Book Image

Learning Java by Building Android Games - Third Edition

By : John Horton
5 (1)
Book Image

Learning Java by Building Android Games - Third Edition

5 (1)
By: John Horton

Overview of this book

Android is one of the most popular mobile operating systems today. It uses the most popular programming language, Java, as one of the primary languages for building apps of all types. Unlike most other Android books, this book doesn’t assume that you have any prior knowledge of Java programming, instead helps you get started with building Android games as a beginner. This new, improved, and updated third edition of Learning Java by Building Android Games helps you to build Android games from scratch. Once you've got to grips with the fundamentals, the difficulty level increases steadily as you explore key Java topics, such as variables, loops, methods, object-oriented programming (OOP), and design patterns while working with up-to-date code and supporting examples. At each stage, you'll be able to test your understanding by implementing the concepts that you’ve learned to develop a game. Toward the end, you’ll build games such as Sub Hunter, Retro Pong, Bullet Hell, Classic Snake, and Scrolling Shooter. By the end of this Java book, you'll not only have a solid understanding of Java and Android basics but will also have developed five cool games for the Android platform.
Table of Contents (24 chapters)

Coding the Bullet class

The Bullet class is not complicated. It is a tiny square bouncing around the screen and will have many similarities to the ball in the Pong game. To get started, add the member variables shown highlighted next to the Bullet class:

import android.graphics.RectF;
class Bullet {
    // A RectF to represent the size and location of the 
    bullet
    private RectF mRect;
    // How fast is the bullet traveling?
    private float mXVelocity;
    private float mYVelocity;
    // How big is a bullet
    private float mWidth;
    private float mHeight;
}

We now have a RectF called mRect that will represent the position of the bullet. You will need to add the import statement for the RectF class as well. In addition, we have two float variables to represent the direction/speed of travel...