# Objective
- All new PRs should get the "S-Needs-Triage" label. But at the moment we for example are getting quite a few PRs to the new renderer branch that do not get the label.
## Solution
- Remove the required target "main" from the workflow
- Also removed configuration for not needed functionality of the labeler action (see [docs](https://github.com/actions/labeler#inputs))
# Objective
- The breakout scoreboard was not using the correct text section to display the score integer.
## Solution
- This updates the code to use the correct text section.
# Objective
Make it easier to check if some set of inputs matches a key, such as if you want to allow all of space or up or w for jumping.
Currently, this requires:
```rust
if keyboard.pressed(KeyCode::Space)
|| keyboard.pressed(KeyCode::Up)
|| keyboard.pressed(KeyCode::W) {
// ...
```
## Solution
Add an implementation of the helper methods, which very simply iterate through the items, used as:
```rust
if keyboard.any_pressed([KeyCode::Space, KeyCode::Up, KeyCode::W]) {
```
# Objective
Sometimes, the unwraps in `entity_mut` could fail here, if the entity was despawned *before* this command was applied.
The simplest case involves two command buffers:
```rust
use bevy::prelude::*;
fn b(mut commands1: Commands, mut commands2: Commands) {
let id = commands2.spawn().insert_bundle(()).id();
commands1.entity(id).despawn();
}
fn main() {
App::build().add_system(b.system()).run();
}
```
However, a more complicated version arises in the case of ambiguity:
```rust
use std::time::Duration;
use bevy::{app::ScheduleRunnerPlugin, prelude::*};
use rand::Rng;
fn cleanup(mut e: ResMut<Option<Entity>>) {
*e = None;
}
fn sleep_randomly() {
let mut rng = rand::thread_rng();
std:🧵:sleep(Duration::from_millis(rng.gen_range(0..50)));
}
fn spawn(mut commands: Commands, mut e: ResMut<Option<Entity>>) {
*e = Some(commands.spawn().insert_bundle(()).id());
}
fn despawn(mut commands: Commands, e: Res<Option<Entity>>) {
let mut rng = rand::thread_rng();
std:🧵:sleep(Duration::from_millis(rng.gen_range(0..50)));
if let Some(e) = *e {
commands.entity(e).despawn();
}
}
fn main() {
App::build()
.add_system(cleanup.system().label("cleanup"))
.add_system(sleep_randomly.system().label("before_despawn"))
.add_system(despawn.system().after("cleanup").after("before_despawn"))
.add_system(sleep_randomly.system().label("before_spawn"))
.add_system(spawn.system().after("cleanup").after("before_spawn"))
.insert_resource(None::<Entity>)
.add_plugin(ScheduleRunnerPlugin::default())
.run();
}
```
In the cases where this example crashes, it's because `despawn` was ordered before `spawn` in the topological ordering of systems (which determines when buffers are applied). However, `despawn` actually ran *after* `spawn`, because these systems are ambiguous, so the jiggles in the sleeping time triggered a case where this works.
## Solution
- Give a better error message
# Objective
Fix `Option<NonSend<T>>` to work when T isn't `Send`
Fix `Option<NonSendMut<T>>` to work when T isnt in the world.
## Solution
Simple two row fix, properly initialize T in `OptionNonSendState` and remove `T: Component` bound for `Option<NonSendMut<T>>`
also added a rudimentary test
Co-authored-by: Ïvar Källström <ivar.kallstrom@gmail.com>
# Objective
- Make it easy to use HexColorError with `thiserror`, i.e. converting it into other error types.
Makes this possible:
```rust
#[derive(Debug, thiserror::Error)]
pub enum LdtkError {
#[error("An error occured while deserializing")]
Json(#[from] serde_json::Error),
#[error("An error occured while parsing a color")]
HexColor(#[from] bevy::render::color::HexColorError),
}
```
## Solution
- Derive thiserror::Error the same way we do elsewhere (see query.rs for instance)
# Objective
M1 Macs / Apple Silicon / simply aarch64 needs to be specified for it to compile with zld, so users might be surprised to find that they aren't getting the benefits and see the fast compiles they might be seeing on other platforms.
## Solution
- Add it? :)
# Objective
- Fixes#2674
- Check that benches build
## Solution
- Adds a job that runs `cargo check --benches`
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
# Objective
- QueryState is lacking documentation.
