57e58ef997
223 Commits
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efd17f133d
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Rename num_entities to entity_count (#19781)
As discussed in https://github.com/bevyengine/bevy/pull/19780#issuecomment-2994554024. |
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6dbe3600ed
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Add num_entities() to World (#19780)
# Objective There is a lot of `world.entities().len()`, especially in tests. In tests, usually, the assumption is made that empty worlds do not contain any entities. This is about to change (#19711), and as such all of these tests are failing for that PR. ## Solution `num_entities` is a convenience method that returns the number of entities inside a world. It can later be adapted to exclude 'unexpected' entities, associated with internal data structures such as Resources, Queries, Systems. In general I argue for a separation of concepts where `World` ignores internal entities in methods such as `iter_entities()` and `clear_entities()`, that discussion is, however, separate from this PR. ## Testing I replaced most occurrences of `world.entities().len()` with `world.num_entities()` and the tests passed. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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38c3423693
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Event Split: Event , EntityEvent , and BufferedEvent (#19647)
# Objective Closes #19564. The current `Event` trait looks like this: ```rust pub trait Event: Send + Sync + 'static { type Traversal: Traversal<Self>; const AUTO_PROPAGATE: bool = false; fn register_component_id(world: &mut World) -> ComponentId { ... } fn component_id(world: &World) -> Option<ComponentId> { ... } } ``` The `Event` trait is used by both buffered events (`EventReader`/`EventWriter`) and observer events. If they are observer events, they can optionally be targeted at specific `Entity`s or `ComponentId`s, and can even be propagated to other entities. However, there has long been a desire to split the trait semantically for a variety of reasons, see #14843, #14272, and #16031 for discussion. Some reasons include: - It's very uncommon to use a single event type as both a buffered event and targeted observer event. They are used differently and tend to have distinct semantics. - A common footgun is using buffered events with observers or event readers with observer events, as there is no type-level error that prevents this kind of misuse. - #19440 made `Trigger::target` return an `Option<Entity>`. This *seriously* hurts ergonomics for the general case of entity observers, as you need to `.unwrap()` each time. If we could statically determine whether the event is expected to have an entity target, this would be unnecessary. There's really two main ways that we can categorize events: push vs. pull (i.e. "observer event" vs. "buffered event") and global vs. targeted: | | Push | Pull | | ------------ | --------------- | --------------------------- | | **Global** | Global observer | `EventReader`/`EventWriter` | | **Targeted** | Entity observer | - | There are many ways to approach this, each with their tradeoffs. Ultimately, we kind of want to split events both ways: - A type-level distinction between observer events and buffered events, to prevent people from using the wrong kind of event in APIs - A statically designated entity target for observer events to avoid accidentally using untargeted events for targeted APIs This PR achieves these goals by splitting event traits into `Event`, `EntityEvent`, and `BufferedEvent`, with `Event` being the shared trait implemented by all events. ## `Event`, `EntityEvent`, and `BufferedEvent` `Event` is now a very simple trait shared by all events. ```rust pub trait Event: Send + Sync + 'static { // Required for observer APIs fn register_component_id(world: &mut World) -> ComponentId { ... } fn component_id(world: &World) -> Option<ComponentId> { ... } } ``` You can call `trigger` for *any* event, and use a global observer for listening to the event. ```rust #[derive(Event)] struct Speak { message: String, } // ... app.add_observer(|trigger: On<Speak>| { println!("{}", trigger.message); }); // ... commands.trigger(Speak { message: "Y'all like these reworked events?".to_string(), }); ``` To allow an event to be targeted at entities and even propagated further, you can additionally implement the `EntityEvent` trait: ```rust pub trait EntityEvent: Event { type Traversal: Traversal<Self>; const AUTO_PROPAGATE: bool = false; } ``` This lets you call `trigger_targets`, and to use targeted observer APIs like `EntityCommands::observe`: ```rust #[derive(Event, EntityEvent)] #[entity_event(traversal = &'static ChildOf, auto_propagate)] struct Damage { amount: f32, } // ... let enemy = commands.spawn((Enemy, Health(100.0))).id(); // Spawn some armor as a child of the enemy entity. // When the armor takes damage, it will bubble the event up to the enemy. let armor_piece = commands .spawn((ArmorPiece, Health(25.0), ChildOf(enemy))) .observe(|trigger: On<Damage>, mut query: Query<&mut Health>| { // Note: `On::target` only exists because this is an `EntityEvent`. let mut health = query.get(trigger.target()).unwrap(); health.0 -= trigger.amount(); }); commands.trigger_targets(Damage { amount: 10.0 }, armor_piece); ``` > [!NOTE] > You *can* still also trigger an `EntityEvent` without targets using `trigger`. We probably *could* make this an either-or thing, but I'm not sure that's actually desirable. To allow an event to be used with the buffered API, you can implement `BufferedEvent`: ```rust pub trait BufferedEvent: Event {} ``` The event can then be used with `EventReader`/`EventWriter`: ```rust #[derive(Event, BufferedEvent)] struct Message(String); fn write_hello(mut writer: EventWriter<Message>) { writer.write(Message("I hope these examples are alright".to_string())); } fn read_messages(mut reader: EventReader<Message>) { // Process all buffered events of type `Message`. for Message(message) in reader.read() { println!("{message}"); } } ``` In summary: - Need a basic event you can trigger and observe? Derive `Event`! - Need the event to be targeted at an entity? Derive `EntityEvent`! - Need the event to be buffered and support the `EventReader`/`EventWriter` API? Derive `BufferedEvent`! ## Alternatives I'll now cover some of the alternative approaches I have considered and briefly explored. I made this section collapsible since it ended up being quite long :P <details> <summary>Expand this to see alternatives</summary> ### 1. Unified `Event` Trait One option is not to have *three* separate traits (`Event`, `EntityEvent`, `BufferedEvent`), and to instead just use associated constants on `Event` to determine whether an event supports targeting and buffering or not: ```rust pub trait Event: Send + Sync + 'static { type Traversal: Traversal<Self>; const AUTO_PROPAGATE: bool = false; const TARGETED: bool = false; const BUFFERED: bool = false; fn register_component_id(world: &mut World) -> ComponentId { ... } fn component_id(world: &World) -> Option<ComponentId> { ... } } ``` Methods can then use bounds like `where E: Event<TARGETED = true>` or `where E: Event<BUFFERED = true>` to limit APIs to specific kinds of events. This would keep everything under one `Event` trait, but I don't think it's necessarily a good idea. It makes APIs harder to read, and docs can't easily refer to specific types of events. You can also create weird invariants: what if you specify `TARGETED = false`, but have `Traversal` and/or `AUTO_PROPAGATE` enabled? ### 2. `Event` and `Trigger` Another option is to only split the traits between buffered events and observer events, since that is the main thing people have been asking for, and they have the largest API difference. If we did this, I think we would need to make the terms *clearly* separate. We can't really use `Event` and `BufferedEvent` as the names, since it would be strange that `BufferedEvent` doesn't implement `Event`. Something like `ObserverEvent` and `BufferedEvent` could work, but it'd be more verbose. For this approach, I would instead keep `Event` for the current `EventReader`/`EventWriter` API, and call the observer event a `Trigger`, since the "trigger" terminology is already used in the observer context within Bevy (both as a noun and a verb). This is also what a long [bikeshed on Discord](https://discord.com/channels/691052431525675048/749335865876021248/1298057661878898791) seemed to land on at the end of last year. ```rust // For `EventReader`/`EventWriter` pub trait Event: Send + Sync + 'static {} // For observers pub trait Trigger: Send + Sync + 'static { type Traversal: Traversal<Self>; const AUTO_PROPAGATE: bool = false; const TARGETED: bool = false; fn register_component_id(world: &mut World) -> ComponentId { ... } fn component_id(world: &World) -> Option<ComponentId> { ... } } ``` The problem is that "event" is just a really good term for something that "happens". Observers are rapidly becoming the more prominent API, so it'd be weird to give them the `Trigger` name and leave the good `Event` name for the less common API. So, even though a split like this seems neat on the surface, I think it ultimately wouldn't really work. We want to keep the `Event` name for observer events, and there is no good alternative for the buffered variant. (`Message` was suggested, but saying stuff like "sends a collision message" is weird.) ### 3. `GlobalEvent` + `TargetedEvent` What if instead of focusing on the buffered vs. observed split, we *only* make a distinction between global and targeted events? ```rust // A shared event trait to allow global observers to work pub trait Event: Send + Sync + 'static { fn register_component_id(world: &mut World) -> ComponentId { ... } fn component_id(world: &World) -> Option<ComponentId> { ... } } // For buffered events and non-targeted observer events pub trait GlobalEvent: Event {} // For targeted observer events pub trait TargetedEvent: Event { type Traversal: Traversal<Self>; const AUTO_PROPAGATE: bool = false; } ``` This is actually the first approach I implemented, and it has the neat characteristic that you can only use non-targeted APIs like `trigger` with a `GlobalEvent` and targeted APIs like `trigger_targets` with a `TargetedEvent`. You have full control over whether the entity should or should not have a target, as they are fully distinct at the type-level. However, there's a few problems: - There is no type-level indication of whether a `GlobalEvent` supports buffered events or just non-targeted observer events - An `Event` on its own does literally nothing, it's just a shared trait required to make global observers accept both non-targeted and targeted events - If an event is both a `GlobalEvent` and `TargetedEvent`, global observers again have ambiguity on whether an event has a target or not, undermining some of the benefits - The names are not ideal ### 4. `Event` and `EntityEvent` We can fix some of the problems of Alternative 3 by accepting that targeted events can also be used in non-targeted contexts, and simply having the `Event` and `EntityEvent` traits: ```rust // For buffered events and non-targeted observer events pub trait Event: Send + Sync + 'static { fn register_component_id(world: &mut World) -> ComponentId { ... } fn component_id(world: &World) -> Option<ComponentId> { ... } } // For targeted observer events pub trait EntityEvent: Event { type Traversal: Traversal<Self>; const AUTO_PROPAGATE: bool = false; } ``` This is essentially identical to this PR, just without a dedicated `BufferedEvent`. The remaining major "problem" is that there is still zero type-level indication of whether an `Event` event *actually* supports the buffered API. This leads us to the solution proposed in this PR, using `Event`, `EntityEvent`, and `BufferedEvent`. </details> ## Conclusion The `Event` + `EntityEvent` + `BufferedEvent` split proposed in this PR aims to solve all the common problems with Bevy's current event model while keeping the "weirdness" factor minimal. It splits in terms of both the push vs. pull *and* global vs. targeted aspects, while maintaining a shared concept for an "event". ### Why I Like