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2755 commits

Author SHA1 Message Date
Gino Valente
e6f34ba47f bevy_reflect: Add statically available type info for reflected types (#4042)
# 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>
2022-06-09 21:18:15 +00:00
Peter Hebden
1679a99738 Fix typo in game_menu.rs (#4977)
Should be trivial

# Objective

There is a typo in a comment that is fixed in this commit

## Solution

Fix the typo
`positionned` -> `positioned`

---
2022-06-09 20:57:43 +00:00
François
c6958b3056 add a SceneBundle to spawn a scene (#2424)
# Objective

- Spawning a scene is handled as a special case with a command `spawn_scene` that takes an handle but doesn't let you specify anything else. This is the only handle that works that way.
- Workaround for this have been to add the `spawn_scene` on `ChildBuilder` to be able to specify transform of parent, or to make the `SceneSpawner` available to be able to select entities from a scene by their instance id

## Solution

Add a bundle
```rust
pub struct SceneBundle {
    pub scene: Handle<Scene>,
    pub transform: Transform,
    pub global_transform: GlobalTransform,
    pub instance_id: Option<InstanceId>,
}
```

and instead of 
```rust
commands.spawn_scene(asset_server.load("models/FlightHelmet/FlightHelmet.gltf#Scene0"));
```
you can do
```rust
commands.spawn_bundle(SceneBundle {
    scene: asset_server.load("models/FlightHelmet/FlightHelmet.gltf#Scene0"),
    ..Default::default()
});
```

The scene will be spawned as a child of the entity with the `SceneBundle`

~I would like to remove the command `spawn_scene` in favor of this bundle but didn't do it yet to get feedback first~

Co-authored-by: François <8672791+mockersf@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-06-09 20:34:09 +00:00
James Liu
cdb62af4bf Replace ComponentSparseSet's internals with a Column (#4909)
# Objective
Following #4855, `Column` is just a parallel `BlobVec`/`Vec<UnsafeCell<ComponentTicks>>` pair, which is identical to the dense and ticks vecs in `ComponentSparseSet`, which has some code duplication with `Column`.

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

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

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

This PR makes does the following:

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

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

One alternative considered is keeping a thread-local reference to the pool for all threads in each pool to enable the same `tokio::spawn` interface. This would spawn tasks on the same pool that a task is currently running in. However this potentially leads to potential footgun situations where long running blocking tasks run on `ComputeTaskPool`.
2022-06-09 02:43:24 +00:00
Cai Bingjun
5ace79ff09 Let the project page support GitHub's new ability to display open source licenses (#4966)
Change _LICENSE-APACHE_ and _LICENSE-MIT_ file location
Delete _LICENSE_
You can make the license in about on bevy's GitHub page display as **Apache-2.0, MIT licenses found** instead of **View license**
2022-06-08 17:55:57 +00:00
Carter Anderson
f28b921209 Add "depth_load_op" configuration to 3d Cameras (#4904)
# Objective

Users should be able to configure depth load operations on cameras. Currently every camera clears depth when it is rendered. But sometimes later passes need to rely on depth from previous passes.

## Solution

This adds the `Camera3d::depth_load_op` field with a new `Camera3dDepthLoadOp` value. This is a custom type because Camera3d uses "reverse-z depth" and this helps us record and document that in a discoverable way. It also gives us more control over reflection + other trait impls, whereas `LoadOp` is owned by the `wgpu` crate.

```rust
commands.spawn_bundle(Camera3dBundle {
    camera_3d: Camera3d {
        depth_load_op: Camera3dDepthLoadOp::Load,
        ..default()
    },
    ..default()
});
```

### two_passes example with the "second pass" camera configured to the default (clear depth to 0.0)

![image](https://user-images.githubusercontent.com/2694663/171743172-46d4fdd5-5090-46ea-abe4-1fbc519f6ee8.png)


### two_passes example with the "second pass" camera configured to "load" the depth
![image](https://user-images.githubusercontent.com/2694663/171743323-74dd9a1d-9c25-4883-98dd-38ca0bed8c17.png)

---

## Changelog

### Added

* `Camera3d` now has a `depth_load_op` field, which can configure the Camera's main 3d pass depth loading behavior.
2022-06-07 22:22:10 +00:00
Aevyrie
cbf032419d Refactor Camera methods and add viewport rect (#4948)
While working on a refactor of `bevy_mod_picking` to include viewport-awareness, I found myself writing these functions to test if a cursor coordinate was inside the camera's rendered area.

