Commit graph

585 commits

Author SHA1 Message Date
Boxy
be19c696bd Add missing ReadOnly = Self bound (#5462)
# Objective
`ReadOnlyWorldQuery` should have required `Self::ReadOnly = Self` so that calling `.iter()` on a readonly query is equivelent to calling `iter_mut()`.

## Solution

add `ReadOnly = Self` to the definition of `ReadOnlyWorldQuery`

---

## Changelog

ReadOnlyWorldQuery's `ReadOnly` assoc type is now always equal to `Self`

## Migration Guide

Make `Self::ReadOnly = Self` hold
2022-07-27 06:49:36 +00:00
Jerome Humbert
d4787111a3 Conversion of ResMut and NonSendMut to Mut (#5438)
# Objective

Enable treating components and resources equally, which can
simplify the implementation of some systems where only the change
detection feature is relevant and not the kind of object (resource or
component).

## Solution

Implement `From<ResMut<T>>` and `From<NonSendMut<T>>` for
`Mut`. Since the 3 structs are similar, and only differ by their system
param role, the conversion is trivial.

---

## Changelog

Added - `From<ResMut>` and `From<NonSendMut>` for `Mut<T>`.
2022-07-25 16:11:29 +00:00
Rob Parrett
cfee0e882e Fix various typos (#5417)
## Objective

- Fix some typos

## Solution

- Fix em. 
- My favorite was `maxizimed`
2022-07-21 20:46:54 +00:00
JoJoJet
56e9a3de88 improve documentation for macro-generated label types (#5367)
# Objective

I noticed while working on #5366 that the documentation for label types wasn't working correctly. Having experimented with this for a few weeks, I believe that generating docs in macros is more effort than it's worth.

## Solution

Add more boilerplate, copy-paste and edit the docs across types. This also lets us add custom doctests for specific types. Also, we don't need `concat_idents` as a dependency anymore.
2022-07-20 19:39:42 +00:00
harudagondi
959f3b1186 Allows conversion of mutable queries to immutable queries (#5376)
# Objective

- Allows conversion of mutable queries to immutable queries.
- Fixes #4606

## Solution

- Add `to_readonly` method on `Query`, which uses `QueryState::as_readonly`
- `AsRef` is not feasible because creation of new queries is needed.

---

## Changelog

### Added

- Allows conversion of mutable queries to immutable queries using `Query::to_readonly`.
2022-07-20 01:09:45 +00:00
François
0fa499a7d0 rename send_default_event to send_event_default on world (#5383)
after #5355, three methods were added on world:
* `send_event`
* `send_event_batch`
* `send_default_event`

rename `send_default_event` to `send_event_default` for better discoverability
2022-07-19 22:28:05 +00:00
Aevyrie
282f8ed0b9 Add helpers to send Events from World (#5355)
# Objective

- With access to `World`, it's not obvious how to send an event.
- This is especially useful if you are writing a `Command` that needs to send an `Event`.
- `Events` are a first-class construct in bevy, even though they are just `Resources` under the hood. Their methods should be discoverable.

## Solution

- Provide a simple helpers to send events through `Res<Events<T>>`.
---

## Changelog

> `send_event`, `send_default_event`, and `send_event_batch` methods added to `World`.
2022-07-19 20:54:03 +00:00
JoJoJet
44e9cd4bfc Add attribute to ignore fields of derived labels (#5366)
# Objective

Fixes #5362 

## Solution

Add the attribute `#[label(ignore_fields)]` for `*Label` types.

```rust
#[derive(SystemLabel)]
pub enum MyLabel {
    One,

    // Previously this was not allowed since labels cannot contain data.
    #[system_label(ignore_fields)]
    Two(PhantomData<usize>),
}
```

## Notes

This label makes it possible for equality to behave differently depending on whether or not you are treating the type as a label. For example:

```rust
#[derive(SystemLabel, PartialEq, Eq)]
#[system_label(ignore_fields)]
pub struct Foo(usize);
```

If you compare it as a label, it will ignore the wrapped fields as the user requested. But if you compare it as a `Foo`, the derive will incorrectly compare the inner fields. I see a few solutions

1. Do nothing. This is technically intended behavior, but I think we should do our best to prevent footguns.
2. Generate impls of `PartialEq` and `Eq` along with the `#[derive(Label)]` macros. This is a breaking change as it requires all users to remove these derives from their types.
3. Only allow `PhantomData` to be used with `ignore_fields` -- seems needlessly prescriptive.

---

## Changelog

* Added the `ignore_fields` attribute to the derive macros for `*Label` types.
* Added an example showing off different forms of the derive macro.

<!--
## Migration Guide

> This section is optional. If there are no breaking changes, you can delete this section.

- If this PR is a breaking change (relative to the last release of Bevy), describe how a user might need to migrate their code to support these changes
- Simply adding new functionality is not a breaking change.
- Fixing behavior that was definitely a bug, rather than a questionable design choice is not a breaking change.
-->
2022-07-19 05:21:19 +00:00
Boxy
1ac8a476cf remove QF generics from all Query/State methods and types (#5170)
# Objective

remove `QF` generics from a bunch of types and methods on query related items. this has a few benefits:
- simplifies type signatures `fn iter(&self) -> QueryIter<'_, 's, Q::ReadOnly, F::ReadOnly>` is (imo) conceptually simpler than `fn iter(&self) -> QueryIter<'_, 's, Q, ROQueryFetch<'_, Q>, F>`
- `Fetch` is mostly an implementation detail but previously we had to expose it on every `iter` `get` etc method
- Allows us to potentially in the future simplify the `WorldQuery` trait hierarchy by removing the `Fetch` trait

## Solution

remove the `QF` generic and add a way to (unsafely) turn `&QueryState<Q1, F1>` into `&QueryState<Q2, F2>`

---

## Changelog/Migration Guide

The `QF` generic was removed from various `Query` iterator types and some methods, you should update your code to use the type of the corresponding worldquery of the fetch type that was being used, or call `as_readonly`/`as_nop` to convert a querystate to the appropriate type. For example:
`.get_single_unchecked_manual::<ROQueryFetch<Q>>(..)` -> `.as_readonly().get_single_unchecked_manual(..)`
`my_field: QueryIter<'w, 's, Q, ROQueryFetch<'w, Q>, F>` -> `my_field: QueryIter<'w, 's, Q::ReadOnly, F::ReadOnly>`
2022-07-19 00:45:00 +00:00
JoJoJet
c43295af80 Simplify design for *Labels (#4957)
# Objective

- Closes #4954 
- Reduce the complexity of the `{System, App, *}Label` APIs.

## Solution

For the sake of brevity I will only refer to `SystemLabel`, but everything applies to all of the other label types as well.

- Add `SystemLabelId`, a lightweight, `copy` struct.
- Convert custom types into `SystemLabelId` using the trait `SystemLabel`.

## Changelog

- String literals implement `SystemLabel` for now, but this should be changed with #4409 .

## Migration Guide

- Any previous use of `Box<dyn SystemLabel>` should be replaced with `SystemLabelId`.
- `AsSystemLabel` trait has been modified.
    - No more output generics.
    - Method `as_system_label` now returns `SystemLabelId`, removing an unnecessary level of indirection.
- If you *need* a label that is determined at runtime, you can use `Box::leak`. Not recommended.

## Questions for later

* Should we generate a `Debug` impl along with `#[derive(*Label)]`?
* Should we rename `as_str()`?
* Should we remove the extra derives (such as `Hash`) from builtin `*Label` types?
* Should we automatically derive types like `Clone, Copy, PartialEq, Eq`?
* More-ergonomic comparisons between `Label` and `LabelId`.
* Move `Dyn{Eq, Hash,Clone}` somewhere else.
* Some API to make interning dynamic labels easier.
* Optimize string representation
    * Empty string for unit structs -- no debug info but faster comparisons
    * Don't show enum types -- same tradeoffs as asbove.
2022-07-14 18:23:01 +00:00
ira
234e5af882 Implement From<bool> for ShouldRun. (#5306)
Make writing simple yes/no run criteria easier.


Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-07-14 17:26:40 +00:00
Daniel Liu
fe59fe5860 Add assert_is_exclusive_system function (#5275)
Add compile time check for if a system is an exclusive system. Resolves #4788 

Co-authored-by: Daniel Liu <mr.picklepinosaur@gmail.com>
Co-authored-by: Daniel Liu <danieliu3120@gmail.com>
2022-07-14 01:12:15 +00:00
Nicola Papale
6c06fc5b7c Add ExactSizeIterator implementation for QueryCombinatonIter (#5148)
Following https://github.com/bevyengine/bevy/pull/5124 I decided to add the `ExactSizeIterator` impl for `QueryCombinationIter`.

Also:
- Clean up the tests for `size_hint` and `len` for both the normal `QueryIter` and `QueryCombinationIter`.
- Add tests to `QueryCombinationIter` when it shouldn't be `ExactSizeIterator`

---

## Changelog

- Added `ExactSizeIterator` implementation for `QueryCombinatonIter`
2022-07-13 16:08:48 +00:00
harudagondi
1dbb1f7b20 Allow iter combinations on custom world queries (#5286)
# Objective

- `.iter_combinations_*()` cannot be used on custom derived `WorldQuery`, so this fixes that
- Fixes #5284

## Solution

- `#[derive(Clone)]` on the `Fetch` of the proc macro derive.
- `#[derive(Clone)]` for `AnyOf` to satisfy tests.
2022-07-13 15:37:27 +00:00
JoJoJet
bb9706c96f Document exotic patterns for Commands and Events (#4840)
# Objective

Improve documentation, information users of the limitations in bevy's idiomatic patterns, and suggesting alternatives for when those limitations are encountered.

## Solution

* Add documentation to `Commands` informing the user of the option of writing one-shot commands with closures.
* Add documentation to `EventWriter` regarding the limitations of event types, and suggesting alternatives using commands.
2022-07-13 14:40:52 +00:00
CGMossa
93a131661d Very minor doc formatting changes (#5287)
# Objective

- Added a bunch of backticks to things that should have them, like equations, abstract variable names,
- Changed all small x, y, and z to capitals X, Y, Z.

