How to clip a background including nodes according to an arbitrary shape?

Question

The following WE

\documentclass[border=10pt]{standalone}
\usepackage[dvipsnames]{xcolor}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,shapes, positioning, fit, backgrounds}

\tikzstyle{backA}=[rectangle,
fill=blue!30,
inner sep=0.2cm,
rounded corners=0mm]

\tikzstyle{backB}=[rectangle,
fill=purple!15,
inner sep=0.2cm,
rounded corners=0mm]

\tikzstyle{backC}=[rectangle,
fill=yellow!40,
inner sep=0.2cm,
rounded corners=0mm]

\tikzset{%
  >={Latex[width=2mm,length=2mm]},
            base/.style = {rectangle, rounded corners, draw=black,
                           minimum width=1cm, minimum height=1cm,
                           text centered,inner sep=0.3cm},
  operation/.style = {base, fill=SkyBlue},
}

\begin{document}    
\begin{tikzpicture}[node distance=0.8cm,
    every node/.style={fill=white}, align=center]
    \node (controller) [operation] {Microcontroller};
    \node (regulator) [operation, below = of controller] {Regulator};
    \node (transceiver) [operation, right = of controller, align = center] {CAN \\ Transceiver};
    \node (sensor) [operation, above = of controller] {Sensor};
    \node (flash) [operation, below = of transceiver, yshift=4mm] {Flash \\ Memeory};
    \node (driver1) [operation, right = of sensor] {Driver 1};
    \node (driver2) [operation, left = of sensor] {Driver 2};
    \node (power) [operation, left = of regulator, align=center] {Input \\ Power};
    \node (motor1) [operation, above = of sensor, align=center, xshift=1cm] {Motor 1};
    \node (motor2) [operation, above = of sensor, align=center, xshift=-1cm] {Motor 2};
    \node[circle,draw,fill=SkyBlue] (computer) [right = of driver1] {Computer};
    \coordinate[left = of power] (d1) {};
    \coordinate[above = of d1, yshift=5.5cm] (d2) {};

    \draw[->]             (controller) -- (transceiver);
    \draw[<->]             (controller) -- (sensor);
    \draw[->]             (driver1) -- (motor1);
    \draw[->]             (driver2) -- (motor2);
    \draw[<->]             (sensor) -- (motor2);
    \draw[<->]             (sensor) -- (motor1);
    \draw[->]             (controller) -- (driver1);
    \draw[->]             (controller) -- (driver2);
    \draw[->]             (controller) -- (flash);
    \draw[->]             (regulator) -- (controller);
    \draw[->]             (power) -- (regulator);
    \draw[<->]             (transceiver) -- (computer);
    \draw[->]             (power) -- (d1) |- (motor2);
    \draw[->]             (power) -- (d1) --  (d2) -| (motor1);

    \begin{pgfonlayer}{background}
    \node [backC,
    fit=(driver1) (driver2) (sensor) (motor1) (motor2),
    label=above:{}] {};

    \node [backA,
    fit=(computer) (transceiver),
    label=above:{}] {};

    \node [backB,
    fit=(regulator) (power),
    label=above:{}] {};
    \end{pgfonlayer}
  \end{tikzpicture}
\end{document}

yields

Since the driver1 node should have been exclusively covered by the yellow background, I need to subtract the specific part of the violet background which interferes with the yellow one. In particular, an acceptable boundary for the violet background may roughly be like this:

How can I achieve something like that?

Might be useful: https://tex.stackexchange.com/questions/53184/tikz-clip-shapes-with-another-built-in-shape — Raaja_is_at_topanswers.xyz, Mar 12 '19 at 14:49
I don't think you need to crop the blue part. You only have to draw the yellow part after the blue part -- in that case, the yellow part will overfill the blue part. — , Mar 12 '19 at 14:49
@Roboticist If I understand your comment, you only need to put a white frame of the yellow part. This can be done with draw=white. — , Mar 12 '19 at 14:52
@JouleV: The yellow background is indeed drawn "after" the blue background in the WE. Additionally, I'd like to know a potential approach to achieving margins with arbitrary shapes. — , Mar 12 '19 at 14:54

score 3 · Accepted Answer · answered Mar 12 '19 at 16:30

I would not overdraw areas with white, imagine you have some background you want to keep. And \tikzstyle is deprecated.

\documentclass[border=10pt]{standalone}
\usepackage[dvipsnames]{xcolor}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,shapes, positioning, fit, backgrounds}

% based on https://tex.stackexchange.com/a/12033/121799
\tikzset{reverseclip/.style={insert path={(current bounding box.south west)rectangle 
  (current bounding box.north east)} }}

\tikzset{backA/.style={rectangle,
fill=blue!30,
inner sep=0.2cm,
rounded corners=0mm},
backB/.style={rectangle,
fill=purple!15,
inner sep=0.2cm,
rounded corners=0mm},
backC/.style={rectangle,
fill=yellow!40,
inner sep=0.2cm,
rounded corners=0mm}}

\tikzset{%
  >={Latex[width=2mm,length=2mm]},
            base/.style = {rectangle, rounded corners, draw=black,
                           minimum width=1cm, minimum height=1cm,
                           text centered,inner sep=0.3cm},
  operation/.style = {base, fill=SkyBlue},
}

\begin{document}    
\begin{tikzpicture}[node distance=0.8cm,
    every node/.style={fill=white}, align=center]
    \node (controller) [operation] {Microcontroller};
    \node (regulator) [operation, below = of controller] {Regulator};
    \node (transceiver) [operation, right = of controller, align = center] {CAN \\ Transceiver};
    \node (sensor) [operation, above = of controller] {Sensor};
    \node (flash) [operation, below = of transceiver, yshift=4mm] {Flash \\ Memeory};
    \node (driver1) [operation, right = of sensor] {Driver 1};
    \node (driver2) [operation, left = of sensor] {Driver 2};
    \node (power) [operation, left = of regulator, align=center] {Input \\ Power};
    \node (motor1) [operation, above = of sensor, align=center, xshift=1cm] {Motor 1};
    \node (motor2) [operation, above = of sensor, align=center, xshift=-1cm] {Motor 2};
    \node[circle,draw,fill=SkyBlue] (computer) [right = of driver1] {Computer};
    \coordinate[left = of power] (d1) {};
    \coordinate[above = of d1, yshift=5.5cm] (d2) {};

    \draw[->]             (controller) -- (transceiver);
    \draw[<->]             (controller) -- (sensor);
    \draw[->]             (driver1) -- (motor1);
    \draw[->]             (driver2) -- (motor2);
    \draw[<->]             (sensor) -- (motor2);
    \draw[<->]             (sensor) -- (motor1);
    \draw[->]             (controller) -- (driver1);
    \draw[->]             (controller) -- (driver2);
    \draw[->]             (controller) -- (flash);
    \draw[->]             (regulator) -- (controller);
    \draw[->]             (power) -- (regulator);
    \draw[<->]             (transceiver) -- (computer);
    \draw[->]             (power) -- (d1) |- (motor2);
    \draw[->]             (power) -- (d1) --  (d2) -| (motor1);

    \begin{pgfonlayer}{background}
    \node [backC,
    fit=(driver1) (driver2) (sensor) (motor1) (motor2),
    label=above:{}] (F1){};

    \node [backB,
    fit=(regulator) (power),
    label=above:{}] {};
    \clip ([xshift=-5pt,yshift=-5pt]F1.south west) -|
    ([xshift=5pt,yshift=5pt]F1.north east) -| cycle  [reverseclip];
    \node [backA,
    fit=(computer) (transceiver),
    label=above:{}] {};
    \end{pgfonlayer}
  \end{tikzpicture}
\end{document}

I just saw your retirement announcement. Thanks for everything, not only for your TikZ and LaTeX knowledge but also for your sense of humor and your passion to share what you know. — , Jul 24 '19 at 18:45

AndréC · Answer 2 · 2019-03-12T15:50:49.713

Like this?

\documentclass[border=10pt]{standalone}
\usepackage[dvipsnames]{xcolor}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,shapes, positioning, fit, backgrounds}
\pgfdeclarelayer{background}
\pgfdeclarelayer{middle}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,middle,foreground}
\tikzstyle{backA}=[rectangle,
fill=blue!30,
inner sep=0.2cm,
rounded corners=0mm]

\tikzstyle{backB}=[rectangle,
fill=purple!15,
inner sep=0.2cm,
rounded corners=0mm]

\tikzstyle{backC}=[rectangle,
fill=yellow!40,
%inner sep=0.2cm,
rounded corners=0mm]

\tikzset{%
  >={Latex[width=2mm,length=2mm]},
            base/.style = {rectangle, rounded corners, draw=black,
                           minimum width=1cm, minimum height=1cm,
                           text centered,inner sep=0.3cm},
  operation/.style = {base, fill=SkyBlue},
}

\begin{document}    
\begin{tikzpicture}[node distance=0.8cm,
    every node/.style={fill=white}, align=center]
    \begin{pgfonlayer}{foreground}
    \node (controller) [operation] {Microcontroller};
    \node (regulator) [operation, below = of controller] {Regulator};
    \node (transceiver) [operation, right = of controller, align = center] {CAN \\ Transceiver};
    \node (sensor) [operation, above = of controller] {Sensor};
    \node (flash) [operation, below = of transceiver, yshift=4mm] {Flash \\ Memeory};
    \node (driver1) [operation, right = of sensor] {Driver 1};
    \node (driver2) [operation, left = of sensor] {Driver 2};
    \node (power) [operation, left = of regulator, align=center] {Input \\ Power};
    \node (motor1) [operation, above = of sensor, align=center, xshift=1cm] {Motor 1};
    \node (motor2) [operation, above = of sensor, align=center, xshift=-1cm] {Motor 2};
    \node[circle,draw,fill=SkyBlue] (computer) [right = of driver1] {Computer};
    \coordinate[left = of power] (d1) {};
    \coordinate[above = of d1, yshift=5.5cm] (d2) {};

