cc69fdd0c6
142 Commits
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cc69fdd0c6
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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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ed7b366b24
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Deprecate insert_or_spawn function family (#18147)
# Objective Based on #18054, this PR builds on #18035 to deprecate: - `Commands::insert_or_spawn_batch` - `Entities::alloc_at_without_replacement` - `Entities::alloc_at` - `World::insert_or_spawn_batch` - `World::insert_or_spawn_batch_with_caller` ## Testing Just deprecation, so no new tests. Note that as of writing #18035 is still under testing and review. ## Open Questions - [x] Should `entity::AllocAtWithoutReplacement` be deprecated? It is internal and only used in `Entities::alloc_at_without_replacement`. **EDIT:** Now deprecated. ## Migration Guide The following functions have been deprecated: - `Commands::insert_or_spawn_batch` - `World::insert_or_spawn_batch` - `World::insert_or_spawn_batch_with_caller` These functions, when used incorrectly, can cause major performance problems and are generally viewed as anti-patterns and foot guns. These are planned to be removed altogether in 0.17. Instead of these functions consider doing one of the following: Option A) Instead of despawing entities and re-spawning them at a particular id, insert the new `Disabled` component without despawning the entity, and use `try_insert_batch` or `insert_batch` and remove `Disabled` instead of re-spawning it. Option B) Instead of giving special meaning to an entity id, simply use `spawn_batch` and ensure entity references are valid when despawning. --------- Co-authored-by: JaySpruce <jsprucebruce@gmail.com> Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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06cb5c5fd9
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Fix Component require() IDE integration (#18165)
# Objective Component `require()` IDE integration is fully broken, as of #16575. ## Solution This reverts us back to the previous "put the docs on Component trait" impl. This _does_ reduce the accessibility of the required components in rust docs, but the complete erasure of "required component IDE experience" is not worth the price of slightly increased prominence of requires in docs. Additionally, Rust Analyzer has recently started including derive attributes in suggestions, so we aren't losing that benefit of the proc_macro attribute impl. |
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a530c07bc5
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Preserve spawned RelationshipTarget order and other improvements (#17858)
Fixes #17720 ## Objective Spawning RelationshipTargets from scenes currently fails to preserve RelationshipTarget ordering (ex: `Children` has an arbitrary order). This is because it uses the normal hook flow to set up the collection, which means we are pushing onto the collection in _spawn order_ (which is currently in archetype order, which will often produce mismatched orderings). We need to preserve the ordering in the original RelationshipTarget collection. Ideally without expensive checking / fixups. ## Solution One solution would be to spawn in hierarchy-order. However this gets complicated as there can be multiple hierarchies, and it also means we can't spawn in more cache-friendly orders (ex: the current per-archetype spawning, or future even-smarter per-table spawning). Additionally, same-world cloning has _slightly_ more nuanced needs (ex: recursively clone linked relationships, while maintaining _original_ relationships outside of the tree via normal hooks). The preferred approach is to directly spawn the remapped RelationshipTarget collection, as this trivially preserves the ordering. Unfortunately we can't _just_ do that, as when we spawn the children with their Relationships (ex: `ChildOf`), that will insert a duplicate. We could "fixup" the collection retroactively by just removing the back half of duplicates, but this requires another pass / more lookups / allocating twice as much space. Additionally, it becomes complicated because observers could insert additional children, making it harder (aka more expensive) to determine which children are dupes and which are not. The path I chose is to support "opting out" of the relationship target hook in the contexts that need that, as this allows us to just cheaply clone the mapped collection. The relationship hook can look for this configuration when it runs and skip its logic when that happens. A "simple" / small-amount-of-code way to do this would be to add a "skip relationship spawn" flag to World. Sadly, any hook / observer that runs _as the result of an insert_ would also read this flag. We really need a way to scope this setting to a _specific_ insert. Therefore I opted to add a new `RelationshipInsertHookMode` enum and an `entity.insert_with_relationship_insert_hook_mode` variant. Obviously this is verbose and ugly. And nobody wants _more_ insert variants. But sadly this was the best I could come up with from a performance and capability perspective. If you have alternatives let me know! There are three variants: 1. `RelationshipInsertHookMode::Run`: always run relationship insert hooks (this is the default) 2. `RelationshipInsertHookMode::Skip`: do not run any relationship insert hooks for this insert (this is used by spawner code) 3. `RelationshipInsertHookMode::RunIfNotLinked`: only run hooks for _unlinked_ relationships (this is used in same-world recursive entity cloning to preserve relationships outside of the deep-cloned tree) Note that I have intentionally only added "insert with relationship hook mode" variants to the cases we absolutely need (everything else uses the default `Run` mode), just to keep the code size in check. I do not think we should add more without real _very necessary_ use cases. I also made some other minor tweaks: 1. I split out `SourceComponent` from `ComponentCloneCtx`. Reading the source component no longer needlessly blocks mutable access to `ComponentCloneCtx`. 2. Thanks to (1), I've removed the `RefCell` wrapper over the cloned component queue. 3. (1) also allowed me to write to the EntityMapper while queuing up clones, meaning we can reserve entities during the component clone and write them to the mapper _before_ inserting the component, meaning cloned collections can be mapped on insert. 4. I've removed the closure from `write_target_component_ptr` to simplify the API / make it compatible with the split `SourceComponent` approach. 5. I've renamed `EntityCloner::recursive` to `EntityCloner::linked_cloning` to connect that feature more directly with `RelationshipTarget::LINKED_SPAWN` 6. I've removed `EntityCloneBehavior::RelationshipTarget`. This was always intended to be temporary, and this new behavior removes the need for it. --------- Co-authored-by: Viktor Gustavsson <villor94@gmail.com> |
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ccb7069e7f
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Change ChildOf to Childof { parent: Entity} and support deriving Relationship and RelationshipTarget with named structs (#17905)
# Objective fixes #17896 ## Solution Change ChildOf ( Entity ) to ChildOf { parent: Entity } by doing this we also allow users to use named structs for relationship derives, When you have more than 1 field in a struct with named fields the macro will look for a field with the attribute #[relationship] and all of the other fields should implement the Default trait. Unnamed fields are still supported. When u have a unnamed struct with more than one field the macro will fail. Do we want to support something like this ? ```rust #[derive(Component)] #[relationship_target(relationship = ChildOf)] pub struct Children (#[relationship] Entity, u8); ``` I could add this, it but doesn't seem nice. ## Testing crates/bevy_ecs - cargo test ## Showcase ```rust use bevy_ecs::component::Component; use bevy_ecs::entity::Entity; #[derive(Component)] #[relationship(relationship_target = Children)] pub struct ChildOf { #[relationship] pub parent: Entity, internal: u8, }; #[derive(Component)] #[relationship_target(relationship = ChildOf)] pub struct Children { children: Vec<Entity> }; ``` --------- Co-authored-by: Tim Overbeek <oorbecktim@Tims-MacBook-Pro.local> Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-042.client.nl.eduvpn.org> Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-059.client.nl.eduvpn.org> Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-054.client.nl.eduvpn.org> Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-027.client.nl.eduvpn.org> |
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36a2f7fdf1
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Remove unnecessary bounds on EntityClonerBuilder::without_required_components (#17969)
## Objective The closure argument for `EntityClonerBuilder::without_required_components` has `Send + Sync + 'static` bounds, but the closure immediately gets called and never needs to be sent anywhere. (This was my fault :P ) ## Solution Remove the bounds so that users aren't unnecessarily restricted. I also took the opportunity to expand the tests a little. |
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a1717331e4
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implement UniqueEntityArray (#17954)
# Objective Continuation of #17589 and #16547. `get_many` is last of the `many` methods with a missing `unique` counterpart. It both takes and returns arrays, thus necessitates a matching `UniqueEntityArray` type! Plus, some slice methods involve returning arrays, which are currently missing from `UniqueEntitySlice`. ## Solution Add the type, the related methods and trait impls. Note that for this PR, we abstain from some methods/trait impls that create `&mut UniqueEntityArray`, because it can be successfully mem-swapped. This can potentially invalidate a larger slice, which is the same reason we punted on some mutable slice methods in #17589. We can follow-up on all of these together in a following PR. The new `unique_array` module is not glob-exported, because the trait alias `unique_array::IntoIter` would conflict with `unique_vec::IntoIter`. The solution for this is to make the various `unique_*` modules public, which I intend to do in yet another PR. |
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5241e09671
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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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ee44560523
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Add EntityDoesNotExistError , replace cases of Entity as an error, do some easy Resultification (#17855)
## Objective There's no general error for when an entity doesn't exist, and some methods are going to need one when they get Resultified. The closest thing is `EntityFetchError`, but that error has a slightly more specific purpose. ## Solution - Added `EntityDoesNotExistError`. - Contains `Entity` and `EntityDoesNotExistDetails`. - Changed `EntityFetchError` and `QueryEntityError`: - Changed `NoSuchEntity` variant to wrap `EntityDoesNotExistError` and renamed the variant to `EntityDoesNotExist`. - Renamed `EntityFetchError` to `EntityMutableFetchError` to make its purpose clearer. - Renamed `TryDespawnError` to `EntityDespawnError` to make it more general. - Changed `World::inspect_entity` to return `Result<[ok], EntityDoesNotExistError>` instead of panicking. - Changed `World::get_entity` and `WorldEntityFetch::fetch_ref` to return `Result<[ok], EntityDoesNotExistError>` instead of `Result<[ok], Entity>`. - Changed `UnsafeWorldCell::get_entity` to return `Result<UnsafeEntityCell, EntityDoesNotExistError>` instead of `Option<UnsafeEntityCell>`. ## Migration Guide - `World::inspect_entity` now returns `Result<impl Iterator<Item = &ComponentInfo>, EntityDoesNotExistError>` instead of `impl Iterator<Item = &ComponentInfo>`. - `World::get_entity` now returns `EntityDoesNotExistError` as an error instead of `Entity`. You can still access the entity's ID through the error's `entity` field. - `UnsafeWorldCell::get_entity` now returns `Result<UnsafeEntityCell, EntityDoesNotExistError>` instead of `Option<UnsafeEntityCell>`. |
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2760692f88
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Update typos to 1.29.6 (#17850)
# Objective Update typos, fix new typos. 1.29.6 was just released to fix an [issue](https://github.com/crate-ci/typos/issues/1228) where January's corrections were not included in the binaries for the last release. Reminder: typos can be tossed in the monthly [non-critical corrections issue](https://github.com/crate-ci/typos/issues/1221). ## Solution I chose to allow `implementors`, because a good argument seems to be being made [here](https://github.com/crate-ci/typos/issues/1226) and there is now a PR to address that. ## Discussion Should I exclude `bevy_mikktspace`? At one point I think we had an informal policy of "don't mess with mikktspace until https://github.com/bevyengine/bevy/pull/9050 is merged" but it doesn't seem like that is likely to be merged any time soon. I think these particular corrections in mikktspace are fine because - The same typo mistake seems to have been fixed in that PR - The entire file containing these corrections was deleted in that PR ## Typo of the Month correspindong -> corresponding |
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153ce468ef
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implement iterators that yield UniqueEntitySlice (#17796)
# Objective Continuation of #17589 and #16547. Slices have several methods that return iterators which themselves yield slices, which we have not yet implemented. An example use is `par_iter_many` style logic. ## Solution Their implementation is rather straightforward, we simply delegate all impls to `[T]`. The resulting iterator types need their own wrappers in the form of `UniqueEntitySliceIter` and `UniqueEntitySliceIterMut`. We also add three free functions that cast slices of entity slices to slices of `UniqueEntitySlice`. These three should be sufficient, though infinite nesting is achievable with a trait (like `TrustedEntityBorrow` works over infinite reference nesting), should the need ever arise. |
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7f9588d4c6
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Fix documentation of Entities::get (#17721)
This method returns `None` if `meta.location.archetype_id` is `ArchetypeId::INVALID`. `EntityLocation::INVALID.archetype_id` is `ArchetypeId::INVALID`. Therefore this method cannot return `Some(EntityLocation::INVALID)`. Linking to it in the docs is futile anyway as that constant is not public. |
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eee7fd5b3e
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Encapsulate cfg(feature = "track_location") in a type. (#17602)
# Objective Eliminate the need to write `cfg(feature = "track_location")` every time one uses an API that may use location tracking. It's verbose, and a little intimidating. And it requires code outside of `bevy_ecs` that wants to use location tracking needs to either unconditionally enable the feature, or include conditional compilation of its own. It would be good for users to be able to log locations when they are available without needing to add feature flags to their own crates. Reduce the number of cases where code compiles with the `track_location` feature enabled, but not with it disabled, or vice versa. It can be hard to remember to test it both ways! Remove the need to store a `None` in `HookContext` when the `track_location` feature is disabled. ## Solution Create an `MaybeLocation<T>` type that contains a `T` if the `track_location` feature is enabled, and is a ZST if it is not. The overall API is similar to `Option`, but whether the value is `Some` or `None` is set at compile time and is the same for all values. Default `T` to `&'static Location<'static>`, since that is the most common case. Remove all `cfg(feature = "track_location")` blocks outside of the implementation of that type, and instead call methods on it. When `track_location` is disabled, `MaybeLocation` is a ZST and all methods are `#[inline]` and empty, so they should be entirely removed by the compiler. But the code will still be visible to the compiler and checked, so if it compiles with the feature disabled then it should also compile with it enabled, and vice versa. ## Open Questions Where should these types live? I put them in `change_detection` because that's where the existing `MaybeLocation` types were, but we now use these outside of change detection. While I believe that the compiler should be able to remove all of these calls, I have not actually tested anything. If we want to take this approach, what testing is required to ensure it doesn't impact performance? ## Migration Guide Methods like `Ref::changed_by()` that return a `&'static Location<'static>` will now be available even when the `track_location` feature is disabled, but they will return a new `MaybeLocation` type. `MaybeLocation` wraps a `&'static Location<'static>` when the feature is enabled, and is a ZST when the feature is disabled. Existing code that needs a `&Location` can call `into_option().unwrap()` to recover it. Many trait impls are forwarded, so if you only need `Display` then no changes will be necessary. If that code was conditionally compiled, you may instead want to use the methods on `MaybeLocation` to remove the need for conditional compilation. Code that constructs a `Ref`, `Mut`, `Res`, or `ResMut` will now need to provide location information unconditionally. If you are creating them from existing Bevy types, you can obtain a `MaybeLocation` from methods like `Table::get_changed_by_slice_for()` or `ComponentSparseSet::get_with_ticks`. Otherwise, you will need to store a `MaybeLocation` next to your data and use methods like `as_ref()` or `as_mut()` to obtain wrapped references. |
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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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3c8fae2390
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Improved Entity Mapping and Cloning (#17687)
Fixes #17535 Bevy's approach to handling "entity mapping" during spawning and cloning needs some work. The addition of [Relations](https://github.com/bevyengine/bevy/pull/17398) both [introduced a new "duplicate entities" bug when spawning scenes in the scene system](#17535) and made the weaknesses of the current mapping system exceedingly clear: 1. Entity mapping requires _a ton_ of boilerplate (implement or derive VisitEntities and VisitEntitesMut, then register / reflect MapEntities). Knowing the incantation is challenging and if you forget to do it in part or in whole, spawning subtly breaks. 2. Entity mapping a spawned component in scenes incurs unnecessary overhead: look up ReflectMapEntities, create a _brand new temporary instance_ of the component using FromReflect, map the entities in that instance, and then apply that on top of the actual component using reflection. We can do much better. Additionally, while our new [Entity cloning system](https://github.com/bevyengine/bevy/pull/16132) is already pretty great, it has some areas we can make better: * It doesn't expose semantic info about the clone (ex: ignore or "clone empty"), meaning we can't key off of that in places where it would be useful, such as scene spawning. Rather than duplicating this info across contexts, I think it makes more sense to add that info to the clone system, especially given that we'd like to use cloning code in some of our spawning scenarios. * EntityCloner is currently built in a way that prioritizes a single entity clone * EntityCloner's recursive cloning is built to be done "inside out" in a parallel context (queue commands that each have a clone of EntityCloner). By making EntityCloner the orchestrator of the clone we can remove internal arcs, improve the clarity of the code, make EntityCloner mutable again, and simplify the builder code. * EntityCloner does not currently take into account entity mapping. This is necessary to do true "bullet proof" cloning, would allow us to unify the per-component scene spawning and cloning UX, and ultimately would allow us to use EntityCloner in place of raw reflection for scenes like `Scene(World)` (which would give us a nice performance boost: fewer archetype moves, less reflection overhead). ## Solution ### Improved Entity Mapping First, components now have first-class "entity visiting and mapping" behavior: ```rust #[derive(Component, Reflect)] #[reflect(Component)] struct Inventory { size: usize, #[entities] items: Vec<Entity>, } ``` Any field with the `#[entities]` annotation will be viewable and mappable when cloning and spawning scenes. Compare that to what was required before! ```rust #[derive(Component, Reflect, VisitEntities, VisitEntitiesMut)] #[reflect(Component, MapEntities)] struct Inventory { #[visit_entities(ignore)] size: usize, items: Vec<Entity>, } ``` Additionally, for relationships `#[entities]` is implied, meaning this "just works" in scenes and cloning: ```rust #[derive(Component, Reflect)] #[relationship(relationship_target = Children)] #[reflect(Component)] struct ChildOf(pub Entity); ``` Note that Component _does not_ implement `VisitEntities` directly. Instead, it has `Component::visit_entities` and `Component::visit_entities_mut` methods. This is for a few reasons: 1. We cannot implement `VisitEntities for C: Component` because that would conflict with our impl of VisitEntities for anything that implements `IntoIterator<Item=Entity>`. Preserving that impl is more important from a UX perspective. 