206c7ce219
Huge thanks to @maniwani, @devil-ira, @hymm, @cart, @superdump and @jakobhellermann for the help with this PR. # Objective - Followup #6587. - Minimal integration for the Stageless Scheduling RFC: https://github.com/bevyengine/rfcs/pull/45 ## Solution - [x] Remove old scheduling module - [x] Migrate new methods to no longer use extension methods - [x] Fix compiler errors - [x] Fix benchmarks - [x] Fix examples - [x] Fix docs - [x] Fix tests ## Changelog ### Added - a large number of methods on `App` to work with schedules ergonomically - the `CoreSchedule` enum - `App::add_extract_system` via the `RenderingAppExtension` trait extension method - the private `prepare_view_uniforms` system now has a public system set for scheduling purposes, called `ViewSet::PrepareUniforms` ### Removed - stages, and all code that mentions stages - states have been dramatically simplified, and no longer use a stack - `RunCriteriaLabel` - `AsSystemLabel` trait - `on_hierarchy_reports_enabled` run criteria (now just uses an ad hoc resource checking run condition) - systems in `RenderSet/Stage::Extract` no longer warn when they do not read data from the main world - `RunCriteriaLabel` - `transform_propagate_system_set`: this was a nonstandard pattern that didn't actually provide enough control. The systems are already `pub`: the docs have been updated to ensure that the third-party usage is clear. ### Changed - `System::default_labels` is now `System::default_system_sets`. - `App::add_default_labels` is now `App::add_default_sets` - `CoreStage` and `StartupStage` enums are now `CoreSet` and `StartupSet` - `App::add_system_set` was renamed to `App::add_systems` - The `StartupSchedule` label is now defined as part of the `CoreSchedules` enum - `.label(SystemLabel)` is now referred to as `.in_set(SystemSet)` - `SystemLabel` trait was replaced by `SystemSet` - `SystemTypeIdLabel<T>` was replaced by `SystemSetType<T>` - The `ReportHierarchyIssue` resource now has a public constructor (`new`), and implements `PartialEq` - Fixed time steps now use a schedule (`CoreSchedule::FixedTimeStep`) rather than a run criteria. - Adding rendering extraction systems now panics rather than silently failing if no subapp with the `RenderApp` label is found. - the `calculate_bounds` system, with the `CalculateBounds` label, is now in `CoreSet::Update`, rather than in `CoreSet::PostUpdate` before commands are applied. - `SceneSpawnerSystem` now runs under `CoreSet::Update`, rather than `CoreStage::PreUpdate.at_end()`. - `bevy_pbr::add_clusters` is no longer an exclusive system - the top level `bevy_ecs::schedule` module was replaced with `bevy_ecs::scheduling` - `tick_global_task_pools_on_main_thread` is no longer run as an exclusive system. Instead, it has been replaced by `tick_global_task_pools`, which uses a `NonSend` resource to force running on the main thread. ## Migration Guide - Calls to `.label(MyLabel)` should be replaced with `.in_set(MySet)` - Stages have been removed. Replace these with system sets, and then add command flushes using the `apply_system_buffers` exclusive system where needed. - The `CoreStage`, `StartupStage, `RenderStage` and `AssetStage` enums have been replaced with `CoreSet`, `StartupSet, `RenderSet` and `AssetSet`. The same scheduling guarantees have been preserved. - Systems are no longer added to `CoreSet::Update` by default. Add systems manually if this behavior is needed, although you should consider adding your game logic systems to `CoreSchedule::FixedTimestep` instead for more reliable framerate-independent behavior. - Similarly, startup systems are no longer part of `StartupSet::Startup` by default. In most cases, this won't matter to you. - For example, `add_system_to_stage(CoreStage::PostUpdate, my_system)` should be replaced with - `add_system(my_system.in_set(CoreSet::PostUpdate)` - When testing systems or otherwise running them in a headless fashion, simply construct and run a schedule using `Schedule::new()` and `World::run_schedule` rather than constructing stages - Run criteria have been renamed to run conditions. These can now be combined with each other and with states. - Looping run criteria and state stacks have been removed. Use an exclusive system that runs a schedule if you need this level of control over system control flow. - For app-level control flow over which schedules get run when (such as for rollback networking), create your own schedule and insert it under the `CoreSchedule::Outer` label. - Fixed timesteps are now evaluated in a schedule, rather than controlled via run criteria. The `run_fixed_timestep` system runs this schedule between `CoreSet::First` and `CoreSet::PreUpdate` by