bevy/examples/window/scale_factor_override.rs
2025-07-07 21:59:15 +02:00

109 lines
3.3 KiB
Rust

//! This example illustrates how to override the window scale factor imposed by the
//! operating system.
use bevy::{
prelude::*,
window::{PrimaryWindow, WindowResolution},
};
#[derive(Component)]
struct CustomText;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_observer(configure_window)
.add_systems(Startup, setup)
.add_systems(
Update,
(display_override, toggle_override, change_scale_factor),
)
.run();
}
fn configure_window(trigger: On<Add, PrimaryWindow>, mut window: Query<&mut Window>) {
let mut window = window.get_mut(trigger.target()).unwrap();
window.resolution = WindowResolution::new(1920.0, 1080.0).with_scale_factor_override(1.0);
}
fn setup(mut commands: Commands) {
// camera
commands.spawn(Camera2d);
// root node
commands
.spawn(Node {
width: Val::Percent(100.0),
height: Val::Percent(100.0),
justify_content: JustifyContent::SpaceBetween,
..default()
})
.with_children(|parent| {
// left vertical fill (border)
parent
.spawn((
Node {
width: Val::Px(300.0),
height: Val::Percent(100.0),
border: UiRect::all(Val::Px(2.0)),
..default()
},
BackgroundColor(Color::srgb(0.65, 0.65, 0.65)),
))
.with_child((
CustomText,
Text::new("Example text"),
TextFont {
font_size: 25.0,
..default()
},
Node {
align_self: AlignSelf::FlexEnd,
..default()
},
));
});
}
/// Set the title of the window to the current override
fn display_override(
mut window: Single<&mut Window>,
mut custom_text: Single<&mut Text, With<CustomText>>,
) {
let text = format!(
"Scale factor: {:.1} {}",
window.scale_factor(),
if window.resolution.scale_factor_override().is_some() {
"(overridden)"
} else {
"(default)"
}
);
window.title.clone_from(&text);
custom_text.0 = text;
}
/// This system toggles scale factor overrides when enter is pressed
fn toggle_override(input: Res<ButtonInput<KeyCode>>, mut window: Single<&mut Window>) {
if input.just_pressed(KeyCode::Enter) {
let scale_factor_override = window.resolution.scale_factor_override();
window
.resolution
.set_scale_factor_override(scale_factor_override.xor(Some(1.0)));
}
}
/// This system changes the scale factor override when up or down is pressed
fn change_scale_factor(input: Res<ButtonInput<KeyCode>>, mut window: Single<&mut Window>) {
let scale_factor_override = window.resolution.scale_factor_override();
if input.just_pressed(KeyCode::ArrowUp) {
window
.resolution
.set_scale_factor_override(scale_factor_override.map(|n| n + 1.0));
} else if input.just_pressed(KeyCode::ArrowDown) {
window
.resolution
.set_scale_factor_override(scale_factor_override.map(|n| (n - 1.0).max(1.0)));
}
}