Robert Green

An Android Game Development Framework

As you may have noticed, we’ve been through four chapters without writing a single line of game code. The reason we’ve put you through all of this boring theory and asked you to implement test programs is simple: if you want to write games, you have to know exactly what’s going on. You can’t just copy and paste code together from all over the Web and hope that it will form the next first-person shooter hit. By now, you should have a firm grasp on how to design a simple game from the ground up, how to structure a nice API for 2D game development, and which Android APIs will provide the functionality you need to implement your ideas.

First Steps with Android Studio

The Android Studio and the Android SDK provide a set of tools that enable you to create applications in a short amount of time. This chapter will guide you through the process of building a simple Android application with the SDK tools.

Marketing and Monetizing

So, having read the previous 13 chapters, you now are imbued with the skill and knowledge required to build a great Android game. Is it as simple as “build it and get rich?” Certainly not! Making money by marketing and monetizing your game is a skill in itself, and there is a lot you need to learn to become successful at it—not just after your game is completed, but even before you start developing it. The real moneymakers are often designed from the planning stage to become popular and to make money, on top of being well made.

An Android in Every Home

As kids of the eighties and nineties, we naturally grew up with our trusty Nintendo Game Boys and Sega Game Gears. We spent countless hours helping Mario rescue the princess, getting the highest score in Tetris, and racing our friends in Super RC Pro-Am via Link Cable. We took these awesome pieces of hardware with us everywhere we could. Our passion for games made us want to create our own worlds and share them with our friends. We started programming on the PC, but soon realized that we couldn’t transfer our little masterpieces to the available portable game consoles. As we continued being enthusiastic programmers, over time our interest in actually playing video games faded. Besides, our Game Boys eventually broke…

Going Native with the NDK

After all the 3D extravagance in the past three chapters, it’s time to look into one more aspect of programming games for Android. While Java and the Dalvik VM are sufficient for a lot of game genres in terms of execution speed, there are times when you need a bit more power. This is especially true for physics simulations, complex 3D animation, collision detection, and so on. This type of code is best written in more “to-the-metal” languages like C/C++ or even assembly language. The Android native development kit (NDK) lets us do exactly that.

Publishing Your Game

The last step in becoming an Android game developer is getting your game to your players. There are two possible routes: • Take the APK file from your project’s bin/ folder, put it up on the web, and tell your friends to download and install it on their devices. • Publish your application on the Android Market, like a real pro. The first option is a great way to let other people test your application before you throw it on the market. All they need to do is get a hold of the APK file and install it on their devices. The real fun starts once your game is ready for prime time.

First Steps with the Android SDK

The Android SDK provides a set of tools that allows creating applications in no time. This chapter will guide you through the process of building a simple Android application with the SDK tools. This involves the following steps: 1. Setting up the development environment 2. Creating a new project in Eclipse and writing our code 3. Running the application on the emulator or on a device 4. Debugging and profiling the application Let’s start with setting up the development environment.

OpenGL ES: Going 3D

Super Jumper worked out rather well with our 2D OpenGL ES rendering engine. Now it’s time to go full 3D. We actually already worked in a 3D space when we defined our view frustum and the vertices of our sprites. In the latter case the z-coordinate of each vertex was simply set to zero by default. The difference from 2D rendering isn’t all that big, really: • Vertices not only have x- and y-coordinates, but also a z-coordinate. • Instead of an orthographic projection, we use a perspective projection. Objects further away from the camera will appear smaller. • Transformations, such as rotations, translations, and scales, have more degrees of freedom in 3D. Instead of just moving the vertices in the x-y plane we can now move them around freely on all 3 axes. • We can define a camera with an arbitrary position and orientation in 3D space. • The order we render the triangles of our objects with is now important. Objects further away from the camera must be overlapped by objects closer to the camera. The best thing is that we have already laid the groundwork for all of this in our framework. We just need to adjust a couple classes slightly to go 3D.

OpenGL ES: A Gentle Introduction

Mr. Nom was a great success. Due to its solid initial design and game framework, implementing Mr. Nom was a breeze for us. Best of all, the game runs smoothly even on low-end devices. Of course, Mr. Nom is not a very complex or graphically intense game, so using the Canvas API for rendering proved to be a good idea.

Super Jumper: A 2D OpenGL ES Game

It’s time to put together all you’ve learned about OpenGL ES into a game. As discussed in Chapter 3 , there are several very popular genres from which to choose when developing a game in the mobile space. For our next game, we decided to stick to the casual genre. We’ll implement a jump-’em-up game similar to Abduction or Doodle Jump. As with Mr. Nom, we’ll start by defining our game mechanics.