Contrast class
Namespace: Arlecchino.Rendering.Colors · Assembly: Arlecchino.Core
How far apart two colors read, by the ratio the accessibility guidelines are written in. It runs from 1 for a color on itself to 21 for black on white.
public static class Contrast
Fields
| Member | Summary |
|---|---|
Pivot | The luminance at which a background is as far from white as it is from black. Below it a background is dark and wants light text; above it the other way. |
Methods
| Member | Summary |
|---|---|
Between(Rgb, Rgb) | The ratio between two colors, whichever way round they are given. |
IsDark(Rgb) | Whether a background wants light text on it. |
Luminance(Rgb) | How much light a color sends back, weighted the way an eye weights the three channels. |
Reach(Rgb) | The most contrast this background can give in the one direction text goes on it. A mid-gray background reaches about 5, so a ladder written for black cannot be had on it at any lightness. |
Fields in detail
Pivot
public static readonly double Pivot { get; }
The luminance at which a background is as far from white as it is from black. Below it a background is dark and wants light text; above it the other way.
Type double
Methods in detail
Between(Rgb, Rgb)
public static double Between(Rgb one, Rgb other);
The ratio between two colors, whichever way round they are given.
Parameters
| Name | Type | Description |
|---|---|---|
one | Rgb | The first color. |
other | Rgb | The second color. |
Returns double — The ratio, from 1 to 21.
IsDark(Rgb)
public static bool IsDark(Rgb background);
Whether a background wants light text on it.
Parameters
| Name | Type | Description |
|---|---|---|
background | Rgb | The color behind the text. |
Returns bool — true when the background is the darker side of Contrast.Pivot.
Luminance(Rgb)
public static double Luminance(Rgb color);
How much light a color sends back, weighted the way an eye weights the three channels.
Parameters
| Name | Type | Description |
|---|---|---|
color | Rgb | The color to measure. |
Returns double — Luminance, from 0 for black to 1 for white.
Reach(Rgb)
public static double Reach(Rgb background);
The most contrast this background can give in the one direction text goes on it. A mid-gray background reaches about 5, so a ladder written for black cannot be had on it at any lightness.
Parameters
| Name | Type | Description |
|---|---|---|
background | Rgb | The color behind the text. |
Returns double — The ratio against white or black, whichever this background is further from.