# Objective

- Simplify conversion from physical to logical pixels
- Add methods that returns the dimensions of the viewport as a min-max rect

---

## Changelog

- Added `Camera::to_logical`
- Added `Camera::physical_viewport_rect`
- Added `Camera::logical_viewport_rect`
2022-06-07 15:23:45 +00:00
Johan Klokkhammer Helsing
d51a87cf28 Recommend posting new plugins in #crates discord channel (#4956)
# Objective

- Guide people to the right discord channel to post about their new plugin. #showcase was split into multiple channels.

## Solution

- recommend posting in #crates
2022-06-07 08:14:10 +00:00
François
73174730e4 use the default() method in examples instead of Default::default() (#4952)
# Objective

- Use the `..default()` method in examples instead of `..Default::default()`
2022-06-07 02:16:47 +00:00
Danny
649e30de09 update system test example to include using events (#4951)
# Objective

- Adds an example of testing systems that handle events. I had a hard time figuring out how to do it a couple days ago so figured an official example could be useful.
- Fixes #4936

## Solution

- Adds a `Score` resource and an `EnemyDied` event. An `update_score` system updates the score when a new event comes through. I'm not sure the example is great, as this probably isn't how you'd do it in a real game, but I didn't want to change the existing example too much.
2022-06-07 02:02:53 +00:00
François
39ea1bb9b7 run examples in wasm in CI (#4818)
# Objective

- Run examples in WASM in CI
- Fix #4817 

## Solution

- on feature `bevy_ci_testing`
  - add an extra log message before exiting
  - when building for wasm, read CI config file at compile time
- add a simple [playwright](https://playwright.dev) test script that opens the browser then waits for the success log, and takes a screenshot
- add a CI job that runs the playwright test for Chromium and Firefox on one example (lighting) and save the screenshots
  - Firefox screenshot is good (with some clusters visible)
  - Chromium screenshot is gray, I don't know why but it's logging `GPU stall due to ReadPixels`
  - Webkit is not enabled for now, to revisit once https://bugs.webkit.org/show_bug.cgi?id=234926 is fixed or worked around
- the CI job only runs on bors validation

example run: https://github.com/mockersf/bevy/actions/runs/2361673465. The screenshots can be downloaded
2022-06-06 20:22:51 +00:00
François
193998b5d4 add NO_STORAGE_BUFFERS_SUPPORT shaderdef when needed (#4949)
# Objective

- fix #4946 
- fix running 3d in wasm

## Solution

- since #4867, the imports are splitter differently, and this shader def was not always set correctly depending on the shader used
- add it when needed
2022-06-06 20:00:30 +00:00
Wybe Westra
25219a4d18 Add transparency examples (#3695)
Adds examples demonstrating transparency for 2d, 3d and UI.

Fixes #3215.
2022-06-06 17:52:09 +00:00
ira
92ddfe8ad4 Add methods for querying lists of entities. (#4879)
# Objective
Improve querying ergonomics around collections and iterators of entities.

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

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

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

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

Also added `unsafe fn iter_many_unsafe`.

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

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

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

```

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

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

Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-06-06 16:09:16 +00:00
dataphract
b47291264b diagnostics: meaningful error when graph node has wrong number of inputs (#4924)
# Objective

Currently, providing the wrong number of inputs to a render graph node triggers this assertion:

```
thread 'main' panicked at 'assertion failed: `(left == right)`
  left: `1`,
 right: `2`', /[redacted]/bevy/crates/bevy_render/src/renderer/graph_runner.rs:164:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

This does not provide the user any context.

## Solution

Add a new `RenderGraphRunnerError` variant to handle this case. The new message looks like this:

```
ERROR bevy_render::renderer: Error running render graph:
ERROR bevy_render::renderer: > node (name: 'Some("outline_pass")') has 2 input slots, but was provided 1 values
```

---

## Changelog

### Changed

`RenderGraphRunnerError` now has a new variant, `MismatchedInputCount`.

## Migration Guide

Exhaustive matches on `RenderGraphRunnerError` will need to add a branch to handle the new `MismatchedInputCount` variant.
2022-06-06 15:47:52 +00:00
Yutao Yuan
c4080c6832 Fix release workflow (#4903)
# Objective

While playing with the code, I found some problems in the recently merged version-bumping workflow:
- Most importantly, now that we are using `0.8.0-dev` in development, the workflow will try to bump it to `0.9.0` 😭 
- The crate filter is outdated now that we have more crates in `tools`.
- We are using `bevy@users.noreply.github.com`, but according to [Github help](https://docs.github.com/en/account-and-profile/setting-up-and-managing-your-personal-account-on-github/managing-email-preferences/setting-your-commit-email-address#about-commit-email-addresses), that email address means "old no-reply email format for the user `bevy`". It is currently not associated with any account, but I feel this is still not appropriate here.

