Collision Detection in C

A live coding session implementing collision detection in C for a custom game engine. Covers the math behind sphere-box and rectangle-circle intersection using the closest-point technique (clamping center coordinates with min/max), then extends it to 3D. Also introduces a voxel-based barrier system using a hash set, adds a new 'barrier' entity kind to the game's entity system, computes axis-aligned bounding boxes from model vertices at asset-build time, and derives a rect-rect collision check by testing segment non-overlap per axis and negating.