The graphic features are as follows:

The following are the audio features:

The various input features are as follows:

The following are the features for the file I/O and storage:

The math and physics features for LibGDX are as follows:

The different utilities in LibGDX are as follows:

The following are the different tools in LibGDX:

Due to the fact that LibGDX is a framework based on Java, it is necessary to download Java Development Kit (JDK). To install it, follow these steps:

The next step is to download and install Eclipse, a freely available and open source Integrated Development Environment (IDE) in order to develop applications in Java. Go to http://www.eclipse.org/downloads/ and choose Eclipse IDE for Java Developers, as shown in the following screenshot, to download for the platform you are using:

Once the download is finished, extract the archive to C:\eclipse\.

Go to http://libgdx.badlogicgames.com/releases/ and choose the libgdx-1.2.0.zip file to download LibGDX.

The following screenshot shows a list of all the available files:

In the meantime, create a new folder inside the root folder of your C drive with the name libgdx. Once the download is finished, move the archive to C:\libgdx\.

The Android mobile OS is one of LibGDX's supported target platforms. Before you can create Android applications, you have to download and install the Android SDK.

Great! You are almost done setting everything up. The remaining steps involve running Eclipse for the first time and installing important plugins, which are required to develop applications for Android, iOS, and HTML5/GWT with Eclipse.

Open Windows Explorer, and go to the location where you extracted Eclipse (here, C:\eclipse\), and simply run the program by double-clicking on the executable called eclipse.

Eclipse will ask you to select a so-called workspace. This is the folder where all your projects will be saved. We want to use the C:\libgdx\ folder we created a bit earlier:

Select the Use this as the default and do not ask again checkbox if you don't want to see this dialog box every time you start Eclipse. To proceed, confirm the dialog box by clicking on the OK button.

The first time Eclipse is started with a new workspace, it will greet you with a welcome screen. Simply click on the small cross (x) of the Welcome tab to close it:

You should now see the standard view of Eclipse, which is also called the Java Perspective. On the left-hand side, you can see the Package Explorer section, as shown in the following screenshot. This is where you will see and manage your different projects. This is all you need to know about Eclipse for the moment.

If you have never worked with Eclipse before, it might seem quite overwhelming with all these windows, toolbars, huge context menus, and so on. However, be rest assured that all the steps will be discussed in detail as required to make it easy for you to follow.

To install new plugins, go to the menu bar, and click on Help, and then click on Install New Software. This will open the Install window, where you can type the special repository URLs to browse for new plugins. Google provides a list of such URLs at https://developers.google.com/eclipse/docs/getting_started. You have to choose the correct URL that corresponds with your Eclipse installation.

At the time of writing this book, Eclipse 4.3.2 (Kepler) was the most current version available. According to Google's website, the suggested URL for our version is http://dl.google.com/eclipse/plugin/4.3.

Type the URL in the text field that is labeled Work with and press return to let Eclipse request a list of available downloads. Select everything in the list that is shown in Developer Tools to add support for Android applications. Then, select everything in Google Plugin for Eclipse (required) to install the required Eclipse plugin. Lastly, select Google Web Toolkit SDK 2.5.1 in SDKs to add support for HTML5/GWT applications and click on Next to continue:

Now, click on Next to start the installation:

You will now be prompted to accept the terms of the license agreements by selecting the I accept the terms of the license agreements option. You have to do this before you can click on Finish to continue, as shown in the following screenshot:

The download process should only take a couple of minutes, depending on the speed of your network connection. When downloading is finished, Eclipse will show a security warning that you are about to install unsigned content and wants to know whether it should continue or abort. There is always a potential risk of installing malicious software. However, in this case, the download is provided by Google, a well-known company, which is trustworthy enough. Click on the OK button to accept the warning and continue the installation, as shown in the following screenshot:

After the installation is finished, a final restart of Eclipse is required. Click on the Yes button to confirm the restart:

Now, let's install the Gradle plugin for Eclipse so that we can import the project into Eclipse via Gradle. For this, let's perform the previous steps again. Go to the Install New Software option in the Help menu.

Enter the URL http://dist.springsource.com/release/TOOLS/gradle in the Work with field:

Select Gradle IDE under Extensions / Gradle Integration and click on Next. Continue as you did while installing Eclipse plugins to finish the process.

