# Objective
Sometimes it's useful to be able to retrieve all the fields of a container type so that they may be processed separately. With reflection, however, we typically only have access to references.
The only alternative is to "clone" the value using `Reflect::clone_value`. This, however, returns a Dynamic type in most cases. The solution there would be to use `FromReflect` instead, but this also has a problem in that it means we need to add `FromReflect` as an additional bound.
## Solution
Add a `drain` method to all container traits. This returns a `Vec<Box<dyn Reflect>>` (except for `Map` which returns `Vec<(Box<dyn Reflect>, Box<dyn Reflect>)>`).
This allows us to do things a lot simpler. For example, if we finished processing a struct and just need a particular value:
```rust
// === OLD === //
/// May or may not return a Dynamic*** value (even if `container` wasn't a `DynamicStruct`)
fn get_output(container: Box<dyn Struct>, output_index: usize) -> Box<dyn Reflect> {
container.field_at(output_index).unwrap().clone_value()
}
// === NEW === //
/// Returns _exactly_ whatever was in the given struct
fn get_output(container: Box<dyn Struct>, output_index: usize) -> Box<dyn Reflect> {
container.drain().remove(output_index).unwrap()
}
```
### Discussion
* Is `drain` the best method name? It makes sense that it "drains" all the fields and that it consumes the container in the process, but I'm open to alternatives.
---
## Changelog
* Added a `drain` method to the following traits:
* `Struct`
* `TupleStruct`
* `Tuple`
* `Array`
* `List`
* `Map`
* `Enum`
# Objective
- The reflection `List` trait does not have a `pop` function.
- Popping elements off a list is a common use case and is almost always supported by `List`-like types.
## Solution
- Add the `pop()` method to the `List` trait and add the appropriate implementations of this function.
## Migration Guide
- Any custom type that implements the `List` trait will now need to implement the `pop` method.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
Fixes#5763
## Solution
Implemented as reflect value like the current `Range`. Is there a benefit to changing everything to a reflect struct?
# Objective
Some of the reflection impls for container types had unnecessary `Clone` bounds on their generic arguments. These come from before `FromReflect` when types were instead bound by `Reflect + Clone`. With `FromReflect` this is no longer necessary.
## Solution
Removed all leftover `Clone` bounds from types that use `FromReflect` instead.
## Note
I skipped `Result<T, E>`, `HashSet<T>`, and `Range<T>` since those do not use `FromReflect`. This should probably be handled in a separate PR since it would be a breaking change.
---
## Changelog
- Remove unnecessary `Clone` bounds on reflected containers
# Objective
#5658 made it so that `FromReflect` was used as the bound for `T` in `Option<T>`. However, it did not use this change effectively for the implementation of `Reflect::apply` (it was still using `take`, which would fail for Dynamic types).
Additionally, the changes were not consistent with other methods within the file, such as the ones for `Vec<T>` and `HashMap<K, V>`.
## Solution
Update `Option<T>` to fallback on `FromReflect` if `take` fails, instead of wholly relying on one or the other.
I also chose to update the error messages, as they weren't all too descriptive before.
---
## Changelog
- Use `FromReflect::from_reflect` as a fallback in the `Reflect::apply` implementation for `Option<T>`
# Objective
`SmallVec<T>` was missing a `GetTypeRegistration` impl.
## Solution
Added a `GetTypeRegistration` impl.
---
## Changelog
* Added a `GetTypeRegistration` impl for `SmallVec<T>`
# Objective
`FromReflect` is a commonly used component to the Reflect API. It's required as a bound for reflecting things like `Vec<T>` and `HashMap<K, V>` and is generally useful (if not necessary) to derive on most structs or enums.
Currently, however, it is not exported in `bevy_reflect`'s prelude. This means a module that uses `bevy_reflect` might have the following two lines:
```rust
use bevy_reflect::prelude::*;
use bevy_reflect::FromReflect;
```
Additionally, users of the full engine might need to put:
```rust
use bevy::prelude::*;
use bevy::reflect::FromReflect;
```
## Solution
Add `FromReflect` to the prelude of `bevy_reflect`.
---
## Changelog
- Added `FromReflect` to the prelude of `bevy_reflect`
# Objective
The reflection impls on `Option<T>` have the bound `T: Reflect + Clone`. This means that using `FromReflect` requires `Clone` even though we can normally get away with just `FromReflect`.
## Solution
Update the bounds on `Option<T>` to match that of `Vec<T>`, where `T: FromReflect`.
This helps remove a `Clone` implementation that may be undesired but added for the sole purpose of getting the code to compile.
---
## Changelog
* Reflection on `Option<T>` now has `T` bound by `FromReflect` rather than `Reflect + Clone`
* Added a `FromReflect` impl for `Instant`
## Migration Guide
If using `Option<T>` with Bevy's reflection API, `T` now needs to implement `FromReflect` rather than just `Clone`. This can be achieved easily by simply deriving `FromReflect`:
```rust
// OLD
#[derive(Reflect, Clone)]
struct Foo;
let reflected: Box<dyn Reflect> = Box::new(Some(Foo));
// NEW
#[derive(Reflect, FromReflect)]
struct Foo;
let reflected: Box<dyn Reflect> = Box::new(Some(Foo));
```
> Note: You can still derive `Clone`, but it's not required in order to compile.
# Objective
- The `Display` impl for `ReflectPathError` is pretty unspecific (e.g. `the current struct doesn't have a field with the given name`
- it has info for better messages available
## Solution
- make the display impl more descriptive by including values from the type
# Objective
Add reflect/from reflect impls for NonZero integer types. I'm guessing these haven't been added yet because no one has needed them as of yet.
# Objective
> This is a revival of #1347. Credit for the original PR should go to @Davier.
Currently, enums are treated as `ReflectRef::Value` types by `bevy_reflect`. Obviously, there needs to be better a better representation for enums using the reflection API.
## Solution
Based on prior work from @Davier, an `Enum` trait has been added as well as the ability to automatically implement it via the `Reflect` derive macro. This allows enums to be expressed dynamically:
```rust
#[derive(Reflect)]
enum Foo {
A,
B(usize),
C { value: f32 },
}
let mut foo = Foo::B(123);
assert_eq!("B", foo.variant_name());
assert_eq!(1, foo.field_len());
let new_value = DynamicEnum::from(Foo::C { value: 1.23 });
foo.apply(&new_value);
assert_eq!(Foo::C{value: 1.23}, foo);
```
### Features
#### Derive Macro
Use the `#[derive(Reflect)]` macro to automatically implement the `Enum` trait for enum definitions. Optionally, you can use `#[reflect(ignore)]` with both variants and variant fields, just like you can with structs. These ignored items will not be considered as part of the reflection and cannot be accessed via reflection.
```rust
#[derive(Reflect)]
enum TestEnum {
A,
// Uncomment to ignore all of `B`
// #[reflect(ignore)]
B(usize),
C {
// Uncomment to ignore only field `foo` of `C`
// #[reflect(ignore)]
foo: f32,
bar: bool,
},
}
```
#### Dynamic Enums
Enums may be created/represented dynamically via the `DynamicEnum` struct. The main purpose of this struct is to allow enums to be deserialized into a partial state and to allow dynamic patching. In order to ensure conversion from a `DynamicEnum` to a concrete enum type goes smoothly, be sure to add `FromReflect` to your derive macro.
```rust
let mut value = TestEnum::A;
// Create from a concrete instance
let dyn_enum = DynamicEnum::from(TestEnum::B(123));
value.apply(&dyn_enum);
assert_eq!(TestEnum::B(123), value);
// Create a purely dynamic instance
let dyn_enum = DynamicEnum::new("TestEnum", "A", ());
value.apply(&dyn_enum);
assert_eq!(TestEnum::A, value);
```
#### Variants
An enum value is always represented as one of its variants— never the enum in its entirety.
```rust
let value = TestEnum::A;
assert_eq!("A", value.variant_name());
// Since we are using the `A` variant, we cannot also be the `B` variant
assert_ne!("B", value.variant_name());
```
All variant types are representable within the `Enum` trait: unit, struct, and tuple.
You can get the current type like:
```rust
match value.variant_type() {
VariantType::Unit => println!("A unit variant!"),
VariantType::Struct => println!("A struct variant!"),
VariantType::Tuple => println!("A tuple variant!"),
}
```
> Notice that they don't contain any values representing the fields. These are purely tags.
If a variant has them, you can access the fields as well:
```rust
let mut value = TestEnum::C {
foo: 1.23,
bar: false
};
// Read/write specific fields
*value.field_mut("bar").unwrap() = true;
// Iterate over the entire collection of fields
for field in value.iter_fields() {
println!("{} = {:?}", field.name(), field.value());
}
```
#### Variant Swapping
It might seem odd to group all variant types under a single trait (why allow `iter_fields` on a unit variant?), but the reason this was done ~~is to easily allow *variant swapping*.~~ As I was recently drafting up the **Design Decisions** section, I discovered that other solutions could have been made to work with variant swapping. So while there are reasons to keep the all-in-one approach, variant swapping is _not_ one of them.
```rust
let mut value: Box<dyn Enum> = Box::new(TestEnum::A);
value.set(Box::new(TestEnum::B(123))).unwrap();
```
#### Serialization
Enums can be serialized and deserialized via reflection without needing to implement `Serialize` or `Deserialize` themselves (which can save thousands of lines of generated code). Below are the ways an enum can be serialized.
> Note, like the rest of reflection-based serialization, the order of the keys in these representations is important!
##### Unit
```json
{
"type": "my_crate::TestEnum",
"enum": {
"variant": "A"
}
}
```
##### Tuple
```json
{
"type": "my_crate::TestEnum",
"enum": {
"variant": "B",
"tuple": [
{
"type": "usize",
"value": 123
}
]
}
}
```
<details>
<summary>Effects on Option</summary>
This ends up making `Option` look a little ugly:
```json
{
"type": "core::option::Option<usize>",
"enum": {
"variant": "Some",
"tuple": [
{
"type": "usize",
"value": 123
}
]
}
}
```
</details>
##### Struct
```json
{
"type": "my_crate::TestEnum",
"enum": {
"variant": "C",
"struct": {
"foo": {
"type": "f32",
"value": 1.23
},
"bar": {
"type": "bool",
"value": false
}
}
}
}
```
## Design Decisions
<details>
<summary><strong>View Section</strong></summary>
This section is here to provide some context for why certain decisions were made for this PR, alternatives that could have been used instead, and what could be improved upon in the future.
### Variant Representation
One of the biggest decisions was to decide on how to represent variants. The current design uses a "all-in-one" design where unit, tuple, and struct variants are all simultaneously represented by the `Enum` trait. This is not the only way it could have been done, though.
#### Alternatives
##### 1. Variant Traits
One way of representing variants would be to define traits for each variant, implementing them whenever an enum featured at least one instance of them. This would allow us to define variants like:
```rust
pub trait Enum: Reflect {
fn variant(&self) -> Variant;
}
pub enum Variant<'a> {
Unit,
Tuple(&'a dyn TupleVariant),
Struct(&'a dyn StructVariant),
}
pub trait TupleVariant {
fn field_len(&self) -> usize;
// ...
}
```
And then do things like:
```rust
fn get_tuple_len(foo: &dyn Enum) -> usize {
match foo.variant() {
Variant::Tuple(tuple) => tuple.field_len(),
_ => panic!("not a tuple variant!")
}
}
```
The reason this PR does not go with this approach is because of the fact that variants are not separate types. In other words, we cannot implement traits on specific variants— these cover the *entire* enum. This means we offer an easy footgun:
```rust
let foo: Option<i32> = None;
let my_enum = Box::new(foo) as Box<dyn TupleVariant>;
```
Here, `my_enum` contains `foo`, which is a unit variant. However, since we need to implement `TupleVariant` for `Option` as a whole, it's possible to perform such a cast. This is obviously wrong, but could easily go unnoticed. So unfortunately, this makes it not a good candidate for representing variants.
##### 2. Variant Structs
To get around the issue of traits necessarily needing to apply to both the enum and its variants, we could instead use structs that are created on a per-variant basis. This was also considered but was ultimately [[removed](71d27ab3c6) due to concerns about allocations.
Each variant struct would probably look something like:
```rust
pub trait Enum: Reflect {
fn variant_mut(&self) -> VariantMut;
}
pub enum VariantMut<'a> {
Unit,
Tuple(TupleVariantMut),
Struct(StructVariantMut),
}
struct StructVariantMut<'a> {
fields: Vec<&'a mut dyn Reflect>,
field_indices: HashMap<Cow<'static, str>, usize>
}
```
This allows us to isolate struct variants into their own defined struct and define methods specifically for their use. It also prevents users from casting to it since it's not a trait. However, this is not an optimal solution. Both `field_indices` and `fields` will require an allocation (remember, a `Box<[T]>` still requires a `Vec<T>` in order to be constructed). This *might* be a problem if called frequently enough.
##### 3. Generated Structs
The original design, implemented by @Davier, instead generates structs specific for each variant. So if we had a variant path like `Foo::Bar`, we'd generate a struct named `FooBarWrapper`. This would be newtyped around the original enum and forward tuple or struct methods to the enum with the chosen variant.
