Consolidation of all the feedback about #6271 as well as the addition of an "unconditionally visible" mode.
# Objective
The current implementation of the `Visibility` struct simply wraps a boolean.. which seems like an odd pattern when rust has such nice enums that allow for more expression using pattern-matching.
Additionally as it stands Bevy only has two settings for visibility of an entity:
- "unconditionally hidden" `Visibility { is_visible: false }`,
- "inherit visibility from parent" `Visibility { is_visible: true }`
where a root level entity set to "inherit" is visible.
Note that given the behaviour, the current naming of the inner field is a little deceptive or unclear.
Using an enum for `Visibility` opens the door for adding an extra behaviour mode. This PR adds a new "unconditionally visible" mode, which causes an entity to be visible even if its Parent entity is hidden. There should not really be any performance cost to the addition of this new mode.
--
The recently added `toggle` method is removed in this PR, as its semantics could be confusing with 3 variants.
## Solution
Change the Visibility component into
```rust
enum Visibility {
Hidden, // unconditionally hidden
Visible, // unconditionally visible
Inherited, // inherit visibility from parent
}
```
---
## Changelog
### Changed
`Visibility` is now an enum
## Migration Guide
- evaluation of the `visibility.is_visible` field should now check for `visibility == Visibility::Inherited`.
- setting the `visibility.is_visible` field should now directly set the value: `*visibility = Visibility::Inherited`.
- usage of `Visibility::VISIBLE` or `Visibility::INVISIBLE` should now use `Visibility::Inherited` or `Visibility::Hidden` respectively.
- `ComputedVisibility::INVISIBLE` and `SpatialBundle::VISIBLE_IDENTITY` have been renamed to `ComputedVisibility::HIDDEN` and `SpatialBundle::INHERITED_IDENTITY` respectively.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- Be able to name the type that `ManualEventReader::iter/iter_with_id` returns and `EventReader::iter/iter_with_id` by proxy.
Currently for the purpose of https://github.com/bevyengine/bevy/pull/5719
## Solution
- Create a custom `Iterator` type.
# Objective
- alternative to #2895
- as mentioned in #2535 the uuid based ids in the render module should be replaced with atomic-counted ones
## Solution
- instead of generating a random UUID for each render resource, this implementation increases an atomic counter
- this might be replaced by the ids of wgpu if they expose them directly in the future
- I have not benchmarked this solution yet, but this should be slightly faster in theory.
- Bevymark does not seem to be affected much by this change, which is to be expected.
- Nothing of our API has changed, other than that the IDs have lost their IMO rather insignificant documentation.
- Maybe the documentation could be added back into the macro, but this would complicate the code.
# Objective
- Describe the objective or issue this PR addresses.
SpritePipelineKey could use more constification.
## Solution
Constify SpritePipelineKey implementation.
## Changelog
Co-authored-by: AxiomaticSemantics <117950168+AxiomaticSemantics@users.noreply.github.com>
# Objective
This PR reorganizes majority of the scene viewer example into a module of plugins which then allows reuse of functionality among new or existing examples. In addition, this enables the scene viewer to be more succinct and showcase the distinct cases of camera control and scene control.
This work is to support future work in organization and future examples. A more complicated 3D scene example has been requested by the community (#6551) which requests functionality currently included in scene_viewer, but previously inaccessible. The future example can now just utilize the two plugins created here. The existing example [animated_fox example] can utilize the scene creation and animation control functionality of `SceneViewerPlugin`.
## Solution
- Created a `scene_viewer` module inside the `tools` example folder.
- Created two plugins: `SceneViewerPlugin` (gltf scene loading, animation control, camera tracking control, light control) and `CameraControllerPlugin` (controllable camera).
- Original `scene_viewer.rs` moved to `scene_viewer/main.rs` and now utilizes the two plugins.
# Objective
Align the hierarchy API between `EntityCommands` and `EntityMut`.
Added missing methods to `EntityMut`.
Replaced the duplicate `Command` implementations with the ones on `EntityMut` (e.g. The `AddChild` command is now just `world.entity_mut(..).add_child(..)`)
Fixed `update_old_parents` not sending `ChildAdded` events.
This PR does not add `add_children` to `EntityMut` as I would like to remove it from `EntityCommands` instead in #6942.
## Changelog
* Added `add_child`, `set_parent` and `remove_parent` to `EntityMut`
* Fixed missing `ChildAdded` events
Co-authored-by: devil-ira <justthecooldude@gmail.com>
# Objective
* Currently, the `SystemParam` derive does not support types with const generic parameters.
* If you try to use const generics, the error message is cryptic and unhelpful.
* Continuation of the work started in #6867 and #6957.
## Solution
Allow const generic parameters to be used with `#[derive(SystemParam)]`.
# Objective
Fixes#4729.
Continuation of #4854.
## Solution
Add documentation to `ParamSet` and its methods. Includes examples suggested by community members in the original PR.
Co-authored-by: Nanox19435 <50684926+Nanox19435@users.noreply.github.com>
Co-authored-by: JoJoJet <21144246+JoJoJet@users.noreply.github.com>
# Objective
Fixes#4231.
## Solution
This PR implements the solution suggested by @bjorn3 : Use an internal property within `App` to detect `App::run()` calls from `Plugin::build()`.
---
## Changelog
- panic when App::run() is called from Plugin::build()
# Objective
Upgrade to Taffy 0.2
## Solution
Do it
## Changelog
Upgraded to Taffy 0.2, improving UI layout performance significantly and adding the flexbox `gap` property and `AlignContent::SpaceEvenly`.
## Notes
`many_buttons` is 8% faster! speed improvements for more highly nested UIs will be much more dramatic. Great work, Team Taffy.
# Objective
* The `SystemParam` derive internally uses tuples, which means it is constrained by the 16-field limit on `all_tuples`.
* The error message if you exceed this limit is abysmal.
* Supercedes #5965 -- this does the same thing, but is simpler.
## Solution
If any tuples have more than 16 fields, they are folded into tuples of tuples until they are under the 16-field limit.
# Objective
Currently, only named structs can be used with the `SystemParam` derive macro.
## Solution
Remove the restriction. Tuple structs and unit structs are now supported.
---
## Changelog
+ Added support for tuple structs and unit structs to the `SystemParam` derive macro.
# Objective
Fixes#6862 (oh hey good catch @alice-i-cecile)
Bevy was failing to print events from `info!()` and friends to the console if the `trace_tracy` feature was enabled. It shouldn't be doing that.
## Solution
The problem was this per-layer filter that was added in #4320 to suppress a noisy per-frame event (which Tracy requires in order to properly close out a frame):
- The problem event's target was `"bevy_render::renderer"`, not `"tracy"`. - So, the filter wasn't specifically targeting the noisy event.
- Without a default, `tracing_subscriber::filter::Targets` will remove _everything_ that doesn't match an explicit target rule. - So, the filter _was_ silencing the noisy event, along with everything else.
This PR changes that filter to do what was probably intended in #4320: suppress ~any events more verbose than `ERROR` from `bevy_render::renderer`~ the one problematically noisy event, but allow anything else that already made it through the top-level filter_layer.
Also, adds a comment to clarify the intent of that filter, since it's otherwise a bit opaque and required some research.
---
## Changelog
Fixed a bug that hid console log messages when the `trace_tracy` feature was enabled.
The Camera link in the UiCameraConfig was not rendered properly by the documentation.
# Objective
- In the UiCameraConfig page (https://docs.rs/bevy/latest/bevy/prelude/struct.UiCameraConfig.html), a link to the Camera page (https://docs.rs/bevy/latest/bevy/render/camera/struct.Camera.html) is broken.
## Solution
- It seems that when using URL fragment specifiers, backtick should not be used. It might be an issue of rust itself. Replacing the URL fragment specifier `[`Camera`]: bevy_render:📷:Camera` with `[Camera]: bevy_render:📷:Camera` solves this.
# Objective
- `bevy_ptr::{Ptr, PtrMut, OwnedPtr}` wrap raw pointers and should be printable using pointer formatting.
