Vendor dependencies for 0.3.0 release

vendor/bevy/examples/app/headless.rs

@@ -0,0 +1,62 @@
+//! 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");
+        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,
+}