This - The term "event" remains as a single concept for all the different kinds of events in Bevy. - Despite all event types being "events", they use fundamentally different APIs. Instead of assuming that you can use an event type with any pattern (when only one is typically supported), you explicitly opt in to each one with dedicated traits. - Using separate traits for each type of event helps with documentation and clearer function signatures. - I can safely make assumptions on expected usage. - If I see that an event is an `EntityEvent`, I can assume that I can use `observe` on it and get targeted events. - If I see that an event is a `BufferedEvent`, I can assume that I can use `EventReader` to read events. - If I see both `EntityEvent` and `BufferedEvent`, I can assume that both APIs are supported. In summary: This allows for a unified concept for events, while limiting the different ways to use them with opt-in traits. No more guess-work involved when using APIs. ### Problems? - Because `BufferedEvent` implements `Event` (for more consistent semantics etc.), you can still use all buffered events for non-targeted observers. I think this is fine/good. The important part is that if you see that an event implements `BufferedEvent`, you know that the `EventReader`/`EventWriter` API should be supported. Whether it *also* supports other APIs is secondary. - I currently only support `trigger_targets` for an `EntityEvent`. However, you can technically target components too, without targeting any entities. I consider that such a niche and advanced use case that it's not a huge problem to only support it for `EntityEvent`s, but we could also split `trigger_targets` into `trigger_entities` and `trigger_components` if we wanted to (or implement components as entities :P). - You can still trigger an `EntityEvent` *without* targets. I consider this correct, since `Event` implements the non-targeted behavior, and it'd be weird if implementing another trait *removed* behavior. However, it does mean that global observers for entity events can technically return `Entity::PLACEHOLDER` again (since I got rid of the `Option<Entity>` added in #19440 for ergonomics). I think that's enough of an edge case that it's not a huge problem, but it is worth keeping in mind. - ~~Deriving both `EntityEvent` and `BufferedEvent` for the same type currently duplicates the `Event` implementation, so you instead need to manually implement one of them.~~ Changed to always requiring `Event` to be derived. ## Related Work There are plans to implement multi-event support for observers, especially for UI contexts. [Cart's example](https://github.com/bevyengine/bevy/issues/14649#issuecomment-2960402508) API looked like this: ```rust // Truncated for brevity trigger: Trigger<( OnAdd<Pressed>, OnRemove<Pressed>, OnAdd<InteractionDisabled>, OnRemove<InteractionDisabled>, OnInsert<Hovered>, )>, ``` I believe this shouldn't be in conflict with this PR. If anything, this PR might *help* achieve the multi-event pattern for entity observers with fewer footguns: by statically enforcing that all of these events are `EntityEvent`s in the context of `EntityCommands::observe`, we can avoid misuse or weird cases where *some* events inside the trigger are targeted while others are not. |
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58c276ab44
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Make the ObservedBy component useful to public consumers (#19591)
# Objective As raised by @Jondolf, this type is `pub`, and useful for various consumers to ensure cleanup or debugging. However, it doesn't offer any way to actually view the data. ## Solution - Add a read-only view of the data. - Don't add any (easy) way to mutate the data, as this presents a huge footgun. - Implement Reflect and register the component so you can see it in inspectors nicely. |
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e5dc177b4b
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Rename Trigger to On (#19596)
# Objective Currently, the observer API looks like this: ```rust app.add_observer(|trigger: Trigger<Explode>| { info!("Entity {} exploded!", trigger.target()); }); ``` Future plans for observers also include "multi-event observers" with a trigger that looks like this (see [Cart's example](https://github.com/bevyengine/bevy/issues/14649#issuecomment-2960402508)): ```rust trigger: Trigger<( OnAdd<Pressed>, OnRemove<Pressed>, OnAdd<InteractionDisabled>, OnRemove<InteractionDisabled>, OnInsert<Hovered>, )>, ``` In scenarios like this, there is a lot of repetition of `On`. These are expected to be very high-traffic APIs especially in UI contexts, so ergonomics and readability are critical. By renaming `Trigger` to `On`, we can make these APIs read more cleanly and get rid of the repetition: ```rust app.add_observer(|trigger: On<Explode>| { info!("Entity {} exploded!", trigger.target()); }); ``` ```rust trigger: On<( Add<Pressed>, Remove<Pressed>, Add<InteractionDisabled>, Remove<InteractionDisabled>, Insert<Hovered>, )>, ``` Names like `On<Add<Pressed>>` emphasize the actual event listener nature more than `Trigger<OnAdd<Pressed>>`, and look cleaner. This *also* frees up the `Trigger` name if we want to use it for the observer event type, splitting them out from buffered events (bikeshedding this is out of scope for this PR though). For prior art: [`bevy_eventlistener`](https://github.com/aevyrie/bevy_eventlistener) used [`On`](https://docs.rs/bevy_eventlistener/latest/bevy_eventlistener/event_listener/struct.On.html) for its event listener type. Though in our case, the observer is the event listener, and `On` is just a type containing information about the triggered event. ## Solution Steal from `bevy_event_listener` by @aevyrie and use `On`. - Rename `Trigger` to `On` - Rename `OnAdd` to `Add` - Rename `OnInsert` to `Insert` - Rename `OnReplace` to `Replace` - Rename `OnRemove` to `Remove` - Rename `OnDespawn` to `Despawn` ## Discussion ### Naming Conflicts?? Using a name like `Add` might initially feel like a very bad idea, since it risks conflict with `core::ops::Add`. However, I don't expect this to be a big problem in practice. - You rarely need to actually implement the `Add` trait, especially in modules that would use the Bevy ECS. - In the rare cases where you *do* get a conflict, it is very easy to fix by just disambiguating, for example using `ops::Add`. - The `Add` event is a struct while the `Add` trait is a trait (duh), so the compiler error should be very obvious. For the record, renaming `OnAdd` to `Add`, I got exactly *zero* errors or conflicts within Bevy itself. But this is of course not entirely representative of actual projects *using* Bevy. You might then wonder, why not use `Added`? This would conflict with the `Added` query filter, so it wouldn't work. Additionally, the current naming convention for observer events does not use past tense. ### Documentation This does make documentation slightly more awkward when referring to `On` or its methods. Previous docs often referred to `Trigger::target` or "sends a `Trigger`" (which is... a bit strange anyway), which would now be `On::target` and "sends an observer `Event`". You can see the diff in this PR to see some of the effects. I think it should be fine though, we may just need to reword more documentation to read better. |
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6ddd0f16a8
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Component lifecycle reorganization and documentation (#19543)
# Objective I set out with one simple goal: clearly document the differences between each of the component lifecycle events via module docs. Unfortunately, no such module existed: the various lifecycle code was scattered to the wind. Without a unified module, it's very hard to discover the related types, and there's nowhere good to put my shiny new documentation. ## Solution 1. Unify the assorted types into a single `bevy_ecs::component_lifecycle` module. 2. Write docs. 3. Write a migration guide. ## Testing Thanks CI! ## Follow-up 1. The lifecycle event names are pretty confusing, especially `OnReplace`. We should consider renaming those. No bikeshedding in my PR though! 2. Observers need real module docs too :( 3. Any additional functional changes should be done elsewhere; this is a simple docs and re-org PR. --------- Co-authored-by: theotherphil <phil.j.ellison@gmail.com> |
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54c9f03021
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Mention in .add_observer() docs that first parameter must be a Trigger (#19315)
# Objective Fix https://github.com/bevyengine/bevy/issues/13860 ## Solution Add note in docs that Trigger must be the first parameter of observer systems |
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e7e9973c80
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Per world error handler (#18810)
# Objective [see original comment](https://github.com/bevyengine/bevy/pull/18801#issuecomment-2796981745) > Alternately, could we store it on the World instead of a global? I think we have a World nearby whenever we call default_error_handler(). That would avoid the need for atomics or locks, since we could do ordinary reads and writes to the World. Global error handlers don't actually need to be global – per world is enough. This allows using different handlers for different worlds and also removes the restrictions on changing the handler only once. ## Solution Each `World` can now store its own error handler in a resource. For convenience, you can also set the default error handler for an `App`, which applies it to the worlds of all `SubApp`s. The old behavior of only being able to set the error handler once is kept for apps. We also don't need the `configurable_error_handler` feature anymore now. ## Testing New/adjusted tests for failing schedule systems & observers. --- ## Showcase ```rust App::new() .set_error_handler(info) … ``` |
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7b1c9f192e
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Adopt consistent FooSystems naming convention for system sets (#18900)
# Objective Fixes a part of #14274. Bevy has an incredibly inconsistent naming convention for its system sets, both internally and across the ecosystem. <img alt="System sets in Bevy" src="https://github.com/user-attachments/assets/d16e2027-793f-4ba4-9cc9-e780b14a5a1b" width="450" /> *Names of public system set types in Bevy* Most Bevy types use a naming of `FooSystem` or just `Foo`, but there are also a few `FooSystems` and `FooSet` types. In ecosystem crates on the other hand, `FooSet` is perhaps the most commonly used name in general. Conventions being so wildly inconsistent can make it harder for users to pick names for their own types, to search for system sets on docs.rs, or to even discern which types *are* system sets. To reign in the inconsistency a bit and help unify the ecosystem, it would be good to establish a common recommended naming convention for system sets in Bevy itself, similar to how plugins are commonly suffixed with `Plugin` (ex: `TimePlugin`). By adopting a consistent naming convention in first-party Bevy, we can softly nudge ecosystem crates to follow suit (for types where it makes sense to do so). Choosing a naming convention is also relevant now, as the [`bevy_cli` recently adopted lints](https://github.com/TheBevyFlock/bevy_cli/pull/345) to enforce naming for plugins and system sets, and the recommended naming used for system sets is still a bit open. ## Which Name To Use? Now the contentious part: what naming convention should we actually adopt? This was discussed on the Bevy Discord at the end of last year, starting [here](<https://discord.com/channels/691052431525675048/692572690833473578/1310659954683936789>). `FooSet` and `FooSystems` were the clear favorites, with `FooSet` very narrowly winning an unofficial poll. However, it seems to me like the consensus was broadly moving towards `FooSystems` at the end and after the poll, with Cart ([source](https://discord.com/channels/691052431525675048/692572690833473578/1311140204974706708)) and later Alice ([source](https://discord.com/channels/691052431525675048/692572690833473578/1311092530732859533)) and