ffi_bench/
ffi_bench.rs

1//! Rust reference for examples/cpp/benchmark.cpp; release builds only.
2//! One million positions, 10 warmups, 200 measured full-column updates.
3use ponko_ecs::World;
4use std::hint::black_box;
5use std::time::Instant;
6
7struct Pos {
8    x: f32,
9    y: f32,
10}
11struct Vel {
12    x: f32,
13    y: f32,
14}
15
16fn main() {
17    let mut world = World::new();
18    world.spawn_batch((0..1_000_000).map(|_| (Pos { x: 0.0, y: 0.0 }, Vel { x: 1.0, y: 2.0 })));
19    let mut samples = Vec::with_capacity(200);
20    for i in 0..210 {
21        let start = Instant::now();
22        world.query::<(&mut Pos, &Vel)>().for_each(|(p, v)| {
23            p.x += v.x;
24            p.y += v.y;
25        });
26        black_box(&world);
27        let elapsed = start.elapsed().as_secs_f64() * 1000.0;
28        if i >= 10 {
29            samples.push(elapsed);
30        }
31    }
32    samples.sort_by(f64::total_cmp);
33    let checksum: f64 = world
34        .query::<&Pos>()
35        .iter()
36        .map(|p| f64::from(p.x) + f64::from(p.y))
37        .sum();
38    assert_eq!(checksum, 630_000_000.0);
39    println!(
40        "Rust: 1000000 entities, median {:.6} ms/update, checksum {checksum:.0}",
41        (samples[99] + samples[100]) / 2.0
42    );
43}
ffi_bench/ffi_bench.rs

ffi_bench/
ffi_bench.rs
