Custom and built in TikZ fill patterns

Question

I can't find much information about creating TikZ fill patterns or even using the custom built-in patterns. Look to do all the common fills like lines, hatches, dots, stars, etc... I need to be able to control the scale, too. (The patterns I did end up finding were way to large.)

Google doesn't seem to return much info on TikZ fill patterns.

Answer 1

Customizing an existing pattern

The fivepointed star pattern is defined in pgflibrarypatterns.code.tex as

\pgfdeclarepatternformonly{fivepointed stars}% name
  {\pgfpointorigin}% bottom left
  {\pgfqpoint{3mm}{3mm}}% top right
  {\pgfqpoint{3mm}{3mm}}% tile size
  {% code
   \pgftransformshift{\pgfqpoint{1mm}{1mm}}
   \pgfpathmoveto{\pgfqpointpolar{18}{1mm}}
   \pgfpathlineto{\pgfqpointpolar{162}{1mm}}
   \pgfpathlineto{\pgfqpointpolar{306}{1mm}}
   \pgfpathlineto{\pgfqpointpolar{90}{1mm}}
   \pgfpathlineto{\pgfqpointpolar{234}{1mm}}
   \pgfpathclose%
   \pgfusepath{fill}
  }

If you want to change the size of stars or how far away they are of each other, you just need to change the 1mm and 3mm values respectively, but you need to define a new pattern for that. If you want full flexibility, you need to define a pattern with variables which you can adjust. Let's say we want the starsize and starspread parameters to customize the pattern. We first define the lengths:

% defining the new dimensions
\newlength{\starsize}
\newlength{\starspread}

then declare the corresponding tikz keys:

% declaring the keys in tikz
\tikzset{starsize/.code={\setlength{\starsize}{#1}},
         starspread/.code={\setlength{\starspread}{#1}}}

then set the default values:

% setting the default values
\tikzset{starsize=1mm,
         starspread=3mm}

and finally declare the pattern itself using our variables:

% declaring the pattern
\pgfdeclarepatternformonly[\starspread,\starsize]% variables
  {custom fivepointed stars}% name
  {\pgfpointorigin}% lower left corner
  {\pgfqpoint{\starspread}{\starspread}}% upper right corner
  {\pgfqpoint{\starspread}{\starspread}}% tilesize
  {% shape description
   \pgftransformshift{\pgfqpoint{\starsize}{\starsize}}
   \pgfpathmoveto{\pgfqpointpolar{18}{\starsize}}
   \pgfpathlineto{\pgfqpointpolar{162}{\starsize}}
   \pgfpathlineto{\pgfqpointpolar{306}{\starsize}}
   \pgfpathlineto{\pgfqpointpolar{90}{\starsize}}
   \pgfpathlineto{\pgfqpointpolar{234}{\starsize}}
   \pgfpathclose%
   \pgfusepath{fill}
  }

You can then just use things like \draw[pattern=custom fivepointed stars,starspread=1.5mm,starsize=0.5mm] (0,0) rectangle (3,4); to produce small stars close to each other in a rectangle. Here's the full code:

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{patterns}

% defining the new dimensions
\newlength{\starsize}
\newlength{\starspread}
% declaring the keys in tikz
\tikzset{starsize/.code={\setlength{\starsize}{#1}},
         starspread/.code={\setlength{\starspread}{#1}}}
% setting the default values
\tikzset{starsize=1mm,
         starspread=3mm}
% declaring the pattern
\pgfdeclarepatternformonly[\starspread,\starsize]% variables
  {custom fivepointed stars}% name
  {\pgfpointorigin}% lower left corner
  {\pgfqpoint{\starspread}{\starspread}}% upper right corner
  {\pgfqpoint{\starspread}{\starspread}}% tilesize
  {% shape description
   \pgftransformshift{\pgfqpoint{\starsize}{\starsize}}
   \pgfpathmoveto{\pgfqpointpolar{18}{\starsize}}
   \pgfpathlineto{\pgfqpointpolar{162}{\starsize}}
   \pgfpathlineto{\pgfqpointpolar{306}{\starsize}}
   \pgfpathlineto{\pgfqpointpolar{90}{\starsize}}
   \pgfpathlineto{\pgfqpointpolar{234}{\starsize}}
   \pgfpathclose%
   \pgfusepath{fill}
  }

