Crate ansi_colours

ansi_colours is a library which converts between 24-bit sRGB colours and 8-bit colour palette used by ANSI terminals such as xterm on rxvt-unicode in 256-colour mode.

The most common use case is when using 24-bit colours in a terminal emulator which only support 8-bit colour palette. This package allows true-colours to be approximated by values supported by the terminal.

When mapping true-colour into available 256-colour palette (of which only 240 are actually usable), this package tries to balance accuracy and performance. It doesn’t implement the fastest algorithm nor is it the most accurate, instead it uses a formula which should be fast enough and accurate enough for most use-cases.

Usage

Using this library with Cargo projects is as simple as adding a single dependency:

[dependencies]
ansi_colours = "^1.0"

and then using one of the two functions that the library provides:

extern crate ansi_colours;

use ansi_colours::*;

fn main() {
    // Colour at given index:
    println!("{:-3}: {:?}", 50, rgb_from_ansi256(50));

    // Approximate true-colour by colour in the palette:
    let rgb = (100, 200, 150);
    let index = ansi256_from_rgb(rgb);
    println!("{:?} ~ {:-3} {:?}", rgb, index, rgb_from_ansi256(index));
}

Traits

AsRGB

A trait for types which (can) represent an sRGB colour. Used to provide overloaded versions of ansi256_from_rgb function.

Functions

ansi256_from_rgb

Returns index of a colour in 256-colour ANSI palette approximating given sRGB colour.

rgb_from_ansi256

Returns sRGB colour corresponding to the index in the 256-colour ANSI palette.