# Objective
- Reduce code duplication in the `gamepad_viewer` example.
- Fixes#6164
## Solution
- Added a custom Bundle called `GamepadButtonBundle` to avoid repeating similar code throughout the example.
- Created a `new()` method on `GamepadButtonBundle`.
Co-authored-by: Alvin Philips <alvinphilips257@gmail.com>
# Objective
Add a method for getting a world space ray from a viewport position.
Opted to add a `Ray` type to `bevy_math` instead of returning a tuple of `Vec3`'s as this is clearer and easier to document
The docs on `viewport_to_world` are okay, but I'm not super happy with them.
## Changelog
* Add `Camera::viewport_to_world`
* Add `Camera::ndc_to_world`
* Add `Ray` to `bevy_math`
* Some doc tweaks
Co-authored-by: devil-ira <justthecooldude@gmail.com>
# Objective
Scene viewer example has switch camera keys defined, but only one camera was instantiated on the scene.
## Solution
More explicit help how to cycle the cameras, explaining that more cameras must be present in loaded scene.
Co-authored-by: Fanda Vacek <fvacek@elektroline.cz>
# Objective
- Fix#5285
## Solution
- Put the panicking system in a single threaded stage during the test
- This way only the main thread will panic, which is handled by `cargo test`
# Objective
- Fixes contradictory docs in Window::PresentMode partaining to PresentMode fallback behavior. Fix based on commit history showing the most recent update didn't remove old references to the gracefal fallback for Immediate and Mailbox.
- Fixes#5831
## Solution
- Updated the docs for Window::PresentMode itself and for each individual enum variant to clarify which will fallback and which will panic.
Co-authored-by: Noah <noahshomette@gmail.com>
# Objective
fix error with pbr shader's spotlight direction calculation when direction.y ~= 0
## Solution
in pbr_lighting.wgsl, clamp `1-x^2-z^2` to `>= 0` so that we can safely `sqrt` it
# Objective
The `Wireframe` type implements `Reflect`, but is never registered, making its reflection inaccessible.
## Solution
Call `App::register_type::<Wireframe>()` in the `Plugin::build` implementation of `WireframePlugin`.
---
## Changelog
Fixed `Wireframe` type reflection not getting registered.
# Objective
Examples should use the correct tools for the job.
## Solution
A fixed timestep, by design, can step multiple times consecutively in a single update.
That property used to crash the `alien_cake_addict` example (#2525), which was "fixed" in #3411 (by just not panicking). The proper fix is to use a timer instead, since the system is supposed to spawn a cake every 5 seconds.
---
A timer guarantees a minimum duration. A fixed timestep guarantees a fixed number of steps per second.
Each one works by essentially sacrificing the other's guarantee.
You can use them together, but no other systems are timestep-based in this example, so the timer is enough.
# Objective
Add more documentation on `StandardMaterial` and improve
consistency on existing doc.
Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
# Objective
Relaxes the trait bound for `World::resource_scope` to allow non-send resources. Fixes#6037.
## Solution
No big changes in code had to be made. Added a check so that the non-send resources won't be accessed from a different thread.
---
## Changelog
- `World::resource_scope` accepts non-send resources now
- `World::resource_scope` verifies non-send access if the resource is non-send
- Two new tests are added, one for valid use of `World::resource_scope` with a non-send resource, and one for invalid use (calling it from a different thread, resulting in panic)
Co-authored-by: Dawid Piotrowski <41804418+Pietrek14@users.noreply.github.com>
# Objective
As explained by #5960, `Commands::get_or_spawn` may return a dangling `EntityCommands` that references a non-existing entities. As explained in [this comment], it may be undesirable to make the method return an `Option`.
- Addresses #5960
- Alternative to #5961
## Solution
This PR adds a doc comment to the method to inform the user that the returned `EntityCommands` is not guaranteed to be valid. It also adds panic doc comments on appropriate `EntityCommands` methods.
