Struct SurfaceSpec 

pub struct SurfaceSpec {
    pub gain: f32,
    pub saturation: f32,
    pub tint: Hsla,
    pub blur: f32,
    pub rim: f32,
    pub edge: f32,
    pub edge_width: f32,
    pub edge_aa: f32,
    pub shadow: bool,
}

One surface’s numbers. out = gain * saturated(backdrop) + tint, over a backdrop blurred at blur.

Fields

gain: f32

Slope of the transfer line. Below 1 compresses contrast toward tint; above 1 it brightens and slightly expands, which is what light Clear measures. Named for what it is, not for one of its directions.

saturation: f32

How far the backdrop’s chroma is pushed from its own grey, before the gain drops the level. A gain alone moves level and colour together, so this is the only way a surface goes dark and keeps its colours. 1 is the pass-through Clear measures.

tint: Hsla

Its offset — the look’s own tone.

blur: f32

Gaussian sigma under the lens, in logical pixels. It stands in for the average attenuation of fine detail, which the real material gets from snapshotting its backdrop coarsely.

rim: f32

How far in from the rim the lens bends the backdrop, in logical pixels. A length rather than a share of the box: the displacement curve measured 2026-08-30 is one curve, the same from a 96pt box to a 320pt one and from r24 to r84. Past it the backdrop is untouched.

edge: f32

How much white the lit rim adds at the edge itself, 0..1.

edge_width: f32

How far in that light falls off to nothing, in logical pixels. Even the whole way round: measured 2026-08-30, the real rim reads the same on all four sides.

edge_aa: f32

The coverage ramp at the shape’s own boundary, in logical pixels. 0.5 is one device pixel at 2x — the plain rasteriser’s answer; 0 is the hard edge it replaced.

shadow: bool

Whether the surface casts a shadow. A lens separates itself from the page by bending it, and reads as a slab under one; a wash has nothing to bend and needs it.

Trait Implementations

impl Clone for SurfaceSpec

fn clone(&self) -> SurfaceSpec

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for SurfaceSpec

impl Debug for SurfaceSpec

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for SurfaceSpec

fn eq(&self, other: &SurfaceSpec) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SurfaceSpec