From 346563a3ccfb00855edf16d04882dd8f136f16ed Mon Sep 17 00:00:00 2001
From: user202729 <25191436+user202729@users.noreply.github.com>
Date: Sat, 28 Sep 2024 15:53:54 +0700
Subject: [PATCH] refactor: simplify divide and reciprocal function

---
 .../pgf/math/pgfmathfunctions.basic.code.tex  | 191 +-----------------
 1 file changed, 11 insertions(+), 180 deletions(-)

diff --git a/tex/generic/pgf/math/pgfmathfunctions.basic.code.tex b/tex/generic/pgf/math/pgfmathfunctions.basic.code.tex
index 1607c386e..ee34faada 100644
--- a/tex/generic/pgf/math/pgfmathfunctions.basic.code.tex
+++ b/tex/generic/pgf/math/pgfmathfunctions.basic.code.tex
@@ -61,192 +61,23 @@
 
 % divide function.
 %
-\newif\ifpgfmath@divide@period
-
 \pgfmathdeclarefunction{divide}{2}{%
-    \begingroup%
-        \pgfmath@x=#1pt\relax%
-        \pgfmath@y=#2pt\relax%
-        \let\pgfmath@sign=\pgfmath@empty%
-        \ifdim0pt=\pgfmath@y%
-            \pgfmath@error{You've asked me to divide `#1' by `#2', %
-                but I cannot divide any number by `#2'}{}%
-        \fi%
-        \afterassignment\pgfmath@xa%
-        \c@pgfmath@counta\the\pgfmath@y\relax%
-        \ifdim0pt=\pgfmath@xa%
-            \divide\pgfmath@x by\c@pgfmath@counta%
-        \else%
-            \ifdim0pt>\pgfmath@x%
-                \def\pgfmath@sign{-}%
-                \pgfmath@x=-\pgfmath@x%
-            \fi%
-            \ifdim0pt>\pgfmath@y%
-                \expandafter\def\expandafter\pgfmath@sign\expandafter{\pgfmath@sign-}%
-                \pgfmath@y=-\pgfmath@y%
-            \fi%
-            \ifdim1pt>\pgfmath@y%
-                \pgfmathreciprocal@{\pgfmath@tonumber{\pgfmath@y}}%
-                \pgfmath@x=\pgfmath@sign\pgfmathresult\pgfmath@x%
-            \else%
-                \def\pgfmathresult{0}%
-                \pgfmath@divide@periodtrue%
-                \c@pgfmath@counta=0\relax%
-                \pgfmathdivide@@%
-                \pgfmath@x=\pgfmath@sign\pgfmathresult pt\relax%
-            \fi%
-        \fi%
-        \pgfmath@returnone\pgfmath@x%
-    \endgroup%
-}
-
-\def\pgfmath@small@number{0.00002}
-
-\def\pgfmathdivide@@{%
-    \let\pgfmath@next=\relax%
-    \ifdim\pgfmath@small@number pt<\pgfmath@x%
-        \ifdim\pgfmath@small@number pt<\pgfmath@y%
-            \ifdim\pgfmath@y>\pgfmath@x%
-                \ifpgfmath@divide@period%
-                    \expandafter\def\expandafter\pgfmathresult\expandafter{\pgfmathresult.}%
-                    \pgfmath@divide@periodfalse%
-                \fi%
-                \pgfmathdivide@dimenbyten\pgfmath@y%
-                \ifdim\pgfmath@y>\pgfmath@x%
-                    \expandafter\def\expandafter\pgfmathresult\expandafter{\pgfmathresult0}%
-                \fi%
-            \else%
-                \c@pgfmath@counta=\pgfmath@x%
-                \c@pgfmath@countb=\pgfmath@y%
-                \divide\c@pgfmath@counta by\c@pgfmath@countb%
-                \pgfmath@ya=\c@pgfmath@counta\pgfmath@y%
-                \advance\pgfmath@x by-\pgfmath@ya%
-                \def\pgfmath@next{%
-                    \toks0=\expandafter{\pgfmathresult}%
-                    \edef\pgfmathresult{\the\toks0 \the\c@pgfmath@counta}%
-                }%
-                \ifpgfmath@divide@period
-                \else
-                    % we are behind the period. It may happen that the
-                    % result is more than one digit - in that case,
-                    % introduce special handling:
-                    \ifnum\c@pgfmath@counta>9 %
-                        \expandafter\pgfmathdivide@advance@last@digit\pgfmathresult CCCCC\@@
-                        \advance\c@pgfmath@counta by-10 %
-                        \ifnum\c@pgfmath@counta=0
-                            \let\pgfmath@next=\relax
-                        \fi
-                    \fi
-                \fi
-                \pgfmath@next
-            \fi%
-            \let\pgfmath@next=\pgfmathdivide@@%
-        \fi%
-    \fi%
-    \pgfmath@next%
-}
-
-% advances the last digit found in the number. Any missing digits are
-% supposed to be filled with 'C'.
-\def\pgfmathdivide@advance@last@digit#1.#2#3#4#5#6#7\@@{%
-    \pgfmath@ya=\pgfmathresult pt %
-    \if#2C%
-        \pgfmath@xa=1pt %
-    \else
-        \if#3C%
-            \pgfmath@xa=0.1pt %
-        \else
-            \if#4C%
-                \pgfmath@xa=0.01pt %
-            \else
-                \if#5C%
-                    \pgfmath@xa=0.001pt %
-                \else
-                    \if#6C%
-                        \pgfmath@xa=0.0001pt %
-                    \else
-                        \pgfmath@xa=0.00001pt %
-                    \fi
-                \fi
-            \fi
-        \fi
-    \fi
-    \advance\pgfmath@ya by\pgfmath@xa
-    \edef\pgfmathresult{\pgfmath@tonumber@notrailingzero\pgfmath@ya}%
-}%
-
-{
-\catcode`\p=12
-\catcode`\t=12
-\gdef\Pgf@geT@NO@TRAILING@ZERO#1.#2pt{%
-    #1.%
-    \ifnum#2=0 \else #2\fi
+    \edef\pgfmathresult{\pgfmath@tonumber{\dimexpr
+        \numexpr
+            65536*\dimexpr #1pt\relax
+            /\dimexpr #2pt\relax
+        \relax
+    sp\relax}}%
 }
-}
-\def\pgfmath@tonumber@notrailingzero#1{\expandafter\Pgf@geT@NO@TRAILING@ZERO\the#1}
-
-
-\def\pgfmathdivide@dimenbyten#1{%
-    \edef\pgfmath@temp{\pgfmath@tonumber{#1}}%
-    \expandafter\pgfmathdivide@@dimenbyten\pgfmath@temp\@@#1\@@}
-\def\pgfmathdivide@@dimenbyten#1.#2\@@#3\@@{%
-    \pgfmath@tempcnta=#1\relax%
-    \divide\pgfmath@tempcnta by10\relax%
-    \pgfmath@tempcntb=\pgfmath@tempcnta%
-    \multiply\pgfmath@tempcnta by-10\relax%
-    \advance\pgfmath@tempcnta by#1\relax%
-    #3=\the\pgfmath@tempcntb.\the\pgfmath@tempcnta#2pt\relax%
-}
-
 
