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https://github.com/bevyengine/bevy
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28 commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Josh Robson Chase
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40e88dceff
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Change ReflectMapEntities to operate on components before insertion (#15422)
Previous PR https://github.com/bevyengine/bevy/pull/14549 was closed in error and couldn't be reopened since I had updated the branch 😿 # Objective Fixes #14465 ## Solution `ReflectMapEntities` now works similarly to `MapEntities` in that it works on the reflected value itself rather than the component in the world after insertion. This makes it so that observers see the remapped entities on insertion rather than the entity IDs from the scene. `ReflectMapEntities` now works for both components and resources, so we only need the one. ## Testing * New unit test for `Observer`s + `DynamicScene`s * New unit test for `Observer`s + `Scene`s * Open to suggestions for other tests! --- ## Migration Guide - Consumers of `ReflectMapEntities` will need to call `map_entities` on values prior to inserting them into the world. - Implementors of `MapEntities` will need to remove the `mappings` method, which is no longer needed for `ReflectMapEntities` and has been removed from the trait. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: Hennadii Chernyshchyk <genaloner@gmail.com> |
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Josh Robson Chase
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f97eba2082
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Add VisitEntities for generic and reflectable Entity iteration (#15425)
# Objective - Provide a generic and _reflectable_ way to iterate over contained entities ## Solution Adds two new traits: * `VisitEntities`: Reflectable iteration, accepts a closure rather than producing an iterator. Implemented by default for `IntoIterator` implementing types. A proc macro is also provided. * A `Mut` variant of the above. Its derive macro uses the same field attribute to avoid repetition. ## Testing Added a test for `VisitEntities` that also transitively tests its derive macro as well as the default `MapEntities` impl. |
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Josh Robson Chase
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fcddb54ce5
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Fix for SceneEntityMapper + hooks panic (#15405)
# Objective - Add a test case for #14300 Fixes #14300 ## Solution `SceneEntityMapper` relies on operations on `Entities` that require flushing in advance, such as `alloc` and `free`. Previously, it wasn't calling `world.flush_entities()` itself and relied on its caller having flushed beforehand. This wasn't an issue before observers and hooks were released, since entity reservation was happening at expected times. Now that hooks and observers are a thing, they can introduce a need to flush. We have a few options: * Flush after each observer/hook run * Flush between each paired observer/hook and operation that requires a flush * Flush before operations requiring it The first option for this case seemed trickier to reason about than I wanted, since it involved the `BundleInserter` and its `UnsafeWorldCell`, and the second is generally harder to track down. The third seemed the most straightforward and conventional, since we can see a flush occurring at the start of a number of `World` methods. Therefore, we're letting `SceneEntityMapper` be in charge of upholding its own invariants and calling `flush_entities` when it's created. ## Testing Added a new test case modeled after #14300 |
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Clar Fon
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efda7f3f9c
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Simpler lint fixes: makes ci lints work but disables a lint for now (#15376)
Takes the first two commits from #15375 and adds suggestions from this comment: https://github.com/bevyengine/bevy/pull/15375#issuecomment-2366968300 See #15375 for more reasoning/motivation. ## Rebasing (rerunning) ```rust git switch simpler-lint-fixes git reset --hard main cargo fmt --all -- --unstable-features --config normalize_comments=true,imports_granularity=Crate cargo fmt --all git add --update git commit --message "rustfmt" cargo clippy --workspace --all-targets --all-features --fix cargo fmt --all -- --unstable-features --config normalize_comments=true,imports_granularity=Crate cargo fmt --all git add --update git commit --message "clippy" git cherry-pick e6c0b94f6795222310fb812fa5c4512661fc7887 ``` |
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Giacomo Stevanato
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d7080369a7
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Fix intra-doc links and make CI test them (#14076)
# Objective - Bevy currently has lot of invalid intra-doc links, let's fix them! - Also make CI test them, to avoid future regressions. - Helps with #1983 (but doesn't fix it, as there could still be explicit links to docs.rs that are broken) ## Solution - Make `cargo r -p ci -- doc-check` check fail on warnings (could also be changed to just some specific lints) - Manually fix all the warnings (note that in some cases it was unclear to me what the fix should have been, I'll try to highlight them in a self-review) |
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Zachary Harrold
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3bfc427666
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Add mappings to EntityMapper (#13727)
# Objective - Fixes #13703 ## Solution - Added `mappings` to the `EntityMapper` trait, which returns an iterator over currently tracked `Entity` to `Entity` mappings. - Added `DynEntityMapper` as an [object safe](https://doc.rust-lang.org/reference/items/traits.html#object-safety) alternative to `EntityMapper`. - Added `assert_object_safe` as a helper for ensuring traits are object safe. ## Testing - Added new unit test `entity_mapper_iteration` which tests the `SceneEntityMapper` implementation of `EntityMapper::mappings`. - Added unit tests to ensure `DynEntityMapper`, `DynEq` and `DynHash` are object safe. - Passed CI on my Windows 10 development environment --- ## Changelog - Added `mappings` to `EntityMapper` trait. ## Migration Guide - If you are implementing `EntityMapper` yourself, you can use the below as a stub implementation: ```rust fn mappings(&self) -> impl Iterator<Item = (Entity, Entity)> { unimplemented!() } ``` - If you were using `EntityMapper` as a trait object (`dyn EntityMapper`), instead use `dyn DynEntityMapper` and its associated methods. ## Notes - The original issue proposed returning a `Vec` from `EntityMapper` instead of an `impl Iterator` to preserve its object safety. This is a simpler option, but also forces an allocation where it isn't strictly needed. I've opted for this split into `DynEntityMapper` and `EntityMapper` as it's been done several times across Bevy already, and provides maximum flexibility to users. - `assert_object_safe` is an empty function, since the assertion actually happens once you try to use a `dyn T` for some trait `T`. I have still added this function to clearly document what object safety is within Bevy, and to create a standard way to communicate that a given trait must be object safe. - Other traits should have tests added to ensure object safety, but I've left those off to avoid cluttering this PR further. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> |
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Alice Cecile
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ec7b3490f6
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Add on_unimplemented Diagnostics to Most Public Traits (#13347) (#13662)
# Objective - #13414 did not have the intended effect. - #13404 is still blocked ## Solution - Re-adds #13347. Co-authored-by: Zachary Harrold <zac@harrold.com.au> Co-authored-by: Jamie Ridding <Themayu@users.noreply.github.com> Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com> |
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Dmytro Banin
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7307d76fb3
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Make SceneEntityMapper constructor/destructor public (#13630)
# Objective `SceneEntityMapper` seems like it could be generally useful. ## Solution Allow end users to call `SceneEntityMapper::new` and `SceneEntityMapper::finish`. |
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Alice Cecile
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ee6dfd35c9
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Revert "Add on_unimplemented Diagnostics to Most Public Traits" (#13413)
# Objective - Rust 1.78 breaks all Android support, see https://github.com/bevyengine/bevy/issues/13331 - We should not bump the MSRV to 1.78 until that's resolved in #13366. ## Solution - Temporarily revert https://github.com/bevyengine/bevy/pull/13347 Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com> |
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Zachary Harrold
