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1105 commits

Author SHA1 Message Date
Cameron
53919c3e70
Wait until FixedUpdate can see events before dropping them (#10077)
## 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>
2023-11-26 23:04:41 +00:00
Mike
11b1b3a24f
delete methods deprecated in 0.12 (#10693)
## Changelog

- delete methods deprecated in 0.12
2023-11-24 16:15:47 +00:00
Stepan Koltsov
48af029f7b
Warn that Added/Changed filters do not see deferred changes (#10681)
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>
2023-11-23 14:04:07 +00:00
Stepan Koltsov
b0cc6bfd7e
Rustdoc example for Ref (#10682) 2023-11-22 20:20:39 +00:00
Mike
208ecb53dc
Append commands (#10400)
# 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`
2023-11-22 00:04:37 +00:00
TheBigCheese
e67cfdf82b
Enable clippy::undocumented_unsafe_blocks warning across the workspace (#10646)
# 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`.
2023-11-21 02:06:24 +00:00
Andrew Safigan
a22020bf5c
Make impl block for RemovedSystem generic (#10651)
# 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.
2023-11-21 01:27:29 +00:00
TheBigCheese
865041de74
Add an Entry api to EntityWorldMut. (#10650)
# 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>
2023-11-21 01:26:06 +00:00
Konstantin Kostiuk
eeb0c2f2e4
Allow #[derive(Bundle)] on tuple structs (take 3) (#10561)
- rework of old @Veykril's work in
[2499](https://github.com/bevyengine/bevy/pull/2499)
- Fixes [3537](https://github.com/bevyengine/bevy/issues/3537)
2023-11-21 01:09:16 +00:00
Ame
951c9bb1a2
Add [lints] table, fix adding #![allow(clippy::type_complexity)] everywhere (#10011)
# 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>
2023-11-18 20:58:48 +00:00
Gonçalo Rica Pais da Silva
9c0fca072d
Optimise Entity with repr align & manual PartialOrd/Ord (#10558)
# 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.


![Screenshot_20231114_132908](https://github.com/bevyengine/bevy/assets/3116268/cb9090c9-ff74-4cc5-abae-8e4561332261)

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`:


![Screenshot_20231114_144217](https://github.com/bevyengine/bevy/assets/3116268/89bdc21c-7209-43c8-85ae-efbf908bfed3)

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>
2023-11-18 20:04:37 +00:00
Stepan Koltsov
0c9f265423
Link to In in pipe documentation (#10596) 2023-11-17 15:34:58 +00:00
Stepan Koltsov
17e509748d
Some docs for IntoSystemSet (#10563)
Co-authored-by: Pascal Hertleif <killercup@gmail.com>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2023-11-16 17:44:42 +00:00
Zachary Harrold
3c689b9ca8
Update Event send methods to return EventId (#10551)
# 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>
2023-11-16 17:20:43 +00:00
Nathan Fenner
1f05e1e2ab
Add 'World::run_system_with_input' function + allow World::run_system to get system output (#10380)
# 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
2023-11-15 13:44:44 +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
Giacomo Stevanato
e75c2f8b16
Remove a ptr-to-int cast in CommandQueue::apply (#10475)
# 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.
2023-11-09 19:32:33 +00:00
Lixou
003765a878
Remove unnecessary if statement in scheduler (#10446)
# 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
2023-11-09 00:57:22 +00:00
Aevyrie
0cc11791b9
Allow registering boxed systems (#10378)
# 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.
2023-11-08 14:54:32 +00:00
BD103
04ceb46fe0
Use EntityHashMap for EntityMapper (#10415)
# 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!
2023-11-07 08:23:04 +00:00
github-actions[bot]
bf30a25efc
Release 0.12 (#10362)
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>
2023-11-04 17:24:23 +00:00
Pascal Hertleif
0c2c52a0cd
Derive Error for more error types (#10240)
# 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
2023-10-28 22:20:37 +00:00
Edgar Geier
a830530be4
Replace all labels with interned labels (#7762)
# 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>
2023-10-25 21:39:23 +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
Joseph
0716922165
ParamSets containing non-send parameters should also be non-send (#10211)
# Objective

Fix #10207

## Solution

Mark a `ParamSet`'s `SystemMeta` as non-send if any of its component
parameters are non-send.
2023-10-21 18:07:52 +00:00
Ame :]
b9ddb37d5b
add and fix shields in Readmes (#9993)
# Objective

Fix shields

## Solution

- Correct shield in the Bevy ECS Readme, where only the MIT license is
displayed
![Screenshot 2023-10-01 at 18 28
27](https://github.com/bevyengine/bevy/assets/104745335/a736a65e-0d47-4d9e-b32d-0b843a00922c)
- Add shields to other Readmes.
- homogenize shields and titles.
2023-10-15 00:52:31 +00:00
Kanabenki
569e2ac80f
Make builder types take and return Self (#10001)
# 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();
```
2023-10-09 19:46:17 +00:00
radiish
262846e702
reflect: TypePath part 2 (#8768)
# 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.
2023-10-09 19:33:03 +00:00
Mike
687e379800
Updates for rust 1.73 (#10035)
# 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
2023-10-06 00:31:10 +00:00
Mike
7c5b324484
Ignore ambiguous components or resources (#9895)
# 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>
2023-10-04 02:34:28 +00:00
Nicola Papale
1bf271d56e
Add a public API to ArchetypeGeneration/Id (#9825)
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>
2023-10-02 12:54:45 +00:00
Joseph
8cc255c2f0
Hide UnsafeWorldCell::unsafe_world (#9741)
# 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.
2023-10-02 12:46:43 +00:00
Testare
dfdc9f8369
as_deref_mut() method for Mut-like types (#9912)
# 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>
2023-10-02 00:53:12 +00:00
Christian Hughes
9c004439b8
Remove States::variants and remove enum-only restriction its derive (#9945)
# 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.
2023-09-30 22:32:39 +00:00
James Liu
95813b87f7
Cache parallel iteration spans (#9950)
# Objective
We cached system spans in #9390, but another common span seen in most
Bevy apps when enabling tracing are Query::par_iter(_mut) related spans.

## Solution
Cache them in QueryState. The one downside to this is that we pay for
the memory for every Query(State) instantiated, not just those that are
used for parallel iteration, but this shouldn't be a significant cost
unless the app is creating hundreds of thousands of Query(State)s
regularly.

## Metrics
Tested against `cargo run --profile stress-test --features trace_tracy
--example many_cubes`. Yellow is this PR, red is main.

`sync_simple_transforms`:


![image](https://github.com/bevyengine/bevy/assets/3137680/d60f6d69-5586-4424-9d78-aac78992aacd)

`check_visibility`:


![image](https://github.com/bevyengine/bevy/assets/3137680/096a58d2-a330-4a32-b806-09cd524e6e15)

Full frame:


![image](https://github.com/bevyengine/bevy/assets/3137680/3b088cf8-9487-4bc7-a308-026e172d6672)
2023-09-30 08:03:35 +00:00
SADIK KUZU
483f2464a8
Fix typos (#9965)
# 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>
2023-09-29 12:26:41 +00:00
Bruce Mitchener
a5a457c3c8
docs: Use intradoc links for method references. (#9958)
# Objective

- Use intradoc links to let the compiler verify correctness.

## Solution

- Use intradoc links.
2023-09-29 07:09:14 +00:00
Robert Swain
b6ead2be95
Use EntityHashMap<Entity, T> for render world entity storage for better performance (#9903)
# 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>
2023-09-27 08:28:28 +00:00
Rob Parrett
7063c86ed4
Fix some typos (#9934)
# Objective

To celebrate the turning of the seasons, I took a small walk through the
codebase guided by the "[code spell
checker](https://marketplace.visualstudio.com/items?itemName=streetsidesoftware.code-spell-checker)"
VS Code extension and fixed a few typos.
2023-09-26 19:46:24 +00:00
Bruce Mitchener
ae95ba5278
Fix typos. (#9922)
# Objective

- Have docs with fewer typos.1

## Solution

- Fix typos as they are found.
2023-09-25 18:35:46 +00:00
James Liu
8ace2ff9e3
Only run event systems if they have tangible work to do (#7728)
# 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>
2023-09-24 00:16:33 +00:00
Joseph
e60249e59d
Improve codegen for world validation (#9464)
# 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>
2023-09-21 20:57:06 +00:00
Sludge
e07c427dea
#[derive(Clone)] on Component{Info,Descriptor} (#9812)
# 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`
2023-09-20 19:35:53 +00:00
Ethereumdegen
3ee9edf280
add try_insert to entity commands (#9844)
# 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.
2023-09-20 19:34:30 +00:00
Nicola Papale
9e52697572
Add mutual exclusion safety info on filter_fetch (#9836)
# 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.
2023-09-19 21:49:33 +00:00
Trashtalk217
e4b368721d
One Shot Systems (#8963)
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>
2023-09-19 20:17:05 +00:00
Joseph
d5d355ae1f
Fix the clippy::explicit_iter_loop lint (#9834)
# 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.
2023-09-19 03:35:22 +00:00
Bruce Mitchener
444245106e
docs: Improve some ComponentId doc cross-linking. (#9839)
# 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`
2023-09-18 21:42:04 +00:00
Bruce Mitchener
5e91e5f3ce
Improve doc formatting. (#9840)
# Objective

- Identifiers in docs should be marked up with backticks.

## Solution

- Mark up more identifiers in the docs with backticks.
2023-09-18 19:43:56 +00:00
Michael Johnson
68fa81e42d
Round up for the batch size to improve par_iter performance (#9814)
# 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`).

![Screenshot from 2023-09-14
20-24-36](https://github.com/bevyengine/bevy/assets/1353401/82099ee4-83a8-47f4-bb6b-944f1e87a818)

### 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.

![Screenshot from 2023-09-14
20-48-51](https://github.com/bevyengine/bevy/assets/1353401/4532211d-ab36-435b-b864-56af3370d90e)
2023-09-18 16:02:58 +00:00
Nicola Papale
0bd4ea7ced
Provide getters for fields of ReflectFromPtr (#9748)
# 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`
2023-09-18 13:41:51 +00:00
Rob Parrett
26359f9b37
Remove some old references to CoreSet (#9833)
# Objective

Remove some references to `CoreSet` which was removed in #8079.
2023-09-18 01:07:11 +00:00
louis-le-cam
9ee9d627d7
Rename RemovedComponents::iter/iter_with_id to read/read_with_id (#9778)
# 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>
2023-09-15 12:37:20 +00:00
Joseph
90b741d3d3
Return a boolean from set_if_neq (#9801)
# 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.
2023-09-14 01:44:53 +00:00
Mike
324c057b71
Cache System Tracing Spans (#9390)
# Objective

- Reduce the overhead of tracing by caching the system spans.

Yellow is this pr. Red is main.


![image](https://github.com/bevyengine/bevy/assets/2180432/fe9bb7c2-ae9a-4522-80a9-75a943a562b6)
2023-09-13 19:10:11 +00:00
Nicola Papale
d3beaff56f
Clarify a comment in Option WorldQuery impl (#9749)
I found a comment a bit confusing

## Solution

Reword it.

---------

Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
2023-09-11 19:27:21 +00:00
Nicola Papale
19c53578e6
Fix naming on "tick" Column and ComponentSparseSet methods (#9744)
# 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`
2023-09-11 19:25:06 +00:00
Johan Klokkhammer Helsing
4fe2b1220d
Implement Reflect for State<S> and NextState<S> (#9742)
# 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.
2023-09-11 19:18:47 +00:00
Zachary Harrold
4c6b6fc24a
Moved get_component(_unchecked_mut) from Query to QueryState (#9686)
# 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>
2023-09-11 19:04:22 +00:00
Joseph
8eb6ccdd87
Remove useless single tuples and trailing commas (#9720)
# Objective

Title
2023-09-08 21:46:54 +00:00
Edgar Geier
118509e4aa
Replace IntoSystemSetConfig with IntoSystemSetConfigs (#9247)
# 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>
2023-09-05 17:15:27 +00:00
Hennadii Chernyshchyk
9309d89bb8
Add panicking helpers for getting components from Query (#9659)
# 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.
2023-09-04 12:31:12 +00:00
Joseph
58f7dac689
Fix unsoundness in QueryState::is_empty (#9463)
# 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.
2023-09-02 23:43:22 +00:00
Félix Lescaudey de Maneville
a2b5d7a198
Fix some nightly warnings (#9672)
# Objective

Fix some nightly warnings found by running

`cargo +nightly clippy`

## Solution

Fix the following warnings:
- [x]
[elided_lifetimes_in_associated_constant](https://github.com/rust-lang/rust/issues/115010)
221986134d
- [x]
[unwrap_or_default](https://rust-lang.github.io/rust-clippy/master/index.html#/unwrap_or_default)
32e21c78f9
- [x]
[needless_pass_by_ref_mut](https://rust-lang.github.io/rust-clippy/master/index.html#/needless_pass_by_ref_mut)
c85d6d4a10

There is no breaking change, some internal `bevy_ecs` code no longer
uses a few mutable references but I don't think it should cause any
regression or be performance sensitive, but there might be some ECS
magic I'm unaware of that could break because of those changes
2023-09-02 18:35:06 +00:00
Mike
02025eff0b
Fix anonymous set name stack overflow (#9650)
# Objective

- Fixes #9641
- Anonymous sets are named by their system members. When
`ScheduleBuildSettings::report_sets` is on, systems are named by their
sets. So when getting the anonymous set name this would cause an
infinite recursion.

## Solution
- When getting the anonymous system set name, don't get their system's
names with the sets the systems belong to.

## Other Possible solutions
- An alternate solution might be to skip anonymous sets when getting the
system's name for an anonymous set's name.
2023-08-31 22:52:59 +00:00
Mike
c2b85f9b52
fix ambiguity reporting (#9648)
# Objective

- I broke ambiguity reporting in one of my refactors.
`conflicts_to_string` should have been using the passed in parameter
rather than the one stored on self.
2023-08-31 19:06:13 +00:00
lelo
42e6dc8987
Refactor EventReader::iter to read (#9631)
# Objective

- The current `EventReader::iter` has been determined to cause confusion
among new Bevy users. It was suggested by @JoJoJet to rename the method
to better clarify its usage.
- Solves #9624 

## Solution

- Rename `EventReader::iter` to `EventReader::read`.
- Rename `EventReader::iter_with_id` to `EventReader::read_with_id`.
- Rename `ManualEventReader::iter` to `ManualEventReader::read`.
- Rename `ManualEventReader::iter_with_id` to
`ManualEventReader::read_with_id`.

---

## Changelog

- `EventReader::iter` has been renamed to `EventReader::read`.
- `EventReader::iter_with_id` has been renamed to
`EventReader::read_with_id`.
- `ManualEventReader::iter` has been renamed to
`ManualEventReader::read`.
- `ManualEventReader::iter_with_id` has been renamed to
`ManualEventReader::read_with_id`.
- Deprecated `EventReader::iter`
- Deprecated `EventReader::iter_with_id`
- Deprecated `ManualEventReader::iter`
- Deprecated `ManualEventReader::iter_with_id`

## Migration Guide

- Existing usages of `EventReader::iter` and `EventReader::iter_with_id`
will have to be changed to `EventReader::read` and
`EventReader::read_with_id` respectively.
- Existing usages of `ManualEventReader::iter` and
`ManualEventReader::iter_with_id` will have to be changed to
`ManualEventReader::read` and `ManualEventReader::read_with_id`
respectively.
2023-08-30 14:20:03 +00:00
Ame :]
fb094eab87
Move default docs (#9638)
# Objective

- Make the default docs more useful like suggested in
https://github.com/bevyengine/bevy/pull/9600#issuecomment-1696452118

## Solution

- Move the documentation to the `fn default()` method instead of the
`impl Default`.

Allows you to view the docs directly on the function without having to
go to the implementation.

### Before
![Screenshot 2023-08-29 at 18 21
03](https://github.com/bevyengine/bevy/assets/104745335/6d31591e-f190-4b8e-8bc3-a570ada294f0)

### After
![Screenshot 2023-08-29 at 18 19
54](https://github.com/bevyengine/bevy/assets/104745335/e2442ec1-593d-47f3-b539-8c77a170f0b6)
2023-08-30 01:13:04 +00:00
Nicola Papale
4f212a5b0c
Remove IntoIterator impl for &mut EventReader (#9583)
# Objective

The latest `clippy` release has a much more aggressive application of
the
[`explicit_iter_loop`](https://rust-lang.github.io/rust-clippy/master/index.html#/explicit_into_iter_loop?groups=pedantic)
pedantic lint.

As a result, clippy now suggests the following:

