TikZ: Handdrawn boxes/arrows/circles for flowcharts

Question

I saw the following style of boxes in Aditya's presentation as he mentioned it during his TeXTalk. I am almost positive that Aditya is using Metafun for this.

But I was wondering how would one go about doing this in tikz. The cool thing about the boxes and arrows is that they keep changing with every new instance. Some sort of randomisation is going on.

Answer 1

Along the site there are several references for hand drawn lines with TikZ (most of them from our hand drawn-guru percusse):

• Create xkcd style diagram in TeX
• Simulating hand-drawn lines
• TikZ two-blocks matrix

Actually, to let the shape change in every instance is something almost straightforward since is the normal behaviour unless you specify a seed: see TikZ: decoration - random steps: how to get twice exactly the same shape?

An example exploiting the oo module:

\documentclass{beamer}
\usepackage{lmodern}

\usepackage{tikz}
\usepgfmodule{oo}
\usetikzlibrary{calc,positioning,decorations.pathmorphing}

\tikzset{pencil draw/.style={
    draw,
    decorate,
    decoration={random steps,segment length=3mm,amplitude=0.2mm}
  }
}


\pgfooclass{module}{

 % class attributes
 \attribute text;
 \attribute text width=2.5cm;
 \attribute label;
 \attribute width=3cm;
 \attribute height=1cm;

 % constructor method
 \method module() {
 }

 \method text(#1) {
  \pgfooset{text}{#1}
 }

 \method set text width(#1) {
  \pgfooset{text width}{#1}
 }

 \method set label(#1) {
  \pgfooset{label}{#1}
 }

 \method set width(#1) {
  \pgfooset{width}{#1}
 }

 \method set height(#1) {
  \pgfooset{height}{#1}
 }

 \method draw(#1,#2) {
  \node [rectangle,
    thick,
    pencil draw,
    align=center,
    text width=\pgfoovalueof{text width},
    minimum width=\pgfoovalueof{width},
    minimum height=\pgfoovalueof{height},
    ] (\pgfoovalueof{label}) at (#1,#2) {\pgfoovalueof{text}};
 }

 \method place(#1) {
  \node [rectangle,
    thick,
    pencil draw,
    align=center,
    text width=\pgfoovalueof{text width},
    minimum width=\pgfoovalueof{width},
    minimum height=\pgfoovalueof{height},
    #1
    ] (\pgfoovalueof{label}) {\pgfoovalueof{text}};
 }

 \method connect(#1,#2) {
    \draw[-stealth,pencil draw,thick,decorate,decoration={raise=1mm}] (#1)--(#2);
    \draw[-stealth,pencil draw,thick,decorate,decoration={raise=1mm}] (#2)--(#1);   
 }

 % shortcut method to easily set labels, text and draw
 % use the \pgfoothis to refer to the current object
 \method set and draw(#1,#2,#3,#4) {
  \pgfoothis.set label(#1)
  \pgfoothis.text(#2)
  \pgfoothis.draw(#3,#4)
 }

 % shortcut method to easily set labels, text and place
 % objects
 \method set and place(#1,#2,#3) {
  \pgfoothis.set label(#1)
  \pgfoothis.text(#2)
  \pgfoothis.place(#3)
 }

 % shortcut method to easily set the dimensions
 \method set dimensions(#1,#2,#3) {
  \pgfoothis.set width(#1)
  \pgfoothis.set height(#2)
  \pgfoothis.set text width(#3)
 }

}

\begin{document}
\begin{frame}{Diagram}
\centering
\only<1-4>{
\begin{tikzpicture}[scale=0.75, transform shape]
\pgfoonew \mod=new module()

\mod.set and draw(reg 1,Region 1,0,0)
\mod.set and place(reg 2,Region 2,right= 3cm of reg 1)
\mod.set and place(contr 1,Controller 1,below= 2cm of reg 1)
\mod.set and place(contr 2,Controller 2,right= 3cm of contr 1)

\mod.connect(reg 1,reg 2)
\mod.connect(reg 1,contr 1)
\mod.connect(reg 2,contr 2)
\mod.connect(contr 1,contr 2)

\node at ($(reg 1)!0.5!(reg 2)-(0,3ex)$) {Interconnect};
\node at ($(contr 1)!0.5!(contr 2)-(0,3ex)$) {Communication};
\end{tikzpicture}
}
\end{frame}
\end{document}

The result: