Code for approximating color names

color_name_approximator.rs

pub fn get_approximate_color_name(color: koi::Color) -> String {
    let considered_exact = 0.1;

    let hues = [
        (0.0, "Pink"),
        ((29.0 / 360.), "Red"),
        ((53.0 / 360.), "Orange"),
        ((110.0 / 360.), "Yellow"),
        ((142.0 / 360.0), "Green"),
        ((195.0 / 360.0), "Cyan"),
        ((264.0 / 360.0), "Blue"),
        ((328.0 / 360.0), "Purple"),
        (1.0, "Pink"),
    ];
    let (lightness, chroma, hue) = color.get_lightness_chroma_hue();

    // println!("LIGHTNESS: {:?}", lightness);
    // println!("CHROMA: {:?}", chroma);
    // println!("HUE: {:?}", hue);

    if lightness > 0.98 && chroma < 0.05 {
        return "White".into();
    } else if lightness == 0.0 {
        return "Black".into();
    } else if lightness < 0.24 {
        return "Near Black".into();
    }

    let lightness_descriptor = if lightness > 0.8 {
        "Light "
    } else if lightness > 0.5 {
        ""
    } else {
        "Dark "
    };

    let chroma_descriptor = if chroma > 0.08 {
        ""
    } else if chroma > 0.05 {
        "Grey-ish "
    } else {
        "Grey "
    };

    for window in hues.windows(2) {
        let left = window[0];
        let right = window[1];
        let window_size = right.0 - left.0;

        if hue >= left.0 && hue <= right.0 {
            let distance_to_left = hue - left.0;

            let percent_to_left = distance_to_left / window_size;

            let (first_name, second_name) = if percent_to_left < considered_exact {
                (left.1, "")
            } else if percent_to_left > (1.0 - considered_exact) {
                (right.1, "")
            } else if distance_to_left < 0.5 {
                (left.1, right.1)
            } else {
                (right.1, left.1)
            };

            return format!(
                "{}{}{} {}",
                chroma_descriptor, lightness_descriptor, first_name, second_name
            );
        }
    }
    // This should be unreachable, but return an empty String.
    String::new()
}