# Objective
Fix#2128. Both `Query::new_archetype` and `SystemParam::new_archetype`
do not check if the `Archetype` comes from the same World the state is
initialized from. This could result in unsoundness via invalid accesses
if called incorrectly.
## Solution
Make them `unsafe` functions and lift the invariant to the caller. This
also caught one instance of us not validating the World in
`SystemState::update_archetypes_unsafe_world_cell`'s implementation.
---
## Changelog
Changed: `QueryState::new_archetype` is now an unsafe function.
Changed: `SystemParam::new_archetype` is now an unsafe function.
## Migration Guide
`QueryState::new_archetype` and `SystemParam::new_archetype` are now an
unsafe functions that must be sure that the provided `Archetype` is from
the same `World` that the state was initialized from. Callers may need
to add additional assertions or propagate the safety invariant upwards
through the callstack to ensure safety.
# Objective
- Fixes#13024.
## Solution
- Run `cargo clippy --target wasm32-unknown-unknown` until there are no
more errors.
- I recommend reviewing one commit at a time :)
---
## Changelog
- Fixed Clippy lints for `wasm32-unknown-unknown` target.
- Updated `bevy_transform`'s `README.md`.
# Objective
- Fixes#12976
## Solution
This one is a doozy.
- Run `cargo +beta clippy --workspace --all-targets --all-features` and
fix all issues
- This includes:
- Moving inner attributes to be outer attributes, when the item in
question has both inner and outer attributes
- Use `ptr::from_ref` in more scenarios
- Extend the valid idents list used by `clippy:doc_markdown` with more
names
- Use `Clone::clone_from` when possible
- Remove redundant `ron` import
- Add backticks to **so many** identifiers and items
- I'm sorry whoever has to review this
---
## Changelog
- Added links to more identifiers in documentation.
# Objective
Improve the code quality of the multithreaded executor.
## Solution
* Remove some unused variables.
* Use `Mutex::get_mut` where applicable instead of locking.
* Use a `startup_systems` FixedBitset to pre-compute the starting
systems instead of building it bit-by-bit on startup.
* Instead of using `FixedBitset::clear` and `FixedBitset::union_with`,
use `FixedBitset::clone_from` instead, which does only a single copy and
will not allocate if the target bitset has a large enough allocation.
* Replace the `Mutex` around `Conditions` with `SyncUnsafeCell`, and add
a `Context::try_lock` that forces it to be synchronized fetched
alongside the executor lock.
This might produce minimal performance gains, but the focus here is on
the code quality improvements.
# Objective
- ~~This PR adds more flexible versions of `set_if_neq` and
`replace_if_neq` to only compare and update certain fields of a
components which is not just a newtype~~
- https://github.com/bevyengine/bevy/pull/12919#issuecomment-2048049786
gave a good solution to the original problem, so let's update the docs
so that this is easier to find
## Solution
- ~~Add `set_if_neq_with` and `replace_if_neq_with` which take an
accessor closure to access the relevant field~~
---
In a recent project, a scenario emerged that required careful
consideration regarding change detection without compromising
performance. The context involves a component that maintains a
collection of `Vec<Vec2>` representing a horizontal surface, alongside a
height field. When the height is updated, there are a few approaches to
consider:
1. Clone the collection of points to utilize the existing `set_if_neq`
method.
2. Inline and adjust the `set_if_neq` code specifically for this
scenario.
3. (Consider splitting the component into more granular components.)
It's worth noting that the third option might be the most suitable in
most cases.
A similar situation arises with the Bevy internal Transform component,
which includes fields for translation, rotation, and scale. These fields
are relatively small (`Vec3` or `Quat` with 3 or 4 `f32` values), but
the creation of a single pointer (`usize`) might be more efficient than
copying the data of the other fields. This is speculative, and insights
from others could be valuable.
Questions remain:
- Is it feasible to develop a more flexible API, and what might that
entail?
- Is there general interest in this change?
There's no hard feelings if this idea or the PR is ultimately rejected.
I just wanted to put this idea out there and hope that this might be
beneficial to others and that feedback could be valuable before
abandoning the idea.
# Objective
The system task span is pretty consistent in how much time it uses, so
all it adds is overhead/additional bandwidth when profiling.
## Solution
Remove it.
# Objective
Improve performance scalability when adding new event types to a Bevy
app. Currently, just using Bevy in the default configuration, all apps
spend upwards of 100+us in the `First` schedule, every app tick,
evaluating if it should update events or not, even if events are not
being used for that particular frame, and this scales with the number of
Events registered in the app.
## Solution
As `Events::update` is guaranteed `O(1)` by just checking if a
resource's value, swapping two Vecs, and then clearing one of them, the
actual cost of running `event_update_system` is *very* cheap. The
overhead of doing system dependency injection, task scheduling ,and the
multithreaded executor outweighs the cost of running the system by a
large margin.
Create an `EventRegistry` resource that keeps a number of function
pointers that update each event. Replace the per-event type
`event_update_system` with a singular exclusive system uses the
`EventRegistry` to update all events instead. Update `SubApp::add_event`
to use `EventRegistry` instead.
## Performance
This speeds reduces the cost of the `First` schedule in both many_foxes
and many_cubes by over 80%. Note this is with system spans on. The
majority of this is now context-switching costs from launching
`time_system`, which should be mostly eliminated with #12869.
The actual `event_update_system` is usually *very* short, using only a
few microseconds on average.
---
## Changelog
TODO
## Migration Guide
TODO
---------
Co-authored-by: Josh Matthews <josh@joshmatthews.net>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- I daily drive nightly Rust when developing Bevy, so I notice when new
warnings are raised by `cargo check` and Clippy.
- `cargo +nightly clippy` raises a few of these new warnings.
## Solution
- Fix most warnings from `cargo +nightly clippy`
- I skipped the docs-related warnings because some were covered by
#12692.
- Use `Clone::clone_from` in applicable scenarios, which can sometimes
avoid an extra allocation.
- Implement `Default` for structs that have a `pub const fn new() ->
Self` method.
- Fix an occurrence where generic constraints were defined in both `<C:
Trait>` and `where C: Trait`.
- Removed generic constraints that were implied by the `Bundle` trait.
---
## Changelog
- `BatchingStrategy`, `NonGenericTypeCell`, and `GenericTypeCell` now
implement `Default`.
# Objective
Minimize the number of dependencies low in the tree.
## Solution
* Remove the dependency on rustc-hash in bevy_ecs (not used) and
bevy_macro_utils (only used in one spot).
* Deduplicate the dependency on `sha1_smol` with the existing blake3
dependency already being used for bevy_asset.
* Remove the unused `ron` dependency on `bevy_app`
* Make the `serde` dependency for `bevy_ecs` optional. It's only used
for serializing Entity.
* Change the `wgpu` dependency to `wgpu-types`, and make it optional for
`bevy_color`.
* Remove the unused `thread-local` dependency on `bevy_render`.
* Make multiple dependencies for `bevy_tasks` optional and enabled only
when running with the `multi-threaded` feature. Preferably they'd be
disabled all the time on wasm, but I couldn't find a clean way to do
this.
---
## Changelog
TODO
## Migration Guide
TODO
# Objective
- Attempts to solve two items from
https://github.com/bevyengine/bevy/issues/11478.
## Solution
- Moved `intern` module from `bevy_utils` into `bevy_ecs` crate and
updated all relevant imports.
- Moved `label` module from `bevy_utils` into `bevy_ecs` crate and
updated all relevant imports.
---
## Migration Guide
- Replace `bevy_utils::define_label` imports with
`bevy_ecs::define_label` imports.
- Replace `bevy_utils:🏷️:DynEq` imports with
`bevy_ecs:🏷️:DynEq` imports.
- Replace `bevy_utils:🏷️:DynHash` imports with
`bevy_ecs:🏷️:DynHash` imports.
- Replace `bevy_utils::intern::Interned` imports with
`bevy_ecs::intern::Interned` imports.
- Replace `bevy_utils::intern::Internable` imports with
`bevy_ecs::intern::Internable` imports.
- Replace `bevy_utils::intern::Interner` imports with
`bevy_ecs::intern::Interner` imports.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
- Make `ReflectComponent::apply`, `ReflectComponent::reflect_mut` and
`ReflectBundle::apply` work with `EntityMut` too (currently they only
work with the more restricting `EntityWorldMut`);
- Note: support for the `Filtered*` variants has been left out since the
conversion in that case is more expensive. Let me know if I should add
support for them too.
## Solution
- Make `ReflectComponent::apply`, `ReflectComponent::reflect_mut` and
`ReflectBundle::apply` take an `impl Into<EntityMut<'a>>`;
- Make the corresponding `*Fns` function pointers take a `EntityMut`.
---
## Changelog
- `ReflectComponent::apply`, `ReflectComponent::reflect_mut` and
`ReflectBundle::apply` now accept `EntityMut` as well
## Migration Guide
- `ReflectComponentFns`'s `apply` and `reflect_mut` fields now take
`EntityMut` instead of `&mut EntityWorldMut`
- `ReflectBundleFns`'s `apply` field now takes `EntityMut` instead of
`&mut EntityWorldMut`
# Objective
- Implement `From<&'w mut EntityMut>` for `EntityMut<'w>`;
- Make it possible to pass `&mut EntityMut` where `impl Into<EntityMut>`
is required;
- Helps with #12895.
## Solution
- Implement `From<&'w mut EntityMut>` for `EntityMut<'w>`
---
## Changelog
- `EntityMut<'w>` now implements `From<&'w mut EntityMut>`
# Objective
- Fix#7303
- bevy would spawn a lot of tasks in parallel iteration when it matchs a
large storage and many small storage ,it significantly increase the
overhead of schedule.
## Solution
- collect small storage into one task
# Objective
Fix#11931
## Solution
- Make stepping a non-default feature
- Adjust documentation and examples
- In particular, make the breakout example not show the stepping prompt
if compiled without the feature (shows a log message instead)
---
## Changelog
- Removed `bevy_debug_stepping` from default features
## Migration Guide
The system-by-system stepping feature is now disabled by default; to use
it, enable the `bevy_debug_stepping` feature explicitly:
```toml
[dependencies]
bevy = { version = "0.14", features = ["bevy_debug_stepping"] }
```
Code using
[`Stepping`](https://docs.rs/bevy/latest/bevy/ecs/schedule/struct.Stepping.html)
will still compile with the feature disabled, but will print a runtime
error message to the console if the application attempts to enable
stepping.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
- Add `remove_by_id` method to `EntityWorldMut` and `EntityCommands`
- This is a duplicate of the awesome work by @mateuseap, last updated
04/09/23 - #9663
- I'm opening a second one to ensure the feature makes it into `0.14`
- Fixes#9261
## Solution
Almost identical to #9663 with three exceptions
- Uses a closure instead of struct for commands, consistent with other
similar commands
- Does not refactor `EntityCommands::insert`, so no migration guide
- `EntityWorldMut::remove_by_id` is now safe containing unsafe blocks, I
think thats what @SkiFire13 was indicating should happen [in this
comment](https://github.com/bevyengine/bevy/pull/9663#discussion_r1314307525)
## Changelog
- Added `EntityWorldMut::remove_by_id` method and its tests.