Fixes#2090
## Solution
- Provide documentation that mirrors Query (as suggested in #2090) and modify as needed.
Co-authored-by: James Leflang <59455417+jleflang@users.noreply.github.com>
This upstreams the code changes used by the new renderer to enable cross-app Entity reuse:
* Spawning at specific entities
* get_or_spawn: spawns an entity if it doesn't already exist and returns an EntityMut
* insert_or_spawn_batch: the batched equivalent to `world.get_or_spawn(entity).insert_bundle(bundle)`
* Clearing entities and storages
* Allocating Entities with "invalid" archetypes. These entities cannot be queried / are treated as "non existent". They serve as "reserved" entities that won't show up when calling `spawn()`. They must be "specifically spawned at" using apis like `get_or_spawn(entity)`.
In combination, these changes enable the "render world" to clear entities / storages each frame and reserve all "app world entities". These can then be spawned during the "render extract step".
This refactors "spawn" and "insert" code in a way that I think is a massive improvement to legibility and re-usability. It also yields marginal performance wins by reducing some duplicate lookups (less than a percentage point improvement on insertion benchmarks). There is also some potential for future unsafe reduction (by making BatchSpawner and BatchInserter generic). But for now I want to cut down generic usage to a minimum to encourage smaller binaries and faster compiles.
This is currently a draft because it needs more tests (although this code has already had some real-world testing on my custom-shaders branch).
I also fixed the benchmarks (which currently don't compile!) / added new ones to illustrate batching wins.
After these changes, Bevy ECS is basically ready to accommodate the new renderer. I think the biggest missing piece at this point is "sub apps".
# Objective
- Clarify vague meaning of "Ltr" and "Rtl". For someone familiar with Flex Box, this is easy to understand, but being more explicit will help beginners or those unfamiliar, without the need to do research.
## Solution
- Change three letter abbreviation to fully descriptive name.
This matches `ahash::RandomState`, which provides both `Debug` and `Clone`.
Notably, implementing `Clone` allows the `StableHashMap`/`Set` to also implement `Clone`.
# Objective
- Allow `bevy_utils::StableHashMap` to be cloned.
## Solution
- Derive `Clone` for `bevy_utils::FixedState`.
- Also derive `Debug`, since we're touching it anyway, and this aligns `FixedState` with `ahash::RandomState`.
# Objective
- the plugin guidelines should be up-to-date and easy to read/understand
## Solution
* point to "Bevy Assets" instead of old "Awesome Bevy"
* restructure sections
* same order for sections and checklist
* Update examples with newest release/rev
Updates the requirements on [glam](https://github.com/bitshifter/glam-rs) to permit the latest version.
<details>
<summary>Changelog</summary>
<p><em>Sourced from <a href="https://github.com/bitshifter/glam-rs/blob/master/CHANGELOG.md">glam's changelog</a>.</em></p>
<blockquote>
<h2>[0.17.3] - 2021-07-18</h2>
<h3>Fixed</h3>
<ul>
<li>Fix alignment unit tests on non x86 platforms.</li>
</ul>
<h2>[0.17.2] - 2021-07-15</h2>
<h3>Fixed</h3>
<ul>
<li>Fix alignment unit tests on i686 and S390x.</li>
</ul>
<h2>[0.17.1] - 2021-06-29</h2>
<h3>Added</h3>
<ul>
<li>Added <code>serde</code> support for <code>Affine2</code>, <code>DAffine2</code>, <code>Affine3A</code> and <code>DAffine3</code>.</li>
</ul>
<h2>[0.17.0] - 2021-06-26</h2>
<h3>Breaking changes</h3>
<ul>
<li>The addition of <code>Add</code> and <code>Sub</code> implementations of scalar values for vector
types may create ambiguities with existing calls to <code>add</code> and <code>sub</code>.</li>
<li>Removed <code>From<Mat3></code> implementation for <code>Mat2</code> and <code>From<DMat3></code> for <code>DMat2</code>.
These have been replaced by <code>Mat2::from_mat3()</code> and <code>DMat2::from_mat3()</code>.</li>
<li>Removed <code>From<Mat4></code> implementation for <code>Mat3</code> and <code>From<DMat4></code> for <code>DMat3</code>.
