 efda7f3f9c
			
		
	
	
		efda7f3f9c
		
			
		
	
	
	
	
		
			
			Takes the first two commits from #15375 and adds suggestions from this comment: https://github.com/bevyengine/bevy/pull/15375#issuecomment-2366968300 See #15375 for more reasoning/motivation. ## Rebasing (rerunning) ```rust git switch simpler-lint-fixes git reset --hard main cargo fmt --all -- --unstable-features --config normalize_comments=true,imports_granularity=Crate cargo fmt --all git add --update git commit --message "rustfmt" cargo clippy --workspace --all-targets --all-features --fix cargo fmt --all -- --unstable-features --config normalize_comments=true,imports_granularity=Crate cargo fmt --all git add --update git commit --message "clippy" git cherry-pick e6c0b94f6795222310fb812fa5c4512661fc7887 ```
		
			
				
	
	
		
			83 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
| //! This example illustrates how to use logs in bevy.
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| 
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| use bevy::{log::once, prelude::*};
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| 
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| fn main() {
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|     App::new()
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|         .add_plugins(DefaultPlugins.set(bevy::log::LogPlugin {
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|             // Uncomment this to override the default log settings:
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|             // level: bevy::log::Level::TRACE,
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|             // filter: "wgpu=warn,bevy_ecs=info".to_string(),
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|             ..default()
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|         }))
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|         .add_systems(Startup, setup)
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|         .add_systems(Update, log_system)
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|         .add_systems(Update, log_once_system)
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|         .add_systems(Update, panic_on_p)
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|         .run();
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| }
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| 
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| fn setup(mut commands: Commands) {
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|     commands.spawn(Camera2dBundle::default());
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|     commands.spawn(TextBundle {
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|         text: Text::from_section("Press P to panic", TextStyle::default()),
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|         style: Style {
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|             position_type: PositionType::Absolute,
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|             top: Val::Px(12.0),
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|             left: Val::Px(12.0),
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|             ..default()
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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 panic_on_p(keys: Res<ButtonInput<KeyCode>>) {
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|     if keys.just_pressed(KeyCode::KeyP) {
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|         panic!("P pressed, panicking");
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|     }
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| }
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| 
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| fn log_system() {
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|     // here is how you write new logs at each "log level" (in "least important" to "most important"
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|     // order)
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|     trace!("very noisy");
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|     debug!("helpful for debugging");
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|     info!("helpful information that is worth printing by default");
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|     warn!("something bad happened that isn't a failure, but thats worth calling out");
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|     error!("something failed");
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| 
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|     // by default, trace and debug logs are ignored because they are "noisy"
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|     // you can control what level is logged by setting up the LogPlugin
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|     // alternatively you can set the log level via the RUST_LOG=LEVEL environment variable
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|     // ex: RUST_LOG=trace, RUST_LOG=info,bevy_ecs=warn
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|     // the format used here is super flexible. check out this documentation for more info:
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|     // https://docs.rs/tracing-subscriber/*/tracing_subscriber/filter/struct.EnvFilter.html
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| }
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| 
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| fn log_once_system() {
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|     // The 'once' variants of each log level are useful when a system is called every frame,
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|     // but we still wish to inform the user only once. In other words, use these to prevent spam :)
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| 
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|     trace_once!("one time noisy message");
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|     debug_once!("one time debug message");
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|     info_once!("some info which is printed only once");
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|     warn_once!("some warning we wish to call out only once");
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|     error_once!("some error we wish to report only once");
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| 
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|     for i in 0..10 {
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|         info_once!("logs once per call site, so this works just fine: {}", i);
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|     }
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| 
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|     // you can also use the `once!` macro directly,
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|     // in situations where you want to do something expensive only once
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|     // within the context of a continuous system.
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|     once!({
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|         info!("doing expensive things");
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|         let mut a: u64 = 0;
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|         for i in 0..100000000 {
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|             a += i;
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|         }
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|         info!("result of some expensive one time calculation: {}", a);
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|     });
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| }
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