# Objective
Currently the `missing_docs` lint is allowed-by-default and enabled at
crate level when their documentations is complete (see #3492).
This PR proposes to inverse this logic by making `missing_docs`
warn-by-default and mark crates with imcomplete docs allowed.
## Solution
Makes `missing_docs` warn at workspace level and allowed at crate level
when the docs is imcomplete.
# Objective
- `AssetTransformer` provides an input asset, and output an asset, but
provides no access to the `LabeledAsset`'s created by the `AssetLoader`.
Labeled sub assets are an extremely important piece of many assets, Gltf
in particular, and without them the amount of transformation on an asset
is limited. In order for `AssetTransformer`'s to be useful, they need to
have access to these sub assets.
- LabeledAsset's loaded by `AssetLoader`s are provided to `AssetSaver`s
in the `LoadAndSave` process, but the `LoadTransformAndSave` process
drops these values in the transform stage, and so `AssetSaver` is given
none.
- Fixes#11606
Ideally the AssetTransformer should not ignore labeled sub assets, and
they should be kept at least for the AssetSaver
## Solution
- I created a new struct similar to `SavedAsset` named
`TransformedAsset` which holds the input asset, and the HashMap of
`LabeledAsset`s. The transform function now takes as input a
`TransformedAsset`, and returns a `TransformedAsset::<AssetOutput>`.
This gives the transform function access to the labeled sub assets
created by the `AssetLoader`.
- I also created `TransformedSubAsset` which holds mutable references to
a sub asset and that sub assets HashMap of `LabeledAsset`s. This allows
you to travers the Tree of `LabeledAsset`s by reference relatively
easily.
- The `LoadTransformAndSave` processor was then reworked to use the new
structs, stopping the `LabeledAsset`s from being dropped.
---
## Changelog
- Created TransformedAsset struct and TransformedSubAsset struct.
- Changed `get_untyped_handle` to return a `UntypedHandle` directly
rather than a reference and added `get_handle` as a typed variant in
SavedAsset and TransformedAsset
- Added `SavedAsset::from_transformed` as a constructor from a
`TransformedAsset`
- Switched LoadTransformAndSave process code to work with new
`TransformedAsset` type
- Added a `ProcessError` for `AssetTransformer` in process.rs
- Switched `AssetTransformer::transform` to use `TransformedAsset` as
input and output.
- Switched `AssetTransformer` to use a `BoxedFuture` like `AssetLoader`
and `AssetSaver` to allow for async transformation code.
- Updated AssetTransformer example to use new structure.
# Objective
- Addresses **Support processing and loading files without extensions**
from #9714
- Addresses **More runtime loading configuration** from #9714
- Fixes#367
- Fixes#10703
## Solution
`AssetServer::load::<A>` and `AssetServer::load_with_settings::<A>` can
now use the `Asset` type parameter `A` to select a registered
`AssetLoader` without inspecting the provided `AssetPath`. This change
cascades onto `LoadContext::load` and `LoadContext::load_with_settings`.
This allows the loading of assets which have incorrect or ambiguous file
extensions.
```rust
// Allow the type to be inferred by context
let handle = asset_server.load("data/asset_no_extension");
// Hint the type through the handle
let handle: Handle<CustomAsset> = asset_server.load("data/asset_no_extension");
// Explicit through turbofish
let handle = asset_server.load::<CustomAsset>("data/asset_no_extension");
```
Since a single `AssetPath` no longer maps 1:1 with an `Asset`, I've also
modified how assets are loaded to permit multiple asset types to be
loaded from a single path. This allows for two different `AssetLoaders`
(which return different types of assets) to both load a single path (if
requested).
```rust
// Uses GltfLoader
let model = asset_server.load::<Gltf>("cube.gltf");
// Hypothetical Blob loader for data transmission (for example)
let blob = asset_server.load::<Blob>("cube.gltf");
```
As these changes are reflected in the `LoadContext` as well as the
`AssetServer`, custom `AssetLoaders` can also take advantage of this
behaviour to create more complex assets.
---
## Change Log
- Updated `custom_asset` example to demonstrate extension-less assets.
- Added `AssetServer::get_handles_untyped` and Added
`AssetServer::get_path_ids`
## Notes
As a part of that refactor, I chose to store `AssetLoader`s (within
`AssetLoaders`) using a `HashMap<TypeId, ...>` instead of a `Vec<...>`.
My reasoning for this was I needed to add a relationship between `Asset`
`TypeId`s and the `AssetLoader`, so instead of having a `Vec` and a
`HashMap`, I combined the two, removing the `usize` index from the
adjacent maps.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
- SavedAsset's iter_labels returns ```&str```, however accessing
LabeledAssets requires ```CowArc<'static, str>```
- Although SavedAsset holds UntypedHandles in its hashmap of
LabeledAssets, they are inaccessible as LabeledAssets are casted to
SavedAsset or ErasedLoadedAsset, which don't contain their
UntypedHandles
- Adresses #11609
## Solution
- Used Trait bounds to allow for either ```CowArc<'static, str>``` or
```&str``` to be used as a label in get_labeled and get_erased_labeled.
- Added method get_untyped_handle to get UntypedHandle from the
LabeledAsset.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Revert the changes to type parameter bounds introduced in #9046,
improves the `#[reflect(where)]` attribute (also from #9046), and adds
the ability to opt out of field bounds.
This is based on suggestions by @soqb and discussion on
[Discord](https://discord.com/channels/691052431525675048/1002362493634629796/1201227833826103427).
## Solution
Reverts the changes to type parameter bounds when deriving `Reflect`,
introduced in #9046. This was originally done as a means of fixing a
recursion issue (#8965). However, as @soqb pointed out, we could achieve
the same result by simply making an opt-out attribute instead of messing
with the type parameter bounds.
This PR has four main changes:
1. Reverts the type parameter bounds from #9046
2. Includes `TypePath` as a default bound for active fields
3. Changes `#reflect(where)]` to be strictly additive
4. Adds `#reflect(no_field_bounds)]` to opt out of field bounds
Change 1 means that, like before, type parameters only receive at most
the `TypePath` bound (if `#[reflect(type_path = false)]` is not present)
and active fields receive the `Reflect` or `FromReflect` bound. And with
Change 2, they will also receive `TypePath` (since it's indirectly
required by `Typed` to construct `NamedField` and `UnnamedField`
instances).
Change 3 was made to make room for Change 4. By splitting out the
responsibility of `#reflect(where)]`, we can use it with or without
`#reflect(no_field_bounds)]` for various use cases.
For example, if we hadn't done this, the following would have failed:
```rust
// Since we're not using `#reflect(no_field_bounds)]`,
// `T::Assoc` is automatically given the required bounds
// of `FromReflect + TypePath`
#[derive(Reflect)]
#[reflect(where T::Assoc: OtherTrait)]
struct Foo<T: MyTrait> {
value: T::Assoc,
}
```
This provides more flexibility to the user while still letting them add
or remove most trait bounds.
And to solve the original recursion issue, we can do:
```rust
#[derive(Reflect)]
#[reflect(no_field_bounds)] // <-- Added
struct Foo {
foo: Vec<Foo>
}
```
#### Bounds
All in all, we now have four sets of trait bounds:
- `Self` gets the bounds `Any + Send + Sync`
- Type parameters get the bound `TypePath`. This can be opted out of
with `#[reflect(type_path = false)]`
- Active fields get the bounds `TypePath` and `FromReflect`/`Reflect`
bounds. This can be opted out of with `#reflect(no_field_bounds)]`
- Custom bounds can be added with `#[reflect(where)]`
---
## Changelog
- Revert some changes #9046
- `#reflect(where)]` is now strictly additive
- Added `#reflect(no_field_bounds)]` attribute to opt out of automatic
field trait bounds when deriving `Reflect`
- Made the `TypePath` requirement on fields when deriving `Reflect` more
explicit
## Migration Guide
> [!important]
> This PR shouldn't be a breaking change relative to the current version
of Bevy (v0.12). And since it removes the breaking parts of #9046, that
PR also won't need a migration guide.
# Objective
- Closes#11490.
- Allow retrieving the current asset watch behavior from the
`AssetServer`.
## Solution
- Add the corresponding getter. (also fixes some trailing whitespace).
A corresponding helper could also be added on the `AssetPlugin` struct
(returning `self.watch_for_changes_override.unwrap_or(cfg!(feature =
"watch"))`), but it seems it isn't a current practice to have actual
methods on the plugin structs appart from the `Plugin` impl.
---
## Changelog
### Added
Added `watching_for_changes` getter on `AssetServer`.
---------
Co-authored-by: Mateusz Wachowiak <mateusz_wachowiak@outlook.com>
# Objective
Fixes#8965.
#### Background
For convenience and to ensure everything is setup properly, we
automatically add certain bounds to the derived types. The current
implementation does this by taking the types from all active fields and
adding them to the where-clause of the generated impls. I believe this
method was chosen because it won't add bounds to types that are
otherwise ignored.
```rust
#[derive(Reflect)]
struct Foo<T, U: SomeTrait, V> {
t: T,
u: U::Assoc,
#[reflect(ignore)]
v: [V; 2]
}
// Generates something like:
impl<T, U: SomeTrait, V> for Foo<T, U, V>
where
// Active:
T: Reflect,
U::Assoc: Reflect,
// Ignored:
[V; 2]: Send + Sync + Any
{
// ...
}
```
The self-referential type fails because it ends up using _itself_ as a
type bound due to being one of its own active fields.
```rust
#[derive(Reflect)]
struct Foo {
foo: Vec<Foo>
}
// Foo where Vec<Foo>: Reflect -> Vec<T> where T: Reflect -> Foo where Vec<Foo>: Reflect -> ...
```
## Solution
We can't simply parse all field types for the name of our type. That
would be both complex and prone to errors and false-positives. And even
if it wasn't, what would we replace the bound with?
Instead, I opted to go for a solution that only adds the bounds to what
really needs it: the type parameters. While the bounds on concrete types
make errors a bit cleaner, they aren't strictly necessary. This means we
can change our generated where-clause to only add bounds to generic type
parameters.
Doing this, though, returns us back to the problem of over-bounding
parameters that don't need to be bounded. To solve this, I added a new
container attribute (based on
[this](https://github.com/dtolnay/syn/issues/422#issuecomment-406882925)
comment and @nicopap's
[comment](https://github.com/bevyengine/bevy/pull/9046#issuecomment-1623593780))
that allows us to pass in a custom where clause to modify what bounds
are added to these type parameters.
This allows us to do stuff like:
```rust
trait Trait {
type Assoc;
}
// We don't need `T` to be reflectable since we only care about `T::Assoc`.
#[derive(Reflect)]
#[reflect(where T::Assoc: FromReflect)]
struct Foo<T: Trait>(T::Assoc);
#[derive(TypePath)]
struct Bar;
impl Trait for Bar {
type Assoc = usize;
}
#[derive(Reflect)]
struct Baz {
a: Foo<Bar>,
}
```
> **Note**
> I also
[tried](dc139ea34c)
allowing `#[reflect(ignore)]` to be used on the type parameters
themselves, but that proved problematic since the derive macro does not
consume the attribute. This is why I went with the container attribute
approach.
### Alternatives
One alternative could possibly be to just not add reflection bounds
automatically (i.e. only add required bounds like `Send`, `Sync`, `Any`,
and `TypePath`).
The downside here is we add more friction to using reflection, which
already comes with its own set of considerations. This is a potentially
viable option, but we really need to consider whether or not the
ergonomics hit is worth it.
If we did decide to go the more manual route, we should at least
consider something like #5772 to make it easier for users to add the
right bounds (although, this could still become tricky with
`FromReflect` also being automatically derived).
### Open Questions
1. Should we go with this approach or the manual alternative?
2. ~~Should we add a `skip_params` attribute to avoid the `T: 'static`
trick?~~ ~~Decided to go with `custom_where()` as it's the simplest~~
Scratch that, went with a normal where clause
3. ~~`custom_where` bikeshedding?~~ No longer needed since we are using
a normal where clause
### TODO
- [x] Add compile-fail tests
---
## Changelog
- Fixed issue preventing recursive types from deriving `Reflect`
- Changed how where-clause bounds are generated by the `Reflect` derive
macro
- They are now only applied to the type parameters, not to all active
fields
- Added `#[reflect(where T: Trait, U::Assoc: Trait, ...)]` container
attribute
## Migration Guide
When deriving `Reflect`, generic type params that do not need the
automatic reflection bounds (such as `Reflect`) applied to them will
need to opt-out using a custom where clause like: `#[reflect(where T:
Trait, U::Assoc: Trait, ...)]`.
The attribute can define custom bounds only used by the reflection
impls. To simply opt-out all the type params, we can pass in an empty
where clause: `#[reflect(where)]`.
```rust
// BEFORE:
#[derive(Reflect)]
struct Foo<T>(#[reflect(ignore)] T);
// AFTER:
#[derive(Reflect)]
#[reflect(where)]
struct Foo<T>(#[reflect(ignore)] T);
```
---------
Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
# Objective
Fixes#11533
When `AssetPath`s are created from a string type, they are parsed into
an `AssetSource`, a `Path`, and a `Label`.
The current method of parsing has some unnecessary quirks:
- The presence of a `:` character is assumed to be the start of an asset
source indicator.
- This is not necessarily true. There are valid uses of a `:` character
in an asset path, for example an http source's port such as
`localhost:80`.
- If there are multiple instances of `://`, the last one is assumed to
be the asset source deliminator.
- This has some unexpected behavior. Even in a fully formed path, such
as `http://localhost:80`, the `:` between `localhost` and `80` is
assumed to be the start of an asset source, causing an error since it
does not form the full sequence `://`.
## Solution
Changes the `AssetPath`'s `parse_internal` method to be more permissive.
- Only the exact sequence `://` is taken to be the asset source
deliminator, and only the first one if there are multiple.
- As a consequence, it is no longer possible to detect a malformed asset
source deliminator, and so the corresponding error was removed.
# Objective
One of a few Bevy Asset improvements I would like to make: #11216.
Currently asset processing and asset saving are handled by the same
trait, `AssetSaver`. This makes it difficult to reuse saving
implementations and impossible to have a single "universal" saver for a
given asset type.
## Solution
This PR splits off the processing portion of `AssetSaver` into
`AssetTransformer`, which is responsible for transforming assets. This
change involves adding the `LoadTransformAndSave` processor, which
utilizes the new API. The `LoadAndSave` still exists since it remains
useful in situations where no "transformation" of the asset is done,
such as when compressing assets.
## Notes:
As an aside, Bikeshedding is welcome on the names. I'm not entirely
convinced by `AssetTransformer`, which was chosen mostly because
`AssetProcessor` is taken. Additionally, `LoadTransformSave` may be
sufficient instead of `LoadTransformAndSave`.