\begin{document}

\begin{center}
%
\begin{tikzpicture}
\draw[pattern=fivepointed stars] (0,0) rectangle (3,4);
\end{tikzpicture}%
%
\begin{tikzpicture}
\draw[pattern=custom fivepointed stars,starspread=5mm] (0,0) rectangle (3,4);
\end{tikzpicture}%
%
\begin{tikzpicture}
\draw[pattern=custom fivepointed stars,starspread=5mm,starsize=2mm] (0,0) rectangle (3,4);
\end{tikzpicture}%
%
\begin{tikzpicture}
\draw[pattern=custom fivepointed stars,starspread=1.5mm,starsize=0.5mm] (0,0) rectangle (3,4);
\end{tikzpicture}
%
\end{center}

\end{document}

In the same vein, you can customize hatch lines. Here's the code for north west lines. I've put options for color and shifting the hatch lines up (not down):

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{patterns}

% defining the new dimensions and parameters
\newlength{\hatchspread}
\newlength{\hatchthickness}
\newlength{\hatchshift}
\newcommand{\hatchcolor}{}
% declaring the keys in tikz
\tikzset{hatchspread/.code={\setlength{\hatchspread}{#1}},
         hatchthickness/.code={\setlength{\hatchthickness}{#1}},
         hatchshift/.code={\setlength{\hatchshift}{#1}},% must be >= 0
         hatchcolor/.code={\renewcommand{\hatchcolor}{#1}}}
% setting the default values
\tikzset{hatchspread=3pt,
         hatchthickness=0.4pt,
         hatchshift=0pt,% must be >= 0
         hatchcolor=black}
% declaring the pattern
\pgfdeclarepatternformonly[\hatchspread,\hatchthickness,\hatchshift,\hatchcolor]% variables
   {custom north west lines}% name
   {\pgfqpoint{\dimexpr-2\hatchthickness}{\dimexpr-2\hatchthickness}}% lower left corner
   {\pgfqpoint{\dimexpr\hatchspread+2\hatchthickness}{\dimexpr\hatchspread+2\hatchthickness}}% upper right corner
   {\pgfqpoint{\dimexpr\hatchspread}{\dimexpr\hatchspread}}% tile size
   {% shape description
    \pgfsetlinewidth{\hatchthickness}
    \pgfpathmoveto{\pgfqpoint{0pt}{\dimexpr\hatchspread+\hatchshift}}
    \pgfpathlineto{\pgfqpoint{\dimexpr\hatchspread+0.15pt+\hatchshift}{-0.15pt}}
    \ifdim \hatchshift > 0pt
      \pgfpathmoveto{\pgfqpoint{0pt}{\hatchshift}}
      \pgfpathlineto{\pgfqpoint{\dimexpr0.15pt+\hatchshift}{-0.15pt}}
    \fi
    \pgfsetstrokecolor{\hatchcolor}
%    \pgfsetdash{{1pt}{1pt}}{0pt}% dashing cannot work correctly in all situation this way
    \pgfusepath{stroke}
   }

\begin{document}

\begin{center}
%
\begin{tikzpicture}
\draw[pattern=custom north west lines] (0,0) rectangle (3,4);
\end{tikzpicture}%
%
\begin{tikzpicture}
\draw[pattern=custom north west lines,hatchspread=6pt,hatchthickness=1pt,hatchcolor=red] (0,0) rectangle (3,4);
\end{tikzpicture}%
%
\begin{tikzpicture}
\draw[pattern=custom north west lines,hatchspread=10pt,hatchthickness=5pt] (0,0) rectangle (3,4);
\end{tikzpicture}%
%
\begin{tikzpicture}% hatchshift must be >= 0
\draw[pattern=custom north west lines,hatchspread=10pt,hatchcolor=red] (0,0) rectangle (3,4);
\draw[pattern=custom north west lines,hatchspread=10pt,hatchcolor=blue,hatchshift=2.5pt] (0,0) rectangle (3,4);
\draw[pattern=custom north west lines,hatchspread=10pt,hatchcolor=green!65!black,hatchshift=5pt] (0,0) rectangle (3,4);
\draw[pattern=custom north west lines,hatchspread=10pt,hatchcolor=violet,hatchshift=7.5pt] (0,0) rectangle (3,4);
\end{tikzpicture}%
%
\end{center}

