% !TeX spellcheck = en_US
% !TeX root = tikz-ext-manual.tex
% Copyright 2022 by Qrrbrbirlbel
%
% This file may be distributed and/or modified
%
% 1. under the LaTeX Project Public License and/or
% 2. under the GNU Free Documentation License.
%
\section{And a little bit more}
\begin{tikzlibrary}{ext.misc}
This library adds miscellaneous utilities to \pgfname math, \pgfname\space or \tikzname.
\inspiration{FullArc-Q}{FullArc-A}
\end{tikzlibrary}
Similar to |\segments[<num>]| in PSTricks, the postfix operator |R| allows the user
to use an arbitrary number of segments of a circle to be used instead of an angle.
\begin{key}{/\pgfext/full arc=\meta{num} (default |\{\}|)}\keycompat{pgf}
The number \meta{num} of segments will be set up.
Using |full arc| with an empty value disables the segmentation and |1R| equals $1^\circ$.
The given value \meta{num} is evaluated when the key is used and doesn't change when
\meta{num} contains variables that change.
\end{key}
The |R| operator can then be used.
\begin{math-operator}{R}{postfix}{extfullarc}
Multiplies \mvar{x} with $\frac{360}{\meta{num}}$.
\end{math-operator}
\subsubsection{Functions}
\begin{math-function}{extstrrepeat("\mvar{Text}", \mvar{x})}\mathcompat{strrepeat}
\mathcommand
Returns a string with \mvar{Text} repeated \mvar{x} times.
\begin{math-function}{extstrcat("\mvar{Text A}", "\mvar{Text B}", …)}\mathcompat{strcat}
\mathcommand
Returns the concatenation of all given parameters.
\begin{math-function}{extatanXY(\mvar{x},\mvar{y})}\mathcompat{atanXY}
\mathcommand
Arctangent of $\mvar y\div \mvar x$ in degrees. This also takes into account the quadrant.
This is just a argument-swapped version of |atan2|\indexMathFunctionO{atan2} which makes it easier to use
the |\p| commands of the |calc|\indexLibraryO{calc} library.
%
\begin{codeexample}[]
\pgfmathparse{extatanXY(3,4)} \pgfmathresult
\end{codeexample}
\end{math-function}
\begin{math-function}{extatanYX(\mvar{y},\mvar{x})}\mathcompat{atanYX}
\mathcommand
Arctangent of $y\div x$ in degrees. This also takes into account the quadrant.
\begin{codeexample}[]
\pgfmathparse{extatanYX(4,3)} \pgfmathresult
\end{codeexample}
\end{math-function}
\subsubsection{Functions: using coordinates}
The following functions can only be used with \pgfname\space and/or \tikzname.
Since the arguments are usually plain text (and not numbers) one has to wrap
them in |"|.
\begin{math-function}{extanglebetween("\mvar{p1}", "\mvar{p2}")}\mathcompat{anglebetween}\mathcommand
Return the angle between the centers of the nodes \mvar{p1} and \mvar{p2}.
\end{math-function}
\begin{math-function}{extqanglebetween("\mvar{p}")}\mathcompat{qanglebetween}\mathcommand
Return the angle between the origin and the center of the node \mvar{p}.
\end{math-function}
\begin{math-function}{extdistancebetween("\mvar{p1}", "\mvar{p2}")}\mathcompat{distancebetween}\mathcommand
Return the distance (in pt) between the centers of the nodes \mvar{p1} and \mvar{p2}.
\end{math-function}
\begin{math-function}{extqdistancebetween("\mvar{p}")}\mathcompat{qdistancebetween}\mathcommand
Return the distance (in pt) between the origin and the center of the node \mvar{p}.
\end{math-function}
This library loads also most of the functions of the
\referencePackageandIndex{pgffor-ext} of section~\ref{pkg:pgffor-ext}
on page~\pageref{pkg:pgffor-ext}.
\subsection{\pgfname keys}
\begin{pgfkeyslibrary}{ext.pgfkeys-plus}
This extends \pgfname keys and adds helpful |/utils| keys as well as handlers.
This library gets loaded by the |ext.misc| library.
