![]() # Objective Upgrade to `wgpu` version `25.0`. Depends on https://github.com/bevyengine/naga_oil/pull/121 ## Solution ### Problem The biggest issue we face upgrading is the following requirement: > To facilitate this change, there was an additional validation rule put in place: if there is a binding array in a bind group, you may not use dynamic offset buffers or uniform buffers in that bind group. This requirement comes from vulkan rules on UpdateAfterBind descriptors. This is a major difficulty for us, as there are a number of binding arrays that are used in the view bind group. Note, this requirement does not affect merely uniform buffors that use dynamic offset but the use of *any* uniform in a bind group that also has a binding array. ### Attempted fixes The easiest fix would be to change uniforms to be storage buffers whenever binding arrays are in use: ```wgsl #ifdef BINDING_ARRAYS_ARE_USED @group(0) @binding(0) var<uniform> view: View; @group(0) @binding(1) var<uniform> lights: types::Lights; #else @group(0) @binding(0) var<storage> view: array<View>; @group(0) @binding(1) var<storage> lights: array<types::Lights>; #endif ``` This requires passing the view index to the shader so that we know where to index into the buffer: ```wgsl struct PushConstants { view_index: u32, } var<push_constant> push_constants: PushConstants; ``` Using push constants is no problem because binding arrays are only usable on native anyway. However, this greatly complicates the ability to access `view` in shaders. For example: ```wgsl #ifdef BINDING_ARRAYS_ARE_USED mesh_view_bindings::view.view_from_world[0].z #else mesh_view_bindings::view[mesh_view_bindings::view_index].view_from_world[0].z #endif ``` Using this approach would work but would have the effect of polluting our shaders with ifdef spam basically *everywhere*. Why not use a function? Unfortunately, the following is not valid wgsl as it returns a binding directly from a function in the uniform path. ```wgsl fn get_view() -> View { #if BINDING_ARRAYS_ARE_USED let view_index = push_constants.view_index; let view = views[view_index]; #endif return view; } ``` This also poses problems for things like lights where we want to return a ptr to the light data. Returning ptrs from wgsl functions isn't allowed even if both bindings were buffers. The next attempt was to simply use indexed buffers everywhere, in both the binding array and non binding array path. This would be viable if push constants were available everywhere to pass the view index, but unfortunately they are not available on webgpu. This means either passing the view index in a storage buffer (not ideal for such a small amount of state) or using push constants sometimes and uniform buffers only on webgpu. However, this kind of conditional layout infects absolutely everything. Even if we were to accept just using storage buffer for the view index, there's also the additional problem that some dynamic offsets aren't actually per-view but per-use of a setting on a camera, which would require passing that uniform data on *every* camera regardless of whether that rendering feature is being used, which is also gross. As such, although it's gross, the simplest solution just to bump binding arrays into `@group(1)` and all other bindings up one bind group. This should still bring us under the device limit of 4 for most users. ### Next steps / looking towards the future I'd like to avoid needing split our view bind group into multiple parts. In the future, if `wgpu` were to add `@builtin(draw_index)`, we could build a list of draw state in gpu processing and avoid the need for any kind of state change at all (see https://github.com/gfx-rs/wgpu/issues/6823). This would also provide significantly more flexibility to handle things like offsets into other arrays that may not be per-view. ### Testing Tested a number of examples, there are probably more that are still broken. --------- Co-authored-by: François Mockers <mockersf@gmail.com> Co-authored-by: Elabajaba <Elabajaba@users.noreply.github.com> |
||
---|---|---|
.cargo | ||
.github | ||
assets | ||
benches | ||
crates | ||
docs | ||
docs-rs | ||
docs-template | ||
errors | ||
examples | ||
release-content | ||
src | ||
tests | ||
tests-integration/simple-ecs-test | ||
tools | ||
.gitattributes | ||
.gitignore | ||
Cargo.toml | ||
clippy.toml | ||
CODE_OF_CONDUCT.md | ||
CONTRIBUTING.md | ||
CREDITS.md | ||
deny.toml | ||
LICENSE-APACHE | ||
LICENSE-MIT | ||
README.md | ||
rustfmt.toml | ||
typos.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
- Quick Start Guide: Bevy's official Quick Start Guide. 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.
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:
- 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.