This is my standalone, simple implementation of game engine for Agar.io with simple graphical interface. I use this engine as submodule in my implementation of C++ game server (you can find it here).
You have to clone repository with all submodules (with --recurse-submodules
option) and install SFML.
To build and run:
$ mkdir build
$ cd build/
$ cmake ..
$ make
$ ./src/AgarioEngineDemo_run