Adding coins

Coins are more fun if there are two value variations. We will create two coins:

• A Bronze Coin, worth one coin

• A Gold Coin, worth five coins

The two coins will be distinguishable by their color, as seen here:

Creating the coin classes

We only need a single Coin class to create both denominations. Everything in the Coin class should look very familiar at this point. To create the Coin class, add a new file named Coin.swift and then enter the following code:

import SpriteKit

class Coin: SKSpriteNode, GameSprite { 
var initialSize = CGSize(width: 26, height: 26) 
var textureAtlas: SKTextureAtlas = 
SKTextureAtlas(named: "Environment") 
var value = 1 

init() { 
        let bronzeTexture = 
textureAtlas.textureNamed("coin-bronze") 
super.init(texture: bronzeTexture, color: .clear, 
            size: initialSize) 
self.physicsBody = SKPhysicsBody(circleOfRadius: 
size.width / 2) 
        self.physicsBody?.affectedByGravity = false 
    } 

    // A function to transform this coin into...