Swift Game Development: Learn iOS 12 game development using SpriteKit, SceneKit and ARKit 2.0, 3rd Edition

Table of Contents

Swift Game Development Third Edition

Why subscribe?

Packt.com

Contributors

About the authors

About the reviewer

Packt is Searching for Authors Like You

Preface

Who this book is for

What this book covers

To get the most out of this book

Download the example code files

Conventions used

Get in touch

Reviews

1. Designing Games with Swift

Why you will love Swift

Prerequisites

What you will learn in this book

Embracing SpriteKit

Reacting to player input

Structuring your game code

Building UI/menus/levels

Integrating with Game Center

Maximizing fun

Crossing the finish line

Monetizing your work

New in Swift 4.2

Setting up your development environment

Introducing and installing Xcode

Creating our first Swift game

Navigating our project

Exploring the SpriteKit demo

Examining the demo code

Cleaning up

Summary

2. Sprites, Camera, Action!

Preparing your project

Drawing your first sprite

Building a SKSpriteNode class

Animation—movement, scaling, and rotation

Sequencing multiple animations

Recapping your first sprite

The story on positioning

Alignment with anchor points

Working with textures

Downloading the free assets

More exceptional art assets

Drawing your first textured sprite

Adding the bee image to your project

Loading images with SKSpriteNode

Designing for Retina

The ideal asset approach

Hands-on with retina in SpriteKit

Organizing art into texture atlases

Exploring Assets.xcassets

Collecting art into texture atlases

Updating our bee node to use the texture atlas

Iterating through texture atlas frames

Putting it all together

Centering the camera on a sprite

Summary

3. Mix in the Physics

Laying the foundations

Adopting a protocol for consistency

Organizing game objects into classes

The icy tundra

Adding the ground texture to Assets.xcassets

Adding the Ground class

Tiling a texture

Running wire to the ground

Adding the player's character

Renovating the GameScene class

Physics bodies and gravity

Dropping like flies

Solidifying the ground

Exploring physics simulation mechanics

Bumping bees into bees

Movement with impulses and forces

Summary

4. Adding Controls

Retrofitting the Player class for flight

The Beekeeper

Updating the Player class

Moving the ground

Assigning a physics body to the player

Creating a physics body shape from a texture

Polling for device movement with Core Motion

Implementing the Core Motion code

Wiring up the sprite onTap events

Implementing touchesBegan in the GameScene

Larger than life

Teaching our penguin to fly

Listening for touches in GameScene

Fine-tuning gravity

Spreading your wings

Improving the camera

Pushing Pierre forward

Tracking the player's progress

Looping the ground as player the moves forward

Summary

5. Spawning Enemies, Coins, and Power-Ups

Introducing the cast

Locating and adding the art assets

Adding the Power-up Star

Adding the Star class

A new enemy - the Mad Fly

Adding the MadFly class

Another terror - Bats!

