Simple pendulum made out of a moving sphere rendered with OpenGL, and based on this video from The Coding Train.
# clone repo with its submodules
$ git clone --recursive https://github.com/OpenGL-Graphics/pendulum
# build & run
$ cd terrain
$ mkdir build && cd build
$ cmake .. && make -j && ./main
# to get new commits from submodules
$ git submodule update --remote