Because it involved using the `Tuple` and `Struct` traits (which are also both bound on `Reflect`), this meant a bit more code had to be generated. For a single struct variant with one field, the generated code amounted to ~110LoC. However, each new field added to that variant only added ~6 more LoC.
In order to work properly, the enum had to be transmuted to the generated struct:
```rust
fn variant(&self) -> crate::EnumVariant<'_> {
match self {
Foo::Bar {value: i32} => {
let wrapper_ref = unsafe {
std::mem::transmute::<&Self, &FooBarWrapper>(self)
};
crate::EnumVariant::Struct(wrapper_ref as &dyn crate::Struct)
}
}
}
```
This works because `FooBarWrapper` is defined as `repr(transparent)`.
Out of all the alternatives, this would probably be the one most likely to be used again in the future. The reasons for why this PR did not continue to use it was because:
* To reduce generated code (which would hopefully speed up compile times)
* To avoid cluttering the code with generated structs not visible to the user
* To keep bevy_reflect simple and extensible (these generated structs act as proxies and might not play well with current or future systems)
* To avoid additional unsafe blocks
* My own misunderstanding of @Davier's code
That last point is obviously on me. I misjudged the code to be too unsafe and unable to handle variant swapping (which it probably could) when I was rebasing it. Looking over it again when writing up this whole section, I see that it was actually a pretty clever way of handling variant representation.
#### Benefits of All-in-One
As stated before, the current implementation uses an all-in-one approach. All variants are capable of containing fields as far as `Enum` is concerned. This provides a few benefits that the alternatives do not (reduced indirection, safer code, etc.).
The biggest benefit, though, is direct field access. Rather than forcing users to have to go through pattern matching, we grant direct access to the fields contained by the current variant. The reason we can do this is because all of the pattern matching happens internally. Getting the field at index `2` will automatically return `Some(...)` for the current variant if it has a field at that index or `None` if it doesn't (or can't).
This could be useful for scenarios where the variant has already been verified or just set/swapped (or even where the type of variant doesn't matter):
```rust
let dyn_enum: &mut dyn Enum = &mut Foo::Bar {value: 123};
// We know it's the `Bar` variant
let field = dyn_enum.field("value").unwrap();
```
Reflection is not a type-safe abstraction— almost every return value is wrapped in `Option<...>`. There are plenty of places to check and recheck that a value is what Reflect says it is. Forcing users to have to go through `match` each time they want to access a field might just be an extra step among dozens of other verification processes.
Some might disagree, but ultimately, my view is that the benefit here is an improvement to the ergonomics and usability of reflected enums.
</details>
---
## Changelog
### Added
* Added `Enum` trait
* Added `Enum` impl to `Reflect` derive macro
* Added `DynamicEnum` struct
* Added `DynamicVariant`
* Added `EnumInfo`
* Added `VariantInfo`
* Added `StructVariantInfo`
* Added `TupleVariantInfo`
* Added `UnitVariantInfo`
* Added serializtion/deserialization support for enums
* Added `EnumSerializer`
* Added `VariantType`
* Added `VariantFieldIter`
* Added `VariantField`
* Added `enum_partial_eq(...)`
* Added `enum_hash(...)`
### Changed
* `Option<T>` now implements `Enum`
* `bevy_window` now depends on `bevy_reflect`
* Implemented `Reflect` and `FromReflect` for `WindowId`
* Derive `FromReflect` on `PerspectiveProjection`
* Derive `FromReflect` on `OrthographicProjection`
* Derive `FromReflect` on `WindowOrigin`
* Derive `FromReflect` on `ScalingMode`
* Derive `FromReflect` on `DepthCalculation`
## Migration Guide
* Enums no longer need to be treated as values and usages of `#[reflect_value(...)]` can be removed or replaced by `#[reflect(...)]`
* Enums (including `Option<T>`) now take a different format when serializing. The format is described above, but this may cause issues for existing scenes that make use of enums.
---
Also shout out to @nicopap for helping clean up some of the code here! It's a big feature so help like this is really appreciated!
Co-authored-by: Gino Valente <gino.valente.code@gmail.com>
# Objective
Some generic types like `Option<T>`, `Vec<T>` and `HashMap<K, V>` implement `Reflect` when where their generic types `T`/`K`/`V` implement `Serialize + for<'de> Deserialize<'de>`.
This is so that in their `GetTypeRegistration` impl they can insert the `ReflectSerialize` and `ReflectDeserialize` type data structs.
This has the annoying side effect that if your struct contains a `Option<NonSerdeStruct>` you won't be able to derive reflect (https://github.com/bevyengine/bevy/issues/4054).
## Solution
- remove the `Serialize + Deserialize` bounds on wrapper types
- this means that `ReflectSerialize` and `ReflectDeserialize` will no longer be inserted even for `.register::<Option<DoesImplSerde>>()`
- add `register_type_data<T, D>` shorthand for `registry.get_mut(T).insert(D::from_type<T>())`
- require users to register their specific generic types **and the serde types** separately like
```rust
.register_type::<Option<String>>()
.register_type_data::<Option<String>, ReflectSerialize>()
.register_type_data::<Option<String>, ReflectDeserialize>()
```
I believe this is the best we can do for extensibility and convenience without specialization.
## Changelog
- `.register_type` for generic types like `Option<T>`, `Vec<T>`, `HashMap<K, V>` will no longer insert `ReflectSerialize` and `ReflectDeserialize` type data. Instead you need to register it separately for concrete generic types like so:
```rust
.register_type::<Option<String>>()
.register_type_data::<Option<String>, ReflectSerialize>()
.register_type_data::<Option<String>, ReflectDeserialize>()
```
TODO: more docs and tweaks to the scene example to demonstrate registering generic types.
# Objective
https://github.com/bevyengine/bevy/pull/4447 adds functions that can fetch resources/components as `*const ()` ptr by providing the `ComponentId`. This alone is not enough for them to be usable safely with reflection, because there is no general way to go from the raw pointer to a `&dyn Reflect` which is the pointer + a pointer to the VTable of the `Reflect` impl.
By adding a `ReflectFromPtr` type that is included in the type type registration when deriving `Reflect`, safe functions can be implemented in scripting languages that don't assume a type layout and can access the component data via reflection:
```rust
#[derive(Reflect)]
struct StringResource {
value: String
}
```
```lua
local res_id = world:resource_id_by_name("example::StringResource")
local res = world:resource(res_id)
print(res.value)
```
## Solution
1. add a `ReflectFromPtr` type with a `FromType<T: Reflect>` implementation and the following methods:
- ` pub unsafe fn as_reflect_ptr<'a>(&self, val: Ptr<'a>) -> &'a dyn Reflect`
- ` pub unsafe fn as_reflect_ptr_mut<'a>(&self, val: PtrMut<'a>) -> &'a mud dyn Reflect`
Safety requirements of the methods are that you need to check that the `ReflectFromPtr` was constructed for the correct type.
2. add that type to the `TypeRegistration` in the `GetTypeRegistration` impl generated by `#[derive(Reflect)]`.
This is different to other reflected traits because it doesn't need `#[reflect(ReflectReflectFromPtr)]` which IMO should be there by default.
Co-authored-by: Jakob Hellermann <hellermann@sipgate.de>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
Remove unnecessary calls to `iter()`/`iter_mut()`.
Mainly updates the use of queries in our code, docs, and examples.
```rust
// From
for _ in list.iter() {
for _ in list.iter_mut() {
// To
for _ in &list {
for _ in &mut list {
```
We already enable the pedantic lint [clippy::explicit_iter_loop](https://rust-lang.github.io/rust-clippy/stable/) inside of Bevy. However, this only warns for a few known types from the standard library.
## Note for reviewers
As you can see the additions and deletions are exactly equal.
Maybe give it a quick skim to check I didn't sneak in a crypto miner, but you don't have to torture yourself by reading every line.
I already experienced enough pain making this PR :)
Co-authored-by: devil-ira <justthecooldude@gmail.com>
# Objective
- To implement `Reflect` for more glam types.
## Solution
insert `impl_reflect_struct` invocations for more glam types. I am not sure about the boolean vectors, since none of them implement `Serde::Serialize/Deserialize`, and the SIMD versions don't have public fields.
I do still think implementing reflection is useful for BVec's since then they can be incorporated into `Reflect`'ed components and set dynamically even if as a whole + it's more consistent.
## Changelog
Implemented `Reflect` for the following types
- BVec2
- BVec3
- **BVec3A** (on simd supported platforms only)
- BVec4
- **BVec4A** (on simd supported platforms only)
- Mat2
- Mat3A
- DMat2
- Affine2
- Affine3A
- DAffine2
- DAffine3
- EulerRot
# Objective
`glam` is an optional feature in `bevy_reflect` and there is a separate `mod test { #[cfg(feature = "glam")] mod glam { .. }}`.
The `reflect_downcast` test is not in that module and doesn't depend on glam, which breaks `cargo test -p bevy_reflect` without the `glam` feature.
## Solution
- Remove the glam types from the test, they're not relevant to it
# Objective
This is a rebase of #3701 which is currently scheduled for 0.8 but is marked for adoption.
> Fixes https://github.com/bevyengine/bevy/discussions/3609
## Solution
> - add an `insert_boxed()` method on the `Map` trait
> - implement it for `HashMap` using a new `FromReflect` generic bound
> - add a `map_apply()` helper method to implement `Map::apply()`, that inserts new values instead of ignoring them
---
## Changelog
TODO
Co-authored-by: james7132 <contact@jamessliu.com>
Removed `const_vec2`/`const_vec3`
and replaced with equivalent `.from_array`.
# Objective
Fixes#5112
## Solution
- `encase` needs to update to `glam` as well. See teoxoy/encase#4 on progress on that.
- `hexasphere` also needs to be updated, see OptimisticPeach/hexasphere#12.
# Summary
This method strips a long type name like `bevy::render:📷:PerspectiveCameraBundle` down into the bare type name (`PerspectiveCameraBundle`). This is generally useful utility method, needed by #4299 and #5121.
As a result:
- This method was moved to `bevy_utils` for easier reuse.
- The legibility and robustness of this method has been significantly improved.
- Harder test cases have been added.
This change was split out of #4299 to unblock it and make merging / reviewing the rest of those changes easier.
## Changelog
- added `bevy_utils::get_short_name`, which strips the path from a type name for convenient display.
- removed the `TypeRegistry::get_short_name` method. Use the function in `bevy_utils` instead.
# Objective
Fixes#5153
## Solution
Search for all enums and manually check if they have default impls that can use this new derive.
By my reckoning:
| enum | num |
|-|-|
| total | 159 |
| has default impl | 29 |
| default is unit variant | 23 |
# Objective
Fix some typos in bevy_reflect's readme
## Solution
- Change `Foo`'s `d` field to be of type `Vec<Baz>`
- Format `&dyn Reflect` to be monospace
# Objective
Currently, `Reflect` is unsafe to implement because of a contract in which `any` and `any_mut` must return `self`, or `downcast` will cause UB. This PR makes `Reflect` safe, makes `downcast` not use unsafe, and eliminates this contract.
## Solution
This PR adds a method to `Reflect`, `any`. It also renames the old `any` to `as_any`.
`any` now takes a `Box<Self>` and returns a `Box<dyn Any>`.
---
## Changelog
### Added:
- `any()` method
- `represents()` method
### Changed:
- `Reflect` is now a safe trait
- `downcast()` is now safe
- The old `any` is now called `as_any`, and `any_mut` is now `as_mut_any`
## Migration Guide
- Reflect derives should not have to change anything
- Manual reflect impls will need to remove the `unsafe` keyword, add `any()` implementations, and rename the old `any` and `any_mut` to `as_any` and `as_mut_any`.
- Calls to `any`/`any_mut` must be changed to `as_any`/`as_mut_any`
## Points of discussion:
- Should renaming `any` be avoided and instead name the new method `any_box`?
- ~~Could there be a performance regression from avoiding the unsafe? I doubt it, but this change does seem to introduce redundant checks.~~
- ~~Could/should `is` and `type_id()` be implemented differently? For example, moving `is` onto `Reflect` as an `fn(&self, TypeId) -> bool`~~
Co-authored-by: PROMETHIA-27 <42193387+PROMETHIA-27@users.noreply.github.com>
builds on top of #4780
# Objective
`Reflect` and `Serialize` are currently very tied together because `Reflect` has a `fn serialize(&self) -> Option<Serializable<'_>>` method. Because of that, we can either implement `Reflect` for types like `Option<T>` with `T: Serialize` and have `fn serialize` be implemented, or without the bound but having `fn serialize` return `None`.
By separating `ReflectSerialize` into a separate type (like how it already is for `ReflectDeserialize`, `ReflectDefault`), we could separately `.register::<Option<T>>()` and `.register_data::<Option<T>, ReflectSerialize>()` only if the type `T: Serialize`.
This PR does not change the registration but allows it to be changed in a future PR.
## Solution
- add the type
```rust
struct ReflectSerialize { .. }
impl<T: Reflect + Serialize> FromType<T> for ReflectSerialize { .. }
```
- remove `#[reflect(Serialize)]` special casing.
