Commit graph

946 commits

Author SHA1 Message Date
Boxy
30e35764a1 Replace WorldQueryGats trait with actual gats (#6319)
# Objective

Replace `WorldQueryGats` trait with actual gats

## Solution

Replace `WorldQueryGats` trait with actual gats

---

## Changelog

- Replaced `WorldQueryGats` trait with actual gats

## Migration Guide

- Replace usage of `WorldQueryGats` assoc types with the actual gats on `WorldQuery` trait
2022-11-03 16:33:05 +00:00
ira
262b3fc40d Fix mesh.wgsl error for meshes without normals (#6439)
# Objective
Split `model` assignment out of `#ifdef VERTEX_NORMALS`.
Remove outdated code/comments talking about required mesh attributes. 

Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-11-03 12:38:47 +00:00
Gabriel Bourgeois
4b5a33d970 Add z-index support with a predictable UI stack (#5877)
# Objective

Add consistent UI rendering and interaction where deep nodes inside two different hierarchies will never render on top of one-another by default and offer an escape hatch (z-index) for nodes to change their depth.

## The problem with current implementation

The current implementation of UI rendering is broken in that regard, mainly because [it sets the Z value of the `Transform` component based on a "global Z" space](https://github.com/bevyengine/bevy/blob/main/crates/bevy_ui/src/update.rs#L43) shared by all nodes in the UI. This doesn't account for the fact that each node's final `GlobalTransform` value will be relative to its parent. This effectively makes the depth unpredictable when two deep trees are rendered on top of one-another. 

At the moment, it's also up to each part of the UI code to sort all of the UI nodes. The solution that's offered here does the full sorting of UI node entities once and offers the result through a resource so that all systems can use it.

## Solution

### New ZIndex component
This adds a new optional `ZIndex` enum component for nodes which offers two mechanism:
- `ZIndex::Local(i32)`: Overrides the depth of the node relative to its siblings.
- `ZIndex::Global(i32)`: Overrides the depth of the node relative to the UI root. This basically allows any node in the tree to "escape" the parent and be ordered relative to the entire UI.

Note that in the current implementation, omitting `ZIndex` on a node has the same result as adding `ZIndex::Local(0)`. Additionally, the "global" stacking context is essentially a way to add your node to the root stacking context, so using `ZIndex::Local(n)` on a root node (one without parent) will share that space with all nodes using `Index::Global(n)`.

### New UiStack resource
This adds a new `UiStack` resource which is calculated from both hierarchy and `ZIndex` during UI update and contains a vector of all node entities in the UI, ordered by depth (from farthest from camera to closest). This is exposed publicly by the bevy_ui crate with the hope that it can be used for consistent ordering and to reduce the amount of sorting that needs to be done by UI systems (i.e. instead of sorting everything by `global_transform.z` in every system, this array can be iterated over).

### New z_index example
This also adds a new z_index example that showcases the new `ZIndex` component. It's also a good general demo of the new UI stack system, because making this kind of UI was very broken with the old system (e.g. nodes would render on top of each other, not respecting hierarchy or insert order at all).

![image](https://user-images.githubusercontent.com/1060971/189015985-8ea8f989-0e9d-4601-a7e0-4a27a43a53f9.png)

---

## Changelog

- Added the `ZIndex` component to bevy_ui.
- Added the `UiStack` resource to bevy_ui, and added implementation in a new `stack.rs` module.
- Removed the previous Z updating system from bevy_ui, because it was replaced with the above.
- Changed bevy_ui rendering to use UiStack instead of z ordering.
- Changed bevy_ui focus/interaction system to use UiStack instead of z ordering.
- Added a new z_index example.

## ZIndex demo
Here's a demo I wrote to test these features
https://user-images.githubusercontent.com/1060971/188329295-d7beebd6-9aee-43ab-821e-d437df5dbe8a.mp4


Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-11-02 22:06:04 +00:00
Edvin Kjell
a8a62fcf3d [Fixes #6059] `Entity`'s “ID” should be named “index” instead (#6107)
# Objective

Fixes #6059, changing all incorrect occurrences of ``id`` in the ``entity`` module to ``index``:

* struct level documentation,
* ``id`` struct field,
* ``id`` method and its documentation.

## Solution

Renaming and verifying using CI. 


Co-authored-by: Edvin Kjell <43633999+Edwox@users.noreply.github.com>
2022-11-02 15:19:50 +00:00
Griffin
5640ec855e Add FXAA postprocessing (#6393)
# Objective

- Add post processing passes for FXAA (Fast Approximate Anti-Aliasing)
- Add example comparing MSAA and FXAA

## Solution

When the FXAA plugin is added, passes for FXAA are inserted between the main pass and the tonemapping pass. Supports using either HDR or LDR output from the main pass.

---

## Changelog

- Add a new FXAANode that runs after the main pass when the FXAA plugin is added.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-11-02 06:51:28 +00:00
Niklas Eicker
558859691e Fix return_after_run example (#6420)
# Objective

- Fixes  #6311
- Make it clearer what should be done in the example (close the Bevy app window)

## Solution

- Remove the second windowed Bevy App [since winit does not support this](https://github.com/rust-windowing/winit/blob/v0.27.4/src/event_loop.rs#L82-L83)
- Add title to the Bevy window asking the user to close it

This is more of a quick fix to have a working example. It would be nicer if we had a small real usecase for this functionality.
Another alternativ that I tried out: If we want to showcase a second Bevy app as it was before, we could still do this as long as one of them does not have a window. But I don't see how this is helpful in the context of the example, so I stuck with only one Bevy app and a simple print afterwards.
2022-10-31 16:35:20 +00:00
François
8cdd977a12 Unique plugin (#6411)
# Objective

- Make it impossible to add a plugin twice
- This is going to be more a risk for plugins with configurations, to avoid things like `App::new().add_plugins(DefaultPlugins).add_plugin(ImagePlugin::default_nearest())`

## Solution

- Panic when a plugin is added twice
- It's still possible to mark a plugin as not unique by overriding `is_unique`
- ~~Simpler version of~~ #3988 (not simpler anymore because of how `PluginGroupBuilder` implements `PluginGroup`)
2022-10-31 16:12:19 +00:00
Lena Milizé
599ca782e3 Add a way to toggle AudioSink (#6321)
# Objective

Currently toggling an `AudioSink` (for example from a game menu) requires writing

```rs
if sink.is_paused() {
    sink.play();
} else {
    sink.pause();
}
```

It would be nicer if we could reduce this down to a single line

```rs
sink.toggle();
```

## Solution

Add an `AudioSink::toggle` method which does exactly that.

---

## Changelog

- Added `AudioSink::toggle` which can be used to toggle state of a sink.
2022-10-31 15:57:51 +00:00
ira
13da481bea Add methods to Query<&Children> and Query<&Parent> to iterate over descendants and ancestors (#6185)
# Objective
Add methods to `Query<&Children>` and `Query<&Parent>` to iterate over descendants and ancestors, respectively.

## Changelog

* Added extension trait for `Query` in `bevy_hierarchy`, `HierarchyQueryExt`
* Added method `iter_descendants` to `Query<&Children>` via `HierarchyQueryExt` for iterating over the descendants of an entity.
* Added method `iter_ancestors` to `Query<&Parent>` via `HierarchyQueryExt` for iterating over the ancestors of an entity.

Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-10-31 15:57:50 +00:00
JoJoJet
336049da68 Remove outdated uses of single-tuple bundles (#6406)
# Objective

Bevy still has many instances of using single-tuples `(T,)` to create a bundle. Due to #2975, this is no longer necessary.

## Solution

Search for regex `\(.+\s*,\)`. This should have found every instance.
2022-10-29 18:15:28 +00:00
Mark Nokalt
306c1ac617 Rename Handle::as_weak() to cast_weak() (#5321)
# Objective

Following discussion on #3536 and #3522, `Handle::as_weak()` takes a type `U`, reinterpreting the handle as of another asset type while keeping the same ID. This is mainly used today in font atlas code. This PR does two things:

- Rename the method to `cast_weak()` to make its intent more clear
- Actually change the type uuid in the handle if it's not an asset path variant.

## Migration Guide

- Rename `Handle::as_weak` uses to `Handle::cast_weak`

    The method now properly sets the associated type uuid if the handle is a direct reference (e.g. not a reference to an `AssetPath`), so adjust you code accordingly if you relied on the previous behavior.
2022-10-28 22:43:14 +00:00
Jakob Hellermann
e71c4d2802 fix nightly clippy warnings (#6395)
# Objective

- fix new clippy lints before they get stable and break CI

## Solution

- run `clippy --fix` to auto-fix machine-applicable lints
- silence `clippy::should_implement_trait` for `fn HandleId::default<T: Asset>`

## Changes
- always prefer `format!("{inline}")` over `format!("{}", not_inline)`
- prefer `Box::default` (or `Box::<T>::default` if necessary) over `Box::new(T::default())`
2022-10-28 21:03:01 +00:00
Jakob Hellermann
838b318863 separate tonemapping and upscaling passes (#3425)
Attempt to make features like bloom https://github.com/bevyengine/bevy/pull/2876 easier to implement.

**This PR:**
- Moves the tonemapping from `pbr.wgsl` into a separate pass
- also add a separate upscaling pass after the tonemapping which writes to the swap chain (enables resolution-independant rendering and post-processing after tonemapping)
- adds a `hdr` bool to the camera which controls whether the pbr and sprite shaders render into a `Rgba16Float` texture

**Open questions:**
- ~should the 2d graph work the same as the 3d one?~ it is the same now
- ~The current solution is a bit inflexible because while you can add a post processing pass that writes to e.g. the `hdr_texture`, you can't write to a separate `user_postprocess_texture` while reading the `hdr_texture` and tell the tone mapping pass to read from the `user_postprocess_texture` instead. If the tonemapping and upscaling render graph nodes were to take in a `TextureView` instead of the view entity this would almost work, but the bind groups for their respective input textures are already created in the `Queue` render stage in the hardcoded order.~ solved by creating bind groups in render node

**New render graph:**

![render_graph](https://user-images.githubusercontent.com/22177966/147767249-57dd4229-cfab-4ec5-9bf3-dc76dccf8e8b.png)
<details>
<summary>Before</summary>

![render_graph_old](https://user-images.githubusercontent.com/22177966/147284579-c895fdbd-4028-41cf-914c-e1ffef60e44e.png)
</details>

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-10-26 20:13:59 +00:00
targrub
c18b1a839b Prepare for upcoming rustlang by fixing upcoming clippy warnings (#6376)
# Objective

- Proactive changing of code to comply with warnings generated by beta of rustlang version of cargo clippy.

## Solution

- Code changed as recommended by `rustup update`, `rustup default beta`, `cargo run -p ci -- clippy`.
- Tested using `beta` and `stable`.  No clippy warnings in either after changes made.

---

## Changelog

- Warnings fixed were: `clippy::explicit-auto-deref` (present in 11 files), `clippy::needless-borrow` (present in 2 files), and `clippy::only-used-in-recursion` (only 1 file).
2022-10-26 19:15:15 +00:00
François
5622d56be1 Use plugin setup for resource only used at setup time (#6360)
# Objective

- Build on #6336 for more plugin configurations

## Solution

- `LogSettings`, `ImageSettings` and `DefaultTaskPoolOptions` are now plugins settings rather than resources

---

## Changelog

- `LogSettings` plugin settings have been move to `LogPlugin`, `ImageSettings` to `ImagePlugin` and `DefaultTaskPoolOptions` to `CorePlugin`

## Migration Guide

The `LogSettings` settings have been moved from a resource to `LogPlugin` configuration:

```rust
// Old (Bevy 0.8)
app
  .insert_resource(LogSettings {
    level: Level::DEBUG,
    filter: "wgpu=error,bevy_render=info,bevy_ecs=trace".to_string(),
  })
  .add_plugins(DefaultPlugins)

// New (Bevy 0.9)
app.add_plugins(DefaultPlugins.set(LogPlugin {
    level: Level::DEBUG,
    filter: "wgpu=error,bevy_render=info,bevy_ecs=trace".to_string(),
}))
```


The `ImageSettings` settings have been moved from a resource to `ImagePlugin` configuration:

```rust
// Old (Bevy 0.8)
app
  .insert_resource(ImageSettings::default_nearest())
  .add_plugins(DefaultPlugins)

// New (Bevy 0.9)
app.add_plugins(DefaultPlugins.set(ImagePlugin::default_nearest()))
```


The `DefaultTaskPoolOptions` settings have been moved from a resource to `CorePlugin::task_pool_options`:

```rust
// Old (Bevy 0.8)
app
  .insert_resource(DefaultTaskPoolOptions::with_num_threads(4))
  .add_plugins(DefaultPlugins)

// New (Bevy 0.9)
app.add_plugins(DefaultPlugins.set(CorePlugin {
  task_pool_options: TaskPoolOptions::with_num_threads(4),
}))
```
2022-10-25 22:19:34 +00:00
Carter Anderson
1bb751cb8d Plugins own their settings. Rework PluginGroup trait. (#6336)
# Objective

Fixes #5884 #2879
Alternative to #2988 #5885 #2886

"Immutable" Plugin settings are currently represented as normal ECS resources, which are read as part of plugin init. This presents a number of problems:

1. If a user inserts the plugin settings resource after the plugin is initialized, it will be silently ignored (and use the defaults instead)
2. Users can modify the plugin settings resource after the plugin has been initialized. This creates a false sense of control over settings that can no longer be changed.

(1) and (2) are especially problematic and confusing for the `WindowDescriptor` resource, but this is a general problem.

## Solution

Immutable Plugin settings now live on each Plugin struct (ex: `WindowPlugin`). PluginGroups have been reworked to support overriding plugin values. This also removes the need for the `add_plugins_with` api, as the `add_plugins` api can use the builder pattern directly. Settings that can be used at runtime continue to be represented as ECS resources.