default. - Command flush points introduced by `AssetStage` have been removed. If you were relying on these, add them back manually. - Adding extract systems is now typically done directly on the main app. Make sure the `RenderingAppExtension` trait is in scope, then call `app.add_extract_system(my_system)`. - the `calculate_bounds` system, with the `CalculateBounds` label, is now in `CoreSet::Update`, rather than in `CoreSet::PostUpdate` before commands are applied. You may need to order your movement systems to occur before this system in order to avoid system order ambiguities in culling behavior. - the `RenderLabel` `AppLabel` was renamed to `RenderApp` for clarity - `App::add_state` now takes 0 arguments: the starting state is set based on the `Default` impl. - Instead of creating `SystemSet` containers for systems that run in stages, simply use `.on_enter::<State::Variant>()` or its `on_exit` or `on_update` siblings. - `SystemLabel` derives should be replaced with `SystemSet`. You will also need to add the `Debug`, `PartialEq`, `Eq`, and `Hash` traits to satisfy the new trait bounds. - `with_run_criteria` has been renamed to `run_if`. Run criteria have been renamed to run conditions for clarity, and should now simply return a bool. - States have been dramatically simplified: there is no longer a "state stack". To queue a transition to the next state, call `NextState::set` ## TODO - [x] remove dead methods on App and World - [x] add `App::add_system_to_schedule` and `App::add_systems_to_schedule` - [x] avoid adding the default system set at inappropriate times - [x] remove any accidental cycles in the default plugins schedule - [x] migrate benchmarks - [x] expose explicit labels for the built-in command flush points - [x] migrate engine code - [x] remove all mentions of stages from the docs - [x] verify docs for States - [x] fix uses of exclusive systems that use .end / .at_start / .before_commands - [x] migrate RenderStage and AssetStage - [x] migrate examples - [x] ensure that transform propagation is exported in a sufficiently public way (the systems are already pub) - [x] ensure that on_enter schedules are run at least once before the main app - [x] re-enable opt-in to execution order ambiguities - [x] revert change to `update_bounds` to ensure it runs in `PostUpdate` - [x] test all examples - [x] unbreak directional lights - [x] unbreak shadows (see 3d_scene, 3d_shape, lighting, transparaency_3d examples) - [x] game menu example shows loading screen and menu simultaneously - [x] display settings menu is a blank screen - [x] `without_winit` example panics - [x] ensure all tests pass - [x] SubApp doc test fails - [x] runs_spawn_local tasks fails - [x] [Fix panic_when_hierachy_cycle test hanging](https://github.com/alice-i-cecile/bevy/pull/120) ## Points of Difficulty and Controversy **Reviewers, please give feedback on these and look closely** 1. Default sets, from the RFC, have been removed. These added a tremendous amount of implicit complexity and result in hard to debug scheduling errors. They're going to be tackled in the form of "base sets" by @cart in a followup. 2. The outer schedule controls which schedule is run when `App::update` is called. 3. I implemented `Label for `Box<dyn Label>` for our label types. This enables us to store schedule labels in concrete form, and then later run them. I ran into the same set of problems when working with one-shot systems. We've previously investigated this pattern in depth, and it does not appear to lead to extra indirection with nested boxes. 4. `SubApp::update` simply runs the default schedule once. This sucks, but this whole API is incomplete and this was the minimal changeset. 5. `time_system` and `tick_global_task_pools_on_main_thread` no longer use exclusive systems to attempt to force scheduling order 6. Implemetnation strategy for fixed timesteps 7. `AssetStage` was migrated to `AssetSet` without reintroducing command flush points. These did not appear to be used, and it's nice to remove these bottlenecks. 8. Migration of `bevy_render/lib.rs` and pipelined rendering. The logic here is unusually tricky, as we have complex scheduling requirements. ## Future Work (ideally before 0.10) - Rename schedule_v3 module to schedule or scheduling - Add a derive macro to states, and likely a `EnumIter` trait of some form - Figure out what exactly to do with the "systems added should basically work by default" problem - Improve ergonomics for working with fixed timesteps and states - Polish FixedTime API to match Time - Rebase and merge #7415 - Resolve all internal ambiguities (blocked on better tools, especially #7442) - Add "base sets" to replace the removed default sets.
