Book Image

Learning Java by Building Android Games - Second Edition

By : John Horton
Book Image

Learning Java by Building Android Games - Second Edition

By: John Horton

Overview of this book

Android is one of the most popular mobile operating systems presently. It uses the most popular programming language, Java, as the primary language for building apps of all types. However, this book is unlike other Android books in that it doesn’t assume that you already have Java proficiency. This new and expanded second edition of Learning Java by Building Android Games shows you how to start building Android games from scratch. The difficulty level will grow steadily as you explore key Java topics, such as variables, loops, methods, object oriented programming, and design patterns, including code and examples that are written for Java 9 and Android P. At each stage, you will put what you’ve learned into practice by developing a game. You will build games such as Minesweeper, Retro Pong, Bullet Hell, and Classic Snake and Scrolling Shooter games. In the later chapters, you will create a time-trial, open-world platform game. By the end of the book, you will not only have grasped Java and Android but will also have developed six cool games for the Android platform.
Table of Contents (30 chapters)
Learning Java by Building Android Games Second Edition
Contributors
Preface
Index

Coding a parallax background


Much of the code that makes the backgrounds work is the same as it was in the scrolling shooter project. However, we will be coding a background-specific transform that extends Transform and we will also be using the Camera class to tweak the position of the backgrounds and make them create a parallax effect as well as vertical movement(compared to just horizontal in the previous project).

We will see the tricks and the code required to achieve a parallax scrolling background effect. The parallax effect is when different layers of backgrounds are moved at different speeds to achieve the effect of motion and depth. By moving the front layer(s) faster than the back the distance/depth effect is achieved.

To be clear, the back layer is the background and the front layer is all the platforms and other game objects.

Video games didn't invent this technique and the first modern use of the parallax effect dates to early cinema. The famous Disney production Snow White used...