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107 commits

Author SHA1 Message Date
Gino Valente
2b4180ca8f
bevy_reflect: Function reflection terminology refactor (#14813)
# Objective

One of the changes in #14704 made `DynamicFunction` effectively the same
as `DynamicClosure<'static>`. This change meant that the de facto
function type would likely be `DynamicClosure<'static>` instead of the
intended `DynamicFunction`, since the former is much more flexible.

We _could_ explore ways of making `DynamicFunction` implement `Copy`
using some unsafe code, but it likely wouldn't be worth it. And users
would likely still reach for the convenience of
`DynamicClosure<'static>` over the copy-ability of `DynamicFunction`.

The goal of this PR is to fix this confusion between the two types.

## Solution

Firstly, the `DynamicFunction` type was removed. Again, it was no
different than `DynamicClosure<'static>` so it wasn't a huge deal to
remove.

Secondly, `DynamicClosure<'env>` and `DynamicClosureMut<'env>` were
renamed to `DynamicFunction<'env>` and `DynamicFunctionMut<'env>`,
respectively.

Yes, we still ultimately kept the naming of `DynamicFunction`, but
changed its behavior to that of `DynamicClosure<'env>`. We need a term
to refer to both functions and closures, and "function" was the best
option.


[Originally](https://discord.com/channels/691052431525675048/1002362493634629796/1274091992162242710),
I was going to go with "callable" as the replacement term to encompass
both functions and closures (e.g. `DynamciCallable<'env>`). However, it
was
[suggested](https://discord.com/channels/691052431525675048/1002362493634629796/1274653581777047625)
by @SkiFire13 that the simpler "function" term could be used instead.

While "callable" is perhaps the better umbrella term—being truly
ambiguous over functions and closures— "function" is more familiar, used
more often, easier to discover, and is subjectively just
"better-sounding".

## Testing

Most changes are purely swapping type names or updating documentation,
but you can verify everything still works by running the following
command:

```
cargo test --package bevy_reflect
```
2024-08-19 21:52:36 +00:00
re0312
3bd039e821
Skip empty archetype/table (#14749)
# Objective

- As sander commneted on discord
[link](https://discord.com/channels/691052431525675048/749335865876021248/1273414144091230228),

![image](https://github.com/user-attachments/assets/62f2b6f3-1aaf-49d9-bafa-bf62b83b10be)





## Performance

![image](https://github.com/user-attachments/assets/11122940-1547-42ae-9576-0e1a93fd9f5f)

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Giacomo Stevanato <giaco.stevanato@gmail.com>
2024-08-15 14:07:20 +00:00
Mike
3d460e98ec
Fix CI bench compile check (#14728)
# Objective

- Fixes #14723 

## Solution

- add the manifest path to the cargo command

## Testing

- ran `cargo run -p ci -- bench-check` locally
2024-08-14 13:23:00 +00:00
Matty
4ace888e4b
Fix broken bezier curve benchmark (#14677)
# Objective

Apparently #14382 broke this, but it's not a part of CI, so it wasn't
found until earlier today.

## Solution

Update the benchmark like we updated the examples.

## Testing

Running `cargo bench` actually works now.
2024-08-12 16:10:11 +00:00
Gino Valente
91fa4bb649
bevy_reflect: Function reflection benchmarks (#14647)
# Objective

It would be good to have benchmarks handy for function reflection as it
continues to be worked on.

## Solution

Add some basic benchmarks for function reflection.

## Testing

To test locally, run the following in the `benches` directory:

```
cargo bench --bench reflect_function
```

## Results

Here are a couple of the results (M1 Max MacBook Pro):

<img width="936" alt="Results of benching calling functions vs closures
via reflection. Closures average about 40ns, while functions average
about 55ns"
src="https://github.com/user-attachments/assets/b9a6c585-5fbe-43db-9a7b-f57dbd3815e3">
<img width="936" alt="Results of benching converting functions vs
closures into their dynamic representations. Closures average about
34ns, while functions average about 37ns"
src="https://github.com/user-attachments/assets/4614560a-7192-4c1e-9ade-7bc5a4ca68e3">

Currently, it seems `DynamicClosure` is just a bit more performant. This
is likely due to the fact that `DynamicFunction` stores its function
object in an `Arc` instead of a `Box` so that it can be `Send + Sync`
(and also `Clone`).

We'll likely need to do the same for `DynamicClosure` so I suspect these
results to change in the near future.
2024-08-11 03:02:06 +00:00
Robert Walter
70a18d26e2
Glam 0.28 update - adopted (#14613)
Basically it's https://github.com/bevyengine/bevy/pull/13792 with the
bumped versions of `encase` and `hexasphere`.

---------

Co-authored-by: Robert Swain <robert.swain@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-08-06 01:28:00 +00:00
Periwink
ec4cf024f8
Add a ComponentIndex and update QueryState creation/update to use it (#13460)
# Objective

To implement relations we will need to add a `ComponentIndex`, which is
a map from a Component to the list of archetypes that contain this
component.
One of the reasons is that with fragmenting relations the number of
archetypes will explode, so it will become inefficient to create and
update the query caches by iterating through the list of all archetypes.

In this PR, we introduce the `ComponentIndex`, and we update the
`QueryState` to make use of it:
- if a query has at least 1 required component (i.e. something other
than `()`, `Entity` or `Option<>`, etc.): for each of the required
components we find the list of archetypes that contain it (using the
ComponentIndex). Then, we select the smallest list among these. This
gives a small subset of archetypes to iterate through compared with
iterating through all new archetypes
- if it doesn't, then we keep using the current approach of iterating
through all new archetypes


# Implementation
- This breaks query iteration order, in the sense that we are not
guaranteed anymore to return results in the order in which the
archetypes were created. I think this should be fine because this wasn't
an explicit bevy guarantee so users should not be relying on this. I
updated a bunch of unit tests that were failing because of this.