## Solution
- Add a `core::fmt::Pointer` impl for `Ptr`, `PtrMut` and `OwnedPtr` based on the wrapped `NonNull` pointer.
---
## Changelog
- Added a `core::fmt::Pointer` impl to `Ptr`, `PtrMut` and `OwnedPtr`.
Co-authored-by: MrGunflame <mrgunflame@protonmail.com>
## Objective
Bevy UI uses a `MeasureFunc` that preserves the aspect ratio of text, not just images. This means that the extent of flex-items containing text may be calculated incorrectly depending on the ratio of the text size compared to the size of its containing node.
Fixes#6748
Related to #6724
with Bevy 0.9:
with this PR (accurately matching the behavior of Flexbox):
## Solution
Only perform the aspect ratio calculations if the uinode contains an image.
## Changelog
* Added a field `preserve_aspect_ratio` to `CalculatedSize`
* The `MeasureFunc` only preserves the aspect ratio when `preserve_aspect_ratio` is true.
* `update_image_calculated_size_system` sets `preserve_aspect_ratio` to true for nodes with images.
# Objective
The `WgpuSettings` resource is only used during plugin build. Move it into the `RenderPlugin` struct.
Changing these settings requires re-initializing the render context, which is currently not supported.
If it is supported in the future it should probably be more explicit than changing a field on a resource, maybe something similar to the `CreateWindow` event.
## Migration Guide
```rust
// Before (0.9)
App::new()
.insert_resource(WgpuSettings { .. })
.add_plugins(DefaultPlugins)
// After (0.10)
App::new()
.add_plugins(DefaultPlugins.set(RenderPlugin {
wgpu_settings: WgpuSettings { .. },
}))
```
Co-authored-by: devil-ira <justthecooldude@gmail.com>
# Objective
Following #4402, extract systems run on the render world instead of the main world, and allow retained state operations on it's resources. We're currently extracting to `ExtractedJoints` and then copying it twice during Prepare. Once into `SkinnedMeshJoints` and again into the actual GPU buffer.
This makes #4902 obsolete.
## Solution
Cut out the middle copy and directly extract joints into `SkinnedMeshJoints` and remove `ExtractedJoints` entirely.
This also removes the per-frame allocation that is being made to send `ExtractedJoints` into the render world.
## Performance
On my local machine, this halves the time for `prepare_skinned _meshes` on `many_foxes` (195.75us -> 93.93us on average).
---
## Changelog
Added: `BufferVec::truncate`
Added: `BufferVec::extend`
Changed: `SkinnedMeshJoints::build` now takes a `&mut BufferVec` instead of a `&mut Vec` as a parameter.
Removed: `ExtractedJoints`.
## Migration Guide
`ExtractedJoints` has been removed. Read the bound bones from `SkinnedMeshJoints` instead.
# Objective
Fix#1991. Allow users to have a bit more control over the creation and finalization of the threads in `TaskPool`.
## Solution
Add new methods to `TaskPoolBuilder` that expose callbacks that are called to initialize and finalize each thread in the `TaskPool`.
Unlike the proposed solution in #1991, the callback is argument-less. If an an identifier is needed, `std:🧵:current` should provide that information easily.
Added a unit test to ensure that they're being called correctly.
# Objective
- Dynamic scene builder can build scenes without components, if they didn't have any matching the type registry
- Those entities are not really useful in the final `DynamicScene`
## Solution
- Add a method `remove_empty_entities` that will remove empty entities. It's not called by default when calling `build`, I'm not sure if that's a good idea or not.
# Objective
This adds a custom profile for testing against stress tests. Bevy seemingly gets notably faster with LTO turned on. To more accurately depict production level performance, LTO and other rustc-level optimizations should be enabled when performance testing on stress tests.
Also updated the stress test docs to reflect that users should be using it.
# Objective
There is currently no way to iterate over key/value pairs inside an `EntityMap`, which makes the usage of this struct very awkward. I couldn't think of a good reason why the `iter()` function should not be exposed, considering the interface already exposes `keys()` and `values()`, so I made this PR.
