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|
use rand::{thread_rng, Rng};
use std::{
io::{stdout, Read, Write},
thread::sleep,
time::Duration,
};
use termion::{async_stdin, raw::IntoRawMode, terminal_size};
const N_FISH: usize = 64;
struct Turbofish {
x: i16,
y: u16,
speed: i16,
blink: bool,
}
impl Turbofish {
fn text(&self, offset: i16) -> String {
let s = if self.speed < 0 { "<>::" } else { "::<>" };
let s = if offset <= -4 {
""
} else if offset < 0 {
&s[(-offset as usize)..]
} else if offset >= 4 {
""
} else if offset > 0 {
&s[0..(4 - offset as usize)]
} else {
s
};
s.to_string()
}
fn tick(&mut self) {
self.x += self.speed;
self.blink = !self.blink;
}
}
fn clear(mut stdout: impl Write) {
write!(stdout, "{}", termion::clear::All).unwrap();
}
fn update(school_of_fish: &mut [Turbofish], columns: u16) {
for fish in school_of_fish.iter_mut() {
fish.tick();
if fish.x < -10 || fish.x > columns as i16 + 10 {
fish.speed *= -1;
}
}
}
fn render(mut stdout: impl Write, school_of_fish: &Vec<Turbofish>, columns: u16) {
for fish in school_of_fish {
let x = fish.x;
let y = fish.y;
if fish.blink {
write!(stdout, "{}", termion::color::Fg(termion::color::LightBlack)).unwrap();
}
write!(
stdout,
"{}{}{}",
termion::cursor::Goto(x.clamp(0, columns as i16 - 1) as u16 + 1, y + 1),
fish.text(if x < 0 {
x
} else if (x as u16) + 4 >= columns {
x + 4 - columns as i16
} else {
0
}),
termion::style::Reset,
)
.unwrap();
}
}
fn main() {
let mut rng = thread_rng();
let mut stdin = async_stdin().bytes();
let mut stdout = stdout().into_raw_mode().unwrap();
let mut stdout = termion::cursor::HideCursor::from(stdout);
let (columns, lines) = terminal_size().unwrap();
let mut school_of_fish = Vec::with_capacity(N_FISH);
for _i in 0..N_FISH {
let x = rng.gen_range(0..(columns as i16 - 1));
let y = rng.gen_range(0..(lines - 1));
let speed = [-2, -1, 1, 2][rng.gen_range(0..4)];
school_of_fish.push(Turbofish {
x,
y,
speed,
blink: rng.gen(),
});
}
clear(&mut stdout);
stdout.flush().unwrap();
loop {
if let Some(Ok(b'q')) = stdin.next() {
break;
}
clear(&mut stdout);
update(&mut school_of_fish, columns);
render(&mut stdout, &school_of_fish, columns);
stdout.flush().unwrap();
sleep(Duration::from_millis(100));
}
clear(&mut stdout);
stdout.flush().unwrap();
}
|
