a371ee3019
25 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Zachary Harrold
|
1f2d0e6308
|
Add no_std support to bevy_ecs (#16758)
# Objective - Contributes to #15460 ## Solution - Added the following features: - `std` (default) - `async_executor` (default) - `edge_executor` - `critical-section` - `portable-atomic` - Gated `tracing` in `bevy_utils` to allow compilation on certain platforms - Switched from `tracing` to `log` for simple message logging within `bevy_ecs`. Note that `tracing` supports capturing from `log` so this should be an uncontroversial change. - Fixed imports and added feature gates as required - Made `bevy_tasks` optional within `bevy_ecs`. Turns out it's only needed for parallel operations which are already gated behind `multi_threaded` anyway. ## Testing - Added to `compile-check-no-std` CI command - `cargo check -p bevy_ecs --no-default-features --features edge_executor,critical-section,portable-atomic --target thumbv6m-none-eabi` - `cargo check -p bevy_ecs --no-default-features --features edge_executor,critical-section` - `cargo check -p bevy_ecs --no-default-features` ## Draft Release Notes Bevy's core ECS now supports `no_std` platforms. In prior versions of Bevy, it was not possible to work with embedded or niche platforms due to our reliance on the standard library, `std`. This has blocked a number of novel use-cases for Bevy, such as an embedded database for IoT devices, or for creating games on retro consoles. With this release, `bevy_ecs` no longer requires `std`. To use Bevy on a `no_std` platform, you must disable default features and enable the new `edge_executor` and `critical-section` features. You may also need to enable `portable-atomic` and `critical-section` if your platform does not natively support all atomic types and operations used by Bevy. ```toml [dependencies] bevy_ecs = { version = "0.16", default-features = false, features = [ # Required for platforms with incomplete atomics (e.g., Raspberry Pi Pico) "portable-atomic", "critical-section", # Optional "bevy_reflect", "serialize", "bevy_debug_stepping", "edge_executor" ] } ``` Currently, this has been tested on bare-metal x86 and the Raspberry Pi Pico. If you have trouble using `bevy_ecs` on a particular platform, please reach out either through a GitHub issue or in the `no_std` working group on the Bevy Discord server. Keep an eye out for future `no_std` updates as we continue to improve the parity between `std` and `no_std`. We look forward to seeing what kinds of applications are now possible with Bevy! ## Notes - Creating PR in draft to ensure CI is passing before requesting reviews. - This implementation has no support for multithreading in `no_std`, especially due to `NonSend` being unsound if allowed in multithreading. The reason is we cannot check the `ThreadId` in `no_std`, so we have no mechanism to at-runtime determine if access is sound. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: Vic <59878206+Victoronz@users.noreply.github.com> |
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SpecificProtagonist
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5f1e114209
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Descriptive error message for circular required components recursion (#16648)
# Objective Fixes #16645 ## Solution Keep track of components in callstack when registering required components. ## Testing Added a test checking that the error fires. --- ## Showcase ```rust #[derive(Component, Default)] #[require(B)] struct A; #[derive(Component, Default)] #[require(A)] struct B; World::new().spawn(A); ``` ``` thread 'main' panicked at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/component.rs:415:13: Recursive required components detected: A → B → A ``` --------- Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com> |
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Joona Aalto
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99b6f1d330
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Link to required components docs in component type docs (#16687)
# Objective #16575 moved required component docs from the `Component` impl to type docs. However, it doesn't actually link to what [required components](https://docs.rs/bevy/0.15.0/bevy/ecs/component/trait.Component.html#required-components) are and how they work. ## Solution Link to [required components](https://docs.rs/bevy/0.15.0/bevy/ecs/component/trait.Component.html#required-components)! ## Testing I tested the link for some components in different Bevy crates. I did not test in external third party crates, but I would assume that it should work there too. --- ## Showcase  Note: The tooltip doesn't show the `#required-components` anchor for some reason, but it is there. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: SpecificProtagonist <vincentjunge@posteo.net> |
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Zachary Harrold
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a35811d088
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Add Immutable Component Support (#16372)
# Objective - Fixes #16208 ## Solution - Added an associated type to `Component`, `Mutability`, which flags whether a component is mutable, or immutable. If `Mutability= Mutable`, the component is mutable. If `Mutability= Immutable`, the component is immutable. - Updated `derive_component` to default to mutable unless an `#[component(immutable)]` attribute is added. - Updated `ReflectComponent` to check if a component is mutable and, if not, panic when attempting to mutate. ## Testing - CI - `immutable_components` example. --- ## Showcase Users can now mark a component as `#[component(immutable)]` to prevent safe mutation of a component while it is attached to an entity: ```rust #[derive(Component)] #[component(immutable)] struct Foo { // ... } ``` This prevents creating an exclusive reference to the component while it is attached to an entity. This is particularly powerful when combined with component hooks, as you can now fully track a component's value, ensuring whatever invariants you desire are upheld. Before this would be done my making a component private, and manually creating a `QueryData` implementation which only permitted read access. <details> <summary>Using immutable components as an index</summary> ```rust /// This is an example of a component like [`Name`](bevy::prelude::Name), but immutable. #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Component)] #[component( immutable, on_insert = on_insert_name, on_replace = on_replace_name, )] pub struct Name(pub &'static str); /// This index allows for O(1) lookups of an [`Entity`] by its [`Name`]. #[derive(Resource, Default)] struct NameIndex { name_to_entity: HashMap<Name, Entity>, } impl NameIndex { fn get_entity(&self, name: &'static str) -> Option<Entity> { self.name_to_entity.get(&Name(name)).copied() } } fn on_insert_name(mut world: DeferredWorld<'_>, entity: Entity, _component: ComponentId) { let Some(&name) = world.entity(entity).get::<Name>() else { unreachable!