- when serializing reflect value types, look for `ReflectSerialize` in the `TypeRegistry` instead of calling `value.serialize()`
# Objective
- Update hashbrown to 0.12
## Solution
- Replace #4004
- As the 0.12 is already in Bevy dependency tree, it shouldn't be an issue to update
- The exception for the 0.11 should be removed once https://github.com/zakarumych/gpu-descriptor/pull/21 is merged and released
- Also removed a few exceptions that weren't needed anymore
# Objective
> Resolves#4504
It can be helpful to have access to type information without requiring an instance of that type. Especially for `Reflect`, a lot of the gathered type information is known at compile-time and should not necessarily require an instance.
## Solution
Created a dedicated `TypeInfo` enum to store static type information. All types that derive `Reflect` now also implement the newly created `Typed` trait:
```rust
pub trait Typed: Reflect {
fn type_info() -> &'static TypeInfo;
}
```
> Note: This trait was made separate from `Reflect` due to `Sized` restrictions.
If you only have access to a `dyn Reflect`, just call `.get_type_info()` on it. This new trait method on `Reflect` should return the same value as if you had called it statically.
If all you have is a `TypeId` or type name, you can get the `TypeInfo` directly from the registry using the `TypeRegistry::get_type_info` method (assuming it was registered).
### Usage
Below is an example of working with `TypeInfo`. As you can see, we don't have to generate an instance of `MyTupleStruct` in order to get this information.
```rust
#[derive(Reflect)]
struct MyTupleStruct(usize, i32, MyStruct);
let info = MyTupleStruct::type_info();
if let TypeInfo::TupleStruct(info) = info {
assert!(info.is::<MyTupleStruct>());
assert_eq!(std::any::type_name::<MyTupleStruct>(), info.type_name());
assert!(info.field_at(1).unwrap().is::<i32>());
} else {
panic!("Expected `TypeInfo::TupleStruct`");
}
```
### Manual Implementations
It's not recommended to manually implement `Typed` yourself, but if you must, you can use the `TypeInfoCell` to automatically create and manage the static `TypeInfo`s for you (which is very helpful for blanket/generic impls):
```rust
use bevy_reflect::{Reflect, TupleStructInfo, TypeInfo, UnnamedField};
use bevy_reflect::utility::TypeInfoCell;
struct Foo<T: Reflect>(T);
impl<T: Reflect> Typed for Foo<T> {
fn type_info() -> &'static TypeInfo {
static CELL: TypeInfoCell = TypeInfoCell::generic();
CELL.get_or_insert::<Self, _>(|| {
let fields = [UnnamedField:🆕:<T>()];
let info = TupleStructInfo:🆕:<Self>(&fields);
TypeInfo::TupleStruct(info)
})
}
}
```
## Benefits
One major benefit is that this opens the door to other serialization methods. Since we can get all the type info at compile time, we can know how to properly deserialize something like:
```rust
#[derive(Reflect)]
struct MyType {
foo: usize,
bar: Vec<String>
}
// RON to be deserialized:
(
type: "my_crate::MyType", // <- We now know how to deserialize the rest of this object
value: {
// "foo" is a value type matching "usize"
"foo": 123,
// "bar" is a list type matching "Vec<String>" with item type "String"
"bar": ["a", "b", "c"]
}
)
```
Not only is this more compact, but it has better compatibility (we can change the type of `"foo"` to `i32` without having to update our serialized data).
Of course, serialization/deserialization strategies like this may need to be discussed and fully considered before possibly making a change. However, we will be better equipped to do that now that we can access type information right from the registry.
## Discussion
Some items to discuss:
1. Duplication. There's a bit of overlap with the existing traits/structs since they require an instance of the type while the type info structs do not (for example, `Struct::field_at(&self, index: usize)` and `StructInfo::field_at(&self, index: usize)`, though only `StructInfo` is accessible without an instance object). Is this okay, or do we want to handle it in another way?
2. Should `TypeInfo::Dynamic` be removed? Since the dynamic types don't have type information available at runtime, we could consider them `TypeInfo::Value`s (or just even just `TypeInfo::Struct`). The intention with `TypeInfo::Dynamic` was to keep the distinction from these dynamic types and actual structs/values since users might incorrectly believe the methods of the dynamic type's info struct would map to some contained data (which isn't possible statically).
4. General usefulness of this change, including missing/unnecessary parts.
5. Possible changes to the scene format? (One possible issue with changing it like in the example above might be that we'd have to be careful when handling generic or trait object types.)
## Compile Tests
I ran a few tests to compare compile times (as suggested [here](https://github.com/bevyengine/bevy/pull/4042#discussion_r876408143)). I toggled `Reflect` and `FromReflect` derive macros using `cfg_attr` for both this PR (aa5178e773) and main (c309acd432).
<details>
<summary>See More</summary>
The test project included 250 of the following structs (as well as a few other structs):
```rust
#[derive(Default)]
#[cfg_attr(feature = "reflect", derive(Reflect))]
#[cfg_attr(feature = "from_reflect", derive(FromReflect))]
pub struct Big001 {
inventory: Inventory,
foo: usize,
bar: String,
baz: ItemDescriptor,
items: [Item; 20],
hello: Option<String>,
world: HashMap<i32, String>,
okay: (isize, usize, /* wesize */),
nope: ((String, String), (f32, f32)),
blah: Cow<'static, str>,
}
```
> I don't know if the compiler can optimize all these duplicate structs away, but I think it's fine either way. We're comparing times, not finding the absolute worst-case time.
I only ran each build 3 times using `cargo build --timings` (thank you @devil-ira), each of which were preceeded by a `cargo clean --package bevy_reflect_compile_test`.
Here are the times I got:
| Test | Test 1 | Test 2 | Test 3 | Average |
| -------------------------------- | ------ | ------ | ------ | ------- |
| Main | 1.7s | 3.1s | 1.9s | 2.33s |
| Main + `Reflect` | 8.3s | 8.6s | 8.1s | 8.33s |
| Main + `Reflect` + `FromReflect` | 11.6s | 11.8s | 13.8s | 12.4s |
| PR | 3.5s | 1.8s | 1.9s | 2.4s |
| PR + `Reflect` | 9.2s | 8.8s | 9.3s | 9.1s |
| PR + `Reflect` + `FromReflect` | 12.9s | 12.3s | 12.5s | 12.56s |
</details>
---
## Future Work
Even though everything could probably be made `const`, we unfortunately can't. This is because `TypeId::of::<T>()` is not yet `const` (see https://github.com/rust-lang/rust/issues/77125). When it does get stabilized, it would probably be worth coming back and making things `const`.
Co-authored-by: MrGVSV <49806985+MrGVSV@users.noreply.github.com>
# Objective
Most of our `Iterator` impls satisfy the requirements of `std::iter::FusedIterator`, which has internal specialization that optimizes `Interator::fuse`. The std lib iterator combinators do have a few that rely on `fuse`, so this could optimize those use cases. I don't think we're using any of them in the engine itself, but beyond a light increase in compile time, it doesn't hurt to implement the trait.
## Solution
Implement the trait for all eligible iterators in first party crates. Also add a missing `ExactSizeIterator` on an iterator that could use it.
# Objective
- Users of bevy_reflect probably always want primitive types registered.
## Solution
- Register them by default.
---
This is a minor incremental change along the path of [removing catch-all functionality from bevy_core](https://github.com/bevyengine/bevy/issues/2931).
# Objective
`bevy_reflect` as different kinds of reflected types (each with their own trait), `trait Struct: Reflect`, `trait List: Reflect`, `trait Map: Reflect`, ...
Types that don't fit either of those are called reflect value types, they are opaque and can't be deconstructed further.
`bevy_reflect` can serialize `dyn Reflect` values. Any container types (struct, list, map) get deconstructed and their elements serialized separately, which can all happen without serde being involved ever (happens [here](https://github.com/bevyengine/bevy/blob/main/crates/bevy_reflect/src/serde/ser.rs#L50-L85=)).
The only point at which we require types to be serde-serializable is for *value types* (happens [here](https://github.com/bevyengine/bevy/blob/main/crates/bevy_reflect/src/serde/ser.rs#L104=)).
So reflect array serializing is solved, since arrays are container types which don't require serde.
#1213 also introduced added the `serialize` method and `Serialize` impls for `dyn Array` and `DynamicArray` which use their element's `Reflect::serializable` function. This is 1. unnecessary, because it is not used for array serialization, and 2. annoying for removing the `Serialize` bound on container types, because these impls don't have access to the `TypeRegistry`, so we can't move the serialization code there.
# Solution
Remove these impls and `fn serialize`. It's not used and annoying for other changes.
# Objective
Currently, `FromReflect` makes a couple assumptions:
* Ignored fields must implement `Default`
* Active fields must implement `FromReflect`
* The reflected must be fully populated for active fields (can't use an empty `DynamicStruct`)
However, one or both of these requirements might be unachievable, such as for external types. In these cases, it might be nice to tell `FromReflect` to use a custom default.
## Solution
Added the `#[reflect(default)]` derive helper attribute. This attribute can be applied to any field (ignored or not) and will allow a default value to be specified in place of the regular `from_reflect()` call.
It takes two forms: `#[reflect(default)]` and `#[reflect(default = "some_func")]`. The former specifies that `Default::default()` should be used while the latter specifies that `some_func()` should be used. This is pretty much [how serde does it](https://serde.rs/field-attrs.html#default).
### Example
```rust
#[derive(Reflect, FromReflect)]
struct MyStruct {
// Use `Default::default()`
#[reflect(default)]
foo: String,
// Use `get_bar_default()`
#[reflect(default = "get_bar_default")]
#[reflect(ignore)]
bar: usize,
}
fn get_bar_default() -> usize {
123
}
```
### Active Fields
As an added benefit, this also allows active fields to be completely missing from their dynamic object. This is because the attribute tells `FromReflect` how to handle missing active fields (it still tries to use `from_reflect` first so the `FromReflect` trait is still required).
```rust
let dyn_struct = DynamicStruct::default();
// We can do this without actually including the active fields since they have `#[reflect(default)]`
let my_struct = <MyStruct as FromReflect>::from_reflect(&dyn_struct);
```
### Container Defaults
Also, with the addition of #3733, people will likely start adding `#[reflect(Default)]` to their types now. Just like with the fields, we can use this to mark the entire container as "defaultable". This grants us the ability to completely remove the field markers altogether if our type implements `Default` (and we're okay with fields using that instead of their own `Default` impls):
```rust
#[derive(Reflect, FromReflect)]
#[reflect(Default)]
struct MyStruct {
foo: String,
#[reflect(ignore)]
bar: usize,
}
impl Default for MyStruct {
fn default() -> Self {
Self {
foo: String::from("Hello"),
bar: 123,
}
}
}
// Again, we can now construct this from nothing pretty much
let dyn_struct = DynamicStruct::default();
let my_struct = <MyStruct as FromReflect>::from_reflect(&dyn_struct);
```
Now if _any_ field is missing when using `FromReflect`, we simply fallback onto the container's `Default` implementation.
This behavior can be completely overridden on a per-field basis, of course, by simply defining those same field attributes like before.
### Related
* #3733
* #1395
* #2377
---
## Changelog
* Added `#[reflect(default)]` field attribute for `FromReflect`
* Allows missing fields to be given a default value when using `FromReflect`
* `#[reflect(default)]` - Use the field's `Default` implementation
* `#[reflect(default = "some_fn")]` - Use a custom function to get the default value
* Allow `#[reflect(Default)]` to have a secondary usage as a container attribute
* Allows missing fields to be given a default value based on the container's `Default` impl when using `FromReflect`
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
Fixes#4353. Fixes#4431. Picks up fixes for a panic for `gilrs` when `getGamepads()` is not available.
## Solution
Update the `gilrs` to `v0.9.0`. Changelog can be seen here: dba36f9186
EDIT: Updated `uuid` to 1.1 to avoid duplicate dependencies. Added `nix`'s two dependencies as exceptions until `rodio` updates their deps.
# Objective
Debugging reflected types can be somewhat frustrating since all `dyn Reflect` trait objects return something like `Reflect(core::option::Option<alloc::string::String>)`.
It would be much nicer to be able to see the actual value— or even use a custom `Debug` implementation.
## Solution
Added `Reflect::debug` which allows users to customize the debug output. It sets defaults for all `ReflectRef` subtraits and falls back to `Reflect(type_name)` if no `Debug` implementation was registered.
To register a custom `Debug` impl, users can add `#[reflect(Debug)]` like they can with other traits.
### Example
Using the following structs:
```rust
#[derive(Reflect)]
pub struct Foo {
a: usize,
nested: Bar,
#[reflect(ignore)]
_ignored: NonReflectedValue,
}
#[derive(Reflect)]
pub struct Bar {
value: Vec2,
tuple_value: (i32, String),
list_value: Vec<usize>,
// We can't determine debug formatting for Option<T> yet
unknown_value: Option<String>,
custom_debug: CustomDebug
}
#[derive(Reflect)]
#[reflect(Debug)]
struct CustomDebug;
impl Debug for CustomDebug {
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
write!(f, "This is a custom debug!")
