bevy/examples/stress_tests/many_animated_sprites.rs
Rob Parrett f0047899d7
Allow users to customize history length in FrameTimeDiagnosticsPlugin (#17259)
# Objective

I have an application where I'd like to measure average frame rate over
the entire life of the application, and it would be handy if I could
just configure this on the existing `FrameTimeDiagnosticsPlugin`.

Probably fixes #10948?

## Solution

Add `max_history_length` to `FrameTimeDiagnosticsPlugin`, and because
`smoothing_factor` seems to be based on history length, add that too.

## Discussion

I'm not totally sure that `DEFAULT_MAX_HISTORY_LENGTH` is a great
default for `FrameTimeDiagnosticsPlugin` (or any diagnostic?). That's
1/3 of a second at typical game frame rates. Moreover, the default print
interval for `LogDiagnosticsPlugin` is 1 second. So when the two are
combined, you are printing the average over the last third of the
duration between now and the previous print, which seems a bit wonky.
(related: #11429)

I'm pretty sure this default value discussed and the current value
wasn't totally arbitrary though.

Maybe it would be nice for `Diagnostic` to have a
`with_max_history_length_and_also_calculate_a_good_default_smoothing_factor`
method? And then make an explicit smoothing factor in
`FrameTimeDiagnosticsPlugin` optional?

Or add a `new(max_history_length: usize)` method to
`FrameTimeDiagnosticsPlugin` that sets a reasonable default
`smoothing_factor`? edit: This one seems like a no-brainer, doing it.

## Alternatives

It's really easy to roll your own `FrameTimeDiagnosticsPlugin`, but that
might not be super interoperable with, for example, third party FPS
overlays. Still, might be the right call.

## Testing

`cargo run --example many_sprites` (modified to use a custom
`max_history_length`)

## Migration Guide

`FrameTimeDiagnosticsPlugin` now contains two fields. Use
`FrameTimeDiagnosticsPlugin::default()` to match Bevy's previous
behavior or, for example, `FrameTimeDiagnosticsPlugin::new(60)` to
configure it.
2025-01-12 18:18:14 +00:00

145 lines
4.6 KiB
Rust

//! Renders a lot of animated sprites to allow performance testing.
//!
//! This example sets up many animated sprites in different sizes, rotations, and scales in the world.
//! It also moves the camera over them to see how well frustum culling works.
use std::time::Duration;
use bevy::{
diagnostic::{FrameTimeDiagnosticsPlugin, LogDiagnosticsPlugin},
prelude::*,
window::{PresentMode, WindowResolution},
winit::{UpdateMode, WinitSettings},
};
use rand::Rng;
const CAMERA_SPEED: f32 = 1000.0;
fn main() {
App::new()
// Since this is also used as a benchmark, we want it to display performance data.
.add_plugins((
LogDiagnosticsPlugin::default(),
FrameTimeDiagnosticsPlugin::default(),
DefaultPlugins.set(WindowPlugin {
primary_window: Some(Window {
present_mode: PresentMode::AutoNoVsync,
resolution: WindowResolution::new(1920.0, 1080.0)
.with_scale_factor_override(1.0),
..default()
}),
..default()
}),
))
.insert_resource(WinitSettings {
focused_mode: UpdateMode::Continuous,
unfocused_mode: UpdateMode::Continuous,
})
.add_systems(Startup, setup)
.add_systems(
Update,
(
animate_sprite,
print_sprite_count,
move_camera.after(print_sprite_count),
),
)
.run();
}
fn setup(
mut commands: Commands,
assets: Res<AssetServer>,
mut texture_atlases: ResMut<Assets<TextureAtlasLayout>>,
) {
warn!(include_str!("warning_string.txt"));
let mut rng = rand::thread_rng();
let tile_size = Vec2::splat(64.0);
let map_size = Vec2::splat(320.0);
let half_x = (map_size.x / 2.0) as i32;
let half_y = (map_size.y / 2.0) as i32;
let texture_handle = assets.load("textures/rpg/chars/gabe/gabe-idle-run.png");
let texture_atlas = TextureAtlasLayout::from_grid(UVec2::splat(24), 7, 1, None, None);
let texture_atlas_handle = texture_atlases.add(texture_atlas);
// Spawns the camera
commands.spawn(Camera2d);
// Builds and spawns the sprites
for y in -half_y..half_y {
for x in -half_x..half_x {
let position = Vec2::new(x as f32, y as f32);
let translation = (position * tile_size).extend(rng.gen::<f32>());
let rotation = Quat::from_rotation_z(rng.gen::<f32>());
let scale = Vec3::splat(rng.gen::<f32>() * 2.0);
let mut timer = Timer::from_seconds(0.1, TimerMode::Repeating);
timer.set_elapsed(Duration::from_secs_f32(rng.gen::<f32>()));
commands.spawn((
Sprite {
image: texture_handle.clone(),
texture_atlas: Some(TextureAtlas::from(texture_atlas_handle.clone())),
custom_size: Some(tile_size),
..default()
},
Transform {
translation,
rotation,
scale,
},
AnimationTimer(timer),
));
}
}
}
// System for rotating and translating the camera
fn move_camera(time: Res<Time>, mut camera_transform: Single<&mut Transform, With<Camera>>) {
camera_transform.rotate(Quat::from_rotation_z(time.delta_secs() * 0.5));
**camera_transform = **camera_transform
* Transform::from_translation(Vec3::X * CAMERA_SPEED * time.delta_secs());
}
#[derive(Component, Deref, DerefMut)]
struct AnimationTimer(Timer);
fn animate_sprite(
time: Res<Time>,
texture_atlases: Res<Assets<TextureAtlasLayout>>,
mut query: Query<(&mut AnimationTimer, &mut Sprite)>,
) {
for (mut timer, mut sprite) in query.iter_mut() {
timer.tick(time.delta());
if timer.just_finished() {
let Some(atlas) = &mut sprite.texture_atlas else {
continue;
};
let texture_atlas = texture_atlases.get(&atlas.layout).unwrap();
atlas.index = (atlas.index + 1) % texture_atlas.textures.len();
}
}
}
#[derive(Deref, DerefMut)]
struct PrintingTimer(Timer);
impl Default for PrintingTimer {
fn default() -> Self {
Self(Timer::from_seconds(1.0, TimerMode::Repeating))
}
}
// System for printing the number of sprites on every tick of the timer
fn print_sprite_count(time: Res<Time>, mut timer: Local<PrintingTimer>, sprites: Query<&Sprite>) {
timer.tick(time.delta());
if timer.just_finished() {
info!("Sprites: {}", sprites.iter().count());
}
}