The prized library that handles all in-game mechanics. I will go over how physics simulations works from client and server’s perspective, the event system, player and map element management. How do you write a game engine that is 100% unit testable? This is how. This part is broken into 4 subparts.
Part 4.1 - Why write a game engine?
Part 4.2 - State based animation and how to test animation logic
Part 4.3 - Client and authoritative server model
Part 4.4 - Extensible components of Trap Labs