P3Comparison

p3comparison.swift

import UIKit
import Foundation
import PlaygroundSupport


UIColor(red: 1.2, green: -0.75, blue: 2, alpha: 1) // Using the extended sRGB color values introduced in iOS 10 to display a wider gamut (P3 in this case)

extension UIColor {
    convenience init(displayP3Hue hue: CGFloat, saturation: CGFloat, brightness: CGFloat, alpha: CGFloat = 1) {
        /// HSB to RGB conversion doesn’t depend on color space, so we can use default UIColor space.
        let converter = UIColor(hue: hue, saturation: saturation, brightness: brightness, alpha: 1)
        
        var red: CGFloat = 0, green: CGFloat = 0, blue: CGFloat = 0
        converter.getRed(&red, green: &green, blue: &blue, alpha: nil)
        
        // Playground debug
        red.description
        green.description
        blue.description
        
        self.init(displayP3Red: red, green: green, blue: blue, alpha: alpha)
    }
    
}

class ColorContraption: UIViewController{
    var i : CGFloat = 0
    var view1 : UIView = UIView()
    var view2 : UIView = UIView()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        view1.frame = CGRect(x: 0, y: 0, width: self.view.bounds.width, height: self.view.bounds.height/2)
        view2.frame = CGRect(x: 0, y: self.view1.bounds.height, width: self.view.bounds.width, height: self.view.bounds.height/2)
        
        view.addSubview(view1)
        view.addSubview(view2)
        self.animateBackgroundColour()
    }
    
    func animateBackgroundColour () {
        if i < 1 {
            i += 1/256
        } else {
            i = 0
        }
        UIView.animate(withDuration: 0.05, delay: 0, options: .allowUserInteraction, animations: { () -> Void in
            self.view1.backgroundColor =  UIColor(displayP3Hue: self.i, saturation: 1, brightness: 1)
            self.view2.backgroundColor = UIColor(hue: self.i, saturation: 1, brightness: 1, alpha: 1)
        }) {(Bool) -> Void in
            self.animateBackgroundColour();
        }
    }
}

PlaygroundPage.current.liveView = ColorContraption()