Instructions

Updated 11th Feb 2014 - instructions for latest Libgdx and lwjgl.

Updated 1st Oct 2013 - instructions now work with 2013 versions of Raspbian.
Note: Versions of Raspbian later than 2012-10-28-wheezy-raspbian have older opengl header files in /opt/vc/include which 
required updates to the instructions below.

On your desktop machine

Set your environment variables to an installed JDK7 and Apache Ant. Note JDK8 can’t (yet) be used for compiling Lwjgl:

export PATH=~/tools/jdk1.7.0_17/bin:$PATH
export PATH=~/tools/apache-ant-1.8.3/bin:$PATH
export JAVA_HOME=~/tools/jdk1.7.0_17/

Create a base directory for your work,

mkdir ~/libgdx-pi
cd ~/libgdx-pi

Get the source code for the development version of libgdx (as of 10th June 2013) from GitHub:

git clone https://github.com/libgdx/libgdx.git

Fetch the latest pre-built binaries from LibGdx’s build servers (saves us from building everything from scratch):

cd libgdx
ant -f fetch.xml

Get the source code for the development version of lwjgl (as of 10th June 2013):

cd ~/libgdx-pi
git clone https://github.com/LWJGL/lwjgl.git

Patch support for initialising the for Raspberry Pi OpenGLES in Lwjgl. Note these changes are based on the excellent work by spsn (https://github.com/spsn/lwjgl) with additional changes to support libGDX available here:

org.lwjgl.opengl.DrawableGLES.java (1 place, Search for ChrisH)

Patch support to initialise the GLES context from LIbGDX:

org.lwjgl.opengles.GLContext.java (1 place, Search for ChrisH)

Build the Lwjgl jars (including the OpenGLES jars) and update the references in LibGDX:

cd ~/libgdx-pi/libgdx/backends/gdx-openal/libs
mv lwjgl.jar lwjgl.jar.old
mv lwjgl-debug.jar lwjgl-debug.jar.old<
cd ~/libgdx-pi/lwjgl/
ant jars
cp libs/lwjgl.jar ~/libgdx-pi/libgdx/backends/gdx-openal/libs/.
ant jars_es
cp libs/lwjgl.jar ~/libgdx-pi/libgdx/backends/gdx-openal/libs/lwjgl_es.jar

Patch libGDX/backends/gdx-backend-lwjgl to use the Lwjgl’s OpenGLES20 (instead of OpenGL):

com.badlogic.gdx.backends.lwjgl.LwjglGraphics.java: (2 places, Search for ChrisH)

Add new class com.badlogic.gdx.backends.lwjgl.LwjglGLES20.java

cd ~/libgdx-pi/libgdx
ant gdx-backend-lwjgl

This version of LibGDX is still usable on the Desktop (using OpenGL). If we specify -DLWJGJ_BACKEND=GLES we can toggle to the Lwjgl’s OpenGLES code for use on the Raspberry Pi. I couldn’t get OpenGLES working on my Desktop Linux machine, but it works OK on the Pi.

Patch Lwjgl’s native code to work with the Raspberry Pi’s OpenGLES:

lwjgl/src/native/common/opengles/org_lwjgl_opengles_EGL.c (3 places, Search for ChrisH)

lwjgl/src/native/common/opengles/org_lwjgl_opengles_CallbackUtil.c (1 place, Search for ChrisH)

Now copy the Lwjgl project to the Pi and compile the native code:

scp -r lwjgl pi@raspberrypi:~/.