also me being in favor of it. Let's do a quick pros and cons list! Of course these are just what I thought of, so take it with a grain of salt. `FooSet`: - Pro: Nice and short! - Pro: Used by many ecosystem crates. - Pro: The `Set` suffix comes directly from the trait name `SystemSet`. - Pro: Pairs nicely with existing APIs like `in_set` and `configure_sets`. - Con: `Set` by itself doesn't actually indicate that it's related to systems *at all*, apart from the implemented trait. A set of what? - Con: Is `FooSet` a set of `Foo`s or a system set related to `Foo`? Ex: `ContactSet`, `MeshSet`, `EnemySet`... `FooSystems`: - Pro: Very clearly indicates that the type represents a collection of systems. The actual core concept, system(s), is in the name. - Pro: Parallels nicely with `FooPlugins` for plugin groups. - Pro: Low risk of conflicts with other names or misunderstandings about what the type is. - Pro: In most cases, reads *very* nicely and clearly. Ex: `PhysicsSystems` and `AnimationSystems` as opposed to `PhysicsSet` and `AnimationSet`. - Pro: Easy to search for on docs.rs. - Con: Usually results in longer names. - Con: Not yet as widely used. Really the big problem with `FooSet` is that it doesn't actually describe what it is. It describes what *kind of thing* it is (a set of something), but not *what it is a set of*, unless you know the type or check its docs or implemented traits. `FooSystems` on the other hand is much more self-descriptive in this regard, at the cost of being a bit longer to type. Ultimately, in some ways it comes down to preference and how you think of system sets. Personally, I was originally in favor of `FooSet`, but have been increasingly on the side of `FooSystems`, especially after seeing what the new names would actually look like in Avian and now Bevy. I prefer it because it usually reads better, is much more clearly related to groups of systems than `FooSet`, and overall *feels* more correct and natural to me in the long term. For these reasons, and because Alice and Cart also seemed to share a preference for it when it was previously being discussed, I propose that we adopt a `FooSystems` naming convention where applicable. ## Solution Rename Bevy's system set types to use a consistent `FooSet` naming where applicable. - `AccessibilitySystem` → `AccessibilitySystems` - `GizmoRenderSystem` → `GizmoRenderSystems` - `PickSet` → `PickingSystems` - `RunFixedMainLoopSystem` → `RunFixedMainLoopSystems` - `TransformSystem` → `TransformSystems` - `RemoteSet` → `RemoteSystems` - `RenderSet` → `RenderSystems` - `SpriteSystem` → `SpriteSystems` - `StateTransitionSteps` → `StateTransitionSystems` - `RenderUiSystem` → `RenderUiSystems` - `UiSystem` → `UiSystems` - `Animation` → `AnimationSystems` - `AssetEvents` → `AssetEventSystems` - `TrackAssets` → `AssetTrackingSystems` - `UpdateGizmoMeshes` → `GizmoMeshSystems` - `InputSystem` → `InputSystems` - `InputFocusSet` → `InputFocusSystems` - `ExtractMaterialsSet` → `MaterialExtractionSystems` - `ExtractMeshesSet` → `MeshExtractionSystems` - `RumbleSystem` → `RumbleSystems` - `CameraUpdateSystem` → `CameraUpdateSystems` - `ExtractAssetsSet` → `AssetExtractionSystems` - `Update2dText` → `Text2dUpdateSystems` - `TimeSystem` → `TimeSystems` - `AudioPlaySet` → `AudioPlaybackSystems` - `SendEvents` → `EventSenderSystems` - `EventUpdates` → `EventUpdateSystems` A lot of the names got slightly longer, but they are also a lot more consistent, and in my opinion the majority of them read much better. For a few of the names I took the liberty of rewording things a bit; definitely open to any further naming improvements. There are still also cases where the `FooSystems` naming doesn't really make sense, and those I left alone. This primarily includes system sets like `Interned<dyn SystemSet>`, `EnterSchedules<S>`, `ExitSchedules<S>`, or `TransitionSchedules<S>`, where the type has some special purpose and semantics. ## Todo - [x] Should I keep all the old names as deprecated type aliases? I can do this, but to avoid wasting work I'd prefer to first reach consensus on whether these renames are even desired. - [x] Migration guide - [x] Release notes |
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e9a0ef49f9
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Rename bevy_platform_support to bevy_platform (#18813)
# Objective The goal of `bevy_platform_support` is to provide a set of platform agnostic APIs, alongside platform-specific functionality. This is a high traffic crate (providing things like HashMap and Instant). Especially in light of https://github.com/bevyengine/bevy/discussions/18799, it deserves a friendlier / shorter name. Given that it hasn't had a full release yet, getting this change in before Bevy 0.16 makes sense. ## Solution - Rename `bevy_platform_support` to `bevy_platform`. |
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5d0505a85e
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Unify and simplify command and system error handling (#18351)
# Objective - ECS error handling is a lovely flagship feature for Bevy 0.16, all in the name of reducing panics and encouraging better error handling (#14275). - Currently though, command and system error handling are completely disjoint and use different mechanisms. - Additionally, there's a number of distinct ways to set the default/fallback/global error handler that have limited value. As far as I can tell, this will be cfg flagged to toggle between dev and production builds in 99.9% of cases, with no real value in more granular settings or helpers. - Fixes #17272 ## Solution - Standardize error handling on the OnceLock global error mechanisms ironed out in https://github.com/bevyengine/bevy/pull/17215 - As discussed there, there are serious performance concerns there, especially for commands - I also think this is a better fit for the use cases, as it's truly global - Move from `SystemErrorContext` to a more general purpose `ErrorContext`, which can handle observers and commands more clearly - Cut the superfluous setter methods on `App` and `SubApp` - Rename the limited (and unhelpful) `fallible_systems` example to `error_handling`, and add an example of command error handling ## Testing Ran the `error_handling` example. ## Notes for reviewers - Do you see a clear way to allow commands to retain &mut World access in the per-command custom error handlers? IMO that's a key feature here (allowing the ad-hoc creation of custom commands), but I'm not sure how to get there without exploding complexity. - I've removed the feature gate on the default_error_handler: contrary to @cart's opinion in #17215 I think that virtually all apps will want to use this. Can you think of a category of app that a) is extremely performance sensitive b) is fine with shipping to production with the panic error handler? If so, I can try to gather performance numbers and/or reintroduce the feature flag. UPDATE: see benches at the end of this message. - ~~`OnceLock` is in `std`: @bushrat011899 what should we do here?~~ - Do you have ideas for more automated tests for this collection of features? ## Benchmarks I checked the impact of the feature flag introduced: benchmarks might show regressions. This bears more investigation. I'm still skeptical that there are users who are well-served by a fast always panicking approach, but I'm going to re-add the feature flag here to avoid stalling this out.  --------- Co-authored-by: Zachary Harrold <zac@harrold.com.au> |
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ab0e3f8714
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Small cleanup for ECS error handling (#18280)
# Objective While poking at https://github.com/bevyengine/bevy/issues/17272, I noticed a few small things to clean up. ## Solution - Improve the docs - ~~move `SystemErrorContext` out of the `handler.rs` module: it's not an error handler~~ |
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ecccd57417
|
Generic system config (#17962)
# Objective Prevents duplicate implementation between IntoSystemConfigs and IntoSystemSetConfigs using a generic, adds a NodeType trait for more config flexibility (opening the door to implement https://github.com/bevyengine/bevy/issues/14195?). ## Solution Followed writeup by @ItsDoot: https://hackmd.io/@doot/rJeefFHc1x Removes IntoSystemConfigs and IntoSystemSetConfigs, instead using IntoNodeConfigs with generics. ## Testing Pending --- ## Showcase N/A ## Migration Guide SystemSetConfigs -> NodeConfigs<InternedSystemSet> SystemConfigs -> NodeConfigs<ScheduleSystem> IntoSystemSetConfigs -> IntoNodeConfigs<InternedSystemSet, M> IntoSystemConfigs -> IntoNodeConfigs<ScheduleSystem, M> --------- Co-authored-by: Christian Hughes <9044780+ItsDoot@users.noreply.github.com> Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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c6204279eb
|
Support for non-browser wasm (#17499)
# Objective - Contributes to #15460 - Supersedes #8520 - Fixes #4906 ## Solution - Added a new `web` feature to `bevy`, and several of its crates. - Enabled new `web` feature automatically within crates without `no_std` support. ## Testing - `cargo build --no-default-features --target wasm32v1-none` --- ## Migration Guide When using Bevy crates which _don't_ automatically enable the `web` feature, please enable it when building for the browser. ## Notes - I added [`cfg_if`](https://crates.io/crates/cfg-if) to help manage some of the feature gate gore that this extra feature introduces. It's still pretty ugly, but I think much easier to read. - Certain `wasm` targets (e.g., [wasm32-wasip1](https://doc.rust-lang.org/nightly/rustc/platform-support/wasm32-wasip1.html#wasm32-wasip1)) provide an incomplete implementation for `std`. I have not tested these platforms, but I suspect Bevy's liberal use of usually unsupported features (e.g., threading) will cause these targets to fail. As such, consider `wasm32-unknown-unknown` as the only `wasm` platform with support from Bevy for `std`. All others likely will need to be treated as `no_std` platforms. |
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cc69fdd0c6
|
Add no_std support to bevy (#17955)
# Objective - Fixes #15460 (will open new issues for further `no_std` efforts) - Supersedes #17715 ## Solution - Threaded in new features as required - Made certain crates optional but default enabled - Removed `compile-check-no-std` from internal `ci` tool since GitHub CI can now simply check `bevy` itself now - Added CI task to check `bevy` on `thumbv6m-none-eabi` to ensure `portable-atomic` support is still valid [^1] [^1]: This may be controversial, since it could be interpreted as implying Bevy will maintain support for `thumbv6m-none-eabi` going forward. In reality, just like `x86_64-unknown-none`, this is a [canary](https://en.wiktionary.org/wiki/canary_in_a_coal_mine) target to make it clear when `portable-atomic` no longer works as intended (fixing atomic support on atomically challenged platforms). If a PR comes through and makes supporting this class of platforms impossible, then this CI task can be removed. I however wager this won't be a problem. ## Testing - CI --- ## Release Notes Bevy now has support for `no_std` directly from the `bevy` crate. Users can disable default features and enable a new `default_no_std` feature instead, allowing `bevy` to be used in `no_std` applications and libraries. ```toml # Bevy for `no_std` platforms bevy = { version = "0.16", default-features = false, features = ["default_no_std"] } ``` `default_no_std` enables certain required features, such as `libm` and `critical-section`, and as many optional crates as possible (currently just `bevy_state`). For atomically-challenged platforms such as the Raspberry Pi Pico, `portable-atomic` will be used automatically. For library authors, we recommend depending on `bevy` with `default-features = false` to allow `std` and `no_std` users to both depend on your crate. Here are some recommended features a library crate may want to expose: ```toml [features] # Most users will be on a platform which has `std` and can use the more-powerful `async_executor`. default = ["std", "async_executor"] # Features for typical platforms. std = ["bevy/std"] async_executor = ["bevy/async_executor"] # Features for `no_std` platforms. libm = ["bevy/libm"] critical-section = ["bevy/critical-section"] [dependencies] # We disable default features to ensure we don't accidentally enable `std` on `no_std` targets, for example. bevy = { version = "0.16", default-features = false } ``` While this is verbose, it gives the maximum control to end-users to decide how they wish to use Bevy on their platform. We encourage library authors to experiment with `no_std` support. For libraries relying exclusively on `bevy` and no other dependencies, it may be as simple as adding `#![no_std]` to your `lib.rs` and exposing features as above! Bevy can also provide many `std` types, such as `HashMap`, `Mutex`, and `Instant` on all platforms. See `bevy::platform_support` for details on what's available out of the box! ## Migration Guide - If you were previously relying on `bevy` with default features disabled, you may need to enable the `std` and `async_executor` features. - `bevy_reflect` has had its `bevy` feature removed. If you were relying on this feature, simply enable `smallvec` and `smol_str` instead. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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cca5813472
|
