well, that works

engine/Scene.ts

@@ -1,3 +1,12 @@
+import {
+	type Draw as EntityDraw,
+	type EntityInstance,
+	type Process as EntityProcess,
+	entityDrawMap,
+	entityMap,
+	entityProcessMap,
+} from "./Entity.ts";
+
 export type SceneData = {
 	id: string;
 	width: number;
@@ -7,6 +16,11 @@ export type SceneData = {
 
 export type Scene = {
 	data: SceneData;
+	entityPool: Array<{
+		draw: EntityDraw;
+		process: EntityProcess;
+		entity: EntityInstance;
+	}>;
 	process: Process;
 };
 
@@ -27,8 +41,21 @@ export const currentScene: Scene = {
 		entities: [],
 	},
 	process: () => {},
+	entityPool: [],
 };
 
+function drawEntities(ctx: CanvasRenderingContext2D): void {
+	for (const entity of currentScene.entityPool) {
+		entity.draw(ctx);
+	}
+}
+
+function processEntities(delta: number): void {
+	for (const entity of currentScene.entityPool) {
+		entity.process(delta);
+	}
+}
+
 export function useScene(data: SceneData): {
 	process: (fn: Process) => void;
 } {
@@ -36,7 +63,11 @@ export function useScene(data: SceneData): {
 
 	return {
 		process(fn: Process): void {
-			sceneProcessMap.set(data.id, fn);
+			sceneProcessMap.set(data.id, (ctx, delta) => {
+				drawEntities(ctx);
+				processEntities(delta);
+				fn(ctx, delta);
+			});
 		},
 	};
 }
@@ -57,6 +88,16 @@ export async function loadScene(name: string): Promise<void> {
 	const data = sceneDataMap.get(name)!;
 	currentScene.data = data;
 
+	for (const entity of data.entities) {
+		await import(`#/entities/${entity}/index.ts`);
+
+		currentScene.entityPool.push({
+			draw: entityDrawMap.get(entity)!,
+			process: entityProcessMap.get(entity)!,
+			entity: entityMap.get(entity)!,
+		});
+	}
+
 	const process = sceneProcessMap.get(name)!;
 	currentScene.process = process;
 }