() }; let Some(mut index) = world.get_resource_mut::<NameIndex>() else { return; }; index.name_to_entity.insert(name, entity); } fn on_replace_name(mut world: DeferredWorld<'_>, entity: Entity, _component: ComponentId) { let Some(&name) = world.entity(entity).get::<Name>() else { unreachable!() }; let Some(mut index) = world.get_resource_mut::<NameIndex>() else { return; }; index.name_to_entity.remove(&name); } // Setup our name index world.init_resource::<NameIndex>(); // Spawn some entities! let alyssa = world.spawn(Name("Alyssa")).id(); let javier = world.spawn(Name("Javier")).id(); // Check our index let index = world.resource::<NameIndex>(); assert_eq!(index.get_entity("Alyssa"), Some(alyssa)); assert_eq!(index.get_entity("Javier"), Some(javier)); // Changing the name of an entity is also fully capture by our index world.entity_mut(javier).insert(Name("Steven")); // Javier changed their name to Steven let steven = javier; // Check our index let index = world.resource::<NameIndex>(); assert_eq!(index.get_entity("Javier"), None); assert_eq!(index.get_entity("Steven"), Some(steven)); ``` </details> Additionally, users can use `Component<Mutability = ...>` in trait bounds to enforce that a component _is_ mutable or _is_ immutable. When using `Component` as a trait bound without specifying `Mutability`, any component is applicable. However, methods which only work on mutable or immutable components are unavailable, since the compiler must be pessimistic about the type. ## Migration Guide - When implementing `Component` manually, you must now provide a type for `Mutability`. The type `Mutable` provides equivalent behaviour to earlier versions of `Component`: ```rust impl Component for Foo { type Mutability = Mutable; // ... } ``` - When working with generic components, you may need to specify that your generic parameter implements `Component<Mutability = Mutable>` rather than `Component` if you require mutable access to said component. - The entity entry API has had to have some changes made to minimise friction when working with immutable components. Methods which previously returned a `Mut<T>` will now typically return an `OccupiedEntry<T>` instead, requiring you to add an `into_mut()` to get the `Mut<T>` item again. ## Draft Release Notes Components can now be made immutable while stored within the ECS. Components are the fundamental unit of data within an ECS, and Bevy provides a number of ways to work with them that align with Rust's rules around ownership and borrowing. One part of this is hooks, which allow for defining custom behavior at key points in a component's lifecycle, such as addition and removal. However, there is currently no way to respond to _mutation_ of a component using hooks. The reasons for this are quite technical, but to summarize, their addition poses a significant challenge to Bevy's core promises around performance. Without mutation hooks, it's relatively trivial to modify a component in such a way that breaks invariants it intends to uphold. For example, you can use `core::mem::swap` to swap the components of two entities, bypassing the insertion and removal hooks. This means the only way to react to this modification is via change detection in a system, which then begs the question of what happens _between_ that alteration and the next run of that system? Alternatively, you could make your component private to prevent mutation, but now you need to provide commands and a custom `QueryData` implementation to allow users to interact with your component at all. Immutable components solve this problem by preventing the creation of an exclusive reference to the component entirely. Without an exclusive reference, the only way to modify an immutable component is via removal or replacement, which is fully captured by component hooks. To make a component immutable, simply add `#[component(immutable)]`: ```rust #[derive(Component)] #[component(immutable)] struct Foo { // ... } ``` When implementing `Component` manually, there is an associated type `Mutability` which controls this behavior: ```rust impl Component for Foo { type Mutability = Mutable; // ... } ``` Note that this means when working with generic components, you may need to specify that a component is mutable to gain access to certain methods: ```rust // Before fn bar<C: Component>() { // ... } // After fn bar<C: Component<Mutability = Mutable>>() { // ... } ``` With this new tool, creating index components, or caching data on an entity should be more user friendly, allowing libraries to provide APIs relying on components and hooks to uphold their invariants. ## Notes - ~~I've done my best to implement this feature, but I'm not happy with how reflection has turned out. If any reflection SMEs know a way to improve this situation I'd greatly appreciate it.~~ There is an outstanding issue around the fallibility of mutable methods on `ReflectComponent`, but the DX is largely unchanged from `main` now. - I've attempted to prevent all safe mutable access to a component that does not implement `Component<Mutability = Mutable>`, but there may still be some methods I have missed. Please indicate so and I will address them, as they are bugs. - Unsafe is an escape hatch I am _not_ attempting to prevent. Whatever you do with unsafe is between you and your compiler. - I am marking this PR as ready, but I suspect it will undergo fairly major revisions based on SME feedback. - I've marked this PR as _Uncontroversial_ based on the feature, not the implementation. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com> Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com> Co-authored-by: Nuutti Kotivuori <naked@iki.fi> |
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SpecificProtagonist
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d92fc1e456
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Move required components doc to type doc (#16575)
# Objective Make documentation of a component's required components more visible by moving it to the type's docs ## Solution Change `#[require]` from a derive macro helper to an attribute macro. Disadvantages: - this silences any unused code warnings on the component, as it is used by the macro! - need to import `require` if not using the ecs prelude (I have not included this in the migration guilde as Rust tooling already suggests the fix) --- ## Showcase  --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: JMS55 <47158642+JMS55@users.noreply.github.com> |
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eugineerd
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2e267bba5a
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Entity cloning (#16132)