}
}
pub struct NonReflectedValue {
_a: usize,
}
```
We can do:
```rust
let value = Foo {
a: 1,
_ignored: NonReflectedValue { _a: 10 },
nested: Bar {
value: Vec2::new(1.23, 3.21),
tuple_value: (123, String::from("Hello")),
list_value: vec![1, 2, 3],
unknown_value: Some(String::from("World")),
custom_debug: CustomDebug
},
};
let reflected_value: &dyn Reflect = &value;
println!("{:#?}", reflected_value)
```
Which results in:
```rust
Foo {
a: 2,
nested: Bar {
value: Vec2(
1.23,
3.21,
),
tuple_value: (
123,
"Hello",
),
list_value: [
1,
2,
3,
],
unknown_value: Reflect(core::option::Option<alloc::string::String>),
custom_debug: This is a custom debug!,
},
}
```
Notice that neither `Foo` nor `Bar` implement `Debug`, yet we can still deduce it. This might be a concern if we're worried about leaking internal values. If it is, we might want to consider a way to exclude fields (possibly with a `#[reflect(hide)]` macro) or make it purely opt in (as opposed to the default implementation automatically handled by ReflectRef subtraits).
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>
# Objective
Allow `Box<dyn Reflect>` to be converted into a `Box<dyn MyTrait>` using the `#[reflect_trait]` macro. The other methods `get` and `get_mut` only provide a reference to the reflected object.
## Solution
Add a `get_boxed` method to the `Reflect***` struct generated by the `#[reflect_trait]` macro. This method takes in a `Box<dyn Reflect>` and returns a `Box<dyn MyTrait>`.
Co-authored-by: MrGVSV <49806985+MrGVSV@users.noreply.github.com>
# Objective
Quick followup to #4712.
While updating some [other PRs](https://github.com/bevyengine/bevy/pull/4218), I realized the `ReflectTraits` struct could be improved. The issue with the current implementation is that `ReflectTraits::get_xxx_impl(...)` returns just the _logic_ to the corresponding `Reflect` trait method, rather than the entire function.
This makes it slightly more annoying to manage since the variable names need to be consistent across files. For example, `get_partial_eq_impl` uses a `value` variable. But the name "value" isn't defined in the `get_partial_eq_impl` method, it's defined in three other methods in a completely separate file.
It's not likely to cause any bugs if we keep it as it is since differing variable names will probably just result in a compile error (except in very particular cases). But it would be useful to someone who wanted to edit/add/remove a method.
## Solution
Made `get_hash_impl`, `get_partial_eq_impl` and `get_serialize_impl` return the entire method implementation for `reflect_hash`, `reflect_partial_eq`, and `serializable`, respectively.
As a result of this, those three `Reflect` methods were also given default implementations. This was fairly simple to do since all three could just be made to return `None`.
---
## Changelog
* Small cleanup/refactor to `ReflectTraits` in `bevy_reflect_derive`
* Gave `Reflect::reflect_hash`, `Reflect::reflect_partial_eq`, and `Reflect::serializable` default implementations
# Objective
> ℹ️ **Note**: This is a rebased version of #2383. A large portion of it has not been touched (only a few minor changes) so that any additional discussion may happen here. All credit should go to @NathanSWard for their work on the original PR.
- Currently reflection is not supported for arrays.
- Fixes#1213
## Solution
* Implement reflection for arrays via the `Array` trait.
* Note, `Array` is different from `List` in the way that you cannot push elements onto an array as they are statically sized.
* Now `List` is defined as a sub-trait of `Array`.
---
## Changelog
* Added the `Array` reflection trait
* Allows arrays up to length 32 to be reflected via the `Array` trait
## Migration Guide
* The `List` trait now has the `Array` supertrait. This means that `clone_dynamic` will need to specify which version to use:
```rust
// Before
let cloned = my_list.clone_dynamic();
// After
let cloned = List::clone_dynamic(&my_list);
```
* All implementers of `List` will now need to implement `Array` (this mostly involves moving the existing methods to the `Array` impl)
Co-authored-by: NathanW <nathansward@comcast.net>
Co-authored-by: MrGVSV <49806985+MrGVSV@users.noreply.github.com>
# Objective
The `bevy_reflect_derive` crate is not the cleanest or easiest to follow/maintain. The `lib.rs` file is especially difficult with over 1000 lines of code written in a confusing order. This is just a result of growth within the crate and it would be nice to clean it up for future work.
## Solution
Split `bevy_reflect_derive` into many more submodules. The submodules include:
* `container_attributes` - Code relating to container attributes
* `derive_data` - Code relating to reflection-based derive metadata
* `field_attributes` - Code relating to field attributes
* `impls` - Code containing actual reflection implementations
* `reflect_value` - Code relating to reflection-based value metadata
* `registration` - Code relating to type registration
* `utility` - General-purpose utility functions
This leaves the `lib.rs` file to contain only the public macros, making it much easier to digest (and fewer than 200 lines).
By breaking up the code into smaller modules, we make it easier for future contributors to find the code they're looking for or identify which module best fits their own additions.
### Metadata Structs
This cleanup also adds two big metadata structs: `ReflectFieldAttr` and `ReflectDeriveData`. The former is used to store all attributes for a struct field (if any). The latter is used to store all metadata for struct-based derive inputs.
Both significantly reduce code duplication and make editing these macros much simpler. The tradeoff is that we may collect more metadata than needed. However, this is usually a small thing (such as checking for attributes when they're not really needed or creating a `ReflectFieldAttr` for every field regardless of whether they actually have an attribute).
We could try to remove these tradeoffs and squeeze some more performance out, but doing so might come at the cost of developer experience. Personally, I think it's much nicer to create a `ReflectFieldAttr` for every field since it means I don't have to do two `Option` checks. Others may disagree, though, and so we can discuss changing this either in this PR or in a future one.
### Out of Scope
_Some_ documentation has been added or improved, but ultimately good docs are probably best saved for a dedicated PR.
## 🔍 Focus Points (for reviewers)
I know it's a lot to sift through, so here is a list of **key points for reviewers**:
- The following files contain code that was mostly just relocated:
- `reflect_value.rs`
- `registration.rs`
- `container_attributes.rs` was also mostly moved but features some general cleanup (reducing nesting, removing hardcoded strings, etc.) and lots of doc comments
- Most impl logic was moved from `lib.rs` to `impls.rs`, but they have been significantly modified to use the new `ReflectDeriveData` metadata struct in order to reduce duplication.
- `derive_data.rs` and `field_attributes.rs` contain almost entirely new code and should probably be given the most attention.
- Likewise, `from_reflect.rs` saw major changes using `ReflectDeriveData` so it should also be given focus.
- There was no change to the `lib.rs` exports so the end-user API should be the same.
## Prior Work
This task was initially tackled by @NathanSWard in #2377 (which was closed in favor of this PR), so hats off to them for beating me to the punch by nearly a year!
---
## Changelog
* **[INTERNAL]** Split `bevy_reflect_derive` into smaller submodules
* **[INTERNAL]** Add `ReflectFieldAttr`
* **[INTERNAL]** Add `ReflectDeriveData`
* Add `BevyManifest::get_path_direct()` method (`bevy_macro_utils`)
Co-authored-by: MrGVSV <49806985+MrGVSV@users.noreply.github.com>
# Objective
Relevant issue: #4474
Currently glam types implement Reflect as a value, which is problematic for reflection, making scripting/editor work much more difficult. This PR re-implements them as structs.
## Solution
Added a new proc macro, `impl_reflect_struct`, which replaces `impl_reflect_value` and `impl_from_reflect_value` for glam types. This macro could also be used for other types, but I don't know of any that would require it. It's specifically useful for foreign types that cannot derive Reflect normally.
---
## Changelog
### Added
- `impl_reflect_struct` proc macro
### Changed
- Glam reflect impls have been replaced with `impl_reflect_struct`
- from_reflect's `impl_struct` altered to take an optional custom constructor, allowing non-default non-constructible foreign types to use it
- Calls to `impl_struct` altered to conform to new signature
- Altered glam types (All vec/mat combinations) have a different serialization structure, as they are reflected differently now.
## Migration Guide
This will break altered glam types serialized to RON scenes, as they will expect to be serialized/deserialized as structs rather than values now. A future PR to add custom serialization for non-value types is likely on the way to restore previous behavior. Additionally, calls to `impl_struct` must add a `None` parameter to the end of the call to restore previous behavior.
Co-authored-by: PROMETHIA-27 <42193387+PROMETHIA-27@users.noreply.github.com>
# Objective
It is possible to get a mutable reference to a `TypeRegistration` using
`TypeRegistry::get_mut`. However, none of its other methods
(`get_mut_with_name`, `get_type_data`, `iter`, etc.) have mutable
versions.
Besides improving consistency, this change would facilitate use cases
which involve storing mutable state data in the `TypeRegistry`.
## Solution
Provides a trivial wrapper around the mutable accessors that the
`TypeRegistration` already provides. Exactly mirrors the existing
immutable versions.
### Problem
It currently isn't possible to construct the default value of a reflected type. Because of that, it isn't possible to use `add_component` of `ReflectComponent` to add a new component to an entity because you can't know what the initial value should be.
### Solution
1. add `ReflectDefault` type
```rust
#[derive(Clone)]
pub struct ReflectDefault {
default: fn() -> Box<dyn Reflect>,
}
impl ReflectDefault {
pub fn default(&self) -> Box<dyn Reflect> {
(self.default)()
}
}
impl<T: Reflect + Default> FromType<T> for ReflectDefault {
fn from_type() -> Self {
ReflectDefault {
default: || Box::new(T::default()),
}
}
}
```
2. add `#[reflect(Default)]` to all component types that implement `Default` and are user facing (so not `ComputedSize`, `CubemapVisibleEntities` etc.)
This makes it possible to add the default value of a component to an entity without any compile-time information:
```rust
fn main() {
let mut app = App::new();
app.register_type::<Camera>();
let type_registry = app.world.get_resource::<TypeRegistry>().unwrap();
let type_registry = type_registry.read();
let camera_registration = type_registry.get(std::any::TypeId::of::<Camera>()).unwrap();
let reflect_default = camera_registration.data::<ReflectDefault>().unwrap();
let reflect_component = camera_registration
.data::<ReflectComponent>()
.unwrap()
.clone();
let default = reflect_default.default();
drop(type_registry);
let entity = app.world.spawn().id();
reflect_component.add_component(&mut app.world, entity, &*default);
let camera = app.world.entity(entity).get::<Camera>().unwrap();
dbg!(&camera);
}
```
### Open questions
- should we have `ReflectDefault` or `ReflectFromWorld` or both?
# Objective
Reflected tuples do not implement `GetTypeRegistration`, preventing us from registering our tuples, like:
```rust
app.register_type::<(i32, i32)>();
```
This is especially important for things like using #4042 to improve the scene format or implementing #4154 to recursively register fields.
## Solution
Added an implementation to the tuple macro:
```rust
impl<$($name: Reflect + for<'de> Deserialize<'de>),*> GetTypeRegistration for ($($name,)*) {
fn get_type_registration() -> TypeRegistration {
let mut registration = TypeRegistration::of::<($($name,)*)>();
registration.insert::<ReflectDeserialize>(FromType::<($($name,)*)>::from_type());
registration
}
}
```
This requires that the tuple's types implement `Deserialize`. This is exactly how `Vec` and `HashMap` handle it:
```rust
impl<T: FromReflect + for<'de> Deserialize<'de>> GetTypeRegistration for Vec<T> {
fn get_type_registration() -> TypeRegistration {
let mut registration = TypeRegistration::of::<Vec<T>>();
registration.insert::<ReflectDeserialize>(FromType::<Vec<T>>::from_type());
registration
}
}
```
# Objective
Reduce from scratch build time.
## Solution
Reduce the size of the critical path by removing dependencies between crates where not necessary. For `cargo check --no-default-features` this reduced build time from ~51s to ~45s. For some commits I am not completely sure if the tradeoff between build time reduction and convenience caused by the commit is acceptable. If not, I can drop them.
# Objective
Comparing two reflected floating points would always fail:
```rust
let a: &dyn Reflect = &1.23_f32;
let b: &dyn Reflect = &1.23_f32;
// Panics:
assert!(a.reflect_partial_eq(b).unwrap_or_default());
```
The comparison returns `None` since `f32` (and `f64`) does not have a reflected `PartialEq` implementation.
## Solution
Include `PartialEq` in the `impl_reflect_value!` macro call for both `f32` and `f64`.
`Hash` is still excluded since neither implement `Hash`.
Also added equality tests for some of the common types from `std` (including `f32`).
Support for deriving `TypeUuid` for types with generics was initially added in https://github.com/bevyengine/bevy/pull/2044 but later reverted https://github.com/bevyengine/bevy/pull/2204 because it lead to `MyStruct<A>` and `MyStruct<B>` having the same type uuid.
This PR fixes this by generating code like
```rust
#[derive(TypeUuid)]
#[uuid = "69b09733-a21a-4dab-a444-d472986bd672"]
struct Type<T>(T);
impl<T: TypeUuid> TypeUuid for Type<T> {
const TYPE_UUID: TypeUuid = generate_compound_uuid(Uuid::from_bytes([/* 69b0 uuid */]), T::TYPE_UUID);
}
```
where `generate_compound_uuid` will XOR the non-metadata bits of the two UUIDs.
Co-authored-by: XBagon <xbagon@outlook.de>
Co-authored-by: Jakob Hellermann <hellermann@sipgate.de>
# Objective
In some cases, you may want to take ownership of the values in `DynamicList` or `DynamicMap`.