[this comment]: https://github.com/bevyengine/bevy/pull/5961#issuecomment-1259870849
# Objective
- Alpha mask was previously ignored when using an unlit material.
- Fixes https://github.com/bevyengine/bevy/issues/4479
## Solution
- Extract the alpha discard to a separate function and use it when unlit is true
## Notes
I tried calling `alpha_discard()` before the `if` in pbr.wgsl, but I had errors related to having a `discard` at the beginning before doing the texture sampling. I'm not sure if there's a way to fix that instead of having the function being called in 2 places.
# Objective
- Currently, errors aren't logged as soon as they are found, they are logged only on the next frame. This means your shader could have an unreported error that could have been reported on the first frame.
## Solution
- Log the error as soon as they are found, don't wait until next frame
## Notes
I discovered this issue because I was simply unwrapping the `Result` from `PipelinCache::get_render_pipeline()` which caused it to fail without any explanations. Admittedly, this was a bit of a user error, I shouldn't have unwrapped that, but it seems a bit strange to wait until the next time the pipeline is processed to log the error instead of just logging it as soon as possible since we already have all the info necessary.
# Objective
- Add ability to create nested spawns. This is needed for stageless. The current executor spawns tasks for each system early and runs the system by communicating through a channel. In stageless we want to spawn the task late, so that archetypes can be updated right before the task is run. The executor is run on a separate task, so this enables the scope to be passed to the spawned executor.
- Fixes#4301
## Solution
- Instantiate a single threaded executor on the scope and use that instead of the LocalExecutor. This allows the scope to be Send, but still able to spawn tasks onto the main thread the scope is run on. This works because while systems can access nonsend data. The systems themselves are Send. Because of this change we lose the ability to spawn nonsend tasks on the scope, but I don't think this is being used anywhere. Users would still be able to use spawn_local on TaskPools.
- Steals the lifetime tricks the `std:🧵:scope` uses to allow nested spawns, but disallow scope to be passed to tasks or threads not associated with the scope.
- Change the storage for the tasks to a `ConcurrentQueue`. This is to allow a &Scope to be passed for spawning instead of a &mut Scope. `ConcurrentQueue` was chosen because it was already in our dependency tree because `async_executor` depends on it.
- removed the optimizations for 0 and 1 spawned tasks. It did improve those cases, but made the cases of more than 1 task slower.
---
## Changelog
Add ability to nest spawns
```rust
fn main() {
let pool = TaskPool::new();
pool.scope(|scope| {
scope.spawn(async move {
// calling scope.spawn from an spawn task was not possible before
scope.spawn(async move {
// do something
});
});
})
}
```
## Migration Guide
If you were using explicit lifetimes and Passing Scope you'll need to specify two lifetimes now.
```rust
fn scoped_function<'scope>(scope: &mut Scope<'scope, ()>) {}
// should become
fn scoped_function<'scope>(scope: &Scope<'_, 'scope, ()>) {}
```
`scope.spawn_local` changed to `scope.spawn_on_scope` this should cover cases where you needed to run tasks on the local thread, but does not cover spawning Nonsend Futures.
## TODO
* [x] think real hard about all the lifetimes
* [x] add doc about what 'env and 'scope mean.
* [x] manually check that the single threaded task pool still works
* [x] Get updated perf numbers
* [x] check and make sure all the transmutes are necessary
* [x] move commented out test into a compile fail test
* [x] look through the tests for scope on std and see if I should add any more tests
Co-authored-by: Michael Hsu <myhsu@benjaminelectric.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Make `Res` cloneable
## Solution
Add an associated fn `clone(self: &Self) -. Self` instead of `Copy + Clone` trait impls to avoid `res.clone()` failing to clone out the underlying `T`
# Objective
Often one wants to create a `UiRect` with a value only specifying a single field. These ways are already available, but not the most ergonomic:
```rust
UiRect::new(Val::Undefined, Val::Undefined, Val::Percent(25.0), Val::Undefined)
```
```rust
UiRect {
top: Val::Percent(25.0),
..default()
}
```
## Solution
Introduce 6 new constructors:
- `horizontal`
- `vertical`
- `left`
- `right`
- `top`
- `bottom`
So the above code can be written instead as:
```rust
UiRect::top(Val::Percent(25.0))
```
This solution is similar to the style fields `margin-left`, `padding-top`, etc. that you would see in CSS, from which bevy's UI has other inspiration. Therefore, it should still feel intuitive to users coming from CSS.
