为什么 tikz 填充命令会出现浅灰色边框？

Question

以下是源代码：

\documentclass{article}
\usepackage{tikz}

\begin{document}

\begin{tikzpicture}
    \draw (0, 0) circle (1cm);
    \path[fill=black] (90:1cm) arc (90:270:1cm);
    \path[fill=black] (0:0cm) arc (-90:90:.5cm);
    \path[fill=white] (0:0cm) arc (90:270:.5cm);
    \path[fill=white] (0, .5) circle (.1cm);
    \path[fill=black] (0, -.5) circle (.1cm);
\end{tikzpicture}

\begin{tikzpicture}
    \draw (0, 0) circle (1cm);
    \filldraw[color=black] (90:1cm) arc (90:270:1cm);
    \fill[color=black] (0, .5) circle (.5cm);
    \fill[color=white] (0, -.5) circle (.5cm);
    \fill[color=white] (0, .5) circle (.1cm);
    \fill[color=black] (0, -.5) circle (.1cm);
\end{tikzpicture}

\end{document}

两种方法都应该可行，但显然第一种方法存在一些缺陷，为什么？

Answer 1

虽然这可能是舍入错误，但它仍然很烦人。这也是您构造符号的方式造成的，因为您绘制并填充了一个半圆。相反，您可以做一些类似的事情：

\documentclass{article}
\usepackage{tikz}
\begin{document}

    \begin{tikzpicture}
      \draw (0, 0) circle (1cm);
      \path[fill=black] (90:1cm) arc (90:-90:0.5cm)
                        (0,0)    arc (90:270:0.5cm)
                        (0,-1cm) arc (-90:-270:1cm);
      \path[fill=white] (0, 0.5) circle (0.1cm);
      \path[fill=black] (0,-0.5) circle (0.1cm);
    \end{tikzpicture}

\end{document}

Answer 2

或者，您可以通过一条路径执行此操作：

代码

\documentclass[tikz]{standalone}
\tikzset{
  YinYang/.style={insert path={{[even odd rule, start angle=90, delta angle=180]
    coordinate (@aux) circle              [radius={#1}]
    arc                                   [radius={(#1)/2}]
    arc                                   [radius={#1},     start angle=270]
    arc                                   [radius={(#1)/2}, delta angle=-180]
    ([shift=(down:{(#1)/2})] @aux) circle [radius={(#1)/10}]
    ([shift=(  up:{(#1)/2})] @aux) circle [radius={(#1)/10}]
    % doing the big circle as an edge allows us to only draw that and only fill the rest
    (@aux) edge[to path={circle [radius={#1}]}] ()}}}}
\begin{document}
\tikz\fill[YinYang=1];
\tikz\fill[
    draw=white, every edge/.style,
    even odd rule, inner color=red,  outer color=blue,
    preaction    ={inner color=blue, outer color=red },
    % the preaction uses nonzero rule, so it is essentially only the full circle.
  ] [YinYang=-1];% negative raduius flips the two halves
\end{document}

输出