Adding the Bat class

Guarding the ground with the Blade

Adding the Blade class

Adding coins

Creating the coin classes

Organizing the project navigator

Testing the new game objects

Preparing for endless flight

Summary

6. Generating a Never-Ending World

Designing levels with the SpriteKit scene editor

Separating level data from game logic

Using custom classes in the scene editor

Building encounters for Pierre Penguin

Creating our first encounter

Integrating scenes into the game

Looping encounters for a never-ending world

Building more encounters

Updating the EncounterManager class

Storing metadata in SKSpriteNodeuserData property

Wiring up EncounterManager in the GameScene class

Adding the Power-up Star at random places

Turning bronze coins into gold coins

Summary

7. Implementing Collision Events

Learning the SpriteKit collision vocabulary

Collision versus contact

Physics category masks

Using category masks in Swift

Adding contact events to our game

Setting up the physics categories

Assigning categories to game objects

The player

The ground

The Power-up Star

Enemies

Coins

Preparing GameScene for contact events

Viewing console output

Testing our contact code

Player health and damage

Animations for damage and game over

The damage animation

The game over animation

Collecting coins

The Power-up Star logic

Summary

8. Polishing to a Shine – HUD, Parallax Backgrounds, Particles, and More

Adding a HUD

Implementing the HUD

Parallax background layers

Adding the background assets

Implementing a background class

Wiring up backgrounds in the GameScene class

Using the particle system

Adding the circle particle asset

Creating a SpriteKit particle file

Configuring the path particle settings

Name

Background

Texture

Emitter

Lifetime

Position Range

Angle

Speed

Acceleration

Alpha

Scale

Rotation

Color Blend

Color Ramp

Adding the particle emitter to the game

Granting safety as the game starts

Summary

9. Adding Menus and Sounds

Building the main menu

Creating the menu scene and menu nodes

Launching the main menu when the game starts

Wiring up the START GAME button

Adding the restart game menu

Extending the HUD

Wiring up GameScene for game over

Informing the GameScene class when the player dies

Implementing touch events for the restart menu

Adding music with AVAudio

Adding sound assets to the game

Playing background music

Playing sound effects

Adding the coin sound effect to the Coin class

Adding the power-up and hurt sound effects to the Player class

Playing sound effects with SKAction

Adding a mute button and volume slider

Adding Options to the Menu Scene

Summary

10. Standing out in the Crowd with Advanced Features

Adding crates to smash open

Creating the Crate particle effects

Recycling emitter nodes with particle pools

Wiring up crate contact events

Creating the health power-up crate

Spawning smashable crates that reward coins

Summary

11. Introduction to SceneKit

Creating a Scene with SCNScene

Adding objects to the scene

Adding a sphere

Adding light sources

Adding a camera to the scene

Adding a floor

Importing scenes from an external 3D application

Creating the hero class and physics

Adding an enemy and collision detection

Adding a SpriteKit overlay

Adding labels and buttons

Adding touch interactivity

Adding the Gameloop

Setting a GameOver condition

Checking for contact

Adding wall and floor parallax

Adding particles

Adding character animation

Summary

12. Choosing a Monetization Strategy

Developing your marketing plan

When to start marketing

Marketing checklist

Leveraging crowdfunding

Pros and cons of crowdfunding

Showing display ads for revenue

The upsides to showing ads

The downsides to showing ads

Adding an AdMob Ad in the App

Selling in-app purchases

In-app purchase strategies

A word about farming your players

Adding In-App Purchases

Localization in foreign markets

Managing scope and completing projects

Summary

13. Integrating with Game Center

Authenticating the player's Game Center account

Opening Game Center in our game

Updating the leaderboard from the code

Adding an achievement

Creating a new achievement in iTunes Connect

Updating achievements from the code

Summary

14. Introduction to Spritekit with ARKit

Requirements for the project

Creating an AR Spritekit project

Adding text and crosshair

Adding anchors at random locations

Adding custom sprite

Registering touch controls to remove game objects

Summary

15. Introduction to Scenekit with ARKit

Going through the basic Scenekit/ARKit project

Project setup and detecting a plane

Adding touches

Adding Game Objects

Stop detecting planes

Adding light source

Adding ground node

Adding Hero and Enemy

Adding Score and Gameover text

Finishing touches

Summary

16. Publishing the Game on the App Store

Creating the Bundle ID for the app

Preparing the project

Create the App in the itunesconnect portal

Upload the App and submit for review

Summary

17. Multipeer Augmented Reality

Multipeer connectivity framework overview

Creating the multipeer session class

Creating a UI for the app

Setting outlets and adding variables

Initializing the view

Update session and tracking

Hosting and joining the session

Sending and receiving data

Initializing a multipeer session

Testing the application

Summary

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Index

Swift Game Development Third Edition

Swift Game Development Third Edition

Copyright © 2018 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the authors, nor Packt Publishing or its dealers and distributors, will be held liable for any damages caused or alleged to have been caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

Commissioning Editor: Ashwin Nair

Acquisition Editor: Reshma Raman

Content Development Editors: Flavian Vaz

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Production Coordinator: Shantanu Zagade

First published: July 2015

Second published: February 2017

Third edition: September 2018

Production reference: 1260918

Published by Packt Publishing Ltd.

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ISBN 978-1-78847-115-2

www.packtpub.com

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Contributors

About the authors

Siddharth Shekar is a game developer and teacher with over 5 years of industry experience and 12 years of experience in C++ and other programming languages, and is adept at graphics libraries such as OpenGL and Vulkan and game engines such as Unity and Unreal. He has also published games on the iOS and Android App Stores.