```diff
-for event in events.iter() {
+for event in &mut events {
```

I'm generally in favor of this lint. Using `for mut item in &mut query`
is also recommended over `for mut item in query.iter_mut()` for good
reasons IMO.

But, it is my personal belief that `&mut events` is much less clear than
`events.iter()`.

Why? The reason is that the events from `EventReader` **are not
mutable**, they are immutable references to each event in the event
reader. `&mut events` suggests we are getting mutable access to events —
similarly to `&mut query` — which is not the case. Using `&mut events`
is therefore misleading.

`IntoIterator` requires a mutable `EventReader` because it updates the
internal `last_event_count`, not because it let you mutate it.

So clippy's suggested improvement is a downgrade.

## Solution

Do not implement `IntoIterator` for `&mut events`.

Without the impl, clippy won't suggest its "fix". This also prevents
generally people from using `&mut events` for iterating `EventReader`s,
which makes the ecosystem every-so-slightly better.

---

## Changelog

- Removed `IntoIterator` impl for `&mut EventReader`

## Migration Guide

- `&mut EventReader` does not implement `IntoIterator` anymore. replace
`for foo in &mut events` by `for foo in events.iter()`
2023-08-29 15:29:46 +00:00
Mike
da9a070d6f
port old ambiguity tests over (#9617)
# Objective

- Some of the old ambiguity tests didn't get ported over during schedule
v3.

## Solution

- Port over tests from
15ee98db8d/crates/bevy_ecs/src/schedule/ambiguity_detection.rs (L279-L612)
with minimal changes
- Make a method to convert the ambiguity conflicts to a string for
easier verification of correct results.
2023-08-29 14:53:26 +00:00
Joseph
bc8bf34818
Allow disjoint mutable world access via EntityMut (#9419)
# Objective

Fix #4278
Fix #5504
Fix #9422

Provide safe ways to borrow an entire entity, while allowing disjoint
mutable access. `EntityRef` and `EntityMut` are not suitable for this,
since they provide access to the entire world -- they are just helper
types for working with `&World`/`&mut World`.

This has potential uses for reflection and serialization

## Solution

Remove `EntityRef::world`, which allows it to soundly be used within
queries.

`EntityMut` no longer supports structural world mutations, which allows
multiple instances of it to exist for different entities at once.
Structural world mutations are performed using the new type
`EntityWorldMut`.

