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https://github.com/bevyengine/bevy
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c2c19e5ae4
**Ready for review. Examples migration progress: 100%.** # Objective - Implement https://github.com/bevyengine/bevy/discussions/15014 ## Solution This implements [cart's proposal](https://github.com/bevyengine/bevy/discussions/15014#discussioncomment-10574459) faithfully except for one change. I separated `TextSpan` from `TextSpan2d` because `TextSpan` needs to require the `GhostNode` component, which is a `bevy_ui` component only usable by UI. Extra changes: - Added `EntityCommands::commands_mut` that returns a mutable reference. This is a blocker for extension methods that return something other than `self`. Note that `sickle_ui`'s `UiBuilder::commands` returns a mutable reference for this reason. ## Testing - [x] Text examples all work. --- ## Showcase TODO: showcase-worthy ## Migration Guide TODO: very breaking ### Accessing text spans by index Text sections are now text sections on different entities in a hierarchy, Use the new `TextReader` and `TextWriter` system parameters to access spans by index. Before: ```rust fn refresh_text(mut query: Query<&mut Text, With<TimeText>>, time: Res<Time>) { let text = query.single_mut(); text.sections[1].value = format_time(time.elapsed()); } ``` After: ```rust fn refresh_text( query: Query<Entity, With<TimeText>>, mut writer: UiTextWriter, time: Res<Time> ) { let entity = query.single(); *writer.text(entity, 1) = format_time(time.elapsed()); } ``` ### Iterating text spans Text spans are now entities in a hierarchy, so the new `UiTextReader` and `UiTextWriter` system parameters provide ways to iterate that hierarchy. The `UiTextReader::iter` method will give you a normal iterator over spans, and `UiTextWriter::for_each` lets you visit each of the spans. --------- Co-authored-by: ickshonpe <david.curthoys@googlemail.com> Co-authored-by: Carter Anderson <mcanders1@gmail.com>
80 lines
2.6 KiB
Rust
80 lines
2.6 KiB
Rust
//! How to use an external thread to run an infinite task and communicate with a channel.
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use bevy::prelude::*;
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// Using crossbeam_channel instead of std as std `Receiver` is `!Sync`
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use crossbeam_channel::{bounded, Receiver};
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use rand::{Rng, SeedableRng};
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use rand_chacha::ChaCha8Rng;
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use std::time::{Duration, Instant};
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fn main() {
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App::new()
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.add_event::<StreamEvent>()
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.add_plugins(DefaultPlugins)
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.add_systems(Startup, setup)
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.add_systems(Update, (read_stream, spawn_text, move_text))
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.run();
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}
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#[derive(Resource, Deref)]
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struct StreamReceiver(Receiver<u32>);
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#[derive(Event)]
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struct StreamEvent(u32);
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fn setup(mut commands: Commands) {
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commands.spawn(Camera2d);
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let (tx, rx) = bounded::<u32>(10);
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std::thread::spawn(move || {
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// We're seeding the PRNG here to make this example deterministic for testing purposes.
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// This isn't strictly required in practical use unless you need your app to be deterministic.
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let mut rng = ChaCha8Rng::seed_from_u64(19878367467713);
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loop {
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// Everything here happens in another thread
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// This is where you could connect to an external data source
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let start_time = Instant::now();
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let duration = Duration::from_secs_f32(rng.gen_range(0.0..0.2));
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while start_time.elapsed() < duration {
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// Spinning for 'duration', simulating doing hard work!
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}
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tx.send(rng.gen_range(0..2000)).unwrap();
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}
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});
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commands.insert_resource(StreamReceiver(rx));
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}
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// This system reads from the receiver and sends events to Bevy
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fn read_stream(receiver: Res<StreamReceiver>, mut events: EventWriter<StreamEvent>) {
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for from_stream in receiver.try_iter() {
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events.send(StreamEvent(from_stream));
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}
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}
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fn spawn_text(mut commands: Commands, mut reader: EventReader<StreamEvent>) {
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let text_style = TextStyle::default();
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for (per_frame, event) in reader.read().enumerate() {
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commands.spawn((
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Text2d::new(event.0.to_string()),
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text_style.clone(),
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TextBlock::new_with_justify(JustifyText::Center),
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Transform::from_xyz(per_frame as f32 * 100.0, 300.0, 0.0),
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));
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}
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}
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fn move_text(
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mut commands: Commands,
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mut texts: Query<(Entity, &mut Transform), With<Text2d>>,
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time: Res<Time>,
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) {
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for (entity, mut position) in &mut texts {
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position.translation -= Vec3::new(0.0, 100.0 * time.delta_seconds(), 0.0);
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if position.translation.y < -300.0 {
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commands.entity(entity).despawn();
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}
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}
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}
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