---
## Changelog
### Added
- `AssetTransformer` which is responsible for transforming Assets.
- `LoadTransformAndSave`, a `Process` implementation.
### Changed
- Changed `AssetSaver`'s responsibilities from processing and saving to
just saving.
- Updated `asset_processing` example to use new API.
- Old asset .meta files regenerated with new processor.
# Objective
- Fix documentation for `AssetReader::is_directory` (it is currently
exactly the same as docs for `read_directory`)
---------
Co-authored-by: Kanabenki <lucien.menassol@gmail.com>
# Objective
TypeUuid is deprecated, remove it.
## Migration Guide
Convert any uses of `#[derive(TypeUuid)]` with `#[derive(TypePath]` for
more complex uses see the relevant
[documentation](https://docs.rs/bevy/latest/bevy/prelude/trait.TypePath.html)
for more information.
---------
Co-authored-by: ebola <dev@axiomatic>
# Objective
- Fixes a hurdle encountered when debugging a panic caused by the file
watcher loading a `.gitignore` file, which was hard to debug because
there was no file name in the report, only `asset paths must have
extensions`
## Solution
- Panic with a formatted message that includes the asset path, e.g.
`missing expected extension for asset path .gitignore`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Doonv <58695417+doonv@users.noreply.github.com>
# Objective
- `AssetPath` implements reflection, but is not registered as a type in
the plugin.
- Fixes#11481.
## Solution
- Register the `AssetPath` type when `AssetPlugin::build` is called.
---
## Changelog
- Registered `AssetPath` type for use in reflection.
# Objective
- Since #11218, example `asset_processing` fails:
```
thread 'main' panicked at crates/bevy_asset/src/io/source.rs:489:18:
Failed to create file watcher: Error { kind: PathNotFound, paths: ["examples/asset/processing/imported_assets/Default"] }
```
start from a fresh git clone or delete the folder before running to
reproduce, it is in gitignore and should not be present on a fresh run
a657478675/.gitignore (L18)
## Solution
- Auto create the `imported_assets` folder if it is configured
---------
Co-authored-by: Kyle <37520732+nvdaz@users.noreply.github.com>
# Objective
This adds events for assets that fail to load along with minor utility
methods to make them useful. This paves the way for users writing their
own error handling and retry systems, plus Bevy including robust retry
handling: #11349.
* Addresses #11288
* Needed for #11349
# Solution
```rust
/// An event emitted when a specific [`Asset`] fails to load.
#[derive(Event, Clone, Debug)]
pub struct AssetLoadFailedEvent<A: Asset> {
pub id: AssetId<A>,
/// The original handle returned when the asset load was requested.
pub handle: Option<Handle<A>>,
/// The asset path that was attempted.
pub path: AssetPath<'static>,
/// Why the asset failed to load.
pub error: AssetLoadError,
}
```
I started implementing `AssetEvent::Failed` like suggested in #11288,
but decided it was better as its own type because:
* I think it makes sense for `AssetEvent` to only refer to assets that
actually exist.
* In order to return `AssetLoadError` in the event (which is useful
information for error handlers that might attempt a retry) we would have
to remove `Copy` from `AssetEvent`.
* There are numerous places in the render app that match against
`AssetEvent`, and I don't think it's worth introducing extra noise about
assets that don't exist.
I also introduced `UntypedAssetLoadErrorEvent`, which is very useful in
places that need to support type flexibility, like an Asset-agnostic
retry plugin.
# Changelog
* **Added:** `AssetLoadFailedEvent<A>`
* **Added**: `UntypedAssetLoadFailedEvent`
* **Added:** `AssetReaderError::Http` for status code information on
HTTP errors. Before this, status codes were only available by parsing
the error message of generic `Io` errors.
* **Added:** `asset_server.get_path_id(path)`. This method simply gets
the asset id for the path. Without this, one was left using
`get_path_handle(path)`, which has the overhead of returning a strong
handle.
* **Fixed**: Made `AssetServer` loads return the same handle for assets
that already exist in a failed state. Now, when you attempt a `load`
that's in a `LoadState::Failed` state, it'll re-use the original asset
id. The advantage of this is that any dependent assets created using the
original handle will "unbreak" if a retry succeeds.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Tried using "embedded_watcher" feature and `embedded_asset!()` from
another crate. The assets embedded fine but were not "watched." The
problem appears to be that checking for the feature was done inside the
macro, so rather than checking if "embedded_watcher" was enabled for
bevy, it would check if it was enabled for the current crate.
## Solution
I extracted the checks for the "embedded_watcher" feature into its own
function called `watched_path()`. No external changes.
### Alternative Solution
An alternative fix would be to not do any feature checking in
`embedded_asset!()` or an extracted function and always send the
full_path to `insert_asset()` where it's promptly dropped when the
feature isn't turned on. That would be simpler.
```
($app: ident, $source_path: expr, $path: expr) => {{
let mut embedded = $app
.world
.resource_mut::<$crate::io::embedded::EmbeddedAssetRegistry>();
let path = $crate::embedded_path!($source_path, $path);
//#[cfg(feature = "embedded_watcher")]
let full_path = std::path::Path::new(file!()).parent().unwrap().join($path);
//#[cfg(not(feature = "embedded_watcher"))]
//let full_path = std::path::PathBuf::new();
embedded.insert_asset(full_path, &path, include_bytes!($path));
}};
```
## Changelog
> Fix embedded_watcher feature to work with external crates
# Objective
When you have no idea what to put after `#` when loading an asset, error
message may help.
## Solution
Add all labels to the error message.
## Test plan
Modified `anti_alias` example to put incorrect label, the error is:
```
2024-01-08T07:41:25.462287Z ERROR bevy_asset::server: The file at 'models/FlightHelmet/FlightHelmet.gltf' does not contain the labeled asset 'Rrrr'; it contains the following 25 assets: 'Material0', 'Material1', 'Material2', 'Material3', 'Material4', 'Material5', 'Mesh0', 'Mesh0/Primitive0', 'Mesh1', 'Mesh1/Primitive0', 'Mesh2', 'Mesh2/Primitive0', 'Mesh3', 'Mesh3/Primitive0', 'Mesh4', 'Mesh4/Primitive0', 'Mesh5', 'Mesh5/Primitive0', 'Node0', 'Node1', 'Node2', 'Node3', 'Node4', 'Node5', 'Scene0'
```
# Motivation
When spawning entities into a scene, it is very common to create assets
like meshes and materials and to add them via asset handles. A common
setup might look like this:
```rust
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
commands.spawn(PbrBundle {
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
material: materials.add(StandardMaterial::from(Color::RED)),
..default()
});
}
```
Let's take a closer look at the part that adds the assets using `add`.
```rust
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
material: materials.add(StandardMaterial::from(Color::RED)),
```
Here, "mesh" and "material" are both repeated three times. It's very
explicit, but I find it to be a bit verbose. In addition to being more
code to read and write, the extra characters can sometimes also lead to
the code being formatted to span multiple lines even though the core
task, adding e.g. a primitive mesh, is extremely simple.
A way to address this is by using `.into()`:
```rust
mesh: meshes.add(shape::Cube { size: 1.0 }.into()),
material: materials.add(Color::RED.into()),
```
This is fine, but from the names and the type of `meshes`, we already
know what the type should be. It's very clear that `Cube` should be
turned into a `Mesh` because of the context it's used in. `.into()` is
just seven characters, but it's so common that it quickly adds up and
gets annoying.
It would be nice if you could skip all of the conversion and let Bevy
handle it for you:
```rust
mesh: meshes.add(shape::Cube { size: 1.0 }),
material: materials.add(Color::RED),
```
# Objective
Make adding assets more ergonomic by making `Assets::add` take an `impl
Into<A>` instead of `A`.
## Solution
`Assets::add` now takes an `impl Into<A>` instead of `A`, so e.g. this
works:
```rust
commands.spawn(PbrBundle {
mesh: meshes.add(shape::Cube { size: 1.0 }),
material: materials.add(Color::RED),
..default()
});
```
I also changed all examples to use this API, which increases consistency
as well because `Mesh::from` and `into` were being used arbitrarily even
in the same file. This also gets rid of some lines of code because
formatting is nicer.
---
## Changelog
- `Assets::add` now takes an `impl Into<A>` instead of `A`
- Examples don't use `T::from(K)` or `K.into()` when adding assets
## Migration Guide
Some `into` calls that worked previously might now be broken because of
the new trait bounds. You need to either remove `into` or perform the
conversion explicitly with `from`:
```rust
// Doesn't compile
let mesh_handle = meshes.add(shape::Cube { size: 1.0 }.into()),
// These compile
let mesh_handle = meshes.add(shape::Cube { size: 1.0 }),
let mesh_handle = meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
```
## Concerns
I believe the primary concerns might be:
1. Is this too implicit?
2. Does this increase codegen bloat?
Previously, the two APIs were using `into` or `from`, and now it's
"nothing" or `from`. You could argue that `into` is slightly more
explicit than "nothing" in cases like the earlier examples where a
`Color` gets converted to e.g. a `StandardMaterial`, but I personally
don't think `into` adds much value even in this case, and you could
still see the actual type from the asset type.
As for codegen bloat, I doubt it adds that much, but I'm not very
familiar with the details of codegen. I personally value the user-facing
code reduction and ergonomics improvements that these changes would
provide, but it might be worth checking the other effects in more
detail.
Another slight concern is migration pain; apps might have a ton of
`into` calls that would need to be removed, and it did take me a while
to do so for Bevy itself (maybe around 20-40 minutes). However, I think
the fact that there *are* so many `into` calls just highlights that the
API could be made nicer, and I'd gladly migrate my own projects for it.
# Objective
- No point in keeping Meshes/Images in RAM once they're going to be sent
to the GPU, and kept in VRAM. This saves a _significant_ amount of
memory (several GBs) on scenes like bistro.
- References
- https://github.com/bevyengine/bevy/pull/1782
- https://github.com/bevyengine/bevy/pull/8624
## Solution
- Augment RenderAsset with the capability to unload the underlying asset
after extracting to the render world.
- Mesh/Image now have a cpu_persistent_access field. If this field is
RenderAssetPersistencePolicy::Unload, the asset will be unloaded from
Assets<T>.
- A new AssetEvent is sent upon dropping the last strong handle for the
asset, which signals to the RenderAsset to remove the GPU version of the
asset.
---
## Changelog
- Added `AssetEvent::NoLongerUsed` and
`AssetEvent::is_no_longer_used()`. This event is sent when the last
strong handle of an asset is dropped.
- Rewrote the API for `RenderAsset` to allow for unloading the asset
data from the CPU.
- Added `RenderAssetPersistencePolicy`.
- Added `Mesh::cpu_persistent_access` for memory savings when the asset
is not needed except for on the GPU.
- Added `Image::cpu_persistent_access` for memory savings when the asset
is not needed except for on the GPU.
- Added `ImageLoaderSettings::cpu_persistent_access`.
- Added `ExrTextureLoaderSettings`.
- Added `HdrTextureLoaderSettings`.
## Migration Guide
- Asset loaders (GLTF, etc) now load meshes and textures without
`cpu_persistent_access`. These assets will be removed from
`Assets<Mesh>` and `Assets<Image>` once `RenderAssets<Mesh>` and
`RenderAssets<Image>` contain the GPU versions of these assets, in order
to reduce memory usage. If you require access to the asset data from the
CPU in future frames after the GLTF asset has been loaded, modify all
dependent `Mesh` and `Image` assets and set `cpu_persistent_access` to
`RenderAssetPersistencePolicy::Keep`.
- `Mesh` now requires a new `cpu_persistent_access` field. Set it to
`RenderAssetPersistencePolicy::Keep` to mimic the previous behavior.
- `Image` now requires a new `cpu_persistent_access` field. Set it to
`RenderAssetPersistencePolicy::Keep` to mimic the previous behavior.
- `MorphTargetImage::new()` now requires a new `cpu_persistent_access`
parameter. Set it to `RenderAssetPersistencePolicy::Keep` to mimic the
previous behavior.
- `DynamicTextureAtlasBuilder::add_texture()` now requires that the
`TextureAtlas` you pass has an `Image` with `cpu_persistent_access:
RenderAssetPersistencePolicy::Keep`. Ensure you construct the image
properly for the texture atlas.
- The `RenderAsset` trait has significantly changed, and requires
adapting your existing implementations.
- The trait now requires `Clone`.
- The `ExtractedAsset` associated type has been removed (the type itself
is now extracted).
- The signature of `prepare_asset()` is slightly different
- A new `persistence_policy()` method is now required (return
RenderAssetPersistencePolicy::Unload to match the previous behavior).
- Match on the new `NoLongerUsed` variant for exhaustive matches of
`AssetEvent`.
# Objective
There are a lot of doctests that are `ignore`d for no documented reason.
And that should be fixed.
## Solution
I searched the bevy repo with the regex ` ```[a-z,]*ignore ` in order to
find all `ignore`d doctests. For each one of the `ignore`d doctests, I
did the following steps:
1. Attempt to remove the `ignored` attribute while still passing the
test. I did this by adding hidden dummy structs and imports.
2. If step 1 doesn't work, attempt to replace the `ignored` attribute
with the `no_run` attribute while still passing the test.
3. If step 2 doesn't work, keep the `ignored` attribute but add
documentation for why the `ignored` attribute was added.
---------
Co-authored-by: François <mockersf@gmail.com>
# Objective
- Make the implementation order consistent between all sources to fit
the order in the trait.
## Solution
- Change the implementation order.
# Objective
- Update winit dependency to 0.29
## Changelog
### KeyCode changes
- Removed `ScanCode`, as it was [replaced by
KeyCode](https://github.com/rust-windowing/winit/blob/master/CHANGELOG.md#0292).
- `ReceivedCharacter.char` is now a `SmolStr`, [relevant
doc](https://docs.rs/winit/latest/winit/event/struct.KeyEvent.html#structfield.text).
- Changed most `KeyCode` values, and added more.
KeyCode has changed meaning. With this PR, it refers to physical
position on keyboard rather than the printed letter on keyboard keys.
In practice this means:
- On QWERTY keyboard layouts, nothing changes
- On any other keyboard layout, `KeyCode` no longer reflects the label
on key.
- This is "good". In bevy 0.12, when you used WASD for movement, users
with non-QWERTY keyboards couldn't play your game! This was especially
bad for non-latin keyboards. Now, WASD represents the physical keys. A
French player will press the ZQSD keys, which are near each other,
Kyrgyz players will use "Цфыв".
- This is "bad" as well. You can't know in advance what the label of the
key for input is. Your UI says "press WASD to move", even if in reality,
they should be pressing "ZQSD" or "Цфыв". You also no longer can use
`KeyCode` for text inputs. In any case, it was a pretty bad API for text
input. You should use `ReceivedCharacter` now instead.