2. We should not implement `Component: VisitEntities` VisitEntities in the Component derive, as that would increase the burden of manual Component trait implementors. 3. Making VisitEntitiesMut directly callable for components would make it easy to invalidate invariants defined by a component author. By putting it in the `Component` impl, we can make it harder to call naturally / unavailable to autocomplete using `fn visit_entities_mut(this: &mut Self, ...)`. `ReflectComponent::apply_or_insert` is now `ReflectComponent::apply_or_insert_mapped`. By moving mapping inside this impl, we remove the need to go through the reflection system to do entity mapping, meaning we no longer need to create a clone of the target component, map the entities in that component, and patch those values on top. This will make spawning mapped entities _much_ faster (The default `Component::visit_entities_mut` impl is an inlined empty function, so it will incur no overhead for unmapped entities). ### The Bug Fix To solve #17535, spawning code now skips entities with the new `ComponentCloneBehavior::Ignore` and `ComponentCloneBehavior::RelationshipTarget` variants (note RelationshipTarget is a temporary "workaround" variant that allows scenes to skip these components. This is a temporary workaround that can be removed as these cases should _really_ be using EntityCloner logic, which should be done in a followup PR. When that is done, `ComponentCloneBehavior::RelationshipTarget` can be merged into the normal `ComponentCloneBehavior::Custom`). ### Improved Cloning * `Option<ComponentCloneHandler>` has been replaced by `ComponentCloneBehavior`, which encodes additional intent and context (ex: `Default`, `Ignore`, `Custom`, `RelationshipTarget` (this last one is temporary)). * Global per-world entity cloning configuration has been removed. This felt overly complicated, increased our API surface, and felt too generic. Each clone context can have different requirements (ex: what a user wants in a specific system, what a scene spawner wants, etc). I'd prefer to see how far context-specific EntityCloners get us first. * EntityCloner's internals have been reworked to remove Arcs and make it mutable. * EntityCloner is now directly stored on EntityClonerBuilder, simplifying the code somewhat * EntityCloner's "bundle scratch" pattern has been moved into the new BundleScratch type, improving its usability and making it usable in other contexts (such as future cross-world cloning code). Currently this is still private, but with some higher level safe APIs it could be used externally for making dynamic bundles * EntityCloner's recursive cloning behavior has been "externalized". It is now responsible for orchestrating recursive clones, meaning it no longer needs to be sharable/clone-able across threads / read-only. * EntityCloner now does entity mapping during clones, like scenes do. This gives behavior parity and also makes it more generically useful. * `RelatonshipTarget::RECURSIVE_SPAWN` is now `RelationshipTarget::LINKED_SPAWN`, and this field is used when cloning relationship targets to determine if cloning should happen recursively. The new `LINKED_SPAWN` term was picked to make it more generically applicable across spawning and cloning scenarios. ## Next Steps * I think we should adapt EntityCloner to support cross world cloning. I think this PR helps set the stage for that by making the internals slightly more generalized. We could have a CrossWorldEntityCloner that reuses a lot of this infrastructure. * Once we support cross world cloning, we should use EntityCloner to spawn `Scene(World)` scenes. This would yield significant performance benefits (no archetype moves, less reflection overhead). --------- Co-authored-by: eugineerd <70062110+eugineerd@users.noreply.github.com> Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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be9b38e372
|
implement UniqueEntitySlice (#17589)
# Objective Follow-up to #17549 and #16547. A large part of `Vec`s usefulness is behind its ability to be sliced, like sorting f.e., so we want the same to be possible for `UniqueEntityVec`. ## Solution Add a `UniqueEntitySlice` type. It is a wrapper around `[T]`, and itself a DST. Because `mem::swap` has a `Sized` bound, DSTs cannot be swapped, and we can freely hand out mutable subslices without worrying about the uniqueness invariant of the backing collection! `UniqueEntityVec` and the relevant `UniqueEntityIter`s now have methods and trait impls that return `UniqueEntitySlice`s. `UniqueEntitySlice` itself can deref into normal slices, which means we can avoid implementing the vast majority of immutable slice methods. Most of the remaining methods: - split a slice/collection in further unique subsections/slices - reorder the slice: `sort`, `rotate_*`, `swap` - construct/deconstruct/convert pointer-like types: `Box`, `Arc`, `Rc`, `Cow` - are comparison trait impls As this PR is already larger than I'd like, we leave several things to follow-ups: - `UniqueEntityArray` and the related slice methods that would return it - denoted by "chunk", "array_*" for iterators - Methods that return iterators with `UniqueEntitySlice` as their item - `windows`, `chunks` and `split` families - All methods that are capable of actively mutating individual elements. While they could be offered unsafely, subslicing makes their safety contract weird enough to warrant its own discussion. - `fill_with`, `swap_with_slice`, `iter_mut`, `split_first/last_mut`, `select_nth_unstable_*` Note that `Arc`, `Rc` and `Cow` are not fundamental types, so even if they contain `UniqueEntitySlice`, we cannot write direct trait impls for them. On top of that, `Cow` is not a receiver (like `self: Arc<Self>` is) so we cannot write inherent methods for it either. |
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9165fb020a
|
Implement Serialize /Deserialize for entity collections (#17620)
# Objective Follow-up to #17615. Bevy's entity collection types like `EntityHashSet` no longer implement serde's `Serialize` and `Deserialize` after becoming newtypes instead of type aliases in #16912. This broke some types that support serde for me in Avian. I also missed creating const constructors for `EntityIndexMap` and `EntityIndexSet` in #17615. Oops! ## Solution Implement `Serialize` and `Deserialize` for Bevy's entity collection types, and add const constructors for `EntityIndexMap` and `EntityIndexSet`. I didn't implement `ReflectSerialize` or `ReflectDeserialize` here, because I had some trouble fixing the resulting errors, and they were not implemented previously either. |
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59697f9ccc
|
Make EntityHashMap::new and EntityHashSet::new const (#17615)
# Objective #16912 turned `EntityHashMap` and `EntityHashSet` into proper newtypes instead of type aliases. However, this removed the ability to create these collections in const contexts; previously, you could use `EntityHashSet::with_hasher(EntityHash)`, but it doesn't exist anymore. ## Solution Make `EntityHashMap::new` and `EntityHashSet::new` const methods. |
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b039bf6768
|
implement UniqueEntityVec (#17549)
# Objective In #16547, we added `EntitySet`s/`EntitySetIterator`s. We can know whenever an iterator only contains unique entities, however we do not yet have the ability to collect and reuse these without either the unsafe `UniqueEntityIter::from_iterator_unchecked`, or the expensive `HashSet::from_iter`. An important piece for being able to do this is a `Vec` that maintains the uniqueness property, can be collected into, and is itself `EntitySet`. A lot of entity collections are already intended to be "unique", but have no way of expressing that when stored, other than using an aforementioned `HashSet`. Such a type helps by limiting or even removing the need for unsafe on the user side when not using a validated `Set` type, and makes it easier to interface with other infrastructure like f.e. `RelationshipSourceCollection`s. ## Solution We implement `UniqueEntityVec`. This is a wrapper around `Vec`, that only ever contains unique elements. It mirrors the API of `Vec`, however restricts any mutation as to not violate the uniqueness guarantee. Meaning: - Any inherent method which can introduce new elements or mutate existing ones is now unsafe, f.e.: `insert`, `retain_mut` - Methods that are impossible to use safely are omitted, f.e.: `fill`, `extend_from_within` A handful of the unsafe methods can do element-wise mutation (`retain_mut`, `dedup_by`), which can be an unwind safety hazard were the element-wise operation to panic. For those methods, we require that each individual execution of the operation upholds uniqueness, not just the entire method as a whole. To be safe for mutable usage, slicing and the associated slice methods require a matching `UniqueEntitySlice` type , which we leave for a follow-up PR. Because this type will deref into the `UniqueEntitySlice` type, we also offer the immutable `Vec` methods on this type (which only amount to a handful). "as inner" functionality is covered by additional `as_vec`/`as_mut_vec` methods + `AsRef`/`Borrow` trait impls. Like `UniqueEntityIter::from_iterator_unchecked`, this type has a `from_vec_unchecked` method as well. The canonical way to safely obtain this type however is via `EntitySetIterator::collect_set` or `UniqueEntityVec::from_entity_set_iter`. Like mentioned in #17513, these are named suboptimally until supertrait item shadowing arrives, since a normal `collect` will still run equality checks. |
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39a1e2b488
