bevy/examples/app/headless.rs
Wybe Westra 55c84cc722
Added HeadlessPlugins (#15203) (#15260)
Added a `HeadlessPlugins` plugin group, that adds more default
functionality (like logging) than the `MinimumPlugins`. Fixes #15203
Changed the headless example to use the new plugin group.

I am not entirely sure if the list of plugins is correct. Are there ones
that should be added / removed?

----
The `TerminalCtrlCHandlerPlugin` has interesting effects in the headless
example: Installing it a second time it will give a log message about
skipping installation, because it is already installed. Ctrl+C will
terminate the application in that case. However, _not_ installing it the
second time (so only on the app that runs once) has the effect that the
app that runs continuously cannot be stopped using Ctrl+C.
This implies that, even though the second app did not install the Ctrl+C
handler, it did _something_ because it was keeping the one from the
first app alive.
Not sure if this is a problem or issue, or can be labeled a wierd quirk
of having multiple Apps in one executable.
2024-09-19 16:44:43 +00:00

50 lines
1.4 KiB
Rust

//! This example only enables a minimal set of plugins required for bevy to run.
//! You can also 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
//! ```
use bevy::{app::ScheduleRunnerPlugin, log::LogPlugin, prelude::*, utils::Duration};
fn main() {
// This app runs once
App::new()
.add_plugins(HeadlessPlugins.set(ScheduleRunnerPlugin::run_once()))
.add_systems(Update, hello_world_system)
.run();
// This app loops forever at 60 fps
App::new()
.add_plugins(
HeadlessPlugins
.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,
}