This might be more annoying than helpful; Feel free to refuse this PR.
2022-07-12 13:06:16 +00:00
ira
4847f7e3ad Update codebase to use IntoIterator where possible. (#5269)
Remove unnecessary calls to `iter()`/`iter_mut()`.
Mainly updates the use of queries in our code, docs, and examples.

```rust
// From
for _ in list.iter() {
for _ in list.iter_mut() {

// To
for _ in &list {
for _ in &mut list {
```

We already enable the pedantic lint [clippy::explicit_iter_loop](https://rust-lang.github.io/rust-clippy/stable/) inside of Bevy. However, this only warns for a few known types from the standard library.

## Note for reviewers
As you can see the additions and deletions are exactly equal.
Maybe give it a quick skim to check I didn't sneak in a crypto miner, but you don't have to torture yourself by reading every line.
I already experienced enough pain making this PR :) 


Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-07-11 15:28:50 +00:00
Hennadii Chernyshchyk
1da6720132 Add apply_or_insert functions to reflected component and resources (#5201)
# Objective

`ReflectResource` and `ReflectComponent` will panic on `apply` method if there is no such component. It's not very ergonomic. And not very good for performance since I need to check if such component exists first.

## Solution

* Add `ReflectComponent::apply_or_insert` and `ReflectResource::apply_or_insert` functions.
* Rename `ReflectComponent::add` into `ReflectComponent::insert` for consistency.

---

## Changelog

### Added

* `ReflectResource::apply_or_insert` and `ReflectComponent::apply_on_insert`.

### Changed

* Rename `ReflectComponent::add` into `ReflectComponent::insert` for consistency.
* Use `ReflectComponent::apply_on_insert` in `DynamicScene` instead of manual checking.

## Migration Guide

* Rename `ReflectComponent::add` into `ReflectComponent::insert`.
2022-07-11 14:11:24 +00:00
Daniel McNab
7b2cf98896 Make RenderStage::Extract run on the render world (#4402)
# Objective

- Currently, the `Extract` `RenderStage` is executed on the main world, with the render world available as a resource.
- However, when needing access to resources in the render world (e.g. to mutate them), the only way to do so was to get exclusive access to the whole `RenderWorld` resource.
- This meant that effectively only one extract which wrote to resources could run at a time.
- We didn't previously make `Extract`ing writing to the world a non-happy path, even though we want to discourage that.

## Solution

- Move the extract stage to run on the render world.
- Add the main world as a `MainWorld` resource.
- Add an `Extract` `SystemParam` as a convenience to access a (read only) `SystemParam` in the main world during `Extract`.

## Future work

It should be possible to avoid needing to use `get_or_spawn` for the render commands, since now the `Commands`' `Entities` matches up with the world being executed on.
We need to determine how this interacts with https://github.com/bevyengine/bevy/pull/3519
It's theoretically possible to remove the need for the `value` method on `Extract`. However, that requires slightly changing the `SystemParam` interface, which would make it more complicated. That would probably mess up the `SystemState` api too.

## Todo
I still need to add doc comments to `Extract`.

---

## Changelog

### Changed
- The `Extract` `RenderStage` now runs on the render world (instead of the main world as before).
   You must use the `Extract` `SystemParam` to access the main world during the extract phase.
   Resources on the render world can now be accessed using `ResMut` during extract.

### Removed
- `Commands::spawn_and_forget`. Use `Commands::get_or_spawn(e).insert_bundle(bundle)` instead

## Migration Guide

The `Extract` `RenderStage` now runs on the render world (instead of the main world as before).
You must use the `Extract` `SystemParam` to access the main world during the extract phase. `Extract` takes a single type parameter, which is any system parameter (such as `Res`, `Query` etc.). It will extract this from the main world, and returns the result of this extraction when `value` is called on it.

For example, if previously your extract system looked like:
```rust
fn extract_clouds(mut commands: Commands, clouds: Query<Entity, With<Cloud>>) {
    for cloud in clouds.iter() {
        commands.get_or_spawn(cloud).insert(Cloud);
    }
}
```
the new version would be:
```rust
fn extract_clouds(mut commands: Commands, mut clouds: Extract<Query<Entity, With<Cloud>>>) {
    for cloud in clouds.value().iter() {
        commands.get_or_spawn(cloud).insert(Cloud);
    }
}
```
The diff is:
```diff
--- a/src/clouds.rs
+++ b/src/clouds.rs
@@ -1,5 +1,5 @@
-fn extract_clouds(mut commands: Commands, clouds: Query<Entity, With<Cloud>>) {
-    for cloud in clouds.iter() {
+fn extract_clouds(mut commands: Commands, mut clouds: Extract<Query<Entity, With<Cloud>>>) {
+    for cloud in clouds.value().iter() {
         commands.get_or_spawn(cloud).insert(Cloud);
     }
 }
```
You can now also access resources from the render world using the normal system parameters during `Extract`:
```rust
fn extract_assets(mut render_assets: ResMut<MyAssets>, source_assets: Extract<Res<MyAssets>>) {
     *render_assets = source_assets.clone();
}
```
Please note that all existing extract systems need to be updated to match this new style; even if they currently compile they will not run as expected. A warning will be emitted on a best-effort basis if this is not met.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-07-08 23:56:33 +00:00
Hennadii Chernyshchyk
17e87f116f Improve EntityMap API (#5231)
# Objective

`EntityMap` lacks documentation, don't have `len()` / `is_empty` and `insert` doesn't work as in the regular HashMap`.

## Solution

* Add `len()` method.
* Return previously mapped entity from `insert()` as in the regular `HashMap`.
* Add documentation.

---

## Changelog

* Add `EntityMap::len()`.
* Return previously mapped entity from `EntityMap::insert()` as in the regular `HashMap`.
* Add documentation for `EntityMap` methods.
2022-07-08 01:14:24 +00:00
Obdzen
cf200f09dd Fix typo in Word::get_by_id docs (#5246)
I believe this should read `immutable` not `mutable`



Co-authored-by: Obdzen <108854527+Obdzen@users.noreply.github.com>
2022-07-07 15:25:17 +00:00
Oliver Pauffley
bf1ca81779 remove component and resource suffixes from reflect structs (#5219)
# Objective

Remove suffixes from reflect component and resource methods to closer match bevy norms.

## Solution

removed suffixes and also fixed a spelling error

---
2022-07-06 02:59:51 +00:00
François
f73987ae84 add a more helpful error to help debug panicking command on despawned entity (#5198)
# Objective

- Help users fix issue when their app panic when executing a command on a despawned entity

## Solution

- Add an error code and a page describing how to debug the issue
2022-07-05 18:44:54 +00:00
Thierry Berger
faa40bfc82 Fix markdownlint privileges complaint (#5216)
# Objective

Fixes an annoying error message in CI.

more info at https://github.com/github/super-linter/pull/2464

![image](https://user-images.githubusercontent.com/2290685/177364755-fe607c9c-615e-477c-8e91-d35aae07ab0b.png)
2022-07-05 15:49:11 +00:00
Alice Cecile
2c9bc0b31f Remove dead SystemLabelMarker struct (#5190)
This struct had no internal use, docs, or intuitable external use.

It has been removed.
2022-07-04 15:12:35 +00:00
Jakob Hellermann
d38a8dfdd7 add more SAFETY comments and lint for missing ones in bevy_ecs (#4835)
# Objective

`SAFETY` comments are meant to be placed before `unsafe` blocks and should contain the reasoning of why in this case the usage of unsafe is okay. This is useful when reading the code because it makes it clear which assumptions are required for safety, and makes it easier to spot possible unsoundness holes. It also forces the code writer to think of something to write and maybe look at the safety contracts of any called unsafe methods again to double-check their correct usage.

There's a clippy lint called `undocumented_unsafe_blocks` which warns when using a block without such a comment. 

## Solution

- since clippy expects `SAFETY` instead of `SAFE`, rename those
- add `SAFETY` comments in more places
- for the last remaining 3 places, add an `#[allow()]` and `// TODO` since I wasn't comfortable enough with the code to justify their safety
- add ` #![warn(clippy::undocumented_unsafe_blocks)]` to `bevy_ecs`


### Note for reviewers

The first commit only renames `SAFETY` to `SAFE` so it doesn't need a thorough review.
cb042a416e..55cef2d6fa is the diff for all other changes.

### Safety comments where I'm not too familiar with the code

774012ece5/crates/bevy_ecs/src/entity/mod.rs (L540-L546)

774012ece5/crates/bevy_ecs/src/world/entity_ref.rs (L249-L252)

### Locations left undocumented with a `TODO` comment

5dde944a30/crates/bevy_ecs/src/schedule/executor_parallel.rs (L196-L199)

5dde944a30/crates/bevy_ecs/src/world/entity_ref.rs (L287-L289)

5dde944a30/crates/bevy_ecs/src/world/entity_ref.rs (L413-L415)

Co-authored-by: Jakob Hellermann <hellermann@sipgate.de>
2022-07-04 14:44:24 +00:00
Hennadii Chernyshchyk
534cad611d Add reflection for resources (#5175)
# Objective

We don't have reflection for resources.

## Solution

Introduce reflection for resources.

Continues #3580 (by @Davier), related to #3576.

---

## Changelog

### Added

* Reflection on a resource type (by adding `ReflectResource`):

```rust
#[derive(Reflect)]
#[reflect(Resource)]
struct MyResourse;
```

### Changed

* Rename `ReflectComponent::add_component` into `ReflectComponent::insert_component` for consistency.

## Migration Guide

* Rename `ReflectComponent::add_component` into `ReflectComponent::insert_component`.
2022-07-04 13:04:20 +00:00
Alice Cecile
3a102e7dc2 Add Events to bevy_ecs prelude (#5159)
# Objective

This is a common and useful type. I frequently use this when working with `Events` resource directly, typically when caching the data or manipulating the `World` directly.

This is also useful when manually configuring the cleanup strategy for events.
2022-07-04 13:04:17 +00:00
LoipesMas
de92054bbe Improve Command(s) docs (#4994)
# Objective

- Improve Command(s) docs
- Fixes #4737 

## Solution

- Update and improve documentation.

