Physics
Collision events flow through engine managers, so gameplay code can react to contact without owning the physics loop.
Quark
A 2D game engine I built for CPSC 4791 at Yale. It has impulse-based physics, a custom scripting language, and threaded subsystems that run at different timesteps.
Summary
Quark is primarily a framework for developing 2D games, providing engine services such as resource management, real-time updates, and user scripts sharing one runtime.
How it works
Scripting
Game behavior can be written in a small custom language interpreted inside the engine.
Scheduling
Subsystems can tick at different rates and coordinate through mutex-controlled threads.
Links
What I would change
The engine ended up much farther than the tooling. Once I'd finished the project, making game content was slower than it needed to be because the scene, collider, and rigidbody construction was still mostly manual.
If I extended this project, I would build an editor first, then add more interesting features like fluid effects, spatial audio, better text rendering, input management, and networking.