---
## Changelog
### Added
- Additional constructors for `UiRect` to specify values for specific fields
# Objective
Currently, arrays cannot indexed using the reflection path API.
This change makes them behave like lists so `x.get_path("list[0]")` will behave the same way, whether x.list is a "List" (e.g. a Vec) or an array.
## Solution
When syntax is encounterd `[ <idx> ]` we check if the referenced type is either a `ReflectRef::List` or `ReflectRef::Array` (or `ReflectMut` for the mutable case). Since both provide the identical API for accessing entries, we do the same for both, although it requires code duplication as far as I can tell.
This was born from working on #5764, but since this seems to be an easier fix (and I am not sure if I can actually solve #5812) I figured it might be worth to split this out.
# Objective
Simple docs/comments only PR that just fixes some outdated file references left over from the render rewrite.
## Solution
- Change the references to point to the correct files
# Objective
The [Stageless RFC](https://github.com/bevyengine/rfcs/pull/45) involves allowing exclusive systems to be referenced and ordered relative to parallel systems. We've agreed that unifying systems under `System` is the right move.
This is an alternative to #4166 (see rationale in the comments I left there). Note that this builds on the learnings established there (and borrows some patterns).
## Solution
This unifies parallel and exclusive systems under the shared `System` trait, removing the old `ExclusiveSystem` trait / impls. This is accomplished by adding a new `ExclusiveFunctionSystem` impl similar to `FunctionSystem`. It is backed by `ExclusiveSystemParam`, which is similar to `SystemParam`. There is a new flattened out SystemContainer api (which cuts out a lot of trait and type complexity).
This means you can remove all cases of `exclusive_system()`:
```rust
// before
commands.add_system(some_system.exclusive_system());
// after
commands.add_system(some_system);
```
I've also implemented `ExclusiveSystemParam` for `&mut QueryState` and `&mut SystemState`, which makes this possible in exclusive systems:
```rust
fn some_exclusive_system(
world: &mut World,
transforms: &mut QueryState<&Transform>,
state: &mut SystemState<(Res<Time>, Query<&Player>)>,
) {
for transform in transforms.iter(world) {
println!("{transform:?}");
}
let (time, players) = state.get(world);
for player in players.iter() {
println!("{player:?}");
}
}
```
Note that "exclusive function systems" assume `&mut World` is present (and the first param). I think this is a fair assumption, given that the presence of `&mut World` is what defines the need for an exclusive system.
I added some targeted SystemParam `static` constraints, which removed the need for this:
``` rust
fn some_exclusive_system(state: &mut SystemState<(Res<'static, Time>, Query<&'static Player>)>) {}
```
## Related
- #2923
- #3001
- #3946
## Changelog
- `ExclusiveSystem` trait (and implementations) has been removed in favor of sharing the `System` trait.
- `ExclusiveFunctionSystem` and `ExclusiveSystemParam` were added, enabling flexible exclusive function systems
- `&mut SystemState` and `&mut QueryState` now implement `ExclusiveSystemParam`
- Exclusive and parallel System configuration is now done via a unified `SystemDescriptor`, `IntoSystemDescriptor`, and `SystemContainer` api.
