我怎样才能改变形状？

Question

我想声明一个自定义形状

\radius \pgf@xa=\pgf@x 
\centerpoint \pgf@xb=\pgf@x \pgf@yb=\pgf@y
\pgfpathcircle{\centerpoint}{\radius/10}
\pgfpathmoveto{\centerpoint}
\pgfpathellipse{\centerpoint}{\pgfpoint{\radius/2-\radius/10}{0}}{\pgfpoint{0}{\radius/10}}
\pgfpathellipse{\centerpoint}{\pgfpoint{\radius/2-\radius/10}{0}}{\pgfpoint{0}{\radius/10}}

自定义形状将继承自圆形。我有以下问题：

1. 如何用给定的颜色填充圆形、椭圆形等？
2. 我怎样才能将第一个半径为/2 的椭圆的中心点向左移动，将第二个半径为/2 的椭圆的中心点向右移动？

Answer 1

您需要对创建的路径进行描边、填充、阴影或剪切。这是一个快速模型（虽然有点太快了，但路径模式确实很老套。有更合适的方法可以做到这一点。只需查看形状库）。对于移动点，您可以使用\pgfpointadd或\pgfpointdiff等。

\documentclass{article}
\usepackage{tikz}
\makeatletter
\pgfdeclareshape{circse}{
\inheritsavedanchors[from=circle]
\inheritanchorborder[from=circle]
\inheritanchor[from=circle]{center}
\backgroundpath{
\radius 
\pgf@xa=\pgf@x 
\centerpoint \pgf@xb=\pgf@x \pgf@yb=\pgf@y
\pgfpathcircle{\centerpoint}{\radius/10}
%\pgfpathmoveto{\centerpoint}
\pgfpathellipse{\pgfpointadd{\centerpoint}{\pgfpoint{10pt}{0pt}}}{\pgfpoint{\radius/2-\radius/10}{0}}{\pgfpoint{0}{\radius/10}}
\pgfpathellipse{\pgfpointadd{\centerpoint}{\pgfpoint{-10pt}{0pt}}}{\pgfpoint{\radius/2-\radius/10}{0}}{\pgfpoint{0}{\radius/10}}
\begingroup
\tikz@mode

\iftikz@mode@fill
    \iftikz@mode@draw
    \pgfusepath{fill,draw}
    \else
    \pgfusepath{fill}
    \fi
\else
    \iftikz@mode@draw
    \pgfusepath{draw}
    \fi
\fi
\endgroup
}
}
\makeatother
\begin{document}
\begin{tikzpicture}
\node[circse,thick,draw=red,fill=yellow,scale=5] {};
\end{tikzpicture}
\end{document}