- Added `EntityCommands::remove_by_id` method and its tests.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
- Closes#12019
- Related to #4955
- Useful for dev_tools and networking
## Solution
- Create `World::iter_resources()` and `World::iter_resources_mut()`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: James Liu <contact@jamessliu.com>
Co-authored-by: Pablo Reinhardt <126117294+pablo-lua@users.noreply.github.com>
# Objective
- Since #10811,Bevy uses `assert `in the hot path of iteration. The
`for_each `method has an assert in the outer loop to help the compiler
remove unnecessary branching in the internal loop.
- However , ` for` style iterations do not receive the same treatment.
it still have a branch check in the internal loop, which could
potentially hurt performance.
## Solution
- use `TableRow::from_u32 ` instead of ` TableRow::from_usize` to avoid
unnecessary branch.
Before
After
----------------------------------------------------------------------------
# Objective
Sometimes it's useful to iterate over removed entities. For example, in
my library
[bevy_replicon](https://github.com/projectharmonia/bevy_replicon) I need
it to iterate over all removals to replicate them over the network.
Right now we do lookups, but it would be more convenient and faster to
just iterate over all removals.
## Solution
Add `RemovedComponentEvents::iter`.
---
## Changelog
### Added
- `RemovedComponentEvents::iter` to iterate over all removed components.
---------
Co-authored-by: Pablo Reinhardt <126117294+pablo-lua@users.noreply.github.com>
# Objective
- There are several redundant imports in the tests and examples that are
not caught by CI because additional flags need to be passed.
## Solution
- Run `cargo check --workspace --tests` and `cargo check --workspace
--examples`, then fix all warnings.
- Add `test-check` to CI, which will be run in the check-compiles job.
This should catch future warnings for tests. Examples are already
checked, but I'm not yet sure why they weren't caught.
## Discussion
- Should the `--tests` and `--examples` flags be added to CI, so this is
caught in the future?
- If so, #12818 will need to be merged first. It was also a warning
raised by checking the examples, but I chose to split off into a
separate PR.
---------
Co-authored-by: François Mockers <francois.mockers@vleue.com>
# Objective
- The `bundles` parameter in `insert_or_spawn_batch` method has
inconsistent naming with docs (e.g. `bundles_iter`) since #11107.
## Solution
- Replace `bundles` with `bundles_iter`, as `bundles_iter` is more
expressive to its type.
# Objective
Other than the exposed functions for reading matched tables and
archetypes, a `QueryState` does not actually need both internal Vecs for
storing matched archetypes and tables. In practice, it will only use one
of the two depending on if it uses dense or archetypal iteration.
Same vein as #12474. The goal is to reduce the memory overhead of using
queries, which Bevy itself, ecosystem plugins, and end users are already
fairly liberally using.
## Solution
Add `StorageId`, which is a union over `TableId` and `ArchetypeId`, and
store only one of the two at runtime. Read the slice as if it was one ID
depending on whether the query is dense or not.
This follows in the same vein as #5085; however, this one directly
impacts heap memory usage at runtime, while #5085 primarily targeted
transient pointers that might not actually exist at runtime.
---
## Changelog
Changed: `QueryState::matched_tables` now returns an iterator instead of
a reference to a slice.
Changed: `QueryState::matched_archetypes` now returns an iterator
instead of a reference to a slice.
## Migration Guide
`QueryState::matched_tables` and `QueryState::matched_archetypes` does
not return a reference to a slice, but an iterator instead. You may need
to use iterator combinators or collect them into a Vec to use it as a
slice.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fixes#12752. Fixes#12750. Document the runtime complexity of all of
the `O(1)` operations on the individual APIs.
## Solution
* Mirror `Query::contains` onto `QueryState::contains`
* Make `QueryState::as_nop` pub(crate)
* Make `NopWorldQuery` pub(crate)
* Document all of the O(1) operations on Query and QueryState.
# Objective
Fixes#12392, fixes#12393, and fixes#11387. Implement QueryData for
Archetype and EntityLocation.
## Solution
Add impls for both of the types.
---
## Changelog
Added: `&Archetype` now implements `QueryData`
Added: `EntityLocation` now implements `QueryData`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Resolves#3824. `unsafe` code should be the exception, not the norm in
Rust. It's obviously needed for various use cases as it's interfacing
with platforms and essentially running the borrow checker at runtime in
the ECS, but the touted benefits of Bevy is that we are able to heavily
leverage Rust's safety, and we should be holding ourselves accountable
to that by minimizing our unsafe footprint.
## Solution
Deny `unsafe_code` workspace wide. Add explicit exceptions for the
following crates, and forbid it in almost all of the others.
* bevy_ecs - Obvious given how much unsafe is needed to achieve
performant results
* bevy_ptr - Works with raw pointers, even more low level than bevy_ecs.
* bevy_render - due to needing to integrate with wgpu
* bevy_window - due to needing to integrate with raw_window_handle
* bevy_utils - Several unsafe utilities used by bevy_ecs. Ideally moved
into bevy_ecs instead of made publicly usable.
* bevy_reflect - Required for the unsafe type casting it's doing.
* bevy_transform - for the parallel transform propagation
* bevy_gizmos - For the SystemParam impls it has.
* bevy_assets - To support reflection. Might not be required, not 100%
sure yet.
* bevy_mikktspace - due to being a conversion from a C library. Pending
safe rewrite.
* bevy_dynamic_plugin - Inherently unsafe due to the dynamic loading
nature.
Several uses of unsafe were rewritten, as they did not need to be using
them:
* bevy_text - a case of `Option::unchecked` could be rewritten as a
normal for loop and match instead of an iterator.
* bevy_color - the Pod/Zeroable implementations were replaceable with
bytemuck's derive macros.
# Objective
Currently the built docs only shows the logo and favicon for the top
level `bevy` crate. This makes views like
https://docs.rs/bevy_ecs/latest/bevy_ecs/ look potentially unrelated to
the project at first glance.
## Solution
Reproduce the docs attributes for every crate that Bevy publishes.
Ideally this would be done with some workspace level Cargo.toml control,
but AFAICT, such support does not exist.
# Objective
Make it easy to get the ids of all the components in a bundle (and
initialise any components not yet initialised). This is fairly similar
to the `Bundle::get_component_ids()` method added in the observers PR
however that will return none for any non-initialised components. This
is exactly the API space covered by `Bundle::component_ids()` however
that isn't possible to call outside of `bevy_ecs` as it requires `&mut
Components` and `&mut Storages`.
## Solution
Added `World.init_bundle<B: Bundle>()` which similarly to
`init_component` and `init_resource`, initialises all components in the
bundle and returns a vector of their component ids.
---
## Changelog
Added the method `init_bundle` to `World` as a counterpart to
`init_component` and `init_resource`.
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
- Tiny PR to clarify that `self.world.bundles.init_info::<T>` must have
been called so that the BundleInfo is present in the World
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
I was reading some of the Archetype and Bundle code and was getting
confused a little bit in some places (is the `archetype_id` in
`AddBundle` the source or the target archetype id?).
Small PR that adds some docstrings to make it easier for first-time
readers.
# Objective
- Allow registering of systems from Commands with
`Commands::register_one_shot_system`
- Make registering of one shot systems more easy
## Solution
- Add the Command `RegisterSystem` for Commands use.
- Creation of SystemId based on lazy insertion of the System
- Changed the privacy of the fields in SystemId so Commands can return
the SystemId
---
## Changelog
### Added
- Added command `RegisterSystem`
- Added function `Commands::register_one_shot_system`
- Added function `App::register_one_shot_system`
### Changed
- Changed the privacy and the type of struct tuple to regular struct of
SystemId
## Migration Guide
- Changed SystemId fields from tuple struct to a normal struct
If you want to access the entity field, you should use
`SystemId::entity` instead of `SystemId::0`
## Showcase
> Before, if you wanted to register a system with `Commands`, you would
need to do:
```rust
commands.add(|world: &mut World| {
let id = world.register_system(your_system);
// You would need to insert the SystemId inside an entity or similar
})
```
> Now, you can:
```rust
let id = commands.register_one_shot_system(your_system);
// Do what you want with the Id
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Pablo Reinhardt <pabloreinhardt@gmail.com>
# Objective
I'm reading through the ecs query code for the first time, and updating
the docs:
- fixed some typos
- added some docs about things I was confused about (in particular what
the difference between `matches_component_set` and
`update_component_access` was)
# Objective
Fix Pr CI failing over dead code in tests and main branch CI failing
over a missing semicolon. Fixes#12620.
## Solution
Add dead_code annotations and a semicolon.
# Objective
Fixes#12549. WorldCell's support of everything a World can do is
incomplete, and represents an alternative, potentially confusing, and
less performant way of pulling multiple fetches from a `World`. The
typical approach is to use `SystemState` for a runtime cached and safe
way, or `UnsafeWorldCell` if the use of `unsafe` is tolerable.
## Solution
Remove it!
---
## Changelog
Removed: `WorldCell`
Removed: `World::cell`
## Migration Guide
`WorldCell` has been removed. If you were using it to fetch multiple
distinct values from a `&mut World`, use `SystemState` by calling
`SystemState::get` instead. Alternatively, if `SystemState` cannot be
used, `UnsafeWorldCell` can instead be used in unsafe contexts.
# Objective
Provide component access to `&'w T`, `Ref<'w, T>`, `Mut<'w, T>`,
`Ptr<'w>` and `MutUntyped<'w>` from `EntityMut<'w>`/`EntityWorldMut<'w>`
with the world `'w` lifetime instead of `'_`.
Fixes#12417
## Solution
Add `into_` prefixed methods for `EntityMut<'w>`/`EntityWorldMut<'w>`
that consume `self` and returns component access with the world `'w`
lifetime unlike the `get_` prefixed methods that takes `&'a self` and
returns component access with `'a` lifetime.