    \draw[->]             (controller) -- (transceiver);
    \draw[<->]             (controller) -- (sensor);
    \draw[->]             (driver1) -- (motor1);
    \draw[->]             (driver2) -- (motor2);
    \draw[<->]             (sensor) -- (motor2);
    \draw[<->]             (sensor) -- (motor1);
    \draw[->]             (controller) -- (driver1);
    \draw[->]             (controller) -- (driver2);
    \draw[->]             (controller) -- (flash);
    \draw[->]             (regulator) -- (controller);
    \draw[->]             (power) -- (regulator);
    \draw[<->]             (transceiver) -- (computer);
    \draw[->]             (power) -- (d1) |- (motor2);
    \draw[->]             (power) -- (d1) --  (d2) -| (motor1);
\end{pgfonlayer}
    \begin{pgfonlayer}{middle}
    \node [backC,
    fit=(driver1) (driver2) (sensor) (motor1) (motor2),
    label=above:{}] {};
\end{pgfonlayer}
    \begin{pgfonlayer}{main}
    \node [fill=white,inner sep=3mm,
    fit=(driver1) (driver2) (sensor) (motor1) (motor2),
    label=above:{}] {};
\end{pgfonlayer}
\begin{pgfonlayer}{background}
    \node [backA,
    fit=(computer) (transceiver),
    label=above:{}] {};
\end{pgfonlayer}
    \node [backB,
    fit=(regulator) (power),
    label=above:{}] {};
  \end{tikzpicture}
\end{document}

How can one insert a little of white margin between the boundaries of the two backgrounds? I mean, the backgrounds are tangent to each other right now. — , Mar 12 '19 at 15:24
@Roboticist I have updated my answer by adding another layer named middle — AndréC, Mar 12 '19 at 15:51

score 1 · Answer 3 · answered Mar 12 '19 at 16:17

For arbitrary shapes (not nodes), one cannot use fitting.

\documentclass[border=10pt]{standalone}
\usepackage[dvipsnames]{xcolor}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,shapes, positioning, calc, backgrounds}

\tikzset{%
  >={Latex[width=2mm,length=2mm]},
            base/.style = {rectangle, rounded corners, draw=black,
                           minimum width=1cm, minimum height=1cm,
                           text centered,inner sep=0.3cm},
  operation/.style = {base, fill=SkyBlue},
}

\begin{document}    
\begin{tikzpicture}[node distance=0.8cm,
    every node/.style={fill=white}, align=center]
    \node (controller) [operation] {Microcontroller};
    \node (regulator) [operation, below = of controller] {Regulator};
    \node (transceiver) [operation, right = of controller, align = center] {CAN \\ Transceiver};
    \node (sensor) [operation, above = of controller] {Sensor};
    \node (flash) [operation, below = of transceiver, yshift=4mm] {Flash \\ Memeory};
    \node (driver1) [operation, right = of sensor] {Driver 1};
    \node (driver2) [operation, left = of sensor] {Driver 2};
    \node (power) [operation, left = of regulator, align=center] {Input \\ Power};
    \node (motor1) [operation, above = of sensor, align=center, xshift=1cm] {Motor 1};
    \node (motor2) [operation, above = of sensor, align=center, xshift=-1cm] {Motor 2};
    \node[circle,draw,fill=SkyBlue] (computer) [right = of driver1] {Computer};
    \coordinate[left = of power] (d1) {};
    \coordinate[above = of d1, yshift=5.5cm] (d2) {};

    \draw[->]             (controller) -- (transceiver);
    \draw[<->]             (controller) -- (sensor);
    \draw[->]             (driver1) -- (motor1);
    \draw[->]             (driver2) -- (motor2);
    \draw[<->]             (sensor) -- (motor2);
    \draw[<->]             (sensor) -- (motor1);
    \draw[->]             (controller) -- (driver1);
    \draw[->]             (controller) -- (driver2);
    \draw[->]             (controller) -- (flash);
    \draw[->]             (regulator) -- (controller);
    \draw[->]             (power) -- (regulator);
    \draw[<->]             (transceiver) -- (computer);
    \draw[->]             (power) -- (d1) |- (motor2);
    \draw[->]             (power) -- (d1) --  (d2) -| (motor1);

    \begin{pgfonlayer}{background}
    \path (driver1.east |- computer.north) ++ (0.2,0.2) coordinate(int1);
    \path (driver2.south -| transceiver.west) ++ (-0.2,-0.2) coordinate(int2);

    \fill[yellow!40] ($(driver2.south west)+(-0.2,-0.2)$) |- ($(motor2.north)+(0,0.2)$) -| (int1) -- (int2) -- cycle;
    \fill[blue!30] ($(transceiver.south west)+(-0.2,-0.2)$) -- (int2) -- (int1) -- 
      ($(computer.north)+(0,0.2)$) -| ($(computer.east)+(0.2,0)$) |- cycle;
    \fill[purple!15] ($(power.south west)+(-0.2,-0.2)$) |- ($(power.north)+(0,0.2)$) -| ($(regulator.east)+(0.2,0.2)$) |- cycle;
    \end{pgfonlayer}
  \end{tikzpicture}
\end{document}

How to clip a background including nodes according to an arbitrary shape?

3 Answers3