### Other changes
- Use `web-time` rather than `instant` crate.
(https://github.com/rust-windowing/winit/pull/2836)
- winit did split `run_return` in `run_onDemand` and `pump_events`, I
did the same change in bevy_winit and used `pump_events`.
- Removed `return_from_run` from `WinitSettings` as `winit::run` now
returns on supported platforms.
- I left the example "return_after_run" as I think it's still useful.
- This winit change is done partly to allow to create a new window after
quitting all windows: https://github.com/emilk/egui/issues/1918 ; this
PR doesn't address.
- added `width` and `height` properties in the `canvas` from wasm
example
(https://github.com/bevyengine/bevy/pull/10702#discussion_r1420567168)
## Known regressions (important follow ups?)
- Provide an API for reacting when a specific key from current layout
was released.
- possible solutions: use winit::Key from winit::KeyEvent ; mapping
between KeyCode and Key ; or .
- We don't receive characters through alt+numpad (e.g. alt + 151 = "ù")
anymore ; reproduced on winit example "ime". maybe related to
https://github.com/rust-windowing/winit/issues/2945
- (windows) Window content doesn't refresh at all when resizing. By
reading https://github.com/rust-windowing/winit/issues/2900 ; I suspect
we should just fire a `window.request_redraw();` from `AboutToWait`, and
handle actual redrawing within `RedrawRequested`. I'm not sure how to
move all that code so I'd appreciate it to be a follow up.
- (windows) unreleased winit fix for using set_control_flow in
AboutToWait https://github.com/rust-windowing/winit/issues/3215 ; ⚠️ I'm
not sure what the implications are, but that feels bad 🤔
## Follow up
I'd like to avoid bloating this PR, here are a few follow up tasks
worthy of a separate PR, or new issue to track them once this PR is
closed, as they would either complicate reviews, or at risk of being
controversial:
- remove CanvasParentResizePlugin
(https://github.com/bevyengine/bevy/pull/10702#discussion_r1417068856)
- avoid mentionning explicitly winit in docs from bevy_window ?
- NamedKey integration on bevy_input:
https://github.com/rust-windowing/winit/pull/3143 introduced a new
NamedKey variant. I implemented it only on the converters but we'd
benefit making the same changes to bevy_input.
- Add more info in KeyboardInput
https://github.com/bevyengine/bevy/pull/10702#pullrequestreview-1748336313
- https://github.com/bevyengine/bevy/pull/9905 added a workaround on a
bug allegedly fixed by winit 0.29. We should check if it's still
necessary.
- update to raw_window_handle 0.6
- blocked by wgpu
- Rename `KeyCode` to `PhysicalKeyCode`
https://github.com/bevyengine/bevy/pull/10702#discussion_r1404595015
- remove `instant` dependency, [replaced
by](https://github.com/rust-windowing/winit/pull/2836) `web_time`), we'd
need to update to :
- fastrand >= 2.0
- [`async-executor`](https://github.com/smol-rs/async-executor) >= 1.7
- [`futures-lite`](https://github.com/smol-rs/futures-lite) >= 2.0
- Verify license, see
[discussion](https://github.com/bevyengine/bevy/pull/8745#discussion_r1402439800)
- we might be missing a short notice or description of changes made
- Consider using https://github.com/rust-windowing/cursor-icon directly
rather than vendoring it in bevy.
- investigate [this
unwrap](https://github.com/bevyengine/bevy/pull/8745#discussion_r1387044986)
(`winit_window.canvas().unwrap();`)
- Use more good things about winit's update
- https://github.com/bevyengine/bevy/pull/10689#issuecomment-1823560428
## Migration Guide
This PR should have one.
# Objective
- Reduce nesting in `process_handle_drop_internal()`.
- Related to #10896.
## Solution
- Use early returns when possible.
- Reduced from 9 levels of indents to 4.
# Objective
Fixes#10444
Currently manually removing an asset prevents it from being reloaded
while there are still active handles. Doing so will result in a panic,
because the storage entry has been marked as "empty / None" but the ID
is still assumed to be active by the asset server.
Patterns like `images.remove() -> asset_server.reload()` and
`images.remove() -> images.insert()` would fail if the handle was still
alive.
## Solution
Most of the groundwork for this was already laid in Bevy Asset V2. This
is largely just a matter of splitting out `remove` into two separate
operations:
* `remove_dropped`: remove the stored asset, invalidate the internal
Assets entry (preventing future insertions with the old id), and recycle
the id
* `remove_still_alive`: remove the stored asset, but leave the entry
otherwise untouched (and dont recycle the id).
`remove_still_alive` and `insert` can be called any number of times (in
any order) for an id until `remove_dropped` has been called, which will
invalidate the id.
From a user-facing perspective, there are no API changes and this is non
breaking. The public `Assets::remove` will internally call
`remove_still_alive`. `remove_dropped` can only be called by the
internal "handle management" system.
---
## Changelog
- Fix a bug preventing `Assets::remove` from blocking future inserts for
a specific `AssetIndex`.
# Objective
Fixes#10401
## Solution
* Allow sources to register specific processed/unprocessed watch
warnings.
* Specify per-platform watch warnings. This removes the need to cover
all platform cases in one warning message.
* Only register watch warnings for the _processed_ embedded source, as
warning about watching unprocessed embedded isn't helpful.
---
## Changelog
- Asset sources can now register specific watch warnings.
# Objective
- Shorten paths by removing unnecessary prefixes
## Solution
- Remove the prefixes from many paths which do not need them. Finding
the paths was done automatically using built-in refactoring tools in
Jetbrains RustRover.
# Objective
Related to #10612.
Enable the
[`clippy::manual_let_else`](https://rust-lang.github.io/rust-clippy/master/#manual_let_else)
lint as a warning. The `let else` form seems more idiomatic to me than a
`match`/`if else` that either match a pattern or diverge, and from the
clippy doc, the lint doesn't seem to have any possible false positive.
## Solution
Add the lint as warning in `Cargo.toml`, refactor places where the lint
triggers.
# Objective
Fixes#10688
There were a number of issues at play:
1. The GLTF loader was not registering Scene dependencies properly. They
were being registered at the root instead of on the scene assets. This
made `LoadedWithDependencies` fire immediately on load.
2. Recursive labeled assets _inside_ of labeled assets were not being
loaded. This only became relevant for scenes after fixing (1) because we
now add labeled assets to the nested scene `LoadContext` instead of the
root load context. I'm surprised nobody has hit this yet. I'm glad I
caught it before somebody hit it.
3. Accessing "loaded with dependencies" state on the Asset Server is
boilerplatey + error prone (because you need to manually query two
states).
## Solution
1. In GltfLoader, use a nested LoadContext for scenes and load
dependencies through that context.
2. In the `AssetServer`, load labeled assets recursively.
3. Added a simple `asset_server.is_loaded_with_dependencies(id)`
I also added some docs to `LoadContext` to help prevent this problem in
the future.
---
## Changelog
- Added `AssetServer::is_loaded_with_dependencies`
- Fixed GLTF Scene dependencies
- Fixed nested labeled assets not being loaded
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fixes#10157
## Solution
Add `AssetMetaCheck` resource which can configure when/if asset meta
files will be read:
```rust
app
// Never attempts to look up meta files. The default meta configuration will be used for each asset.
.insert_resource(AssetMetaCheck::Never)
.add_plugins(DefaultPlugins)
```
This serves as a band-aid fix for the issue with wasm's
`HttpWasmAssetReader` creating a bunch of requests for non-existent
meta, which can slow down asset loading (by waiting for the 404
response) and creates a bunch of noise in the logs. This also provides a
band-aid fix for the more serious issue of itch.io deployments returning
403 responses, which results in full failure of asset loads.
If users don't want to include meta files for all deployed assets for
web builds, and they aren't using meta files at all, they should set
this to `AssetMetaCheck::Never`.
If users do want to include meta files for specific assets, they can use
`AssetMetaCheck::Paths`, which will only look up meta for those paths.
Currently, this defaults to `AssetMetaCheck::Always`, which makes this
fully non-breaking for the `0.12.1` release. _**However it _is_ worth
discussing making this `AssetMetaCheck::Never` by default**_, given that
I doubt most people are using meta files without the Asset Processor
enabled. This would be a breaking change, but it would make WASM / Itch
deployments work by default, which is a pretty big win imo. The downside
is that people using meta files _without_ processing would need to
manually enable `AssetMetaCheck::Always`, which is also suboptimal.
When in `AssetMetaCheck::Processed`, the meta check resource is ignored,
as processing requires asset meta files to function.
In general, I don't love adding this knob as things should ideally "just
work" in all cases. But this is the reality of the current situation.
---
## Changelog
- Added `AssetMetaCheck` resource, which can configure when/if asset
meta files will be read
# Objective
Updates [`futures-lite`](https://github.com/smol-rs/futures-lite) in
bevy_tasks to the next major version (1 -> 2).
Also removes the duplication of `futures-lite`, as `async-fs` requires v
2, so there are currently 2 copies of futures-lite in the dependency
tree.
Futures-lite has received [a number of
updates](https://github.com/smol-rs/futures-lite/blob/master/CHANGELOG.md)
since bevy's current version `1.4`.
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Mike <mike.hsu@gmail.com>
# Objective
- Fixes#10695
## Solution
Fixed obvious blunder in `PartialEq` implementation for
`UntypedAssetId`'s where the `TypeId` was not included in the
comparison. This was not picked up in the unit tests I added because
they only tested over a single asset type.
# Objective
- Fixes#10629
- `UntypedAssetId` and `AssetId` (along with `UntypedHandle` and
`Handle`) do not hash to the same values when pointing to the same
`Asset`. Additionally, comparison and conversion between these types
does not follow idiomatic Rust standards.
## Solution
- Added new unit tests to validate/document expected behaviour
- Added trait implementations to make working with Un/Typed values more
ergonomic
- Ensured hashing and comparison between Un/Typed values is consistent
- Removed `From` trait implementations that panic, and replaced them
with `TryFrom`
---
## Changelog
- Ensured `Handle::<A>::hash` and `UntypedHandle::hash` will produce the
same value for the same `Asset`
- Added non-panicing `Handle::<A>::try_typed`
- Added `PartialOrd` to `UntypedHandle` to match `Handle<A>` (this will
return `None` for `UntypedHandles` for differing `Asset` types)
- Added `TryFrom<UntypedHandle>` for `Handle<A>`
- Added `From<Handle<A>>` for `UntypedHandle`
- Removed panicing `From<Untyped...>` implementations. These are
currently unused within the Bevy codebase, and shouldn't be used
externally, hence removal.
- Added cross-implementations of `PartialEq` and `PartialOrd` for
`UntypedHandle` and `Handle<A>` allowing direct comparison when
`TypeId`'s match.
- Near-identical changes to `AssetId` and `UntypedAssetId`
## Migration Guide
If you relied on any of the panicing `From<Untyped...>` implementations,
simply call the existing `typed` methods instead. Alternatively, use the
new `TryFrom` implementation instead to directly expose possible
mistakes.
## Notes
I've made these changes since `Handle` is such a fundamental type to the
entire `Asset` ecosystem within Bevy, and yet it had pretty unclear
behaviour with no direct testing. The fact that hashing untyped vs typed
versions of the same handle would produce different values is something
I expect to cause a very subtle bug for someone else one day.
I haven't included it in this PR to avoid any controversy, but I also
believe the `typed_unchecked` methods should be removed from these
types, or marked as `unsafe`. The `texture_atlas` example currently uses
it, and I believe it is a bad choice. The performance gained by not
type-checking before conversion would be entirely dwarfed by the act of
actually loading an asset and creating its handle anyway. If an end user
is in a tight loop repeatedly calling `typed_unchecked` on an
`UntypedHandle` for the entire runtime of their application, I think the
small performance drop caused by that safety check is ~~a form of cosmic
justice~~ reasonable.
# Objective
Fix the `bevy_asset/file_watcher` feature in practice depending on
multithreading, while not informing the user of it.
**As I understand it** (I didn't check it), the file watcher feature
depends on spawning a concurrent thread to receive file update events
from the `notify-debouncer-full` crate. But if multithreading is
disabled, that thread will never have time to read the events and
consume them.
- Fixes#10573
## Solution
Add a `compile_error!` causing compilation failure if `file_watcher` is
enabled while `multi-threaded` is disabled.
This is considered better than adding a dependency on `multi-threaded`
on the `file_watcher`, as (according to @mockersf) toggling on/off
`multi-threaded` has a non-zero chance of changing behavior. And we
shouldn't implicitly change behavior. A compilation failure prevents
compilation of code that is invalid, while informing the user of the
steps needed to fix it.
# Objective
- Fix adding `#![allow(clippy::type_complexity)]` everywhere. like #9796
## Solution
- Use the new [lints] table that will land in 1.74
(https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#lints)
- inherit lint to the workspace, crates and examples.
```
[lints]
workspace = true
```
## Changelog
- Bump rust version to 1.74
- Enable lints table for the workspace
```toml
[workspace.lints.clippy]
type_complexity = "allow"
```
- Allow type complexity for all crates and examples
```toml
[lints]
workspace = true
```
---------
Co-authored-by: Martín Maita <47983254+mnmaita@users.noreply.github.com>
# Objective
- Allow bevy applications that does not have any assets folder to start
from a read-only directory. (typically installed to a systems folder)
Fixes#10613
## Solution
- warn instead of panic when assets folder creation fails.
# Objective
- Currently, in 0.12 there is an issue that it is not possible to build
bevy for Wasm with feature "file_watcher" enabled. It still would not
compile, but now with proper explanation.
- Fixes https://github.com/bevyengine/bevy/issues/10507
## Solution
- Remove `notify-debouncer-full` dependency on WASM platform entirely.
- Compile with "file_watcher" feature now on platform `wasm32` gives
meaningful compile error.
---
## Changelog
### Fixed
- Compile with "file_watcher" feature now on platform `wasm32` gives
meaningful compile error.
# Objective
- Fixes#10518
## Solution
I've added a method to `LoadContext`, `load_direct_with_reader`, which
mirrors the behaviour of `load_direct` with a single key difference: it
is provided with the `Reader` by the caller, rather than getting it from
the contained `AssetServer`. This allows for an `AssetLoader` to process
its `Reader` stream, and then directly hand the results off to the
`LoadContext` to handle further loading. The outer `AssetLoader` can
control how the `Reader` is interpreted by providing a relevant
`AssetPath`.
For example, a Gzip decompression loader could process the asset
`images/my_image.png.gz` by decompressing the bytes, then handing the
decompressed result to the `LoadContext` with the new path
`images/my_image.png.gz/my_image.png`. This intuitively reflects the
nature of contained assets, whilst avoiding unintended behaviour, since
the generated path cannot be a real file path (a file and folder of the
same name cannot coexist in most file-systems).