Plugins are now configured like this:

```rust
app.add_plugin(AssetPlugin {
  watch_for_changes: true,
  ..default()
})
```

PluginGroups are now configured like this:

```rust
app.add_plugins(DefaultPlugins
  .set(AssetPlugin {
    watch_for_changes: true,
    ..default()
  })
)
```

This is an alternative to #2988, which is similar. But I personally prefer this solution for a couple of reasons:
* ~~#2988 doesn't solve (1)~~ #2988 does solve (1) and will panic in that case. I was wrong!
* This PR directly ties plugin settings to Plugin types in a 1:1 relationship, rather than a loose "setup resource" <-> plugin coupling (where the setup resource is consumed by the first plugin that uses it).
* I'm not a huge fan of overloading the ECS resource concept and implementation for something that has very different use cases and constraints.

## Changelog

- PluginGroups can now be configured directly using the builder pattern. Individual plugin values can be overridden by using `plugin_group.set(SomePlugin {})`, which enables overriding default plugin values.  
- `WindowDescriptor` plugin settings have been moved to `WindowPlugin` and `AssetServerSettings` have been moved to `AssetPlugin`
- `app.add_plugins_with` has been replaced by using `add_plugins` with the builder pattern.

## Migration Guide

The `WindowDescriptor` settings have been moved from a resource to `WindowPlugin::window`:

```rust
// Old (Bevy 0.8)
app
  .insert_resource(WindowDescriptor {
    width: 400.0,
    ..default()
  })
  .add_plugins(DefaultPlugins)

// New (Bevy 0.9)
app.add_plugins(DefaultPlugins.set(WindowPlugin {
  window: WindowDescriptor {
    width: 400.0,
    ..default()
  },
  ..default()
}))
```


The `AssetServerSettings` resource has been removed in favor of direct `AssetPlugin` configuration:

```rust
// Old (Bevy 0.8)
app
  .insert_resource(AssetServerSettings {
    watch_for_changes: true,
    ..default()
  })
  .add_plugins(DefaultPlugins)

// New (Bevy 0.9)
app.add_plugins(DefaultPlugins.set(AssetPlugin {
  watch_for_changes: true,
  ..default()
}))
```

`add_plugins_with` has been replaced by `add_plugins` in combination with the builder pattern:

```rust
// Old (Bevy 0.8)
app.add_plugins_with(DefaultPlugins, |group| group.disable::<AssetPlugin>());

// New (Bevy 0.9)
app.add_plugins(DefaultPlugins.build().disable::<AssetPlugin>());
```
2022-10-24 21:20:33 +00:00
dataphract
bcc33f6757 feat: add GamepadInfo, expose gamepad names (#6342)
# Objective

Fixes #6339.

## Solution

This PR adds a new type, `GamepadInfo`, which holds metadata associated with a particular `Gamepad`. The `Gamepads` resource now holds a `HashMap<Gamepad, GamepadInfo>`. The `GamepadInfo` is created when the gamepad backend (by default `bevy_gilrs`) emits a "gamepad connected" event.

The `gamepad_viewer` example has been updated to showcase the new functionality.

Before:

![bevy-gamepad-old](https://user-images.githubusercontent.com/86984145/197359427-2130a3c0-bd8a-4683-ae24-2a9eaa98b586.png)

After:

![bevy-gamepad-new](https://user-images.githubusercontent.com/86984145/197359429-f7963163-df26-4906-af7f-6186fe3bd338.png)


---

## Changelog

### Added

- Added `GamepadInfo`.
- Added `Gamepads::name()`, which returns the name of the specified gamepad if it exists.

### Changed

- `GamepadEventType::Connected` is now a tuple variant with a single field of type `GamepadInfo`.
- Since `GamepadInfo` is not `Copy`, `GamepadEventType` is no longer `Copy`. The same is true of `GamepadEvent` and `GamepadEventRaw`.

## Migration Guide

- Pattern matches on `GamepadEventType::Connected` will need to be updated, as the form of the variant has changed.
- Code that requires `GamepadEvent`, `GamepadEventRaw` or `GamepadEventType` to be `Copy` will need to be updated.
2022-10-24 14:33:50 +00:00
Christopher Durham
c19aa5939d Add Exponential Moving Average into diagnostics (#4992)
# Objective

- Add Time-Adjusted Rolling EMA-based smoothing to diagnostics.
- Closes #4983; see that issue for more more information.

## Terms

- EMA - [Exponential Moving Average](https://en.wikipedia.org/wiki/Moving_average#Exponential_moving_average)
- SMA - [Simple Moving Average](https://en.wikipedia.org/wiki/Moving_average#Simple_moving_average)

## Solution

- We use a fairly standard approximation of a true EMA where $EMA_{\text{frame}} = EMA_{\text{previous}} + \alpha \left( x_{\text{frame}} - EMA_{\text{previous}} \right)$ where $\alpha = \Delta t / \tau$ and $\tau$ is an arbitrary smoothness factor. (See #4983 for more discussion of the math.)
- The smoothness factor is here defaulted to $2 / 21$; this was chosen fairly arbitrarily as supposedly related to the existing 20-bucket SMA.
- The smoothness factor can be set on a per-diagnostic basis via `Diagnostic::with_smoothing_factor`.

---

## Changelog

### Added

- `Diagnostic::smoothed` - provides an exponentially smoothed view of a recorded diagnostic, to e.g. reduce jitter in frametime readings.

### Changed
- `LogDiagnosticsPlugin` now records the smoothed value rather than the raw value.
  - For diagnostics recorded less often than every 0.1 seconds, this change to defaults will have no visible effect.
  - For discrete diagnostics where this smoothing is not desirable, set a smoothing factor of 0 to disable smoothing.
  - The average of the recent history is still shown when available.
2022-10-24 13:46:37 +00:00
Cameron
7989cb2650 Add global time scaling (#5752)
# Objective

- Make `Time` API more consistent.
- Support time accel/decel/pause.

## Solution

This is just the `Time` half of #3002. I was told that part isn't controversial.

- Give the "delta time" and "total elapsed time" methods `f32`, `f64`, and `Duration` variants with consistent naming.
- Implement accelerating / decelerating the passage of time.
- Implement stopping time.

---

## Changelog

- Changed `time_since_startup` to `elapsed` because `time.time_*` is just silly.
- Added `relative_speed` and `set_relative_speed` methods.
- Added `is_paused`, `pause`, `unpause` , and methods. (I'd prefer `resume`, but `unpause` matches `Timer` API.)
- Added `raw_*` variants of the "delta time" and "total elapsed time" methods.
- Added `first_update` method because there's a non-zero duration between startup and the first update.

## Migration Guide

- `time.time_since_startup()` -> `time.elapsed()`
- `time.seconds_since_startup()` -> `time.elapsed_seconds_f64()`
- `time.seconds_since_startup_wrapped_f32()` -> `time.elapsed_seconds_wrapped()`

If you aren't sure which to use, most systems should continue to use "scaled" time (e.g. `time.delta_seconds()`). The realtime "unscaled" time measurements (e.g. `time.raw_delta_seconds()`) are mostly for debugging and profiling.
2022-10-22 18:52:29 +00:00
VitalyR
c313e21d65 Update wgpu to 0.14.0, naga to 0.10.0, winit to 0.27.4, raw-window-handle to 0.5.0, ndk to 0.7 (#6218)
# Objective

- Update `wgpu` to 0.14.0, `naga` to `0.10.0`, `winit` to 0.27.4, `raw-window-handle` to 0.5.0, `ndk` to 0.7.

