These are codes for my Advanced Physics II (PH162) class project for the Fall semester.
Code in the physics_engine folder is a recreation of that explained in Ian Millington's Game Physics Engine Design textbook, written in Processing environment of Java language.
Only Part I: Particle Physics was recreated.
Other folders contain this engine applied to various situations: particle connected to an anchored spring with zero natural length, two particles connected via a spring with nonzero natural length, two particles and gravity acting between them, and a billiard situation as described in Gregory Galperin's paper, Playing pool with pi.
In the four folders, three integration methods - explicit Euler, simpletic Euler, and Verlet - are used to predict the motions.
In addition, the theoretical solution is drawn among the particles in white.
The only exception is the pi_collision code, where Verlet integration is excluded, for the method of applying impulses in case of collisions could not be implicated there.
The rec codes in each folder except the physics_engine folder are applied from Tim Rodenbröker's blog:
https://timrodenbroeker.de/processing-tutorial-video-export/.
The R codes in the data folders are used for plotting graphs, and was heavily inspired by Winston Chang's boock, R Graphics Cookbook.