```rust
#[derive(Asset, TypePath)]
pub struct GzAsset {
pub uncompressed: ErasedLoadedAsset,
}
#[derive(Default)]
pub struct GzAssetLoader;
impl AssetLoader for GzAssetLoader {
type Asset = GzAsset;
type Settings = ();
type Error = GzAssetLoaderError;
fn load<'a>(
&'a self,
reader: &'a mut Reader,
_settings: &'a (),
load_context: &'a mut LoadContext,
) -> BoxedFuture<'a, Result<Self::Asset, Self::Error>> {
Box::pin(async move {
let compressed_path = load_context.path();
let file_name = compressed_path
.file_name()
.ok_or(GzAssetLoaderError::IndeterminateFilePath)?
.to_string_lossy();
let uncompressed_file_name = file_name
.strip_suffix(".gz")
.ok_or(GzAssetLoaderError::IndeterminateFilePath)?;
let contained_path = compressed_path.join(uncompressed_file_name);
let mut bytes_compressed = Vec::new();
reader.read_to_end(&mut bytes_compressed).await?;
let mut decoder = GzDecoder::new(bytes_compressed.as_slice());
let mut bytes_uncompressed = Vec::new();
decoder.read_to_end(&mut bytes_uncompressed)?;
// Now that we have decompressed the asset, let's pass it back to the
// context to continue loading
let mut reader = VecReader::new(bytes_uncompressed);
let uncompressed = load_context
.load_direct_with_reader(&mut reader, contained_path)
.await?;
Ok(GzAsset { uncompressed })
})
}
fn extensions(&self) -> &[&str] {
&["gz"]
}
}
```
Because this example is so prudent, I've included an
`asset_decompression` example which implements this exact behaviour:
```rust
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.init_asset::<GzAsset>()
.init_asset_loader::<GzAssetLoader>()
.add_systems(Startup, setup)
.add_systems(Update, decompress::<Image>)
.run();
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
commands.spawn(Camera2dBundle::default());
commands.spawn((
Compressed::<Image> {
compressed: asset_server.load("data/compressed_image.png.gz"),
..default()
},
Sprite::default(),
TransformBundle::default(),
VisibilityBundle::default(),
));
}
fn decompress<A: Asset>(
mut commands: Commands,
asset_server: Res<AssetServer>,
mut compressed_assets: ResMut<Assets<GzAsset>>,
query: Query<(Entity, &Compressed<A>)>,
) {
for (entity, Compressed { compressed, .. }) in query.iter() {
let Some(GzAsset { uncompressed }) = compressed_assets.remove(compressed) else {
continue;
};
let uncompressed = uncompressed.take::<A>().unwrap();
commands
.entity(entity)
.remove::<Compressed<A>>()
.insert(asset_server.add(uncompressed));
}
}
```
A key limitation to this design is how to type the internally loaded
asset, since the example `GzAssetLoader` is unaware of the internal
asset type `A`. As such, in this example I store the contained asset as
an `ErasedLoadedAsset`, and leave it up to the consumer of the `GzAsset`
to handle typing the final result, which is the purpose of the
`decompress` system. This limitation can be worked around by providing
type information to the `GzAssetLoader`, such as `GzAssetLoader<Image,
ImageAssetLoader>`, but this would require registering the asset loader
for every possible decompression target.
Aside from this limitation, nested asset containerisation works as an
end user would expect; if the user registers a `TarAssetLoader`, and a
`GzAssetLoader`, then they can load assets with compound
containerisation, such as `images.tar.gz`.
---
## Changelog
- Added `LoadContext::load_direct_with_reader`
- Added `asset_decompression` example
## Notes
- While I believe my implementation of a Gzip asset loader is
reasonable, I haven't included it as a public feature of `bevy_asset` to
keep the scope of this PR as focussed as possible.
- I have included `flate2` as a `dev-dependency` for the example; it is
not included in the main dependency graph.
# Objective
Addresses #[10438](https://github.com/bevyengine/bevy/issues/10438)
The objective was to include the failing path in the error for the user
to see.
## Solution
Add a `path` field to the `ReadAssetBytesError::Io` variant to expose
the failing path in the error message.
## Migration Guide
- The `ReadAssetBytesError::Io` variant now contains two named fields
instead of converting from `std::io::Error`.
1. `path`: The requested (failing) path (`PathBuf`)
2. `source`: The source `std::io::Error`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Give us the ability to load untyped assets in AssetLoaders.
## Solution
Basically just copied the code from `load`, but used
`asset_server.load_untyped` instead internally.
## Changelog
Added `load_untyped` method to `LoadContext`
# Objective
Close#10504. Improve the development experience for working with scenes
by not requiring the user to specify a matching version of `ron` in
their `Cargo.toml`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Fixes#10436
Alternative to #10465
## Solution
`load_untyped_async` / `load_internal` currently has a bug. In
`load_untyped_async`, we pass None into `load_internal` for the
`UntypedHandle` of the labeled asset path. This results in a call to
`get_or_create_path_handle_untyped` with `loader.asset_type_id()`
This is a new code path that wasn't hit prior to the newly added
`load_untyped` because `load_untyped_async` was a private method only
used in the context of the `load_folder` impl (which doesn't have
labels)
The fix required some refactoring to catch that case and defer handle
retrieval. I have also made `load_untyped_async` public as it is now
"ready for public use" and unlocks new scenarios.
# Objective
Fixes an issue where Bevy will look for `.meta` files in the root of the
server instead of `imported_assets/Default` on the web.
## Solution
`self.root_path.join` was seemingly forgotten in the `read_meta`
function on `HttpWasmAssetReader`, though it was included in the `read`
function. This PR simply adds the missing function call.
# Objective
* In Bevy 0.11 asset loaders used `anyhow::Error` for returning errors.
In Bevy 0.12 `AssetLoader` (and `AssetSaver`) have associated `Error`
type. Unfortunately it's type bounds does not allow `anyhow::Error` to
be used despite migration guide claiming otherwise. This makes migration
to 0.12 more challenging. Solve this by changing type bounds for
associated `Error` type.
* Fix#10350
## Solution
Change associated `Error` type bounds to require `Into<Box<dyn
std::error::Error + Send + Sync + 'static>>` to be implemented instead
of `std::error::Error + Send + Sync + 'static`. Both `anyhow::Error` and
errors generated by `thiserror` seems to be fine with such type bound.
---
## Changelog
### Fixed
* Fixed compatibility with `anyhow::Error` in `AssetLoader` and
`AssetSaver` associated `Error` type
# Objective
- The docs on `AssetPath::try_parse` say that it will return an error
when the string is malformed, but it actually just `.unwrap()`s the
result.
## Solution
- Use `?` instead of unwrapping the result.
Preparing next release
This PR has been auto-generated
---------
Co-authored-by: Bevy Auto Releaser <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: François <mockersf@gmail.com>
# Objective
- Fixes#10209
- Assets should work in single threaded
## Solution
- In single threaded mode, don't use `async_fs` but fallback on
`std::fs` with a thin layer to mimic the async API
- file `file_asset.rs` is the async imps from `mod.rs`
- file `sync_file_asset.rs` is the same with `async_fs` APIs replaced by
`std::fs`
- which module is used depends on the `multi-threaded` feature
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- Folder handles are not shared. Loading the same folder multiple times
will result in different handles.
- Once folder handles are shared, they can no longer be manually
reloaded, so we should add support for hot-reloading them
## Solution
- Reuse folder handles based on their path
- Trigger a reload of a folder if a file contained in it (or a sub
folder) is added or removed
- This also covers adding/removing/moving sub folders containing files
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- Assets v2 does not currently offer a public API to load untyped assets
## Solution
- Wrap the untyped handle in a `LoadedUntypedAsset` asset to offer a
non-blocking load for untyped assets. The user does not need to know the
actual asset type.
- Handles to `LoadedUntypedAsset` have the same path as the wrapped
asset, but their handles are shared using a label.
The user side of `load_untyped` looks like this:
```rust
use bevy::prelude::*;
use bevy_internal::asset::LoadedUntypedAsset;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, check)
.run();
}
#[derive(Resource)]
struct UntypedAsset {
handle: Handle<LoadedUntypedAsset>,
}
fn setup(
mut commands: Commands,
asset_server: Res<AssetServer>,
) {
let handle = asset_server.load_untyped("branding/banner.png");
commands.insert_resource(UntypedAsset { handle });
commands.spawn(Camera2dBundle::default());
}
fn check(
mut commands: Commands,
res: Option<Res<UntypedAsset>>,
assets: Res<Assets<LoadedUntypedAsset>>,
) {
if let Some(untyped_asset) = res {
if let Some(asset) = assets.get(&untyped_asset.handle) {
commands.spawn(SpriteBundle {
texture: asset.handle.clone().typed(),
..default()
});
commands.remove_resource::<UntypedAsset>();
}
}
}
```
---
## Changelog
- `load_untyped` on the asset server now returns a handle to a
`LoadedUntypedAsset` instead of an untyped handle to the asset at the
given path. The untyped handle for the given path can be retrieved from
the `LoadedUntypedAsset` once it is done loading.
## Migration Guide
Whenever possible use the typed API in order to directly get a handle to
your asset. If you do not know the type or need to use `load_untyped`
for a different reason, Bevy 0.12 introduces an additional layer of
indirection. The asset server will return a handle to a
`LoadedUntypedAsset`, which will load in the background. Once it is
loaded, the untyped handle to the asset file can be retrieved from the
`LoadedUntypedAsset`s field `handle`.
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- Hot reloading doesn't work the first time it is used
## Solution
- Currently, Bevy processor:
1. Create the `imported_assets` folder
2. Setup a watcher on it
3. Clear empty folders, so the `imported_assets` folder is deleted
4. Recreate the `imported_assets` folder and add all the imported assets
- On a first run without an existing `imported_assets` with some
content, hot reloading won't work as step 3 breaks the file watcher
- This PR stops the empty root folder from being deleted
- Also don't setup the processor internal asset server for file
watching, freeing up a thread
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Fixes#9473
## Solution
Added `resolve()` method to AssetPath. This method accepts a relative
asset path string and returns a "full" path that has been resolved
relative to the current (self) path.
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- Replace md5 by another hasher, as suggested in
https://github.com/bevyengine/bevy/pull/8624#discussion_r1359291028
- md5 is not secure, and is slow. use something more secure and faster
## Solution
- Replace md5 by blake3
Putting this PR in the 0.12 as once it's released, changing the hash
algorithm will be a painful breaking change
# Objective
Users shouldn't need to change their source code between "development
workflows" and "releasing". Currently, Bevy Asset V2 has two "processed"
asset modes `Processed` (assumes assets are already processed) and
`ProcessedDev` (starts an asset processor and processes assets). This
means that the mode must be changed _in code_ when switching from "app
dev" to "release". Very suboptimal.
We have already removed "runtime opt-in" for hot-reloading. Enabling the
`file_watcher` feature _automatically_ enables file watching in code.
This means deploying a game (without hot reloading enabled) just means
calling `cargo build --release` instead of `cargo run --features
bevy/file_watcher`.
We should adopt this pattern for asset processing.
## Solution
This adds the `asset_processor` feature, which will start the
`AssetProcessor` when an `AssetPlugin` runs in `AssetMode::Processed`.
The "asset processing workflow" is now:
1. Enable `AssetMode::Processed` on `AssetPlugin`
2. When developing, run with the `asset_processor` and `file_watcher`
features
3. When releasing, build without these features.
The `AssetMode::ProcessedDev` mode has been removed.
# Objective
I encountered a problem where I had a plugin `FooPlugin` which did
```rust
impl Plugin for FooPlugin {
fn build(&self, app: &mut App) {
app
.register_asset_source(...); // more stuff after
}
}
```
And when I tried using it, e.g.
```rust
asset_server.load("foo://data/asset.custom");
```
I got an error that `foo` was not recognized as a source.
I found that this is because asset sources must be registered _before_
`AssetPlugin` is added, and I had `FooPlugin` _after_.
## Solution
Add clarifying note about having to register sources before
`AssetPlugin` is added.
Signed-off-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
Co-authored-by: Torstein Grindvik <torstein.grindvik@muybridge.com>
# Objective
- Provides actionable feedback when users encounter the error in
https://github.com/bevyengine/bevy/issues/10162
- Complements https://github.com/bevyengine/bevy/pull/10186
## Solution
- Log an error when registering an AssetSource after the AssetPlugin has
been built (via DefaultPlugins). This will let users know that their
registration order needs changing
The outputted error message will look like this:
```rust
ERROR bevy_asset::server: 'AssetSourceId::Name(test)' must be registered before `AssetPlugin` (typically added as part of `DefaultPlugins`)
```
---------
Co-authored-by: 66OJ66 <hi0obxud@anonaddy.me>
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
# Objective
Calling `asset_server.load("scene.gltf#SomeLabel")` will silently fail
if `SomeLabel` does not exist.
Referenced in #9714
## Solution
We now detect this case and return an error. I also slightly refactored
`load_internal` to make the logic / dataflow much clearer.
---------
Co-authored-by: Pascal Hertleif <killercup@gmail.com>
# Objective
As called out in #9714, Bevy Asset V2 fails to hot-reload labeled assets
whose source asset has changed (in cases where the root asset is not
alive).
## Solution
Track alive labeled assets for a given source asset and allow hot
reloads in cases where a labeled asset is still alive.
# Objective
- Since #9885, running on an iOS device crashes trying to create the
processed folder
- This only happens on real device, not on the simulator
## Solution
- Setup processed assets only if needed
# Objective
Currently, the asset loader outputs
```
2023-10-14T15:11:09.328850Z WARN bevy_asset::asset_server: no `AssetLoader` found
```
when user forgets to add an extension to a file. This is very confusing
behaviour, it sounds like there aren't any asset loaders existing.
## Solution
Add an extra message on the end when there are no file extensions.
This adds support for **Multiple Asset Sources**. You can now register a
named `AssetSource`, which you can load assets from like you normally
would:
```rust
let shader: Handle<Shader> = asset_server.load("custom_source://path/to/shader.wgsl");
```
Notice that `AssetPath` now supports `some_source://` syntax. This can
now be accessed through the `asset_path.source()` accessor.
Asset source names _are not required_. If one is not specified, the
default asset source will be used:
```rust
let shader: Handle<Shader> = asset_server.load("path/to/shader.wgsl");
```
The behavior of the default asset source has not changed. Ex: the
`assets` folder is still the default.
