donut.c

int 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 sini=sin(i),
                      cosj=cos(j),
                      sinA=sin(A),
                      sinj=sin(j),
                      cosA=cos(A),
                      cosj2=cosj+2,
                      mess=1/(sini*cosj2*sinA+sinj*cosA+5),
                      cosi=cos(i),
                      cosB=cos(B),
                      sinB=sin(B),
                      t=sini*cosj2*cosA-sinj* sinA;
                int x=40+30*mess*(cosi*cosj2*cosB-t*sinB),
                    y= 12+15*mess*(cosi*cosj2*sinB +t*cosB),
                    o=x+80*y,
                    N=8*((sinj*sinA-sini*cosj*cosA)*cosB-sini*cosj*sinA-sinj*cosA-cosi *cosj*sinB);
                if(22>y&&y>0&&x>0&&80>x&&mess>z[o]){
                    z[o]=mess;
                    b[o]=".,-~:;=!*#$@"[N>0?N:0];
                }
            }
        }
        printf("\x1b[d");
        for(k=0; 1761>k; k++)
            putchar(k%80?b[k]:10);
        A+=0.04;
        B+= 0.02;
    }
}

in windows this donut spins way too slow

use clang compiler it's a little better than gcc or zig cc.

system("cls");

that gives an error

in windows this donut spins way too slow

to change rotation speed just decrease or increase the increment of A & B in the last 2 lines of code

I just found a quick solution to make it faster on windows (using claude to help me)
and it used fwrite instead of using putchar
here is the full code :

#include <stdio.h>
#include <math.h>
#include <string.h>
#include <windows.h>

int main() {
    float A = 0, B = 0;
    float i, j;
    int k;
    float z[1760];
    char b[1760];
    
    // Set console to UTF-8 for better performance
    SetConsoleOutputCP(CP_UTF8);
    
    printf("\x1b[2J");
    for(;;) {
        memset(b,32,1760);
        memset(z,0,7040);
        for(j=0; j < 6.28; j += 0.07) {
            for(i=0; i < 6.28; i += 0.02) {
                float c = sin(i);
                float d = cos(j);
                float e = sin(A);
                float f = sin(j);
                float g = cos(A);
                float h = d + 2;
                float D = 1 / (c * h * e + f * g + 5);
                float l = cos(i);
                float m = cos(B);
                float n = sin(B);
                float t = c * h * g - f * e;
                int x = 40 + 30 * D * (l * h * m - t * n);
                int y= 12 + 15 * D * (l * h * n + t * m);
                int o = x + 80 * y;
                int 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");
        
        // Use fwrite instead of putchar for better performance
        for(k = 0; k < 1760; k++) {
            if(k % 80 == 79) {
                b[k] = '\n';
            }
        }
        fwrite(b, 1, 1760, stdout);
        fflush(stdout);
        
        A += 0.08 ;
        B += 0.04 ;
        
        Sleep(30);
    }
    return 0;
}