A fork of bevy to implement some features for forestia
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Alice Cecile aa09b6601d
Add basic directional (gamepad) navigation for UI (and non-UI) (#17102)
# Objective

While directional navigation is helpful for UI in general for
accessibility reasons, it is *especially* valuable for a game engine,
where menus may be navigated primarily or exclusively through the use of
a game controller.

Thumb-stick powered cursor-based navigation can work as a fallback, but
is generally a pretty poor user experience. We can do better!

## Prior art

Within Bevy, https://github.com/nicopap/ui-navigation and
https://github.com/rparrett/bevy-alt-ui-navigation-lite exist to solve
this same problem. This isn't yet a complete replacement for that
ecosystem, but hopefully we'll be there for 0.16.

## Solution

UI navigation is complicated, and the right tradeoffs will vary based on
the project and even the individual scene.

We're starting with something simple and flexible, hooking into the
existing `InputFocus` resource, and storing a manually constructed graph
of entities to explore in a `DirectionalNavigationMap` resource. The
developer experience won't be great (so much wiring to do!), but the
tools are all there for a great user experience.

We could have chosen to represent these linkages via component-flavored
not-quite-relations. This would be useful for inspectors, and would give
us automatic cleanup when the entities were despawned, but seriously
complicates the developer experience when building and checking this
API. For now, we're doing a dumb "entity graph in a resource" thing and
`remove` helpers. Once relations are added, we can re-evaluate.

I've decided to use a `CompassOctant` as our key for the possible paths.
This should give users a reasonable amount of precise control without
being fiddly, and playing reasonably nicely with arrow-key navigation.
This design lets us store the set of entities that we're connected to as
a 8-byte array (yay Entity-niching). In theory, this is maybe nicer than
the double indirection of two hashmaps. but if this ends up being slow
we should create benchmarks.

To make this work more pleasant, I've added a few utilities to the
`CompassOctant` type: converting to and from usize, and adding a helper
to find the 180 degrees opposite direction. These have been mirrored
onto `CompassQuadrant` for consistency: they should be generally useful
for game logic.

## Future work

This is a relatively complex initiative! In the hopes of easing review
and avoiding merge conflicts, I've opted to split this work into
bite-sized chunks.

Before 0.16, I'd like to have:

- An example demonstrating gamepad and tab-based navigation in a
realistic game menu
- Helpers to convert axis-based inputs into compass quadrants / octants
- Tools to check the listed graph desiderata
- A helper to build a graph from a grid of entities
- A tool to automatically build a graph given a supplied UI layout

One day, it would be sweet if:

- We had an example demonstrating how to use focus navigation in a
non-UI scene to cycle between game objects
- Standard actions for tab-style and directional navigation with a
first-party bevy_actions integration
- We had a visual debugging tool to display these navigation graphs for
QC purposes
- There was a built-in way to go "up a level" by cancelling the current
action
- The navigation graph is built completely out of relations

## Testing

- tests for the new `CompassQuadrant` / `CompassOctant` methods
- tests for the new directional navigation module

---------

Co-authored-by: Rob Parrett <robparrett@gmail.com>
2025-01-06 18:51:44 +00:00
.cargo Fix typos in config_fast_builds.toml (#16025) 2024-10-20 16:50:40 +00:00
.github Fix workflows for version bump (#17162) 2025-01-05 20:27:58 +00:00
assets Introduce two-level bins for multidrawable meshes. (#16898) 2025-01-06 18:34:40 +00:00
benches Update entity cloning benchmarks (#17084) 2025-01-02 19:55:35 +00:00
crates Add basic directional (gamepad) navigation for UI (and non-UI) (#17102) 2025-01-06 18:51:44 +00:00
docs Updated nixos link in linux_dependencies.md. (#17146) 2025-01-05 02:35:36 +00:00
docs-template ✏️ Fix typos across bevy (#16702) 2024-12-08 01:18:39 +00:00
errors Remove all deprecated code (#16338) 2025-01-05 20:33:39 +00:00
examples Anamorphic Bloom (#17096) 2025-01-06 18:43:21 +00:00
src Fix common capitalization errors in documentation (#14562) 2024-07-31 21:16:05 +00:00
tests Remove bevy_core (#16897) 2024-12-19 18:36:51 +00:00
tools Remove tracing re-export from bevy_utils (#17161) 2025-01-05 23:06:34 +00:00
.gitattributes
.gitignore Gitignore all target folders (#16336) 2024-11-11 18:48:11 +00:00
Cargo.toml Bump Version after Release (#17176) 2025-01-06 00:04:44 +00:00
clippy.toml Migrate to core::hint::black_box() (#16980) 2024-12-29 19:33:42 +00:00
CODE_OF_CONDUCT.md
CONTRIBUTING.md Reworded the CONTRIBUTING.md doc (#16849) 2024-12-17 19:18:34 +00:00
CREDITS.md Programmed soundtrack example (#12774) 2024-03-29 20:32:30 +00:00
deny.toml Ignore the 'instant is unmaintained' advisory. (#16763) 2024-12-11 17:25:55 +00:00
LICENSE-APACHE Let the project page support GitHub's new ability to display open source licenses (#4966) 2022-06-08 17:55:57 +00:00
LICENSE-MIT Let the project page support GitHub's new ability to display open source licenses (#4966) 2022-06-08 17:55:57 +00:00
README.md Update Contributor's Guide link in README.md (#16592) 2024-12-02 15:18:19 +00:00
rustfmt.toml Simpler lint fixes: makes ci lints work but disables a lint for now (#15376) 2024-09-24 11:42:59 +00:00
typos.toml Derivative access patterns for curves (#16503) 2024-12-10 20:27:37 +00:00

Bevy

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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

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.

Contributing

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 Quick Start Guide for a brief introduction.

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.

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.

Thanks

Bevy is the result of the hard work of many people. A huge thanks to all Bevy contributors, the many open source projects that have come before us, the Rust gamedev ecosystem, and the many libraries we build on.

A huge thanks to Bevy's generous sponsors. Bevy will always be free and open source, but it isn't free to make. Please consider sponsoring our work if you like what we're building.

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:

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.