As referenced in #9714
## Why?
**Multiple Asset Sources** enables a number of often-asked-for
scenarios:
* **Loading some assets from other locations on disk**: you could create
a `config` asset source that reads from the OS-default config folder
(not implemented in this PR)
* **Loading some assets from a remote server**: you could register a new
`remote` asset source that reads some assets from a remote http server
(not implemented in this PR)
* **Improved "Binary Embedded" Assets**: we can use this system for
"embedded-in-binary assets", which allows us to replace the old
`load_internal_asset!` approach, which couldn't support asset
processing, didn't support hot-reloading _well_, and didn't make
embedded assets accessible to the `AssetServer` (implemented in this pr)
## Adding New Asset Sources
An `AssetSource` is "just" a collection of `AssetReader`, `AssetWriter`,
and `AssetWatcher` entries. You can configure new asset sources like
this:
```rust
app.register_asset_source(
"other",
AssetSource::build()
.with_reader(|| Box::new(FileAssetReader::new("other")))
)
)
```
Note that `AssetSource` construction _must_ be repeatable, which is why
a closure is accepted.
`AssetSourceBuilder` supports `with_reader`, `with_writer`,
`with_watcher`, `with_processed_reader`, `with_processed_writer`, and
`with_processed_watcher`.
Note that the "asset source" system replaces the old "asset providers"
system.
## Processing Multiple Sources
The `AssetProcessor` now supports multiple asset sources! Processed
assets can refer to assets in other sources and everything "just works".
Each `AssetSource` defines an unprocessed and processed `AssetReader` /
`AssetWriter`.
Currently this is all or nothing for a given `AssetSource`. A given
source is either processed or it is not. Later we might want to add
support for "lazy asset processing", where an `AssetSource` (such as a
remote server) can be configured to only process assets that are
directly referenced by local assets (in order to save local disk space
and avoid doing extra work).
## A new `AssetSource`: `embedded`
One of the big features motivating **Multiple Asset Sources** was
improving our "embedded-in-binary" asset loading. To prove out the
**Multiple Asset Sources** implementation, I chose to build a new
`embedded` `AssetSource`, which replaces the old `load_interal_asset!`
system.
The old `load_internal_asset!` approach had a number of issues:
* The `AssetServer` was not aware of (or capable of loading) internal
assets.
* Because internal assets weren't visible to the `AssetServer`, they
could not be processed (or used by assets that are processed). This
would prevent things "preprocessing shaders that depend on built in Bevy
shaders", which is something we desperately need to start doing.
* Each "internal asset" needed a UUID to be defined in-code to reference
it. This was very manual and toilsome.
The new `embedded` `AssetSource` enables the following pattern:
```rust
// Called in `crates/bevy_pbr/src/render/mesh.rs`
embedded_asset!(app, "mesh.wgsl");
// later in the app
let shader: Handle<Shader> = asset_server.load("embedded://bevy_pbr/render/mesh.wgsl");
```
Notice that this always treats the crate name as the "root path", and it
trims out the `src` path for brevity. This is generally predictable, but
if you need to debug you can use the new `embedded_path!` macro to get a
`PathBuf` that matches the one used by `embedded_asset`.
You can also reference embedded assets in arbitrary assets, such as WGSL
shaders:
```rust
#import "embedded://bevy_pbr/render/mesh.wgsl"
```
This also makes `embedded` assets go through the "normal" asset
lifecycle. They are only loaded when they are actually used!
We are also discussing implicitly converting asset paths to/from shader
modules, so in the future (not in this PR) you might be able to load it
like this:
```rust
#import bevy_pbr::render::mesh::Vertex
```
Compare that to the old system!
```rust
pub const MESH_SHADER_HANDLE: Handle<Shader> = Handle::weak_from_u128(3252377289100772450);
load_internal_asset!(app, MESH_SHADER_HANDLE, "mesh.wgsl", Shader::from_wgsl);
// The mesh asset is the _only_ accessible via MESH_SHADER_HANDLE and _cannot_ be loaded via the AssetServer.
```
## Hot Reloading `embedded`
You can enable `embedded` hot reloading by enabling the
`embedded_watcher` cargo feature:
```
cargo run --features=embedded_watcher
```
## Improved Hot Reloading Workflow
First: the `filesystem_watcher` cargo feature has been renamed to
`file_watcher` for brevity (and to match the `FileAssetReader` naming
convention).
More importantly, hot asset reloading is no longer configured in-code by
default. If you enable any asset watcher feature (such as `file_watcher`
or `rust_source_watcher`), asset watching will be automatically enabled.
This removes the need to _also_ enable hot reloading in your app code.
That means you can replace this:
```rust
app.add_plugins(DefaultPlugins.set(AssetPlugin::default().watch_for_changes()))
```
with this:
```rust
app.add_plugins(DefaultPlugins)
```
If you want to hot reload assets in your app during development, just
run your app like this:
```
cargo run --features=file_watcher
```
This means you can use the same code for development and deployment! To
deploy an app, just don't include the watcher feature
```
cargo build --release
```
My intent is to move to this approach for pretty much all dev workflows.
In a future PR I would like to replace `AssetMode::ProcessedDev` with a
`runtime-processor` cargo feature. We could then group all common "dev"
cargo features under a single `dev` feature:
```sh
# this would enable file_watcher, embedded_watcher, runtime-processor, and more
cargo run --features=dev
```
## AssetMode
`AssetPlugin::Unprocessed`, `AssetPlugin::Processed`, and
`AssetPlugin::ProcessedDev` have been replaced with an `AssetMode` field
on `AssetPlugin`.
```rust
// before
app.add_plugins(DefaultPlugins.set(AssetPlugin::Processed { /* fields here */ })
// after
app.add_plugins(DefaultPlugins.set(AssetPlugin { mode: AssetMode::Processed, ..default() })
```
This aligns `AssetPlugin` with our other struct-like plugins. The old
"source" and "destination" `AssetProvider` fields in the enum variants
have been replaced by the "asset source" system. You no longer need to
configure the AssetPlugin to "point" to custom asset providers.
## AssetServerMode
To improve the implementation of **Multiple Asset Sources**,
`AssetServer` was made aware of whether or not it is using "processed"
or "unprocessed" assets. You can check that like this:
```rust
if asset_server.mode() == AssetServerMode::Processed {
/* do something */
}
```
Note that this refactor should also prepare the way for building "one to
many processed output files", as it makes the server aware of whether it
is loading from processed or unprocessed sources. Meaning we can store
and read processed and unprocessed assets differently!
## AssetPath can now refer to folders
The "file only" restriction has been removed from `AssetPath`. The
`AssetServer::load_folder` API now accepts an `AssetPath` instead of a
`Path`, meaning you can load folders from other asset sources!
## Improved AssetPath Parsing
AssetPath parsing was reworked to support sources, improve error
messages, and to enable parsing with a single pass over the string.
`AssetPath::new` was replaced by `AssetPath::parse` and
`AssetPath::try_parse`.
## AssetWatcher broken out from AssetReader
`AssetReader` is no longer responsible for constructing `AssetWatcher`.
This has been moved to `AssetSourceBuilder`.
## Duplicate Event Debouncing
Asset V2 already debounced duplicate filesystem events, but this was
_input_ events. Multiple input event types can produce the same _output_
`AssetSourceEvent`. Now that we have `embedded_watcher`, which does
expensive file io on events, it made sense to debounce output events
too, so I added that! This will also benefit the AssetProcessor by
preventing integrity checks for duplicate events (and helps keep the
noise down in trace logs).
## Next Steps
* **Port Built-in Shaders**: Currently the primary (and essentially
only) user of `load_interal_asset` in Bevy's source code is "built-in
shaders". I chose not to do that in this PR for a few reasons:
1. We need to add the ability to pass shader defs in to shaders via meta
files. Some shaders (such as MESH_VIEW_TYPES) need to pass shader def
values in that are defined in code.
2. We need to revisit the current shader module naming system. I think
we _probably_ want to imply modules from source structure (at least by
default). Ideally in a way that can losslessly convert asset paths
to/from shader modules (to enable the asset system to resolve modules
using the asset server).
3. I want to keep this change set minimal / get this merged first.
* **Deprecate `load_internal_asset`**: we can't do that until we do (1)
and (2)
* **Relative Asset Paths**: This PR significantly increases the need for
relative asset paths (which was already pretty high). Currently when
loading dependencies, it is assumed to be an absolute path, which means
if in an `AssetLoader` you call `context.load("some/path/image.png")` it
will assume that is the "default" asset source, _even if the current
asset is in a different asset source_. This will cause breakage for
AssetLoaders that are not designed to add the current source to whatever
paths are being used. AssetLoaders should generally not need to be aware
of the name of their current asset source, or need to think about the
"current asset source" generally. We should build apis that support
relative asset paths and then encourage using relative paths as much as
possible (both via api design and docs). Relative paths are also
important because they will allow developers to move folders around
(even across providers) without reprocessing, provided there is no path
breakage.
# Objective
- Fixes#8140
## Solution
- Added Explicit Error Typing for `AssetLoader` and `AssetSaver`, which
were the last instances of `anyhow` in use across Bevy.
---
## Changelog
- Added an associated type `Error` to `AssetLoader` and `AssetSaver` for
use with the `load` and `save` methods respectively.
- Changed `ErasedAssetLoader` and `ErasedAssetSaver` `load` and `save`
methods to use `Box<dyn Error + Send + Sync + 'static>` to allow for
arbitrary `Error` types from the non-erased trait variants. Note the
strict requirements match the pre-existing requirements around
`anyhow::Error`.
## Migration Guide
- `anyhow` is no longer exported by `bevy_asset`; Add it to your own
project (if required).
- `AssetLoader` and `AssetSaver` have an associated type `Error`; Define
an appropriate error type (e.g., using `thiserror`), or use a pre-made
error type (e.g., `anyhow::Error`). Note that using `anyhow::Error` is a
drop-in replacement.
- `AssetLoaderError` has been removed; Define a new error type, or use
an alternative (e.g., `anyhow::Error`)
- All the first-party `AssetLoader`'s and `AssetSaver`'s now return
relevant (and narrow) error types instead of a single ambiguous type;
Match over the specific error type, or encapsulate (`Box<dyn>`,
`thiserror`, `anyhow`, etc.)
## Notes
A simpler PR to resolve this issue would simply define a Bevy `Error`
type defined as `Box<dyn std::error::Error + Send + Sync + 'static>`,
but I think this type of error handling should be discouraged when
possible. Since only 2 traits required the use of `anyhow`, it isn't a
substantive body of work to solidify these error types, and remove
`anyhow` entirely. End users are still encouraged to use `anyhow` if
that is their preferred error handling style. Arguably, adding the
`Error` associated type gives more freedom to end-users to decide
whether they want more or less explicit error handling (`anyhow` vs
`thiserror`).
As an aside, I didn't perform any testing on Android or WASM. CI passed
locally, but there may be mistakes for those platforms I missed.
# Objective
- Fixes#9884
- Add API for ignoring ambiguities on certain resource or components.
## Solution
- Add a `IgnoreSchedulingAmbiguitiy` resource to the world which holds
the `ComponentIds` to be ignored
- Filter out ambiguities with those component id's.
## Changelog
- add `allow_ambiguous_component` and `allow_ambiguous_resource` apis
for ignoring ambiguities
---------
Co-authored-by: Ryan Johnson <ryanj00a@gmail.com>
# Objective
- See fewer warnings when running `cargo clippy` locally.
## Solution
- allow `clippy::type_complexity` in more places, which also signals to
users they should do the same.
# Objective
Fixes#9625
## Solution
Adds `async-io` as an optional dependency of `bevy_tasks`. When enabled,
this causes calls to `futures_lite::future::block_on` to be replaced
with calls to `async_io::block_on`.
---
## Changelog
- Added a new `async-io` feature to `bevy_tasks`. When enabled, this
causes `bevy_tasks` to use `async-io`'s implemention of `block_on`
instead of `futures-lite`'s implementation. You should enable this if
you use `async-io` in your application.
# Objective
Replace instances of
```rust
for x in collection.iter{_mut}() {
```
with
```rust
for x in &{mut} collection {
```
This also changes CI to no longer suppress this lint. Note that since
this lint only shows up when using clippy in pedantic mode, it was
probably unnecessary to suppress this lint in the first place.
# Objective
Fix#9747
## Solution
Linkers don't like what we're doing with CowArc (I'm guessing it has
something to do with `?Sized`). Weirdly the `Reflect` derive on
`AssetPath` doesn't fail, despite `CowArc` not implementing `Reflect`.
To resolve this, we manually implement "reflect value" for
`AssetPath<'static>`. It sadly cannot use `impl_reflect_value` because
that macro doesn't support static lifetimes.
---------
Co-authored-by: Martin Dickopp <martin@zero-based.org>
This needs to be much higher to avoid failures in CI. I don't love the
"loop until" test methodology generally, but this is testing internal
state and making this event driven would change the nature of the test.
# Objective
The `AssetServer` and `AssetProcessor` do a lot of `AssetPath` cloning
(across many threads). To store the path on the handle, to store paths
in dependency lists, to pass an owned path to the offloaded thread, to
pass a path to the LoadContext, etc , etc. Cloning multiple string
allocations multiple times like this will add up. It is worth optimizing
this.
Referenced in #9714
## Solution
Added a new `CowArc<T>` type to `bevy_util`, which behaves a lot like
`Cow<T>`, but the Owned variant is an `Arc<T>`. Use this in place of
`Cow<str>` and `Cow<Path>` on `AssetPath`.
---
## Changelog
- `AssetPath` now internally uses `CowArc`, making clone operations much
cheaper
- `AssetPath` now serializes as `AssetPath("some_path.extension#Label")`
instead of as `AssetPath { path: "some_path.extension", label:
Some("Label) }`
## Migration Guide
```rust
// Old
AssetPath::new("logo.png", None);
// New
AssetPath::new("logo.png");
// Old
AssetPath::new("scene.gltf", Some("Mesh0");
// New
AssetPath::new("scene.gltf").with_label("Mesh0");
```
`AssetPath` now serializes as `AssetPath("some_path.extension#Label")`
instead of as `AssetPath { path: "some_path.extension", label:
Some("Label) }`
---------
Co-authored-by: Pascal Hertleif <killercup@gmail.com>
# Objective
- Fix these warnings
```rust
warning: unused doc comment
--> /bevy/crates/bevy_pbr/src/light.rs:62:13
|
62 | /// Luminous power in lumens
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
63 | intensity: 800.0, // Roughly a 60W non-halogen incandescent bulb
| ---------------- rustdoc does not generate documentation for expression fields
|
= help: use `//` for a plain comment
= note: `#[warn(unused_doc_comments)]` on by default
```
```rust
warning: `&` without an explicit lifetime name cannot be used here
--> /bevy/crates/bevy_asset/src/lib.rs:89:32
|
89 | const DEFAULT_FILE_SOURCE: &str = "assets";
| ^
|
= warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
= note: for more information, see issue #115010 <https://github.com/rust-lang/rust/issues/115010>
= note: `#[warn(elided_lifetimes_in_associated_constant)]` on by default
help: use the `'static` lifetime
|
89 | const DEFAULT_FILE_SOURCE: &'static str = "assets";
|
```
# Objective
- Related to #9715
- Example `asset_processing` logs the following error:
```
thread 'IO Task Pool (1)' panicked at 'Failed to initialize asset processor log. This cannot be recovered. Try restarting. If that doesn't work, try deleting processed asset folder. No such file or directory (os error 2)', crates/bevy_asset/src/processor/mod.rs:867:25
```
## Solution
- Create the log directory if needed
---------
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Bevy Asset V2 Proposal
## Why Does Bevy Need A New Asset System?
Asset pipelines are a central part of the gamedev process. Bevy's
current asset system is missing a number of features that make it
non-viable for many classes of gamedev. After plenty of discussions and
[a long community feedback
period](https://github.com/bevyengine/bevy/discussions/3972), we've
identified a number missing features:
* **Asset Preprocessing**: it should be possible to "preprocess" /
"compile" / "crunch" assets at "development time" rather than when the
game starts up. This enables offloading expensive work from deployed
apps, faster asset loading, less runtime memory usage, etc.
