# Objective
Since #10776 split `WorldQuery` to `WorldQueryData` and
`WorldQueryFilter`, it should be clear that the query is actually
composed of two parts. It is not factually correct to call "query" only
the data part. Therefore I suggest to rename the `Q` parameter to `D` in
`Query` and related items.
As far as I know, there shouldn't be breaking changes from renaming
generic type parameters.
## Solution
I used a combination of rust-analyzer go to reference and `Ctrl-F`ing
various patterns to catch as many cases as possible. Hopefully I got
them all. Feel free to check if you're concerned of me having missed
some.
## Notes
This and #10779 have many lines in common, so merging one will cause a
lot of merge conflicts to the other.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- The example in the docs is unsound.
Demo:
```rust
#[derive(Resource)]
struct MyRes(u32);
fn main() {
let mut w = World::new();
w.insert_resource(MyRes(0));
let (mut res, comp) = split_world_access(&mut w);
let mut r1 = res.get_resource_mut::<MyRes>().unwrap();
let mut r2 = res.get_resource_mut::<MyRes>().unwrap();
*r1 = MyRes(1);
*r2 = MyRes(2);
}
```
The API in the example allows aliasing mutable references to the same
resource. Miri also complains when running this.
## Solution
- Change the example API to make the returned `Mut` borrow from the
`OnlyResourceAccessWorld` instead of borrowing from the world via `'w`.
This prevents obtaining more than one `Mut` at the same time from it.
# Objective
The `Despawn` command breaks the hierarchy whenever you use it if the
despawned entity has a parent or any children. This is a serious footgun
because the `Despawn` command has the shortest name, the behavior is
unexpected and not likely to be what you want, and the crash that it
causes can be very difficult to track down.
## Solution
Until this can be fixed by relations, add a note mentioning the footgun
in the documentation.
## Solution
`Commands.remove` and `.retain` (because I copied `remove`s doc)
referenced `EntityWorldMut.remove` and `retain` for more detail but the
`Commands` docs are much more detailed (which makes sense because it is
the most common api), so I have instead inverted this so that
`EntityWorldMut` docs link to `Commands`.
I also made `EntityWorldMut.despawn` reference `World.despawn` for more
details, like `Commands.despawn` does.
# Objective
Adds `EntityCommands.retain` and `EntityWorldMut.retain` to remove all
components except the given bundle from the entity.
Fixes#10865.
## Solution
I added a private unsafe function in `EntityWorldMut` called
`remove_bundle_info` which performs the shared behaviour of `remove` and
`retain`, namely taking a `BundleInfo` of components to remove, and
removing them from the given entity. Then `retain` simply gets all the
components on the entity and filters them by whether they are in the
bundle it was passed, before passing this `BundleInfo` into
`remove_bundle_info`.
`EntityCommands.retain` just creates a new type `Retain` which runs
`EntityWorldMut.retain` when run.
---
## Changelog
Added `EntityCommands.retain` and `EntityWorldMut.retain`, which remove
all components except the given bundle from the entity, they can also be
used to remove all components by passing `()` as the bundle.
# Objective
- Shorten paths by removing unnecessary prefixes
## Solution
- Remove the prefixes from many paths which do not need them. Finding
the paths was done automatically using built-in refactoring tools in
Jetbrains RustRover.
# Objective
Related to #10612.
Enable the
[`clippy::manual_let_else`](https://rust-lang.github.io/rust-clippy/master/#manual_let_else)
lint as a warning. The `let else` form seems more idiomatic to me than a
`match`/`if else` that either match a pattern or diverge, and from the
clippy doc, the lint doesn't seem to have any possible false positive.
## Solution
Add the lint as warning in `Cargo.toml`, refactor places where the lint
triggers.
# Objective
- Fixes#7680
- This is an updated for https://github.com/bevyengine/bevy/pull/8899
which had the same objective but fell a long way behind the latest
changes
## Solution
The traits `WorldQueryData : WorldQuery` and `WorldQueryFilter :
WorldQuery` have been added and some of the types and functions from
`WorldQuery` has been moved into them.
