为什么边缘弯曲会去除路径上的装饰？

Question

谢谢这个答案，这是我的代码：

\documentclass{article}
\usepackage{tikz}
  \usetikzlibrary{math}
  \usetikzlibrary{calc}
    \usetikzlibrary{positioning}
    \usetikzlibrary{arrows.meta}
    \usetikzlibrary{decorations.pathmorphing}
    \usetikzlibrary{decorations.pathreplacing}
\tikzset{%
  rev/.style={
    postaction={%
      decoration={
        show path construction,
        lineto code={
          \tikzmath{
            coordinate \I, \F, \v;
            \I = (\tikzinputsegmentfirst);
            \F = (\tikzinputsegmentlast);
            \v = ($(\I) -(\F)$);
            real \d, \a, \r, \t;
            \d = 0.8;
            \t = atan2(\vy, \vx);
            if \vx<0 then { \a = 90; } else { \a = -90; };
            {
              \draw[arrows={-latex}, decorate,
              decoration={%
                snake, amplitude=.4mm,
                segment length=2mm,
                post length=1mm
              }]
              ($(\F)!.5!(\I) +(\t: -\d em) +(\t +\a: 1ex)$)
              -- ++(\t: 2*\d em);
            };
          }
        }
      },
      decorate
    }
  }
}
\begin{document}
\begin{tikzpicture}[->,thick,every node/.style={draw,circle}]
\node (v) {v};
\node [below left=1cm of v] (a) {a};
\node [below right=2cm of v] (b) {b};
\draw (v) edge[bend right=10,rev] (a);
\draw (v) edge[rev] (b);
\end{tikzpicture}
\end{document}

其渲染效果如下：

如您所见，当bend right存在时，蛇形箭头不会被渲染。为什么以及如何修复？

Answer 1

弯曲线不是 lineto 操作而是 curveto 操作，因此您也需要执行此操作的代码：

\documentclass{article}
\usepackage{tikz}
  \usetikzlibrary{math}
  \usetikzlibrary{calc}
    \usetikzlibrary{positioning}
    \usetikzlibrary{arrows.meta}
    \usetikzlibrary{decorations.pathmorphing}
    \usetikzlibrary{decorations.pathreplacing}
\tikzset{%
  rev/.style={
    postaction={%
      decoration={
        show path construction,
        curveto code={
          \tikzmath{
            coordinate \I, \F, \v;
            \I = (\tikzinputsegmentfirst);
            \F = (\tikzinputsegmentlast);
            \v = ($(\I) -(\F)$);
            real \d, \a, \r, \t;
            \d = 0.8;
            \t = atan2(\vy, \vx);
            if \vx<0 then { \a = 90; } else { \a = -90; };
            {
              \draw[arrows={-latex}, decorate,
              decoration={%
                snake, amplitude=.4mm,
                segment length=2mm,
                post length=1mm
              }]
              ($(\F)!.5!(\I) +(\t: -\d em) +(\t +\a: 1ex)$)
              -- ++(\t: 2*\d em);
            };
          }
        },
          lineto code={
          \tikzmath{
            coordinate \I, \F, \v;
            \I = (\tikzinputsegmentfirst);
            \F = (\tikzinputsegmentlast);
            \v = ($(\I) -(\F)$);
            real \d, \a, \r, \t;
            \d = 0.8;
            \t = atan2(\vy, \vx);
            if \vx<0 then { \a = 90; } else { \a = -90; };
            {
              \draw[arrows={-latex}, decorate,
              decoration={%
                snake, amplitude=.4mm,
                segment length=2mm,
                post length=1mm
              }]
              ($(\F)!.5!(\I) +(\t: -\d em) +(\t +\a: 1ex)$)
              -- ++(\t: 2*\d em);
            };
          }
        }      
      },
      decorate
    }
  }
}
\begin{document}
\begin{tikzpicture}[->,thick,every node/.style={draw,circle}]
\node (v) {v};
\node [below left=1cm of v] (a) {a};
\node [below right=2cm of v] (b) {b};
\draw (v) edge[bend right=10,rev] (a);
\draw (v) edge[rev] (b);
\end{tikzpicture}
\end{document}