These have been replaced by <code>Mat3::from_mat4()</code> and <code>DMat3::from_mat4()</code>.</li>
<li>Removed deprecated <code>from_slice_unaligned()</code>, <code>write_to_slice_unaligned()</code>,
<code>from_rotation_mat4</code> and <code>from_rotation_ypr()</code> methods.</li>
</ul>
<h3>Added</h3>
<ul>
<li>Added <code>col_mut()</code> method which returns a mutable reference to a matrix column
to all matrix types.</li>
<li>Added <code>AddAssign</code>, <code>MulAssign</code> and <code>SubAssign</code> implementations for all matrix
types.</li>
<li>Added <code>Add</code> and <code>Sub</code> implementations of scalar values for vector types.</li>
<li>Added more <code>glam_assert!</code> checks and documented methods where they are used.</li>
<li>Added vector projection and rejection methods <code>project_onto()</code>,
<code>project_onto_normalized()</code>, <code>reject_from()</code> and <code>reject_from_normalized()</code>.</li>
<li>Added <code>Mat2::from_mat3()</code>, <code>DMat2::from_mat3()</code>, <code>Mat3::from_mat4()</code>,
<code>DMat3::from_mat4()</code> which create a smaller matrix from a larger one,
discarding a final row and column of the input matrix.</li>
<li>Added <code>Mat3::from_mat2()</code>, <code>DMat3::from_mat2()</code>, <code>Mat4::from_mat3()</code> and
<code>DMat4::from_mat3()</code> which create an affine transform from a smaller linear
transform matrix.</li>
</ul>
<h3>Changed</h3>
<!-- raw HTML omitted -->
</blockquote>
<p>... (truncated)</p>
</details>
<details>
<summary>Commits</summary>
<ul>
<li><a href="ecf3904b2f"><code>ecf3904</code></a> Prepare release 0.17.3</li>
<li><a href="95e02bb43e"><code>95e02bb</code></a> Merge branch 'master' of github.com:bitshifter/glam-rs</li>
<li><a href="c6dc702583"><code>c6dc702</code></a> More alignment test fixes for when SSE2 is not avaialable.</li>
<li><a href="87a3b25872"><code>87a3b25</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/216">#216</a> from bitshifter/prepare-0.17.2</li>
<li><a href="269e514090"><code>269e514</code></a> Prepare for 0.17.2 release.</li>
<li><a href="1da7d6459c"><code>1da7d64</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/215">#215</a> from bitshifter/issue-213</li>
<li><a href="dc60e20925"><code>dc60e20</code></a> Fix align asserts on i686 and S390x architectures.</li>
<li><a href="bd8b30e9fb"><code>bd8b30e</code></a> Merge pull request <a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/212">#212</a> from remilauzier/master</li>
<li><a href="a4e97c0b54"><code>a4e97c0</code></a> Update approx to 0.5</li>
<li><a href="059f619525"><code>059f619</code></a> Prepare 0.17.1 release (<a href="https://github-redirect.dependabot.com/bitshifter/glam-rs/issues/211">#211</a>)</li>
<li>Additional commits viewable in <a href="https://github.com/bitshifter/glam-rs/compare/0.15.1...0.17.3">compare view</a></li>
</ul>
</details>
<br />
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</details>
# Objective
- We currently depends on ndk 0.2, 0.3, 0.4
- Only 0.2 dependencies comes from Bevy itself
## Solution
- Replace #1371
- Update Bevy to ndk-glue 0.4
- Also fixes duplicate dependency CI issue
# Objective
While implementing a plugin for my rollback networking library, I needed to load/save parts of the world. For this, I made a WorldSnapshot that works quite like the current DynamicScene. Using a TypeRegistry to register component types I want to save/load and then using ReflectComponents methods to add or apply components of the given types.
However, I noticed there is no method to remove components from entities through the ReflectComponent.
## Solution
I added a `remove_component` field to the `ReflectComponent` struct, as well as a `pub fn remove_component(&self, world: &mut World, entity: Entity)` to call that function in `remove_component`. This follows exactly the same pattern all other methods/fields in this struct look like.
This is an example how it could be used (at least how I would use it):
6c003f86f1/src/world_snapshot.rs (L133)
# Objective
Enable using exact World lifetimes during read-only access . This is motivated by the new renderer's need to allow read-only world-only queries to outlive the query itself (but still be constrained by the world lifetime).
