# Objective
Complete the first part of the migration detailed in bevyengine/rfcs#45.
## Solution
Add all the new stuff.
### TODO
- [x] Impl tuple methods.
- [x] Impl chaining.
- [x] Port ambiguity detection.
- [x] Write docs.
- [x] ~~Write more tests.~~(will do later)
- [ ] Write changelog and examples here?
- [x] ~~Replace `petgraph`.~~ (will do later)
Co-authored-by: james7132 <contact@jamessliu.com>
Co-authored-by: Michael Hsu <mike.hsu@gmail.com>
Co-authored-by: Mike Hsu <mike.hsu@gmail.com>
# Objective
- Fixes#7066
## Solution
- Split the ChangeDetection trait into ChangeDetection and ChangeDetectionMut
- Added Ref as equivalent to &T with change detection
---
## Changelog
- Support for Ref which allow inspecting change detection flags in an immutable way
## Migration Guide
- While bevy prelude includes both ChangeDetection and ChangeDetectionMut any code explicitly referencing ChangeDetection might need to be updated to ChangeDetectionMut or both. Specifically any reading logic requires ChangeDetection while writes requires ChangeDetectionMut.
use bevy_ecs::change_detection::DetectChanges -> use bevy_ecs::change_detection::{DetectChanges, DetectChangesMut}
- Previously Res had methods to access change detection `is_changed` and `is_added` those methods have been moved to the `DetectChanges` trait. If you are including bevy prelude you will have access to these types otherwise you will need to `use bevy_ecs::change_detection::DetectChanges` to continue using them.
# Objective
Fixes#3310. Fixes#6282. Fixes#6278. Fixes#3666.
## Solution
Split out `!Send` resources into `NonSendResources`. Add a `origin_thread_id` to all `!Send` Resources, check it on dropping `NonSendResourceData`, if there's a mismatch, panic. Moved all of the checks that `MainThreadValidator` would do into `NonSendResources` instead.
All `!Send` resources now individually track which thread they were inserted from. This is validated against for every access, mutation, and drop that could be done against the value.
A regression test using an altered version of the example from #3310 has been added.
This is a stopgap solution for the current status quo. A full solution may involve fully removing `!Send` resources/components from `World`, which will likely require a much more thorough design on how to handle the existing in-engine and ecosystem use cases.
This PR also introduces another breaking change:
```rust
use bevy_ecs::prelude::*;
#[derive(Resource)]
struct Resource(u32);
fn main() {
let mut world = World::new();
world.insert_resource(Resource(1));
world.insert_non_send_resource(Resource(2));
let res = world.get_resource_mut::<Resource>().unwrap();
assert_eq!(res.0, 2);
}
```
This code will run correctly on 0.9.1 but not with this PR, since NonSend resources and normal resources have become actual distinct concepts storage wise.
## Changelog
Changed: Fix soundness bug with `World: Send`. Dropping a `World` that contains a `!Send` resource on the wrong thread will now panic.
## Migration Guide
Normal resources and `NonSend` resources no longer share the same backing storage. If `R: Resource`, then `NonSend<R>` and `Res<R>` will return different instances from each other. If you are using both `Res<T>` and `NonSend<T>` (or their mutable variants), to fetch the same resources, it's strongly advised to use `Res<T>`.
# Objective
[Rust 1.66](https://blog.rust-lang.org/inside-rust/2022/12/12/1.66.0-prerelease.html) is coming in a few days, and bevy doesn't build with it.
Fix that.
## Solution
Replace output from a trybuild test, and fix a few new instances of `needless_borrow` and `unnecessary_cast` that are now caught.
## Note
Due to the trybuild test, this can't be merged until 1.66 is released.
# Objective
Fixes#6224, add ``dbg``, ``info``, ``warn`` and ``error`` system piping adapter variants to expand #5776, which call the corresponding re-exported [bevy_log macros](https://docs.rs/bevy/latest/bevy/log/macro.info.html) when the result is an error.
## Solution
* Added ``dbg``, ``info``, ``warn`` and ``error`` system piping adapter variants to ``system_piping.rs``.
* Modified and added tests for these under examples in ``system_piping.rs``.
# Objective
#6547 accidentally broke change detection for SparseSet components by using `Ticks::from_tick_cells` with the wrong argument order.
## Solution
Use the right argument order. Add a regression test.
# 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>
This reverts commit 53d387f340.
# Objective
Reverts #6448. This didn't have the intended effect: we're now getting bevy::prelude shown in the docs again.
Co-authored-by: Alejandro Pascual <alejandro.pascual.pozo@gmail.com>
# Objective
- Right now re-exports are completely hidden in prelude docs.
- Fixes#6433
## Solution
- We could show the re-exports without inlining their documentation.
# Objective
Fixes#6059, changing all incorrect occurrences of ``id`` in the ``entity`` module to ``index``:
* struct level documentation,
* ``id`` struct field,
* ``id`` method and its documentation.
## Solution
Renaming and verifying using CI.
Co-authored-by: Edvin Kjell <43633999+Edwox@users.noreply.github.com>
# Objective
Clean up code surrounding fetch by pulling out the common parts into the iteration code.
