# Objective
- Many strings in bevy_ecs are created but only used for debug: system
name, component name, ...
- Those strings make a significant part of the final binary and are no
use in a released game
## Solution
- Use [`strings`](https://linux.die.net/man/1/strings) to find ...
strings in a binary
- Try to find where they come from
- Many are made from `type_name::<T>()` and only used in error / debug
messages
- Add a new structure `DebugName` that holds no value if `debug` feature
is disabled
- Replace `core::any::type_name::<T>()` by `DebugName::type_name::<T>()`
## Testing
Measurements were taken without the new feature being enabled by
default, to help with commands
### File Size
I tried building the `breakout` example with `cargo run --release
--example breakout`
|`debug` enabled|`debug` disabled|
|-|-|
|81621776 B|77735728B|
|77.84MB|74.13MB|
### Compilation time
`hyperfine --min-runs 15 --prepare "cargo clean && sleep 5"
'RUSTC_WRAPPER="" cargo build --release --example breakout'
'RUSTC_WRAPPER="" cargo build --release --example breakout --features
debug'`
```
breakout' 'RUSTC_WRAPPER="" cargo build --release --example breakout --features debug'
Benchmark 1: RUSTC_WRAPPER="" cargo build --release --example breakout
Time (mean ± σ): 84.856 s ± 3.565 s [User: 1093.817 s, System: 32.547 s]
Range (min … max): 78.038 s … 89.214 s 15 runs
Benchmark 2: RUSTC_WRAPPER="" cargo build --release --example breakout --features debug
Time (mean ± σ): 92.303 s ± 2.466 s [User: 1193.443 s, System: 33.803 s]
Range (min … max): 90.619 s … 99.684 s 15 runs
Summary
RUSTC_WRAPPER="" cargo build --release --example breakout ran
1.09 ± 0.05 times faster than RUSTC_WRAPPER="" cargo build --release --example breakout --features debug
```
# Objective
Let `FilteredEntityRef` and `FilteredEntityMut` receive access when
nested inside tuples or `#[derive(QueryData)]` types. Make sure to
exclude any access that would conflict with other subqueries!
Fixes#14349
## Solution
Replace `WorldQuery::set_access(state, access)` with a new method,
`QueryData::provide_extra_access(state, access, available_access)`, that
passes both the total available access and the currently used access.
This is called after `WorldQuery::update_component_access()`, so any
access used by ordinary subqueries will be known. `FilteredEntityRef`
and `FilteredEntityMut` can use the combination to determine how much
access they can safely take, while tuples can safely pass those
parameters directly to their subqueries.
This requires a new `Access::remove_conflicting_access()` method that
can be used to remove any access that would conflict with existing
access. Implementing this method was easier by first factoring some
common set manipulation code out of `Access::extend`. I can extract that
refactoring to a separate PR if desired.
Have `FilteredEntity(Ref|Mut)` store `Access` instead of
`FilteredAccess` because they do not need to keep track of the filter.
This was necessary in an early draft but no longer is. I left it in
because it's small and I'm touching that code anyway, but I can extract
it to a separate PR if desired.
# Objective
Fixes#17803
## Solution
- Add an `Allows<T>` `QueryFilter` that adds archetypal access for `T`
- Fix access merging to include archetypal from both sides
## Testing
- Added a case to the unit test for the application of
`DefaultQueryFilters`
# Objective
Stop using `ArchetypeComponentId` in the executor. These IDs will grow
even more quickly with relations, and the size may start to degrade
performance.
## Solution
Have systems expose their `FilteredAccessSet<ComponentId>`, and have the
executor use that to determine which systems conflict. This can be
determined statically, so determine all conflicts during initialization
and only perform bit tests when running.
## Testing
I ran many_foxes and didn't see any performance changes. It's probably
worth testing this with a wider range of realistic schedules to see
whether the reduced concurrency has a cost in practice, but I don't know
what sort of test cases to use.
## Migration Guide
The schedule will now prevent systems from running in parallel if there
*could* be an archetype that they conflict on, even if there aren't
actually any. For example, these systems will now conflict even if no
entity has both `Player` and `Enemy` components:
```rust
fn player_system(query: Query<(&mut Transform, &Player)>) {}
fn enemy_system(query: Query<(&mut Transform, &Enemy)>) {}
```
To allow them to run in parallel, use `Without` filters, just as you
would to allow both queries in a single system:
```rust
// Either one of these changes alone would be enough
fn player_system(query: Query<(&mut Transform, &Player), Without<Enemy>>) {}
fn enemy_system(query: Query<(&mut Transform, &Enemy), Without<Player>>) {}
```
# Objective
When implementing `SystemParam` for an object which contains a mutable
reference to World, which cannot be derived due to a required lifetime
parameter, it's necessary to check that there aren't any conflicts.
As far as I know, the is_empty method is the only way provided to check
for no conflicts at all
# Objective
#18173 allows components to be queued without being fully registered.
But much of bevy's debug logging contained
`components.get_name(id).unwrap()`. However, this panics when the id is
queued. This PR fixes this, allowing names to be retrieved for debugging
purposes, etc, even while they're still queued.
## Solution
We change `ComponentInfo::descriptor` to be `Arc<ComponentDescriptor>`
instead of not arc'd. This lets us pass the descriptor around (as a name
or otherwise) as needed. The alternative would require some form of
`MappedRwLockReadGuard`, which is unstable, and would be terribly
blocking. Putting it in an arc also signifies that it doesn't change,
which is a nice signal to users. This does mean there's an extra pointer
dereference, but I don't think that's an issue here, as almost all paths
that use this are for debugging purposes or one-time set ups.
## Testing
Existing tests.
## Migration Guide
`Components::get_name` now returns `Option<Cow<'_, str>` instead of
`Option<&str>`. This is because it now returns results for queued
components. If that behavior is not desired, or you know the component
is not queued, you can use
`components.get_info().map(ComponentInfo::name)` instead.
Similarly, `ScheduleGraph::conflicts_to_string` now returns `impl
Iterator<Item = (String, String, Vec<Cow<str>>)>` instead of `impl
Iterator<Item = (String, String, Vec<&str>)>`. Because `Cow<str>` derefs
to `&str`, most use cases can remain unchanged.
---------
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
# Objective
- Fixes#16339
## Solution
- Replaced `component_reads_and_writes` and `component_writes` with
`try_iter_component_access`.
## Testing
- Ran `dynamic` example to confirm behaviour is unchanged.
