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 the player's components and transform


Since Bob is the most significant object that uses an Animator, let's code all the necessary classes to get the player game object working. There are three components, AnimatedGraphicsComponent, PlayerInputComponent and PlayerUpdateComponent.

Before we code the components, we will also need a more advanced version of the Transform class.

PlayerTransform

Create a new class called PlayerTransform and add the member variables along with the constructor method. Notice the class extends Transform so it will also have access to the methods and members of the simpler Transform class we coded in Chapter 23: Coding the basic Transform.

import android.graphics.PointF;
import android.graphics.RectF;

import java.util.ArrayList;

class PlayerTransform extends Transform {

    private ArrayList<RectF> mColliders;

    private final float TENTH = .1f;
    private final float HALF = .5f;
    private final float THIRD = .3f;
    private final float FIFTH ...