- I had an issue with the borrow checker because iterating the list of
potential archetypes requires access to `&state.component_access`, which
was conflicting with the calls to
```
  if state.new_archetype_internal(archetype) {
      state.update_archetype_component_access(archetype, access);
  }
```
which need a mutable access to the state.

The solution I chose was to introduce a `QueryStateView` which is a
temporary view into the `QueryState` which enables a "split-borrows"
kind of approach. It is described in detail in this blog post:
https://smallcultfollowing.com/babysteps/blog/2018/11/01/after-nll-interprocedural-conflicts/

# Test

The unit tests pass.

Benchmark results:
```
❯ critcmp main pr
group                                  main                                   pr
-----                                  ----                                   --
iter_fragmented/base                   1.00   342.2±25.45ns        ? ?/sec    1.02   347.5±16.24ns        ? ?/sec
iter_fragmented/foreach                1.04   165.4±11.29ns        ? ?/sec    1.00    159.5±4.27ns        ? ?/sec
iter_fragmented/foreach_wide           1.03      3.3±0.04µs        ? ?/sec    1.00      3.2±0.06µs        ? ?/sec
iter_fragmented/wide                   1.03      3.1±0.06µs        ? ?/sec    1.00      3.0±0.08µs        ? ?/sec
iter_fragmented_sparse/base            1.00      6.5±0.14ns        ? ?/sec    1.02      6.6±0.08ns        ? ?/sec
iter_fragmented_sparse/foreach         1.00      6.3±0.08ns        ? ?/sec    1.04      6.6±0.08ns        ? ?/sec
iter_fragmented_sparse/foreach_wide    1.00     43.8±0.15ns        ? ?/sec    1.02     44.6±0.53ns        ? ?/sec
iter_fragmented_sparse/wide            1.00     29.8±0.44ns        ? ?/sec    1.00     29.8±0.26ns        ? ?/sec
iter_simple/base                       1.00      8.2±0.10µs        ? ?/sec    1.00      8.2±0.09µs        ? ?/sec
iter_simple/foreach                    1.00      3.8±0.02µs        ? ?/sec    1.02      3.9±0.03µs        ? ?/sec
iter_simple/foreach_sparse_set         1.00     19.0±0.26µs        ? ?/sec    1.01     19.3±0.16µs        ? ?/sec
iter_simple/foreach_wide               1.00     17.8±0.24µs        ? ?/sec    1.00     17.9±0.31µs        ? ?/sec
iter_simple/foreach_wide_sparse_set    1.06     95.6±6.23µs        ? ?/sec    1.00     90.6±0.59µs        ? ?/sec
iter_simple/sparse_set                 1.00     19.3±1.63µs        ? ?/sec    1.01     19.5±0.29µs        ? ?/sec
iter_simple/system                     1.00      8.1±0.10µs        ? ?/sec    1.00      8.1±0.09µs        ? ?/sec
iter_simple/wide                       1.05     37.7±2.53µs        ? ?/sec    1.00     35.8±0.57µs        ? ?/sec
iter_simple/wide_sparse_set            1.00     95.7±1.62µs        ? ?/sec    1.00     95.9±0.76µs        ? ?/sec
par_iter_simple/with_0_fragment        1.04     35.0±2.51µs        ? ?/sec    1.00     33.7±0.49µs        ? ?/sec
par_iter_simple/with_1000_fragment     1.00     50.4±2.52µs        ? ?/sec    1.01     51.0±3.84µs        ? ?/sec
par_iter_simple/with_100_fragment      1.02     40.3±2.23µs        ? ?/sec    1.00     39.5±1.32µs        ? ?/sec
par_iter_simple/with_10_fragment       1.14     38.8±7.79µs        ? ?/sec    1.00     34.0±0.78µs        ? ?/sec
```
2024-08-06 00:57:15 +00:00
re0312
8235daaea0
Opportunistically use dense iteration for archetypal iteration (#14049)
# Objective
- currently, bevy employs sparse iteration if any of the target
components in the query are stored in a sparse set. it may lead to
increased cache misses in some cases, potentially impacting performance.
- partial fixes #12381 

## Solution

- use dense iteration when an archetype and its table have the same
entity count.
- to avoid introducing complicate unsafe noise, this pr only implement
for `for_each ` style iteration.
- added a benchmark to test performance for hybrid iteration.


## Performance


![image](https://github.com/bevyengine/bevy/assets/45868716/5cce13cf-6ff2-4861-9576-e75edc63bd46)

nearly 2x win in specific scenarios, and no performance degradation in
other test cases.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Christian Hughes <9044780+ItsDoot@users.noreply.github.com>
2024-08-02 21:18:15 +00:00
re0312
e5bf59d712
Recalibrated observe benchmark (#14381)
# Objective

- The event propagation benchmark is largely derived from
bevy_eventlistener. However, it doesn't accurately reflect performance
of bevy side, as our event bubble propagation is based on observer.


## Solution

- added several new benchmarks that focuse on observer itself rather
than event bubble
2024-07-18 18:25:33 +00:00
Miles Silberling-Cook
ed2b8e0f35
Minimal Bubbling Observers (#13991)
# Objective

Add basic bubbling to observers, modeled off `bevy_eventlistener`.

## Solution

- Introduce a new `Traversal` trait for components which point to other
entities.
- Provide a default `TraverseNone: Traversal` component which cannot be
constructed.
- Implement `Traversal` for `Parent`.
- The `Event` trait now has an associated `Traversal` which defaults to
`TraverseNone`.
- Added a field `bubbling: &mut bool` to `Trigger` which can be used to
instruct the runner to bubble the event to the entity specified by the
event's traversal type.
- Added an associated constant `SHOULD_BUBBLE` to `Event` which
configures the default bubbling state.
- Added logic to wire this all up correctly.

Introducing the new associated information directly on `Event` (instead
of a new `BubblingEvent` trait) lets us dispatch both bubbling and
non-bubbling events through the same api.

## Testing

I have added several unit tests to cover the common bugs I identified
during development. Running the unit tests should be enough to validate
correctness. The changes effect unsafe portions of the code, but should
not change any of the safety assertions.

## Changelog

Observers can now bubble up the entity hierarchy! To create a bubbling
event, change your `Derive(Event)` to something like the following:

```rust
#[derive(Component)]
struct MyEvent;

impl Event for MyEvent {
    type Traverse = Parent; // This event will propagate up from child to parent.
    const AUTO_PROPAGATE: bool = true; // This event will propagate by default.
}
```

You can dispatch a bubbling event using the normal
`world.trigger_targets(MyEvent, entity)`.

Halting an event mid-bubble can be done using
`trigger.propagate(false)`. Events with `AUTO_PROPAGATE = false` will
not propagate by default, but you can enable it using
`trigger.propagate(true)`.

If there are multiple observers attached to a target, they will all be
triggered by bubbling. They all share a bubbling state, which can be
accessed mutably using `trigger.propagation_mut()` (`trigger.propagate`
is just sugar for this).

You can choose to implement `Traversal` for your own types, if you want
to bubble along a different structure than provided by `bevy_hierarchy`.
Implementers must be careful never to produce loops, because this will
cause bevy to hang.

## Migration Guide
+ Manual implementations of `Event` should add associated type `Traverse
= TraverseNone` and associated constant `AUTO_PROPAGATE = false`;
+ `Trigger::new` has new field `propagation: &mut Propagation` which
provides the bubbling state.
+ `ObserverRunner` now takes the same `&mut Propagation` as a final
parameter.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Torstein Grindvik <52322338+torsteingrindvik@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2024-07-15 13:39:41 +00:00
re0312
f0bdce7425
Fair Change Detection Benchmarking (#11173)
# Objective

- #4972 introduce a benchmark to measure chang detection performance
- However,it uses `iter_batch ` cause a lot of overhead in clone data to
each routine closure(it feels like a bug in`iter_batch `) and constructs
new query in every iter.This overhead masks the real change detection
throughput we want to measure. Instead of evaluating raw change
detection, the benchmark ends up dominated by data cloning and
allocation costs.


## Solution

- Use iter_batch_ref to reduce the benchmark overload 
- Use cached query to better reflect real-world usage scenarios.
- Add more benmark

---

## Changelog
2024-06-26 12:46:41 +00:00
charlotte
4c3b7679ec
#12502 Remove limit on RenderLayers. (#13317)
# Objective

Remove the limit of `RenderLayer` by using a growable mask using
`SmallVec`.

Changes adopted from @UkoeHB's initial PR here
https://github.com/bevyengine/bevy/pull/12502 that contained additional
changes related to propagating render layers.

Changes

## Solution

The main thing needed to unblock this is removing `RenderLayers` from
our shader code. This primarily affects `DirectionalLight`. We are now
computing a `skip` field on the CPU that is then used to skip the light
in the shader.

## Testing

Checked a variety of examples and did a quick benchmark on `many_cubes`.
There were some existing problems identified during the development of
the original pr (see:
https://discord.com/channels/691052431525675048/1220477928605749340/1221190112939872347).
This PR shouldn't change any existing behavior besides removing the
layer limit (sans the comment in migration about `all` layers no longer
being possible).

---

## Changelog

Removed the limit on `RenderLayers` by using a growable bitset that only
allocates when layers greater than 64 are used.

## Migration Guide

- `RenderLayers::all()` no longer exists. Entities expecting to be
visible on all layers, e.g. lights, should compute the active layers
that are in use.

---------

Co-authored-by: robtfm <50659922+robtfm@users.noreply.github.com>
2024-05-16 16:15:47 +00:00
andristarr
bb76a2c69c
multi_threaded feature rename (#12997)
# Objective

Fixes #12966

## Solution

Renaming multi_threaded feature to match snake case

## Migration Guide

Bevy feature multi-threaded should be refered to multi_threaded from now
on.
2024-05-06 20:49:32 +00:00
Martín Maita
32cd0c5dc1
Update glam version requirement from 0.25 to 0.27 (#12757)
# Objective

- Update glam version requirement to latest version.

## Solution

- Updated `glam` version requirement from 0.25 to 0.27.
- Updated `encase` and `encase_derive_impl` version requirement from 0.7
to 0.8.
- Updated `hexasphere` version requirement from 10.0 to 12.0.
- Breaking changes from glam changelog:
- [0.26.0] Minimum Supported Rust Version bumped to 1.68.2 for impl
From<bool> for {f32,f64} support.
- [0.27.0] Changed implementation of vector fract method to match the
Rust implementation instead of the GLSL implementation, that is self -
self.trunc() instead of self - self.floor().

---

## Migration Guide

- When using `glam` exports, keep in mind that `vector` `fract()` method
now matches Rust implementation (that is `self - self.trunc()` instead
of `self - self.floor()`). If you want to use the GLSL implementation
you should now use `fract_gl()`.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2024-05-02 18:42:34 +00:00
BD103
9ee02e87d3
Remove version field for non-publish crates and update descriptions (#13100)
# Objective

- The [`version`] field in `Cargo.toml` is optional for crates not
published on <https://crates.io>.
- We have several `publish = false` tools in this repository that still
have a version field, even when it's not useful.