## Solution

- Create a new workflow, `Post-release version bump`, that should be run after a release and bumps version from `0.X.0` to `0.X+1.0-dev`. Unfortunately, cargo-release doesn't have a builtin way to do this, so we need to parse and increment the version manually.
- Add the new crates in `tools` to exclusion list. Also removes the dependency version specifier from `bevy_ecs_compile_fail_tests`. It is not in the workspace so the dependency version will not get automatically updated by cargo-release.
- Change the author email to `41898282+github-actions[bot]@users.noreply.github.com`. According to the discussion [here](https://github.com/actions/checkout/issues/13#issuecomment-724415212) and [here](https://github.community/t/github-actions-bot-email-address/17204/6), this is the email address associated with the github-actions bot account.
- Also add the workflows to our release checklist.

See infmagic2047#5 and infmagic2047#6 for examples of release and post-release PRs.
2022-06-06 15:47:51 +00:00
TheRawMeatball
85cd0eb445 Add ParallelCommands system parameter (#4749)
(follow-up to #4423)
# Objective
Currently, it isn't possible to easily fire commands from within par_for_each blocks. This PR allows for issuing commands from within parallel scopes.
2022-06-06 14:46:41 +00:00
Yoshiera
2f5a1c6e16 remove redundant query parameters (#4945)
# Objective

In the `queue_custom` system in `shader_instancing` example, the query of `material_meshes`  has a redundant `With<Handle<Mesh>>` query filter because `Handle<Mesh>` is included in the component access.

## Solution

Remove the `With<Handle<Mesh>>` filter
2022-06-06 14:24:41 +00:00
Thierry Berger
765bd46c2e add a post-processing example (#4797)
# Objective

- Add an example showing a custom post processing effect, done after the first rendering pass.

## Solution

- A simple post processing "chromatic aberration" effect. I mixed together examples `3d/render_to_texture`, and `shader/shader_material_screenspace_texture`
- Reading a bit how https://github.com/bevyengine/bevy/pull/3430 was done gave me pointers to apply the main pass to the 2d render rather than using a 3d quad.

This work might be or not be relevant to https://github.com/bevyengine/bevy/issues/2724

<details>

<summary> ⚠️ Click for a video of the render ⚠️ I’ve been told it might hurt the eyes 👀 , maybe we should choose another effect just in case ?</summary>

https://user-images.githubusercontent.com/2290685/169138830-a6dc8a9f-8798-44b9-8d9e-449e60614916.mp4

</details>

# Request for feedbacks

- [ ] Is chromatic aberration effect ok ? (Correct term, not a danger for the eyes ?) I'm open to suggestion to make something different.
- [ ] Is the code idiomatic ? I preferred a "main camera -> **new camera with post processing applied to a quad**" approach to emulate minimum modification to existing code wanting to add global post processing.

---

## Changelog

- Add a full screen post processing shader example
2022-06-06 00:06:49 +00:00
Carter Anderson
5e2cfb2f19 Camera Driven Viewports (#4898)
# Objective

Users should be able to render cameras to specific areas of a render target, which enables scenarios like split screen, minimaps, etc.

Builds on the new Camera Driven Rendering added here: #4745 
Fixes: #202
Alternative to #1389 and #3626 (which are incompatible with the new Camera Driven Rendering)

## Solution

![image](https://user-images.githubusercontent.com/2694663/171560044-f0694f67-0cd9-4598-83e2-a9658c4fed57.png)


Cameras can now configure an optional "viewport", which defines a rectangle within their render target to draw to. If a `Viewport` is defined, the camera's `CameraProjection`, `View`, and visibility calculations will use the viewport configuration instead of the full render target. 

```rust
// This camera will render to the first half of the primary window (on the left side).
commands.spawn_bundle(Camera3dBundle {
    camera: Camera {
        viewport: Some(Viewport {
            physical_position: UVec2::new(0, 0),
            physical_size: UVec2::new(window.physical_width() / 2, window.physical_height()),
            depth: 0.0..1.0,
        }),
        ..default()
    },
    ..default()
});
```

To account for this, the `Camera` component has received a few adjustments:

* `Camera` now has some new getter functions:
  * `logical_viewport_size`, `physical_viewport_size`, `logical_target_size`, `physical_target_size`, `projection_matrix`
*  All computed camera values are now private and live on the `ComputedCameraValues` field (logical/physical width/height, the projection matrix). They are now exposed on `Camera` via getters/setters  This wasn't _needed_ for viewports, but it was long overdue.