BevyError: Bevy's new catch-all error type (#18144)
## Objective Fixes #18092 Bevy's current error type is a simple type alias for `Box<dyn Error + Send + Sync + 'static>`. This largely works as a catch-all error, but it is missing a critical feature: the ability to capture a backtrace at the point that the error occurs. The best way to do this is `anyhow`-style error handling: a new error type that takes advantage of the fact that the `?` `From` conversion happens "inline" to capture the backtrace at the point of the error. ## Solution This PR adds a new `BevyError` type (replacing our old `std::error::Error` type alias), which uses the "from conversion backtrace capture" approach: ```rust fn oh_no() -> Result<(), BevyError> { // this fails with Rust's built in ParseIntError, which // is converted into the catch-all BevyError type let number: usize = "hi".parse()?; println!("parsed {number}"); Ok(()) } ``` This also updates our exported `Result` type alias to default to `BevyError`, meaning you can write this instead: ```rust fn oh_no() -> Result { let number: usize = "hi".parse()?; println!("parsed {number}"); Ok(()) } ``` When a BevyError is encountered in a system, it will use Bevy's default system error handler (which panics by default). BevyError does custom "backtrace filtering" by default, meaning we can cut out the _massive_ amount of "rust internals", "async executor internals", and "bevy system scheduler internals" that show up in backtraces. It also trims out the first generally-unnecssary `From` conversion backtrace lines that make it harder to locate the real error location. The result is a blissfully simple backtrace by default:  The full backtrace can be shown by setting the `BEVY_BACKTRACE=full` environment variable. Non-BevyError panics still use the default Rust backtrace behavior. One issue that prevented the truly noise-free backtrace during panics that you see above is that Rust's default panic handler will print the unfiltered (and largely unhelpful real-panic-point) backtrace by default, in _addition_ to our filtered BevyError backtrace (with the helpful backtrace origin) that we capture and print. To resolve this, I have extended Bevy's existing PanicHandlerPlugin to wrap the default panic handler. If we panic from the result of a BevyError, we will skip the default "print full backtrace" panic handler. This behavior can be enabled and disabled using the new `error_panic_hook` cargo feature in `bevy_app` (which is enabled by default). One downside to _not_ using `Box<dyn Error>` directly is that we can no longer take advantage of the built-in `Into` impl for strings to errors. To resolve this, I have added the following: ```rust // Before Err("some error")? // After Err(BevyError::message("some error"))? ``` We can discuss adding shorthand methods or macros for this (similar to anyhow's `anyhow!("some error")` macro), but I'd prefer to discuss that later. I have also added the following extension method: ```rust // Before some_option.ok_or("some error")?; // After some_option.ok_or_message("some error")?; ``` I've also moved all of our existing error infrastructure from `bevy_ecs::result` to `bevy_ecs::error`, as I think that is the better home for it ## Why not anyhow (or eyre)? The biggest reason is that `anyhow` needs to be a "generically useful error type", whereas Bevy is a much narrower scope. By using our own error, we can be significantly more opinionated. For example, anyhow doesn't do the extensive (and invasive) backtrace filtering that BevyError does because it can't operate on Bevy-specific context, and needs to be generically useful. Bevy also has a lot of operational context (ex: system info) that could be useful to attach to errors. If we have control over the error type, we can add whatever context we want to in a structured way. This could be increasingly useful as we add more visual / interactive error handling tools and editor integrations. Additionally, the core approach used is simple and requires almost no code. anyhow clocks in at ~2500 lines of code, but the impl here uses 160. We are able to boil this down to exactly what we need, and by doing so we improve our compile times and the understandability of our code. |
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5241e09671
|
Upgrade to Rust Edition 2024 (#17967)
# Objective - Fixes #17960 ## Solution - Followed the [edition upgrade guide](https://doc.rust-lang.org/edition-guide/editions/transitioning-an-existing-project-to-a-new-edition.html) ## Testing - CI --- ## Summary of Changes ### Documentation Indentation When using lists in documentation, proper indentation is now linted for. This means subsequent lines within the same list item must start at the same indentation level as the item. ```rust /* Valid */ /// - Item 1 /// Run-on sentence. /// - Item 2 struct Foo; /* Invalid */ /// - Item 1 /// Run-on sentence. /// - Item 2 struct Foo; ``` ### Implicit `!` to `()` Conversion `!` (the never return type, returned by `panic!`, etc.) no longer implicitly converts to `()`. This is particularly painful for systems with `todo!` or `panic!` statements, as they will no longer be functions returning `()` (or `Result<()>`), making them invalid systems for functions like `add_systems`. The ideal fix would be to accept functions returning `!` (or rather, _not_ returning), but this is blocked on the [stabilisation of the `!` type itself](https://doc.rust-lang.org/std/primitive.never.html), which is not done. The "simple" fix would be to add an explicit `-> ()` to system signatures (e.g., `|| { todo!() }` becomes `|| -> () { todo!() }`). However, this is _also_ banned, as there is an existing lint which (IMO, incorrectly) marks this as an unnecessary annotation. So, the "fix" (read: workaround) is to put these kinds of `|| -> ! { ... }` closuers into variables and give the variable an explicit type (e.g., `fn()`). ```rust // Valid let system: fn() = || todo!("Not implemented yet!"); app.add_systems(..., system); // Invalid app.add_systems(..., || todo!("Not implemented yet!")); ``` ### Temporary Variable Lifetimes The order in which temporary variables are dropped has changed. The simple fix here is _usually_ to just assign temporaries to a named variable before use. ### `gen` is a keyword We can no longer use the name `gen` as it is reserved for a future generator syntax. This involved replacing uses of the name `gen` with `r#gen` (the raw-identifier syntax). ### Formatting has changed Use statements have had the order of imports changed, causing a substantial +/-3,000 diff when applied. For now, I have opted-out of this change by amending `rustfmt.toml` ```toml style_edition = "2021" ``` This preserves the original formatting for now, reducing the size of this PR. It would be a simple followup to update this to 2024 and run `cargo fmt`. ### New `use<>` Opt-Out Syntax Lifetimes are now implicitly included in RPIT types. There was a handful of instances where it needed to be added to satisfy the borrow checker, but there may be more cases where it _should_ be added to avoid breakages in user code. ### `MyUnitStruct { .. }` is an invalid pattern Previously, you could match against unit structs (and unit enum variants) with a `{ .. }` destructuring. This is no longer valid. ### Pretty much every use of `ref` and `mut` are gone Pattern binding has changed to the point where these terms are largely unused now. They still serve a purpose, but it is far more niche now. ### `iter::repeat(...).take(...)` is bad New lint recommends using the more explicit `iter::repeat_n(..., ...)` instead. ## Migration Guide The lifetimes of functions using return-position impl-trait (RPIT) are likely _more_ conservative than they had been previously. If you encounter lifetime issues with such a function, please create an issue to investigate the addition of `+ use<...>`. ## Notes - Check the individual commits for a clearer breakdown for what _actually_ changed. --------- Co-authored-by: François Mockers <francois.mockers@vleue.com> |
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5f86668bbb
|
Renamed EventWriter::send methods to write . (#17977)
Fixes #17856. ## Migration Guide - `EventWriter::send` has been renamed to `EventWriter::write`. - `EventWriter::send_batch` has been renamed to `EventWriter::write_batch`. - `EventWriter::send_default` has been renamed to `EventWriter::write_default`. --------- Co-authored-by: François Mockers <mockersf@gmail.com> |
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6bcb2b633b
|
Remove unused #[must_used] (#17959)
# Objective - Fixed CI compilation failure on Rust Nightly 1.87 due to [this PR](https://github.com/rust-lang/rust/pull/136923) ## Solution - Removed unused `#[must_use]` ## Testing - cargo +nightly check --target wasm32-unknown-unknown -Z build-std=std,panic_abort |
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fd67ca7eb0
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feat(ecs): configurable error handling for fallible systems (#17753)
You can now configure error handlers for fallible systems. These can be configured on several levels: - Globally via `App::set_systems_error_handler` - Per-schedule via `Schedule::set_error_handler` - Per-system via a piped system (this is existing functionality) The default handler of panicking on error keeps the same behavior as before this commit. The "fallible_systems" example demonstrates the new functionality. This builds on top of #17731, #16589, #17051. --------- Signed-off-by: Jean Mertz <git@jeanmertz.com> |
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fcc77fe3d6
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Allow users to register their own disabling components / default query filters (#17768)
# Objective Currently, default query filters, as added in #13120 / #17514 are hardcoded to only use a single query filter. This is limiting, as multiple distinct disabling components can serve important distinct roles. I ran into this limitation when experimenting with a workflow for prefabs, which don't represent the same state as "an entity which is temporarily nonfunctional". ## Solution 1. Change `DefaultQueryFilters` to store a SmallVec of ComponentId, rather than an Option. 2. Expose methods on `DefaultQueryFilters`, `World` and `App` to actually configure this. 3. While we're here, improve the docs, write some tests, make use of FromWorld and make some method names more descriptive. ## Follow-up I'm not convinced that supporting sparse set disabling components is useful, given the hit to iteration performance and runtime checks incurred. That's disjoint from this PR though, so I'm not doing it here. The existing warnings are fine for now. ## Testing I've added both a doc test and an mid-level unit test to verify that this works! |
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1b7db895b7
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Harden proc macro path resolution and add integration tests. (#17330)