325 lines
14 KiB
Rust
325 lines
14 KiB
Rust
//! This example illustrates the various features of Bevy UI.
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use bevy::{
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input::mouse::{MouseScrollUnit, MouseWheel},
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prelude::*,
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winit::WinitSettings,
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};
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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// Only run the app when there is user input. This will significantly reduce CPU/GPU use.
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.insert_resource(WinitSettings::desktop_app())
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.add_startup_system(setup)
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.add_system(mouse_scroll.in_set(CoreSet::Update))
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.run();
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}
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fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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// Camera
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commands.spawn(Camera2dBundle::default());
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// root node
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commands
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.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Percent(100.0), Val::Percent(100.0)),
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justify_content: JustifyContent::SpaceBetween,
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..default()
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},
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..default()
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})
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.with_children(|parent| {
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// left vertical fill (border)
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parent
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.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Px(200.0), Val::Percent(100.0)),
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border: UiRect::all(Val::Px(2.0)),
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..default()
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},
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background_color: Color::rgb(0.65, 0.65, 0.65).into(),
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..default()
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})
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.with_children(|parent| {
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// left vertical fill (content)
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parent
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.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Percent(100.0), Val::Percent(100.0)),
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..default()
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},
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background_color: Color::rgb(0.15, 0.15, 0.15).into(),
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..default()
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})
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.with_children(|parent| {
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// text
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parent.spawn(
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TextBundle::from_section(
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"Text Example",
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TextStyle {
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font: asset_server.load("fonts/FiraSans-Bold.ttf"),
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font_size: 30.0,
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color: Color::WHITE,
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},
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)
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.with_style(Style {
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margin: UiRect::all(Val::Px(5.0)),
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..default()
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}),
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);
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});
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});
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// right vertical fill
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parent
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.spawn(NodeBundle {
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style: Style {
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flex_direction: FlexDirection::Column,
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justify_content: JustifyContent::Center,
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size: Size::new(Val::Px(200.0), Val::Percent(100.0)),
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..default()
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},
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background_color: Color::rgb(0.15, 0.15, 0.15).into(),
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..default()
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})
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.with_children(|parent| {
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// Title
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parent.spawn(
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TextBundle::from_section(
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"Scrolling list",
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TextStyle {
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font: asset_server.load("fonts/FiraSans-Bold.ttf"),
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font_size: 25.,
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color: Color::WHITE,
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},
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)
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.with_style(Style {
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size: Size::new(Val::Undefined, Val::Px(25.)),
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margin: UiRect {
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left: Val::Auto,
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right: Val::Auto,
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..default()
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},
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..default()
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}),
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);
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// List with hidden overflow
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parent
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.spawn(NodeBundle {
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style: Style {
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flex_direction: FlexDirection::Column,
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align_self: AlignSelf::Center,
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size: Size::new(Val::Percent(100.0), Val::Percent(50.0)),
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overflow: Overflow::Hidden,
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..default()
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},
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background_color: Color::rgb(0.10, 0.10, 0.10).into(),
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..default()
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})
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.with_children(|parent| {
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// Moving panel
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parent
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.spawn((
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NodeBundle {
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style: Style {
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flex_direction: FlexDirection::Column,
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flex_grow: 1.0,
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max_size: Size::UNDEFINED,
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..default()
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},
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..default()
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},
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ScrollingList::default(),
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))
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.with_children(|parent| {
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// List items
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for i in 0..30 {
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parent.spawn(
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TextBundle::from_section(
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format!("Item {i}"),
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TextStyle {
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font: asset_server
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.load("fonts/FiraSans-Bold.ttf"),
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font_size: 20.,
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color: Color::WHITE,
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},
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)
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.with_style(Style {
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flex_shrink: 0.,
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size: Size::new(Val::Undefined, Val::Px(20.)),
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margin: UiRect {
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left: Val::Auto,
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right: Val::Auto,
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..default()
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},
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..default()
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}),
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);
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}
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});
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});
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});
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parent
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.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Px(200.0), Val::Px(200.0)),