* **Per-Asset Loader Settings**: Individual assets cannot define their
own loaders that override the defaults. Additionally, they cannot
provide per-asset settings to their loaders. This is a huge limitation,
as many asset types don't provide all information necessary for Bevy
_inside_ the asset. For example, a raw PNG image says nothing about how
it should be sampled (ex: linear vs nearest).
* **Asset `.meta` files**: assets should have configuration files stored
adjacent to the asset in question, which allows the user to configure
asset-type-specific settings. These settings should be accessible during
the pre-processing phase. Modifying a `.meta` file should trigger a
re-processing / re-load of the asset. It should be possible to configure
asset loaders from the meta file.
* **Processed Asset Hot Reloading**: Changes to processed assets (or
their dependencies) should result in re-processing them and re-loading
the results in live Bevy Apps.
* **Asset Dependency Tracking**: The current bevy_asset has no good way
to wait for asset dependencies to load. It punts this as an exercise for
consumers of the loader apis, which is unreasonable and error prone.
There should be easy, ergonomic ways to wait for assets to load and
block some logic on an asset's entire dependency tree loading.
* **Runtime Asset Loading**: it should be (optionally) possible to load
arbitrary assets dynamically at runtime. This necessitates being able to
deploy and run the asset server alongside Bevy Apps on _all platforms_.
For example, we should be able to invoke the shader compiler at runtime,
stream scenes from sources like the internet, etc. To keep deployed
binaries (and startup times) small, the runtime asset server
configuration should be configurable with different settings compared to
the "pre processor asset server".
* **Multiple Backends**: It should be possible to load assets from
arbitrary sources (filesystems, the internet, remote asset serves, etc).
* **Asset Packing**: It should be possible to deploy assets in
compressed "packs", which makes it easier and more efficient to
distribute assets with Bevy Apps.
* **Asset Handoff**: It should be possible to hold a "live" asset
handle, which correlates to runtime data, without actually holding the
asset in memory. Ex: it must be possible to hold a reference to a GPU
mesh generated from a "mesh asset" without keeping the mesh data in CPU
memory
* **Per-Platform Processed Assets**: Different platforms and app
distributions have different capabilities and requirements. Some
platforms need lower asset resolutions or different asset formats to
operate within the hardware constraints of the platform. It should be
possible to define per-platform asset processing profiles. And it should
be possible to deploy only the assets required for a given platform.
These features have architectural implications that are significant
enough to require a full rewrite. The current Bevy Asset implementation
got us this far, but it can take us no farther. This PR defines a brand
new asset system that implements most of these features, while laying
the foundations for the remaining features to be built.
## Bevy Asset V2
Here is a quick overview of the features introduced in this PR.
* **Asset Preprocessing**: Preprocess assets at development time into
more efficient (and configurable) representations
* **Dependency Aware**: Dependencies required to process an asset are
tracked. If an asset's processed dependency changes, it will be
reprocessed
* **Hot Reprocessing/Reloading**: detect changes to asset source files,
reprocess them if they have changed, and then hot-reload them in Bevy
Apps.
* **Only Process Changes**: Assets are only re-processed when their
source file (or meta file) has changed. This uses hashing and timestamps
to avoid processing assets that haven't changed.
* **Transactional and Reliable**: Uses write-ahead logging (a technique
commonly used by databases) to recover from crashes / forced-exits.
Whenever possible it avoids full-reprocessing / only uncompleted
transactions will be reprocessed. When the processor is running in
parallel with a Bevy App, processor asset writes block Bevy App asset
reads. Reading metadata + asset bytes is guaranteed to be transactional
/ correctly paired.
* **Portable / Run anywhere / Database-free**: The processor does not
rely on an in-memory database (although it uses some database techniques
for reliability). This is important because pretty much all in-memory
databases have unsupported platforms or build complications.
* **Configure Processor Defaults Per File Type**: You can say "use this
processor for all files of this type".
* **Custom Processors**: The `Processor` trait is flexible and
unopinionated. It can be implemented by downstream plugins.
* **LoadAndSave Processors**: Most asset processing scenarios can be
expressed as "run AssetLoader A, save the results using AssetSaver X,
and then load the result using AssetLoader B". For example, load this
png image using `PngImageLoader`, which produces an `Image` asset and
then save it using `CompressedImageSaver` (which also produces an
`Image` asset, but in a compressed format), which takes an `Image` asset
as input. This means if you have an `AssetLoader` for an asset, you are
already half way there! It also means that you can share AssetSavers
across multiple loaders. Because `CompressedImageSaver` accepts Bevy's
generic Image asset as input, it means you can also use it with some
future `JpegImageLoader`.
* **Loader and Saver Settings**: Asset Loaders and Savers can now define
their own settings types, which are passed in as input when an asset is
loaded / saved. Each asset can define its own settings.
* **Asset `.meta` files**: configure asset loaders, their settings,
enable/disable processing, and configure processor settings
* **Runtime Asset Dependency Tracking** Runtime asset dependencies (ex:
if an asset contains a `Handle<Image>`) are tracked by the asset server.
An event is emitted when an asset and all of its dependencies have been
loaded
* **Unprocessed Asset Loading**: Assets do not require preprocessing.
They can be loaded directly. A processed asset is just a "normal" asset
with some extra metadata. Asset Loaders don't need to know or care about
whether or not an asset was processed.
* **Async Asset IO**: Asset readers/writers use async non-blocking
interfaces. Note that because Rust doesn't yet support async traits,
there is a bit of manual Boxing / Future boilerplate. This will
hopefully be removed in the near future when Rust gets async traits.
* **Pluggable Asset Readers and Writers**: Arbitrary asset source
readers/writers are supported, both by the processor and the asset
server.
* **Better Asset Handles**
* **Single Arc Tree**: Asset Handles now use a single arc tree that
represents the lifetime of the asset. This makes their implementation
simpler, more efficient, and allows us to cheaply attach metadata to
handles. Ex: the AssetPath of a handle is now directly accessible on the
handle itself!
* **Const Typed Handles**: typed handles can be constructed in a const
context. No more weird "const untyped converted to typed at runtime"
patterns!
* **Handles and Ids are Smaller / Faster To Hash / Compare**: Typed
`Handle<T>` is now much smaller in memory and `AssetId<T>` is even
smaller.
* **Weak Handle Usage Reduction**: In general Handles are now considered
to be "strong". Bevy features that previously used "weak `Handle<T>`"
have been ported to `AssetId<T>`, which makes it statically clear that
the features do not hold strong handles (while retaining strong type
information). Currently Handle::Weak still exists, but it is very
possible that we can remove that entirely.
* **Efficient / Dense Asset Ids**: Assets now have efficient dense
runtime asset ids, which means we can avoid expensive hash lookups.
Assets are stored in Vecs instead of HashMaps. There are now typed and
untyped ids, which means we no longer need to store dynamic type
information in the ID for typed handles. "AssetPathId" (which was a
nightmare from a performance and correctness standpoint) has been
entirely removed in favor of dense ids (which are retrieved for a path
on load)
* **Direct Asset Loading, with Dependency Tracking**: Assets that are
defined at runtime can still have their dependencies tracked by the
Asset Server (ex: if you create a material at runtime, you can still
wait for its textures to load). This is accomplished via the (currently
optional) "asset dependency visitor" trait. This system can also be used
to define a set of assets to load, then wait for those assets to load.
* **Async folder loading**: Folder loading also uses this system and
immediately returns a handle to the LoadedFolder asset, which means
folder loading no longer blocks on directory traversals.
* **Improved Loader Interface**: Loaders now have a specific "top level
asset type", which makes returning the top-level asset simpler and
statically typed.
* **Basic Image Settings and Processing**: Image assets can now be
processed into the gpu-friendly Basic Universal format. The ImageLoader
now has a setting to define what format the image should be loaded as.
Note that this is just a minimal MVP ... plenty of additional work to do
here. To demo this, enable the `basis-universal` feature and turn on
asset processing.
* **Simpler Audio Play / AudioSink API**: Asset handle providers are
cloneable, which means the Audio resource can mint its own handles. This
means you can now do `let sink_handle = audio.play(music)` instead of
`let sink_handle = audio_sinks.get_handle(audio.play(music))`. Note that
this might still be replaced by
https://github.com/bevyengine/bevy/pull/8424.
**Removed Handle Casting From Engine Features**: Ex: FontAtlases no
longer use casting between handle types
## Using The New Asset System
### Normal Unprocessed Asset Loading
By default the `AssetPlugin` does not use processing. It behaves pretty
much the same way as the old system.
If you are defining a custom asset, first derive `Asset`:
```rust
#[derive(Asset)]
struct Thing {
value: String,
}
```
Initialize the asset:
```rust
app.init_asset:<Thing>()
```
Implement a new `AssetLoader` for it:
```rust
#[derive(Default)]
struct ThingLoader;
#[derive(Serialize, Deserialize, Default)]
pub struct ThingSettings {
some_setting: bool,
}
impl AssetLoader for ThingLoader {
type Asset = Thing;
type Settings = ThingSettings;
fn load<'a>(
&'a self,
reader: &'a mut Reader,
settings: &'a ThingSettings,
load_context: &'a mut LoadContext,
) -> BoxedFuture<'a, Result<Thing, anyhow::Error>> {
Box::pin(async move {
let mut bytes = Vec::new();
reader.read_to_end(&mut bytes).await?;
// convert bytes to value somehow
Ok(Thing {
value
})
})
}
fn extensions(&self) -> &[&str] {
&["thing"]
}
}
```
Note that this interface will get much cleaner once Rust gets support
for async traits. `Reader` is an async futures_io::AsyncRead. You can
stream bytes as they come in or read them all into a `Vec<u8>`,
depending on the context. You can use `let handle =
load_context.load(path)` to kick off a dependency load, retrieve a
handle, and register the dependency for the asset.
Then just register the loader in your Bevy app:
```rust
app.init_asset_loader::<ThingLoader>()
```
Now just add your `Thing` asset files into the `assets` folder and load
them like this:
```rust
fn system(asset_server: Res<AssetServer>) {
let handle = Handle<Thing> = asset_server.load("cool.thing");
}
```
You can check load states directly via the asset server:
```rust
if asset_server.load_state(&handle) == LoadState::Loaded { }
```
You can also listen for events:
```rust
fn system(mut events: EventReader<AssetEvent<Thing>>, handle: Res<SomeThingHandle>) {
for event in events.iter() {
if event.is_loaded_with_dependencies(&handle) {
}
}
}
```
Note the new `AssetEvent::LoadedWithDependencies`, which only fires when
the asset is loaded _and_ all dependencies (and their dependencies) have
loaded.
Unlike the old asset system, for a given asset path all `Handle<T>`
values point to the same underlying Arc. This means Handles can cheaply
hold more asset information, such as the AssetPath:
```rust
// prints the AssetPath of the handle
info!("{:?}", handle.path())
```
### Processed Assets
Asset processing can be enabled via the `AssetPlugin`. When developing
Bevy Apps with processed assets, do this:
```rust
app.add_plugins(DefaultPlugins.set(AssetPlugin::processed_dev()))
```
This runs the `AssetProcessor` in the background with hot-reloading. It
reads assets from the `assets` folder, processes them, and writes them
to the `.imported_assets` folder. Asset loads in the Bevy App will wait
for a processed version of the asset to become available. If an asset in
the `assets` folder changes, it will be reprocessed and hot-reloaded in
the Bevy App.
When deploying processed Bevy apps, do this:
```rust
app.add_plugins(DefaultPlugins.set(AssetPlugin::processed()))
```
This does not run the `AssetProcessor` in the background. It behaves
like `AssetPlugin::unprocessed()`, but reads assets from
`.imported_assets`.
When the `AssetProcessor` is running, it will populate sibling `.meta`
files for assets in the `assets` folder. Meta files for assets that do
not have a processor configured look like this:
```rust
(
meta_format_version: "1.0",
asset: Load(
loader: "bevy_render::texture::image_loader::ImageLoader",
settings: (
format: FromExtension,
),
),
)
```
This is metadata for an image asset. For example, if you have
`assets/my_sprite.png`, this could be the metadata stored at
`assets/my_sprite.png.meta`. Meta files are totally optional. If no
metadata exists, the default settings will be used.
In short, this file says "load this asset with the ImageLoader and use
the file extension to determine the image type". This type of meta file
is supported in all AssetPlugin modes. If in `Unprocessed` mode, the
asset (with the meta settings) will be loaded directly. If in
`ProcessedDev` mode, the asset file will be copied directly to the
`.imported_assets` folder. The meta will also be copied directly to the
`.imported_assets` folder, but with one addition:
```rust
(
meta_format_version: "1.0",
processed_info: Some((
hash: 12415480888597742505,
full_hash: 14344495437905856884,
process_dependencies: [],
)),
asset: Load(
loader: "bevy_render::texture::image_loader::ImageLoader",
settings: (
format: FromExtension,
),
),
)
```
`processed_info` contains `hash` (a direct hash of the asset and meta
bytes), `full_hash` (a hash of `hash` and the hashes of all
`process_dependencies`), and `process_dependencies` (the `path` and
`full_hash` of every process_dependency). A "process dependency" is an
asset dependency that is _directly_ used when processing the asset.
Images do not have process dependencies, so this is empty.