This pr uses the `extern crate self as` trick to make proc macros behave the same way inside and outside bevy. # Objective - Removes noise introduced by `crate as` in the whole bevy repo. - Fixes #17004. - Hardens proc macro path resolution. ## TODO - [x] `BevyManifest` needs cleanup. - [x] Cleanup remaining `crate as`. - [x] Add proper integration tests to the ci. ## Notes - `cargo-manifest-proc-macros` is written by me and based/inspired by the old `BevyManifest` implementation and [`bkchr/proc-macro-crate`](https://github.com/bkchr/proc-macro-crate). - What do you think about the new integration test machinery I added to the `ci`? More and better integration tests can be added at a later stage. The goal of these integration tests is to simulate an actual separate crate that uses bevy. Ideally they would lightly touch all bevy crates. ## Testing - Needs RA test - Needs testing from other users - Others need to run at least `cargo run -p ci integration-test` and verify that they work. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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9bc0ae33c3
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Move hashbrown and foldhash out of bevy_utils (#17460)
# Objective - Contributes to #16877 ## Solution - Moved `hashbrown`, `foldhash`, and related types out of `bevy_utils` and into `bevy_platform_support` - Refactored the above to match the layout of these types in `std`. - Updated crates as required. ## Testing - CI --- ## Migration Guide - The following items were moved out of `bevy_utils` and into `bevy_platform_support::hash`: - `FixedState` - `DefaultHasher` - `RandomState` - `FixedHasher` - `Hashed` - `PassHash` - `PassHasher` - `NoOpHash` - The following items were moved out of `bevy_utils` and into `bevy_platform_support::collections`: - `HashMap` - `HashSet` - `bevy_utils::hashbrown` has been removed. Instead, import from `bevy_platform_support::collections` _or_ take a dependency on `hashbrown` directly. - `bevy_utils::Entry` has been removed. Instead, import from `bevy_platform_support::collections::hash_map` or `bevy_platform_support::collections::hash_set` as appropriate. - All of the above equally apply to `bevy::utils` and `bevy::platform_support`. ## Notes - I left `PreHashMap`, `PreHashMapExt`, and `TypeIdMap` in `bevy_utils` as they might be candidates for micro-crating. They can always be moved into `bevy_platform_support` at a later date if desired. |
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44ad3bf62b
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Move Resource trait to its own file (#17469)
# Objective `bevy_ecs`'s `system` module is something of a grab bag, and *very* large. This is particularly true for the `system_param` module, which is more than 2k lines long! While it could be defensible to put `Res` and `ResMut` there (lol no they're in change_detection.rs, obviously), it doesn't make any sense to put the `Resource` trait there. This is confusing to navigate (and painful to work on and review). ## Solution - Create a root level `bevy_ecs/resource.rs` module to mirror `bevy_ecs/component.rs` - move the `Resource` trait to that module - move the `Resource` derive macro to that module as well (Rust really likes when you pun on the names of the derive macro and trait and put them in the same path) - fix all of the imports ## Notes to reviewers - We could probably move more stuff into here, but I wanted to keep this PR as small as possible given the absurd level of import changes. - This PR is ground work for my upcoming attempts to store resource data on components (resources-as-entities). Splitting this code out will make the work and review a bit easier, and is the sort of overdue refactor that's good to do as part of more meaningful work. ## Testing cargo build works! ## Migration Guide `bevy_ecs::system::Resource` has been moved to `bevy_ecs::resource::Resource`. |
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ba5e71f53d
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Parent -> ChildOf (#17427)
Fixes #17412 ## Objective `Parent` uses the "has a X" naming convention. There is increasing sentiment that we should use the "is a X" naming convention for relationships (following #17398). This leaves `Children` as-is because there is prevailing sentiment that `Children` is clearer than `ParentOf` in many cases (especially when treating it like a collection). This renames `Parent` to `ChildOf`. This is just the implementation PR. To discuss the path forward, do so in #17412. ## Migration Guide - The `Parent` component has been renamed to `ChildOf`. |
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a7051a4815
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Diagnostics for label traits (#17441)
# Objective Diagnostics for labels don't suggest how to best implement them. ``` error[E0277]: the trait bound `Label: ScheduleLabel` is not satisfied --> src/main.rs:15:35 | 15 | let mut sched = Schedule::new(Label); | ------------- ^^^^^ the trait `ScheduleLabel` is not implemented for `Label` | | | required by a bound introduced by this call | = help: the trait `ScheduleLabel` is implemented for `Interned<(dyn ScheduleLabel + 'static)>` note: required by a bound in `bevy_ecs::schedule::Schedule::new` --> /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/schedule/schedule.rs:297:28 | 297 | pub fn new(label: impl ScheduleLabel) -> Self { | ^^^^^^^^^^^^^ required by this bound in `Schedule::new` ``` ## Solution `diagnostics::on_unimplemented` and `diagnostics::do_not_recommend` ## Showcase New error message: ``` error[E0277]: the trait bound `Label: ScheduleLabel` is not satisfied --> src/main.rs:15:35 | 15 | let mut sched = Schedule::new(Label); | ------------- ^^^^^ the trait `ScheduleLabel` is not implemented for `Label` | | | required by a bound introduced by this call | = note: consider annotating `Label` with `#[derive(ScheduleLabel)]` note: required by a bound in `bevy_ecs::schedule::Schedule::new` --> /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/schedule/schedule.rs:297:28 | 297 | pub fn new(label: impl ScheduleLabel) -> Self { | ^^^^^^^^^^^^^ required by this bound in `Schedule::new` ``` |
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21f1e3045c
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Relationships (non-fragmenting, one-to-many) (#17398)
This adds support for one-to-many non-fragmenting relationships (with planned paths for fragmenting and non-fragmenting many-to-many relationships). "Non-fragmenting" means that entities with the same relationship type, but different relationship targets, are not forced into separate tables (which would cause "table fragmentation"). Functionally, this fills a similar niche as the current Parent/Children system. The biggest differences are: 1. Relationships have simpler internals and significantly improved performance and UX. Commands and specialized APIs are no longer necessary to keep everything in sync. Just spawn entities with the relationship components you want and everything "just works". 2. Relationships are generalized. Bevy can provide additional built in relationships, and users can define their own. **REQUEST TO REVIEWERS**: _please don't leave top level comments and instead comment on specific lines of code. That way we can take advantage of threaded discussions. Also dont leave comments simply pointing out CI failures as I can read those just fine._ ## Built on top of what we have Relationships are implemented on top of the Bevy ECS features we already have: components, immutability, and hooks. This makes them immediately compatible with all of our existing (and future) APIs for querying, spawning, removing, scenes, reflection, etc. The fewer specialized APIs we need to build, maintain, and teach, the better. ## Why focus on one-to-many non-fragmenting first? 1. This allows us to improve Parent/Children relationships immediately, in a way that is reasonably uncontroversial. Switching our hierarchy to fragmenting relationships would have significant performance implications. ~~Flecs is heavily considering a switch to non-fragmenting relations after careful considerations of the performance tradeoffs.~~ _(Correction from @SanderMertens: Flecs is implementing non-fragmenting storage specialized for asset hierarchies, where asset hierarchies are many instances of small trees that have a well defined structure)_ 2. Adding generalized one-to-many relationships is currently a priority for the [Next Generation Scene / UI effort](https://github.com/bevyengine/bevy/discussions/14437). Specifically, we're interested in building reactions and observers on top. ## The changes This PR does the following: 1. Adds a generic one-to-many Relationship system 3. Ports the existing Parent/Children system to Relationships, which now lives in `bevy_ecs::hierarchy`. The old `bevy_hierarchy` crate has been removed. 4. Adds on_despawn component hooks 5. Relationships can opt-in to "despawn descendants" behavior, meaning that the entire relationship hierarchy is despawned when `entity.despawn()` is called. The built in Parent/Children hierarchies enable this behavior, and `entity.despawn_recursive()` has been removed. 6. `world.spawn` now applies commands after spawning. This ensures that relationship bookkeeping happens immediately and removes the need to manually flush. This is in line with the equivalent behaviors recently added to the other APIs (ex: insert). 7. Removes the ValidParentCheckPlugin (system-driven / poll based) in favor of a `validate_parent_has_component` hook. ## Using Relationships The `Relationship` trait looks like this: ```rust pub trait Relationship: Component + Sized { type RelationshipSources: RelationshipSources<Relationship = Self>; fn get(&self) -> Entity; fn from(entity: Entity) -> Self; } ``` A relationship is a component that: 1. Is a simple wrapper over a "target" Entity. 2. Has a corresponding `RelationshipSources` component, which is a simple wrapper over a collection of entities. Every "target entity" targeted by a "source entity" with a `Relationship` has a `RelationshipSources` component, which contains every "source entity" that targets it. For example, the `Parent` component (as it currently exists in Bevy) is the `Relationship` component and the entity containing the Parent is the "source entity". The entity _inside_ the `Parent(Entity)` component is the "target entity". And that target entity has a `Children` component (which implements `RelationshipSources`). In practice, the Parent/Children relationship looks like this: ```rust #[derive(Relationship)] #[relationship(relationship_sources = Children)] pub struct Parent(pub Entity); #[derive(RelationshipSources)] #[relationship_sources(relationship = Parent)] pub struct Children(Vec<Entity>); ``` The Relationship and RelationshipSources derives automatically implement Component with the relevant configuration (namely, the hooks necessary to keep everything in sync). The most direct way to add relationships is to spawn entities with relationship components: ```rust let a = world.spawn_empty().id(); let b = world.spawn(Parent(a)).id(); assert_eq!