Methods implemented:
- EntityMut::into_borrow
- EntityMut::into_ref
- EntityMut::into_mut
- EntityMut::into_borrow_by_id
- EntityMut::into_mut_by_id
- EntityWorldMut::into_borrow
- EntityWorldMut::into_ref
- EntityWorldMut::into_mut
- EntityWorldMut::into_borrow_by_id
- EntityWorldMut::into_mut_by_id
# Objective
`QueryState::archetype_component_access` is only really ever used to
extend `SystemMeta`'s. It can be removed to save some memory for every
`Query` in an app.
## Solution
* Remove it.
* Have `new_archetype` pass in a `&mut Access<ArchetypeComponentId>`
instead and pull it from `SystemMeta` directly.
* Split `QueryState::new` from `QueryState::new_with_access` and a
common `QueryState::new_uninitialized`.
* Split `new_archetype` into an internal and public version. Call the
internal version in `update_archetypes`.
This should make it faster to construct new QueryStates, and by proxy
lenses and joins as well.
`matched_tables` also similarly is only used to deduplicate inserting
into `matched_table_ids`. If we can find another efficient way to do so,
it might also be worth removing.
The [generated
assembly](https://github.com/james7132/bevy_asm_tests/compare/main...remove-query-state-archetype-component-access#diff-496530101f0b16e495b7e9b77c0e906ae3068c8adb69ed36c92d5a1be5a9efbe)
reflects this well, with all of the access related updates in
`QueryState` being removed.
---
## Changelog
Removed: `QueryState::archetype_component_access`.
Changed: `QueryState::new_archetype` now takes a `&mut
Access<ArchetypeComponentId>` argument, which will be updated with the
new accesses.
Changed: `QueryState::update_archetype_component_access` now takes a
`&mut Access<ArchetypeComponentId>` argument, which will be updated with
the new accesses.
## Migration Guide
TODO
# Objective
Improve code quality involving fixedbitset.
## Solution
Update to fixedbitset 0.5. Use the new `grow_and_insert` function
instead of `grow` and `insert` functions separately.
This should also speed up most of the set operations involving
fixedbitset. They should be ~2x faster, but testing this against the
stress tests seems to show little to no difference. The multithreaded
executor doesn't seem to be all that much faster in many_cubes and
many_foxes. These use cases are likely dominated by other operations or
the bitsets aren't big enough to make them the bottleneck.
This introduces a duplicate dependency due to petgraph and wgpu, but the
former may take some time to update.
## Changelog
Removed: `Access::grow`
## Migration Guide
`Access::grow` has been removed. It's no longer needed. Remove all
references to it.
# Objective
Fixes#12139
## Solution
- Derive `Debug` impl for `Entity`
- Add impl `Display` for `Entity`
- Add `entity_display` test to check the output contains all required
info
I decided to go with `0v0|1234` format as opposed to the `0v0[1234]`
which was initially discussed in the issue.
My rationale for this is that `[1234]` may be confused for index values,
which may be common in logs, and so searching for entities by text would
become harder. I figured `|1234` would help the entity IDs stand out
more.
Additionally, I'm a little concerned that this change is gonna break
existing logging for projects because `Debug` is now going to be a
multi-line output. But maybe this is ok.
We could implement `Debug` to be a single-line output, but then I don't
see why it would be different from `Display` at all.
@alice-i-cecile Let me know if we'd like to make any changes based on
these points.
# Objective
`System<f32>` currently does not implement `Eq` even though it should
## Solution
Manually implement `Eq` like other traits are manually implemented
# Objective
- Add a way to combine 2 queries together in a similar way to
`Query::transmute_lens`
- Fixes#1658
## Solution
- Use a similar method to query transmute, but take the intersection of
matched archetypes between the 2 queries and the union of the accesses
to create the new underlying QueryState.
---
## Changelog
- Add query joins
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fix#10876. Improve `Query` and `QueryState`'s docs.
## Solution
Explicitly denote that Query is always guaranteed to return results from
all matching entities once and only once for each entity, and that
iteration order is not guaranteed in any way.
# Objective
Remove Bevy internals from backtraces
## Solution
Executors insert `__rust_begin_short_backtrace` into the callstack
before running a system.
<details>
<summary>Example current output</summary>
```
thread 'Compute Task Pool (3)' panicked at src/main.rs:7:33:
Foo
stack backtrace:
0: rust_begin_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:647:5
1: core::panicking::panic_fmt
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panicking.rs:72:14
2: foo::main::{{closure}}
at ./src/main.rs:7:33
3: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/ops/function.rs:294:13
4: <Func as bevy_ecs::system::function_system::SystemParamFunction<fn() .> Out>>::run::call_inner
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:661:21
5: <Func as bevy_ecs::system::function_system::SystemParamFunction<fn() .> Out>>::run
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:664:17
6: <bevy_ecs::system::function_system::FunctionSystem<Marker,F> as bevy_ecs::system::system::System>::run_unsafe
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:504:19
7: bevy_ecs::schedule::executor::multi_threaded::ExecutorState::spawn_system_task::{{closure}}::{{closure}}
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/schedule/executor/multi_threaded.rs:621:26
8: core::ops::function::FnOnce::call_once
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/ops/function.rs:250:5
9: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panic/unwind_safe.rs:272:9
10: std::panicking::try::do_call
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:554:40
11: __rust_try
12: std::panicking::try
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:518:19
13: std::panic::catch_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panic.rs:142:14
14: bevy_ecs::schedule::executor::multi_threaded::ExecutorState::spawn_system_task::{{closure}}
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/schedule/executor/multi_threaded.rs:614:23
15: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::future::future::Future>::poll
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panic/unwind_safe.rs:297:9
16: <futures_lite::future::CatchUnwind<F> as core::future::future::Future>::poll::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-lite-2.2.0/src/future.rs:588:42
17: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panic/unwind_safe.rs:272:9
18: std::panicking::try::do_call
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:554:40
19: __rust_try
20: std::panicking::try
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:518:19
21: std::panic::catch_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panic.rs:142:14
22: <futures_lite::future::CatchUnwind<F> as core::future::future::Future>::poll
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-lite-2.2.0/src/future.rs:588:9
23: async_executor::Executor::spawn::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-executor-1.8.0/src/lib.rs:158:20
24: async_task::raw::RawTask<F,T,S,M>::run::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-task-4.7.0/src/raw.rs:550:21
25: core::ops::function::FnOnce::call_once
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/ops/function.rs:250:5
26: <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panic/unwind_safe.rs:272:9
27: std::panicking::try::do_call
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:554:40
28: __rust_try
29: std::panicking::try
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:518:19
30: std::panic::catch_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panic.rs:142:14
31: async_task::raw::RawTask<F,T,S,M>::run
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-task-4.7.0/src/raw.rs:549:23
32: async_task::runnable::Runnable<M>::run
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-task-4.7.0/src/runnable.rs:781:18
33: async_executor::Executor::run::{{closure}}::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-executor-1.8.0/src/lib.rs:254:21
34: <futures_lite::future::Or<F1,F2> as core::future::future::Future>::poll
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-lite-2.2.0/src/future.rs:449:33
35: async_executor::Executor::run::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/async-executor-1.8.0/src/lib.rs:261:32
36: futures_lite::future::block_on::{{closure}}
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-lite-2.2.0/src/future.rs:99:19
37: std:🧵:local::LocalKey<T>::try_with
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/thread/local.rs:286:16
38: std:🧵:local::LocalKey<T>::with
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/thread/local.rs:262:9
39: futures_lite::future::block_on
at /home/vj/.cargo/registry/src/index.crates.io-6f17d22bba15001f/futures-lite-2.2.0/src/future.rs:78:5
40: bevy_tasks::task_pool::TaskPool::new_internal::{{closure}}::{{closure}}::{{closure}}::{{closure}}
at /home/vj/workspace/rust/bevy/crates/bevy_tasks/src/task_pool.rs:180:37
41: std::panicking::try::do_call
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:554:40
42: __rust_try
43: std::panicking::try
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:518:19
44: std::panic::catch_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panic.rs:142:14
45: bevy_tasks::task_pool::TaskPool::new_internal::{{closure}}::{{closure}}::{{closure}}
at /home/vj/workspace/rust/bevy/crates/bevy_tasks/src/task_pool.rs:174:43
46: std:🧵:local::LocalKey<T>::try_with
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/thread/local.rs:286:16
47: std:🧵:local::LocalKey<T>::with
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/thread/local.rs:262:9
48: bevy_tasks::task_pool::TaskPool::new_internal::{{closure}}::{{closure}}
at /home/vj/workspace/rust/bevy/crates/bevy_tasks/src/task_pool.rs:167:25
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
Encountered a panic in system `foo::main::{{closure}}`!
Encountered a panic in system `bevy_app::main_schedule::Main::run_main`!
get on your knees and beg mommy for forgiveness you pervert~ 💖
```
</details>
<details>
<summary>Example output with this PR</summary>
```
Panic at src/main.rs:7:33:
Foo
stack backtrace:
0: rust_begin_unwind
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/std/src/panicking.rs:647:5
1: core::panicking::panic_fmt
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/panicking.rs:72:14
2: foo::main::{{closure}}
at ./src/main.rs:7:59
3: core::ops::function::impls::<impl core::ops::function::FnMut<A> for &mut F>::call_mut
at /rustc/8ace7ea1f7cbba7b4f031e66c54ca237a0d65de6/library/core/src/ops/function.rs:294:13
4: <Func as bevy_ecs::system::function_system::SystemParamFunction<fn() .> Out>>::run::call_inner
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:661:21
5: <Func as bevy_ecs::system::function_system::SystemParamFunction<fn() .> Out>>::run
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:664:17
6: <bevy_ecs::system::function_system::FunctionSystem<Marker,F> as bevy_ecs::system::system::System>::run_unsafe
at /home/vj/workspace/rust/bevy/crates/bevy_ecs/src/system/function_system.rs:504:19
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
Encountered a panic in system `foo::main::{{closure}}`!
Encountered a panic in system `bevy_app::main_schedule::Main::run_main`!
```
</details>
Full backtraces (`RUST_BACKTRACE=full`) are unchanged.
## Alternative solutions
Write a custom panic hook. This could potentially let use exclude a few
more callstack frames but requires a dependency on `backtrace` and is
incompatible with user-provided panic hooks.
---
## Changelog
- Backtraces now exclude many Bevy internals (unless
`RUST_BACKTRACE=full` is used)
---------
Co-authored-by: James Liu <contact@jamessliu.com>
# Objective
Fix missing `TextBundle` (and many others) which are present in the main
crate as default features but optional in the sub-crate. See:
- https://docs.rs/bevy/0.13.0/bevy/ui/node_bundles/index.html
- https://docs.rs/bevy_ui/0.13.0/bevy_ui/node_bundles/index.html
~~There are probably other instances in other crates that I could track
down, but maybe "all-features = true" should be used by default in all
sub-crates? Not sure.~~ (There were many.) I only noticed this because
rust-analyzer's "open docs" features takes me to the sub-crate, not the
main one.