```rust
fn disjoint_system(
     q2: Query<&mut A>,
     q1: Query<EntityMut, Without<A>>,
) { ... }

let [entity1, entity2] = world.many_entities_mut([id1, id2]);
*entity1.get_mut::<T>().unwrap() = *entity2.get().unwrap();

for entity in world.iter_entities_mut() {
    ...
}
```

---

## Changelog

- Removed `EntityRef::world`, to fix a soundness issue with queries.
+ Removed the ability to structurally mutate the world using
`EntityMut`, which allows it to be used in queries.
+ Added `EntityWorldMut`, which is used to perform structural mutations
that are no longer allowed using `EntityMut`.

## Migration Guide

**Note for maintainers: ensure that the guide for #9604 is updated
accordingly.**

Removed the method `EntityRef::world`, to fix a soundness issue with
queries. If you need access to `&World` while using an `EntityRef`,
consider passing the world as a separate parameter.

`EntityMut` can no longer perform 'structural' world mutations, such as
adding or removing components, or despawning the entity. Additionally,
`EntityMut::world`, `EntityMut::world_mut` , and
`EntityMut::world_scope` have been removed.
Instead, use the newly-added type `EntityWorldMut`, which is a helper
type for working with `&mut World`.

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2023-08-28 23:30:59 +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
Joseph
c440de06f1
Add a variant of Events::update that returns the removed events (#9542)
# Objective

Every frame, `Events::update` gets called, which clears out any old
events from the buffer. There should be a way of taking ownership of
these old events instead of throwing them away. My use-case is dumping
old events into a debug menu so they can be inspected later.

One potential workaround is to just have a system that clones any
incoming events and stores them in a list -- however, this requires the
events to implement `Clone`.

## Solution

Add `Events::update_drain`, which returns an iterator of the events that
were removed from the buffer.
2023-08-28 18:55:59 +00:00
DevinLeamy
a8dc8350c6
Add configure_schedules to App and Schedules to apply ScheduleBuildSettings to all schedules (#9514)
# Objective

- Fixes: #9508 
- Fixes: #9526 

## Solution

- Adds
```rust 
fn configure_schedules(&mut self, schedule_build_settings: ScheduleBuildSettings)
``` 
to `Schedules`, and `App` to simplify applying `ScheduleBuildSettings`
to all schedules.

---

## Migration Guide
- No breaking changes.
- Adds `Schedule::get_build_settings()` getter for the schedule's
`ScheduleBuildSettings`.
- Can replaced manual configuration of all schedules:
```rust
// Old 
for (_, schedule) in app.world.resource_mut::<Schedules>().iter_mut() {
    schedule.set_build_settings(build_settings);
}

