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180 | import * as THREE from "three";
import { World, WorldApi, Schedule, SystemFn } from "archetype-ecs-lib";
// --------------------
// Components (data only)
// --------------------
class Position { constructor(public x = 0, public y = 0, public z = 0) {} }
class Velocity { constructor(public x = 0, public y = 0, public z = 0) {} }
class Lifetime { constructor(public seconds = 2.0) {} }
class Renderable { constructor(public kind: "cube" = "cube") {} }
// --------------------
// Three.js setup
// --------------------
const renderer = new THREE.WebGLRenderer({ antialias: true });
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
const scene = new THREE.Scene();
scene.background = new THREE.Color(0x101018);
const camera = new THREE.PerspectiveCamera(
60,
window.innerWidth / window.innerHeight,
0.1,
1000
);
camera.position.set(0, 6, 14);
camera.lookAt(0, 0, 0);
const grid = new THREE.GridHelper(40, 40);
scene.add(grid);
window.addEventListener("resize", () => {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize(window.innerWidth, window.innerHeight);
});
// --------------------
// ECS setup
// --------------------
const world = new World();
const sched = new Schedule();
// Map ECS entities -> Three.js objects
// Use id+gen so reuse of ids never points to the wrong mesh.
const entityKey = (e: { id: number; gen: number }) => `${e.id}:${e.gen}`;
const objects = new Map<string, THREE.Object3D>();
function makeObject(r: Renderable): THREE.Object3D {
// MeshNormalMaterial doesn't need lights
const geo = new THREE.BoxGeometry(1, 1, 1);
const mat = new THREE.MeshNormalMaterial();
const mesh = new THREE.Mesh(geo, mat);
mesh.castShadow = false;
mesh.receiveShadow = false;
return mesh;
}
// --------------------
// Input: click to spawn
// --------------------
let pendingClicks = 0;
window.addEventListener("pointerdown", () => pendingClicks++);
const inputPhase: SystemFn = (w: WorldApi) => {
if (pendingClicks <= 0) return;
const cmd = w.cmd();
for (let i = 0; i < pendingClicks; i++) {
cmd.spawn((e: any) => {
// Spawn near origin with random velocity and short lifetime
const x = (Math.random() - 0.5) * 8;
const z = (Math.random() - 0.5) * 8;
const vx = (Math.random() - 0.5) * 6;
const vz = (Math.random() - 0.5) * 6;
cmd.addBundle(
e,
[new Position(x, 0.5, z), new Velocity(vx, 0, vz), new Lifetime(2.0 + Math.random() * 2.0), new Renderable("cube")]
);
});
}
pendingClicks = 0;
}
// --------------------
// Simulation: movement
// --------------------
const movementSystem: SystemFn = (w: WorldApi, dt: number) => {
for (const { c1: pos, c2: vel } of w.query(Position, Velocity)) {
pos.x += vel.x * dt;
pos.y += vel.y * dt;
pos.z += vel.z * dt;
// simple bounds bounce
const limit = 12;
if (pos.x < -limit || pos.x > limit) vel.x *= -1;
if (pos.z < -limit || pos.z > limit) vel.z *= -1;
}
}
// --------------------
// Simulation: lifetime -> despawn (deferred)
// --------------------
const lifetimeSystem: SystemFn = (w: WorldApi, dt: number) => {
for (const { e, c1: life } of w.query(Lifetime)) {
life.seconds -= dt;
if (life.seconds <= 0) {
w.cmd().despawn(e); // structural change deferred
}
}
}
// --------------------
// Render phase: ECS -> Three.js sync + remove despawned
// --------------------
const renderSync: SystemFn = (w: WorldApi) => {
const alive = new Set<string>();
// Create/update objects for all renderables
for (const { e, c1: pos, c2: rend } of w.query(Position, Renderable)) {
const key = entityKey(e);
alive.add(key);
let obj = objects.get(key);
if (!obj) {
obj = makeObject(rend);
scene.add(obj);
objects.set(key, obj);
}
obj.position.set(pos.x, pos.y, pos.z);
}
// Remove objects whose entities are gone
for (const [key, obj] of objects) {
if (!alive.has(key)) {
scene.remove(obj);
objects.delete(key);
}
}
}
// --------------------
// Schedule: phase ordering + flush boundaries
// --------------------
// Schedule runs phases in order and calls world.flush() after each phase. :contentReference[oaicite:2]{index=2}
sched.add("input", inputPhase);
sched.add("sim", movementSystem);
sched.add("sim", lifetimeSystem);
sched.add("render", renderSync);
const phases = ["input", "sim", "render"];
// --------------------
// Animation loop
// --------------------
let last = performance.now();
function frame(now: number) {
const dt = Math.min(0.05, (now - last) / 1000);
last = now;
// Run ECS phases (flush after each phase)
sched.run(world, dt, phases);
// Render Three.js
renderer.render(scene, camera);
requestAnimationFrame(frame);
}
requestAnimationFrame(frame);
// Spawn a few cubes at start (via commands so it behaves like gameplay)
pendingClicks = 6;
|