Chromatic

Chromatic is a Rust library for building and sampling colour maps with perceptually uniform interpolation. It provides a flexible, type-safe way to work with various colour representations and create smooth transitions between colours.

Features

• Multiple colour space representations:
  • Basic colour types: Rgb, Rgba, Grey, GreyAlpha
  • Perceptually uniform colour types: LabRgb, LabRgba (using CIE Lab colour space)
• Flexible ColourMap for interpolation between multiple colours
• Perceptually uniform colour mixing with Lab colour space
• Type-safe conversions between colour spaces
• String parsing and formatting (hex notation and comma-separated values)
• Generic implementation with Float trait support

Installation

Add this to your Cargo.toml:

[dependencies]
chromatic = "0.1.0"

Examples

Creating and Using Colors

use chromatic::{Rgb, Rgba, LabRgb, Grey, Colour};

// Create RGB colours
let red = Rgb::new(1.0, 0.0, 0.0);
let blue = Rgb::new(0.0, 0.0, 1.0);

// Create with alpha
let transparent_green = Rgba::new(0.0, 1.0, 0.0, 0.5);

// Parse from string (hex notation)
let purple = Rgb::<f32>::from_str("#800080").unwrap();

// Convert between colour spaces
let grey = red.to_grey();
let lab_red = red.to_lab_rgb(); // Better for interpolation

Creating a Color Map

use chromatic::{ColourMap, Rgb};

// Create colours
let red = Rgb::new(1.0, 0.0, 0.0);
let green = Rgb::new(0.0, 1.0, 0.0);
let blue = Rgb::new(0.0, 0.0, 1.0);

// Create a colour map with positions
let colours = vec![red, green, blue];
let positions = vec![0.0, 0.5, 1.0];
let colour_map = ColourMap::new(&colours, &positions);

// Sample the colour map
let middle = colour_map.sample(0.25); // Returns a colour between red and green

Using Perceptually Uniform Interpolation

use chromatic::{LabRgb, Colour};

// Create colours in Lab space for better interpolation
let yellow = LabRgb::new(1.0, 1.0, 0.0);
let blue = LabRgb::new(0.0, 0.0, 1.0);

// Interpolate in Lab colour space (perceptually uniform)
let mixed = LabRgb::lerp(&yellow, &blue, 0.5);