01649f13e2
# Objective This is a necessary precursor to #9122 (this was split from that PR to reduce the amount of code to review all at once). Moving `!Send` resource ownership to `App` will make it unambiguously `!Send`. `SubApp` must be `Send`, so it can't wrap `App`. ## Solution Refactor `App` and `SubApp` to not have a recursive relationship. Since `SubApp` no longer wraps `App`, once `!Send` resources are moved out of `World` and into `App`, `SubApp` will become unambiguously `Send`. There could be less code duplication between `App` and `SubApp`, but that would break `App` method chaining. ## Changelog - `SubApp` no longer wraps `App`. - `App` fields are no longer publicly accessible. - `App` can no longer be converted into a `SubApp`. - Various methods now return references to a `SubApp` instead of an `App`. ## Migration Guide - To construct a sub-app, use `SubApp::new()`. `App` can no longer convert into `SubApp`. - If you implemented a trait for `App`, you may want to implement it for `SubApp` as well. - If you're accessing `app.world` directly, you now have to use `app.world()` and `app.world_mut()`. - `App::sub_app` now returns `&SubApp`. - `App::sub_app_mut` now returns `&mut SubApp`. - `App::get_sub_app` now returns `Option<&SubApp>.` - `App::get_sub_app_mut` now returns `Option<&mut SubApp>.`
83 lines
3.0 KiB
Rust
83 lines
3.0 KiB
Rust
//! Demonstrates how to add custom schedules that run in Bevy's `Main` schedule, ordered relative to Bevy's built-in
|
|
//! schedules such as `Update` or `Last`.
|
|
|
|
use bevy::app::MainScheduleOrder;
|
|
use bevy::ecs::schedule::{ExecutorKind, ScheduleLabel};
|
|
use bevy::prelude::*;
|
|
|
|
#[derive(ScheduleLabel, Debug, Hash, PartialEq, Eq, Clone)]
|
|
struct SingleThreadedUpdate;
|
|
|
|
#[derive(ScheduleLabel, Debug, Hash, PartialEq, Eq, Clone)]
|
|
struct CustomStartup;
|
|
|
|
fn main() {
|
|
let mut app = App::new();
|
|
|
|
// Create a new [`Schedule`]. For demonstration purposes, we configure it to use a single threaded executor so that
|
|
// systems in this schedule are never run in parallel. However, this is not a requirement for custom schedules in
|
|
// general.
|
|
let mut custom_update_schedule = Schedule::new(SingleThreadedUpdate);
|
|
custom_update_schedule.set_executor_kind(ExecutorKind::SingleThreaded);
|
|
|
|
// Adding the schedule to the app does not automatically run the schedule. This merely registers the schedule so
|
|
// that systems can look it up using the `Schedules` resource.
|
|
app.add_schedule(custom_update_schedule);
|
|
|
|
// Bevy `App`s have a `main_schedule_label` field that configures which schedule is run by the App's `runner`.
|
|
// By default, this is `Main`. The `Main` schedule is responsible for running Bevy's main schedules such as
|
|
// `Update`, `Startup` or `Last`.
|
|
//
|
|
// We can configure the `Main` schedule to run our custom update schedule relative to the existing ones by modifying
|
|
// the `MainScheduleOrder` resource.
|
|
//
|
|
// Note that we modify `MainScheduleOrder` directly in `main` and not in a startup system. The reason for this is
|
|
// that the `MainScheduleOrder` cannot be modified from systems that are run as part of the `Main` schedule.
|
|
let mut main_schedule_order = app.world_mut().resource_mut::<MainScheduleOrder>();
|
|
main_schedule_order.insert_after(Update, SingleThreadedUpdate);
|
|
|
|
// Adding a custom startup schedule works similarly, but needs to use `insert_startup_after`
|
|
// instead of `insert_after`.
|
|
app.add_schedule(Schedule::new(CustomStartup));
|
|
|
|
let mut main_schedule_order = app.world_mut().resource_mut::<MainScheduleOrder>();
|
|
main_schedule_order.insert_startup_after(PreStartup, CustomStartup);
|
|
|
|
app.add_systems(SingleThreadedUpdate, single_threaded_update_system)
|
|
.add_systems(CustomStartup, custom_startup_system)
|
|
.add_systems(PreStartup, pre_startup_system)
|
|
.add_systems(Startup, startup_system)
|
|
.add_systems(First, first_system)
|
|
.add_systems(Update, update_system)
|
|
.add_systems(Last, last_system)
|
|
.run();
|
|
}
|
|
|
|
fn pre_startup_system() {
|
|
println!("Pre Startup");
|
|
}
|
|
|
|
fn startup_system() {
|
|
println!("Startup");
|
|
}
|
|
|
|
fn custom_startup_system() {
|
|
println!("Custom Startup");
|
|
}
|
|
|
|
fn first_system() {
|
|
println!("First");
|
|
}
|
|
|
|
fn update_system() {
|
|
println!("Update");
|
|
}
|
|
|
|
fn single_threaded_update_system() {
|
|
println!("Single Threaded Update");
|
|
}
|
|
|
|
fn last_system() {
|
|
println!("Last");
|
|
}
|