## Solution
Merge `Fetch::table_fetch` and `Fetch::archetype_fetch` into a single API: `Fetch::fetch(&mut self, entity: &Entity, table_row: &usize)`. This provides everything any fetch requires to internally decide which storage to read from and get the underlying data. All of these functions are marked as `#[inline(always)]` and the arguments are passed as references to attempt to optimize out the argument that isn't being used.
External to `Fetch`, Query iteration has been changed to keep track of the table row and entity outside of fetch, which moves a lot of the expensive bookkeeping `Fetch` structs had previously done internally into the outer loop.
~~TODO: Benchmark, docs~~ Done.
---
## Changelog
Changed: `Fetch::table_fetch` and `Fetch::archetype_fetch` have been merged into a single `Fetch::fetch` function.
## Migration Guide
TODO
Co-authored-by: Brian Merchant <bhmerchang@gmail.com>
Co-authored-by: Saverio Miroddi <saverio.pub2@gmail.com>
# Objective
Fixes#5559
Replaces #5628
## Solution
Because the generated method from_components() creates an instance of Self my implementation requires any field type that is marked to be ignored to implement Default.
---
## Changelog
Added the possibility to ignore fields in a bundle with `#[bundle(ignore)]`. Typically used when `PhantomData` needs to be added to a `Bundle`.
# Objective
At least partially addresses #6282.
Resources are currently stored as a dedicated Resource archetype (ID 1). This allows for easy code reusability, but unnecessarily adds 72 bytes (on 64-bit systems) to the struct that is only used for that one archetype. It also requires several fields to be `pub(crate)` which isn't ideal.
This should also remove one sparse-set lookup from fetching, inserting, and removing resources from a `World`.
## Solution
- Add `Resources` parallel to `Tables` and `SparseSets` and extract the functionality used by `Archetype` in it.
- Remove `unique_components` from `Archetype`
- Remove the `pub(crate)` on `Archetype::components`.
- Remove `ArchetypeId::RESOURCE`
- Remove `Archetypes::resource` and `Archetypes::resource_mut`
---
## Changelog
Added: `Resources` type to store resources.
Added: `Storages::resource`
Removed: `ArchetypeId::RESOURCE`
Removed: `Archetypes::resource` and `Archetypes::resources`
Removed: `Archetype::unique_components` and `Archetypes::unique_components_mut`
## Migration Guide
Resources have been moved to `Resources` under `Storages` in `World`. All code dependent on `Archetype::unique_components(_mut)` should access it via `world.storages().resources()` instead.
All APIs accessing the raw data of individual resources (mutable *and* read-only) have been removed as these APIs allowed for unsound unsafe code. All usages of these APIs should be changed to use `World::{get, insert, remove}_resource`.
# Objective
> System chaining is a confusing name: it implies the ability to construct non-linear graphs, and suggests a sense of system ordering that is only incidentally true. Instead, it actually works by passing data from one system to the next, much like the pipe operator.
> In the accepted [stageless RFC](https://github.com/bevyengine/rfcs/blob/main/rfcs/45-stageless.md), this concept is renamed to piping, and "system chaining" is used to construct groups of systems with ordering dependencies between them.
Fixes#6225.
## Changelog
System chaining has been renamed to system piping to improve clarity (and free up the name for new ordering APIs).
## Migration Guide
The `.chain(handler_system)` method on systems is now `.pipe(handler_system)`.
The `IntoChainSystem` trait is now `IntoPipeSystem`, and the `ChainSystem` struct is now `PipeSystem`.
# Objective
Relaxes the trait bound for `World::resource_scope` to allow non-send resources. Fixes#6037.
## Solution
No big changes in code had to be made. Added a check so that the non-send resources won't be accessed from a different thread.
---
## Changelog
- `World::resource_scope` accepts non-send resources now
- `World::resource_scope` verifies non-send access if the resource is non-send
- Two new tests are added, one for valid use of `World::resource_scope` with a non-send resource, and one for invalid use (calling it from a different thread, resulting in panic)
Co-authored-by: Dawid Piotrowski <41804418+Pietrek14@users.noreply.github.com>
# Objective
The [Stageless RFC](https://github.com/bevyengine/rfcs/pull/45) involves allowing exclusive systems to be referenced and ordered relative to parallel systems. We've agreed that unifying systems under `System` is the right move.
This is an alternative to #4166 (see rationale in the comments I left there). Note that this builds on the learnings established there (and borrows some patterns).
## Solution
This unifies parallel and exclusive systems under the shared `System` trait, removing the old `ExclusiveSystem` trait / impls. This is accomplished by adding a new `ExclusiveFunctionSystem` impl similar to `FunctionSystem`. It is backed by `ExclusiveSystemParam`, which is similar to `SystemParam`. There is a new flattened out SystemContainer api (which cuts out a lot of trait and type complexity).