\end{pgfkeyslibrary}
\begin{multicols}{2}
\subsubsection{Conditionals}
\begin{key}{/\utilsext/pgfmath if=\marg{cond}\marg{true}\opt{\marg{false}}}{\def\myname{if}\keycompat{utils}}
This key checks the conditional \meta{cond} and applies the styles \meta{true}
if \meta{cond} is true, otherwise \meta{false}.
\meta{cond} can be anything that \pgfname math understands.
As a side effect on how \pgfname keys parses argument, the \meta{false} argument is
actually optional.
\end{key}
The following keys use \TeX' macros |\if|, |\ifx|, |\ifnum| and |\ifdim| for faster
executions.
\begin{key}{/\utilsext/if=\meta{token A}\meta{token B}\marg{true}\opt{\marg{false}}}\keycompat{utils/TeX}
This key checks via |\if| if \meta{token A} matches \meta{token B}
and applies the styles \meta{true} if it does, otherwise \meta{false}.
As a side effect on how \pgfname keys parses argument, the \meta{false} argument is
actually optional.
\end{key}
\begin{key}{/\utilsext/ifx=\meta{token A}\meta{token B}\marg{true}\opt{\marg{false}}}\keycompat{utils/TeX}
As above but via |\ifx|.
\end{key}
\begin{key}{/\utilsext/ifnum=\marg{num cond}\marg{true}\opt{\marg{false}}}\keycompat{utils/TeX}
This key checks |\ifnum|\meta{num cond}
and applies the styles \meta{true} if true, otherwise \meta{false}.
A delimiting |\relax| will be inserted after \meta{num cond}.
As a side effect on how \pgfname keys parses arguments, the \meta{false} argument is
actually optional.
\end{key}
\begin{key}{/\utilsext/ifdim=\meta{dim cond}\meta{true}\opt{\meta{false}}}\keycompat{utils/TeX}
As above but with |\ifdim|.
\end{key}
\begin{key}{/\utilsext/ifempty=\meta{Text}\meta{true}\opt{\meta{false}}}\keycompat{utils/TeX}
This checks whether \meta{Text} is empty and applies styles \meta{true} if true,
otherwise \meta{false}.
\end{key}
\begin{key}{/\utilsext/ifxempty=\meta{Text}\meta{true}\opt{\meta{false}}}\keycompat{utils/TeX}
This checks whether fully expanded \meta{Text} is empty and applies styles \meta{true} if true,
otherwise \meta{false}.
\end{key}
\subsubsection{Handlers}
While already a lot of values given to keys are evaluated by \pgfname math at some point,
not all of them are.
\begin{ext_handler}{{pgfmath}|=|\meta{eval}}\handlercompat{.pgfmath}
This handler evaluates \meta{eval} before it is handed to the key.
This handler works almost the same as the |.evaluated|\indexHandlerO{.evaluated}
handler but it does its evaluation in a group so that the result will
not overwrite any other results.
\end{ext_handler}
\begin{ext_handler}{{pgfmath int}|=|\meta{eval}}\handlercompat{.pgfmath int}
As above but truncates the result.
\end{ext_handler}
\begin{ext_handler}{{pgfmath wrap}|=|\marg{wrapper}\marg{eval}}\handlercompat{.pgfmath wrap}
This feeds the result of \meta{eval} as |#1| to \meta{wrapper}.
In the example below, one could have used the \referenceKeyandIndexO[/pgf/foreach/]{evaluate}
key from the |\foreach| loop.
\begin{codeexample}[width=3.7cm,preamble=\usepgfkeyslibrary{ext.pgfkeys-plus}]
\tikz\foreach \i in {0,10,...,100}
\draw[
line width=+.25cm,
% needs ## because its inside the \foreach body
color/.ext_pgfmath wrap={red!##1!blue}{sqrt(\i)*10}
]
(0,\i/40) -- +(right:3);
\end{codeexample}
\end{ext_handler}
\begin{ext_handler}{{pgfmath if}|=|\marg{cond}\marg{true}\opt{\marg{false}}}\handlercompat{.pgfmath if}
Evaluates \meta{cond} with \pgfname Math and returns \meta{true} or \meta{false} to the used key respectively.
\end{ext_handler}
\begin{ext_handler}{{if}|=|\meta{token A}\meta{token B}\marg{true}\opt{\marg{false}}}\handlercompat{.if}
Checks via |\if| if \meta{token A} matches \meta{token B}
and applies the value \meta{true} if it does, otherwise \meta{false}.
