mirror of
https://github.com/bevyengine/bevy
synced 2024-12-01 17:09:12 +00:00
79b4f26158
# Objective Fixes #11411 ## Solution - Added a simple example how to create and configure custom schedules that are run by the `Main` schedule. - Spot checked some of the API docs used, fixed `App::add_schedule` docs that referred to a function argument that was removed by #9600. ## Open Questions - While spot checking the docs, I noticed that the `Schedule` label is stored in a field called `name` instead of `label`. This seems unintuitive since the term label is used everywhere else. Should we change that field name? It was introduced in #9600. If so, I do think this change would be out of scope for this PR that mainly adds the example.
82 lines
3 KiB
Rust
82 lines
3 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.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.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");
|
|
}
|