## Solution

---

## Changelog

### Changed

- Changed `RawWindowHandleWrapper` to `RawHandleWrapper` which wraps both `RawWindowHandle` and `RawDisplayHandle`, which satisfies the `impl HasRawWindowHandle and HasRawDisplayHandle` that `wgpu` 0.14.0 requires.

- Changed `bevy_window::WindowDescriptor`'s `cursor_locked` to `cursor_grab_mode`, change its type from `bool` to `bevy_window::CursorGrabMode`.

## Migration Guide

- Adjust usage of `bevy_window::WindowDescriptor`'s `cursor_locked` to `cursor_grab_mode`, and adjust its type from `bool` to `bevy_window::CursorGrabMode`.
2022-10-19 17:40:23 +00:00
Rob Parrett
b2ca3fb8b5 Fix camera ambiguity warning in IOS example (#6300)
# Objective

Fix a camera ambiguity warning in the IOS example

## Solution

I'm assuming that this was accidentally added when UI cameras stopped being a thing. So just delete the extra camera.
2022-10-19 15:05:12 +00:00
张林伟
c7fe4027a1 Rename example file scaling.rs to ui_scaling.rs (#6296)
# Objective

To be consistent like other examples, it's better to keep file name and example name same, so we don't need to find correct example name in Cargo.toml.

## Solution

Rename example file scaling.rs to ui_scaling.rs.
2022-10-19 11:36:26 +00:00
Michel van der Hulst
4407cdb423 Fixes scroll example after inverting UI Y axis (#6290) 2022-10-18 13:28:35 +00:00
Michel van der Hulst
0981789ec7 Fixes incorrect glyph positioning for text2d (#6273)
# Objective
Fixes #6272

## Solution
Revert to old way of positioning text for Text2D rendered text.


Co-authored-by: Michel van der Hulst <hulstmichel@gmail.com>
2022-10-18 13:28:34 +00:00
targrub
c11fbfb3e1 Add getters and setters for InputAxis and ButtonSettings (#6088)
# Objective
Fixes https://github.com/bevyengine/bevy/issues/3418

## Solution

Originally a rebase of https://github.com/bevyengine/bevy/pull/3446.  Work was originally done by mfdorst, who should receive considerable credit.  Then the error types were extensively reworked by targrub.

## Migration Guide

`AxisSettings` now has a `new()`, which may return an `AxisSettingsError`.
`AxisSettings` fields made private; now must be accessed through getters and setters.  There's a dead zone, from `.deadzone_upperbound()` to `.deadzone_lowerbound()`, and a live zone, from `.deadzone_upperbound()` to `.livezone_upperbound()` and from `.deadzone_lowerbound()` to `.livezone_lowerbound()`.
`AxisSettings` setters no longer panic.
`ButtonSettings` fields made private; now must be accessed through getters and setters.
`ButtonSettings` now has a `new()`, which may return a `ButtonSettingsError`.

Co-authored-by: targrub <62773321+targrub@users.noreply.github.com>
2022-10-17 14:38:55 +00:00
Lena Milizé
73605f43b6 Replace the bool argument of Timer with TimerMode (#6247)
As mentioned in #2926, it's better to have an explicit type that clearly communicates the intent of the timer mode rather than an opaque boolean, which can be only understood when knowing the signature or having to look up the documentation.

This also opens up a way to merge different timers, such as `Stopwatch`, and possibly future ones, such as `DiscreteStopwatch` and `DiscreteTimer` from #2683, into one struct.

Signed-off-by: Lena Milizé <me@lvmn.org>

# Objective

Fixes #2926.

## Solution

Introduce `TimerMode` which replaces the `bool` argument of `Timer` constructors. A `Default` value for `TimerMode` is `Once`.

---

## Changelog

### Added

- `TimerMode` enum, along with variants `TimerMode::Once` and `TimerMode::Repeating`

### Changed

- Replace `bool` argument of `Timer::new` and `Timer::from_seconds` with `TimerMode`
- Change `repeating: bool` field of `Timer` with `mode: TimerMode`

## Migration Guide

- Replace `Timer::new(duration, false)` with `Timer::new(duration, TimerMode::Once)`.
- Replace `Timer::new(duration, true)` with `Timer::new(duration, TimerMode::Repeating)`.
- Replace `Timer::from_seconds(seconds, false)` with `Timer::from_seconds(seconds, TimerMode::Once)`.
- Replace `Timer::from_seconds(seconds, true)` with `Timer::from_seconds(seconds, TimerMode::Repeating)`.
- Change `timer.repeating()` to `timer.mode() == TimerMode::Repeating`.
2022-10-17 13:47:01 +00:00
Sergi-Ferrez
05c7babba2 Clarify bevy::ui::Node field and documentation (#5995)
# Objective
Fixes #5820

## Solution

Change field name and documentation from `bevy::ui::Node` struct

---

## Changelog

`bevy::ui::Node` `size` field has renamed to `calculated_size`

## Migration Guide

All references to the old `size` name has been changed, to access `bevy::ui::Node` `size` field use `calculated_size`
2022-10-17 13:27:24 +00:00
ira
92ba6224b9 Use SpatialBundle/TransformBundle in examples (#6002)
Does what it do

Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-10-13 12:53:18 +00:00
Alice Cecile
c0a93aa7a4 Rename system chaining to system piping (#6230)
# Objective

> System chaining is a confusing name: it implies the ability to construct non-linear graphs, and suggests a sense of system ordering that is only incidentally true. Instead, it actually works by passing data from one system to the next, much like the pipe operator.

> In the accepted [stageless RFC](https://github.com/bevyengine/rfcs/blob/main/rfcs/45-stageless.md), this concept is renamed to piping, and "system chaining" is used to construct groups of systems with ordering dependencies between them.

Fixes #6225.

## Changelog

System chaining has been renamed to system piping to improve clarity (and free up the name for new ordering APIs). 

## Migration Guide

The `.chain(handler_system)` method on systems is now `.pipe(handler_system)`.
The `IntoChainSystem` trait is now `IntoPipeSystem`, and the `ChainSystem` struct is now `PipeSystem`.
2022-10-11 15:21:12 +00:00
Michel van der Hulst
6ce7ce208e Change UI coordinate system to have origin at top left corner (#6000)
# Objective
Fixes #5572

## Solution

Approach is to invert the Y-axis of the UI Camera by changing the UI projection matrix to render the UI upside down.

After that I'm trying to fix all issues, that pop up:
- interaction expected the "old" position
- images and text were displayed upside-down
- baseline of text was based on the top of the glyph instead of bottom

... probably a lot more.

---

Result when running examples:
<details>
    <summary>Button example</summary>

main branch:
![button main](https://user-images.githubusercontent.com/4232644/190856087-61dd1d98-42b5-4238-bd97-149744ddfeba.png)
this pr:
![button pr](https://user-images.githubusercontent.com/4232644/190856097-3f4bc97a-ed15-4e97-b7f1-2b2dd6bb8b14.png)

</details>

<details>
    <summary>Text example</summary>

m
![text main](https://user-images.githubusercontent.com/4232644/192142831-4cf19aa1-f49a-485e-af7b-374d6f5c396c.png)
ain branch: 


this pr:
![text pr fixed](https://user-images.githubusercontent.com/4232644/192142829-c433db3b-32e1-4ee8-b493-0b4a4d9c8e70.png)


</details>

<details>
    <summary>Text debug example</summary>

main branch:
![text_debug main](https://user-images.githubusercontent.com/4232644/192142822-940aefa6-e502-410b-8da4-5570f77b5df2.png)

this pr:
![text_debug pr fixed](https://user-images.githubusercontent.com/4232644/194547010-8c968f5c-5a71-4ffc-871d-790c06d48016.png)

</details>

<details>
    <summary>Transparency UI example</summary>

main branch:
![transparency_ui main](https://user-images.githubusercontent.com/4232644/190856172-328c60fe-3622-4598-97d5-2f1595db13b3.png)


this pr:
![transperency_ui pr](https://user-images.githubusercontent.com/4232644/190856179-a2dafb99-41ea-45a9-9dd6-400fa3ef24b9.png)

</details>

<details>
    <summary>UI example</summary>

**ui example**
main branch:
![ui main](https://user-images.githubusercontent.com/4232644/192142812-e20ba31a-6841-46d9-a785-4198cf22dc99.png)

this pr:
![ui pr fixed](https://user-images.githubusercontent.com/4232644/192142788-cc0b74e0-7710-4faa-b5a2-60270a5da77c.png)

</details>

## Changelog
UI coordinate system and cursor position was changed from bottom left origin, y+ up to top left origin, y+ down.

## Migration Guide
All flex layout should be inverted (ColumnReverse => Column, FlexStart => FlexEnd, WrapReverse => Wrap)
System where dealing with cursor position should be changed to account for cursor position being based on the top left instead of bottom left
2022-10-11 12:51:44 +00:00
ira
9423cb6a8d Rename Transform::mul_vec3 to transform_point and improve docs (#6132)
The docs ended up quite verbose :v

Also added a missing `#[inline]` to `GlobalTransform::mul_transform`.

I'd say this resolves #5500

# Migration Guide
`Transform::mul_vec3` has been renamed to `transform_point`.

Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-10-10 16:50:17 +00:00
TimJentzsch
1738527902 Make the default background color of NodeBundle transparent (#6211)
# Objective

Closes #6202.

The default background color for `NodeBundle` is currently white.
However, it's very rare that you actually want a white background color.
Instead, you often want a background color specific to the style of your game or a transparent background (e.g. for UI layout nodes).

## Solution

`Default` is not derived for `NodeBundle` anymore, but explicitly specified.
The default background color is now transparent (`Color::NONE.into()`) as this is the most common use-case, is familiar from the web and makes specifying a layout for your UI less tedious.

---

## Changelog

- Changed the default `NodeBundle.background_color` to be transparent (`Color::NONE.into()`).

## Migration Guide

If you want a `NodeBundle` with a white background color, you must explicitly specify it:

Before:

```rust
let node = NodeBundle {
    ..default()
}
```

After:

```rust
let node = NodeBundle {
    background_color: Color::WHITE.into(),
    ..default()
}
```
2022-10-09 21:03:05 +00:00
Alvin Philips
f2106bb3ce Reduced code duplication in gamepad_viewer example (#6175)
# Objective

- Reduce code duplication in the `gamepad_viewer` example.
- Fixes #6164 

## Solution

- Added a custom Bundle called `GamepadButtonBundle` to avoid repeating similar code throughout the example.
- Created a `new()` method on `GamepadButtonBundle`.



Co-authored-by: Alvin Philips <alvinphilips257@gmail.com>
2022-10-06 13:33:29 +00:00
Fanda Vacek
2362cebcae More explicit help how to cycle the cameras (#6162)
# Objective

Scene viewer example has switch camera keys defined, but only one camera was instantiated on the scene.

## Solution

More explicit help how to cycle the cameras, explaining that more cameras must be present in loaded scene.





Co-authored-by: Fanda Vacek <fvacek@elektroline.cz>
2022-10-05 21:22:11 +00:00
ira
3aaf746675 Example cleanup (#6131)
Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-09-30 13:25:27 +00:00
Cameron
6929d95f7f Replace fixed timestep in alien_cake_addict example with timer (#5760)
# Objective

Examples should use the correct tools for the job.

## Solution

A fixed timestep, by design, can step multiple times consecutively in a single update.

That property used to crash the `alien_cake_addict` example (#2525), which was "fixed" in #3411 (by just not panicking). The proper fix is to use a timer instead, since the system is supposed to spawn a cake every 5 seconds. 

---

A timer guarantees a minimum duration. A fixed timestep guarantees a fixed number of steps per second.
Each one works by essentially sacrificing the other's guarantee.

You can use them together, but no other systems are timestep-based in this example, so the timer is enough.
2022-09-30 11:37:33 +00:00
rustui
59f872647d StreamReceiver does not need to be mutable (#6119)
ResMut -> Res
2022-09-28 17:39:36 +00:00
Charles
197392a2cd use alpha mask even when unlit (#6047)
# Objective

- Alpha mask was previously ignored when using an unlit material. 
- Fixes https://github.com/bevyengine/bevy/issues/4479

## Solution

- Extract the alpha discard to a separate function and use it when unlit is true

## Notes
I tried calling `alpha_discard()` before the `if` in pbr.wgsl, but I had errors related to having a `discard` at the beginning before doing the texture sampling. I'm not sure if there's a way to fix that instead of having the function being called in 2 places.
2022-09-28 05:54:11 +00:00
Charles
8073362039 add globals to mesh view bind group (#5409)
# Objective

- It's often really useful to have access to the time when writing shaders.

## Solution

- Add a UnifformBuffer in the mesh view bind group
- This buffer contains the time, delta time and a wrapping frame count

https://user-images.githubusercontent.com/8348954/180130314-97948c2a-2d11-423d-a9c4-fb5c9d1892c7.mp4

---

## Changelog

- Added a `GlobalsUniform` at position 9 of the mesh view bind group

## Notes

The implementation is currently split between bevy_render and bevy_pbr because I was basing my implementation on the `ViewPlugin`. I'm not sure if that's the right way to structure it.

I named this `globals` instead of just time because we could potentially add more things to it.

## References in other engines

- Godot: <https://docs.godotengine.org/en/stable/tutorials/shaders/shader_reference/canvas_item_shader.html#global-built-ins>
    - Global time since startup, in seconds, by default resets to 0 after 3600 seconds
    - Doesn't seem to have anything else
- Unreal: <https://docs.unrealengine.com/4.26/en-US/RenderingAndGraphics/Materials/ExpressionReference/Constant/>
    - Generic time value that updates every frame. Can be paused or scaled.
    - Frame count node, doesn't seem to be an equivalent for shaders: <https://docs.unrealengine.com/4.26/en-US/BlueprintAPI/Utilities/GetFrameCount/>
- Unity: <https://docs.unity3d.com/Manual/SL-UnityShaderVariables.html>
    - time since startup in seconds. No mention of time wrapping. Stored as a `vec4(t/20, t, t*2, t*3)` where `t` is the value in seconds
    - Also has delta time, sin time and cos time
- ShaderToy: <https://www.shadertoy.com/howto>
    - iTime is the time since startup in seconds.
    - iFrameRate
    - iTimeDelta
    - iFrame frame counter

Co-authored-by: Charles <IceSentry@users.noreply.github.com>
2022-09-28 04:20:27 +00:00
Carter Anderson
dc3f801239 Exclusive Systems Now Implement System. Flexible Exclusive System Params (#6083)
# Objective

The [Stageless RFC](https://github.com/bevyengine/rfcs/pull/45) involves allowing exclusive systems to be referenced and ordered relative to parallel systems. We've agreed that unifying systems under `System` is the right move.