## Objective Fixes #1515 This PR implements a flexible entity cloning system. The primary use case for it is to clone dynamically-generated entities. Example: ```rs #[derive(Component, Clone)] pub struct Projectile; #[derive(Component, Clone)] pub struct Damage { value: f32, } fn player_input( mut commands: Commands, projectiles: Query<Entity, With<Projectile>>, input: Res<ButtonInput<KeyCode>>, ) { // Fire a projectile if input.just_pressed(KeyCode::KeyF) { commands.spawn((Projectile, Damage { value: 10.0 })); } // Triplicate all active projectiles if input.just_pressed(KeyCode::KeyT) { for projectile in projectiles.iter() { // To triplicate a projectile we need to create 2 more clones for _ in 0..2{ commands.clone_entity(projectile) } } } } ``` ## Solution ### Commands Add a `clone_entity` command to create a clone of an entity with all components that can be cloned. Components that can't be cloned will be ignored. ```rs commands.clone_entity(entity) ``` If there is a need to configure the cloning process (like set to clone recursively), there is a second command: ```rs commands.clone_entity_with(entity, |builder| { builder.recursive(true) }); ``` Both of these commands return `EntityCommands` of the cloned entity, so the copy can be modified afterwards. ### Builder All these commands use `EntityCloneBuilder` internally. If there is a need to clone an entity using `World` instead, it is also possible: ```rs let entity = world.spawn(Component).id(); let entity_clone = world.spawn_empty().id(); EntityCloneBuilder::new(&mut world).clone_entity(entity, entity_clone); ``` Builder has methods to `allow` or `deny` certain components during cloning if required and can be extended by implementing traits on it. This PR includes two `EntityCloneBuilder` extensions: `CloneEntityWithObserversExt` to configure adding cloned entity to observers of the original entity, and `CloneEntityRecursiveExt` to configure cloning an entity recursively. ### Clone implementations By default, all components that implement either `Clone` or `Reflect` will be cloned (with `Clone`-based implementation preferred in case component implements both). This can be overriden on a per-component basis: ```rs impl Component for SomeComponent { const STORAGE_TYPE: StorageType = StorageType::Table; fn get_component_clone_handler() -> ComponentCloneHandler { // Don't clone this component ComponentCloneHandler::Ignore } } ``` ### `ComponentCloneHandlers` Clone implementation specified in `get_component_clone_handler` will get registered in `ComponentCloneHandlers` (stored in `bevy_ecs::component::Components`) at component registration time. The clone handler implementation provided by a component can be overriden after registration like so: ```rs let component_id = world.components().component_id::<Component>().unwrap() world.get_component_clone_handlers_mut() .set_component_handler(component_id, ComponentCloneHandler::Custom(component_clone_custom)) ``` The default clone handler for all components that do not explicitly define one (or don't derive `Component`) is `component_clone_via_reflect` if `bevy_reflect` feature is enabled, and `component_clone_ignore` (noop) otherwise. Default handler can be overriden using `ComponentCloneHandlers::set_default_handler` ### Handlers Component clone handlers can be used to modify component cloning behavior. The general signature for a handler that can be used in `ComponentCloneHandler::Custom` is as follows: ```rs pub fn component_clone_custom( world: &mut DeferredWorld, entity_cloner: &EntityCloner, ) { // implementation } ``` The `EntityCloner` implementation (used internally by `EntityCloneBuilder`) assumes that after calling this custom handler, the `target` entity has the desired version of the component from the `source` entity. ### Builder handler overrides Besides component-defined and world-overriden handlers, `EntityCloneBuilder` also has a way to override handlers locally. It is mainly used to allow configuration methods like `recursive` and `add_observers`. ```rs // From observer clone handler implementation impl CloneEntityWithObserversExt for EntityCloneBuilder<'_> { fn add_observers(&mut self, add_observers: bool) -> &mut Self { if add_observers { self.override_component_clone_handler::<ObservedBy>(ComponentCloneHandler::Custom( component_clone_observed_by, )) } else { self.remove_component_clone_handler_override::<ObservedBy>() } } } ``` ## Testing Includes some basic functionality tests and doctests. Performance-wise this feature is the same as calling `clone` followed by `insert` for every entity component. There is also some inherent overhead due to every component clone handler having to access component data through `World`, but this can be reduced without breaking current public API in a later PR. |
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Volodymyr Enhelhardt
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db1915a1f0
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Use the fully qualified name for Component in the require attribute (#16378)
# Objective - Describe the objective or issue this PR addresses. Use the fully qualified name for `Component` in the `require` attribute - If you're fixing a specific issue, say "Fixes #X". Fixes #16377 ## Solution - Describe the solution used to achieve the objective above. Use the fully qualified name for `Component` in the `require` attribute, i.e.,`<#ident as #bevy_ecs_path::component::Component>` ## Testing - Did you test these changes? If so, how? `cargo run -p ci -- lints` `cargo run -p ci -- compile` `cargo run -p ci -- test` - Are there any parts that need more testing? no - How can other people (reviewers) test your changes? Is there anything specific they need to know? try to compile ```rust #[derive(::bevy::ecs::component::Component, Default)] pub struct A; #[derive(::bevy::ecs::component::Component)] #[require(A)] pub struct B; ``` - If relevant, what platforms did you test these changes on, and are there any important ones you can't test? Mac only --- </details> ## Migration Guide > This section is optional. If there are no breaking changes, you can delete this section. - If this PR is a breaking change (relative to the last release of Bevy), describe how a user might need to migrate their code to support these changes - Simply adding new functionality is not a breaking change. - Fixing behavior that was definitely a bug, rather than a questionable design choice is not a breaking change. Co-authored-by: Volodymyr Enhelhardt <volodymyr.enhelhardt@ambr.net> |
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fluffiac
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f0704cffa4
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Allow a closure to be used as a required component default (#15269)
# Objective
Allow required component default values to be provided in-line.
```rust
#[derive(Component)]
#[require(
FocusPolicy(block_focus_policy)
)]
struct SomeComponent;
fn block_focus_policy() -> FocusPolicy {
FocusPolicy::Block
}
```
May now be expressed as:
```rust
#[derive(Component)]
#[require(
FocusPolicy(|| FocusPolicy::Block)
)]
struct SomeComponent;
```
## Solution
Modified the #[require] proc macro to accept a closure.
