Function to generate an image consisting of a gradient between 2 colors

UIImageFromGradient.swift

  func imageWithGradient(startColor: UIColor, endColor: UIColor, size: CGSize, horizontally: Bool = true) -> UIImage? {
        let gradientLayer = CAGradientLayer()
        gradientLayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height)
        gradientLayer.colors = [startColor.cgColor, endColor.cgColor]

        if horizontally {
            gradientLayer.startPoint = CGPoint(x: 0.0, y: 0.5)
            gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.5)
        } else {
            gradientLayer.startPoint = CGPoint(x: 0.5, y: 0.0)
            gradientLayer.endPoint = CGPoint(x: 0.5, y: 1.0)
        }

        UIGraphicsBeginImageContext(gradientLayer.bounds.size)
        gradientLayer.render(in: UIGraphicsGetCurrentContext()!)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }