main.c

/*
   Spinning 3D donut with option of playback music
    Original video: https://www.youtube.com/watch?v=DEqXNfs_HhY
    Modifier for featuring playback music and speed adjustment: https://github.com/BurntRanch/

   Using libvlc with license GPL-2.0-or-later with some libraries under LGPL-2.1-or-later VLC for iOS (MPLv2.0)
*/

#include <unistd.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <vlc/vlc.h>
#include <signal.h>

libvlc_instance_t * inst;
libvlc_media_player_t *mp;

void end()
{
    printf("\nBye!\n");
    libvlc_media_player_stop(mp);
    libvlc_media_player_release(mp);
    libvlc_release(inst);
    exit(0);
}


int main(int argc, char* argv[])
{
    libvlc_media_t *m;
    char file_name[256];
    float speed;

    /* Load the VLC engine */
    inst = libvlc_new (0, NULL);
    
    /* asking for the fike to play and speed */
    printf("Enter the name of the path and/or file you would like to play: ");
    scanf("%s", file_name);
    printf("%s\n", file_name);
    
    printf("Insert speed: ");
    scanf("%f", &speed);
    if (speed == 0){
      printf("%s\n", "not valid speed");
      return 1;
    }

    /* Create a media player playing environement */
    m = libvlc_media_new_path (inst, file_name);
    mp = libvlc_media_player_new_from_media (m);
    signal(SIGINT, end);
    signal(SIGTERM, end);
    
    /* No need to keep the media now */
    libvlc_media_release (m);
    
    /* The Donut */
    float A = 0, B = 0;
    float i, j;
    int k;
    float z[1760];
    char b[1760];
    float Xspeed = speed / 100;
    float Yspeed = Xspeed / 2;
    printf("\n%f\n", Xspeed);
    libvlc_media_player_play(mp);
    printf("\x1b[2J");
    while (1) {
        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");
        if (!libvlc_media_player_is_playing(mp))
        {
            libvlc_media_player_stop(mp);
            libvlc_media_player_play(mp);
        }
        for(k = 0; k < 1761; k++) {
            putchar(k % 80 ? b[k] : 10);
        }
        A += Xspeed;
        B += Yspeed;
        usleep(30000);
    }

    return 0;
}