I came across this need while trying to implement a custom deserializer, but couldn't get ownership of the values in the list.
## Solution
Implemented `IntoIter` for both `DynamicList` and `DynamicMap`.
# Objective
Trait objects that have `Reflect` as a supertrait cannot be upcast to a `dyn Reflect`.
Attempting something like:
```rust
trait MyTrait: Reflect {
// ...
}
fn foo(value: &dyn MyTrait) {
let reflected = value as &dyn Reflect; // Error!
// ...
}
```
Results in `error[E0658]: trait upcasting coercion is experimental`.
The reason this is important is that a lot of `bevy_reflect` methods require a `&dyn Reflect`. This is trivial with concrete types, but if we don't know the concrete type (we only have the trait object), we can't use these methods. For example, we couldn't create a `ReflectSerializer` for the type since it expects a `&dyn Reflect` value— even though we should be able to.
## Solution
Add `as_reflect` and `as_reflect_mut` to `Reflect` to allow upcasting to a `dyn Reflect`:
```rust
trait MyTrait: Reflect {
// ...
}
fn foo(value: &dyn MyTrait) {
let reflected = value.as_reflect();
// ...
}
```
## Alternatives
We could defer this type of logic to the crate/user. They can add these methods to their trait in the same exact way we do here. The main benefit of doing it ourselves is it makes things convenient for them (especially when using the derive macro).
We could also create an `AsReflect` trait with a blanket impl over all reflected types, however, I could not get that to work for trait objects since they aren't sized.
---
## Changelog
- Added trait method `Reflect::as_reflect(&self)`
- Added trait method `Reflect::as_reflect_mut(&mut self)`
## Migration Guide
- Manual implementors of `Reflect` will need to add implementations for the methods above (this should be pretty easy as most cases just need to return `self`)
A couple more uncontroversial changes extracted from #3886.
* Enable full feature of syn
It is necessary for the ItemFn and ItemTrait type. Currently it is indirectly
enabled through the tracing dependency of bevy_utils, but this may no
longer be the case in the future.
* Remove unused function from bevy_macro_utils
## Objective
A step towards `f64` `Transform`s (#1680). For now, I am rolling my own `Transform`. But in order to derive Reflect, I specifically need `DQuat` to be reflectable.
```rust
#[derive(Component, Reflect, Copy, Clone, PartialEq, Debug)]
#[reflect(Component, PartialEq)]
pub struct Transform {
pub translation: DVec3,
pub rotation: DQuat, // error: the trait `bevy::prelude::Reflect` is not implemented for `DQuat`
pub scale: DVec3,
}
```
## Solution
I have added a `DQuat` impl for `Reflect` alongside the other glam impls. I've also added impls for `DMat3` and `DMat4` to match.
# Objective
The `#[reflect_trait]` macro did not maintain the visibility of its trait. It also did not make its accessor methods public, which made them inaccessible outside the current module.
## Solution
Made the `Reflect***` struct match the visibility of its trait and made both the `get` and `get_mut` methods always public.
# Objective
`Vec3A` is does not implement `Reflect`. This is generally useful for `Reflect` derives using `Vec3A` fields, and may speed up some animation blending use cases.
## Solution
Extend the existing macro uses to include `Vec3A`.
For some keys, it is too expensive to hash them on every lookup. Historically in Bevy, we have regrettably done the "wrong" thing in these cases (pre-computing hashes, then re-hashing them) because Rust's built in hashed collections don't give us the tools we need to do otherwise. Doing this is "wrong" because two different values can result in the same hash. Hashed collections generally get around this by falling back to equality checks on hash collisions. You can't do that if the key _is_ the hash. Additionally, re-hashing a hash increase the odds of collision!
#3959 needs pre-hashing to be viable, so I decided to finally properly solve the problem. The solution involves two different changes:
1. A new generalized "pre-hashing" solution in bevy_utils: `Hashed<T>` types, which store a value alongside a pre-computed hash. And `PreHashMap<K, V>` (which uses `Hashed<T>` internally) . `PreHashMap` is just an alias for a normal HashMap that uses `Hashed<T>` as the key and a new `PassHash` implementation as the Hasher.
2. Replacing the `std::collections` re-exports in `bevy_utils` with equivalent `hashbrown` impls. Avoiding re-hashes requires the `raw_entry_mut` api, which isn't stabilized yet (and may never be ... `entry_ref` has favor now, but also isn't available yet). If std's HashMap ever provides the tools we need, we can move back to that. The latest version of `hashbrown` adds support for the `entity_ref` api, so we can move to that in preparation for an std migration, if thats the direction they seem to be going in. Note that adding hashbrown doesn't increase our dependency count because it was already in our tree.
In addition to providing these core tools, I also ported the "table identity hashing" in `bevy_ecs` to `raw_entry_mut`, which was a particularly egregious case.
The biggest outstanding case is `AssetPathId`, which stores a pre-hash. We need AssetPathId to be cheaply clone-able (and ideally Copy), but `Hashed<AssetPath>` requires ownership of the AssetPath, which makes cloning ids way more expensive. We could consider doing `Hashed<Arc<AssetPath>>`, but cloning an arc is still a non-trivial expensive that needs to be considered. I would like to handle this in a separate PR. And given that we will be re-evaluating the Bevy Assets implementation in the very near future, I'd prefer to hold off until after that conversation is concluded.
What is says on the tin.
This has got more to do with making `clippy` slightly more *quiet* than it does with changing anything that might greatly impact readability or performance.
that said, deriving `Default` for a couple of structs is a nice easy win
This adds documentation for:
- The trait methods of `Reflect` and its subtraits
- The `partial_eq` and `apply` functions for `Map` et al.
- `DynamicList` and `DynamicMap`
- `TypeRegistry` and related types & traits
- `GetPath`, including an explanation of path string syntax
among other things.
Still to be documented are the various macros and `bevy_reflect::serde`.
# Objective
These traits are undocumented on `main`.
## Solution
Now they have docs! Included are examples for each trait and their corresponding `GetTypeField` trait. The docs also mention that `#[derive(Reflect)]` will automatically derive the correct subtrait on structs and tuple structs.
# Objective
Resolves#3277
Currenty if we try to serialize a scene that contains a `Duration` (which is very common, since `Timer` contains one), we get an error saying:
> Type 'core::time::Duration' does not support ReflectValue serialization
## Solution
Let `Duration` implement `SerializeValue`.
Co-authored-by: Jonathan Cornaz <jcornaz@users.noreply.github.com>
#3457 adds the `doc_markdown` clippy lint, which checks doc comments to make sure code identifiers are escaped with backticks. This causes a lot of lint errors, so this is one of a number of PR's that will fix those lint errors one crate at a time.
This PR fixes lints in the `bevy_reflect` crate.
Dynamic types (`DynamicStruct`, `DynamicTupleStruct`, `DynamicTuple`, `DynamicList` and `DynamicMap`) are used when deserializing scenes, but currently they can only be applied to existing concrete types. This leads to issues when trying to spawn non trivial deserialized scene.
For components, the issue is avoided by requiring that reflected components implement ~~`FromResources`~~ `FromWorld` (or `Default`). When spawning, a new concrete type is created that way, and the dynamic type is applied to it. Unfortunately, some components don't have any valid implementation of these traits.
In addition, any `Vec` or `HashMap` inside a component will panic when a dynamic type is pushed into it (for instance, `Text` panics when adding a text section).
To solve this issue, this PR adds the `FromReflect` trait that creates a concrete type from a dynamic type that represent it, derives the trait alongside the `Reflect` trait, drops the ~~`FromResources`~~ `FromWorld` requirement on reflected components, ~~and enables reflection for UI and Text bundles~~. It also adds the requirement that fields ignored with `#[reflect(ignore)]` implement `Default`, since we need to initialize them somehow.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
Fixes#2566Fixes#3005
There are only READMEs in the 4 crates here (with the exception of bevy itself).
Those 4 crates are ecs, reflect, tasks, and transform.
These should each now include their respective README files.
Co-authored-by: Hoidigan <57080125+Hoidigan@users.noreply.github.com>
Co-authored-by: Daniel Nelsen <57080125+Hoidigan@users.noreply.github.com>
# Objective
- there are a few new versions for `ron`, `winit`, `ndk`, `raw-window-handle`
- `cargo-deny` is failing due to new security issues / duplicated dependencies
## Solution
- Update our dependencies
- Note all new security issues, with which of Bevy direct dependency it comes from
- Update duplicate crate list, with which of Bevy direct dependency it comes from
`notify` is not updated here as it's in #2993
# Objective
- Update vendor crevice to have the latest update from crevice 0.8.0
- Using https://github.com/ElectronicRU/crevice/tree/arrays which has the changes to make arrays work
## Solution
- Also updated glam and hexasphere to only have one version of glam
- From the original PR, using crevice to write GLSL code containing arrays would probably not work but it's not something used by Bevy
Objective
During work on #3009 I've found that not all jobs use actions-rs, and therefore, an previous version of Rust is used for them. So while compilation and other stuff can pass, checking markup and Android build may fail with compilation errors.
Solution
This PR adds `action-rs` for any job running cargo, and updates the edition to 2021.
# Objective
- Avoid usages of `format!` that ~immediately get passed to another `format!`. This avoids a temporary allocation and is just generally cleaner.
## Solution
- `bevy_derive::shader_defs` does a `format!("{}", val.to_string())`, which is better written as just `format!("{}", val)`
- `bevy_diagnostic::log_diagnostics_plugin` does a `format!("{:>}", format!(...))`, which is better written as `format!("{:>}", format_args!(...))`
- `bevy_ecs::schedule` does `tracing::info!(..., name = &*format!("{:?}", val))`, which is better written with the tracing shorthand `tracing::info!(..., name = ?val)`
- `bevy_reflect::reflect` does `f.write_str(&format!(...))`, which is better written as `write!(f, ...)` (this could also be written using `f.debug_tuple`, but I opted to maintain alt debug behavior)
- `bevy_reflect::serde::{ser, de}` do `serde::Error::custom(format!(...))`, which is better written as `Error::custom(format_args!(...))`, as `Error::custom` takes `impl Display` and just immediately calls `format!` again
A few minor changes to fix warnings emitted from clippy on the nightly toolchain, including redundant_allocation, unwrap_or_else_default, and collapsible_match, fixes#2698
Updates the requirements on [glam](https://github.com/bitshifter/glam-rs) to permit the latest version.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/bitshifter/glam-rs/blob/main/CHANGELOG.md">glam's changelog</a>.</em></p>
<blockquote>
<h2>[0.18.0] - 2021-08-26</h2>
<h3>Breaking changes</h3>
<ul>
<li>Minimum Supported Version of Rust bumped to 1.51.0 for <code>wasm-bindgen-test</code>
and <code>rustdoc</code> <code>alias</code> support.</li>
</ul>
<h3>Added</h3>
<ul>
<li>Added <code>wasm32</code> SIMD intrinsics support.</li>
<li>Added optional support for the <code>rkyv</code> serialization crate.</li>
<li>Added <code>Rem</code> and <code>RemAssign</code> implementations for all vector types.</li>
<li>Added quaternion <code>xyz()</code> method for returning the vector part of the
quaternion.</li>
<li>Added <code>From((Scalar, Vector3))</code> for 4D vector types.</li>
</ul>
<h3>Changed</h3>
<ul>
<li>Deprecated <code>as_f32()</code>, <code>as_f64()</code>, <code>as_i32()</code> and <code>as_u32()</code> methods in favor
of more specific methods such as <code>as_vec2()</code>, <code>as_dvec2()</code>, <code>as_ivec2()</code> and
<code>as_uvec2()</code> and so on.</li>
</ul>
<h2>[0.17.3] - 2021-07-18</h2>
<h3>Fixed</h3>
<ul>
<li>Fix alignment unit tests on non x86 platforms.</li>
</ul>
<h2>[0.17.2] - 2021-07-15</h2>
<h3>Fixed</h3>
<ul>
<li>Fix alignment unit tests on i686 and S390x.</li>
</ul>
<h2>[0.17.1] - 2021-06-29</h2>
<h3>Added</h3>
<ul>
<li>Added <code>serde</code> support for <code>Affine2</code>, <code>DAffine2</code>, <code>Affine3A</code> and <code>DAffine3</code>.</li>
</ul>
<h2>[0.17.0] - 2021-06-26</h2>
<h3>Breaking changes</h3>
<ul>
<li>The addition of <code>Add</code> and <code>Sub</code> implementations of scalar values for vector
types may create ambiguities with existing calls to <code>add</code> and <code>sub</code>.</li>
<li>Removed <code>From<Mat3></code> implementation for <code>Mat2</code> and <code>From<DMat3></code> for <code>DMat2</code>.
These have been replaced by <code>Mat2::from_mat3()</code> and <code>DMat2::from_mat3()</code>.</li>
<li>Removed <code>From<Mat4></code> implementation for <code>Mat3</code> and <code>From<DMat4></code> for <code>DMat3</code>.