For example:
115b170d1f/pipelined/bevy_pbr2/src/render/mod.rs (L774)
## Solution
Split out SystemParam state and world lifetimes and pipe those lifetimes up to read-only Query ops (and add into_inner for Res). According to every safety test I've run so far (except one), this is safe (see the temporary safety test commit). Note that changing the mutable variants to the new lifetimes would allow aliased mutable pointers (try doing that to see how it affects the temporary safety tests).
The new state lifetime on SystemParam does make `#[derive(SystemParam)]` more cumbersome (the current impl requires PhantomData if you don't use both lifetimes). We can make this better by detecting whether or not a lifetime is used in the derive and adjusting accordingly, but that should probably be done in its own pr.
## Why is this a draft?
The new lifetimes break QuerySet safety in one very specific case (see the query_set system in system_safety_test). We need to solve this before we can use the lifetimes given.
This is due to the fact that QuerySet is just a wrapper over Query, which now relies on world lifetimes instead of `&self` lifetimes to prevent aliasing (but in systems, each Query has its own implied lifetime, not a centralized world lifetime). I believe the fix is to rewrite QuerySet to have its own World lifetime (and own the internal reference). This will complicate the impl a bit, but I think it is doable. I'm curious if anyone else has better ideas.
Personally, I think these new lifetimes need to happen. We've gotta have a way to directly tie read-only World queries to the World lifetime. The new renderer is the first place this has come up, but I doubt it will be the last. Worst case scenario we can come up with a second `WorldLifetimeQuery<Q, F = ()>` parameter to enable these read-only scenarios, but I'd rather not add another type to the type zoo.
[**RENDERED**](https://github.com/alice-i-cecile/bevy/blob/better-contributing/CONTRIBUTING.md)
Improves #910. As discussed in #1309, we'll need to synchronize content between this and the Bevy website in some way (and clean up the .github file perhaps?).
I think doing it as a root-directory file is nicer for discovery, but that's a conversation I'm interested in having.
This document is intended to be helpful to beginners to open source and Bevy, and captures what I've learned about our informal practices and values.
Reviewers: I'm particularly interested in:
- opinions on the items **What we're trying to build**, where I discuss some of the project's high-level values and goals
- more relevant details on the `bevy` subcrates for **Getting oriented**
- useful tricks and best practices that I missed
- better guidance on how to contribute to the Bevy book from @cart <3
# Objective
This:
```rust
use bevy::prelude::*;
fn main() {
App::new()
.add_system(test)
.run();
}
fn test(entities: Query<Entity>) {
let mut combinations = entities.iter_combinations_mut();
while let Some([e1, e2]) = combinations.fetch_next() {
dbg!(e1);
}
}
```
fails with the message "the trait bound `bevy::ecs::query::EntityFetch: std::clone::Clone` is not satisfied".
## Solution
It works after adding the naive clone implementation to EntityFetch. I'm not super familiar with ECS internals, so I'd appreciate input on this.
## Objective
- Clean up remaining references to the trait `FromResources`, which was replaced in favor of `FromWorld` during the ECS rework.
## Solution
- Remove the derive macro for `FromResources`
- Change doc references of `FromResources` to `FromWorld`
(this is the first item in #2576)
# Objective
- Provides more useful error messages when using unsupported shader features.
## Solution Fixes#869
- Provided a error message as follows (adding name, set and binding):
```
Unsupported shader bind type CombinedImageSampler (name noiseVol0, set 0, binding 9)
```
This is an updated version of #1434 PR. I've encountered this macro problem while trying to use @woubuc's bevy-event-set crate.
Co-authored-by: Piotr Balcer <piotr@balcer.eu>
I didn't know about MinimalPlugins for way too long. This should increase visibility for others.
# Objective
Improve visibility and discover in the docs for Default and Minimal Plugins.
## Solution
Links the two Docs pages.
Co-authored-by: Mirko Rainer <52899592+mirkoRainer@users.noreply.github.com>
# Objective
- Allow `ScheduleRunnerPlugin` to be instantiated without curly braces. Other plugins in the library already use the semicolon syntax.
- Currently, you have to do the following:
```rust
App::build()
.add_plugin(bevy::core::CorePlugin)
.add_plugin(bevy::app::ScheduleRunnerPlugin {})
```
- With the proposed change you can do this:
```rust
App::build()
.add_plugin(bevy::core::CorePlugin)
.add_plugin(bevy::app::ScheduleRunnerPlugin)
```
## Solution
- Change the `ScheduleRunnerPlugin` definition to use a semicolon instead of curly braces.