// New
app.configure_schedules(build_settings);
```
2023-08-28 18:54:45 +00:00
Noah
72fc63e594
implement insert and remove reflected entity commands (#8895)
# Objective

To enable non exclusive system usage of reflected components and make
reflection more ergonomic to use by making it more in line with standard
entity commands.

## Solution

- Implements a new `EntityCommands` extension trait for reflection
related functions in the reflect module of bevy_ecs.
- Implements 4 new commands, `insert_reflect`,
`insert_reflect_with_registry`, `remove_reflect`, and
`remove_reflect_with_registry`. Both insert commands take a `Box<dyn
Reflect>` component while the remove commands take the component type
name.

- Made `EntityCommands` fields pub(crate) to allow access in the reflect
module. (Might be worth making these just public to enable user end
custom entity commands in a different pr)
- Added basic tests to ensure the commands are actually working.
- Documentation of functions.

---

## Changelog

Added:
-  Implements 4 new commands on the new entity commands extension.
- `insert_reflect`
- `remove_reflect`
- `insert_reflect_with_registry`
- `remove_reflect_with_registry`

The commands operate the same except the with_registry commands take a
generic parameter for a resource that implements `AsRef<TypeRegistry>`.
Otherwise the default commands use the `AppTypeRegistry` for reflection
data.

Changed:

- Made `EntityCommands` fields pub(crate) to allow access in the reflect
module.

> Hopefully this time it works. Please don't make me rebase again ☹
2023-08-28 18:21:20 +00:00
Zachary Harrold
1839ff7e2a
Replaced EntityCommand Implementation for FnOnce (#9604)
# Objective

- Fixes #4917
- Replaces #9602

## Solution

- Replaced `EntityCommand` implementation for `FnOnce` to apply to
`FnOnce(EntityMut)` instead of `FnOnce(Entity, &mut World)`

---

## Changelog

- `FnOnce(Entity, &mut World)` no longer implements `EntityCommand`.
This is a breaking change.

## Migration Guide

### 1. New-Type `FnOnce`

Create an `EntityCommand` type which implements the method you
previously wrote:

```rust
pub struct ClassicEntityCommand<F>(pub F);

impl<F> EntityCommand for ClassicEntityCommand<F>
where
    F: FnOnce(Entity, &mut World) + Send + 'static,
{
    fn apply(self, id: Entity, world: &mut World) {
        (self.0)(id, world);
    }
}

commands.add(ClassicEntityCommand(|id: Entity, world: &mut World| {
    /* ... */
}));
```

### 2. Extract `(Entity, &mut World)` from `EntityMut`

The method `into_world_mut` can be used to gain access to the `World`
from an `EntityMut`.

```rust
let old = |id: Entity, world: &mut World| {
    /* ... */
};

let new = |mut entity: EntityMut| {
    let id = entity.id();
    let world = entity.into_world_mut();
    /* ... */
};
```
2023-08-28 18:08:53 +00:00
Joseph
a47a5b30fe
Rename ManualEventIterator (#9592)
# Objective

The name `ManualEventIterator` is long and unnecessary, as this is the
iterator type used for both `EventReader` and `ManualEventReader`.

## Solution

Rename `ManualEventIterator` to `EventIterator`. To ease migration, add
a deprecated type alias with the old name.

---

## Changelog

- The types `ManualEventIterator{WithId}` have been renamed to
`EventIterator{WithId}`.

## Migration Guide

The type `ManualEventIterator` has been renamed to `EventIterator`.
Additonally, `ManualEventIteratorWithId` has been renamed to
`EventIteratorWithId`.
2023-08-28 17:49:25 +00:00
Joseph
da8ab16d83
Relax more Sync bounds on Local (#9589)
# Objective

#5483 allows for the creation of non-`Sync` locals. However, it's not
actually possible to use these types as there is a `Sync` bound on the
`Deref` impls.

## Solution

Remove the unnecessary bounds.
2023-08-28 17:47:15 +00:00
Mike
4e59671ae7
clean up configure_set(s) erroring (#9577)
# Objective

- have errors in configure_set and configure_sets show the line number
of the user calling location rather than pointing to schedule.rs
- use display formatting for the errors

## Example Error Text
```text
// dependency loop
// before
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: DependencyLoop("A")', crates\bevy_ecs\src\schedule\schedule.rs:682:39
// after
thread 'main' panicked at 'System set `A` depends on itself.', examples/stress_tests/bevymark.rs:16:9

// hierarchy loop
// before
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: HierarchyLoop("A")', crates\bevy_ecs\src\schedule\schedule.rs:682:3
// after
thread 'main' panicked at 'System set `A` contains itself.', examples/stress_tests/bevymark.rs:16:9

// configuring a system type set
// before
thread 'main' panicked at 'configuring system type sets is not allowed', crates\bevy_ecs\src\schedule\config.rs:394:9
//after
thread 'main' panicked at 'configuring system type sets is not allowed', examples/stress_tests/bevymark.rs:16:9
```

Code to produce errors:
```rust
use bevy::prelude::*;

#[derive(SystemSet, Clone, Debug, PartialEq, Eq, Hash)]
enum TestSet {
    A,
}

fn main() {
    fn foo() {}
    let mut app = App::empty();
    // Hierarchy Loop
    app.configure_set(Main, TestSet::A.in_set(TestSet::A));
    // Dependency Loop
    app.configure_set(Main, TestSet::A.after(TestSet::A));
    // Configure System Type Set
    app.configure_set(Main, foo.into_system_set());
}
```
2023-08-28 17:44:52 +00:00
Zachary Harrold
394e2b0c91
Replaced EntityMap with HashMap (#9461)
# Objective

- Fixes #9321

## Solution

- `EntityMap` has been replaced by a simple `HashMap<Entity, Entity>`.

---

## Changelog

- `EntityMap::world_scope` has been replaced with `World::world_scope`
to avoid creating a new trait. This is a public facing change to the
call semantics, but has no effect on results or behaviour.
- `EntityMap`, as a `HashMap`, now operates on `&Entity` rather than
`Entity`. This changes many standard access functions (e.g, `.get`) in a
public-facing way.

## Migration Guide

- Calls to `EntityMap::world_scope` can be directly replaced with the
following:
  `map.world_scope(&mut world)` -> `world.world_scope(&mut map)`
- Calls to legacy `EntityMap` methods such as `EntityMap::get` must
explicitly include de/reference symbols:
  `let entity = map.get(parent);` -> `let &entity = map.get(&parent);`
2023-08-28 17:18:16 +00:00
Sélène Amanita
f38549c68d
Reorganize Events and EventSequence code (#9306)
# Objective

Make code relating to event more readable.

Currently the `impl` block of `Events` is split in two, and the big part
of its implementations are put at the end of the file, far from the
definition of the `struct`.

## Solution

- Move and merge the `impl` blocks of `Events` next to its definition.
- Move the `EventSequence` definition and implementations before the
`Events`, because they're pretty trivial and help understand how
`Events` work, rather than being buried bellow `Events`.

I separated those two steps in two commits to not be too confusing. I
didn't modify any code of documentation. I want to do a second PR with
such modifications after this one is merged.
2023-08-28 16:56:22 +00:00
Hennadii Chernyshchyk
fb9a65fa0d
bevy_scene: Add ReflectBundle (#9165)
# Objective

Similar to #6344, but contains only `ReflectBundle` changes. Useful for
scripting. The implementation has also been updated to look exactly like
`ReflectComponent`.

---

## Changelog

### Added

- Reflection for bundles.

---------

Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
2023-08-28 16:50:43 +00:00
Joseph
474b55a29c
Add system.map(...) for transforming the output of a system (#8526)
# Objective

Any time we wish to transform the output of a system, we currently use
system piping to do so:

```rust
my_system.pipe(|In(x)| do_something(x))
```

Unfortunately, system piping is not a zero cost abstraction. Each call
to `.pipe` requires allocating two extra access sets: one for the second
system and one for the combined accesses of both systems. This also adds
extra work to each call to `update_archetype_component_access`, which
stacks as one adds multiple layers of system piping.

## Solution

Add the `AdapterSystem` abstraction: similar to `CombinatorSystem`, this
allows you to implement a trait to generically control how a system is
run and how its inputs and outputs are processed. Unlike
`CombinatorSystem`, this does not have any overhead when computing world
accesses which makes it ideal for simple operations such as inverting or
ignoring the output of a system.

Add the extension method `.map(...)`: this is similar to `.pipe(...)`,
only it accepts a closure as an argument instead of an `In<T>` system.

```rust
my_system.map(do_something)
```

This has the added benefit of making system names less messy: a system
that ignores its output will just be called `my_system`, instead of
`Pipe(my_system, ignore)`

---

## Changelog

TODO

## Migration Guide

The `system_adapter` functions have been deprecated: use `.map` instead,
which is a lightweight alternative to `.pipe`.

```rust
// Before:
my_system.pipe(system_adapter::ignore)
my_system.pipe(system_adapter::unwrap)
my_system.pipe(system_adapter::new(T::from))

// After:
my_system.map(std::mem::drop)
my_system.map(Result::unwrap)
my_system.map(T::from)

// Before:
my_system.pipe(system_adapter::info)
my_system.pipe(system_adapter::dbg)
my_system.pipe(system_adapter::warn)
my_system.pipe(system_adapter::error)

// After:
my_system.map(bevy_utils::info)
my_system.map(bevy_utils::dbg)
my_system.map(bevy_utils::warn)
my_system.map(bevy_utils::error)
```

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2023-08-28 16:36:46 +00:00
Mike
7b6f8659f8
Refactor build_schedule and related errors (#9579)
# Objective

- break up large build_schedule system to make it easier to read
- Clean up related error messages.
- I have a follow up PR that adds the schedule name to the error
messages, but wanted to break this up from that.

## Changelog

- refactor `build_schedule` to be easier to read

## Sample Error Messages

Dependency Cycle
```text
thread 'main' panicked at 'System dependencies contain cycle(s).
schedule has 1 before/after cycle(s):
cycle 1: system set 'A' must run before itself
system set 'A'
 ... which must run before system set 'B'
 ... which must run before system set 'A'

', crates\bevy_ecs\src\schedule\schedule.rs:228:13
```
```text
thread 'main' panicked at 'System dependencies contain cycle(s).
schedule has 1 before/after cycle(s):
cycle 1: system 'foo' must run before itself
system 'foo'
 ... which must run before system 'bar'
 ... which must run before system 'foo'

', crates\bevy_ecs\src\schedule\schedule.rs:228:13
```
Hierarchy Cycle
```text
thread 'main' panicked at 'System set hierarchy contains cycle(s).
schedule has 1 in_set cycle(s):
cycle 1: set 'A' contains itself
set 'A'
 ... which contains set 'B'
 ... which contains set 'A'

