# 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
Add a new method so you can do `set_if_neq` with dereferencing
components: `as_deref_mut()`!
## Solution
Added an as_deref_mut method so that we can use `set_if_neq()` without
having to wrap up types for derefencable components
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
# Objective
The `States::variants` method was once used to construct `OnExit` and
`OnEnter` schedules for every possible value of a given `States` type.
[Since the switch to lazily initialized
schedules](https://github.com/bevyengine/bevy/pull/8028/files#diff-b2fba3a0c86e496085ce7f0e3f1de5960cb754c7d215ed0f087aa556e529f97f),
we no longer need to track every possible value.
This also opens the door to `States` types that aren't enums.
## Solution
- Remove the unused `States::variants` method and its associated type.
- Remove the enum-only restriction on derived States types.
---
## Changelog
- Removed `States::variants` and its associated type.
- Derived `States` can now be datatypes other than enums.
## Migration Guide
- `States::variants` no longer exists. If you relied on this function,
consider using a library that provides enum iterators.
# 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
- Improve rendering performance, particularly by avoiding the large
system commands costs of using the ECS in the way that the render world
does.
## Solution
- Define `EntityHasher` that calculates a hash from the
`Entity.to_bits()` by `i | (i.wrapping_mul(0x517cc1b727220a95) << 32)`.
`0x517cc1b727220a95` is something like `u64::MAX / N` for N that gives a
value close to π and that works well for hashing. Thanks for @SkiFire13
for the suggestion and to @nicopap for alternative suggestions and
discussion. This approach comes from `rustc-hash` (a.k.a. `FxHasher`)
with some tweaks for the case of hashing an `Entity`. `FxHasher` and
`SeaHasher` were also tested but were significantly slower.
- Define `EntityHashMap` type that uses the `EntityHashser`
- Use `EntityHashMap<Entity, T>` for render world entity storage,
including:
- `RenderMaterialInstances` - contains the `AssetId<M>` of the material
associated with the entity. Also for 2D.
- `RenderMeshInstances` - contains mesh transforms, flags and properties
about mesh entities. Also for 2D.
- `SkinIndices` and `MorphIndices` - contains the skin and morph index
for an entity, respectively
- `ExtractedSprites`
- `ExtractedUiNodes`
## Benchmarks
All benchmarks have been conducted on an M1 Max connected to AC power.
The tests are run for 1500 frames. The 1000th frame is captured for
comparison to check for visual regressions. There were none.
### 2D Meshes
`bevymark --benchmark --waves 160 --per-wave 1000 --mode mesh2d`
#### `--ordered-z`
This test spawns the 2D meshes with z incrementing back to front, which
is the ideal arrangement allocation order as it matches the sorted
render order which means lookups have a high cache hit rate.
<img width="1112" alt="Screenshot 2023-09-27 at 07 50 45"
src="https://github.com/bevyengine/bevy/assets/302146/e140bc98-7091-4a3b-8ae1-ab75d16d2ccb">
-39.1% median frame time.
#### Random
This test spawns the 2D meshes with random z. This not only makes the
batching and transparent 2D pass lookups get a lot of cache misses, it
also currently means that the meshes are almost certain to not be
batchable.
<img width="1108" alt="Screenshot 2023-09-27 at 07 51 28"
src="https://github.com/bevyengine/bevy/assets/302146/29c2e813-645a-43ce-982a-55df4bf7d8c4">
-7.2% median frame time.
### 3D Meshes
`many_cubes --benchmark`
<img width="1112" alt="Screenshot 2023-09-27 at 07 51 57"
src="https://github.com/bevyengine/bevy/assets/302146/1a729673-3254-4e2a-9072-55e27c69f0fc">
-7.7% median frame time.
### Sprites
**NOTE: On `main` sprites are using `SparseSet<Entity, T>`!**
`bevymark --benchmark --waves 160 --per-wave 1000 --mode sprite`
#### `--ordered-z`
This test spawns the sprites with z incrementing back to front, which is
the ideal arrangement allocation order as it matches the sorted render
order which means lookups have a high cache hit rate.
