CODEWITHSUNDEEP
iosswiftsprite-kit
SwiftAholicGuy
SwiftAholicGuy

Reputation: 37

Looking for ways to update instance's property per frame

I implemented a class subclassing SKSpriteNode with an additional property. Then I created an instance of it and attempted to modify its property's value each frame but I encountered an error.

Are there any ways to handle this?

import SpriteKit
import GameplayKit

class SomeSprite: SKSpriteNode {
    var direction: CGVector = CGVector(dx: 0, dy: 0)
    convenience init() {
        self.init(imageNamed: "imgSprite")
    }
}

class GameScene: SKScene {
    override func didMove(to view: SKView) {
        //Create a sprite instance
        var sampleSprite = SomeSprite()
        sampleSprite.name = "Sprite"
        sampleSprite.zPosition = 1
        sampleSprite.position = CGPoint(x: 100, y: 100)
        sampleSprite.direction = CGVector(dx: 10, dy: 10)
        sampleSprite.setScale(1)
        self.addChild(sampleSprite)
    }

    override func update(_ currentTime: TimeInterval) {
        //Calculate before rendering frame
        self.enumerateChildNodes(withName: "Sprite") { (sprite, stop) in
            sprite.position = CGPoint(x: 150, y: 150) //This works properly
            sprite.direction = CGVector(dx: 15, dy: 15) //Error: Value of type SKNode has no member 'direction'
        }
    }
}

Upvotes: 1

Views: 50

Answers (1)

Maetschl
Maetschl

Reputation: 1339

The method enumerateChildNodes return a list of SKNodes

You have to try to cast the object to your class SomeSprite

    override func update(_ currentTime: TimeInterval) {
        //Calculate before rendering frame
        self.enumerateChildNodes(withName: "Sprite") { (sprite, stop) in
            sprite.position = CGPoint(x: 150, y: 150) //This works properly
            if let someSprite = sprite as? SomeSprite {
                someSprite.direction = CGVector(dx: 15, dy: 15)
            }
        }
    }

Upvotes: 1

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