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11f0a2dcde
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Add on_unimplemented Diagnostics to Most Public Traits (#13347)
# Objective - Fixes #12377 ## Solution Added simple `#[diagnostic::on_unimplemented(...)]` attributes to some critical public traits providing a more approachable initial error message. Where appropriate, a `note` is added indicating that a `derive` macro is available. ## Examples <details> <summary>Examples hidden for brevity</summary> Below is a collection of examples showing the new error messages produced by this change. In general, messages will start with a more Bevy-centric error message (e.g., _`MyComponent` is not a `Component`_), and a note directing the user to an available derive macro where appropriate. ### Missing `#[derive(Resource)]` <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; struct MyResource; fn main() { App::new() .insert_resource(MyResource) .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `MyResource` is not a `Resource` --> examples/app/empty.rs:7:26 | 7 | .insert_resource(MyResource) | --------------- ^^^^^^^^^^ invalid `Resource` | | | required by a bound introduced by this call | = help: the trait `Resource` is not implemented for `MyResource` = note: consider annotating `MyResource` with `#[derive(Resource)]` = help: the following other types implement trait `Resource`: AccessibilityRequested ManageAccessibilityUpdates bevy::bevy_a11y::Focus DiagnosticsStore FrameCount bevy::prelude::State<S> SystemInfo bevy::prelude::Axis<T> and 141 others note: required by a bound in `bevy::prelude::App::insert_resource` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:419:31 | 419 | pub fn insert_resource<R: Resource>(&mut self, resource: R) -> &mut Self { | ^^^^^^^^ required by this bound in `App::insert_resource` ``` </details> ### Putting A `QueryData` in a `QueryFilter` Slot <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; #[derive(Component)] struct A; #[derive(Component)] struct B; fn my_system(_query: Query<&A, &B>) {} fn main() { App::new() .add_systems(Update, my_system) .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `&B` is not a valid `Query` filter --> examples/app/empty.rs:9:22 | 9 | fn my_system(_query: Query<&A, &B>) {} | ^^^^^^^^^^^^^ invalid `Query` filter | = help: the trait `QueryFilter` is not implemented for `&B` = help: the following other types implement trait `QueryFilter`: With<T> Without<T> bevy::prelude::Or<()> bevy::prelude::Or<(F0,)> bevy::prelude::Or<(F0, F1)> bevy::prelude::Or<(F0, F1, F2)> bevy::prelude::Or<(F0, F1, F2, F3)> bevy::prelude::Or<(F0, F1, F2, F3, F4)> and 28 others note: required by a bound in `bevy::prelude::Query` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\query.rs:349:51 | 349 | pub struct Query<'world, 'state, D: QueryData, F: QueryFilter = ()> { | ^^^^^^^^^^^ required by this bound in `Query` ``` </details> ### Missing `#[derive(Component)]` <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; struct A; fn my_system(mut commands: Commands) { commands.spawn(A); } fn main() { App::new() .add_systems(Startup, my_system) .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `A` is not a `Bundle` --> examples/app/empty.rs:6:20 | 6 | commands.spawn(A); | ----- ^ invalid `Bundle` | | | required by a bound introduced by this call | = help: the trait `bevy::prelude::Component` is not implemented for `A`, which is required by `A: Bundle` = note: consider annotating `A` with `#[derive(Component)]` or `#[derive(Bundle)]` = help: the following other types implement trait `Bundle`: TransformBundle SceneBundle DynamicSceneBundle AudioSourceBundle<Source> SpriteBundle SpriteSheetBundle Text2dBundle MaterialMesh2dBundle<M> and 34 others = note: required for `A` to implement `Bundle` note: required by a bound in `bevy::prelude::Commands::<'w, 's>::spawn` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\commands\mod.rs:243:21 | 243 | pub fn spawn<T: Bundle>(&mut self, bundle: T) -> EntityCommands { | ^^^^^^ required by this bound in `Commands::<'w, 's>::spawn` ``` </details> ### Missing `#[derive(Asset)]` <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; struct A; fn main() { App::new() .init_asset::<A>() .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `A` is not an `Asset` --> examples/app/empty.rs:7:23 | 7 | .init_asset::<A>() | ---------- ^ invalid `Asset` | | | required by a bound introduced by this call | = help: the trait `Asset` is not implemented for `A` = note: consider annotating `A` with `#[derive(Asset)]` = help: the following other types implement trait `Asset`: Font AnimationGraph DynamicScene Scene AudioSource Pitch bevy::bevy_gltf::Gltf GltfNode and 17 others note: required by a bound in `init_asset` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_asset\src\lib.rs:307:22 | 307 | fn init_asset<A: Asset>(&mut self) -> &mut Self; | ^^^^^ required by this bound in `AssetApp::init_asset` ``` </details> ### Mismatched Input and Output on System Piping <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; fn producer() -> u32 { 123 } fn consumer(_: In<u16>) {} fn main() { App::new() .add_systems(Update, producer.pipe(consumer)) .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `fn(bevy::prelude::In<u16>) {consumer}` is not a valid system with input `u32` and output `_` --> examples/app/empty.rs:11:44 | 11 | .add_systems(Update, producer.pipe(consumer)) | ---- ^^^^^^^^ invalid system | | | required by a bound introduced by this call | = help: the trait `bevy::prelude::IntoSystem<u32, _, _>` is not implemented for fn item `fn(bevy::prelude::In<u16>) {consumer}` = note: expecting a system which consumes `u32` and produces `_` note: required by a bound in `pipe` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_ecs\src\system\mod.rs:168:12 | 166 | fn pipe<B, Final, MarkerB>(self, system: B) -> PipeSystem<Self::System, B::System> | ---- required by a bound in this associated function 167 | where 168 | B: IntoSystem<Out, Final, MarkerB>, | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `IntoSystem::pipe` ``` </details> ### Missing Reflection <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; #[derive(Component)] struct MyComponent; fn main() { App::new() .register_type::<MyComponent>() .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `MyComponent` does not provide type registration information --> examples/app/empty.rs:8:26 | 8 | .register_type::<MyComponent>() | ------------- ^^^^^^^^^^^ the trait `GetTypeRegistration` is not implemented for `MyComponent` | | | required by a bound introduced by this call | = note: consider annotating `MyComponent` with `#[derive(Reflect)]` = help: the following other types implement trait `GetTypeRegistration`: bool char isize i8 i16 i32 i64 i128 and 443 others note: required by a bound in `bevy::prelude::App::register_type` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:619:29 | 619 | pub fn register_type<T: bevy_reflect::GetTypeRegistration>(&mut self) -> &mut Self { | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::register_type` ``` </details> ### Missing `#[derive(States)]` Implementation <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; #[derive(Debug, Clone, Copy, Default, Eq, PartialEq, Hash)] enum AppState { #[default] Menu, InGame { paused: bool, turbo: bool, }, } fn main() { App::new() .init_state::<AppState>() .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: the trait bound `AppState: FreelyMutableState` is not satisfied --> examples/app/empty.rs:15:23 | 15 | .init_state::<AppState>() | ---------- ^^^^^^^^ the trait `FreelyMutableState` is not implemented for `AppState` | | | required by a bound introduced by this call | = note: consider annotating `AppState` with `#[derive(States)]` note: required by a bound in `bevy::prelude::App::init_state` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:282:26 | 282 | pub fn init_state<S: FreelyMutableState + FromWorld>(&mut self) -> &mut Self { | ^^^^^^^^^^^^^^^^^^ required by this bound in `App::init_state` ``` </details> ### Adding a `System` with Unhandled Output <details> <summary>Example Code</summary> ```rust use bevy::prelude::*; fn producer() -> u32 { 123 } fn main() { App::new() .add_systems(Update, consumer) .run(); } ``` </details> <details> <summary>Error Generated</summary> ```error error[E0277]: `fn() -> u32 {producer}` does not describe a valid system configuration --> examples/app/empty.rs:9:30 | 9 | .add_systems(Update, producer) | ----------- ^^^^^^^^ invalid system configuration | | | required by a bound introduced by this call | = help: the trait `IntoSystem<(), (), _>` is not implemented for fn item `fn() -> u32 {producer}`, which is required by `fn() -> u32 {producer}: IntoSystemConfigs<_>` = help: the following other types implement trait `IntoSystemConfigs<Marker>`: <Box<(dyn bevy::prelude::System<In = (), Out = ()> + 'static)> as IntoSystemConfigs<()>> <NodeConfigs<Box<(dyn bevy::prelude::System<In = (), Out = ()> + 'static)>> as IntoSystemConfigs<()>> <(S0,) as IntoSystemConfigs<(SystemConfigTupleMarker, P0)>> <(S0, S1) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1)>> <(S0, S1, S2) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2)>> <(S0, S1, S2, S3) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3)>> <(S0, S1, S2, S3, S4) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3, P4)>> <(S0, S1, S2, S3, S4, S5) as IntoSystemConfigs<(SystemConfigTupleMarker, P0, P1, P2, P3, P4, P5)>> and 14 others = note: required for `fn() -> u32 {producer}` to implement `IntoSystemConfigs<_>` note: required by a bound in `bevy::prelude::App::add_systems` --> C:\Users\Zac\Documents\GitHub\bevy\crates\bevy_app\src\app.rs:342:23 | 339 | pub fn add_systems<M>( | ----------- required by a bound in this associated function ... 