A fork of bevy to implement some features for forestia
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Mads Marquart e6a6c9fb4c
Link iOS example with rustc, and avoid C trampoline (#14780)
# Objective

On iOS:
- Allow `std` to do its runtime initialization.
- Avoid requiring the user to specify linked libraries and framework in
Xcode.
- Reduce the amount of work that `#[bevy_main]` does
- In the future we may also be able to eliminate the need for it on
Android, cc @daxpedda.

## Solution

We previously:
- Exposed an `extern "C" fn main_rs` entry point.
- Ran Cargo in a separate Xcode target as an external build system.
- Imported that as a dependency of `bevy_mobile_example.app`.
- Compiled a trampoline C file with Xcode that called `main_rs`.
- Linked that via. Xcode.

All of this is unnecessary; `rustc` is well capable of creating iOS
executables, the trick is just to place it at the correct location for
Xcode to understand it, namely `$TARGET_BUILD_DIR/$EXECUTABLE_PATH`
(places it in `bevy_mobile_example.app/bevy_mobile_example`).

Note: We might want to wait with the changes to `#[bevy_main]` until the
problem is resolved on Android too, to make the migration easier.

## Testing

Open the Xcode project, and build for an iOS target.

---

## Migration Guide

**If you have been building your application for iOS:**

Previously, the `#[bevy_main]` attribute created a `main_rs` entry point
that most Xcode templates were using to run your Rust code from C. This
was found to be unnecessary, as you can simply let Rust build your
application as a binary, and run that directly.

You have two options for dealing with this:

If you've added further C code and Xcode customizations, or it makes
sense for your use-case to continue link with Xcode, you can revert to
the old behaviour by adding `#[no_mangle] extern "C" main_rs() { main()
}` to your `main.rs`. Note that the old approach of linking a static
library prevents the Rust standard library from doing runtime
initialization, so certain functionality provided by `std` might be
unavailable (stack overflow handlers, stdout/stderr flushing and other
such functionality provided by the initialization routines).

The other, preferred option is to remove your "compile" and "link" build
phases, and instead replace it with a "run script" phase that invokes
`cargo build --bin ...`, and moves the built binary to the Xcode path
`$TARGET_BUILD_DIR/$EXECUTABLE_PATH`. An example of how to do this can
be viewed at [INSERT LINK TO UPDATED EXAMPLE PROJECT].
To make the debugging experience in Xcode nicer after this, you might
also want to consider either enabling `panic = "abort"` or to set a
breakpoint on the `rust_panic` symbol.

---------

Co-authored-by: François Mockers <mockersf@gmail.com>
Co-authored-by: François Mockers <francois.mockers@vleue.com>
2025-03-17 21:14:07 +00:00
.cargo Fix typos in config_fast_builds.toml (#16025) 2024-10-20 16:50:40 +00:00
.github Link iOS example with rustc, and avoid C trampoline (#14780) 2025-03-17 21:14:07 +00:00
assets Fix non-crate typos (#18219) 2025-03-11 06:17:48 +00:00
benches bevy_reflect: Deprecate PartialReflect::clone_value (#18284) 2025-03-14 19:33:57 +00:00
crates Link iOS example with rustc, and avoid C trampoline (#14780) 2025-03-17 21:14:07 +00:00
docs Build performance advice (#18339) 2025-03-16 11:37:41 +00:00
docs-rs Relationship(…Target) html trait tag (#18140) 2025-03-04 08:05:16 +00:00
docs-template Fix a few typos (#17292) 2025-01-10 22:48:30 +00:00
errors Upgrade to Rust Edition 2024 (#17967) 2025-02-24 03:54:47 +00:00
examples Link iOS example with rustc, and avoid C trampoline (#14780) 2025-03-17 21:14:07 +00:00
src Add no_std support to bevy (#17955) 2025-03-07 03:39:46 +00:00
tests Fix non-crate typos (#18219) 2025-03-11 06:17:48 +00:00
tests-integration/simple-ecs-test Internalize BevyManifest logic. Switch to RwLock (#18263) 2025-03-12 00:46:01 +00:00
tools Update ui_test requirement from 0.23.0 to 0.29.1 (#18289) 2025-03-13 16:34:33 +00:00
.gitattributes Enforce linux-style line endings for .rs and .toml (#3197) 2021-11-26 21:05:35 +00:00
.gitignore Harden proc macro path resolution and add integration tests. (#17330) 2025-02-09 19:45:45 +00:00
Cargo.toml Add examples/helpers/* as library examples (#18288) 2025-03-13 16:34:16 +00:00
clippy.toml Enable nonstandard_macro_braces and enforce [] for children! (#17974) 2025-02-22 01:54:49 +00:00
CODE_OF_CONDUCT.md Update CODE_OF_CONDUCT.md 2020-08-19 20:25:58 +01:00
CONTRIBUTING.md Reworded the CONTRIBUTING.md doc (#16849) 2024-12-17 19:18:34 +00:00
CREDITS.md Fix typos CREDITS.md (#17899) 2025-02-17 09:30:04 +00:00
deny.toml Ignore unmaintained security advisory about paste for now (#18209) 2025-03-09 20:17:29 +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 Upgrade to Rust Edition 2024 (#17967) 2025-02-24 03:54:47 +00:00
typos.toml Bump typos to 1.29.7 (#17902) 2025-02-17 20:41:25 +00:00

Bevy

License Crates.io Downloads Docs CI Discord

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.