Latex Tikz/Pgf declaring shapes with parameters and anchors with numbers

2
votes

I am writing some shapes in pgf and i don't really know everything about how this works but i managed to get through the documentation.

\pgfdeclareshape{reg}{
  % The 'minimum width' and 'minimum height' keys, not the content, determine
  % the size
  \savedanchor\northeast{%
    \pgfmathsetlength\pgf@x{\pgfshapeminwidth}%
    \pgfmathsetlength\pgf@y{\pgfshapeminheight}%
    \pgf@x=0.11\pgf@x
    \pgf@y=0.15\pgf@y
  }
  % This is redundant, but makes some things easier:
  \savedanchor\southwest{%
    \pgfmathsetlength\pgf@x{\pgfshapeminwidth}%
    \pgfmathsetlength\pgf@y{\pgfshapeminheight}%
    \pgf@x=-0.11\pgf@x
    \pgf@y=-0.15\pgf@y
  }
  % Inherit from rectangle
  \inheritanchorborder[from=rectangle]

  % Define same anchor a normal rectangle has
  \anchor{center}{\pgfpointorigin}
  \anchor{north}{\northeast \pgf@x=0pt}
  \anchor{east}{\northeast \pgf@y=0pt}
  \anchor{south}{\southwest \pgf@x=0pt}
  \anchor{west}{\southwest \pgf@y=0pt}
  \anchor{north east}{\northeast}
  \anchor{north west}{\northeast \pgf@x=-\pgf@x}
  \anchor{south west}{\southwest}
  \anchor{south east}{\southwest \pgf@x=-\pgf@x}
  \anchor{text}{
    \pgfpointorigin
    \advance\pgf@x by -.5\wd\pgfnodeparttextbox%
    \advance\pgf@y by -.5\ht\pgfnodeparttextbox%
    \advance\pgf@y by +.5\dp\pgfnodeparttextbox%
  }

  % Define anchors for signal ports

  \anchor{CLK}{
    \pgf@process{\northeast}%
    \pgf@x=0\pgf@x%
    \pgf@y=1\pgf@y%
  }
  \anchor{PC}{
    \pgf@process{\northeast}%
    \pgf@x=-2.5\pgf@x%
    \pgf@y=0\pgf@y%
  }

  \anchor{PCS}{
    \pgf@process{\northeast}%
    \pgf@x=2.5\pgf@x%
    \pgf@y=0\pgf@y%
  }

  % Draw the rectangle box and the port labels
  \backgroundpath{
    % Rectangle box
    \pgfpathrectanglecorners{\southwest}{\northeast}

    % Drawing Triangle for clock input
    % upper left x
    \southwest \pgf@xa=\pgf@x 
    \northeast \pgf@ya=\pgf@y \pgf@yb=\pgf@y \pgf@xb=\pgf@x
    \pgf@anchor@reg@CLK
    \pgf@xc=\pgf@x \pgf@yc=\pgf@y
    \pgfmathsetlength\pgf@x{1.3ex}
    \advance\pgf@xa by .15mm
    \advance\pgf@xb by -.15mm
    \advance\pgf@yc by -\pgf@x
    \pgfpathmoveto{\pgfpoint{\pgf@xa}{\pgf@ya}}
    \pgfpathlineto{\pgfpoint{\pgf@xb}{\pgf@yb}}
    \pgfpathlineto{\pgfpoint{\pgf@xc}{\pgf@yc}}
    \pgfclosepath


    \tikzset{flip flop/port labels} % Use font from this style
    \tikz@textfont



    %Drawing CLK circuit
    \pgf@anchor@reg@CLK
    \pgf@xa=\pgf@x \pgf@ya=\pgf@y
    \pgf@xb=\pgf@x \pgf@yb=\pgf@y
    \pgfmathsetlength\pgf@x{1.8ex}
    \advance\pgf@yb by \pgf@x
    \pgfpathmoveto{\pgfpoint{\pgf@xa}{\pgf@ya}}
    \pgfpathlineto{\pgfpoint{\pgf@xb}{\pgf@yb}}
    %Draw clock label
    \pgf@anchor@reg@CLK\pgftext[base,at={\pgfpoint{\pgf@x}{\pgf@y}}]{\raisebox{2.5ex}{CLK}}

    %Drawing PC circuit
    \pgf@anchor@reg@PC
    \pgf@ya=\pgf@y \pgf@yb=\pgf@y \pgf@xa=\pgf@x
    \pgf@anchor@reg@west
    \pgf@xb=\pgf@x 
    %\pgfmathsetlength\pgf@x{2.7ex}
    %\advance\pgf@xb by \pgf@x
    \pgfpathmoveto{\pgfpoint{\pgf@xa}{\pgf@ya}}
    \pgfpathlineto{\pgfpoint{\pgf@xb}{\pgf@yb}}
    \pgf@anchor@reg@PC\pgftext[base,at={\pgfpoint{\pgf@x+0.5ex}{\pgf@y}}]{\raisebox{.5ex}{PC}}