|
implement EntityIndexMap/Set (#17449)
# Objective We do not have `EntityIndexMap`/`EntityIndexSet`. Usual `HashMap`s/`HashSet`s do not guarantee any order, which can be awkward for some use cases. The `indexmap` versions remember insertion order, which then also becomes their iteration order. They can be thought of as a `HashTable` + `Vec`, which means fast iteration and removal, indexing by index (not just key), and slicing! Performance should otherwise be comparable. ## Solution Because `indexmap` is structured to mirror `hashbrown`, it suffers the same issue of not having the `Hasher` generic on their iterators. #16912 solved this issue for `EntityHashMap`/`EntityHashSet` with a wrapper around the hashbrown version, so this PR does the same. Hopefully these wrappers can be removed again in the future by having `hashbrown`/`indexmap` adopt that generic in their iterators themselves! |
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94a238b0ef
|
implement FromEntitySetIterator (#17513)
# Objective Some collections are more efficient to construct when we know that every element is unique in advance. We have `EntitySetIterator`s from #16547, but currently no API to safely make use of them this way. ## Solution Add `FromEntitySetIterator` as a subtrait to `FromIterator`, and implement it for the `EntityHashSet`/`hashbrown::HashSet` types. To match the normal `FromIterator`, we also add a `EntitySetIterator::collect_set` method. It'd be better if these methods could shadow `from_iter` and `collect` completely, but https://github.com/rust-lang/rust/issues/89151 is needed for that. While currently only `HashSet`s implement this trait, future `UniqueEntityVec`/`UniqueEntitySlice` functionality comes with more implementors. Because `HashMap`s are collected from tuples instead of singular types, implementing this same optimization for them is more complex, and has to be done separately. ## Showcase This is basically a free speedup for collecting `EntityHashSet`s! ```rust pub fn collect_milk_dippers(dippers: Query<Entity, (With<Milk>, With<Cookies>)>) { dippers.iter().collect_set::<EntityHashSet>(); // or EntityHashSet::from_entity_set_iter(dippers); } --------- Co-authored-by: SpecificProtagonist <vincentjunge@posteo.net> |
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9bc0ae33c3
|
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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f32a6fb205
|
Track callsite for observers & hooks (#15607)
# Objective Fixes #14708 Also fixes some commands not updating tracked location. ## Solution `ObserverTrigger` has a new `caller` field with the `track_change_detection` feature; hooks take an additional caller parameter (which is `Some(…)` or `None` depending on the feature). ## Testing See the new tests in `src/observer/mod.rs` --- ## Showcase Observers now know from where they were triggered (if `track_change_detection` is enabled): ```rust world.observe(move |trigger: Trigger<OnAdd, Foo>| { println!("Added Foo from {}", trigger.caller()); }); ``` ## Migration - hooks now take an additional `Option<&'static Location>` argument --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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93e5e6cb95
|
fix double comment characters (#17484)
# Objective - Improve docs by removing duplicate comment characters - Fixes #17483 ## Solution - Replaced `/// ///` with `///` |
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![]() |
ba5e71f53d
|
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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59657ed1e2
|
remove unsound DerefMut impls from EntityHashMap /EntityHashSet (#17450)
# Objective Noticed while doing #17449, I had left these `DerefMut` impls in. Obtaining mutable references to those inner iterator types allows for `mem::swap`, which can be used to swap an incorrectly behaving instance into the wrappers. ## Solution Remove them! |
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5a9bc28502
|
Support non-Vec data structures in relations (#17447)
# Objective
The existing `RelationshipSourceCollection` uses `Vec` as the only
possible backing for our relationships. While a reasonable choice,
benchmarking use cases might reveal that a different data type is better
or faster.
For example:
- Not all relationships require a stable ordering between the
relationship sources (i.e. children). In cases where we a) have many
such relations and b) don't care about the ordering between them, a hash
set is likely a better datastructure than a `Vec`.
- The number of children-like entities may be small on average, and a
`smallvec` may be faster
## Solution
- Implement `RelationshipSourceCollection` for `EntityHashSet`, our
custom entity-optimized `HashSet`.
-~~Implement `DoubleEndedIterator` for `EntityHashSet` to make things
compile.~~
- This implementation was cursed and very surprising.
- Instead, by moving the iterator type on `RelationshipSourceCollection`
from an erased RPTIT to an explicit associated type we can add a trait
bound on the offending methods!
- Implement `RelationshipSourceCollection` for `SmallVec`
## Testing
I've added a pair of new tests to make sure this pattern compiles
successfully in practice!
## Migration Guide
`EntityHashSet` and `EntityHashMap` are no longer re-exported in
`bevy_ecs::entity` directly. If you were not using `bevy_ecs` / `bevy`'s
`prelude`, you can access them through their now-public modules,
`hash_set` and `hash_map` instead.
## Notes to reviewers
The `EntityHashSet::Iter` type needs to be public for this impl to be
allowed. I initially renamed it to something that wasn't ambiguous and
re-exported it, but as @Victoronz pointed out, that was somewhat
unidiomatic.
In
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a64446b77e
|
Create bevy_platform_support Crate (#17250)
# Objective - Contributes to #16877 ## Solution - Initial creation of `bevy_platform_support` crate. - Moved `bevy_utils::Instant` into new `bevy_platform_support` crate. - Moved `portable-atomic`, `portable-atomic-util`, and `critical-section` into new `bevy_platform_support` crate. ## Testing - CI --- ## Showcase Instead of needing code like this to import an `Arc`: ```rust #[cfg(feature = "portable-atomic")] use portable_atomic_util::Arc; #[cfg(not(feature = "portable-atomic"))] use alloc::sync::Arc; ``` We can now use: ```rust use bevy_platform_support::sync::Arc; ``` This applies to many other types, but the goal is overall the same: allowing crates to use `std`-like types without the boilerplate of conditional compilation and platform-dependencies. ## Migration Guide - Replace imports of `bevy_utils::Instant` with `bevy_platform_support::time::Instant` - Replace imports of `bevy::utils::Instant` with `bevy::platform_support::time::Instant` ## Notes - `bevy_platform_support` hasn't been reserved on `crates.io` - ~~`bevy_platform_support` is not re-exported from `bevy` at this time. It may be worthwhile exporting this crate, but I am unsure of a reasonable name to export it under (`platform_support` may be a bit wordy for user-facing).~~ - I've included an implementation of `Instant` which is suitable for `no_std` platforms that are not Wasm for the sake of eliminating feature gates around its use. It may be a controversial inclusion, so I'm happy to remove it if required. - There are many other items (`spin`, `bevy_utils::Sync(Unsafe)Cell`, etc.) which should be added to this crate. I have kept the initial scope small to demonstrate utility without making this too unwieldy. --------- Co-authored-by: TimJentzsch <TimJentzsch@users.noreply.github.com> Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com> Co-authored-by: François Mockers <francois.mockers@vleue.com> |
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21f1e3045c
|
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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17c46f4add
|
bevy_ecs: Apply #![warn(clippy::allow_attributes, clippy::allow_attributes_without_reason)] (#17335)
# Objective - https://github.com/bevyengine/bevy/issues/17111 ## Solution Set the `clippy::allow_attributes` and `clippy::allow_attributes_without_reason` lints to `warn`, and bring `bevy_ecs` in line with the new restrictions. ## Testing This PR is a WIP; testing will happen after it's finished. |
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f5d38f30cc
|
Fix entity does not exist message on index reuse (#17264)
# Objective With the `track_location` feature, the error message of trying to acquire an entity that was despawned pointed to the wrong line if the entity index has been reused. ## Showcase ```rust use bevy_ecs::prelude::*; fn main() { let mut world = World::new(); let e = world.spawn_empty().id(); world.despawn(e); world.flush(); let _ = world.spawn_empty(); world.entity(e); } ``` Old message: ``` Entity 0v1 was despawned by src/main.rs:8:19 ``` New message: ``` Entity 0v1 does not exist (its index has been reused) ``` |
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4fde223831
|
Optimize Entities::entity_does_not_exist_error_details_message , remove UnsafeWorldCell from error (#17115)
