Swift UIColor manipulation

UIColorManipulation.swift

//Combine colors: add, subtract, multiply components, set and adjust color components

import UIKit

func + (left: UIColor, right: UIColor) -> UIColor {
    var leftRGBA = [CGFloat](repeating: 0.0, count: 4)
    var rightRGBA = [CGFloat](repeating: 0.0, count: 4)

    left.getRed(&leftRGBA[0], green: &leftRGBA[1], blue: &leftRGBA[2], alpha: &leftRGBA[3])
    right.getRed(&rightRGBA[0], green: &rightRGBA[1], blue: &rightRGBA[2], alpha: &rightRGBA[3])

    return UIColor(
            red: min(max(leftRGBA[0] + rightRGBA[0], 0.0), 1.0),
            green: min(max(leftRGBA[1] + rightRGBA[1], 0.0), 1.0),
            blue: min(max(leftRGBA[2] + rightRGBA[2], 0.0), 1.0),
            alpha: min(max(leftRGBA[3] + rightRGBA[3], 0.0), 1.0)
    )
}

func - (left: UIColor, right: UIColor) -> UIColor {
    var leftRGBA = [CGFloat](repeating: 0.0, count: 4)
    var rightRGBA = [CGFloat](repeating: 0.0, count: 4)

    left.getRed(&leftRGBA[0], green: &leftRGBA[1], blue: &leftRGBA[2], alpha: &leftRGBA[3])
    right.getRed(&rightRGBA[0], green: &rightRGBA[1], blue: &rightRGBA[2], alpha: &rightRGBA[3])

    return UIColor(
            red: min(max(leftRGBA[0] - rightRGBA[0], 0.0), 1.0),
            green: min(max(leftRGBA[1] - rightRGBA[1], 0.0), 1.0),
            blue: min(max(leftRGBA[2] - rightRGBA[2], 0.0), 1.0),
            alpha: min(max(leftRGBA[3] - rightRGBA[3], 0.0), 1.0)
    )
}

func * (left: UIColor, right: CGFloat) -> UIColor {
    var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

    left.getRed(&leftRGBA[0], green: &leftRGBA[1], blue: &leftRGBA[2], alpha: &leftRGBA[3])

    return UIColor(
            red: min(max(leftRGBA[0] * right, 0.0), 1.0),
            green: min(max(leftRGBA[1] * right, 0.0), 1.0),
            blue: min(max(leftRGBA[2] * right, 0.0), 1.0),
            alpha: min(max(leftRGBA[3] * right, 0.0), 1.0)
    )
}

extension UIColor {
    func color(withAlpha alpha: CGFloat) -> UIColor {
        var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

        self.getRed(&leftRGBA[0], green: &leftRGBA[1], blue: &leftRGBA[2], alpha: &leftRGBA[3])

        return UIColor(
                red: leftRGBA[0],
                green: leftRGBA[1],
                blue: leftRGBA[2],
                alpha: min(max(leftRGBA[3] + alpha, 0.0), 1.0)
        )
    }

    func color(withRed red: CGFloat) -> UIColor {
        var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

        self.getRed(&leftRGBA[0], green: &leftRGBA[1], blue: &leftRGBA[2], alpha: &leftRGBA[3])

        return UIColor(
                red: min(max(red, 0.0), 1.0),
                green: leftRGBA[1],
                blue: leftRGBA[2],
                alpha: leftRGBA[3]
        )
    }

    func color(withGreen green: CGFloat) -> UIColor {
        var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

        self.getRed(&leftRGBA[0], green: &leftRGBA[1], blue: &leftRGBA[2], alpha: &leftRGBA[3])

        return UIColor(
                red: leftRGBA[0],
                green: min(max(green, 0.0), 1.0),
                blue: leftRGBA[2],
                alpha: leftRGBA[3]
        )
    }

    func color(withBlue blue: CGFloat) -> UIColor {
        var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

        self.getRed(&leftRGBA[0], green: &leftRGBA[1], blue: &leftRGBA[2], alpha: &leftRGBA[3])

        return UIColor(
                red: leftRGBA[0],
                green: leftRGBA[1],
                blue: min(max(blue, 0.0), 1.0),
                alpha: leftRGBA[3]
        )
    }

    func color(withBrightness brightness: CGFloat) -> UIColor {
        var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

        self.getHue(&leftRGBA[0], saturation: &leftRGBA[1], brightness: &leftRGBA[2], alpha: &leftRGBA[3])

        return UIColor(
                hue: leftRGBA[0],
                saturation: leftRGBA[1],
                brightness: min(max(brightness, 0.0), 1.0),
                alpha: leftRGBA[3]
        )
    }

    func color(withSaturation saturation: CGFloat) -> UIColor {
        var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

        self.getHue(&leftRGBA[0], saturation: &leftRGBA[1], brightness: &leftRGBA[2], alpha: &leftRGBA[3])

        return UIColor(
                hue: leftRGBA[0],
                saturation: min(max(saturation, 0.0), 1.0),
                brightness: leftRGBA[2],
                alpha: leftRGBA[3]
        )
    }

    func color(withHue hue: CGFloat) -> UIColor {
        var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

        self.getHue(&leftRGBA[0], saturation: &leftRGBA[1], brightness: &leftRGBA[2], alpha: &leftRGBA[3])

        return UIColor(
                hue: min(max(hue, 0.0), 1.0),
                saturation: leftRGBA[1],
                brightness: leftRGBA[2],
                alpha: leftRGBA[3]
        )
    }

    func color(byShiftingHue hue: CGFloat) -> UIColor {
        var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

        self.getHue(&leftRGBA[0], saturation: &leftRGBA[1], brightness: &leftRGBA[2], alpha: &leftRGBA[3])

        return UIColor(
                hue: (leftRGBA[0] + hue).truncatingRemainder(dividingBy: 1.0),
                saturation: leftRGBA[1],
                brightness: leftRGBA[2],
                alpha: leftRGBA[3]
        )
    }

    func color(byAdjustingBrightness brightness: CGFloat) -> UIColor {
        var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

        self.getHue(&leftRGBA[0], saturation: &leftRGBA[1], brightness: &leftRGBA[2], alpha: &leftRGBA[3])

        return UIColor(
                hue: leftRGBA[0],
                saturation: leftRGBA[1],
                brightness: min(max(leftRGBA[2] + brightness, 0.0), 1.0),
                alpha: leftRGBA[3]
        )
    }

    func color(byAdjustingSaturation saturation: CGFloat) -> UIColor {
        var leftRGBA = [CGFloat](repeating: 0.0, count: 4)

        self.getHue(&leftRGBA[0], saturation: &leftRGBA[1], brightness: &leftRGBA[2], alpha: &leftRGBA[3])

        return UIColor(
                hue: leftRGBA[0],
                saturation: min(max(leftRGBA[1] + saturation, 0.0), 1.0),
                brightness: leftRGBA[2],
                alpha: leftRGBA[3]
        )
    }
}