[`version`]:
https://doc.rust-lang.org/cargo/reference/manifest.html#the-version-field

## Solution

- Remove the [`version`] field for all crates where `publish = false`.
- Update the description on a few crates and remove extra newlines as
well.
2024-04-26 11:55:03 +00:00
re0312
4ca8cf5d66
Cluster small table/archetype into single Task in parallel iteration (#12846)
# 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
2024-04-04 07:09:26 +00:00
Cameron
01649f13e2
Refactor App and SubApp internals for better separation (#9202)
# Objective

This is a necessary precursor to #9122 (this was split from that PR to
reduce the amount of code to review all at once).

Moving `!Send` resource ownership to `App` will make it unambiguously
`!Send`. `SubApp` must be `Send`, so it can't wrap `App`.

## Solution

Refactor `App` and `SubApp` to not have a recursive relationship. Since
`SubApp` no longer wraps `App`, once `!Send` resources are moved out of
`World` and into `App`, `SubApp` will become unambiguously `Send`.

There could be less code duplication between `App` and `SubApp`, but
that would break `App` method chaining.

## Changelog

- `SubApp` no longer wraps `App`.
- `App` fields are no longer publicly accessible.
- `App` can no longer be converted into a `SubApp`.
- Various methods now return references to a `SubApp` instead of an
`App`.
## Migration Guide

- To construct a sub-app, use `SubApp::new()`. `App` can no longer
convert into `SubApp`.
- If you implemented a trait for `App`, you may want to implement it for
`SubApp` as well.
- If you're accessing `app.world` directly, you now have to use
`app.world()` and `app.world_mut()`.
- `App::sub_app` now returns `&SubApp`.
- `App::sub_app_mut`  now returns `&mut SubApp`.
- `App::get_sub_app` now returns `Option<&SubApp>.`
- `App::get_sub_app_mut` now returns `Option<&mut SubApp>.`
2024-03-31 03:16:10 +00:00
W. Black
622f9a35b6
Torus benchmark (#12781)
# Objective

- Primitive meshing is suboptimal
- Improve primitive meshing

## Solution

- Add primitive meshing benchmark
- Allows measuring future improvements

---

First of a few PRs to refactor and improve primitive meshing.
2024-03-29 20:30:26 +00:00
targrub
13cbb9cf10
Move commands module into bevy::ecs::world (#12234)
# 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.
2024-03-02 23:13:45 +00:00
James Liu
bc82749012
Remove APIs deprecated in 0.13 (#11974)
# 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.
2024-02-19 19:04:47 +00:00
David M. Lary
0dccfb5788
Stepping disabled performance fix (#11959)
# 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
2024-02-19 17:02:14 +00:00
Doonv
1c67e020f7
Move EntityHash related types into bevy_ecs (#11498)
# 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`.
2024-02-12 15:02:24 +00:00
BD103
3d2d61d063
Use batch spawn in benchmarks (#11611)
# Objective

- The benchmarks for `bevy_ecs`' `iter_simple` group use `for` loops
instead of `World::spawn_batch`.
- There's a TODO comment that says to batch spawn them.

## Solution

- Replace the `for` loops with `World::spawn_batch`.
2024-02-01 19:23:09 +00:00
Doonv
99449931d2
Add README to benches (#11508)
# Objective

It is unclear how to run Bevy's benchmarks

## Solution

Add a README to the benches, with documentation that tells you what the
benchmarks are, and how to run them.

---------

Co-authored-by: Rob Parrett <robparrett@gmail.com>
2024-01-24 17:11:28 +00:00
Natalie Bonnibel Baker
b257fffef8
Change Entity::generation from u32 to NonZeroU32 for niche optimization (#9907)
# 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>
2024-01-08 23:03:00 +00:00
irate
ec14e946b8
Update glam, encase and hexasphere (#11082)
Update to `glam` 0.25, `encase` 0.7 and `hexasphere` to 10.0

## Changelog
Added the `FloatExt` trait to the `bevy_math` prelude which adds `lerp`,
`inverse_lerp` and `remap` methods to the `f32` and `f64` types.
2024-01-08 22:58:45 +00:00
James Liu
2148518758
Override QueryIter::fold to port Query::for_each perf gains to select Iterator combinators (#6773)
# 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>
2023-12-01 09:09:55 +00:00
Zachary Harrold
52c11f6986
Ran cargo fmt on benches crate (#10758)
# Objective

- Format `benches` crate to match current Rust standards.

## Solution

- Ran `cargo fmt` in the `benches` crate.

## Notes

I accidentally came across this when working on the `Drop`
implementation for `CommandQueue` and rather embarrassingly let it sneak
into my PR there. I think it makes sense to ensure this crate is also
well formatted to avoid it in the future.
2023-11-27 18:41:35 +00:00
scottmcm
713b1d8fa4
Optimize Entity::eq (#10519)
(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:

![image](https://github.com/bevyengine/bevy/assets/18526288/24226308-4616-4082-b0ff-88fc06285ef1)

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):

![image](https://github.com/bevyengine/bevy/assets/18526288/58bb8c96-9c45-487f-a5ab-544bbfe9fba0)

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.)
2023-11-14 02:06:21 +00:00
Pixelstorm
faa1b57de5
Global TaskPool API improvements (#10008)
# 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`.
2023-10-23 20:48:48 +00:00
Nicola Papale
47409c8a72
Add inline(never) to bench systems (#9824)
# Objective

It is difficult to inspect the generated assembly of benchmark systems
using a tool such as `cargo-asm`

## Solution

Mark the related functions as `#[inline(never)]`. This way, you can pass
the module name as argument to `cargo-asm` to get the generated assembly
for the given function.

It may have as side effect to make benchmarks a bit more predictable and
useful too. As it prevents inlining where in bevy no inlining could
possibly take place.

