Enum AlphaFromCoverage

pub enum AlphaFromCoverage {
    Linear,
    Gamma(f32),
    TwoCoverageMinusCoverageSq,
}

How to convert font coverage values into alpha and color values.

Variants

Linear

alpha = coverage.

Looks good for black-on-white text, i.e. light mode.

Same as Self::Gamma(1.0), but more efficient.

Gamma(f32)

alpha = coverage^gamma.

TwoCoverageMinusCoverageSq

alpha = 2 * coverage - coverage^2

This looks good for white-on-black text, i.e. dark mode.

Very similar to a gamma of 0.5, but produces sharper text. See https://www.desmos.com/calculator/w0ndf5blmn for a comparison to gamma=0.5.

Implementations

impl AlphaFromCoverage

pub const LIGHT_MODE_DEFAULT: Self = Self::Linear

A good-looking default for light mode (black-on-white text).

pub const DARK_MODE_DEFAULT: Self = Self::TwoCoverageMinusCoverageSq

A good-looking default for dark mode (white-on-black text).

pub fn alpha_from_coverage(&self, coverage: f32) -> f32

Convert coverage to alpha.

pub fn color_from_coverage(&self, coverage: f32) -> Color32

Trait Implementations

impl Clone for AlphaFromCoverage

fn clone(&self) -> AlphaFromCoverage

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for AlphaFromCoverage

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

Formats the value using the given formatter.

impl Default for AlphaFromCoverage

fn default() -> AlphaFromCoverage

Returns the “default value” for a type.

impl PartialEq for AlphaFromCoverage

fn eq(&self, other: &AlphaFromCoverage) -> 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 AlphaFromCoverage

impl StructuralPartialEq for AlphaFromCoverage