This means you can remove all cases of `exclusive_system()`:
```rust
// before
commands.add_system(some_system.exclusive_system());
// after
commands.add_system(some_system);
```
I've also implemented `ExclusiveSystemParam` for `&mut QueryState` and `&mut SystemState`, which makes this possible in exclusive systems:
```rust
fn some_exclusive_system(
world: &mut World,
transforms: &mut QueryState<&Transform>,
state: &mut SystemState<(Res<Time>, Query<&Player>)>,
) {
for transform in transforms.iter(world) {
println!("{transform:?}");
}
let (time, players) = state.get(world);
for player in players.iter() {
println!("{player:?}");
}
}
```
Note that "exclusive function systems" assume `&mut World` is present (and the first param). I think this is a fair assumption, given that the presence of `&mut World` is what defines the need for an exclusive system.
I added some targeted SystemParam `static` constraints, which removed the need for this:
``` rust
fn some_exclusive_system(state: &mut SystemState<(Res<'static, Time>, Query<&'static Player>)>) {}
```
## Related
- #2923
- #3001
- #3946
## Changelog
- `ExclusiveSystem` trait (and implementations) has been removed in favor of sharing the `System` trait.
- `ExclusiveFunctionSystem` and `ExclusiveSystemParam` were added, enabling flexible exclusive function systems
- `&mut SystemState` and `&mut QueryState` now implement `ExclusiveSystemParam`
- Exclusive and parallel System configuration is now done via a unified `SystemDescriptor`, `IntoSystemDescriptor`, and `SystemContainer` api.
## Migration Guide
Calling `.exclusive_system()` is no longer required (or supported) for converting exclusive system functions to exclusive systems:
```rust
// Old (0.8)
app.add_system(some_exclusive_system.exclusive_system());
// New (0.9)
app.add_system(some_exclusive_system);
```
Converting "normal" parallel systems to exclusive systems is done by calling the exclusive ordering apis:
```rust
// Old (0.8)
app.add_system(some_system.exclusive_system().at_end());
// New (0.9)
app.add_system(some_system.at_end());
```
Query state in exclusive systems can now be cached via ExclusiveSystemParams, which should be preferred for clarity and performance reasons:
```rust
// Old (0.8)
fn some_system(world: &mut World) {
let mut transforms = world.query::<&Transform>();
for transform in transforms.iter(world) {
}
}
// New (0.9)
fn some_system(world: &mut World, transforms: &mut QueryState<&Transform>) {
for transform in transforms.iter(world) {
}
}
```
# Objective
Now that we can consolidate Bundles and Components under a single insert (thanks to #2975 and #6039), almost 100% of world spawns now look like `world.spawn().insert((Some, Tuple, Here))`. Spawning an entity without any components is an extremely uncommon pattern, so it makes sense to give spawn the "first class" ergonomic api. This consolidated api should be made consistent across all spawn apis (such as World and Commands).
## Solution
All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input:
```rust
// before:
commands
.spawn()
.insert((A, B, C));
world
.spawn()
.insert((A, B, C);
// after
commands.spawn((A, B, C));
world.spawn((A, B, C));
```
All existing instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api. A new `spawn_empty` has been added, replacing the old `spawn` api.
By allowing `world.spawn(some_bundle)` to replace `world.spawn().insert(some_bundle)`, this opened the door to removing the initial entity allocation in the "empty" archetype / table done in `spawn()` (and subsequent move to the actual archetype in `.insert(some_bundle)`).
This improves spawn performance by over 10%:
To take this measurement, I added a new `world_spawn` benchmark.
Unfortunately, optimizing `Commands::spawn` is slightly less trivial, as Commands expose the Entity id of spawned entities prior to actually spawning. Doing the optimization would (naively) require assurances that the `spawn(some_bundle)` command is applied before all other commands involving the entity (which would not necessarily be true, if memory serves). Optimizing `Commands::spawn` this way does feel possible, but it will require careful thought (and maybe some additional checks), which deserves its own PR. For now, it has the same performance characteristics of the current `Commands::spawn_bundle` on main.
**Note that 99% of this PR is simple renames and refactors. The only code that needs careful scrutiny is the new `World::spawn()` impl, which is relatively straightforward, but it has some new unsafe code (which re-uses battle tested BundlerSpawner code path).**
---
## Changelog
- All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input
- All instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api
- World and Commands now have `spawn_empty()`, which is equivalent to the old `spawn()` behavior.
## Migration Guide
```rust
// Old (0.8):
commands
.spawn()
.insert_bundle((A, B, C));
// New (0.9)
commands.spawn((A, B, C));
// Old (0.8):
commands.spawn_bundle((A, B, C));
// New (0.9)
commands.spawn((A, B, C));
// Old (0.8):
let entity = commands.spawn().id();
// New (0.9)
let entity = commands.spawn_empty().id();
// Old (0.8)
let entity = world.spawn().id();
// New (0.9)
let entity = world.spawn_empty();
```
# Objective
Take advantage of the "impl Bundle for Component" changes in #2975 / add the follow up changes discussed there.