## Solution
Add "all-features = true" to docs.rs metadata for crates that use
features.
## Changelog
### Changed
- Unified features documented on docs.rs between main crate and
sub-crates
# Objective
Make bevy_utils less of a compilation bottleneck. Tackle #11478.
## Solution
* Move all of the directly reexported dependencies and move them to
where they're actually used.
* Remove the UUID utilities that have gone unused since `TypePath` took
over for `TypeUuid`.
* There was also a extraneous bytemuck dependency on `bevy_core` that
has not been used for a long time (since `encase` became the primary way
to prepare GPU buffers).
* Remove the `all_tuples` macro reexport from bevy_ecs since it's
accessible from `bevy_utils`.
---
## Changelog
Removed: Many of the reexports from bevy_utils (petgraph, uuid, nonmax,
smallvec, and thiserror).
Removed: bevy_core's reexports of bytemuck.
## Migration Guide
bevy_utils' reexports of petgraph, uuid, nonmax, smallvec, and thiserror
have been removed.
bevy_core' reexports of bytemuck's types has been removed.
Add them as dependencies in your own crate instead.
# 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>
# Objective
The documentation for the `States` trait contains an error! There is a
single colon missing from `OnExit<T:Variant>`.
## Solution
Replace `OnExit<T:Variant>` with `OnExit<T::Variant>`. (Notice the added
colon.)
---
## Changelog
### Added
- Added missing colon in `States` documentation.
---
Bevy community, you may now rest easy.
# Objective
Fix#10731.
## Solution
Rename `App::add_state<T>(&mut self)` to `init_state`, and add
`App::insert_state<T>(&mut self, state: T)`. I decided on these names
because they are more similar to `init_resource` and `insert_resource`.
I also removed the `States` trait's requirement for `Default`. Instead,
`init_state` requires `FromWorld`.
---
## Changelog
- Renamed `App::add_state` to `init_state`.
- Added `App::insert_state`.
- Removed the `States` trait's requirement for `Default`.
## Migration Guide
- Renamed `App::add_state` to `init_state`.
# Objective
`Has<T>` in some niche cases may behave in an unexpected way.
Specifically, when using `Query::get` on a `Has<T>` with a despawned
entity.
## Solution
Add precision about cases wehre `Query::get` could return an `Err`.
Use `'w` for world lifetime consistently.
When implementing system params, useful to look at how other params are
implemented. `'w` makes it clear it is world, not state.
# Objective
- Allow checking if a resource has changed by its ComponentId
---
## Changelog
- Added `World::is_resource_changed_by_id()` and
`World::is_resource_added_by_id()`.
# Objective
The definition of several `QueryState` methods use unnecessary explicit
lifetimes, which adds to visual noise.
## Solution
Elide the lifetimes.
# Objective
- Users are often confused when their command effects are not visible in
the next system. This PR auto inserts sync points if there are deferred
buffers on a system and there are dependents on that system (systems
with after relationships).
- Manual sync points can lead to users adding more than needed and it's
hard for the user to have a global understanding of their system graph
to know which sync points can be merged. However we can easily calculate
which sync points can be merged automatically.
## Solution
1. Add new edge types to allow opting out of new behavior
2. Insert an sync point for each edge whose initial node has deferred
system params.
3. Reuse nodes if they're at the number of sync points away.
* add opt outs for specific edges with `after_ignore_deferred`,
`before_ignore_deferred` and `chain_ignore_deferred`. The
`auto_insert_apply_deferred` boolean on `ScheduleBuildSettings` can be
set to false to opt out for the whole schedule.
## Perf
This has a small negative effect on schedule build times.
```text
group auto-sync main-for-auto-sync
----- ----------- ------------------
build_schedule/1000_schedule 1.06 2.8±0.15s ? ?/sec 1.00 2.7±0.06s ? ?/sec
build_schedule/1000_schedule_noconstraints 1.01 26.2±0.88ms ? ?/sec 1.00 25.8±0.36ms ? ?/sec
build_schedule/100_schedule 1.02 13.1±0.33ms ? ?/sec 1.00 12.9±0.28ms ? ?/sec
build_schedule/100_schedule_noconstraints 1.08 505.3±29.30µs ? ?/sec 1.00 469.4±12.48µs ? ?/sec
build_schedule/500_schedule 1.00 485.5±6.29ms ? ?/sec 1.00 485.5±9.80ms ? ?/sec
build_schedule/500_schedule_noconstraints 1.00 6.8±0.10ms ? ?/sec 1.02 6.9±0.16ms ? ?/sec
```
---
## Changelog
- Auto insert sync points and added `after_ignore_deferred`,
`before_ignore_deferred`, `chain_no_deferred` and
`auto_insert_apply_deferred` APIs to opt out of this behavior
## Migration Guide
- `apply_deferred` points are added automatically when there is ordering
relationship with a system that has deferred parameters like `Commands`.
If you want to opt out of this you can switch from `after`, `before`,
and `chain` to the corresponding `ignore_deferred` API,
`after_ignore_deferred`, `before_ignore_deferred` or
`chain_ignore_deferred` for your system/set ordering.
- You can also set `ScheduleBuildSettings::auto_insert_sync_points` to
`false` if you want to do it for the whole schedule. Note that in this
mode you can still add `apply_deferred` points manually.
- For most manual insertions of `apply_deferred` you should remove them
as they cannot be merged with the automatically inserted points and
might reduce parallelizability of the system graph.
## TODO
- [x] remove any apply_deferred used in the engine
- [x] ~~decide if we should deprecate manually using apply_deferred.~~
We'll still allow inserting manual sync points for now for whatever edge
cases users might have.
- [x] Update migration guide
- [x] rerun schedule build benchmarks
---------
Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
# Objective
- Make the implementation order consistent between all sources to fit
the order in the trait.
## Solution
- Change the implementation order.
# Objective
Since #10776 split `WorldQuery` to `WorldQueryData` and
`WorldQueryFilter`, it should be clear that the query is actually
composed of two parts. It is not factually correct to call "query" only
the data part. Therefore I suggest to rename the `Q` parameter to `D` in
`Query` and related items.
As far as I know, there shouldn't be breaking changes from renaming
generic type parameters.
## Solution
I used a combination of rust-analyzer go to reference and `Ctrl-F`ing
various patterns to catch as many cases as possible. Hopefully I got
them all. Feel free to check if you're concerned of me having missed
some.
## Notes
This and #10779 have many lines in common, so merging one will cause a
lot of merge conflicts to the other.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- The example in the docs is unsound.
Demo:
```rust
#[derive(Resource)]
struct MyRes(u32);
fn main() {
let mut w = World::new();
w.insert_resource(MyRes(0));
let (mut res, comp) = split_world_access(&mut w);
let mut r1 = res.get_resource_mut::<MyRes>().unwrap();
let mut r2 = res.get_resource_mut::<MyRes>().unwrap();
*r1 = MyRes(1);
*r2 = MyRes(2);
}
```
The API in the example allows aliasing mutable references to the same
resource. Miri also complains when running this.
## Solution
- Change the example API to make the returned `Mut` borrow from the
`OnlyResourceAccessWorld` instead of borrowing from the world via `'w`.
This prevents obtaining more than one `Mut` at the same time from it.
# Objective
The `Despawn` command breaks the hierarchy whenever you use it if the
despawned entity has a parent or any children. This is a serious footgun
because the `Despawn` command has the shortest name, the behavior is
unexpected and not likely to be what you want, and the crash that it
causes can be very difficult to track down.
## Solution
Until this can be fixed by relations, add a note mentioning the footgun
in the documentation.
## Solution
`Commands.remove` and `.retain` (because I copied `remove`s doc)
referenced `EntityWorldMut.remove` and `retain` for more detail but the
`Commands` docs are much more detailed (which makes sense because it is
the most common api), so I have instead inverted this so that
`EntityWorldMut` docs link to `Commands`.
I also made `EntityWorldMut.despawn` reference `World.despawn` for more
details, like `Commands.despawn` does.
# Objective
Test more complex function signatures for exclusive systems, and test
that `StaticSystemParam` is indeed a `SystemParam`.
I mean, it currently works, but might as well add a test for it.
# Objective
Adds `EntityCommands.retain` and `EntityWorldMut.retain` to remove all
components except the given bundle from the entity.
Fixes#10865.
## Solution
I added a private unsafe function in `EntityWorldMut` called
`remove_bundle_info` which performs the shared behaviour of `remove` and
`retain`, namely taking a `BundleInfo` of components to remove, and
removing them from the given entity. Then `retain` simply gets all the
components on the entity and filters them by whether they are in the
bundle it was passed, before passing this `BundleInfo` into
`remove_bundle_info`.
`EntityCommands.retain` just creates a new type `Retain` which runs
`EntityWorldMut.retain` when run.
---
## Changelog
Added `EntityCommands.retain` and `EntityWorldMut.retain`, which remove
all components except the given bundle from the entity, they can also be
used to remove all components by passing `()` as the bundle.
# Objective
- Fixes#10806
## Solution
Replaced `new` and `index` methods for both `TableRow` and `TableId`
with `from_*` and `as_*` methods. These remove the need to perform
casting at call sites, reducing the total number of casts in the Bevy
codebase. Within these methods, an appropriate `debug_assertion` ensures
the cast will behave in an expected manner (no wrapping, etc.). I am
using a `debug_assertion` instead of an `assert` to reduce any possible
runtime overhead, however minimal. This choice is something I am open to
changing (or leaving up to another PR) if anyone has any strong
arguments for it.
---
## Changelog
- `ComponentSparseSet::sparse` stores a `TableRow` instead of a `u32`
(private change)
- Replaced `TableRow::new` and `TableRow::index` methods with
`TableRow::from_*` and `TableRow::as_*`, with `debug_assertions`
protecting any internal casting.
- Replaced `TableId::new` and `TableId::index` methods with
`TableId::from_*` and `TableId::as_*`, with `debug_assertions`
protecting any internal casting.
- All `TableId` methods are now `const`
## Migration Guide
- `TableRow::new` -> `TableRow::from_usize`
- `TableRow::index` -> `TableRow::as_usize`
- `TableId::new` -> `TableId::from_usize`
- `TableId::index` -> `TableId::as_usize`
---
## Notes
I have chosen to remove the `index` and `new` methods for the following
chain of reasoning:
- Across the codebase, `new` was called with a mixture of `u32` and
`usize` values. Likewise for `index`.
