# Objective
Following #10756, we're now using raw pointers in BundleInserter and
BundleSpawner. This is primarily to get around the need to split the
borrow on the World, but it leaves a lot to be desired in terms of
safety guarantees. There's no type level guarantee the code can't
dereference a null pointer, and it's restoring them to borrows fairly
liberally within the associated functions.
## Solution
* Replace the pointers with `NonNull` and a new `bevy_ptr::ConstNonNull`
that only allows conversion back to read-only borrows
* Remove the closure to avoid potentially aliasing through the closure
by restructuring the match expression.
* Move all conversions back into borrows as far up as possible to ensure
that the borrow checker is at least locally followed.
# Objective
`initialize_resource<T>` and it's non-send equivalent is only used in
two locations each. Fix#6285.
## Solution
Remove them, replace their calls with their internals. Cut down on a bit
of generic codegen.
This does mean that `initialize_resource_internal` is now `pub(crate)`,
but that's likely OK given that only one variant will remain once
NonSend resources are removed from the World.
# Objective
When doing a final pass for #3362, it appeared that `ComponentStorage`
as a trait, the two types implementing it, and the associated type on
`Component` aren't really necessary anymore. This likely was due to an
earlier constraint on the use of consts in traits, but that definitely
doesn't seem to be a problem in Rust 1.76.
## Solution
Remove them.
---
## Changelog
Changed: `Component::Storage` has been replaced with
`Component::STORAGE_TYPE` as a const.
Removed: `bevy::ecs::component::ComponentStorage` trait
Removed: `bevy::ecs::component::TableStorage` struct
Removed: `bevy::ecs::component::SparseSetStorage` struct
## Migration Guide
If you were manually implementing `Component` instead of using the
derive macro, replace the associated `Storage` associated type with the
`STORAGE_TYPE` const:
```rust
// in Bevy 0.13
impl Component for MyComponent {
type Storage = TableStorage;
}
// in Bevy 0.14
impl Component for MyComponent {
const STORAGE_TYPE: StorageType = StorageType::Table;
}
```
Component is no longer object safe. If you were relying on `&dyn
Component`, `Box<dyn Component>`, etc. please [file an issue
](https://github.com/bevyengine/bevy/issues) to get [this
change](https://github.com/bevyengine/bevy/pull/12311) reverted.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
- Explain it is flushed in the same schedule run (was not obvious to me)
- Point to `apply_deferred` example
- Remove mentions of `System::apply_deferred` and
`Schedule::apply_deferred` which are probably too low level for the most
users
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
- The doc example for `World::run_system_with_input` mistakenly
indicates that systems share state
- Some of the doc example code is unnecessary and/or could be cleaned up
## Solution
Replace the incorrect result value for the correct one in the doc
example. I also went with an explicit `assert_eq` check as it presents
the same information but can be validated by CI via doc tests.
Also removed some unnecessary code, such as the `Resource` derives on
`Counter`. In fact, I just replaced `Counter` with a `u8` in the
`Local`. I think it makes the example a little cleaner.
---
## Changelog
- Update docs for `World::run_system` and `World::run_system_with_input`
# Objective
Adoption of #2104 and #11843. The `Option<usize>` wastes 3-7 bytes of
memory per potential entry, and represents a scaling memory overhead as
the ID space grows.
The goal of this PR is to reduce memory usage without significantly
impacting common use cases.
Co-Authored By: @NathanSWard
Co-Authored By: @tygyh
## Solution
Replace `usize` in `SparseSet`'s sparse array with
`nonmax::NonMaxUsize`. NonMaxUsize wraps a NonZeroUsize, and applies a
bitwise NOT to the value when accessing it. This allows the compiler to
niche the value and eliminate the extra padding used for the `Option`
inside the sparse array, while moving the niche value from 0 to
usize::MAX instead.
Checking the [diff in x86 generated
assembly](6e4da653cc),
this change actually results in fewer instructions generated. One
potential downside is that it seems to have moved a load before a
branch, which means we may be incurring a cache miss even if the element
is not there.
Note: unlike #2104 and #11843, this PR only targets the metadata stores
for the ECS and not the component storage itself. Due to #9907 targeting
`Entity::generation` instead of `Entity::index`, `ComponentSparseSet`
storing only up to `u32::MAX` elements would become a correctness issue.
This will come with a cost when inserting items into the SparseSet, as
now there is a potential for a panic. These cost are really only
incurred when constructing a new Table, Archetype, or Resource that has
never been seen before by the World. All operations that are fairly cold
and not on any particular hotpath, even for command application.
---
## Changelog
Changed: `SparseSet` now can only store up to `usize::MAX - 1` elements
instead of `usize::MAX`.
Changed: `SparseSet` now uses 33-50% less memory overhead per stored
item.
# Objective
Fixes https://github.com/bevyengine/bevy/issues/11628
## Migration Guide
`Command` and `CommandQueue` have migrated from `bevy_ecs::system` to
`bevy_ecs::world`, so `use bevy_ecs::world::{Command, CommandQueue};`
when necessary.
# Objective
bevy_ecs has been developed with a de facto assumption that `Entity` is
to be treated as an opaque identifier by external users, and that its
internal representation is readable but in no way guaranteed to be
stable between versions of bevy_ecs.
This hasn't been clear to users, and the functions on the type that
expose its guts speak a different story.
## Solution
Explicitly document the lack of stability here and define internal
representation changes as a non-breaking change under SemVer. Give it
the same treatment that the standard lib gives `TypeId`.
# Objective
- Fix mismatch between the `Component` trait method and the `World`
method.
## Solution
- Replace init_component_info with register_component_hooks.
# Objective
- Provide a reliable and performant mechanism to allows users to keep
components synchronized with external sources: closing/opening sockets,
updating indexes, debugging etc.
- Implement a generic mechanism to provide mutable access to the world
without allowing structural changes; this will not only be used here but
is a foundational piece for observers, which are key for a performant
implementation of relations.
## Solution
- Implement a new type `DeferredWorld` (naming is not important,
`StaticWorld` is also suitable) that wraps a world pointer and prevents
user code from making any structural changes to the ECS; spawning
entities, creating components, initializing resources etc.
- Add component lifecycle hooks `on_add`, `on_insert` and `on_remove`
that can be assigned callbacks in user code.
---
## Changelog
- Add new `DeferredWorld` type.
- Add new world methods: `register_component::<T>` and
`register_component_with_descriptor`. These differ from `init_component`
in that they provide mutable access to the created `ComponentInfo` but
will panic if the component is already in any archetypes. These
restrictions serve two purposes:
1. Prevent users from defining hooks for components that may already
have associated hooks provided in another plugin. (a use case better
served by observers)
2. Ensure that when an `Archetype` is created it gets the appropriate
flags to early-out when triggering hooks.