<img width="1116" alt="Screenshot 2023-09-27 at 07 52 31"
src="https://github.com/bevyengine/bevy/assets/302146/bc8eab90-e375-4d31-b5cd-f55f6f59ab67">
+13.0% median frame time.
#### Random
This test spawns the sprites with random z. This makes the batching and
transparent 2D pass lookups get a lot of cache misses.
<img width="1109" alt="Screenshot 2023-09-27 at 07 53 01"
src="https://github.com/bevyengine/bevy/assets/302146/22073f5d-99a7-49b0-9584-d3ac3eac3033">
+0.6% median frame time.
### UI
**NOTE: On `main` UI is using `SparseSet<Entity, T>`!**
`many_buttons`
<img width="1111" alt="Screenshot 2023-09-27 at 07 53 26"
src="https://github.com/bevyengine/bevy/assets/302146/66afd56d-cbe4-49e7-8b64-2f28f6043d85">
+15.1% median frame time.
## Alternatives
- Cart originally suggested trying out `SparseSet<Entity, T>` and indeed
that is slightly faster under ideal conditions. However,
`PassHashMap<Entity, T>` has better worst case performance when data is
randomly distributed, rather than in sorted render order, and does not
have the worst case memory usage that `SparseSet`'s dense `Vec<usize>`
that maps from the `Entity` index to sparse index into `Vec<T>`. This
dense `Vec` has to be as large as the largest Entity index used with the
`SparseSet`.
- I also tested `PassHashMap<u32, T>`, intending to use `Entity.index()`
as the key, but this proved to sometimes be slower and mostly no
different.
- The only outstanding approach that has not been implemented and tested
is to _not_ clear the render world of its entities each frame. That has
its own problems, though they could perhaps be solved.
- Performance-wise, if the entities and their component data were not
cleared, then they would incur table moves on spawn, and should not
thereafter, rather just their component data would be overwritten.
Ideally we would have a neat way of either updating data in-place via
`&mut T` queries, or inserting components if not present. This would
likely be quite cumbersome to have to remember to do everywhere, but
perhaps it only needs to be done in the more performance-sensitive
systems.
- The main problem to solve however is that we want to both maintain a
mapping between main world entities and render world entities, be able
to run the render app and world in parallel with the main app and world
for pipelined rendering, and at the same time be able to spawn entities
in the render world in such a way that those Entity ids do not collide
with those spawned in the main world. This is potentially quite
solvable, but could well be a lot of ECS work to do it in a way that
makes sense.
---
## Changelog
- Changed: Component data for entities to be drawn are no longer stored
on entities in the render world. Instead, data is stored in a
`EntityHashMap<Entity, T>` in various resources. This brings significant
performance benefits due to the way the render app clears entities every
frame. Resources of most interest are `RenderMeshInstances` and
`RenderMaterialInstances`, and their 2D counterparts.
## Migration Guide
Previously the render app extracted mesh entities and their component
data from the main world and stored them as entities and components in
the render world. Now they are extracted into essentially
`EntityHashMap<Entity, T>` where `T` are structs containing an
appropriate group of data. This means that while extract set systems
will continue to run extract queries against the main world they will
store their data in hash maps. Also, systems in later sets will either
need to look up entities in the available resources such as
`RenderMeshInstances`, or maintain their own `EntityHashMap<Entity, T>`
for their own data.
Before:
```rust
fn queue_custom(
material_meshes: Query<(Entity, &MeshTransforms, &Handle<Mesh>), With<InstanceMaterialData>>,
) {
...
for (entity, mesh_transforms, mesh_handle) in &material_meshes {
...
}
}
```
After:
```rust
fn queue_custom(
render_mesh_instances: Res<RenderMeshInstances>,
instance_entities: Query<Entity, With<InstanceMaterialData>>,
) {
...
for entity in &instance_entities {
let Some(mesh_instance) = render_mesh_instances.get(&entity) else { continue; };
// The mesh handle in `AssetId<Mesh>` form, and the `MeshTransforms` can now
// be found in `mesh_instance` which is a `RenderMeshInstance`
...
}
}
```
---------
Co-authored-by: robtfm <50659922+robtfm@users.noreply.github.com>
# Objective
Scheduling low cost systems has significant overhead due to task pool
contention and the extra machinery to schedule and run them. Event
update systems are the prime example of a low cost system, requiring a
guaranteed O(1) operation, and there are a *lot* of them.