- CI
---
## Migration Guide
The following methods (some removed in previous PRs) are now replaced by
`Access::try_iter_component_access`:
* `Access::component_reads_and_writes`
* `Access::component_reads`
* `Access::component_writes`
As `try_iter_component_access` returns a `Result`, you'll now need to
handle the failing case (e.g., `unwrap()`). There is currently a single
failure mode, `UnboundedAccess`, which occurs when the `Access` is for
all `Components` _except_ certain exclusions. Since this list is
infinite, there is no meaningful way for `Access` to provide an
iterator. Instead, get a list of components (e.g., from the `Components`
structure) and iterate over that instead, filtering using
`Access::has_component_read`, `Access::has_component_write`, etc.
Additionally, you'll need to `filter_map` the accesses based on which
method you're attempting to replace:
* `Access::component_reads_and_writes` -> `Exclusive(_) | Shared(_)`
* `Access::component_reads` -> `Shared(_)`
* `Access::component_writes` -> `Exclusive(_)`
To ease migration, please consider the below extension trait which you
can include in your project:
```rust
pub trait AccessCompatibilityExt {
/// Returns the indices of the components this has access to.
fn component_reads_and_writes(&self) -> impl Iterator<Item = T> + '_;
/// Returns the indices of the components this has non-exclusive access to.
fn component_reads(&self) -> impl Iterator<Item = T> + '_;
/// Returns the indices of the components this has exclusive access to.
fn component_writes(&self) -> impl Iterator<Item = T> + '_;
}
impl<T: SparseSetIndex> AccessCompatibilityExt for Access<T> {
fn component_reads_and_writes(&self) -> impl Iterator<Item = T> + '_ {
self
.try_iter_component_access()
.expect("Access is unbounded. Please refactor the usage of this method to directly use try_iter_component_access")
.filter_map(|component_access| {
let index = component_access.index().sparse_set_index();
match component_access {
ComponentAccessKind::Archetypal(_) => None,
ComponentAccessKind::Shared(_) => Some(index),
ComponentAccessKind::Exclusive(_) => Some(index),
}
})
}
fn component_reads(&self) -> impl Iterator<Item = T> + '_ {
self
.try_iter_component_access()
.expect("Access is unbounded. Please refactor the usage of this method to directly use try_iter_component_access")
.filter_map(|component_access| {
let index = component_access.index().sparse_set_index();
match component_access {
ComponentAccessKind::Archetypal(_) => None,
ComponentAccessKind::Shared(_) => Some(index),
ComponentAccessKind::Exclusive(_) => None,
}
})
}
fn component_writes(&self) -> impl Iterator<Item = T> + '_ {
self
.try_iter_component_access()
.expect("Access is unbounded. Please refactor the usage of this method to directly use try_iter_component_access")
.filter_map(|component_access| {
let index = component_access.index().sparse_set_index();
match component_access {
ComponentAccessKind::Archetypal(_) => None,
ComponentAccessKind::Shared(_) => None,
ComponentAccessKind::Exclusive(_) => Some(index),
}
})
}
}
```
Please take note of the use of `expect(...)` in these methods. You
should consider using these as a starting point for a more appropriate
migration based on your specific needs.
## Notes
- This new method is fallible based on whether the `Access` is bounded
or unbounded (unbounded occurring with inverted component sets). If
bounded, will return an iterator of every item and its access level. I
believe this makes sense without exposing implementation details around
`Access`.
- The access level is defined by an `enum` `ComponentAccessKind<T>`,
either `Archetypical`, `Shared`, or `Exclusive`. As a convenience, this
`enum` has a method `index` to get the inner `T` value without a match
statement. It does add more code, but the API is clearer.
- Within `QueryBuilder` this new method simplifies several pieces of
logic without changing behaviour.
- Within `QueryState` the logic is simplified and the amount of
iteration is reduced, potentially improving performance.
- Within the `dynamic` example it has identical behaviour, with the
inversion footgun explicitly highlighted by an `unwrap`.
---------
Co-authored-by: Chris Russell <8494645+chescock@users.noreply.github.com>
Co-authored-by: Mike <2180432+hymm@users.noreply.github.com>
# Objective
- Fixes#17960
## Solution
- Followed the [edition upgrade
guide](https://doc.rust-lang.org/edition-guide/editions/transitioning-an-existing-project-to-a-new-edition.html)
## Testing
- CI
---
## Summary of Changes
### Documentation Indentation
When using lists in documentation, proper indentation is now linted for.
This means subsequent lines within the same list item must start at the
same indentation level as the item.
```rust
/* Valid */
/// - Item 1
/// Run-on sentence.
/// - Item 2
struct Foo;
/* Invalid */
/// - Item 1
/// Run-on sentence.
/// - Item 2
struct Foo;
```
### Implicit `!` to `()` Conversion
`!` (the never return type, returned by `panic!`, etc.) no longer
implicitly converts to `()`. This is particularly painful for systems
with `todo!` or `panic!` statements, as they will no longer be functions
returning `()` (or `Result<()>`), making them invalid systems for
functions like `add_systems`. The ideal fix would be to accept functions
returning `!` (or rather, _not_ returning), but this is blocked on the
[stabilisation of the `!` type
itself](https://doc.rust-lang.org/std/primitive.never.html), which is
not done.
The "simple" fix would be to add an explicit `-> ()` to system
signatures (e.g., `|| { todo!() }` becomes `|| -> () { todo!() }`).
However, this is _also_ banned, as there is an existing lint which (IMO,
incorrectly) marks this as an unnecessary annotation.
So, the "fix" (read: workaround) is to put these kinds of `|| -> ! { ...
}` closuers into variables and give the variable an explicit type (e.g.,
`fn()`).
```rust
// Valid
let system: fn() = || todo!("Not implemented yet!");
app.add_systems(..., system);
// Invalid
app.add_systems(..., || todo!("Not implemented yet!"));
```
### Temporary Variable Lifetimes
The order in which temporary variables are dropped has changed. The
simple fix here is _usually_ to just assign temporaries to a named
variable before use.
### `gen` is a keyword
We can no longer use the name `gen` as it is reserved for a future
generator syntax. This involved replacing uses of the name `gen` with
`r#gen` (the raw-identifier syntax).
### Formatting has changed
Use statements have had the order of imports changed, causing a
substantial +/-3,000 diff when applied. For now, I have opted-out of
this change by amending `rustfmt.toml`
```toml
style_edition = "2021"
```
This preserves the original formatting for now, reducing the size of
this PR. It would be a simple followup to update this to 2024 and run
`cargo fmt`.