## Solution
- Change `insert` and `remove` to accept a Bundle instead of a Component (for both Commands and World)
- Deprecate `insert_bundle`, `remove_bundle`, and `remove_bundle_intersection`
- Add `remove_intersection`
---
## Changelog
- Change `insert` and `remove` now accept a Bundle instead of a Component (for both Commands and World)
- `insert_bundle` and `remove_bundle` are deprecated
## Migration Guide
Replace `insert_bundle` with `insert`:
```rust
// Old (0.8)
commands.spawn().insert_bundle(SomeBundle::default());
// New (0.9)
commands.spawn().insert(SomeBundle::default());
```
Replace `remove_bundle` with `remove`:
```rust
// Old (0.8)
commands.entity(some_entity).remove_bundle::<SomeBundle>();
// New (0.9)
commands.entity(some_entity).remove::<SomeBundle>();
```
Replace `remove_bundle_intersection` with `remove_intersection`:
```rust
// Old (0.8)
world.entity_mut(some_entity).remove_bundle_intersection::<SomeBundle>();
// New (0.9)
world.entity_mut(some_entity).remove_intersection::<SomeBundle>();
```
Consider consolidating as many operations as possible to improve ergonomics and cut down on archetype moves:
```rust
// Old (0.8)
commands.spawn()
.insert_bundle(SomeBundle::default())
.insert(SomeComponent);
// New (0.9) - Option 1
commands.spawn().insert((
SomeBundle::default(),
SomeComponent,
))
// New (0.9) - Option 2
commands.spawn_bundle((
SomeBundle::default(),
SomeComponent,
))
```
## Next Steps
Consider changing `spawn` to accept a bundle and deprecate `spawn_bundle`.
@BoxyUwU this is your fault.
Also cart didn't arrive in time to tell us not to do this.
# Objective
- Fix#2974
## Solution
- The first commit just does the actual change
- Follow up commits do steps to prove that this method works to unify as required, but this does not remove `insert_bundle`.
## Changelog
### Changed
Nested bundles now collapse automatically, and every `Component` now implements `Bundle`.
This means that you can combine bundles and components arbitrarily, for example:
```rust
// before:
.insert(A).insert_bundle(MyBBundle{..})
// after:
.insert_bundle((A, MyBBundle {..}))
```
Note that there will be a follow up PR that removes the current `insert` impl and renames `insert_bundle` to `insert`.
### Removed
The `bundle` attribute in `derive(Bundle)`.
## Migration guide
In `derive(Bundle)`, the `bundle` attribute has been removed. Nested bundles are not collapsed automatically. You should remove `#[bundle]` attributes.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Fixes Issue #6005.
## Solution
Replaced WorldQuery with ReadOnlyWorldQuery on F generic in Query filters and QueryState to restrict its trait bound.
## Migration Guide
Query filter (`F`) generics are now bound by `ReadOnlyWorldQuery`, rather than `WorldQuery`. If for some reason you were requesting `Query<&A, &mut B>`, please use `Query<&A, With<B>>` instead.
# Objective
Ambiguity sets are used to ignore system order ambiguities between groups of systems. However, they are not very useful: they are clunky, poorly integrated, and generally hampered by the difficulty using (or discovering) the ambiguity detector.
As a first step to the work in #4299, we're removing them.
## Migration Guide
Ambiguity sets have been removed.
# Objective
Right now, users have to implement basic system adapters such as `Option` <-> `Result` conversions by themselves. This is slightly annoying and discourages the use of system chaining.
## Solution
Add the module `system_adapter` to the prelude, which contains a collection of common adapters. This is very ergonomic in practice.
## Examples
Convenient early returning.
```rust
use bevy::prelude::*;
App::new()
// If the system fails, just try again next frame.
.add_system(pet_dog.chain(system_adapter::ignore))
.run();
#[derive(Component)]
struct Dog;
fn pet_dog(dogs: Query<(&Name, Option<&Parent>), With<Dog>>) -> Option<()> {
let (dog, dad) = dogs.iter().next()?;
println!("You pet {dog}. He/she/they are a good boy/girl/pupper.");
let (dad, _) = dogs.get(dad?.get()).ok()?;
println!("Their dad's name is {dad}");
Some(())
}
```
Converting the output of a system
```rust
use bevy::prelude::*;
App::new()
.add_system(
find_name
.chain(system_adapter::new(String::from))
.chain(spawn_with_name),
)
.run();
fn find_name() -> &'static str { /* ... */ }
fn spawn_with_name(In(name): In<String>, mut commands: Commands) {
commands.spawn().insert(Name::new(name));
}
```
---
## Changelog
* Added the module `bevy_ecs::prelude::system_adapter`, which contains a collection of common system chaining adapters.
* `new` - Converts a regular fn to a system adapter.
* `unwrap` - Similar to `Result::unwrap`
* `ignore` - Discards the output of the previous system.
*This PR description is an edited copy of #5007, written by @alice-i-cecile.*
# Objective
Follow-up to https://github.com/bevyengine/bevy/pull/2254. The `Resource` trait currently has a blanket implementation for all types that meet its bounds.