These have been replaced by <code>Mat3::from_mat4()</code> and <code>DMat3::from_mat4()</code>.</li>
</ul>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="1b703518e7"><code>1b70351</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/231">#231</a> from bitshifter/prepare-0.18.0</li>
<li><a href="935ad5cf64"><code>935ad5c</code></a> Prepare 0.18.0 release.</li>
<li><a href="8d79d8e907"><code>8d79d8e</code></a> Still managed to mess up the tarpaulin config...</li>
<li><a href="78c30fc72c"><code>78c30fc</code></a> Fix syntax error in tarpaulin config.</li>
<li><a href="0258ce710d"><code>0258ce7</code></a> Can use rustdoc alias after msrv bump to 1.51.0.</li>
<li><a href="f9f7f2407c"><code>f9f7f24</code></a> Tidy up tarpaulin exlcudes.</li>
<li><a href="95dab216e1"><code>95dab21</code></a> Make some dev deps wasm only on not wasm.</li>
<li><a href="342176dde9"><code>342176d</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/230">#230</a> from DJMcNab/bytemuck-spirv</li>
<li><a href="837e5ebf7f"><code>837e5eb</code></a> Bytemuck now compiles on spirv</li>
<li><a href="bb35b1a691"><code>bb35b1a</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/228">#228</a> from bitshifter/wasm32-simd</li>
<li>Additional commits viewable in <a href="https://github.com/bitshifter/glam-rs/compare/0.17.3...0.18.0">compare view</a></li>
</ul>
</details>
<br />
Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`.
[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)
---
<details>
<summary>Dependabot commands and options</summary>
<br />
You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
- `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
</details>
Updates the requirements on [glam](https://github.com/bitshifter/glam-rs) to permit the latest version.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/bitshifter/glam-rs/blob/master/CHANGELOG.md">glam's changelog</a>.</em></p>
<blockquote>
<h2>[0.17.3] - 2021-07-18</h2>
<h3>Fixed</h3>
<ul>
<li>Fix alignment unit tests on non x86 platforms.</li>
</ul>
<h2>[0.17.2] - 2021-07-15</h2>
<h3>Fixed</h3>
<ul>
<li>Fix alignment unit tests on i686 and S390x.</li>
</ul>
<h2>[0.17.1] - 2021-06-29</h2>
<h3>Added</h3>
<ul>
<li>Added <code>serde</code> support for <code>Affine2</code>, <code>DAffine2</code>, <code>Affine3A</code> and <code>DAffine3</code>.</li>
</ul>
<h2>[0.17.0] - 2021-06-26</h2>
<h3>Breaking changes</h3>
<ul>
<li>The addition of <code>Add</code> and <code>Sub</code> implementations of scalar values for vector
types may create ambiguities with existing calls to <code>add</code> and <code>sub</code>.</li>
<li>Removed <code>From<Mat3></code> implementation for <code>Mat2</code> and <code>From<DMat3></code> for <code>DMat2</code>.
These have been replaced by <code>Mat2::from_mat3()</code> and <code>DMat2::from_mat3()</code>.</li>
<li>Removed <code>From<Mat4></code> implementation for <code>Mat3</code> and <code>From<DMat4></code> for <code>DMat3</code>.
These have been replaced by <code>Mat3::from_mat4()</code> and <code>DMat3::from_mat4()</code>.</li>
<li>Removed deprecated <code>from_slice_unaligned()</code>, <code>write_to_slice_unaligned()</code>,
<code>from_rotation_mat4</code> and <code>from_rotation_ypr()</code> methods.</li>
</ul>
<h3>Added</h3>
<ul>
<li>Added <code>col_mut()</code> method which returns a mutable reference to a matrix column
to all matrix types.</li>
<li>Added <code>AddAssign</code>, <code>MulAssign</code> and <code>SubAssign</code> implementations for all matrix
types.</li>
<li>Added <code>Add</code> and <code>Sub</code> implementations of scalar values for vector types.</li>
<li>Added more <code>glam_assert!</code> checks and documented methods where they are used.</li>
<li>Added vector projection and rejection methods <code>project_onto()</code>,
<code>project_onto_normalized()</code>, <code>reject_from()</code> and <code>reject_from_normalized()</code>.</li>
<li>Added <code>Mat2::from_mat3()</code>, <code>DMat2::from_mat3()</code>, <code>Mat3::from_mat4()</code>,
<code>DMat3::from_mat4()</code> which create a smaller matrix from a larger one,
discarding a final row and column of the input matrix.</li>
<li>Added <code>Mat3::from_mat2()</code>, <code>DMat3::from_mat2()</code>, <code>Mat4::from_mat3()</code> and
<code>DMat4::from_mat3()</code> which create an affine transform from a smaller linear
transform matrix.</li>
</ul>
<h3>Changed</h3>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="ecf3904b2f"><code>ecf3904</code></a> Prepare release 0.17.3</li>
<li><a href="95e02bb43e"><code>95e02bb</code></a> Merge branch 'master' of github.com:bitshifter/glam-rs</li>
<li><a href="c6dc702583"><code>c6dc702</code></a> More alignment test fixes for when SSE2 is not avaialable.</li>
<li><a href="87a3b25872"><code>87a3b25</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/216">#216</a> from bitshifter/prepare-0.17.2</li>
<li><a href="269e514090"><code>269e514</code></a> Prepare for 0.17.2 release.</li>
<li><a href="1da7d6459c"><code>1da7d64</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/215">#215</a> from bitshifter/issue-213</li>
<li><a href="dc60e20925"><code>dc60e20</code></a> Fix align asserts on i686 and S390x architectures.</li>
<li><a href="bd8b30e9fb"><code>bd8b30e</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/212">#212</a> from remilauzier/master</li>
<li><a href="a4e97c0b54"><code>a4e97c0</code></a> Update approx to 0.5</li>
<li><a href="059f619525"><code>059f619</code></a> Prepare 0.17.1 release (<a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/211">#211</a>)</li>
<li>Additional commits viewable in <a href="https://github.com/bitshifter/glam-rs/compare/0.15.1...0.17.3">compare view</a></li>
</ul>
</details>
<br />
Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`.
[//]: # (dependabot-automerge-start)
[//]: # (dependabot-automerge-end)
---
<details>
<summary>Dependabot commands and options</summary>
<br />
You can trigger Dependabot actions by commenting on this PR:
- `@dependabot rebase` will rebase this PR
- `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it
- `@dependabot merge` will merge this PR after your CI passes on it
- `@dependabot squash and merge` will squash and merge this PR after your CI passes on it
- `@dependabot cancel merge` will cancel a previously requested merge and block automerging
- `@dependabot reopen` will reopen this PR if it is closed
- `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
- `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
- `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
</details>
This relicenses Bevy under the dual MIT or Apache-2.0 license. For rationale, see #2373.
* Changes the LICENSE file to describe the dual license. Moved the MIT license to docs/LICENSE-MIT. Added the Apache-2.0 license to docs/LICENSE-APACHE. I opted for this approach over dumping both license files at the root (the more common approach) for a number of reasons:
* Github links to the "first" license file (LICENSE-APACHE) in its license links (you can see this in the wgpu and rust-analyzer repos). People clicking these links might erroneously think that the apache license is the only option. Rust and Amethyst both use COPYRIGHT or COPYING files to solve this problem, but this creates more file noise (if you do everything at the root) and the naming feels way less intuitive.
* People have a reflex to look for a LICENSE file. By providing a single license file at the root, we make it easy for them to understand our licensing approach.
* I like keeping the root clean and noise free
* There is precedent for putting the apache and mit license text in sub folders (amethyst)
* Removed the `Copyright (c) 2020 Carter Anderson` copyright notice from the MIT license. I don't care about this attribution, it might make license compliance more difficult in some cases, and it didn't properly attribute other contributors. We shoudn't replace it with something like "Copyright (c) 2021 Bevy Contributors" because "Bevy Contributors" is not a legal entity. Instead, we just won't include the copyright line (which has precedent ... Rust also uses this approach).
* Updates crates to use the new "MIT OR Apache-2.0" license value
* Removes the old legion-transform license file from bevy_transform. bevy_transform has been its own, fully custom implementation for a long time and that license no longer applies.
* Added a License section to the main readme
* Updated our Bevy Plugin licensing guidelines.
As a follow-up we should update the website to properly describe the new license.
Closes#2373
# Objective
Prevent future unnecessary mental effort spent figuring out why this trait exists and how to resolve the `TODO`.
## Solution
I happened to notice this trait being used when expanding the `#[derive(Reflect)]` macro in my own crate to figure out how it worked, and noticed that there was a `TODO` comment on it because it is only used in the derive macro and thus appeared to be unused.
I figured I should document my findings to prevent someone else from finding them out the hard way in the future 😆
Co-authored-by: Waridley <Waridley64@gmail.com>
Fixes#2037 (and then some)
Problem:
- `TypeUuid`, `RenderResource`, and `Bytes` derive macros did not properly handle generic structs.
Solution:
- Rework the derive macro implementations to handle the generics.
fix a few dead links
* Links in `Input` missed a refactor
* `Reflect::downcast` can't use the intra doc link format, as it's not a link to a trait function, but to a function implemented on `dyn Reflect`
noticed in https://github.com/bevyengine/bevy/pull/1781#discussion_r619777879
After #1697 I looked at all other Iterators from Bevy and added overrides for `size_hint` where it wasn't done.
Also implemented `ExactSizeIterator` where applicable.
Fixes#1100
Implementors must make sure that `Reflect::any` and `Reflect::any_mut` both return the `self` reference passed in (both for logical correctness and downcast safety).
Error message noticed in #1475
When an asset type hasn't been added to the app but a load was attempted, the error message wasn't helpful:
```
thread 'IO Task Pool (0)' panicked at 'Failed to find AssetLifecycle for label Some("Mesh0/Primitive0"), which has an asset type 8ecbac0f-f545-4473-ad43-e1f4243af51e. Are you sure that is a registered asset type?', /.cargo/git/checkouts/bevy-f7ffde730c324c74/89a41bc/crates/bevy_asset/src/asset_server.rs:435:17
```
means that
```rust
.add_asset::<bevy::render::prelude::Mesh>()
```
needs to be added.
* type name was not given, only UUID, which may make it hard to identify type across bevy/plugins
* instruction were not helpful as the `register_asset_type` method is not public
new error message:
```
thread 'IO Task Pool (1)' panicked at 'Failed to find AssetLifecycle for label 'Some("Mesh0/Primitive0")', which has an asset type "bevy_render::mesh::mesh::Mesh" (UUID 8ecbac0f-f545-4473-ad43-e1f4243af51e). Are you sure this asset type has been added to your app builder?', /bevy/crates/bevy_asset/src/asset_server.rs:435:17
```
This is an effort to provide the correct `#[reflect_value(...)]` attributes where they are needed.
Supersedes #1533 and resolves#1528.
---
I am working under the following assumptions (thanks to @bjorn3 and @Davier for advice here):
- Any `enum` that derives `Reflect` and one or more of { `Serialize`, `Deserialize`, `PartialEq`, `Hash` } needs a `#[reflect_value(...)]` attribute containing the same subset of { `Serialize`, `Deserialize`, `PartialEq`, `Hash` } that is present on the derive.
- Same as above for `struct` and `#[reflect(...)]`, respectively.
- If a `struct` is used as a component, it should also have `#[reflect(Component)]`
- All reflected types should be registered in their plugins
I treated the following as components (added `#[reflect(Component)]` if necessary):
- `bevy_render`
- `struct RenderLayers`
- `bevy_transform`
- `struct GlobalTransform`
- `struct Parent`
- `struct Transform`
- `bevy_ui`
- `struct Style`
Not treated as components:
- `bevy_math`
- `struct Size<T>`
- `struct Rect<T>`
- Note: The updates for `Size<T>` and `Rect<T>` in `bevy::math::geometry` required using @Davier's suggestion to add `+ PartialEq` to the trait bound. I then registered the specific types used over in `bevy_ui` such as `Size<Val>`, etc. in `bevy_ui`'s plugin, since `bevy::math` does not contain a plugin.
- `bevy_render`
- `struct Color`
- `struct PipelineSpecialization`
- `struct ShaderSpecialization`
- `enum PrimitiveTopology`
- `enum IndexFormat`
Not Addressed:
- I am not searching for components in Bevy that are _not_ reflected. So if there are components that are not reflected that should be reflected, that will need to be figured out in another PR.
- I only added `#[reflect(...)]` or `#[reflect_value(...)]` entries for the set of four traits { `Serialize`, `Deserialize`, `PartialEq`, `Hash` } _if they were derived via `#[derive(...)]`_. I did not look for manual trait implementations of the same set of four, nor did I consider any traits outside the four. Are those other possibilities something that needs to be looked into?
This pull request is following the discussion on the issue #1127. Additionally, it integrates the change proposed by #1112.
The list of change of this pull request:
* ✨ Add `Timer::times_finished` method that counts the number of wraps for repeating timers.
* ♻️ Refactored `Timer`
* 🐛 Fix a bug where 2 successive calls to `Timer::tick` which makes a repeating timer to finish makes `Timer::just_finished` to return `false` where it should return `true`. Minimal failing example:
```rust
use bevy::prelude::*;
let mut timer: Timer<()> = Timer::from_seconds(1.0, true);
timer.tick(1.5);
assert!(timer.finished());
assert!(timer.just_finished());
timer.tick(1.5);
assert!(timer.finished());
assert!(timer.just_finished()); // <- This fails where it should not
```
* 📚 Add extensive documentation for Timer with doc examples.
* ✨ Add a `Stopwatch` struct similar to `Timer` with extensive doc and tests.