`ReadOnlyWorldQuery` has been replaced with `ReadOnlyWorldQueryData`.
`WorldQueryFilter` is safe (as long as `WorldQuery` is implemented
safely).
`WorldQueryData` is unsafe - safely implementing it requires that
`Self::ReadOnly` is a readonly version of `Self` (this used to be a
safety requirement of `WorldQuery`)
The type parameters `Q` and `F` of `Query` must now implement
`WorldQueryData` and `WorldQueryFilter` respectively.
This makes it impossible to accidentally use a filter in the data
position or vice versa which was something that could lead to bugs.
~~Compile failure tests have been added to check this.~~
It was previously sometimes useful to use `Option<With<T>>` in the data
position. Use `Has<T>` instead in these cases.
The `WorldQuery` derive macro has been split into separate derive macros
for `WorldQueryData` and `WorldQueryFilter`.
Previously it was possible to derive both `WorldQuery` for a struct that
had a mixture of data and filter items. This would not work correctly in
some cases but could be a useful pattern in others. *This is no longer
possible.*
---
## Notes
- The changes outside of `bevy_ecs` are all changing type parameters to
the new types, updating the macro use, or replacing `Option<With<T>>`
with `Has<T>`.
- All `WorldQueryData` types always returned `true` for `IS_ARCHETYPAL`
so I moved it to `WorldQueryFilter` and
replaced all calls to it with `true`. That should be the only logic
change outside of the macro generation code.
- `Changed<T>` and `Added<T>` were being generated by a macro that I
have expanded. Happy to revert that if desired.
- The two derive macros share some functions for implementing
`WorldQuery` but the tidiest way I could find to implement them was to
give them a ton of arguments and ask clippy to ignore that.
## Changelog
### Changed
- Split `WorldQuery` into `WorldQueryData` and `WorldQueryFilter` which
now have separate derive macros. It is not possible to derive both for
the same type.
- `Query` now requires that the first type argument implements
`WorldQueryData` and the second implements `WorldQueryFilter`
## Migration Guide
- Update derives
```rust
// old
#[derive(WorldQuery)]
#[world_query(mutable, derive(Debug))]
struct CustomQuery {
entity: Entity,
a: &'static mut ComponentA
}
#[derive(WorldQuery)]
struct QueryFilter {
_c: With<ComponentC>
}
// new
#[derive(WorldQueryData)]
#[world_query_data(mutable, derive(Debug))]
struct CustomQuery {
entity: Entity,
a: &'static mut ComponentA,
}
#[derive(WorldQueryFilter)]
struct QueryFilter {
_c: With<ComponentC>
}
```
- Replace `Option<With<T>>` with `Has<T>`
```rust
/// old
fn my_system(query: Query<(Entity, Option<With<ComponentA>>)>)
{
for (entity, has_a_option) in query.iter(){
let has_a:bool = has_a_option.is_some();
//todo!()
}
}
/// new
fn my_system(query: Query<(Entity, Has<ComponentA>)>)
{
for (entity, has_a) in query.iter(){
//todo!()
}
}
```
- Fix queries which had filters in the data position or vice versa.
```rust
// old
fn my_system(query: Query<(Entity, With<ComponentA>)>)
{
for (entity, _) in query.iter(){
//todo!()
}
}
// new
fn my_system(query: Query<Entity, With<ComponentA>>)
{
for entity in query.iter(){
//todo!()
}
}
// old
fn my_system(query: Query<AnyOf<(&ComponentA, With<ComponentB>)>>)
{
for (entity, _) in query.iter(){
//todo!()
}
}
// new
fn my_system(query: Query<Option<&ComponentA>, Or<(With<ComponentA>, With<ComponentB>)>>)
{
for entity in query.iter(){
//todo!()
}
}
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Adds `.entry` to `EntityWorldMut` with `Entry`, `OccupiedEntry` and
`VacantEntry` for easier in-situ modification, based on `HashMap.entry`.