## Objective The error `EntityFetchError::NoSuchEntity` has an `UnsafeWorldCell` inside it, which it uses to call `Entities::entity_does_not_exist_error_details_message` when being printed. That method returns a `String` that, if the `track_location` feature is enabled, contains the location of whoever despawned the relevant entity. I initially had to modify this error while working on #17043. The `UnsafeWorldCell` was causing borrow problems when being returned from a command, so I tried replacing it with the `String` that the method returns, since that was the world cell's only purpose. Unfortunately, `String`s are slow, and it significantly impacted performance (on top of that PR's performance hit): <details> <summary>17043 benchmarks</summary> ### With `String`  ### No `String`  </details> For that PR, I just removed the error details entirely, but I figured I'd try to find a way to keep them around. ## Solution - Replace the `String` with a helper struct that holds the location, and only turn it into a string when someone actually wants to print it. - Replace the `UnsafeWorldCell` with the aforementioned struct. - Do the same for `QueryEntityError::NoSuchEntity`. ## Benchmarking This had some interesting performance impact: <details> <summary>This PR vs main</summary>    </details> ## Other work `QueryEntityError::QueryDoesNotMatch` also has an `UnsafeWorldCell` inside it. This one would be more complicated to rework while keeping the same functionality. ## Migration Guide The errors `EntityFetchError::NoSuchEntity` and `QueryEntityError::NoSuchEntity` now contain an `EntityDoesNotExistDetails` struct instead of an `UnsafeWorldCell`. If you were just printing these, they should work identically. --------- Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com> |
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0403948aa2
|
Remove Implicit std Prelude from no_std Crates (#17086)
# Background In `no_std` compatible crates, there is often an `std` feature which will allow access to the standard library. Currently, with the `std` feature _enabled_, the [`std::prelude`](https://doc.rust-lang.org/std/prelude/index.html) is implicitly imported in all modules. With the feature _disabled_, instead the [`core::prelude`](https://doc.rust-lang.org/core/prelude/index.html) is implicitly imported. This creates a subtle and pervasive issue where `alloc` items _may_ be implicitly included (if `std` is enabled), or must be explicitly included (if `std` is not enabled). # Objective - Make the implicit imports for `no_std` crates consistent regardless of what features are/not enabled. ## Solution - Replace the `cfg_attr` "double negative" `no_std` attribute with conditional compilation to _include_ `std` as an external crate. ```rust // Before #![cfg_attr(not(feature = "std"), no_std)] // After #![no_std] #[cfg(feature = "std")] extern crate std; ``` - Fix imports that are currently broken but are only now visible with the above fix. ## Testing - CI ## Notes I had previously used the "double negative" version of `no_std` based on general consensus that it was "cleaner" within the Rust embedded community. However, this implicit prelude issue likely was considered when forming this consensus. I believe the reason why is the items most affected by this issue are provided by the `alloc` crate, which is rarely used within embedded but extensively used within Bevy. |
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294e0db719
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Rename track_change_detection flag to track_location (#17075)
# Objective - As stated in the related issue, this PR is to better align the feature flag name with what it actually does and the plans for the future. - Fixes #16852 ## Solution - Simple find / replace ## Testing - Local run of `cargo run -p ci` ## Migration Guide The `track_change_detection` feature flag has been renamed to `track_location` to better reflect its extended capabilities. |
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847c3a1719
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Fix random clippy warning (#17010)
# Objective Follow-up to #16984 ## Solution Fix the lint ## Testing ``` PS C:\Users\BenjaminBrienen\source\bevy> cargo clippy Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.71s PS C:\Users\BenjaminBrienen\source\bevy> cargo clippy -p bevy_ecs Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.21s ``` |
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1675d68366
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Fix beta CI (#16984)
# Objective Fixes #16607 ## Solution Satisfy clippy ## Testing Ran clippy |
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8ac90ac542
|
make EntityHashMap and EntityHashSet proper types (#16912)
# Objective `EntityHashMap` and `EntityHashSet` iterators do not implement `EntitySetIterator`. ## Solution Make them newtypes instead of aliases. The methods that create the iterators can then produce their own newtypes that carry the `Hasher` generic and implement `EntitySetIterator`. Functionality remains the same otherwise. There are some other small benefits, f.e. the removal of `with_hasher` associated functions, and the ability to implement more traits ourselves. `MainEntityHashMap` and `MainEntityHashSet` are currently left as the previous type aliases, because supporting general `TrustedEntityBorrow` hashing is more complex. However, it can also be done. ## Testing Pre-existing `EntityHashMap` tests. ## Migration Guide Users of `with_hasher` and `with_capacity_and_hasher` on `EntityHashMap`/`Set` must now use `new` and `with_capacity` respectively. If the non-newtyped versions are required, they can be obtained via `Deref`, `DerefMut` or `into_inner` calls. |
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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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20049d4c34
|
Faster entity cloning (#16717)
# Objective #16132 introduced entity cloning functionality, and while it works and is useful, it can be made faster. This is the promised follow-up to improve performance. ## Solution **PREFACE**: This is my first time writing `unsafe` in rust and I have only vague idea about what I'm doing. I would encourage reviewers to scrutinize `unsafe` parts in particular. The solution is to clone component data to an intermediate buffer and use `EntityWorldMut::insert_by_ids` to insert components without additional archetype moves. To facilitate this, `EntityCloner::clone_entity` now reads all components of the source entity and provides clone handlers with the ability to read component data straight from component storage using `read_source_component` and write to an intermediate buffer using `write_target_component`. `ComponentId` is used to check that requested type corresponds to the type available on source entity. Reflect-based handler is a little trickier to pull of: we only have `&dyn Reflect` and no direct access to the underlying data. `ReflectFromPtr` can be used to get `&dyn Reflect` from concrete component data, but to write it we need to create a clone of the underlying data using `Reflect`. For this reason only components that have `ReflectDefault` or `ReflectFromReflect` or `ReflectFromWorld` can be cloned, all other components will be skipped. The good news is that this is actually only a temporary limitation: once #13432 lands we will be able to clone component without requiring one of these `type data`s. This PR also introduces `entity_cloning` benchmark to better compare changes between the PR and main, you can see the results in the **showcase** section. ## Testing - All previous tests passing - Added test for fast reflect clone path (temporary, will be removed after reflection-based cloning lands) - Ran miri ## Showcase Here's a table demonstrating the improvement: | **benchmark** | **main, avg** | **PR, avg** | **change, avg** | | ----------------------- | ------------- | ----------- | --------------- | | many components reflect | 18.505 µs | 2.1351 µs | -89.095% | | hierarchy wide reflect* | 22.778 ms | 4.1875 ms | -81.616% | | hierarchy tall reflect* | 107.24 µs | 26.322 µs | -77.141% | | hierarchy many reflect | 78.533 ms | 9.7415 ms | -87.596% | | many components clone | 1.3633 µs | 758.17 ns | -45.937% | | hierarchy wide clone* | 2.7716 ms | 3.3411 ms | +20.546% | | hierarchy tall clone* | 17.646 µs | 20.190 µs | +17.379% | | hierarchy many clone | 5.8779 ms | 4.2650 ms | -27.439% | *: these benchmarks have entities with only 1 component ## Considerations Once #10154 is resolved a large part of the functionality in this PR will probably become obsolete. It might still be a little bit faster than using command batching, but the complexity might not be worth it. ## Migration Guide - `&EntityCloner` in component clone handlers is changed to `&mut ComponentCloneCtx` to better separate data. - Changed `EntityCloneHandler` from enum to struct and added convenience functions to add default clone and reflect handler more easily. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com> |
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a4b89d0d5e
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implement EntitySet and iter_many_unique methods (#16547)