Siddharth has also authored 4 books, including Mastering Android Game Development with Unity and Learning iOS 8 Game Development Using Swift, all published by Packt Publishing

He currently lives in New Zealand and is a lecturer in the Games Department at Media Design School. He teaches graphics programming and PlayStation 4 native game development, and mentors final year production students.

I would like to thank my parents for supporting me in everything that I choose to do. I would also like to thank Media Design School for encouraging me to continue working on this book. Finally, I would like to thank Packt Publishing for putting this book together and offering me the opportunity to write the book.

Stephen Haney has written two books on iOS game development. He began his programming journey at the age of 8 years on a dusty, ancient laptop using BASIC. He has been fascinated with building software and games ever since. Now well versed in multiple languages, he enjoys programming as a creative outlet the most. He believes that indie game development is an art form—an amazing combination of visual, auditory, and psychological challenges—rewarding to both the player and the creator.

He enjoyed writing this book and sincerely hopes that it directly furthers your career or hobby.

About the reviewer

Rafał Sroka is a Software Engineer with extensive expertise in iOS development, building-up mobile apps, QA and release process, API design, and complex software projects. He has worked on various high-value projects in Poland, Germany, and Switzerland. He prefers working in cross-functional start-up environments where fast delivery of well-written and tested code is crucial. He holds a Master's degree in Electronics and Telecommunications. In his free time, he's a dedicated rock climber and mountaineer. He is a doer.

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Preface

Swift is the perfect choice for game development. Developers are intrigued by Swift and want to make use of new features to develop their best games yet. Packed with best practices and easy-to-use examples, this book leads you step-by-step through the development of your first Swift game.

The book starts by introducing Swift's newest and best features for game development. Using SpriteKit, you will learn how to animate sprites and textures. Along the way, you will master the physics, animations, collision effects and required to build the UI aspects of the game.

You will then work on creating a 3D game using the SceneKit framework. You will see how to add monetization and integrate Game Center. Then you will dive into creating augmented reality (AR) games using SpriteKit and SceneKit.

Finally, you will see how to create a Multipeer AR project to connect two devices and send and receive data back and forth between the devices in real time.

By the end of this book, you will be able to create your own iOS games using Swift and publish them on the iOS App Store.

Who this book is for

The book is targeted at new and intermediate developers who want to update their knowledge about the changes in the new version of Swift and want to learn about the new ARKit framework for making AR games for iOS using Xcode 10.

What this book covers

Chapter 1, Designing Games with Swift, introduces you to the best features of Swift, outlines what is new in Swift 3, helps you set up your development environment, and launches your first SpriteKit project.

Chapter 2, Sprites, Camera, Action!, teaches you the basics of drawing and animating with Swift. You will draw sprites, import textures into your project, and center the camera on the main character.

Chapter 3, Mix in the Physics, covers the physics simulation fundamentals: physics bodies, impulses, forces, gravity, collisions, and more.

Chapter 4, Adding Controls, explores the various methods of mobile game controls: device tilt and touch input. We will also improve the camera and core gameplay of our example game.

Chapter 5, Spawning Enemies, Coins, and Power-ups, introduces the cast of characters we use in our example game and shows you how to create custom classes for each NPC type.

Chapter 6, Generating a Never-Ending World, explores the SpriteKit scene editor, builds encounters for the example game, and creates a system to loop encounters endlessly.

Chapter 7, Implementing Collision Events, delves into advanced physics simulation topics and adds custom events when sprites collide.

Chapter 8, Polishing to a Shine – HUD, Parallax Backgrounds, Particles, and More, adds the extra fun that makes every game shine. In this chapter, you will learn how to create parallax backgrounds, learn about SpriteKit's particle emitters, and add a heads-up display overlay to your games.

Chapter 9, Adding Menus and Sounds, builds a basic menu system and illustrates two methods of playing sounds in your games.

Chapter 10, Standing Out in the Crowd with Advanced Features, shows you how to combine the techniques you have learned to build advanced gameplay systems.

