rotate.c

void *memset(void *a, int b, int c);
void printf(char *msg);
void usleep(int time);
void putchar(char c);
int m(int a, int b) { return (a * b + 5000) / 10000; }
void a(int *c, int *s, int d, int t)
{
    int k = m(*c, d) - m(*s, t);
    int l = m(*s, d) + m(*c, t);
    *c = k;
    *s = l;
}
int main()
{
    int z[1760];
    char b[1760];
    printf("\e[2J");
    int q = 10000;
    int r = 0;
    int u = 10000;
    int v = 0;
    for (;;)
    {
        memset(b, 32, 1760);
        memset(z, 0, 1760 * sizeof(int));
        int l = 0;
        int p = 10000;
        for (int i = 0; i < 88; i = i + 1)
        {
            int w = 0;
            int e = 10000;
            for (int j = 0; j < 314; j = j + 1)
            {
                int f = p + 20000;
                int g = 100000000 / (m(m(w, f), r) + m(l, q) + 50000);
                int t = m(m(w, q), f) - m(l, r);
                int x = 40 + 30 * m(g, m(m(e, u), f) - m(t, v)) / 10000;
                int y = 12 + 15 * m(g, m(m(e, v), f) + m(t, u)) / 10000;
                int o = x + 80 * y;
                int N = 8 * (m(m(l, r) - m(m(w, q), p), u) - m(m(w, r), p) - m(l, q) - m(m(e, v), p)) / 10000;
                if (22 > y)
                {
                    if (y > 0)
                    {
                        if (x > 0)
                        {
                            if (80 > x)
                            {
                                if (g > z[o])
                                {
                                    z[o] = g;
                                    if (N >= 1)
                                    {
                                        b[o] = ".,-~:;=!*#$@"[N];
                                    }
                                    else
                                    {
                                        b[o] = ".,-~:;=!*#$@"[0];
                                    }
                                }
                            }
                        }
                    }
                }
                a(&e, &w, 9998, 200);
            }
            a(&p, &l, 9974 + i % 2, 714);
        }
        printf("\e[H");
        for (int k = 0; k < 1761; k = k + 1)
        {
            if (k % 80)
            {
            }
            else
            {
                putchar(10);
            }
            putchar(b[k]);
        }
        a(&q, &r, 9992, 400);
        a(&u, &v, 9998, 200);
        printf("Author: @a1k0n. Rewritten by @hsjoihs so that it works without flo");
        printf("ating types.\nNote that rounding errors gradually reduce the donut's size.\n");
        usleep(50000);
    }
    return 0;
}