---
- "list" -> "queue" in `Commands` doc (this better represents reality)
- expand `Command` doc
- update/improve `Commands::add` doc, as specified in linked issue

Let me know if you want any changes!
2022-07-02 09:49:20 +00:00
Boxy
a1a07945d6 fix some memory leaks detected by miri (#4959)
The first leak:
```rust
    #[test]
    fn blob_vec_drop_empty_capacity() {
        let item_layout = Layout:🆕:<Foo>();
        let drop = drop_ptr::<Foo>;
        let _ = unsafe { BlobVec::new(item_layout, Some(drop), 0) };
    }
```
this is because we allocate the swap scratch in blobvec regardless of what the capacity is, but we only deallocate if capacity is > 0

The second leak:
```rust
    #[test]
    fn panic_while_overwriting_component() {
        let helper = DropTestHelper::new();

        let res = panic::catch_unwind(|| {
            let mut world = World::new();
            world
                .spawn()
                .insert(helper.make_component(true, 0))
                .insert(helper.make_component(false, 1));

            println!("Done inserting! Dropping world...");
        });

        let drop_log = helper.finish(res);

        assert_eq!(
            &*drop_log,
            [
                DropLogItem::Create(0),
                DropLogItem::Create(1),
                DropLogItem::Drop(0),
            ]
        );
    }
```
this is caused by us not running the drop impl on the to-be-inserted component if the drop impl of the overwritten component panics

---

managed to figure out where the leaks were by using this 10/10 command
```
cargo --quiet test --lib -- --list | sed 's/: test$//' | MIRIFLAGS="-Zmiri-disable-isolation" xargs -n1 cargo miri test --lib -- --exact
```
which runs every test one by one rather than all at once which let miri actually tell me which test had the leak 🙃
2022-07-01 21:54:28 +00:00
Jakob Hellermann
49ff42cc69 fix new clippy lints (#5160)
# Objective

- Nightly clippy lints should be fixed before they get stable and break CI
  
## Solution

- fix new clippy lints
- ignore `significant_drop_in_scrutinee` since it isn't relevant in our loop https://github.com/rust-lang/rust-clippy/issues/8987
```rust
for line in io::stdin().lines() {
    ...
}
```

Co-authored-by: Jakob Hellermann <hellermann@sipgate.de>
2022-07-01 13:41:23 +00:00
Rob Parrett
5e1756954f Derive default for enums where possible (#5158)
# Objective

Fixes #5153

## Solution

Search for all enums and manually check if they have default impls that can use this new derive.

By my reckoning:

| enum | num |
|-|-|
| total | 159 |
| has default impl | 29 |
| default is unit variant | 23 |
2022-07-01 03:42:15 +00:00
Carter Anderson
96f0ebb9af Fix rust 1.62 changes (#5154)
# Objective

CI is now failing with some changes that landed in 1.62.

## Solution

* Fix an unused lifetime by using it (we double-used the `w` lifetime).
* Update compile_fail error messages
* temporarily disable check-unused-dependencies
2022-06-30 19:24:28 +00:00
harudagondi
b3fa4790b7 Add ability to inspect entity's components (#5136)
# Objective

- Provide a way to see the components of an entity.
- Fixes #1467

## Solution

- Add `World::inspect_entity`. It accepts an `Entity` and returns a vector of `&ComponentInfo` that the entity has.
- Add `EntityCommands::log_components`. It logs the component names of the entity. (info level)

---

## Changelog

### Added
- Ability to inspect components of an entity through `World::inspect_entity` or `EntityCommands::log_components`
2022-06-30 15:23:09 +00:00
Jakob Hellermann
5b5660ea08 remove unnecessary unsafe impl of Send+Sync for ParallelSystemContainer (#5137)
`ParallelSystemContainer` has no `!Send` or `!Sync` fields, so it doesn't need unsafe impls of these traits.
2022-06-29 15:44:33 +00:00
Mike
510ce5e832 fix resource not found error message (#5128)
There are some outdated error messages for when a resource is not found. It references `add_resource` and `add_non_send_resource` which were renamed to `insert_resource` and `insert_non_send_resource`.
2022-06-29 02:29:51 +00:00
harudagondi
6e50b249a4 Update ExactSizeIterator impl to support archetypal filters (With, Without) (#5124)
# Objective

- Fixes #3142

## Solution

- Done according to #3142
- Created new marker trait `ArchetypeFilter`
- Implement said trait to:
  - `With<T>`
  - `Without<T>`
  - tuples containing only types that implement `ArchetypeFilter`, from 0 to 15 elements
  - `Or<T>` where T is a tuple as described previously
- Changed `ExactSizeIterator` impl to include a new generic that must implement `WorldQuery` and `ArchetypeFilter`
- Added new tests

---

## Changelog

### Added
- `Query`s with archetypal filters can now use `.iter().len()` to get the exact size of the iterator.
2022-06-29 02:15:28 +00:00
Saverio Miroddi
e28b88b378 Fix Events example link (#5126)
The `crate` intermediate directory is missing from the path, which currently leads to 404.
2022-06-28 16:37:36 +00:00
James Liu
9eb69282ef Directly copy moved Table components to the target location (#5056)
# Objective
Speed up entity moves between tables by reducing the number of copies conducted. Currently three separate copies are conducted: `src[index] -> swap scratch`, `src[last] -> src[index]`, and `swap scratch -> dst[target]`. The first and last copies can be merged by directly using the copy `src[index] -> dst[target]`, which can save quite some time if the component(s) in question are large.

## Solution
This PR does the  following:

 - Adds `BlobVec::swap_remove_unchecked(usize, PtrMut<'_>)`, which is identical to `swap_remove_and_forget_unchecked`, but skips the `swap_scratch` and directly copies the component into the provided `PtrMut<'_>`.
 - Build `Column::initialize_from_unchecked(&mut Column, usize, usize)` on top of it, which uses the above to directly initialize a row from another column. 
 - Update most of the table move APIs to use `initialize_from_unchecked` instead of a combination of `swap_remove_and_forget_unchecked` and `initialize`.

This is an alternative, though orthogonal, approach to achieve the same performance gains as seen in #4853. This (hopefully) shouldn't run into the same Miri limitations that said PR currently does.  After this PR, `swap_remove_and_forget_unchecked` is still in use for Resources and swap_scratch likely still should be removed, so #4853 still has use, even if this PR is merged.

## Performance
TODO: Microbenchmark

This PR shows similar improvements to commands that add or remove table components that result in a table move. When tested on `many_cubes sphere`, some of the more command heavy systems saw notable improvements. In particular, `prepare_uniform_components<T>`, this saw a reduction in time from 1.35ms to 1.13ms (a 16.3% improvement) on my local machine, a similar if not slightly better gain than what #4853 showed [here](https://github.com/bevyengine/bevy/pull/4853#issuecomment-1159346106).

![image](https://user-images.githubusercontent.com/3137680/174570088-1c4c6fd7-3215-478c-9eb7-8bd9fe486b32.png)

The command heavy `Extract` stage also saw a smaller overall improvement:

![image](https://user-images.githubusercontent.com/3137680/174572261-8a48f004-ab9f-4cb2-b304-a882b6d78065.png)
---

## Changelog
Added: `BlobVec::swap_remove_unchecked`.
Added: `Column::initialize_from_unchecked`.
2022-06-27 16:52:26 +00:00
Federico Rinaldi
e57abc1c42 Remove double blank line from component docs (#5102)
A small trivial documentation fix. Check the changed file.
2022-06-26 14:24:04 +00:00
Garett Cooper
fa56a5cd51 Add component_id function to World and Components (#5066)
# Objective

- Simplify the process of obtaining a `ComponentId` instance corresponding to a `Component`.
- Resolves #5060.

## Solution

- Add a `component_id::<T: Component>(&self)` function to both `World` and `Components` to retrieve the `ComponentId` associated with `T` from a immutable reference.

---

## Changelog

- Added `World::component_id::<C>()` and `Components::component_id::<C>()` to retrieve a `Component`'s corresponding `ComponentId` if it exists.
2022-06-25 20:41:54 +00:00
James Liu
c988264180 Mark mutable APIs under ECS storage as pub(crate) (#5065)
# Objective
Closes #1557. Partially addresses #3362.

Cleanup the public facing API for storage types. Most of these APIs are difficult to use safely when directly interfacing with these types, and is also currently impossible to interact with in normal ECS use as there is no `World::storages_mut`. The majority of these types should be easy enough to read, and perhaps mutate the contents, but never structurally altered without the same checks in the rest of bevy_ecs code. This both cleans up the public facing types and helps use unused code detection to remove a few of the APIs we're not using internally. 

## Solution

 - Mark all APIs that take `&mut T` under `bevy_ecs::storage` as `pub(crate)` or `pub(super)`
 - Cleanup after it all.

Entire type visibility changes:

 - `BlobVec` is `pub(super)`, only storage code should be directly interacting with it.
 - `SparseArray` is now `pub(crate)` for the entire type. It's an implementation detail for `Table` and `(Component)SparseSet`.
 - `TableMoveResult` is now `pub(crate)

---

## Changelog
TODO

## Migration Guide
Dear God, I hope not.
2022-06-21 20:35:26 +00:00
Federico Rinaldi
511bcc9633 Improve entity and component API docs (#4767)
# Objective

The descriptions included in the API docs of `entity` module, `Entity` struct, and `Component` trait have some issues:
1. the concept of entity is not clearly defined,
2. descriptions are a little bit out of place,
3. in a case the description leak too many details about the implementation,
4. some descriptions are not exhaustive,
5. there are not enough examples,
6. the content can be formatted in a much better way.

## Solution

1. ~~Stress the fact that entity is an abstract and elementary concept. Abstract because the concept of entity is not hardcoded into the library but emerges from the interaction of `Entity` with every other part of `bevy_ecs`, like components and world methods. Elementary because it is a fundamental concept that cannot be defined with other terms (like point in euclidean geometry, or time in classical physics).~~ We decided to omit the definition of entity in the API docs ([see why]). It is only described in its relationship with components.
2. Information has been moved to relevant places and links are used instead in the other places.
3. Implementation details about `Entity` have been reduced.
4. Descriptions have been made more exhaustive by stating how to obtain and use items. Entity operations are enriched with `World` methods.
5. Examples have been added or enriched.
6. Sections have been added to organize content. Entity operations are now laid out in a table.

### Todo list

- [x] Break lines at sentence-level.

## For reviewers

- ~~I added a TODO over `Component` docs, make sure to check it out and discuss it if necessary.~~ ([Resolved])
- You can easily check the rendered documentation by doing `cargo doc -p bevy_ecs --no-deps --open`.

[see why]: https://github.com/bevyengine/bevy/pull/4767#discussion_r875106329
[Resolved]: https://github.com/bevyengine/bevy/pull/4767#discussion_r874127825
2022-06-21 15:29:22 +00:00
Jakob Hellermann
218b0fd3b6 bevy_reflect: put serialize into external ReflectSerialize type (#4782)
builds on top of #4780 

# Objective

`Reflect` and `Serialize` are currently very tied together because `Reflect` has a `fn serialize(&self) -> Option<Serializable<'_>>` method. Because of that, we can either implement `Reflect` for types like `Option<T>` with `T: Serialize` and have `fn serialize` be implemented, or without the bound but having `fn serialize` return `None`.

By separating `ReflectSerialize` into a separate type (like how it already is for `ReflectDeserialize`, `ReflectDefault`), we could separately `.register::<Option<T>>()` and `.register_data::<Option<T>, ReflectSerialize>()` only if the type `T: Serialize`.

This PR does not change the registration but allows it to be changed in a future PR.

## Solution

- add the type
```rust
struct ReflectSerialize { .. }
impl<T: Reflect + Serialize> FromType<T> for ReflectSerialize { .. }
```

- remove `#[reflect(Serialize)]` special casing. 

- when serializing reflect value types, look for `ReflectSerialize` in the `TypeRegistry` instead of calling `value.serialize()`
2022-06-20 17:18:58 +00:00
Alice Cecile
dc950a4d2f Fix broken WorldCell test (#5009)
# Objective

Fixes #5008. Aliasing references is allowed under Rust if and only if they are immutable.

This logic applies to `WorldCell` as well.
2022-06-14 16:14:33 +00:00
Boxy
407c080e59 Replace ReadOnlyFetch with ReadOnlyWorldQuery (#4626)
# Objective

- Fix a type inference regression introduced by #3001
- Make read only bounds on world queries more user friendly

ptrification required you to write `Q::Fetch: ReadOnlyFetch` as `for<'w> QueryFetch<'w, Q>: ReadOnlyFetch` which has the same type inference problem as `for<'w> QueryFetch<'w, Q>: FilterFetch<'w>` had, i.e. the following code would error:
```rust
#[derive(Component)]
struct Foo;

fn bar(a: Query<(&Foo, Without<Foo>)>) {
    foo(a);
}

fn foo<Q: WorldQuery>(a: Query<Q, ()>)
where
    for<'w> QueryFetch<'w, Q>: ReadOnlyFetch,
{
}
```
`for<..>` bounds are also rather user unfriendly..

## Solution

Remove the `ReadOnlyFetch` trait in favour of a `ReadOnlyWorldQuery` trait, and remove `WorldQueryGats::ReadOnlyFetch` in favor of `WorldQuery::ReadOnly` allowing the previous code snippet to be written as:
```rust
#[derive(Component)]
struct Foo;

fn bar(a: Query<(&Foo, Without<Foo>)>) {
    foo(a);
}

fn foo<Q: ReadOnlyWorldQuery>(a: Query<Q, ()>) {}
``` 
This avoids the `for<...>` bound which makes the code simpler and also fixes the type inference issue.

The reason for moving the two functions out of `FetchState` and into `WorldQuery` is to allow the world query `&mut T` to share a `State` with the `&T` world query so that it can have `type ReadOnly = &T`. Presumably it would be possible to instead have a `ReadOnlyRefMut<T>` world query and then do `type ReadOnly = ReadOnlyRefMut<T>` much like how (before this PR) we had a `ReadOnlyWriteFetch<T>`. A side benefit of the current solution in this PR is that it will likely make it easier in the future to support an API such as `Query<&mut T> -> Query<&T>`. The primary benefit IMO is just that `ReadOnlyRefMut<T>` and its associated fetch would have to reimplement all of the logic that the `&T` world query impl does but this solution avoids that :)

---

## Changelog/Migration Guide

The trait `ReadOnlyFetch` has been replaced with `ReadOnlyWorldQuery` along with the `WorldQueryGats::ReadOnlyFetch` assoc type which has been replaced with `<WorldQuery::ReadOnly as WorldQueryGats>::Fetch`
- Any where clauses such as `QueryFetch<Q>: ReadOnlyFetch` should be replaced with `Q: ReadOnlyWorldQuery`.
- Any custom world query impls should implement `ReadOnlyWorldQuery` insead of `ReadOnlyFetch`

Functions `update_component_access` and `update_archetype_component_access` have been moved from the `FetchState` trait to `WorldQuery`
- Any callers should now call `Q::update_component_access(state` instead of `state.update_component_access` (and `update_archetype_component_access` respectively)
- Any custom world query impls should move the functions from the `FetchState` impl to `WorldQuery` impl

`WorldQuery` has been made an `unsafe trait`, `FetchState` has been made a safe `trait`. (I think this is how it should have always been, but regardless this is _definitely_ necessary now that the two functions have been moved to `WorldQuery`)
- If you have a custom `FetchState` impl make it a normal `impl` instead of `unsafe impl`
- If you have a custom `WorldQuery` impl make it an `unsafe impl`, if your code was sound before it is going to still be sound
2022-06-13 23:35:54 +00:00
Chris Dawkins
b7d784de6e Bugfix State::set transition condition infinite loop (#4890)
# Objective

- Fixes #4271

## Solution

- Check for a pending transition in addition to a scheduled operation.
- I don't see a valid reason for updating the state unless both `scheduled` and `transition` are empty.
2022-06-12 19:34:26 +00:00
James Liu
cdb62af4bf Replace ComponentSparseSet's internals with a Column (#4909)
# Objective
Following #4855, `Column` is just a parallel `BlobVec`/`Vec<UnsafeCell<ComponentTicks>>` pair, which is identical to the dense and ticks vecs in `ComponentSparseSet`, which has some code duplication with `Column`.

## Solution
Replace dense and ticks in `ComponentSparseSet` with a `Column`.
2022-06-09 03:34:51 +00:00
James Liu
f2b545049c Implement FusedIterator for eligible Iterator types (#4942)
# Objective
Most of our `Iterator` impls satisfy the requirements of `std::iter::FusedIterator`, which has internal specialization that optimizes `Interator::fuse`. The std lib iterator combinators do have a few that rely on `fuse`, so this could optimize those use cases. I don't think we're using any of them in the engine itself, but beyond a light increase in compile time, it doesn't hurt to implement the trait.

## Solution
Implement the trait for all eligible iterators in first party crates. Also add a missing `ExactSizeIterator` on an iterator that could use it.
2022-06-09 03:19:31 +00:00
James Liu
012ae07dc8 Add global init and get accessors for all newtyped TaskPools (#2250)
Right now, a direct reference to the target TaskPool is required to launch tasks on the pools, despite the three newtyped pools (AsyncComputeTaskPool, ComputeTaskPool, and IoTaskPool) effectively acting as global instances. The need to pass a TaskPool reference adds notable friction to spawning subtasks within existing tasks. Possible use cases for this may include chaining tasks within the same pool like spawning separate send/receive I/O tasks after waiting on a network connection to be established, or allowing cross-pool dependent tasks like starting dependent multi-frame computations following a long I/O load. 

Other task execution runtimes provide static access to spawning tasks (i.e. `tokio::spawn`), which is notably easier to use than the reference passing required by `bevy_tasks` right now.

This PR makes does the following:

 * Adds `*TaskPool::init` which initializes a `OnceCell`'ed with a provided TaskPool. Failing if the pool has already been initialized.
 * Adds `*TaskPool::get` which fetches the initialized global pool of the respective type or panics. This generally should not be an issue in normal Bevy use, as the pools are initialized before they are accessed.
 * Updated default task pool initialization to either pull the global handles and save them as resources, or if they are already initialized, pull the a cloned global handle as the resource.

This should make it notably easier to build more complex task hierarchies for dependent tasks. It should also make writing bevy-adjacent, but not strictly bevy-only plugin crates easier, as the global pools ensure it's all running on the same threads.

One alternative considered is keeping a thread-local reference to the pool for all threads in each pool to enable the same `tokio::spawn` interface. This would spawn tasks on the same pool that a task is currently running in. However this potentially leads to potential footgun situations where long running blocking tasks run on `ComputeTaskPool`.
2022-06-09 02:43:24 +00:00
ira
92ddfe8ad4 Add methods for querying lists of entities. (#4879)
# Objective
Improve querying ergonomics around collections and iterators of entities.

Example how queries over Children might be done currently. 
```rust
fn system(foo_query: Query<(&Foo, &Children)>, bar_query: Query<(&Bar, &Children)>) {
    for (foo, children) in &foo_query {
        for child in children.iter() {
            if let Ok((bar, children)) = bar_query.get(*child) {
                for child in children.iter() {
                    if let Ok((foo, children)) = foo_query.get(*child) {
                        // D:
                    }
                }
            }
        }
    }
}
```
Answers #4868
Partially addresses #4864
Fixes #1470
## Solution
Based on the great work by @deontologician in #2563 

Added `iter_many` and `many_for_each_mut` to `Query`.
These take a list of entities (Anything that implements `IntoIterator<Item: Borrow<Entity>>`).

`iter_many` returns a `QueryManyIter` iterator over immutable results of a query (mutable data will be cast to an immutable form).

`many_for_each_mut` calls a closure for every result of the query, ensuring not aliased mutability. 
This iterator goes over the list of entities in order and returns the result from the query for it. Skipping over any entities that don't match the query.

Also added `unsafe fn iter_many_unsafe`.

### Examples
```rust
#[derive(Component)]
struct Counter {
    value: i32
}

#[derive(Component)]
struct Friends {
    list: Vec<Entity>,
}

fn system(
    friends_query: Query<&Friends>,
    mut counter_query: Query<&mut Counter>,
) {
    for friends in &friends_query {
        for counter in counter_query.iter_many(&friends.list) {
            println!("Friend's counter: {:?}", counter.value);
        }
        
        counter_query.many_for_each_mut(&friends.list, |mut counter| {
            counter.value += 1;
            println!("Friend's counter: {:?}", counter.value);
        });
    }
}

```

Here's how example in the Objective section can be written with this PR.
```rust
fn system(foo_query: Query<(&Foo, &Children)>, bar_query: Query<(&Bar, &Children)>) {
    for (foo, children) in &foo_query {
        for (bar, children) in bar_query.iter_many(children) {
            for (foo, children) in foo_query.iter_many(children) {
                // :D
            }
        }
    }
}
```
## Additional changes
Implemented `IntoIterator` for `&Children` because why not.
## Todo
- Bikeshed!

Co-authored-by: deontologician <deontologician@gmail.com>

Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-06-06 16:09:16 +00:00
TheRawMeatball
85cd0eb445 Add ParallelCommands system parameter (#4749)
(follow-up to #4423)
# Objective
Currently, it isn't possible to easily fire commands from within par_for_each blocks. This PR allows for issuing commands from within parallel scopes.
2022-06-06 14:46:41 +00:00
Alex Saveau
caef967d14 Derive default on ReportExecutionOrderAmbiguities (#4873) 2022-05-31 15:54:38 +00:00
Félix Lescaudey de Maneville
f000c2b951 Clippy improvements (#4665)
# Objective

Follow up to my previous MR #3718 to add new clippy warnings to bevy:

- [x] [~~option_if_let_else~~](https://rust-lang.github.io/rust-clippy/master/#option_if_let_else) (reverted)
- [x] [redundant_else](https://rust-lang.github.io/rust-clippy/master/#redundant_else)
- [x] [match_same_arms](https://rust-lang.github.io/rust-clippy/master/#match_same_arms)
- [x] [semicolon_if_nothing_returned](https://rust-lang.github.io/rust-clippy/master/#semicolon_if_nothing_returned)
- [x] [explicit_iter_loop](https://rust-lang.github.io/rust-clippy/master/#explicit_iter_loop)
- [x] [map_flatten](https://rust-lang.github.io/rust-clippy/master/#map_flatten)

There is one commit per clippy warning, and the matching flags are added to the CI execution.

To test the CI execution you may run `cargo run -p ci -- clippy` at the root.

I choose the add the flags in the `ci` tool crate to avoid having them in every `lib.rs` but I guess it could become an issue with suprise warnings coming up after a commit/push


Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-05-31 01:38:07 +00:00
Giacomo Stevanato
e543941fb9 Improve soundness of CommandQueue (#4863)
# Objective

This PR aims to improve the soundness of `CommandQueue`. In particular it aims to:
- make it sound to store commands that contain padding or uninitialized bytes;
- avoid uses of commands after moving them in the queue's buffer (`std::mem::forget` is technically a use of its argument);
- remove useless checks: `self.bytes.as_mut_ptr().is_null()` is always `false` because even `Vec`s that haven't allocated use a dangling pointer. Moreover the same pointer was used to write the command, so it ought to be valid for reads if it was for writes.

## Solution

- To soundly store padding or uninitialized bytes `CommandQueue` was changed to contain a `Vec<MaybeUninit<u8>>` instead of `Vec<u8>`;
- To avoid uses of the command through `std::mem::forget`, `ManuallyDrop` was used.
 
## Other observations

While writing this PR I noticed that `CommandQueue` doesn't seem to drop the commands that weren't applied. While this is a pretty niche case (you would have to be manually using `CommandQueue`/`std::mem::swap`ping one), I wonder if it should be documented anyway.
2022-05-30 22:45:09 +00:00
James Liu
d313ba59bd Don't allocate for ComponentDescriptors of non-dynamic component types (#4725)
# Objective
Don't allocate memory for Component types known at compile-time. Save a bit of memory.

## Solution
Change `ComponentDescriptor::name` from `String` to `Cow<'static, str>` to use the `&'static str` returned by `std::any::type_name`.
2022-05-30 21:16:47 +00:00
James Liu
c174945208 Fix release builds: Move asserts under #[cfg(debug_assertions)] (#4871)
# Objective
`debug_assert!` macros must still compile properly in release mode due to how they're implemented. This is causing release builds to fail.

## Solution
Change them to `assert!` macros inside `#[cfg(debug_assertions)]` blocks.
2022-05-30 20:57:33 +00:00
Daniel McNab
80b08ea45d Allow higher order systems (#4833)
# Objective

- Higher order system could not be created by users.
- However, a simple change to `SystemParamFunction` allows this.
- Higher order systems in this case mean functions which return systems created using other systems, such as `chain` (which is basically equivalent to map)

## Solution

- Change `SystemParamFunction` to be a safe abstraction over `FnMut([In<In>,] ...params)->Out`.
- Note that I believe `SystemParamFunction` should not have been counted as part of our public api before this PR.
    - This is because its only use was an unsafe function without an actionable safety comment.
    - The safety comment was basically 'call this within bevy code'.
    - I also believe that there are no external users in its current form. 
        - A quick search on Google and in the discord confirmed this.

## See also

- https://github.com/bevyengine/bevy/pull/4666, which uses this and subsumes the example here

---

## Changelog

### Added

- `SystemParamFunction`, which can be used to create higher order systems.
2022-05-30 17:59:20 +00:00
James Liu
8e4e5a5634 Use u32 over usize for ComponentSparseSet indicies (#4723)
# Objective
Use less memory to store SparseSet components.

## Solution
Change `ComponentSparseSet` to only use `Entity::id` in it's key internally, and change the usize value in it's SparseArray to use u32 instead, as it cannot have more than u32::MAX live entities stored at once.

This should reduce the overhead of storing components in sparse set storage by 50%.
2022-05-30 16:59:40 +00:00
James Liu
c5e89894f4 Remove task_pool parameter from par_for_each(_mut) (#4705)
# Objective
Fixes #3183. Requiring a `&TaskPool` parameter is sort of meaningless if the only correct one is to use the one provided by `Res<ComputeTaskPool>` all the time.

## Solution
Have `QueryState` save a clone of the `ComputeTaskPool` which is used for all `par_for_each` functions.

~~Adds a small overhead of the internal `Arc` clone as a part of the startup, but the ergonomics win should be well worth this hardly-noticable overhead.~~

Updated the docs to note that it will panic the task pool is not present as a resource.

# Future Work
If https://github.com/bevyengine/rfcs/pull/54 is approved, we can replace these resource lookups with a static function call instead to get the `ComputeTaskPool`.

---

## Changelog
Removed: The `task_pool` parameter of `Query(State)::par_for_each(_mut)`. These calls will use the `World`'s `ComputeTaskPool` resource instead.

## Migration Guide
The `task_pool` parameter for `Query(State)::par_for_each(_mut)` has been removed. Remove these parameters from all calls to these functions.

Before:
```rust
fn parallel_system(
   task_pool: Res<ComputeTaskPool>,
   query: Query<&MyComponent>,
) {
   query.par_for_each(&task_pool, 32, |comp| {
        ...
   });
}
```

After:

```rust
fn parallel_system(query: Query<&MyComponent>) {
   query.par_for_each(32, |comp| {
        ...
   });
}
```

If using `Query(State)` outside of a system run by the scheduler, you may need to manually configure and initialize a `ComputeTaskPool` as a resource in the `World`.
2022-05-30 16:59:38 +00:00
James Liu
f59ea7e6e8 Remove redundant ComponentId in Column (#4855)
# Objective
The `ComponentId` in `Column` is redundant as it's stored in parallel in the surrounding `SparseSet` all the time.

## Solution
Remove it. Add `SparseSet::iter(_mut)` to parallel `HashMap::iter(_mut)` to allow iterating pairs of columns and their IDs.

---

## Changelog
Added: `SparseSet::iter` and `SparseSet::iter_mut`.
2022-05-30 16:41:34 +00:00
Hennadii Chernyshchyk
c02beabe22 Add QueryState::get_single_unchecked_manual and its family (#4841)
# Objective

- Rebase of #3159.
- Fixes https://github.com/bevyengine/bevy/issues/3156
- add #[inline] to single related functions so that they matches with other function defs

## Solution

* added functions to QueryState
  *  get_single_unchecked_manual
  *  get_single_unchecked
  *  get_single
  *  get_single_mut
  *  single
  *  single_mut
* make Query::get_single use QueryState::get_single_unchecked_manual
* added #[inline]

---

## Changelog

### Added

Functions `QueryState::single`, `QueryState::get_single`, `QueryState::single_mut`, `QueryState::get_single_mut`, `QueryState::get_single_unchecked`, `QueryState::get_single_unchecked_manual`.

### Changed

`QuerySingleError` is now in the `state` module.

## Migration Guide

Change `query::QuerySingleError` to `state::QuerySingleError`


Co-authored-by: 2ne1ugly <chattermin@gmail.com>
Co-authored-by: 2ne1ugly <47616772+2ne1ugly@users.noreply.github.com>
2022-05-30 16:41:33 +00:00
Boxy
e528b63e11 merge matches_archetype and matches_table (#4807)
# Objective

the code in these fns are always identical so stop having two functions

## Solution

make them the same function

---

## Changelog

change `matches_archetype` and `matches_table` to `fn matches_component_set(&self, &SparseArray<ComponentId, usize>) -> bool` then do extremely boring updating of all `FetchState` impls

## Migration Guide

- move logic of `matches_archetype` and `matches_table` into `matches_component_set` in any manual `FetchState` impls
2022-05-30 16:41:32 +00:00
Jakob Hellermann
60584139de untyped APIs for components and resources (#4447)
# Objective

Even if bevy itself does not provide any builtin scripting or modding APIs, it should have the foundations for building them yourself.
For that it should be enough to have APIs that are not tied to the actual rust types with generics, but rather accept `ComponentId`s and `bevy_ptr` ptrs.