## Testing
Tested using my branch as a dependency, and switching between the inline
closure syntax and function syntax for a bunch of different components.
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Joona Aalto
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f3e8ae03cd
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Runtime required components (#15458)
# Objective Fixes #15367. Currently, required components can only be defined through the `require` macro attribute. While this should be used in most cases, there are also several instances where you may want to define requirements at runtime, commonly in plugins. Example use cases: - Require components only if the relevant optional plugins are enabled. For example, a `SleepTimer` component (for physics) is only relevant if the `SleepPlugin` is enabled. - Third party crates can define their own requirements for first party types. For example, "each `Handle<Mesh>` should require my custom rendering data components". This also gets around the orphan rule. - Generic plugins that add marker components based on the existence of other components, like a generic `ColliderPlugin<C: AnyCollider>` that wants to add a `ColliderMarker` component for all types of colliders. - This is currently relevant for the retained render world in #15320. The `ExtractComponentPlugin<C>` should add `SyncToRenderWorld` to all components that should be extracted. This is currently done with observers, which is more expensive than required components, and causes archetype moves. - Replace some built-in components with custom versions. For example, if `GlobalTransform` required `Transform` through `TransformPlugin`, but we wanted to use a `CustomTransform` type, we could replace `TransformPlugin` with our own plugin. (This specific example isn't good, but there are likely better use cases where this may be useful) See #15367 for more in-depth reasoning. ## Solution Add `register_required_components::<T, R>` and `register_required_components_with::<T, R>` methods for `Default` and custom constructors respectively. These methods exist on `App` and `World`. ```rust struct BirdPlugin; impl Plugin for BirdPlugin { fn plugin(app: &mut App) { // Make `Bird` require `Wings` with a `Default` constructor. app.register_required_components::<Bird, Wings>(); // Make `Wings` require `FlapSpeed` with a custom constructor. // Fun fact: Some hummingbirds can flutter their wings 80 times per second! app.register_required_components_with::<Wings, FlapSpeed>(|| FlapSpeed::from_duration(1.0 / 80.0)); } } ``` The custom constructor is a function pointer to match the `require` API, though it could take a raw value too. Requirement inheritance works similarly as with the `require` attribute. If `Bird` required `FlapSpeed` directly, it would take precedence over indirectly requiring it through `Wings`. The same logic applies to all levels of the inheritance tree. Note that registering the same component requirement more than once will panic, similarly to trying to add multiple component hooks of the same type to the same component. This avoids constructor conflicts and confusing ordering issues. ### Implementation Runtime requirements have two additional challenges in comparison to the `require` attribute. 1. The `require` attribute uses recursion and macros with clever ordering to populate hash maps of required components for each component type. The expected semantics are that "more specific" requirements override ones deeper in the inheritance tree. However, at runtime, there is no representation of how "specific" each requirement is. 2. If you first register the requirement `X -> Y`, and later register `Y -> Z`, then `X` should also indirectly require `Z`. However, `Y` itself doesn't know that it is required by `X`, so it's not aware that it should update the list of required components for `X`. My solutions to these problems are: 1. Store the depth in the inheritance tree for each entry of a given component's `RequiredComponents`. This is used to determine how "specific" each requirement is. For `require`-based registration, these depths are computed as part of the recursion. 2. Store and maintain a `required_by` list in each component's `ComponentInfo`, next to `required_components`. For `require`-based registration, these are also added after each registration, as part of the recursion. When calling `register_required_components`, it works as follows: 1. Get the required components of `Foo`, and check that `Bar` isn't already a *direct* requirement. 3. Register `Bar` as a required component for `Foo`, and add `Foo` to the `required_by` list for `Bar`. 4. Find and register all indirect requirements inherited from `Bar`, adding `Foo` to the `required_by` list for each component. 5. Iterate through components that require `Foo`, registering the new inherited requires for them as indirect requirements. The runtime registration is likely slightly more expensive than the `require` version, but it is a one-time cost, and quite negligible in practice, unless projects have hundreds or thousands of runtime requirements. I have not benchmarked this however. This does also add a small amount of extra cost to the `require` attribute for updating `required_by` lists, but I expect it to be very minor. ## Testing I added some tests that are copies of the `require` versions, as well as some tests that are more specific to the runtime implementation. I might add a few more tests though. ## Discussion - Is `register_required_components` a good name? Originally I went for `register_component_requirement` to be consistent with `register_component_hooks`, but the general feature is often referred to as "required components", which is why I changed it to `register_required_components`. - Should we *not* panic for duplicate requirements? If so, should they just be ignored, or should the latest registration overwrite earlier ones? - If we do want to panic for duplicate, conflicting registrations, should we at least not panic if the registrations are *exactly* the same, i.e. same component and same constructor? The current implementation panics for all duplicate direct registrations regardless of the constructor. ## Next Steps - Allow `register_required_components` to take a `Bundle` instead of a single required component. - I could also try to do it in this PR if that would be preferable. - Not directly related, but archetype invariants? |
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Benjamin Brienen
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27bea6abf7
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Bubbling observers traversal should use query data (#15385)
# Objective Fixes #14331 ## Solution - Make `Traversal` a subtrait of `ReadOnlyQueryData` - Update implementations and usages ## Testing - Updated unit tests ## Migration Guide Update implementations of `Traversal`. --------- Co-authored-by: Christian Hughes <9044780+ItsDoot@users.noreply.github.com> |
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Carter Anderson