## Solution
Add a run condition to every event system so they only run when there is
an event in either of it's two internal Vecs.
---
## Changelog
Changed: Event update systems will not run if there are no events to
process.
## Migration Guide
`Events<T>::update_system` has been split off from the the type and can
be found at `bevy_ecs::event::event_update_system`.
---------
Co-authored-by: IceSentry <IceSentry@users.noreply.github.com>
# Objective
Improve code-gen for `QueryState::validate_world` and
`SystemState::validate_world`.
## Solution
* Move panics into separate, non-inlined functions, to reduce the code
size of the outer methods.
* Mark the panicking functions with `#[cold]` to help the compiler
optimize for the happy path.
* Mark the functions with `#[track_caller]` to make debugging easier.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
Occasionally, it is useful to pull `ComponentInfo` or
`ComponentDescriptor` out of the `Components` collection so that they
can be inspected without borrowing the whole `World`.
## Solution
Make `ComponentInfo` and `ComponentDescriptor` `Clone`, so that
reflection-heavy code can store them in a side table.
---
## Changelog
- Implement `Clone` for `ComponentInfo` and `ComponentDescriptor`
# Objective
- I spoke with some users in the ECS channel of bevy discord today and
they suggested that I implement a fallible form of .insert for
components.
- In my opinion, it would be nice to have a fallible .insert like
.try_insert (or to just make insert be fallible!) because it was causing
a lot of panics in my game. In my game, I am spawning terrain chunks and
despawning them in the Update loop. However, this was causing bevy_xpbd
to panic because it was trying to .insert some physics components on my
chunks and a race condition meant that its check to see if the entity
exists would pass but then the next execution step it would not exist
and would do an .insert and then panic. This means that there is no way
to avoid a panic with conditionals.
Luckily, bevy_xpbd does not care about inserting these components if the
entity is being deleted and so if there were a .try_insert, like this PR
provides it could use that instead in order to NOT panic.
( My interim solution for my own game has been to run the entity despawn
events in the Last schedule but really this is just a hack and I should
not be expected to manage the scheduling of despawns like this - it
should just be easy and simple. IF it just so happened that bevy_xpbd
ran .inserts in the Last schedule also, this would be an untenable soln
overall )
## Solution
- Describe the solution used to achieve the objective above.
Add a new command named TryInsert (entitycommands.try_insert) which
functions exactly like .insert except if the entity does not exist it
will not panic. Instead, it will log to info. This way, crates that are
attaching components in ways which they do not mind that the entity no
longer exists can just use try_insert instead of insert.
---
## Changelog
## Additional Thoughts
In my opinion, NOT panicing should really be the default and having an
.insert that does panic should be the odd edgecase but removing the
panic! from .insert seems a bit above my paygrade -- although i would
love to see it. My other thought is it would be good for .insert to
return an Option AND not panic but it seems it uses an event bus right
now so that seems to be impossible w the current architecture.
# Objective
Currently, in bevy, it's valid to do `Query<&mut Foo, Changed<Foo>>`.
This assumes that `filter_fetch` and `fetch` are mutually exclusive,
because of the mutable reference to the tick that `Mut<Foo>` implies and
the reference that `Changed<Foo>` implies. However nothing guarantees
that.
## Solution
Documenting this assumption as a safety invariant is the least thing.
I'm adopting this ~~child~~ PR.
# Objective
- Working with exclusive world access is not always easy: in many cases,
a standard system or three is more ergonomic to write, and more
modularly maintainable.
- For small, one-off tasks (commonly handled with scripting), running an
event-reader system incurs a small but flat overhead cost and muddies
the schedule.
- Certain forms of logic (e.g. turn-based games) want very fine-grained
linear and/or branching control over logic.
- SystemState is not automatically cached, and so performance can suffer
and change detection breaks.
- Fixes https://github.com/bevyengine/bevy/issues/2192.
- Partial workaround for https://github.com/bevyengine/bevy/issues/279.
## Solution
- Adds a SystemRegistry resource to the World, which stores initialized
systems keyed by their SystemSet.