When the processor is enabled, you can use the `Process` metadata
config:
```rust
(
meta_format_version: "1.0",
asset: Process(
processor: "bevy_asset::processor::process::LoadAndSave<bevy_render::texture::image_loader::ImageLoader, bevy_render::texture::compressed_image_saver::CompressedImageSaver>",
settings: (
loader_settings: (
format: FromExtension,
),
saver_settings: (
generate_mipmaps: true,
),
),
),
)
```
This configures the asset to use the `LoadAndSave` processor, which runs
an AssetLoader and feeds the result into an AssetSaver (which saves the
given Asset and defines a loader to load it with). (for terseness
LoadAndSave will likely get a shorter/friendlier type name when [Stable
Type Paths](#7184) lands). `LoadAndSave` is likely to be the most common
processor type, but arbitrary processors are supported.
`CompressedImageSaver` saves an `Image` in the Basis Universal format
and configures the ImageLoader to load it as basis universal. The
`AssetProcessor` will read this meta, run it through the LoadAndSave
processor, and write the basis-universal version of the image to
`.imported_assets`. The final metadata will look like this:
```rust
(
meta_format_version: "1.0",
processed_info: Some((
hash: 905599590923828066,
full_hash: 9948823010183819117,
process_dependencies: [],
)),
asset: Load(
loader: "bevy_render::texture::image_loader::ImageLoader",
settings: (
format: Format(Basis),
),
),
)
```
To try basis-universal processing out in Bevy examples, (for example
`sprite.rs`), change `add_plugins(DefaultPlugins)` to
`add_plugins(DefaultPlugins.set(AssetPlugin::processed_dev()))` and run
with the `basis-universal` feature enabled: `cargo run
--features=basis-universal --example sprite`.
To create a custom processor, there are two main paths:
1. Use the `LoadAndSave` processor with an existing `AssetLoader`.
Implement the `AssetSaver` trait, register the processor using
`asset_processor.register_processor::<LoadAndSave<ImageLoader,
CompressedImageSaver>>(image_saver.into())`.
2. Implement the `Process` trait directly and register it using:
`asset_processor.register_processor(thing_processor)`.
You can configure default processors for file extensions like this:
```rust
asset_processor.set_default_processor::<ThingProcessor>("thing")
```
There is one more metadata type to be aware of:
```rust
(
meta_format_version: "1.0",
asset: Ignore,
)
```
This will ignore the asset during processing / prevent it from being
written to `.imported_assets`.
The AssetProcessor stores a transaction log at `.imported_assets/log`
and uses it to gracefully recover from unexpected stops. This means you
can force-quit the processor (and Bevy Apps running the processor in
parallel) at arbitrary times!
`.imported_assets` is "local state". It should _not_ be checked into
source control. It should also be considered "read only". In practice,
you _can_ modify processed assets and processed metadata if you really
need to test something. But those modifications will not be represented
in the hashes of the assets, so the processed state will be "out of
sync" with the source assets. The processor _will not_ fix this for you.
Either revert the change after you have tested it, or delete the
processed files so they can be re-populated.
## Open Questions
There are a number of open questions to be discussed. We should decide
if they need to be addressed in this PR and if so, how we will address
them:
### Implied Dependencies vs Dependency Enumeration
There are currently two ways to populate asset dependencies:
* **Implied via AssetLoaders**: if an AssetLoader loads an asset (and
retrieves a handle), a dependency is added to the list.
* **Explicit via the optional Asset::visit_dependencies**: if
`server.load_asset(my_asset)` is called, it will call
`my_asset.visit_dependencies`, which will grab dependencies that have
been manually defined for the asset via the Asset trait impl (which can
be derived).
This means that defining explicit dependencies is optional for "loaded
assets". And the list of dependencies is always accurate because loaders
can only produce Handles if they register dependencies. If an asset was
loaded with an AssetLoader, it only uses the implied dependencies. If an
asset was created at runtime and added with
`asset_server.load_asset(MyAsset)`, it will use
`Asset::visit_dependencies`.
However this can create a behavior mismatch between loaded assets and
equivalent "created at runtime" assets if `Assets::visit_dependencies`
doesn't exactly match the dependencies produced by the AssetLoader. This
behavior mismatch can be resolved by completely removing "implied loader
dependencies" and requiring `Asset::visit_dependencies` to supply
dependency data. But this creates two problems:
* It makes defining loaded assets harder and more error prone: Devs must
remember to manually annotate asset dependencies with `#[dependency]`
when deriving `Asset`. For more complicated assets (such as scenes), the
derive likely wouldn't be sufficient and a manual `visit_dependencies`
impl would be required.
* Removes the ability to immediately kick off dependency loads: When
AssetLoaders retrieve a Handle, they also immediately kick off an asset
load for the handle, which means it can start loading in parallel
_before_ the asset finishes loading. For large assets, this could be
significant. (although this could be mitigated for processed assets if
we store dependencies in the processed meta file and load them ahead of
time)
### Eager ProcessorDev Asset Loading
I made a controversial call in the interest of fast startup times ("time
to first pixel") for the "processor dev mode configuration". When
initializing the AssetProcessor, current processed versions of unchanged
assets are yielded immediately, even if their dependencies haven't been
checked yet for reprocessing. This means that
non-current-state-of-filesystem-but-previously-valid assets might be
returned to the App first, then hot-reloaded if/when their dependencies
change and the asset is reprocessed.
Is this behavior desirable? There is largely one alternative: do not
yield an asset from the processor to the app until all of its
dependencies have been checked for changes. In some common cases (load
dependency has not changed since last run) this will increase startup
time. The main question is "by how much" and is that slower startup time
worth it in the interest of only yielding assets that are true to the
current state of the filesystem. Should this be configurable? I'm
starting to think we should only yield an asset after its (historical)
dependencies have been checked for changes + processed as necessary, but
I'm curious what you all think.
### Paths Are Currently The Only Canonical ID / Do We Want Asset UUIDs?
In this implementation AssetPaths are the only canonical asset
identifier (just like the previous Bevy Asset system and Godot). Moving
assets will result in re-scans (and currently reprocessing, although
reprocessing can easily be avoided with some changes). Asset
renames/moves will break code and assets that rely on specific paths,
unless those paths are fixed up.
Do we want / need "stable asset uuids"? Introducing them is very
possible:
1. Generate a UUID and include it in .meta files
2. Support UUID in AssetPath
3. Generate "asset indices" which are loaded on startup and map UUIDs to
paths.
4 (maybe). Consider only supporting UUIDs for processed assets so we can
generate quick-to-load indices instead of scanning meta files.
The main "pro" is that assets referencing UUIDs don't need to be
migrated when a path changes. The main "con" is that UUIDs cannot be
"lazily resolved" like paths. They need a full view of all assets to
answer the question "does this UUID exist". Which means UUIDs require
the AssetProcessor to fully finish startup scans before saying an asset
doesnt exist. And they essentially require asset pre-processing to use
in apps, because scanning all asset metadata files at runtime to resolve
a UUID is not viable for medium-to-large apps. It really requires a
pre-generated UUID index, which must be loaded before querying for
assets.
I personally think this should be investigated in a separate PR. Paths
aren't going anywhere ... _everyone_ uses filesystems (and
filesystem-like apis) to manage their asset source files. I consider
them permanent canonical asset information. Additionally, they behave
well for both processed and unprocessed asset modes. Given that Bevy is
supporting both, this feels like the right canonical ID to start with.
UUIDS (and maybe even other indexed-identifier types) can be added later
as necessary.
### Folder / File Naming Conventions
All asset processing config currently lives in the `.imported_assets`
folder. The processor transaction log is in `.imported_assets/log`.
Processed assets are added to `.imported_assets/Default`, which will
make migrating to processed asset profiles (ex: a
`.imported_assets/Mobile` profile) a non-breaking change. It also allows
us to create top-level files like `.imported_assets/log` without it
being interpreted as an asset. Meta files currently have a `.meta`
suffix. Do we like these names and conventions?
### Should the `AssetPlugin::processed_dev` configuration enable
`watch_for_changes` automatically?
Currently it does (which I think makes sense), but it does make it the
only configuration that enables watch_for_changes by default.
### Discuss on_loaded High Level Interface:
This PR includes a very rough "proof of concept" `on_loaded` system
adapter that uses the `LoadedWithDependencies` event in combination with
`asset_server.load_asset` dependency tracking to support this pattern
```rust
fn main() {
App::new()
.init_asset::<MyAssets>()
.add_systems(Update, on_loaded(create_array_texture))
.run();
}
#[derive(Asset, Clone)]
struct MyAssets {
#[dependency]
picture_of_my_cat: Handle<Image>,
#[dependency]
picture_of_my_other_cat: Handle<Image>,
}
impl FromWorld for ArrayTexture {
fn from_world(world: &mut World) -> Self {
picture_of_my_cat: server.load("meow.png"),
picture_of_my_other_cat: server.load("meeeeeeeow.png"),
}
}
fn spawn_cat(In(my_assets): In<MyAssets>, mut commands: Commands) {
commands.spawn(SpriteBundle {
texture: my_assets.picture_of_my_cat.clone(),
..default()
});
commands.spawn(SpriteBundle {
texture: my_assets.picture_of_my_other_cat.clone(),
..default()
});
}
```
The implementation is _very_ rough. And it is currently unsafe because
`bevy_ecs` doesn't expose some internals to do this safely from inside
`bevy_asset`. There are plenty of unanswered questions like:
* "do we add a Loadable" derive? (effectively automate the FromWorld
implementation above)
* Should `MyAssets` even be an Asset? (largely implemented this way
because it elegantly builds on `server.load_asset(MyAsset { .. })`
dependency tracking).
We should think hard about what our ideal API looks like (and if this is
a pattern we want to support). Not necessarily something we need to
solve in this PR. The current `on_loaded` impl should probably be
removed from this PR before merging.
## Clarifying Questions
### What about Assets as Entities?
This Bevy Asset V2 proposal implementation initially stored Assets as
ECS Entities. Instead of `AssetId<T>` + the `Assets<T>` resource it used
`Entity` as the asset id and Asset values were just ECS components.
There are plenty of compelling reasons to do this:
1. Easier to inline assets in Bevy Scenes (as they are "just" normal
entities + components)
2. More flexible queries: use the power of the ECS to filter assets (ex:
`Query<Mesh, With<Tree>>`).
3. Extensible. Users can add arbitrary component data to assets.
4. Things like "component visualization tools" work out of the box to
visualize asset data.
However Assets as Entities has a ton of caveats right now:
* We need to be able to allocate entity ids without a direct World
reference (aka rework id allocator in Entities ... i worked around this
in my prototypes by just pre allocating big chunks of entities)
* We want asset change events in addition to ECS change tracking ... how
do we populate them when mutations can come from anywhere? Do we use
Changed queries? This would require iterating over the change data for
all assets every frame. Is this acceptable or should we implement a new
"event based" component change detection option?
* Reconciling manually created assets with asset-system managed assets
has some nuance (ex: are they "loaded" / do they also have that
component metadata?)
* "how do we handle "static" / default entity handles" (ties in to the
Entity Indices discussion:
https://github.com/bevyengine/bevy/discussions/8319). This is necessary
for things like "built in" assets and default handles in things like
SpriteBundle.
* Storing asset information as a component makes it easy to "invalidate"
asset state by removing the component (or forcing modifications).
Ideally we have ways to lock this down (some combination of Rust type
privacy and ECS validation)
In practice, how we store and identify assets is a reasonably
superficial change (porting off of Assets as Entities and implementing
dedicated storage + ids took less than a day). So once we sort out the
remaining challenges the flip should be straightforward. Additionally, I
do still have "Assets as Entities" in my commit history, so we can reuse
that work. I personally think "assets as entities" is a good endgame,
but it also doesn't provide _significant_ value at the moment and it
certainly isn't ready yet with the current state of things.
### Why not Distill?
[Distill](https://github.com/amethyst/distill) is a high quality fully
featured asset system built in Rust. It is very natural to ask "why not
just use Distill?".
It is also worth calling out that for awhile, [we planned on adopting
Distill / I signed off on
it](https://github.com/bevyengine/bevy/issues/708).
However I think Bevy has a number of constraints that make Distill
adoption suboptimal:
* **Architectural Simplicity:**
* Distill's processor requires an in-memory database (lmdb) and RPC
networked API (using Cap'n Proto). Each of these introduces API
complexity that increases maintenance burden and "code grokability".
Ignoring tests, documentation, and examples, Distill has 24,237 lines of
Rust code (including generated code for RPC + database interactions). If
you ignore generated code, it has 11,499 lines.
* Bevy builds the AssetProcessor and AssetServer using pluggable
AssetReader/AssetWriter Rust traits with simple io interfaces. They do
not necessitate databases or RPC interfaces (although Readers/Writers
could use them if that is desired). Bevy Asset V2 (at the time of
writing this PR) is 5,384 lines of Rust code (ignoring tests,
documentation, and examples). Grain of salt: Distill does have more
features currently (ex: Asset Packing, GUIDS, remote-out-of-process
asset processor). I do plan to implement these features in Bevy Asset V2
and I personally highly doubt they will meaningfully close the 6115
lines-of-code gap.
* This complexity gap (which while illustrated by lines of code, is much
bigger than just that) is noteworthy to me. Bevy should be hackable and
there are pillars of Distill that are very hard to understand and
extend. This is a matter of opinion (and Bevy Asset V2 also has
complicated areas), but I think Bevy Asset V2 is much more approachable
for the average developer.
* Necessary disclaimer: counting lines of code is an extremely rough
complexity metric. Read the code and form your own opinions.
* **Optional Asset Processing:** Not all Bevy Apps (or Bevy App
developers) need / want asset preprocessing. Processing increases the
complexity of the development environment by introducing things like
meta files, imported asset storage, running processors in the
background, waiting for processing to finish, etc. Distill _requires_
preprocessing to work. With Bevy Asset V2 processing is fully opt-in.
The AssetServer isn't directly aware of asset processors at all.
AssetLoaders only care about converting bytes to runtime Assets ... they
don't know or care if the bytes were pre-processed or not. Processing is
"elegantly" (forgive my self-congratulatory phrasing) layered on top and
builds on the existing Asset system primitives.
* **Direct Filesystem Access to Processed Asset State:** Distill stores
processed assets in a database. This makes debugging / inspecting the
processed outputs harder (either requires special tooling to query the
database or they need to be "deployed" to be inspected). Bevy Asset V2,
on the other hand, stores processed assets in the filesystem (by default
... this is configurable). This makes interacting with the processed
state more natural. Note that both Godot and Unity's new asset system
store processed assets in the filesystem.
* **Portability**: Because Distill's processor uses lmdb and RPC
networking, it cannot be run on certain platforms (ex: lmdb is a
non-rust dependency that cannot run on the web, some platforms don't
support running network servers). Bevy should be able to process assets
everywhere (ex: run the Bevy Editor on the web, compile + process
shaders on mobile, etc). Distill does partially mitigate this problem by
supporting "streaming" assets via the RPC protocol, but this is not a
full solve from my perspective. And Bevy Asset V2 can (in theory) also
stream assets (without requiring RPC, although this isn't implemented
yet)
Note that I _do_ still think Distill would be a solid asset system for
Bevy. But I think the approach in this PR is a better solve for Bevy's
specific "asset system requirements".