Fixes#10635
## Solution
This adds the `entry` method to `EntityWorldMut` which returns an
`Entry`. This is an enum of `OccupiedEntry` and `VacantEntry` and has
the methods `and_modify`, `insert_entry`, `or_insert`, `or_insert_with`
and `or_default`. The only difference between `OccupiedEntry` and
`VacantEntry` is the type, they are both a mutable reference to the
`EntityWorldMut` and a marker for the component type, `HashMap` also
stores things to make it quicker to access the data in `OccupiedEntry`
but I wasn't sure if we had anything it would be logical to store to
make accessing/modifying the component faster? As such, the differences
are that `OccupiedEntry` assumes the entity has the component (because
nothing else can have an `EntityWorldMut` so it can't be changed outside
the entry api) and has different methods.
All the methods are based very closely off `hashbrown::HashMap` (because
its easier to read the source of) with a couple of quirks like
`OccupiedEntry.insert` doesn't return the old value because we don't
appear to have an api for mem::replacing components.
---
## Changelog
- Added a new function `EntityWorldMut.entry` which returns an `Entry`,
allowing easier in-situ modification of a component.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Pascal Hertleif <killercup@gmail.com>
# Objective
- Fixes#10532
## Solution
I've updated the various `Event` send methods to return the sent
`EventId`(s). Since these methods previously returned nothing, and this
information is cheap to copy, there should be minimal negative
consequences to providing this additional information. In the case of
`send_batch`, an iterator is returned built from `Range` and `Map`,
which only consumes 16 bytes on the stack with no heap allocations for
all batch sizes. As such, the cost of this information is negligible.
These changes are reflected for `EventWriter` and `World`. For `World`,
the return types are optional to account for the possible lack of an
`Events` resource. Again, these methods previously returned no
information, so its inclusion should only be a benefit.
## Usage
Now when sending events, the IDs of those events is available for
immediate use:
```rust
// Example of a request-response system where the requester can track handled requests.
/// A system which can make and track requests
fn requester(
mut requests: EventWriter<Request>,
mut handled: EventReader<Handled>,
mut pending: Local<HashSet<EventId<Request>>>,
) {
// Check status of previous requests
for Handled(id) in handled.read() {
pending.remove(&id);
}
if !pending.is_empty() {
error!("Not all my requests were handled on the previous frame!");
pending.clear();
}
// Send a new request and remember its ID for later
let request_id = requests.send(Request::MyRequest { /* ... */ });
pending.insert(request_id);
}
/// A system which handles requests
fn responder(
mut requests: EventReader<Request>,
mut handled: EventWriter<Handled>,
) {
for (request, id) in requests.read_with_id() {
if handle(request).is_ok() {
handled.send(Handled(id));
}
}
}
```
In the above example, a `requester` system can send request events, and
keep track of which ones are currently pending by `EventId`. Then, a
`responder` system can act on that event, providing the ID as a
reference that the `requester` can use. Before this PR, it was not
trivial for a system sending events to keep track of events by ID. This
is unfortunate, since for a system reading events, it is trivial to
access the ID of a event.
---
## Changelog
- Updated `Events`:
- Added `send_batch`
- Modified `send` to return the sent `EventId`
- Modified `send_default` to return the sent `EventId`
- Updated `EventWriter`
- Modified `send_batch` to return all sent `EventId`s
- Modified `send` to return the sent `EventId`
- Modified `send_default` to return the sent `EventId`
- Updated `World`
- Modified `send_event` to return the sent `EventId` if sent, otherwise
`None`.
- Modified `send_event_default` to return the sent `EventId` if sent,
otherwise `None`.
- Modified `send_event_batch` to return all sent `EventId`s if sent,
otherwise `None`.
- Added unit test `test_send_events_ids` to ensure returned `EventId`s
match the sent `Event`s
- Updated uses of modified methods.
## Migration Guide
### `send` / `send_default` / `send_batch`
For the following methods:
- `Events::send`
- `Events::send_default`
- `Events::send_batch`
- `EventWriter::send`
- `EventWriter::send_default`
- `EventWriter::send_batch`
- `World::send_event`
- `World::send_event_default`
- `World::send_event_batch`
Ensure calls to these methods either handle the returned value, or
suppress the result with `;`.
