Tikz 中支撑尖端/夹点处的节点

Question

underext此外，我认为将（我的实现）作为键会更清楚decoration={...}；有没有办法设置它，例如decoration/underext/.style={pre=moveto,pre length=#1,post=moveto,post length=#1}？

几乎，因为整个decoration过程都是由 PGF 完成的，所以键实际上位于/pgf命名空间中。因此，您需要执行以下任一操作

\pgfset{decoration/underext/.style={…}}

或者

\tikzset{/pgf/decoration/underext/.style={…}}

这个答案提供了两个新auto功能：

left with offset和
right with offset

它们的工作原理与left和类似，right但它们将节点（或坐标）正交地推向长度约为的一侧/tikz/auto offset。
请记住，这些与八个罗盘锚点对齐。

该值键用振幅值和升高值进行初始化。

进行了很多类似的计算，但这是我区分倾斜节点和非倾斜节点的唯一方法。变换到处都是，非常令人困惑！

如果你查看draw节点，你会看到它们仅接触尖端：

该every brace node风格设置了适当的auto功能和正确的pos设置。

举个sloped例子，我在旋转之外使用了相同的路径，scope因为否则会很奇怪。

代码

\documentclass[tikz]{standalone}
\usetikzlibrary{calc, decorations.pathreplacing}
\pgfset{decoration/raise/.append code=% Ugh!
  \pgfkeyssetevalue{/pgf/decoration/raise}{#1}}%
\pgfkeyssetvalue{/pgf/decoration/raise}{0pt}
\makeatletter
\tikzset{% https://tex.stackexchange.com/a/665784/16595
  swap/.style={swap auto/.expand once=\tikz@auto@anchor@direction},
  swap auto/.is choice,
  /utils/temp/.style args={#1=#2}{
    /utils/exec=\pgfutil@namedef{tikz@install@auto@anchor@#1}{%
                \let\tikz@do@auto@anchor\tikz@auto@anchor@on
                \def\tikz@auto@anchor@direction{#1}},
    swap auto/#1/.code=\def\tikz@auto@anchor@direction{#2}},
  /utils/temp/.list={left=right, right=left,
    left with offset=right with offset, right with offset=left with offset},
  % which side → mirror/reverse path → auto
  % where      → reverse path/aspect → pos
  every brace node/.style={
    auto=% Ugh?
      \ifx\tikz@dec@mirror\relax
        \ifpgf@decorate@inputsegmentobjects@reverse right\else left\fi
      \else
        \ifpgf@decorate@inputsegmentobjects@reverse left\else right\fi
      \fi\space with offset,
    pos=\ifpgf@decorate@inputsegmentobjects@reverse
          1-\fi(\pgfdecorationsegmentaspect)},
  auto offset/.initial=% doesn't need to be used with decoration,
                       % can just be a fixed distance
    \pgfdecorationsegmentamplitude+(\pgfkeysvalueof{/pgf/decoration/raise})}
\pgfutil@namedef{tikz@auto@anchor@left with offset}{%
  \tikz@auto@pre\tikz@auto@anchor
  \xdef\tikz@marshal{%
      \pgf@process{%
        \noexpand\pgftransformreset
        \noexpand\pgftransformrotate{+90}%
        \noexpand\pgfpointtransformed{%
          \noexpand\pgfpointscale{\noexpand\pgfkeysvalueof{/tikz/auto offset}}
                                 {\noexpand\pgfqpoint{\the\pgf@x}{\the\pgf@y}}}}%
      \advance\pgf@pt@x\pgf@x
      \advance\pgf@pt@y\pgf@y}%
  \tikz@auto@post
  \ifpgfslopedattime
    \pgf@xb=\pgf@x
    \pgf@yb=\pgf@y
    \pgf@process{%
      \pgftransformreset
      \pgftransformrotate{90}%
      \pgfpointtransformed{%
        \pgf@process{%
          \tikz@timer%
          \pgf@x=\pgf@pt@aa pt
          \pgf@y=\pgf@pt@ab pt
          \pgfpointnormalised{}%
          \pgfpointscale{\pgfkeysvalueof{/tikz/auto offset}}{}}}}%
    \advance\pgf@pt@x\pgf@x
    \advance\pgf@pt@y\pgf@y
    \pgf@x=\pgf@xb
    \pgf@y=\pgf@yb
  \else
    \tikz@marshal
  \fi}
\pgfutil@namedef{tikz@auto@anchor@right with offset}{%
  \tikz@auto@pre\tikz@auto@anchor@prime
  \xdef\tikz@marshal{%
    \pgf@process{%
      \noexpand\pgftransformreset
      \noexpand\pgftransformrotate{-90}%
      \noexpand\pgfpointtransformed{%
        \noexpand\pgfpointscale{\noexpand\pgfkeysvalueof{/tikz/auto offset}}
                               {\noexpand\pgfqpoint{\the\pgf@x}{\the\pgf@y}}}}%
    \advance\pgf@pt@x\pgf@x
    \advance\pgf@pt@y\pgf@y}%
  \tikz@auto@post
  \ifpgfslopedattime
    \pgf@xb=\pgf@x
    \pgf@yb=\pgf@y
    \pgf@process{%
      \pgftransformreset
      \pgftransformrotate{-90}%
      \pgfpointtransformed{%
        \pgf@process{%
          \tikz@timer%
          \pgf@x=\pgf@pt@aa pt
          \pgf@y=\pgf@pt@ab pt
          \pgfpointnormalised{}%
          \pgfpointscale{\pgfkeysvalueof{/tikz/auto offset}}{}}}}%
    \advance\pgf@pt@x\pgf@x
    \advance\pgf@pt@y\pgf@y
    \pgf@x=\pgf@xb
    \pgf@y=\pgf@yb
  \else
    \tikz@marshal
  \fi}
\makeatother
\begin{document}
\begin{tikzpicture}[
  scale=1.5,
  /pgf/decoration/underext/.style={
    pre=moveto, pre length={#1}, post=moveto, post length={#1}}]
\pgfmathsetmacro\ang{asin(1/6)}
\clip (-\ang:6) arc [start angle=-\ang, end angle=90+\ang, radius=6] -- (-1,-1) -- cycle;