(world.entity(a).get::<Children>().unwrap(), &[b]); ``` There are also convenience APIs for spawning more than one entity with the same relationship: ```rust world.spawn_empty().with_related::<Children>(|s| { s.spawn_empty(); s.spawn_empty(); }) ``` The existing `with_children` API is now a simpler wrapper over `with_related`. This makes this change largely non-breaking for existing spawn patterns. ```rust world.spawn_empty().with_children(|s| { s.spawn_empty(); s.spawn_empty(); }) ``` There are also other relationship APIs, such as `add_related` and `despawn_related`. ## Automatic recursive despawn via the new on_despawn hook `RelationshipSources` can opt-in to "despawn descendants" behavior, which will despawn all related entities in the relationship hierarchy: ```rust #[derive(RelationshipSources)] #[relationship_sources(relationship = Parent, despawn_descendants)] pub struct Children(Vec<Entity>); ``` This means that `entity.despawn_recursive()` is no longer required. Instead, just use `entity.despawn()` and the relevant related entities will also be despawned. To despawn an entity _without_ despawning its parent/child descendants, you should remove the `Children` component first, which will also remove the related `Parent` components: ```rust entity .remove::<Children>() .despawn() ``` This builds on the on_despawn hook introduced in this PR, which is fired when an entity is despawned (before other hooks). ## Relationships are the source of truth `Relationship` is the _single_ source of truth component. `RelationshipSources` is merely a reflection of what all the `Relationship` components say. By embracing this, we are able to significantly improve the performance of the system as a whole. We can rely on component lifecycles to protect us against duplicates, rather than needing to scan at runtime to ensure entities don't already exist (which results in quadratic runtime). A single source of truth gives us constant-time inserts. This does mean that we cannot directly spawn populated `Children` components (or directly add or remove entities from those components). I personally think this is a worthwhile tradeoff, both because it makes the performance much better _and_ because it means theres exactly one way to do things (which is a philosophy we try to employ for Bevy APIs). As an aside: treating both sides of the relationship as "equivalent source of truth relations" does enable building simple and flexible many-to-many relationships. But this introduces an _inherent_ need to scan (or hash) to protect against duplicates. [`evergreen_relations`](https://github.com/EvergreenNest/evergreen_relations) has a very nice implementation of the "symmetrical many-to-many" approach. Unfortunately I think the performance issues inherent to that approach make it a poor choice for Bevy's default relationship system. ## Followup Work * Discuss renaming `Parent` to `ChildOf`. I refrained from doing that in this PR to keep the diff reasonable, but I'm personally biased toward this change (and using that naming pattern generally for relationships). * [Improved spawning ergonomics](https://github.com/bevyengine/bevy/discussions/16920) * Consider adding relationship observers/triggers for "relationship targets" whenever a source is added or removed. This would replace the current "hierarchy events" system, which is unused upstream but may have existing users downstream. I think triggers are the better fit for this than a buffered event queue, and would prefer not to add that back. * Fragmenting relations: My current idea hinges on the introduction of "value components" (aka: components whose type _and_ value determines their ComponentId, via something like Hashing / PartialEq). By labeling a Relationship component such as `ChildOf(Entity)` as a "value component", `ChildOf(e1)` and `ChildOf(e2)` would be considered "different components". This makes the transition between fragmenting and non-fragmenting a single flag, and everything else continues to work as expected. * Many-to-many support * Non-fragmenting: We can expand Relationship to be a list of entities instead of a single entity. I have largely already written the code for this. * Fragmenting: With the "value component" impl mentioned above, we get many-to-many support "for free", as it would allow inserting multiple copies of a Relationship component with different target entities. Fixes #3742 (If this PR is merged, I think we should open more targeted followup issues for the work above, with a fresh tracking issue free of the large amount of less-directed historical context) Fixes #17301 Fixes #12235 Fixes #15299 Fixes #15308 ## Migration Guide * Replace `ChildBuilder` with `ChildSpawnerCommands`. * Replace calls to `.set_parent(parent_id)` with `.insert(Parent(parent_id))`. * Replace calls to `.replace_children()` with `.remove::<Children>()` followed by `.add_children()`. Note that you'll need to manually despawn any children that are not carried over. * Replace calls to `.despawn_recursive()` with `.despawn()`. * Replace calls to `.despawn_descendants()` with `.despawn_related::<Children>()`. * If you have any calls to `.despawn()` which depend on the children being preserved, you'll need to remove the `Children` component first. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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b77e3ef33a
|
Fix a few typos (#17292)
# Objective Stumbled upon a `from <-> form` transposition while reviewing a PR, thought it was interesting, and went down a bit of a rabbit hole. ## Solution Fix em |
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d60764908c
|
Update downcast-rs to version 2 (#17223)
# Objective & Solution - Update `downcast-rs` to the latest version, 2. - Disable (new) `sync` feature to improve compatibility with atomically challenged platforms. - Remove stub `downcast-rs` alternative code from `bevy_app` ## Testing - CI ## Notes The only change from version 1 to version 2 is the addition of a new `sync` feature, which allows disabling the `DowncastSync` parts of `downcast-rs`, which require access to `alloc::sync::Arc`, which is not available on atomically challenged platforms. Since Bevy makes no use of the functionality provided by the `sync` feature, I've disabled it in all crates. Further details can be found [here](https://github.com/marcianx/downcast-rs/pull/22). |
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4a681c3f05
|
Expose access to SubApps within App (#16952)
# Objective `SubApps` is visible within the documentation for `bevy_app`. However, no way of accessing the `SubApps` field in `App` is currently available. ## Solution Expose two new functions, `App::sub_apps()` and `App::sub_apps_mut()`, which give immutable and mutable access to `SubApps` respectively. The other solution is to hide `SubApps`, which I submitted as a PR at <https://github.com/bevyengine/bevy/pull/16953>. ## Testing Because of the simplicity of the changes, I only tested by compiling `bevy_app` - which compiled successfully. Note: `SubApps`, and its corresponding field on `App`, are not used outside of `bevy_app` - which means that compiling the other crates is not necessary. |
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21786632c3
|
Remove bevy_core (#16897)
# Objective - Fixes #16892 ## Solution - Removed `TypeRegistryPlugin` (`Name` is now automatically registered with a default `App`) - Moved `TaskPoolPlugin` to `bevy_app` - Moved `FrameCountPlugin` to `bevy_diagnostic` - Deleted now-empty `bevy_core` ## Testing - CI ## Migration Guide - `TypeRegistryPlugin` no longer exists. If you can't use a default `App` but still need `Name` registered, do so manually with `app.register_type::<Name>()`. - References to `TaskPoolPlugin` and associated types will need to import it from `bevy_app` instead of `bevy_core` - References to `FrameCountPlugin` and associated types will need to import it from `bevy_diagnostic` instead of `bevy_core` ## Notes This strategy was agreed upon by Cart and several other members in [Discord](https://discord.com/channels/691052431525675048/692572690833473578/1319137218312278077). |
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f45e78e658
|
Add no_std support to bevy_app (#16874)
# Objective - Contributes to #15460 ## Solution - Added the following features: - `std` (default) - `bevy_tasks` (default) - `downcast ` (default) - `portable-atomic` - `critical-section` - `downcast` and `bevy_tasks` are now optional dependencies for `bevy_app`. ## Testing - CI - Personal UEFI and Raspberry Pi Pico demo applications compile and run against this branch ## Draft Release Notes Bevy's application framework now supports `no_std` platforms. Following up on `bevy_ecs` gaining `no_std` support, `bevy_app` extends the functionality available on these targets to include the powerful `App` and `Plugin` abstractions. With this, library authors now have the option of making their plugins `no_std` compatible, or even offering plugins specifically to improve Bevy on certain embedded platforms! To start making a `no_std` compatible plugin, simply disable default features when including `bevy_app`: ```toml [dependencies] bevy_app = { version = "0.16", default-features = false } ``` We encourage library authors to do this anyway, as it can also help with compile times and binary size on all platforms. 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 - `downcast-rs` is optional as it isn't compatible with `portable-atomic`. I will investigate making a PR upstream to add support for this functionality, as it should be very straightforward. - In line with the `bevy_ecs` no-std-ification, I've added documentation to all features, and grouped them as well. - ~~Creating this PR in draft while CI runs and so I can polish before review.~~ --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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711246aa34
|
Update hashbrown to 0.15 (#15801)
Updating dependencies; adopted version of #15696. (Supercedes #15696.) Long answer: hashbrown is no longer using ahash by default, meaning that we can't use the default-hasher methods with ahasher. So, we have to use the longer-winded versions instead. This takes the opportunity to also switch our default hasher as well, but without actually enabling the default-hasher feature for hashbrown, meaning that we'll be able to change our hasher more easily at the cost of all of these method calls being obnoxious forever. One large change from 0.15 is that `insert_unique_unchecked` is now `unsafe`, and for cases where unsafe code was denied at the crate level, I replaced it with `insert`. ## Migration Guide `bevy_utils` has updated its version of `hashbrown` to 0.15 and now defaults to `foldhash` instead of `ahash`. This means that if you've hard-coded your hasher to `bevy_utils::AHasher` or separately used the `ahash` crate in your code, you may need to switch to `foldhash` to ensure that everything works like it does in Bevy. |
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a6adced9ed
|
Deny derive_more error feature and replace it with thiserror (#16684)
# Objective - Remove `derive_more`'s error derivation and replace it with `thiserror` ## Solution - Added `derive_more`'s `error` feature to `deny.toml` to prevent it sneaking back in. - Reverted to `thiserror` error derivation ## Notes Merge conflicts were too numerous to revert the individual changes, so this reversion was done manually. Please scrutinise carefully during review. |
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2a66bf0909
|
Clarify that bevy_app::App.world() (and mut variant) returns the main SubApp 's World (#16527)
# Objective The documentation for `bevy_app::App.world()` (and its mut variant) could confuse some into thinking that this is the only World that the App will contain. ## Solution Clarify the documentation for `bevy_app::App.world()` (and its mut variant), to say that it returns the main subapp's world. This helps imply that Apps can contain more than one world (albeit, only one per SubApp). ## Testing This is a documentation change, with no changes to doctests. Thus, testing is not necessary beyond ensuring the link syntax is correct. |
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d96a9d15f6
|
Migrate from Query::single and friends to Single (#15872)
# Objective - closes #15866 ## Solution - Simply migrate where possible. ## Testing - Expect that CI will do most of the work. Examples is another way of testing this, as most of the work is in that area. --- ## Notes For now, this PR doesn't migrate `QueryState::single` and friends as for now, this look like another issue. So for example, QueryBuilders that used single or `World::query` that used single wasn't migrated. If there is a easy way to migrate those, please let me know. Most of the uses of `Query::single` were removed, the only other uses that I found was related to tests of said methods, so will probably be removed when we remove `Query::single`. |
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219b5930f1
|
Rename App/World::observe to add_observer , EntityWorldMut::observe_entity to observe . (#15754)