While ergonomic, this results in several drawbacks:
* it is possible to make confusing, silent mistakes such as inserting a function pointer (Foo) rather than a value (Foo::Bar) as a resource
* it is challenging to discover if a type is intended to be used as a resource
* we cannot later add customization options (see the [RFC](https://github.com/bevyengine/rfcs/blob/main/rfcs/27-derive-component.md) for the equivalent choice for Component).
* dependencies can use the same Rust type as a resource in invisibly conflicting ways
* raw Rust types used as resources cannot preserve privacy appropriately, as anyone able to access that type can read and write to internal values
* we cannot capture a definitive list of possible resources to display to users in an editor
## Notes to reviewers
* Review this commit-by-commit; there's effectively no back-tracking and there's a lot of churn in some of these commits.
*ira: My commits are not as well organized :')*
* I've relaxed the bound on Local to Send + Sync + 'static: I don't think these concerns apply there, so this can keep things simple. Storing e.g. a u32 in a Local is fine, because there's a variable name attached explaining what it does.
* I think this is a bad place for the Resource trait to live, but I've left it in place to make reviewing easier. IMO that's best tackled with https://github.com/bevyengine/bevy/issues/4981.
## Changelog
`Resource` is no longer automatically implemented for all matching types. Instead, use the new `#[derive(Resource)]` macro.
## Migration Guide
Add `#[derive(Resource)]` to all types you are using as a resource.
If you are using a third party type as a resource, wrap it in a tuple struct to bypass orphan rules. Consider deriving `Deref` and `DerefMut` to improve ergonomics.
`ClearColor` no longer implements `Component`. Using `ClearColor` as a component in 0.8 did nothing.
Use the `ClearColorConfig` in the `Camera3d` and `Camera2d` components instead.
Co-authored-by: Alice <alice.i.cecile@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: devil-ira <justthecooldude@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
`SAFETY` comments are meant to be placed before `unsafe` blocks and should contain the reasoning of why in this case the usage of unsafe is okay. This is useful when reading the code because it makes it clear which assumptions are required for safety, and makes it easier to spot possible unsoundness holes. It also forces the code writer to think of something to write and maybe look at the safety contracts of any called unsafe methods again to double-check their correct usage.
There's a clippy lint called `undocumented_unsafe_blocks` which warns when using a block without such a comment.
## Solution
- since clippy expects `SAFETY` instead of `SAFE`, rename those
- add `SAFETY` comments in more places
- for the last remaining 3 places, add an `#[allow()]` and `// TODO` since I wasn't comfortable enough with the code to justify their safety
- add ` #![warn(clippy::undocumented_unsafe_blocks)]` to `bevy_ecs`
### Note for reviewers
The first commit only renames `SAFETY` to `SAFE` so it doesn't need a thorough review.
cb042a416e..55cef2d6fa is the diff for all other changes.
### Safety comments where I'm not too familiar with the code
774012ece5/crates/bevy_ecs/src/entity/mod.rs (L540-L546)774012ece5/crates/bevy_ecs/src/world/entity_ref.rs (L249-L252)
### Locations left undocumented with a `TODO` comment
5dde944a30/crates/bevy_ecs/src/schedule/executor_parallel.rs (L196-L199)5dde944a30/crates/bevy_ecs/src/world/entity_ref.rs (L287-L289)5dde944a30/crates/bevy_ecs/src/world/entity_ref.rs (L413-L415)
Co-authored-by: Jakob Hellermann <hellermann@sipgate.de>
# Objective
We don't have reflection for resources.
## Solution
Introduce reflection for resources.
Continues #3580 (by @Davier), related to #3576.
---
## Changelog
### Added
* Reflection on a resource type (by adding `ReflectResource`):
```rust
#[derive(Reflect)]
#[reflect(Resource)]
struct MyResourse;
```
### Changed
* Rename `ReflectComponent::add_component` into `ReflectComponent::insert_component` for consistency.
## Migration Guide
* Rename `ReflectComponent::add_component` into `ReflectComponent::insert_component`.
# Objective
This is a common and useful type. I frequently use this when working with `Events` resource directly, typically when caching the data or manipulating the `World` directly.
This is also useful when manually configuring the cleanup strategy for events.
Right now, a direct reference to the target TaskPool is required to launch tasks on the pools, despite the three newtyped pools (AsyncComputeTaskPool, ComputeTaskPool, and IoTaskPool) effectively acting as global instances. The need to pass a TaskPool reference adds notable friction to spawning subtasks within existing tasks. Possible use cases for this may include chaining tasks within the same pool like spawning separate send/receive I/O tasks after waiting on a network connection to be established, or allowing cross-pool dependent tasks like starting dependent multi-frame computations following a long I/O load.
Other task execution runtimes provide static access to spawning tasks (i.e. `tokio::spawn`), which is notably easier to use than the reference passing required by `bevy_tasks` right now.
This PR makes does the following:
* Adds `*TaskPool::init` which initializes a `OnceCell`'ed with a provided TaskPool. Failing if the pool has already been initialized.
* Adds `*TaskPool::get` which fetches the initialized global pool of the respective type or panics. This generally should not be an issue in normal Bevy use, as the pools are initialized before they are accessed.
