bevy/crates/bevy_ecs/examples/resources.rs
Daniel McNab c26be39719 Remove unnecessary system labels (#4340)
# Objective

- Since #4224, using labels which only refer to one system doesn't make sense.

## Solution

- Remove some of those.

## Future work

- We should remove the ability to use strings as system labels entirely. I haven't in this PR because there are tests which use this, and that's a lot of code to change.
   - The only use cases for labels are either intra-crate, which use #4224, or inter-crate, which should either use #4224 or explicit types. Neither of those should use strings.
2022-04-01 21:11:05 +00:00

44 lines
1.2 KiB
Rust

use bevy_ecs::prelude::*;
use rand::Rng;
use std::ops::Deref;
// In this example we add a counter resource and increase it's value in one system,
// while a different system prints the current count to the console.
fn main() {
// Create a world
let mut world = World::new();
// Add the counter resource
world.insert_resource(Counter { value: 0 });
// Create a schedule and a stage
let mut schedule = Schedule::default();
let mut update = SystemStage::parallel();
// Add systems to increase the counter and to print out the current value
update.add_system(increase_counter);
update.add_system(print_counter.after(increase_counter));
schedule.add_stage("update", update);
for iteration in 1..=10 {
println!("Simulating frame {}/10", iteration);
schedule.run(&mut world);
}
}
// Counter resource to be increased and read by systems
#[derive(Debug)]
struct Counter {
pub value: i32,
}
fn increase_counter(mut counter: ResMut<Counter>) {
if rand::thread_rng().gen_bool(0.5) {
counter.value += 1;
println!(" Increased counter value");
}
}
fn print_counter(counter: Res<Counter>) {
println!(" {:?}", counter.deref());
}