\foreach \r / \i [evaluate=\r as \ang using 90/\r] in {8/4}{ % radius and number of slice
  \begin{scope}[rotate={(\i-1)*\ang}]
  \foreach \m in {2}{
    % Minkowski sum
    \filldraw [fill=black!5, draw=black, delta angle=-90, radius=\m]
      ($(-\ang:\r/2)+(-\ang-90:\m)$)
      arc [start angle=-\ang-90]
      arc [start angle=-\ang, end angle=\ang, radius=\r/2-\m]
      arc [start angle=\ang+180]
      -- ($(\ang:2*\r)+(\ang+90:\m)$)
      arc [start angle=\ang+90]
      arc [start angle=\ang, end angle=-\ang, radius=2*\r+\m]
      arc [start angle=-\ang] -- cycle;

    % support
    \filldraw[draw=black,fill=black!20]
      (-\ang:\r/2)
      arc [start angle=-\ang, end angle=\ang, radius=\r/2] coordinate[midway] (B)
      -- (\ang:2*\r)
      arc [start angle=\ang, end angle=-\ang, radius=2*\r] -- cycle;

    % axis of cone
    \draw[very thin] (0,0) coordinate (A) -- (B);
    \draw[
      decorate,
      decoration={
        brace, mirror,
        amplitude=10pt, raise=3pt, aspect=0.6
      },
      very thin] (A)-- node[every brace node]{$2^{j-1}$} (B);
    \coordinate (base) at ($(A)!0.6!(B)$);
    \coordinate (ortho) at ($(0,0)!1!90:($(B)-(A)$)$);
    \node[inner sep=2pt,gray] at ($(base)!-15pt!($(base)+(ortho)$)$) {$2^{j-1}$};
  }
  \end{scope}
  \draw[decorate, decoration={brace, reverse path, mirror,
    amplitude=10pt, raise=3pt, aspect=0.6}, very thin]
    (A)-- node[every brace node,sloped]{$2^{j-1}$} (B);
}
\path[very thin, <->] (-1,0) edge (6,0) (0,-1) edge (0,6);
\end{tikzpicture}
\end{document}

输出

Answer 1