- Allows users to call world.run_system(my_system) and
commands.run_system(my_system), without re-initializing or losing state
(essential for change detection).
- Add a Callback type to enable convenient use of dynamic one shot
systems and reduce the mental overhead of working with Box<dyn
SystemSet>.
- Allow users to run systems based on their SystemSet, enabling more
complex user-made abstractions.
## Future work
- Parameterized one-shot systems would improve reusability and bring
them closer to events and commands. The API could be something like
run_system_with_input(my_system, my_input) and use the In SystemParam.
- We should evaluate the unification of commands and one-shot systems
since they are two different ways to run logic on demand over a World.
### Prior attempts
- https://github.com/bevyengine/bevy/pull/2234
- https://github.com/bevyengine/bevy/pull/2417
- https://github.com/bevyengine/bevy/pull/4090
- https://github.com/bevyengine/bevy/pull/7999
This PR continues the work done in
https://github.com/bevyengine/bevy/pull/7999.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Federico Rinaldi <gisquerin@gmail.com>
Co-authored-by: MinerSebas <66798382+MinerSebas@users.noreply.github.com>
Co-authored-by: Aevyrie <aevyrie@gmail.com>
Co-authored-by: Alejandro Pascual Pozo <alejandro.pascual.pozo@gmail.com>
Co-authored-by: Rob Parrett <robparrett@gmail.com>
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: Dmytro Banin <banind@cs.washington.edu>
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
Replace instances of
```rust
for x in collection.iter{_mut}() {
```
with
```rust
for x in &{mut} collection {
```
This also changes CI to no longer suppress this lint. Note that since
this lint only shows up when using clippy in pedantic mode, it was
probably unnecessary to suppress this lint in the first place.
# 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 default division for a `usize` rounds down which means the batch
sizes were too small when the `max_size` isn't exactly divisible by the
batch count.
## Solution
Changing the division to round up fixes this which can dramatically
improve performance when using `par_iter`.
I created a small example to proof this out and measured some results. I
don't know if it's worth committing this permanently so I left it out of
the PR for now.
```rust
use std::{thread, time::Duration};
use bevy::{
prelude::*,
window::{PresentMode, WindowPlugin},
};
fn main() {
App::new()
.add_plugins((DefaultPlugins.set(WindowPlugin {
primary_window: Some(Window {
present_mode: PresentMode::AutoNoVsync,
..default()
}),
..default()
}),))
.add_systems(Startup, spawn)
.add_systems(Update, update_counts)
.run();
}
#[derive(Component, Default, Debug, Clone, Reflect)]
pub struct Count(u32);
fn spawn(mut commands: Commands) {
// Worst case
let tasks = bevy::tasks::available_parallelism() * 5 - 1;
// Best case
// let tasks = bevy::tasks::available_parallelism() * 5 + 1;
for _ in 0..tasks {
commands.spawn(Count(0));
}
}
// changing the bounds of the text will cause a recomputation
fn update_counts(mut count_query: Query<&mut Count>) {
count_query.par_iter_mut().for_each(|mut count| {
count.0 += 1;
thread::sleep(Duration::from_millis(10))
});
}
```
## Results
I ran this four times, with and without the change, with best case
(should favour the old maths) and worst case (should favour the new
maths) task numbers.
### Worst case
Before the change the batches were 9 on each thread, plus the 5
remainder ran on one of the threads in addition. With the change its 10
on each thread apart from one which has 9. The results show a decrease
from ~140ms to ~100ms which matches what you would expect from the maths
(`10 * 10ms` vs `(9 + 4) * 10ms`).
### Best case
Before the change the batches were 10 on each thread, plus the 1
remainder ran on one of the threads in addition. With the change its 11
on each thread apart from one which has 5. The results slightly favour
the new change but are basically identical as the total time is
determined by the worse case which is `11 * 10ms` for both tests.
# Objective
The reasoning is similar to #8687.
I'm building a dynamic query. Currently, I store the ReflectFromPtr in
my dynamic `Fetch` type.