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9cdb915809
|
Required Components (#14791)
## Introduction This is the first step in my [Next Generation Scene / UI Proposal](https://github.com/bevyengine/bevy/discussions/14437). Fixes https://github.com/bevyengine/bevy/issues/7272 #14800. Bevy's current Bundles as the "unit of construction" hamstring the UI user experience and have been a pain point in the Bevy ecosystem generally when composing scenes: * They are an additional _object defining_ concept, which must be learned separately from components. Notably, Bundles _are not present at runtime_, which is confusing and limiting. * They can completely erase the _defining component_ during Bundle init. For example, `ButtonBundle { style: Style::default(), ..default() }` _makes no mention_ of the `Button` component symbol, which is what makes the Entity a "button"! * They are not capable of representing "dependency inheritance" without completely non-viable / ergonomically crushing nested bundles. This limitation is especially painful in UI scenarios, but it applies to everything across the board. * They introduce a bunch of additional nesting when defining scenes, making them ugly to look at * They introduce component name "stutter": `SomeBundle { component_name: ComponentName::new() }` * They require copious sprinklings of `..default()` when spawning them in Rust code, due to the additional layer of nesting **Required Components** solve this by allowing you to define which components a given component needs, and how to construct those components when they aren't explicitly provided. This is what a `ButtonBundle` looks like with Bundles (the current approach): ```rust #[derive(Component, Default)] struct Button; #[derive(Bundle, Default)] struct ButtonBundle { pub button: Button, pub node: Node, pub style: Style, pub interaction: Interaction, pub focus_policy: FocusPolicy, pub border_color: BorderColor, pub border_radius: BorderRadius, pub image: UiImage, pub transform: Transform, pub global_transform: GlobalTransform, pub visibility: Visibility, pub inherited_visibility: InheritedVisibility, pub view_visibility: ViewVisibility, pub z_index: ZIndex, } commands.spawn(ButtonBundle { style: Style { width: Val::Px(100.0), height: Val::Px(50.0), ..default() }, focus_policy: FocusPolicy::Block, ..default() }) ``` And this is what it looks like with Required Components: ```rust #[derive(Component)] #[require(Node, UiImage)] struct Button; commands.spawn(( Button, Style { width: Val::Px(100.0), height: Val::Px(50.0), ..default() }, FocusPolicy::Block, )); ``` With Required Components, we mention only the most relevant components. Every component required by `Node` (ex: `Style`, `FocusPolicy`, etc) is automatically brought in! ### Efficiency 1. At insertion/spawn time, Required Components (including recursive required components) are initialized and inserted _as if they were manually inserted alongside the given components_. This means that this is maximally efficient: there are no archetype or table moves. 2. Required components are only initialized and inserted if they were not manually provided by the developer. For the code example in the previous section, because `Style` and `FocusPolicy` are inserted manually, they _will not_ be initialized and inserted as part of the required components system. Efficient! 3. The "missing required components _and_ constructors needed for an insertion" are cached in the "archetype graph edge", meaning they aren't computed per-insertion. When a component is inserted, the "missing required components" list is iterated (and that graph edge (AddBundle) is actually already looked up for us during insertion, because we need that for "normal" insert logic too). ### IDE Integration The `#[require(SomeComponent)]` macro has been written in such a way that Rust Analyzer can provide type-inspection-on-hover and `F12` / go-to-definition for required components. ### Custom Constructors The `require` syntax expects a `Default` constructor by default, but it can be overridden with a custom constructor: ```rust #[derive(Component)] #[require( Node, Style(button_style), UiImage )] struct Button; fn button_style() -> Style { Style { width: Val::Px(100.0), ..default() } } ``` ### Multiple Inheritance You may have noticed by now that this behaves a bit like "multiple inheritance". One of the problems that this presents is that it is possible to have duplicate requires for a given type at different levels of the inheritance tree: ```rust #[derive(Component) struct X(usize); #[derive(Component)] #[require(X(x1)) struct Y; fn x1() -> X { X(1) } #[derive(Component)] #[require( Y, X(x2), )] struct Z; fn x2() -> X { X(2) } // What version of X is inserted for Z? commands.spawn(Z); ``` This is allowed (and encouraged), although this doesn't appear to occur much in practice. First: only one version of `X` is initialized and inserted for `Z`. In the case above, I think we can all probably agree that it makes the most sense to use the `x2` constructor for `X`, because `Y`'s `x1` constructor exists "beneath" `Z` in the inheritance hierarchy; `Z`'s constructor is "more specific". The algorithm is simple and predictable: 1. Use all of the constructors (including default constructors) directly defined in the spawned component's require list 2. In the order the requires are defined in `#[require()]`, recursively visit the require list of each of the components in the list (this is a depth Depth First Search). When a constructor is found, it will only be used if one has not already been found. From a user perspective, just think about this as the following: 1. Specifying a required component constructor for `Foo` directly on a spawned component `Bar` will result in that constructor being used (and overriding existing constructors lower in the inheritance tree). This is the classic "inheritance override" behavior people expect. 2. For cases where "multiple inheritance" results in constructor clashes, Components should be listed in "importance order". List a component earlier in the requirement list to initialize its inheritance tree earlier. Required Components _does_ generally result in a model where component values are decoupled from each other at construction time. Notably, some existing Bundle patterns use bundle constructors to initialize multiple components with shared state. I think (in general) moving away from this is necessary: 1. It allows Required Components (and the Scene system more generally) to operate according to simple rules 2. The "do arbitrary init value sharing in Bundle constructors" approach _already_ causes data consistency problems, and those problems would be exacerbated in the context of a Scene/UI system. For cases where shared state is truly necessary, I think we are better served by observers / hooks. 