## Migration Guide
Calling `.exclusive_system()` is no longer required (or supported) for converting exclusive system functions to exclusive systems:
```rust
// Old (0.8)
app.add_system(some_exclusive_system.exclusive_system());
// New (0.9)
app.add_system(some_exclusive_system);
```
Converting "normal" parallel systems to exclusive systems is done by calling the exclusive ordering apis:
```rust
// Old (0.8)
app.add_system(some_system.exclusive_system().at_end());
// New (0.9)
app.add_system(some_system.at_end());
```
Query state in exclusive systems can now be cached via ExclusiveSystemParams, which should be preferred for clarity and performance reasons:
```rust
// Old (0.8)
fn some_system(world: &mut World) {
let mut transforms = world.query::<&Transform>();
for transform in transforms.iter(world) {
}
}
// New (0.9)
fn some_system(world: &mut World, transforms: &mut QueryState<&Transform>) {
for transform in transforms.iter(world) {
}
}
```
# Objective
I was working with the TextBundle component bundle because I wanted to change the position of the text that the bundle was holding. I used the transform field on the TextBundle at first because that is normally what controls the position of sprites in Bevy and that's what I was used to working with.
But the actual way to change the position of text inside of a TextBundle is to use the Style's position field, not the TextBundle's transform field.
Anecdotally, it was mentioned on the discord that other users have had this issue too.
## Solution
I added a small doc comment to the TextBundle's transform telling users not to use it to set the position of text. And since this issue applies to the other UI bundles, I added comments there as well!
Fixes#6077
# Objective
- Make many_sprites and many_animated_sprites work again
## Solution
- Removed the extra transform from the camera bundle - not sure why it was necessary, since `Camera2dBundle::default()` already contains a transform with the same parameters.
---
# Objective
I was about to submit a PR to add these two examples to `bevy-website` and re-discovered the inconsistency.
Although it's not a major issue on the website where only the filenames are shown, this would help to visually distinguish the two examples in the list because the names are very prominent.
This also helps out when fuzzy-searching the codebase for these files.
## Solution
Rename `shapes` to `2d_shapes`. Now the filename matches the example name, and the naming structure matches the 3d example.
## Notes
@Nilirad proposed this in https://github.com/bevyengine/bevy/pull/4613#discussion_r862455631 but it had slipped away from my brain at that time.
# Objective
Fixes#6078. The `UiColor` component is unhelpfully named: it is unclear, ambiguous with border color and
## Solution
Rename the `UiColor` component (and associated fields) to `BackgroundColor` / `background_colorl`.
## Migration Guide
`UiColor` has been renamed to `BackgroundColor`. This change affects `NodeBundle`, `ButtonBundle` and `ImageBundle`. In addition, the corresponding field on `ExtractedUiNode` has been renamed to `background_color` for consistency.
This is an adoption of #3775
This merges `TextureAtlas` `from_grid_with_padding` into `from_grid` , adding optional padding and optional offset.
Since the orignal PR, the offset had already been added to from_grid_with_padding through #4836
## Changelog
- Added `padding` and `offset` arguments to `TextureAtlas::from_grid`
- Removed `TextureAtlas::from_grid_with_padding`
## Migration Guide
`TextureAtlas::from_grid_with_padding` was merged into `from_grid` which takes two additional parameters for padding and an offset.
```
// 0.8
TextureAtlas::from_grid(texture_handle, Vec2::new(24.0, 24.0), 7, 1);
// 0.9
TextureAtlas::from_grid(texture_handle, Vec2::new(24.0, 24.0), 7, 1, None, None)
// 0.8
TextureAtlas::from_grid_with_padding(texture_handle, Vec2::new(24.0, 24.0), 7, 1, Vec2::new(4.0, 4.0));
// 0.9
TextureAtlas::from_grid(texture_handle, Vec2::new(24.0, 24.0), 7, 1, Some(Vec2::new(4.0, 4.0)), None)
```
Co-authored-by: olefish <88390729+oledfish@users.noreply.github.com>
# Objective
- Sometimes, like when using shaders, you can only use a time value in `f32`. Unfortunately this suffers from floating precision issues pretty quickly. The standard approach to this problem is to wrap the time after a given period
- This is necessary for https://github.com/bevyengine/bevy/pull/5409
## Solution
- Add a `seconds_since_last_wrapping_period` method on `Time` that returns a `f32` that is the `seconds_since_startup` modulo the `max_wrapping_period`
---
## Changelog
Added `seconds_since_last_wrapping_period` to `Time`
## Additional info
I'm very opened to hearing better names. I don't really like the current naming, I just went with something descriptive.
