Illusion d'optique...
verbatimtex
%&latex
\documentclass{article}
\usepackage{amsmath}
\usepackage[latin1]{inputenc}
\usepackage{xcolor}
\usepackage[charter]{mathdesign}
\begin{document}
etex
color vert;
color vb;
color orange;
color bleu;
vb = 1/2 green + 1/3 blue;
vert = 2/3red + green ;
orange = red + 1/3 green +1/5 blue;
bleu = blue + 1/3 red ;
u:=1cm;
picture ell;
path ellt,demiell,demicercle,cercle, droite;
cercle := fullcircle scaled 0.5pt;
droite:=(-3u,0)--(3u,0);
ell = image(
pickup pencircle scaled 0.5pt;
ellt:=fullcircle xscaled (0.26u) yscaled(0.14u);
demiell:=(halfcircle xscaled (0.3u) yscaled(0.18u))--cycle;
fill demiell withcolor black;
fill demiell rotated 180 withcolor white;
fill ellt withcolor orange;
);
j:=0.35u;
beginfig(1);
path carre;
carre:=(-j,-j)--(17*j,-j)--(17*j,13j)--(-j,13j)--cycle;
fill carre withcolor vb;
for h:=0 upto 12:
for i:=0 upto 16:
draw ell rotated (i*30+h*30) shifted (j*i,h*j);
endfor;
endfor;
endfig;
end.
