pubstructCubemapSpec{pubsize:u32, // cubemaps are square per face
pubformat:wgpu::TextureFormat,
/// `Some` uploads 6 faces of pixel data up front (wgpu's expected
/// order: +X, -X, +Y, -Y, +Z, -Z). `None` allocates an empty cubemap
/// meant to be filled later by rendering into per-face views — e.g. an
/// environment-map capture pass — in which case [`wgpu_descriptor`](Self::wgpu_descriptor)
/// adds `RENDER_ATTACHMENT` usage instead of requiring upload data.
pubfaces:Option<[Vec<u8>;6]>,
}implCubemapSpec{pubfnwith_format(mutself, format:wgpu::TextureFormat)->Self{self.format = format;self}}