### Measurements

Following the recommendations in
<https://easyperf.net/blog/2019/08/02/Perf-measurement-environment-on-Linux>,
I

1. Put my CPU in "AMD ECO" mode, which surprisingly is the equivalent of
disabling turboboost, giving more consistent performances
2. Disabled all hyperthreading cores using `echo 0 >
/sys/devices/system/cpu/cpu{11,12…}/online`
3. Set the scaling governor to `performance`
4. Manually disabled AMD boost with `echo 0 >
/sys/devices/system/cpu/cpufreq/boost`
5. Set the nice level of the criterion benchmark using `cargo bench … &
sudo renice -n -5 -p $! ; fg`
6. Not running any other program than the benchmarks (outside of system
daemons and the X11 server)

With this setup, running multiple times the same benchmarks on `main`
gives me a lot of "regression" and "improvement" messages, which is
absurd given that no code changed.

On this branch, there is still some spurious performance change
detection, but they are much less frequent.

This only accounts for `iter_simple` and `iter_frag` benchmarks of
course.
2023-10-02 12:52:18 +00:00
Nicola Papale
359e6c718d
Use single threaded executor for archetype benches (#9835)
# Objective

`no_archetype` benchmark group results were very noisy

## Solution

Use the `SingeThreaded` executor.

On my machine, this makes the `no_archetype` bench group 20 to 30 times
faster. Meaning that most of the runtime was accounted by the
multithreaded scheduler. ie: the benchmark was not testing system
archetype update, but the overhead of multithreaded scheduling.

With this change, the benchmark results are more meaningful.

The add_archetypes function is also simplified.
2023-09-18 16:06:42 +00:00
Mike
c61faf35b8
fix deprecation warning in bench (#9823)
# Objective

- Fix deprecation warning when running benches.

## Solution

- iter -> read
2023-09-16 09:27:13 +00:00
Joseph
8eb6ccdd87
Remove useless single tuples and trailing commas (#9720)
# Objective

Title
2023-09-08 21:46:54 +00:00
Nicola Papale
ee3cc8ca86
Fix erronenous glam version (#9653)
# Objective

- Fix compilation issue with wrongly specified glam version
- bevy uses `Vec2::INFINITY`, depends on `0.24` (equivalent to `0.24.0`)
yet it was only introduced in version `0.24.1`

Context:
https://discord.com/channels/691052431525675048/692572690833473578/1146586570787397794

## Solution

- Bump glam version.
2023-08-31 12:55:17 +00:00
Mike
33fdc5f5db
Move schedule name into Schedule (#9600)
# Objective

- Move schedule name into `Schedule` to allow the schedule name to be
used for errors and tracing in Schedule methods
- Fixes #9510

## Solution

- Move label onto `Schedule` and adjust api's on `World` and `Schedule`
to not pass explicit label where it makes sense to.
- add name to errors and tracing.
- `Schedule::new` now takes a label so either add the label or use
`Schedule::default` which uses a default label. `default` is mostly used
in doc examples and tests.

---

## Changelog

- move label onto `Schedule` to improve error message and logging for
schedules.

## Migration Guide

`Schedule::new` and `App::add_schedule`
```rust
// old
let schedule = Schedule::new();
app.add_schedule(MyLabel, schedule);

// new
let schedule = Schedule::new(MyLabel);
app.add_schedule(schedule);
```

if you aren't using a label and are using the schedule struct directly
you can use the default constructor.
```rust
// old
let schedule = Schedule::new();
schedule.run(world);

// new
let schedule = Schedule::default();
schedule.run(world);
```

`Schedules:insert`
```rust
// old
let schedule = Schedule::new();
schedules.insert(MyLabel, schedule);

// new
let schedule = Schedule::new(MyLabel);
schedules.insert(schedule);
```

`World::add_schedule`
```rust
// old
let schedule = Schedule::new();
world.add_schedule(MyLabel, schedule);

// new
let schedule = Schedule::new(MyLabel);
world.add_schedule(schedule);
```
2023-08-28 20:44:48 +00:00
jnhyatt
087a345579
Rename Bezier to CubicBezier for clarity (#9554)
# Objective

A Bezier curve is a curve defined by two or more control points. In the
simplest form, it's just a line. The (arguably) most common type of
Bezier curve is a cubic Bezier, defined by four control points. These
are often used in animation, etc. Bevy has a Bezier curve struct called
`Bezier`. However, this is technically a misnomer as it only represents
cubic Bezier curves.

## Solution

This PR changes the struct name to `CubicBezier` to more accurately
reflect the struct's usage. Since it's exposed in Bevy's prelude, it can
potentially collide with other `Bezier` implementations. While that
might instead be an argument for removing it from the prelude, there's
also something to be said for adding a more general `Bezier` into Bevy,
in which case we'd likely want to use the name `Bezier`. As a final
motivator, not only is the struct located in `cubic_spines.rs`, there
are also several other spline-related structs which follow the
`CubicXxx` naming convention where applicable. For example,
`CubicSegment` represents a cubic Bezier curve (with coefficients
pre-baked).

---

## Migration Guide

- Change all `Bezier` references to `CubicBezier`
2023-08-28 17:37:42 +00:00
Nicola Papale
7b0809b532
Add reflect path parsing benchmark (#9364)
# Objective

We want to measure performance on path reflection parsing.

## Solution

Benchmark path-based reflection:
- Add a benchmark for `ParsedPath::parse`

It's fairly noisy, this is why I added the 3% threshold.

Ideally we would fix the noisiness though. Supposedly I'm seeding the
RNG correctly, so there shouldn't be much observable variance. Maybe
someone can help spot the issue.
2023-08-25 14:30:26 +00:00
Mike
ac8f36743e
enable multithreading on benches (#9388)
# Objective

- Enable the new multithreading feature on benches
2023-08-11 22:08:36 +00:00
Joseph
ddbfa48711
Simplify parallel iteration methods (#8854)
# Objective

The `QueryParIter::for_each_mut` function is required when doing
parallel iteration with mutable queries.
This results in an unfortunate stutter:
`query.par_iter_mut().par_for_each_mut()` ('mut' is repeated).