Co-authored-by: Charles <IceSentry@users.noreply.github.com>
# Objective
Now that we can consolidate Bundles and Components under a single insert (thanks to #2975 and #6039), almost 100% of world spawns now look like `world.spawn().insert((Some, Tuple, Here))`. Spawning an entity without any components is an extremely uncommon pattern, so it makes sense to give spawn the "first class" ergonomic api. This consolidated api should be made consistent across all spawn apis (such as World and Commands).
## Solution
All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input:
```rust
// before:
commands
.spawn()
.insert((A, B, C));
world
.spawn()
.insert((A, B, C);
// after
commands.spawn((A, B, C));
world.spawn((A, B, C));
```
All existing instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api. A new `spawn_empty` has been added, replacing the old `spawn` api.
By allowing `world.spawn(some_bundle)` to replace `world.spawn().insert(some_bundle)`, this opened the door to removing the initial entity allocation in the "empty" archetype / table done in `spawn()` (and subsequent move to the actual archetype in `.insert(some_bundle)`).
This improves spawn performance by over 10%:
![image](https://user-images.githubusercontent.com/2694663/191627587-4ab2f949-4ccd-4231-80eb-80dd4d9ad6b9.png)
To take this measurement, I added a new `world_spawn` benchmark.
Unfortunately, optimizing `Commands::spawn` is slightly less trivial, as Commands expose the Entity id of spawned entities prior to actually spawning. Doing the optimization would (naively) require assurances that the `spawn(some_bundle)` command is applied before all other commands involving the entity (which would not necessarily be true, if memory serves). Optimizing `Commands::spawn` this way does feel possible, but it will require careful thought (and maybe some additional checks), which deserves its own PR. For now, it has the same performance characteristics of the current `Commands::spawn_bundle` on main.
**Note that 99% of this PR is simple renames and refactors. The only code that needs careful scrutiny is the new `World::spawn()` impl, which is relatively straightforward, but it has some new unsafe code (which re-uses battle tested BundlerSpawner code path).**
---
## Changelog
- All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input
- All instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api
- World and Commands now have `spawn_empty()`, which is equivalent to the old `spawn()` behavior.
## Migration Guide
```rust
// Old (0.8):
commands
.spawn()
.insert_bundle((A, B, C));
// New (0.9)
commands.spawn((A, B, C));
// Old (0.8):
commands.spawn_bundle((A, B, C));
// New (0.9)
commands.spawn((A, B, C));
// Old (0.8):
let entity = commands.spawn().id();
// New (0.9)
let entity = commands.spawn_empty().id();
// Old (0.8)
let entity = world.spawn().id();
// New (0.9)
let entity = world.spawn_empty();
```
# Objective
- Add unit tests for ambiguity detection reporting.
- Incremental implementation of #4299.
## Solution
- Refactor ambiguity detection internals to make it testable. As a bonus, this should make it easier to extend in the future.
## Notes
* This code was copy-pasted from #4299 and modified. Credit goes to @alice-i-cecile and @afonsolage, though I'm not sure who wrote what at this point.
## Objective
Fixes https://github.com/bevyengine/bevy/issues/6063
## Solution
- Use `then_some(x)` instead of `then( || x)`.
- Updated error logs from `bevy_ecs_compile_fail_tests`.
## Migration Guide
From Rust 1.63 to 1.64, a new Clippy error was added; now one should use `then_some(x)` instead of `then( || x)`.
# Objective
Both components already derives `Reflect` and it would be nice to have `FromReflect` in order to ser/de between those types without relaying on `downcast`, since it can fail between different platforms, like WebAssembly.
## Solution
Derive `FromReflect` for `Transform` and `GlobalTransform`.