\end{ext_handler}
\begin{ext_handler}{{ifx}|=|\meta{token A}\meta{token B}\marg{true}\opt{\marg{false}}}\handlercompat{.ifx}
As above but via |\ifx|.
\end{ext_handler}
\begin{ext_handler}{{ifnum}|=|\marg{ifnum cond}\marg{true}\opt{\marg{false}}}\handlercompat{.ifnum}
Checks via |\ifnum| if \meta{ifnum cond}
and applies the value \meta{true} if it does, otherwise \meta{false}.
\end{ext_handler}
\begin{ext_handler}{{ifdim}|=|\marg{ifdim cond}\marg{true}\opt{\marg{false}}}\handlercompat{.ifdim}
As above but via |\ifdim|.
\end{ext_handler}
\begin{ext_handler}{{ifxempty}|=|\marg{Text}\marg{true}\opt{\marg{false}}}\handlercompat{.ifxempty}
Checks whether a fully expanded \meta{Text} is empty
and applies the value \meta{true} if it does, otherwise \meta{false}.
\end{ext_handler}
\begin{ext_handler}{{ifempty}|=|\marg{Text}\marg{true}\opt{\marg{false}}}
Checks whether \meta{Text} is empty
and applies the value \meta{true} if it does, otherwise \meta{false}.
\end{ext_handler}
\begin{ext_handler}{{List}|=|\marg{\meta{e1}, \meta{e2}, \dots, \meta{en}}}\handlercompat{.List}
This handler evaluates the given list with |\foreach| and concatenates the element and
the result is then given to the used key.
\end{ext_handler}
\end{multicols}
\begin{codeexample}[width=6cm,preamble=\usetikzlibrary{fit,ext.misc}]
\begin{tikzpicture}[nodes={draw, dashed, inner sep=+10pt}]
\foreach \point [count=\cnt] in {(0,0), (0,2), (2,0), (2,2), (3,3), (-1,-1)}
\node[circle, fill, inner sep=1pt, text=white] (point-\cnt) at \point {\cnt};
\node[gray, fit/.ext_List={(point-1),(point-...),(point-4)}] {};
\node[red, fit/.ext_List={(point-1),(point-...),(point-5)}] {};
\node[blue, fit/.ext_List={(point-1),(point-...),(point-6)}] {};
\end{tikzpicture}
\end{codeexample}
\pagebreak
\subsection{\tikzname}
\begin{multicols}{2}
\begin{key}{/\tikzext/reverse clip=\meta{direction} (default counter clockwise)}\keycompat{tikz}
This key installs a very big rectangle which is either constructed
\texttt{counter clockwise} (like the \referencePathOperationandIndexO{circle}
path operation) or |clockwise|.
\end{key}
\begin{key}{/\tikzext/clip rule=\meta{direction} (default even odd)}\keycompat{tikz}
This key switches directly\footnote{%
Meaning, it directly executes
\referenceCommandandIndexO{\pgfseteorule}/%
\referenceCommandandIndexO{\pgfsetnonzerorule}
and doesn't accumulates where \tikzname\space
throws an error.}
to the specified rule which is
either |even odd| or |nonzero|.
This corresponds to the \referenceKeyandIndexO{even odd rule} and
\referenceKeyandIndexO{nonzero rule} keys.
\end{key}
\end{multicols}
\begingroup\catcode`\&=\active
\begin{codeexample}[preamble=\usetikzlibrary{ext.misc},width=6cm]
\newcommand*\myDiagram[1]{
\fill[left color=blue, right color=green] (0, 0) rectangle (2, 1);
\clip (1, .5) #1 [ext/reverse clip];
\fill[left color=green, right color=blue] (0, 0) rectangle (2, 1);
}
\begin{tikzpicture}[radius=.4, row sep=5mm, column sep=5mm]
\matrix[
row 2/.append style={ext/clip rule=even odd},
column 1/.append style={ext/reverse clip/.default=clockwise}
]{
\myDiagram{circle[]} &
\myDiagram{+(0:.4) arc[start angle=0, delta angle=-360] -- cycle}
\\
\myDiagram{circle[]} &
\myDiagram{+(0:.4) arc[start angle=0, delta angle=-360] -- cycle}
\\};
\end{tikzpicture}
\end{codeexample}
\endgroup
\endinput