Even if the type specialization is not retained for bevy, the doc, bugfix and added method are worth salvaging 😅.
This is my first PR for bevy, please be kind to me ❤️ .
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Bevy ECS V2
This is a rewrite of Bevy ECS (basically everything but the new executor/schedule, which are already awesome). The overall goal was to improve the performance and versatility of Bevy ECS. Here is a quick bulleted list of changes before we dive into the details:
* Complete World rewrite
* Multiple component storage types:
* Tables: fast cache friendly iteration, slower add/removes (previously called Archetypes)
* Sparse Sets: fast add/remove, slower iteration
* Stateful Queries (caches query results for faster iteration. fragmented iteration is _fast_ now)
* Stateful System Params (caches expensive operations. inspired by @DJMcNab's work in #1364)
* Configurable System Params (users can set configuration when they construct their systems. once again inspired by @DJMcNab's work)
* Archetypes are now "just metadata", component storage is separate
* Archetype Graph (for faster archetype changes)
* Component Metadata
* Configure component storage type
* Retrieve information about component size/type/name/layout/send-ness/etc
* Components are uniquely identified by a densely packed ComponentId
* TypeIds are now totally optional (which should make implementing scripting easier)
* Super fast "for_each" query iterators
* Merged Resources into World. Resources are now just a special type of component
* EntityRef/EntityMut builder apis (more efficient and more ergonomic)
* Fast bitset-backed `Access<T>` replaces old hashmap-based approach everywhere
* Query conflicts are determined by component access instead of archetype component access (to avoid random failures at runtime)
* With/Without are still taken into account for conflicts, so this should still be comfy to use
* Much simpler `IntoSystem` impl
* Significantly reduced the amount of hashing throughout the ecs in favor of Sparse Sets (indexed by densely packed ArchetypeId, ComponentId, BundleId, and TableId)
* Safety Improvements
* Entity reservation uses a normal world reference instead of unsafe transmute
* QuerySets no longer transmute lifetimes
* Made traits "unsafe" where relevant
* More thorough safety docs
* WorldCell
* Exposes safe mutable access to multiple resources at a time in a World
* Replaced "catch all" `System::update_archetypes(world: &World)` with `System::new_archetype(archetype: &Archetype)`
* Simpler Bundle implementation
* Replaced slow "remove_bundle_one_by_one" used as fallback for Commands::remove_bundle with fast "remove_bundle_intersection"
* Removed `Mut<T>` query impl. it is better to only support one way: `&mut T`
* Removed with() from `Flags<T>` in favor of `Option<Flags<T>>`, which allows querying for flags to be "filtered" by default
* Components now have is_send property (currently only resources support non-send)
* More granular module organization
* New `RemovedComponents<T>` SystemParam that replaces `query.removed::<T>()`
* `world.resource_scope()` for mutable access to resources and world at the same time
* WorldQuery and QueryFilter traits unified. FilterFetch trait added to enable "short circuit" filtering. Auto impled for cases that don't need it
* Significantly slimmed down SystemState in favor of individual SystemParam state
* System Commands changed from `commands: &mut Commands` back to `mut commands: Commands` (to allow Commands to have a World reference)
Fixes#1320
## `World` Rewrite
This is a from-scratch rewrite of `World` that fills the niche that `hecs` used to. Yes, this means Bevy ECS is no longer a "fork" of hecs. We're going out our own!
(the only shared code between the projects is the entity id allocator, which is already basically ideal)
A huge shout out to @SanderMertens (author of [flecs](https://github.com/SanderMertens/flecs)) for sharing some great ideas with me (specifically hybrid ecs storage and archetype graphs). He also helped advise on a number of implementation details.
## Component Storage (The Problem)
Two ECS storage paradigms have gained a lot of traction over the years:
* **Archetypal ECS**:
* Stores components in "tables" with static schemas. Each "column" stores components of a given type. Each "row" is an entity.
* Each "archetype" has its own table. Adding/removing an entity's component changes the archetype.
* Enables super-fast Query iteration due to its cache-friendly data layout
* Comes at the cost of more expensive add/remove operations for an Entity's components, because all components need to be copied to the new archetype's "table"
* **Sparse Set ECS**:
* Stores components of the same type in densely packed arrays, which are sparsely indexed by densely packed unsigned integers (Entity ids)
* Query iteration is slower than Archetypal ECS because each entity's component could be at any position in the sparse set. This "random access" pattern isn't cache friendly. Additionally, there is an extra layer of indirection because you must first map the entity id to an index in the component array.
* Adding/removing components is a cheap, constant time operation
Bevy ECS V1, hecs, legion, flec, and Unity DOTS are all "archetypal ecs-es". I personally think "archetypal" storage is a good default for game engines. An entity's archetype doesn't need to change frequently in general, and it creates "fast by default" query iteration (which is a much more common operation). It is also "self optimizing". Users don't need to think about optimizing component layouts for iteration performance. It "just works" without any extra boilerplate.
Shipyard and EnTT are "sparse set ecs-es". They employ "packing" as a way to work around the "suboptimal by default" iteration performance for specific sets of components. This helps, but I didn't think this was a good choice for a general purpose engine like Bevy because:
1. "packs" conflict with each other. If bevy decides to internally pack the Transform and GlobalTransform components, users are then blocked if they want to pack some custom component with Transform.
2. users need to take manual action to optimize
Developers selecting an ECS framework are stuck with a hard choice. Select an "archetypal" framework with "fast iteration everywhere" but without the ability to cheaply add/remove components, or select a "sparse set" framework to cheaply add/remove components but with slower iteration performance.
## Hybrid Component Storage (The Solution)
In Bevy ECS V2, we get to have our cake and eat it too. It now has _both_ of the component storage types above (and more can be added later if needed):
* **Tables** (aka "archetypal" storage)
* The default storage. If you don't configure anything, this is what you get
* Fast iteration by default
* Slower add/remove operations
* **Sparse Sets**
* Opt-in
* Slower iteration
* Faster add/remove operations
These storage types complement each other perfectly. By default Query iteration is fast. If developers know that they want to add/remove a component at high frequencies, they can set the storage to "sparse set":
```rust
world.register_component(
ComponentDescriptor:🆕:<MyComponent>(StorageType::SparseSet)
).unwrap();
```
## Archetypes
Archetypes are now "just metadata" ... they no longer store components directly. They do store:
* The `ComponentId`s of each of the Archetype's components (and that component's storage type)
* Archetypes are uniquely defined by their component layouts
* For example: entities with "table" components `[A, B, C]` _and_ "sparse set" components `[D, E]` will always be in the same archetype.
* The `TableId` associated with the archetype
* For now each archetype has exactly one table (which can have no components),
* There is a 1->Many relationship from Tables->Archetypes. A given table could have any number of archetype components stored in it:
* Ex: an entity with "table storage" components `[A, B, C]` and "sparse set" components `[D, E]` will share the same `[A, B, C]` table as an entity with `[A, B, C]` table component and `[F]` sparse set components.
* This 1->Many relationship is how we preserve fast "cache friendly" iteration performance when possible (more on this later)
* A list of entities that are in the archetype and the row id of the table they are in
* ArchetypeComponentIds
* unique densely packed identifiers for (ArchetypeId, ComponentId) pairs
* used by the schedule executor for cheap system access control
* "Archetype Graph Edges" (see the next section)
## The "Archetype Graph"
Archetype changes in Bevy (and a number of other archetypal ecs-es) have historically been expensive to compute. First, you need to allocate a new vector of the entity's current component ids, add or remove components based on the operation performed, sort it (to ensure it is order-independent), then hash it to find the archetype (if it exists). And thats all before we get to the _already_ expensive full copy of all components to the new table storage.
The solution is to build a "graph" of archetypes to cache these results. @SanderMertens first exposed me to the idea (and he got it from @gjroelofs, who came up with it). They propose adding directed edges between archetypes for add/remove component operations. If `ComponentId`s are densely packed, you can use sparse sets to cheaply jump between archetypes.
Bevy takes this one step further by using add/remove `Bundle` edges instead of `Component` edges. Bevy encourages the use of `Bundles` to group add/remove operations. This is largely for "clearer game logic" reasons, but it also helps cut down on the number of archetype changes required. `Bundles` now also have densely-packed `BundleId`s. This allows us to use a _single_ edge for each bundle operation (rather than needing to traverse N edges ... one for each component). Single component operations are also bundles, so this is strictly an improvement over a "component only" graph.
As a result, an operation that used to be _heavy_ (both for allocations and compute) is now two dirt-cheap array lookups and zero allocations.
## Stateful Queries
World queries are now stateful. This allows us to:
1. Cache archetype (and table) matches
* This resolves another issue with (naive) archetypal ECS: query performance getting worse as the number of archetypes goes up (and fragmentation occurs).
2. Cache Fetch and Filter state
* The expensive parts of fetch/filter operations (such as hashing the TypeId to find the ComponentId) now only happen once when the Query is first constructed
3. Incrementally build up state
* When new archetypes are added, we only process the new archetypes (no need to rebuild state for old archetypes)
As a result, the direct `World` query api now looks like this:
```rust
let mut query = world.query::<(&A, &mut B)>();
for (a, mut b) in query.iter_mut(&mut world) {
}
```
Requiring `World` to generate stateful queries (rather than letting the `QueryState` type be constructed separately) allows us to ensure that _all_ queries are properly initialized (and the relevant world state, such as ComponentIds). This enables QueryState to remove branches from its operations that check for initialization status (and also enables query.iter() to take an immutable world reference because it doesn't need to initialize anything in world).
However in systems, this is a non-breaking change. State management is done internally by the relevant SystemParam.
## Stateful SystemParams
Like Queries, `SystemParams` now also cache state. For example, `Query` system params store the "stateful query" state mentioned above. Commands store their internal `CommandQueue`. This means you can now safely use as many separate `Commands` parameters in your system as you want. `Local<T>` system params store their `T` value in their state (instead of in Resources).
SystemParam state also enabled a significant slim-down of SystemState. It is much nicer to look at now.
Per-SystemParam state naturally insulates us from an "aliased mut" class of errors we have hit in the past (ex: using multiple `Commands` system params).
(credit goes to @DJMcNab for the initial idea and draft pr here #1364)
## Configurable SystemParams
@DJMcNab also had the great idea to make SystemParams configurable. This allows users to provide some initial configuration / values for system parameters (when possible). Most SystemParams have no config (the config type is `()`), but the `Local<T>` param now supports user-provided parameters:
```rust
fn foo(value: Local<usize>) {
}
app.add_system(foo.system().config(|c| c.0 = Some(10)));
```
## Uber Fast "for_each" Query Iterators
Developers now have the choice to use a fast "for_each" iterator, which yields ~1.5-3x iteration speed improvements for "fragmented iteration", and minor ~1.2x iteration speed improvements for unfragmented iteration.
```rust
fn system(query: Query<(&A, &mut B)>) {
// you now have the option to do this for a speed boost
query.for_each_mut(|(a, mut b)| {
});
// however normal iterators are still available
for (a, mut b) in query.iter_mut() {
}
}
```
I think in most cases we should continue to encourage "normal" iterators as they are more flexible and more "rust idiomatic". But when that extra "oomf" is needed, it makes sense to use `for_each`.
We should also consider using `for_each` for internal bevy systems to give our users a nice speed boost (but that should be a separate pr).
## Component Metadata
`World` now has a `Components` collection, which is accessible via `world.components()`. This stores mappings from `ComponentId` to `ComponentInfo`, as well as `TypeId` to `ComponentId` mappings (where relevant). `ComponentInfo` stores information about the component, such as ComponentId, TypeId, memory layout, send-ness (currently limited to resources), and storage type.
## Significantly Cheaper `Access<T>`
We used to use `TypeAccess<TypeId>` to manage read/write component/archetype-component access. This was expensive because TypeIds must be hashed and compared individually. The parallel executor got around this by "condensing" type ids into bitset-backed access types. This worked, but it had to be re-generated from the `TypeAccess<TypeId>`sources every time archetypes changed.
This pr removes TypeAccess in favor of faster bitset access everywhere. We can do this thanks to the move to densely packed `ComponentId`s and `ArchetypeComponentId`s.
## Merged Resources into World
Resources had a lot of redundant functionality with Components. They stored typed data, they had access control, they had unique ids, they were queryable via SystemParams, etc. In fact the _only_ major difference between them was that they were unique (and didn't correlate to an entity).
Separate resources also had the downside of requiring a separate set of access controls, which meant the parallel executor needed to compare more bitsets per system and manage more state.
I initially got the "separate resources" idea from `legion`. I think that design was motivated by the fact that it made the direct world query/resource lifetime interactions more manageable. It certainly made our lives easier when using Resources alongside hecs/bevy_ecs. However we already have a construct for safely and ergonomically managing in-world lifetimes: systems (which use `Access<T>` internally).
This pr merges Resources into World:
```rust
world.insert_resource(1);
world.insert_resource(2.0);
let a = world.get_resource::<i32>().unwrap();
let mut b = world.get_resource_mut::<f64>().unwrap();
*b = 3.0;
```
Resources are now just a special kind of component. They have their own ComponentIds (and their own resource TypeId->ComponentId scope, so they don't conflict wit components of the same type). They are stored in a special "resource archetype", which stores components inside the archetype using a new `unique_components` sparse set (note that this sparse set could later be used to implement Tags). This allows us to keep the code size small by reusing existing datastructures (namely Column, Archetype, ComponentFlags, and ComponentInfo). This allows us the executor to use a single `Access<ArchetypeComponentId>` per system. It should also make scripting language integration easier.
