# Objective
Adds a new `Readback` component to request for readback of a
`Handle<Image>` or `Handle<ShaderStorageBuffer>` to the CPU in a future
frame.
## Solution
We track the `Readback` component and allocate a target buffer to write
the gpu resource into and map it back asynchronously, which then fires a
trigger on the entity in the main world. This proccess is asynchronous,
and generally takes a few frames.
## Showcase
```rust
let mut buffer = ShaderStorageBuffer::from(vec![0u32; 16]);
buffer.buffer_description.usage |= BufferUsages::COPY_SRC;
let buffer = buffers.add(buffer);
commands
.spawn(Readback::buffer(buffer.clone()))
.observe(|trigger: Trigger<ReadbackComplete>| {
info!("Buffer data from previous frame {:?}", trigger.event());
});
```
---------
Co-authored-by: Kristoffer Søholm <k.soeholm@gmail.com>
Co-authored-by: IceSentry <IceSentry@users.noreply.github.com>
# Objective
Fixes#14782
## Solution
Enable the lint and fix all upcoming hints (`--fix`). Also tried to
figure out the false-positive (see review comment). Maybe split this PR
up into multiple parts where only the last one enables the lint, so some
can already be merged resulting in less many files touched / less
potential for merge conflicts?
Currently, there are some cases where it might be easier to read the
code with the qualifier, so perhaps remove the import of it and adapt
its cases? In the current stage it's just a plain adoption of the
suggestions in order to have a base to discuss.
## Testing
`cargo clippy` and `cargo run -p ci` are happy.
# Objective
- Where possible, it's recommended to use `BufferVec` over
`encase::StorageBuffer` for performance reason. It doesn't really matter
for the example, but it's still important to teach the better solution.
## Solution
- Use BufferVec in the gpu_readback example
# Objective
- It's pretty common for users to want to read data back from the gpu
and into the main world
## Solution
- Add a simple example that shows how to read data back from the gpu and
send it to the main world using a channel.
- The example is largely based on this wgpu example but adapted to bevy
-
fb305b85f6/examples/src/repeated_compute/mod.rs
---------
Co-authored-by: stormy <120167078+stowmyy@users.noreply.github.com>
Co-authored-by: Torstein Grindvik <52322338+torsteingrindvik@users.noreply.github.com>