# Objective - Closes #15752 Calling the functions `App::observe` and `World::observe` doesn't make sense because you're not "observing" the `App` or `World`, you're adding an observer that listens for an event that occurs *within* the `World`. We should rename them to better fit this. ## Solution Renames: - `App::observe` -> `App::add_observer` - `World::observe` -> `World::add_observer` - `Commands::observe` -> `Commands::add_observer` - `EntityWorldMut::observe_entity` -> `EntityWorldMut::observe` (Note this isn't a breaking change as the original rename was introduced earlier this cycle.) ## Testing Reusing current tests. |
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1be0ed33fc
|
Remove thiserror from bevy_app (#15779)
# Objective - Contributes to #15460 ## Solution - Removed `thiserror` from `bevy_app` |
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f3e8ae03cd
|
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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d70595b667
|
Add core and alloc over std Lints (#15281)
# Objective - Fixes #6370 - Closes #6581 ## Solution - Added the following lints to the workspace: - `std_instead_of_core` - `std_instead_of_alloc` - `alloc_instead_of_core` - Used `cargo +nightly fmt` with [item level use formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Item%5C%3A) to split all `use` statements into single items. - Used `cargo clippy --workspace --all-targets --all-features --fix --allow-dirty` to _attempt_ to resolve the new linting issues, and intervened where the lint was unable to resolve the issue automatically (usually due to needing an `extern crate alloc;` statement in a crate root). - Manually removed certain uses of `std` where negative feature gating prevented `--all-features` from finding the offending uses. - Used `cargo +nightly fmt` with [crate level use formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Crate%5C%3A) to re-merge all `use` statements matching Bevy's previous styling. - Manually fixed cases where the `fmt` tool could not re-merge `use` statements due to conditional compilation attributes. ## Testing - Ran CI locally ## Migration Guide The MSRV is now 1.81. Please update to this version or higher. ## Notes - This is a _massive_ change to try and push through, which is why I've outlined the semi-automatic steps I used to create this PR, in case this fails and someone else tries again in the future. - Making this change has no impact on user code, but does mean Bevy contributors will be warned to use `core` and `alloc` instead of `std` where possible. - This lint is a critical first step towards investigating `no_std` options for Bevy. --------- Co-authored-by: François Mockers <francois.mockers@vleue.com> |
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efda7f3f9c
|
Simpler lint fixes: makes ci lints work but disables a lint for now (#15376)
Takes the first two commits from #15375 and adds suggestions from this comment: https://github.com/bevyengine/bevy/pull/15375#issuecomment-2366968300 See #15375 for more reasoning/motivation. ## Rebasing (rerunning) ```rust git switch simpler-lint-fixes git reset --hard main cargo fmt --all -- --unstable-features --config normalize_comments=true,imports_granularity=Crate cargo fmt --all git add --update git commit --message "rustfmt" cargo clippy --workspace --all-targets --all-features --fix cargo fmt --all -- --unstable-features --config normalize_comments=true,imports_granularity=Crate cargo fmt --all git add --update git commit --message "clippy" git cherry-pick e6c0b94f6795222310fb812fa5c4512661fc7887 ``` |
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c7ec456e50
|
Support systems that take references as input (#15184)
# Objective - Fixes #14924 - Closes #9584 ## Solution - We introduce a new trait, `SystemInput`, that serves as a type function from the `'static` form of the input, to its lifetime'd version, similarly to `SystemParam` or `WorldQuery`. - System functions now take the lifetime'd wrapped version, `SystemInput::Param<'_>`, which prevents the issue presented in #14924 (i.e. `InRef<T>`). - Functions for running systems now take the lifetime'd unwrapped version, `SystemInput::Inner<'_>` (i.e. `&T`). - Due to the above change, system piping had to be re-implemented as a standalone type, rather than `CombinatorSystem` as it was previously. - Removes the `Trigger<'static, E, B>` transmute in observer runner code. ## Testing - All current tests pass. - Added additional tests and doc-tests. --- ## Showcase ```rust let mut world = World::new(); let mut value = 2; // Currently possible: fn square(In(input): In<usize>) -> usize { input * input } value = world.run_system_once_with(value, square); // Now possible: fn square_mut(InMut(input): InMut<usize>) { *input *= *input; } world.run_system_once_with(&mut value, square_mut); // Or: fn square_ref(InRef(input): InRef<usize>) -> usize { *input * *input } value = world.run_system_once_with(&value, square_ref); ``` ## Migration Guide - All current explicit usages of the following types must be changed in the way specified: - `SystemId<I, O>` to `SystemId<In<I>, O>` - `System<In = T>` to `System<In = In<T>>` - `IntoSystem<I, O, M>` to `IntoSystem<In<I>, O, M>` - `Condition<M, T>` to `Condition<M, In<T>>` - `In<Trigger<E, B>>` is no longer a valid input parameter type. Use `Trigger<E, B>` directly, instead. --------- Co-authored-by: Giacomo Stevanato <giaco.stevanato@gmail.com> |
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fd329c0426
|
Allow to expect (adopted) (#15301)
# Objective > Rust 1.81 released the #[expect(...)] attribute, which works like #[allow(...)] but throws a warning if the lint isn't raised. This is preferred to #[allow(...)] because it tells us when it can be removed. - Adopts the parts of #15118 that are complete, and updates the branch so it can be merged. - There were a few conflicts, let me know if I misjudged any of 'em. Alice's [recommendation](https://github.com/bevyengine/bevy/issues/15059#issuecomment-2349263900) seems well-taken, let's do this crate by crate now that @BD103 has done the lion's share of this! (Relates to, but doesn't yet completely finish #15059.) Crates this _doesn't_ cover: - bevy_input - bevy_gilrs - bevy_window - bevy_winit - bevy_state - bevy_render - bevy_picking - bevy_core_pipeline - bevy_sprite - bevy_text - bevy_pbr - bevy_ui - bevy_gltf - bevy_gizmos - bevy_dev_tools - bevy_internal - bevy_dylib --------- Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com> Co-authored-by: Ben Frankel <ben.frankel7@gmail.com> Co-authored-by: Antony <antony.m.3012@gmail.com> |
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1b8c1c1242
|
simplify std::mem references (#15315)
# Objective - Fixes #15314 ## Solution - Remove unnecessary usings and simplify references to those functions. ## Testing CI |
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bc13161416
|
Migrated NonZero* to NonZero<*> (#14978)
# Objective - Fixes #14974 ## Solution - Replace all* instances of `NonZero*` with `NonZero<*>` ## Testing - CI passed locally. --- ## Notes Within the `bevy_reflect` implementations for `std` types, `impl_reflect_value!()` will continue to use the type aliases instead, as it inappropriately parses the concrete type parameter as a generic argument. If the `ZeroablePrimitive` trait was stable, or the macro could be modified to accept a finite list of types, then we could fully migrate. |
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6250698b56
|
Added on_unimplemented Diagnostic for IntoObserverSystem (#14840)
# Objective - Fixes #14658. ## Solution - Added `on_unimplemented` Diagnostic for `IntoObserverSystem` calling out argument ordering in a `note` - Added an example to the documentation on `App::observe` to provide some explanation to users. ## Testing - Ran CI locally - Deliberately introduced a parameter order error in the `ecs/observers.rs` example as a test. --- ## Showcase <details> <summary>Error Before</summary> ``` error[E0277]: the trait bound `{closure@examples/ecs/observers.rs:19:13: 22:37}: IntoObserverSystem<_, _, _>` is not satisfied --> examples/ecs/observers.rs:19:13 | 18 | .observe( | ------- required by a bound introduced by this call 19 | / |mines: Query<&Mine>, 20 | | trigger: Trigger<ExplodeMines>, 21 | | index: Res<SpatialIndex>, 22 | | mut commands: Commands| { ... | 34 | | } 35 | | }, | |_____________^ the trait `bevy::prelude::IntoSystem<bevy::prelude::Trigger<'static, _, _>, (), _>` is not implemented for closure `{closure@examples/ecs/observers.rs:19:13: 22:37}`, which is required by `{closure@examples/ecs/observers.rs:19:13: 22:37}: IntoObserverSystem<_, _, _>` | = note: required for `{closure@examples/ecs/observers.rs:19:13: 22:37}` to implement `IntoObserverSystem<_, _, _>` note: required by a bound in `bevy::prelude::App::observe` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:995:24 | 993 | pub fn observe<E: Event, B: Bundle, M>( | ------- required by a bound in this associated function 994 | &mut self, 995 | observer: impl IntoObserverSystem<E, B, M>, | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::observe` For more information about this error, try `rustc --explain E0277`. error: could not compile `bevy` (example "observers") due to 1 previous error ``` </details> <details> <summary>Error After</summary> ``` error[E0277]: `{closure@examples/ecs/observers.rs:19:13: 22:37}` cannot become an `ObserverSystem` --> examples/ecs/observers.rs:19:13 | 18 | .observe( | ------- required by a bound introduced by this call 19 | / |mines: Query<&Mine>, 20 | | trigger: Trigger<ExplodeMines>, 21 | | index: Res<SpatialIndex>, 22 | | mut commands: Commands| { ... | 34 | | } 35 | | }, | |_____________^ the trait `IntoObserverSystem` is not implemented | = help: the trait `bevy::prelude::IntoSystem<bevy::prelude::Trigger<'static, _, _>, (), _>` is not implemented for closure `{closure@examples/ecs/observers.rs:19:13: 22:37}`, which is required by `{closure@examples/ecs/observers.rs:19:13: 22:37}: IntoObserverSystem<_, _, _>` = note: for function `ObserverSystem`s, ensure the first argument is a `Trigger<T>` and any subsequent ones are `SystemParam` = note: required for `{closure@examples/ecs/observers.rs:19:13: 22:37}` to implement `IntoObserverSystem<_, _, _>` note: required by a bound in `bevy::prelude::App::observe` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:1025:24 | 1023 | pub fn observe<E: Event, B: Bundle, M>( | ------- required by a bound in this associated function 1024 | &mut self, 1025 | observer: impl IntoObserverSystem<E, B, M>, | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::observe` For more information about this error, try `rustc --explain E0277`. error: could not compile `bevy` (example "observers") due to 1 previous error ``` </details> |
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938d810766
|
Apply unused_qualifications lint (#14828)
# Objective Fixes #14782 ## Solution Enable the lint and fix all upcoming hints (`--fix`). Also tried to figure out the false-positive (see review comment). Maybe split this PR up into multiple parts where only the last one enables the lint, so some can already be merged resulting in less many files touched / less potential for merge conflicts? Currently, there are some cases where it might be easier to read the code with the qualifier, so perhaps remove the import of it and adapt its cases? In the current stage it's just a plain adoption of the suggestions in order to have a base to discuss. ## Testing `cargo clippy` and `cargo run -p ci` are happy. |
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2b4180ca8f
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bevy_reflect: Function reflection terminology refactor (#14813)