```rust
// Now fails to compile due to mismatched return type
fn send_my_event(mut events: EventWriter<MyEvent>) {
events.send_default()
}
// Fix
fn send_my_event(mut events: EventWriter<MyEvent>) {
events.send_default();
}
```
This will most likely be noticed within `match` statements:
```rust
// Before
match is_pressed {
true => events.send(PlayerAction::Fire),
// ^--^ No longer returns ()
false => {}
}
// After
match is_pressed {
true => {
events.send(PlayerAction::Fire);
},
false => {}
}
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
# Objective
First of all, this PR took heavy inspiration from #7760 and #5715. It
intends to also fix#5569, but with a slightly different approach.
This also fixes#9335 by reexporting `DynEq`.
## Solution
The advantage of this API is that we can intern a value without
allocating for zero-sized-types and for enum variants that have no
fields. This PR does this automatically in the `SystemSet` and
`ScheduleLabel` derive macros for unit structs and fieldless enum
variants. So this should cover many internal and external use cases of
`SystemSet` and `ScheduleLabel`. In these optimal use cases, no memory
will be allocated.
- The interning returns a `Interned<dyn SystemSet>`, which is just a
wrapper around a `&'static dyn SystemSet`.
- `Hash` and `Eq` are implemented in terms of the pointer value of the
reference, similar to my first approach of anonymous system sets in
#7676.
- Therefore, `Interned<T>` does not implement `Borrow<T>`, only `Deref`.
- The debug output of `Interned<T>` is the same as the interned value.
Edit:
- `AppLabel` is now also interned and the old
`derive_label`/`define_label` macros were replaced with the new
interning implementation.
- Anonymous set ids are reused for different `Schedule`s, reducing the
amount of leaked memory.
### Pros
- `InternedSystemSet` and `InternedScheduleLabel` behave very similar to
the current `BoxedSystemSet` and `BoxedScheduleLabel`, but can be copied
without an allocation.
- Many use cases don't allocate at all.
- Very fast lookups and comparisons when using `InternedSystemSet` and
`InternedScheduleLabel`.
- The `intern` module might be usable in other areas.
- `Interned{ScheduleLabel, SystemSet, AppLabel}` does implement
`{ScheduleLabel, SystemSet, AppLabel}`, increasing ergonomics.
### Cons
- Implementors of `SystemSet` and `ScheduleLabel` still need to
implement `Hash` and `Eq` (and `Clone`) for it to work.
## Changelog
### Added
- Added `intern` module to `bevy_utils`.
- Added reexports of `DynEq` to `bevy_ecs` and `bevy_app`.
### Changed
- Replaced `BoxedSystemSet` and `BoxedScheduleLabel` with
`InternedSystemSet` and `InternedScheduleLabel`.
- Replaced `impl AsRef<dyn ScheduleLabel>` with `impl ScheduleLabel`.
- Replaced `AppLabelId` with `InternedAppLabel`.
- Changed `AppLabel` to use `Debug` for error messages.
- Changed `AppLabel` to use interning.
- Changed `define_label`/`derive_label` to use interning.
- Replaced `define_boxed_label`/`derive_boxed_label` with
`define_label`/`derive_label`.
- Changed anonymous set ids to be only unique inside a schedule, not
globally.
- Made interned label types implement their label trait.
### Removed
- Removed `define_boxed_label` and `derive_boxed_label`.
## Migration guide
- Replace `BoxedScheduleLabel` and `Box<dyn ScheduleLabel>` with
`InternedScheduleLabel` or `Interned<dyn ScheduleLabel>`.
- Replace `BoxedSystemSet` and `Box<dyn SystemSet>` with
`InternedSystemSet` or `Interned<dyn SystemSet>`.
- Replace `AppLabelId` with `InternedAppLabel` or `Interned<dyn
AppLabel>`.
