Add stress test

Author: tim-blackbird

Cargo.toml

@@ -1331,6 +1331,16 @@ description = "Simple benchmark to test per-entity draw overhead. Run with the `
 category = "Stress Tests"
 wasm = true
 
+[[example]]
+name = "many_debug_lines"
+path = "examples/stress_tests/many_debug_lines.rs"
+
+[package.metadata.example.many_debug_lines]
+name = "Many Debug Lines"
+description = "Test rendering of many debug lines"
+category = "Stress Tests"
+wasm = true
+
 [[example]]
 name = "many_foxes"
 path = "examples/stress_tests/many_foxes.rs"

examples/stress_tests/many_debug_lines.rs

@@ -0,0 +1,96 @@
+use std::f32::consts::TAU;
+
+use bevy::{
+    diagnostic::{Diagnostics, FrameTimeDiagnosticsPlugin},
+    prelude::*,
+};
+
+fn main() {
+    App::new()
+        .add_plugins(DefaultPlugins)
+        .add_plugin(FrameTimeDiagnosticsPlugin::default())
+        .insert_resource(Config {
+            line_count: 50_000,
+            simple: false,
+        })
+        .insert_resource(DebugDrawConfig {
+            always_on_top: false,
+            ..default()
+        })
+        .add_startup_system(setup)
+        .add_system(system)
+        .add_system(ui_system)
+        .run();
+}
+
+#[derive(Resource, Debug)]
+struct Config {
+    line_count: u32,
+    simple: bool,
+}
+
+fn system(
+    mut draw: ResMut<DebugDraw>,
+    mut config: ResMut<Config>,
+    input: Res<Input<KeyCode>>,
+    time: Res<Time>,
+) {
+    if input.just_pressed(KeyCode::Up) {
+        config.line_count += 10_000;
+    }
+    if input.just_pressed(KeyCode::Down) {
+        config.line_count = config.line_count.saturating_sub(10_000);
+    }
+    if input.just_pressed(KeyCode::Space) {
+        config.simple = !config.simple;
+    }
+
+    if config.simple {
+        for _ in 0..config.line_count {
+            draw.line(Vec3::NEG_Y, Vec3::Y, Color::BLACK);
+        }
+    } else {
+        for i in 0..config.line_count {
+            let angle = i as f32 / config.line_count as f32 * TAU;
+
+            let vector = (Vec2::from(angle.sin_cos())).extend(time.elapsed_seconds().sin());
+            let start_color = Color::rgb(vector.x, vector.z, 0.5);
+            let end_color = Color::rgb(-vector.z, -vector.y, 0.5);
+
+            draw.line_gradient(vector, -vector, start_color, end_color);
+        }
+    }
+}
+
+fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
+    commands.spawn(Camera3dBundle {
+        transform: Transform::from_xyz(1., 3., 5.).looking_at(Vec3::ZERO, Vec3::Y),
+        ..default()
+    });
+
+    commands.spawn(TextBundle::from_section(
+        "",
+        TextStyle {
+            font: asset_server.load("fonts/FiraSans-Bold.ttf"),
+            font_size: 30.,
+            ..default()
+        },
+    ));
+}
+
+fn ui_system(mut query: Query<&mut Text>, config: Res<Config>, diag: Res<Diagnostics>) {
+    let mut text = query.single_mut();
+
+    let Some(fps) = diag.get(FrameTimeDiagnosticsPlugin::FPS).and_then(|fps| fps.smoothed()) else {
+        return;
+    };
+
+    text.sections[0].value = format!(
+        "Line count: {}\n\
+        FPS: {:.0}\n\n\
+        Controls:\n\
+        Up/Down: Raise or lower the line count.\n\
+        Spacebar: Toggle simple mode.",
+        config.line_count, fps,
+    );
+}