https://github.com/Kjolnyr/bevy_app_compute
App compute plugin for Bevy
https://github.com/Kjolnyr/bevy_app_compute
bevy bevy-plugin compute-shader rust
Last synced: 5 days ago
JSON representation
App compute plugin for Bevy
- Host: GitHub
- URL: https://github.com/Kjolnyr/bevy_app_compute
- Owner: Kjolnyr
- Created: 2023-04-14T14:32:05.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2024-07-25T17:16:16.000Z (10 months ago)
- Last Synced: 2025-04-26T19:59:25.241Z (14 days ago)
- Topics: bevy, bevy-plugin, compute-shader, rust
- Language: Rust
- Homepage:
- Size: 70.3 KB
- Stars: 82
- Watchers: 6
- Forks: 25
- Open Issues: 11
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
- awesome-bevy - `bevy_app_compute`
README
# Bevy App Compute
[](https://docs.rs/bevy_app_compute)
[](https://crates.io/crates/bevy_app_compute)
An easy way to run wgpu compute shaders within a bevy app.
## Getting Started
Add the following line to your `Cargo.toml`
```toml
[dependencies]
bevy_app_compute = "0.16"
```
## Usage
### Setup
Declare your shaders in structs implementing `ComputeShader`. The `shader()` fn
should point to your shader source code. You need to derive `TypePath` as well:
```rust
#[derive(TypePath)]
struct SimpleShader;
impl ComputeShader for SimpleShader {
fn shader() -> ShaderRef {
"shaders/simple.wgsl".into()
}
}
```
Next, declare a struct implementing `ComputeWorker` to declare the bindings and
the logic of your worker:
```rust
#[derive(Resource)]
struct SimpleComputeWorker;
impl ComputeWorker for SimpleComputeWorker {
fn build(world: &mut World) -> AppComputeWorker {
let worker = AppComputeWorkerBuilder::new(world)
// Add a uniform variable
.add_uniform("uni", &5.)
// Add a staging buffer, it will be available from
// both CPU and GPU land.
.add_staging("values", &[1., 2., 3., 4.])
// Create a compute pass from your compute shader
// and define used variables
.add_pass::([4, 1, 1], &["uni", "values"])
.build();
worker
}
}
```
Don't forget to add a shader file to your `assets/` folder:
```rust
@group(0) @binding(0)
var uni: f32;
@group(0) @binding(1)
var my_storage: array;
@compute @workgroup_size(1)
fn main(@builtin(global_invocation_id) invocation_id: vec3) {
my_storage[invocation_id.x] = my_storage[invocation_id.x] + uni;
}
```
Add the `AppComputePlugin` plugin to your app, as well as one
`AppComputeWorkerPlugin` per struct implementing `ComputeWorker`:
```rust
App::new()
// ... other plugins ...
.add_plugins(bevy_app_compute::AppComputeWorkerPlugin::::default());
```
Your compute worker will now run every frame, during the `PostUpdate` stage. To
read/write from it, use the `AppComputeWorker` resource!
```rust
fn my_system(
mut compute_worker: ResMut>
) {
if !compute_worker.ready() {
return;
};
let result: Vec = compute_worker.read_vec("values");
compute_worker.write_slice("values", [2., 3., 4., 5.]);
println!("got {:?}", result)
}
```
(see
[simple.rs](https://github.com/Kjolnyr/bevy_app_compute/tree/main/examples/simple.rs))
### Multiple passes
You can have multiple passes without having to copy data back to the CPU in
between:
```rust
let worker = AppComputeWorkerBuilder::new(world)
.add_uniform("value", &3.)
.add_storage("input", &[1., 2., 3., 4.])
.add_staging("output", &[0f32; 4])
// add each item + `value` from `input` to `output`
// the order of the values represents their binding order
.add_pass::([4, 1, 1], &["value", "input", "output"])
// multiply each element of `output` by itself
.add_pass::([4, 1, 1], &["output"])
.build();
// the `output` buffer will contain [16.0, 25.0, 36.0, 49.0]
```
(see
[multi_pass.rs](https://github.com/Kjolnyr/bevy_app_compute/tree/main/examples/multi_pass.rs))
### One shot computes
You can configure your worker to execute only when requested:
```rust
let worker = AppComputeWorkerBuilder::new(world)
.add_uniform("uni", &5.)
.add_staging("values", &[1., 2., 3., 4.])
.add_pass::([4, 1, 1], &["uni", "values"])
// This `one_shot()` function will configure your worker accordingly
.one_shot()
.build();
```
Then, you can call `execute()` on your worker when you are ready to execute it:
```rust
// Execute it only when the left mouse button is pressed.
fn on_click_compute(
buttons: Res>,
mut compute_worker: ResMut>
) {
if !buttons.just_pressed(MouseButton::Left) { return; }
compute_worker.execute();
}
```
It will run at the end of the current frame, and you'll be able to read the data
in the next frame.
(see
[one_shot.rs](https://github.com/Kjolnyr/bevy_app_compute/tree/main/examples/one_shot.rs))
## Examples
See [examples](https://github.com/Kjolnyr/bevy_app_compute/tree/main/examples)
## Bevy version mapping
| Bevy | bevy_app_compute |
| ---- | ---------------- |
| 0.16 | 0.16 |