我有以下 tikz 图的代码：
\documentclass{standalone}
\usepackage{tikz}
\NeedsTeXFormat{LaTeX2e}[1999/01/01]
\ProvidesPackage{freetikz}
\RequirePackage{tikz}
\pgfdeclarelayer{edgelayer}
\pgfdeclarelayer{nodelayer}
\pgfdeclarelayer{foreground}
\pgfdeclarelayer{background}
\pgfsetlayers{background,edgelayer,nodelayer,main,foreground,background}
\def\thickness{0.7pt}
\tikzstyle{dot}=[circle, draw=black, fill=black!25, inner sep=.4ex, line width=\thickness, node on layer=foreground]
\tikzstyle{blackdot}=[dot, fill=black!50]
\tikzstyle{blackdot}=[dot, fill=gray!40!white]
\tikzstyle{whitedot}=[dot, fill=white]
\tikzstyle{reddot}=[dot, fill=red]
\tikzstyle{greendot}=[dot, fill=green]
\makeatletter
\pgfkeys{%
/tikz/on layer/.code={
\pgfonlayer{#1}\begingroup
\aftergroup\endpgfonlayer
\aftergroup\endgroup
},
/tikz/node on layer/.code={
\gdef\node@@on@layer{%
\setbox\tikz@tempbox=\hbox\bgroup\pgfonlayer{#1}\unhbox\tikz@tempbox\endpgfonlayer\egroup}
\aftergroup\node@on@layer
},
/tikz/end node on layer/.code={
\endpgfonlayer\endgroup\endgroup
}
}
\def\node@on@layer{\aftergroup\node@@on@layer}
\makeatother
% Lengths
\newlength\morphismheight
\setlength\morphismheight{0.6cm}
\newlength\minimummorphismwidth
\setlength\minimummorphismwidth{0.6cm}
\newlength\stateheight
\setlength\stateheight{0.6cm}
\newlength\minimumstatewidth
\setlength\minimumstatewidth{0.89cm}
\newlength\connectheight
\setlength\connectheight{0.5cm}
\tikzset{width/.initial=\minimummorphismwidth}
% Keys
\newif\ifwedge\pgfkeys{/tikz/wedge/.is if=wedge}
\tikzset{wedge}
\newif\ifvflip\pgfkeys{/tikz/vflip/.is if=vflip}
\newif\ifhflip\pgfkeys{/tikz/hflip/.is if=hflip}
\newif\ifhvflip\pgfkeys{/tikz/hvflip/.is if=hvflip}
\newif\ifconnectnw\pgfkeys{/tikz/connect nw/.is if=connectnw}
\newif\ifconnectne\pgfkeys{/tikz/connect ne/.is if=connectne}
\newif\ifconnectsw\pgfkeys{/tikz/connect sw/.is if=connectsw}
\newif\ifconnectse\pgfkeys{/tikz/connect se/.is if=connectse}
\newif\ifconnectn\pgfkeys{/tikz/connect n/.is if=connectn}
\newif\ifconnects\pgfkeys{/tikz/connect s/.is if=connects}
\newif\ifconnectnwf\pgfkeys{/tikz/connect nw >/.is if=connectnwf}
\newif\ifconnectnef\pgfkeys{/tikz/connect ne >/.is if=connectnef}
\newif\ifconnectswf\pgfkeys{/tikz/connect sw >/.is if=connectswf}
\newif\ifconnectsef\pgfkeys{/tikz/connect se >/.is if=connectsef}
\newif\ifconnectnf\pgfkeys{/tikz/connect n >/.is if=connectnf}
\newif\ifconnectsf\pgfkeys{/tikz/connect s >/.is if=connectsf}
\newif\ifconnectnwr\pgfkeys{/tikz/connect nw </.is if=connectnwr}
\newif\ifconnectner\pgfkeys{/tikz/connect ne </.is if=connectner}
\newif\ifconnectswr\pgfkeys{/tikz/connect sw </.is if=connectswr}
\newif\ifconnectser\pgfkeys{/tikz/connect se </.is if=connectser}
\newif\ifconnectnr\pgfkeys{/tikz/connect n </.is if=connectnr}
\newif\ifconnectsr\pgfkeys{/tikz/connect s </.is if=connectsr}
\tikzset{keylengthnw/.initial=\connectheight}
\tikzset{keylengthn/.initial =\connectheight}
\tikzset{keylengthne/.initial=\connectheight}
\tikzset{keylengthsw/.initial=\connectheight}
\tikzset{keylengths/.initial =\connectheight}