    %Drawing PC' circuit
    \pgf@anchor@reg@PCS
    \pgf@ya=\pgf@y \pgf@yb=\pgf@y\pgf@xa=\pgf@x 
    \pgf@anchor@reg@east
    \pgf@xb=\pgf@x 
    %\pgfmathsetlength\pgf@x{2.5ex}
    %\advance\pgf@xb by \pgf@x
    \pgfpathmoveto{\pgfpoint{\pgf@xa}{\pgf@ya}}
    \pgfpathlineto{\pgfpoint{\pgf@xb}{\pgf@yb}}
    \pgf@anchor@reg@PCS\pgftext[base,at={\pgfpoint{\pgf@x}{\pgf@y}}]{\raisebox{.5ex}{PC'}}
  }

}

Here i created a shape with some connection points on the outside, and it actually works great. But i really want to have a parameter when i create this shape so that i can specify the amount of ports.

For example like this

\begin{tikzpicture}
    \node [reg,black!50,ports=3] (PC) at (0,0) {};
\end{tikzpicture}

But i can't find something in the documentation that allows for custom parameters. Also i wanted to name the anchors A1,A2 and A3 but i can't seem to add numbers in the names, even if in the documentation it explicitly says names like "1" and "::" should be no problem but still "A1" is.

If someone has any idea on how to do this i appreciate the help. And maybe some better references for creating shapes with pgf.

For editing the tex files i use Overleaf with pdflatex.

Edit: I now found out you can use \pgfkeys to add parameters to the shapes, but they don't seem to work right and i don't really know what to with that.

\def\microarchbasekey{/tikz/microarch}
\pgfkeys{\microarchbasekey/.is family}

\pgfdeclareshape{mux}{

    \pgfkeys{\microarchbasekey,inputs/.initial=2,spacing/.initial=5}

    \savedmacro{\numpins}{
        \def\numpins{\pgfkeysvalueof{\microarchbasekey/inputs}}
    }

    \saveddimen{\spacing}{
        \pgf@x = \pgfkeysvalueof{\microarchbasekey/spacing}
    }

%a lot of code down there
}

but it gives me the following error

A number should have been here; I inserted `0'.
(If you can't figure out why I needed to see a number,
look up `weird error' in the index to The TeXbook.)

but i can't find the missing part of the code.

1
parameterslatextikzpgf
I have zero time now, but you could find interesting the definition of muxdemux in circuitikz: github.com/circuitikz/circuitikz/blob/master/tex/… --- it's not so heavily commented but there are a lot of techniques for anchors there. – Rmano
i found some things in the github repo and added them to the post. But im struggling to get it to work. I would really appreciate the help. – MrDiver
I posted my method --- maybe there are better ways to do it. – Rmano

1 Answers

3
votes

Probably this is a question better suited for the TeX/LaTeX site, but anyway...

The key things are the following:

  1. Add keys for the parameters. Be careful about the hierarchy, node expects keys under the /tikz family:

    %
% better to create a family, but as an example...
\tikzset{flip flop/port labels/.initial={\tiny}}
%
% number of ports
\tikzset{ports/.initial=4}
%
% we need a counter
\newcount\tmp@a

  2. Add stable (linked to the specific node, and not to the generic shape) parameters, all those you need to compute the position of the anchors:

    % you have to save the relevant parameters as \savedmacro
    \savedmacro\numports{
        \edef\numports{\pgfkeysvalueof{/tikz/ports}}%
    }
    % and \saveddimen
    \saveddimen\pinsdelta{
        % you can't use savedmacros nor savedanchors here (bummer!)
        \edef\numports{\pgfkeysvalueof{/tikz/ports}}%
        \pgfmathsetlength\pgf@x{0.22*\pgfshapeminheight/(\numports+1)}%
    }

  3. In the shape definition, you have to add the anchors with a trick --- anchors have to be added to the shape internal function. Dangerous, because the developers can change it in the future (it happened already), but I know no other way.

    % create input anchors
    % this touch internal things, so beware...
    % anchors are named pgf@anchor@<name-of-the-shape>@<name of the anchors>
    \pgfutil@g@addto@macro\pgf@sh@s@reg{%
        \tmp@a=\numports\relax
        \pgfmathloop%
        \ifnum\pgfmathcounter>\tmp@a%
        \else%
        % assign the anchor "in \pgfmathcounter" to the macro \reg@port with the number as argument
        \expandafter\xdef\csname pgf@anchor@reg@in \pgfmathcounter\endcsname{%
            \noexpand\reg@port{\pgfmathcounter}% defined below
        }%
        % \typeout{YAY\space\pgfmathcounter}
        \repeatpgfmathloop%
    }

  4. Define the specific functions that calculate the variable anchors. You must use only \saved... kind of parameters here, otherwise, your anchors will use the last value of the parameter, not the correct one specified with the node. 

