bevy/examples/app/headless.rs
Sung-jin Brian Hong 694db96ab8
Fix compile errors on headless example (#18497)
# Objective

- Fixes compile errors on headless example when running `cargo run
--example headless --no-default-features`

```
error[E0432]: unresolved import `bevy::log`
  --> examples/app/headless.rs:13:39
   |
13 | use bevy::{app::ScheduleRunnerPlugin, log::LogPlugin, prelude::*};
   |                                       ^^^ could not find `log` in `bevy`

For more information about this error, try `rustc --explain E0432`.
error: could not compile `bevy` (example "headless") due to 1 previous error
```

## Solution

- Since commit cc69fdd bevy_log has been identified as a separate
feature, thus requiring additional parameters to build headless example.
- Changed the command to run to: `cargo run --example headless
--no-default-features --features bevy_log`

## Testing

- The new command successfully builds the example
2025-03-23 21:24:20 +00:00

63 lines
2.0 KiB
Rust

//! This example shows how to configure the `ScheduleRunnerPlugin` to run your
//! application without windowing. You can completely remove rendering / windowing
//! Plugin code from bevy by making your import look like this in your Cargo.toml.
//!
//! ```toml
//! [dependencies]
//! bevy = { version = "*", default-features = false }
//! # replace "*" with the most recent version of bevy
//! ```
//!
//! And then enabling the features you need.
//! See the full list: <https://docs.rs/bevy/latest/bevy/#cargo-features>
use bevy::{app::ScheduleRunnerPlugin, log::LogPlugin, prelude::*};
use core::time::Duration;
fn main() {
if cfg!(feature = "bevy_window") {
println!("This example is running with the bevy_window feature enabled and will not run headless.");
println!("Disable the default features and rerun the example to run headless.");
println!("To do so, run:");
println!();
println!(" cargo run --example headless --no-default-features --features bevy_log");
return;
}
// This app runs once
App::new()
.add_plugins(DefaultPlugins.set(ScheduleRunnerPlugin::run_once()))
.add_systems(Update, hello_world_system)
.run();
// This app loops forever at 60 fps
App::new()
.add_plugins(
DefaultPlugins
.set(ScheduleRunnerPlugin::run_loop(Duration::from_secs_f64(
1.0 / 60.0,
)))
// The log and ctrl+c plugin can only be registered once globally,
// which means we need to disable it here, because it was already registered with the
// app that runs once.
.disable::<LogPlugin>(),
)
.add_systems(Update, counter)
.run();
}
fn hello_world_system() {
println!("hello world");
}
fn counter(mut state: Local<CounterState>) {
if state.count % 60 == 0 {
println!("{}", state.count);
}
state.count += 1;
}
#[derive(Default)]
struct CounterState {
count: u32,
}