b6a647cc01
Adds a `default()` shorthand for `Default::default()` ... because life is too short to constantly type `Default::default()`.
```rust
use bevy::prelude::*;
#[derive(Default)]
struct Foo {
bar: usize,
baz: usize,
}
// Normally you would do this:
let foo = Foo {
bar: 10,
..Default::default()
};
// But now you can do this:
let foo = Foo {
bar: 10,
..default()
};
```
The examples have been adapted to use `..default()`. I've left internal crates as-is for now because they don't pull in the bevy prelude, and the ergonomics of each case should be considered individually.
90 lines
2.7 KiB
Rust
90 lines
2.7 KiB
Rust
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;
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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_startup_system(setup)
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.add_system(read_stream)
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.add_system(spawn_text)
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.add_system(move_text)
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.run();
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}
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struct StreamReceiver(Receiver<u32>);
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struct StreamEvent(u32);
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struct LoadedFont(Handle<Font>);
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fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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commands.spawn_bundle(OrthographicCameraBundle::new_2d());
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let (tx, rx) = bounded::<u32>(10);
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std::thread::spawn(move || 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 mut rng = rand::thread_rng();
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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 Instant::now() - start_time < 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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commands.insert_resource(StreamReceiver(rx));
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commands.insert_resource(LoadedFont(asset_server.load("fonts/FiraSans-Bold.ttf")));
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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: ResMut<StreamReceiver>, mut events: EventWriter<StreamEvent>) {
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for from_stream in receiver.0.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(
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mut commands: Commands,
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mut reader: EventReader<StreamEvent>,
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loaded_font: Res<LoadedFont>,
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) {
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let text_style = TextStyle {
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font: loaded_font.0.clone(),
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font_size: 20.0,
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color: Color::WHITE,
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};
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let text_alignment = TextAlignment {
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vertical: VerticalAlign::Center,
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horizontal: HorizontalAlign::Center,
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};
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for (per_frame, event) in reader.iter().enumerate() {
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commands.spawn_bundle(Text2dBundle {
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text: Text::with_section(format!("{}", event.0), text_style.clone(), text_alignment),
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transform: Transform::from_xyz(
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per_frame as f32 * 100.0 + rand::thread_rng().gen_range(-40.0..40.0),
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300.0,
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0.0,
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),
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..default()
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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<Text>>,
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time: Res<Time>,
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) {
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for (entity, mut position) in texts.iter_mut() {
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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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