## Solution
Implement `iter()` for `EntityMap` in terms of its inner map type.
# Objective
Some settings were only applied in windowed mode.
Fix the issue in #6933
# Solution
Always apply the settings.
Co-authored-by: devil-ira <justthecooldude@gmail.com>
# Objective
Remove a method with an unfortunate name and questionable usefulness.
Added in #4708
It doesn't make sense to me for us to provide a method to work around a limitation of closures when we can simply, *not* use a closure.
The limitation in this case is not being able to initialize a variable from inside a closure:
```rust
let child_id;
commands.spawn_empty().with_children(|parent| {
// Error: passing uninitalized variable to a closure.
child_id = parent.spawn_empty().id();
});
// Do something with child_id
```
The docs for `add_children` suggest the following:
```rust
let child_id = commands
.spawn_empty()
.add_children(|parent| parent.spawn_empty().id());
```
I would instead suggest using the following snippet.
```rust
let parent_id = commands.spawn_empty().id();
let child_id = commands.spawn_empty().set_parent(parent_id).id();
// To be fair, at the time of #4708 this would have been a bit more cumbersome since `set_parent` did not exist.
```
Using `add_children` gets more unwieldy when you also want the `parent_id`.
```rust
let parent_commands = commands.spawn_empty();
let parent_id = parent_commands.id();
let child_id = parent_commands.add_children(|parent| parent.spawn_empty().id());
```
### The name
I see why `add_children` is named that way, it's the non-builder variant of `with_children` so it kinda makes sense,
but now the method name situation for `add_child`, `add_children` and `push_children` is *rather* unfortunate.
Removing `add_children` and renaming `push_children` to `add_children` in one go is kinda bleh, but that way we end up with the matching methods `add_child` and `add_children`.
Another reason to rename `push_children` is that it's trying to mimick the `Vec` api naming but fails because `push` is for single elements. I guess it should have been `extend_children_from_slice`, but lets not name it that :)
### Questions
~~Should `push_children` be renamed in this PR? This would make the migration guide easier to deal with.~~
Let's do that later.
Does anyone know of a way to do a simple text/regex search through all the github repos for usage of `add_children`?
That way we can have a better idea of how this will affect users. My guess is that usage of `add_children` is quite rare.
## Migration Guide
The method `add_children` on `EntityCommands` was removed.
If you were using `add_children` over `with_children` to return data out of the closure you can use `set_parent` or `add_child` to avoid the closure instead.
Co-authored-by: devil-ira <justthecooldude@gmail.com>
# Objective
`AsBindGroup` can't be used as a trait object because of the constraint `Sized` and because of the associated function.
This is a problem for [`bevy_atmosphere`](https://github.com/JonahPlusPlus/bevy_atmosphere) because it needs to use a trait that depends on `AsBindGroup` as a trait object, for switching out different shaders at runtime. The current solution it employs is reimplementing the trait and derive macro into that trait, instead of constraining to `AsBindGroup`.
## Solution
Remove the `Sized` constraint from `AsBindGroup` and add the constraint `where Self: Sized` to the associated function `bind_group_layout`. Also change `PreparedBindGroup<T: AsBindGroup>` to `PreparedBindGroup<T>` and use it as `PreparedBindGroup<Self::Data>` instead of `PreparedBindGroup<Self>`.
This weakens the constraints, but increases the flexibility of `AsBindGroup`.
I'm not entirely sure why the `Sized` constraint was there, because it worked fine without it (maybe @cart wasn't aware of use cases for `AsBindGroup` as a trait object or this was just leftover from legacy code?).
---
## Changelog
- `AsBindGroup` can be used as a trait object.
# Objective
[Rust 1.66](https://blog.rust-lang.org/inside-rust/2022/12/12/1.66.0-prerelease.html) is coming in a few days, and bevy doesn't build with it.
Fix that.
## Solution
Replace output from a trybuild test, and fix a few new instances of `needless_borrow` and `unnecessary_cast` that are now caught.
## Note
Due to the trybuild test, this can't be merged until 1.66 is released.