[See relevant
code](97ba68ae1e/src/fetches.rs (L14-L17))
However, `ReflectFromPtr` is:
- 16 bytes for TypeId
- 8 bytes for the non-mutable function pointer
- 8 bytes for the mutable function pointer
It's a lot, it adds 32 bytes to my base `Fetch` which is only
`ComponendId` (8 bytes) for a total of 40 bytes.
I only need one function per fetch, reducing the total dynamic fetch
size to 16 bytes.
Since I'm querying the components by the ComponendId associated with the
function pointer I'm using, I don't need the TypeId, it's a redundant
check.
In fact, I've difficulties coming up with situations where checking the
TypeId beforehand is relevant. So to me, if ReflectFromPtr makes sense
as a public API, exposing the function pointers also makes sense.
## Solution
- Make the fields public through methods.
---
## Changelog
- Add `from_ptr` and `from_ptr_mut` methods to `ReflectFromPtr` to
access the underlying function pointers
- `ReflectFromPtr::as_reflect_ptr` is now `ReflectFromPtr::as_reflect`
- `ReflectFromPtr::as_reflect_ptr_mut` is now
`ReflectFromPtr::as_reflect_mut`
## Migration guide
- `ReflectFromPtr::as_reflect_ptr` is now `ReflectFromPtr::as_reflect`
- `ReflectFromPtr::as_reflect_ptr_mut` is now
`ReflectFromPtr::as_reflect_mut`
# Objective
Rename RemovedComponents::iter/iter_with_id to read/read_with_id to make
it clear that it consume the data
Fixes#9755.
(It's my first pull request, if i've made any mistake, please let me
know)
## Solution
Refactor RemovedComponents::iter/iter_with_id to read/read_with_id
## Changelog
Refactor RemovedComponents::iter/iter_with_id to read/read_with_id
Deprecate RemovedComponents::iter/iter_with_id
Remove IntoIterator implementation
Update removal_detection example accordingly
---
## Migration Guide
Rename calls of RemovedComponents::iter/iter_with_id to
read/read_with_id
Replace IntoIterator iteration (&mut <RemovedComponents>) with .read()
---------
Co-authored-by: denshi_ika <mojang2824@gmail.com>
# Objective
When using `set_if_neq`, sometimes you'd like to know if the new value
was different from the old value so that you can perform some additional
branching.
## Solution
Return a bool from this function, which indicates whether or not the
value was overwritten.
---
## Changelog
* `DetectChangesMut::set_if_neq` now returns a boolean indicating
whether or not the value was changed.
## Migration Guide
The trait method `DetectChangesMut::set_if_neq` now returns a boolean
value indicating whether or not the value was changed. If you were
implementing this function manually, you must now return `true` if the
value was overwritten and `false` if the value was not.
# 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
- Make it possible to snapshot/save states
- Useful for re-using parts of the state system for rollback safe states
- Or to save states with scenes/savegames
## Solution
- Conditionally add the derive if the `bevy_reflect` is enabled
---
## Changelog
- `NextState<S>` and `State<S>` now implement `Reflect` as long as `S`
does.
# Objective
- Fixes#9683
## Solution
- Moved `get_component` from `Query` to `QueryState`.
- Moved `get_component_unchecked_mut` from `Query` to `QueryState`.
- Moved `QueryComponentError` from `bevy_ecs::system` to
`bevy_ecs::query`. Minor Breaking Change.
- Narrowed scope of `unsafe` blocks in `Query` methods.
---
## Migration Guide
- `use bevy_ecs::system::QueryComponentError;` -> `use
bevy_ecs::query::QueryComponentError;`
## Notes
I am not very familiar with unsafe Rust nor its use within Bevy, so I
may have committed a Rust faux pas during the migration.
---------
Co-authored-by: Zac Harrold <zharrold@c5prosolutions.com>
Co-authored-by: Tristan Guichaoua <33934311+tguichaoua@users.noreply.github.com>
# Objective
- Fixes#9244.
## Solution
- Changed the `(Into)SystemSetConfigs` traits and structs be more like
the `(Into)SystemConfigs` traits and structs.
- Replaced uses of `IntoSystemSetConfig` with `IntoSystemSetConfigs`
- Added generic `ItemConfig` and `ItemConfigs` types.