- Choosing `new` to either be `usize` or `u32` would break half of these
call-sites, requiring `as` casting at the site.
- Adding a second method `new_u32` or `new_usize` avoids the above, bu
looks visually inconsistent.
- Therefore, they should be replaced with `from_*` and `as_*` methods
instead.
Worth noting is that by updating `ComponentSparseSet`, there are now
zero instances of interacting with the inner value of `TableRow` as a
`u32`, it is exclusively used as a `usize` value (due to interactions
with methods like `len` and slice indexing). I have left the `as_u32`
and `from_u32` methods as the "proper" constructors/getters.
# Objective
Resolves Issue #10772.
## Solution
Added the deprecated warning for QueryState::for_each_unchecked, as
noted in the comments of PR #6773.
Followed the wording in the deprecation messages for `for_each` and
`for_each_mut`
# Objective
After #6547, `Query::for_each` has been capable of automatic
vectorization on certain queries, which is seeing a notable (>50% CPU
time improvements) for iteration. However, `Query::for_each` isn't
idiomatic Rust, and lacks the flexibility of iterator combinators.
Ideally, `Query::iter` and friends should be able to achieve the same
results. However, this does seem to blocked upstream
(rust-lang/rust#104914) by Rust's loop optimizations.
## Solution
This is an intermediate solution and refactor. This moves the
`Query::for_each` implementation onto the `Iterator::fold`
implementation for `QueryIter` instead. This should result in the same
automatic vectorization optimization on all `Iterator` functions that
internally use fold, including `Iterator::for_each`, `Iterator::count`,
etc.
With this, it should close the gap between the two completely.
Internally, this PR changes `Query::for_each` to use
`query.iter().for_each(..)` instead of the duplicated implementation.
Separately, the duplicate implementations of internal iteration (i.e.
`Query::par_for_each`) now use portions of the current `Query::for_each`
implementation factored out into their own functions.
This also massively cleans up our internal fragmentation of internal
iteration options, deduplicating the iteration code used in `for_each`
and `par_iter().for_each()`.
---
## Changelog
Changed: `Query::for_each`, `Query::for_each_mut`, `Query::for_each`,
and `Query::for_each_mut` have been moved to `QueryIter`'s
`Iterator::for_each` implementation, and still retains their performance
improvements over normal iteration. These APIs are deprecated in 0.13
and will be removed in 0.14.
---------
Co-authored-by: JoJoJet <21144246+JoJoJet@users.noreply.github.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- Shorten paths by removing unnecessary prefixes
## Solution
- Remove the prefixes from many paths which do not need them. Finding
the paths was done automatically using built-in refactoring tools in
Jetbrains RustRover.
# Objective
Keep essentially the same structure of `EntityHasher` from #9903, but
rephrase the multiplication slightly to save an instruction.
cc @superdump
Discord thread:
https://discord.com/channels/691052431525675048/1172033156845674507/1174969772522356756
## Solution
Today, the hash is
```rust
self.hash = i | (i.wrapping_mul(FRAC_U64MAX_PI) << 32);
```
with `i` being `(generation << 32) | index`.
Expanding things out, we get
```rust
i | ( (i * CONST) << 32 )
= (generation << 32) | index | ((((generation << 32) | index) * CONST) << 32)
= (generation << 32) | index | ((index * CONST) << 32) // because the generation overflowed
= (index * CONST | generation) << 32 | index
```
What if we do the same thing, but with `+` instead of `|`? That's almost
the same thing, except that it has carries, which are actually often
better in a hash function anyway, since it doesn't saturate. (`|` can be
dangerous, since once something becomes `-1` it'll stay that, and
there's no mixing available.)
```rust
(index * CONST + generation) << 32 + index
= (CONST << 32 + 1) * index + generation << 32
= (CONST << 32 + 1) * index + (WHATEVER << 32 + generation) << 32 // because the extra overflows and thus can be anything
= (CONST << 32 + 1) * index + ((CONST * generation) << 32 + generation) << 32 // pick "whatever" to be something convenient
= (CONST << 32 + 1) * index + ((CONST << 32 + 1) * generation) << 32
= (CONST << 32 + 1) * index +((CONST << 32 + 1) * (generation << 32)
= (CONST << 32 + 1) * (index + generation << 32)
= (CONST << 32 + 1) * (generation << 32 | index)
= (CONST << 32 + 1) * i
```
So we can do essentially the same thing using a single multiplication
instead of doing multiply-shift-or.
LLVM was already smart enough to merge the shifting into a
multiplication, but this saves the extra `or`:
<https://rust.godbolt.org/z/MEvbz4eo4>
It's a very small change, and often will disappear in load latency
anyway, but it's a couple percent faster in lookups:
(There was more of an improvement here before #10558, but with `to_bits`
being a single `qword` load now, keeping things mostly as it is turned
out to be better than the bigger changes I'd tried in #10605.)
---
## Changelog
(Probably skip it)
## Migration Guide
(none needed)
# Objective
Related to #10612.
Enable the
[`clippy::manual_let_else`](https://rust-lang.github.io/rust-clippy/master/#manual_let_else)
lint as a warning. The `let else` form seems more idiomatic to me than a
`match`/`if else` that either match a pattern or diverge, and from the
clippy doc, the lint doesn't seem to have any possible false positive.
## Solution
Add the lint as warning in `Cargo.toml`, refactor places where the lint
triggers.
# Objective
- Fixes#7680
- This is an updated for https://github.com/bevyengine/bevy/pull/8899
which had the same objective but fell a long way behind the latest
changes
## Solution
The traits `WorldQueryData : WorldQuery` and `WorldQueryFilter :
WorldQuery` have been added and some of the types and functions from
`WorldQuery` has been moved into them.
`ReadOnlyWorldQuery` has been replaced with `ReadOnlyWorldQueryData`.
`WorldQueryFilter` is safe (as long as `WorldQuery` is implemented
safely).
`WorldQueryData` is unsafe - safely implementing it requires that
`Self::ReadOnly` is a readonly version of `Self` (this used to be a
safety requirement of `WorldQuery`)
The type parameters `Q` and `F` of `Query` must now implement
`WorldQueryData` and `WorldQueryFilter` respectively.
This makes it impossible to accidentally use a filter in the data
position or vice versa which was something that could lead to bugs.
~~Compile failure tests have been added to check this.~~
It was previously sometimes useful to use `Option<With<T>>` in the data
position. Use `Has<T>` instead in these cases.
The `WorldQuery` derive macro has been split into separate derive macros
for `WorldQueryData` and `WorldQueryFilter`.
Previously it was possible to derive both `WorldQuery` for a struct that
had a mixture of data and filter items. This would not work correctly in
some cases but could be a useful pattern in others. *This is no longer
possible.*
---
## Notes
- The changes outside of `bevy_ecs` are all changing type parameters to
the new types, updating the macro use, or replacing `Option<With<T>>`
with `Has<T>`.
- All `WorldQueryData` types always returned `true` for `IS_ARCHETYPAL`
so I moved it to `WorldQueryFilter` and
replaced all calls to it with `true`. That should be the only logic
change outside of the macro generation code.
- `Changed<T>` and `Added<T>` were being generated by a macro that I
have expanded. Happy to revert that if desired.
- The two derive macros share some functions for implementing
`WorldQuery` but the tidiest way I could find to implement them was to
give them a ton of arguments and ask clippy to ignore that.
## Changelog
### Changed
- Split `WorldQuery` into `WorldQueryData` and `WorldQueryFilter` which
now have separate derive macros. It is not possible to derive both for
the same type.
- `Query` now requires that the first type argument implements
`WorldQueryData` and the second implements `WorldQueryFilter`
## Migration Guide
- Update derives
```rust
// old
#[derive(WorldQuery)]
#[world_query(mutable, derive(Debug))]
struct CustomQuery {
entity: Entity,
a: &'static mut ComponentA
}
#[derive(WorldQuery)]
struct QueryFilter {
_c: With<ComponentC>
}
// new
#[derive(WorldQueryData)]
#[world_query_data(mutable, derive(Debug))]
struct CustomQuery {
entity: Entity,
a: &'static mut ComponentA,
}
#[derive(WorldQueryFilter)]
struct QueryFilter {
_c: With<ComponentC>
}
```
- Replace `Option<With<T>>` with `Has<T>`
```rust
/// old
fn my_system(query: Query<(Entity, Option<With<ComponentA>>)>)
{
for (entity, has_a_option) in query.iter(){
let has_a:bool = has_a_option.is_some();
//todo!()
}
}
/// new
fn my_system(query: Query<(Entity, Has<ComponentA>)>)
{
for (entity, has_a) in query.iter(){
//todo!()
}
}
```
- Fix queries which had filters in the data position or vice versa.
```rust
// old
fn my_system(query: Query<(Entity, With<ComponentA>)>)
{
for (entity, _) in query.iter(){
//todo!()
}
}
// new
fn my_system(query: Query<Entity, With<ComponentA>>)
{
for entity in query.iter(){
//todo!()
}
}
// old
fn my_system(query: Query<AnyOf<(&ComponentA, With<ComponentB>)>>)
{
for (entity, _) in query.iter(){
//todo!()
}
}
// new
fn my_system(query: Query<Option<&ComponentA>, Or<(With<ComponentA>, With<ComponentB>)>>)
{
for entity in query.iter(){
//todo!()
}
}
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- `insert_reflect` relies on `reflect_type_path`, which doesn't gives
the actual type path for object created by `clone_value`, leading to an
unexpected panic. This is a workaround for it.
- Fix#10590
## Solution
- Tries to get type path from `get_represented_type_info` if get failed
from `reflect_type_path`.
---
## Defect remaining
- `get_represented_type_info` implies a shortage on performance than
using `TypeRegistry`.
# Objective
- Fixes#10676, preventing a possible memory leak for commands which
owned resources.
## Solution
Implemented `Drop` for `CommandQueue`. This has been done entirely in
the private API of `CommandQueue`, ensuring no breaking changes. Also
added a unit test, `test_command_queue_inner_drop_early`, based on the
reproduction steps as outlined in #10676.
## Notes
I believe this can be applied to `0.12.1` as well, but I am uncertain of
the process to make that kind of change. Please let me know if there's
anything I can do to help with the back-porting of this change.
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Resolves#10743.
## Solution
Copied over the documentation written by @stepancheng from PR #10718.
I left out the lines from the doctest where `<()>` is removed, as that
seemed to be the part people couldn't decide on whether to keep or not.