- Types manually implementing `ScheduleLabel`, `AppLabel` or `SystemSet`
need to implement:
- `dyn_hash` directly instead of implementing `DynHash`
- `as_dyn_eq`
- Pass labels to `World::try_schedule_scope`, `World::schedule_scope`,
`World::try_run_schedule`. `World::run_schedule`, `Schedules::remove`,
`Schedules::remove_entry`, `Schedules::contains`, `Schedules::get` and
`Schedules::get_mut` by value instead of by reference.
---------
Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- Updates for rust 1.73
## Solution
- new doc check for `redundant_explicit_links`
- updated to text for compile fail tests
---
## Changelog
- updates for rust 1.73
# Objective
- Fixes#9884
- Add API for ignoring ambiguities on certain resource or components.
## Solution
- Add a `IgnoreSchedulingAmbiguitiy` resource to the world which holds
the `ComponentIds` to be ignored
- Filter out ambiguities with those component id's.
## Changelog
- add `allow_ambiguous_component` and `allow_ambiguous_resource` apis
for ignoring ambiguities
---------
Co-authored-by: Ryan Johnson <ryanj00a@gmail.com>
# Objective
We've done a lot of work to remove the pattern of a `&World` with
interior mutability (#6404, #8833). However, this pattern still persists
within `bevy_ecs` via the `unsafe_world` method.
## Solution
* Make `unsafe_world` private. Adjust any callsites to use
`UnsafeWorldCell` for interior mutability.
* Add `UnsafeWorldCell::removed_components`, since it is always safe to
access the removed components collection through `UnsafeWorldCell`.
## Future Work
Remove/hide `UnsafeWorldCell::world_metadata`, once we have provided
safe ways of accessing all world metadata.
---
## Changelog
+ Added `UnsafeWorldCell::removed_components`, which provides read-only
access to a world's collection of removed components.
# Objective
- There were a few typos in the project.
- This PR fixes these typos.
## Solution
- Fixing the typos.
Signed-off-by: SADIK KUZU <sadikkuzu@hotmail.com>
# Objective
- When reading API docs and seeing a reference to `ComponentId`, it
isn't immediately clear how to get one from your `Component`. It could
be made to be more clear.
## Solution
- Improve cross-linking of docs about `ComponentId`
# Objective
- The tick access methods mention "ticks" (as in: plural). Yet, most of
them only access a single tick.
## Solution
- Rename those methods and fix docs to reflect the singular aspect of
the return values
---
## Migration Guide
The following method names were renamed, from `foo_ticks_bar` to
`foo_tick_bar` (`ticks` is now singular, `tick`):
- `ComponentSparseSet::get_added_ticks` → `get_added_tick`
- `ComponentSparseSet::get_changed_ticks` → `get_changed_tick`
- `Column::get_added_ticks` → `get_added_tick`
- `Column::get_changed_ticks` → `get_changed_tick`
- `Column::get_added_ticks_unchecked` → `get_added_tick_unchecked`
- `Column::get_changed_ticks_unchecked` → `get_changed_tick_unchecked`
# 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
- Move schedule name into `Schedule` to allow the schedule name to be
used for errors and tracing in Schedule methods
- Fixes#9510
## Solution
- Move label onto `Schedule` and adjust api's on `World` and `Schedule`
to not pass explicit label where it makes sense to.
- add name to errors and tracing.
- `Schedule::new` now takes a label so either add the label or use
`Schedule::default` which uses a default label. `default` is mostly used
in doc examples and tests.
---
## Changelog
- move label onto `Schedule` to improve error message and logging for
schedules.
## Migration Guide
`Schedule::new` and `App::add_schedule`
```rust
// old
let schedule = Schedule::new();
app.add_schedule(MyLabel, schedule);
// new
let schedule = Schedule::new(MyLabel);
app.add_schedule(schedule);
```
if you aren't using a label and are using the schedule struct directly
you can use the default constructor.