\tikzset{keylengthse/.initial=\connectheight}
\tikzset{connect nw length/.style={connect nw=true, keylengthnw={#1}}}
\tikzset{connect n length/.style ={connect n =true, keylengthn ={#1}}}
\tikzset{connect ne length/.style={connect ne=true, keylengthne={#1}}}
\tikzset{connect sw length/.style={connect sw=true, keylengthsw={#1}}}
\tikzset{connect s length/.style ={connect s =true, keylengths ={#1}}}
\tikzset{connect se length/.style={connect se=true, keylengthse={#1}}}
\tikzset{connect nw < length/.style={connect nw <=true, keylengthnw={#1}}}
\tikzset{connect n < length/.style ={connect n <=true, keylengthn ={#1}}}
\tikzset{connect ne < length/.style={connect ne <=true, keylengthne={#1}}}
\tikzset{connect sw < length/.style={connect sw <=true, keylengthnw={#1}}}
\tikzset{connect s < length/.style ={connect s <=true, keylengths ={#1}}}
\tikzset{connect se < length/.style={connect se <=true, keylengthse={#1}}}
\tikzset{connect nw > length/.style={connect nw >=true, keylengthnw={#1}}}
\tikzset{connect n > length/.style ={connect n >=true, keylengthn ={#1}}}
\tikzset{connect ne > length/.style={connect ne >=true, keylengthne={#1}}}
\tikzset{connect sw > length/.style={connect sw >=true, keylengthsw={#1}}}
\tikzset{connect s > length/.style ={connect s >=true, keylengths ={#1}}}
\tikzset{connect se > length/.style={connect se >=true, keylengthse={#1}}}
% Shapes
\makeatletter
\pgfdeclareshape{morphism}
{
\savedanchor\centerpoint
{
\pgf@x=0pt
\pgf@y=0pt
}
\anchor{center}{\centerpoint}
\anchorborder{\centerpoint}
\saveddimen\savedlengthnw
{
\pgfkeysgetvalue{/tikz/keylengthnw}{\len}
\pgf@x=\len
}
\saveddimen\savedlengthn
{
\pgfkeysgetvalue{/tikz/keylengthn}{\len}
\pgf@x=\len
}
\saveddimen\savedlengthne
{
\pgfkeysgetvalue{/tikz/keylengthne}{\len}
\pgf@x=\len
}
\saveddimen\savedlengthsw
{
\pgfkeysgetvalue{/tikz/keylengthsw}{\len}
\pgf@x=\len
}
\saveddimen\savedlengths
{
\pgfkeysgetvalue{/tikz/keylengths}{\len}
\pgf@x=\len
}
\saveddimen\savedlengthse
{
\pgfkeysgetvalue{/tikz/keylengthse}{\len}
\pgf@x=\len
}
\saveddimen\overallwidth
{
\pgfkeysgetvalue{/tikz/width}{\minwidth}
\pgf@x=\wd\pgfnodeparttextbox
\ifdim\pgf@x<\minwidth
\pgf@x=\minwidth
\fi
}
\savedanchor{\upperrightcorner}
{
\pgf@y=.5\ht\pgfnodeparttextbox
\advance\pgf@y by -.5\dp\pgfnodeparttextbox
\pgf@x=.5\wd\pgfnodeparttextbox
}
\anchor{north}
{
\pgf@x=0pt
\pgf@y=0.5\morphismheight
}
\anchor{north east}
{
\pgf@x=\overallwidth
\multiply \pgf@x by 2
\divide \pgf@x by 5
\pgf@y=0.5\morphismheight
}
\anchor{east}
{
\pgf@x=\overallwidth
\divide \pgf@x by 2
\advance \pgf@x by 5pt
\pgf@y=0pt
}
\anchor{west}
{
\pgf@x=-\overallwidth
\divide \pgf@x by 2
\advance \pgf@x by -5pt
\pgf@y=0pt
}
\anchor{north west}
{
\pgf@x=-\overallwidth
\multiply \pgf@x by 2
\divide \pgf@x by 5
\pgf@y=0.5\morphismheight
}
\anchor{connect nw}
{
\pgf@x=-\overallwidth
\multiply \pgf@x by 2
\divide \pgf@x by 5
\pgf@y=0.5\morphismheight
\advance\pgf@y by \savedlengthnw
}
\anchor{connect ne}
{
\pgf@x=\overallwidth
\multiply \pgf@x by 2
\divide \pgf@x by 5
\pgf@y=0.5\morphismheight
