Function surface_config 

pub fn surface_config(
    format: TextureFormat,
    alpha_mode: CompositeAlphaMode,
    size: (u32, u32),
    present_mode: PresentMode,
) -> SurfaceConfiguration

Builds the wgpu::SurfaceConfiguration a surface is brought up with.

Split out of ConfiguredSurface::configure so the configuration a surface gets is decided by a pure function over plain values and can be asserted without a device: RENDER_ATTACHMENT usage only, the caller’s format and alpha mode verbatim, no view formats, the fixed frame latency (DESIRED_MAXIMUM_FRAME_LATENCY, two frames in flight), and SurfaceColorSpace::Auto.

Auto is the deliberate choice for the colour space, not a placeholder. It is the only value guaranteed to be supported for every format a surface advertises, and wgpu defines it as “reproduce the historical behaviour”: Srgb for every non-Rgba16Float format, which is exactly the pair select_surface_format can return (Rgba8Unorm/Bgra8Unorm). Naming Srgb explicitly would resolve identically today but would start failing validation the moment a driver in HDR mode stopped advertising it for the chosen format, and frust encodes no wide-gamut or HDR output — the engine writes sRGB-encoded values a non-*Srgb swapchain format carries through untouched. A wide-gamut/HDR surface is a deliberate feature, not a version-bump side effect.

size is (width, height) in physical pixels and must be non-zero on both axes; a zero-sized swapchain is a wgpu validation error, and the shell’s own resize path is where a minimized/zero-extent window is filtered out.