342 | systems: impl IntoSystemConfigs<M>, | ^^^^^^^^^^^^^^^^^^^^ required by this bound in `App::add_systems` ``` </details> </details> ## Testing CI passed locally. ## Migration Guide Upgrade to version 1.78 (or higher) of Rust. ## Future Work - Currently, hints are not supported in this diagnostic. Ideally, suggestions like _"consider using ..."_ would be in a hint rather than a note, but that is the best option for now. - System chaining and other `all_tuples!(...)`-based traits have bad error messages due to the slightly different error message format. --------- Co-authored-by: Jamie Ridding <Themayu@users.noreply.github.com> Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: BD103 <59022059+BD103@users.noreply.github.com> |
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James Liu
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bc82749012
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Remove APIs deprecated in 0.13 (#11974)
# Objective We deprecated quite a few APIs in 0.13. 0.13 has shipped already. It should be OK to remove them in 0.14's release. Fixes #4059. Fixes #9011. ## Solution Remove them. |
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Doonv
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1c67e020f7
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Move EntityHash related types into bevy_ecs (#11498)
# Objective Reduce the size of `bevy_utils` (https://github.com/bevyengine/bevy/issues/11478) ## Solution Move `EntityHash` related types into `bevy_ecs`. This also allows us access to `Entity`, which means we no longer need `EntityHashMap`'s first generic argument. --- ## Changelog - Moved `bevy::utils::{EntityHash, EntityHasher, EntityHashMap, EntityHashSet}` into `bevy::ecs::entity::hash` . - Removed `EntityHashMap`'s first generic argument. It is now hardcoded to always be `Entity`. ## Migration Guide - Uses of `bevy::utils::{EntityHash, EntityHasher, EntityHashMap, EntityHashSet}` now have to be imported from `bevy::ecs::entity::hash`. - Uses of `EntityHashMap` no longer have to specify the first generic parameter. It is now hardcoded to always be `Entity`. |
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Charles Bournhonesque
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b17d42dbe9
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Add a doctest example for EntityMapper (#11583)
# Objective Fixes: https://github.com/bevyengine/bevy/issues/11549 Add a doctest example of what a custom implementation of an `EntityMapper` would look like. (need to wait until https://github.com/bevyengine/bevy/pull/11428 is merged) --------- Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com> Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: Hennadii Chernyshchyk <genaloner@gmail.com> |
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Charles Bournhonesque
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9223201d54
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Make the MapEntities trait generic over Mappers, and add a simpler EntityMapper (#11428)
# Objective My motivation are to resolve some of the issues I describe in this [PR](https://github.com/bevyengine/bevy/issues/11415): - not being able to easily mapping entities because the current EntityMapper requires `&mut World` access - not being able to create my own `EntityMapper` because some components (`Parent` or `Children`) do not provide any public way of modifying the inner entities This PR makes the `MapEntities` trait accept a generic type that implements `Mapper` to perform the mapping. This means we don't need to use `EntityMapper` to perform our mapping, we can use any type that implements `Mapper`. Basically this change is very similar to what `serde` does. Instead of specifying directly how to map entities for a given type, we have 2 distinct steps: - the user implements `MapEntities` to define how the type will be traversed and which `Entity`s will be mapped - the `Mapper` defines how the mapping is actually done This is similar to the distinction between `Serialize` (`MapEntities`) and `Serializer` (`Mapper`). This allows networking library to map entities without having to use the existing `EntityMapper` (which requires `&mut World` access and the use of `world_scope()`) ## Migration Guide - The existing `EntityMapper` (notably used to replicate `Scenes` across different `World`s) has been renamed to `SceneEntityMapper` - The `MapEntities` trait now works with a generic `EntityMapper` instead of the specific struct `EntityMapper`. Calls to `fn map_entities(&mut self, entity_mapper: &mut EntityMapper)` need to be updated to `fn map_entities<M: EntityMapper>(&mut self, entity_mapper: &mut M)` - The new trait `EntityMapper` has been added to the prelude --------- Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com> Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: UkoeHB <37489173+UkoeHB@users.noreply.github.com> |
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Gonçalo Rica Pais da Silva
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e6a324a11a
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Unified identifer for entities & relations (#9797)
# Objective The purpose of this PR is to begin putting together a unified identifier structure that can be used by entities and later components (as entities) as well as relationship pairs for relations, to enable all of these to be able to use the same storages. For the moment, to keep things small and focused, only `Entity` is being changed to make use of the new `Identifier` type, keeping `Entity`'s API and serialization/deserialization the same. Further changes are for follow-up PRs. ## Solution `Identifier` is a wrapper around `u64` split into two `u32` segments with the idea of being generalised to not impose restrictions on variants. That is for `Entity` to do. Instead, it is a general API for taking bits to then merge and map into a `u64` integer. It exposes low/high methods to return the two value portions as `u32` integers, with then the MSB masked for usage as a type flag, enabling entity kind discrimination and future activation/deactivation semantics. The layout in this PR for `Identifier` is described as below, going from MSB -> LSB. ``` |F| High value | Low value | |_|_______________________________|________________________________| |1| 31 | 32 | F = Bit Flags ``` The high component in this implementation has only 31 bits, but that still leaves 2^31 or 2,147,483,648 values that can be stored still, more than enough for any generation/relation kinds/etc usage. The low part is a full 32-bit index. The flags allow for 1 bit to be used for entity/pair discrimination, as these have different usages for the low/high portions of the `Identifier`. More bits can be reserved for more variants or activation/deactivation purposes, but this currently has no use in bevy. More bits could be reserved for future features at the cost of bits for the high component, so how much to reserve is up for discussion. Also, naming of the struct and methods are also subject to further bikeshedding and feedback. Also, because IDs can have different variants, I wonder if `Entity::from_bits` needs to return a `Result` instead of potentially panicking on receiving an invalid ID. PR is provided as an early WIP to obtain feedback and notes on whether this approach is viable. --- ## Changelog ### Added New `Identifier` struct for unifying IDs. ### Changed `Entity` changed to use new `Identifier`/`IdentifierMask` as the underlying ID logic. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: vero <email@atlasdostal.com> |
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Natalie Bonnibel Baker
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b257fffef8
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Change Entity::generation from u32 to NonZeroU32 for niche optimization (#9907)
