How to change an SKSpriteNode image once a condition is met? - swift

Question

I'm trying to change the image of the SKSpriteNode in my shop scene when an upgrade is bought, I believe I'm on the right track with the variable, but I think I am doing it wrong. Thanks for the help in advanced, I've been trying for a while to figure it out with no luck.
// ShopScene.swift
// TheLastFlight
//
// Created by -Zachary Walensa- on 8/3/16.
// Copyright © 2016 -Zachary Walensa-. All rights reserved.
//
import Foundation
import SpriteKit
var coinUpgrade = defaults.integer(forKey: "coinUpgradeSaved")
var missileUpgrade = defaults.integer(forKey: "missileUpgradeSaved")
class ShopScene: SKScene {
var coinLabel = SKLabelNode(fontNamed: "The Bold Font")
var missileUpgrades = SKSpriteNode(imageNamed: "missile1")
override func didMove(to view: SKView) {
coinLabel.text = "Coins: \(coinNumber)"
coinLabel.fontSize = 100
coinLabel.fontColor = SKColor.black
coinLabel.zPosition = 1
coinLabel.position = CGPoint(x: self.size.width/2, y: self.size.height*0.1)
self.addChild(coinLabel)
let background = SKSpriteNode(imageNamed: "background")
background.size = self.size
background.position = CGPoint(x: self.size.width/2, y: self.size.height/2)
background.zPosition = 0
self.addChild(background)
let mainMenu = SKLabelNode(fontNamed: "The Bold Font")
mainMenu.text = "Main Menu"
mainMenu.fontSize = 100
mainMenu.fontColor = SKColor.darkGray
mainMenu.position = CGPoint(x: self.size.width*0.5, y: self.size.height*0.3)
mainMenu.zPosition = 1
mainMenu.name = "Main Menu"
self.addChild(mainMenu)
let Life = SKSpriteNode(imageNamed: "lifeButton")
Life.position = CGPoint(x: self.size.width*0.3, y: self.size.height*0.8)
Life.zPosition = 1
Life.name = "Life"
self.addChild(Life)
let coinUpgrades = SKSpriteNode(imageNamed: "coinUpgrade")
coinUpgrades.position = CGPoint(x: self.size.width*0.5, y: self.size.height*0.8)
coinUpgrades.zPosition = 1
coinUpgrades.name = "Coin"
self.addChild(coinUpgrades)
missileUpgrades.position = CGPoint(x: self.size.width*0.8, y: self.size.height*0.8)
missileUpgrades.zPosition = 1
missileUpgrades.name = "missile"
self.addChild(missileUpgrades)
/*let coinLabel = SKLabelNode(fontNamed: "The Bold Font")
coinLabel.text = "Coins: \(coinNumber)"
coinLabel.fontSize = 100
coinLabel.fontColor = SKColor.black
coinLabel.zPosition = 1
coinLabel.position = CGPoint(x: self.size.width/2, y: self.size.height*0.1)
self.addChild(coinLabel) */
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch: AnyObject in touches {
let pointOfTouch = touch.location(in: self)
let nodeITapped = atPoint(pointOfTouch)
if nodeITapped.name == "Main Menu" {
let sceneToMoveTo = MainMenuScene(size: self.size)
sceneToMoveTo.scaleMode = self.scaleMode
let myTrasition = SKTransition.fade(withDuration: 0.5)
self.view!.presentScene(sceneToMoveTo, transition: myTrasition)
}
if nodeITapped.name == "Life" {
if coinNumber >= 50 {
lifeNumber += 1
coinNumber -= 50
defaults.set(coinNumber, forKey: "coinNumberSaved")
defaults.set(lifeNumber, forKey: "lifeNumberSaved")
coinLabel.text = "Coins: \(coinNumber)"
}
}
if nodeITapped.name == "Coin" {
if coinNumber >= 600 {
coinNumber -= 600
defaults.set(coinNumber, forKey: "coinNumberSaved")
coinUpgrade = 1
defaults.set(coinUpgrade, forKey: "coinUpgradeSaved")
coinLabel.text = "Coins: \(coinNumber)"
}
}
if nodeITapped.name == "missile" {
if missileUpgrade == 2 {
missileUpgrade = 1
defaults.set(missileUpgrade, forKey: "missileUpgradeSaved")
if missileUpgrade == 1 {
missileUpgrade = 2
defaults.set(missileUpgrade, forKey: "missileUpgradeSaved")
}
}
else if missileUpgrade == 0 || coinNumber >= 1400 {
coinNumber -= 1400
defaults.set(coinNumber, forKey: "coinNumberSaved")
missileUpgrade = 2
defaults.set(missileUpgrade, forKey: "missileUpgradeSaved")
coinLabel.text = "Coins: \(coinNumber)"
missileUpgrades = SKSpriteNode(imageNamed: "missile")
}
}
}
}
}

Answer 1

There are a few ways to do this:
1) Create a Boolean variable that switches to true when the condition is met. Then in the update function, you can constantly check for if the condition is met:
var conditionIsMet = false
// Your code
//
//...
override func update(_ currentTime: CFTimeInterval) {
if conditionIsMet {
// Change your texture here
}
}
2) Where you get the trigger for when you want to change the texture, you can simply change the texture as part of the code/function that runs. That means that if you are trying to do this on a touch, you would add the code to change the texture there.
FYI: To change the texture just do something like this:
node.texture = SKTexture(imageNamed: "image name goes here")