* Updated default task pool initialization to either pull the global handles and save them as resources, or if they are already initialized, pull the a cloned global handle as the resource.
This should make it notably easier to build more complex task hierarchies for dependent tasks. It should also make writing bevy-adjacent, but not strictly bevy-only plugin crates easier, as the global pools ensure it's all running on the same threads.
One alternative considered is keeping a thread-local reference to the pool for all threads in each pool to enable the same `tokio::spawn` interface. This would spawn tasks on the same pool that a task is currently running in. However this potentially leads to potential footgun situations where long running blocking tasks run on `ComputeTaskPool`.
(follow-up to #4423)
# Objective
Currently, it isn't possible to easily fire commands from within par_for_each blocks. This PR allows for issuing commands from within parallel scopes.
# Objective
Fixes#3183. Requiring a `&TaskPool` parameter is sort of meaningless if the only correct one is to use the one provided by `Res<ComputeTaskPool>` all the time.
## Solution
Have `QueryState` save a clone of the `ComputeTaskPool` which is used for all `par_for_each` functions.
~~Adds a small overhead of the internal `Arc` clone as a part of the startup, but the ergonomics win should be well worth this hardly-noticable overhead.~~
Updated the docs to note that it will panic the task pool is not present as a resource.
# Future Work
If https://github.com/bevyengine/rfcs/pull/54 is approved, we can replace these resource lookups with a static function call instead to get the `ComputeTaskPool`.
---
## Changelog
Removed: The `task_pool` parameter of `Query(State)::par_for_each(_mut)`. These calls will use the `World`'s `ComputeTaskPool` resource instead.
## Migration Guide
The `task_pool` parameter for `Query(State)::par_for_each(_mut)` has been removed. Remove these parameters from all calls to these functions.
Before:
```rust
fn parallel_system(
task_pool: Res<ComputeTaskPool>,
query: Query<&MyComponent>,
) {
query.par_for_each(&task_pool, 32, |comp| {
...
});
}
```
After:
```rust
fn parallel_system(query: Query<&MyComponent>) {
query.par_for_each(32, |comp| {
...
});
}
```
If using `Query(State)` outside of a system run by the scheduler, you may need to manually configure and initialize a `ComputeTaskPool` as a resource in the `World`.
# Objective
`bevy_ecs` assumes that `u32 as usize` is a lossless operation and in a few cases relies on this for soundness and correctness. The only platforms that Rust compiles to where this invariant is broken are 16-bit systems.
A very clear example of this behavior is in the SparseSetIndex impl for Entity, where it converts a u32 into a usize to act as an index. If usize is 16-bit, the conversion will overflow and provide the caller with the wrong index. This can easily result in previously unforseen aliased mutable borrows (i.e. Query::get_many_mut).
## Solution
Explicitly fail compilation on 16-bit platforms instead of introducing UB.
Properly supporting 16-bit systems will likely need a workable use case first.
---
## Changelog
Removed: Ability to compile `bevy_ecs` on 16-bit platforms.
## Migration Guide
`bevy_ecs` will now explicitly fail to compile on 16-bit platforms. If this is required, there is currently no alternative. Please file an issue (https://github.com/bevyengine/bevy/issues) to help detail your use case.
# Objective
The pointer types introduced in #3001 are useful not just in `bevy_ecs`, but also in crates like `bevy_reflect` (#4475) or even outside of bevy.
## Solution
Extract `Ptr<'a>`, `PtrMut<'a>`, `OwnedPtr<'a>`, `ThinSlicePtr<'a, T>` and `UnsafeCellDeref` from `bevy_ecs::ptr` into `bevy_ptr`.
**Note:** `bevy_ecs` still reexports the `bevy_ptr` as `bevy_ecs::ptr` so that crates like `bevy_transform` can use the `Bundle` derive without needing to depend on `bevy_ptr` themselves.
# Objective
`bevy_ecs` has large amounts of unsafe code which is hard to get right and makes it difficult to audit for soundness.
## Solution
Introduce lifetimed, type-erased pointers: `Ptr<'a>` `PtrMut<'a>` `OwningPtr<'a>'` and `ThinSlicePtr<'a, T>` which are newtypes around a raw pointer with a lifetime and conceptually representing strong invariants about the pointee and validity of the pointer.
The process of converting bevy_ecs to use these has already caught multiple cases of unsound behavior.
## Changelog
TL;DR for release notes: `bevy_ecs` now uses lifetimed, type-erased pointers internally, significantly improving safety and legibility without sacrificing performance. This should have approximately no end user impact, unless you were meddling with the (unfortunately public) internals of `bevy_ecs`.