# Objective - Implements change described in https://github.com/bevyengine/bevy/issues/3022 - Goal is to allow Entity to benefit from niche optimization, especially in the case of Option<Entity> to reduce memory overhead with structures with empty slots ## Discussion - First PR attempt: https://github.com/bevyengine/bevy/pull/3029 - Discord: https://discord.com/channels/691052431525675048/1154573759752183808/1154573764240093224 ## Solution - Change `Entity::generation` from u32 to NonZeroU32 to allow for niche optimization. - The reason for changing generation rather than index is so that the costs are only encountered on Entity free, instead of on Entity alloc - There was some concern with generations being used, due to there being some desire to introduce flags. This was more to do with the original retirement approach, however, in reality even if generations were reduced to 24-bits, we would still have 16 million generations available before wrapping and current ideas indicate that we would be using closer to 4-bits for flags. - Additionally, another concern was the representation of relationships where NonZeroU32 prevents us using the full address space, talking with Joy it seems unlikely to be an issue. The majority of the time these entity references will be low-index entries (ie. `ChildOf`, `Owes`), these will be able to be fast lookups, and the remainder of the range can use slower lookups to map to the address space. - It has the additional benefit of being less visible to most users, since generation is only ever really set through `from_bits` type methods. - `EntityMeta` was changed to match - On free, generation now explicitly wraps: - Originally, generation would panic in debug mode and wrap in release mode due to using regular ops. - The first attempt at this PR changed the behavior to "retire" slots and remove them from use when generations overflowed. This change was controversial, and likely needs a proper RFC/discussion. - Wrapping matches current release behaviour, and should therefore be less controversial. - Wrapping also more easily migrates to the retirement approach, as users likely to exhaust the exorbitant supply of generations will code defensively against aliasing and that defensive code is less likely to break than code assuming that generations don't wrap. - We use some unsafe code here when wrapping generations, to avoid branch on NonZeroU32 construction. It's guaranteed safe due to how we perform wrapping and it results in significantly smaller ASM code. - https://godbolt.org/z/6b6hj8PrM ## Migration - Previous `bevy_scene` serializations have a high likelihood of being broken, as they contain 0th generation entities. ## Current Issues - `Entities::reserve_generations` and `EntityMapper` wrap now, even in debug - although they technically did in release mode already so this probably isn't a huge issue. It just depends if we need to change anything here? --------- Co-authored-by: Natalie Baker <natalie.baker@advancednavigation.com> |
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|
Doonv
|
189ceaf0d3
|
Replace or document ignored doctests (#11040)
# Objective There are a lot of doctests that are `ignore`d for no documented reason. And that should be fixed. ## Solution I searched the bevy repo with the regex ` ```[a-z,]*ignore ` in order to find all `ignore`d doctests. For each one of the `ignore`d doctests, I did the following steps: 1. Attempt to remove the `ignored` attribute while still passing the test. I did this by adding hidden dummy structs and imports. 2. If step 1 doesn't work, attempt to replace the `ignored` attribute with the `no_run` attribute while still passing the test. 3. If step 2 doesn't work, keep the `ignored` attribute but add documentation for why the `ignored` attribute was added. --------- Co-authored-by: François <mockersf@gmail.com> |
||
tygyh
|
fd308571c4
|
Remove unnecessary path prefixes (#10749)
# Objective - Shorten paths by removing unnecessary prefixes ## Solution - Remove the prefixes from many paths which do not need them. Finding the paths was done automatically using built-in refactoring tools in Jetbrains RustRover. |
||
BD103
|
04ceb46fe0
|
Use EntityHashMap for EntityMapper (#10415)
# Objective - There is a specialized hasher for entities: [`EntityHashMap`](https://docs.rs/bevy/latest/bevy/utils/type.EntityHashMap.html) - [`EntityMapper`] currently uses a normal `HashMap<Entity, Entity>` - Fixes #10391 ## Solution - Replace the normal `HashMap` with the more performant `EntityHashMap` ## Questions - This does change public API. Should a system be implemented to help migrate code? - Perhaps an `impl From<HashMap<K, V, S>> for EntityHashMap<K, V>` - I updated to docs for each function that I changed, but I may have missed something --- ## Changelog - Changed `EntityMapper` to use `EntityHashMap` instead of normal `HashMap` ## Migration Guide If you are using the following types, update their listed methods to use the new `EntityHashMap`. `EntityHashMap` has the same methods as the normal `HashMap`, so you just need to replace the name. ### `EntityMapper` - `get_map` - `get_mut_map` - `new` - `world_scope` ### `ReflectMapEntities` - `map_all_entities` - `map_entities` - `write_to_world` ### `InstanceInfo` - `entity_map` - This is a property, not a method. --- This is my first time contributing in a while, and I'm not familiar with the usage of `EntityMapper`. I changed the type definition and fixed all errors, but there may have been things I've missed. Please keep an eye out for me! |
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|
Zachary Harrold
|
394e2b0c91
|
Replaced EntityMap with HashMap (#9461)
# Objective - Fixes #9321 ## Solution - `EntityMap` has been replaced by a simple `HashMap<Entity, Entity>`. --- ## Changelog - `EntityMap::world_scope` has been replaced with `World::world_scope` to avoid creating a new trait. This is a public facing change to the call semantics, but has no effect on results or behaviour. - `EntityMap`, as a `HashMap`, now operates on `&Entity` rather than `Entity`. This changes many standard access functions (e.g, `.get`) in a public-facing way. ## Migration Guide - Calls to `EntityMap::world_scope` can be directly replaced with the following: `map.world_scope(&mut world)` -> `world.world_scope(&mut map)` - Calls to legacy `EntityMap` methods such as `EntityMap::get` must explicitly include de/reference symbols: `let entity = map.get(parent);` -> `let &entity = map.get(&parent);` |
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Hennadii Chernyshchyk
|
c6a1bf063b
|
Add EntityMap::clear (#9291)
# Objective If you use `EntityMap` to map entities over network (https://github.com/lifescapegame/bevy_replicon) you need to reset it sometimes, but keep allocated memory for reuse. ## Solution - Add [clear](https://doc.rust-lang.org/std/collections/struct.HashMap.html#method.clear) method. --- ## Changelog ### Added - `EntityMap::clear`. |
||
Illiux
|
eebc92a7d4
|
Make scene handling of entity references robust (#7335)
# Objective - Handle dangling entity references inside scenes - Handle references to entities with generation > 0 inside scenes - Fix a latent bug in `Parent`'s `MapEntities` implementation, which would, if the parent was outside the scene, cause the scene to be loaded into the new world with a parent reference potentially pointing to some random entity in that new world. - Fixes #4793 and addresses #7235 ## Solution - DynamicScenes now identify entities with a `Entity` instead of a u32, therefore including generation - `World` exposes a new `reserve_generations` function that despawns an entity and advances its generation by some extra amount. - `MapEntities` implementations have a new `get_or_reserve` function available that will always return an `Entity`, establishing a new mapping to a dead entity when the entity they are called with is not in the `EntityMap`. Subsequent calls with that same `Entity` will return the same newly created dead entity reference, preserving equality semantics. - As a result, after loading a scene containing references to dead entities (or entities otherwise outside the scene), those references will all point to different generations on a single entity id in the new world. --- ## Changelog ### Changed - In serialized scenes, entities are now identified by a u64 instead of a u32. - In serialized scenes, components with entity references now have those references serialize as u64s instead of structs. ### Fixed - Scenes containing components with entity references will now deserialize and add to a world reliably. ## Migration Guide - `MapEntities` implementations must change from a `&EntityMap` parameter to a `&mut EntityMapper` parameter and can no longer return a `Result`. Finally, they should switch from calling `EntityMap::get` to calling `EntityMapper::get_or_reserve`. --------- Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com> |
||
Zeenobit
|
f8e4b755ff |
Add EntityMap::iter() (#6935)
# Objective There is currently no way to iterate over key/value pairs inside an `EntityMap`, which makes the usage of this struct very awkward. I couldn't think of a good reason why the `iter()` function should not be exposed, considering the interface already exposes `keys()` and `values()`, so I made this PR. ## Solution Implement `iter()` for `EntityMap` in terms of its inner map type. |
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James Liu
|