', crates\bevy_ecs\src\schedule\schedule.rs:230:13
```

System Type Set
```text
thread 'main' panicked at 'Tried to order against `SystemTypeSet(fn foo())` in a schedule that has more than one `SystemTypeSet(fn foo())` instance. `SystemTypeSet(fn foo())` is a `SystemTypeSet` and cannot be used for ordering if ambiguous. Use a different set without this restriction.', crates\bevy_ecs\src\schedule\schedule.rs:230:13
```

Hierarchy Redundancy
```text
thread 'main' panicked at 'System set hierarchy contains redundant edges.
hierarchy contains redundant edge(s) -- system set 'X' cannot be child of set 'A', longer path exists
', crates\bevy_ecs\src\schedule\schedule.rs:230:13
```

Systems have ordering but interset
```text
thread 'main' panicked at '`A` and `C` have a `before`-`after` relationship (which may be transitive) but share systems.', crates\bevy_ecs\src\schedule\schedule.rs:227:51
```

Cross Dependency
```text
thread 'main' panicked at '`A` and `B` have both `in_set` and `before`-`after` relationships (these might be transitive). This combination is unsolvable as a system cannot run before or after a set it belongs to.', crates\bevy_ecs\src\schedule\schedule.rs:230:13
```

Ambiguity
```text
thread 'main' panicked at 'Systems with conflicting access have indeterminate run order.
1 pairs of systems with conflicting data access have indeterminate execution order. Consider adding `before`, `after`, or `ambiguous_with` relationships between these:
 -- res_mut and res_ref
    conflict on: ["bevymark::ambiguity::X"]
', crates\bevy_ecs\src\schedule\schedule.rs:230:13
```
2023-08-27 17:54:59 +00:00
st0rmbtw
9d804a231e
Make run_if_inner public and rename to run_if_dyn (#9576)
# Objective

Sometimes you want to create a plugin with a custom run condition. In a
function, you take the `Condition` trait and then make a
`BoxedCondition` from it to store it. And then you want to add that
condition to a system, but you can't, because there is only the `run_if`
function available which takes `impl Condition<M>` instead of
`BoxedCondition`. So you have to create a wrapper type for the
`BoxedCondition` and implement the `System` and `ReadOnlySystem` traits
for the wrapper (Like it's done in the picture below). It's very
inconvenient and boilerplate. But there is an easy solution for that:
make the `run_if_inner` system that takes a `BoxedCondition` public.
Also, it makes sense to make `in_set_inner` function public as well with
the same motivation.


![image](https://github.com/bevyengine/bevy/assets/61053971/a4455180-7e0c-4c2b-9372-cd8b4a9e682e)
A chunk of the source code of the `bevy-inspector-egui` crate.

## Solution

Make `run_if_inner` function public.
Rename `run_if_inner` to `run_if_dyn`.

Make `in_set_inner` function public.
Rename `in_set_inner` to `in_set_dyn`.

## Changelog

Changed visibility of `run_if_inner` from `pub(crate)` to `pub`.
Renamed `run_if_inner` to `run_if_dyn`.

Changed visibility of `in_set_inner` from `pub(crate)` to `pub`.
Renamed `in_set_inner` to `in_set_dyn`.

## Migration Guide

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Joseph <21144246+JoJoJet@users.noreply.github.com>
2023-08-27 17:53:37 +00:00
Joseph
e8b3892517
Improve various Debug implementations (#9588)
# Objective

* `Local` and `SystemName` implement `Debug` manually, but they could
derive it.
* `QueryState` and `dyn System` have unconventional debug formatting.
2023-08-26 21:27:41 +00:00
Christian Hughes
349dd8bd45
Relax In/Out bounds on impl Debug for dyn System (#9581)
# Objective

Resolves #9580

## Solution

Relaxed the bounds on the `Debug` impl for `dyn System`
2023-08-26 13:57:19 +00:00
Rob Parrett
a788e31ad5
Fix CI for Rust 1.72 (#9562)
# Objective

[Rust 1.72.0](https://blog.rust-lang.org/2023/08/24/Rust-1.72.0.html) is
now stable.

# Notes

- `let-else` formatting has arrived!
- I chose to allow `explicit_iter_loop` due to
https://github.com/rust-lang/rust-clippy/issues/11074.
  
We didn't hit any of the false positives that prevent compilation, but
fixing this did produce a lot of the "symbol soup" mentioned, e.g. `for
image in &mut *image_events {`.
  
  Happy to undo this if there's consensus the other way.

---------

Co-authored-by: François <mockersf@gmail.com>
2023-08-25 12:34:24 +00:00
Joseph
69750a03ca
Implement Debug for UnsafeWorldCell (#9460)
# Objective

* Add more ways to use `UnsafeWorldCell` in safe code -- you no longer
need to call `.world_metadata()` to format it.
2023-08-20 22:00:12 +00:00
hesiod
6ccb26885f
Fix incorrect documentation link in DetectChangesMut (#9431)
# Objective

- Fix a trivial incorrect documentation link in  `DetectChangesMut`.
2023-08-15 21:48:12 +00:00
urben1680
5b5806406d
Adding Copy, Clone, Debug to derived traits of ExecutorKind (#9385)
While being nobody other's issue as far I can tell, I want to create a
trait I plan to implement on `App` where more than one schedule is
modified.
My workaround so far was working with a closure that returns an
`ExecutorKind` from a match of the method variable.

It makes it easier for me to being able to clone `ExecutorKind` and I
don't see this being controversial for others working with Bevy.

I did nothing more than adding `Clone` to the derived traits, no
migration guide needed.

(If this worked out then the GitHub editor is not too shabby.)
2023-08-11 21:45:32 +00:00
Tristan Guichaoua
cfb65c1eaf
Add replace_if_neq to DetectChangesMut (#9418)
# Objective

Just like
[`set_if_neq`](https://docs.rs/bevy_ecs/latest/bevy_ecs/change_detection/trait.DetectChangesMut.html#method.set_if_neq),
being able to express the "I don't want to unnecessarily trigger the
change detection" but with the ability to handle the previous value if
change occurs.

## Solution

Add `replace_if_neq` to `DetectChangesMut`.

---

## Changelog

- Added `DetectChangesMut::replace_if_neq`: like `set_if_neq` change the
value only if the new value if different from the current one, but
return the previous value if the change occurs.
2023-08-11 21:10:16 +00:00
Zeenobit
1e170d2e90
Add RunSystem (#9366)
Add a `RunSystem` extension trait to allow for immediate execution of
systems on a `World` for debugging and/or testing purposes.

# Objective

Fixes #6184

Initially, I made this CL as `ApplyCommands`. After a discussion with
@cart , we decided a more generic implementation would be better to
support all systems. This is the new revised CL. Sorry for the long
delay! 😅

This CL allows users to do this:
```rust
use bevy::prelude::*;
use bevy::ecs::system::RunSystem;

struct T(usize);

impl Resource for T {}

fn system(In(n): In<usize>, mut commands: Commands) -> usize {
    commands.insert_resource(T(n));
    n + 1
}

