Crate colorgrad 

Overview

Rust color scales library for data visualization, charts, games, maps, generative art and others.

Usage

Using preset gradient:

use colorgrad::Gradient;

let g = colorgrad::preset::rainbow();

assert_eq!(g.domain(), (0.0, 1.0)); // all preset gradients are in the domain [0..1]
assert_eq!(g.at(0.5).to_rgba8(), [175, 240, 91, 255]);
assert_eq!(g.at(0.5).to_css_hex(), "#aff05b");

for color in g.colors_iter(20) {
    println!("{:?}", color.to_rgba8());
}

Custom gradient:

use colorgrad::Gradient;

let g = GradientBuilder::new()
    .colors(&[
        Color::from_rgba8(255, 0, 0, 255),
        Color::from_rgba8(0, 255, 0, 255),
    ])
    .build::<LinearGradient>()?;

for color in g.colors_iter(20) {
    println!("{:?}", color.to_rgba8());
}

Using HTML color format:

let g = GradientBuilder::new()
    .html_colors(&["red", "#abc", "gold"])
    .build::<LinearGradient>()?;

Using CSS gradient format:

let g = GradientBuilder::new()
    .css("gold, 35%, #f00")
    .build::<LinearGradient>()?;

Examples

Gradient Image

use colorgrad::Gradient;

let grad = colorgrad::GradientBuilder::new()
    .html_colors(&["deeppink", "gold", "seagreen"])
    .build::<colorgrad::CatmullRomGradient>()?;

let width = 1500;
let height = 70;

let imgbuf = image::RgbaImage::from_fn(width, height, |x, _| {
    image::Rgba(grad.at(x as f32 / width as f32).to_rgba8())
});

imgbuf.save("gradient.png")?;

Example output:

Colored Noise

use colorgrad::Gradient;
use noise::NoiseFn;

let scale = 0.015;
let grad = colorgrad::preset::rainbow().sharp(5, 0.15);
let ns = noise::OpenSimplex::new();

let imgbuf = image::RgbaImage::from_fn(600, 350, |x, y| {
    let t = ns.get([x as f32 * scale, y as f32 * scale]);
    let t = remap(t, -0.5, 0.5, 0.0, 1.0);
    image::Rgba(grad.at(t).to_rgba8())
});

imgbuf.save("noise.png")?;

// Map t which is in range [a, b] to range [c, d]
fn remap(t: f32, a: f32, b: f32, c: f32, d: f32) -> f32 {
    (t - a) * ((d - c) / (b - a)) + c
}

Example output:

Preset Gradients

See here

Modules

preset

Preset Gradients

Structs

BasisGradient

CatmullRomGradient

Color

The color

GimpGradient

Parse GIMP gradient (ggr)

GradientBuilder

Create custom gradient

GradientColors

Iterator for evenly spaced colors across gradient

InverseGradient

A special gradient that inverts the inner gradient.

LinearGradient

ParseGgrError

SharpGradient

Enums

BlendMode

Color blending mode

GradientBuilderError

ParseColorError

An error which can be returned when parsing a CSS color string.

Traits

Gradient

All gradient types in colorgrad implement Gradient trait.