---

## Changelog

### Added

* `Camera` components now have a `viewport` field, which can be set to draw to a portion of a render target instead of the full target.
* `Camera` component has some new functions: `logical_viewport_size`, `physical_viewport_size`, `logical_target_size`, `physical_target_size`, and `projection_matrix`
* Added a new split_screen example illustrating how to render two cameras to the same scene

## Migration Guide

`Camera::projection_matrix` is no longer a public field. Use the new `Camera::projection_matrix()` method instead:

```rust

// Bevy 0.7
let projection = camera.projection_matrix;

// Bevy 0.8
let projection = camera.projection_matrix();
```
2022-06-05 00:27:49 +00:00
Henry Sloan
8e08e26c25 Update commented vsync code in example to use present_mode (#4926)
# Objective

- To fix the broken commented code in `examples/shader/compute_shader_game_of_life.rs` for disabling frame throttling

## Solution

- Change the commented code from using the old `WindowDescriptor::vsync` to the new `WindowDescriptor::present_mode`

### Note
I chose to use the fully qualified scope `bevy:🪟:PresentWindow::Immediate` rather than explicitly including `PresentWindow` to avoid an unused import when the code is commented.
2022-06-04 20:00:01 +00:00
Alice Cecile
3a9383f997 Revert ndk-glue to 0.5 to synchronize with winit (#4916)
# Objective

- Upgrading ndk-glue (our Android interop layer) desynchronized us from winit
- This further broke Android builds, see #4905 (oops...)
- Reverting to 0.5 should help with this, until the new `winit` version releases
- Fixes #4774 and closes #4529
2022-06-04 14:30:44 +00:00
Matthias Deiml
1fcb7d0c2e Set naga capabilities corresponding to wgpu features (#4824)
# Objective

At the moment all extra capabilities are disabled when validating shaders with naga:
c7c08f95cb/crates/bevy_render/src/render_resource/shader.rs (L146-L149)
This means these features can't be used even if the corresponding wgpu features are active.

## Solution

With these changes capabilities are now set corresponding to `RenderDevice::features`.

---

I have validated these changes for push constants with a project I am currently working on. Though bevy does not support creating pipelines with push constants yet, so I was only able to see that shaders are validated and compiled as expected.
2022-06-03 20:50:50 +00:00
Christopher Durham
f0218b9b2b Move primitive type registration into bevy_reflect (#4844)
# 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).
2022-06-03 20:28:44 +00:00
Alex Saveau
9976ecb810 Fix crash when using Duration::MAX (#4900)
# Objective

If you set the `ReactiveLowPower` max wait to `Duration::MAX`, stuff panics. Fix that.

## Solution

Wait forever if addition failed.
2022-06-02 19:42:20 +00:00
Carter Anderson
f487407e07 Camera Driven Rendering (#4745)
This adds "high level camera driven rendering" to Bevy. The goal is to give users more control over what gets rendered (and where) without needing to deal with render logic. This will make scenarios like "render to texture", "multiple windows", "split screen", "2d on 3d", "3d on 2d", "pass layering", and more significantly easier. 

Here is an [example of a 2d render sandwiched between two 3d renders (each from a different perspective)](https://gist.github.com/cart/4fe56874b2e53bc5594a182fc76f4915):
![image](https://user-images.githubusercontent.com/2694663/168411086-af13dec8-0093-4a84-bdd4-d4362d850ffa.png)

Users can now spawn a camera, point it at a RenderTarget (a texture or a window), and it will "just work". 

Rendering to a second window is as simple as spawning a second camera and assigning it to a specific window id:
```rust
// main camera (main window)
commands.spawn_bundle(Camera2dBundle::default());

// second camera (other window)
commands.spawn_bundle(Camera2dBundle {
    camera: Camera {
        target: RenderTarget::Window(window_id),
        ..default()
    },
    ..default()
});
```

Rendering to a texture is as simple as pointing the camera at a texture:

```rust
commands.spawn_bundle(Camera2dBundle {
    camera: Camera {
        target: RenderTarget::Texture(image_handle),
        ..default()
    },
    ..default()
});
```

Cameras now have a "render priority", which controls the order they are drawn in. If you want to use a camera's output texture as a texture in the main pass, just set the priority to a number lower than the main pass camera (which defaults to `0`).

```rust
// main pass camera with a default priority of 0
commands.spawn_bundle(Camera2dBundle::default());

commands.spawn_bundle(Camera2dBundle {
    camera: Camera {
        target: RenderTarget::Texture(image_handle.clone()),
        priority: -1,
        ..default()
    },
    ..default()
});

commands.spawn_bundle(SpriteBundle {
    texture: image_handle,
    ..default()
})
```

Priority can also be used to layer to cameras on top of each other for the same RenderTarget. This is what "2d on top of 3d" looks like in the new system:

```rust
commands.spawn_bundle(Camera3dBundle::default());

commands.spawn_bundle(Camera2dBundle {
    camera: Camera {
        // this will render 2d entities "on top" of the default 3d camera's render
        priority: 1,
        ..default()
    },
    ..default()
});
```

There is no longer the concept of a global "active camera". Resources like `ActiveCamera<Camera2d>` and `ActiveCamera<Camera3d>` have been replaced with the camera-specific `Camera::is_active` field. This does put the onus on users to manage which cameras should be active.

