Add Lorenz attractor animation

This commit is contained in:
Juergen Stuber 2023-10-21 17:51:15 +02:00
parent e5389416b6
commit 3fb9e955fc

99
src/bin/lorenz/main.rs Normal file
View File

@ -0,0 +1,99 @@
use std::env::args;
use std::io::stdout;
use std::io::Write;
use std::iter::repeat;
use std::thread::sleep;
use std::time::Duration;
use pixelfoo::color::Color;
type Frame = Vec<Vec<Color>>;
fn send<T: Write>(w: &mut T, f: &Frame) -> std::io::Result<()> {
for l in f {
for c in l {
w.write_all(&c.rgb())?;
}
}
w.flush()
}
const DEFAULT_ARG: usize = 10;
fn main() -> std::io::Result<()> {
let args = args().collect::<Vec<_>>();
eprintln!("executing {}", args[0]);
let x_size = args[1].parse::<usize>().unwrap();
let y_size = args[2].parse::<usize>().unwrap();
let arg = args[3].parse::<usize>().unwrap_or(DEFAULT_ARG);
eprintln!("screen size {}x{}, arg {}", x_size, y_size, arg);
let t_frame = 0.040; // s
let delay = Duration::new(0, (1_000_000_000.0 * t_frame) as u32);
// Background color.
let c0 = Color::new(0, 0, 80);
let [r0, g0, b0] = c0.rgb();
let c1 = Color::new(0, 255, 80);
let mut frame = repeat(repeat(c0).take(x_size).collect::<Vec<_>>())
.take(y_size)
.collect::<Vec<_>>();
let x0 = (x_size as f64) / 2.0;
let y0 = (y_size as f64) / 2.0;
let xc = 0.0;
let zc = 26.0;
let x_scale = 2.0;
let z_scale = 1.0;
let dt = 0.005;
let a = 10.0;
let b = 27.0;
let c = 8.0 / 3.0;
let mut x = 1.0;
let mut y = 0.0;
let mut z = zc;
loop {
//eprintln!("{:10.3} {:10.3} {:10.3}", x, y, z);
// Decay towards the background color.
for row in &mut frame {
for pixel in row {
let [mut r, mut g, mut b] = pixel.rgb();
if r > r0 {
r -= 1;
}
if g > g0 {
g -= 1;
}
if b > b0 {
b -= 1;
}
*pixel = Color::new(r, g, b);
}
}
for _ in 0..arg {
x += dt * a * (y - x);
y += dt * (x * (b - z) - y);
z += dt * (x * y - c * z);
let xf = (x_scale * (x - xc) + x0).round();
let yf = (z_scale * (z - zc) + y0).round();
if xf >= 0.0 && xf < x_size as f64 && yf >= 0.0 && yf < y_size as f64 {
frame[yf as usize][xf as usize] = c1;
}
}
let mut buf = Vec::with_capacity(x_size * y_size * 3);
send(&mut buf, &frame)?;
stdout().write_all(&buf)?;
stdout().flush()?;
sleep(delay);
}
}