Note: Be aware the initial installation of openFrameworks on the Raspberry Pi will take about 1-2 hours of unattended time while the framework is compiled on the Pi. Set aside some time before you continue further.
To install openFrameworks on the Raspberry Pi, carefully follow the steps at the official installation instructions. In particular, don't miss the step to configure the GPU/CPU memory split to 128 MB before compiling. I recommend installing openFrameworks to the /home/pi/openFrameworks folder like the installation guide suggests. Also, you can skip the optional steps at the end to setup a cross compiler or DISTCC for faster compilation.
Once openFrameworks is compiled, make sure you can compile one of the example applications by following the 'Compile your first app' step at the end of the instructions. Don't move on until you can successfully compile an openFrameworks application.
Continue on to compile and use the code for this project.