## Objective
Currently, events are dropped after two frames. This cadence wasn't
*chosen* for a specific reason, double buffering just lets events
persist for at least two frames. Events only need to be dropped at a
predictable point so that the event queues don't grow forever (i.e.
events should never cause a memory leak).
Events (and especially input events) need to be observable by systems in
`FixedUpdate`, but as-is events are dropped before those systems even
get a chance to see them.
## Solution
Instead of unconditionally dropping events in `First`, require
`FixedUpdate` to first queue the buffer swap (if the `TimePlugin` has
been installed). This way, events are only dropped after a frame that
runs `FixedUpdate`.
## Future Work
In the same way we have independent copies of `Time` for tracking time
in `Main` and `FixedUpdate`, we will need independent copies of `Input`
for tracking press/release status correctly in `Main` and `FixedUpdate`.
--
Every run of `FixedUpdate` covers a specific timespan. For example, if
the fixed timestep `Δt` is 10ms, the first three `FixedUpdate` runs
cover `[0ms, 10ms)`, `[10ms, 20ms)`, and `[20ms, 30ms)`.
`FixedUpdate` can run many times in one frame. For truly
framerate-independent behavior, each `FixedUpdate` should only see the
events that occurred in its covered timespan, but what happens right now
is the first step in the frame reads all pending events.
Fixing that will require timestamped events.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Explain https://github.com/bevyengine/bevy/issues/10625.
This might be obvious to those familiar with Bevy internals, but it
surprised me.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- I've been experimenting with different patterns to try and make async
tasks more convenient. One of the better ones I've found is to return a
command queue to allow for deferred &mut World access. It can be
convenient to check for task completion in a normal system, but it is
hard to do something with the command queue after getting it back. This
pr adds a `append` to Commands. This allows appending the returned
command queue onto the system's commands.
## Solution
- I edited the async compute example to use the new `append`, but not
sure if I should keep the example changed as this might be too
opinionated.
## Future Work
- It would be very easy to pull the pattern used in the example out into
a plugin or a external crate, so users wouldn't have to add the checking
system.
---
## Changelog
- add `append` to `Commands` and `CommandQueue`
# Objective
Enables warning on `clippy::undocumented_unsafe_blocks` across the
workspace rather than only in `bevy_ecs`, `bevy_transform` and
`bevy_utils`. This adds a little awkwardness in a few areas of code that
have trivial safety or explain safety for multiple unsafe blocks with
one comment however automatically prevents these comments from being
missed.
## Solution
This adds `undocumented_unsafe_blocks = "warn"` to the workspace
`Cargo.toml` and fixes / adds a few missed safety comments. I also added
`#[allow(clippy::undocumented_unsafe_blocks)]` where the safety is
explained somewhere above.
There are a couple of safety comments I added I'm not 100% sure about in
`bevy_animation` and `bevy_render/src/view` and I'm not sure about the
use of `#[allow(clippy::undocumented_unsafe_blocks)]` compared to adding
comments like `// SAFETY: See above`.
# Objective
Make the impl block for RemovedSystem generic so that the methods can be
called for systems that have inputs or outputs.
## Solution
Simply adding generics to the impl block.
# Objective
Adds `.entry` to `EntityWorldMut` with `Entry`, `OccupiedEntry` and
`VacantEntry` for easier in-situ modification, based on `HashMap.entry`.
Fixes#10635
## Solution
This adds the `entry` method to `EntityWorldMut` which returns an
`Entry`. This is an enum of `OccupiedEntry` and `VacantEntry` and has
the methods `and_modify`, `insert_entry`, `or_insert`, `or_insert_with`
and `or_default`. The only difference between `OccupiedEntry` and
`VacantEntry` is the type, they are both a mutable reference to the
`EntityWorldMut` and a marker for the component type, `HashMap` also
stores things to make it quicker to access the data in `OccupiedEntry`
but I wasn't sure if we had anything it would be logical to store to
make accessing/modifying the component faster? As such, the differences
are that `OccupiedEntry` assumes the entity has the component (because
nothing else can have an `EntityWorldMut` so it can't be changed outside
the entry api) and has different methods.
All the methods are based very closely off `hashbrown::HashMap` (because
its easier to read the source of) with a couple of quirks like
`OccupiedEntry.insert` doesn't return the old value because we don't
appear to have an api for mem::replacing components.
---
## Changelog
- Added a new function `EntityWorldMut.entry` which returns an `Entry`,
allowing easier in-situ modification of a component.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Pascal Hertleif <killercup@gmail.com>
# Objective
- Fix adding `#![allow(clippy::type_complexity)]` everywhere. like #9796
## Solution
- Use the new [lints] table that will land in 1.74
(https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#lints)
- inherit lint to the workspace, crates and examples.
```
[lints]
workspace = true
```
## Changelog
- Bump rust version to 1.74
- Enable lints table for the workspace
```toml
[workspace.lints.clippy]
type_complexity = "allow"
```
- Allow type complexity for all crates and examples
```toml
[lints]
workspace = true
```
---------
Co-authored-by: Martín Maita <47983254+mnmaita@users.noreply.github.com>
# Objective
- Follow up on https://github.com/bevyengine/bevy/pull/10519, diving
deeper into optimising `Entity` due to the `derive`d `PartialOrd`
`partial_cmp` not being optimal with codegen:
https://github.com/rust-lang/rust/issues/106107
- Fixes#2346.
## Solution
Given the previous PR's solution and the other existing LLVM codegen
bug, there seemed to be a potential further optimisation possible with
`Entity`. In exploring providing manual `PartialOrd` impl, it turned out
initially that the resulting codegen was not immediately better than the
derived version. However, once `Entity` was given `#[repr(align(8)]`,
the codegen improved remarkably, even more once the fields in `Entity`
were rearranged to correspond to a `u64` layout (Rust doesn't
automatically reorder fields correctly it seems). The field order and
`align(8)` additions also improved `to_bits` codegen to be a single
`mov` op. In turn, this led me to replace the previous
"non-shortcircuiting" impl of `PartialEq::eq` to use direct `to_bits`
comparison.
The result was remarkably better codegen across the board, even for
hastable lookups.
The current baseline codegen is as follows:
https://godbolt.org/z/zTW1h8PnY
Assuming the following example struct that mirrors with the existing
`Entity` definition:
```rust
#[derive(Clone, Copy, Eq, PartialEq, PartialOrd, Ord)]
pub struct FakeU64 {
high: u32,
low: u32,
}
```
the output for `to_bits` is as follows:
```
example::FakeU64::to_bits:
shl rdi, 32
mov eax, esi
or rax, rdi
ret
```
Changing the struct to:
```rust
#[derive(Clone, Copy, Eq)]
#[repr(align(8))]
pub struct FakeU64 {
low: u32,
high: u32,
}
```
and providing manual implementations for `PartialEq`/`PartialOrd`/`Ord`,
`to_bits` now optimises to:
```
example::FakeU64::to_bits:
mov rax, rdi
ret
```
The full codegen example for this PR is here for reference:
https://godbolt.org/z/n4Mjx165a
To highlight, `gt` comparison goes from
```
example::greater_than:
cmp edi, edx
jae .LBB3_2
xor eax, eax
ret
.LBB3_2:
setne dl
cmp esi, ecx
seta al
or al, dl
ret
```
to
```
example::greater_than:
cmp rdi, rsi
seta al
ret
```
As explained on Discord by @scottmcm :
>The root issue here, as far as I understand it, is that LLVM's
middle-end is inexplicably unwilling to merge loads if that would make
them under-aligned. It leaves that entirely up to its target-specific
back-end, and thus a bunch of the things that you'd expect it to do that
would fix this just don't happen.
## Benchmarks
Before discussing benchmarks, everything was tested on the following
specs:
AMD Ryzen 7950X 16C/32T CPU
64GB 5200 RAM
AMD RX7900XT 20GB Gfx card
Manjaro KDE on Wayland
I made use of the new entity hashing benchmarks to see how this PR would
improve things there. With the changes in place, I first did an
implementation keeping the existing "non shortcircuit" `PartialEq`
implementation in place, but with the alignment and field ordering
changes, which in the benchmark is the `ord_shortcircuit` column. The
`to_bits` `PartialEq` implementation is the `ord_to_bits` column. The
main_ord column is the current existing baseline from `main` branch.
My machine is not super set-up for benchmarking, so some results are
within noise, but there's not just a clear improvement between the
non-shortcircuiting implementation, but even further optimisation taking
place with the `to_bits` implementation.
On my machine, a fair number of the stress tests were not showing any
difference (indicating other bottlenecks), but I was able to get a clear
difference with `many_foxes` with a fox count of 10,000:
Test with `cargo run --example many_foxes --features
bevy/trace_tracy,wayland --release -- --count 10000`:
On avg, a framerate of about 28-29FPS was improved to 30-32FPS. "This
trace" represents the current PR's perf, while "External trace"
represents the `main` branch baseline.
## Changelog
Changed: micro-optimized Entity align and field ordering as well as
providing manual `PartialOrd`/`Ord` impls to help LLVM optimise further.
## Migration Guide
Any `unsafe` code relying on field ordering of `Entity` or sufficiently
cursed shenanigans should change to reflect the different internal
representation and alignment requirements of `Entity`.
Co-authored-by: james7132 <contact@jamessliu.com>
Co-authored-by: NathanW <nathansward@comcast.net>
# Objective
- Fixes#10532
## Solution
I've updated the various `Event` send methods to return the sent
`EventId`(s). Since these methods previously returned nothing, and this
information is cheap to copy, there should be minimal negative
consequences to providing this additional information. In the case of
`send_batch`, an iterator is returned built from `Range` and `Map`,
which only consumes 16 bytes on the stack with no heap allocations for
all batch sizes. As such, the cost of this information is negligible.
These changes are reflected for `EventWriter` and `World`. For `World`,
the return types are optional to account for the possible lack of an
`Events` resource. Again, these methods previously returned no
information, so its inclusion should only be a benefit.
## Usage
Now when sending events, the IDs of those events is available for
immediate use:
```rust
// Example of a request-response system where the requester can track handled requests.