```rust
// old
let schedule = Schedule::new();
schedule.run(world);
// new
let schedule = Schedule::default();
schedule.run(world);
```
`Schedules:insert`
```rust
// old
let schedule = Schedule::new();
schedules.insert(MyLabel, schedule);
// new
let schedule = Schedule::new(MyLabel);
schedules.insert(schedule);
```
`World::add_schedule`
```rust
// old
let schedule = Schedule::new();
world.add_schedule(MyLabel, schedule);
// new
let schedule = Schedule::new(MyLabel);
world.add_schedule(schedule);
```
# Objective
[Rust 1.72.0](https://blog.rust-lang.org/2023/08/24/Rust-1.72.0.html) is
now stable.
# Notes
- `let-else` formatting has arrived!
- I chose to allow `explicit_iter_loop` due to
https://github.com/rust-lang/rust-clippy/issues/11074.
We didn't hit any of the false positives that prevent compilation, but
fixing this did produce a lot of the "symbol soup" mentioned, e.g. `for
image in &mut *image_events {`.
Happy to undo this if there's consensus the other way.
---------
Co-authored-by: François <mockersf@gmail.com>
# Objective
Title. This is necessary in order to update
[`bevy-trait-query`](https://crates.io/crates/bevy-trait-query) to Bevy
0.11.
---
## Changelog
Added the unsafe function `UnsafeWorldCell::storages`, which provides
unchecked access to the internal data stores of a `World`.
# Objective
`World::entity`, `World::entity_mut` and `Commands::entity` should be
marked with `track_caller` to display where (in user code) the call with
the invalid `Entity` was made. `Commands::entity` already has the
attibute, but it does nothing due to the call to `unwrap_or_else`.
## Solution
- Apply the `track_caller` attribute to the `World::entity_mut` and
`World::entity`.
- Remove the call to `unwrap_or_else` which makes the `track_caller`
attribute useless (because `unwrap_or_else` is not `track_caller`
itself). The avoid eager evaluation of the panicking branch it is never
inlined.
---------
Co-authored-by: Giacomo Stevanato <giaco.stevanato@gmail.com>
# Objective
Follow-up to #6404 and #8292.
Mutating the world through a shared reference is surprising, and it
makes the meaning of `&World` unclear: sometimes it gives read-only
access to the entire world, and sometimes it gives interior mutable
access to only part of it.
This is an up-to-date version of #6972.
## Solution
Use `UnsafeWorldCell` for all interior mutability. Now, `&World`
*always* gives you read-only access to the entire world.
---
## Changelog
TODO - do we still care about changelogs?
## Migration Guide
Mutating any world data using `&World` is now considered unsound -- the
type `UnsafeWorldCell` must be used to achieve interior mutability. The
following methods now accept `UnsafeWorldCell` instead of `&World`:
- `QueryState`: `get_unchecked`, `iter_unchecked`,
`iter_combinations_unchecked`, `for_each_unchecked`,
`get_single_unchecked`, `get_single_unchecked_manual`.
- `SystemState`: `get_unchecked_manual`
```rust
let mut world = World::new();
let mut query = world.query::<&mut T>();
// Before:
let t1 = query.get_unchecked(&world, entity_1);
let t2 = query.get_unchecked(&world, entity_2);
// After:
let world_cell = world.as_unsafe_world_cell();
let t1 = query.get_unchecked(world_cell, entity_1);
let t2 = query.get_unchecked(world_cell, entity_2);
```
The methods `QueryState::validate_world` and
`SystemState::matches_world` now take a `WorldId` instead of `&World`:
```rust
// Before:
query_state.validate_world(&world);
// After:
query_state.validate_world(world.id());
```
The methods `QueryState::update_archetypes` and
`SystemState::update_archetypes` now take `UnsafeWorldCell` instead of
`&World`:
```rust
// Before:
query_state.update_archetypes(&world);
// After:
query_state.update_archetypes(world.as_unsafe_world_cell_readonly());
```
# Objective
The method `UnsafeWorldCell::read_change_tick` was renamed in #8588, but
I forgot to update a usage of this method in a doctest.
## Solution
Update the method call.
# Objective
To mirror the `Ref` added as `WorldQuery`, and the `Mut` in
`EntityMut::get_mut`, we add `EntityRef::get_ref`, which retrieves `T`
with tick information, but *immutably*.