3. If a situation _truly_ needs shared state constructors (which should be rare / generally discouraged), Bundles are still there if they are needed. ## Next Steps * **Require Construct-ed Components**: I have already implemented this (as defined in the [Next Generation Scene / UI Proposal](https://github.com/bevyengine/bevy/discussions/14437). However I've removed `Construct` support from this PR, as that has not landed yet. Adding this back in requires relatively minimal changes to the current impl, and can be done as part of a future Construct pr. * **Port Built-in Bundles to Required Components**: This isn't something we should do right away. It will require rethinking our public interfaces, which IMO should be done holistically after the rest of Next Generation Scene / UI lands. I think we should merge this PR first and let people experiment _inside their own code with their own Components_ while we wait for the rest of the new scene system to land. * **_Consider_ Automatic Required Component Removal**: We should evaluate _if_ automatic Required Component removal should be done. Ex: if all components that explicitly require a component are removed, automatically remove that component. This issue has been explicitly deferred in this PR, as I consider the insertion behavior to be desirable on its own (and viable on its own). I am also doubtful that we can find a design that has behavior we actually want. Aka: can we _really_ distinguish between a component that is "only there because it was automatically inserted" and "a component that was necessary / should be kept". See my [discussion response here](https://github.com/bevyengine/bevy/discussions/14437#discussioncomment-10268668) for more details. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com> Co-authored-by: Pascal Hertleif <killercup@gmail.com> |
||
|
Pixelstorm
|
0f7c548a4a
|
Component Lifecycle Hook & Observer Trigger for replaced values (#14212)
# Objective Fixes #14202 ## Solution Add `on_replaced` component hook and `OnReplaced` observer trigger ## Testing - Did you test these changes? If so, how? - Updated & added unit tests --- ## Changelog - Added new `on_replaced` component hook and `OnReplaced` observer trigger for performing cleanup on component values when they are overwritten with `.insert()` |
||
|
Miles Silberling-Cook
|
ed2b8e0f35
|
Minimal Bubbling Observers (#13991)
# Objective
Add basic bubbling to observers, modeled off `bevy_eventlistener`.
## Solution
- Introduce a new `Traversal` trait for components which point to other
entities.
- Provide a default `TraverseNone: Traversal` component which cannot be
constructed.
- Implement `Traversal` for `Parent`.
- The `Event` trait now has an associated `Traversal` which defaults to
`TraverseNone`.
- Added a field `bubbling: &mut bool` to `Trigger` which can be used to
instruct the runner to bubble the event to the entity specified by the
event's traversal type.
- Added an associated constant `SHOULD_BUBBLE` to `Event` which
configures the default bubbling state.
- Added logic to wire this all up correctly.
Introducing the new associated information directly on `Event` (instead
of a new `BubblingEvent` trait) lets us dispatch both bubbling and
non-bubbling events through the same api.
## Testing
I have added several unit tests to cover the common bugs I identified
during development. Running the unit tests should be enough to validate
correctness. The changes effect unsafe portions of the code, but should
not change any of the safety assertions.
## Changelog
Observers can now bubble up the entity hierarchy! To create a bubbling
event, change your `Derive(Event)` to something like the following:
```rust
#[derive(Component)]
struct MyEvent;
impl Event for MyEvent {
type Traverse = Parent; // This event will propagate up from child to parent.
const AUTO_PROPAGATE: bool = true; // This event will propagate by default.
}
```
You can dispatch a bubbling event using the normal
`world.trigger_targets(MyEvent, entity)`.
Halting an event mid-bubble can be done using
`trigger.propagate(false)`. Events with `AUTO_PROPAGATE = false` will
not propagate by default, but you can enable it using
`trigger.propagate(true)`.
If there are multiple observers attached to a target, they will all be
triggered by bubbling. They all share a bubbling state, which can be
accessed mutably using `trigger.propagation_mut()` (`trigger.propagate`
is just sugar for this).
You can choose to implement `Traversal` for your own types, if you want
to bubble along a different structure than provided by `bevy_hierarchy`.
Implementers must be careful never to produce loops, because this will
cause bevy to hang.
## Migration Guide
+ Manual implementations of `Event` should add associated type `Traverse
= TraverseNone` and associated constant `AUTO_PROPAGATE = false`;
+ `Trigger::new` has new field `propagation: &mut Propagation` which
provides the bubbling state.
+ `ObserverRunner` now takes the same `&mut Propagation` as a final
parameter.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Torstein Grindvik <52322338+torsteingrindvik@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
|
||
|
Jenya705
|
330911f1bf
|
Component Hook functions as attributes for Component derive macro (#14005)
# Objective Fixes https://github.com/bevyengine/bevy/issues/13972 ## Solution Added 3 new attributes to the `Component` macro. ## Testing Added `component_hook_order_spawn_despawn_with_macro_hooks`, that makes the same as `component_hook_order_spawn_despawn` but uses a struct, that defines it's hooks with the `Component` macro. --- --------- Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com> |
||
|
James O'Brien
|
eb3c81374a
|
Generalised ECS reactivity with Observers (#10839)
# Objective
- Provide an expressive way to register dynamic behavior in response to
ECS changes that is consistent with existing bevy types and traits as to
provide a smooth user experience.
- Provide a mechanism for immediate changes in response to events during
command application in order to facilitate improved query caching on the
path to relations.
## Solution
- A new fundamental ECS construct, the `Observer`; inspired by flec's
observers but adapted to better fit bevy's access patterns and rust's
type system.
---
## Examples
There are 3 main ways to register observers. The first is a "component
observer" that looks like this:
```rust
world.observe(|trigger: Trigger<OnAdd, Transform>, query: Query<&Transform>| {
let transform = query.get(trigger.entity()).unwrap();
});
```
The above code will spawn a new entity representing the observer that
will run it's callback whenever the `Transform` component is added to an
entity. This is a system-like function that supports dependency
injection for all the standard bevy types: `Query`, `Res`, `Commands`
etc. It also has a `Trigger` parameter that provides information about
the trigger such as the target entity, and the event being triggered.
