# Objective
Fixes https://github.com/bevyengine/bevy/issues/10786
## Solution
The bind_group_layout entries for the prepass were wrong when not all 4
prepass textures were used, as it just zipped [17, 18, 19, 20] with the
smallvec of prepass `bind_group_layout` entries that potentially didn't
contain 4 entries. (eg. if you had a depth and motion vector prepass but
no normal prepass, then depth would be correct but the entry for the
motion vector prepass would be 18 (normal prepass' spot) instead of 19).
Change the prepass `get_bind_group_layout_entries` function to return an
array of `[Option<BindGroupLayoutEntryBuilder>; 4]` and only add the
layout entry if it exists.
# Objective
- Follow up to #9694
## Solution
- Same api as #9694 but adapted for `BindGroupLayoutEntry`
- Use the same `ShaderStages` visibilty for all entries by default
- Add `BindingType` helper function that mirror the wgsl equivalent and
that make writing layouts much simpler.
Before:
```rust
let layout = render_device.create_bind_group_layout(&BindGroupLayoutDescriptor {
label: Some("post_process_bind_group_layout"),
entries: &[
BindGroupLayoutEntry {
binding: 0,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Texture {
sample_type: TextureSampleType::Float { filterable: true },
view_dimension: TextureViewDimension::D2,
multisampled: false,
},
count: None,
},
BindGroupLayoutEntry {
binding: 1,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Sampler(SamplerBindingType::Filtering),
count: None,
},
BindGroupLayoutEntry {
binding: 2,
visibility: ShaderStages::FRAGMENT,
ty: BindingType::Buffer {
ty: bevy::render::render_resource::BufferBindingType::Uniform,
has_dynamic_offset: false,
min_binding_size: Some(PostProcessSettings::min_size()),
},
count: None,
},
],
});
```
After:
```rust
let layout = render_device.create_bind_group_layout(
"post_process_bind_group_layout"),
&BindGroupLayoutEntries::sequential(
ShaderStages::FRAGMENT,
(
texture_2d_f32(),
sampler(SamplerBindingType::Filtering),
uniform_buffer(false, Some(PostProcessSettings::min_size())),
),
),
);
```
Here's a more extreme example in bevy_solari:
86dab7f5da
---
## Changelog
- Added `BindGroupLayoutEntries` and all `BindingType` helper functions.
## Migration Guide
`RenderDevice::create_bind_group_layout()` doesn't take a
`BindGroupLayoutDescriptor` anymore. You need to provide the parameters
separately
```rust
// 0.12
let layout = render_device.create_bind_group_layout(&BindGroupLayoutDescriptor {
label: Some("post_process_bind_group_layout"),
entries: &[
BindGroupLayoutEntry {
// ...
},
],
});
// 0.13
let layout = render_device.create_bind_group_layout(
"post_process_bind_group_layout",
&[
BindGroupLayoutEntry {
// ...
},
],
);
```
## TODO
- [x] implement a `Dynamic` variant
- [x] update the `RenderDevice::create_bind_group_layout()` api to match
the one from `RenderDevice::creat_bind_group()`
- [x] docs
# Objective
Simplify bind group creation code. alternative to (and based on) #9476
## Solution
- Add a `BindGroupEntries` struct that can transparently be used where
`&[BindGroupEntry<'b>]` is required in BindGroupDescriptors.
Allows constructing the descriptor's entries as:
```rust
render_device.create_bind_group(
"my_bind_group",
&my_layout,
&BindGroupEntries::with_indexes((
(2, &my_sampler),
(3, my_uniform),
)),
);
```
instead of
```rust
render_device.create_bind_group(
"my_bind_group",
&my_layout,
&[
BindGroupEntry {
binding: 2,
resource: BindingResource::Sampler(&my_sampler),
},
BindGroupEntry {
binding: 3,
resource: my_uniform,
},
],
);
```
or
```rust
render_device.create_bind_group(
"my_bind_group",
&my_layout,
&BindGroupEntries::sequential((&my_sampler, my_uniform)),
);
```
instead of
```rust
render_device.create_bind_group(
"my_bind_group",
&my_layout,
&[
BindGroupEntry {
binding: 0,
resource: BindingResource::Sampler(&my_sampler),
},
BindGroupEntry {
binding: 1,
resource: my_uniform,
},
],
);
```
the structs has no user facing macros, is tuple-type-based so stack
allocated, and has no noticeable impact on compile time.
- Also adds a `DynamicBindGroupEntries` struct with a similar api that
uses a `Vec` under the hood and allows extending the entries.
- Modifies `RenderDevice::create_bind_group` to take separate arguments
`label`, `layout` and `entries` instead of a `BindGroupDescriptor`
struct. The struct can't be stored due to the internal references, and
with only 3 members arguably does not add enough context to justify
itself.
- Modify the codebase to use the new api and the `BindGroupEntries` /
`DynamicBindGroupEntries` structs where appropriate (whenever the
entries slice contains more than 1 member).
## Migration Guide
- Calls to `RenderDevice::create_bind_group({BindGroupDescriptor {
label, layout, entries })` must be amended to
`RenderDevice::create_bind_group(label, layout, entries)`.
- If `label`s have been specified as `"bind_group_name".into()`, they
need to change to just `"bind_group_name"`. `Some("bind_group_name")`
and `None` will still work, but `Some("bind_group_name")` can optionally
be simplified to just `"bind_group_name"`.
---------
Co-authored-by: IceSentry <IceSentry@users.noreply.github.com>
# Objective
This PR aims to make it so that we don't accidentally go over
`MAX_TEXTURE_IMAGE_UNITS` (in WebGL) or
`maxSampledTexturesPerShaderStage` (in WebGPU), giving us some extra
leeway to add more view bind group textures.
(This PR is extracted from—and unblocks—#8015)
## Solution
- We replace the existing `view_layout` and `view_layout_multisampled`
pair with an array of 32 bind group layouts, generated ahead of time;
- For now, these layouts cover all the possible combinations of:
`multisampled`, `depth_prepass`, `normal_prepass`,
`motion_vector_prepass` and `deferred_prepass`:
- In the future, as @JMS55 pointed out, we can likely take out
`motion_vector_prepass` and `deferred_prepass`, as these are not really
needed for the mesh pipeline and can use separate pipelines. This would
bring the possible combinations down to 8;
- We can also add more "optional" textures as they become needed,
allowing the engine to scale to a wider variety of use cases in lower
end/web environments (e.g. some apps might just want normal and depth
prepasses, others might only want light probes), while still keeping a
high ceiling for high end native environments where more textures are
supported.
- While preallocating bind group layouts is relatively cheap, the number
of combinations grows exponentially, so we should likely limit ourselves
to something like at most 256–1024 total layouts until we find a better
solution (like generating them lazily)
- To make this mechanism a little bit more explicit/discoverable, so
that compatibility with WebGPU/WebGL is not broken by accident, we add a
`MESH_PIPELINE_VIEW_LAYOUT_SAFE_MAX_TEXTURES` const and warn whenever
the number of textures in the layout crosses it.
- The warning is gated by `#[cfg(debug_assertions)]` and not issued in
release builds;
- We're counting the actual textures in the bind group layout instead of
using some roundabout metric so it should be accurate;
- Right now `MESH_PIPELINE_VIEW_LAYOUT_SAFE_MAX_TEXTURES` is set to 10
in order to leave 6 textures free for other groups;
- Currently there's no combination that would cause us to go over the
limit, but that will change once #8015 lands.
---
## Changelog
- `MeshPipeline` view bind group layouts now vary based on the current
multisampling and prepass states, saving a couple of texture binding
entries when prepasses are not in use.
## Migration Guide
- `MeshPipeline::view_layout` and
`MeshPipeline::view_layout_multisampled` have been replaced with a
private array to accomodate for variable view bind group layouts. To
obtain a view bind group layout for the current pipeline state, use the
new `MeshPipeline::get_view_layout()` or
`MeshPipeline::get_view_layout_from_key()` methods.