- Add methods to `ComponentInfo`: `on_add`, `on_insert` and `on_remove`
to be used to register hooks of the form `fn(DeferredWorld, Entity,
ComponentId)`
- Modify `BundleInserter`, `BundleSpawner` and `EntityWorldMut` to
trigger component hooks when appropriate.
- Add bit flags to `Archetype` indicating whether or not any contained
components have each type of hook, this can be expanded for other flags
as needed.
- Add `component_hooks` example to illustrate usage. Try it out! It's
fun to mash keys.
## Safety
The changes to component insertion, removal and deletion involve a large
amount of unsafe code and it's fair for that to raise some concern. I
have attempted to document it as clearly as possible and have confirmed
that all the hooks examples are accepted by `cargo miri` as not causing
any undefined behavior. The largest issue is in ensuring there are no
outstanding references when passing a `DeferredWorld` to the hooks which
requires some use of raw pointers (as was already happening to some
degree in those places) and I have taken some time to ensure that is the
case but feel free to let me know if I've missed anything.
## Performance
These changes come with a small but measurable performance cost of
between 1-5% on `add_remove` benchmarks and between 1-3% on `insert`
benchmarks. One consideration to be made is the existence of the current
`RemovedComponents` which is on average more costly than the addition of
`on_remove` hooks due to the early-out, however hooks doesn't completely
remove the need for `RemovedComponents` as there is a chance you want to
respond to the removal of a component that already has an `on_remove`
hook defined in another plugin, so I have not removed it here. I do
intend to deprecate it with the introduction of observers in a follow up
PR.
## Discussion Questions
- Currently `DeferredWorld` implements `Deref` to `&World` which makes
sense conceptually, however it does cause some issues with rust-analyzer
providing autocomplete for `&mut World` references which is annoying.
There are alternative implementations that may address this but involve
more code churn so I have attempted them here. The other alternative is
to not implement `Deref` at all but that leads to a large amount of API
duplication.
- `DeferredWorld`, `StaticWorld`, something else?
- In adding support for hooks to `EntityWorldMut` I encountered some
unfortunate difficulties with my desired API. If commands are flushed
after each call i.e. `world.spawn() // flush commands .insert(A) //
flush commands` the entity may be despawned while `EntityWorldMut` still
exists which is invalid. An alternative was then to add
`self.world.flush_commands()` to the drop implementation for
`EntityWorldMut` but that runs into other problems for implementing
functions like `into_unsafe_entity_cell`. For now I have implemented a
`.flush()` which will flush the commands and consume `EntityWorldMut` or
users can manually run `world.flush_commands()` after using
`EntityWorldMut`.
- In order to allowing querying on a deferred world we need
implementations of `WorldQuery` to not break our guarantees of no
structural changes through their `UnsafeWorldCell`. All our
implementations do this, but there isn't currently any safety
documentation specifying what is or isn't allowed for an implementation,
just for the caller, (they also shouldn't be aliasing components they
didn't specify access for etc.) is that something we should start doing?
(see 10752)
Please check out the example `component_hooks` or the tests in
`bundle.rs` for usage examples. I will continue to expand this
description as I go.
See #10839 for a more ergonomic API built on top of this one that isn't
subject to the same restrictions and supports `SystemParam` dependency
injection.
# Objective
- In #9623 I forgot to change the `FromWorld` requirement for
`ReflectResource`, fix that;
- Fix#12129
## Solution
- Use the same approach as in #9623 to try using `FromReflect` and
falling back to the `ReflectFromWorld` contained in the `TypeRegistry`
provided
- Just reflect `Resource` on `State<S>` since now that's possible
without introducing new bounds.
---
## Changelog
- `ReflectResource`'s `FromType<T>` implementation no longer requires
`T: FromWorld`, but instead now requires `FromReflect`.
- `ReflectResource::insert`, `ReflectResource::apply_or_insert` and
`ReflectResource::copy` now take an extra `&TypeRegistry` parameter.
## Migration Guide
- Users of `#[reflect(Resource)]` will need to also implement/derive
`FromReflect` (should already be the default).
- Users of `#[reflect(Resource)]` may now want to also add `FromWorld`
to the list of reflected traits in case their `FromReflect`
implementation may fail.
- Users of `ReflectResource` will now need to pass a `&TypeRegistry` to
its `insert`, `apply_or_insert` and `copy` methods.
# Objective
`downcast-rs` is not used within bevy_ecs. This is probably a remnant
from before Schedule v3 landed, since stages needed the downcasting.
## Solution
Remove it.
# Objective
Memory usage optimisation
## Solution
`HashMap` and `HashSet`'s keys are immutable. So using mutable types
like `String`, `Vec<T>`, or `PathBuf` as a key is a waste of memory:
they have an extra `usize` for their capacity and may have spare
capacity.
This PR replaces these types by their immutable equivalents `Box<str>`,
`Box<[T]>`, and `Box<Path>`.
For more context, I recommend watching the [Use Arc Instead of
Vec](https://www.youtube.com/watch?v=A4cKi7PTJSs) video.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
- Avoid misspellings throughout the codebase by using
[`typos`](https://github.com/crate-ci/typos) in CI
Inspired by https://github.com/gfx-rs/wgpu/pull/5191
Typos is a minimal code speller written in rust that finds and corrects
spelling mistakes among source code.
- Fast enough to run on monorepos
- Low false positives so you can run on PRs
## Solution
- Use
[typos-action](https://github.com/marketplace/actions/typos-action) in
CI
- Add how to use typos in the Contribution Guide
---------
Co-authored-by: François <mockersf@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
# Objective
Right now when using egui, systems are inserted without any identifier
and to the root. I'd like to name those systems and insert them as
children to a root entity. This helps to keep the editor organized.
## Solution
- Although the `SystemId` is documented as an opaque type, examples
depicted above benefit from tear down of the abstraction.
---
## Changelog
### Added
- Implemented `From<SystemId>` for `Entity`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Add Archetype::component_count utility method
# Objective
I wanted a method to count components on an archetype without iterating
over them.
## Solution
Added `Archetype::component_count`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
The multi-threaded executor currently runs in a dedicated task on a
single thread. When a system finishes running, it needs to notify that
task and wait for the thread to be available and running before the
executor can process the completion.
See #8304
## Solution
Run the multi-threaded executor at the end of each system task. This
allows it to run immediately instead of needing to wait for the main
thread to wake up. Move the mutable executor state into a separate
struct and wrap it in a mutex so it can be shared among the worker
threads.