Importantly these systems run during command application which is key
for their future use to keep ECS internals up to date. There are similar
events for `OnInsert` and `OnRemove`, and this will be expanded with
things such as `ArchetypeCreated`, `TableEmpty` etc. in follow up PRs.
Another way to register an observer is an "entity observer" that looks
like this:
```rust
world.entity_mut(entity).observe(|trigger: Trigger<Resize>| {
// ...
});
```
Entity observers run whenever an event of their type is triggered
targeting that specific entity. This type of observer will de-spawn
itself if the entity (or entities) it is observing is ever de-spawned so
as to not leave dangling observers.
Entity observers can also be spawned from deferred contexts such as
other observers, systems, or hooks using commands:
```rust
commands.entity(entity).observe(|trigger: Trigger<Resize>| {
// ...
});
```
Observers are not limited to in built event types, they can be used with
any type that implements `Event` (which has been extended to implement
Component). This means events can also carry data:
```rust
#[derive(Event)]
struct Resize { x: u32, y: u32 }
commands.entity(entity).observe(|trigger: Trigger<Resize>, query: Query<&mut Size>| {
let event = trigger.event();
// ...
});
// Will trigger the observer when commands are applied.
commands.trigger_targets(Resize { x: 10, y: 10 }, entity);
```
You can also trigger events that target more than one entity at a time:
```rust
commands.trigger_targets(Resize { x: 10, y: 10 }, [e1, e2]);
```
Additionally, Observers don't _need_ entity targets:
```rust
app.observe(|trigger: Trigger<Quit>| {
})
commands.trigger(Quit);
```
In these cases, `trigger.entity()` will be a placeholder.
Observers are actually just normal entities with an `ObserverState` and
`Observer` component! The `observe()` functions above are just shorthand
for:
```rust
world.spawn(Observer::new(|trigger: Trigger<Resize>| {});
```
This will spawn the `Observer` system and use an `on_add` hook to add
the `ObserverState` component.
Dynamic components and trigger types are also fully supported allowing
for runtime defined trigger types.
## Possible Follow-ups
1. Deprecate `RemovedComponents`, observers should fulfill all use cases
while being more flexible and performant.
2. Queries as entities: Swap queries to entities and begin using
observers listening to archetype creation triggers to keep their caches
in sync, this allows unification of `ObserverState` and `QueryState` as
well as unlocking several API improvements for `Query` and the
management of `QueryState`.
3. Trigger bubbling: For some UI use cases in particular users are
likely to want some form of bubbling for entity observers, this is
trivial to implement naively but ideally this includes an acceleration
structure to cache hierarchy traversals.
4. All kinds of other in-built trigger types.
5. Optimization; in order to not bloat the complexity of the PR I have
kept the implementation straightforward, there are several areas where
performance can be improved. The focus for this PR is to get the
behavior implemented and not incur a performance cost for users who
don't use observers.
I am leaving each of these to follow up PR's in order to keep each of
them reviewable as this already includes significant changes.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: MiniaczQ <xnetroidpl@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
|
||
|
James Liu
|
dc40cd134f
|
Remove ComponentStorage and associated types (#12311)
# Objective When doing a final pass for #3362, it appeared that `ComponentStorage` as a trait, the two types implementing it, and the associated type on `Component` aren't really necessary anymore. This likely was due to an earlier constraint on the use of consts in traits, but that definitely doesn't seem to be a problem in Rust 1.76. ## Solution Remove them. --- ## Changelog Changed: `Component::Storage` has been replaced with `Component::STORAGE_TYPE` as a const. Removed: `bevy::ecs::component::ComponentStorage` trait Removed: `bevy::ecs::component::TableStorage` struct Removed: `bevy::ecs::component::SparseSetStorage` struct ## Migration Guide If you were manually implementing `Component` instead of using the derive macro, replace the associated `Storage` associated type with the `STORAGE_TYPE` const: ```rust // in Bevy 0.13 impl Component for MyComponent { type Storage = TableStorage; } // in Bevy 0.14 impl Component for MyComponent { const STORAGE_TYPE: StorageType = StorageType::Table; } ``` Component is no longer object safe. If you were relying on `&dyn Component`, `Box<dyn Component>`, etc. please [file an issue ](https://github.com/bevyengine/bevy/issues) to get [this change](https://github.com/bevyengine/bevy/pull/12311) reverted. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
||
|
ClayenKitten
|
ffc572728f
|
Fix typos throughout the project (#9090)
# Objective
Fix typos throughout the project.
## Solution
[`typos`](https://github.com/crate-ci/typos) project was used for
scanning, but no automatic corrections were applied. I checked
everything by hand before fixing.
Most of the changes are documentation/comments corrections. Also, there
are few trivial changes to code (variable name, pub(crate) function name
and a few error/panic messages).
