blazingly_fast_rust_donut 1.0.0

use std::time::Instant;

fn main() {
    let (mut a, mut b): (f64, f64) = (0., 0.);
    let s: [char; 12] = ['.', ',', '-', '~', ':', ';', '=', '!', '*', '#', '$', '@'];
    print!("\x1B[2J");

    let mut last_instant = Instant::now();
    let mut frame_count = 0;

    loop {
        let (mut b2, mut z) = ([' '; 1760], [0.; 1760]);
        for j in (0..628).step_by(7) {
            for i in (0..628).step_by(2) {
                let sini = ((i as f64) / 100.).sin();
                let cosi = ((i as f64) / 100.0).cos();
                let sinj = ((j as f64) / 100.).sin();
                let cosj = ((j as f64) / 100.).cos();
                let cosj2 = cosj + 2.;
                let sina = a.sin();
                let cosa = a.cos();
                let sinb = b.sin();
                let cosb = b.cos();
                let m = 1. / (sini * cosj2 * sina + sinj * cosa + 5.);
                let t = sini * cosj2 * cosa - sinj * sina;
                let x = 40. + 30. * m * (cosi * cosj2 * cosb - t * sinb);
                let y = 12. + 15. * m * (cosi * cosj2 * sinb + t * cosb);
                let o = x as usize + 80 * y as usize;
                let 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 && m > z[o] {
                    z[o] = m;
                    b2[o] = s[n as usize];
                }
            }
        }
        print!("\x1b[H");
        for k in 0..1760 {
            if k % 80 != 0 {
                print!("{}", b2[k]);
            } else {
                println!("");
            }
        }
        a += 0.04;
        b += 0.02;

        frame_count += 1;

        if last_instant.elapsed().as_secs_f32() >= 1.0 {
            println!("FPS: {}", frame_count);
            frame_count = 0;
            last_instant = Instant::now();
        }
    }
}