Expose native C API support for R64Uint atomic storage textures

[Milky2018]

Summary

Rust wgpu exposes native API surface for R64Uint atomic storage textures, but the wgpu-native C API does not appear to expose equivalent native C ABI values.

This means C API consumers cannot express WGSL resources such as:

@group(0) @binding(0)
var visibility_buffer: texture_storage_2d<r64uint, atomic>;

I am not asking for this to become WebGPU-standard API. This seems more appropriate as a wgpu-native native-only extension surface in wgpu.h.

Versions checked

• wgpu-native: v29.0.0.0 latest release, checked ffi/wgpu.h
• Also observed in older release headers from v27.0.4.0
• Rust wgpu API used for comparison: wgpu 29.0.3

Rust API that exists

Rust wgpu exposes the required pieces:

wgpu::TextureFormat::R64Uint
wgpu::TextureUsages::STORAGE_ATOMIC
wgpu::StorageTextureAccess::Atomic

A Rust bind group layout can express:

wgpu::BindingType::StorageTexture {
    access: wgpu::StorageTextureAccess::Atomic,
    format: wgpu::TextureFormat::R64Uint,
    view_dimension: wgpu::TextureViewDimension::D2,
}

C API surface that appears missing

In wgpu-native v29.0.0.0 ffi/wgpu.h, I can find native texture format constants such as:

WGPUNativeTextureFormat_R16Unorm
WGPUNativeTextureFormat_R16Snorm
WGPUNativeTextureFormat_Rg16Unorm
WGPUNativeTextureFormat_Rg16Snorm
WGPUNativeTextureFormat_Rgba16Unorm
WGPUNativeTextureFormat_Rgba16Snorm
WGPUNativeTextureFormat_NV12
WGPUNativeTextureFormat_P010

but no native C ABI equivalent for:

• wgpu::TextureFormat::R64Uint
• wgpu::TextureUsages::STORAGE_ATOMIC
• wgpu::StorageTextureAccess::Atomic

Suggested direction

Would wgpu-native accept native-only C ABI constants for this capability in wgpu.h, for example:

WGPUNativeTextureFormat_R64Uint
WGPUNativeTextureUsage_StorageAtomic
WGPUNativeStorageTextureAccess_Atomic

The C descriptor conversion would then map these to:

• wgpu_types::TextureFormat::R64Uint
• wgpu_types::TextureUsages::STORAGE_ATOMIC
• wgpu_types::StorageTextureAccess::Atomic

with the same feature/capability validation as the Rust API, notably TEXTURE_ATOMIC and TEXTURE_INT64_ATOMIC.

Question

Is a wgpu.h native extension the preferred way to make this Rust wgpu native capability available to C API users, or is there another intended C ABI path for R64Uint atomic storage textures?