klein-artur

extension String {
    subscript (i: Int) -> Character {
        get {
            assert(i < self.characters.count && i >= 0, "Index out of range.")
            return self[self.index(self.startIndex, offsetBy: String.IndexDistance(i))]
        }
        set {
            assert(i < self.characters.count && i >= 0, "Index out of range.")
            let index = self.index(self.startIndex, offsetBy: String.IndexDistance(i))
            let endIndex = self.index(self.startIndex, offsetBy: String.IndexDistance(i+1))

klein-artur

func getRandomColor(minVal: Int = 0, maxVal: Int = 255) -> UIColor {
    
    // get random values between the min value (0) and max value (255):
    let randomRed: Int = Int(arc4random_uniform(UInt32(maxVal-minVal+1)))+minVal
    let randomGreen: Int = Int(arc4random_uniform(UInt32(maxVal-minVal+1)))+minVal
    let randomBlue: Int = Int(arc4random_uniform(UInt32(maxVal-minVal+1)))+minVal
    
    return UIColor(red: CGFloat(Float(randomRed) / Float(255)), green: CGFloat(Float(randomGreen) / Float(255)), blue: CGFloat(Float(randomBlue) / Float(255)), alpha: 1.0)
}

klein-artur

// get a complementary color to this color:
func getComplementaryForColor(color: UIColor) -> UIColor {
    
    let ciColor = CIColor(color: color)
    
    // get the current values and make the difference from white:
    let compRed: CGFloat = 1.0 - ciColor.red
    let compGreen: CGFloat = 1.0 - ciColor.green
    let compBlue: CGFloat = 1.0 - ciColor.blue