### New `use<>` Opt-Out Syntax
Lifetimes are now implicitly included in RPIT types. There was a handful
of instances where it needed to be added to satisfy the borrow checker,
but there may be more cases where it _should_ be added to avoid
breakages in user code.
### `MyUnitStruct { .. }` is an invalid pattern
Previously, you could match against unit structs (and unit enum
variants) with a `{ .. }` destructuring. This is no longer valid.
### Pretty much every use of `ref` and `mut` are gone
Pattern binding has changed to the point where these terms are largely
unused now. They still serve a purpose, but it is far more niche now.
### `iter::repeat(...).take(...)` is bad
New lint recommends using the more explicit `iter::repeat_n(..., ...)`
instead.
## Migration Guide
The lifetimes of functions using return-position impl-trait (RPIT) are
likely _more_ conservative than they had been previously. If you
encounter lifetime issues with such a function, please create an issue
to investigate the addition of `+ use<...>`.
## Notes
- Check the individual commits for a clearer breakdown for what
_actually_ changed.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
Prevent unsound uses of `DeferredWorld` as a `SystemParam`. It is
currently unsound because it does not check for existing access, and
because it incorrectly registers filtered access.
## Solution
Have `DeferredWorld` panic if a previous parameter has conflicting
access.
Have `DeferredWorld` update `archetype_component_access` so that the
multi-threaded executor sees the access.
Fix `FilteredAccessSet::read_all()` and `write_all()` to correctly add a
`FilteredAccess` with no filter so that `Query` is able to detect the
conflicts.
Remove redundant `read_all()` call, since `write_all()` already declares
read access.
Remove unnecessary `set_has_deferred()` call, since `<DeferredWorld as
SystemParam>::apply_deferred()` does nothing. Previously we were
inserting unnecessary `apply_deferred` systems in the schedule.
## Testing
Added unit tests for systems where `DeferredWorld` conflicts with a
`Query` in the same system.
# Objective
Some usecases in the ecosystems are blocked by the inability to stop
bevy internals and third party plugins from touching their entities.
However the specifics of a general purpose entity disabling system are
controversial and further complicated by hierarchies. We can partially
unblock these usecases with an opt-in approach: default query filters.
## Solution
- Introduce DefaultQueryFilters, these filters are automatically applied
to queries that don't otherwise mention the filtered component.
- End users and third party plugins can register default filters and are
responsible for handling entities they have hidden this way.
- Extra features can be left for after user feedback
- The default value could later include official ways to hide entities
---
## Changelog
- Add DefaultQueryFilters
# Background
In `no_std` compatible crates, there is often an `std` feature which
will allow access to the standard library. Currently, with the `std`
feature _enabled_, the
[`std::prelude`](https://doc.rust-lang.org/std/prelude/index.html) is
implicitly imported in all modules. With the feature _disabled_, instead
the [`core::prelude`](https://doc.rust-lang.org/core/prelude/index.html)
is implicitly imported. This creates a subtle and pervasive issue where
`alloc` items _may_ be implicitly included (if `std` is enabled), or
must be explicitly included (if `std` is not enabled).
# Objective
- Make the implicit imports for `no_std` crates consistent regardless of
what features are/not enabled.
## Solution
- Replace the `cfg_attr` "double negative" `no_std` attribute with
conditional compilation to _include_ `std` as an external crate.
```rust
// Before
#![cfg_attr(not(feature = "std"), no_std)]
// After
#![no_std]
#[cfg(feature = "std")]
extern crate std;
```
- Fix imports that are currently broken but are only now visible with
the above fix.
## Testing
- CI
## Notes
I had previously used the "double negative" version of `no_std` based on
general consensus that it was "cleaner" within the Rust embedded
community. However, this implicit prelude issue likely was considered
when forming this consensus. I believe the reason why is the items most
affected by this issue are provided by the `alloc` crate, which is
rarely used within embedded but extensively used within Bevy.
# Objective
- Made certain methods public for advanced use cases. Methods that
returns mutable references are marked as unsafe due to the possibility
of violating internal lifetime constraint assumptions.
- Fixes an issue introduced by #15184
# Objective
- Contributes to #15460
## Solution
- Added the following features:
- `std` (default)
- `async_executor` (default)
- `edge_executor`
- `critical-section`
- `portable-atomic`
- Gated `tracing` in `bevy_utils` to allow compilation on certain
platforms
- Switched from `tracing` to `log` for simple message logging within
`bevy_ecs`. Note that `tracing` supports capturing from `log` so this
should be an uncontroversial change.
- Fixed imports and added feature gates as required
- Made `bevy_tasks` optional within `bevy_ecs`. Turns out it's only
needed for parallel operations which are already gated behind
`multi_threaded` anyway.
## Testing
- Added to `compile-check-no-std` CI command
- `cargo check -p bevy_ecs --no-default-features --features
edge_executor,critical-section,portable-atomic --target
thumbv6m-none-eabi`
- `cargo check -p bevy_ecs --no-default-features --features
edge_executor,critical-section`
- `cargo check -p bevy_ecs --no-default-features`
## Draft Release Notes
Bevy's core ECS now supports `no_std` platforms.
In prior versions of Bevy, it was not possible to work with embedded or
niche platforms due to our reliance on the standard library, `std`. This
has blocked a number of novel use-cases for Bevy, such as an embedded
database for IoT devices, or for creating games on retro consoles.
With this release, `bevy_ecs` no longer requires `std`. To use Bevy on a
`no_std` platform, you must disable default features and enable the new
`edge_executor` and `critical-section` features. You may also need to
enable `portable-atomic` and `critical-section` if your platform does
not natively support all atomic types and operations used by Bevy.
```toml
[dependencies]
bevy_ecs = { version = "0.16", default-features = false, features = [
# Required for platforms with incomplete atomics (e.g., Raspberry Pi Pico)
"portable-atomic",
"critical-section",
# Optional
"bevy_reflect",
"serialize",
"bevy_debug_stepping",
"edge_executor"
] }
```
Currently, this has been tested on bare-metal x86 and the Raspberry Pi
Pico. If you have trouble using `bevy_ecs` on a particular platform,
please reach out either through a GitHub issue or in the `no_std`
working group on the Bevy Discord server.
Keep an eye out for future `no_std` updates as we continue to improve
the parity between `std` and `no_std`. We look forward to seeing what
kinds of applications are now possible with Bevy!
## Notes
- Creating PR in draft to ensure CI is passing before requesting
reviews.
- This implementation has no support for multithreading in `no_std`,
especially due to `NonSend` being unsound if allowed in multithreading.
The reason is we cannot check the `ThreadId` in `no_std`, so we have no
mechanism to at-runtime determine if access is sound.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Vic <59878206+Victoronz@users.noreply.github.com>
# Objective
Allow resources to be accessed soundly by `QueryData` and `QueryFilter`
implementations.
This mostly works today, and is used in `bevy-trait-query` and will be
used by #16810. The problem is that the access is not made visible to
the executor, so it would be possible for a system with resource access
in a query to run concurrently with a system that accesses the resource
with `ResMut`, resulting in Undefined Behavior.
## Solution
Define calling `add_resource_read` or `add_resource_write` in
`WorldQuery::update_component_access` to be a supported way to declare
resource access in a query.
Modify `QueryState::new_with_access` to check for resource access and
report it in `archetype_component_acccess`.
Modify `FilteredAccess::is_compatible` to consider resource access
conflicting even on queries with disjoint filters.
# Objective
Support accessing dynamic resources in a dynamic system, including
accessing them by component id. This is similar to how dynamic
components can be queried using `Query<FilteredEntityMut>`.
## Solution
Create `FilteredResources` and `FilteredResourcesMut` types that act
similar to `FilteredEntityRef` and `FilteredEntityMut` and that can be
used as system parameters.
## Example
```rust
// Use `FilteredResourcesParamBuilder` to declare access to resources.
let system = (FilteredResourcesParamBuilder::new(|builder| {
builder.add_read::<B>().add_read::<C>();
}),)
.build_state(&mut world)
.build_system(resource_system);
world.init_resource::<A>();
world.init_resource::<C>();
fn resource_system(res: FilteredResources) {
// The resource exists, but we have no access, so we can't read it.
assert!(res.get::<A>().is_none());
// The resource doesn't exist, so we can't read it.
assert!(res.get::<B>().is_none());
// The resource exists and we have access, so we can read it.
let c = res.get::<C>().unwrap();
// The type parameter can be left out if it can be determined from use.
let c: Res<C> = res.get().unwrap();
}
```
## Future Work
As a follow-up PR, `ReflectResource` can be modified to take `impl
Into<FilteredResources>`, similar to how `ReflectComponent` takes `impl
Into<FilteredEntityRef>`. That will allow dynamic resources to be
accessed using reflection.
# Objective
- Fixes#6370
- Closes#6581
## Solution
- Added the following lints to the workspace:
- `std_instead_of_core`
- `std_instead_of_alloc`
- `alloc_instead_of_core`
- Used `cargo +nightly fmt` with [item level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Item%5C%3A)
to split all `use` statements into single items.
- Used `cargo clippy --workspace --all-targets --all-features --fix
--allow-dirty` to _attempt_ to resolve the new linting issues, and
intervened where the lint was unable to resolve the issue automatically
(usually due to needing an `extern crate alloc;` statement in a crate
root).
- Manually removed certain uses of `std` where negative feature gating
prevented `--all-features` from finding the offending uses.
- Used `cargo +nightly fmt` with [crate level use
formatting](https://rust-lang.github.io/rustfmt/?version=v1.6.0&search=#Crate%5C%3A)
to re-merge all `use` statements matching Bevy's previous styling.
- Manually fixed cases where the `fmt` tool could not re-merge `use`
statements due to conditional compilation attributes.
## Testing
- Ran CI locally
## Migration Guide
The MSRV is now 1.81. Please update to this version or higher.
## Notes
- This is a _massive_ change to try and push through, which is why I've
outlined the semi-automatic steps I used to create this PR, in case this
fails and someone else tries again in the future.
- Making this change has no impact on user code, but does mean Bevy
contributors will be warned to use `core` and `alloc` instead of `std`
where possible.
- This lint is a critical first step towards investigating `no_std`
options for Bevy.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
This commit adds two new `WorldQuery` types: `EntityRefExcept` and
`EntityMutExcept`. These types work just like `EntityRef` and
`EntityMut`, but they prevent access to a statically-specified list of
components. For example, `EntityMutExcept<(AnimationPlayer,
Handle<AnimationGraph>)>` provides mutable access to all components
except for `AnimationPlayer` and `Handle<AnimationGraph>`. These types
are useful when you need to be able to process arbitrary queries while
iterating over the results of another `EntityMut` query.
The motivating use case is *generalized animation*, which is an upcoming
feature that allows animation of any component property, not just
rotation, translation, scaling, or morph weights. To implement this, we
must change the current `AnyOf<(&mut Transform, &mut MorphWeights)>` to
instead be `EntityMutExcept<(AnimationPlayer, Handle<AnimationGraph>)>`.
It's possible to use `FilteredEntityMut` in conjunction with a
dynamically-generated system instead, but `FilteredEntityMut` isn't
optimized for the use case of a large number of allowed components
coupled with a small set of disallowed components. No amount of
optimization of `FilteredEntityMut` produced acceptable performance on
the `many_foxes` benchmark. `Query<EntityMut, Without<AnimationPlayer>>`
will not suffice either, as it's legal and idiomatic for an
`AnimationTarget` and an `AnimationPlayer` to coexist on the same
entity.
An alternate proposal was to implement a somewhat-more-general
`Except<Q, CL>` feature, where Q is a `WorldQuery` and CL is a
`ComponentList`. I wasn't able to implement that proposal in a
reasonable way, because of the fact that methods like
`EntityMut::get_mut` and `EntityRef::get` are inherent methods instead
of methods on `WorldQuery`, and therefore there was no way to delegate
methods like `get` and `get_mut` to the inner query in a generic way.
Refactoring those methods into a trait would probably be possible.
However, I didn't see a use case for a hypothetical `Except` with
arbitrary queries: `Query<Except<(&Transform, &Visibility),
Visibility>>` would just be a complicated equivalent to
`Query<&Transform>`, for instance. So, out of a desire for simplicity, I
omitted a generic `Except` mechanism.
I've tested the performance of generalized animation on `many_foxes` and
found that, with this patch, `animate_targets` has a 7.4% slowdown over
`main`. With `FilteredEntityMut` optimized to use `Arc<Access>`, the
slowdown is 75.6%, due to contention on the reference count. Without
`Arc<Access>`, the slowdown is even worse, over 2x.
## Testing
New tests have been added that check that `EntityRefExcept` and
`EntityMutExcept` allow and disallow access to components properly and
that the query engine can correctly reject conflicting queries involving
those types.
A Tracy profile of `many_foxes` with 10,000 foxes showing generalized
animation using `FilteredEntityMut` (red) vs. main (yellow) is as
follows:
A Tracy profile of `many_foxes` with 10,000 foxes showing generalized
animation using this `EntityMutExcept` (yellow) vs. main (red) is as
follows:
# Objective
Fixes#14782
## Solution
Enable the lint and fix all upcoming hints (`--fix`). Also tried to
figure out the false-positive (see review comment). Maybe split this PR
up into multiple parts where only the last one enables the lint, so some
can already be merged resulting in less many files touched / less
potential for merge conflicts?
Currently, there are some cases where it might be easier to read the
code with the qualifier, so perhaps remove the import of it and adapt
its cases? In the current stage it's just a plain adoption of the
suggestions in order to have a base to discuss.
## Testing
`cargo clippy` and `cargo run -p ci` are happy.
# Objective
- I made a mistake when fixing the merge conflicts here:
https://github.com/bevyengine/bevy/pull/14579#discussion_r1705377452
It wasn't caught because there's no easy way to trigger access conflicts
with resources without triggering them with components first.
# Objective
- Fixes https://github.com/bevyengine/bevy/issues/14575
- There is a soundness issue because we use `conflicts()` to check for
system ambiguities + soundness issues. However since the current
conflicts is a `Vec<T>`, we cannot express conflicts where there is no
specific `ComponentId` at fault. For example `q1: Query<EntityMut>, q2:
Query<EntityMut>`
There was a TODO to handle the `write_all` case but it was never
resolved
## Solution
- Introduce an `AccessConflict` enum that is either a list of specific
ids that are conflicting or `All` if all component ids are conflicting
## Testing
- Introduced a new unit test to check for the `EntityMut` case
## Migration guide
The `get_conflicts` method of `Access` now returns an `AccessConflict`
enum instead of simply a `Vec` of `ComponentId`s that are causing the
access conflict. This can be useful in cases where there are no
particular `ComponentId`s conflicting, but instead **all** of them are;
for example `fn system(q1: Query<EntityMut>, q2: Query<EntityRef>)`
# Objective
Optimize the cloning process for Access-related structs in the ECS
system, specifically targeting the `clone_from` method.
Previously, profiling showed that 1% of CPU time was spent in
`FixedBitSet`'s `drop_in_place`, due to the default `clone_from`
implementation:
```rust
fn clone_from(&mut self, source: &Self) {
*self = source.clone()
}
```
This implementation causes unnecessary allocations and deallocations.
However, [FixedBitSet provides a more optimized clone_from
method](https://github.com/petgraph/fixedbitset/blob/master/src/lib.rs#L1445-L1465)
that avoids these allocations and utilizes SIMD instructions for better
performance.
This PR aims to leverage the optimized clone_from method of FixedBitSet
and implement custom clone_from methods for Access-related structs to
take full advantage of this optimization. By doing so, we expect to
significantly reduce CPU time spent on cloning operations and improve
overall system performance.
## Solution
- Implemented custom `clone` and `clone_from` methods for `Access`,
`FilteredAccess`, `AccessFilters`, and `FilteredAccessSet` structs.
- Removed `#[derive(Clone)]` and manually implemented `Clone` trait to
use optimized `clone_from` method from `FixedBitSet`.
- Added unit tests for cloning and `clone_from` methods to ensure
correctness.
## Testing
- Conducted performance testing comparing the original and optimized
versions.
- Measured CPU time consumption for the `clone_from` method:
- Original version: 1.34% of CPU time
- Optimized version: 0.338% of CPU time
- Compared FPS before and after the changes (results may vary depending
on the run):
Before optimization:
```
2024-07-28T12:49:11.864019Z INFO bevy diagnostic: fps : 213.489463 (avg 214.502488)
2024-07-28T12:49:11.864037Z INFO bevy diagnostic: frame_time : 4.704746ms (avg 4.682251ms)
2024-07-28T12:49:11.864042Z INFO bevy diagnostic: frame_count: 7947.000000 (avg 7887.500000)
```
After optimization:
```
2024-07-28T12:29:42.705738Z INFO bevy diagnostic: fps : 220.273721 (avg 220.912227)
2024-07-28T12:29:42.705762Z INFO bevy diagnostic: frame_time : 4.559127ms (avg 4.544905ms)
2024-07-28T12:29:42.705769Z INFO bevy diagnostic: frame_count: 7596.000000 (avg 7536.500000)
```
---
Reviewers can test these changes by running `cargo run --release
--example ssr`
# Objective
- The implementation of `update_component_access` for `AnyOf`/`Or` is
kinda weird due to special casing the first filter, let's simplify it;
- Fundamentally we want to fold/reduce the various filters using an OR
operation, however in order to do a proper fold we need a neutral
element for the initial accumulator, which for OR is FALSE. However we
didn't have a way to create a `FilteredAccess` value corresponding to
FALSE and thus the only option was reducing, which special cases the
first element as being the initial accumulator.
This is an alternative to https://github.com/bevyengine/bevy/pull/14026
## Solution
- Introduce `FilteredAccess::empty` as a way to create a
`FilteredAccess` corresponding to the logical proposition FALSE;
- Use it as the initial accumulator for the above operations, allowing
to handle all the elements to fold in the same way.
---
## Migration Guide
- The behaviour of `AnyOf<()>` and `Or<()>` has been changed to match no
archetypes rather than all archetypes to naturally match the
corresponding logical operation. Consider replacing them with `()`
instead.
# Objective
- Provide an expressive way to register dynamic behavior in response to
ECS changes that is consistent with existing bevy types and traits as to
provide a smooth user experience.
- Provide a mechanism for immediate changes in response to events during
command application in order to facilitate improved query caching on the
path to relations.
## Solution
- A new fundamental ECS construct, the `Observer`; inspired by flec's
observers but adapted to better fit bevy's access patterns and rust's
type system.
---
## Examples
There are 3 main ways to register observers. The first is a "component
observer" that looks like this:
```rust
world.observe(|trigger: Trigger<OnAdd, Transform>, query: Query<&Transform>| {
let transform = query.get(trigger.entity()).unwrap();
});
```
The above code will spawn a new entity representing the observer that
will run it's callback whenever the `Transform` component is added to an
entity. This is a system-like function that supports dependency
injection for all the standard bevy types: `Query`, `Res`, `Commands`
etc. It also has a `Trigger` parameter that provides information about
the trigger such as the target entity, and the event being triggered.
