bevy/examples/ecs/event.rs
Carter Anderson 11b41206eb Add upstream bevy_ecs and prepare for custom-shaders merge (#2815)
This updates the `pipelined-rendering` branch to use the latest `bevy_ecs` from `main`. This accomplishes a couple of goals:

1. prepares for upcoming `custom-shaders` branch changes, which were what drove many of the recent bevy_ecs changes on `main`
2. prepares for the soon-to-happen merge of `pipelined-rendering` into `main`. By including bevy_ecs changes now, we make that merge simpler / easier to review. 

I split this up into 3 commits:

1. **add upstream bevy_ecs**: please don't bother reviewing this content. it has already received thorough review on `main` and is a literal copy/paste of the relevant folders (the old folders were deleted so the directories are literally exactly the same as `main`).
2. **support manual buffer application in stages**: this is used to enable the Extract step. we've already reviewed this once on the `pipelined-rendering` branch, but its worth looking at one more time in the new context of (1).
3. **support manual archetype updates in QueryState**: same situation as (2).
2021-09-14 06:14:19 +00:00

49 lines
1.2 KiB
Rust

use bevy::prelude::*;
/// This example creates a new event, a system that triggers the event once per second,
/// and a system that prints a message whenever the event is received.
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_event::<MyEvent>()
.init_resource::<EventTriggerState>()
.add_system(event_trigger_system)
.add_system(event_listener_system)
.run();
}
struct MyEvent {
pub message: String,
}
struct EventTriggerState {
event_timer: Timer,
}
impl Default for EventTriggerState {
fn default() -> Self {
EventTriggerState {
event_timer: Timer::from_seconds(1.0, true),
}
}
}
// sends MyEvent every second
fn event_trigger_system(
time: Res<Time>,
mut state: ResMut<EventTriggerState>,
mut my_events: EventWriter<MyEvent>,
) {
if state.event_timer.tick(time.delta()).finished() {
my_events.send(MyEvent {
message: "MyEvent just happened!".to_string(),
});
}
}
// prints events as they come in
fn event_listener_system(mut events: EventReader<MyEvent>) {
for my_event in events.iter() {
info!("{}", my_event.message);
}
}