scale_factor_override/
scale_factor_override.rs

1//! This example illustrates how to override the window scale factor imposed by the
2//! operating system.
3
4use bevy::{prelude::*, window::WindowResolution};
5
6#[derive(Component)]
7struct CustomText;
8
9fn main() {
10    App::new()
11        .add_plugins(DefaultPlugins.set(WindowPlugin {
12            primary_window: Some(Window {
13                resolution: WindowResolution::new(500, 300).with_scale_factor_override(1.0),
14                ..default()
15            }),
16            ..default()
17        }))
18        .add_systems(Startup, setup)
19        .add_systems(
20            Update,
21            (display_override, toggle_override, change_scale_factor),
22        )
23        .run();
24}
25
26fn setup(mut commands: Commands) {
27    // camera
28    commands.spawn(Camera2d);
29    // root node
30    commands.spawn((
31        Node {
32            width: percent(100),
33            height: percent(100),
34            justify_content: JustifyContent::SpaceBetween,
35            ..default()
36        },
37        children![(
38            Node {
39                width: px(300),
40                height: percent(100),
41                border: UiRect::all(px(2)),
42                ..default()
43            },
44            BackgroundColor(Color::srgb(0.65, 0.65, 0.65)),
45            children![(
46                CustomText,
47                Text::new("Example text"),
48                TextFont {
49                    font_size: 25.0,
50                    ..default()
51                },
52                Node {
53                    align_self: AlignSelf::FlexEnd,
54                    ..default()
55                },
56            )]
57        )],
58    ));
59}
60
61/// Set the title of the window to the current override
62fn display_override(
63    mut window: Single<&mut Window>,
64    mut custom_text: Single<&mut Text, With<CustomText>>,
65) {
66    let text = format!(
67        "Scale factor: {:.1} {}",
68        window.scale_factor(),
69        if window.resolution.scale_factor_override().is_some() {
70            "(overridden)"
71        } else {
72            "(default)"
73        }
74    );
75
76    window.title.clone_from(&text);
77    custom_text.0 = text;
78}
79
80/// This system toggles scale factor overrides when enter is pressed
81fn toggle_override(input: Res<ButtonInput<KeyCode>>, mut window: Single<&mut Window>) {
82    if input.just_pressed(KeyCode::Enter) {
83        let scale_factor_override = window.resolution.scale_factor_override();
84        window
85            .resolution
86            .set_scale_factor_override(scale_factor_override.xor(Some(1.0)));
87    }
88}
89
90/// This system changes the scale factor override when up or down is pressed
91fn change_scale_factor(input: Res<ButtonInput<KeyCode>>, mut window: Single<&mut Window>) {
92    let scale_factor_override = window.resolution.scale_factor_override();
93    if input.just_pressed(KeyCode::ArrowUp) {
94        window
95            .resolution
96            .set_scale_factor_override(scale_factor_override.map(|n| n + 1.0));
97    } else if input.just_pressed(KeyCode::ArrowDown) {
98        window
99            .resolution
100            .set_scale_factor_override(scale_factor_override.map(|n| (n - 1.0).max(1.0)));
101    }
102}
scale_factor_override/scale_factor_override.rs

scale_factor_override/
scale_factor_override.rs