/// A system which can make and track requests
fn requester(
mut requests: EventWriter<Request>,
mut handled: EventReader<Handled>,
mut pending: Local<HashSet<EventId<Request>>>,
) {
// Check status of previous requests
for Handled(id) in handled.read() {
pending.remove(&id);
}
if !pending.is_empty() {
error!("Not all my requests were handled on the previous frame!");
pending.clear();
}
// Send a new request and remember its ID for later
let request_id = requests.send(Request::MyRequest { /* ... */ });
pending.insert(request_id);
}
/// A system which handles requests
fn responder(
mut requests: EventReader<Request>,
mut handled: EventWriter<Handled>,
) {
for (request, id) in requests.read_with_id() {
if handle(request).is_ok() {
handled.send(Handled(id));
}
}
}
```
In the above example, a `requester` system can send request events, and
keep track of which ones are currently pending by `EventId`. Then, a
`responder` system can act on that event, providing the ID as a
reference that the `requester` can use. Before this PR, it was not
trivial for a system sending events to keep track of events by ID. This
is unfortunate, since for a system reading events, it is trivial to
access the ID of a event.
---
## Changelog
- Updated `Events`:
- Added `send_batch`
- Modified `send` to return the sent `EventId`
- Modified `send_default` to return the sent `EventId`
- Updated `EventWriter`
- Modified `send_batch` to return all sent `EventId`s
- Modified `send` to return the sent `EventId`
- Modified `send_default` to return the sent `EventId`
- Updated `World`
- Modified `send_event` to return the sent `EventId` if sent, otherwise
`None`.
- Modified `send_event_default` to return the sent `EventId` if sent,
otherwise `None`.
- Modified `send_event_batch` to return all sent `EventId`s if sent,
otherwise `None`.
- Added unit test `test_send_events_ids` to ensure returned `EventId`s
match the sent `Event`s
- Updated uses of modified methods.
## Migration Guide
### `send` / `send_default` / `send_batch`
For the following methods:
- `Events::send`
- `Events::send_default`
- `Events::send_batch`
- `EventWriter::send`
- `EventWriter::send_default`
- `EventWriter::send_batch`
- `World::send_event`
- `World::send_event_default`
- `World::send_event_batch`
Ensure calls to these methods either handle the returned value, or
suppress the result with `;`.
```rust
// Now fails to compile due to mismatched return type
fn send_my_event(mut events: EventWriter<MyEvent>) {
events.send_default()
}
// Fix
fn send_my_event(mut events: EventWriter<MyEvent>) {
events.send_default();
}
```
This will most likely be noticed within `match` statements:
```rust
// Before
match is_pressed {
true => events.send(PlayerAction::Fire),
// ^--^ No longer returns ()
false => {}
}
// After
match is_pressed {
true => {
events.send(PlayerAction::Fire);
},
false => {}
}
```
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
# Objective
Allows chained systems taking an `In<_>` input parameter to be run as
one-shot systems. This API was mentioned in #8963.
In addition, `run_system(_with_input)` returns the system output, for
any `'static` output type.
## Solution
A new function, `World::run_system_with_input` allows a `SystemId<I, O>`
to be run by providing an `I` value as input and producing `O` as an
output.
`SystemId<I, O>` is now generic over the input type `I` and output type
`O`, along with the related functions and types `RegisteredSystem`,
`RemovedSystem`, `register_system`, `remove_system`, and
`RegisteredSystemError`. These default to `()`, preserving the existing
API, for all of the public types.
---
## Changelog
- Added `World::run_system_with_input` function to allow one-shot
systems that take `In<_>` input parameters
- Changed `World::run_system` and `World::register_system` to support
systems with return types beyond `()`
- Added `Commands::run_system_with_input` command that schedules a
one-shot system with an `In<_>` input parameter
(This is my first PR here, so I've probably missed some things. Please
let me know what else I should do to help you as a reviewer!)
# Objective
Due to https://github.com/rust-lang/rust/issues/117800, the `derive`'d
`PartialEq::eq` on `Entity` isn't as good as it could be. Since that's
used in hashtable lookup, let's improve it.
## Solution
The derived `PartialEq::eq` short-circuits if the generation doesn't
match. However, having a branch there is sub-optimal, especially on
64-bit systems like x64 that could just load the whole `Entity` in one
load anyway.
Due to complications around `poison` in LLVM and the exact details of
what unsafe code is allowed to do with reference in Rust
(https://github.com/rust-lang/unsafe-code-guidelines/issues/346), LLVM
isn't allowed to completely remove the short-circuiting. `&Entity` is
marked `dereferencable(8)` so LLVM knows it's allowed to *load* all 8
bytes -- and does so -- but it has to assume that the `index` might be
undef/poison if the `generation` doesn't match, and thus while it finds
a way to do it without needing a branch, it has to do something slightly
more complicated than optimal to combine the results. (LLVM is allowed
to change non-short-circuiting code to use branches, but not the other
way around.)
Here's a link showing the codegen today:
<https://rust.godbolt.org/z/9WzjxrY7c>
```rust
#[no_mangle]
pub fn demo_eq_ref(a: &Entity, b: &Entity) -> bool {
a == b
}
```
ends up generating the following assembly:
```asm
demo_eq_ref:
movq xmm0, qword ptr [rdi]
movq xmm1, qword ptr [rsi]
pcmpeqd xmm1, xmm0
pshufd xmm0, xmm1, 80
movmskpd eax, xmm0
cmp eax, 3
sete al
ret
```
(It's usually not this bad in real uses after inlining and LTO, but it
makes a strong demo.)
This PR manually implements `PartialEq::eq` *without* short-circuiting,
and because that tells LLVM that neither the generations nor the index
can be poison, it doesn't need to be so careful and can generate the
"just compare the two 64-bit values" code you'd have probably already
expected:
```asm
demo_eq_ref:
mov rax, qword ptr [rsi]
cmp qword ptr [rdi], rax
sete al
ret
```
Since this doesn't change the representation of `Entity`, if it's
instead passed by *value*, then each `Entity` is two `u32` registers,
and the old and the new code do exactly the same thing. (Other
approaches, like changing `Entity` to be `[u32; 2]` or `u64`, affect
this case.)
This should hopefully merge easily with changes like
https://github.com/bevyengine/bevy/pull/9907 that also want to change
`Entity`.
## Benchmarks
I'm not super-confident that I got my machine fully consistent for
benchmarking, but whether I run the old or the new one first I get
reasonably consistent results.
Here's a fairly typical example of the benchmarks I added in this PR:
Building the sets seems to be basically the same. It's usually reported
as noise, but sometimes I see a few percent slower or faster.
But lookup hits in particular -- since a hit checks that the key is
equal -- consistently shows around 10% improvement.
`cargo run --example many_cubes --features bevy/trace_tracy --release --
--benchmark` showed as slightly faster with this change, though if I had
to bet I'd probably say it's more noise than meaningful (but at least
it's not worse either):
This is my first PR here -- and my first time running Tracy -- so please
let me know what else I should run, or run things on your own more
reliable machines to double-check.
---
## Changelog
(probably not worth including)
Changed: micro-optimized `Entity::eq` to help LLVM slightly.
## Migration Guide
(I really hope nobody was using this on uninitialized entities where
sufficiently tortured `unsafe` could could technically notice that this
has changed.)
# Objective
- `CommandQueue::apply` calculates the address of the end of the
internal buffer as a `usize` rather than as a pointer, requiring two
casts of `cursor` to `usize`. Casting pointers to integers is generally
discouraged and may also prevent optimizations. It's also unnecessary
here.
## Solution
- Calculate the end address as a pointer rather than a `usize`.
Small note:
A trivial translation of the old code to use pointers would have
computed `end_addr` as `cursor.add(self.bytes.len())`, which is not
wrong but is an additional `unsafe` operation that also needs to be
properly documented and proven correct. However this operation is
already implemented in the form of the safe `as_mut_ptr_range`, so I
just used that.
# Objective
There is an if statement checking if a node is present in a graph
moments after it explicitly being added.
Unless the edge function has super weird side effects and the tests
don't pass, this is unnecessary.
## Solution
Removed it
# Objective
- Allow registration of one-shot systems when those systems have already
been `Box`ed.
- Needed for `bevy_eventlisteners` which allows adding event listeners
with callbacks in normal systems. The current one shot system
implementation requires systems be registered from an exclusive system,
and that those systems be passed in as types that implement
`IntoSystem`. However, the eventlistener callback crate allows users to
define their callbacks in normal systems, by boxing the system and
deferring initialization to an exclusive system.
## Solution
- Separate the registration of the system from the boxing of the system.
This is non-breaking, and adds a new method.
---
## Changelog
- Added `World::register_boxed_system` to allow registration of
already-boxed one shot systems.
# Objective
- There is a specialized hasher for entities:
[`EntityHashMap`](https://docs.rs/bevy/latest/bevy/utils/type.EntityHashMap.html)
- [`EntityMapper`] currently uses a normal `HashMap<Entity, Entity>`
- Fixes#10391
## Solution
- Replace the normal `HashMap` with the more performant `EntityHashMap`
## Questions
- This does change public API. Should a system be implemented to help
migrate code?
- Perhaps an `impl From<HashMap<K, V, S>> for EntityHashMap<K, V>`
- I updated to docs for each function that I changed, but I may have
missed something
---
## Changelog
- Changed `EntityMapper` to use `EntityHashMap` instead of normal
`HashMap`
## Migration Guide
If you are using the following types, update their listed methods to use
the new `EntityHashMap`. `EntityHashMap` has the same methods as the
normal `HashMap`, so you just need to replace the name.
### `EntityMapper`
- `get_map`
- `get_mut_map`
- `new`
- `world_scope`
### `ReflectMapEntities`
- `map_all_entities`
- `map_entities`
- `write_to_world`
### `InstanceInfo`
- `entity_map`
- This is a property, not a method.
---
This is my first time contributing in a while, and I'm not familiar with
the usage of `EntityMapper`. I changed the type definition and fixed all
errors, but there may have been things I've missed. Please keep an eye
out for me!
Preparing next 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
Align all error-like types to implement `Error`.
Fixes #10176
## Solution
- Derive `Error` on more types
- Refactor instances of manual implementations that could be derived
This adds thiserror as a dependency to bevy_transform, which might
increase compilation time -- but I don't know of any situation where you
might only use that but not any other crate that pulls in bevy_utils.
The `contributors` example has a `LoadContributorsError` type, but as
it's an example I have not updated it. Doing that would mean either
having a `use bevy_internal::utils::thiserror::Error;` in an example
file, or adding `thiserror` as a dev-dependency to the main `bevy`
crate.
---
## Changelog
- All `…Error` types now implement the `Error` trait
# Objective
First of all, this PR took heavy inspiration from #7760 and #5715. It
intends to also fix#5569, but with a slightly different approach.
This also fixes#9335 by reexporting `DynEq`.