Importantly these systems run during command application which is key
for their future use to keep ECS internals up to date. There are similar
events for `OnInsert` and `OnRemove`, and this will be expanded with
things such as `ArchetypeCreated`, `TableEmpty` etc. in follow up PRs.
Another way to register an observer is an "entity observer" that looks
like this:
```rust
world.entity_mut(entity).observe(|trigger: Trigger<Resize>| {
// ...
});
```
Entity observers run whenever an event of their type is triggered
targeting that specific entity. This type of observer will de-spawn
itself if the entity (or entities) it is observing is ever de-spawned so
as to not leave dangling observers.
Entity observers can also be spawned from deferred contexts such as
other observers, systems, or hooks using commands:
```rust
commands.entity(entity).observe(|trigger: Trigger<Resize>| {
// ...
});
```
Observers are not limited to in built event types, they can be used with
any type that implements `Event` (which has been extended to implement
Component). This means events can also carry data:
```rust
#[derive(Event)]
struct Resize { x: u32, y: u32 }
commands.entity(entity).observe(|trigger: Trigger<Resize>, query: Query<&mut Size>| {
let event = trigger.event();
// ...
});
// Will trigger the observer when commands are applied.
commands.trigger_targets(Resize { x: 10, y: 10 }, entity);
```
You can also trigger events that target more than one entity at a time:
```rust
commands.trigger_targets(Resize { x: 10, y: 10 }, [e1, e2]);
```
Additionally, Observers don't _need_ entity targets:
```rust
app.observe(|trigger: Trigger<Quit>| {
})
commands.trigger(Quit);
```
In these cases, `trigger.entity()` will be a placeholder.
Observers are actually just normal entities with an `ObserverState` and
`Observer` component! The `observe()` functions above are just shorthand
for:
```rust
world.spawn(Observer::new(|trigger: Trigger<Resize>| {});
```
This will spawn the `Observer` system and use an `on_add` hook to add
the `ObserverState` component.
Dynamic components and trigger types are also fully supported allowing
for runtime defined trigger types.
## Possible Follow-ups
1. Deprecate `RemovedComponents`, observers should fulfill all use cases
while being more flexible and performant.
2. Queries as entities: Swap queries to entities and begin using
observers listening to archetype creation triggers to keep their caches
in sync, this allows unification of `ObserverState` and `QueryState` as
well as unlocking several API improvements for `Query` and the
management of `QueryState`.
3. Trigger bubbling: For some UI use cases in particular users are
likely to want some form of bubbling for entity observers, this is
trivial to implement naively but ideally this includes an acceleration
structure to cache hierarchy traversals.
4. All kinds of other in-built trigger types.
5. Optimization; in order to not bloat the complexity of the PR I have
kept the implementation straightforward, there are several areas where
performance can be improved. The focus for this PR is to get the
behavior implemented and not incur a performance cost for users who
don't use observers.
I am leaving each of these to follow up PR's in order to keep each of
them reviewable as this already includes significant changes.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: MiniaczQ <xnetroidpl@gmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Improve code quality involving fixedbitset.
## Solution
Update to fixedbitset 0.5. Use the new `grow_and_insert` function
instead of `grow` and `insert` functions separately.
This should also speed up most of the set operations involving
fixedbitset. They should be ~2x faster, but testing this against the
stress tests seems to show little to no difference. The multithreaded
executor doesn't seem to be all that much faster in many_cubes and
many_foxes. These use cases are likely dominated by other operations or
the bitsets aren't big enough to make them the bottleneck.
This introduces a duplicate dependency due to petgraph and wgpu, but the
former may take some time to update.
## Changelog
Removed: `Access::grow`
## Migration Guide
`Access::grow` has been removed. It's no longer needed. Remove all
references to it.
# Objective
It would be useful to be able to inspect a `QueryState`'s accesses so we
can detect when the data it accesses changes without having to iterate
it. However there are two things preventing this:
* These accesses are unnecessarily encapsulated.
* `Has<T>` indirectly accesses `T`, but does not register it.
## Solution
* Expose accesses and matches used by `QueryState`.
* Add the notion of "archetypal" accesses, which are not accessed
directly, but whose presence in an archetype affects a query result.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Expand the existing `Query` API to support more dynamic use cases i.e.
scripting.
## Prior Art
- #6390
- #8308
- #10037
## Solution
- Create a `QueryBuilder` with runtime methods to define the set of
component accesses for a built query.
- Create new `WorldQueryData` implementations `FilteredEntityMut` and
`FilteredEntityRef` as variants of `EntityMut` and `EntityRef` that
provide run time checked access to the components included in a given
query.
- Add new methods to `Query` to create "query lens" with a subset of the
access of the initial query.
### Query Builder
The `QueryBuilder` API allows you to define a query at runtime. At it's
most basic use it will simply create a query with the corresponding type
signature:
```rust
let query = QueryBuilder::<Entity, With<A>>::new(&mut world).build();
// is equivalent to
let query = QueryState::<Entity, With<A>>::new(&mut world);
```
Before calling `.build()` you also have the opportunity to add
additional accesses and filters. Here is a simple example where we add
additional filter terms:
```rust
let entity_a = world.spawn((A(0), B(0))).id();
let entity_b = world.spawn((A(0), C(0))).id();
let mut query_a = QueryBuilder::<Entity>::new(&mut world)
.with::<A>()
.without::<C>()
.build();
assert_eq!(entity_a, query_a.single(&world));
```
This alone is useful in that allows you to decide which archetypes your
query will match at runtime. However it is also very limited, consider a
case like the following:
```rust
let query_a = QueryBuilder::<&A>::new(&mut world)
// Add an additional access
.data::<&B>()
.build();
```
This will grant the query an additional read access to component B
however we have no way of accessing the data while iterating as the type
signature still only includes &A. For an even more concrete example of
this consider dynamic components:
```rust
let query_a = QueryBuilder::<Entity>::new(&mut world)
// Adding a filter is easy since it doesn't need be read later
.with_id(component_id_a)
// How do I access the data of this component?
.ref_id(component_id_b)
.build();
```
With this in mind the `QueryBuilder` API seems somewhat incomplete by
itself, we need some way method of accessing the components dynamically.
