Crate cichlid 

A no-std compatible library for fast color math, intended for use in programming addressable LEDs.

Currently this library is geared toward use in embedded systems, but does contain useful APIs that are more generally useful.

• Fast u8 and u16 math — Cichlid includes functions for scaling, dimming, and brightening single and double byte values. Basic trigonometric functions (sine, cosine) are implemented as well.

• HSV and RGB support — Full control over each color is provided by the HSV and ColorRGB structures. Different means of converting from HSV to ColorRGB are also implemented.

• Axial (Two Point) Color Gradients — Create smooth transitions between any two colors for any number of steps.

• Power Consumption Estimating — Estimating power requirements can be done with structs implementing the PowerEstimator trait.

This Library is still in its infancy, and as such there may be a lack of documentation and vigorous testing.

Examples

General Color operations:

use cichlid::ColorRGB;

let red = ColorRGB::Red;
let blue = ColorRGB::Blue;
let mut purple = red + blue;
assert_eq!(purple, ColorRGB::new(255, 0, 255));

purple.scale(128); // Scale by half
assert_eq!(purple, ColorRGB::new(128, 0, 128));

purple *= 2;  // Multiple all components by two
assert_eq!(purple, red + blue);

Using HSV (Hue, Saturation, Value) and converting to ColorRGB:

use cichlid::{HSV, ColorRGB, prelude::*};

let red_hsv = HSV::new(0, 255, 255);
let red_rgb = ColorRGB::from(red_hsv);
assert_eq!(red_rgb, ColorRGB::Red);

Creating a gradient is very easy, simply import the trait and call the method:

use cichlid::{HSV, ColorRGB, GradientDirection, prelude::*};
let mut colors = [ColorRGB::Black; 100];

let start = HSV::new(0, 255, 255);
let end = HSV::new(100, 255, 180);
colors.gradient_fill(start, end, GradientDirection::Longest);

We can also create rainbows from both a step size, as well as a forming a complete rainbow.

use cichlid::{HSV, ColorRGB, GradientDirection, prelude::*};
let mut colors = [ColorRGB::Black; 256];

let start_hue: u8 = 0;
let hue_delta: u16 = (1 << 8);

colors.rainbow_fill(start_hue, hue_delta); // From step size
colors.rainbow_fill_single_cycle(start_hue); // Complete rainbow

no-std

To use in a no-std environment, simply add the following to your project’s cargo.toml:

[dependencies.cichlid]
version = "*"
features = ["no-std"]

Low memory usage

The low-mem feature creates a binary that is smaller due to relying less on in memory tables, preferring direct computation instead. The only drawback of this is a slight speed decrease.

Nightly features

To use some unstable nightly features and optimizations, use the nightly feature flag.

Acknowledgements

This library takes heavy inspiration and code-reuse from FastLED, an Arduino library for talking to addressable LEDs.

Modules

color_codes

Raw Color codes.

math

Collection of math Traits and functions for manipulating integers.

prelude

Easy importing of integer and color auto traits.

Structs

ColorRGB

Object representing a color through the standard single byte red, green, and blue values.

DefaultPowerEstimator

Default estimator.

HSV

Represents a color encoded in (hue, saturation, value) format.

Enums

GradientDirection

Possible Directions around the color wheel a gradient can go.

Traits

PowerEstimator

Trait for estimating the power consumption of a strand of ColorRGBs.

Functions

hsv_gradient

Creates a axial (two-color) gradient from the HSV values start to (exclusive) end.

rgb_gradient

Creates a two-color gradient from two RGB values.