While this should be faster in theory, I don't actually know how to
measure the performance impact myself.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
Co-authored-by: Mike <mike.hsu@gmail.com>
# Objective
- A tiny nit I noticed; I think the type of these function is
`EntityCommand`, not `Command`
Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com>
# Objective
- Add the new `-Zcheck-cfg` checks to catch more warnings
- Fixes#12091
## Solution
- Create a new `cfg-check` to the CI that runs `cargo check -Zcheck-cfg
--workspace` using cargo nightly (and fails if there are warnings)
- Fix all warnings generated by the new check
---
## Changelog
- Remove all redundant imports
- Fix cfg wasm32 targets
- Add 3 dead code exceptions (should StandardColor be unused?)
- Convert ios_simulator to a feature (I'm not sure if this is the right
way to do it, but the check complained before)
## Migration Guide
No breaking changes
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fixes#11821.
## Solution
* Run `System::apply_deferred` in `System::run` after executing the
system.
* Switch to using `System::run_unsafe` in `SingleThreadedExecutor` to
preserve the current behavior.
* Remove the `System::apply_deferred` in `SimpleExecutor` as it's now
redundant.
* Remove the `System::apply_deferred` when running one-shot systems, as
it's now redundant.
---
## Changelog
Changed: `System::run` will now immediately apply deferred system params
after running the system.
## Migration Guide
`System::run` will now always run `System::apply_deferred` immediately
after running the system now. If you were running systems and then
applying their deferred buffers at a later point in time, you can
eliminate the latter.
```rust
// in 0.13
system.run(world);
// .. sometime later ...
system.apply_deferred(world);
// in 0.14
system.run(world);
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Since #9822, `SimpleExecutor` panics when an automatic sync point is
inserted:
```rust
let mut sched = Schedule::default();
sched.set_executor_kind(ExecutorKind::Simple);
sched.add_systems((|_: Commands| (), || ()).chain());
sched.run(&mut World::new());
```
```
System's param_state was not found. Did you forget to initialize this system before running it?
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Encountered a panic in system `bevy_ecs::schedule::executor::apply_deferred`!
```
## Solution
Don't try to run the `apply_deferred` system.
# Objective
- Part of #11590
- Fix `unsafe_op_in_unsafe_fn` for trivial cases in bevy_ecs
## Solution
Fix `unsafe_op_in_unsafe_fn` in bevy_ecs for trivial cases, i.e., add an
`unsafe` block when the safety comment already exists or add a comment
like "The invariants are uphold by the caller".
---------
Co-authored-by: James Liu <contact@jamessliu.com>
## Objective
Always have `some_system.into_system().type_id() ==
some_system.into_system_set().system_type().unwrap()`.
System sets have a `fn system_type() -> Option<TypeId>` that is
implemented by `SystemTypeSet` to returning the TypeId of the system's
function type. This was implemented in
https://github.com/bevyengine/bevy/pull/7715 and is used in
`bevy_mod_debugdump` to handle `.after(function)` constraints.
Back then, `System::type_id` always also returned the type id of the
function item, not of `FunctionSystem<M, F>`.
https://github.com/bevyengine/bevy/pull/11728 changes the behaviour of
`System::type_id` so that it returns the id of the
`FunctionSystem`/`ExclusiveFunctionSystem` wrapper, but it did not
change `SystemTypeSet::system_type`, so doing the lookup breaks in
`bevy_mod_debugdump`.
## Solution
Change `IntoSystemSet` for functions to return a
`SystemTypeSet<FunctionSystem>` /
`SystemTypeSet<ExclusiveFunctionSystem>` instead of `SystemTypeSet<F>`.
Fixes#12016.
Bump version after release
This PR has been auto-generated
Co-authored-by: Bevy Auto Releaser <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: François <mockersf@gmail.com>
# Objective
We deprecated quite a few APIs in 0.13. 0.13 has shipped already. It
should be OK to remove them in 0.14's release. Fixes#4059. Fixes#9011.
## Solution
Remove them.
# Objective
* Fixes#11932 (performance impact when stepping is disabled)
## Solution
The `Option<FixedBitSet>` argument added to `ScheduleExecutor::run()` in
#8453 caused a measurable performance impact even when stepping is
disabled. This can be seen by the benchmark of running `Schedule:run()`
on an empty schedule in a tight loop
(https://github.com/bevyengine/bevy/issues/11932#issuecomment-1950970236).
I was able to get the same performance results as on 0.12.1 by changing
the argument
`ScheduleExecutor::run()` from `Option<FixedBitSet>` to
`Option<&FixedBitSet>`. The down-side of this change is that
`Schedule::run()` now takes about 6% longer (3.7319 ms vs 3.9855ns) when
stepping is enabled
---
## Changelog
* Change `ScheduleExecutor::run()` `_skipped_systems` from
`Option<FixedBitSet>` to `Option<&FixedBitSet>`
* Added a few benchmarks to measure `Schedule::run()` performance with
various executors
# Objective
There's a repeating pattern of `ThreadLocal<Cell<Vec<T>>>` which is very
useful for low overhead, low contention multithreaded queues that have
cropped up in a few places in the engine. This pattern is surprisingly
useful when building deferred mutation across multiple threads, as noted
by it's use in `ParallelCommands`.
However, `ThreadLocal<Cell<Vec<T>>>` is not only a mouthful, it's also
hard to ensure the thread-local queue is replaced after it's been
temporarily removed from the `Cell`.
## Solution
Wrap the pattern into `bevy_utils::Parallel<T>` which codifies the
entire pattern and ensures the user follows the contract. Instead of
fetching indivdual cells, removing the value, mutating it, and replacing
it, `Parallel::get` returns a `ParRef<'a, T>` which contains the
temporarily removed value and a reference back to the cell, and will
write the mutated value back to the cell upon being dropped.
I would like to use this to simplify the remaining part of #4899 that
has not been adopted/merged.
---
## Changelog
TODO
---------
Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
# Objective
`update_archetype_component_access` was removed from queries in #9774,
but some documentation still refers to it.
## Solution
Update the documentation. Since a bunch of these were in SAFETY comments
it would be nice if someone who knows the details better could check
that the rest of those comments are still valid.
# Objective
- There are multiple instances of `let Some(x) = ... else { None };`
throughout the project.
- Because `Option<T>` implements
[`Try`](https://doc.rust-lang.org/stable/std/ops/trait.Try.html), it can
use the question mark `?` operator.
## Solution
- Use question mark operator instead of `let Some(x) = ... else { None
}`.