## Solution
The advantage of this API is that we can intern a value without
allocating for zero-sized-types and for enum variants that have no
fields. This PR does this automatically in the `SystemSet` and
`ScheduleLabel` derive macros for unit structs and fieldless enum
variants. So this should cover many internal and external use cases of
`SystemSet` and `ScheduleLabel`. In these optimal use cases, no memory
will be allocated.
- The interning returns a `Interned<dyn SystemSet>`, which is just a
wrapper around a `&'static dyn SystemSet`.
- `Hash` and `Eq` are implemented in terms of the pointer value of the
reference, similar to my first approach of anonymous system sets in
#7676.
- Therefore, `Interned<T>` does not implement `Borrow<T>`, only `Deref`.
- The debug output of `Interned<T>` is the same as the interned value.
Edit:
- `AppLabel` is now also interned and the old
`derive_label`/`define_label` macros were replaced with the new
interning implementation.
- Anonymous set ids are reused for different `Schedule`s, reducing the
amount of leaked memory.
### Pros
- `InternedSystemSet` and `InternedScheduleLabel` behave very similar to
the current `BoxedSystemSet` and `BoxedScheduleLabel`, but can be copied
without an allocation.
- Many use cases don't allocate at all.
- Very fast lookups and comparisons when using `InternedSystemSet` and
`InternedScheduleLabel`.
- The `intern` module might be usable in other areas.
- `Interned{ScheduleLabel, SystemSet, AppLabel}` does implement
`{ScheduleLabel, SystemSet, AppLabel}`, increasing ergonomics.
### Cons
- Implementors of `SystemSet` and `ScheduleLabel` still need to
implement `Hash` and `Eq` (and `Clone`) for it to work.
## Changelog
### Added
- Added `intern` module to `bevy_utils`.
- Added reexports of `DynEq` to `bevy_ecs` and `bevy_app`.
### Changed
- Replaced `BoxedSystemSet` and `BoxedScheduleLabel` with
`InternedSystemSet` and `InternedScheduleLabel`.
- Replaced `impl AsRef<dyn ScheduleLabel>` with `impl ScheduleLabel`.
- Replaced `AppLabelId` with `InternedAppLabel`.
- Changed `AppLabel` to use `Debug` for error messages.
- Changed `AppLabel` to use interning.
- Changed `define_label`/`derive_label` to use interning.
- Replaced `define_boxed_label`/`derive_boxed_label` with
`define_label`/`derive_label`.
- Changed anonymous set ids to be only unique inside a schedule, not
globally.
- Made interned label types implement their label trait.
### Removed
- Removed `define_boxed_label` and `derive_boxed_label`.
## Migration guide
- Replace `BoxedScheduleLabel` and `Box<dyn ScheduleLabel>` with
`InternedScheduleLabel` or `Interned<dyn ScheduleLabel>`.
- Replace `BoxedSystemSet` and `Box<dyn SystemSet>` with
`InternedSystemSet` or `Interned<dyn SystemSet>`.
- Replace `AppLabelId` with `InternedAppLabel` or `Interned<dyn
AppLabel>`.
- Types manually implementing `ScheduleLabel`, `AppLabel` or `SystemSet`
need to implement:
- `dyn_hash` directly instead of implementing `DynHash`
- `as_dyn_eq`
- Pass labels to `World::try_schedule_scope`, `World::schedule_scope`,
`World::try_run_schedule`. `World::run_schedule`, `Schedules::remove`,
`Schedules::remove_entry`, `Schedules::contains`, `Schedules::get` and
`Schedules::get_mut` by value instead of by reference.
---------
Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Reduce code duplication and improve APIs of Bevy's [global
taskpools](https://github.com/bevyengine/bevy/blob/main/crates/bevy_tasks/src/usages.rs).
## Solution
- As all three of the global taskpools have identical implementations
and only differ in their identifiers, this PR moves the implementation
into a macro to reduce code duplication.
- The `init` method is renamed to `get_or_init` to more accurately
reflect what it really does.
- Add a new `try_get` method that just returns `None` when the pool is
uninitialized, to complement the other getter methods.
- Minor documentation improvements to accompany the above changes.
---
## Changelog
- Added a new `try_get` method to the global TaskPools
- The global TaskPools' `init` method has been renamed to `get_or_init`
for clarity
- Documentation improvements
## Migration Guide
- Uses of `ComputeTaskPool::init`, `AsyncComputeTaskPool::init` and
`IoTaskPool::init` should be changed to `::get_or_init`.
# Objective
Closes#9955.
Use the same interface for all "pure" builder types: taking and
returning `Self` (and not `&mut Self`).
## Solution
Changed `DynamicSceneBuilder`, `SceneFilter` and `TableBuilder` to take
and return `Self`.
## Changelog
### Changed
- `DynamicSceneBuilder` and `SceneBuilder` methods in `bevy_ecs` now
take and return `Self`.
## Migration guide
When using `bevy_ecs::DynamicSceneBuilder` and `bevy_ecs::SceneBuilder`,
instead of binding the builder to a variable, directly use it. Methods
on those types now consume `Self`, so you will need to re-bind the
builder if you don't `build` it immediately.
Before:
```rust
let mut scene_builder = DynamicSceneBuilder::from_world(&world);
let scene = scene_builder.extract_entity(a).extract_entity(b).build();
```
After:
```rust
let scene = DynamicSceneBuilder::from_world(&world)
.extract_entity(a)
.extract_entity(b)
.build();
```
# Objective
- Followup to #7184.
- ~Deprecate `TypeUuid` and remove its internal references.~ No longer
part of this PR.
- Use `TypePath` for the type registry, and (de)serialisation instead of
`std::any::type_name`.
- Allow accessing type path information behind proxies.
## Solution
- Introduce methods on `TypeInfo` and friends for dynamically querying
type path. These methods supersede the old `type_name` methods.
- Remove `Reflect::type_name` in favor of `DynamicTypePath::type_path`
and `TypeInfo::type_path_table`.
- Switch all uses of `std::any::type_name` in reflection, non-debugging
contexts to use `TypePath`.
---
## Changelog
- Added `TypePathTable` for dynamically accessing methods on `TypePath`
through `TypeInfo` and the type registry.
- Removed `type_name` from all `TypeInfo`-like structs.
- Added `type_path` and `type_path_table` methods to all `TypeInfo`-like
structs.
- Removed `Reflect::type_name` in favor of
`DynamicTypePath::reflect_type_path` and `TypeInfo::type_path`.
- Changed the signature of all `DynamicTypePath` methods to return
strings with a static lifetime.
## Migration Guide
- Rely on `TypePath` instead of `std::any::type_name` for all stability
guarantees and for use in all reflection contexts, this is used through
with one of the following APIs:
- `TypePath::type_path` if you have a concrete type and not a value.
- `DynamicTypePath::reflect_type_path` if you have an `dyn Reflect`
value without a concrete type.
- `TypeInfo::type_path` for use through the registry or if you want to
work with the represented type of a `DynamicFoo`.
- Remove `type_name` from manual `Reflect` implementations.
- Use `type_path` and `type_path_table` in place of `type_name` on
`TypeInfo`-like structs.
- Use `get_with_type_path(_mut)` over `get_with_type_name(_mut)`.
## Note to reviewers
I think if anything we were a little overzealous in merging #7184 and we
should take that extra care here.
In my mind, this is the "point of no return" for `TypePath` and while I
think we all agree on the design, we should carefully consider if the
finer details and current implementations are actually how we want them
moving forward.
For example [this incorrect `TypePath` implementation for
`String`](3fea3c6c0b/crates/bevy_reflect/src/impls/std.rs (L90))
(note that `String` is in the default Rust prelude) snuck in completely
under the radar.
# Objective
- Updates for rust 1.73
## Solution
- new doc check for `redundant_explicit_links`
- updated to text for compile fail tests
---
## Changelog
- updates for rust 1.73
# Objective
- Fixes#9884
- Add API for ignoring ambiguities on certain resource or components.
## Solution
- Add a `IgnoreSchedulingAmbiguitiy` resource to the world which holds
the `ComponentIds` to be ignored
- Filter out ambiguities with those component id's.
## Changelog
- add `allow_ambiguous_component` and `allow_ambiguous_resource` apis
for ignoring ambiguities
---------
Co-authored-by: Ryan Johnson <ryanj00a@gmail.com>
Objective
---------
- Since #6742, It is not possible to build an `ArchetypeId` from a
`ArchetypeGeneration`
- This was useful to 3rd party crate extending the base bevy ECS
capabilities, such as [`bevy_ecs_dynamic`] and now
[`bevy_mod_dynamic_query`]
- Making `ArchetypeGeneration` opaque this way made it completely
useless, and removed the ability to limit archetype updates to a subset
of archetypes.
- Making the `index` method on `ArchetypeId` private prevented the use
of bitfields and other optimized data structure to store sets of
archetype ids. (without `transmute`)
This PR is not a simple reversal of the change. It exposes a different
API, rethought to keep the private stuff private and the public stuff
less error-prone.
- Add a `StartRange<ArchetypeGeneration>` `Index` implementation to
`Archetypes`
- Instead of converting the generation into an index, then creating a
ArchetypeId from that index, and indexing `Archetypes` with it, use
directly the old `ArchetypeGeneration` to get the range of new
archetypes.
From careful benchmarking, it seems to also be a performance improvement
(~0-5%) on add_archetypes.
---
Changelog
---------
- Added `impl Index<RangeFrom<ArchetypeGeneration>> for Archetypes` this
allows you to get a slice of newly added archetypes since the last
recorded generation.
- Added `ArchetypeId::index` and `ArchetypeId::new` methods. It should
enable 3rd party crates to use the `Archetypes` API in a meaningful way.
[`bevy_ecs_dynamic`]:
https://github.com/jakobhellermann/bevy_ecs_dynamic/tree/main
[`bevy_mod_dynamic_query`]:
https://github.com/nicopap/bevy_mod_dynamic_query/
---------
Co-authored-by: vero <email@atlasdostal.com>
# Objective
We've done a lot of work to remove the pattern of a `&World` with
interior mutability (#6404, #8833). However, this pattern still persists
within `bevy_ecs` via the `unsafe_world` method.
## Solution
* Make `unsafe_world` private. Adjust any callsites to use
`UnsafeWorldCell` for interior mutability.
* Add `UnsafeWorldCell::removed_components`, since it is always safe to
access the removed components collection through `UnsafeWorldCell`.
## Future Work
Remove/hide `UnsafeWorldCell::world_metadata`, once we have provided
safe ways of accessing all world metadata.
---
## Changelog
+ Added `UnsafeWorldCell::removed_components`, which provides read-only
access to a world's collection of removed components.
# Objective
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.
