Book Image

Android Game Programming by Example

By : John Horton
Book Image

Android Game Programming by Example

By: John Horton

Overview of this book

Table of Contents (18 chapters)
Android Game Programming by Example
About the Author
About the Reviewers
Platformer – Guns, Life, Money, and the Enemy

Bringing the spaceship to life

First, we need to add a bit more functionality to our GameObject class. We do so in GameObject because bullets and asteroids share a surprising amount of similarities with a spaceship.

We need a bunch of getters and setters to get and set the rotation rate, traveling angle, and facing angle. Add the following methods to the GameObject class:

public void setRotationRate(float rotationRate) {
  this.rotationRate = rotationRate;

public float getTravellingAngle() {
  return travellingAngle;

public void setTravellingAngle(float travellingAngle) {
  this.travellingAngle = travellingAngle;

public float getFacingAngle() {
  return facingAngle;

public void setFacingAngle(float facingAngle) {
  this.facingAngle = facingAngle;

Now, we add a move method, which adjusts the x and y coordinates as well as the facingAngle of the object based on the current frames per second. Add the move method:

void move(float fps){
  if(xVelocity != 0) {