/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    An extension of `BaseScene` to provide iOS platform specific functionality. This file is only included in the iOS target.

*/

import UIKit

/*

    Extend `BaseScene` to forward events from the scene to a platform-specific

    control input source. On iOS, this is a `TouchControlInputNode`, which is

    overlaid on the scene to receive touch events.

*/

extension BaseScene {

    // MARK: Properties

    var touchControlInputNode: TouchControlInputNode {

        return sceneManager.gameInput.nativeControlInputSource as! TouchControlInputNode

    }

    // MARK: Setup Touch Handling

    func addTouchInputToScene() {

        guard let camera = camera else { fatalError("Touch input controls can only be added to a scene that has an associated camera.") }

        // Ensure the touch input source is not associated any other parent.

        touchControlInputNode.removeFromParent()

        if self is LevelScene {

            // Ensure the control node fills the scene's size.

            touchControlInputNode.size = size

            // Center the control node on the camera.

            touchControlInputNode.position = CGPoint.zero

            /*

                Assign a `zPosition` that is above in-game elements, but below the top

                layer where buttons are added.

            */

            touchControlInputNode.zPosition = WorldLayer.top.rawValue - CGFloat(1.0)

            // Add the control node to the camera node so the controls remain stationary as the camera moves.

            camera.addChild(touchControlInputNode)

            // Make sure the controls are visible.

            touchControlInputNode.hideThumbStickNodes = false

        }

    }

}