# Objective In current Bevy, it is very inconvenient to mutably retrieve a user-provided list of entities more than one element at a time. If the list contains any duplicate entities, we risk mutable aliasing. Users of `Query::iter_many_mut` do not have access to `Iterator` trait, and thus miss out on common functionality, for instance collecting their `QueryManyIter`. We can circumvent this issue with validation, however that entails checking every entity against all others for inequality, or utilizing an `EntityHashSet`. Even if an entity list remains unchanged, this validation is/would have to be redone every time we wish to fetch with the list. This presents a lot of wasted work, as we often trivially know an entity list to be unique f.e.: `QueryIter` will fetch every `Entity` once and only once. As more things become entities – assets, components, queries – this issue will become more pronounced. `get_many`/`many`/`iter_many`/`par_iter_many`-like functionality is all affected. ## Solution The solution this PR proposes is to introduce functionality built around a new trait: `EntitySet`. The goal is to preserve the property of "uniqueness" in a list wherever possible, and then rely on it as a bound within new `*_many_unique` methods to avoid the need for validation. This is achieved using `Iterator`: `EntitySet` is blanket implemented for any `T` that implements `IntoIterator<IntoIter: EntitySetIterator>`. `EntitySetIterator` is the unsafe trait that actually guarantees an iterator to be "unique" via its safety contract. We define an "Iterator over unique entities" as: "No two entities returned by the iterator may compare equal." For iterators that cannot return more than 1 element, this is trivially true. Whether an iterator can satisfy this is up to the `EntitySetIterator` implementor to ensure, hence the unsafe. However, this is not yet a complete solution. Looking at the signature of `iter_many`, we find that `IntoIterator::Item` is not `Entity`, but is instead bounded by the `Borrow<Entity>` trait. That is because iteration without consuming the collection will often yield us references, not owned items. `Borrow<Entity>` presents an issue: The `Borrow` docs state that `x = y` should equal `x.borrow() = y.borrow()`, but unsafe cannot rely on this for soundness. We run into similar problems with other trait implementations of any `Borrow<Entity>` type: `PartialEq`, `Eq`, `PartialOrd`, `Ord`, `Hash`, `Clone`, `Borrow`, and `BorrowMut`. This PR solves this with the unsafe `TrustedEntityBorrow` trait: Any implementor promises that the behavior of the aforementioned traits matches that of the underlying entity. While `Borrow<Entity>` was the inspiration, we use our own counterpart trait `EntityBorrow` as the supertrait to `TrustedEntityBorrow`, so we can circumvent the limitations of the existing `Borrow<T>` blanket impls. All together, these traits allow us to implement `*_many_unique` functionality with a lone `EntitySet` bound. `EntitySetIterator` is implemented for all the std iterators and iterator adapters that guarantee or preserve uniqueness, so we can filter, skip, take, step, reverse, ... our unique entity iterators without worry! Sadly, current `HashSet` iterators do not carry the necessary type information with them to determine whether the source `HashSet` produces logic errors; A malicious `Hasher` could compromise a `HashSet`. `HashSet` iteration is generally discouraged in the first place, so we also exclude the set operation iterators, even though they do carry the `Hasher` type parameter. `BTreeSet` implements `EntitySet` without any problems. If an iterator type cannot guarantee uniqueness at compile time, then a user can still attach `EntitySetIterator` to an individual instance of that type via `UniqueEntityIter::from_iterator_unchecked`. With this, custom types can use `UniqueEntityIter<I>` as their `IntoIterator::IntoIter` type, if necessary. This PR is focused on the base concept, and expansions on it are left for follow-up PRs. See "Potential Future Work" below. ## Testing Doctests on `iter_many_unique`/`iter_many_unique_mut` + 2 tests in entity_set.rs. ## Showcase ```rust // Before: fn system(player_list: Res<SomeUniquePlayerList>, players: Query<&mut Player>) { let value = 0; while let Some(player) = players.iter_many_mut(player_list).fetch_next() { value += mem::take(player.value_mut()) } } // After: fn system(player_list: Res<SomeUniquePlayerList>, players: Query<&mut Player>) { let value = players .iter_many_unique_mut(player_list) .map(|player| mem::take(player.value_mut())) .sum(); } ``` ## Changelog - added `EntityBorrow`, `TrustedEntityBorrow`, `EntitySet` and `EntitySetIterator` traits - added `iter_many_unique`, `iter_many_unique_mut`, `iter_many_unique_unsafe` methods on `Query` - added `iter_many_unique`, `iter_many_unique_mut`, `iter_many_unique_manual` and `iter_many_unique_unchecked_manual` methods on `QueryState` - added corresponding `QueryManyUniqueIter` - added `UniqueEntityIter` ## Migration Guide Any custom type used as a `Borrow<Entity>` entity list item for an `iter_many` method now has to implement `EntityBorrow` instead. Any type that implements `Borrow<Entity>` can trivially implement `EntityBorrow`. ## Potential Future Work - `ToEntitySet` trait for converting any entity iterator into an `EntitySetIterator` - `EntityIndexSet/Map` to tie in hashing with `EntitySet` - add `EntityIndexSetSlice/MapSlice` - requires: `EntityIndexSet/Map` - Implementing `par_iter_many_unique_mut` for parallel mutable iteration - requires: `par_iter_many` - allow collecting into `UniqueEntityVec` to store entity sets - add `UniqueEntitySlice`s - Doesn't require, but should be done after: `UniqueEntityVec` - add `UniqueEntityArray`s - Doesn't require, but should be done after: `UniqueEntitySlice` - `get_many_unique`/`many_unique` methods - requires: `UniqueEntityArray` - `World::entity_unique` to match `World::entity` methods - Doesn't require, but makes sense after: `get_many_unique`/`many_unique` - implement `TrustedEntityBorrow` for the `EntityRef` family - Doesn't require, but makes sense after: `UniqueEntityVec` |
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1f2d0e6308
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Add no_std support to bevy_ecs (#16758)
# Objective - Contributes to #15460 ## Solution - Added the following features: - `std` (default) - `async_executor` (default) - `edge_executor` - `critical-section` - `portable-atomic` - Gated `tracing` in `bevy_utils` to allow compilation on certain platforms - Switched from `tracing` to `log` for simple message logging within `bevy_ecs`. Note that `tracing` supports capturing from `log` so this should be an uncontroversial change. - Fixed imports and added feature gates as required - Made `bevy_tasks` optional within `bevy_ecs`. Turns out it's only needed for parallel operations which are already gated behind `multi_threaded` anyway. ## Testing - Added to `compile-check-no-std` CI command - `cargo check -p bevy_ecs --no-default-features --features edge_executor,critical-section,portable-atomic --target thumbv6m-none-eabi` - `cargo check -p bevy_ecs --no-default-features --features edge_executor,critical-section` - `cargo check -p bevy_ecs --no-default-features` ## Draft Release Notes Bevy's core ECS now supports `no_std` platforms. In prior versions of Bevy, it was not possible to work with embedded or niche platforms due to our reliance on the standard library, `std`. This has blocked a number of novel use-cases for Bevy, such as an embedded database for IoT devices, or for creating games on retro consoles. With this release, `bevy_ecs` no longer requires `std`. To use Bevy on a `no_std` platform, you must disable default features and enable the new `edge_executor` and `critical-section` features. You may also need to enable `portable-atomic` and `critical-section` if your platform does not natively support all atomic types and operations used by Bevy. ```toml [dependencies] bevy_ecs = { version = "0.16", default-features = false, features = [ # Required for platforms with incomplete atomics (e.g., Raspberry Pi Pico) "portable-atomic", "critical-section", # Optional "bevy_reflect", "serialize", "bevy_debug_stepping", "edge_executor" ] } ``` Currently, this has been tested on bare-metal x86 and the Raspberry Pi Pico. If you have trouble using `bevy_ecs` on a particular platform, please reach out either through a GitHub issue or in the `no_std` working group on the Bevy Discord server. Keep an eye out for future `no_std` updates as we continue to improve the parity between `std` and `no_std`. We look forward to seeing what kinds of applications are now possible with Bevy! ## Notes - Creating PR in draft to ensure CI is passing before requesting reviews. - This implementation has no support for multithreading in `no_std`, especially due to `NonSend` being unsound if allowed in multithreading. The reason is we cannot check the `ThreadId` in `no_std`, so we have no mechanism to at-runtime determine if access is sound. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: Vic <59878206+Victoronz@users.noreply.github.com> |
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21195a75e6
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track_change_detection: Also track spawns/despawns (#16047)
# Objective Expand `track_change_detection` feature to also track entity spawns and despawns. Use this to create better error messages. # Solution Adds `Entities::entity_get_spawned_or_despawned_by` as well as `{all entity reference types}::spawned_by`. This also removes the deprecated `get_many_entities_mut` & co (and therefore can't land in 0.15) because we don't yet have no Polonius. ## Testing Added a test that checks that the locations get updated and these updates are ordered correctly vs hooks & observers. --- ## Showcase Access location: ```rust let mut world = World::new(); let entity = world.spawn_empty().id(); println!("spawned by: {}", world.entity(entity).spawned_by()); ``` ``` spawned by: src/main.rs:5:24 ``` Error message (with `track_change_detection`): ```rust world.despawn(entity); world.entity(entity); ``` ``` thread 'main' panicked at src/main.rs:11:11: Entity 0v1#4294967296 was despawned by src/main.rs:10:11 ``` and without: ``` thread 'main' panicked at src/main.rs:11:11: Entity 0v1#4294967296 does not exist (enable `track_change_detection` feature for more details) ``` Similar error messages now also exists for `Query::get`, `World::entity_mut`, `EntityCommands` creation and everything that causes `B0003`, e.g. ``` error[B0003]: Could not insert a bundle (of type `MaterialMeshBundle<StandardMaterial>`) for entity Entity { index: 7, generation: 1 }, which was despawned by src/main.rs:10:11. See: https://bevyengine.org/learn/errors/#b0003 ``` --------- Co-authored-by: kurk070ff <108901106+kurk070ff@users.noreply.github.com> Co-authored-by: Freya Pines <freya@MacBookAir.lan> Co-authored-by: Freya Pines <freya@Freyas-MacBook-Air.local> Co-authored-by: Matty Weatherley <weatherleymatthew@gmail.com> |
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5a94beb239
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Extend cloning functionality and add convenience methods to EntityWorldMut and EntityCommands (#16826)