let mut world = World::default();
let n = world.run_system_with(1, system);
assert_eq!(n, 2);
assert_eq!(world.resource::<T>().0, 1);
```

## Solution

This is implemented as a trait extension and not included in any
preludes to ensure it's being used consciously.
Internally, it just initializes and runs a systems, and applies any
deferred parameters all "in place".
The trait has 2 functions (one of which calls the other by default):
- `run_system_with` is the general implementation, which allows user to
pass system input parameters
- `run_system` is the ergonomic wrapper for systems with no input
parameter (to avoid having the user pass `()` as input).

~~Additionally, this trait is also implemented for `&mut App`. I added
this mainly for ergonomics (`app.run_system` vs.
`app.world.run_system`).~~ (Removed based on feedback)

---------

Co-authored-by: Pascal Hertleif <killercup@gmail.com>
2023-08-11 20:41:48 +00:00
Edgar Geier
731a6fbb92
Fix ambiguous_with breaking run conditions (#9253)
# Objective

- Fixes #9114

## Solution

Inside `ScheduleGraph::build_schedule()` the variable `node_count =
self.systems.len() + self.system_sets.len()` is used to calculate the
indices for the `reachable` bitset derived from `self.hierarchy.graph`.
However, the number of nodes inside `self.hierarchy.graph` does not
always correspond to `self.systems.len() + self.system_sets.len()` when
`ambiguous_with` is used, because an ambiguous set is added to
`system_sets` (because we need an `NodeId` for the ambiguity graph)
without adding a node to `self.hierarchy`.

In this PR, we rename `node_count` to the more descriptive name
`hg_node_count` and set it to `self.hierarchy.graph.node_count()`.

---------

Co-authored-by: James Liu <contact@jamessliu.com>
2023-08-03 07:53:20 +00:00
尹吉峰
d9702d35f1
opt-out multi-threaded feature flag (#9269)
# Objective

Fixes #9113

## Solution

disable `multi-threaded` default feature

## Migration Guide
The `multi-threaded` feature in `bevy_ecs` and `bevy_tasks` is no longer
enabled by default. However, this remains a default feature for the
umbrella `bevy` crate. If you depend on `bevy_ecs` or `bevy_tasks`
directly, you should consider enabling this to allow systems to run in
parallel.
2023-08-03 07:47:09 +00:00
Nicola Papale
77fa8a9a9c
Add a paragraph to the lifetimeless module doc (#9312)
# Objective

The `lifetimeless` module has been a source of confusion for bevy users
for a while now.

## Solution

Add a couple paragraph explaining that, yes, you can use one of the type
alias safely, without ever leaking any memory.
2023-08-02 22:01:56 +00:00
Hennadii Chernyshchyk
c6a1bf063b
Add EntityMap::clear (#9291)
# Objective

If you use `EntityMap` to map entities over network
(https://github.com/lifescapegame/bevy_replicon) you need to reset it
sometimes, but keep allocated memory for reuse.

## Solution

- Add
[clear](https://doc.rust-lang.org/std/collections/struct.HashMap.html#method.clear)
method.

---

## Changelog

### Added

- `EntityMap::clear`.
2023-07-31 22:02:16 +00:00
FlippinBerger
e02938f9dd
Derive debug for ManualEventIterator (#9293)
# Objective
Fixes #9284 by deriving Debug on ManualEventIterator
2023-07-30 15:30:52 +00:00
Joseph
02688a99b8
Fix safety invariants for WorldQuery::fetch and simplify cloning (#8246)
# Objective

Cloning a `WorldQuery` type's "fetch" struct was made unsafe in #5593,
by adding the `unsafe fn clone_fetch` to `WorldQuery`. However, as that
method's documentation explains, it is not the right place to put the
safety invariant:

> While calling this method on its own cannot cause UB it is marked
`unsafe` as the caller must ensure that the returned value is not used
in any way that would cause two `QueryItem<Self>` for the same
`archetype_index` or `table_row` to be alive at the same time.

You can clone a fetch struct all you want and it will never cause
undefined behavior -- in order for something to go wrong, you need to
improperly call `WorldQuery::fetch` with it (which is marked unsafe).
Additionally, making it unsafe to clone a fetch struct does not even
prevent undefined behavior, since there are other ways to incorrectly
use a fetch struct. For example, you could just call fetch more than
once for the same entity, which is not currently forbidden by any
documented invariants.

## Solution

Document a safety invariant on `WorldQuery::fetch` that requires the
caller to not create aliased `WorldQueryItem`s for mutable types. Remove
the `clone_fetch` function, and add the bound `Fetch: Clone` instead.

---

## Changelog

- Removed the associated function `WorldQuery::clone_fetch`, and added a
`Clone` bound to `WorldQuery::Fetch`.

## Migration Guide

### `fetch` invariants

The function `WorldQuery::fetch` has had the following safety invariant
added:

> If this type does not implement `ReadOnlyWorldQuery`, then the caller
must ensure that it is impossible for more than one `Self::Item` to
exist for the same entity at any given time.

This invariant was always required for soundness, but was previously
undocumented. If you called this function manually anywhere, you should
check to make sure that this invariant is not violated.

### Removed `clone_fetch`

The function `WorldQuery::clone_fetch` has been removed. The associated
type `WorldQuery::Fetch` now has the bound `Clone`.

Before:

```rust
struct MyFetch<'w> { ... }

unsafe impl WorldQuery for MyQuery {
    ...
    type Fetch<'w> = MyFetch<'w>
    unsafe fn clone_fetch<'w>(fetch: &Self::Fetch<'w>) -> Self::Fetch<'w> {
        MyFetch {
            field1: fetch.field1,
            field2: fetch.field2.clone(),
            ...
        }
    }
}
```

After:

```rust
#[derive(Clone)]
struct MyFetch<'w> { ... }

unsafe impl WorldQuery for MyQuery {
    ...
    type Fetch<'w> = MyFetch<'w>;
}
```

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
2023-07-25 21:16:22 +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