Cameras are now assigned a single render graph as an "entry point", which is configured on each camera entity using the new `CameraRenderGraph` component. The old `PerspectiveCameraBundle` and `OrthographicCameraBundle` (generic on camera marker components like Camera2d and Camera3d) have been replaced by `Camera3dBundle` and `Camera2dBundle`, which set 3d and 2d default values for the `CameraRenderGraph` and projections.

```rust
// old 3d perspective camera
commands.spawn_bundle(PerspectiveCameraBundle::default())

// new 3d perspective camera
commands.spawn_bundle(Camera3dBundle::default())
```

```rust
// old 2d orthographic camera
commands.spawn_bundle(OrthographicCameraBundle::new_2d())

// new 2d orthographic camera
commands.spawn_bundle(Camera2dBundle::default())
```

```rust
// old 3d orthographic camera
commands.spawn_bundle(OrthographicCameraBundle::new_3d())

// new 3d orthographic camera
commands.spawn_bundle(Camera3dBundle {
    projection: OrthographicProjection {
        scale: 3.0,
        scaling_mode: ScalingMode::FixedVertical,
        ..default()
    }.into(),
    ..default()
})
```

Note that `Camera3dBundle` now uses a new `Projection` enum instead of hard coding the projection into the type. There are a number of motivators for this change: the render graph is now a part of the bundle, the way "generic bundles" work in the rust type system prevents nice `..default()` syntax, and changing projections at runtime is much easier with an enum (ex for editor scenarios). I'm open to discussing this choice, but I'm relatively certain we will all come to the same conclusion here. Camera2dBundle and Camera3dBundle are much clearer than being generic on marker components / using non-default constructors.

If you want to run a custom render graph on a camera, just set the `CameraRenderGraph` component:

```rust
commands.spawn_bundle(Camera3dBundle {
    camera_render_graph: CameraRenderGraph::new(some_render_graph_name),
    ..default()
})
```

Just note that if the graph requires data from specific components to work (such as `Camera3d` config, which is provided in the `Camera3dBundle`), make sure the relevant components have been added.

Speaking of using components to configure graphs / passes, there are a number of new configuration options:

```rust
commands.spawn_bundle(Camera3dBundle {
    camera_3d: Camera3d {
        // overrides the default global clear color 
        clear_color: ClearColorConfig::Custom(Color::RED),
        ..default()
    },
    ..default()
})

commands.spawn_bundle(Camera3dBundle {
    camera_3d: Camera3d {
        // disables clearing
        clear_color: ClearColorConfig::None,
        ..default()
    },
    ..default()
})
```

Expect to see more of the "graph configuration Components on Cameras" pattern in the future.

By popular demand, UI no longer requires a dedicated camera. `UiCameraBundle` has been removed. `Camera2dBundle` and `Camera3dBundle` now both default to rendering UI as part of their own render graphs. To disable UI rendering for a camera, disable it using the CameraUi component:

```rust
commands
    .spawn_bundle(Camera3dBundle::default())
    .insert(CameraUi {
        is_enabled: false,
        ..default()
    })
```

## Other Changes

* The separate clear pass has been removed. We should revisit this for things like sky rendering, but I think this PR should "keep it simple" until we're ready to properly support that (for code complexity and performance reasons). We can come up with the right design for a modular clear pass in a followup pr.
* I reorganized bevy_core_pipeline into Core2dPlugin and Core3dPlugin (and core_2d / core_3d modules). Everything is pretty much the same as before, just logically separate. I've moved relevant types (like Camera2d, Camera3d, Camera3dBundle, Camera2dBundle) into their relevant modules, which is what motivated this reorganization.
* I adapted the `scene_viewer` example (which relied on the ActiveCameras behavior) to the new system. I also refactored bits and pieces to be a bit simpler. 
* All of the examples have been ported to the new camera approach. `render_to_texture` and `multiple_windows` are now _much_ simpler. I removed `two_passes` because it is less relevant with the new approach. If someone wants to add a new "layered custom pass with CameraRenderGraph" example, that might fill a similar niche. But I don't feel much pressure to add that in this pr.
* Cameras now have `target_logical_size` and `target_physical_size` fields, which makes finding the size of a camera's render target _much_ simpler. As a result, the `Assets<Image>` and `Windows` parameters were removed from `Camera::world_to_screen`, making that operation much more ergonomic.
* Render order ambiguities between cameras with the same target and the same priority now produce a warning. This accomplishes two goals:
    1. Now that there is no "global" active camera, by default spawning two cameras will result in two renders (one covering the other). This would be a silent performance killer that would be hard to detect after the fact. By detecting ambiguities, we can provide a helpful warning when this occurs.
    2. Render order ambiguities could result in unexpected / unpredictable render results. Resolving them makes sense.