I thought if I should also derive `FromReflect` for `GlobalTransform`, since it's a computed component, but there may be some use cases where a `GlobalTransform` is needed to be sent over the wire, so I decided to do it.
# Objective
- Reconfigure surface after present mode changes. It seems that this is not done currently at runtime. It's pretty common for games to change such graphical settings at runtime.
- Fixes present mode issue in #5111
## Solution
- Exactly like resolution change gets tracked when extracting window, do the same for present mode.
Additionally, I added present mode (vsync) toggling to window settings example.
# Objective
Take advantage of the "impl Bundle for Component" changes in #2975 / add the follow up changes discussed there.
## Solution
- Change `insert` and `remove` to accept a Bundle instead of a Component (for both Commands and World)
- Deprecate `insert_bundle`, `remove_bundle`, and `remove_bundle_intersection`
- Add `remove_intersection`
---
## Changelog
- Change `insert` and `remove` now accept a Bundle instead of a Component (for both Commands and World)
- `insert_bundle` and `remove_bundle` are deprecated
## Migration Guide
Replace `insert_bundle` with `insert`:
```rust
// Old (0.8)
commands.spawn().insert_bundle(SomeBundle::default());
// New (0.9)
commands.spawn().insert(SomeBundle::default());
```
Replace `remove_bundle` with `remove`:
```rust
// Old (0.8)
commands.entity(some_entity).remove_bundle::<SomeBundle>();
// New (0.9)
commands.entity(some_entity).remove::<SomeBundle>();
```
Replace `remove_bundle_intersection` with `remove_intersection`:
```rust
// Old (0.8)
world.entity_mut(some_entity).remove_bundle_intersection::<SomeBundle>();
// New (0.9)
world.entity_mut(some_entity).remove_intersection::<SomeBundle>();
```
Consider consolidating as many operations as possible to improve ergonomics and cut down on archetype moves:
```rust
// Old (0.8)
commands.spawn()
.insert_bundle(SomeBundle::default())
.insert(SomeComponent);
// New (0.9) - Option 1
commands.spawn().insert((
SomeBundle::default(),
SomeComponent,
))
// New (0.9) - Option 2
commands.spawn_bundle((
SomeBundle::default(),
SomeComponent,
))
```
## Next Steps
Consider changing `spawn` to accept a bundle and deprecate `spawn_bundle`.
# Objective
The doc comments for `Command` methods are a bit inconsistent on the format, they sometimes go out of scope, and most importantly they are wrong, in the sense that they claim to perform the action described by the command, while in reality, they just push a command to perform the action.
- Follow-up of #5938.
- Related to #5913.
## Solution
- Where applicable, only stated that a `Command` is pushed.
- Added a “See also” section for similar methods.
- Added a missing “Panics” section for `Commands::entity`.
- Removed a wrong comment about `Commands::get_or_spawn` returning `None` (It does not return an option).
- Removed polluting descriptions of other items.
- Misc formatting changes.
## Future possibilities
Since the `Command` implementors (`Spawn`, `InsertBundle`, `InitResource`, ...) are public, I thought that it might be appropriate to describe the action of the command there instead of the method, and to add a `method → command struct` link to fill the gap.
If that seems too far-fetched, we may opt to make them private, if possible, or `#[doc(hidden)]`.
# Objective
Working on issue #1934 , with linking examples to the documentation. PR for transform examples.
## Solution
Added to the documentation in bevy_transform transform.rs and global_transform.rs utilizing links from examples.
[X] 3d_rotations.rs linked to rotate in Transform
[X] global_vs_local_translation.rs linked to top of Transform and GlobalTransform documentation
[X] scale.rs linked to scale Struct in Transform
[X] transform.rs linked to top of Transform documentation
[X] translation.rs linked to from_translation in Transform
Co-authored-by: bwhitt7 <103079612+bwhitt7@users.noreply.github.com>
@BoxyUwU this is your fault.
Also cart didn't arrive in time to tell us not to do this.