# Objective
A separate `tracing` span for running a system's commands is created, even if the system doesn't have commands. This is adding extra measuring overhead (see #4892) where it's not needed.
## Solution
Move the span into `ParallelCommandState` and `CommandQueue`'s `SystemParamState::apply`. To get the right metadata for the span, a additional `&SystemMeta` parameter was added to `SystemParamState::apply`.
---
## Changelog
Added: `SystemMeta::name`
Changed: Systems without `Commands` and `ParallelCommands` will no longer show a "system_commands" span when profiling.
Changed: `SystemParamState::apply` now takes a `&SystemMeta` parameter in addition to the provided `&mut World`.
# Objective
Change detection can be spuriously triggered by setting a field to the same value as before. As a result, a common pattern is to write:
```rust
if *foo != value {
*foo = value;
}
```
This is confusing to read, and heavy on boilerplate.
Adopted from #5373, but untangled and rebased to current `bevy/main`.
## Solution
1. Add a method to the `DetectChanges` trait that implements this boilerplate when the appropriate trait bounds are met.
2. Document this minor footgun, and point users to it.
## Changelog
* added the `set_if_neq` method to avoid triggering change detection when the new and previous values are equal. This will work on both components and resources.
## Migration Guide
If you are manually checking if a component or resource's value is equal to its new value before setting it to avoid triggering change detection, migrate to the clearer and more convenient `set_if_neq` method.
## Context
Related to #2363 as it avoids triggering change detection, but not a complete solution (as it still requires triggering it when real changes are made).
Co-authored-by: Zoey <Dessix@Dessix.net>
Add a section about install `vulkan-loader` on Gentoo.
# Objective
- Clarify the dependency about install on Gentoo with NVIDIA GPU and using a proprietary driver.
## Solution
- Emerge `vulkan-loader` to help Bevy to find the correct ICD.
# Objective
The following code:
```rs
use bevy::prelude::Image;
use image::{ DynamicImage, GenericImage, Rgba };
fn main() {
let mut dynamic_image = DynamicImage::new_rgb32f(1, 1);
dynamic_image.put_pixel(0, 0, Rgba([1, 1, 1, 1]));
let image = Image::from_dynamic(dynamic_image, false); // Panic!
println!("{image:?}");
}
```
Can cause an assertion failed:
```
thread 'main' panicked at 'assertion failed: `(left == right)`
left: `16`,
right: `14`: Pixel data, size and format have to match', .../bevy_render-0.9.1/src/texture/image.rs:209:9
stack backtrace:
...
4: core::panicking::assert_failed<usize,usize>
at /rustc/897e37553bba8b42751c67658967889d11ecd120/library/core/src/panicking.rs:181
5: bevy_render::texture::image::Image::new
at .../bevy_render-0.9.1/src/texture/image.rs:209
6: bevy_render::texture::image::Image::from_dynamic
at .../bevy_render-0.9.1/src/texture/image_texture_conversion.rs:159
7: bevy_test::main
at ./src/main.rs:8
...
```
It seems to be cause by a copypasta in `crates/bevy_render/src/texture/image_texture_conversion.rs`. Let's fix it.
## Solution
```diff
// DynamicImage::ImageRgb32F(image) => {
- let a = u16::max_value();
+ let a = 1f32;
```
This will fix the conversion.
---
## Changelog
- Fixed the alpha channel of the `image::DynamicImage::ImageRgb32F` to `bevy_render::texture::Image` conversion in `bevy_render::texture::Image::from_dynamic()`.
# Objective
The feature doesn't have any use case in libraries or applications and many users use this feature incorrectly. See the issue for details.
Closes#5753.
## Solution
Remove it.
---
## Changelog
### Removed
- `render` feature group.
## Migration Guide
Instead of using `render` feature group use dependencies directly. This group consisted of `bevy_core_pipeline`, `bevy_pbr`, `bevy_gltf`, `bevy_render`, `bevy_sprite`, `bevy_text` and `bevy_ui`. You probably want to check if you need all of them.