# Objective One of the changes in #14704 made `DynamicFunction` effectively the same as `DynamicClosure<'static>`. This change meant that the de facto function type would likely be `DynamicClosure<'static>` instead of the intended `DynamicFunction`, since the former is much more flexible. We _could_ explore ways of making `DynamicFunction` implement `Copy` using some unsafe code, but it likely wouldn't be worth it. And users would likely still reach for the convenience of `DynamicClosure<'static>` over the copy-ability of `DynamicFunction`. The goal of this PR is to fix this confusion between the two types. ## Solution Firstly, the `DynamicFunction` type was removed. Again, it was no different than `DynamicClosure<'static>` so it wasn't a huge deal to remove. Secondly, `DynamicClosure<'env>` and `DynamicClosureMut<'env>` were renamed to `DynamicFunction<'env>` and `DynamicFunctionMut<'env>`, respectively. Yes, we still ultimately kept the naming of `DynamicFunction`, but changed its behavior to that of `DynamicClosure<'env>`. We need a term to refer to both functions and closures, and "function" was the best option. [Originally](https://discord.com/channels/691052431525675048/1002362493634629796/1274091992162242710), I was going to go with "callable" as the replacement term to encompass both functions and closures (e.g. `DynamciCallable<'env>`). However, it was [suggested](https://discord.com/channels/691052431525675048/1002362493634629796/1274653581777047625) by @SkiFire13 that the simpler "function" term could be used instead. While "callable" is perhaps the better umbrella term—being truly ambiguous over functions and closures— "function" is more familiar, used more often, easier to discover, and is subjectively just "better-sounding". ## Testing Most changes are purely swapping type names or updating documentation, but you can verify everything still works by running the following command: ``` cargo test --package bevy_reflect ``` |
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423285cf1c
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bevy_reflect: Store functions as DynamicClosure<'static> in FunctionRegistry (#14704)
# Objective #14098 added the `FunctionRegistry` for registering functions such that they can be retrieved by name and used dynamically. One thing we chose to leave out in that initial PR is support for closures. Why support closures? Mainly, we don't want to prohibit users from injecting environmental data into their registered functions. This allows these functions to not leak their internals to the public API. For example, let's say we're writing a library crate that allows users to register callbacks for certain actions. We want to perform some actions before invoking the user's callback so we can't just call it directly. We need a closure for this: ```rust registry.register("my_lib::onclick", move |event: ClickEvent| { // ...other work... user_onclick.call(event); // <-- Captured variable }); ``` We could have made our callback take a reference to the user's callback. This would remove the need for the closure, but it would change our desired API to place the burden of fetching the correct callback on the caller. ## Solution Modify the `FunctionRegistry` to store registered functions as `DynamicClosure<'static>` instead of `DynamicFunction` (now using `IntoClosure` instead of `IntoFunction`). Due to limitations in Rust and how function reflection works, `DynamicClosure<'static>` is functionally equivalent to `DynamicFunction`. And a normal function is considered a subset of closures (it's a closure that doesn't capture anything), so there shouldn't be any difference in usage: all functions that satisfy `IntoFunction` should satisfy `IntoClosure`. This means that the registration API introduced in #14098 should require little-to-no changes on anyone following `main`. ### Closures vs Functions One consideration here is whether we should keep closures and functions separate. This PR unifies them into `DynamicClosure<'static>`, but we can consider splitting them up. The reasons we might want to do so are: - Simplifies mental model and terminology (users don't have to understand that functions turn into closures) - If Rust ever improves its function model, we may be able to add additional guarantees to `DynamicFunction` that make it useful to separate the two - Adding support for generic functions may be less confusing for users since closures in Rust technically can't be generic The reasons behind this PR's unification approach are: - Reduces the number of methods needed on `FunctionRegistry` - Reduces the number of lookups a user may have to perform (i.e. "`get_function` or else `get_closure`") - Establishes `DynamicClosure<'static>` as the de facto dynamic callable (similar to how most APIs in Rust code tend to prefer `impl Fn() -> String` over `fn() -> String`) I'd love to hear feedback on this matter, and whether we should continue with this PR's approach or switch to a split model. ## Testing You can test locally by running: ``` cargo test --package bevy_reflect ``` --- ## Showcase Closures can now be registered into the `FunctionRegistry`: ```rust let punct = String::from("!!!"); registry.register_with_name("my_crate::punctuate", move |text: String| { format!("{}{}", text, punct) }); ``` |
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a0cc636ea3
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bevy_reflect: Anonymous function parsing (#14641)
# Objective ### TL;DR #14098 added the `FunctionRegistry` but had some last minute complications due to anonymous functions. It ended up going with a "required name" approach to ensure anonymous functions would always have a name. However, this approach isn't ideal for named functions since, by definition, they will always have a name. Therefore, this PR aims to modify function reflection such that we can make function registration easier for named functions, while still allowing anonymous functions to be registered as well. ### Context Function registration (#14098) ran into a little problem: anonymous functions. Anonymous functions, including function pointers, have very non-unique type names. For example, the anonymous function `|a: i32, b: i32| a + b` has the type name of `fn(i32, i32) -> i32`. This obviously means we'd conflict with another function like `|a: i32, b: i32| a - b`. The solution that #14098 landed on was to always require a name during function registration. The downside with this is that named functions (e.g. `fn add(a: i32, b: i32) -> i32 { a + b }`) had to redundantly provide a name. Additionally, manually constructed `DynamicFunction`s also ran into this ergonomics issue. I don't entirely know how the function registry will be used, but I have a strong suspicion that most of its registrations will either be named functions or manually constructed `DynamicFunction`s, with anonymous functions only being used here and there for quick prototyping or adding small functionality. Why then should the API prioritize the anonymous function use case by always requiring a name during registration? #### Telling Functions Apart Rust doesn't provide a lot of out-of-the-box tools for reflecting functions. One of the biggest hurdles in attempting to solve the problem outlined above would be to somehow tell the different kinds of functions apart. Let's briefly recap on the categories of functions in Rust: | Category | Example | | ------------------ | ----------------------------------------- | | Named function | `fn add(a: i32, b: i32) -> i32 { a + b }` | | Closure | `\|a: i32\| a + captured_variable` | | Anonymous function | `\|a: i32, b: i32\| a + b` | | Function pointer | `fn(i32, i32) -> i32` | My first thought was to try and differentiate these categories based on their size. However, we can see that this doesn't quite work: | Category | `size_of` | | ------------------ | --------- | | Named function | 0 | | Closure | 0+ | | Anonymous function | 0 | | Function pointer | 8 | Not only does this not tell anonymous functions from named ones, but it struggles with pretty much all of them. My second then was to differentiate based on type name: | Category | `type_name` | | ------------------ | ----------------------- | | Named function | `foo::bar::baz` | | Closure | `foo::bar::{{closure}}` | | Anonymous function | `fn() -> String` | | Function pointer | `fn() -> String` | This is much better. While it can't distinguish between function pointers and anonymous functions, this doesn't matter too much since we only care about whether we can _name_ the function. So why didn't we implement this in #14098? #### Relying on `type_name` While this solution was known about while working on #14098, it was left out from that PR due to it being potentially controversial. The [docs](https://doc.rust-lang.org/stable/std/any/fn.type_name.html) for `std::any::type_name` state: > The returned string must not be considered to be a unique identifier of a type as multiple types may map to the same type name. Similarly, there is no guarantee that all parts of a type will appear in the returned string: for example, lifetime specifiers are currently not included. In addition, the output may change between versions of the compiler. So that's it then? We can't use `type_name`? Well, this statement isn't so much a rule as it is a guideline. And Bevy is no stranger to bending the rules to make things work or to improve ergonomics. Remember that before `TypePath`, Bevy's scene system was entirely dependent on `type_name`. Not to mention that `type_name` is being used as a key into both the `TypeRegistry` and the `FunctionRegistry`. Bevy's practices aside, can we reliably use `type_name` for this? My answer would be "yes". Anonymous functions are anonymous. They have no name. There's nothing Rust could do to give them a name apart from generating a random string of characters. But remember that this is a diagnostic tool, it doesn't make sense to obfuscate the type by randomizing the output. So changing it to be anything other than what it is now is very unlikely. The only changes that I could potentially see happening are: 1. Closures replace `{{closure}}` with the name of their variable 2. Lifetimes are included in the output I don't think the first is likely to happen, but if it does then it actually works out in our favor: closures are now named! The second point is probably the likeliest. However, adding lifetimes doesn't mean we can't still rely on `type_name` to determine whether or not a function is named. So we should be okay in this case as well. ## Solution Parse the `type_name` of the function in the `TypedFunction` impl to determine if the function is named or anonymous. This once again makes `FunctionInfo::name` optional. For manual constructions of `DynamicFunction`, `FunctionInfo::named` or ``FunctionInfo::anonymous` can be used. The `FunctionRegistry` API has also been reworked to account for this change. `FunctionRegistry::register` no longer takes a name and instead takes it from the supplied function, returning a `FunctionRegistrationError::MissingName` error if the name is `None`. This also doubles as a replacement for the old `FunctionRegistry::register_dynamic` method, which has been removed. To handle anonymous functions, a `FunctionRegistry::register_with_name` method has been added. This works in the same way `FunctionRegistry::register` used to work before this PR. The overwriting methods have been updated in a similar manner, with modifications to `FunctionRegistry::overwrite_registration`, the removal of `FunctionRegistry::overwrite_registration_dynamic`, and the addition of `FunctionRegistry::overwrite_registration_with_name`. This PR also updates the methods on `App` in a similar way: `App::register_function` no longer requires a name argument and `App::register_function_with_name` has been added to handle anonymous functions (and eventually closures). ## Testing You can run the tests locally by running: ``` cargo test --package bevy_reflect --features functions ``` --- ## Internal Migration Guide > [!important] > Function reflection was introduced as part of the 0.15 dev cycle. This migration guide was written for developers relying on `main` during this cycle, and is not a breaking change coming from 0.14. > [!note] > This list is not exhaustive. It only contains some of the most important changes. `FunctionRegistry::register` no longer requires a name string for named functions. Anonymous functions, however, need to be registered using `FunctionRegistry::register_with_name`. ```rust // BEFORE registry .register(std::any::type_name_of_val(&foo), foo)? .register("bar", || println!("Hello world!")); // AFTER registry .register(foo)? .register_with_name("bar", || println!("Hello world!")); ``` `FunctionInfo::name` is now optional. Anonymous functions and closures will now have their name set to `None` by default. Additionally, `FunctionInfo::new` has been renamed to `FunctionInfo::named`. |