bevy/examples/stress_tests/many_gradients.rs
2025-07-12 19:16:33 -04:00

145 lines
4.3 KiB
Rust

//! Stress test demonstrating gradient performance improvements.
//!
//! This example creates many UI nodes with gradients to measure the performance
//! impact of pre-converting colors to the target color space on the CPU.
use argh::FromArgs;
use bevy::{
color::palettes::css::*,
diagnostic::{FrameTimeDiagnosticsPlugin, LogDiagnosticsPlugin},
prelude::*,
ui::{BackgroundGradient, LinearGradient, ColorStop, Gradient, RepeatedGridTrack, Display, InterpolationColorSpace},
window::{PresentMode, WindowResolution},
};
const COLS: usize = 30;
#[derive(FromArgs, Resource, Debug)]
/// Gradient stress test
struct Args {
/// how many gradients per group (default: 900)
#[argh(option, default = "900")]
gradient_count: usize,
/// whether to animate gradients by changing colors
#[argh(switch)]
animate: bool,
/// use sRGB interpolation
#[argh(switch)]
srgb: bool,
/// use HSL interpolation
#[argh(switch)]
hsl: bool,
}
fn main() {
let args: Args = argh::from_env();
let total_gradients = args.gradient_count;
println!("Gradient stress test with {} gradients", total_gradients);
println!("Color space: {}", if args.srgb {
"sRGB"
} else if args.hsl {
"HSL"
} else {
"OkLab (default)"
});
App::new()
.add_plugins((
LogDiagnosticsPlugin::default(),
FrameTimeDiagnosticsPlugin::default(),
DefaultPlugins.set(WindowPlugin {
primary_window: Some(Window {
title: "Gradient Stress Test".to_string(),
resolution: WindowResolution::new(1920.0, 1080.0),
present_mode: PresentMode::AutoNoVsync,
..default()
}),
..default()
}),
))
.insert_resource(args)
.add_systems(Startup, setup)
.add_systems(Update, animate_gradients)
.run();
}
fn setup(mut commands: Commands, args: Res<Args>) {
commands.spawn(Camera2d);
let rows_to_spawn = (args.gradient_count + COLS - 1) / COLS;
// Create a grid of gradients
commands
.spawn(Node {
width: Val::Percent(100.0),
height: Val::Percent(100.0),
display: Display::Grid,
grid_template_columns: RepeatedGridTrack::flex(COLS as u16, 1.0),
grid_template_rows: RepeatedGridTrack::flex(rows_to_spawn as u16, 1.0),
..default()
})
.with_children(|parent| {
for i in 0..args.gradient_count {
let angle = (i as f32 * 10.0) % 360.0;
let mut gradient = LinearGradient::new(angle, vec![
ColorStop::new(RED, Val::Percent(0.0)),
ColorStop::new(BLUE, Val::Percent(100.0)),
]);
gradient.color_space = if args.srgb {
InterpolationColorSpace::Srgb
} else if args.hsl {
InterpolationColorSpace::Hsl
} else {
InterpolationColorSpace::OkLab
};
parent.spawn((
Node {
width: Val::Percent(100.0),
height: Val::Percent(100.0),
..default()
},
BackgroundGradient(vec![Gradient::Linear(gradient)]),
GradientNode { index: i },
));
}
});
}
#[derive(Component)]
struct GradientNode {
index: usize,
}
fn animate_gradients(
mut gradients: Query<(&mut BackgroundGradient, &GradientNode)>,
args: Res<Args>,
time: Res<Time>,
) {
if !args.animate {
return;
}
let t = time.elapsed_secs();
for (mut bg_gradient, node) in &mut gradients {
let offset = node.index as f32 * 0.01;
let hue_shift = (t + offset).sin() * 0.5 + 0.5;
if let Some(Gradient::Linear(gradient)) = bg_gradient.0.get_mut(0) {
let color1 = Color::hsl(hue_shift * 360.0, 1.0, 0.5);
let color2 = Color::hsl((hue_shift + 0.3) * 360.0 % 360.0, 1.0, 0.5);
gradient.stops = vec![
ColorStop::new(color1, Val::Percent(0.0)),
ColorStop::new(color2, Val::Percent(100.0)),
];
}
}
}