bevy/crates/bevy_utils/macros
robtfm 6f2a5cb862
Bind group entries (#9694)
# 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>
2023-10-21 15:39:22 +00:00
..
src Bind group entries (#9694) 2023-10-21 15:39:22 +00:00
Cargo.toml Bump Version after Release (#9106) 2023-07-10 21:19:27 +00:00