---
There was another PR that did a similar thing a few weeks ago, but I
couldn't find it.
# Objective
At the start of every schedule run, there's currently a guaranteed piece
of overhead as the async executor spawns the MultithreadeExecutor task
onto one of the ComputeTaskPool threads.
## Solution
Poll the executor once to immediately schedule systems without waiting
for the async executor, then spawn the task if and only if the executor
does not immediately terminate.
On a similar note, having the executor task immediately start executing
a system in the same async task might yield similar results over a
broader set of cases. However, this might be more involved, and may need
a solution like #8304.
# Objective
When applying a command, we currently use double indirection for the
world reference `&mut Option<&mut World>`. Since this is used across a
`fn` pointer boundary, this can't get optimized away.
## Solution
Reborrow the world reference and pass `Option<&mut World>` instead.
# Objective
Bevy's change detection functionality is invaluable for writing robust
apps, but it only works in the context of systems and exclusive systems.
Oftentimes it is necessary to detect changes made in earlier code
without having to place the code in separate systems, but it is not
currently possible to do so since there is no way to set the value of
`World::last_change_tick`.
`World::clear_trackers` allows you to update the change tick, but this
has unintended side effects, since it irreversibly affects the behavior
of change and removal detection for the entire app.
## Solution
Add a method `World::last_change_tick_scope`. This allows you to set
`last_change_tick` to a specific value for a region of code. To ensure
that misuse doesn't break unrelated functions, we restore the world's
original change tick at the end of the provided scope.
### Example
A function that uses this to run an update loop repeatedly, allowing
each iteration of the loop to react to changes made in the previous loop
iteration.
```rust
fn update_loop(
world: &mut World,
mut update_fn: impl FnMut(&mut World) -> std::ops::ControlFlow<()>,
) {
let mut last_change_tick = world.last_change_tick();
// Repeatedly run the update function until it requests a break.
loop {
// Update once.
let control_flow = world.last_change_tick_scope(last_change_tick, |world| {
update_fn(world)
});
// End the loop when the closure returns `ControlFlow::Break`.
if control_flow.is_break() {
break;
}
// Increment the change tick so the next update can detect changes from this update.
last_change_tick = world.change_tick();
world.increment_change_tick();
}
}
```
---
## Changelog
+ Added `World::last_change_tick_scope`, which allows you to specify the
reference for change detection within a certain scope.
# Objective
Reduce the size of `bevy_utils`
(https://github.com/bevyengine/bevy/issues/11478)
## Solution
Move `EntityHash` related types into `bevy_ecs`. This also allows us
access to `Entity`, which means we no longer need `EntityHashMap`'s
first generic argument.
---
## Changelog
- Moved `bevy::utils::{EntityHash, EntityHasher, EntityHashMap,
EntityHashSet}` into `bevy::ecs::entity::hash` .
- Removed `EntityHashMap`'s first generic argument. It is now hardcoded
to always be `Entity`.
## Migration Guide
- Uses of `bevy::utils::{EntityHash, EntityHasher, EntityHashMap,
EntityHashSet}` now have to be imported from `bevy::ecs::entity::hash`.
- Uses of `EntityHashMap` no longer have to specify the first generic
parameter. It is now hardcoded to always be `Entity`.
# 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
I want to keep track of despawned entities.
I am aware of
[`RemovedComponents`](https://docs.rs/bevy/0.12.1/bevy/ecs/prelude/struct.RemovedComponents.html).
However, the docs don't explicitly mention that despawned entities are
also included in this event iterator.
I searched through the bevy tests to find `removal_tracking` in
`crates/bevy_ecs/src/system/mod.rs` that confirmed the behavior:
```rust
...
assert_eq!(
removed_i32.read().collect::<Vec<_>>(),
&[despawned.0],
"despawning causes the correct entity to show up in the 'RemovedComponent' system parameter."
);
...
```
## Solution
- Explicitly mention this behavior in docs.
[`ScheduleLabel`] derive macro uses "ScheduleName" as the trait name by
mistake. This only affects the error message when a user tries to use
the derive macro on a union type. No other code is affected.
# Objective
- Fixes#11679
## Solution
- Added `IntoSystem::system_type_id` which returns the equivalent of
`system.into_system().type_id()` without construction. This allows for
getting the `TypeId` of functions (a function is an unnamed type and
therefore you cannot call `TypeId::of::<apply_deferred::System>()`)
- Added default implementation of `System::type_id` to ensure
consistency between implementations. Some returned `Self`, while others
were returning an inner value instead. This ensures consistency with
`IntoSystem::system_type_id`.
## Migration Guide
If you use `System::type_id()` on function systems (exclusive or not),
ensure you are comparing its value to other `System::type_id()` calls,
or `IntoSystem::system_type_id()`.
This code wont require any changes, because `IntoSystem`'s are directly
compared to each other.
```rust
fn test_system() {}
let type_id = test_system.type_id();
// ...
// No change required
assert_eq!(test_system.type_id(), type_id);
```
Likewise, this code wont, because `System`'s are directly compared.
```rust
fn test_system() {}
let type_id = IntoSystem::into_system(test_system).type_id();
// ...
// No change required
assert_eq!(IntoSystem::into_system(test_system).type_id(), type_id);
```
The below _does_ require a change, since you're comparing a `System`
type to a `IntoSystem` type.
```rust
fn test_system() {}
// Before
assert_eq!(test_system.type_id(), IntoSystem::into_system(test_system).type_id());
// After
assert_eq!(test_system.system_type_id(), IntoSystem::into_system(test_system).type_id());
```
# Objective
- (Partially) Fixes#9904
- Acts on #9910
## Solution
- Deprecated the relevant methods from `Query`, cascading changes as
required across Bevy.
---
## Changelog
- Deprecated `QueryState::get_component_unchecked_mut` method
- Deprecated `Query::get_component` method
- Deprecated `Query::get_component_mut` method
- Deprecated `Query::component` method
- Deprecated `Query::component_mut` method
- Deprecated `Query::get_component_unchecked_mut` method
## Migration Guide
### `QueryState::get_component_unchecked_mut`
Use `QueryState::get_unchecked_manual` and select for the exact
component based on the structure of the exact query as required.
### `Query::(get_)component(_unchecked)(_mut)`
Use `Query::get` and select for the exact component based on the
structure of the exact query as required.
- For mutable access (`_mut`), use `Query::get_mut`
- For unchecked access (`_unchecked`), use `Query::get_unchecked`
- For panic variants (non-`get_`), add `.unwrap()`
## Notes
- `QueryComponentError` can be removed once these deprecated methods are
also removed. Due to an interaction with `thiserror`'s derive macro, it
is not marked as deprecated.
Use `TypeIdMap<T>` instead of `HashMap<TypeId, T>`
- ~~`TypeIdMap` was in `bevy_ecs`. I've kept it there because of
#11478~~
- ~~I haven't swapped `bevy_reflect` over because it doesn't depend on
`bevy_ecs`, but I'd also be happy with moving `TypeIdMap` to
`bevy_utils` and then adding a dependency to that~~
- ~~this is a slight change in the public API of
`DrawFunctionsInternal`, does this need to go in the changelog?~~
## Changelog
- moved `TypeIdMap` to `bevy_utils`
- changed `DrawFunctionsInternal::indices` to `TypeIdMap`
## Migration Guide
- `TypeIdMap` now lives in `bevy_utils`
- `DrawFunctionsInternal::indices` now uses a `TypeIdMap`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Currently the `missing_docs` lint is allowed-by-default and enabled at
crate level when their documentations is complete (see #3492).
This PR proposes to inverse this logic by making `missing_docs`
warn-by-default and mark crates with imcomplete docs allowed.
## Solution
Makes `missing_docs` warn at workspace level and allowed at crate level
when the docs is imcomplete.
# Objective
Add interactive system debugging capabilities to bevy, providing
step/break/continue style capabilities to running system schedules.
* Original implementation: #8063
- `ignore_stepping()` everywhere was too much complexity
* Schedule-config & Resource discussion: #8168
- Decided on selective adding of Schedules & Resource-based control
## Solution
Created `Stepping` Resource. This resource can be used to enable
stepping on a per-schedule basis. Systems within schedules can be
individually configured to:
* AlwaysRun: Ignore any stepping state and run every frame
* NeverRun: Never run while stepping is enabled
- this allows for disabling of systems while debugging
* Break: If we're running the full frame, stop before this system is run
Stepping provides two modes of execution that reflect traditional
debuggers:
* Step-based: Only execute one system at a time
* Continue/Break: Run all systems, but stop before running a system
marked as Break
### Demo
https://user-images.githubusercontent.com/857742/233630981-99f3bbda-9ca6-4cc4-a00f-171c4946dc47.mov
Breakout has been modified to use Stepping. The game runs normally for a
couple of seconds, then stepping is enabled and the game appears to
pause. A list of Schedules & Systems appears with a cursor at the first
System in the list. The demo then steps forward full frames using the
spacebar until the ball is about to hit a brick. Then we step system by
system as the ball impacts a brick, showing the cursor moving through
the individual systems. Finally the demo switches back to frame stepping
as the ball changes course.
### Limitations
Due to architectural constraints in bevy, there are some cases systems
stepping will not function as a user would expect.
#### Event-driven systems
Stepping does not support systems that are driven by `Event`s as events
are flushed after 1-2 frames. Although game systems are not running
while stepping, ignored systems are still running every frame, so events
will be flushed.
This presents to the user as stepping the event-driven system never
executes the system. It does execute, but the events have already been
flushed.
This can be resolved by changing event handling to use a buffer for
events, and only dropping an event once all readers have read it.
The work-around to allow these systems to properly execute during
stepping is to have them ignore stepping:
`app.add_systems(event_driven_system.ignore_stepping())`. This was done
in the breakout example to ensure sound played even while stepping.
#### Conditional Systems
When a system is stepped, it is given an opportunity to run. If the
conditions of the system say it should not run, it will not.
Similar to Event-driven systems, if a system is conditional, and that
condition is only true for a very small time window, then stepping the
system may not execute the system. This includes depending on any sort
of external clock.
This exhibits to the user as the system not always running when it is
stepped.
A solution to this limitation is to ensure any conditions are consistent
while stepping is enabled. For example, all systems that modify any
state the condition uses should also enable stepping.
#### State-transition Systems
Stepping is configured on the per-`Schedule` level, requiring the user
to have a `ScheduleLabel`.
To support state-transition systems, bevy generates needed schedules
dynamically. Currently it’s very difficult (if not impossible, I haven’t
verified) for the user to get the labels for these schedules.
Without ready access to the dynamically generated schedules, and a
resolution for the `Event` lifetime, **stepping of the state-transition
systems is not supported**
---
## Changelog
- `Schedule::run()` updated to consult `Stepping` Resource to determine
which Systems to run each frame
- Added `Schedule.label` as a `BoxedSystemLabel`, along with supporting
`Schedule::set_label()` and `Schedule::label()` methods
- `Stepping` needed to know which `Schedule` was running, and prior to
this PR, `Schedule` didn't track its own label
- Would have preferred to add `Schedule::with_label()` and remove
`Schedule::new()`, but this PR touches enough already
- Added calls to `Schedule.set_label()` to `App` and `World` as needed
- Added `Stepping` resource
- Added `Stepping::begin_frame()` system to `MainSchedulePlugin`
- Run before `Main::run_main()`
- Notifies any `Stepping` Resource a new render frame is starting
## Migration Guide
- Add a call to `Schedule::set_label()` for any custom `Schedule`
- This is only required if the `Schedule` will be stepped
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Fix an issue where events are not being dropped after being read. I
believe #10077 introduced this issue. The code currently works as
follows:
1. `EventUpdateSignal` is **shared for all event types**
2. During the fixed update phase, `EventUpdateSignal` is set to true
3. `event_update_system`, **unique per event type**, runs to update
Events<T>
4. `event_update_system` reads value of `EventUpdateSignal` to check if
it should update, and then **resets** the value to false
If there are multiple event types, the first `event_update_system` run
will reset the shared `EventUpdateSignal` signal, preventing other
events from being cleared.
## Solution
I've updated the code to have separate signals per event type and added
a shared signal to notify all systems that the time plugin is installed.
## Changelog
- Fixed bug where events were not being dropped
# Objective
- Deriving `Reflect` for some public ChangeDetection/Tick structs in
bevy_ecs
---------
Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com>
# Objective
Fixes: https://github.com/bevyengine/bevy/issues/11549
Add a doctest example of what a custom implementation of an
`EntityMapper` would look like.
(need to wait until https://github.com/bevyengine/bevy/pull/11428 is
merged)
---------
Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Hennadii Chernyshchyk <genaloner@gmail.com>
# Objective
- Sending and receiving events of the same type in the same system is a
reasonably common need, generally due to event filtering.
- However, actually doing so is non-trivial, as the borrow checker
simultaneous hates mutable and immutable access.
## Solution
- Demonstrate two sensible patterns for doing so.
- Update the `ManualEventReader` docs to be more clear and link to this
example.
---------
Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
Co-authored-by: Joona Aalto <jondolf.dev@gmail.com>
Co-authored-by: ickk <git@ickk.io>
# Objective
My motivation are to resolve some of the issues I describe in this
[PR](https://github.com/bevyengine/bevy/issues/11415):
- not being able to easily mapping entities because the current
EntityMapper requires `&mut World` access
- not being able to create my own `EntityMapper` because some components
(`Parent` or `Children`) do not provide any public way of modifying the
inner entities
This PR makes the `MapEntities` trait accept a generic type that
implements `Mapper` to perform the mapping.
This means we don't need to use `EntityMapper` to perform our mapping,
we can use any type that implements `Mapper`. Basically this change is
very similar to what `serde` does. Instead of specifying directly how to
map entities for a given type, we have 2 distinct steps:
- the user implements `MapEntities` to define how the type will be
traversed and which `Entity`s will be mapped
- the `Mapper` defines how the mapping is actually done
This is similar to the distinction between `Serialize` (`MapEntities`)
and `Serializer` (`Mapper`).
This allows networking library to map entities without having to use the
existing `EntityMapper` (which requires `&mut World` access and the use
of `world_scope()`)
## Migration Guide
- The existing `EntityMapper` (notably used to replicate `Scenes` across
different `World`s) has been renamed to `SceneEntityMapper`
- The `MapEntities` trait now works with a generic `EntityMapper`
instead of the specific struct `EntityMapper`.
Calls to `fn map_entities(&mut self, entity_mapper: &mut EntityMapper)`
need to be updated to
`fn map_entities<M: EntityMapper>(&mut self, entity_mapper: &mut M)`
- The new trait `EntityMapper` has been added to the prelude
---------
Co-authored-by: Charles Bournhonesque <cbournhonesque@snapchat.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: UkoeHB <37489173+UkoeHB@users.noreply.github.com>
# Objective
Fixes#11311
## Solution
Adds an example to the documentation for `par_iter_mut`. I didn't add
any examples to `par_iter`, because I couldn't think of a good example
and I figure users can infer that `par_iter` and `par_iter_mut` are
similar.
# Objective
It's sometimes desirable to get a `Res<T>` rather than `&T` from
`World::get_resource`.
Alternative to #9940, partly adresses #9926
## Solution
added additional methods to `World` and `UnsafeWorldCell` to retrieve a
resource wrapped in a `Res`.
- `UnsafeWorldCell::get_resource_ref`
- `World::get_resource_ref`
- `World::resource_ref`
I can change it so `World::resource_mut` returns `ResMut` instead of
`Mut` as well if that's desired, but that could also be added later in a
seperate pr.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Mike <mike.hsu@gmail.com>
Co-authored-by: MinerSebas <66798382+MinerSebas@users.noreply.github.com>
# Objective
While working on #11527 I spotted that the internal field for the label
of a `Schedule` is called `name`. Using `label` seems more in line with
the other naming across Bevy.
## Solution
Renaming the field was straightforward since it's not exposed outside of
the module. This also means a changelog or migration guide isn't
necessary.
# Objective
- `World::get_resource`'s comment on it's `unsafe` usage meant to say
"mutably" but instead said "immutably."
- Fixes#11430.
## Solution
- Replace "immutably" with "mutably."
# Objective
It would be convenient to be able to call functions with `Commands` as a
parameter without having to move your own instance of `Commands`. Since
this struct is composed entirely of references, we can easily get an
owned instance of `Commands` by shortening the lifetime.
## Solution
Add `Commands::reborrow`, `EntiyCommands::reborrow`, and
`Deferred::reborrow`, which returns an owned version of themselves with
a shorter lifetime.
Remove unnecessary lifetimes from `EntityCommands`. The `'w` and `'s`
lifetimes only have to be separate for `Commands` because it's used as a
`SystemParam` -- this is not the case for `EntityCommands`.
---
## Changelog
Added `Commands::reborrow`. This is useful if you have `&mut Commands`
but need `Commands`. Also added `EntityCommands::reborrow` and
`Deferred:reborrow` which serve the same purpose.
## Migration Guide
The lifetimes for `EntityCommands` have been simplified.
```rust
// Before (Bevy 0.12)
struct MyStruct<'w, 's, 'a> {
commands: EntityCommands<'w, 's, 'a>,
}
// After (Bevy 0.13)
struct MyStruct<'a> {
commands: EntityCommands<'a>,
}
```
The method `EntityCommands::commands` now returns `Commands` rather than
`&mut Commands`.
```rust
// Before (Bevy 0.12)
let commands = entity_commands.commands();
commands.spawn(...);
// After (Bevy 0.13)
let mut commands = entity_commands.commands();
commands.spawn(...);
```
# Objective
Document a few common cases of which lifetime is required when using
SystemParam Derive
## Solution
Added a table in the doc comment
---------
Co-authored-by: laund <me@laund.moe>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Adjust bevy internals to utilize `Option<Res<State<S>>>` instead of
`Res<State<S>>`, to allow for adding/removing states at runtime and
avoid unexpected panics.
As requested here:
https://github.com/bevyengine/bevy/pull/10088#issuecomment-1869185413
---
## Changelog
- Changed the use of `world.resource`/`world.resource_mut` to
`world.get_resource`/`world.get_resource_mut` in the
`run_enter_schedule` and `apply_state_transition` systems and handled
the `None` option.
- `in_state` now returns a ` FnMut(Option<Res<State<S>>>) -> bool +
Clone`, returning `false` if the resource doesn't exist.
- `state_exists_and_equals` was marked as deprecated, and now just runs
and returns `in_state`, since their bevhaviour is now identical
- `state_changed` now takes an `Option<Res<State<S>>>` and returns
`false` if it does not exist.
I would like to remove `state_exists_and_equals` fully, but wanted to
ensure that is acceptable before doing so.
---------
Co-authored-by: Mike <mike.hsu@gmail.com>
# Objective
- `FromType<T>` for `ReflectComponent` and `ReflectBundle` currently
require `T: FromWorld` for two reasons:
- they include a `from_world` method;
- they create dummy `T`s using `FromWorld` and then `apply` a `&dyn
Reflect` to it to simulate `FromReflect`.
- However `FromWorld`/`Default` may be difficult/weird/impractical to
implement, while `FromReflect` is easier and also more natural for the
job.
- See also
https://discord.com/channels/691052431525675048/1146022009554337792
## Solution
- Split `from_world` from `ReflectComponent` and `ReflectBundle` into
its own `ReflectFromWorld` struct.
- Replace the requirement on `FromWorld` in `ReflectComponent` and
`ReflectBundle` with `FromReflect`
---
## Changelog
- `ReflectComponent` and `ReflectBundle` no longer offer a `from_world`
method.
- `ReflectComponent` and `ReflectBundle`'s `FromType<T>` implementation
no longer requires `T: FromWorld`, but now requires `FromReflect`.
- `ReflectComponent::insert`, `ReflectComponent::apply_or_insert` and
`ReflectComponent::copy` now take an extra `&TypeRegistry` parameter.
- There is now a new `ReflectFromWorld` struct.
## Migration Guide
- Existing uses of `ReflectComponent::from_world` and
`ReflectBundle::from_world` will have to be changed to
`ReflectFromWorld::from_world`.
- Users of `#[reflect(Component)]` and `#[reflect(Bundle)]` will need to
also implement/derive `FromReflect`.
- Users of `#[reflect(Component)]` and `#[reflect(Bundle)]` may now want
to also add `FromWorld` to the list of reflected traits in case their
`FromReflect` implementation may fail.
- Users of `ReflectComponent` will now need to pass a `&TypeRegistry` to
its `insert`, `apply_or_insert` and `copy` methods.
# Objective
- Add methods to get Change Ticks for a given resource by type or
ComponentId
- Fixes#11390
The `is_resource_id_changed` requested in the Issue already exists, this
adds their request for `get_resource_change_ticks`
## Solution
- Added two methods to get change ticks by Type or ComponentId
# 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
- Update async channel to v2.
## Solution
- async channel doesn't support `send_blocking` on wasm anymore. So
don't compile the pipelined rendering plugin on wasm anymore.
- Replaces https://github.com/bevyengine/bevy/pull/10405
## Migration Guide
- The `PipelinedRendering` plugin is no longer exported on wasm. If you
are including it in your wasm builds you should remove it.
```rust
#[cfg(all(not(target_arch = "wasm32"))]
app.add_plugins(bevy_render::pipelined_rendering::PipelinedRenderingPlugin);
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Based on discussion after #11268 was merged:
Instead of panicking should the impl of `TypeId::hash` change
significantly, have a fallback and detect this in a test.
# Objective
`TypeId` contains a high-quality hash. Whenever a lookup based on a
`TypeId` is performed (e.g. to insert/remove components), the hash is
run through a second hash function. This is unnecessary.
## Solution
Skip re-hashing `TypeId`s.
In my
[testing](https://gist.github.com/SpecificProtagonist/4b49ad74c6b82b0aedd3b4ea35121be8),
this improves lookup performance consistently by 10%-15% (of course, the
lookup is only a small part of e.g. a bundle insertion).
# Objective
The purpose of this PR is to begin putting together a unified identifier
structure that can be used by entities and later components (as
entities) as well as relationship pairs for relations, to enable all of
these to be able to use the same storages. For the moment, to keep
things small and focused, only `Entity` is being changed to make use of
the new `Identifier` type, keeping `Entity`'s API and
serialization/deserialization the same. Further changes are for
follow-up PRs.
## Solution
`Identifier` is a wrapper around `u64` split into two `u32` segments
with the idea of being generalised to not impose restrictions on
variants. That is for `Entity` to do. Instead, it is a general API for
taking bits to then merge and map into a `u64` integer. It exposes
low/high methods to return the two value portions as `u32` integers,
with then the MSB masked for usage as a type flag, enabling entity kind
discrimination and future activation/deactivation semantics.
The layout in this PR for `Identifier` is described as below, going from
MSB -> LSB.
```
|F| High value | Low value |
|_|_______________________________|________________________________|
|1| 31 | 32 |
F = Bit Flags
```
The high component in this implementation has only 31 bits, but that
still leaves 2^31 or 2,147,483,648 values that can be stored still, more
than enough for any generation/relation kinds/etc usage. The low part is
a full 32-bit index. The flags allow for 1 bit to be used for
entity/pair discrimination, as these have different usages for the
low/high portions of the `Identifier`. More bits can be reserved for
more variants or activation/deactivation purposes, but this currently
has no use in bevy.
More bits could be reserved for future features at the cost of bits for
the high component, so how much to reserve is up for discussion. Also,
naming of the struct and methods are also subject to further
bikeshedding and feedback.
Also, because IDs can have different variants, I wonder if
`Entity::from_bits` needs to return a `Result` instead of potentially
panicking on receiving an invalid ID.
PR is provided as an early WIP to obtain feedback and notes on whether
this approach is viable.
---
## Changelog
### Added
New `Identifier` struct for unifying IDs.
### Changed
`Entity` changed to use new `Identifier`/`IdentifierMask` as the
underlying ID logic.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: vero <email@atlasdostal.com>
# Objective
This dependency is seemingly no longer used directly after #7267.
Unfortunately, this doesn't fix us having versions of `event-listener`
in our tree.
Closes#10654
## Solution
Remove it, see if anything breaks.
# Objective
- Implements change described in
https://github.com/bevyengine/bevy/issues/3022
- Goal is to allow Entity to benefit from niche optimization, especially
in the case of Option<Entity> to reduce memory overhead with structures
with empty slots
## Discussion
- First PR attempt: https://github.com/bevyengine/bevy/pull/3029
- Discord:
https://discord.com/channels/691052431525675048/1154573759752183808/1154573764240093224
## Solution
- Change `Entity::generation` from u32 to NonZeroU32 to allow for niche
optimization.
- The reason for changing generation rather than index is so that the
costs are only encountered on Entity free, instead of on Entity alloc
- There was some concern with generations being used, due to there being
some desire to introduce flags. This was more to do with the original
retirement approach, however, in reality even if generations were
reduced to 24-bits, we would still have 16 million generations available
before wrapping and current ideas indicate that we would be using closer
to 4-bits for flags.
- Additionally, another concern was the representation of relationships
where NonZeroU32 prevents us using the full address space, talking with
Joy it seems unlikely to be an issue. The majority of the time these
entity references will be low-index entries (ie. `ChildOf`, `Owes`),
these will be able to be fast lookups, and the remainder of the range
can use slower lookups to map to the address space.
- It has the additional benefit of being less visible to most users,
since generation is only ever really set through `from_bits` type
methods.
- `EntityMeta` was changed to match
- On free, generation now explicitly wraps:
- Originally, generation would panic in debug mode and wrap in release
mode due to using regular ops.
- The first attempt at this PR changed the behavior to "retire" slots
and remove them from use when generations overflowed. This change was
controversial, and likely needs a proper RFC/discussion.