e954b8573c |
Lock down access to Entities (#6740)
# Objective The soundness of the ECS `World` partially relies on the correctness of the state of `Entities` stored within it. We're currently allowing users to (unsafely) mutate it, as well as readily construct it without using a `World`. While this is not strictly unsound so long as users (including `bevy_render`) safely use the APIs, it's a fairly easy path to unsoundness without much of a guard rail. Addresses #3362 for `bevy_ecs::entity`. Incorporates the changes from #3985. ## Solution Remove `Entities`'s `Default` implementation and force access to the type to only be through a properly constructed `World`. Additional cleanup for other parts of `bevy_ecs::entity`: - `Entity::index` and `Entity::generation` are no longer `pub(crate)`, opting to force the rest of bevy_ecs to use the public interface to access these values. - `EntityMeta` is no longer `pub` and also not `pub(crate)` to attempt to cut down on updating `generation` without going through an `Entities` API. It's currently inaccessible except via the `pub(crate)` Vec on `Entities`, there was no way for an outside user to use it. - Added `Entities::set`, an unsafe `pub(crate)` API for setting the location of an Entity (parallel to `Entities::get`) that replaces the internal case where we need to set the location of an entity when it's been spawned, moved, or despawned. - `Entities::alloc_at_without_replacement` is only used in `World::get_or_spawn` within the first party crates, and I cannot find a public use of this API in any ecosystem crate that I've checked (via GitHub search). - Attempted to document the few remaining undocumented public APIs in the module. --- ## Changelog Removed: `Entities`'s `Default` implementation. Removed: `EntityMeta` Removed: `Entities::alloc_at_without_replacement` and `AllocAtWithoutReplacement`. Co-authored-by: james7132 <contact@jamessliu.com> Co-authored-by: James Liu <contact@jamessliu.com> |
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|
Hennadii Chernyshchyk
|
17e87f116f |
Improve EntityMap API (#5231)
# Objective `EntityMap` lacks documentation, don't have `len()` / `is_empty` and `insert` doesn't work as in the regular HashMap`. ## Solution * Add `len()` method. * Return previously mapped entity from `insert()` as in the regular `HashMap`. * Add documentation. --- ## Changelog * Add `EntityMap::len()`. * Return previously mapped entity from `EntityMap::insert()` as in the regular `HashMap`. * Add documentation for `EntityMap` methods. |
||
bjorn3
|
ddce22b614 |
Decouple some dependencies (#3886)
# Objective Reduce from scratch build time. ## Solution Reduce the size of the critical path by removing dependencies between crates where not necessary. For `cargo check --no-default-features` this reduced build time from ~51s to ~45s. For some commits I am not completely sure if the tradeoff between build time reduction and convenience caused by the commit is acceptable. If not, I can drop them. |
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Carter Anderson
|
b3a1db60f2 |
Proper prehashing (#3963)
For some keys, it is too expensive to hash them on every lookup. Historically in Bevy, we have regrettably done the "wrong" thing in these cases (pre-computing hashes, then re-hashing them) because Rust's built in hashed collections don't give us the tools we need to do otherwise. Doing this is "wrong" because two different values can result in the same hash. Hashed collections generally get around this by falling back to equality checks on hash collisions. You can't do that if the key _is_ the hash. Additionally, re-hashing a hash increase the odds of collision! #3959 needs pre-hashing to be viable, so I decided to finally properly solve the problem. The solution involves two different changes: 1. A new generalized "pre-hashing" solution in bevy_utils: `Hashed<T>` types, which store a value alongside a pre-computed hash. And `PreHashMap<K, V>` (which uses `Hashed<T>` internally) . `PreHashMap` is just an alias for a normal HashMap that uses `Hashed<T>` as the key and a new `PassHash` implementation as the Hasher. 2. Replacing the `std::collections` re-exports in `bevy_utils` with equivalent `hashbrown` impls. Avoiding re-hashes requires the `raw_entry_mut` api, which isn't stabilized yet (and may never be ... `entry_ref` has favor now, but also isn't available yet). If std's HashMap ever provides the tools we need, we can move back to that. The latest version of `hashbrown` adds support for the `entity_ref` api, so we can move to that in preparation for an std migration, if thats the direction they seem to be going in. Note that adding hashbrown doesn't increase our dependency count because it was already in our tree. In addition to providing these core tools, I also ported the "table identity hashing" in `bevy_ecs` to `raw_entry_mut`, which was a particularly egregious case. The biggest outstanding case is `AssetPathId`, which stores a pre-hash. We need AssetPathId to be cheaply clone-able (and ideally Copy), but `Hashed<AssetPath>` requires ownership of the AssetPath, which makes cloning ids way more expensive. We could consider doing `Hashed<Arc<AssetPath>>`, but cloning an arc is still a non-trivial expensive that needs to be considered. I would like to handle this in a separate PR. And given that we will be re-evaluating the Bevy Assets implementation in the very near future, I'd prefer to hold off until after that conversation is concluded. |
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|
Carter Anderson
|
3a2a68852c |
Bevy ECS V2 (#1525)
# Bevy ECS V2
This is a rewrite of Bevy ECS (basically everything but the new executor/schedule, which are already awesome). The overall goal was to improve the performance and versatility of Bevy ECS. Here is a quick bulleted list of changes before we dive into the details:
* Complete World rewrite
* Multiple component storage types:
* Tables: fast cache friendly iteration, slower add/removes (previously called Archetypes)
* Sparse Sets: fast add/remove, slower iteration
* Stateful Queries (caches query results for faster iteration. fragmented iteration is _fast_ now)
* Stateful System Params (caches expensive operations. inspired by @DJMcNab's work in #1364)
* Configurable System Params (users can set configuration when they construct their systems. once again inspired by @DJMcNab's work)
* Archetypes are now "just metadata", component storage is separate
* Archetype Graph (for faster archetype changes)
* Component Metadata
* Configure component storage type
* Retrieve information about component size/type/name/layout/send-ness/etc
* Components are uniquely identified by a densely packed ComponentId
* TypeIds are now totally optional (which should make implementing scripting easier)
* Super fast "for_each" query iterators
* Merged Resources into World. Resources are now just a special type of component
* EntityRef/EntityMut builder apis (more efficient and more ergonomic)
* Fast bitset-backed `Access<T>` replaces old hashmap-based approach everywhere
* Query conflicts are determined by component access instead of archetype component access (to avoid random failures at runtime)
* With/Without are still taken into account for conflicts, so this should still be comfy to use
* Much simpler `IntoSystem` impl
* Significantly reduced the amount of hashing throughout the ecs in favor of Sparse Sets (indexed by densely packed ArchetypeId, ComponentId, BundleId, and TableId)
* Safety Improvements
* Entity reservation uses a normal world reference instead of unsafe transmute
* QuerySets no longer transmute lifetimes
* Made traits "unsafe" where relevant
* More thorough safety docs
* WorldCell
* Exposes safe mutable access to multiple resources at a time in a World
* Replaced "catch all" `System::update_archetypes(world: &World)` with `System::new_archetype(archetype: &Archetype)`
* Simpler Bundle implementation
* Replaced slow "remove_bundle_one_by_one" used as fallback for Commands::remove_bundle with fast "remove_bundle_intersection"
* Removed `Mut<T>` query impl. it is better to only support one way: `&mut T`
* Removed with() from `Flags<T>` in favor of `Option<Flags<T>>`, which allows querying for flags to be "filtered" by default
* Components now have is_send property (currently only resources support non-send)
* More granular module organization
* New `RemovedComponents<T>` SystemParam that replaces `query.removed::<T>()`
* `world.resource_scope()` for mutable access to resources and world at the same time
* WorldQuery and QueryFilter traits unified. FilterFetch trait added to enable "short circuit" filtering. Auto impled for cases that don't need it
* Significantly slimmed down SystemState in favor of individual SystemParam state
* System Commands changed from `commands: &mut Commands` back to `mut commands: Commands` (to allow Commands to have a World reference)
Fixes #1320
## `World` Rewrite
This is a from-scratch rewrite of `World` that fills the niche that `hecs` used to. Yes, this means Bevy ECS is no longer a "fork" of hecs. We're going out our own!
