This is a 28-line function for drawing strings using SDL2 with no dependencies. It's good for writing prototype tools!

SDL_DrawString.c

void DrawString(SDL_Renderer* renderer, const char* txt, int x, int y) {
    static uint64_t font[] = {0x7cfc3cfcfefe3cc6,0x7e7ec6c0c6c67cfc,0x7cfc7cfcc6c6c6c6,0xccfe187c0000600c,0x0000c6c666c6c0c0,
           0x66c61818ccc0eee6,0xc6c6c6c6c630c6c6,0xc6c6cc0618c60000,0x30180000c6c6c0c6,0xc0c0c0c61818d8c0,0xfef6c6c6c6c6c030,
           0xc6c6c66ccc0c1806,0x00001830fc00fefc,0xc0c6f8f8c0fe1818,0xf0c0d6dec6c6c6c6,0x7030c6c6c6387818,0x180c00000c600000,
           0xc6c6c0c6c0c0cec6,0x1818d8c0c6cec6fc,0xc6fc1c30c6c6d66c,0x3030181800000c60,0x0000c6c6c0c6c0c0,0xc2c61818ccc0c6c6,
           0xc6c0c6c60630c6c6,0xfec6306018300000,0x1830fc00c6c666c6,0xc0c066c61818c6c0,0xc6c6c6c0ccc6c630,0xc66ceec630c00000,
           0x180830180000c6fc,0x3cfcfec03cc67e70,0xc6fec6c67cc07ac6,0x7c307c38c6c630fe,0x18301818600c0000,0x0c0000007c187c7c,
           0xccfe7cfe7c7c7c30,0x467c6c000000d8c0,0xe0e060c030c03060,0x3c3c0c000000c638,0xc6c6ccc0c606c6c6,0xc678e6d66c00c0c0,
           0xd8c0c060c0606060,0x30604242183000cc,0xc6180606ccc0c006,0xc6c6c6cc4cd0fe00,0xc0c04840c060c060,0x6060303099991830,
           0x00ccd6180c1cfe7c,0xfc0c7c7e6c001870,0x6c6c00009080c060,0xc060c0303030a1a5,0x30fcfc30d6181806,0x0c06c618c6063000,
           0x301c6cd800000000,0xc060c06060603018,0xa1a5303000ccc618,0x30060c06c630c606,0xd8006416fe00c040,0x0000c060c0606060,
           0x3018999d603000cc,0xc61860c60cc6c630,0xc6c6cc00ced66c00,0xc0c00000c060c060,0x6060300c42466000,0x00007c3cfe7c0c7c,
           0x7c307c7c7600c47c,0x6c0000000000e0e0,0x60c030c0300c3c3c};
    static const char*  font_mapping = "abcdefghijklmnopqrstuvwxyz!?.,><= /+-*0123456789&^%$#~:;\"'[](){}|\\`@";
    static SDL_Surface* font_surface = NULL;
    static SDL_Texture* font_texture = NULL;
    if (!font_surface) {
        font_surface = SDL_CreateRGBSurfaceWithFormat(0, 272, 16, 32, SDL_PIXELFORMAT_ABGR8888);
        for (int i = 0; i < 272 * 16; i++)
            ((uint32_t*)font_surface->pixels)[i] = ((font[i >> 6] >> (63 - (i & 63))) & 1) * 0xFFFFFFFF;
        font_texture = SDL_CreateTextureFromSurface(renderer, font_surface);
    }
    for (int i = 0; i < strlen(txt); i++) {
        const char* pos = strchr(font_mapping, tolower(txt[i]));
        size_t ci = pos ? pos - font_mapping : 0;
        SDL_Rect src_rect = {(ci % 34) * 8, (ci / 34) * 8, 8, 8};
        SDL_Rect dst_rect = {x + i * 8, y, 8, 8};
        SDL_RenderCopy(renderer, font_texture, &src_rect, &dst_rect);
    }
}