bevy/crates/bevy_ecs/examples/resources.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

50 lines
1.4 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.label(CounterSystem::Increase));
update.add_system(print_counter.after(CounterSystem::Increase));
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,
}
// System label to enforce a run order of our systems
#[derive(SystemLabel, Debug, Clone, PartialEq, Eq, Hash)]
enum CounterSystem {
Increase,
}
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());
}