 % reciprocal function.
 %
 \pgfmathdeclarefunction{reciprocal}{1}{%
-    \begingroup%
-        \expandafter\pgfmath@x#1pt\relax%
-        \ifdim\pgfmath@x=0pt\relax%
-            \pgfmath@error{You asked me to calculate `1/#1', but I cannot divide any number by zero}{}%
-        \fi%
-        \edef\pgfmath@reciprocaltemp{\pgfmath@tonumber{\pgfmath@x}}%
-        \expandafter\pgfmathreciprocal@@\pgfmath@reciprocaltemp0000000\pgfmath@}
-\def\pgfmathreciprocal@@#1.#2#3#4#5#6#7\pgfmath@{%
-        \c@pgfmath@counta#2#3#4#5#6\relax%
-        % If the number is an integer, use TeX arithmetic.
-        \ifnum\c@pgfmath@counta=0\relax%
-            \pgfmath@x1pt\relax%
-            \divide\pgfmath@x#1\relax%
-        \else%
-            \ifnum#1>100\relax%
-                \c@pgfmath@counta#1#2#3#4\relax%
-                \c@pgfmath@countb1000000000\relax%
-                \divide\c@pgfmath@countb\c@pgfmath@counta%
-                \c@pgfmath@counta\c@pgfmath@countb%
-                \divide\c@pgfmath@counta10000\relax%
-                \pgfmath@x\c@pgfmath@counta pt\relax%
-                \multiply\c@pgfmath@counta-10000\relax%
-                \advance\c@pgfmath@countb\c@pgfmath@counta%
-                \pgfmath@y\c@pgfmath@countb pt\relax%
-                \divide\pgfmath@y1000000\relax%
-                \advance\pgfmath@x\pgfmath@y%
-            \else%
-                \c@pgfmath@counta#1#2#3#4#5#6\relax%
-                \c@pgfmath@countb1000000000\relax%
-                \divide\c@pgfmath@countb\c@pgfmath@counta%
-                \c@pgfmath@counta\c@pgfmath@countb%
-                \divide\c@pgfmath@counta10000\relax%
-                \pgfmath@x\c@pgfmath@counta pt\relax%
-                \multiply\c@pgfmath@counta-10000\relax%
-                \advance\c@pgfmath@countb\c@pgfmath@counta%
-                \pgfmath@y\c@pgfmath@countb pt\relax%
-                \pgfmath@y.1\pgfmath@y% Yes! This way is more accurate. Go figure...
-                \pgfmath@y.1\pgfmath@y%
-                \pgfmath@y.1\pgfmath@y%
-                \pgfmath@y.1\pgfmath@y%
-                \advance\pgfmath@x\pgfmath@y%
-            \fi%
-        \fi%
-        \pgfmath@returnone\pgfmath@x%
-    \endgroup%
+    \edef\pgfmathresult{\pgfmath@tonumber{\dimexpr
+        \numexpr
+            65536*65536/\dimexpr #1pt\relax
+        \relax
+    sp\relax}}%
 }
 
 % div function.