## Objective
This code would result in a crash:
```rust
use bevy::prelude::*;
fn main() {
let mut world = World::new();
let child = world.spawn().id();
world.spawn().push_children(&[child]);
}
```
## Solution
Update the `EntityMut`'s location after inserting a component on the children entities, as it may have changed.
# Objective
- #2551 revamped our CI setup which included running clippy and rustfmt in another Job.
- This new Job wasn't added to the bors.toml, which means that PRs would be accepted that didn't run them.
## Solution
- Add the "ci" job to the bors.toml
It doesn't compile on wasm, and it's full of footguns
# Objective
- If bevy is used with default features on wasm, there's more of a chance it will compile
- Note that I haven't done a full audit - it's possible that there are other problematic crates
## Solution
- `bevy_dynamic_plugin` is no longer a default plugin
- I've also done an accidental drive by reformatting of the root `Cargo.toml`, as I have [Even Better Toml](https://github.com/tamasfe/taplo) installed.
- (Please, rustfmt do this for us)
# Objective
notify 5.0.0-pre.11 breaks the interface again, but apparently in a way that's similar to how it used to be
## Solution
Bump `bevy_asset` dependency on notify to `5.0.0-pre.11` and fix the errors that crop up.
It looks like `pre.11` was mentioned in #2528 by @mockersf but there's no mention of why `pre.10` was chosen ultimately.
# Objective
There is currently a 1-to-1 mapping between components and real rust types. This means that it is impossible for multiple components to be represented by the same rust type or for a component to not have a rust type at all. This means that component types can't be defined in languages other than rust like necessary for scripting or sandboxed (wasm?) plugins.
## Solution
Refactor `ComponentDescriptor` and `Bundle` to remove `TypeInfo`. `Bundle` now uses `ComponentId` instead. `ComponentDescriptor` is now always created from a rust type instead of through the `TypeInfo` indirection. A future PR may make it possible to construct a `ComponentDescriptor` from it's fields without a rust type being involved.
# Objective
- Remove all the `.system()` possible.
- Check for remaining missing cases.
## Solution
- Remove all `.system()`, fix compile errors
- 32 calls to `.system()` remains, mostly internals, the few others should be removed after #2446
# Objective
While looking at the code of `World`, I noticed two basic functions (`get` and `get_mut`) that are probably called a lot and with simple code that are not `inline`
## Solution
- Add benchmark to check impact
- Add `#[inline]`
```
group this pr main
----- ---- ----
world_entity/50000_entities 1.00 115.9±11.90µs ? ?/sec 1.71 198.5±29.54µs ? ?/sec
world_get/50000_entities_SparseSet 1.00 409.9±46.96µs ? ?/sec 1.18 483.5±36.41µs ? ?/sec
world_get/50000_entities_Table 1.00 391.3±29.83µs ? ?/sec 1.16 455.6±57.85µs ? ?/sec
world_query_for_each/50000_entities_SparseSet 1.02 121.3±18.36µs ? ?/sec 1.00 119.4±13.88µs ? ?/sec
world_query_for_each/50000_entities_Table 1.03 13.8±0.96µs ? ?/sec 1.00 13.3±0.54µs ? ?/sec
world_query_get/50000_entities_SparseSet 1.00 666.9±54.36µs ? ?/sec 1.03 687.1±57.77µs ? ?/sec
world_query_get/50000_entities_Table 1.01 584.4±55.12µs ? ?/sec 1.00 576.3±36.13µs ? ?/sec
world_query_iter/50000_entities_SparseSet 1.01 169.7±19.50µs ? ?/sec 1.00 168.6±32.56µs ? ?/sec
world_query_iter/50000_entities_Table 1.00 26.2±1.38µs ? ?/sec 1.91 50.0±4.40µs ? ?/sec
```
I didn't add benchmarks for the mutable path but I don't see how it could hurt to make it inline too...
This is extracted out of eb8f973646476b4a4926ba644a77e2b3a5772159 and includes some additional changes to remove all references to AppBuilder and fix examples that still used App::build() instead of App::new(). In addition I didn't extract the sub app feature as it isn't ready yet.
