lastxsaved=\tikz@foreach@save@lastxsaved%
- \tikz@lastysaved=\tikz@foreach@save@lastysaved%
+ \tikzforeach@smugglers@cove%
+ \gdef\tikzforeach@smugglers@cove{}%
  \setbox\tikz@figbox=\box\tikz@tempbox%
  \setbox\tikz@figbox@bg=\box\tikz@tempbox@bg%
  \expandafter\tikz@scan@next@command\pgfutil@firstofone}%
  \def\pgffor@endhook{\pgfextra{%
- \xdef\tikz@foreach@save@lastx{\the\tikz@lastx}%
- \xdef\tikz@foreach@save@lasty{\the\tikz@lasty}%
- \xdef\tikz@foreach@save@lastxsaved{\the\tikz@lastxsaved}%
- \xdef\tikz@foreach@save@lastysaved{\the\tikz@lastysaved}%
+ \tikzforeach@smugglers@loot%
  \global\setbox\tikz@tempbox=\box\tikz@figbox%
  \global\setbox\tikz@tempbox@bg=\box\tikz@figbox@bg%
  \pgfutil@gobble}}%
  \def\pgffor@afterhook{%
- \tikz@lastx=\tikz@foreach@save@lastx%
- \tikz@lasty=\tikz@foreach@save@lasty%
- \tikz@lastxsaved=\tikz@foreach@save@lastxsaved%
- \tikz@lastysaved=\tikz@foreach@save@lastysaved%
+ \tikzforeach@smugglers@cove%
+ \gdef\tikzforeach@smugglers@cove{}%
  \let\pgffor@beginhook\relax%
  \let\pgffor@endhook\relax%
  \let\pgffor@afterhook\relax%
@@ -2610,10 +2659,7 @@
  \tikz@scan@next@command}%
  \global\setbox\tikz@tempbox=\box\tikz@figbox%
  \global\setbox\tikz@tempbox@bg=\box\tikz@figbox@bg%
- \xdef\tikz@foreach@save@lastx{\the\tikz@lastx}%
- \xdef\tikz@foreach@save@lasty{\the\tikz@lasty}%
- \xdef\tikz@foreach@save@lastxsaved{\the\tikz@lastxsaved}%
- \xdef\tikz@foreach@save@lastysaved{\the\tikz@lastysaved}%
+ \tikzforeach@smugglers@loot%
  \foreach}%