\advance\pgf@y by \savedlengthne
}
\anchor{connect sw}
{
\pgf@x=-\overallwidth
\multiply \pgf@x by 2
\divide \pgf@x by 5
\pgf@y=-0.5\morphismheight
\advance\pgf@y by -\savedlengthsw
}
\anchor{connect se}
{
\pgf@x=\overallwidth
\multiply \pgf@x by 2
\divide \pgf@x by 5
\pgf@y=-0.5\morphismheight
\advance\pgf@y by -\savedlengthse
}
\anchor{connect n}
{
\pgf@x=0pt
\pgf@y=0.5\morphismheight
\advance\pgf@y by \savedlengthn
}
\anchor{connect s}
{
\pgf@x=0pt
\pgf@y=-0.5\morphismheight
\advance\pgf@y by -\savedlengths
}
\anchor{south east}
{
\pgf@x=\overallwidth
\multiply \pgf@x by 2
\divide \pgf@x by 5
\pgf@y=-0.5\morphismheight
}
\anchor{south west}
{
\pgf@x=-\overallwidth
\multiply \pgf@x by 2
\divide \pgf@x by 5
\pgf@y=-0.5\morphismheight
}
\anchor{south}
{
\pgf@x=0pt
\pgf@y=-0.5\morphismheight
}
\anchor{text}
{
\upperrightcorner
\pgf@x=-\pgf@x
\pgf@y=-\pgf@y
}
\backgroundpath
{
\pgfsetstrokecolor{black}
\pgfsetlinewidth{\thickness}
\begin{scope}
\ifhflip
\pgftransformyscale{-1}
\fi
\ifvflip
\pgftransformxscale{-1}
\fi
\ifhvflip
\pgftransformxscale{-1}
\pgftransformyscale{-1}
\fi
\pgfpathmoveto{\pgfpoint
{-0.5*\overallwidth-5pt}
{0.5*\morphismheight}}
\pgfpathlineto{\pgfpoint
{0.5*\overallwidth+5pt}
{0.5*\morphismheight}}
\ifwedge
\pgfpathlineto{\pgfpoint
{0.5*\overallwidth + 15pt}
{-0.5*\morphismheight}}
\else
\pgfpathlineto{\pgfpoint
{0.5*\overallwidth + 5pt}
{-0.5*\morphismheight}}
\fi
\pgfpathlineto{\pgfpoint
{-0.5*\overallwidth-5pt}
{-0.5*\morphismheight}}
\pgfpathclose
\pgfusepath{stroke}
\end{scope}
\ifconnectnw
\pgfpathmoveto{\pgfpoint
{-0.4*\overallwidth}
{0.5*\morphismheight}}
\pgfpathlineto{\pgfpoint
{-0.4*\overallwidth}
{0.5*\morphismheight+\savedlengthnw}}
\pgfusepath{stroke}
\fi
\ifconnectne
\pgfpathmoveto{\pgfpoint
{0.4*\overallwidth}
{0.5*\morphismheight}}
\pgfpathlineto{\pgfpoint
{0.4*\overallwidth}
{0.5*\morphismheight+\savedlengthne}}
\pgfusepath{stroke}
\fi
\ifconnectsw
\pgfpathmoveto{\pgfpoint
{-0.4*\overallwidth}
{-0.5*\morphismheight}}
\pgfpathlineto{\pgfpoint
{-0.4*\overallwidth}
{-0.5*\morphismheight-\savedlengthsw}}
\pgfusepath{stroke}
\fi
\ifconnectse
\pgfpathmoveto{\pgfpoint
{0.4*\overallwidth}
{-0.5*\morphismheight}}
\pgfpathlineto{\pgfpoint
{0.4*\overallwidth}
{-0.5*\morphismheight-\savedlengthse}}
\pgfusepath{stroke}
\fi
\ifconnectn
\pgfpathmoveto{\pgfpoint
{0pt}
{0.5*\morphismheight}}
\pgfpathlineto{\pgfpoint
{0pt}
{0.5*\morphismheight+\savedlengthn}}
\pgfusepath{stroke}
\fi
\ifconnects
\pgfpathmoveto{\pgfpoint
{0pt}
{-0.5*\morphismheight}}
\pgfpathlineto{\pgfpoint
{0pt}
{-0.5*\morphismheight-\savedlengths}}
\pgfusepath{stroke}
\fi
\ifconnectnwf
\draw [forward arrow style] (-0.4*\overallwidth,0.5*\morphismheight)
to (-0.4*\overallwidth,0.5*\morphismheight+\savedlengthnw);
\fi
\ifconnectnef
\draw [forward arrow style] (0.4*\overallwidth,0.5*\morphismheight)
to (0.4*\overallwidth,0.5*\morphismheight+\savedlengthne);
\fi
\ifconnectswf
\draw [forward arrow style] (-0.4*\overallwidth,-0.5*\morphismheight-\savedlengthsw)
to (-0.4*\overallwidth,-0.5*\morphismheight);
\fi
\ifconnectsef
