libgdx-sample

This is a sample libgdx project to get familiar with libgdx integration with Chilitags, camera etc. It should display a growing and swaying funky palm tree on each detected tag.

The build system uses Gradle extensively, which can be thought of a CMake counterpart for Java that also downloads and maintains missing packages.

Below are the official libgdx documentation for Gradle:

• How to create a new libgdx project with Gradle
• Gradle-enabled libgdx project structure details
• Gradle guide for command line
• IDE setup for Gradle

The following GUI is used to create new libgdx projects: http://libgdx.badlogicgames.com/nightlies/dist/gdx-setup.jar It sets up the initial project structure as described in the following section.

Project structure

libgdx projects come in the following directory structure:

├── android/
│   ├── AndroidManifest.xml
│   ├── assets
│   ├── build.gradle
│   ├── proguard-project.txt
│   ├── project.properties
│   └── src/
├── build.gradle
├── core/
│   ├── build.gradle
│   └── src/
├── desktop/
│   ├── build.gradle
│   └── src/
├── gradle/
├── gradlew
├── gradlew.bat
├── html/
│   ├── build.gradle
│   ├── src/
│   └── webapp/
├── ios/
│   ├── build.gradle
│   ├── Info.plist.xml
│   ├── robovm.properties
│   ├── robovm.xml
│   └── src/
└── settings.gradle

• The core directory contains the actual application that is platform independent.
• The desktop,android, html and ios directories contains the small platform dependent portions of the project. With any luck, you won't even have to touch them.
• The build.gradle in the root directory has all of the library dependencies of your project, including the platform specific dependencies. Most of these dependencies are automatically installed by Maven when you build your project. This file also contains general information about your project.
• The build.gradle files in the platform specific directories have platform specific configurations such as small run and debug scripts.
• The android/assets/ directory contains all the assets for the project like 3D models or sprites. It is under the android directory because of technical reasons and is currently being worked on.
• libgdx projects come with gradlew and gradlew.bat scripts that can run in Linux/MacOS and Windows respectively. You can use these to build/run your projects in the command line. Alternatively, you can use one of Eclipse, Netbeans or Intellij IDEA.

How to Build & Run

Currently, only the desktop and Android versions of this sample are in working condition. Web version needs proper javascript bindings for Chilitags and iOS version might be available at a (much) later date.

1. Clone this sample: git clone [email protected]:chili-epfl/libgdx-sample.git

2. Follow the instructions at https://github.com/chili-epfl/chilitags/blob/master/README-ANDROID.md to build and install Chilitags/OpenCV inside the Android specific portion of the project. That guide will work you through installing the Android SDK and NDK. In this case, the ANDROID_PROJECT_ROOT variable inside the guide would be <libgdx-sample-path>/android. It is necessary at this point to install Chilitags inside the Android project even if you are only going to run the desktop version, since the JNI wrappers inside the Android project are also referenced by the desktop project. In the near future, this is going to be replaced by proper libraries that will be automatically downloaded from Maven repositories.

3. Set the ANDROID_HOME environment variable to the Android SDK root if you don't have it already.

Once you install Chilitags/OpenCV inside the sample project, you should be able to run everything. Follow the instructions below for different build/run options.

Using the command line

Go to the project's root directory and run the following:

• For desktop, run ./gradlew desktop:run. Since we are using JNI to reference native Chilitags and OpenCV libraries, make sure that you have them installed on your system as dynamic libraries and the LD_LIBRARY_PATH environment variable contains their paths, e.g /usr/lib/:/usr/lib32/:/usr/lib64/:/usr/local/lib/:/usr/local/lib32/:/usr/local/lib64/
• For Android, run ./gradlew android:installDebug android:run. This will package the project in an APK, upload it to the first device/emulator and run it.
• For web, run ./gradlew html:superDev. This will compile the Java code to Javascript using Google Web Toolkit and launch it in superDev mode, which will enable you to debug it. Go to http://localhost:8080/gwt to view the project. This will of course work after we have proper javascript bindings for Chilitags.

Using Eclipse

To import the project:

• Install the ADT plugin from this update site: https://dl-ssl.google.com/android/eclipse/.
• Install Gradle integration plugin for Eclipse from this update site http://dist.springsource.com/release/TOOLS/gradle.
• Import the root directory of your project as a Gradle Project.
• Click Build Model.
• Select all projects (including the root one) and click Finish.

To run the project:

• For desktop, run as Java Application and select Main.java in the ch.epfl.chili.libgdx_sample.desktop package. Important note: The LD_LIBRARY_PATH must be set inside Eclipse since Eclipse will not be aware of it when it's exported inside .bashrc. An alternative is to set -Djava.library.path=... inside the Java Application run configuration's VM args.
• For Android, run as Android Application.
• For web, configure an external Program via External Tools Configuration. Set Location to the gradlew in your project root. Set the Working Directory to your project root. Set the Argument to html:superDev. Now you can use this external tool to launch the project in superDev mode just like the command line. Again, this will work after we have proper javascript bindings for Chilitags.

For other IDEs, please see the official libgdx documentation.