donut.c

donut.c

k;
double sin() ,cos();
main()
{
  float A=0,B=0,i,j,z[1760];
  char b[1760];
  printf("\x1b[2J");
  for(;;){
    memset(b,32,1760);
    memset(z,0,7040);
    for(j=0;6.28>j;j+=0.07)
      for(i=0;6.28>i;i+=0.02){
        float c=sin(i),d=cos(j),e=sin(A),f=sin(j),g=cos(A),h=d+2,D=1/(c*h*e+f*g+5),l=cos(i),m=cos(B),n=sin(B),t=c*h*g-f*e;
        int x=40+30*D*(l*h*m-t*n), y=12+15*D*(l*h*n+t*m), o=x+80*y, N=8*((f*e-c*d*g)*m-c*d*e-f*g-l*d*n);
        if(22>y&&y>0&&x>0&&80>x&&D>z[o]){
          z[o]=D;;;b[o]=".,-~:;=!*#$@"[N>0?N:0];
        }
      }
    printf("\x1b[H");
    for(k=0;1761>k;k++)
    putchar(k%80?b[k]:10);A+=0.04;B+=0.02;
    }                
}

https://www.a1k0n.net/2006/09/15/obfuscated-c-donut.html