This is an alternative to #4166 (see rationale in the comments I left there). Note that this builds on the learnings established there (and borrows some patterns).

## Solution

This unifies parallel and exclusive systems under the shared `System` trait, removing the old `ExclusiveSystem` trait / impls. This is accomplished by adding a new `ExclusiveFunctionSystem` impl similar to `FunctionSystem`. It is backed by `ExclusiveSystemParam`, which is similar to `SystemParam`. There is a new flattened out SystemContainer api (which cuts out a lot of trait and type complexity). 

This means you can remove all cases of `exclusive_system()`:

```rust
// before
commands.add_system(some_system.exclusive_system());
// after
commands.add_system(some_system);
```

I've also implemented `ExclusiveSystemParam` for `&mut QueryState` and `&mut SystemState`, which makes this possible in exclusive systems:

```rust
fn some_exclusive_system(
    world: &mut World,
    transforms: &mut QueryState<&Transform>,
    state: &mut SystemState<(Res<Time>, Query<&Player>)>,
) {
    for transform in transforms.iter(world) {
        println!("{transform:?}");
    }
    let (time, players) = state.get(world);
    for player in players.iter() {
        println!("{player:?}");
    }
}
```

Note that "exclusive function systems" assume `&mut World` is present (and the first param). I think this is a fair assumption, given that the presence of `&mut World` is what defines the need for an exclusive system.

I added some targeted SystemParam `static` constraints, which removed the need for this:
``` rust
fn some_exclusive_system(state: &mut SystemState<(Res<'static, Time>, Query<&'static Player>)>) {}
```

## Related

- #2923
- #3001
- #3946

## Changelog

- `ExclusiveSystem` trait (and implementations) has been removed in favor of sharing the `System` trait.
- `ExclusiveFunctionSystem` and `ExclusiveSystemParam` were added, enabling flexible exclusive function systems
- `&mut SystemState` and `&mut QueryState` now implement `ExclusiveSystemParam`
- Exclusive and parallel System configuration is now done via a unified `SystemDescriptor`, `IntoSystemDescriptor`, and `SystemContainer` api.

## Migration Guide

Calling `.exclusive_system()` is no longer required (or supported) for converting exclusive system functions to exclusive systems:

```rust
// Old (0.8)
app.add_system(some_exclusive_system.exclusive_system());
// New (0.9)
app.add_system(some_exclusive_system);
```

Converting "normal" parallel systems to exclusive systems is done by calling the exclusive ordering apis:

```rust
// Old (0.8)
app.add_system(some_system.exclusive_system().at_end());
// New (0.9)
app.add_system(some_system.at_end());
```

Query state in exclusive systems can now be cached via ExclusiveSystemParams, which should be preferred for clarity and performance reasons:
```rust
// Old (0.8)
fn some_system(world: &mut World) {
  let mut transforms = world.query::<&Transform>();
  for transform in transforms.iter(world) {
  }
}
// New (0.9)
fn some_system(world: &mut World, transforms: &mut QueryState<&Transform>) {
  for transform in transforms.iter(world) {
  }
}
```
2022-09-26 23:57:07 +00:00
Carlrs
750ec41c86 Don't bundle extra transform with camera in many sprites examples (#6079)
Fixes #6077 
# Objective

- Make many_sprites and many_animated_sprites work again

## Solution

- Removed the extra transform from the camera bundle - not sure why it was necessary, since `Camera2dBundle::default()` already contains a transform with the same parameters.

---
2022-09-25 18:03:53 +00:00
Rob Parrett
847c26b8dc Rename shapes examples for consistency (#6082)
# Objective

I was about to submit a PR to add these two examples to `bevy-website` and re-discovered the inconsistency.

Although it's not a major issue on the website where only the filenames are shown, this would help to visually distinguish the two examples in the list  because the names are very prominent.

This also helps out when fuzzy-searching the codebase for these files.

## Solution

Rename `shapes` to `2d_shapes`. Now the filename matches the example name, and the naming structure matches the 3d example.

## Notes

@Nilirad proposed this in https://github.com/bevyengine/bevy/pull/4613#discussion_r862455631 but it had slipped away from my brain at that time.
2022-09-25 00:57:07 +00:00
Alice Cecile
481eec2c92 Rename UiColor to BackgroundColor (#6087)
# Objective

Fixes #6078. The `UiColor` component is unhelpfully named: it is unclear, ambiguous with border color and 

## Solution

Rename the `UiColor` component (and associated fields) to `BackgroundColor` / `background_colorl`.

## Migration Guide

`UiColor` has been renamed to `BackgroundColor`. This change affects `NodeBundle`, `ButtonBundle` and `ImageBundle`. In addition, the corresponding field on `ExtractedUiNode` has been renamed to `background_color` for consistency.
2022-09-25 00:39:17 +00:00
Rob Parrett
e7cd9c1b86 Add a Gamepad Viewer tool to examples (#6074)
# Objective

Give folks an easy way to test their gamepad with bevy.

~~This is a lot of very boring code for an example. Maybe it belongs in the "tools" directory?~~

## Solution

https://user-images.githubusercontent.com/200550/191884342-ace213c0-b423-449a-9295-530cbceaa19e.mp4

## Notes

This has brought to light (to me, anyway) some fairly major issues with gamepads on the web. See:

[WASM mappings (gilrs issue 107)](https://gitlab.com/gilrs-project/gilrs/-/issues/107)
[Inaccurate value for trigger button of Xbox gamepad with WASM (gilrs issue 121)](https://gitlab.com/gilrs-project/gilrs/-/issues/121)
2022-09-24 13:21:01 +00:00
Boutillier
b91945b54d Merge TextureAtlas::from_grid_with_padding into TextureAtlas::from_grid through option arguments (#6057)
This is an adoption of #3775
This merges `TextureAtlas` `from_grid_with_padding` into `from_grid` , adding optional padding and optional offset.
Since the orignal PR, the offset had already been added to from_grid_with_padding through #4836 

## Changelog

- Added `padding` and `offset` arguments to  `TextureAtlas::from_grid`
- Removed `TextureAtlas::from_grid_with_padding`

## Migration Guide

`TextureAtlas::from_grid_with_padding` was merged into `from_grid` which takes two additional parameters for padding and an offset.
```
// 0.8
TextureAtlas::from_grid(texture_handle, Vec2::new(24.0, 24.0), 7, 1);
// 0.9
TextureAtlas::from_grid(texture_handle, Vec2::new(24.0, 24.0), 7, 1, None, None)

// 0.8
TextureAtlas::from_grid_with_padding(texture_handle, Vec2::new(24.0, 24.0), 7, 1, Vec2::new(4.0, 4.0));
// 0.9
TextureAtlas::from_grid(texture_handle, Vec2::new(24.0, 24.0), 7, 1, Some(Vec2::new(4.0, 4.0)), None)
```

Co-authored-by: olefish <88390729+oledfish@users.noreply.github.com>
2022-09-24 12:58:06 +00:00
Carter Anderson
01aedc8431 Spawn now takes a Bundle (#6054)
# Objective

Now that we can consolidate Bundles and Components under a single insert (thanks to #2975 and #6039), almost 100% of world spawns now look like `world.spawn().insert((Some, Tuple, Here))`. Spawning an entity without any components is an extremely uncommon pattern, so it makes sense to give spawn the "first class" ergonomic api. This consolidated api should be made consistent across all spawn apis (such as World and Commands).