- Changed `SystemConfig(s)` and `SystemSetConfig(s)` to be type aliases
to `ItemConfig(s)`.
- Added generic `process_configs` to `ScheduleGraph`.
- Changed `configure_sets_inner` and `add_systems_inner` to reuse
`process_configs`.
---
## Changelog
- Added `run_if` to `IntoSystemSetConfigs`
- Deprecated `Schedule::configure_set` and `App::configure_set`
- Removed `IntoSystemSetConfig`
## Migration Guide
- Use `App::configure_sets` instead of `App::configure_set`
- Use `Schedule::configure_sets` instead of `Schedule::configure_set`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- Currently we don't have panicking alternative for getting components
from `Query` like for resources. Partially addresses #9443.
## Solution
- Add these functions.
---
## Changelog
### Added
- `Query::component` and `Query::component_mut` to get specific
component from query and panic on error.
# Objective
`QueryState::is_empty` is unsound, as it does not validate the world. If
a mismatched world is passed in, then the query filter may cast a
component to an incorrect type, causing undefined behavior.
## Solution
Add world validation. To prevent a performance regression in `Query`
(whose world does not need to be validated), the unchecked function
`is_empty_unsafe_world_cell` has been added. This also allows us to
remove one of the last usages of the private function
`UnsafeWorldCell::unsafe_world`, which takes us a step towards being
able to remove that method entirely.
# Objective
- Fixes#9641
- Anonymous sets are named by their system members. When
`ScheduleBuildSettings::report_sets` is on, systems are named by their
sets. So when getting the anonymous set name this would cause an
infinite recursion.
## Solution
- When getting the anonymous system set name, don't get their system's
names with the sets the systems belong to.
## Other Possible solutions
- An alternate solution might be to skip anonymous sets when getting the
system's name for an anonymous set's name.
# Objective
- I broke ambiguity reporting in one of my refactors.
`conflicts_to_string` should have been using the passed in parameter
rather than the one stored on self.
# Objective
- The current `EventReader::iter` has been determined to cause confusion
among new Bevy users. It was suggested by @JoJoJet to rename the method
to better clarify its usage.
- Solves #9624
## Solution
- Rename `EventReader::iter` to `EventReader::read`.
- Rename `EventReader::iter_with_id` to `EventReader::read_with_id`.
- Rename `ManualEventReader::iter` to `ManualEventReader::read`.
- Rename `ManualEventReader::iter_with_id` to
`ManualEventReader::read_with_id`.
---
## Changelog
- `EventReader::iter` has been renamed to `EventReader::read`.
- `EventReader::iter_with_id` has been renamed to
`EventReader::read_with_id`.
- `ManualEventReader::iter` has been renamed to
`ManualEventReader::read`.
- `ManualEventReader::iter_with_id` has been renamed to
`ManualEventReader::read_with_id`.
- Deprecated `EventReader::iter`
- Deprecated `EventReader::iter_with_id`
- Deprecated `ManualEventReader::iter`
- Deprecated `ManualEventReader::iter_with_id`
## Migration Guide
- Existing usages of `EventReader::iter` and `EventReader::iter_with_id`
will have to be changed to `EventReader::read` and
`EventReader::read_with_id` respectively.
- Existing usages of `ManualEventReader::iter` and
`ManualEventReader::iter_with_id` will have to be changed to
`ManualEventReader::read` and `ManualEventReader::read_with_id`
respectively.
# Objective
The latest `clippy` release has a much more aggressive application of
the
[`explicit_iter_loop`](https://rust-lang.github.io/rust-clippy/master/index.html#/explicit_into_iter_loop?groups=pedantic)
pedantic lint.
As a result, clippy now suggests the following:
```diff
-for event in events.iter() {
+for event in &mut events {
```
I'm generally in favor of this lint. Using `for mut item in &mut query`
is also recommended over `for mut item in query.iter_mut()` for good
reasons IMO.
But, it is my personal belief that `&mut events` is much less clear than
`events.iter()`.
Why? The reason is that the events from `EventReader` **are not
mutable**, they are immutable references to each event in the event
reader. `&mut events` suggests we are getting mutable access to events —
similarly to `&mut query` — which is not the case. Using `&mut events`
is therefore misleading.