## Follow Up Work

* Per-Camera viewports, which will make it possible to render to a smaller area inside of a RenderTarget (great for something like splitscreen)
* Camera-specific MSAA config (should use the same "overriding" pattern used for ClearColor)
* Graph Based Camera Ordering: priorities are simple, but they make complicated ordering constraints harder to express. We should consider adopting a "graph based" camera ordering model with "before" and "after" relationships to other cameras (or build it "on top" of the priority system).
* Consider allowing graphs to run subgraphs from any nest level (aka a global namespace for graphs). Right now the 2d and 3d graphs each need their own UI subgraph, which feels "fine" in the short term. But being able to share subgraphs between other subgraphs seems valuable.
* Consider splitting `bevy_core_pipeline` into `bevy_core_2d` and `bevy_core_3d` packages. Theres a shared "clear color" dependency here, which would need a new home.
2022-06-02 00:12:17 +00:00
François
f2b53de4aa Do not bundle the assets from wasm example in the crate (#4895)
# Objective

- Fix #4881 

## Solution

- Do not bundle the assets from wasm example in the crate; tested with `cargo package` to check the produced crate
2022-06-01 23:05:30 +00:00
François
5a1866c13d Bevy release train - add a workflow to manually create a PR updating Bevy version (#3283)
# Objective

- Ensure future Bevy releases happens smoothly

## Solution

- Add a workflow that will open a PR updating all Bevy crate that can be created manually

example PR opened: https://github.com/mockersf/bevy/pull/62

The day from this PR does not need to be the release day, it will just open the PR to prepare it. Later if we feel confident, it could push automatically to crates.io.


how to trigger the workflow: https://docs.github.com/en/actions/managing-workflow-runs/manually-running-a-workflow
2022-06-01 22:31:24 +00:00
François
a16ffe6239 create font atlas that can contains fonts of any size (#3592)
# Objective

- Bevy currently panics when displaying text with a *very* big font size  (with font size greater than 400, the glyph would have a width or height greater than 512)
```
thread 'main' panicked at 'Fatal error when processing text: failed to add glyph to newly-created atlas GlyphId(514).', crates/bevy_ui/src/widget/text.rs:118:21
```

## Solution

- Create font atlas that scales up with the size of the glyphs
2022-06-01 20:44:30 +00:00
Robert Swain
cc4062ec43 Split mesh shader files (#4867)
# Objective

- Split PBR and 2D mesh shaders into types and bindings to prepare the shaders to be more reusable.
- See #3969 for details. I'm doing this in multiple steps to make review easier.

---

## Changelog

- Changed: 2D and PBR mesh shaders are now split into types and bindings, the following shader imports are available: `bevy_pbr::mesh_view_types`, `bevy_pbr::mesh_view_bindings`, `bevy_pbr::mesh_types`, `bevy_pbr::mesh_bindings`, `bevy_sprite::mesh2d_view_types`, `bevy_sprite::mesh2d_view_bindings`, `bevy_sprite::mesh2d_types`, `bevy_sprite::mesh2d_bindings`

## Migration Guide

- In shaders for 3D meshes:
  - `#import bevy_pbr::mesh_view_bind_group` -> `#import bevy_pbr::mesh_view_bindings`
  - `#import bevy_pbr::mesh_struct` -> `#import bevy_pbr::mesh_types`
    - NOTE: If you are using the mesh bind group at bind group index 2, you can remove those binding statements in your shader and just use `#import bevy_pbr::mesh_bindings` which itself imports the mesh types needed for the bindings.
- In shaders for 2D meshes:
  - `#import bevy_sprite::mesh2d_view_bind_group` -> `#import bevy_sprite::mesh2d_view_bindings`
  - `#import bevy_sprite::mesh2d_struct` -> `#import bevy_sprite::mesh2d_types`
    - NOTE: If you are using the mesh2d bind group at bind group index 2, you can remove those binding statements in your shader and just use `#import bevy_sprite::mesh2d_bindings` which itself imports the mesh2d types needed for the bindings.
2022-05-31 23:23:25 +00:00
Robert Swain
bdef86ea6e Generate vertex tangents using mikktspace (#3872)
# Objective

Models can be produced that do not have vertex tangents but do have normal map textures. The tangents can be generated. There is a way that the vertex tangents can be generated to be exactly invertible to avoid introducing error when recreating the normals in the fragment shader.