## Solution

All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input:

```rust
// before:
commands
  .spawn()
  .insert((A, B, C));
world
  .spawn()
  .insert((A, B, C);

// after
commands.spawn((A, B, C));
world.spawn((A, B, C));
```

All existing instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api. A new `spawn_empty` has been added, replacing the old `spawn` api.  

By allowing `world.spawn(some_bundle)` to replace `world.spawn().insert(some_bundle)`, this opened the door to removing the initial entity allocation in the "empty" archetype / table done in `spawn()` (and subsequent move to the actual archetype in `.insert(some_bundle)`).

This improves spawn performance by over 10%:
![image](https://user-images.githubusercontent.com/2694663/191627587-4ab2f949-4ccd-4231-80eb-80dd4d9ad6b9.png)

To take this measurement, I added a new `world_spawn` benchmark.

Unfortunately, optimizing `Commands::spawn` is slightly less trivial, as Commands expose the Entity id of spawned entities prior to actually spawning. Doing the optimization would (naively) require assurances that the `spawn(some_bundle)` command is applied before all other commands involving the entity (which would not necessarily be true, if memory serves). Optimizing `Commands::spawn` this way does feel possible, but it will require careful thought (and maybe some additional checks), which deserves its own PR. For now, it has the same performance characteristics of the current `Commands::spawn_bundle` on main.

**Note that 99% of this PR is simple renames and refactors. The only code that needs careful scrutiny is the new `World::spawn()` impl, which is relatively straightforward, but it has some new unsafe code (which re-uses battle tested BundlerSpawner code path).** 

---

## Changelog

- All `spawn` apis (`World::spawn`, `Commands:;spawn`, `ChildBuilder::spawn`, and `WorldChildBuilder::spawn`) now accept a bundle as input
- All instances of `spawn_bundle` have been deprecated in favor of the new `spawn` api
- World and Commands now have `spawn_empty()`, which is equivalent to the old `spawn()` behavior.  

## Migration Guide

```rust
// Old (0.8):
commands
  .spawn()
  .insert_bundle((A, B, C));
// New (0.9)
commands.spawn((A, B, C));

// Old (0.8):
commands.spawn_bundle((A, B, C));
// New (0.9)
commands.spawn((A, B, C));

// Old (0.8):
let entity = commands.spawn().id();
// New (0.9)
let entity = commands.spawn_empty().id();

// Old (0.8)
let entity = world.spawn().id();
// New (0.9)
let entity = world.spawn_empty();
```
2022-09-23 19:55:54 +00:00
Okko Hakola
69d08c5ef4 Reconfigure surface on present mode change (#6049)
# Objective

- Reconfigure surface after present mode changes. It seems that this is not done currently at runtime. It's pretty common for games to change such graphical settings at runtime.
- Fixes present mode issue in #5111 

## Solution

- Exactly like resolution change gets tracked when extracting window, do the same for present mode.

Additionally, I added present mode (vsync) toggling to window settings example.
2022-09-21 22:35:15 +00:00
Carter Anderson
cd15f0f5be Accept Bundles for insert and remove. Deprecate insert/remove_bundle (#6039)
# Objective

Take advantage of the "impl Bundle for Component" changes in #2975 / add the follow up changes discussed there.

## Solution

- Change `insert` and `remove` to accept a Bundle instead of a Component (for both Commands and World)
- Deprecate `insert_bundle`, `remove_bundle`, and `remove_bundle_intersection`
- Add `remove_intersection`

---

## Changelog

- Change `insert` and `remove` now accept a Bundle instead of a Component (for both Commands and World)
- `insert_bundle` and `remove_bundle` are deprecated
 

## Migration Guide

Replace `insert_bundle` with `insert`:
```rust
// Old (0.8)
commands.spawn().insert_bundle(SomeBundle::default());
// New (0.9)
commands.spawn().insert(SomeBundle::default());
```

Replace `remove_bundle` with `remove`:
```rust
// Old (0.8)
commands.entity(some_entity).remove_bundle::<SomeBundle>();
// New (0.9)
commands.entity(some_entity).remove::<SomeBundle>();
```

Replace `remove_bundle_intersection` with `remove_intersection`:
```rust
// Old (0.8)
world.entity_mut(some_entity).remove_bundle_intersection::<SomeBundle>();
// New (0.9)
world.entity_mut(some_entity).remove_intersection::<SomeBundle>();
```

Consider consolidating as many operations as possible to improve ergonomics and cut down on archetype moves:
```rust
// Old (0.8)
commands.spawn()
  .insert_bundle(SomeBundle::default())
  .insert(SomeComponent);

// New (0.9) - Option 1
commands.spawn().insert((
  SomeBundle::default(),
  SomeComponent,
))

// New (0.9) - Option 2
commands.spawn_bundle((
  SomeBundle::default(),
  SomeComponent,
))
```

## Next Steps

Consider changing `spawn` to accept a bundle and deprecate `spawn_bundle`.
2022-09-21 21:47:53 +00:00
Daniel McNab
1a2aedd165 Implement Bundle for Component. Use Bundle tuples for insertion (#2975)
@BoxyUwU this is your fault. 

Also cart didn't arrive in time to tell us not to do this.

# Objective

- Fix #2974

## Solution

- The first commit just does the actual change
- Follow up commits do steps to prove that this method works to unify as required, but this does not remove `insert_bundle`.

## Changelog

### Changed
Nested bundles now collapse automatically, and every `Component` now implements `Bundle`.
This means that you can combine bundles and components arbitrarily, for example:
```rust
// before:
.insert(A).insert_bundle(MyBBundle{..})
// after:
.insert_bundle((A, MyBBundle {..}))
```

Note that there will be a follow up PR that removes the current `insert` impl and renames `insert_bundle` to `insert`.

### Removed
The `bundle` attribute in `derive(Bundle)`.

## Migration guide

In `derive(Bundle)`, the `bundle` attribute has been removed. Nested bundles are not collapsed automatically. You should remove `#[bundle]` attributes.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-09-20 20:17:08 +00:00
Gino Valente
d30d3e752a bevy_reflect: Improve serialization format even more (#5723)
> Note: This is rebased off #4561 and can be viewed as a competitor to that PR. See `Comparison with #4561` section for details.