# Objective
- Fix#2974
## Solution
- The first commit just does the actual change
- Follow up commits do steps to prove that this method works to unify as required, but this does not remove `insert_bundle`.
## Changelog
### Changed
Nested bundles now collapse automatically, and every `Component` now implements `Bundle`.
This means that you can combine bundles and components arbitrarily, for example:
```rust
// before:
.insert(A).insert_bundle(MyBBundle{..})
// after:
.insert_bundle((A, MyBBundle {..}))
```
Note that there will be a follow up PR that removes the current `insert` impl and renames `insert_bundle` to `insert`.
### Removed
The `bundle` attribute in `derive(Bundle)`.
## Migration guide
In `derive(Bundle)`, the `bundle` attribute has been removed. Nested bundles are not collapsed automatically. You should remove `#[bundle]` attributes.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
> Note: This is rebased off #4561 and can be viewed as a competitor to that PR. See `Comparison with #4561` section for details.
# Objective
The current serialization format used by `bevy_reflect` is both verbose and error-prone. Taking the following structs[^1] for example:
```rust
// -- src/inventory.rs
#[derive(Reflect)]
struct Inventory {
id: String,
max_storage: usize,
items: Vec<Item>
}
#[derive(Reflect)]
struct Item {
name: String
}
```
Given an inventory of a single item, this would serialize to something like:
```rust
// -- assets/inventory.ron
{
"type": "my_game::inventory::Inventory",
"struct": {
"id": {
"type": "alloc::string::String",
"value": "inv001",
},
"max_storage": {
"type": "usize",
"value": 10
},
"items": {
"type": "alloc::vec::Vec<alloc::string::String>",
"list": [
{
"type": "my_game::inventory::Item",
"struct": {
"name": {
"type": "alloc::string::String",
"value": "Pickaxe"
},
},
},
],
},
},
}
```
Aside from being really long and difficult to read, it also has a few "gotchas" that users need to be aware of if they want to edit the file manually. A major one is the requirement that you use the proper keys for a given type. For structs, you need `"struct"`. For lists, `"list"`. For tuple structs, `"tuple_struct"`. And so on.
It also ***requires*** that the `"type"` entry come before the actual data. Despite being a map— which in programming is almost always orderless by default— the entries need to be in a particular order. Failure to follow the ordering convention results in a failure to deserialize the data.
This makes it very prone to errors and annoyances.
## Solution
Using #4042, we can remove a lot of the boilerplate and metadata needed by this older system. Since we now have static access to type information, we can simplify our serialized data to look like:
```rust
// -- assets/inventory.ron
{
"my_game::inventory::Inventory": (
id: "inv001",
max_storage: 10,
items: [
(
name: "Pickaxe"
),
],
),
}
```
This is much more digestible and a lot less error-prone (no more key requirements and no more extra type names).
Additionally, it is a lot more familiar to users as it follows conventional serde mechanics. For example, the struct is represented with `(...)` when serialized to RON.
#### Custom Serialization
Additionally, this PR adds the opt-in ability to specify a custom serde implementation to be used rather than the one created via reflection. For example[^1]:
```rust
// -- src/inventory.rs
#[derive(Reflect, Serialize)]
#[reflect(Serialize)]
struct Item {
#[serde(alias = "id")]
name: String
}
```
```rust
// -- assets/inventory.ron
{
"my_game::inventory::Inventory": (
id: "inv001",
max_storage: 10,
items: [
(
id: "Pickaxe"
),
],
),
},
```
By allowing users to define their own serialization methods, we do two things:
1. We give more control over how data is serialized/deserialized to the end user
2. We avoid having to re-define serde's attributes and forcing users to apply both (e.g. we don't need a `#[reflect(alias)]` attribute).
