use std::time::Instant;

use rand::distributions::Standard;
use rand::{thread_rng, Rng};

fn main() {
    // make some sample pixels
    let rng = thread_rng();
    // 1080p ARGB image
    let mut v: Vec<u8> = rng.sample_iter(&Standard).take(1920 * 1080 * 4).collect();

    // set alpha to 255
    v.iter_mut().step_by(4).for_each(|x| *x = 255);

    // ARGBARGBARGB -> AAARRRGGGBBB
    let mut pixel_order = (0..4).cycle();

    // AoS -> SoA
    let timer = Instant::now();
    v.sort_by_cached_key(|_| pixel_order.next());
    println!("{:#?}", timer.elapsed());
}