On the Pi:

Install ant:

ssh pi@raspberrypi
sudo apt-get install ant

We need to build Lwjgl using jdk7:

export PATH=/usr/lib/jvm/java-1.7.0-openjdk-armhf/bin/:$PATH
export JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-armhf
cd lwjgl

Update build.xml and remove reference to eclipse-update

Update paths in platform_build/linux_ant/build.xml:

  <property name="libs32" value="-L/usr/X11R6/lib -L/usr/X11/lib -lm -lX11 -lXext -lXcursor -lXrandr 
-lXxf86vm -lpthread -L${java.home}/lib/i386 -ljawt -lGLESv2 -L/opt/vc/lib 
-L/usr/lib/jvm/java-7-openjdk-armhf/jre/lib/arm" />

Update paths in platform_build/linux_ant/build_es.xml:

  <property name="libs32" value="-L/home/spasi/lwjgl/libs/linux -lEGL -L/usr/X11R6/lib -L/usr/X11/lib 
-lm -lX11 -lXext -lXcursor -lXrandr -lpthread -L${java.home}/lib/i386 -ljawt -lGLESv2 -L/opt/vc/lib 
-L/usr/lib/jvm/java-1.7.0-openjdk-armhf/jre/lib/arm/ -lEGL" />

Install xorg dev libraries:

apt-get install xorg-dev

Add /opt/vc symlinks

cd /opt/vc/include/interface/vcos 
ln -s /opt/vc/include/interface/vcos/pthreads/vcos_futex_mutex.h .
ln -s /opt/vc/include/interface/vcos/pthreads/vcos_platform.h .
ln -s /opt/vc/include/interface/vcos/pthreads/vcos_platform_types.h .
cd /opt/vc/include/EGL
ln -s /opt/vc/include/bcm_host.h .

Add lwjgl -> /opt/vc symlinks

cd ~/lwjgl/src/native/common
ln -s /opt/vc/include/IL .
ln -s /opt/vc/include/interface .
ln -s /opt/vc/include/vcinclude .
ln -s /opt/vc/include/VG .

cd EGL
mv eglplatform.h egl platform.h.old
ln -s /opt/vc/include/EGL/eglplatform.h .

Compile Lwjgl:

cd ~/lwjgl
ant
ant compile_native_es

Note: You will get quite a lot of warnings.

Install openal on the Pi:

sudo apt-get install libopenal1

This installs a library: /usr/lib/arm-linux-gnueabihf/libopenal.so.1

Next create release directory on the Pi:

mkdir ~/gdx-test

Copy binaries:

cp /usr/lib/arm-linux-gnueabihf/libopenal.so.1 ~/gdx-test/libopenal.so
cp ~/lwjgl/libs/linux/liblwjgl.so ~/gdx-test/.

Copy over the libGDX libraries from your Desktop machine:

scp ~/libgdx-pi/libgdx/dist/gdx.jar pi@raspberrypi:~/gdx-test/.
scp ~/libgdx-pi/libgdx/dist/gdx-openal.jar pi@raspberrypi:~/gdx-test/.
scp ~/libgdx-pi/libgdx/dist/gdx-backend-lwjgl.jar pi@raspberrypi:~/gdx-test/.

compile libGDX natives for Arm (based on noxo’s work - http://forum.jogamp.org/JOGL-2-0-OpenGL-OpenGL-ES-backend-for-LibGDX-td4027689.html):

scp -r libgdx-pi/libgdx pi@raspberrypi:~
ssh pi@raspberrypi
cd libgdx/gdx/jni

edit build-linux32.xml
remove -m32 and -msse and -mfpmath=sse flags

ant -f build-linux32.xml
cp ~/libgdx/gdx/libs/linux32/libgdx.so ~/gdx-test/libgdxarm.so

Build and copy over the gdx-invaders example:

Import the libGDX projects into Eclipse (following information here) and export the gdx-invaders project as a jar.

scp gdx-invaders.jar pi@raspberrypi:~/gdx-test/.

Install JDK8 beta on the Pi:

wget http://www.java.net/download/JavaFXarm/jdk-8-ea-b36e-linux-arm-hflt-29_nov_2012.tar.gz

You can use the openjdk vm but it is not as fast as jdk8 and gdx-invaders is noticeably slower.

Then create a launcher script:

export PATH=/opt/jdk1.8.0/bin:$PATH
export JAVA_HOME=/opt/jdk1.8.0
java -Xmx128M -DPI=true -DLWJGJ_BACKEND=GLES -Djava.library.path=libs:/opt/vc/lib:. 
-classpath *:. com.badlogic.gdxinvaders.GdxInvadersDesktop $1