Draw a symmetric alien head

Question

I am trying to draw the following "symmetrical alien head":

Using the mirror code from Can we mirror a part in tikz? I was able to produce the following result

While the result looks good I am not particularly happy with the code, as I had to juggle a lot of coordinates and a lot of manual adjustments had to be made. In particular

Is there an easier way to remove the white squares from the figure while still keeping the transparent background?
Can one make one half of the face and then mirror or across x=6? I tried this, but it was only possible with the coordinates not the fill functions.

Other solutions using TikZ, Asymptote, MetaPost, PSTricks are also welcome.

\documentclass[border=2mm]{standalone}
\usepackage{tkz-euclide}
\usetkzobj{all} % on charge tous les objets

\definecolor{maincolorMedium}{HTML}{a757b2}%

\makeatletter
\tikzset{
  mirror/.code={\pgfutil@in@{--}{#1}\ifpgfutil@in@\tikz@trans@mirror#1\@nil
    \else\tikz@scan@one@point\pgftransformmirror#1\relax\fi},
  ymirror/.code={\pgfutil@ifnextchar(\tikz@trans@ymirror@coordinate\tikz@trans@ymirror@simple#1\@nil},
  xmirror/.code={\pgfutil@ifnextchar(\tikz@trans@xmirror@coordinate\tikz@trans@xmirror@simple#1\@nil}}
\def\tikz@trans@mirror#1--#2\@nil{%
  \pgfextract@process\pgf@trans@mirror@A{\tikz@scan@one@point\pgfutil@firstofone#1}%
  \pgfextract@process\pgf@trans@mirror@B{\tikz@scan@one@point\pgfutil@firstofone#2}%
  \pgftransformMirror{\pgf@trans@mirror@A}{\pgf@trans@mirror@B}}
\def\pgftransformxmirror#1{\pgfmathparse{2*(#1)}\pgftransformcm{-1}{0}{0}{1}{\pgfqpoint{+\pgfmathresult pt}{+0pt}}}
\def\pgftransformymirror#1{\pgfmathparse{2*(#1)}\pgftransformcm{1}{0}{0}{-1}{\pgfqpoint{+0pt}{+\pgfmathresult pt}}}
\def\tikz@trans@ymirror@simple#1\@nil{
  \pgfmathparse{#1}\let\tikz@temp\pgfmathresult
  \ifpgfmathunitsdeclared
    \pgftransformymirror{\tikz@temp pt}%
  \else
    \pgf@process{\pgfpointxy{0}{\tikz@temp}}%
    \pgftransformymirror{+\the\pgf@y}%
  \fi}
\def\tikz@trans@xmirror@simple#1\@nil{
  \pgfmathparse{#1}\let\tikz@temp\pgfmathresult
  \ifpgfmathunitsdeclared
    \pgftransformxmirror{\tikz@temp pt}%
  \else
    \pgf@process{\pgfpointxy{\tikz@temp}{0}}%
    \pgftransformxmirror{+\the\pgf@x}%
  \fi}
\def\tikz@trans@xmirror@coordinate#1\@nil{\tikz@scan@one@point\pgfutil@firstofone#1\pgftransformxmirror{+\the\pgf@x}}
\def\tikz@trans@ymirror@coordinate#1\@nil{\tikz@scan@one@point\pgfutil@firstofone#1\pgftransformymirror{+\the\pgf@y}}
\def\pgftransformmirror#1{%
  \pgfpointnormalised{#1}%
  \pgf@xa=\pgf@sys@tonumber\pgf@y\pgf@x
  \pgf@xb=\pgf@sys@tonumber\pgf@x\pgf@x
  \pgf@yb=\pgf@sys@tonumber\pgf@y\pgf@y
  \multiply\pgf@xa2\relax
  \pgf@xc=-\pgf@yb\advance\pgf@xc\pgf@xb
  \pgf@yc=-\pgf@xb\advance\pgf@yc\pgf@yb
  \edef\pgf@temp{{\the\pgf@xc}{+\the\pgf@xa}{+\the\pgf@xa}{+\the\pgf@yc}}%
  \expandafter\pgf@transformcm\pgf@temp{\pgfpointorigin}}
\def\pgftransformMirror#1#2{%
  \pgfextract@process\pgf@trans@mirror@A{#1}%
  \pgfextract@process\pgf@trans@mirror@B{#2}%
  \pgfextract@process\pgf@trans@mirror@g{\pgfpointdiff{\pgf@trans@mirror@A}{\pgf@trans@mirror@B}}%
  \pgftransformshift{\pgf@trans@mirror@A}%
  \pgftransformmirror{\pgf@trans@mirror@g}%
  \pgftransformshift{\pgfpointscale{-1}{\pgf@trans@mirror@A}}}
\makeatother


\begin{document}

\begin{tikzpicture}
\def\opa{0.4}
    \tkzInit[xmin=-0.5,xmax=12.5, ymin=-0.5,ymax=9.5]

    % Draw dashed grid
    \begin{scope}[dashed]
        \tkzGrid
    \end{scope}

    % Def points
    \tkzDefPoint(3,0){A}
    \tkzDefPoint(3,3){B}
    \tkzDefPoint(6,4){C}
    \tkzDefPoint(6,6){D}

    % Define the white squares
    \tkzDefPoint(5,4){e1}\tkzDefPoint(5,6){e2}\tkzDefSquare(e1,e2) \tkzGetPoints{e3}{e4}

    \begin{scope}[xmirror=6]
        \tkzDefPoint(3,0){A1}
        \tkzDefPoint(3,3){B1}
        \tkzDefPoint(5,4){f1}\tkzDefPoint(5,6){f2}
    \end{scope}