## Solution
- Add the method in question, also add it to`UnsafeEntityCell` since
this seems to be the best way of getting that information.
Also update/add safety comments to neighboring code.
---
## Changelog
- Add `EntityRef::get_ref` to get an `Option<Ref<T>>` from `EntityRef`
---------
Co-authored-by: James Liu <contact@jamessliu.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>
# Objective
Fix#7833.
Safety comments in the multi-threaded executor don't really talk about
system world accesses, which makes it unclear if the code is actually
valid.
## Solution
Update the `System` trait to use `UnsafeWorldCell`. This type's API is
written in a way that makes it much easier to cleanly maintain safety
invariants. Use this type throughout the multi-threaded executor, with a
liberal use of safety comments.
---
## Migration Guide
The `System` trait now uses `UnsafeWorldCell` instead of `&World`. This
type provides a robust API for interior mutable world access.
- The method `run_unsafe` uses this type to manage world mutations
across multiple threads.
- The method `update_archetype_component_access` uses this type to
ensure that only world metadata can be used.
```rust
let mut system = IntoSystem::into_system(my_system);
system.initialize(&mut world);
// Before:
system.update_archetype_component_access(&world);
unsafe { system.run_unsafe(&world) }
// After:
system.update_archetype_component_access(world.as_unsafe_world_cell_readonly());
unsafe { system.run_unsafe(world.as_unsafe_world_cell()) }
```
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
This method has no documentation and it's extremely unclear what it
does, or what the returned tick represents.
## Solution
Write documentation.
# Objective
The method `UnsafeWorldCell::world_mut` is a special case, since its
safety contract is more difficult to satisfy than the other methods on
`UnsafeWorldCell`. Rewrite its documentation to be specific about when
it can and cannot be used. Provide examples and emphasize that it is
unsound to call in most cases.
# Objective
The method `UnsafeWorldCell::read_change_tick` is longer than it needs
to be. `World` only has a method called this because it has two methods
for getting a change tick: one that takes `&self` and one that takes
`&mut self`. Since this distinction is not applicable to
`UnsafeWorldCell`, we should just call this method `change_tick`.
## Solution
Deprecate the current method and add a new one called `change_tick`.
---
## Changelog
- Renamed `UnsafeWorldCell::read_change_tick` to `change_tick`.
## Migration Guide
The `UnsafeWorldCell` method `read_change_tick` has been renamed to
`change_tick`.
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
Methods for interacting with world schedules currently have two
variants: one that takes `impl ScheduleLabel` and one that takes `&dyn
ScheduleLabel`. Operations such as `run_schedule` or `schedule_scope`
only use the label by reference, so there is little reason to have an
owned variant of these functions.
## Solution
Decrease maintenance burden by merging the `ref` variants of these
functions with the owned variants.
---
## Changelog
- Deprecated `World::run_schedule_ref`. It is now redundant, since
`World::run_schedule` can take values by reference.
## Migration Guide
The method `World::run_schedule_ref` has been deprecated, and will be
removed in the next version of Bevy. Use `run_schedule` instead.
# Objective
If you want to execute a schedule on the world using arbitrarily complex
behavior, you currently need to use "hokey-pokey strats": remove the
schedule from the world, do your thing, and add it back to the world.
Not only is this cumbersome, it's potentially error-prone as one might
forget to re-insert the schedule.
## Solution
Add the `World::{try}schedule_scope{ref}` family of functions, which is
a convenient abstraction over hokey pokey strats. This method
essentially works the same way as `World::resource_scope`.
### Example
```rust
// Run the schedule five times.
world.schedule_scope(MySchedule, |world, schedule| {
for _ in 0..5 {
schedule.run(world);
}
});
```
---
## Changelog
Added the `World::schedule_scope` family of methods, which provide a way
to get mutable access to a world and one of its schedules at the same
time.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
Upon closer inspection, there are a few functions in the ECS that are
not being inlined, even with the highest optimizations and LTO enabled:
- Almost all
[WorldQuery::init_fetch](9fd5f20e25/results/query_get.s (L57))
calls. Affects `Query::get` calls in hot loops. In particular, the
`WorldQuery` implementation for `()` is used *everywhere* as the default
filter and is effectively a no-op.