## Solution

- After attempts to get https://github.com/gltf-rs/mikktspace to integrate simple glam changes and version bumps, and releases of that crate taking weeks / not being made (no offense intended to the authors/maintainers, bevy just has its own timelines and needs to take care of) it was decided to fork that repository. The following steps were taken:
  - mikktspace was forked to https://github.com/bevyengine/mikktspace in order to preserve the repository's history in case the original is ever taken down
  - The README in that repo was edited to add a note stating from where the repository was forked and explaining why
  - The repo was locked for changes as its only purpose is historical
  - The repo was integrated into the bevy repo using `git subtree add --prefix crates/bevy_mikktspace git@github.com:bevyengine/mikktspace.git master`
  - In `bevy_mikktspace`:
    - The travis configuration was removed
    - `cargo fmt` was run
    - The `Cargo.toml` was conformed to bevy's (just adding bevy to the keywords, changing the homepage and repository, changing the version to 0.7.0-dev - importantly the license is exactly the same)
    - Remove the features, remove `nalgebra` entirely, only use `glam`, suppress clippy.
      - This was necessary because our CI runs clippy with `--all-features` and the `nalgebra` and `glam` features are mutually exclusive, plus I don't want to modify this highly numerically-sensitive code just to appease clippy and diverge even more from upstream.
- Rebase https://github.com/bevyengine/bevy/pull/1795
  - @jakobhellermann said it was fine to copy and paste but it ended up being almost exactly the same with just a couple of adjustments when validating correctness so I decided to actually rebase it and then build on top of it.
- Use the exact same fragment shader code to ensure correct normal mapping.
- Tested with both https://github.com/KhronosGroup/glTF-Sample-Models/tree/master/2.0/NormalTangentMirrorTest which has vertex tangents and https://github.com/KhronosGroup/glTF-Sample-Models/tree/master/2.0/NormalTangentTest which requires vertex tangent generation

Co-authored-by: alteous <alteous@outlook.com>
2022-05-31 22:53:54 +00:00
François
27c321e33f run examples on windows (#4437)
# Objective

- ~~Running examples on Linux in CI timeout~~Linux is back!
- But hey we can run examples on windows too!

## Solution

- Run examples on windows daily
- I also added a 30 minutes timeout so that when it explodes, it doesn't explodes in 6 hours (the default timeout)
- And simplified the linux examples by not requiring a custom feature set
2022-05-31 17:30:31 +00:00
Daniikk1012
ae0ccfb4f6 Make ScalingMode more flexible (#3253)
Adds ability to specify scaling factor for `WindowSize`, size of the fixed axis for `FixedVertical` and `FixedHorizontal` and a new `ScalingMode` that is a mix of `FixedVertical` and `FixedHorizontal`

# The issue

Currently, only available options are to:

* Have one of the axes fixed to value 1
* Have viewport size match the window size
* Manually adjust viewport size

In most of the games these options are not enough and more advanced scaling methods have to be used

## Solution

The solution is to provide additional parameters to current scaling modes, like scaling factor for `WindowSize`. Additionally, a more advanced `Auto` mode is added, which dynamically switches between behaving like `FixedVertical` and `FixedHorizontal` depending on the window's aspect ratio.

Co-authored-by: Daniikk1012 <49123959+Daniikk1012@users.noreply.github.com>
2022-05-31 17:14:12 +00:00
Alex Saveau
caef967d14 Derive default on ReportExecutionOrderAmbiguities (#4873) 2022-05-31 15:54:38 +00:00
Chris Dawkins
cea23b9969 Update "C-Bug" label and url in CONTRIBUTING.md (#4880)
'bug' is not a valid label. Changed it to "C-Bug".

