Crate ecolor

Color conversions and types.

This crate is built for the wants and needs of egui.

If you want an actual good color crate, use color instead.

If you want a compact color representation, use Color32. If you want to manipulate RGBA colors in linear space use Rgba. If you want to manipulate colors in a way closer to how humans think about colors, use HsvaGamma.

Conventions

The word “gamma” or “srgb” is used to refer to values in the non-linear space defined by the sRGB transfer function. We use u8 for anything in the “gamma” space.

We use f32 in 0-1 range for anything in the linear space.

Feature flags

Structs

Color32

This format is used for space-efficient color representation (32 bits).

Hsva

Hue, saturation, value, alpha. All in the range [0, 1]. No premultiplied alpha.

HsvaGamma

Like Hsva but with the v value (brightness) being gamma corrected so that it is somewhat perceptually even.

Rgba

0-1 linear space RGBA color with premultiplied alpha.

Enums

HexColor

A wrapper around Color32 that converts to and from a hex-color string

ParseHexColorError

Functions

gamma_from_linear

linear [0, 1] -> gamma [0, 1] (not clamped). Works for numbers outside this range (e.g. negative numbers).

gamma_u8_from_linear_f32

linear [0, 1] -> gamma [0, 255] (clamped). Values outside this range will be clamped to the range.

hsv_from_rgb

All ranges in 0-1, rgb is linear.

linear_f32_from_gamma_u8

gamma [0, 255] -> linear [0, 1].

linear_f32_from_linear_u8

linear [0, 255] -> linear [0, 1]. Useful for alpha-channel.

linear_from_gamma

gamma [0, 1] -> linear [0, 1] (not clamped). Works for numbers outside this range (e.g. negative numbers).

linear_u8_from_linear_f32

linear [0, 1] -> linear [0, 255] (clamped). Useful for alpha-channel.

rgb_from_hsv

All ranges in 0-1, rgb is linear.

tint_color_towards

Cheap and ugly. Made for graying out disabled Uis.