## Solution

Add the following APIs to bevy
```rust
fn EntityRef::get_by_id(ComponentId) -> Option<Ptr<'w>>;
fn EntityMut::get_by_id(ComponentId) -> Option<Ptr<'_>>;
fn EntityMut::get_mut_by_id(ComponentId) -> Option<MutUntyped<'_>>;

fn World::get_resource_by_id(ComponentId) -> Option<Ptr<'_>>;
fn World::get_resource_mut_by_id(ComponentId) -> Option<MutUntyped<'_>>;

// Safety: `value` must point to a valid value of the component
unsafe fn World::insert_resource_by_id(ComponentId, value: OwningPtr);

fn ComponentDescriptor::new_with_layout(..) -> Self;
fn World::init_component_with_descriptor(ComponentDescriptor) -> ComponentId;
```

~~This PR would definitely benefit from #3001 (lifetime'd pointers) to make sure that the lifetimes of the pointers are valid and the my-move pointer in `insert_resource_by_id` could be an `OwningPtr`, but that can be adapter later if/when #3001 is merged.~~

### Not in this PR
- inserting components on entities (this is very tied to types with bundles and the `BundleInserter`)
- an untyped version of a query (needs good API design, has a large implementation complexity, can be done in a third-party crate)

Co-authored-by: Jakob Hellermann <hellermann@sipgate.de>
2022-05-30 15:32:47 +00:00
Boxy
1320818f96 Fix unsoundness with Or/AnyOf/Option component access' (#4659)
# Objective

Fixes #4657

Example code that wasnt panic'ing before this PR (and so was unsound):
```rust
    #[test]
    #[should_panic = "error[B0001]"]
    fn option_has_no_filter_with() {
        fn sys(_1: Query<(Option<&A>, &mut B)>, _2: Query<&mut B, Without<A>>) {}
        let mut world = World::default();
        run_system(&mut world, sys);
    }

    #[test]
    #[should_panic = "error[B0001]"]
    fn any_of_has_no_filter_with() {
        fn sys(_1: Query<(AnyOf<(&A, ())>, &mut B)>, _2: Query<&mut B, Without<A>>) {}
        let mut world = World::default();
        run_system(&mut world, sys);
    }

    #[test]
    #[should_panic = "error[B0001]"]
    fn or_has_no_filter_with() {
        fn sys(_1: Query<&mut B, Or<(With<A>, With<B>)>>, _2: Query<&mut B, Without<A>>) {}
        let mut world = World::default();
        run_system(&mut world, sys);
    }
```
## Solution

- Only add the intersection of `with`/`without` accesses of all the elements in `Or/AnyOf` to the world query's `FilteredAccess<ComponentId>` instead of the union.
- `Option`'s fix can be thought of the same way since its basically `AnyOf<T, ()>` but its impl is just simpler as `()` has no `with`/`without` accesses
---

## Changelog

- `Or`/`AnyOf`/`Option` will now report more query conflicts in order to fix unsoundness

## Migration Guide

- If you are now getting query conflicts from `Or`/`AnyOf`/`Option` rip to you and ur welcome for it now being caught
2022-05-18 20:57:24 +00:00
James Liu
2c93b5cf73 Reduce code duplication by using QueryIterationCursor in QueryIter (#4733)
# Objective
We have duplicated code between `QueryIter` and `QueryIterationCursor`. Reuse that code.

## Solution
 - Reuse `QueryIterationCursor` inside `QueryIter`.
 - Slim down `QueryIter` by removing the `&'w World`. It was only being used by the `size_hint` and `ExactSizeIterator` impls, which can use the QueryState and &Archetypes in the type already.
 - Benchmark to make sure there is no significant regression.

Relevant benchmark results seem to show that there is no tangible difference between the two. Everything seems to be either identical or within a workable margin of error here.

```
group                                          embed-cursor                            main
-----                                          ------------                            ----
fragmented_iter/base                           1.00   387.4±19.70ns        ? ?/sec     1.07   413.1±27.95ns        ? ?/sec
many_maps_iter                                 1.00     27.3±0.22ms        ? ?/sec     1.00     27.4±0.10ms        ? ?/sec
simple_iter/base                               1.00     13.8±0.07µs        ? ?/sec     1.00     13.7±0.17µs        ? ?/sec
simple_iter/sparse                             1.00     61.9±0.37µs        ? ?/sec     1.00     62.2±0.64µs        ? ?/sec
simple_iter/system                             1.00     13.7±0.34µs        ? ?/sec     1.00     13.7±0.10µs        ? ?/sec
sparse_fragmented_iter/base                    1.00     11.0±0.54ns        ? ?/sec     1.03     11.3±0.48ns        ? ?/sec
world_query_iter/50000_entities_sparse         1.08    105.0±2.68µs        ? ?/sec     1.00     97.5±2.18µs        ? ?/sec
world_query_iter/50000_entities_table          1.00     27.3±0.13µs        ? ?/sec     1.00     27.3±0.37µs        ? ?/sec
```
2022-05-18 18:34:52 +00:00
Daniel McNab
7da21b12f7 Add some more documentation to SystemParam (#4787)
# Objective

- Fixes https://github.com/bevyengine/bevy/issues/4783

## Solution

- Add more documentation about the derive, and the obscure failure case for this.
- Link to [`StaticSystemParam`](https://docs.rs/bevy/latest/bevy/ecs/system/struct.StaticSystemParam.html) in these docs.
- Also explain the attributes whilst here.
2022-05-17 22:24:50 +00:00
SarthakSingh31
dbd856de71 Nightly clippy fixes (#3491)
Fixes the following nightly clippy lints:
- ~~[map_flatten](https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten)~~ (Fixed on main)
- ~~[needless_borrow](https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow)~~ (Fixed on main)
- [return_self_not_must_use](https://rust-lang.github.io/rust-clippy/master/index.html#return_self_not_must_use) (Added in 1.59.0)
- ~~[unnecessary_lazy_evaluations](https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_lazy_evaluations)~~ (Fixed on main)
- [extra_unused_lifetimes](https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes) outside of macros
- [let_unit_value](https://rust-lang.github.io/rust-clippy/master/index.html#let_unit_value)
2022-05-17 04:38:03 +00:00
Daniel McNab
b1b3bd533b Skip drop when needs_drop is false (#4773)
# Objective

- We do a lot of function pointer calls in a hot loop (clearing entities in render). This is slow, since calling function pointers cannot be optimised out. We can avoid that in the cases where the function call is a no-op.
- Alternative to https://github.com/bevyengine/bevy/pull/2897
- On my machine, in `many_cubes`, this reduces dropping time from ~150μs to ~80μs.

## Solution
-  Make `drop` in `BlobVec` an `Option`, recording whether the given drop impl is required or not.
- Note that this does add branching in some cases - we could consider splitting this into two fields, i.e. unconditionally call the `drop` fn pointer.
- My intuition of how often types stored in `World` should have non-trivial drops makes me think that would be slower, however. 

N.B. Even once this lands, we should still test having a 'drop_multiple' variant - for types with a real `Drop` impl, the current implementation is definitely optimal.
2022-05-17 04:16:55 +00:00
TheRawMeatball
516e4aaa10 Add Commands::new_from_entities (#4423)
This change allows for creating `Commands` objects from just an entities reference, which allows for creating multiple dynamically in a normal system.

Context: https://discord.com/channels/691052431525675048/774027865020039209/960857605943726142
2022-05-14 14:40:09 +00:00
James Liu
c309acd432 Fail to compile on 16-bit platforms (#4736)
# Objective
`bevy_ecs` assumes that `u32 as usize` is a lossless operation and in a few cases relies on this for soundness and correctness. The only platforms that Rust compiles to where this invariant is broken are 16-bit systems.

A very clear example of this behavior is in the SparseSetIndex impl for Entity, where it converts a u32 into a usize to act as an index. If usize is 16-bit, the conversion will overflow and provide the caller with the wrong index. This can easily result in previously unforseen aliased mutable borrows (i.e. Query::get_many_mut).

## Solution
Explicitly fail compilation on 16-bit platforms instead of introducing UB. 

Properly supporting 16-bit systems will likely need a workable use case first.

---

## Changelog
Removed: Ability to compile `bevy_ecs` on 16-bit platforms.

## Migration Guide
`bevy_ecs` will now explicitly fail to compile on 16-bit platforms.  If this is required, there is currently no alternative. Please file an issue (https://github.com/bevyengine/bevy/issues) to help detail your use case.
2022-05-13 13:18:53 +00:00
Charles
dfee7879c3 Add a clear() method to the EventReader that consumes the iterator (#4693)
# Objective

- It's pretty common to want to check if an EventReader has received one or multiple events while also needing to consume the iterator to "clear" the EventReader.
- The current approach is to do something like `events.iter().count() > 0` or `events.iter().last().is_some()`. It's not immediately obvious that the purpose of that is to consume the events and check if there were any events. My solution doesn't really solve that part, but it encapsulates the pattern.

## Solution

- Add a `.clear()` method that consumes the iterator.
	- It takes the EventReader by value to make sure it isn't used again after it has been called.

---

## Migration Guide

Not a breaking change, but if you ever found yourself in a situation where you needed to consume the EventReader and check if there was any events you can now use

```rust
fn system(events: EventReader<MyEvent>) {
	if !events.is_empty {
		events.clear();
		// Process the fact that one or more event was received
	}
}
```


Co-authored-by: Charles <IceSentry@users.noreply.github.com>
2022-05-13 00:57:04 +00:00
James Liu
0166c4f7fc Profile par_for_each(_mut) tasks (#4711)
# Objective
`Query::par_for_each` and it's variants do not show up when profiling using `tracy` or other profilers. Failing to show the impact of changing batch size, the overhead of scheduling tasks, overall thread utilization, etc. other than the effect on the surrounding system.

## Solution
Add a child span that is entered on every spawned task.

Example view of the results in `tracy` using a modified `parallel_query`: 
![image](https://user-images.githubusercontent.com/3137680/167560036-626bd091-344b-4664-b323-b692f4f16084.png)

---

## Changelog
Added: `tracing` spans for `Query::par_for_each` and its variants. Spans should now be visible for all
2022-05-13 00:33:13 +00:00
Daniel McNab
94d941661d Tidy up the code of events (#4713)
# Objective

- The code in `events.rs` was a bit messy. There was lots of duplication between `EventReader` and `ManualEventReader`, and the state management code is not needed.

## Solution

- Clean it up.

## Future work

Should we remove the type parameter from `ManualEventReader`? 
It doesn't have any meaning outside of its source `Events`. But there's no real reason why it needs to have a type parameter - it's just plain data. I didn't remove it yet to keep the type safety in some of the users of it (primarily related to `&mut World` usage)
2022-05-10 20:18:59 +00:00
Mike
9a54e2bed6 Add a tracing span for run criteria. (#4709)
# Objective

Adds a tracing span for run critieria.

