bevy/examples/ecs/system_param.rs
Tristan Guichaoua 694c06f3d0
Inverse missing_docs logic (#11676)
# Objective

Currently the `missing_docs` lint is allowed-by-default and enabled at
crate level when their documentations is complete (see #3492).
This PR proposes to inverse this logic by making `missing_docs`
warn-by-default and mark crates with imcomplete docs allowed.

## Solution

Makes `missing_docs` warn at workspace level and allowed at crate level
when the docs is imcomplete.
2024-02-03 21:40:55 +00:00

47 lines
1.2 KiB
Rust

//! This example creates a custom [`SystemParam`] struct that counts the number of players.
use bevy::{ecs::system::SystemParam, prelude::*};
fn main() {
App::new()
.insert_resource(PlayerCount(0))
.add_systems(Startup, spawn)
.add_systems(Update, count_players)
.run();
}
#[derive(Component)]
struct Player;
#[derive(Resource)]
struct PlayerCount(usize);
/// The [`SystemParam`] struct can contain any types that can also be included in a
/// system function signature.
///
/// In this example, it includes a query and a mutable resource.
#[derive(SystemParam)]
struct PlayerCounter<'w, 's> {
players: Query<'w, 's, &'static Player>,
count: ResMut<'w, PlayerCount>,
}
impl<'w, 's> PlayerCounter<'w, 's> {
fn count(&mut self) {
self.count.0 = self.players.iter().len();
}
}
/// Spawn some players to count
fn spawn(mut commands: Commands) {
commands.spawn(Player);
commands.spawn(Player);
commands.spawn(Player);
}
/// The [`SystemParam`] can be used directly in a system argument.
fn count_players(mut counter: PlayerCounter) {
counter.count();
println!("{} players in the game", counter.count.0);
}