mirror of
https://github.com/bevyengine/bevy
synced 2024-11-23 13:13:49 +00:00
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.
91 lines
3.1 KiB
Rust
91 lines
3.1 KiB
Rust
//! Generic types allow us to reuse logic across many related systems,
|
|
//! allowing us to specialize our function's behavior based on which type (or types) are passed in.
|
|
//!
|
|
//! This is commonly useful for working on related components or resources,
|
|
//! where we want to have unique types for querying purposes but want them all to work the same way.
|
|
//! This is particularly powerful when combined with user-defined traits to add more functionality to these related types.
|
|
//! Remember to insert a specialized copy of the system into the schedule for each type that you want to operate on!
|
|
//!
|
|
//! For more advice on working with generic types in Rust, check out <https://doc.rust-lang.org/book/ch10-01-syntax.html>
|
|
//! or <https://doc.rust-lang.org/rust-by-example/generics.html>
|
|
|
|
use bevy::{ecs::component::Component, prelude::*};
|
|
|
|
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
|
|
enum AppState {
|
|
MainMenu,
|
|
InGame,
|
|
}
|
|
|
|
#[derive(Component)]
|
|
struct TextToPrint(String);
|
|
|
|
#[derive(Component, Deref, DerefMut)]
|
|
struct PrinterTick(bevy::prelude::Timer);
|
|
|
|
#[derive(Component)]
|
|
struct MenuClose;
|
|
|
|
#[derive(Component)]
|
|
struct LevelUnload;
|
|
|
|
fn main() {
|
|
App::new()
|
|
.add_plugins(DefaultPlugins)
|
|
.add_state(AppState::MainMenu)
|
|
.add_startup_system(setup_system)
|
|
.add_system(print_text_system)
|
|
.add_system_set(
|
|
SystemSet::on_update(AppState::MainMenu).with_system(transition_to_in_game_system),
|
|
)
|
|
// add the cleanup systems
|
|
.add_system_set(
|
|
// Pass in the types your system should operate on using the ::<T> (turbofish) syntax
|
|
SystemSet::on_exit(AppState::MainMenu).with_system(cleanup_system::<MenuClose>),
|
|
)
|
|
.add_system_set(
|
|
SystemSet::on_exit(AppState::InGame).with_system(cleanup_system::<LevelUnload>),
|
|
)
|
|
.run();
|
|
}
|
|
|
|
fn setup_system(mut commands: Commands) {
|
|
commands
|
|
.spawn()
|
|
.insert(PrinterTick(bevy::prelude::Timer::from_seconds(1.0, true)))
|
|
.insert(TextToPrint(
|
|
"I will print until you press space.".to_string(),
|
|
))
|
|
.insert(MenuClose);
|
|
|
|
commands
|
|
.spawn()
|
|
.insert(PrinterTick(bevy::prelude::Timer::from_seconds(1.0, true)))
|
|
.insert(TextToPrint("I will always print".to_string()))
|
|
.insert(LevelUnload);
|
|
}
|
|
|
|
fn print_text_system(time: Res<Time>, mut query: Query<(&mut PrinterTick, &TextToPrint)>) {
|
|
for (mut timer, text) in query.iter_mut() {
|
|
if timer.tick(time.delta()).just_finished() {
|
|
info!("{}", text.0);
|
|
}
|
|
}
|
|
}
|
|
|
|
fn transition_to_in_game_system(
|
|
mut state: ResMut<State<AppState>>,
|
|
keyboard_input: Res<Input<KeyCode>>,
|
|
) {
|
|
if keyboard_input.pressed(KeyCode::Space) {
|
|
state.set(AppState::InGame).unwrap();
|
|
}
|
|
}
|
|
|
|
// Type arguments on functions come after the function name, but before ordinary arguments.
|
|
// Here, the `Component` trait is a trait bound on T, our generic type
|
|
fn cleanup_system<T: Component>(mut commands: Commands, query: Query<Entity, With<T>>) {
|
|
for e in query.iter() {
|
|
commands.entity(e).despawn_recursive();
|
|
}
|
|
}
|