Animate Game Controller light. This little code snippet will allow you to animate the light of the controller when using GameController API.

README.md

GameController Light Animations

This will help you animate the DualShock 4 controller's light color as seen in this session.

Quick start

1. Create a file in your project called ControllerAnimatable.swift and paste the code from below into it.
2. Make your ViewController adopt the ControllerAnimatable protocol
3. Add controller variable which will return the current GCController, you are responsible for handling, Example: var controller: GCController { GCController.current! }. Note that if you already have stored controller property just return it in the controller's getter, like here var controller: GCConotroller { myController }.

Usage

Call animate(to:duration:completion:) to animate the controller's light color.

ControllerAnimatable.swift

import Foundation
import GameController

protocol ControllerAnimatable: class {
    var controller: GCController { get }
}

extension ControllerAnimatable {
    /// Animates controller light color to a specified color of `GCColor` type.
    /// - Parameters:
    ///   - color: Defines what color the animation will resolve to.
    ///   - duration: Duration of the animation.
    ///   - completion: **Closure** Called upon animation completion.
    func animate(to color: GCColor, duration: TimeInterval, _ completion: (() -> ())? = nil) {
        let queue = OperationQueue()

        let currentColor = controller.light!.color
        // The difference between the color to animate to and the current color.
        let diff = (color.red - currentColor.red, color.green - currentColor.green, color.blue - currentColor.blue)
        let steps = Int(duration * 20)
        
        // Iterates through each colors and interpolates them.
        for i in 0..<steps {
            // Schedule the color update
            queue.schedule(after: .init(Date() + Double(i) * duration / Double(steps))) { [weak self] in
                guard let self = self else { return }
                self.controller.light?.color = GCColor(red: currentColor.red + Float(i) * diff.0 / Float(steps),
                                                       green: currentColor.green + Float(i) * diff.1 / Float(steps),
                                                       blue: currentColor.blue + Float(i) * diff.2 / Float(steps))
            }
        }
    }
}

Adopted OperationQueue @ revision 7 as suggested by @chih98