From ca05d36bc043fc36a5de790b607b5ec67dd01dea Mon Sep 17 00:00:00 2001
From: Andy <andy.conlon@gmail.com>
Date: Fri, 6 Mar 2026 18:53:19 -0500
Subject: [PATCH] feat: add game loop with NPC spawning and system execution

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 server/src/game/GameLoop.ts | 76 +++++++++++++++++++++++++++++++++++++
 server/src/game/spawner.ts  | 28 ++++++++++++++
 shared/tsconfig.json        |  1 +
 3 files changed, 105 insertions(+)
 create mode 100644 server/src/game/GameLoop.ts
 create mode 100644 server/src/game/spawner.ts

diff --git a/server/src/game/GameLoop.ts b/server/src/game/GameLoop.ts
new file mode 100644
index 0000000..2fe9393
--- /dev/null
+++ b/server/src/game/GameLoop.ts
@@ -0,0 +1,76 @@
+import { TICK_RATE, BROADCAST_EVERY_N_TICKS } from '@dflike/shared';
+import { World } from '../ecs/World.js';
+import { GameMap } from '../map/GameMap.js';
+import { needsDecaySystem } from '../systems/needsDecaySystem.js';
+import { npcBrainSystem } from '../systems/npcBrainSystem.js';
+import { movementSystem } from '../systems/movementSystem.js';
+import { spawnNPC } from './spawner.js';
+
+export class GameLoop {
+  readonly world: World;
+  readonly map: GameMap;
+  private tick = 0;
+  private interval: ReturnType<typeof setInterval> | null = null;
+  private onBroadcast: (() => void) | null = null;
+
+  constructor() {
+    this.world = new World();
+    this.map = new GameMap();
+    this.setupMap();
+    this.spawnInitialNPCs(8);
+  }
+
+  private setupMap(): void {
+    // Add some obstacle clusters for pathfinding interest
+    for (let x = 10; x <= 14; x++) for (let y = 10; y <= 12; y++) this.map.setObstacle(x, y);
+    for (let x = 30; x <= 33; x++) for (let y = 25; y <= 28; y++) this.map.setObstacle(x, y);
+    for (let x = 50; x <= 53; x++) for (let y = 40; y <= 43; y++) this.map.setObstacle(x, y);
+
+    // Points of interest
+    this.map.addPointOfInterest({ type: 'food', position: { x: 15, y: 15 } });
+    this.map.addPointOfInterest({ type: 'food', position: { x: 45, y: 30 } });
+    this.map.addPointOfInterest({ type: 'rest', position: { x: 8, y: 8 } });
+    this.map.addPointOfInterest({ type: 'rest', position: { x: 55, y: 50 } });
+  }
+
+  private spawnInitialNPCs(count: number): void {
+    for (let i = 0; i < count; i++) {
+      spawnNPC(this.world, this.map);
+    }
+  }
+
+  setBroadcastHandler(handler: () => void): void {
+    this.onBroadcast = handler;
+  }
+
+  start(): void {
+    const tickInterval = 1000 / TICK_RATE;
+    this.interval = setInterval(() => this.update(), tickInterval);
+    console.log(`Game loop started at ${TICK_RATE} ticks/sec`);
+  }
+
+  stop(): void {
+    if (this.interval) {
+      clearInterval(this.interval);
+      this.interval = null;
+    }
+  }
+
+  private update(): void {
+    this.tick++;
+
+    // Run systems in order
+    needsDecaySystem(this.world);
+    npcBrainSystem(this.world, this.map);
+    movementSystem(this.world);
+
+    // Broadcast state periodically
+    if (this.tick % BROADCAST_EVERY_N_TICKS === 0 && this.onBroadcast) {
+      this.onBroadcast();
+    }
+  }
+
+  getTick(): number {
+    return this.tick;
+  }
+}
diff --git a/server/src/game/spawner.ts b/server/src/game/spawner.ts
new file mode 100644
index 0000000..942668d
--- /dev/null
+++ b/server/src/game/spawner.ts
@@ -0,0 +1,28 @@
+import type { World } from '../ecs/World.js';
+import type { GameMap } from '../map/GameMap.js';
+import { generateRandomAppearance } from '../spawner/appearanceGenerator.js';
+import type { EntityId, Position, Needs, Movement, NPCBrain, Appearance } from '@dflike/shared';
+
+export function spawnNPC(world: World, map: GameMap): EntityId {
+  const entity = world.createEntity();
+  const pos = map.getRandomWalkable();
+
+  world.addComponent<Position>(entity, 'position', pos);
+  world.addComponent<Needs>(entity, 'needs', {
+    hunger: 40 + Math.random() * 40, // 40-80
+    energy: 40 + Math.random() * 40,
+  });
+  world.addComponent<Movement>(entity, 'movement', {
+    state: 'idle',
+    target: null,
+    path: [],
+    direction: 0,
+  });
+  world.addComponent<NPCBrain>(entity, 'npcBrain', {
+    currentGoal: null,
+    goalQueue: [],
+  });
+  world.addComponent<Appearance>(entity, 'appearance', generateRandomAppearance());
+
+  return entity;
+}
diff --git a/shared/tsconfig.json b/shared/tsconfig.json
index 43a4e4a..2a15387 100644
--- a/shared/tsconfig.json
+++ b/shared/tsconfig.json
@@ -5,6 +5,7 @@
     "moduleResolution": "bundler",
     "strict": true,
     "esModuleInterop": true,
+    "composite": true,
     "declaration": true,
     "outDir": "dist",
     "rootDir": "src"