## Solution

- Make `for_each` compatible with mutable queries, and deprecate
`for_each_mut`. In order to prevent `for_each` from being called
multiple times in parallel, we take ownership of the QueryParIter.

---

## Changelog

- `QueryParIter::for_each` is now compatible with mutable queries.
`for_each_mut` has been deprecated as it is now redundant.

## Migration Guide

The method `QueryParIter::for_each_mut` has been deprecated and is no
longer functional. Use `for_each` instead, which now supports mutable
queries.

```rust
// Before:
query.par_iter_mut().for_each_mut(|x| ...);

// After:
query.par_iter_mut().for_each(|x| ...);
```

The method `QueryParIter::for_each` now takes ownership of the
`QueryParIter`, rather than taking a shared reference.

```rust
// Before:
let par_iter = my_query.par_iter().batching_strategy(my_batching_strategy);
par_iter.for_each(|x| {
    // ...Do stuff with x...
    par_iter.for_each(|y| {
        // ...Do nested stuff with y...
    });
});

// After:
my_query.par_iter().batching_strategy(my_batching_strategy).for_each(|x| {
    // ...Do stuff with x...
    my_query.par_iter().batching_strategy(my_batching_strategy).for_each(|y| {
        // ...Do nested stuff with y...
    });
});
```
2023-07-23 11:09:24 +00:00
JoJoJet
db8d3651e0
Migrate the rest of the engine to UnsafeWorldCell (#8833)
# Objective

Follow-up to #6404 and #8292.

Mutating the world through a shared reference is surprising, and it
makes the meaning of `&World` unclear: sometimes it gives read-only
access to the entire world, and sometimes it gives interior mutable
access to only part of it.

This is an up-to-date version of #6972.

## Solution

Use `UnsafeWorldCell` for all interior mutability. Now, `&World`
*always* gives you read-only access to the entire world.

---

## Changelog

TODO - do we still care about changelogs?

## Migration Guide

Mutating any world data using `&World` is now considered unsound -- the
type `UnsafeWorldCell` must be used to achieve interior mutability. The
following methods now accept `UnsafeWorldCell` instead of `&World`:

- `QueryState`: `get_unchecked`, `iter_unchecked`,
`iter_combinations_unchecked`, `for_each_unchecked`,
`get_single_unchecked`, `get_single_unchecked_manual`.
- `SystemState`: `get_unchecked_manual`

```rust
let mut world = World::new();
let mut query = world.query::<&mut T>();

// Before:
let t1 = query.get_unchecked(&world, entity_1);
let t2 = query.get_unchecked(&world, entity_2);

// After:
let world_cell = world.as_unsafe_world_cell();
let t1 = query.get_unchecked(world_cell, entity_1);
let t2 = query.get_unchecked(world_cell, entity_2);
```

The methods `QueryState::validate_world` and
`SystemState::matches_world` now take a `WorldId` instead of `&World`:

```rust
// Before:
query_state.validate_world(&world);

// After:
query_state.validate_world(world.id());
```

The methods `QueryState::update_archetypes` and
`SystemState::update_archetypes` now take `UnsafeWorldCell` instead of
`&World`:

```rust
// Before:
query_state.update_archetypes(&world);

// After:
query_state.update_archetypes(world.as_unsafe_world_cell_readonly());
```
2023-06-15 01:31:56 +00:00
Natanael Mojica
f135535cd6
Rename Command's "write" method to "apply" (#8814)
# Objective

- Fixes #8811 .

## Solution

- Rename "write" method to "apply" in Command trait definition.
- Rename other implementations of command trait throughout bevy's code
base.

---

## Changelog

- Changed: `Command::write` has been changed to `Command::apply`
- Changed: `EntityCommand::write` has been changed to
`EntityCommand::apply`

## Migration Guide

- `Command::write` implementations need to be changed to implement
`Command::apply` instead. This is a mere name change, with no further
actions needed.
- `EntityCommand::write` implementations need to be changed to implement
`EntityCommand::apply` instead. This is a mere name change, with no
further actions needed.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2023-06-12 17:53:47 +00:00
CatThingy
89cbc78d3d
Require #[derive(Event)] on all Events (#7086)
# Objective

Be consistent with `Resource`s and `Components` and have `Event` types
be more self-documenting.
Although not susceptible to accidentally using a function instead of a
value due to `Event`s only being initialized by their type, much of the
same reasoning for removing the blanket impl on `Resource` also applies
here.

* Not immediately obvious if a type is intended to be an event
* Prevent invisible conflicts if the same third-party or primitive types
are used as events
* Allows for further extensions (e.g. opt-in warning for missed events)

## Solution

Remove the blanket impl for the `Event` trait. Add a derive macro for
it.

---

## Changelog

- `Event` is no longer implemented for all applicable types. Add the
`#[derive(Event)]` macro for events.

## Migration Guide

* Add the `#[derive(Event)]` macro for events. Third-party types used as
events should be wrapped in a newtype.
2023-06-06 14:44:32 +00:00
JoJoJet
85a918a8dd
Improve safety for the multi-threaded executor using UnsafeWorldCell (#8292)
# Objective

Fix #7833.

Safety comments in the multi-threaded executor don't really talk about
system world accesses, which makes it unclear if the code is actually
valid.

## Solution

Update the `System` trait to use `UnsafeWorldCell`. This type's API is
written in a way that makes it much easier to cleanly maintain safety
invariants. Use this type throughout the multi-threaded executor, with a
liberal use of safety comments.

