453bd058fe
8 Commits
| Author | SHA1 | Message | Date | |
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Gino Valente
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aeeb20ec4c
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bevy_reflect: FromReflect Ergonomics Implementation (#6056)
# Objective **This implementation is based on https://github.com/bevyengine/rfcs/pull/59.** --- Resolves #4597 Full details and motivation can be found in the RFC, but here's a brief summary. `FromReflect` is a very powerful and important trait within the reflection API. It allows Dynamic types (e.g., `DynamicList`, etc.) to be formed into Real ones (e.g., `Vec<i32>`, etc.). This mainly comes into play concerning deserialization, where the reflection deserializers both return a `Box<dyn Reflect>` that almost always contain one of these Dynamic representations of a Real type. To convert this to our Real type, we need to use `FromReflect`. It also sneaks up in other ways. For example, it's a required bound for `T` in `Vec<T>` so that `Vec<T>` as a whole can be made `FromReflect`. It's also required by all fields of an enum as it's used as part of the `Reflect::apply` implementation. So in other words, much like `GetTypeRegistration` and `Typed`, it is very much a core reflection trait. The problem is that it is not currently treated like a core trait and is not automatically derived alongside `Reflect`. This makes using it a bit cumbersome and easy to forget. ## Solution Automatically derive `FromReflect` when deriving `Reflect`. Users can then choose to opt-out if needed using the `#[reflect(from_reflect = false)]` attribute. ```rust #[derive(Reflect)] struct Foo; #[derive(Reflect)] #[reflect(from_reflect = false)] struct Bar; fn test<T: FromReflect>(value: T) {} test(Foo); // <-- OK test(Bar); // <-- Panic! Bar does not implement trait `FromReflect` ``` #### `ReflectFromReflect` This PR also automatically adds the `ReflectFromReflect` (introduced in #6245) registration to the derived `GetTypeRegistration` impl— if the type hasn't opted out of `FromReflect` of course. <details> <summary><h4>Improved Deserialization</h4></summary> > **Warning** > This section includes changes that have since been descoped from this PR. They will likely be implemented again in a followup PR. I am mainly leaving these details in for archival purposes, as well as for reference when implementing this logic again. And since we can do all the above, we might as well improve deserialization. We can now choose to deserialize into a Dynamic type or automatically convert it using `FromReflect` under the hood. `[Un]TypedReflectDeserializer::new` will now perform the conversion and return the `Box`'d Real type. `[Un]TypedReflectDeserializer::new_dynamic` will work like what we have now and simply return the `Box`'d Dynamic type. ```rust // Returns the Real type let reflect_deserializer = UntypedReflectDeserializer::new(®istry); let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?; let output: SomeStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?; // Returns the Dynamic type let reflect_deserializer = UntypedReflectDeserializer::new_dynamic(®istry); let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?; let output: DynamicStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?; ``` </details> --- ## Changelog * `FromReflect` is now automatically derived within the `Reflect` derive macro * This includes auto-registering `ReflectFromReflect` in the derived `GetTypeRegistration` impl * ~~Renamed `TypedReflectDeserializer::new` and `UntypedReflectDeserializer::new` to `TypedReflectDeserializer::new_dynamic` and `UntypedReflectDeserializer::new_dynamic`, respectively~~ **Descoped** * ~~Changed `TypedReflectDeserializer::new` and `UntypedReflectDeserializer::new` to automatically convert the deserialized output using `FromReflect`~~ **Descoped** ## Migration Guide * `FromReflect` is now automatically derived within the `Reflect` derive macro. Items with both derives will need to remove the `FromReflect` one. ```rust // OLD #[derive(Reflect, FromReflect)] struct Foo; // NEW #[derive(Reflect)] struct Foo; ``` If using a manual implementation of `FromReflect` and the `Reflect` derive, users will need to opt-out of the automatic implementation. ```rust // OLD #[derive(Reflect)] struct Foo; impl FromReflect for Foo {/* ... */} // NEW #[derive(Reflect)] #[reflect(from_reflect = false)] struct Foo; impl FromReflect for Foo {/* ... */} ``` <details> <summary><h4>Removed Migrations</h4></summary> > **Warning** > This section includes changes that have since been descoped from this