bevy/crates/bevy_text/src
ickshonpe b90329aef5
update_text2d_layout creates new font atlases when the primary window is closed (#7849)
# Objective

Necessary conditions:
* Scale factor != 1
* Text is being displayed with Text2d
* The primary window is closed on a frame where the text or text's
bounds are modified.

Then when `update_text2d_layout` runs, it finds no primary window and
assumes a scale factor of 1.
The previous scale_factor was not equal to 1 and the text pipeline's old
font atlases were created for a non-1 scale factor, so it creates new
font atlases even though the app is closing.

The bug was first identified in #6666

## Minimal Example

```rust
use bevy::prelude::*;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins.set(WindowPlugin {
            primary_window: Some(Window {
                present_mode: bevy:🪟:PresentMode::Immediate,
                ..Default::default()
            }),
            ..default()
        }))
        .insert_resource(UiScale { scale: std::f64::consts::PI })
        .add_startup_system(setup)
        .add_system(update)
        .run();
}

fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
    commands.spawn(Camera2dBundle::default());
    commands.spawn(Text2dBundle {
        text: Text {
            sections: (0..10).map(|i| TextSection {
                value: i.to_string(),
                style: TextStyle {
                    font: asset_server.load("fonts/FiraSans-Bold.ttf"),
                    font_size: (10 + i) as f32,
                    color: Color::WHITE,
                }
            }).collect(),
            ..Default::default()            
        },
        ..Default::default()
    });
}

fn update(mut text: Query<&mut Text>) {
    for mut text in text.iter_mut() {
        text.set_changed();
    }
}
```
## Output
On closing the window you'll see the warning (if you don't, increase the
number of text sections):
```
WARN bevy_text::glyph_brush: warning[B0005]: Number of font atlases has exceeded the maximum of 16. Performance and memory usage may suffer.
```
The app should only create font atlases on startup, but it doesn't
display this warning until after you close the window

## Solution

Skip `update_text_layout` when there is no primary window.

## Changelog
* If no primary window is found, skip `update_text2d_layout`.
* Added a `Local` flag `skipped` to `update_text2d_layout`. This should
ensure there are no edge cases where text might not get drawn at all.

---------

Co-authored-by: François Mockers <mockersf@gmail.com>
2025-01-14 01:01:31 +00:00
..
bounds.rs Simpler lint fixes: makes ci lints work but disables a lint for now (#15376) 2024-09-24 11:42:59 +00:00
error.rs Deny derive_more error feature and replace it with thiserror (#16684) 2024-12-06 17:03:55 +00:00
FiraMono-subset.ttf add a default font (#8445) 2023-04-21 22:30:18 +00:00
font_atlas_set.rs Move TextureAtlas and friends into bevy_image (#17219) 2025-01-07 18:43:11 +00:00
font_atlas.rs Move TextureAtlas and friends into bevy_image (#17219) 2025-01-07 18:43:11 +00:00
font_loader.rs Deny derive_more error feature and replace it with thiserror (#16684) 2024-12-06 17:03:55 +00:00
font.rs Add core and alloc over std Lints (#15281) 2024-09-27 00:59:59 +00:00
glyph.rs Move TextureAtlas and friends into bevy_image (#17219) 2025-01-07 18:43:11 +00:00
lib.rs Downgrade clippy::allow_attributes and clippy::allow_attributes_without_reason to warn (#17320) 2025-01-12 05:28:26 +00:00
pipeline.rs Fix text alignment for unbounded text (#17270) 2025-01-11 05:45:32 +00:00
text2d.rs update_text2d_layout creates new font atlases when the primary window is closed (#7849) 2025-01-14 01:01:31 +00:00
text_access.rs Add Immutable Component Support (#16372) 2024-12-05 14:27:48 +00:00
text.rs Add builder method for TextFont::line_height (#17203) 2025-01-07 00:40:00 +00:00