aeeb20ec4c
# Objective **This implementation is based on https://github.com/bevyengine/rfcs/pull/59.** --- Resolves #4597 Full details and motivation can be found in the RFC, but here's a brief summary. `FromReflect` is a very powerful and important trait within the reflection API. It allows Dynamic types (e.g., `DynamicList`, etc.) to be formed into Real ones (e.g., `Vec<i32>`, etc.). This mainly comes into play concerning deserialization, where the reflection deserializers both return a `Box<dyn Reflect>` that almost always contain one of these Dynamic representations of a Real type. To convert this to our Real type, we need to use `FromReflect`. It also sneaks up in other ways. For example, it's a required bound for `T` in `Vec<T>` so that `Vec<T>` as a whole can be made `FromReflect`. It's also required by all fields of an enum as it's used as part of the `Reflect::apply` implementation. So in other words, much like `GetTypeRegistration` and `Typed`, it is very much a core reflection trait. The problem is that it is not currently treated like a core trait and is not automatically derived alongside `Reflect`. This makes using it a bit cumbersome and easy to forget. ## Solution Automatically derive `FromReflect` when deriving `Reflect`. Users can then choose to opt-out if needed using the `#[reflect(from_reflect = false)]` attribute. ```rust #[derive(Reflect)] struct Foo; #[derive(Reflect)] #[reflect(from_reflect = false)] struct Bar; fn test<T: FromReflect>(value: T) {} test(Foo); // <-- OK test(Bar); // <-- Panic! Bar does not implement trait `FromReflect` ``` #### `ReflectFromReflect` This PR also automatically adds the `ReflectFromReflect` (introduced in #6245) registration to the derived `GetTypeRegistration` impl— if the type hasn't opted out of `FromReflect` of course. <details> <summary><h4>Improved Deserialization</h4></summary> > **Warning** > This section includes changes that have since been descoped from this PR. They will likely be implemented again in a followup PR. I am mainly leaving these details in for archival purposes, as well as for reference when implementing this logic again. And since we can do all the above, we might as well improve deserialization. We can now choose to deserialize into a Dynamic type or automatically convert it using `FromReflect` under the hood. `[Un]TypedReflectDeserializer::new` will now perform the conversion and return the `Box`'d Real type. `[Un]TypedReflectDeserializer::new_dynamic` will work like what we have now and simply return the `Box`'d Dynamic type. ```rust // Returns the Real type let reflect_deserializer = UntypedReflectDeserializer::new(®istry); let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?; let output: SomeStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?; // Returns the Dynamic type let reflect_deserializer = UntypedReflectDeserializer::new_dynamic(®istry); let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?; let output: DynamicStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?; ``` </details> --- ## Changelog * `FromReflect` is now automatically derived within the `Reflect` derive macro * This includes auto-registering `ReflectFromReflect` in the derived `GetTypeRegistration` impl * ~~Renamed `TypedReflectDeserializer::new` and `UntypedReflectDeserializer::new` to `TypedReflectDeserializer::new_dynamic` and `UntypedReflectDeserializer::new_dynamic`, respectively~~ **Descoped** * ~~Changed `TypedReflectDeserializer::new` and `UntypedReflectDeserializer::new` to automatically convert the deserialized output using `FromReflect`~~ **Descoped** ## Migration Guide * `FromReflect` is now automatically derived within the `Reflect` derive macro. Items with both derives will need to remove the `FromReflect` one. ```rust // OLD #[derive(Reflect, FromReflect)] struct Foo; // NEW #[derive(Reflect)] struct Foo; ``` If using a manual implementation of `FromReflect` and the `Reflect` derive, users will need to opt-out of the automatic implementation. ```rust // OLD #[derive(Reflect)] struct Foo; impl FromReflect for Foo {/* ... */} // NEW #[derive(Reflect)] #[reflect(from_reflect = false)] struct Foo; impl FromReflect for Foo {/* ... */} ``` <details> <summary><h4>Removed Migrations</h4></summary> > **Warning** > This section includes changes that have since been descoped from this PR. They will likely be implemented again in a followup PR. I am mainly leaving these details in for archival purposes, as well as for reference when implementing this logic again. * The reflect deserializers now perform a `FromReflect` conversion internally. The expected output of `TypedReflectDeserializer::new` and `UntypedReflectDeserializer::new` is no longer a Dynamic (e.g., `DynamicList`), but its Real counterpart (e.g., `Vec<i32>`). ```rust let reflect_deserializer = UntypedReflectDeserializer::new_dynamic(®istry); let mut deserializer = ron:🇩🇪:Deserializer::from_str(input)?; // OLD let output: DynamicStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?; // NEW let output: SomeStruct = reflect_deserializer.deserialize(&mut deserializer)?.take()?; ``` Alternatively, if this behavior isn't desired, use the `TypedReflectDeserializer::new_dynamic` and `UntypedReflectDeserializer::new_dynamic` methods instead: ```rust // OLD let reflect_deserializer = UntypedReflectDeserializer::new(®istry); // NEW let reflect_deserializer = UntypedReflectDeserializer::new_dynamic(®istry); ``` </details> --------- Co-authored-by: Carter Anderson <mcanders1@gmail.com> |
||
|---|---|---|
| .cargo | ||
| .github | ||
| assets | ||
| benches | ||
| crates | ||
| docs | ||
| docs-template | ||
| errors | ||
| examples | ||
| src | ||
| tests | ||
| tools | ||
| .gitattributes | ||
| .gitignore | ||
| Cargo.toml | ||
| CHANGELOG.md | ||
| clippy.toml | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| CREDITS.md | ||
| deny.toml | ||
| LICENSE-APACHE | ||
| LICENSE-MIT | ||
| README.md | ||
| rustfmt.toml | ||
What is Bevy?