PR. They will likely be implemented again in a followup PR. I am mainly leaving these details in for archival purposes, as well as for reference when implementing this logic again. * The reflect deserializers now perform a `FromReflect` conversion internally. The expected output of `TypedReflectDeserializer::new` and `UntypedReflectDeserializer::new` is no longer a Dynamic (e.g., `DynamicList`), but its Real counterpart (e.g., `Vec<i32>`). ```rust let reflect_deserializer = UntypedReflectDeserializer::new_dynamic(®istry); let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?; // OLD let output: DynamicStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?; // NEW let output: SomeStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?; ``` Alternatively, if this behavior isn't desired, use the `TypedReflectDeserializer::new_dynamic` and `UntypedReflectDeserializer::new_dynamic` methods instead: ```rust // OLD let reflect_deserializer = UntypedReflectDeserializer::new(®istry); // NEW let reflect_deserializer = UntypedReflectDeserializer::new_dynamic(®istry); ``` </details> --------- Co-authored-by: Carter Anderson <mcanders1@gmail.com> |
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Edgar Geier
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f18f28874a
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Allow tuples and single plugins in add_plugins, deprecate add_plugin (#8097)
# Objective - Better consistency with `add_systems`. - Deprecating `add_plugin` in favor of a more powerful `add_plugins`. - Allow passing `Plugin` to `add_plugins`. - Allow passing tuples to `add_plugins`. ## Solution - `App::add_plugins` now takes an `impl Plugins` parameter. - `App::add_plugin` is deprecated. - `Plugins` is a new sealed trait that is only implemented for `Plugin`, `PluginGroup` and tuples over `Plugins`. - All examples, benchmarks and tests are changed to use `add_plugins`, using tuples where appropriate. --- ## Changelog ### Changed - `App::add_plugins` now accepts all types that implement `Plugins`, which is implemented for: - Types that implement `Plugin`. - Types that implement `PluginGroup`. - Tuples (up to 16 elements) over types that implement `Plugins`. - Deprecated `App::add_plugin` in favor of `App::add_plugins`. ## Migration Guide - Replace `app.add_plugin(plugin)` calls with `app.add_plugins(plugin)`. --------- Co-authored-by: Carter Anderson <mcanders1@gmail.com> |
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Nicola Papale
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0294bb191d
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Move AppTypeRegistry to bevy_ecs (#8901)
# Objective - Use `AppTypeRegistry` on API defined in `bevy_ecs` (https://github.com/bevyengine/bevy/pull/8895#discussion_r1234748418) A lot of the API on `Reflect` depends on a registry. When it comes to the ECS. We should use `AppTypeRegistry` in the general case. This is however impossible in `bevy_ecs`, since `AppTypeRegistry` is defined in `bevy_app`. ## Solution - Move `AppTypeRegistry` resource definition from `bevy_app` to `bevy_ecs` - Still add the resource in the `App` plugin, since bevy_ecs itself doesn't know of plugins Note that `bevy_ecs` is a dependency of `bevy_app`, so nothing revolutionary happens. ## Alternative - Define the API as a trait in `bevy_app` over `bevy_ecs`. (though this prevents us from using bevy_ecs internals) - Do not rely on `AppTypeRegistry` for the API in question, requring users to extract themselves the resource and pass it to the API methods. --- ## Changelog - Moved `AppTypeRegistry` resource definition from `bevy_app` to `bevy_ecs` ## Migration Guide - If you were **not** using a `prelude::*` to import `AppTypeRegistry`, you should update your imports: ```diff - use bevy::app::AppTypeRegistry; + use bevy::ecs::reflect::AppTypeRegistry ``` |
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Wybe Westra
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abf12f3b3b
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Fixed several missing links in docs. (#8117)
Links in the api docs are nice. I noticed that there were several places where structs / functions and other things were referenced in the docs, but weren't linked. I added the links where possible / logical. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com> Co-authored-by: François <mockersf@gmail.com> |
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Rob Parrett
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b39f83640f |
Fix some typos (#7763)
# Objective Stumbled on a typo and went on a typo hunt. ## Solution Fix em |
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Jakob Hellermann