Additionally, in order to enable the iOS development, you need to install the RoboVM plugin in Eclipse. RoboVM for Eclipse integrates the RoboVM AOT (ahead-of-time) compiler with the Eclipse Java IDE. With this plugin, you will be able to develop native iOS apps in Java and launch them on the iOS simulator and iOS devices from within Eclipse.

To download and install the latest RoboVM plugin, we will perform the same steps that we did to install Eclipse plugins earlier. Go to the Install New Software option in the Help menu.

Enter the URL http://download.robovm.org/eclipse/ and continue, as shown in the following screenshot:

The latest RoboVM release while writing the book was v0.0.13.

Congratulations! You have just finished the installation of everything that you will need to develop and build your own games with LibGDX.

The old project setup tool is an executable JAR file called gdx-setup-ui.jar.

Step 1

You can download the old setup tool from https://github.com/libgdx/libgdx-old-setup-ui, as shown here:

Step 2

To run the tool, double-click on the gdx-setup-ui file. When the program starts, click on the big Create button:

Step 3

In the next window, you will see a box labeled CONFIGURATION on the left-hand side. Here, you can configure what the tool will generate.

Enter demo in the Name field, which defines a common project name for your application. Each launcher project will add its own suffix to it, such as -desktop, -android, or -html. A preview of the outcome is shown in the OVERVIEW box on the right-hand side of the window.

The Package field defines the name of your Java package. This needs to be a unique identifier written in lowercase, which is usually derived from a reversed domain name. You do not have to own a domain name nor does it have to really exist, but it helps in choosing nonconflicting namespaces for Java applications. This is especially important on Android, as identical package names for two separate applications would mean that the already installed application is going to be overwritten by the second one while trying to install it. For this demo application, use com.packtpub.libgdx.demo as the package name for now.

The Game class field defines the name of the main class in the shared game code project. Enter MyDemo as the game class name.

The Destination field defines the destination folder where all the projects will be generated. Click on the blue folder button (just next to the field) and set the destination folder to C:\libgdx\.

In another box called LIBRARY SELECTION, the status of required libraries is shown. If there is any item listed in red, it needs to be fixed before any project can be generated. You will see LibGDX being listed in red in the Required section. Click on the blue folder icon next to it:

Step 4

Then, choose the downloaded archive file libgdx-1.2.0.zip from C:\libgdx\ and click on Open, as shown in the following screenshot:

Step 5

The text color of the LibGDX label should have changed from red to green by now. Click on the Open the generation screen button to continue:

Step 6

Next, click on the Launch! button to generate all the projects, as shown here:

Step 7

All done! You can now go to Eclipse and start importing the generated projects into your workspace. To do this, simply navigate to the Import option in the File menu.

Step 8

In the Import dialog box, open the General category, select Existing Projects into Workspace, and click on the Next button, as shown here:

Step 9

Click on the radio button Select root directory and enter C:\libgdx in the text field. This is the directory where all your generated projects were created. You need to confirm your text input by pressing the return key once. Eclipse will start to scan the directory for your projects and list them. Leave all checkboxes selected and click on the Finish button, as shown in the following screenshot:

Step 10

Eclipse will automatically try to build (compile) all the four newly imported projects in your workspace and probably fail. There are two issues that need to be resolved manually after the import. The first one is reported directly to the Console window in Eclipse. It complains about being unable to resolve the target android-15, as shown in the following screenshot:

You have to open the project properties of the demo-android project. First, select it in the Package Explorer box on the left-hand side. Then, go to the menu bar and navigate to Properties option in the Project menu:

Step 11

The title of the window will say Properties for demo-android. If this is not the case, close the window and make sure you have selected the correct project and try again. Next, select Android from the list on the left-hand side. You will see a list of targets that are available on your system. Select Android 2.2, which uses API level 8, and click on the OK button, as shown here:

Step 12

Eclipse will recognize the change and successfully build the Android project this time.

The second issue requires you to click on the Problems tab in Eclipse. Open the Errors list and right-click on the reported problem, which will say The GWT SDK JAR gwt-servlet.jar is missing in the WEB-INF/lib directory. Choose Quick Fix from the context menu, as shown in the following screenshot:

Step 13

In the Quick Fix dialog box, select Synchronize <WAR>/WEB-INF/lib with SDK libraries as the desired fix and click on the Finish button, as shown here:

The two issues will be solved by now, which means that all the projects are now automatically built without failure and can be compiled.