## Objective Thanks to @eugineerd's work on entity cloning (#16132), we now have a robust way to copy components between entities. We can extend this to implement some useful functionality that would have been more complicated before. Closes #15350. ## Solution `EntityCloneBuilder` now automatically includes required components alongside any component added/removed from the component filter. Added the following methods to `EntityCloneBuilder`: - `move_components` - `without_required_components` Added the following methods to `EntityWorldMut` and `EntityCommands`: - `clone_with` - `clone_components` - `move_components` Also added `clone_and_spawn` and `clone_and_spawn_with` to `EntityWorldMut` (`EntityCommands` already had them). ## Showcase ``` assert_eq!(world.entity(entity_a).get::<B>(), Some(&B)); assert_eq!(world.entity(entity_b).get::<B>(), None); world.entity_mut(entity_a).clone_components::<B>(entity_b); assert_eq!(world.entity(entity_a).get::<B>(), Some(&B)); assert_eq!(world.entity(entity_b).get::<B>(), Some(&B)); assert_eq!(world.entity(entity_a).get::<C>(), Some(&C(5))); assert_eq!(world.entity(entity_b).get::<C>(), None); world.entity_mut(entity_a).move_components::<C>(entity_b); assert_eq!(world.entity(entity_a).get::<C>(), None); assert_eq!(world.entity(entity_b).get::<C>(), Some(&C(5))); ``` |
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711246aa34
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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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76d610d465
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Flush commands after every mutation in WorldEntityMut (#16219)
# Objective - Currently adding observers spawns an entity which implicitly flushes the command queue, which can cause undefined behaviour if the `WorldEntityMut` is used after this - The reason `WorldEntityMut` attempted to (unsuccessfully) avoid flushing commands until finished was that such commands may move or despawn the entity being referenced, invalidating the cached location. - With the introduction of hooks and observers, this isn't sensible anymore as running the commands generated by hooks immediately is required to maintain correct ordering of operations and to not expose the world in an inconsistent state - Objective is to make command flushing deterministic and fix the related issues - Fixes #16212 - Fixes #14621 - Fixes #16034 ## Solution - Allow `WorldEntityMut` to exist even when it refers to a despawned entity by allowing `EntityLocation` to be marked invalid - Add checks to all methods to panic if trying to access a despawned entity - Flush command queue after every operation that might trigger hooks or observers - Update entity location always after flushing command queue ## Testing - Added test cases for currently broken behaviour - Added test cases that flushes happen in all operations - Added test cases to ensure hooks and commands are run exactly in correct order when nested --- Todo: - [x] Write migration guide - [x] Add tests that using `EntityWorldMut` on a despawned entity panics - [x] Add tests that commands are flushed after every operation that is supposed to flush them - [x] Add tests that hooks, observers and their spawned commands are run in the correct order when nested --- ## Migration Guide Previously `EntityWorldMut` triggered command queue flushes in unpredictable places, which could interfere with hooks and observers. Now the command queue is flushed always immediately after any call in `EntityWorldMut` that spawns or despawns an entity, or adds, removes or replaces a component. This means hooks and observers will run their commands in the correct order. As a side effect, there is a possibility that a hook or observer could despawn the entity that is being referred to by `EntityWorldMut`. This could already currently happen if an observer was added while keeping an `EntityWorldMut` referece and would cause unsound behaviour. If the entity has been despawned, calling any methods which require the entity location will panic. This matches the behaviour that `Commands` will panic if called on an already despawned entity. In the extremely rare case where taking a new `EntityWorldMut` reference or otherwise restructuring the code so that this case does not happen is not possible, there's a new `is_despawned` method that can be used to check if the referred entity has been despawned. |
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a35811d088
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Add Immutable Component Support (#16372)
# Objective - Fixes #16208 ## Solution - Added an associated type to `Component`, `Mutability`, which flags whether a component is mutable, or immutable. If `Mutability= Mutable`, the component is mutable. If `Mutability= Immutable`, the component is immutable. - Updated `derive_component` to default to mutable unless an `#[component(immutable)]` attribute is added. - Updated `ReflectComponent` to check if a component is mutable and, if not, panic when attempting to mutate. ## Testing - CI - `immutable_components` example. --- ## Showcase Users can now mark a component as `#[component(immutable)]` to prevent safe mutation of a component while it is attached to an entity: ```rust #[derive(Component)] #[component(immutable)] struct Foo { // ... } ``` This prevents creating an exclusive reference to the component while it is attached to an entity. This is particularly powerful when combined with component hooks, as you can now fully track a component's value, ensuring whatever invariants you desire are upheld. Before this would be done my making a component private, and manually creating a `QueryData` implementation which only permitted read access. <details> <summary>Using immutable components as an index</summary> ```rust /// This is an example of a component like [`Name`](bevy::prelude::Name), but immutable. #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Component)] #[component( immutable, on_insert = on_insert_name, on_replace = on_replace_name, )] pub struct Name(pub &'static str); /// This index allows for O(1) lookups of an [`Entity`] by its [`Name`]. #[derive(Resource, Default)] struct NameIndex { name_to_entity: HashMap<Name, Entity>, } impl NameIndex { fn get_entity(&self, name: &'static str) -> Option<Entity> { self.name_to_entity.get(&Name(name)).copied() } } fn on_insert_name(mut world: DeferredWorld<'_>, entity: Entity, _component: ComponentId) { let Some(&name) = world.entity(entity).get::<Name>() else { unreachable!() }; let Some(mut index) = world.get_resource_mut::<NameIndex>() else { return; }; index.name_to_entity.insert(name, entity); } fn on_replace_name(mut world: DeferredWorld<'_>, entity: Entity, _component: ComponentId) { let Some(&name) = world.entity(entity).get::<Name>() else { unreachable!() }; let Some(mut index) = world.get_resource_mut::<NameIndex>() else { return; }; index.name_to_entity.remove(&name); } // Setup our name index world.init_resource::<NameIndex>(); // Spawn some entities! let alyssa = world.spawn(Name("Alyssa")).id(); let javier = world.spawn(Name("Javier")).id(); // Check our index let index = world.resource::<NameIndex>(); assert_eq!(index.get_entity("Alyssa"), Some(alyssa)); assert_eq!(index.get_entity("Javier"), Some(javier)); // Changing the name of an entity is also fully capture by our index world.entity_mut(javier).insert(Name("Steven")); // Javier changed their name to Steven let steven = javier; // Check our index let index = world.resource::<NameIndex>(); assert_eq!(index.get_entity("Javier"), None); assert_eq!(index.get_entity("Steven"), Some(steven)); ``` </details> Additionally, users can use `Component<Mutability = ...>` in trait bounds to enforce that a component _is_ mutable or _is_ immutable. When using `Component` as a trait bound without specifying `Mutability`, any component is applicable. However, methods which only work on mutable or immutable components are unavailable, since the compiler must be pessimistic about the type. ## Migration Guide - When implementing `Component` manually, you must now provide a type for `Mutability`. The type `Mutable` provides equivalent behaviour to earlier versions of `Component`: ```rust impl Component for Foo { type Mutability = Mutable; // ... } ``` - When working with generic components, you may need to specify that your generic parameter implements `Component<Mutability = Mutable>` rather than `Component` if you require mutable access to said component. - The entity entry API has had to have some changes made to minimise friction when working with immutable components. Methods which previously returned a `Mut<T>` will now typically return an `OccupiedEntry<T>` instead, requiring you to add an `into_mut()` to get the `Mut<T>` item again. ## Draft Release Notes Components can now be made immutable while stored within the ECS. Components are the fundamental unit of data within an ECS, and Bevy provides a number of ways to work with them that align with Rust's rules around ownership and borrowing. One part of this is hooks, which allow for defining custom behavior at key points in a component's lifecycle, such as addition and removal. However, there is currently no way to respond to _mutation_ of a component using hooks. The reasons for this are quite technical, but to summarize, their addition poses a significant challenge to Bevy's core promises around performance. Without mutation hooks, it's relatively trivial to modify a component in such a way that breaks invariants it intends to uphold. For example, you can use `core::mem::swap` to swap the components of two entities, bypassing the insertion and removal hooks. This means the only way to react to this modification is via change detection in a system, which then begs the question of what happens _between_ that alteration and the next run of that system? Alternatively, you could make your component private to prevent mutation, but now you need to provide commands and a custom `QueryData` implementation to allow users to interact with your component at all. Immutable components solve this problem by preventing the creation of an exclusive reference to the component entirely. Without an exclusive reference, the only way to modify an immutable component is via removal or replacement, which is fully captured by component hooks. To make a component immutable, simply add `#[component(immutable)]`: ```rust #[derive(Component)] #[component(immutable)] struct Foo { // ... } ``` When implementing `Component` manually, there is an associated type `Mutability` which controls this behavior: ```rust impl Component for Foo { type Mutability = Mutable; // ... } ``` Note that this means when working with generic components, you may need to specify that a component is mutable to gain access to certain methods: ```rust // Before fn bar<C: Component>() { // ... } // After fn bar<C: Component<Mutability = Mutable>>() { // ... } ``` With this new tool, creating index components, or caching data on an entity should be more user friendly, allowing libraries to provide APIs relying on components and hooks to uphold their invariants. ## Notes - ~~I've done my best to implement this feature, but I'm not happy with how reflection has turned out. If any reflection SMEs know a way to improve this situation I'd greatly appreciate it.