# Objective
- https://github.com/bevyengine/bevy/pull/5364 Added a few features to the AsBindGroup derive, but if you don't know they exist they aren't documented anywhere.
## Solution
- Document the new arguments in the doc block for the derive.
# Objective
Speed up bundle insertion and spawning from a bundle.
## Solution
Use the same technique used in #6800 to remove the branch on storage type when writing components from a `Bundle` into storage.
- Add a `StorageType` argument to the closure on `Bundle::get_components`.
- Pass `C::Storage::STORAGE_TYPE` into that argument.
- Match on that argument instead of reading from a `Vec<StorageType>` in `BundleInfo`.
- Marked all implementations of `Bundle::get_components` as inline to encourage dead code elimination.
The `Vec<StorageType>` in `BundleInfo` was also removed as it's no longer needed. If users were reliant on this, they can either use the compile time constants or fetch the information from `Components`. Should save a rather negligible amount of memory.
## Performance
Microbenchmarks show a slight improvement to inserting components into existing entities, as well as spawning from a bundle. Ranging about 8-16% faster depending on the benchmark.
```
group main soft-constant-write-components
----- ---- ------------------------------
add_remove/sparse_set 1.08 1019.0±80.10µs ? ?/sec 1.00 944.6±66.86µs ? ?/sec
add_remove/table 1.07 1343.3±20.37µs ? ?/sec 1.00 1257.3±18.13µs ? ?/sec
add_remove_big/sparse_set 1.08 1132.4±263.10µs ? ?/sec 1.00 1050.8±240.74µs ? ?/sec
add_remove_big/table 1.02 2.6±0.05ms ? ?/sec 1.00 2.5±0.08ms ? ?/sec
get_or_spawn/batched 1.15 401.4±17.76µs ? ?/sec 1.00 349.3±11.26µs ? ?/sec
get_or_spawn/individual 1.13 732.1±43.35µs ? ?/sec 1.00 645.6±41.44µs ? ?/sec
insert_commands/insert 1.12 623.9±37.48µs ? ?/sec 1.00 557.4±34.99µs ? ?/sec
insert_commands/insert_batch 1.16 401.4±17.00µs ? ?/sec 1.00 347.4±12.87µs ? ?/sec
insert_simple/base 1.08 416.9±5.60µs ? ?/sec 1.00 385.2±4.14µs ? ?/sec
insert_simple/unbatched 1.06 934.5±44.58µs ? ?/sec 1.00 881.3±47.86µs ? ?/sec
spawn_commands/2000_entities 1.09 190.7±11.41µs ? ?/sec 1.00 174.7±9.15µs ? ?/sec
spawn_commands/4000_entities 1.10 386.5±25.33µs ? ?/sec 1.00 352.3±18.81µs ? ?/sec
spawn_commands/6000_entities 1.10 586.2±34.42µs ? ?/sec 1.00 535.3±27.25µs ? ?/sec
spawn_commands/8000_entities 1.08 778.5±45.15µs ? ?/sec 1.00 718.0±33.66µs ? ?/sec
spawn_world/10000_entities 1.04 1026.4±195.46µs ? ?/sec 1.00 985.8±253.37µs ? ?/sec
spawn_world/1000_entities 1.06 103.8±20.23µs ? ?/sec 1.00 97.6±18.22µs ? ?/sec
spawn_world/100_entities 1.15 11.4±4.25µs ? ?/sec 1.00 9.9±1.87µs ? ?/sec
spawn_world/10_entities 1.05 1030.8±229.78ns ? ?/sec 1.00 986.2±231.12ns ? ?/sec
spawn_world/1_entities 1.01 105.1±23.33ns ? ?/sec 1.00 104.6±31.84ns ? ?/sec
```
---
## Changelog
Changed: `Bundle::get_components` now takes a `FnMut(StorageType, OwningPtr)`. The provided storage type must be correct for the component being fetched.
# Objective
Partially address #3492.
## Solution
Document the remaining undocumented members of `bevy_utils` and set `warn(missing_docs)` on the crate level. Also enabled `clippy::undocumented_unsafe_blocks` as a warning on the crate to keep it in sync with `bevy_ecs`'s warnings.
