mirror of
https://github.com/bevyengine/bevy
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40c26f80aa
# 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>
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|---|---|---|
| .. | ||
| animate_shader.wgsl | ||
| array_texture.wgsl | ||
| cubemap_unlit.wgsl | ||
| custom_gltf_2d.wgsl | ||
| custom_material.frag | ||
| custom_material.vert | ||
| custom_material.wgsl | ||
| custom_material_2d.wgsl | ||
| custom_material_import.wgsl | ||
| custom_material_screenspace_texture.wgsl | ||
| custom_phase_item.wgsl | ||
| custom_ui_material.wgsl | ||
| custom_vertex_attribute.wgsl | ||
| extended_material.wgsl | ||
| fallback_image_test.wgsl | ||
| game_of_life.wgsl | ||
| gpu_readback.wgsl | ||
| instancing.wgsl | ||
| irradiance_volume_voxel_visualization.wgsl | ||
| line_material.wgsl | ||
| post_processing.wgsl | ||
| shader_defs.wgsl | ||
| show_prepass.wgsl | ||
| specialized_mesh_pipeline.wgsl | ||
| storage_buffer.wgsl | ||
| texture_binding_array.wgsl | ||
| tonemapping_test_patterns.wgsl | ||
| water_material.wgsl | ||