1ba7429371
# Objective Provide a starting point for #3951, or a partial solution. Providing a few comment blocks to discuss, and hopefully find better one in the process. ## Solution Since I am pretty new to pretty much anything in this context, I figured I'd just start with a draft for some file level doc blocks. For some of them I found more relevant details (or at least things I considered interessting), for some others there is less. ## Changelog - Moved some existing comments from main() functions in the 2d examples to the file header level - Wrote some more comment blocks for most other 2d examples TODO: - [x] 2d/sprite_sheet, wasnt able to come up with something good yet - [x] all other example groups... Also: Please let me know if the commit style is okay, or to verbose. I could certainly squash these things, or add more details if needed. I also hope its okay to raise this PR this early, with just a few files changed. Took me long enough and I dont wanted to let it go to waste because I lost motivation to do the whole thing. Additionally I am somewhat uncertain over the style and contents of the commets. So let me know what you thing please.
47 lines
1.2 KiB
Rust
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_startup_system(spawn)
|
|
.add_system(count_players)
|
|
.run();
|
|
}
|
|
|
|
#[derive(Component)]
|
|
pub struct Player;
|
|
#[derive(Component)]
|
|
pub 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().insert(Player);
|
|
commands.spawn().insert(Player);
|
|
commands.spawn().insert(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);
|
|
}
|