Box2D

Box2D is an open-source, high-performance 2D physics engine designed for games and interactive simulations. Written in portable C17, it simulates rigid bodies, collisions, gravity, and physical constraints. The engine supports circles, capsules, polygons, rounded shapes, segments, and connected chains. Continuous collision detection improves accuracy when objects move or rotate rapidly. Developers can construct mechanical systems using revolute, prismatic, distance, motor, weld, and wheel joints. Its Soft Step solver, multithreading, and SIMD optimizations efficiently handle complex scenes containing many objects. Additional capabilities include character movement, collision queries, sensors, deterministic simulation, and state restoration. Interactive examples help developers explore its physics behavior.