You can use `git diff --diff-filter=M eb8f973646476b4a4926ba644a77e2b3a5772159` to find all differences in this PR. The `--diff-filtered=M` filters all files added in the original commit but not in this commit away.
Co-Authored-By: Carter Anderson <mcanders1@gmail.com>
This logic was in both `remove_bundle` and ` remove_bundle_intersection` but only differed by whether we call `.._forget_missing_..` or `.._drop_missing_..`
# Objective
- There are a few random failures in CI, mostly due to contacting crates.io or checking for deadlinks
- CI can take some time, more than 20 minutes for a full status
- A clippy/format issue stops running tests on other platforms
## Solution
- Use GitHub cache for cargo artefacts
- This speeds up builds and reduce dependencies on outside world
- Reorder and add dependencies between short jobs. They are still setup to run even if one of the dependency failed
- This reduce the number of parallel jobs that are running for one PR. On GitHub free tier, we're limited to 20.
- Split CI checks (format & clippy) in its own job
- This speeds up test jobs, and allow us to not kill all platform tests for a format issue
- Retry in case of dead links check failure
- Internet is just that kind of place where things may seem dead at some point but back alive 5 seconds later
## Before
<img width="1062" alt="Screenshot 2021-07-27 at 01 18 52" src="https://user-images.githubusercontent.com/8672791/127071973-9a2c5ce8-c871-4f8d-9b17-08871824b6c4.png">
## After (with all cache live)
<img width="1063" alt="Screenshot 2021-07-27 at 01 18 28" src="https://user-images.githubusercontent.com/8672791/127071986-767a7e65-53ed-45fd-8d75-51a571f0b851.png">
# Objective
- Related to #2514 - not sure if it's a proper fix long term
- CI was complaining Error: Path `"/usr/local/lib/android/sdk/ndk-bundle/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android31-clang"` was not found
- A lot of questions started popping up 10 days ago about ["android build tools 31 corrupted"](https://www.google.com/search?q=android+build+tools+31+corrupted)
- https://stackoverflow.com/questions/68387270/android-studio-error-installed-build-tools-revision-31-0-0-is-corrupted
- Uninstalling `"build-tools;31.0.0"` doesn't seem to work, as it removes other components even though `"build-tools;30.0.3"` are available
## Solution
- Uninstalling `"platforms;android-31"` seems to do the trick and `cargo-apk` stops trying to target `...31`
Android is not my thing, this solution was found with a lot of trials and errors. I am not sure how long term it is, I don't know the release schedule of android build tools, or if we need to target this 31 thing. I just wanted to stop all those failed ci everywhere...
This relicenses Bevy under the dual MIT or Apache-2.0 license. For rationale, see #2373.
* Changes the LICENSE file to describe the dual license. Moved the MIT license to docs/LICENSE-MIT. Added the Apache-2.0 license to docs/LICENSE-APACHE. I opted for this approach over dumping both license files at the root (the more common approach) for a number of reasons:
* Github links to the "first" license file (LICENSE-APACHE) in its license links (you can see this in the wgpu and rust-analyzer repos). People clicking these links might erroneously think that the apache license is the only option. Rust and Amethyst both use COPYRIGHT or COPYING files to solve this problem, but this creates more file noise (if you do everything at the root) and the naming feels way less intuitive.
* People have a reflex to look for a LICENSE file. By providing a single license file at the root, we make it easy for them to understand our licensing approach.
* I like keeping the root clean and noise free
* There is precedent for putting the apache and mit license text in sub folders (amethyst)
* Removed the `Copyright (c) 2020 Carter Anderson` copyright notice from the MIT license. I don't care about this attribution, it might make license compliance more difficult in some cases, and it didn't properly attribute other contributors. We shoudn't replace it with something like "Copyright (c) 2021 Bevy Contributors" because "Bevy Contributors" is not a legal entity. Instead, we just won't include the copyright line (which has precedent ... Rust also uses this approach).
* Updates crates to use the new "MIT OR Apache-2.0" license value
* Removes the old legion-transform license file from bevy_transform. bevy_transform has been its own, fully custom implementation for a long time and that license no longer applies.
* Added a License section to the main readme
* Updated our Bevy Plugin licensing guidelines.
As a follow-up we should update the website to properly describe the new license.
Closes#2373