(the only shared code between the projects is the entity id allocator, which is already basically ideal)
A huge shout out to @SanderMertens (author of [flecs](https://github.com/SanderMertens/flecs)) for sharing some great ideas with me (specifically hybrid ecs storage and archetype graphs). He also helped advise on a number of implementation details.
## Component Storage (The Problem)
Two ECS storage paradigms have gained a lot of traction over the years:
* **Archetypal ECS**:
* Stores components in "tables" with static schemas. Each "column" stores components of a given type. Each "row" is an entity.
* Each "archetype" has its own table. Adding/removing an entity's component changes the archetype.
* Enables super-fast Query iteration due to its cache-friendly data layout
* Comes at the cost of more expensive add/remove operations for an Entity's components, because all components need to be copied to the new archetype's "table"
* **Sparse Set ECS**:
* Stores components of the same type in densely packed arrays, which are sparsely indexed by densely packed unsigned integers (Entity ids)
* Query iteration is slower than Archetypal ECS because each entity's component could be at any position in the sparse set. This "random access" pattern isn't cache friendly. Additionally, there is an extra layer of indirection because you must first map the entity id to an index in the component array.
* Adding/removing components is a cheap, constant time operation
Bevy ECS V1, hecs, legion, flec, and Unity DOTS are all "archetypal ecs-es". I personally think "archetypal" storage is a good default for game engines. An entity's archetype doesn't need to change frequently in general, and it creates "fast by default" query iteration (which is a much more common operation). It is also "self optimizing". Users don't need to think about optimizing component layouts for iteration performance. It "just works" without any extra boilerplate.
Shipyard and EnTT are "sparse set ecs-es". They employ "packing" as a way to work around the "suboptimal by default" iteration performance for specific sets of components. This helps, but I didn't think this was a good choice for a general purpose engine like Bevy because:
1. "packs" conflict with each other. If bevy decides to internally pack the Transform and GlobalTransform components, users are then blocked if they want to pack some custom component with Transform.
2. users need to take manual action to optimize
Developers selecting an ECS framework are stuck with a hard choice. Select an "archetypal" framework with "fast iteration everywhere" but without the ability to cheaply add/remove components, or select a "sparse set" framework to cheaply add/remove components but with slower iteration performance.
## Hybrid Component Storage (The Solution)
In Bevy ECS V2, we get to have our cake and eat it too. It now has _both_ of the component storage types above (and more can be added later if needed):
* **Tables** (aka "archetypal" storage)
* The default storage. If you don't configure anything, this is what you get
* Fast iteration by default
* Slower add/remove operations
* **Sparse Sets**
* Opt-in
* Slower iteration
* Faster add/remove operations
These storage types complement each other perfectly. By default Query iteration is fast. If developers know that they want to add/remove a component at high frequencies, they can set the storage to "sparse set":
```rust
world.register_component(
ComponentDescriptor:🆕:<MyComponent>(StorageType::SparseSet)
).unwrap();
```
## Archetypes
Archetypes are now "just metadata" ... they no longer store components directly. They do store:
* The `ComponentId`s of each of the Archetype's components (and that component's storage type)
* Archetypes are uniquely defined by their component layouts
* For example: entities with "table" components `[A, B, C]` _and_ "sparse set" components `[D, E]` will always be in the same archetype.
* The `TableId` associated with the archetype
* For now each archetype has exactly one table (which can have no components),
* There is a 1->Many relationship from Tables->Archetypes. A given table could have any number of archetype components stored in it:
* Ex: an entity with "table storage" components `[A, B, C]` and "sparse set" components `[D, E]` will share the same `[A, B, C]` table as an entity with `[A, B, C]` table component and `[F]` sparse set components.
* This 1->Many relationship is how we preserve fast "cache friendly" iteration performance when possible (more on this later)
* A list of entities that are in the archetype and the row id of the table they are in
* ArchetypeComponentIds
* unique densely packed identifiers for (ArchetypeId, ComponentId) pairs
* used by the schedule executor for cheap system access control
* "Archetype Graph Edges" (see the next section)
## The "Archetype Graph"
Archetype changes in Bevy (and a number of other archetypal ecs-es) have historically been expensive to compute. First, you need to allocate a new vector of the entity's current component ids, add or remove components based on the operation performed, sort it (to ensure it is order-independent), then hash it to find the archetype (if it exists). And thats all before we get to the _already_ expensive full copy of all components to the new table storage.
The solution is to build a "graph" of archetypes to cache these results. @SanderMertens first exposed me to the idea (and he got it from @gjroelofs, who came up with it). They propose adding directed edges between archetypes for add/remove component operations. If `ComponentId`s are densely packed, you can use sparse sets to cheaply jump between archetypes.
Bevy takes this one step further by using add/remove `Bundle` edges instead of `Component` edges. Bevy encourages the use of `Bundles` to group add/remove operations. This is largely for "clearer game logic" reasons, but it also helps cut down on the number of archetype changes required. `Bundles` now also have densely-packed `BundleId`s. This allows us to use a _single_ edge for each bundle operation (rather than needing to traverse N edges ... one for each component). Single component operations are also bundles, so this is strictly an improvement over a "component only" graph.
As a result, an operation that used to be _heavy_ (both for allocations and compute) is now two dirt-cheap array lookups and zero allocations.
## Stateful Queries
World queries are now stateful. This allows us to:
1. Cache archetype (and table) matches
* This resolves another issue with (naive) archetypal ECS: query performance getting worse as the number of archetypes goes up (and fragmentation occurs).
2. Cache Fetch and Filter state
* The expensive parts of fetch/filter operations (such as hashing the TypeId to find the ComponentId) now only happen once when the Query is first constructed
3. Incrementally build up state
* When new archetypes are added, we only process the new archetypes (no need to rebuild state for old archetypes)
As a result, the direct `World` query api now looks like this:
```rust
let mut query = world.query::<(&A, &mut B)>();
for (a, mut b) in query.iter_mut(&mut world) {
}
```
Requiring `World` to generate stateful queries (rather than letting the `QueryState` type be constructed separately) allows us to ensure that _all_ queries are properly initialized (and the relevant world state, such as ComponentIds). This enables QueryState to remove branches from its operations that check for initialization status (and also enables query.iter() to take an immutable world reference because it doesn't need to initialize anything in world).
