adamgraham

/// An extension to derive web safe colors.
extension UIColor {

    /// The nearest web safe color to the current color. All web safe colors have RGB
    /// component values of 0, 51, 102, 153, 204, or 255 (20% intervals).
    var webSafe: UIColor {
        var (r, g, b, a) = (CGFloat(), CGFloat(), CGFloat(), CGFloat())
        getRed(&r, green: &g, blue: &b, alpha: &a)

        let clusters: [CGFloat] = [0.0, 0.2, 0.4, 0.6, 0.8, 1.0]

adamgraham

/// An extension to provide conversion to and from Y′IQ colors.
extension UIColor {

    /// The Y′IQ components of a color - luma (Y′) and chroma (I,Q).
    struct YIQ: Hashable {

        /// The luma component of the color, in the range [0, 1] (black to white).
        var Y: CGFloat
        /// The orange-blue chroma component of the color, in the range [-0.596, 0.596].
        var I: CGFloat

adamgraham

/// An extension to provide conversion to and from Y′UV colors.
extension UIColor {

    /// The Y′UV components of a color - luma (Y′) and chroma (U,V).
    struct YUV: Hashable {

        /// The luma component of the color, in the range [0, 1] (black to white).
        var Y: CGFloat
        /// The blue-difference chroma component of the color, in the range [-0.436, 0.436].
        var U: CGFloat

adamgraham

/// An extension to provide conversion to and from HSI (hue, saturation, intensity) colors.
extension UIColor {

    /// The HSI (hue, saturation, intensity) components of a color.
    struct HSI: Hashable {

        /// The hue component of the color, in the range [0, 360°].
        var hue: CGFloat
        /// The saturation component of the color, in the range [0, 100%].
        var saturation: CGFloat

adamgraham

/// An extension to provide conversion to and from Y′PbPr colors.
extension UIColor {
    
    /// The Rec.601 (standard-definition) coefficients used to calculate luma.
    private static let encoding: (r: CGFloat, g: CGFloat, b: CGFloat) = (0.299, 0.587, 0.114)

    /// The Y′PbPr components of a color - luma (Y′) and chroma (Pb,Pr).
    struct YPbPr: Hashable {

        /// The luma component of the color, in the range [0, 1] (black to white).

adamgraham

/// An extension to provide conversion to and from linear RGB colors.
extension UIColor {

    /// A set of non-gamma corrected linear RGB values, in the range [0, 1].
    typealias LinearRGB = (r: CGFloat, g: CGFloat, b: CGFloat)

    /// The inverse companded sRGB components to get non-gamma corrected linear values,
    /// in the range [0, 1].
    var linearRGB: LinearRGB {
        var (r, g, b) = (CGFloat(), CGFloat(), CGFloat())

adamgraham

/// An extension to provide conversion to and from CIELCh° colors.
extension UIColor {

    /// The CIELCh° components of a color - lightness (L), chroma (C), and hue (h).
    struct CIELCh: Hashable {

        /// The lightness component of the color, in the range [0, 100] (darkest to brightest).
        var L: CGFloat
        /// The chroma component of the color.
        var C: CGFloat

adamgraham

/// An extension to provide conversion to and from CIELUV colors.
extension UIColor {

    /// The CIELUV components of a color - lightness (L) and chromaticity (u,v).
    struct CIELUV: Hashable {

        /// The lightness component of the color, in the range [0, 100] (darkest to brightest).
        var L: CGFloat
        /// The green-red chromaticity component of the color, typically in the range [-100, 100].
        var u: CGFloat

adamgraham

/// An extension to traverse the responder chain for the nearest parent view controller.
extension UIView {

    /// The nearest parent view controller in the responder chain.
    var parentViewController: UIViewController? {
        if let nextResponder = self.next as? UIViewController {
            return nextResponder
        } else if let nextResponder = self.next as? UIView {
            return nextResponder.parentViewController
        } else {

adamgraham

/// An extension to provide conversion to and from Hunter Lab colors.
extension UIColor {
  
    /// XYZ tristimulus values of d65 illuminant with standard 2° observer.
    private static let d65: (X: CGFloat, Y: CGFloat, Z: CGFloat) = (95.047, 100.000, 108.883)

    /// The Hunter Lab components of a color - lightness (L) and chromaticity (a,b).
    struct HunterLab: Hashable {

        /// The lightness component of the color, in the range [0, 100] (darkest to brightest).