bevy/examples/ui/ui_texture_atlas.rs
ickshonpe 6f7d0e5725
split up TextStyle (#15857)
# Objective

Currently text is recomputed unnecessarily on any changes to its color,
which is extremely expensive.

## Solution
Split up `TextStyle` into two separate components `TextFont` and
`TextColor`.

## Testing

I added this system to `many_buttons`:
```rust
fn set_text_colors_changed(mut colors: Query<&mut TextColor>) {
    for mut text_color in colors.iter_mut() {
        text_color.set_changed();
    }
}
```

reports ~4fps on main, ~50fps with this PR.

## Migration Guide
`TextStyle` has been renamed to `TextFont` and its `color` field has
been moved to a separate component named `TextColor` which newtypes
`Color`.
2024-10-13 17:06:22 +00:00

83 lines
2.9 KiB
Rust

//! This example illustrates how to use `TextureAtlases` within ui
use bevy::{color::palettes::css::*, prelude::*, winit::WinitSettings};
fn main() {
App::new()
.add_plugins(DefaultPlugins.set(
// This sets image filtering to nearest
// This is done to prevent textures with low resolution (e.g. pixel art) from being blurred
// by linear filtering.
ImagePlugin::default_nearest(),
))
// Only run the app when there is user input. This will significantly reduce CPU/GPU use.
.insert_resource(WinitSettings::desktop_app())
.add_systems(Startup, setup)
.add_systems(Update, increment_atlas_index)
.run();
}
fn setup(
mut commands: Commands,
asset_server: Res<AssetServer>,
mut texture_atlases: ResMut<Assets<TextureAtlasLayout>>,
) {
// Camera
commands.spawn(Camera2d);
let text_font = TextFont::default();
let texture_handle = asset_server.load("textures/rpg/chars/gabe/gabe-idle-run.png");
let texture_atlas = TextureAtlasLayout::from_grid(UVec2::splat(24), 7, 1, None, None);
let texture_atlas_handle = texture_atlases.add(texture_atlas);
// root node
commands
.spawn(NodeBundle {
style: Style {
width: Val::Percent(100.0),
height: Val::Percent(100.0),
flex_direction: FlexDirection::Column,
justify_content: JustifyContent::Center,
align_items: AlignItems::Center,
row_gap: Val::Px(text_font.font_size * 2.),
..default()
},
..default()
})
.with_children(|parent| {
parent.spawn((
ImageBundle {
style: Style {
width: Val::Px(256.),
height: Val::Px(256.),
..default()
},
image: UiImage::new(texture_handle),
background_color: BackgroundColor(ANTIQUE_WHITE.into()),
..default()
},
TextureAtlas::from(texture_atlas_handle),
Outline::new(Val::Px(8.0), Val::ZERO, CRIMSON.into()),
));
parent
.spawn((Text::new("press "), text_font.clone()))
.with_child((
TextSpan::new("space"),
TextColor(YELLOW.into()),
text_font.clone(),
))
.with_child((TextSpan::new(" to advance frames"), text_font));
});
}
fn increment_atlas_index(
mut atlas_images: Query<&mut TextureAtlas>,
keyboard: Res<ButtonInput<KeyCode>>,
) {
if keyboard.just_pressed(KeyCode::Space) {
for mut atlas_image in &mut atlas_images {
atlas_image.index = (atlas_image.index + 1) % 6;
}
}
}