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自动绘制圆弧上不同形状节点之间的路径

tag-icon • tag-icon tikz-pgf
自动绘制圆弧上不同形状节点之间的路径

我有一张图像，我想在节点之间绘制箭头，并且所有箭头都“在同一个圆上”。我可以手动实现我想要的效果，如下所示：

\documentclass{standalone}

\usepackage{tikz}
\usetikzlibrary{shapes}
\begin{document}
\begin{tikzpicture}[ultra thick, -stealth]
  \node[circle,fill] (a) at (0: 1) {};
  \node[rectangle,minimum width=1cm,fill](b) at (120: 1) {};
  \node[rectangle,minimum height=1cm,fill](c) at (240: 1) {};
  \draw[dashed] (85: 1) arc (85: 30: 1) ;
  \draw (330:1) arc (330: 280:1) ;
  \draw[dashed] (200:1) arc (200: 140:1);
\end{tikzpicture}
\end{document}

但是如果我的节点形状和大小不同，我必须手动找到可用的坐标。我真正想做的是找到节点边缘与圆相交的位置，并使用这些边缘绘制圆弧。有没有自动的方法可以做到这一点？这个答案是一个部分解决方案，但似乎我仍然必须shorten手动选择弧和长度......

实际用例是节点将包含不同纵横比的图片。我使用一些形状奇怪的节点来近似解决这个问题。

答案1

Heiko Oberdiek 太棒了！！！——

https://tex.stackexchange.com/a/250270/197451

在此处输入图片描述

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{bending}

\begin{document}
    \begin{tikzpicture}[
    ->,   
    thick,
    main node/.style={circle, fill=blue!20, draw},
    ]
    \newcommand*{\MainNum}{5}
    \newcommand*{\MainRadius}{1.5cm} 
    \newcommand*{\MainStartAngle}{90}
    
    % Print main nodes, node names: p1, p2, ...
    \path
    (0, 0) coordinate (M)
    \foreach \t [count=\i] in {A, Hello\\World, 3, foobar, $\cdot$} {
        +({\i-1)*360/\MainNum + \MainStartAngle}:\MainRadius)
        node[main node, align=center] (p\i) {\t}
    }
    ;  
    
    % Calculate the angle between the equal sides of the triangle
    % with side length \MainRadius, \MainRadius and radius of circle node
    % Result is stored in \p1-angle, \p2-angle, ...
    \foreach \i in {1, ..., \MainNum} {
        \pgfextracty{\dimen0 }{\pgfpointanchor{p\i}{north}} 
        \pgfextracty{\dimen2 }{\pgfpointanchor{p\i}{center}}
        \dimen0=\dimexpr\dimen2 - \dimen0\relax 
        \ifdim\dimen0<0pt \dimen0 = -\dimen0 \fi
        \pgfmathparse{2*asin(\the\dimen0/\MainRadius/2)}
        \global\expandafter\let\csname p\i-angle\endcsname\pgfmathresult
    }
    
    % Draw the arrow arcs
    \foreach \i [evaluate=\i as \nexti using {int(mod(\i, \MainNum)+1}]
    in {1, ..., \MainNum} {  
        \pgfmathsetmacro\StartAngle{   
            (\i-1)*360/\MainNum + \MainStartAngle
            + \csname p\i-angle\endcsname
        }
        \pgfmathsetmacro\EndAngle{
            (\nexti-1)*360/\MainNum + \MainStartAngle
            - \csname p\nexti-angle\endcsname
        }
        \ifdim\EndAngle pt < \StartAngle pt
        \pgfmathsetmacro\EndAngle{\EndAngle + 360}
        \fi
        \draw
        (M) ++(\StartAngle:\MainRadius)
        arc[start angle=\StartAngle, end angle=\EndAngle, radius=\MainRadius]
        ;
    }
    \end{tikzpicture}
\end{document}

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