However in systems, this is a non-breaking change. State management is done internally by the relevant SystemParam.
## Stateful SystemParams
Like Queries, `SystemParams` now also cache state. For example, `Query` system params store the "stateful query" state mentioned above. Commands store their internal `CommandQueue`. This means you can now safely use as many separate `Commands` parameters in your system as you want. `Local<T>` system params store their `T` value in their state (instead of in Resources).
SystemParam state also enabled a significant slim-down of SystemState. It is much nicer to look at now.
Per-SystemParam state naturally insulates us from an "aliased mut" class of errors we have hit in the past (ex: using multiple `Commands` system params).
(credit goes to @DJMcNab for the initial idea and draft pr here #1364)
## Configurable SystemParams
@DJMcNab also had the great idea to make SystemParams configurable. This allows users to provide some initial configuration / values for system parameters (when possible). Most SystemParams have no config (the config type is `()`), but the `Local<T>` param now supports user-provided parameters:
```rust
fn foo(value: Local<usize>) {
}
app.add_system(foo.system().config(|c| c.0 = Some(10)));
```
## Uber Fast "for_each" Query Iterators
Developers now have the choice to use a fast "for_each" iterator, which yields ~1.5-3x iteration speed improvements for "fragmented iteration", and minor ~1.2x iteration speed improvements for unfragmented iteration.
```rust
fn system(query: Query<(&A, &mut B)>) {
// you now have the option to do this for a speed boost
query.for_each_mut(|(a, mut b)| {
});
// however normal iterators are still available
for (a, mut b) in query.iter_mut() {
}
}
```
I think in most cases we should continue to encourage "normal" iterators as they are more flexible and more "rust idiomatic". But when that extra "oomf" is needed, it makes sense to use `for_each`.
We should also consider using `for_each` for internal bevy systems to give our users a nice speed boost (but that should be a separate pr).
## Component Metadata
`World` now has a `Components` collection, which is accessible via `world.components()`. This stores mappings from `ComponentId` to `ComponentInfo`, as well as `TypeId` to `ComponentId` mappings (where relevant). `ComponentInfo` stores information about the component, such as ComponentId, TypeId, memory layout, send-ness (currently limited to resources), and storage type.
## Significantly Cheaper `Access<T>`
We used to use `TypeAccess<TypeId>` to manage read/write component/archetype-component access. This was expensive because TypeIds must be hashed and compared individually. The parallel executor got around this by "condensing" type ids into bitset-backed access types. This worked, but it had to be re-generated from the `TypeAccess<TypeId>`sources every time archetypes changed.
This pr removes TypeAccess in favor of faster bitset access everywhere. We can do this thanks to the move to densely packed `ComponentId`s and `ArchetypeComponentId`s.
## Merged Resources into World
Resources had a lot of redundant functionality with Components. They stored typed data, they had access control, they had unique ids, they were queryable via SystemParams, etc. In fact the _only_ major difference between them was that they were unique (and didn't correlate to an entity).
Separate resources also had the downside of requiring a separate set of access controls, which meant the parallel executor needed to compare more bitsets per system and manage more state.
I initially got the "separate resources" idea from `legion`. I think that design was motivated by the fact that it made the direct world query/resource lifetime interactions more manageable. It certainly made our lives easier when using Resources alongside hecs/bevy_ecs. However we already have a construct for safely and ergonomically managing in-world lifetimes: systems (which use `Access<T>` internally).
This pr merges Resources into World:
```rust
world.insert_resource(1);
world.insert_resource(2.0);
let a = world.get_resource::<i32>().unwrap();
let mut b = world.get_resource_mut::<f64>().unwrap();
*b = 3.0;
```
Resources are now just a special kind of component. They have their own ComponentIds (and their own resource TypeId->ComponentId scope, so they don't conflict wit components of the same type). They are stored in a special "resource archetype", which stores components inside the archetype using a new `unique_components` sparse set (note that this sparse set could later be used to implement Tags). This allows us to keep the code size small by reusing existing datastructures (namely Column, Archetype, ComponentFlags, and ComponentInfo). This allows us the executor to use a single `Access<ArchetypeComponentId>` per system. It should also make scripting language integration easier.
_But_ this merge did create problems for people directly interacting with `World`. What if you need mutable access to multiple resources at the same time? `world.get_resource_mut()` borrows World mutably!
## WorldCell
WorldCell applies the `Access<ArchetypeComponentId>` concept to direct world access:
```rust
let world_cell = world.cell();
let a = world_cell.get_resource_mut::<i32>().unwrap();
let b = world_cell.get_resource_mut::<f64>().unwrap();
```
This adds cheap runtime checks (a sparse set lookup of `ArchetypeComponentId` and a counter) to ensure that world accesses do not conflict with each other. Each operation returns a `WorldBorrow<'w, T>` or `WorldBorrowMut<'w, T>` wrapper type, which will release the relevant ArchetypeComponentId resources when dropped.
World caches the access sparse set (and only one cell can exist at a time), so `world.cell()` is a cheap operation.
WorldCell does _not_ use atomic operations. It is non-send, does a mutable borrow of world to prevent other accesses, and uses a simple `Rc<RefCell<ArchetypeComponentAccess>>` wrapper in each WorldBorrow pointer.
The api is currently limited to resource access, but it can and should be extended to queries / entity component access.
## Resource Scopes
WorldCell does not yet support component queries, and even when it does there are sometimes legitimate reasons to want a mutable world ref _and_ a mutable resource ref (ex: bevy_render and bevy_scene both need this). In these cases we could always drop down to the unsafe `world.get_resource_unchecked_mut()`, but that is not ideal!
Instead developers can use a "resource scope"
```rust
world.resource_scope(|world: &mut World, a: &mut A| {
})
```
This temporarily removes the `A` resource from `World`, provides mutable pointers to both, and re-adds A to World when finished. Thanks to the move to ComponentIds/sparse sets, this is a cheap operation.
If multiple resources are required, scopes can be nested. We could also consider adding a "resource tuple" to the api if this pattern becomes common and the boilerplate gets nasty.
## Query Conflicts Use ComponentId Instead of ArchetypeComponentId
For safety reasons, systems cannot contain queries that conflict with each other without wrapping them in a QuerySet. On bevy `main`, we use ArchetypeComponentIds to determine conflicts. This is nice because it can take into account filters:
```rust
// these queries will never conflict due to their filters
fn filter_system(a: Query<&mut A, With<B>>, b: Query<&mut B, Without<B>>) {
}
```
But it also has a significant downside:
```rust
// these queries will not conflict _until_ an entity with A, B, and C is spawned
fn maybe_conflicts_system(a: Query<(&mut A, &C)>, b: Query<(&mut A, &B)>) {
}
```
The system above will panic at runtime if an entity with A, B, and C is spawned. This makes it hard to trust that your game logic will run without crashing.
In this pr, I switched to using `ComponentId` instead. This _is_ more constraining. `maybe_conflicts_system` will now always fail, but it will do it consistently at startup. Naively, it would also _disallow_ `filter_system`, which would be a significant downgrade in usability. Bevy has a number of internal systems that rely on disjoint queries and I expect it to be a common pattern in userspace.
