PhysicsWorld.ts

import RAPIER from '@dimforge/rapier2d-compat';

/**
 * Wraps a Rapier 2D physics world.
 *
 * Rapier is a Rust → WASM physics engine — deterministic, fast, and the
 * modern choice for 2D and 3D web physics. We use the `-compat` build,
 * which embeds the WASM in the JS bundle so there's no separate fetch.
 *
 * After construction, you MUST `await world.init()` before using it (the
 * WASM module loads asynchronously). The Game class does this for you.
 *
 * Usage:
 *   const body = world.createDynamicBody(x, y);
 *   const collider = world.createBoxCollider(body, halfW, halfH);
 *   world.step();
 *   const { x, y } = body.translation();
 */
export class PhysicsWorld {
  private world?: RAPIER.World;