Cocos2D-X Game Development in Android Studio

When we create a new Cocos2D-X project using Cocos2D-Console, an Eclipse project is generated by default. The problem is that Google needs to drop support for Eclipse ADT; they're fully pushing IntelliJ Idea-based Android Studio.

This post will show you how to convert your Cocos2D-X Android Eclipse ADT game project into an Android Studio project and how to configure NDK and JNI in Android Studio to run your game from Android Studio directly.

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Note: A reader recently commented that he was using Cocos2D-JS on Linux; this article helped resolve his problem. Things get buried in the comments section; that's why I am putting an important fact inside the post. Please read the comments section; it has some valuable information.

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Important

  Look at the previous article in this series; the link is below. This article explains essential concepts like setting important environment variables like NDK_ROOT. The article also shows you how to compile a project in obsolete Eclipse ADT. A quick look will be helpful.

Compile Cocos2D-x Project For Android Game Development

Create a new Cocos2D-X Project

First, let's create a new Cocos2D-X game development project; you may skip this part if you already have a project. Run the Cosos-Console command.
cocos new -p com.honesitconsultancy.indiegame -d "D:\Cocos\Projects" -l cpp "IndieGame"

Fig 1: Cocos-Console New Project

Once the command line operation is done, you will have a new " IndieGame " project folder on the path "D:\Cocos\Projects\." The folder will look like the screenshot below:

Fig 2: Cocos2D-X New Project Structure

1. Import Android project into Android Studio

Run Android Studio; if you already have a project opened, close it. Otherwise, it will show the project selection dialog exhibited below:

Fig 3: Android Studio New Project Dialog

I've blurred the project names on the left to hide the names of a few client projects I'm consulting through oDesk.

1. Click on the item "Import project(Eclipse ADT, Gradle, etc.)
2. The project selection dialog will open. Browse to your game path; in my case, it was "D:\Cocos\Projects\IndieGame\." The user interface did not show the subfolder " IndieGame "; I had to click the refresh button.
3. Select the Android project generated by the Cocos-Console command line. The name currently will be "proj.android". The refresh button is highlighted by a circle, and the Android project is shown by an arrow.

Fig 4: Select Project Dialog Android Studio

The following dialog will ask for a path to save the new Android Studio project. You must keep the new project alongside the other projects.

Fig 5: Android Studio Select Destination Path

• Change the name of the project folder to proj.androidstudio and click Next

You'll see a few options on the next screen. Android Studio is trying to help you; we don't need it. Check all 3 check-boxes reading "Replace jars with dependencies, when possible,"; "Replace library sources with dependencies, when possible,"; and "Create Gradle-style(camelCase) module names" on the next screen, as shown below. Click the Finish button.

Fig 6: Android Studio Import project from ADT Options

The Android Studio will ask that the directory does not exist and do you want to create it? Click "OK" and a new directory/folder will be created for you.

2. Add NDK to your project properties

Android Native Development Kit(NDK) path will be added to your "local.properties" Android Studio project file, an auto-generated file.
Click on the proj.androidstudio name on the top left of your screen, and select local.properties as shown in the screen grab below.

Android Studio Open local.properties

By default, this file will contain the path to Android SDK, don't mess with it. We need to add a line of text below the existing SDK line.
The format of the NDK entry will be ndk.dir=%Path of your NDK directory%
In my case, the precise statement is shown below:

ndk.dir=D\:\\cocos\\android-ndk-r10d-windows\\android-ndk-r10d

Important: Windows users must modify the path string and add a backslash in the following places:

• Right after the drive letter
• Right every backslash in the path

Save the local.properties file and close it.

3. Modify Build.Gradle to handle JNI

• On the top left, click proj.androidstudio
• Click IndieGame(or whatever project name you've chosen)
• Click build.gradle

Add a new line right after closing bracket } pertaining to defaultConfig section.
Add the following magic lines down there:

sourceSets.main
            {
                jni.srcDirs = []
            }

The sourceSets.main line will enable using Java Native Interface or JNI in your project. JNI does the same thing as Interop on Microsoft .Net.

Running your Cocos2D-x Indie Game on Android Devices

We need to perform just one more step before hitting the build icon.

• Open a command prompt.
• Change the directory to the location of your project.
• Once there, type the following cocos-console command.

cocos compile -s ".\proj.androidstudio" -p android --ndk-mode debug

Be Patient: I got a system with Core-i7 CPU and 8 GB RAM; my system takes about a minute to compile the code. If someone's got a slower/older system, getting a cup of coffee while the code compiles is a good idea.

4. API Level 9 Error

By default, the Cocos-Console generates a project with Android SDK level 9. It's an old platform; if you still need Android Studio installed, it will show an error. To fix the problem, you must modify the Android SDK level values in your game Manifest.xml and Gradle configuration file.

4a. Changes in Gradle Build File

• Luckily you would already have the Gradle file opened to make half of the changes(otherwise, follow Modify Build. Gradle to enable the JNI section above). Find the defaultConfig section shown below and change values accordingly. I got platform 14 installed, so I changed it to 14.

defaultConfig {
        applicationId "com.honesitconsultancy.indiegame"
        minSdkVersion 14
        targetSdkVersion 14

        ndk {
            moduleName "cocos2dcpp_shared"
        }
    }

• Change the compileSDKVersion value as well. By default, it was 10; I'll change it to 14.
•     compileSdkVersion 14

Save the file.

4b. Changes in Android Studio Manifest File

Now open the Manifest file; you can do so by clicking the project name hierarchy as shown by the thunderbolt in the screen grab below(proj.androidstudio -> IndieGame -> src -> main). I replaced the arrow; it looked boring :)

We need to change the minSDKVersion property here. We'll change it to 14(or any suitable SDK platform level you got installed).

<uses-sdk android:minSdkVersion="14"/>

After changing the value, save the manifest file. And hit the Synchronize button as well.

How to Make The Cocos-2DX Project

Here comes the climax!

Click the "Build" menu and select the "Make Project" menu item. You may use the shortcut key Ctrl + F9
Again, stay calm and wait for a while as the project is done.
Click the "Run" button, or use the shortcut key Shift + F10.

Note: I assume you've already configured a phone or emulator to work with your Android Studio; how to do so is beyond the scope of this article.

Once your blank Cocos2D-X game project starts running, the following screen will be displayed by default:

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