Chapter 11, Introduction to SceneKit, explains how to create a basic 3D game using the SceneKit framework.

Chapter 12, Choosing a Monetization Strategy, outlines the strategies available to indie developers who want to make money from their games.

Chapter 13 , Integrating with Game Center, links our example game to the Apple Game Center for leaderboards, achievements, and friendly challenges.

Chapter 14 , Introduction to SpriteKit in ArKit, gives an introduction to how to make an AR game using Arkit and SpriteKit.

Chapter 15 , Introduction to SceneKit in ArKit, demonstrates how to make a 3D augmented reality game using SceneKit and Arkit.

Chapter 16, Ship It! Preparing for the App Store and Publication, covers the essentials of packaging your game and submitting it to the App Store.

Chapter 17, Multipeer Augmented Reality, shows you how to create a multiplayer AR project to connect two devices in real time so they can send and receive data.

To get the most out of this book

This book uses the Xcode IDE version 10 (Swift 4.2). If you use a different version of Xcode, you will likely encounter syntax differences; Apple is constantly upgrading Swift's syntax. You can use Xcode's Edit | Convert | To Current Swift Syntax to update the code examples in this book to a newer version of Xcode.

Visit https://developer.apple.com/xcode/to download Xcode.

You will need an Apple developer account to integrate your apps with Game Center and submit your games to the App Store.

To run ARKit games you will need an iPhone SE or higher, a fifth-generation iPad, or an iPad Pro. To run the Multipeer AR project you will need two devices because it can't be tested on an emulator.

Download the example code files

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The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Swift-Game-Development-Third-Edition. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. For example; Locate the Enemies folder in the downloadable asset bundle.

A block of code is set as follows:

import SpriteKit

class Coin: SKSpriteNode, GameSprite {

var initialSize = CGSize(width: 26, height: 26)

var textureAtlas: SKTextureAtlas =

SKTextureAtlas(named: Environment)

var value = 1

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

import SpriteKit

import ARKit

class Scene: SKScene {

    var crosshair: SKSpriteNode!     let scoreText = SKLabelNode(text: 00)

Bold: Indicates a new term, an important word, or words that you see on the screen, for example, in menus or dialog boxes, also appear in the text like this. For example: Select System info from the Administration panel.

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.

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Chapter 1. Designing Games with Swift

Apple's newest version of its flagship programming language, Swift 4.2, is the perfect choice for game developers. As it matures, Swift is realizing its potential to be something special, a revolutionary tool for app creators. Swift is the gateway for developers to create the next big game in the Apple ecosystem. We have only started to explore the wonderful potential of mobile gaming, and Swift is the modernization we need for our toolset. Swift is fast, safe, current, and attractive to developers coming from other languages. Whether you are new to the Apple world, or a seasoned veteran of Objective-C, I think you will enjoy making games with Swift.

Apple's website states the following:

Swift is a successor to the C and Objective-C languages.

My goal in this book is to guide you step by step through the creation of a 2D and a 3D game for iPhones and iPads. We will start with installing the necessary software, working through each layer of game development, ultimately publishing our new game to the App Store.

We will also have some fun along the way! For the 2D game, we aim to create an endless flyer game featuring a magnificent flying penguin named Pierre. What is an endless flyer? Picture hit games such as iCopter, Flappy Bird, Whale Trail, Jetpack Joyride, and many more—the list is quite long.

Endless flyer games are popular on the App Store, and the genre necessitates that we cover many reusable components of 2D game design. I will show you how to modify our mechanics to create many different game styles.

For the 3D game, we will be using SceneKit. Like SpriteKit, which is used to develop 2D games, SceneKit is a framework developed by Apple to make 3D games. The 3D game we will be an obstacle avoidance game, in which there will be obstacles players will have to either go under or jump over.

In later chapters, we will see how to make augmented reality games using Apple's newest framework, ARKit. With ARKit, you can make really stunning augmented reality games. We will see see how to develop AR games using SpriteKit and SceneKit. Along with developing a 2D AR game, we will also see how to bring the SceneKit game we developed for 3D to life using the ARKit. In addition, we will also see how to create a Multipeer Augemented Reality App using ARKit and Multipeer Connectivity framework.