## Unsolved
`bevy_reflect_derive` has
[typo](
|
||
|
CatThingy
|
89cbc78d3d
|
Require #[derive(Event)] on all Events (#7086)
# Objective Be consistent with `Resource`s and `Components` and have `Event` types be more self-documenting. Although not susceptible to accidentally using a function instead of a value due to `Event`s only being initialized by their type, much of the same reasoning for removing the blanket impl on `Resource` also applies here. * Not immediately obvious if a type is intended to be an event * Prevent invisible conflicts if the same third-party or primitive types are used as events * Allows for further extensions (e.g. opt-in warning for missed events) ## Solution Remove the blanket impl for the `Event` trait. Add a derive macro for it. --- ## Changelog - `Event` is no longer implemented for all applicable types. Add the `#[derive(Event)]` macro for events. ## Migration Guide * Add the `#[derive(Event)]` macro for events. Third-party types used as events should be wrapped in a newtype. |
||
|
François
|
0736195a1e
|
update syn, encase, glam and hexasphere (#8573)
# Objective - Fixes #8282 - Update `syn` to 2.0, `encase` to 0.6, `glam` to 0.24 and `hexasphere` to 9.0 Blocked ~~on https://github.com/teoxoy/encase/pull/42~~ and ~~on https://github.com/OptimisticPeach/hexasphere/pull/17~~ --------- Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com> Co-authored-by: JoJoJet <21144246+JoJoJet@users.noreply.github.com> |
||
|
张林伟
|
0d2cdb450d |
Fix beta clippy lints (#7154)
# Objective - When I run `cargo run -p ci` for my pr locally using latest beta toolchain, the ci failed due to [uninlined_format_args](https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args) and [needless_lifetimes](https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes) lints ## Solution - Fix lints according to clippy suggestions. |
||
|
ira
|
992681b59b |
Make Resource trait opt-in, requiring #[derive(Resource)] V2 (#5577)
*This PR description is an edited copy of #5007, written by @alice-i-cecile.* # Objective Follow-up to https://github.com/bevyengine/bevy/pull/2254. The `Resource` trait currently has a blanket implementation for all types that meet its bounds. While ergonomic, this results in several drawbacks: * it is possible to make confusing, silent mistakes such as inserting a function pointer (Foo) rather than a value (Foo::Bar) as a resource * it is challenging to discover if a type is intended to be used as a resource * we cannot later add customization options (see the [RFC](https://github.com/bevyengine/rfcs/blob/main/rfcs/27-derive-component.md) for the equivalent choice for Component). * dependencies can use the same Rust type as a resource in invisibly conflicting ways * raw Rust types used as resources cannot preserve privacy appropriately, as anyone able to access that type can read and write to internal values * we cannot capture a definitive list of possible resources to display to users in an editor ## Notes to reviewers * Review this commit-by-commit; there's effectively no back-tracking and there's a lot of churn in some of these commits. *ira: My commits are not as well organized :')* * I've relaxed the bound on Local to Send + Sync + 'static: I don't think these concerns apply there, so this can keep things simple. Storing e.g. a u32 in a Local is fine, because there's a variable name attached explaining what it does. * I think this is a bad place for the Resource trait to live, but I've left it in place to make reviewing easier. IMO that's best tackled with https://github.com/bevyengine/bevy/issues/4981. ## Changelog `Resource` is no longer automatically implemented for all matching types. Instead, use the new `#[derive(Resource)]` macro. ## Migration Guide Add `#[derive(Resource)]` to all types you are using as a resource. If you are using a third party type as a resource, wrap it in a tuple struct to bypass orphan rules. Consider deriving `Deref` and `DerefMut` to improve ergonomics. `ClearColor` no longer implements `Component`. Using `ClearColor` as a component in 0.8 did nothing. Use the `ClearColorConfig` in the `Camera3d` and `Camera2d` components instead. Co-authored-by: Alice <alice.i.cecile@gmail.com> Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: devil-ira <justthecooldude@gmail.com> Co-authored-by: Carter Anderson <mcanders1@gmail.com> |
||
|
danieleades
|
d8974e7c3d |
small and mostly pointless refactoring (#2934)
What is says on the tin. This has got more to do with making `clippy` slightly more *quiet* than it does with changing anything that might greatly impact readability or performance. that said, deriving `Default` for a couple of structs is a nice easy win |
||
|
Yilin Wei
|
d44c3cd150 |
Fix error message for the Component macro's component storage attribute. (#3534)
# Objective Fixes the error message for the `component` attribute when users use the wrong literals. |
||
|
Carter Anderson
|
ffecb05a0a |
Replace old renderer with new renderer (#3312)
This makes the [New Bevy Renderer](#2535) the default (and only) renderer. The new renderer isn't _quite_ ready for the final release yet, but I want as many people as possible to start testing it so we can identify bugs and address feedback prior to release. The examples are all ported over and operational with a few exceptions: * I removed a good portion of the examples in the `shader` folder. We still have some work to do in order to make these examples possible / ergonomic / worthwhile: #3120 and "high level shader material plugins" are the big ones. This is a temporary measure. * Temporarily removed the multiple_windows example: doing this properly in the new renderer will require the upcoming "render targets" changes. Same goes for the render_to_texture example. * Removed z_sort_debug: entity visibility sort info is no longer available in app logic. we could do this on the "render app" side, but i dont consider it a priority. |
||
|
Paweł Grabarz
|
07ed1d053e |
Implement and require #[derive(Component)] on all component structs (#2254)
This implements the most minimal variant of #1843 - a derive for marker trait. This is a prerequisite to more complicated features like statically defined storage type or opt-out component reflection. In order to make component struct's purpose explicit and avoid misuse, it must be annotated with `#[derive(Component)]` (manual impl is discouraged for compatibility). Right now this is just a marker trait, but in the future it might be expanded. Making this change early allows us to make further changes later without breaking backward compatibility for derive macro users. This already prevents a lot of issues, like using bundles in `insert` calls. Primitive types are no longer valid components as well. This can be easily worked around by adding newtype wrappers and deriving `Component` for them. One funny example of prevented bad code (from our own tests) is when an newtype struct or enum variant is used. Previously, it was possible to write `insert(Newtype)` instead of `insert(Newtype(value))`. That code compiled, because function pointers (in this case newtype struct constructor) implement `Send + Sync + 'static`, so we allowed them to be used as components. This is no longer the case and such invalid code will trigger a compile error. Co-authored-by: = <=> Co-authored-by: TheRawMeatball <therawmeatball@gmail.com> Co-authored-by: Carter Anderson <mcanders1@gmail.com> |