# Objective
- Fixes#6630, fixes#6679
- Improve scene viewer in cases where there are more than one scene in a gltf file
## Solution
- Can select which scene to display using `#SceneN`, defaults to scene 0 if not present
- Display the number of scenes available if there are more than one
# Objective
```rust
// makes clippy complain about 'taking a mutable reference to a `const` item'
let color = *Color::RED.set_a(0.5);
// Now you can do
let color = Color::RED.with_a(0.5);
```
## Changelog
Added `with_r`, `with_g`, `with_b`, and `with_a` to `Color`.
Co-authored-by: devil-ira <justthecooldude@gmail.com>
# Objective
- Fixes https://github.com/bevyengine/bevy/issues/6417
## Solution
- clear_trackers was not being called on the render world. This causes the removed components vecs to continuously grow. This PR adds clear trackers to the end of RenderStage::Cleanup
## Migration Guide
The call to `clear_trackers` in `App` has been moved from the schedule to App::update for the main world and calls to `clear_trackers` have been added for sub_apps in the same function. This was due to needing stronger guarantees. If clear_trackers isn't called on a world it can lead to memory leaks in `RemovedComponents`.
# Objective
* Implementing a custom `SystemParam` by hand requires implementing three traits -- four if it is read-only.
* The trait `SystemParamFetch<'w, 's>` is a workaround from before we had generic associated types, and is no longer necessary.
## Solution
* Combine the trait `SystemParamFetch` with `SystemParamState`.
* I decided to remove the `Fetch` name and keep the `State` name, since the former was consistently conflated with the latter.
* Replace the trait `ReadOnlySystemParamFetch` with `ReadOnlySystemParam`, which simplifies trait bounds in generic code.
---
## Changelog
- Removed the trait `SystemParamFetch`, moving its functionality to `SystemParamState`.
- Replaced the trait `ReadOnlySystemParamFetch` with `ReadOnlySystemParam`.
## Migration Guide
The trait `SystemParamFetch` has been removed, and its functionality has been transferred to `SystemParamState`.
```rust
// Before
impl SystemParamState for MyParamState {
fn init(world: &mut World, system_meta: &mut SystemMeta) -> Self { ... }
}
impl<'w, 's> SystemParamFetch<'w, 's> for MyParamState {
type Item = MyParam<'w, 's>;
fn get_param(...) -> Self::Item;
}
// After
impl SystemParamState for MyParamState {
type Item<'w, 's> = MyParam<'w, 's>; // Generic associated types!
fn init(world: &mut World, system_meta: &mut SystemMeta) -> Self { ... }
fn get_param<'w, 's>(...) -> Self::Item<'w, 's>;
}
```
The trait `ReadOnlySystemParamFetch` has been replaced with `ReadOnlySystemParam`.
```rust
// Before
unsafe impl ReadOnlySystemParamFetch for MyParamState {}
// After
unsafe impl<'w, 's> ReadOnlySystemParam for MyParam<'w, 's> {}
```
# Objective
It's not clear to users how to handle `!Sync` types as components and resources in the absence of engine level support for them.
## Solution
Added a section to `Component`'s and `Resource`'s type level docs on available options for making a type `Sync` when it holds `!Sync` fields, linking `bevy_utils::synccell::SyncCell` and the currently unstable `std::sync::Exclusive`.
Also added a compile_fail doctest that illustrates how to apply `SyncCell`. These will break when/if #6572 gets merged, at which point these docs should be updated.
# Objective
- Make running animation fluid skipping 'idle' frame.
## Solution
- Loop through the specified indices instead of through the whole sprite sheet.
The example is correct, is just the feeling that the animation loop is not seamless.
Based on the solution suggested by @mockersf in #5429.
# Objective
This is an adoption of #5792. Fixes#5791.
## Solution
Implemented all the required reflection traits for `VecDeque`, taking from `Vec`'s impls.
---
## Changelog
Added: `std::collections::VecDeque` now implements `Reflect` and all relevant traits.
Co-authored-by: james7132 <contact@jamessliu.com>