So here's one:
### Query Transmutation
If the problem is not having the component in the type signature why not
just add it? This PR also adds transmute methods to `QueryBuilder` and
`QueryState`. Here's a simple example:
```rust
world.spawn(A(0));
world.spawn((A(1), B(0)));
let mut query = QueryBuilder::<()>::new(&mut world)
.with::<B>()
.transmute::<&A>()
.build();
query.iter(&world).for_each(|a| assert_eq!(a.0, 1));
```
The `QueryState` and `QueryBuilder` transmute methods look quite similar
but are different in one respect. Transmuting a builder will always
succeed as it will just add the additional accesses needed for the new
terms if they weren't already included. Transmuting a `QueryState` will
panic in the case that the new type signature would give it access it
didn't already have, for example:
```rust
let query = QueryState::<&A, Option<&B>>::new(&mut world);
/// This is fine, the access for Option<&A> is less restrictive than &A
query.transmute::<Option<&A>>(&world);
/// Oh no, this would allow access to &B on entities that might not have it, so it panics
query.transmute::<&B>(&world);
/// This is right out
query.transmute::<&C>(&world);
```
This is quite an appealing API to also have available on `Query` however
it does pose one additional wrinkle: In order to to change the iterator
we need to create a new `QueryState` to back it. `Query` doesn't own
it's own state though, it just borrows it, so we need a place to borrow
it from. This is why `QueryLens` exists, it is a place to store the new
state so it can be borrowed when you call `.query()` leaving you with an
API like this:
```rust
fn function_that_takes_a_query(query: &Query<&A>) {
// ...
}
fn system(query: Query<(&A, &B)>) {
let lens = query.transmute_lens::<&A>();
let q = lens.query();
function_that_takes_a_query(&q);
}
```
Now you may be thinking: Hey, wait a second, you introduced the problem
with dynamic components and then described a solution that only works
for static components! Ok, you got me, I guess we need a bit more:
### Filtered Entity References
Currently the only way you can access dynamic components on entities
through a query is with either `EntityMut` or `EntityRef`, however these
can access all components and so conflict with all other accesses. This
PR introduces `FilteredEntityMut` and `FilteredEntityRef` as
alternatives that have additional runtime checking to prevent accessing
components that you shouldn't. This way you can build a query with a
`QueryBuilder` and actually access the components you asked for:
```rust
let mut query = QueryBuilder::<FilteredEntityRef>::new(&mut world)
.ref_id(component_id_a)
.with(component_id_b)
.build();
let entity_ref = query.single(&world);
// Returns Some(Ptr) as we have that component and are allowed to read it
let a = entity_ref.get_by_id(component_id_a);
// Will return None even though the entity does have the component, as we are not allowed to read it
let b = entity_ref.get_by_id(component_id_b);
```
For the most part these new structs have the exact same methods as their
non-filtered equivalents.
Putting all of this together we can do some truly dynamic ECS queries,
check out the `dynamic` example to see it in action:
```
Commands:
comp, c Create new components
spawn, s Spawn entities
query, q Query for entities
Enter a command with no parameters for usage.
> c A, B, C, Data 4
Component A created with id: 0
Component B created with id: 1
Component C created with id: 2
Component Data created with id: 3
> s A, B, Data 1
Entity spawned with id: 0v0
> s A, C, Data 0
Entity spawned with id: 1v0
> q &Data
0v0: Data: [1, 0, 0, 0]
1v0: Data: [0, 0, 0, 0]
> q B, &mut Data
0v0: Data: [2, 1, 1, 1]
> q B || C, &Data
0v0: Data: [2, 1, 1, 1]
1v0: Data: [0, 0, 0, 0]
```
## Changelog
- Add new `transmute_lens` methods to `Query`.
- Add new types `QueryBuilder`, `FilteredEntityMut`, `FilteredEntityRef`
and `QueryLens`
- `update_archetype_component_access` has been removed, archetype
component accesses are now determined by the accesses set in
`update_component_access`
- Added method `set_access` to `WorldQuery`, this is called before
`update_component_access` for queries that have a restricted set of
accesses, such as those built by `QueryBuilder` or `QueryLens`. This is
primarily used by the `FilteredEntity*` variants and has an empty trait
implementation.
- Added method `get_state` to `WorldQuery` as a fallible version of
`init_state` when you don't have `&mut World` access.
## Future Work
Improve performance of `FilteredEntityMut` and `FilteredEntityRef`,
currently they have to determine the accesses a query has in a given
archetype during iteration which is far from ideal, especially since we
already did the work when matching the archetype in the first place. To
avoid making more internal API changes I have left it out of this PR.
---------
Co-authored-by: Mike Hsu <mike.hsu@gmail.com>
# Objective
Fix#4278Fix#5504Fix#9422
Provide safe ways to borrow an entire entity, while allowing disjoint
mutable access. `EntityRef` and `EntityMut` are not suitable for this,
since they provide access to the entire world -- they are just helper
types for working with `&World`/`&mut World`.
This has potential uses for reflection and serialization
## Solution
Remove `EntityRef::world`, which allows it to soundly be used within
queries.
`EntityMut` no longer supports structural world mutations, which allows
multiple instances of it to exist for different entities at once.
Structural world mutations are performed using the new type
`EntityWorldMut`.
```rust
fn disjoint_system(
q2: Query<&mut A>,
q1: Query<EntityMut, Without<A>>,
) { ... }
let [entity1, entity2] = world.many_entities_mut([id1, id2]);
*entity1.get_mut::<T>().unwrap() = *entity2.get().unwrap();
for entity in world.iter_entities_mut() {
...
}
```
---
## Changelog
- Removed `EntityRef::world`, to fix a soundness issue with queries.
+ Removed the ability to structurally mutate the world using
`EntityMut`, which allows it to be used in queries.
+ Added `EntityWorldMut`, which is used to perform structural mutations
that are no longer allowed using `EntityMut`.
## Migration Guide
**Note for maintainers: ensure that the guide for #9604 is updated
accordingly.**
Removed the method `EntityRef::world`, to fix a soundness issue with
queries. If you need access to `&World` while using an `EntityRef`,
consider passing the world as a separate parameter.
`EntityMut` can no longer perform 'structural' world mutations, such as
adding or removing components, or despawning the entity. Additionally,
`EntityMut::world`, `EntityMut::world_mut` , and
`EntityMut::world_scope` have been removed.
Instead, use the newly-added type `EntityWorldMut`, which is a helper
type for working with `&mut World`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Partially address #5504. Fix#4278. Provide "whole entity" access in
queries. This can be useful when you don't know at compile time what
you're accessing (i.e. reflection via `ReflectComponent`).
## Solution
Implement `WorldQuery` for `EntityRef`.
- This provides read-only access to the entire entity, and supports
anything that `EntityRef` can normally do.
- It matches all archetypes and tables and will densely iterate when
possible.
- It marks all of the ArchetypeComponentIds of a matched archetype as
read.