\end{document}

Here's the code for north east lines:

\pgfdeclarepatternformonly[\hatchspread,\hatchthickness,\hatchshift,\hatchcolor]% variables
   {custom north east lines}% name
   {\pgfqpoint{\dimexpr-2\hatchthickness}{\dimexpr-2\hatchthickness}}% lower left corner
   {\pgfqpoint{\dimexpr\hatchspread+2\hatchthickness}{\dimexpr\hatchspread+2\hatchthickness}}% upper right corner
   {\pgfqpoint{\dimexpr\hatchspread}{\dimexpr\hatchspread}}% tile size
   {% shape description
    \pgfsetlinewidth{\hatchthickness}
    \pgfpathmoveto{\pgfqpoint{\dimexpr\hatchshift-0.15pt}{-0.15pt}}
    \pgfpathlineto{\pgfqpoint{\dimexpr\hatchspread+0.15pt}{\dimexpr\hatchspread-\hatchshift+0.15pt}}
    \ifdim \hatchshift > 0pt
      \pgfpathmoveto{\pgfqpoint{-0.15pt}{\dimexpr\hatchspread-\hatchshift-0.15pt}}
      \pgfpathlineto{\pgfqpoint{\dimexpr\hatchshift+0.15pt}{\dimexpr\hatchspread+0.15pt}}
    \fi
    \pgfsetstrokecolor{\hatchcolor}
%    \pgfsetdash{{1pt}{1pt}}{0pt}% dashing cannot work correctly in all situation this way
    \pgfusepath{stroke}
   }

Creating new patterns

Creating new patterns is a bit more complex and needs choosing the right shape, the bounding box overlapping, etc. You can see an example with hexagons in the question Drawing Hexagons. I didn't do the work to control the size within Tikz, but it's straightforward to adapt the method described above.

Answer 2

I tried to use the answer from Philippe Goutet to create a custom pattern in pgfgantt bars. However, the hatching was off and did not align with the bar borders very well. I ended up using the mylines example from http://mirror.ctan.org/graphics/pgf/base/doc/pgfmanual.pdf#page=737 which worked great. You can easily customize the hatching's spacing, line width and angle.

\documentclass{standalone}

\PassOptionsToPackage{usenames,dvipsnames}{xcolor}
\usepackage{tikz}
\usepackage{pgfgantt}

\usetikzlibrary {patterns.meta}
\tikzdeclarepattern{
  name=mylines,
  parameters={
      \pgfkeysvalueof{/pgf/pattern keys/size},
      \pgfkeysvalueof{/pgf/pattern keys/angle},
      \pgfkeysvalueof{/pgf/pattern keys/line width},
  },
  bounding box={
    (0,-0.5*\pgfkeysvalueof{/pgf/pattern keys/line width}) and
    (\pgfkeysvalueof{/pgf/pattern keys/size},
     0.5*\pgfkeysvalueof{/pgf/pattern keys/line width})},
  tile size={(\pgfkeysvalueof{/pgf/pattern keys/size},
              \pgfkeysvalueof{/pgf/pattern keys/size})},
  tile transformation={rotate=\pgfkeysvalueof{/pgf/pattern keys/angle}},
  defaults={
    size/.initial=5pt,
    angle/.initial=45,
    line width/.initial=.4pt,
}, code={
\draw [line width=\pgfkeysvalueof{/pgf/pattern keys/line width}] (0,0) -- (\pgfkeysvalueof{/pgf/pattern keys/size},0);
}, }

\begin{document}

\begin{ganttchart}{1}{12}
    \gantttitle{2022}{12} \\
    \gantttitlelist{1,...,12}{1} \\
    \ganttbar[bar/.append style={preaction={fill, LimeGreen},pattern={mylines[size=5pt,line width=2.5pt,angle=45]},pattern color=NavyBlue}]{Work Package 1}{1}{12}
\end{ganttchart}

\end{document}