Co-authored-by: siph <siph@github>
2022-05-31 15:37:23 +00:00
robtfm
ee4bcbea3c add depth_bias to SpecializedMaterial (#4101)
# Objective

allow meshes with equal z-depth to be rendered in a chosen order / avoid z-fighting

## Solution

add a depth_bias to SpecializedMaterial that is added to the mesh depth used for render-ordering.
2022-05-31 02:02:49 +00:00
Félix Lescaudey de Maneville
f000c2b951 Clippy improvements (#4665)
# Objective

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

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

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

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

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


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

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

## Solution

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

While writing this PR I noticed that `CommandQueue` doesn't seem to drop the commands that weren't applied. While this is a pretty niche case (you would have to be manually using `CommandQueue`/`std::mem::swap`ping one), I wonder if it should be documented anyway.
2022-05-30 22:45:09 +00:00
Niklas Eicker
48289984ea Add license files to all published crates (#4828)
# Objective

Add our licenses to every published crate

Fixes #4719

## Solution

- Copy licenses to every crate before publishing
2022-05-30 22:28:32 +00:00
Alice Cecile
53bcecbbfc Make bug template more beginner-friendly (#4652)
# Objective

1. "What you expected to happen" and "what actually happened" often involves trivial duplication.
2. "Please provide full reproduction steps" is not helpful advice to new contributors.
3. The OS field was commonly useless or inadequate.
4. The description for "additional information" effectively just repeated the title of the field.

## Solution

1. Unify these fields into a single "what went wrong" field.
2. Provide an example of a useful reproduction.
3. Replace OS field with an optional "Setup Information" field that captures information about other critical setup like Rust version and hardware.
4. Provide helpful advice about what sort of information may be useful to add.
2022-05-30 22:11:44 +00:00
ira
ef032040dd Cargo --timings option has been stabilized. Update profiling.md. (#4850)
As of https://github.com/rust-lang/cargo/pull/10245 `--timings` has been stabilized.
Update profiling.md to reflect this.

Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-05-30 21:16:48 +00:00
James Liu
d313ba59bd Don't allocate for ComponentDescriptors of non-dynamic component types (#4725)
# Objective
Don't allocate memory for Component types known at compile-time. Save a bit of memory.

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

## Solution
Change them to `assert!` macros inside `#[cfg(debug_assertions)]` blocks.
2022-05-30 20:57:33 +00:00
Jakob Hellermann
4b7f904cfc remove Serialize impl for dyn Array and friends (#4780)
# 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.
2022-05-30 20:22:57 +00:00
Robert Swain
1e8ca45aeb scene_viewer: Make it possible to disable the animation feature (#4849)
# Objective

- The `scene_viewer` example assumes the `animation` feature is enabled, which it is by default. However, animations may have a performance cost that is undesirable when testing performance, for example. Then it is useful to be able to disable the `animation` feature and one would still like the `scene_viewer` example to work.

## Solution

- Gate animation code in `scene_viewer` on the `animation` feature being enabled.
2022-05-30 20:10:26 +00:00
FraserLee
575ffa7c0c Added offset parameter to TextureAtlas::from_grid_with_padding (#4836)
# Objective
Increase compatibility with a fairly common format of padded spritesheets, in which half the padding value occurs before the first sprite box begins. The original behaviour falls out when `Vec2::ZERO` is used for `offset`.

See below unity screenshot for an example of a spritesheet with padding

![Screen Shot 2022-05-24 at 4 11 49 PM](https://user-images.githubusercontent.com/30442265/170123682-287e5733-b69d-452b-b2e6-46d8d29293fb.png)

## Solution
Tiny change to `crates/bevy_sprite/src/texture_atlas.rs`

## Migration Guide

Calls to `TextureAtlas::from_grid_with_padding` should be modified to include a new parameter, which can be set to `Vec2::ZERO` to retain old behaviour.
```rust
from_grid_with_padding(texture, tile_size, columns, rows, padding)
                                  |
                                  V
from_grid_with_padding(texture, tile_size, columns, rows, padding, Vec2::ZERO)
```


Co-authored-by: FraserLee <30442265+FraserLee@users.noreply.github.com>
2022-05-30 19:58:16 +00:00
Gino Valente
fb813a3a64 bevy_reflect: Add #[reflect(default)] attribute for FromReflect (#4140)
# 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>
2022-05-30 19:06:25 +00:00
Robert Swain
a0a3d8798b ExtractResourcePlugin (#3745)
# Objective

- Add an `ExtractResourcePlugin` for convenience and consistency

## Solution

- Add an `ExtractResourcePlugin` similar to `ExtractComponentPlugin` but for ECS `Resource`s. The system that is executed simply clones the main world resource into a render world resource, if and only if the main world resource was either added or changed since the last execution of the system.
- Add an `ExtractResource` trait with a `fn extract_resource(res: &Self) -> Self` function. This is used by the `ExtractResourcePlugin` to extract the resource
- Add a derive macro for `ExtractResource` on a `Resource` with the `Clone` trait, that simply returns `res.clone()`
- Use `ExtractResourcePlugin` wherever both possible and appropriate
2022-05-30 18:36:03 +00:00