- Adding it to a query will cause it to panic if used in conjunction
with any other mutable access.
- Expanded the docs on Query to advertise this feature.
- Added tests to ensure the panics were working as intended.
- Added `EntityRef` to the ECS prelude.
To make this safe, `EntityRef::world` was removed as it gave potential
`UnsafeCell`-like access to other parts of the `World` including aliased
mutable access to the components it would otherwise read safely.
## Performance
Not great beyond the additional parallelization opportunity over
exclusive systems. The `EntityRef` is fetched from `Entities` like any
other call to `World::entity`, which can be very random access heavy.
This could be simplified if `ArchetypeRow` is available in
`WorldQuery::fetch`'s arguments, but that's likely not something we
should optimize for.
## Future work
An equivalent API where it gives mutable access to all components on a
entity can be done with a scoped version of `EntityMut` where it does
not provide `&mut World` access nor allow for structural changes to the
entity is feasible as well. This could be done as a safe alternative to
exclusive system when structural mutation isn't required or the target
set of entities is scoped.
---
## Changelog
Added: `Access::has_any_write`
Added: `EntityRef` now implements `WorldQuery`. Allows read-only access
to the entire entity, incompatible with any other mutable access, can be
mixed with `With`/`Without` filters for more targeted use.
Added: `EntityRef` to `bevy::ecs::prelude`.
Removed: `EntityRef::world`
## Migration Guide
TODO
---------
Co-authored-by: Carter Weinberg <weinbergcarter@gmail.com>
Co-authored-by: Jakob Hellermann <jakob.hellermann@protonmail.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Title.
---------
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: James Liu <contact@jamessliu.com>
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>
# Objective
This PR attempts to improve query compatibility checks in scenarios
involving `Or` filters.
Currently, for the following two disjoint queries, Bevy will throw a
panic:
```
fn sys(_: Query<&mut C, Or<(With<A>, With<B>)>>, _: Query<&mut C, (Without<A>, Without<B>)>) {}
```
This PR addresses this particular scenario.
## Solution
`FilteredAccess::with` now stores a vector of `AccessFilters`
(representing a pair of `with` and `without` bitsets), where each member
represents an `Or` "variant".
Filters like `(With<A>, Or<(With<B>, Without<C>)>` are expected to be
expanded into `A * B + A * !C`.
When calculating whether queries are compatible, every `AccessFilters`
of a query is tested for incompatibility with every `AccessFilters` of
another query.
---
## Changelog
- Improved system and query data access compatibility checks in
scenarios involving `Or` filters
---------
Co-authored-by: MinerSebas <66798382+MinerSebas@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
* Enable `Res` and `Query` parameter mutual exclusion
* Required for https://github.com/bevyengine/bevy/pull/5080
The `FilteredAccessSet::get_conflicts` methods didn't work properly with
`Res` and `ResMut` parameters. Because those added their access by using
the `combined_access_mut` method and directly modifying the global
access state of the FilteredAccessSet. This caused an inconsistency,
because get_conflicts assumes that ALL added access have a corresponding
`FilteredAccess` added to the `filtered_accesses` field.
In practice, that means that SystemParam that adds their access through
the `Access` returned by `combined_access_mut` and the ones that add
their access using the `add` method lived in two different universes. As
a result, they could never be mutually exclusive.
## Solution
This commit fixes it by removing the `combined_access_mut` method. This
ensures that the `combined_access` field of FilteredAccessSet is always
updated consistently with the addition of a filter. When checking for
filtered access, it is now possible to account for `Res` and `ResMut`
invalid access. This is currently not needed, but might be in the
future.
We add the `add_unfiltered_{read,write}` methods to replace previous
usages of `combined_access_mut`.
We also add improved Debug implementations on FixedBitSet so that their
meaning is much clearer in debug output.
---
## Changelog
* Fix `Res` and `Query` parameter never being mutually exclusive.
## Migration Guide
Note: this mostly changes ECS internals, but since the API is public, it is technically breaking:
* Removed `FilteredAccessSet::combined_access_mut`
* Replace _immutable_ usage of those by `combined_access`
* For _mutable_ usages, use the new `add_unfiltered_{read,write}` methods instead of `combined_access_mut` followed by `add_{read,write}`
# Objective
Fixes#4657
Example code that wasnt panic'ing before this PR (and so was unsound):
```rust
#[test]
#[should_panic = "error[B0001]"]
fn option_has_no_filter_with() {
fn sys(_1: Query<(Option<&A>, &mut B)>, _2: Query<&mut B, Without<A>>) {}
let mut world = World::default();
run_system(&mut world, sys);
}
#[test]
#[should_panic = "error[B0001]"]
fn any_of_has_no_filter_with() {
fn sys(_1: Query<(AnyOf<(&A, ())>, &mut B)>, _2: Query<&mut B, Without<A>>) {}
let mut world = World::default();
run_system(&mut world, sys);
}
#[test]
#[should_panic = "error[B0001]"]
fn or_has_no_filter_with() {
fn sys(_1: Query<&mut B, Or<(With<A>, With<B>)>>, _2: Query<&mut B, Without<A>>) {}
let mut world = World::default();
run_system(&mut world, sys);
}
```
## Solution
- Only add the intersection of `with`/`without` accesses of all the elements in `Or/AnyOf` to the world query's `FilteredAccess<ComponentId>` instead of the union.
- `Option`'s fix can be thought of the same way since its basically `AnyOf<T, ()>` but its impl is just simpler as `()` has no `with`/`without` accesses
---
## Changelog
- `Or`/`AnyOf`/`Option` will now report more query conflicts in order to fix unsoundness
## Migration Guide
- If you are now getting query conflicts from `Or`/`AnyOf`/`Option` rip to you and ur welcome for it now being caught
# Objective
- (Eventually) reduce noise in reporting access conflicts between unordered systems.
- `SystemStage` only looks at unfiltered `ComponentId` access, any conflicts reported are potentially `false`.
- the systems could still be accessing disjoint archetypes
- Comparing systems' filtered access sets can maybe avoid that (for statically known component types).
- #4204
## Solution
- Modify `SparseSetIndex` trait to require `PartialEq`, `Eq`, and `Hash` (all internal types except `BundleId` already did).
- Add `is_compatible` and `get_conflicts` methods to `FilteredAccessSet<T>`
- (existing method renamed to `get_conflicts_single`)
- Add docs for those and all the other methods while I'm at it.
# 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>
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
Make it possible to use `&World` as a system parameter
## Solution
It seems like all the pieces were already in place, very simple impl
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