# Objective

The current serialization format used by `bevy_reflect` is both verbose and error-prone. Taking the following structs[^1] for example:

```rust
// -- src/inventory.rs

#[derive(Reflect)]
struct Inventory {
  id: String,
  max_storage: usize,
  items: Vec<Item>
}

#[derive(Reflect)]
struct Item {
  name: String
}
```

Given an inventory of a single item, this would serialize to something like:

```rust
// -- assets/inventory.ron

{
  "type": "my_game::inventory::Inventory",
  "struct": {
    "id": {
      "type": "alloc::string::String",
      "value": "inv001",
    },
    "max_storage": {
      "type": "usize",
      "value": 10
    },
    "items": {
      "type": "alloc::vec::Vec<alloc::string::String>",
      "list": [
        {
          "type": "my_game::inventory::Item",
          "struct": {
            "name": {
              "type": "alloc::string::String",
              "value": "Pickaxe"
            },
          },
        },
      ],
    },
  },
}
```

Aside from being really long and difficult to read, it also has a few "gotchas" that users need to be aware of if they want to edit the file manually. A major one is the requirement that you use the proper keys for a given type. For structs, you need `"struct"`. For lists, `"list"`. For tuple structs, `"tuple_struct"`. And so on.

It also ***requires*** that the `"type"` entry come before the actual data. Despite being a map— which in programming is almost always orderless by default— the entries need to be in a particular order. Failure to follow the ordering convention results in a failure to deserialize the data.

This makes it very prone to errors and annoyances.


## Solution

Using #4042, we can remove a lot of the boilerplate and metadata needed by this older system. Since we now have static access to type information, we can simplify our serialized data to look like:

```rust
// -- assets/inventory.ron

{
  "my_game::inventory::Inventory": (
    id: "inv001",
    max_storage: 10,
    items: [
      (
        name: "Pickaxe"
      ),
    ],
  ),
}
```

This is much more digestible and a lot less error-prone (no more key requirements and no more extra type names).

Additionally, it is a lot more familiar to users as it follows conventional serde mechanics. For example, the struct is represented with `(...)` when serialized to RON.

#### Custom Serialization

Additionally, this PR adds the opt-in ability to specify a custom serde implementation to be used rather than the one created via reflection. For example[^1]:

```rust
// -- src/inventory.rs

#[derive(Reflect, Serialize)]
#[reflect(Serialize)]
struct Item {
  #[serde(alias = "id")]
  name: String
}
```

```rust
// -- assets/inventory.ron

{
  "my_game::inventory::Inventory": (
    id: "inv001",
    max_storage: 10,
    items: [
      (
        id: "Pickaxe"
      ),
    ],
  ),
},
```

By allowing users to define their own serialization methods, we do two things:

1. We give more control over how data is serialized/deserialized to the end user
2. We avoid having to re-define serde's attributes and forcing users to apply both (e.g. we don't need a `#[reflect(alias)]` attribute).

### Improved Formats

One of the improvements this PR provides is the ability to represent data in ways that are more conventional and/or familiar to users. Many users are familiar with RON so here are some of the ways we can now represent data in RON:

###### Structs

```js
{
  "my_crate::Foo": (
    bar: 123
  )
}
// OR
{
  "my_crate::Foo": Foo(
    bar: 123
  )
}
```

<details>
<summary>Old Format</summary>

```js
{
  "type": "my_crate::Foo",
  "struct": {
    "bar": {
      "type": "usize",
      "value": 123
    }
  }
}
```

</details>

###### Tuples

```js
{
  "(f32, f32)": (1.0, 2.0)
}
```

<details>
<summary>Old Format</summary>

```js
{
  "type": "(f32, f32)",
  "tuple": [
    {
      "type": "f32",
      "value": 1.0
    },
    {
      "type": "f32",
      "value": 2.0
    }
  ]
}
```

</details>

###### Tuple Structs

```js
{
  "my_crate::Bar": ("Hello World!")
}
// OR
{
  "my_crate::Bar": Bar("Hello World!")
}
```

<details>
<summary>Old Format</summary>

```js
{
  "type": "my_crate::Bar",
  "tuple_struct": [
    {
      "type": "alloc::string::String",
      "value": "Hello World!"
    }
  ]
}
```

</details>

###### Arrays

It may be a bit surprising to some, but arrays now also use the tuple format. This is because they essentially _are_ tuples (a sequence of values with a fixed size), but only allow for homogenous types. Additionally, this is how RON handles them and is probably a result of the 32-capacity limit imposed on them (both by [serde](https://docs.rs/serde/latest/serde/trait.Serialize.html#impl-Serialize-for-%5BT%3B%2032%5D) and by [bevy_reflect](https://docs.rs/bevy/latest/bevy/reflect/trait.GetTypeRegistration.html#impl-GetTypeRegistration-for-%5BT%3B%2032%5D)).

```js
{
  "[i32; 3]": (1, 2, 3)
}
```

<details>
<summary>Old Format</summary>

```js
{
  "type": "[i32; 3]",
  "array": [
    {
      "type": "i32",
      "value": 1
    },
    {
      "type": "i32",
      "value": 2
    },
    {
      "type": "i32",
      "value": 3
    }
  ]
}
```

</details>

###### Enums

To make things simple, I'll just put a struct variant here, but the style applies to all variant types:

```js
{
  "my_crate::ItemType": Consumable(
    name: "Healing potion"
  )
}
```

<details>
<summary>Old Format</summary>

```js
{
  "type": "my_crate::ItemType",
  "enum": {
    "variant": "Consumable",
    "struct": {
      "name": {
        "type": "alloc::string::String",
        "value": "Healing potion"
      }
    }
  }
}
```

</details>

### Comparison with #4561

This PR is a rebased version of #4561. The reason for the split between the two is because this PR creates a _very_ different scene format. You may notice that the PR descriptions for either PR are pretty similar. This was done to better convey the changes depending on which (if any) gets merged first. If #4561 makes it in first, I will update this PR description accordingly.

---

## Changelog

* Re-worked serialization/deserialization for reflected types
* Added `TypedReflectDeserializer` for deserializing data with known `TypeInfo`
* Renamed `ReflectDeserializer` to `UntypedReflectDeserializer` 
* ~~Replaced usages of `deserialize_any` with `deserialize_map` for non-self-describing formats~~ Reverted this change since there are still some issues that need to be sorted out (in a separate PR). By reverting this, crates like `bincode` can throw an error when attempting to deserialize non-self-describing formats (`bincode` results in `DeserializeAnyNotSupported`)
* Structs, tuples, tuple structs, arrays, and enums are now all de/serialized using conventional serde methods

## Migration Guide

* This PR reduces the verbosity of the scene format. Scenes will need to be updated accordingly:

```js
// Old format
{
  "type": "my_game::item::Item",
  "struct": {
    "id": {
      "type": "alloc::string::String",
      "value": "bevycraft:stone",
    },
    "tags": {
      "type": "alloc::vec::Vec<alloc::string::String>",
      "list": [
        {
          "type": "alloc::string::String",
          "value": "material"
        },
      ],
    },
}

// New format
{
  "my_game::item::Item": (
    id: "bevycraft:stone",
    tags: ["material"]
  )
}
```

[^1]: Some derives omitted for brevity.
2022-09-20 19:38:18 +00:00