# 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>
6f2a5cb862