- `Fetch`, `FilterFetch` and `ReadOnlyFetch` trait no longer have a `'state` lifetime
- this was unneeded
- `ReadOnly/Fetch` associated types on `WorldQuery` are now on a new `WorldQueryGats<'world>` trait
- was required to work around lack of Generic Associated Types (we wish to express `type Fetch<'a>: Fetch<'a>`)
- `derive(WorldQuery)` no longer requires `'w` lifetime on struct
- this was unneeded, and improves the end user experience
- `EntityMut::get_unchecked_mut` returns `&'_ mut T` not `&'w mut T`
- allows easier use of unsafe API with less footguns, and can be worked around via lifetime transmutery as a user
- `Bundle::from_components` now takes a `ctx` parameter to pass to the `FnMut` closure
- required because closure return types can't borrow from captures
- `Fetch::init` takes `&'world World`, `Fetch::set_archetype` takes `&'world Archetype` and `&'world Tables`, `Fetch::set_table` takes `&'world Table`
- allows types implementing `Fetch` to store borrows into world
- `WorldQuery` trait now has a `shrink` fn to shorten the lifetime in `Fetch::<'a>::Item`
- this works around lack of subtyping of assoc types, rust doesnt allow you to turn `<T as Fetch<'static>>::Item'` into `<T as Fetch<'a>>::Item'`
- `QueryCombinationsIter` requires this
- Most types implementing `Fetch` now have a lifetime `'w`
- allows the fetches to store borrows of world data instead of using raw pointers
## Migration guide
- `EntityMut::get_unchecked_mut` returns a more restricted lifetime, there is no general way to migrate this as it depends on your code
- `Bundle::from_components` implementations must pass the `ctx` arg to `func`
- `Bundle::from_components` callers have to use a fn arg instead of closure captures for borrowing from world
- Remove lifetime args on `derive(WorldQuery)` structs as it is nonsensical
- `<Q as WorldQuery>::ReadOnly/Fetch` should be changed to either `RO/QueryFetch<'world>` or `<Q as WorldQueryGats<'world>>::ReadOnly/Fetch`
- `<F as Fetch<'w, 's>>` should be changed to `<F as Fetch<'w>>`
- Change the fn sigs of `Fetch::init/set_archetype/set_table` to match respective trait fn sigs
- Implement the required `fn shrink` on any `WorldQuery` implementations
- Move assoc types `Fetch` and `ReadOnlyFetch` on `WorldQuery` impls to `WorldQueryGats` impls
- Pass an appropriate `'world` lifetime to whatever fetch struct you are for some reason using
### Type inference regression
in some cases rustc may give spurrious errors when attempting to infer the `F` parameter on a query/querystate this can be fixed by manually specifying the type, i.e. `QueryState:🆕:<_, ()>(world)`. The error is rather confusing:
```rust=
error[E0271]: type mismatch resolving `<() as Fetch<'_>>::Item == bool`
--> crates/bevy_pbr/src/render/light.rs:1413:30
|
1413 | main_view_query: QueryState::new(world),
| ^^^^^^^^^^^^^^^ expected `bool`, found `()`
|
= note: required because of the requirements on the impl of `for<'x> FilterFetch<'x>` for `<() as WorldQueryGats<'x>>::Fetch`
note: required by a bound in `bevy_ecs::query::QueryState::<Q, F>::new`
--> crates/bevy_ecs/src/query/state.rs:49:32
|
49 | for<'x> QueryFetch<'x, F>: FilterFetch<'x>,
| ^^^^^^^^^^^^^^^ required by this bound in `bevy_ecs::query::QueryState::<Q, F>::new`
```
---
Made with help from @BoxyUwU and @alice-i-cecile
Co-authored-by: Boxy <supbscripter@gmail.com>
## Objective
This fixes#1686.
`size_hint` can be useful even if a little niche. For example,
`collect::<Vec<_>>()` uses the `size_hint` of Iterator it collects from
to pre-allocate a memory slice large enough to not require re-allocating
when pushing all the elements of the iterator.
## Solution
To this effect I made the following changes:
* Add a `IS_ARCHETYPAL` associated constant to the `Fetch` trait,
this constant tells us when it is safe to assume that the `Fetch`
relies exclusively on archetypes to filter queried entities
* Add `IS_ARCHETYPAL` to all the implementations of `Fetch`
* Use that constant in `QueryIter::size_hint` to provide a more useful
## Migration guide
The new associated constant is an API breaking change. For the user,
if they implemented a custom `Fetch`, it means they have to add this
associated constant to their implementation. Either `true` if it doesn't limit
the number of entities returned in a query beyond that of archetypes, or
`false` for when it does.
Remove the 'chaining' api, as it's peculiar
~~Implement the label traits for `Box<dyn ThatTrait>` (n.b. I'm not confident about this change, but it was the quickest path to not regressing)~~
Remove the need for '`.system`' when using run criteria piping
# Objective
Add a system parameter `ParamSet` to be used as container for conflicting parameters.
## Solution
Added two methods to the SystemParamState trait, which gives the access used by the parameter. Did the implementation. Added some convenience methods to FilteredAccessSet. Changed `get_conflicts` to return every conflicting component instead of breaking on the first conflicting `FilteredAccess`.
