labeled drawn node

Question

Sorry, this has to be extremly easy somehow but I don't find it... I want to label images (which works very well using \node[circle], but now I need to point to locations close to each other which I would like to do by having pointy things like in the mwe, but (unlike the mwe) I'd like to put them at a location, relative locations, label them, ... like I do with \node, like I indicate with the comment. The label should not rotate with the shape drawn (but I could do with the easy to place, scale and rotate shape adding a second labeling node for each). I simple don't see how I create \node with anything else than a predifined shape (or can I define own non-elemental shapes and use there? If so don't find that)

    \documentclass[border=1mm]{standalone}
    \usepackage{amsmath}
    \usepackage{tikz}
\begin{document}

    \begin{tikzpicture}

        %pointing circle
        \draw [fill=gray] (1,1) arc [start angle=0, end angle=270, radius=1cm] -- (1,0) -- (1,1);
        \node (n) at (0,1) {1};


        %\node[pointingcircle, rotate=-90, scale=0.5] (n) at (0,1) {1};

    \end{tikzpicture}
\end{document}

Can you provide a hand-drawn sketch of what you want to achieve. From your MWE and your text I have no glue what yoou want do draw. — Roland, Oct 22 '21 at 05:16
Yes, the custom shape node drawing topic seems to cover it. Now trying to understand what of that I need (probably only little more than my mwe). Thanks. — Erik Itter, Oct 22 '21 at 06:55
Are you after something like the node shapes defined by the shapes.callouts library? (Chapter 71.7, page 822, in the manual for version 3.1.9a.) Edit: sorry, hadn't actually compiled your example first. The callouts shapes aren't exactly what you show. — Torbjørn T., Oct 26 '21 at 17:26

score 1 · Answer 1 · answered Dec 02 '21 at 11:08

Based on predefined node shapes circle and rectangle, a custom node shape three forth circle is provided below.

\documentclass[border=1mm]{standalone}
\usepackage{amsmath}
\usepackage{tikz}
\makeatletter
\pgfdeclareshape{three forth circle}
{%
  \inheritsavedanchors[from=circle]%
  \pgfutil@for@anchor:=center,%
      north,south,west,east,%
      mid,mid west,mid east,base,base west,base east,%
      north west,north east,south west,%
      % south east%
  \do{%
    \inheritanchor[from=circle]{@anchor}%
  }%
  \anchor{south east}{%
    \centerpoint
    \pgf@xa=\radius
    \advance\pgf@x by\pgf@xa
    \advance\pgf@y by-\pgf@xa
  }%
  \backgroundpath{%
    \pgfutil@tempdima=\radius%
    \pgfmathsetlength{\pgf@xb}{\pgfkeysvalueof{/pgf/outer xsep}}%
    \pgfmathsetlength{\pgf@yb}{\pgfkeysvalueof{/pgf/outer ysep}}%
    \ifdim\pgf@xb<\pgf@yb%
      \advance\pgfutil@tempdima by-\pgf@yb%
    \else%
      \advance\pgfutil@tempdima by-\pgf@xb%
    \fi%
    %% draw border
    % move to south east
    \pgfpathmoveto{\pgfpointadd{\centerpoint}{\pgfqpoint{\pgfutil@tempdima}{-\pgfutil@tempdima}}}%
    % line to east
    \pgfpathlineto{\pgfpointadd{\centerpoint}{\pgfqpoint{\pgfutil@tempdima}{0pt}}}%
    % arc to south
    \pgfpatharc{0}{270}{\pgfutil@tempdima}%
    % close (line to south east)
    \pgfpathclose
  }%
  \anchorborder{%
    \pgf@xa=\pgf@x%
    \pgf@ya=\pgf@y%
    \edef\pgf@marshal{%
      \noexpand\pgfpointborderellipse
      {\noexpand\pgfqpoint{\the\pgf@xa}{\the\pgf@ya}}
      {\noexpand\pgfqpoint{\radius}{\radius}}%
    }%
    \ifdim\pgf@xa>0pt
      \ifdim\pgf@ya<0pt
        \edef\pgf@marshal{%
          \noexpand\pgfpointborderrectangle
          {\noexpand\pgfqpoint{\the\pgf@xa}{\the\pgf@ya}}
          {\noexpand\pgfqpoint{\radius}{\radius}}%
        }%
      \fi
    \fi
    \pgf@marshal%
    \pgf@xa=\pgf@x%
    \pgf@ya=\pgf@y%
    \centerpoint%
    \advance\pgf@x by\pgf@xa%
    \advance\pgf@y by\pgf@ya%
  }%
}
\makeatother
\begin{document}
  \begin{tikzpicture}
    \node[draw, fill=gray, three forth circle] (x) {x};
% test anchor &quot;south east&quot;
\draw[blue, -&gt;] (1,0) -- (x.south east);
% test \anchorborder
\draw[help lines] foreach \i in {10,20,...,360} {(\i:1cm) -- (x)};

\end{tikzpicture}
\end{document}

labeled drawn node

1 Answers1