How to add patterns inside shapes bounded by curves?

Question

It is easy to use patterns for nice shapes like rectangle. How to fill an area by patterns enclosed by some curves? For example I have trouble with adding pattern to the following between two arcs:

\documentclass{article}
\usepackage{tikz}

\begin{document}
\begin{tikzpicture}
\draw  (-1,1) node (v1) {} circle (4.5);
\draw  (v1) circle (2.5);
\draw (-5.5,1) arc (180:360:1 and .25);
\draw (1.5,1) arc (180:360:1 and .25);
\end{tikzpicture}
\end{document}

score 9 · Accepted Answer · answered Feb 03 '19 at 07:55

9

You need a closed shape to use patterns or fill. Shapes bounded by curves can be converted or redrawn like this:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{patterns}
\begin{document}
\begin{tikzpicture}
\draw[pattern=horizontal lines] (-5.5,1) arc (180:360:1 and .25) arc (180:360:2.5) arc (180:360:1 and .25) arc (0:-180:4.5) -- cycle;
\end{tikzpicture}
\end{document}

answered Feb 03 '19 at 07:55

hpekristiansen

37,006

@CarLaTeX I do not understand what you mean!? – hpekristiansen Feb 03 '19 at 10:15
@CarLaTeX You meant to say \path[pattern=horizontal lines] ...? (\fill also does what you want it to do but this is in a way an accident.) – Feb 03 '19 at 16:22
1

@marmot Yes, \path, lapsus! – CarLaTeX Feb 03 '19 at 16:28
Thanks @hpekristiansen. Is it possible to increase number of horizontal lines? – Feb 04 '19 at 05:30
@C.F.G: Yes, but not easily. - see e.g. https://tex.stackexchange.com/questions/54358/custom-and-built-in-tikz-fill-patterns – hpekristiansen Feb 04 '19 at 07:05

score 6 · Answer 2 · answered Feb 03 '19 at 07:53

\documentclass{article}
\usepackage{tikz}

\begin{document}

\begin{tikzpicture}
\draw  (-1,1) node (v1) {} circle (4.5);
\draw  (v1) circle (2.5);

\fill[red](-5.5,1) arc (180:360:1 and .25)
arc(180:0:2.5)
arc (180:360:1 and .25)
arc (0:180:4.5) ;
\end{tikzpicture}
\end{document}

How to add patterns inside shapes bounded by curves?

2 Answers2