_But_ this merge did create problems for people directly interacting with `World`. What if you need mutable access to multiple resources at the same time? `world.get_resource_mut()` borrows World mutably!
## WorldCell
WorldCell applies the `Access<ArchetypeComponentId>` concept to direct world access:
```rust
let world_cell = world.cell();
let a = world_cell.get_resource_mut::<i32>().unwrap();
let b = world_cell.get_resource_mut::<f64>().unwrap();
```
This adds cheap runtime checks (a sparse set lookup of `ArchetypeComponentId` and a counter) to ensure that world accesses do not conflict with each other. Each operation returns a `WorldBorrow<'w, T>` or `WorldBorrowMut<'w, T>` wrapper type, which will release the relevant ArchetypeComponentId resources when dropped.
World caches the access sparse set (and only one cell can exist at a time), so `world.cell()` is a cheap operation.
WorldCell does _not_ use atomic operations. It is non-send, does a mutable borrow of world to prevent other accesses, and uses a simple `Rc<RefCell<ArchetypeComponentAccess>>` wrapper in each WorldBorrow pointer.
The api is currently limited to resource access, but it can and should be extended to queries / entity component access.
## Resource Scopes
WorldCell does not yet support component queries, and even when it does there are sometimes legitimate reasons to want a mutable world ref _and_ a mutable resource ref (ex: bevy_render and bevy_scene both need this). In these cases we could always drop down to the unsafe `world.get_resource_unchecked_mut()`, but that is not ideal!
Instead developers can use a "resource scope"
```rust
world.resource_scope(|world: &mut World, a: &mut A| {
})
```
This temporarily removes the `A` resource from `World`, provides mutable pointers to both, and re-adds A to World when finished. Thanks to the move to ComponentIds/sparse sets, this is a cheap operation.
If multiple resources are required, scopes can be nested. We could also consider adding a "resource tuple" to the api if this pattern becomes common and the boilerplate gets nasty.
## Query Conflicts Use ComponentId Instead of ArchetypeComponentId
For safety reasons, systems cannot contain queries that conflict with each other without wrapping them in a QuerySet. On bevy `main`, we use ArchetypeComponentIds to determine conflicts. This is nice because it can take into account filters:
```rust
// these queries will never conflict due to their filters
fn filter_system(a: Query<&mut A, With<B>>, b: Query<&mut B, Without<B>>) {
}
```
But it also has a significant downside:
```rust
// these queries will not conflict _until_ an entity with A, B, and C is spawned
fn maybe_conflicts_system(a: Query<(&mut A, &C)>, b: Query<(&mut A, &B)>) {
}
```
The system above will panic at runtime if an entity with A, B, and C is spawned. This makes it hard to trust that your game logic will run without crashing.
In this pr, I switched to using `ComponentId` instead. This _is_ more constraining. `maybe_conflicts_system` will now always fail, but it will do it consistently at startup. Naively, it would also _disallow_ `filter_system`, which would be a significant downgrade in usability. Bevy has a number of internal systems that rely on disjoint queries and I expect it to be a common pattern in userspace.
To resolve this, I added a new `FilteredAccess<T>` type, which wraps `Access<T>` and adds with/without filters. If two `FilteredAccess` have with/without values that prove they are disjoint, they will no longer conflict.
## EntityRef / EntityMut
World entity operations on `main` require that the user passes in an `entity` id to each operation:
```rust
let entity = world.spawn((A, )); // create a new entity with A
world.get::<A>(entity);
world.insert(entity, (B, C));
world.insert_one(entity, D);
```
This means that each operation needs to look up the entity location / verify its validity. The initial spawn operation also requires a Bundle as input. This can be awkward when no components are required (or one component is required).
These operations have been replaced by `EntityRef` and `EntityMut`, which are "builder-style" wrappers around world that provide read and read/write operations on a single, pre-validated entity:
```rust
// spawn now takes no inputs and returns an EntityMut
let entity = world.spawn()
.insert(A) // insert a single component into the entity
.insert_bundle((B, C)) // insert a bundle of components into the entity
.id() // id returns the Entity id
// Returns EntityMut (or panics if the entity does not exist)
world.entity_mut(entity)
.insert(D)
.insert_bundle(SomeBundle::default());
{
// returns EntityRef (or panics if the entity does not exist)
let d = world.entity(entity)
.get::<D>() // gets the D component
.unwrap();
// world.get still exists for ergonomics
let d = world.get::<D>(entity).unwrap();
}
// These variants return Options if you want to check existence instead of panicing
world.get_entity_mut(entity)
.unwrap()
.insert(E);
if let Some(entity_ref) = world.get_entity(entity) {
let d = entity_ref.get::<D>().unwrap();
}
```
This _does not_ affect the current Commands api or terminology. I think that should be a separate conversation as that is a much larger breaking change.
## Safety Improvements
* Entity reservation in Commands uses a normal world borrow instead of an unsafe transmute
* QuerySets no longer transmutes lifetimes
* Made traits "unsafe" when implementing a trait incorrectly could cause unsafety
* More thorough safety docs
## RemovedComponents SystemParam
The old approach to querying removed components: `query.removed:<T>()` was confusing because it had no connection to the query itself. I replaced it with the following, which is both clearer and allows us to cache the ComponentId mapping in the SystemParamState:
```rust
fn system(removed: RemovedComponents<T>) {
for entity in removed.iter() {
}
}
```
## Simpler Bundle implementation
Bundles are no longer responsible for sorting (or deduping) TypeInfo. They are just a simple ordered list of component types / data. This makes the implementation smaller and opens the door to an easy "nested bundle" implementation in the future (which i might even add in this pr). Duplicate detection is now done once per bundle type by World the first time a bundle is used.
## Unified WorldQuery and QueryFilter types
(don't worry they are still separate type _parameters_ in Queries .. this is a non-breaking change)
WorldQuery and QueryFilter were already basically identical apis. With the addition of `FetchState` and more storage-specific fetch methods, the overlap was even clearer (and the redundancy more painful).
QueryFilters are now just `F: WorldQuery where F::Fetch: FilterFetch`. FilterFetch requires `Fetch<Item = bool>` and adds new "short circuit" variants of fetch methods. This enables a filter tuple like `(With<A>, Without<B>, Changed<C>)` to stop evaluating the filter after the first mismatch is encountered. FilterFetch is automatically implemented for `Fetch` implementations that return bool.
This forces fetch implementations that return things like `(bool, bool, bool)` (such as the filter above) to manually implement FilterFetch and decide whether or not to short-circuit.
## More Granular Modules
World no longer globs all of the internal modules together. It now exports `core`, `system`, and `schedule` separately. I'm also considering exporting `core` submodules directly as that is still pretty "glob-ey" and unorganized (feedback welcome here).
## Remaining Draft Work (to be done in this pr)
* ~~panic on conflicting WorldQuery fetches (&A, &mut A)~~
* ~~bevy `main` and hecs both currently allow this, but we should protect against it if possible~~
* ~~batch_iter / par_iter (currently stubbed out)~~
* ~~ChangedRes~~
* ~~I skipped this while we sort out #1313. This pr should be adapted to account for whatever we land on there~~.
* ~~The `Archetypes` and `Tables` collections use hashes of sorted lists of component ids to uniquely identify each archetype/table. This hash is then used as the key in a HashMap to look up the relevant ArchetypeId or TableId. (which doesn't handle hash collisions properly)~~
* ~~It is currently unsafe to generate a Query from "World A", then use it on "World B" (despite the api claiming it is safe). We should probably close this gap. This could be done by adding a randomly generated WorldId to each world, then storing that id in each Query. They could then be compared to each other on each `query.do_thing(&world)` operation. This _does_ add an extra branch to each query operation, so I'm open to other suggestions if people have them.~~
* ~~Nested Bundles (if i find time)~~
## Potential Future Work
* Expand WorldCell to support queries.
* Consider not allocating in the empty archetype on `world.spawn()`
* ex: return something like EntityMutUninit, which turns into EntityMut after an `insert` or `insert_bundle` op
* this actually regressed performance last time i tried it, but in theory it should be faster
* Optimize SparseSet::insert (see `PERF` comment on insert)
* Replace SparseArray `Option<T>` with T::MAX to cut down on branching
* would enable cheaper get_unchecked() operations
* upstream fixedbitset optimizations
* fixedbitset could be allocation free for small block counts (store blocks in a SmallVec)
* fixedbitset could have a const constructor
* Consider implementing Tags (archetype-specific by-value data that affects archetype identity)
* ex: ArchetypeA could have `[A, B, C]` table components and `[D(1)]` "tag" component. ArchetypeB could have `[A, B, C]` table components and a `[D(2)]` tag component. The archetypes are different, despite both having D tags because the value inside D is different.
* this could potentially build on top of the `archetype.unique_components` added in this pr for resource storage.
* Consider reverting `all_tuples` proc macro in favor of the old `macro_rules` implementation
* all_tuples is more flexible and produces cleaner documentation (the macro_rules version produces weird type parameter orders due to parser constraints)
* but unfortunately all_tuples also appears to make Rust Analyzer sad/slow when working inside of `bevy_ecs` (does not affect user code)
* Consider "resource queries" and/or "mixed resource and entity component queries" as an alternative to WorldCell
* this is basically just "systems" so maybe it's not worth it
* Add more world ops
* `world.clear()`
* `world.reserve<T: Bundle>(count: usize)`
* Try using the old archetype allocation strategy (allocate new memory on resize and copy everything over). I expect this to improve batch insertion performance at the cost of unbatched performance. But thats just a guess. I'm not an allocation perf pro :)
* Adapt Commands apis for consistency with new World apis
## Benchmarks
key:
* `bevy_old`: bevy `main` branch
* `bevy`: this branch
* `_foreach`: uses an optimized for_each iterator
* ` _sparse`: uses sparse set storage (if unspecified assume table storage)
* `_system`: runs inside a system (if unspecified assume test happens via direct world ops)
### Simple Insert (from ecs_bench_suite)
### Simpler Iter (from ecs_bench_suite)
### Fragment Iter (from ecs_bench_suite)
### Sparse Fragmented Iter
Iterate a query that matches 5 entities from a single matching archetype, but there are 100 unmatching archetypes
### Schedule (from ecs_bench_suite)
### Add Remove Component (from ecs_bench_suite)
### Add Remove Component Big
Same as the test above, but each entity has 5 "large" matrix components and 1 "large" matrix component is added and removed
### Get Component
Looks up a single component value a large number of times
This PR is easiest to review commit by commit.
Followup on https://github.com/bevyengine/bevy/pull/1309#issuecomment-767310084
- [x] Switch from a bash script to an xtask rust workspace member.
- Results in ~30s longer CI due to compilation of the xtask itself
- Enables Bevy contributors on any platform to run `cargo ci` to run linting -- if the default available Rust is the same version as on CI, then the command should give an identical result.
- [x] Use the xtask from official CI so there's only one place to update.
- [x] Bonus: Run clippy on the _entire_ workspace (existing CI setup was missing the `--workspace` flag
- [x] Clean up newly-exposed clippy errors
~#1388 builds on this to clean up newly discovered clippy errors -- I thought it might be nicer as a separate PR.~ Nope, merged it into this one so CI would pass.
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
I have run the VSCode Extension [markdownlint](https://marketplace.visualstudio.com/items?itemName=DavidAnson.vscode-markdownlint) on all Markdown Files in the Repo.
The provided Rules are documented here: https://github.com/DavidAnson/markdownlint/blob/v0.23.1/doc/Rules.md
Rules I didn't follow/fix:
* MD024/no-duplicate-heading
* Changelog: Here Heading will always repeat.
* Examples Readme: Platform-specific documentation should be symmetrical.
* MD025/single-title
* MD026/no-trailing-punctuation
* Caused by the ! in "Hello, World!".
* MD033/no-inline-html
* The plugins_guidlines file does need HTML, so the shown badges aren't downscaled too much.
* ~~MD036/no-emphasis-as-heading:~~
* ~~This Warning only Appears in the Github Issue Templates and can be ignored.~~
* ~~MD041/first-line-heading~~
* ~~Only appears in the Readme for the AlienCake example Assets, which is unimportant.~~
---
I also sorted the Examples in the Readme and Cargo.toml in this order/Priority:
* Topic/Folder
* Introductionary Examples
* Alphabetical Order
The explanation for each case, where it isn't Alphabetical :
* Diagnostics
* log_diagnostics: The usage of inbuild Diagnostics is more important than creating your own.
* ECS (Entity Component System)
* ecs_guide: The guide should be read, before diving into other Features.
* Reflection
* reflection: Basic Explanation should be read, before more advanced Topics.
* WASM Examples
* hello_wasm: It's "Hello, World!".
* Rename reflect 'hash' method to 'reflect_hash' to avoid colliding with std:#️⃣:Hash::hash to resolve#943.
* Rename partial_eq to reflect_partial_eq to avoid collisions with implementations of PartialEq on primitives.