~~ There is an outstanding issue around the fallibility of mutable methods on `ReflectComponent`, but the DX is largely unchanged from `main` now. - I've attempted to prevent all safe mutable access to a component that does not implement `Component<Mutability = Mutable>`, but there may still be some methods I have missed. Please indicate so and I will address them, as they are bugs. - Unsafe is an escape hatch I am _not_ attempting to prevent. Whatever you do with unsafe is between you and your compiler. - I am marking this PR as ready, but I suspect it will undergo fairly major revisions based on SME feedback. - I've marked this PR as _Uncontroversial_ based on the feature, not the implementation. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com> Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com> Co-authored-by: Nuutti Kotivuori <naked@iki.fi> |
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1a6b94c5e8
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Remove flush_and_reserve_invalid_assuming_no_entities (#16460)
# Objective `flush_and_reserve_invalid_assuming_no_entities` was made for the old rendering world (which was reset every frame) and is usused since the 0.15 retained rendering world, but wasn't removed yet. It is pub, but is undocumented apart from the safety comment. ## Solution Remove `flush_and_reserve_invalid_assuming_no_entities` and the safety invariants this method required for `EntityMeta`, `EntityLocation`, `TableId` and `TableRow`. This reduces the amount of unsafe code & safety invariants and makes #16047 easier. ## Alternatives - Document `flush_and_reserve_invalid_assuming_no_entities` and keep it unchanged - Document `flush_and_reserve_invalid_assuming_no_entities` and change it to be based on `EntityMeta::INVALID` ## Migration Guide - exchange `Entities::flush_and_reserve_invalid_assuming_no_entities` for `reserve` and `flush_as_invalid` and notify us if that's insufficient --------- Co-authored-by: Benjamin Brienen <benjamin.brienen@outlook.com> |
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2e267bba5a
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Entity cloning (#16132)
## Objective Fixes #1515 This PR implements a flexible entity cloning system. The primary use case for it is to clone dynamically-generated entities. Example: ```rs #[derive(Component, Clone)] pub struct Projectile; #[derive(Component, Clone)] pub struct Damage { value: f32, } fn player_input( mut commands: Commands, projectiles: Query<Entity, With<Projectile>>, input: Res<ButtonInput<KeyCode>>, ) { // Fire a projectile if input.just_pressed(KeyCode::KeyF) { commands.spawn((Projectile, Damage { value: 10.0 })); } // Triplicate all active projectiles if input.just_pressed(KeyCode::KeyT) { for projectile in projectiles.iter() { // To triplicate a projectile we need to create 2 more clones for _ in 0..2{ commands.clone_entity(projectile) } } } } ``` ## Solution ### Commands Add a `clone_entity` command to create a clone of an entity with all components that can be cloned. Components that can't be cloned will be ignored. ```rs commands.clone_entity(entity) ``` If there is a need to configure the cloning process (like set to clone recursively), there is a second command: ```rs commands.clone_entity_with(entity, |builder| { builder.recursive(true) }); ``` Both of these commands return `EntityCommands` of the cloned entity, so the copy can be modified afterwards. ### Builder All these commands use `EntityCloneBuilder` internally. If there is a need to clone an entity using `World` instead, it is also possible: ```rs let entity = world.spawn(Component).id(); let entity_clone = world.spawn_empty().id(); EntityCloneBuilder::new(&mut world).clone_entity(entity, entity_clone); ``` Builder has methods to `allow` or `deny` certain components during cloning if required and can be extended by implementing traits on it. This PR includes two `EntityCloneBuilder` extensions: `CloneEntityWithObserversExt` to configure adding cloned entity to observers of the original entity, and `CloneEntityRecursiveExt` to configure cloning an entity recursively. ### Clone implementations By default, all components that implement either `Clone` or `Reflect` will be cloned (with `Clone`-based implementation preferred in case component implements both). This can be overriden on a per-component basis: ```rs impl Component for SomeComponent { const STORAGE_TYPE: StorageType = StorageType::Table; fn get_component_clone_handler() -> ComponentCloneHandler { // Don't clone this component ComponentCloneHandler::Ignore } } ``` ### `ComponentCloneHandlers` Clone implementation specified in `get_component_clone_handler` will get registered in `ComponentCloneHandlers` (stored in `bevy_ecs::component::Components`) at component registration time. The clone handler implementation provided by a component can be overriden after registration like so: ```rs let component_id = world.components().component_id::<Component>().unwrap() world.get_component_clone_handlers_mut() .set_component_handler(component_id, ComponentCloneHandler::Custom(component_clone_custom)) ``` The default clone handler for all components that do not explicitly define one (or don't derive `Component`) is `component_clone_via_reflect` if `bevy_reflect` feature is enabled, and `component_clone_ignore` (noop) otherwise. Default handler can be overriden using `ComponentCloneHandlers::set_default_handler` ### Handlers Component clone handlers can be used to modify component cloning behavior. The general signature for a handler that can be used in `ComponentCloneHandler::Custom` is as follows: ```rs pub fn component_clone_custom( world: &mut DeferredWorld, entity_cloner: &EntityCloner, ) { // implementation } ``` The `EntityCloner` implementation (used internally by `EntityCloneBuilder`) assumes that after calling this custom handler, the `target` entity has the desired version of the component from the `source` entity. ### Builder handler overrides Besides component-defined and world-overriden handlers, `EntityCloneBuilder` also has a way to override handlers locally. It is mainly used to allow configuration methods like `recursive` and `add_observers`. ```rs // From observer clone handler implementation impl CloneEntityWithObserversExt for EntityCloneBuilder<'_> { fn add_observers(&mut self, add_observers: bool) -> &mut Self { if add_observers { self.override_component_clone_handler::<ObservedBy>(ComponentCloneHandler::Custom( component_clone_observed_by, )) } else { self.remove_component_clone_handler_override::<ObservedBy>() } } } ``` ## Testing Includes some basic functionality tests and doctests. Performance-wise this feature is the same as calling `clone` followed by `insert` for every entity component. There is also some inherent overhead due to every component clone handler having to access component data through `World`, but this can be reduced without breaking current public API in a later PR. |
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30d84519a2
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Use en-us locale for typos (#16037)
# Objective Bevy seems to want to standardize on "American English" spellings. Not sure if this is laid out anywhere in writing, but see also #15947. While perusing the docs for `typos`, I noticed that it has a `locale` config option and tried it out. ## Solution Switch to `en-us` locale in the `typos` config and run `typos -w` ## Migration Guide The following methods or fields have been renamed from `*dependants*` to `*dependents*`. - `ProcessorAssetInfo::dependants` - `ProcessorAssetInfos::add_dependant` - `ProcessorAssetInfos::non_existent_dependants` - `AssetInfo::dependants_waiting_on_load` - `AssetInfo::dependants_waiting_on_recursive_dep_load` - `AssetInfos::loader_dependants` - `AssetInfos::remove_dependants_and_labels` |
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da4e7769ad
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bevy_ecs: Special-case Entity::PLACEHOLDER formatting (#15839)
# Objective Oftentimes, users will store an entity on a component or resource. To make this component/resource `Default`-able, they might initialize it with `Entity::PLACEHOLDER`. This is sometimes done to avoid the need for an `Option<Entity>`, especially if it complicates other logic. For example, it's used in this `Selection` resource to denote "no selection": ```rust #[derive(Resource, Debug)] struct Selection(Entity); impl Default for Selection { fn default() -> Self { Self(Entity::PLACEHOLDER) } } ``` The problem is that if we try to `Debug` the current `Selection`, we get back: `4294967295v1#8589934591`. It's not immediately obvious whether or not the entity is an actual entity or the placeholder. Now while it doesn't take long to realize that this is in fact just the value of `Entity::PLACEHOLDER`, it would be a lot clearer if this was made explicit, especially for these particular use cases. ## Solution This PR makes the `Debug` and `Display` impls for `Entity` return `PLACEHOLDER` for the `Entity::PLACEHOLDER` constant. ~~Feel free to bikeshed the actual value returned here. I think `PLACEHOLDER` on its own could work too.~~ Swapped to `PLACEHOLDER` from `Entity::PLACEHOLDER`. ## Testing You can test locally by running: ``` cargo test --package bevy_ecs ``` --- ## Migration Guide The `Debug` and `Display` impls for `Entity` now return `PLACEHOLDER` for the `Entity::PLACEHOLDER` constant. If you had any code relying on these values, you may need to account for this change. |