For the first game, we will use the projects generated using the old setup tool; however, read this section and understand how it works, so that we can use it later in Chapter 14, Bullet Physics.

You can download the gdx-setup.jar file from http://libgdx.badlogicgames.com/download.html and then click on Download Setup App, as shown in the following screenshot:

However, we have already downloaded the libgdx-1.2.0.zip file, which contains gdx-setup.jar; hence, we will extract gdx-setup from the archive. To run the tool, double-click on gdx-setup to get the following screenshot:

The Name, Package, Game Class, and Destination fields are the same that we learned for the old project setup tool.

The Android SDK field defines the path to where you have installed your android sdk. Click on the Browse button and set it to the android sdk folder. Here, it's C:\Program Files\Android\android-sdk.

We will now select Release 1.2.0 from the drop-down list in the Libgdx Version field. Next under the Sub Projects tab, you can select the hardware platforms that you want to support. Here, we select all four, namely, Desktop, Android, Ios, and Html.

Finally, you can select the extensions (for example, box2d, physics bullet, and so on) to be included in your app. Some might not work on all the platforms for which you'll get a warning. For the demo, we don't need any extensions, hence ignore this part.

Now, click on the Advanced button, enable Eclipse, and then click on Save, as shown in the following screenshot:

Now that we have set everything, click on Generate.

It will take a while to download and generate the projects. Make sure that you are connected to the Internet. Finally, it will display BUILD SUCCESSFUL like this:

This means you are now ready to import the project into your IDE, run, debug, and package it! All done! You can now go to Eclipse and start importing the generated projects into your workspace.

You can import projects to Eclipse as in the old project setup by following Step 7 to Step 9. However, in order to access the features of the Gradle plugin, you need to import it quite differently. Navigate to the Import option in the File menu. In the Import dialog box, select the Gradle Project subfolder from the Gradle folder, as shown in the following screenshot:

Now in the Import Gradle Project window, click on Browse and select the folder where you created the demo project. Here, it's C:\libgdx. Then, click on the Build Model button:

It will take a while to build the project. After this, select the different projects and click on Finish, as shown in the following screenshot:

All done! After importing, change the API level of Android to 8 by following Step 10 and Step 11 from the old project setup.

The game world is presented in a 2D-side view to the player. The view will scroll horizontally to the right-hand side when the player character moves forward. The background shows distant canyons and clouds in the sky. The bottom of the level is filled with water and will instantly kill the player character if both get in touch with each other.

The player character will move on and jump over to random rocks, sticking out of the water. The width and height will be different to make the game more challenging. The player is only in control of a jump button, which will keep the automatically forward-moving player character from falling down into the deadly water.

The level will be randomly populated with collectible items consisting of gold coins and feather power-ups. Collecting the gold coins will increase the player's high score. The feather power-up grants the player character the ability to fly for a limited time and can be used by repeatedly pressing the jump button. The player's goal is to beat the last high score.

As a picture is worth a thousand words, creating a sketch based on our outline can help us even more to get a better idea of the resulting game. Moreover, changing a sketch is usually a lot easier than having to change (complex) game code. So, you really want to keep it very simple; just grab your pen and paper and start to draw. If you feel lucky or have some time to spend, you can do something more elaborate, of course.

Here is a mock-up for Canyon Bunny:

The previous mock-up has been created entirely by using vector graphics. Using vector graphics in favor of raster graphics for your sketches can be an advantage as they are infinitely scalable to any size without losing the image quality. However, the final graphics used in games are almost, always, rasterized graphics, simply because vector graphics are costly to render in real time. So, the common approach is to create vector graphics and later on export them choosing an appropriate rasterized graphics file format, such as Portable Network Graphics (PNG) for lossless compression with alpha channel support, or Joint Photographic Experts Group (JPEG) for lossy but high compression without alpha channel support.

For more details, check out the following Wikipedia articles:

There is a free and open source tool called Inkscape similar to Adobe Illustrator. It allows you to easily create your own drawings as vector graphics and is available for Windows, Linux, and Mac OS X. Check out the project's website http://inkscape.org/.