`IntoIterator` requires a mutable `EventReader` because it updates the
internal `last_event_count`, not because it let you mutate it.
So clippy's suggested improvement is a downgrade.
## Solution
Do not implement `IntoIterator` for `&mut events`.
Without the impl, clippy won't suggest its "fix". This also prevents
generally people from using `&mut events` for iterating `EventReader`s,
which makes the ecosystem every-so-slightly better.
---
## Changelog
- Removed `IntoIterator` impl for `&mut EventReader`
## Migration Guide
- `&mut EventReader` does not implement `IntoIterator` anymore. replace
`for foo in &mut events` by `for foo in events.iter()`
# Objective
- Some of the old ambiguity tests didn't get ported over during schedule
v3.
## Solution
- Port over tests from
15ee98db8d/crates/bevy_ecs/src/schedule/ambiguity_detection.rs (L279-L612)
with minimal changes
- Make a method to convert the ambiguity conflicts to a string for
easier verification of correct results.
# 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
Every frame, `Events::update` gets called, which clears out any old
events from the buffer. There should be a way of taking ownership of
these old events instead of throwing them away. My use-case is dumping
old events into a debug menu so they can be inspected later.
One potential workaround is to just have a system that clones any
incoming events and stores them in a list -- however, this requires the
events to implement `Clone`.
## Solution
Add `Events::update_drain`, which returns an iterator of the events that
were removed from the buffer.
# Objective
- Fixes: #9508
- Fixes: #9526
## Solution
- Adds
```rust
fn configure_schedules(&mut self, schedule_build_settings: ScheduleBuildSettings)
```
to `Schedules`, and `App` to simplify applying `ScheduleBuildSettings`
to all schedules.
---
## Migration Guide
- No breaking changes.
- Adds `Schedule::get_build_settings()` getter for the schedule's
`ScheduleBuildSettings`.
- Can replaced manual configuration of all schedules:
```rust
// Old
for (_, schedule) in app.world.resource_mut::<Schedules>().iter_mut() {
schedule.set_build_settings(build_settings);
}
// New
app.configure_schedules(build_settings);
```
# Objective
To enable non exclusive system usage of reflected components and make
reflection more ergonomic to use by making it more in line with standard
entity commands.
## Solution
- Implements a new `EntityCommands` extension trait for reflection
related functions in the reflect module of bevy_ecs.
- Implements 4 new commands, `insert_reflect`,
`insert_reflect_with_registry`, `remove_reflect`, and
`remove_reflect_with_registry`. Both insert commands take a `Box<dyn
Reflect>` component while the remove commands take the component type
name.
- Made `EntityCommands` fields pub(crate) to allow access in the reflect
module. (Might be worth making these just public to enable user end
custom entity commands in a different pr)
- Added basic tests to ensure the commands are actually working.
- Documentation of functions.
---
## Changelog
Added:
- Implements 4 new commands on the new entity commands extension.
- `insert_reflect`
- `remove_reflect`
- `insert_reflect_with_registry`
- `remove_reflect_with_registry`
The commands operate the same except the with_registry commands take a
generic parameter for a resource that implements `AsRef<TypeRegistry>`.
Otherwise the default commands use the `AppTypeRegistry` for reflection
data.
Changed:
- Made `EntityCommands` fields pub(crate) to allow access in the reflect
module.
> Hopefully this time it works. Please don't make me rebase again ☹
# Objective
- Fixes#4917
- Replaces #9602
## Solution
- Replaced `EntityCommand` implementation for `FnOnce` to apply to
`FnOnce(EntityMut)` instead of `FnOnce(Entity, &mut World)`
---
## Changelog
- `FnOnce(Entity, &mut World)` no longer implements `EntityCommand`.
This is a breaking change.
## Migration Guide
### 1. New-Type `FnOnce`
Create an `EntityCommand` type which implements the method you
previously wrote:
```rust
pub struct ClassicEntityCommand<F>(pub F);
impl<F> EntityCommand for ClassicEntityCommand<F>
where
F: FnOnce(Entity, &mut World) + Send + 'static,
{
fn apply(self, id: Entity, world: &mut World) {
(self.0)(id, world);
}
}
commands.add(ClassicEntityCommand(|id: Entity, world: &mut World| {
/* ... */
}));
```
### 2. Extract `(Entity, &mut World)` from `EntityMut`
The method `into_world_mut` can be used to gain access to the `World`
from an `EntityMut`.