### Improved Formats
One of the improvements this PR provides is the ability to represent data in ways that are more conventional and/or familiar to users. Many users are familiar with RON so here are some of the ways we can now represent data in RON:
###### Structs
```js
{
"my_crate::Foo": (
bar: 123
)
}
// OR
{
"my_crate::Foo": Foo(
bar: 123
)
}
```
<details>
<summary>Old Format</summary>
```js
{
"type": "my_crate::Foo",
"struct": {
"bar": {
"type": "usize",
"value": 123
}
}
}
```
</details>
###### Tuples
```js
{
"(f32, f32)": (1.0, 2.0)
}
```
<details>
<summary>Old Format</summary>
```js
{
"type": "(f32, f32)",
"tuple": [
{
"type": "f32",
"value": 1.0
},
{
"type": "f32",
"value": 2.0
}
]
}
```
</details>
###### Tuple Structs
```js
{
"my_crate::Bar": ("Hello World!")
}
// OR
{
"my_crate::Bar": Bar("Hello World!")
}
```
<details>
<summary>Old Format</summary>
```js
{
"type": "my_crate::Bar",
"tuple_struct": [
{
"type": "alloc::string::String",
"value": "Hello World!"
}
]
}
```
</details>
###### Arrays
It may be a bit surprising to some, but arrays now also use the tuple format. This is because they essentially _are_ tuples (a sequence of values with a fixed size), but only allow for homogenous types. Additionally, this is how RON handles them and is probably a result of the 32-capacity limit imposed on them (both by [serde](https://docs.rs/serde/latest/serde/trait.Serialize.html#impl-Serialize-for-%5BT%3B%2032%5D) and by [bevy_reflect](https://docs.rs/bevy/latest/bevy/reflect/trait.GetTypeRegistration.html#impl-GetTypeRegistration-for-%5BT%3B%2032%5D)).
```js
{
"[i32; 3]": (1, 2, 3)
}
```
<details>
<summary>Old Format</summary>
```js
{
"type": "[i32; 3]",
"array": [
{
"type": "i32",
"value": 1
},
{
"type": "i32",
"value": 2
},
{
"type": "i32",
"value": 3
}
]
}
```
</details>
###### Enums
To make things simple, I'll just put a struct variant here, but the style applies to all variant types:
```js
{
"my_crate::ItemType": Consumable(
name: "Healing potion"
)
}
```
<details>
<summary>Old Format</summary>
```js
{
"type": "my_crate::ItemType",
"enum": {
"variant": "Consumable",
"struct": {
"name": {
"type": "alloc::string::String",
"value": "Healing potion"
}
}
}
}
```
</details>
### Comparison with #4561
This PR is a rebased version of #4561. The reason for the split between the two is because this PR creates a _very_ different scene format. You may notice that the PR descriptions for either PR are pretty similar. This was done to better convey the changes depending on which (if any) gets merged first. If #4561 makes it in first, I will update this PR description accordingly.
---
## Changelog
* Re-worked serialization/deserialization for reflected types
* Added `TypedReflectDeserializer` for deserializing data with known `TypeInfo`
* Renamed `ReflectDeserializer` to `UntypedReflectDeserializer`
* ~~Replaced usages of `deserialize_any` with `deserialize_map` for non-self-describing formats~~ Reverted this change since there are still some issues that need to be sorted out (in a separate PR). By reverting this, crates like `bincode` can throw an error when attempting to deserialize non-self-describing formats (`bincode` results in `DeserializeAnyNotSupported`)
* Structs, tuples, tuple structs, arrays, and enums are now all de/serialized using conventional serde methods
## Migration Guide
* This PR reduces the verbosity of the scene format. Scenes will need to be updated accordingly:
```js
// Old format
{
"type": "my_game::item::Item",
"struct": {
"id": {
"type": "alloc::string::String",
"value": "bevycraft:stone",
},
"tags": {
"type": "alloc::vec::Vec<alloc::string::String>",
"list": [
{
"type": "alloc::string::String",
"value": "material"
},
],
},
}
// New format
{
"my_game::item::Item": (
id: "bevycraft:stone",
tags: ["material"]
)
}
```
[^1]: Some derives omitted for brevity.