-
[Entities::get](9fd5f20e25/results/query_get.s (L39)).
Affects `Query::get`, `World::get`, and any component insertion or
removal.
-
[Entities::set](9fd5f20e25/results/entity_remove.s (L2487)).
Affects any component insertion or removal.
-
[Tick::new](9fd5f20e25/results/entity_insert.s (L1368)).
I've only seen this in component insertion and spawning.
- ArchetypeRow::new
- BlobVec::set_len
Almost all of these have trivial or even empty implementations or have
significant opportunity to be optimized into surrounding code when
inlined with LTO enabled.
## Solution
Inline them
# Objective
The method `World::try_run_schedule` currently panics if the `Schedules`
resource does not exist, but it should just return an `Err`. Similarly,
`World::add_schedule` panics unnecessarily if the resource does not
exist.
Also, the documentation for `World::add_schedule` is completely wrong.
## Solution
When the `Schedules` resource does not exist, we now treat it the same
as if it did exist but was empty. When calling `add_schedule`, we
initialize it if it does not exist.
# Objective
While migrating the engine to use the `Tick` type in #7905, I forgot to
update `UnsafeWorldCell::increment_change_tick`.
## Solution
Update the function.
---
## Changelog
- The function `UnsafeWorldCell::increment_change_tick` is now
strongly-typed, returning a value of type `Tick` instead of a raw `u32`.
## Migration Guide
The function `UnsafeWorldCell::increment_change_tick` is now
strongly-typed, returning a value of type `Tick` instead of a raw `u32`.
# Objective
The type `&World` is currently in an awkward place, since it has two
meanings:
1. Read-only access to the entire world.
2. Interior mutable access to the world; immutable and/or mutable access
to certain portions of world data.
This makes `&World` difficult to reason about, and surprising to see in
function signatures if one does not know about the interior mutable
property.
The type `UnsafeWorldCell` was added in #6404, which is meant to
alleviate this confusion by adding a dedicated type for interior mutable
world access. However, much of the engine still treats `&World` as an
interior mutable-ish type. One of those places is `SystemParam`.
## Solution
Modify `SystemParam::get_param` to accept `UnsafeWorldCell` instead of
`&World`. Simplify the safety invariants, since the `UnsafeWorldCell`
type encapsulates the concept of constrained world access.
---
## Changelog
`SystemParam::get_param` now accepts an `UnsafeWorldCell` instead of
`&World`. This type provides a high-level API for unsafe interior
mutable world access.
## Migration Guide
For manual implementers of `SystemParam`: the function `get_item` now
takes `UnsafeWorldCell` instead of `&World`. To access world data, use:
* `.get_entity()`, which returns an `UnsafeEntityCell` which can be used
to access component data.
* `get_resource()` and its variants, to access resource data.
This MR is a rebased and alternative proposal to
https://github.com/bevyengine/bevy/pull/5602
# Objective
- https://github.com/bevyengine/bevy/pull/4447 implemented untyped
(using component ids instead of generics and TypeId) APIs for
inserting/accessing resources and accessing components, but left
inserting components for another PR (this one)
## Solution
- add `EntityMut::insert_by_id`
- split `Bundle` into `DynamicBundle` with `get_components` and `Bundle:
DynamicBundle`. This allows the `BundleInserter` machinery to be reused
for bundles that can only be written, not read, and have no statically
available `ComponentIds`
- Compared to the original MR this approach exposes unsafe endpoints and
requires the user to manage instantiated `BundleIds`. This is quite easy
for the end user to do and does not incur the performance penalty of
checking whether component input is correctly provided for the
`BundleId`.
- This MR does ensure that constructing `BundleId` itself is safe
---
## Changelog
- add methods for inserting bundles and components to:
`world.entity_mut(entity).insert_by_id`