    \tkzDefSquare(f2,f1) \tkzGetPoints{f3}{f4}

    % Fill the figure
    \tkzFillPolygon[color=maincolorMedium,opacity=\opa](A,e4,C) 
    \tkzFillPolygon[color=maincolorMedium,opacity=\opa](A1,f3,C)
    \tkzFillPolygon[color=maincolorMedium,opacity=\opa](e1,f1,f2,e2)
    \tkzFillSector[color=maincolorMedium,opacity=\opa](e3,D)(B) 
    \tkzFillSector[color=maincolorMedium,opacity=\opa](f4,B1)(D)

    % Perform the outline
    \tkzDrawArc[color=black,thick](e3,D)(B) 
    \tkzDrawArc[color=black,thick](f4,B1)(D)
    \tkzDrawSquare[thick](e1,e2)\tkzDrawSquare(f2,f1)
    \tkzDrawSegments[thick](B,A A,C C,A1 A1,B1)
\end{tikzpicture}

\end{document}

score 12 · Accepted Answer · 2019-06-16T18:00:49.933

12

In simple cases like this you could just use a pic and mirror it.

\documentclass[tikz,border=3.14mm]{standalone}
\definecolor{maincolorMedium}{HTML}{a757b2}%
\begin{document}
\begin{tikzpicture}[pics/lhead/.style={code={
\draw[fill=maincolorMedium,even odd rule] (0,0) -- (-3,-4) -- (-3,-1) arc(270:0:3) (-3,0) rectangle (-1,2);}}]
\draw[dashed] (-6.5,-4.5) grid (6.5,5.5);
\path[fill opacity=0.4] (0,0) pic{lhead} pic[xscale=-1]{lhead};
\end{tikzpicture}
\end{document}

edited Jun 16 '19 at 18:00

answered Jun 16 '19 at 17:55

It's worth mentioning that the "even odd rule" produces the squares by making a path with a hole, i.e. the squares are truly transparent. – Erlkoenig Jun 17 '19 at 09:54
@Erlkoenig Yes, this is the intention behind this. Otherwise the grid will be covered, as in Bernhard's answer below. – Jun 17 '19 at 18:08
Right, just wanted to make it clear in case anyone wonders how it works. – Erlkoenig Jun 17 '19 at 18:52
@Erlkoenig Thanks! – Jun 17 '19 at 18:52

score 11 · Answer 2 · answered Jun 16 '19 at 18:13

As a mathematical figure, it's a poor match.

But as an alien head in the style of Cthulhu, I think it gives the OP's a run for the money.

\documentclass{article}
\usepackage{graphicx,xcolor,stackengine}
\begin{document}
\bgroup
\savestack\halfhead{\Huge\stackinset{c}{3pt}{c}{23pt}{%
  \color{red!15}\rule{7pt}{7pt}}{\scalebox{10}{,}}\kern-19pt}
\halfhead\reflectbox{\halfhead}
\egroup
\end{document}

Bernard · Answer 3 · 2019-06-16T20:28:15.003

A pstricks code:

\documentclass[border = 5pt, svgnames]{standalone}
\usepackage{pstricks}
\usepackage{auto-pst-pdf}% to compile with pdflatex --enable-write18 (MiKTeX) or pdflatex --shell-escape (TeXLive, MacTeX)

 \begin{document}

\begin{pspicture}[showgrid](-6.5, -6.5)(6.5, 3.5)
\psset{linewidth=0.6pt, linecolor=Plum, fillstyle=solid, fillcolor=white}
\pscustom[fillstyle=solid, fillcolor=Plum, opacity=0.4]{%
\psarc(-3,0){3}{0}{270}\psline(-3,-6)(0,-2)(3,-6)
\psarc(3,0){3}{-90}{180} }%
\psframe[](-3,-2)(-1,0)\psframe[](1,-2)(3,0)
\end{pspicture}

\end{document}

score 7 · Answer 4 · answered Jun 16 '19 at 20:22

7

\documentclass[pstricks,border=4mm]{standalone}
\begin{document}

\def\Path{\psline(0,0)(-3,-4)(-3,-1)\psarcn(-3,2){3}{270}{0}\psframe(-3,0)(-1,2)}
\begin{pspicture}[showgrid](-6,-4)(6,5)
\pscustom[fillstyle=eofill,fillcolor={[HTML]{a757b2}},opacity=0.4]{%
  \Path\moveto(0,0)\code{-1 1 scale}\Path}
\end{pspicture}
\end{document}

answered Jun 16 '19 at 20:22

user187802

16,850

fillcolor={[HTML]{a757b2}} Where can we find? (I think it is a new feature) – Jun 17 '19 at 08:39
Documentation of xcolor – user187802 Jun 17 '19 at 08:43

score 6 · Answer 5 · answered Jun 17 '19 at 08:06

Just another customizable template with PSTricks. It will be useful for others who look for non-alien head.

\documentclass[pstricks,border=12pt,12pt]{standalone}

\def\obj{%
    \psline(0,0)(-1,0)(-2,1)(-3,0)(-3,-2)(0,-2)
    \moveto(0,-3)
    \psline(-4,-3)(-4,1)(-3,4)(-2,2)(0,2)
    \psframe(2.5,1.5)(3.25,2.5)
    \pscircle(3,1){.2}}

\begin{document}
\begin{pspicture}[showgrid=b](-5,-5)(5,5)   
\pscustom[fillstyle=eofill,fillcolor=red]{\obj\reversepath\scale{-1 1}\obj}
\end{pspicture}
\end{document}

Draw a symmetric alien head

5 Answers5