Fichier rouladescr4.mp (figure 1) — Modifié le 21 Mars 2008 à 20 h 45
input geometriesyr16;
%input marith;% à utiliser pour de grandes valeurs des côtés !!!
vardef pgcd(expr a,b)=
save $;
numeric $;
boolean reste;
reste=true;
if a>b:
dividende0=a;
diviseur0=b;
else:
dividende0=b;
diviseur0=a;
fi;
re0=diviseur0;
j=0;
forever: exitunless reste;
if (dividende[j] mod diviseur[j])=0:
reste:=false;
else:
j:=j+1;
re[j]=(dividende[j-1] mod diviseur[j-1]);
dividende[j]=diviseur[j-1];
diviseur[j]=re[j];
fi;
endfor;
$=re[j];
$
enddef;
vardef ppcm(expr a,b)=
save $;
numeric $;
$=a*b/pgcd(a,b);
$
enddef;
prologues:=2;
vardef roulades(expr num,deno,total)=
save $;
picture $;
path cc,poly;
%définition des constantes de bases
cote:=3;
totalcen:=0;
totaltour:=num-1;
%définition des points de bases
pair O,A[],B[],C,D;
O=(0,0);
B2=u*(-5,-5);
B0=u*(5,-5);
B1=rotation(B0,B2,60);
B3=B0;
A0=B0;
A1=(num/deno)[B0,B1];
A2=rotation(A1,A0,-60);
A3=A0;
%définition des centres de rotation
marque_p:="plein";
pair cen[];
cen[0]=B0;
for k=0 upto 2:
for j=1 upto deno:
cen[deno*k+j]:=(j/deno)[B[k],B[k+1]];
pointe(cen[deno*k+j]);
totalcen:=totalcen+1;
endfor;
endfor;
totalcentre:=totalcen;
for p=1 upto totaltour:
for k=0 upto totalcen:
cen[p*totalcen+k]=cen[k];
totalcentre:=totalcentre+1;
endfor;
endfor;
%définition des polygones
poly=A0--A1--A2--cycle;
cc=B0--B1--B2--cycle;
%traçage
trace cc withcolor bleu;
trace poly withcolor violet;
pair I[],J[];
I0=A0;
J0=iso(A0,A1,A2);
w:=0;
for k=num step num until total:
if 7*((k div 7)+1)-k<num:
if (k mod 3)=0:
for j=1 upto 120:
I[120*w+j]=rotation(I[120*w+j-1],cen[7*((k div 7)+1)],1);
endfor;
w:=w+1;
else:
for j=1 upto 120:
I[120*w+j]=rotation(I[120*w+j-1],cen[k],1);
endfor;
for j=1 upto 120:
I[120*w+120+j]=rotation(I[120*w+120+j-1],cen[7*((k div 7)+1)],1);
endfor;
w:=w+2
fi;
elseif (k mod 7)=0:
for j=1 upto 240:
I[120*w+j]=rotation(I[120*w+j-1],cen[k],1);
endfor;
w:=w+2;
else:
for j=1 upto 120:
I[120*w+j]=rotation(I[120*w+j-1],cen[k],1);
endfor;
w:=w+1;
fi;
endfor;
path cd;
cd=I0
for j=2 step 1 until (120*w):
..I[j]
endfor;
$=image(
trace cd withcolor orange;
);
$
enddef;
figure(-12u,-12u,12u,12u);
trace roulades(2,7,4);
fin;
figure(-12u,-12u,12u,12u);
trace roulades(2,7,6);
fin;
figure(-12u,-12u,12u,12u);
trace roulades(2,7,8);
fin;
end