\draw [forward arrow style] (0.4*\overallwidth,-0.5*\morphismheight-\savedlengthse)
to (0.4*\overallwidth,-0.5*\morphismheight);
\fi
\ifconnectnf
\draw [forward arrow style] (0,0.5*\morphismheight)
to (0,0.5*\morphismheight+\savedlengthn);
\fi
\ifconnectsf
\draw [forward arrow style] (0,-0.5*\morphismheight-\savedlengths)
to (0,-0.5*\morphismheight);
\fi
\ifconnectnwr
\draw [reverse arrow style] (-0.4*\overallwidth,0.5*\morphismheight)
to (-0.4*\overallwidth,0.5*\morphismheight+\savedlengthnw);
\fi
\ifconnectner
\draw [reverse arrow style] (0.4*\overallwidth,0.5*\morphismheight)
to (0.4*\overallwidth,0.5*\morphismheight+\savedlengthne);
\fi
\ifconnectswr
\draw [reverse arrow style] (-0.4*\overallwidth,-0.5*\morphismheight-\savedlengthsw)
to (-0.4*\overallwidth,-0.5*\morphismheight);
\fi
\ifconnectser
\draw [reverse arrow style] (0.4*\overallwidth,-0.5*\morphismheight-\savedlengthse)
to (0.4*\overallwidth,-0.5*\morphismheight);
\fi
\ifconnectnr
\draw [reverse arrow style] (0,0.5*\morphismheight)
to (0,0.5*\morphismheight+\savedlengthn);
\fi
\ifconnectsr
\draw [reverse arrow style] (0,-0.5*\morphismheight-\savedlengths)
to (0,-0.5*\morphismheight);
\fi
}
}
\makeatother
\begin{document}
\begin{tikzpicture}
\node [whitedot] (d0) at (2/2, 4/2) {$\alpha$};
\node [whitedot] (d1) at (1/2, 2/2) {$\beta$};
\node [whitedot] (d2) at (3/2, 2/2) {$\gamma$};
\node [whitedot] (d3) at (0,6/2) {$a$};
\node [whitedot] (d4) at (4/2,6/2) {$b$};
\node [whitedot] (d5) at (0,0) {$c$};
\node [whitedot] (d6) at (2/2,0) {$d$};
\node [whitedot] (d7) at (4/2,0) {$e$};
\draw [->] (d0.center) to[out=180, in=-90] (0,6/2);
\draw [->] (d0.center) to[out=0, in=-90] (4/2, 6/2);
\draw [->] (d0.center) to[out=-90, in=0] (d1.center);
\draw (d0.center) to[out=-90, in=180] (d2.center);
\draw (d1.center) to[out=180, in=90] (0, 0);
\draw (d1.center) to[out=0, in=90] (2/2,0);
\draw (d2.center) to[out=180, in=90] (2/2, 0);
\draw (d2.center) to[out=0, in=90] (4/2, 0);
\end{tikzpicture}
\end{document}
这将产生以下输出：
看起来不错，只是箭头被节点挡住了。有什么方法可以让箭头指向节点外部吗？
答案1
我怀疑您是在看下面的图片：
我可以通过您在问题中提供的更短更简单的代码来绘制：
\documentclass[border=3.141592]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,
positioning}
\begin{document}
\begin{tikzpicture}[
node distance = 16mm and 8mm, on grid,
V/.style = {circle, minimum size=7mm, draw, semithick},
every edge/.append style = {draw, - Stealth}
]
\begin{scope}[nodes=V]
\node (v0) {$\alpha$};
\node (v1) [below left=of v0] {$\beta$};
\node (v2) [below right=of v0] {$\gamma$};
\node (v3) [below left=of v1] {$c$};
\node (v4) [below right=of v1] {$d$};
\node (v5) [below right=of v2] {$e$};
%
\node (v6) [above left=16mm and 16mm of v0] {$a$};
\node (v7) [above right=16mm and 16mm of v0] {$b$};
\end{scope}
% edges
\path (v0) edge[out=180, in=-90] (v6)
(v0) edge[out=0, in=-90] (v7)
%
(v0) edge[out=-90, in= 30] (v1)
(v0) edge[out=-90, in=150] (v2)
%
(v1) edge[out=210, in= 90] (v3)
(v1) edge[out=330, in= 90] (v4)
%
(v2) edge[out=210, in= 90] (v4)
(v2) edge[out=330, in= 90] (v5);
\end{tikzpicture}
\end{document}
所以我想知道，你那长篇大论的目的是什么？可能是我没注意到你的问题。