Co-authored-by: bilsen <40690317+bilsen@users.noreply.github.com>
# Objective
Fixes#1529
Run bevy_ecs in miri
## Solution
- Don't set thread names when running in miri rust-lang/miri/issues/1717
- Update `event-listener` to `2.5.2` as previous versions have UB that is detected by miri: [event-listener commit](1fa31c553e)
- Ignore memory leaks when running in miri as they are impossible to track down rust-lang/miri/issues/1481
- Make `table_add_remove_many` test less "many" because miri is really quite slow :)
- Make CI run `RUSTFLAGS="-Zrandomize-layout" MIRIFLAGS="-Zmiri-ignore-leaks -Zmiri-tag-raw-pointers -Zmiri-disable-isolation" cargo +nightly miri test -p bevy_ecs`
This adds the concept of "default labels" for systems (currently scoped to "parallel systems", but this could just as easily be implemented for "exclusive systems"). Function systems now include their function's `SystemTypeIdLabel` by default.
This enables the following patterns:
```rust
// ordering two systems without manually defining labels
app
.add_system(update_velocity)
.add_system(movement.after(update_velocity))
// ordering sets of systems without manually defining labels
app
.add_system(foo)
.add_system_set(
SystemSet::new()
.after(foo)
.with_system(bar)
.with_system(baz)
)
```
Fixes: #4219
Related to: #4220
Credit to @aevyrie @alice-i-cecile @DJMcNab (and probably others) for proposing (and supporting) this idea about a year ago. I was a big dummy that both shut down this (very good) idea and then forgot I did that. Sorry. You all were right!
# Objective
- In the large majority of cases, users were calling `.unwrap()` immediately after `.get_resource`.
- Attempting to add more helpful error messages here resulted in endless manual boilerplate (see #3899 and the linked PRs).
## Solution
- Add an infallible variant named `.resource` and so on.
- Use these infallible variants over `.get_resource().unwrap()` across the code base.
## Notes
I did not provide equivalent methods on `WorldCell`, in favor of removing it entirely in #3939.
## Migration Guide
Infallible variants of `.get_resource` have been added that implicitly panic, rather than needing to be unwrapped.
Replace `world.get_resource::<Foo>().unwrap()` with `world.resource::<Foo>()`.
## Impact
- `.unwrap` search results before: 1084
- `.unwrap` search results after: 942
- internal `unwrap_or_else` calls added: 4
- trivial unwrap calls removed from tests and code: 146
- uses of the new `try_get_resource` API: 11
- percentage of the time the unwrapping API was used internally: 93%
# Objective
- Fix the ugliness of the `config` api.
- Supercedes #2440, #2463, #2491
## Solution
- Since #2398, capturing closure systems have worked.
- Use those instead where we needed config before
- Remove the rest of the config api.
- Related: #2777
What is says on the tin.
This has got more to do with making `clippy` slightly more *quiet* than it does with changing anything that might greatly impact readability or performance.
that said, deriving `Default` for a couple of structs is a nice easy win
# Objective
- Fixes#3078
- Fixes#1397
## Solution
- Implement Commands::init_resource.
- Also implement for World, for consistency and to simplify internal structure.
- While we're here, clean up some of the docs for Command and World resource modification.
Implements a new Queryable called AnyOf, which will return an item as long as at least one of it's requested Queryables returns something. For example, a `Query<AnyOf<(&A, &B, &C)>>` will return items with type `(Option<&A>, Option<&B>, Option<&C>)`, and will guarantee that for every element at least one of the option s is Some. This is a shorthand for queries like `Query<(Option<&A>, Option<&B>, Option<&C>), Or<(With<A>, With<B>, With&C>)>>`.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- Calling .id() has no purpose unless you use the Entity returned
- This is an easy source of confusion for beginners.
- This is easily missed during refactors.
## Solution
- Mark the appropriate methods as #[must_use]
Fixes#2566Fixes#3005
There are only READMEs in the 4 crates here (with the exception of bevy itself).
Those 4 crates are ecs, reflect, tasks, and transform.
These should each now include their respective README files.
Co-authored-by: Hoidigan <57080125+Hoidigan@users.noreply.github.com>
Co-authored-by: Daniel Nelsen <57080125+Hoidigan@users.noreply.github.com>
This implements the most minimal variant of #1843 - a derive for marker trait. This is a prerequisite to more complicated features like statically defined storage type or opt-out component reflection.
In order to make component struct's purpose explicit and avoid misuse, it must be annotated with `#[derive(Component)]` (manual impl is discouraged for compatibility). Right now this is just a marker trait, but in the future it might be expanded. Making this change early allows us to make further changes later without breaking backward compatibility for derive macro users.
This already prevents a lot of issues, like using bundles in `insert` calls. Primitive types are no longer valid components as well. This can be easily worked around by adding newtype wrappers and deriving `Component` for them.
One funny example of prevented bad code (from our own tests) is when an newtype struct or enum variant is used. Previously, it was possible to write `insert(Newtype)` instead of `insert(Newtype(value))`. That code compiled, because function pointers (in this case newtype struct constructor) implement `Send + Sync + 'static`, so we allowed them to be used as components. This is no longer the case and such invalid code will trigger a compile error.
Co-authored-by: = <=>
Co-authored-by: TheRawMeatball <therawmeatball@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