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position_type: PositionType::Absolute,
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position: UiRect {
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left: Val::Px(210.0),
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bottom: Val::Px(10.0),
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..default()
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},
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border: UiRect::all(Val::Px(20.0)),
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..default()
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},
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background_color: Color::rgb(0.4, 0.4, 1.0).into(),
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..default()
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})
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.with_children(|parent| {
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parent.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Percent(100.0), Val::Percent(100.0)),
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..default()
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},
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background_color: Color::rgb(0.8, 0.8, 1.0).into(),
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..default()
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});
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});
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// render order test: reddest in the back, whitest in the front (flex center)
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parent
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.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Percent(100.0), Val::Percent(100.0)),
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position_type: PositionType::Absolute,
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align_items: AlignItems::Center,
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justify_content: JustifyContent::Center,
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..default()
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},
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..default()
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})
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.with_children(|parent| {
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parent
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.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Px(100.0), Val::Px(100.0)),
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..default()
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},
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background_color: Color::rgb(1.0, 0.0, 0.0).into(),
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..default()
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})
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.with_children(|parent| {
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parent.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Px(100.0), Val::Px(100.0)),
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position_type: PositionType::Absolute,
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position: UiRect {
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left: Val::Px(20.0),
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bottom: Val::Px(20.0),
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..default()
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},
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..default()
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},
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background_color: Color::rgb(1.0, 0.3, 0.3).into(),
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..default()
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});
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parent.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Px(100.0), Val::Px(100.0)),
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position_type: PositionType::Absolute,
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position: UiRect {
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left: Val::Px(40.0),
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bottom: Val::Px(40.0),
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..default()
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},
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..default()
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},
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background_color: Color::rgb(1.0, 0.5, 0.5).into(),
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..default()
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});
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parent.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Px(100.0), Val::Px(100.0)),
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position_type: PositionType::Absolute,
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position: UiRect {
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left: Val::Px(60.0),
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bottom: Val::Px(60.0),
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..default()
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},
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..default()
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},
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background_color: Color::rgb(1.0, 0.7, 0.7).into(),
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..default()
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});
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// alpha test
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parent.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Px(100.0), Val::Px(100.0)),
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position_type: PositionType::Absolute,
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position: UiRect {
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left: Val::Px(80.0),
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bottom: Val::Px(80.0),
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..default()
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},
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..default()
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},
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background_color: Color::rgba(1.0, 0.9, 0.9, 0.4).into(),
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..default()
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});
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});
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});
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// bevy logo (flex center)
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parent
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.spawn(NodeBundle {
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style: Style {
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size: Size::new(Val::Percent(100.0), Val::Percent(100.0)),
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position_type: PositionType::Absolute,
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justify_content: JustifyContent::Center,
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align_items: AlignItems::FlexStart,
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..default()
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},
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..default()
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})
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.with_children(|parent| {
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// bevy logo (image)
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parent.spawn(ImageBundle {
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style: Style {
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size: Size::new(Val::Px(500.0), Val::Auto),
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..default()
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},
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image: asset_server.load("branding/bevy_logo_dark_big.png").into(),
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..default()
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});
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});
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});
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}
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#[derive(Component, Default)]
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struct ScrollingList {
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position: f32,
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}
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fn mouse_scroll(
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mut mouse_wheel_events: EventReader<MouseWheel>,
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mut query_list: Query<(&mut ScrollingList, &mut Style, &Children, &Node)>,
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query_item: Query<&Node>,
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) {
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for mouse_wheel_event in mouse_wheel_events.iter() {
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for (mut scrolling_list, mut style, children, uinode) in &mut query_list {
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let items_height: f32 = children
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.iter()
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.map(|entity| query_item.get(*entity).unwrap().size().y)
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.sum();
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let panel_height = uinode.size().y;
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let max_scroll = (items_height - panel_height).max(0.);
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let dy = match mouse_wheel_event.unit {
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MouseScrollUnit::Line => mouse_wheel_event.y * 20.,
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MouseScrollUnit::Pixel => mouse_wheel_event.y,
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};
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scrolling_list.position += dy;
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scrolling_list.position = scrolling_list.position.clamp(-max_scroll, 0.);
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style.position.top = Val::Px(scrolling_list.position);
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}
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}
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}
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