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0cb0d8b55d |
add UnsafeWorldCell abstraction (#6404)
alternative to #5922, implements #5956 builds on top of https://github.com/bevyengine/bevy/pull/6402 # Objective https://github.com/bevyengine/bevy/issues/5956 goes into more detail, but the TLDR is: - bevy systems ensure disjoint accesses to resources and components, and for that to work there are methods `World::get_resource_unchecked_mut(&self)`, ..., `EntityRef::get_mut_unchecked(&self)` etc. - we don't have these unchecked methods for `by_id` variants, so third-party crate authors cannot build their own safe disjoint-access abstractions with these - having `_unchecked_mut` methods is not great, because in their presence safe code can accidentally violate subtle invariants. Having to go through `world.as_unsafe_world_cell().unsafe_method()` forces you to stop and think about what you want to write in your `// SAFETY` comment. The alternative is to keep exposing `_unchecked_mut` variants for every operation that we want third-party crates to build upon, but we'd prefer to avoid using these methods alltogether: https://github.com/bevyengine/bevy/pull/5922#issuecomment-1241954543 Also, this is something that **cannot be implemented outside of bevy**, so having either this PR or #5922 as an escape hatch with lots of discouraging comments would be great. ## Solution - add `UnsafeWorldCell` with `unsafe fn get_resource(&self)`, `unsafe fn get_resource_mut(&self)` - add `fn World::as_unsafe_world_cell(&mut self) -> UnsafeWorldCell<'_>` (and `as_unsafe_world_cell_readonly(&self)`) - add `UnsafeWorldCellEntityRef` with `unsafe fn get`, `unsafe fn get_mut` and the other utilities on `EntityRef` (no methods for spawning, despawning, insertion) - use the `UnsafeWorldCell` abstraction in `ReflectComponent`, `ReflectResource` and `ReflectAsset`, so these APIs are easier to reason about - remove `World::get_resource_mut_unchecked`, `EntityRef::get_mut_unchecked` and use `unsafe { world.as_unsafe_world_cell().get_mut() }` and `unsafe { world.as_unsafe_world_cell().get_entity(entity)?.get_mut() }` instead This PR does **not** make use of `UnsafeWorldCell` for anywhere else in `bevy_ecs` such as `SystemParam` or `Query`. That is a much larger change, and I am convinced that having `UnsafeWorldCell` is already useful for third-party crates. Implemented API: ```rust struct World { .. } impl World { fn as_unsafe_world_cell(&self) -> UnsafeWorldCell<'_>; } struct UnsafeWorldCell<'w>(&'w World); impl<'w> UnsafeWorldCell { unsafe fn world(&self) -> &World; fn get_entity(&self) -> UnsafeWorldCellEntityRef<'w>; // returns 'w which is `'self` of the `World::as_unsafe_world_cell(&'w self)` unsafe fn get_resource<T>(&self) -> Option<&'w T>; unsafe fn get_resource_by_id(&self, ComponentId) -> Option<&'w T>; unsafe fn get_resource_mut<T>(&self) -> Option<Mut<'w, T>>; unsafe fn get_resource_mut_by_id(&self) -> Option<MutUntyped<'w>>; unsafe fn get_non_send_resource<T>(&self) -> Option<&'w T>; unsafe fn get_non_send_resource_mut<T>(&self) -> Option<Mut<'w, T>>>; // not included: remove, remove_resource, despawn, anything that might change archetypes } struct UnsafeWorldCellEntityRef<'w> { .. } impl UnsafeWorldCellEntityRef<'w> { unsafe fn get<T>(&self, Entity) -> Option<&'w T>; unsafe fn get_by_id(&self, Entity, ComponentId) -> Option<Ptr<'w>>; unsafe fn get_mut<T>(&self, Entity) -> Option<Mut<'w, T>>; unsafe fn get_mut_by_id(&self, Entity, ComponentId) -> Option<MutUntyped<'w>>; unsafe fn get_change_ticks<T>(&self, Entity) -> Option<Mut<'w, T>>; // fn id, archetype, contains, contains_id, containts_type_id } ``` <details> <summary>UnsafeWorldCell docs</summary> Variant of the [`World`] where resource and component accesses takes a `&World`, and the responsibility to avoid aliasing violations are given to the caller instead of being checked at compile-time by rust's unique XOR shared rule. ### Rationale In rust, having a `&mut World` means that there are absolutely no other references to the safe world alive at the same time, without exceptions. Not even unsafe code can change this. But there are situations where careful shared mutable access through a type is possible and safe. For this, rust provides the [`UnsafeCell`](std::cell::UnsafeCell) escape hatch, which allows you to get a `*mut T` from a `&UnsafeCell<T>` and around which safe abstractions can be built. Access to resources and components can be done uniquely using [`World::resource_mut`] and [`World::entity_mut`], and shared using [`World::resource`] and [`World::entity`]. These methods use lifetimes to check at compile time that no aliasing rules are being broken. This alone is not enough to implement bevy systems where multiple systems can access *disjoint* parts of the world concurrently. For this, bevy stores all values of resources and components (and [`ComponentTicks`](crate::component::ComponentTicks)) in [`UnsafeCell`](std::cell::UnsafeCell)s, and carefully validates disjoint access patterns using APIs like [`System::component_access`](crate::system::System::component_access). A system then can be executed using [`System::run_unsafe`](crate::system::System::run_unsafe) with a `&World` and use methods with interior mutability to access resource values. access resource values. ### Example Usage [`UnsafeWorldCell`] can be used as a building block for writing APIs that safely allow disjoint access into the world. In the following example, the world is split into a resource access half and a component access half, where each one can safely hand out mutable references. ```rust use bevy_ecs::world::World; use bevy_ecs::change_detection::Mut; use bevy_ecs::system::Resource; use bevy_ecs::world::unsafe_world_cell_world::UnsafeWorldCell; // INVARIANT: existance of this struct means that users of it are the only ones being able to access resources in the world struct OnlyResourceAccessWorld<'w>(UnsafeWorldCell<'w>); // INVARIANT: existance of this struct means that users of it are the only ones being able to access components in the world struct OnlyComponentAccessWorld<'w>(UnsafeWorldCell<'w>); impl<'w> OnlyResourceAccessWorld<'w> { fn get_resource_mut<T: Resource>(&mut self) -> Option<Mut<'w, T>> { // SAFETY: resource access is allowed through this UnsafeWorldCell unsafe { self.0.get_resource_mut::<T>() } } } // impl<'w> OnlyComponentAccessWorld<'w> { // ... // } // the two interior mutable worlds borrow from the `&mut World`, so it cannot be accessed while they are live fn split_world_access(world: &mut World) -> (OnlyResourceAccessWorld<'_>, OnlyComponentAccessWorld<'_>) { let resource_access = OnlyResourceAccessWorld(unsafe { world.as_unsafe_world_cell() }); let component_access = OnlyComponentAccessWorld(unsafe { world.as_unsafe_world_cell() }); (resource_access, component_access) } ``` </details> |
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张林伟
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0d2cdb450d |
Fix beta clippy lints (#7154)
# Objective - When I run `cargo run -p ci` for my pr locally using latest beta toolchain, the ci failed due to [uninlined_format_args](https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args) and [needless_lifetimes](https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes) lints ## Solution - Fix lints according to clippy suggestions. |
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Jakob Hellermann
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f867319336 |
add ReflectAsset and ReflectHandle (#5923)
# Objective  ^ enable this Concretely, I need to - list all handle ids for an asset type - fetch the asset as `dyn Reflect`, given a `HandleUntyped` - when encountering a `Handle<T>`, find out what asset type that handle refers to (`T`'s type id) and turn the handle into a `HandleUntyped` ## Solution - add `ReflectAsset` type containing function pointers for working with assets ```rust pub struct ReflectAsset { type_uuid: Uuid, assets_resource_type_id: TypeId, // TypeId of the `Assets<T>` resource get: fn(&World, HandleUntyped) -> Option<&dyn Reflect>, get_mut: fn(&mut World, HandleUntyped) -> Option<&mut dyn Reflect>, get_unchecked_mut: unsafe fn(&World, HandleUntyped) -> Option<&mut dyn Reflect>, add: fn(&mut World, &dyn Reflect) -> HandleUntyped, set: fn(&mut World, HandleUntyped, &dyn Reflect) -> HandleUntyped, len: fn(&World) -> usize, ids: for<'w> fn(&'w World) -> Box<dyn Iterator<Item = HandleId> + 'w>, remove: fn(&mut World, HandleUntyped) -> Option<Box<dyn Reflect>>, } ``` - add `ReflectHandle` type relating the handle back to the asset type and providing a way to create a `HandleUntyped` ```rust pub struct ReflectHandle { type_uuid: Uuid, asset_type_id: TypeId, downcast_handle_untyped: fn(&dyn Any) -> Option<HandleUntyped>, } ``` - add the corresponding `FromType` impls - add a function `app.register_asset_reflect` which is supposed to be called after `.add_asset` and registers `ReflectAsset` and `ReflectHandle` in the type registry --- ## Changelog - add `ReflectAsset` and `ReflectHandle` types, which allow code to use reflection to manipulate arbitrary assets without knowing their types at compile time |