This change will be invalidated by stageless, but it was a simple change.

Fixes #4681.

## Changelog

Shows how long a run criteria takes to run when tracing is enabled.
![image](https://user-images.githubusercontent.com/2180432/167517447-93dba7db-8c85-4686-90e0-30e9636f120f.png)
2022-05-10 20:18:58 +00:00
Daniel McNab
38a940dbbe Make derived SystemParam readonly if possible (#4650)
Required for https://github.com/bevyengine/bevy/pull/4402.

# Objective

- derived `SystemParam` implementations were never `ReadOnlySystemParamFetch`
- We want them to be, e.g. for `EventReader`

## Solution

- If possible, 'forward' the impl of `ReadOnlySystemParamFetch`.
2022-05-09 16:09:33 +00:00
Joy
4c878ef790 Add comparison methods to FilteredAccessSet (#4211)
# Objective

- (Eventually) reduce noise in reporting access conflicts between unordered systems. 
	- `SystemStage` only looks at unfiltered `ComponentId` access, any conflicts reported are potentially `false`.
		- the systems could still be accessing disjoint archetypes
	- Comparing systems' filtered access sets can maybe avoid that (for statically known component types).
		- #4204

## Solution

- Modify `SparseSetIndex` trait to require `PartialEq`, `Eq`, and `Hash` (all internal types except `BundleId` already did).
- Add `is_compatible` and `get_conflicts` methods to `FilteredAccessSet<T>`
	- (existing method renamed to `get_conflicts_single`)
- Add docs for those and all the other methods while I'm at it.
2022-05-09 14:39:22 +00:00
Joy
fca1c861d2 Make change lifespan deterministic and update docs (#3956)
## Objective

- ~~Make absurdly long-lived changes stay detectable for even longer (without leveling up to `u64`).~~
- Give all changes a consistent maximum lifespan.
- Improve code clarity.

## Solution

- ~~Increase the frequency of `check_tick` scans to increase the oldest reliably-detectable change.~~
(Deferred until we can benchmark the cost of a scan.)
- Ignore changes older than the maximum reliably-detectable age.
- General refactoring—name the constants, use them everywhere, and update the docs.
- Update test cases to check for the specified behavior.

## Related

This PR addresses (at least partially) the concerns raised in:

- #3071
- #3082 (and associated PR #3084)

## Background

- #1471

Given the minimum interval between `check_ticks` scans, `N`, the oldest reliably-detectable change is `u32::MAX - (2 * N - 1)` (or `MAX_CHANGE_AGE`). Reducing `N` from ~530 million (current value) to something like ~2 million would extend the lifetime of changes by a billion.

| minimum `check_ticks` interval | oldest reliably-detectable change  | usable % of `u32::MAX` |
| --- | --- | --- |
| `u32::MAX / 8`  (536,870,911) | `(u32::MAX / 4) * 3` | 75.0% |
| `2_000_000` | `u32::MAX - 3_999_999` | 99.9% |

Similarly, changes are still allowed to be between `MAX_CHANGE_AGE`-old and `u32::MAX`-old in the interim between `check_tick` scans. While we prevent their age from overflowing, the test to detect changes still compares raw values. This makes failure ultimately unreliable, since when ancient changes stop being detected varies depending on when the next scan occurs.

## Open Question

Currently, systems and system states are incorrectly initialized with their `last_change_tick` set to `0`, which doesn't handle wraparound correctly.

For consistent behavior, they should either be initialized to the world's `last_change_tick` (and detect no changes) or to `MAX_CHANGE_AGE` behind the world's current `change_tick` (and detect everything as a change). I've currently gone with the latter since that was closer to the existing behavior.

## Follow-up Work

(Edited: entire section)

We haven't actually profiled how long a `check_ticks` scan takes on a "large" `World` , so we don't know if it's safe to increase their frequency. However, we are currently relying on play sessions not lasting long enough to trigger a scan and apps not having enough entities/archetypes for it to be "expensive" (our assumption). That isn't a real solution. (Either scanning never costs enough to impact frame times or we provide an option to use `u64` change ticks. Nobody will accept random hiccups.)

To further extend the lifetime of changes, we actually only need to increment the world tick if a system has `Fetch: !ReadOnlySystemParamFetch`. The behavior will be identical because all writes are sequenced, but I'm not sure how to implement that in a way that the compiler can optimize the branch out.

Also, since having no false positives depends on a `check_ticks` scan running at least every `2 * N - 1` ticks, a `last_check_tick` should also be stored in the `World` so that any lull in system execution (like a command flush) could trigger a scan if needed. To be completely robust, all the systems initialized on the world should be scanned, not just those in the current stage.
2022-05-09 14:00:16 +00:00
TheRawMeatball
900e339a33 Add IntoIterator impls for &Query and &mut Query (#4692)
# Objective

These types of IntoIterator impls are a common pattern in Rust, and these implementations make this common pattern work for bevy queries.
2022-05-09 13:37:39 +00:00
François
89f4943157 exact sized event iterators (#3863)
# Objective

- Remove `Resource` binding on events, introduce a new `Event` trait
- Ensure event iterators are `ExactSizeIterator`

## Solution

- Builds on #2382 and #2969

## Changelog

- Events<T>, EventWriter<T>, EventReader<T> and so on now require that the underlying type is Event, rather than Resource. Both of these are trivial supertraits of Send + Sync + 'static with universal blanket implementations: this change is currently purely cosmetic.
- Event reader iterators now implement ExactSizeIterator
2022-05-09 13:19:32 +00:00
Jakob Hellermann
d63b7e9568 some cleanup for bevy_ptr (#4668)
1. change `PtrMut::as_ptr(self)` and `OwnedPtr::as_ptr(self)` to take `&self`, otherwise printing the pointer will prevent doing anything else afterwards
2. make all `as_ptr` methods safe. There's nothing unsafe about obtaining a pointer, these kinds of methods are safe in std as well [str::as_ptr](https://doc.rust-lang.org/stable/std/primitive.str.html#method.as_ptr), [Rc::as_ptr](https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.as_ptr)
3. rename `offset`/`add` to `byte_offset`/`byte_add`. The unprefixed methods in std add in increments of `std::mem::size_of::<T>`, not in bytes. There's a PR for rust to add these byte_ methods https://github.com/rust-lang/rust/pull/95643 and at the call site it makes it much more clear that you need to do `.byte_add(i * layout_size)` instead of `.add(i)`
2022-05-06 19:15:24 +00:00
Daniel McNab
ec805e9e07 Apply buffers in ParamSet (#4677)
# Objective

- Fix https://github.com/bevyengine/bevy/issues/4676

## Solution

- Fixes https://github.com/bevyengine/bevy/issues/4676
- I have no reason to think this isn't sound, but `ParamSet` is a bit spooky
2022-05-06 18:52:26 +00:00
Boxy
96b4956126 Fix CI (#4675) 2022-05-06 18:27:37 +00:00
Jakob Hellermann
1e322d9f76 bevy_ptr standalone crate (#4653)
# Objective

The pointer types introduced in #3001 are useful not just in `bevy_ecs`, but also in crates like `bevy_reflect` (#4475) or even outside of bevy.

## Solution

Extract `Ptr<'a>`, `PtrMut<'a>`, `OwnedPtr<'a>`, `ThinSlicePtr<'a, T>` and `UnsafeCellDeref` from `bevy_ecs::ptr` into `bevy_ptr`.

**Note:** `bevy_ecs` still reexports the `bevy_ptr` as `bevy_ecs::ptr` so that crates like `bevy_transform` can use the `Bundle` derive without needing to depend on `bevy_ptr` themselves.
2022-05-04 19:16:10 +00:00
Daniel McNab
9d440fbcb5 Make RunOnce a non-manual System impl (#3922)
# Objective

- `RunOnce` was a manual `System` implementation.
- Adding run criteria to stages was yet to be systemyoten

## Solution

- Make it a normal function
- yeet

##  Changelog

- Replaced `RunOnce` with `ShouldRun::once`

## Migration guide

The run criterion `RunOnce`, which would make the controlled systems run only once, has been replaced with a new run criterion function `ShouldRun::once`. Replace all instances of `RunOnce` with `ShouldRun::once`.
2022-05-04 18:41:37 +00:00
James Liu
3e24b725af Pointerfication followup: Type safety and cleanup (#4621)
# Objective
The `Ptr` types gives free access to the underlying `NonNull<u8>`, which adds more publicly visible pointer wrangling than there needs to be. There are also a few edge cases where Ptr types could be more readily utilized for properly validating the soundness of ECS operations.

## Solution
 - Replace `*Ptr(Mut)::inner` with `cast` which requires a concrete type to give the pointer. This function could also have a `debug_assert` with an alignment check to ensure that the pointer is aligned properly, but is currently not included.
 - Use `OwningPtr::read` in ECS macros over casting the inner pointer around.
2022-05-03 20:07:58 +00:00
TheRawMeatball
5ca78b1e27 Add get_change_ticks method to EntityRef and EntityMut (#2539)
Direct access to the change ticks is useful for integrating the reliable change detection with external stuff.
2022-05-02 18:44:58 +00:00
Alice Cecile
3fbe3683d9 Improve debugging tools for change detection (#4160)
# Objective

1. Previously, the `change_tick` and `last_change_tick` fields on `SystemChangeTick` [were `pub`](https://docs.rs/bevy/0.6.1/bevy/ecs/system/struct.SystemChangeTick.html).
   1.  This was actively misleading, as while this can be fetched as a `SystemParam`, a copy is returned instead
2. This information could be useful for debugging, but there was no way to investigate when data was changed.
3. There were no docs!

## Solution

1. Move these to a getter method.
2. Add `last_changed` method to the `DetectChanges` trait to enable inspection of when data was last changed.
3. Add docs.

# Changelog

 `SystemChangeTick` now provides getter methods for the current and previous change tick, rather than public fields.
 This can be combined with `DetectChanges::last_changed()` to debug the timing of changes.

# Migration guide

The `change_tick` and `last_change_tick` fields on `SystemChangeTick` are now private, use the corresponding getter method instead.
2022-05-02 18:26:52 +00:00
robtfm
b9f738da8d move system_param fetch struct into anonymous scope to avoid name collisions (#4100)
# Objective

avoid naming collisions with user structs when deriving ``system_param``.

