Struct Legible 

pub struct Legible {
    pub dark: f64,
    pub light: f64,
}

The luminance range what shows through a translucent surface is compressed into, so ink chosen against the surface’s ground stays legible over anything below it: the material’s band (material_band) as relative luminances. The backdrop pass maps what it sampled into it (Self::tone is the same arithmetic): luminance is compressed evenly in contrast (a contrast ratio below becomes a smaller, fixed power of itself), and each colour keeps its hue: dimmed, its channels scale with its luminance; lifted, it keeps how far its channels stand off its grey, so a near-grey stays near-grey. A bright photo shows dimmed but in its own colours and shapes, a dark page lifted without a cast, never as one flat colour.

Fields

dark: f64

Relative luminance black maps to.

light: f64

Relative luminance white maps to.

Implementations

impl Legible

pub const ANY: Legible

No compression: what lies below shows as it is.

pub fn of(theme: &Theme, ground: AlphaColor<Srgb>) -> Legible

The range a surface of ground under theme holds what shows through it in.

pub fn compresses(&self) -> bool

Whether anything is compressed.

pub fn tone(&self, rgb: [f64; 3]) -> [f64; 3]

rgb (sRGB-encoded, 0–1) as it shows through: its relative luminance y mapped so (y + 0.05) / 0.05 becomes that ratio to the power the band allows over the whole 21:1 range; its linear channels’ offsets from y carried to the new luminance, scaled down with it where it falls and kept where it rises; and pulled toward grey only where a channel would leave the gamut. The backdrop pass’s tone computes the same.

Trait Implementations

impl Clone for Legible

fn clone(&self) -> Legible

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Legible

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

Formats the value using the given formatter.

impl Default for Legible

fn default() -> Legible

Returns the “default value” for a type.

impl PartialEq for Legible

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Legible

impl StructuralPartialEq for Legible