simple game physics lib

High-performance 2D physics engine for TypeScript & JavaScript — rigid bodies, constraints, fluid simulation, raycasting, and deterministic multiplayer. Tree-shakeable, zero dependencies.

Zero-GC 2D axis-aligned bounding box primitives. 22 ops on a flat Float32Array(4) [minX, minY, maxX, maxY], including packed 4xN batch ops; every op writes into a caller-provided out buffer — no per-frame allocation. ~230 lines, zero deps, ESM only.

Zero-GC dynamic Bounding Volume Hierarchy for 2D. Flat Structure-of-Arrays layout, O(1) free-list allocation, SAH insertion, iterative query — every operation is allocation-free after construction. Companion to @zakkster/lite-aabb.

Zero-GC persistent overlap events over a dynamic BVH (2D): turns a per-frame set of overlapping pairs into a per-frame delta -- enter / stay / exit -- with zero allocation per frame. Open-addressed Int32Array pair table, 1-bit alternating-tag mark-sweep.

Zero-GC spatial hash grid with linked-list chaining, epoch deduplication, box + radius queries, and O(1) insert/remove. SoA-aligned for particle engines.

Engine-neutral continuous 2D contact queries for moving circles, segments, and capsules with earliest time of impact and deterministic ordering.