```rust
let old = |id: Entity, world: &mut World| {
/* ... */
};
let new = |mut entity: EntityMut| {
let id = entity.id();
let world = entity.into_world_mut();
/* ... */
};
```
# Objective
The name `ManualEventIterator` is long and unnecessary, as this is the
iterator type used for both `EventReader` and `ManualEventReader`.
## Solution
Rename `ManualEventIterator` to `EventIterator`. To ease migration, add
a deprecated type alias with the old name.
---
## Changelog
- The types `ManualEventIterator{WithId}` have been renamed to
`EventIterator{WithId}`.
## Migration Guide
The type `ManualEventIterator` has been renamed to `EventIterator`.
Additonally, `ManualEventIteratorWithId` has been renamed to
`EventIteratorWithId`.
# Objective
#5483 allows for the creation of non-`Sync` locals. However, it's not
actually possible to use these types as there is a `Sync` bound on the
`Deref` impls.
## Solution
Remove the unnecessary bounds.
# Objective
- have errors in configure_set and configure_sets show the line number
of the user calling location rather than pointing to schedule.rs
- use display formatting for the errors
## Example Error Text
```text
// dependency loop
// before
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: DependencyLoop("A")', crates\bevy_ecs\src\schedule\schedule.rs:682:39
// after
thread 'main' panicked at 'System set `A` depends on itself.', examples/stress_tests/bevymark.rs:16:9
// hierarchy loop
// before
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: HierarchyLoop("A")', crates\bevy_ecs\src\schedule\schedule.rs:682:3
// after
thread 'main' panicked at 'System set `A` contains itself.', examples/stress_tests/bevymark.rs:16:9
// configuring a system type set
// before
thread 'main' panicked at 'configuring system type sets is not allowed', crates\bevy_ecs\src\schedule\config.rs:394:9
//after
thread 'main' panicked at 'configuring system type sets is not allowed', examples/stress_tests/bevymark.rs:16:9
```
Code to produce errors:
```rust
use bevy::prelude::*;
#[derive(SystemSet, Clone, Debug, PartialEq, Eq, Hash)]
enum TestSet {
A,
}
fn main() {
fn foo() {}
let mut app = App::empty();
// Hierarchy Loop
app.configure_set(Main, TestSet::A.in_set(TestSet::A));
// Dependency Loop
app.configure_set(Main, TestSet::A.after(TestSet::A));
// Configure System Type Set
app.configure_set(Main, foo.into_system_set());
}
```
# Objective
- Fixes#9321
## Solution
- `EntityMap` has been replaced by a simple `HashMap<Entity, Entity>`.
---
## Changelog
- `EntityMap::world_scope` has been replaced with `World::world_scope`
to avoid creating a new trait. This is a public facing change to the
call semantics, but has no effect on results or behaviour.
- `EntityMap`, as a `HashMap`, now operates on `&Entity` rather than
`Entity`. This changes many standard access functions (e.g, `.get`) in a
public-facing way.
## Migration Guide
- Calls to `EntityMap::world_scope` can be directly replaced with the
following:
`map.world_scope(&mut world)` -> `world.world_scope(&mut map)`
- Calls to legacy `EntityMap` methods such as `EntityMap::get` must
explicitly include de/reference symbols:
`let entity = map.get(parent);` -> `let &entity = map.get(&parent);`
# Objective
Make code relating to event more readable.
Currently the `impl` block of `Events` is split in two, and the big part
of its implementations are put at the end of the file, far from the
definition of the `struct`.
## Solution
- Move and merge the `impl` blocks of `Events` next to its definition.
- Move the `EventSequence` definition and implementations before the
`Events`, because they're pretty trivial and help understand how
`Events` work, rather than being buried bellow `Events`.
I separated those two steps in two commits to not be too confusing. I
didn't modify any code of documentation. I want to do a second PR with
such modifications after this one is merged.