## Solution

~rename the fetch struct created by ``#[derive(system_param)]`` from ``{}State`` to ``{}SysParamState``.~
place the fetch struct into an anonymous scope.

## Migration Guide

For code that was using a system param's fetch struct, such as ``EventReader``'s ``EventReaderState``, the fetch struct can now be identified via the SystemParam trait associated type ``Fetch``, e.g. for ``EventReader<T>`` it can be identified as ``<EventReader<'static, 'static, T> as SystemParam>::Fetch``
2022-05-02 18:26:50 +00:00
Alice Cecile
8283db69b4 Remind users to initialize their systems before running them (#3947)
# Objective

- Manually running systems is a somewhat obscure process: systems must be initialized before they are run
- The unwrap is rather hard to debug.

## Solution

- Replace unwraps in `FunctionSystem` methods with expects (progress towards #3892).
- Briefly document this requirement.
2022-05-02 16:04:49 +00:00
Yutao Yuan
2c145826a3 Fix type parameter name conflicts of derive(Bundle) (#4636)
# Objective

This code currently fails to compile with error ``the name `T` is already used for a generic parameter in this item's generic parameters``, because `T` is also used in code generated by `derive(Bundle)`.

```rust
#[derive(Bundle)]
struct MyBundle<T: Component> {
    component: T,
}
```

## Solution

Add double underscores to type parameter names in `derive(Bundle)`.
2022-05-02 11:58:51 +00:00
Boxy
b9102b8836 Introduce tests for derive(WorldQuery) (#4625)
The only tests we had for `derive(WorldQuery)` checked that the derive doesnt panic/emit a `compiler_error!`. This PR adds tests that actually assert the returned values of a query using the derived `WorldQuery` impl. Also adds a compile fail test to check that we correctly error on read only world queries containing mutable world queries.
2022-04-28 21:06:20 +00:00
TheRawMeatball
73c78c3667 Use lifetimed, type erased pointers in bevy_ecs (#3001)
# Objective

`bevy_ecs` has large amounts of unsafe code which is hard to get right and makes it difficult to audit for soundness.

## Solution

Introduce lifetimed, type-erased pointers: `Ptr<'a>` `PtrMut<'a>` `OwningPtr<'a>'` and `ThinSlicePtr<'a, T>` which are newtypes around a raw pointer with a lifetime and conceptually representing strong invariants about the pointee and validity of the pointer.

The process of converting bevy_ecs to use these has already caught multiple cases of unsound behavior.

## Changelog

TL;DR for release notes: `bevy_ecs` now uses lifetimed, type-erased pointers internally, significantly improving safety and legibility without sacrificing performance. This should have approximately no end user impact, unless you were meddling with the (unfortunately public) internals of `bevy_ecs`.

- `Fetch`, `FilterFetch` and `ReadOnlyFetch` trait no longer have a `'state` lifetime
    - this was unneeded
- `ReadOnly/Fetch` associated types on `WorldQuery` are now on a new `WorldQueryGats<'world>` trait
    - was required to work around lack of Generic Associated Types (we wish to express `type Fetch<'a>: Fetch<'a>`)
- `derive(WorldQuery)` no longer requires `'w` lifetime on struct
    - this was unneeded, and improves the end user experience
- `EntityMut::get_unchecked_mut` returns `&'_ mut T` not `&'w mut T`
    - allows easier use of unsafe API with less footguns, and can be worked around via lifetime transmutery as a user
- `Bundle::from_components` now takes a `ctx` parameter to pass to the `FnMut` closure
    - required because closure return types can't borrow from captures
- `Fetch::init` takes `&'world World`, `Fetch::set_archetype` takes `&'world Archetype` and `&'world Tables`, `Fetch::set_table` takes `&'world Table`
    - allows types implementing `Fetch` to store borrows into world
- `WorldQuery` trait now has a `shrink` fn to shorten the lifetime in `Fetch::<'a>::Item`
    - this works around lack of subtyping of assoc types, rust doesnt allow you to turn `<T as Fetch<'static>>::Item'` into `<T as Fetch<'a>>::Item'`
    - `QueryCombinationsIter` requires this
- Most types implementing `Fetch` now have a lifetime `'w`
    - allows the fetches to store borrows of world data instead of using raw pointers

## Migration guide

- `EntityMut::get_unchecked_mut` returns a more restricted lifetime, there is no general way to migrate this as it depends on your code
- `Bundle::from_components` implementations must pass the `ctx` arg to `func`
- `Bundle::from_components` callers have to use a fn arg instead of closure captures for borrowing from world
- Remove lifetime args on `derive(WorldQuery)` structs as it is nonsensical
- `<Q as WorldQuery>::ReadOnly/Fetch` should be changed to either `RO/QueryFetch<'world>` or `<Q as WorldQueryGats<'world>>::ReadOnly/Fetch`
- `<F as Fetch<'w, 's>>` should be changed to `<F as Fetch<'w>>`
- Change the fn sigs of `Fetch::init/set_archetype/set_table` to match respective trait fn sigs
- Implement the required `fn shrink` on any `WorldQuery` implementations
- Move assoc types `Fetch` and `ReadOnlyFetch` on `WorldQuery` impls to `WorldQueryGats` impls
- Pass an appropriate `'world` lifetime to whatever fetch struct you are for some reason using

### Type inference regression

in some cases rustc may give spurrious errors when attempting to infer the `F` parameter on a query/querystate this can be fixed by manually specifying the type, i.e. `QueryState:🆕:<_, ()>(world)`. The error is rather confusing:

```rust=
error[E0271]: type mismatch resolving `<() as Fetch<'_>>::Item == bool`
    --> crates/bevy_pbr/src/render/light.rs:1413:30
     |
1413 |             main_view_query: QueryState::new(world),
     |                              ^^^^^^^^^^^^^^^ expected `bool`, found `()`
     |
     = note: required because of the requirements on the impl of `for<'x> FilterFetch<'x>` for `<() as WorldQueryGats<'x>>::Fetch`
note: required by a bound in `bevy_ecs::query::QueryState::<Q, F>::new`
    --> crates/bevy_ecs/src/query/state.rs:49:32
     |
49   |     for<'x> QueryFetch<'x, F>: FilterFetch<'x>,
     |                                ^^^^^^^^^^^^^^^ required by this bound in `bevy_ecs::query::QueryState::<Q, F>::new`
```

---

Made with help from @BoxyUwU and @alice-i-cecile 

Co-authored-by: Boxy <supbscripter@gmail.com>
2022-04-27 23:44:06 +00:00
bjorn3
ddce22b614 Decouple some dependencies (#3886)
# Objective

Reduce from scratch build time.

## Solution

Reduce the size of the critical path by removing dependencies between crates where not necessary. For `cargo check --no-default-features` this reduced build time from ~51s to ~45s. For some commits I am not completely sure if the tradeoff between build time reduction and convenience caused by the commit is acceptable. If not, I can drop them.
2022-04-27 19:08:11 +00:00
Nicola Papale
71a246ce9e Improve QueryIter size_hint hints (#4244)
## Objective

This fixes #1686.

`size_hint` can be useful even if a little niche. For example,
`collect::<Vec<_>>()` uses the `size_hint` of Iterator it collects from
to pre-allocate a memory slice large enough to not require re-allocating
when pushing all the elements of the iterator.

## Solution

To this effect I made the following changes:
* Add a `IS_ARCHETYPAL` associated constant to the `Fetch` trait,
  this constant tells us when it is safe to assume that the `Fetch`
  relies exclusively on archetypes to filter queried entities
* Add `IS_ARCHETYPAL` to all the implementations of `Fetch`
* Use that constant in `QueryIter::size_hint` to provide a more useful

## Migration guide

The new associated constant is an API breaking change. For the user,
if they implemented a custom `Fetch`, it means they have to add this
associated constant to their implementation. Either `true` if it doesn't limit
the number of entities returned in a query beyond that of archetypes, or
`false` for when it does.
2022-04-27 18:02:06 +00:00
Aevyrie
4aa56050b6 Add infallible resource getters for WorldCell (#4104)
# Objective

- Eliminate all `worldcell.get_resource().unwrap()` cases.
- Provide helpful messages on panic.

## Solution

- Adds infallible resource getters to `WorldCell`, mirroring `World`.
2022-04-25 23:19:13 +00:00
Alice Cecile
4bcb310008 Basic EntityRef and EntityMut docs (#3388)
# Objective

- `EntityRef` and `EntityMut` are surpisingly important public types when working directly with the `World`.
- They're undocumented.

## Solution

- Just add docs!
2022-04-25 14:32:57 +00:00
SpecificProtagonist
46acb7753c SystemSet::before and after: take AsSystemLabel (#4503)
# Objective

`AsSystemLabel` has been introduced on system descriptors to make ordering systems more convenient, but `SystemSet::before` and `SystemSet::after` still take `SystemLabels` directly:

    use bevy::ecs::system::AsSystemLabel;
    /*…*/ SystemSet::new().before(foo.as_system_label()) /*…*/

is currently necessary instead of

    /*…*/ SystemSet::new().before(foo) /*…*/

## Solution

Use `AsSystemLabel` for `SystemSet`
2022-04-23 06:03:50 +00:00
TheRawMeatball
0fdb45ce90 Remove EntityMut::get_unchecked (#4547)
The only way to soundly use this API is already encapsulated within `EntityMut::get`, so this api is removed.

# Migration guide

Replace calls to `EntityMut::get_unchecked` with calls to `EntityMut::get`.
2022-04-22 20:06:41 +00:00
CGMossa
7a0f46c21b fixes complaints about missing docs (#4551)
# Objective

When using `derive(WorldQuery)`, then clippy complains with the following:

```rust
warning: missing documentation for a struct
  --> src\wild_boar_type\marker_vital_status.rs:35:17
   |
35 | #[derive(Debug, WorldQuery)]
   |                 ^^^^^^^^^^
   |
   = note: this warning originates in the derive macro `WorldQuery` (in Nightly builds, run with -Z macro-backtrace for more info)
```

## Solution

* Either `#[doc(hidden)]` or
* Add a generic documentation line to it.

I don't know what is preferred, but I'd gladly add it in here.
2022-04-22 08:45:04 +00:00