    \def\reg@port#1{%
    % this macro has the function to return the position of the anchor
    % it must use only \savedanchors and \savedmacros
    % the parameter is the number of the anchor (see above)
    \northeast
    \pgf@x=-\pgf@x
    \pgf@ya=\pgf@y
    \pgfmathsetlength{\pgf@y}{\pgf@ya-(#1+0.5)*\pinsdelta}%
}

Now, I do not understand exactly how you draw your shape so the anchors are not exactly where they should go, but well:

Output

My full code is here:

\documentclass[border=10pt]{standalone}
\usepackage{tikz}
\makeatletter
%
% better to create a family, but as an example...
\tikzset{flip flop/port labels/.initial={\tiny}}
%
% number of ports
\tikzset{ports/.initial=4}
%
% we need a counter
\newcount\tmp@a

\pgfdeclareshape{reg}{

    % you have to save the relevant parameters as \savedmacro
    \savedmacro\numports{
        \edef\numports{\pgfkeysvalueof{/tikz/ports}}%
    }
    % and \saveddimen
    \saveddimen\pinsdelta{
        % you can't use savedmacros nor savedanchors here (bummer!)
        \edef\numports{\pgfkeysvalueof{/tikz/ports}}%
        \pgfmathsetlength\pgf@x{0.22*\pgfshapeminheight/(\numports+1)}%
    }

    % The 'minimum width' and 'minimum height' keys, not the content, determine
    % the size
    \savedanchor\northeast{%
        \pgfmathsetlength\pgf@x{\pgfshapeminwidth}%
        \pgfmathsetlength\pgf@y{\pgfshapeminheight}%
        \pgf@x=0.11\pgf@x
        \pgf@y=0.15\pgf@y
    }
    % This is redundant, but makes some things easier:
    \savedanchor\southwest{%
        \pgfmathsetlength\pgf@x{\pgfshapeminwidth}%
        \pgfmathsetlength\pgf@y{\pgfshapeminheight}%
        \pgf@x=-0.11\pgf@x
        \pgf@y=-0.15\pgf@y
    }
    % Inherit from rectangle
    \inheritanchorborder[from=rectangle]

    % Define same anchor a normal rectangle has
    \anchor{center}{\pgfpointorigin}
    \anchor{north}{\northeast \pgf@x=0pt}
    \anchor{east}{\northeast \pgf@y=0pt}
    \anchor{south}{\southwest \pgf@x=0pt}
    \anchor{west}{\southwest \pgf@y=0pt}
    \anchor{north east}{\northeast}
    \anchor{north west}{\northeast \pgf@x=-\pgf@x}
    \anchor{south west}{\southwest}
    \anchor{south east}{\southwest \pgf@x=-\pgf@x}
    \anchor{text}{
        \pgfpointorigin
        \advance\pgf@x by -.5\wd\pgfnodeparttextbox%
        \advance\pgf@y by -.5\ht\pgfnodeparttextbox%
        \advance\pgf@y by +.5\dp\pgfnodeparttextbox%
    }

    % Define anchors for signal ports

    \anchor{CLK}{
        \pgf@process{\northeast}%
        \pgf@x=0\pgf@x%
        \pgf@y=1\pgf@y%
    }
    \anchor{PC}{
        \pgf@process{\northeast}%
        \pgf@x=-2.5\pgf@x%
        \pgf@y=0\pgf@y%
    }

    \anchor{PCS}{
        \pgf@process{\northeast}%
        \pgf@x=2.5\pgf@x%
        \pgf@y=0\pgf@y%
    }

    % Draw the rectangle box and the port labels
    \backgroundpath{
        % Rectangle box
        \pgfpathrectanglecorners{\southwest}{\northeast}

        % Drawing Triangle for clock input
        % upper left x
        \southwest \pgf@xa=\pgf@x
        \northeast \pgf@ya=\pgf@y \pgf@yb=\pgf@y \pgf@xb=\pgf@x
        \pgf@anchor@reg@CLK
        \pgf@xc=\pgf@x \pgf@yc=\pgf@y
        \pgfmathsetlength\pgf@x{1.3ex}
        \advance\pgf@xa by .15mm
        \advance\pgf@xb by -.15mm
        \advance\pgf@yc by -\pgf@x
        \pgfpathmoveto{\pgfpoint{\pgf@xa}{\pgf@ya}}
        \pgfpathlineto{\pgfpoint{\pgf@xb}{\pgf@yb}}
        \pgfpathlineto{\pgfpoint{\pgf@xc}{\pgf@yc}}
        \pgfclosepath