---

## Migration Guide

The `System` trait now uses `UnsafeWorldCell` instead of `&World`. This
type provides a robust API for interior mutable world access.
- The method `run_unsafe` uses this type to manage world mutations
across multiple threads.
- The method `update_archetype_component_access` uses this type to
ensure that only world metadata can be used.

```rust
let mut system = IntoSystem::into_system(my_system);
system.initialize(&mut world);

// Before:
system.update_archetype_component_access(&world);
unsafe { system.run_unsafe(&world) }

// After:
system.update_archetype_component_access(world.as_unsafe_world_cell_readonly());
unsafe { system.run_unsafe(world.as_unsafe_world_cell()) }
```

---------

Co-authored-by: James Liu <contact@jamessliu.com>
2023-05-29 15:22:10 +00:00
François
0736195a1e
update syn, encase, glam and hexasphere (#8573)
# Objective

- Fixes #8282 
- Update `syn` to 2.0, `encase` to 0.6, `glam` to 0.24 and `hexasphere`
to 9.0


Blocked ~~on https://github.com/teoxoy/encase/pull/42~~ and ~~on
https://github.com/OptimisticPeach/hexasphere/pull/17~~

---------

Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
Co-authored-by: JoJoJet <21144246+JoJoJet@users.noreply.github.com>
2023-05-16 01:24:17 +00:00
Gino Valente
75130bd5ec
bevy_reflect: Better proxies (#6971)
# Objective

> This PR is based on discussion from #6601

The Dynamic types (e.g. `DynamicStruct`, `DynamicList`, etc.) act as
both:
1. Dynamic containers which may hold any arbitrary data
2. Proxy types which may represent any other type

Currently, the only way we can represent the proxy-ness of a Dynamic is
by giving it a name.

```rust
// This is just a dynamic container
let mut data = DynamicStruct::default();

// This is a "proxy"
data.set_name(std::any::type_name::<Foo>());
```

This type name is the only way we check that the given Dynamic is a
proxy of some other type. When we need to "assert the type" of a `dyn
Reflect`, we call `Reflect::type_name` on it. However, because we're
only using a string to denote the type, we run into a few gotchas and
limitations.

For example, hashing a Dynamic proxy may work differently than the type
it proxies:

```rust
#[derive(Reflect, Hash)]
#[reflect(Hash)]
struct Foo(i32);

let concrete = Foo(123);
let dynamic = concrete.clone_dynamic();

let concrete_hash = concrete.reflect_hash();
let dynamic_hash = dynamic.reflect_hash();

// The hashes are not equal because `concrete` uses its own `Hash` impl
// while `dynamic` uses a reflection-based hashing algorithm
assert_ne!(concrete_hash, dynamic_hash);
```

Because the Dynamic proxy only knows about the name of the type, it's
unaware of any other information about it. This means it also differs on
`Reflect::reflect_partial_eq`, and may include ignored or skipped fields
in places the concrete type wouldn't.

## Solution

Rather than having Dynamics pass along just the type name of proxied
types, we can instead have them pass around the `TypeInfo`.

Now all Dynamic types contain an `Option<&'static TypeInfo>` rather than
a `String`:

```diff
pub struct DynamicTupleStruct {
-    type_name: String,
+    represented_type: Option<&'static TypeInfo>,
    fields: Vec<Box<dyn Reflect>>,
}
```

By changing `Reflect::get_type_info` to
`Reflect::represented_type_info`, hopefully we make this behavior a
little clearer. And to account for `None` values on these dynamic types,
`Reflect::represented_type_info` now returns `Option<&'static
TypeInfo>`.

```rust
let mut data = DynamicTupleStruct::default();

// Not proxying any specific type
assert!(dyn_tuple_struct.represented_type_info().is_none());

let type_info = <Foo as Typed>::type_info();
dyn_tuple_struct.set_represented_type(Some(type_info));
// Alternatively:
// let dyn_tuple_struct = foo.clone_dynamic();

// Now we're proxying `Foo`
assert!(dyn_tuple_struct.represented_type_info().is_some());
```

This means that we can have full access to all the static type
information for the proxied type. Future work would include
transitioning more static type information (trait impls, attributes,
etc.) over to the `TypeInfo` so it can actually be utilized by Dynamic
proxies.

### Alternatives & Rationale

> **Note** 
> These alternatives were written when this PR was first made using a
`Proxy` trait. This trait has since been removed.

<details>
<summary>View</summary>

#### Alternative: The `Proxy<T>` Approach

I had considered adding something like a `Proxy<T>` type where `T` would
be the Dynamic and would contain the proxied type information.

This was nice in that it allows us to explicitly determine whether
something is a proxy or not at a type level. `Proxy<DynamicStruct>`
proxies a struct. Makes sense.

The reason I didn't go with this approach is because (1) tuples, (2)
complexity, and (3) `PartialReflect`.

The `DynamicTuple` struct allows us to represent tuples at runtime. It
also allows us to do something you normally can't with tuples: add new
fields. Because of this, adding a field immediately invalidates the
proxy (e.g. our info for `(i32, i32)` doesn't apply to `(i32, i32,
NewField)`). By going with this PR's approach, we can just remove the
type info on `DynamicTuple` when that happens. However, with the
`Proxy<T>` approach, it becomes difficult to represent this behavior—
we'd have to completely control how we access data for `T` for each `T`.

Secondly, it introduces some added complexities (aside from the manual
impls for each `T`). Does `Proxy<T>` impl `Reflect`? Likely yes, if we
want to represent it as `dyn Reflect`. What `TypeInfo` do we give it?
How would we forward reflection methods to the inner type (remember, we
don't have specialization)? How do we separate this from Dynamic types?
And finally, how do all this in a way that's both logical and intuitive
for users?