- Wrapping matches current release behaviour, and should therefore be
less controversial.
- Wrapping also more easily migrates to the retirement approach, as
users likely to exhaust the exorbitant supply of generations will code
defensively against aliasing and that defensive code is less likely to
break than code assuming that generations don't wrap.
- We use some unsafe code here when wrapping generations, to avoid
branch on NonZeroU32 construction. It's guaranteed safe due to how we
perform wrapping and it results in significantly smaller ASM code.
- https://godbolt.org/z/6b6hj8PrM
## Migration
- Previous `bevy_scene` serializations have a high likelihood of being
broken, as they contain 0th generation entities.
## Current Issues
- `Entities::reserve_generations` and `EntityMapper` wrap now, even in
debug - although they technically did in release mode already so this
probably isn't a huge issue. It just depends if we need to change
anything here?
---------
Co-authored-by: Natalie Baker <natalie.baker@advancednavigation.com>
# Objective
`Column` unconditionally requires three separate allocations: one for
the data, and two for the tick Vecs. The tick Vecs aren't really needed
for Resources, so we're allocating a bunch of one-element Vecs, and it
costs two extra dereferences when fetching/inserting/removing resources.
## Solution
Drop one level lower in `ResourceData` and directly store a `BlobVec`
and two `UnsafeCell<Tick>`s. This should significantly shrink
`ResourceData` (exchanging 6 usizes for 2 u32s), removes the need to
dereference two separate ticks when inserting/removing/fetching
resources, and can significantly decrease the number of small
allocations the ECS makes by default.
This tentatively might have a non-insignificant impact on the CPU cost
for rendering since we're constantly fetching resources in draw
functions, depending on how aggressively inlined the functions are.
This requires reimplementing some of the unsafe functions that `Column`
wraps, but it also allows us to delete a few Column APIs that were only
used for Resources, so the total amount of unsafe we're maintaining
shouldn't change significantly.
---------
Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
# Objective
In #9604 we removed the ability to define an `EntityCommand` as
`fn(Entity, &mut World)`. However I have since realized that `fn(Entity,
&mut World)` is an incredibly expressive and powerful way to define a
command for an entity that may or may not exist (`fn(EntityWorldMut)`
only works on entities that are alive).
## Solution
Support `EntityCommand`s in the style of `fn(Entity, &mut World)`, as
well as `fn(EntityWorldMut)`. Use a marker generic on the
`EntityCommand` trait to allow multiple impls.
The second commit in this PR replaces all of the internal command
definitions with ones using `fn` definitions. This is mostly just to
show off how expressive this style of command is -- we can revert this
commit if we'd rather avoid breaking changes.
---
## Changelog
Re-added support for expressively defining an `EntityCommand` as a
function that takes `Entity, &mut World`.
## Migration Guide
All `Command` types in `bevy_ecs`, such as `Spawn`, `SpawnBatch`,
`Insert`, etc., have been made private. Use the equivalent methods on
`Commands` or `EntityCommands` instead.
# Objective
- Make it possible to react to arbitrary state changes
- this will be useful regardless of the other changes to states
currently being discussed
## Solution
- added `StateTransitionEvent<S>` struct
- previously, this would have been impossible:
```rs
#[derive(States, Eq, PartialEq, Hash, Copy, Clone, Default)]
enum MyState {
#[default]
Foo,
Bar(MySubState),
}
enum MySubState {
Spam,
Eggs,
}
app.add_system(Update, on_enter_bar);
fn on_enter_bar(trans: EventReader<StateTransition<MyState>>){
for (befoare, after) in trans.read() {
match before, after {
MyState::Foo, MyState::Bar(_) => info!("detected transition foo => bar");
_, _ => ();
}
}
}
```
---
## Changelog
- Added
- `StateTransitionEvent<S>` - Fired on state changes of `S`
## Migration Guide
N/A no breaking changes
---------
Co-authored-by: Federico Rinaldi <gisquerin@gmail.com>
# Objective
When `BlobVec::reserve` is called with an argument causing capacity
overflow, in release build capacity overflow is ignored, and capacity is
decreased.
I'm not sure it is possible to exploit this issue using public API of
`bevy_ecs`, but better fix it anyway.
## Solution
Check for capacity overflow.
# Objective
`SystemName` might be useful in systems which accept `&mut World`.
## Solution
- `impl ExclusiveSystemParam for SystemName`
- move `SystemName` into a separate file, because it no longer belongs
to a file which defines `SystemParam`
- add a test for new impl, and for existing impl
## Changelog
- `impl ExclusiveSystemParam for SystemName`
# Objective
There are a lot of doctests that are `ignore`d for no documented reason.
And that should be fixed.
## Solution
I searched the bevy repo with the regex ` ```[a-z,]*ignore ` in order to
find all `ignore`d doctests. For each one of the `ignore`d doctests, I
did the following steps:
1. Attempt to remove the `ignored` attribute while still passing the
test. I did this by adding hidden dummy structs and imports.
2. If step 1 doesn't work, attempt to replace the `ignored` attribute
with the `no_run` attribute while still passing the test.
3. If step 2 doesn't work, keep the `ignored` attribute but add
documentation for why the `ignored` attribute was added.
---------
Co-authored-by: François <mockersf@gmail.com>
# Objective
Fixes#11050
Rename ArchetypeEntity::entity to ArchetypeEntity::id to be consistent
with `EntityWorldMut`, `EntityMut` and `EntityRef`.
## Migration Guide
The method `ArchetypeEntity::entity` has been renamed to
`ArchetypeEntity::id`
# Objective
- There is an warning about non snake case on system_param.rs generated
by a macro
## Solution
- Allow non snake case on the function at fault
# Objective
Implement `ExclusiveSystemParam` for `PhantomData`.
For the same reason `SystemParam` impl exists: to simplify writing
generic code.
786abbf3f5/crates/bevy_ecs/src/system/system_param.rs (L1557)
Also for consistency.
## Solution
`impl ExclusiveSystemParam for PhantomData`.
## Changelog
Added: PhantomData<T> now implements ExclusiveSystemParam.
# Objective
Mostly for consistency.
## Solution
```rust
impl ExclusiveSystemParam for WorldId
```
- Also add a test for `SystemParam for WorldId`
## Changelog
Added: Worldd now implements ExclusiveSystemParam.
# Objective
Fix ci hang, so we can merge pr's again.
## Solution
- switch ppa action to use mesa stable versions
https://launchpad.net/~kisak/+archive/ubuntu/turtle
- use commit from #11123
---------
Co-authored-by: Stepan Koltsov <stepan.koltsov@gmail.com>