        \tikzset{flip flop/port labels} % Use font from this style
        \tikz@textfont



        %Drawing CLK circuit
        \pgf@anchor@reg@CLK
        \pgf@xa=\pgf@x \pgf@ya=\pgf@y
        \pgf@xb=\pgf@x \pgf@yb=\pgf@y
        \pgfmathsetlength\pgf@x{1.8ex}
        \advance\pgf@yb by \pgf@x
        \pgfpathmoveto{\pgfpoint{\pgf@xa}{\pgf@ya}}
        \pgfpathlineto{\pgfpoint{\pgf@xb}{\pgf@yb}}
        %Draw clock label
        \pgf@anchor@reg@CLK\pgftext[base,at={\pgfpoint{\pgf@x}{\pgf@y}}]{\raisebox{2.5ex}{CLK}}

        %Drawing PC circuit
        \pgf@anchor@reg@PC
        \pgf@ya=\pgf@y \pgf@yb=\pgf@y \pgf@xa=\pgf@x
        \pgf@anchor@reg@west
        \pgf@xb=\pgf@x
        %\pgfmathsetlength\pgf@x{2.7ex}
        %\advance\pgf@xb by \pgf@x
        \pgfpathmoveto{\pgfpoint{\pgf@xa}{\pgf@ya}}
        \pgfpathlineto{\pgfpoint{\pgf@xb}{\pgf@yb}}
        \pgf@anchor@reg@PC\pgftext[base,at={\pgfpoint{\pgf@x+0.5ex}{\pgf@y}}]{\raisebox{.5ex}{PC}}

        %Drawing PC' circuit
        \pgf@anchor@reg@PCS
        \pgf@ya=\pgf@y \pgf@yb=\pgf@y\pgf@xa=\pgf@x
        \pgf@anchor@reg@east
        \pgf@xb=\pgf@x
        %\pgfmathsetlength\pgf@x{2.5ex}
        %\advance\pgf@xb by \pgf@x
        \pgfpathmoveto{\pgfpoint{\pgf@xa}{\pgf@ya}}
        \pgfpathlineto{\pgfpoint{\pgf@xb}{\pgf@yb}}
        \pgf@anchor@reg@PCS\pgftext[base,at={\pgfpoint{\pgf@x}{\pgf@y}}]{\raisebox{.5ex}{PC'}}
    }

    % create input anchors
    % this touch internal things, so beware...
    % anchors are named pgf@anchor@<name-of-the-shape>@<name of the anchors>
    \pgfutil@g@addto@macro\pgf@sh@s@reg{%
        \tmp@a=\numports\relax
        \pgfmathloop%
        \ifnum\pgfmathcounter>\tmp@a%
        \else%
        % assign the anchor "in \pgfmathcounter" to the macro \reg@port with the number as argument
        \expandafter\xdef\csname pgf@anchor@reg@in \pgfmathcounter\endcsname{%
            \noexpand\reg@port{\pgfmathcounter}% defined below
        }%
        % \typeout{YAY\space\pgfmathcounter}
        \repeatpgfmathloop%
    }

}
%
\def\reg@port#1{%
    % this macro has the function to return the position of the anchor
    % it must use only \savedanchors and \savedmacros
    % the parameter is the number of the anchor (see above)
    \northeast
    \pgf@x=-\pgf@x
    \pgf@ya=\pgf@y
    \pgfmathsetlength{\pgf@y}{\pgf@ya-(#1+0.5)*\pinsdelta}%
}
\makeatother

%%% handy macro to show the anchors

\def\showcoord(#1)<#2:#3>{%
    node[circle, red, draw, inner sep=1pt,pin={%
        [red, inner sep=0.5pt, font=\small,
        pin distance=#3cm, pin edge={red, }%
    ]#2:#1}](#1){}}

\begin{document}
\begin{tikzpicture}
    \node [draw,reg,minimum width=3cm, minimum height=3cm, black!50] (PC1) at (0,0) {};
    \path (PC1.north west) \showcoord(NW)<45:0.2>;
    \node [draw, reg,black!50,minimum width=3cm, minimum height=5cm, ports=6, blue] (PC2) at (3,0) {};
    \foreach \p in {1,...,4} \path(PC1.in \p) \showcoord(in \p)<145:0.3>;
    \foreach \p in {1,...,6} \path(PC2.in \p) \showcoord(in \p)<145:0.3>;
\end{tikzpicture}
\end{document}