To resolve this, I added a new `FilteredAccess<T>` type, which wraps `Access<T>` and adds with/without filters. If two `FilteredAccess` have with/without values that prove they are disjoint, they will no longer conflict.
## EntityRef / EntityMut
World entity operations on `main` require that the user passes in an `entity` id to each operation:
```rust
let entity = world.spawn((A, )); // create a new entity with A
world.get::<A>(entity);
world.insert(entity, (B, C));
world.insert_one(entity, D);
```
This means that each operation needs to look up the entity location / verify its validity. The initial spawn operation also requires a Bundle as input. This can be awkward when no components are required (or one component is required).
These operations have been replaced by `EntityRef` and `EntityMut`, which are "builder-style" wrappers around world that provide read and read/write operations on a single, pre-validated entity:
```rust
// spawn now takes no inputs and returns an EntityMut
let entity = world.spawn()
.insert(A) // insert a single component into the entity
.insert_bundle((B, C)) // insert a bundle of components into the entity
.id() // id returns the Entity id
// Returns EntityMut (or panics if the entity does not exist)
world.entity_mut(entity)
.insert(D)
.insert_bundle(SomeBundle::default());
{
// returns EntityRef (or panics if the entity does not exist)
let d = world.entity(entity)
.get::<D>() // gets the D component
.unwrap();
// world.get still exists for ergonomics
let d = world.get::<D>(entity).unwrap();
}
// These variants return Options if you want to check existence instead of panicing
world.get_entity_mut(entity)
.unwrap()
.insert(E);
if let Some(entity_ref) = world.get_entity(entity) {
let d = entity_ref.get::<D>().unwrap();
}
```
This _does not_ affect the current Commands api or terminology. I think that should be a separate conversation as that is a much larger breaking change.
## Safety Improvements
* Entity reservation in Commands uses a normal world borrow instead of an unsafe transmute
* QuerySets no longer transmutes lifetimes
* Made traits "unsafe" when implementing a trait incorrectly could cause unsafety
* More thorough safety docs
## RemovedComponents SystemParam
The old approach to querying removed components: `query.removed:<T>()` was confusing because it had no connection to the query itself. I replaced it with the following, which is both clearer and allows us to cache the ComponentId mapping in the SystemParamState:
```rust
fn system(removed: RemovedComponents<T>) {
for entity in removed.iter() {
}
}
```
## Simpler Bundle implementation
Bundles are no longer responsible for sorting (or deduping) TypeInfo. They are just a simple ordered list of component types / data. This makes the implementation smaller and opens the door to an easy "nested bundle" implementation in the future (which i might even add in this pr). Duplicate detection is now done once per bundle type by World the first time a bundle is used.
## Unified WorldQuery and QueryFilter types
(don't worry they are still separate type _parameters_ in Queries .. this is a non-breaking change)
WorldQuery and QueryFilter were already basically identical apis. With the addition of `FetchState` and more storage-specific fetch methods, the overlap was even clearer (and the redundancy more painful).
QueryFilters are now just `F: WorldQuery where F::Fetch: FilterFetch`. FilterFetch requires `Fetch<Item = bool>` and adds new "short circuit" variants of fetch methods. This enables a filter tuple like `(With<A>, Without<B>, Changed<C>)` to stop evaluating the filter after the first mismatch is encountered. FilterFetch is automatically implemented for `Fetch` implementations that return bool.
This forces fetch implementations that return things like `(bool, bool, bool)` (such as the filter above) to manually implement FilterFetch and decide whether or not to short-circuit.
## More Granular Modules
World no longer globs all of the internal modules together. It now exports `core`, `system`, and `schedule` separately. I'm also considering exporting `core` submodules directly as that is still pretty "glob-ey" and unorganized (feedback welcome here).
## Remaining Draft Work (to be done in this pr)
* ~~panic on conflicting WorldQuery fetches (&A, &mut A)~~
* ~~bevy `main` and hecs both currently allow this, but we should protect against it if possible~~
* ~~batch_iter / par_iter (currently stubbed out)~~
* ~~ChangedRes~~
* ~~I skipped this while we sort out #1313. This pr should be adapted to account for whatever we land on there~~.
* ~~The `Archetypes` and `Tables` collections use hashes of sorted lists of component ids to uniquely identify each archetype/table. This hash is then used as the key in a HashMap to look up the relevant ArchetypeId or TableId. (which doesn't handle hash collisions properly)~~
* ~~It is currently unsafe to generate a Query from "World A", then use it on "World B" (despite the api claiming it is safe). We should probably close this gap. This could be done by adding a randomly generated WorldId to each world, then storing that id in each Query. They could then be compared to each other on each `query.do_thing(&world)` operation. This _does_ add an extra branch to each query operation, so I'm open to other suggestions if people have them.~~
* ~~Nested Bundles (if i find time)~~
## Potential Future Work
* Expand WorldCell to support queries.
* Consider not allocating in the empty archetype on `world.spawn()`
* ex: return something like EntityMutUninit, which turns into EntityMut after an `insert` or `insert_bundle` op
* this actually regressed performance last time i tried it, but in theory it should be faster
* Optimize SparseSet::insert (see `PERF` comment on insert)
* Replace SparseArray `Option<T>` with T::MAX to cut down on branching
* would enable cheaper get_unchecked() operations
* upstream fixedbitset optimizations
* fixedbitset could be allocation free for small block counts (store blocks in a SmallVec)
* fixedbitset could have a const constructor
* Consider implementing Tags (archetype-specific by-value data that affects archetype identity)
* ex: ArchetypeA could have `[A, B, C]` table components and `[D(1)]` "tag" component. ArchetypeB could have `[A, B, C]` table components and a `[D(2)]` tag component. The archetypes are different, despite both having D tags because the value inside D is different.
* this could potentially build on top of the `archetype.unique_components` added in this pr for resource storage.
* Consider reverting `all_tuples` proc macro in favor of the old `macro_rules` implementation
* all_tuples is more flexible and produces cleaner documentation (the macro_rules version produces weird type parameter orders due to parser constraints)
* but unfortunately all_tuples also appears to make Rust Analyzer sad/slow when working inside of `bevy_ecs` (does not affect user code)
* Consider "resource queries" and/or "mixed resource and entity component queries" as an alternative to WorldCell
* this is basically just "systems" so maybe it's not worth it
* Add more world ops
* `world.clear()`
* `world.reserve<T: Bundle>(count: usize)`
* Try using the old archetype allocation strategy (allocate new memory on resize and copy everything over). I expect this to improve batch insertion performance at the cost of unbatched performance. But thats just a guess. I'm not an allocation perf pro :)
* Adapt Commands apis for consistency with new World apis
## Benchmarks
key:
* `bevy_old`: bevy `main` branch
* `bevy`: this branch
* `_foreach`: uses an optimized for_each iterator
* ` _sparse`: uses sparse set storage (if unspecified assume table storage)
* `_system`: runs inside a system (if unspecified assume test happens via direct world ops)
### Simple Insert (from ecs_bench_suite)
### Simpler Iter (from ecs_bench_suite)
### Fragment Iter (from ecs_bench_suite)
### Sparse Fragmented Iter
Iterate a query that matches 5 entities from a single matching archetype, but there are 100 unmatching archetypes
### Schedule (from ecs_bench_suite)
### Add Remove Component (from ecs_bench_suite)
### Add Remove Component Big
Same as the test above, but each entity has 5 "large" matrix components and 1 "large" matrix component is added and removed
### Get Component
Looks up a single component value a large number of times
|
Renamed from crates/bevy_ecs/src/core/entity_map.rs (Browse further)