N14: Bevy Engine

Author: cart

content/posts/newsletter-014/bevy_logo.png

@@ -66,6 +66,90 @@ If needed, a section can be split into subsections with a "------" delimiter.
 
 ## Library & Tooling Updates
 
+### [Bevy Engine][bevy]
+
+[![bevy logo](bevy_logo.png)](https://bevyengine.org/)
+
+[Bevy][bevy] is a refreshingly simple data-driven
+game engine built in Rust. It is [free and open source][bevy-repo] forever!
+
+#### **Bevy 0.2 Released**
+
+This month, thanks to 87 contributors, 174 pull requests, and their
+[generous sponsors][bevy-sponsors], **Bevy 0.2** was released. You can view the
+[full Bevy 0.2 announcement here][bevy-0-2]. Here are some highlights:
+
+- **Async Task System**: Bevy now has a brand new async-friendly task system,
+which enables the creation of context-specific task pools. For example, you might
+have separate pools for compute, IO, networking, etc. This also provides the
+flexibility to load balance work appropriately according to work type and/or priority.
+Bevy (and a number of other rust game engines and ecs frameworks using rayon)
+have received feedback that they were overly cpu hungry / usage was not proportional
+to "real" work done. This new task system completely replaces Rayon and the cpu
+usage wins were huge!
+- **Initial Web Platform Support**: (A subset of) Bevy now runs on the web using
+WebAssembly/WASM! Specifically, Bevy apps can run Bevy ECS schedules, react to
+input events, create an empty canvas (using winit), and a few other things. This
+is a huge first step, but it is important to call out that there are still a
+number of missing pieces, such as 2D/3D rendering, multi-threading, and sound.
+- **Parallel Queries**: Bevy ECS Queries are a flexible way to retrieve data from
+the Entity Component System. Systems that use queries already run in parallel,
+but before this change the queries themselves could not be iterated in parallel.
+Bevy 0.2 adds the ability to easily iterate queries in parallel, which builds on
+top of the new Async Task System.
+- **Transform System Rewrite**: Bevy's old transform system used separate
+`Translation`, `Rotation`, and `Scale` components as the "source of truth",
+which were then synced to a `LocalTransform` component after each update. There
+are Good Reasons™ to use this approach, but it created a "lag" between the
+calculated LocalTransform and the source components and dataflow between components
+is hard to reason about. This problem was resolved by making a newer, simpler
+transform system that uses a consolidated `Transform` type.  
+- **Joystick/Gamepad Input**: The Bevy Input plugin now has cross-platform support
+for most controllers thanks to the gilrs library!
+- **Bevy ECS Performance Improvements**:
+  - *Generational Entity IDs*: Entity IDs have changed from being UUIDs to incrementing
+  generational indices. Random UUIDs were nice because they could be created anywhere,
+  were unique across game runs, and could be safely persisted to files or reused across
+  networks. Unfortunately they ended up being too slow relative to the alternatives.
+  The randomness had a measurable cost and entity locations had to be looked up
+  using a hash map.
+  - *Read Only Queries*: A "read only" trait was implemented for queries that
+  don't mutate anything. This allows Bevy to guarantee that a query won't mutate
+  anything.
+  - *Lock-Free World Apis*: This gave a really nice speed boost. World APIs are
+  still safe due to a combination of the new "read only queries" and changing
+  World mutation apis to be a mutable World borrow.
+  - *Direct Component Lookup*: As a result of the changes above, direct component
+  lookup is about 4x faster than it used to be!
+
+#### **Community Plugin Updates**
+
+- **[bevy_rapier](https://github.com/dimforge/bevy_rapier)**: Rapier Physics'
+official Bevy plugin was updated to support Bevy 0.2
+- **[bevy_ninepatch](https://crates.io/crates/bevy_ninepatch)**: Display 9-Patch
+UI elements, where you can specify how different parts of a PNG should grow
+- **[bevy_mod_picking](https://github.com/aevyrie/bevy_mod_picking)**: 3d cursor
+picking and highlighting
+- **[bevy_contrib_colors](https://crates.io/crates/bevy_contrib_colors)**: A
+simple color library
+- **[bevy_input_map](https://crates.io/crates/bevy_prototype_input_map)**: Converts
+user inputs from different input hardware into game specific actions. Ex: keyboard
+"Space" or joystick "A" can be mapped to a "Jump" Action.
+- **[bevy_prototype_lyon](https://github.com/Nilirad/bevy_prototype_lyon)**: Draw
+2D shapes, like triangles, circles, and beziers
+- **[bevy_contrib_inspector](https://github.com/jakobhellermann/bevy-contrib-inspector)**:
+Visually edit fields of your bevy resources in a browser or native view.
+
+_Discussions:
+[/r/rust](https://www.reddit.com/r/rust/comments/iw1yyp/bevy_02),
+[hacker news](https://news.ycombinator.com/item?id=24530698),
+[twitter](https://twitter.com/cart_cart/status/1307445918535315456)_
+
+[bevy]: https://bevyengine.org
+[bevy-repo]: https://github.com/bevyengine/bevy
+[bevy-0-2]: https://bevyengine.org/news/bevy-0-2
+[bevy-sponsors]: https://github.com/sponsors/cart
+
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 ## Requests for Contribution