Bevy is a refreshingly simple data-driven game engine built in Rust. It is free and open-source forever!
WARNING
Bevy is still in the early stages of development. Important features are missing. Documentation is sparse. A new version of Bevy containing breaking changes to the API is released approximately once every 3 months. We provide migration guides, but we can't guarantee migrations will always be easy. Use only if you are willing to work in this environment.
MSRV: Bevy relies heavily on improvements in the Rust language and compiler. As a result, the Minimum Supported Rust Version (MSRV) is generally close to "the latest stable release" of Rust.
Design Goals
- Capable: Offer a complete 2D and 3D feature set
- Simple: Easy for newbies to pick up, but infinitely flexible for power users
- Data Focused: Data-oriented architecture using the Entity Component System paradigm
- Modular: Use only what you need. Replace what you don't like
- Fast: App logic should run quickly, and when possible, in parallel
- Productive: Changes should compile quickly ... waiting isn't fun
About
- Features: A quick overview of Bevy's features.
- News: A development blog that covers our progress, plans and shiny new features.
Docs
- The Bevy Book: Bevy's official documentation. The best place to start learning Bevy.
- Bevy Rust API Docs: Bevy's Rust API docs, which are automatically generated from the doc comments in this repo.
- Official Examples: Bevy's dedicated, runnable examples, which are great for digging into specific concepts.
- Community-Made Learning Resources: More tutorials, documentation, and examples made by the Bevy community.
Community
Before contributing or participating in discussions with the community, you should familiarize yourself with our Code of Conduct.
- Discord: Bevy's official discord server.
- Reddit: Bevy's official subreddit.
- GitHub Discussions: The best place for questions about Bevy, answered right here!
- Bevy Assets: A collection of awesome Bevy projects, tools, plugins and learning materials.
If you'd like to help build Bevy, check out the Contributor's Guide. For simple problems, feel free to open an issue or PR and tackle it yourself!
For more complex architecture decisions and experimental mad science, please open an RFC (Request For Comments) so we can brainstorm together effectively!
Getting Started
We recommend checking out The Bevy Book for a full tutorial.
Follow the Setup guide to ensure your development environment is set up correctly. Once set up, you can quickly try out the examples by cloning this repo and running the following commands:
# Switch to the correct version (latest release, default is main development branch)
git checkout latest
# Runs the "breakout" example
cargo run --example breakout
To draw a window with standard functionality enabled, use:
use bevy::prelude::*;
fn main(){
App::new()
.add_plugins(DefaultPlugins)
.run();
}
Fast Compiles
Bevy can be built just fine using default configuration on stable Rust. However for really fast iterative compiles, you should enable the "fast compiles" setup by following the instructions here.
Libraries Used
Bevy is only possible because of the hard work put into these foundational technologies:
- wgpu: modern / low-level / cross-platform graphics library inspired by Vulkan
- glam-rs: a simple and fast 3D math library for games and graphics
- winit: cross-platform window creation and management in Rust
Bevy Cargo Features
This list outlines the different cargo features supported by Bevy. These allow you to customize the Bevy feature set for your use-case.
Third Party Plugins
Plugins are very welcome to extend Bevy's features. Guidelines are available to help integration and usage.
Thanks and Alternatives
Additionally, we would like to thank the Amethyst, macroquad, coffee, ggez, Fyrox, and Piston projects for providing solid examples of game engine development in Rust. If you are looking for a Rust game engine, it is worth considering all of your options. Each engine has different design goals, and some will likely resonate with you more than others.
This project is tested with BrowserStack.
License
Bevy is free, open source and permissively licensed! Except where noted (below and/or in individual files), all code in this repository is dual-licensed under either:
- MIT License (LICENSE-MIT or http://opensource.org/licenses/MIT)
- Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
at your option. This means you can select the license you prefer! This dual-licensing approach is the de-facto standard in the Rust ecosystem and there are very good reasons to include both.
Some of the engine's code carries additional copyright notices and license terms due to their external origins.
These are generally BSD-like, but exact details vary by crate:
If the README of a crate contains a 'License' header (or similar), the additional copyright notices and license terms applicable to that crate will be listed.
The above licensing requirement still applies to contributions to those crates, and sections of those crates will carry those license terms.
The license field of each crate will also reflect this.
For example, bevy_mikktspace has code under the Zlib license (as well as a copyright notice when choosing the MIT license).
The assets included in this repository (for our examples) typically fall under different open licenses. These will not be included in your game (unless copied in by you), and they are not distributed in the published bevy crates. See CREDITS.md for the details of the licenses of those files.
Your contributions
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.