### Doesn't async-fs just shim requests to "sync" `std::fs`? What is the
point?
"True async file io" has limited / spotty platform support. async-fs
(and the rust async ecosystem generally ... ex Tokio) currently use
async wrappers over std::fs that offload blocking requests to separate
threads. This may feel unsatisfying, but it _does_ still provide value
because it prevents our task pools from blocking on file system
operations (which would prevent progress when there are many tasks to
do, but all threads in a pool are currently blocking on file system
ops).
Additionally, using async APIs for our AssetReaders and AssetWriters
also provides value because we can later add support for "true async
file io" for platforms that support it. _And_ we can implement other
"true async io" asset backends (such as networked asset io).
## Draft TODO
- [x] Fill in missing filesystem event APIs: file removed event (which
is expressed as dangling RenameFrom events in some cases), file/folder
renamed event
- [x] Assets without loaders are not moved to the processed folder. This
breaks things like referenced `.bin` files for GLTFs. This should be
configurable per-non-asset-type.
- [x] Initial implementation of Reflect and FromReflect for Handle. The
"deserialization" parity bar is low here as this only worked with static
UUIDs in the old impl ... this is a non-trivial problem. Either we add a
Handle::AssetPath variant that gets "upgraded" to a strong handle on
scene load or we use a separate AssetRef type for Bevy scenes (which is
converted to a runtime Handle on load). This deserves its own discussion
in a different pr.
- [x] Populate read_asset_bytes hash when run by the processor (a bit of
a special case .. when run by the processor the processed meta will
contain the hash so we don't need to compute it on the spot, but we
don't want/need to read the meta when run by the main AssetServer)
- [x] Delay hot reloading: currently filesystem events are handled
immediately, which creates timing issues in some cases. For example hot
reloading images can sometimes break because the image isn't finished
writing. We should add a delay, likely similar to the [implementation in
this PR](https://github.com/bevyengine/bevy/pull/8503).
- [x] Port old platform-specific AssetIo implementations to the new
AssetReader interface (currently missing Android and web)
- [x] Resolve on_loaded unsafety (either by removing the API entirely or
removing the unsafe)
- [x] Runtime loader setting overrides
- [x] Remove remaining unwraps that should be error-handled. There are
number of TODOs here
- [x] Pretty AssetPath Display impl
- [x] Document more APIs
- [x] Resolve spurious "reloading because it has changed" events (to
repro run load_gltf with `processed_dev()`)
- [x] load_dependency hot reloading currently only works for processed
assets. If processing is disabled, load_dependency changes are not hot
reloaded.
- [x] Replace AssetInfo dependency load/fail counters with
`loading_dependencies: HashSet<UntypedAssetId>` to prevent reloads from
(potentially) breaking counters. Storing this will also enable
"dependency reloaded" events (see [Next Steps](#next-steps))
- [x] Re-add filesystem watcher cargo feature gate (currently it is not
optional)
- [ ] Migration Guide
- [ ] Changelog
## Followup TODO
- [ ] Replace "eager unchanged processed asset loading" behavior with
"don't returned unchanged processed asset until dependencies have been
checked".
- [ ] Add true `Ignore` AssetAction that does not copy the asset to the
imported_assets folder.
- [ ] Finish "live asset unloading" (ex: free up CPU asset memory after
uploading an image to the GPU), rethink RenderAssets, and port renderer
features. The `Assets` collection uses `Option<T>` for asset storage to
support its removal. (1) the Option might not actually be necessary ...
might be able to just remove from the collection entirely (2) need to
finalize removal apis
- [ ] Try replacing the "channel based" asset id recycling with
something a bit more efficient (ex: we might be able to use raw atomic
ints with some cleverness)
- [ ] Consider adding UUIDs to processed assets (scoped just to helping
identify moved assets ... not exposed to load queries ... see [Next
Steps](#next-steps))
- [ ] Store "last modified" source asset and meta timestamps in
processed meta files to enable skipping expensive hashing when the file
wasn't changed
- [ ] Fix "slow loop" handle drop fix
- [ ] Migrate to TypeName
- [x] Handle "loader preregistration". See #9429
## Next Steps
* **Configurable per-type defaults for AssetMeta**: It should be
possible to add configuration like "all png image meta should default to
using nearest sampling" (currently this hard-coded per-loader/processor
Settings::default() impls). Also see the "Folder Meta" bullet point.
* **Avoid Reprocessing on Asset Renames / Moves**: See the "canonical
asset ids" discussion in [Open Questions](#open-questions) and the
relevant bullet point in [Draft TODO](#draft-todo). Even without
canonical ids, folder renames could avoid reprocessing in some cases.
* **Multiple Asset Sources**: Expand AssetPath to support "asset source
names" and support multiple AssetReaders in the asset server (ex:
`webserver://some_path/image.png` backed by an Http webserver
AssetReader). The "default" asset reader would use normal
`some_path/image.png` paths. Ideally this works in combination with
multiple AssetWatchers for hot-reloading
* **Stable Type Names**: this pr removes the TypeUuid requirement from
assets in favor of `std::any::type_name`. This makes defining assets
easier (no need to generate a new uuid / use weird proc macro syntax).
It also makes reading meta files easier (because things have "friendly
names"). We also use type names for components in scene files. If they
are good enough for components, they are good enough for assets. And
consistency across Bevy pillars is desirable. However,
`std::any::type_name` is not guaranteed to be stable (although in
practice it is). We've developed a [stable type
path](https://github.com/bevyengine/bevy/pull/7184) to resolve this,
which should be adopted when it is ready.
* **Command Line Interface**: It should be possible to run the asset
processor in a separate process from the command line. This will also
require building a network-server-backed AssetReader to communicate
between the app and the processor. We've been planning to build a "bevy
cli" for awhile. This seems like a good excuse to build it.
* **Asset Packing**: This is largely an additive feature, so it made
sense to me to punt this until we've laid the foundations in this PR.
* **Per-Platform Processed Assets**: It should be possible to generate
assets for multiple platforms by supporting multiple "processor
profiles" per asset (ex: compress with format X on PC and Y on iOS). I
think there should probably be arbitrary "profiles" (which can be
separate from actual platforms), which are then assigned to a given
platform when generating the final asset distribution for that platform.
Ex: maybe devs want a "Mobile" profile that is shared between iOS and
Android. Or a "LowEnd" profile shared between web and mobile.
* **Versioning and Migrations**: Assets, Loaders, Savers, and Processors
need to have versions to determine if their schema is valid. If an asset
/ loader version is incompatible with the current version expected at
runtime, the processor should be able to migrate them. I think we should
try using Bevy Reflect for this, as it would allow us to load the old
version as a dynamic Reflect type without actually having the old Rust
type. It would also allow us to define "patches" to migrate between
versions (Bevy Reflect devs are currently working on patching). The
`.meta` file already has its own format version. Migrating that to new
versions should also be possible.
* **Real Copy-on-write AssetPaths**: Rust's actual Cow (clone-on-write
type) currently used by AssetPath can still result in String clones that
aren't actually necessary (cloning an Owned Cow clones the contents).
Bevy's asset system requires cloning AssetPaths in a number of places,
which result in actual clones of the internal Strings. This is not
efficient. AssetPath internals should be reworked to exhibit truer
cow-like-behavior that reduces String clones to the absolute minimum.
* **Consider processor-less processing**: In theory the AssetServer
could run processors "inline" even if the background AssetProcessor is
disabled. If we decide this is actually desirable, we could add this.
But I don't think its a priority in the short or medium term.
* **Pre-emptive dependency loading**: We could encode dependencies in
processed meta files, which could then be used by the Asset Server to
kick of dependency loads as early as possible (prior to starting the
actual asset load). Is this desirable? How much time would this save in
practice?
* **Optimize Processor With UntypedAssetIds**: The processor exclusively
uses AssetPath to identify assets currently. It might be possible to
swap these out for UntypedAssetIds in some places, which are smaller /
cheaper to hash and compare.
* **One to Many Asset Processing**: An asset source file that produces
many assets currently must be processed into a single "processed" asset
source. If labeled assets can be written separately they can each have
their own configured savers _and_ they could be loaded more granularly.
Definitely worth exploring!
* **Automatically Track "Runtime-only" Asset Dependencies**: Right now,
tracking "created at runtime" asset dependencies requires adding them
via `asset_server.load_asset(StandardMaterial::default())`. I think with
some cleverness we could also do this for
`materials.add(StandardMaterial::default())`, making tracking work
"everywhere". There are challenges here relating to change detection /
ensuring the server is made aware of dependency changes. This could be
expensive in some cases.
* **"Dependency Changed" events**: Some assets have runtime artifacts
that need to be re-generated when one of their dependencies change (ex:
regenerate a material's bind group when a Texture needs to change). We
are generating the dependency graph so we can definitely produce these
events. Buuuuut generating these events will have a cost / they could be
high frequency for some assets, so we might want this to be opt-in for
specific cases.
* **Investigate Storing More Information In Handles**: Handles can now
store arbitrary information, which makes it cheaper and easier to
access. How much should we move into them? Canonical asset load states
(via atomics)? (`handle.is_loaded()` would be very cool). Should we
store the entire asset and remove the `Assets<T>` collection?
(`Arc<RwLock<Option<Image>>>`?)
* **Support processing and loading files without extensions**: This is a
pretty arbitrary restriction and could be supported with very minimal
changes.
* **Folder Meta**: It would be nice if we could define per folder
processor configuration defaults (likely in a `.meta` or `.folder_meta`
file). Things like "default to linear filtering for all Images in this
folder".
* **Replace async_broadcast with event-listener?** This might be
approximately drop-in for some uses and it feels more light weight
* **Support Running the AssetProcessor on the Web**: Most of the hard
work is done here, but there are some easy straggling TODOs (make the
transaction log an interface instead of a direct file writer so we can
write a web storage backend, implement an AssetReader/AssetWriter that
reads/writes to something like LocalStorage).
* **Consider identifying and preventing circular dependencies**: This is
especially important for "processor dependencies", as processing will
silently never finish in these cases.
* **Built-in/Inlined Asset Hot Reloading**: This PR regresses
"built-in/inlined" asset hot reloading (previously provided by the
DebugAssetServer). I'm intentionally punting this because I think it can
be cleanly implemented with "multiple asset sources" by registering a
"debug asset source" (ex: `debug://bevy_pbr/src/render/pbr.wgsl` asset
paths) in combination with an AssetWatcher for that asset source and
support for "manually loading pats with asset bytes instead of
AssetReaders". The old DebugAssetServer was quite nasty and I'd love to
avoid that hackery going forward.
* **Investigate ways to remove double-parsing meta files**: Parsing meta
files currently involves parsing once with "minimal" versions of the
meta file to extract the type name of the loader/processor config, then
parsing again to parse the "full" meta. This is suboptimal. We should be
able to define custom deserializers that (1) assume the loader/processor
type name comes first (2) dynamically looks up the loader/processor
registrations to deserialize settings in-line (similar to components in
the bevy scene format). Another alternative: deserialize as dynamic
Reflect objects and then convert.
* **More runtime loading configuration**: Support using the Handle type
as a hint to select an asset loader (instead of relying on AssetPath
extensions)
* **More high level Processor trait implementations**: For example, it
might be worth adding support for arbitrary chains of "asset transforms"
that modify an in-memory asset representation between loading and
saving. (ex: load a Mesh, run a `subdivide_mesh` transform, followed by
a `flip_normals` transform, then save the mesh to an efficient
compressed format).
* **Bevy Scene Handle Deserialization**: (see the relevant [Draft TODO
item](#draft-todo) for context)
* **Explore High Level Load Interfaces**: See [this
discussion](#discuss-on_loaded-high-level-interface) for one prototype.
* **Asset Streaming**: It would be great if we could stream Assets (ex:
stream a long video file piece by piece)
* **ID Exchanging**: In this PR Asset Handles/AssetIds are bigger than
they need to be because they have a Uuid enum variant. If we implement
an "id exchanging" system that trades Uuids for "efficient runtime ids",
we can cut down on the size of AssetIds, making them more efficient.
This has some open design questions, such as how to spawn entities with
"default" handle values (as these wouldn't have access to the exchange
api in the current system).
* **Asset Path Fixup Tooling**: Assets that inline asset paths inside
them will break when an asset moves. The asset system provides the
functionality to detect when paths break. We should build a framework
that enables formats to define "path migrations". This is especially
important for scene files. For editor-generated files, we should also
consider using UUIDs (see other bullet point) to avoid the need to
migrate in these cases.
---------
Co-authored-by: BeastLe9enD <beastle9end@outlook.de>
Co-authored-by: Mike <mike.hsu@gmail.com>
Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
# Objective
I've been collecting some mistakes in the documentation and fixed them
---------
Co-authored-by: Emi <emanuel.boehm@gmail.com>
Co-authored-by: Nicola Papale <nicopap@users.noreply.github.com>
Fixes https://github.com/bevyengine/bevy/issues/9458.
On case-insensitive filesystems (Windows, Mac, NTFS mounted in Linux,
etc.), a path can be represented in a multiple ways:
- `c:\users\user\rust\assets\hello\world`
- `c:/users/user/rust/assets/hello/world`
- `C:\USERS\USER\rust\assets\hello\world`
If user specifies a path variant that doesn't match asset folder path
bevy calculates, `path.strip_prefix()` will fail, as demonstrated below:
```rs
dbg!(Path::new("c:/foo/bar/baz").strip_prefix("c:/foo"));
// Ok("bar/baz")
dbg!(Path::new("c:/FOO/bar/baz").strip_prefix("c:/foo"));
// StripPrefixError(())
```
This commit rewrites the code in question in a way that prefix stripping
is no longer necessary.
I've tested with the following paths on my computer:
```rs
let res = asset_server.load_folder("C:\\Users\\user\\rust\\assets\\foo\\bar");
dbg!(res);
let res = asset_server.load_folder("c:\\users\\user\\rust\\assets\\foo\\bar");
dbg!(res);
let res = asset_server.load_folder("C:/Users/user/rust/assets/foo/bar");
dbg!(res);
```
# Objective
[Rust 1.72.0](https://blog.rust-lang.org/2023/08/24/Rust-1.72.0.html) is
now stable.
# Notes
- `let-else` formatting has arrived!
- I chose to allow `explicit_iter_loop` due to
https://github.com/rust-lang/rust-clippy/issues/11074.
We didn't hit any of the false positives that prevent compilation, but
fixing this did produce a lot of the "symbol soup" mentioned, e.g. `for
image in &mut *image_events {`.
Happy to undo this if there's consensus the other way.
---------
Co-authored-by: François <mockersf@gmail.com>
