@jexs/physics

Entity store, physics simulation, collision detection, raycasting, vectors, and GLB/GLTF mesh loading for Jexs.

Environment-agnostic — runs in browser or Node.js. Used by @jexs/gl for rendering and by @jexs/client for in-browser physics.

Part of Jexs.

Install

npm install @jexs/physics @jexs/core

What's inside

EntityStore — TypedArray-backed contiguous TRS layout (translation / rotation as quaternion / scale, plus velocity, mass, friction, color, UV, flags). Cache-friendly, GC-free for the hot loop.

Nodes:

| Node | Keys | Purpose | |---|---|---| | EntityNode | entity-init, entity-add, entity-remove, entity-move, entity-update, entity-list, entity-nearest, entity-get, entity-clear | Manage entities | | PhysicsNode | physics-init, physics-step, physics-pause, physics-resume, physics-apply, physics-destroy | Fixed-timestep simulation | | CollisionNode | collision-on, collision-off | Register collision handlers | | JointNode | joint-add, joint-remove | Constraints between entities | | VectorNode | v-distance, v-lerp, v-toward, v-normalize, v-scale, v-add, v-sub, v-direction, v-cross, v-dot | Vector math | | MeshNode | parseGLB, parseGLTF, register-mesh | Load 3D meshes; auto-builds a BVH |

Utilities — physicsStep, applyImpulse, wakeBody, raycastStore, rayAABB, buildBvh, queryAabb, raycastBvh, rayTriangle, computeBounds.

Quick example

[
  { "entity-init": { "capacity": 1000 } },
  { "physics-init": { "gravity": [0, -9.8, 0] } },

  { "entity-add": { "id": "ball",  "position": [0, 10, 0], "mass": 1, "restitution": 0.8 } },
  { "entity-add": { "id": "floor", "position": [0, 0, 0], "mass": 0, "fixed": true } },

  { "collision-on": "ball", "do": [
    { "console-log": "Bounce!" }
  ] },

  { "physics-step": { "dt": 0.016 } }
]

Using directly from TypeScript

import { EntityStore, physicsStep, F_TY } from "@jexs/physics";

const store = new EntityStore(1000);
const id = store.add({ position: [0, 10, 0], mass: 1 });

physicsStep(store, 0.016, { gravity: [0, -9.8, 0] });

console.log(store.data[id * store.stride + F_TY]); // current Y

License

MIT