Lastly, introducing a `Proxy` trait rather than a `Proxy<T>` struct is
actually more inline with the [Unique Reflect
RFC](https://github.com/bevyengine/rfcs/pull/56). In a way, the `Proxy`
trait is really one part of the `PartialReflect` trait introduced in
that RFC (it's technically not in that RFC but it fits well with it),
where the `PartialReflect` serves as a way for proxies to work _like_
concrete types without having full access to everything a concrete
`Reflect` type can do. This would help bridge the gap between the
current state of the crate and the implementation of that RFC.

All that said, this is still a viable solution. If the community
believes this is the better path forward, then we can do that instead.
These were just my reasons for not initially going with it in this PR.

#### Alternative: The Type Registry Approach

The `Proxy` trait is great and all, but how does it solve the original
problem? Well, it doesn't— yet!

The goal would be to start moving information from the derive macro and
its attributes to the generated `TypeInfo` since these are known
statically and shouldn't change. For example, adding `ignored: bool` to
`[Un]NamedField` or a list of impls.

However, there is another way of storing this information. This is, of
course, one of the uses of the `TypeRegistry`. If we're worried about
Dynamic proxies not aligning with their concrete counterparts, we could
move more type information to the registry and require its usage.

For example, we could replace `Reflect::reflect_hash(&self)` with
`Reflect::reflect_hash(&self, registry: &TypeRegistry)`.

That's not the _worst_ thing in the world, but it is an ergonomics loss.

Additionally, other attributes may have their own requirements, further
restricting what's possible without the registry. The `Reflect::apply`
method will require the registry as well now. Why? Well because the
`map_apply` function used for the `Reflect::apply` impls on `Map` types
depends on `Map::insert_boxed`, which (at least for `DynamicMap`)
requires `Reflect::reflect_hash`. The same would apply when adding
support for reflection-based diffing, which will require
`Reflect::reflect_partial_eq`.

Again, this is a totally viable alternative. I just chose not to go with
it for the reasons above. If we want to go with it, then we can close
this PR and we can pursue this alternative instead.

#### Downsides

Just to highlight a quick potential downside (likely needs more
investigation): retrieving the `TypeInfo` requires acquiring a lock on
the `GenericTypeInfoCell` used by the `Typed` impls for generic types
(non-generic types use a `OnceBox which should be faster). I am not sure
how much of a performance hit that is and will need to run some
benchmarks to compare against.

</details>

### Open Questions

1. Should we use `Cow<'static, TypeInfo>` instead? I think that might be
easier for modding? Perhaps, in that case, we need to update
`Typed::type_info` and friends as well?
2. Are the alternatives better than the approach this PR takes? Are
there other alternatives?

---

## Changelog

### Changed

- `Reflect::get_type_info` has been renamed to
`Reflect::represented_type_info`
- This method now returns `Option<&'static TypeInfo>` rather than just
`&'static TypeInfo`

### Added

- Added `Reflect::is_dynamic` method to indicate when a type is dynamic
- Added a `set_represented_type` method on all dynamic types

### Removed

- Removed `TypeInfo::Dynamic` (use `Reflect::is_dynamic` instead)
- Removed `Typed` impls for all dynamic types

## Migration Guide

- The Dynamic types no longer take a string type name. Instead, they
require a static reference to `TypeInfo`:

    ```rust
    #[derive(Reflect)]
    struct MyTupleStruct(f32, f32);
    
    let mut dyn_tuple_struct = DynamicTupleStruct::default();
    dyn_tuple_struct.insert(1.23_f32);
    dyn_tuple_struct.insert(3.21_f32);
    
    // BEFORE:
    let type_name = std::any::type_name::<MyTupleStruct>();
    dyn_tuple_struct.set_name(type_name);
    
    // AFTER:
    let type_info = <MyTupleStruct as Typed>::type_info();
    dyn_tuple_struct.set_represented_type(Some(type_info));
    ```

- `Reflect::get_type_info` has been renamed to
`Reflect::represented_type_info` and now also returns an
`Option<&'static TypeInfo>` (instead of just `&'static TypeInfo`):

    ```rust
    // BEFORE:
    let info: &'static TypeInfo = value.get_type_info();
    // AFTER:
let info: &'static TypeInfo = value.represented_type_info().unwrap();
    ```

- `TypeInfo::Dynamic` and `DynamicInfo` has been removed. Use
`Reflect::is_dynamic` instead:
   
    ```rust
    // BEFORE:
    if matches!(value.get_type_info(), TypeInfo::Dynamic) {
      // ...
    }
    // AFTER:
    if value.is_dynamic() {
      // ...
    }
    ```

---------

Co-authored-by: radiish <cb.setho@gmail.com>
2023-04-26 12:17:46 +00:00
Gino Valente
c320f54b50
bevy_reflect: Add benches for Struct::clone_dynamic and Reflect::get_type_info (#7764)
# Objective

There aren't any reflection bench tests for `Struct::clone_dynamic` or
`Reflect::get_type_info`.

## Solution

Add benches for `Struct::clone_dynamic` and `Reflect::get_type_info`.
2023-04-17 15:19:08 +00:00
James Liu
8e82c88131
Basic event benchmarks (#8251)
# Objective
Fix #7731. Add basic Event sending and iteration benchmarks to
bevy_ecs's benchmark suite.

## Solution
Add said benchmarks scaling from 100 to 50,000 events.

Not sure if I want to include a randomization of the events going in,
the current implementation might be too easy for the compiler to
optimize.

---------

Co-authored-by: JoJoJet <21144246+JoJoJet@users.noreply.github.com>
2023-03-31 07:12:18 +00:00
Carter Anderson
aefe1f0739
Schedule-First: the new and improved add_systems (#8079)
Co-authored-by: Mike <mike.hsu@gmail.com>
2023-03-18 01:45:34 +00:00
JoJoJet
fd1af7c8b8
Replace multiple calls to add_system with add_systems (#8001) 2023-03-10 18:15:22 +00:00