freeblox/packages/engine/src/components/level.ts

import { Renderer } from '../core/renderer';
import { EngineComponent } from '../types/engine-component';
import {
  ChangeEvent,
  EngineEvents,
  InstanceEvent,
  RemoveEvent,
  ReparentEvent,
} from '../types/events';
import { EventEmitter } from '../utils/events';
import { Environment } from '../gameobjects/environment.object';
import { assetManager } from '../assets/manager';
import { WorldFile } from '../types/world-file';
import { World } from '../gameobjects/world.object';
import { instancableGameObjects } from '../gameobjects';
import { Object3D } from 'three';
import { GameObject, SerializedObject } from '../types/game-object';
import { environmentDefaults } from '../defaults/environment';

/**
 * Game level management component. This component provides the World.
 *
 * EnvironmentComponent must be initialized before this component.
 * @listens change Applies changes to objects
 * @listens remove Removes objects from scene
 * @listens reparent Reparents object
 */
export class LevelComponent extends EngineComponent {
  public name = LevelComponent.name;
  public world = new World();
  private environment!: Environment;
  private cleanUpEvents?: Function;

  constructor(
    protected renderer: Renderer,
    protected events: EventEmitter<EngineEvents>
  ) {
    super(renderer, events);
  }

  initialize(): void {
    this.renderer.scene.add(this.world);
    this.environment = this.renderer.scene.getObjectByName(
      'Environment'
    ) as Environment;
    this.cleanUpEvents = this.bindEvents();
  }

  update(delta: number): void {}

  dispose(): void {
    this.cleanUpEvents?.call(this);
  }

  public getSceneTree() {
    return {
      world: this.world,
      environment: this.environment,
    };
  }

  public createObject(object: string, setParent?: Object3D, skipJoin = false) {
    const parent = setParent || this.world;
    const ObjectType = instancableGameObjects[object];
    if (!ObjectType) return;
    const newObject = new ObjectType();
    parent.add(newObject);
    if (!skipJoin) this.events.emit('sceneJoin', newObject);
    return newObject;
  }

  public deserializeObject(root: SerializedObject, setParent?: Object3D) {
    const parent = setParent || this.world;

    if (root.objectType === 'World') {
      root.children.forEach((entry) => this.recursiveCreate(entry, parent));
      return parent;
    }

    return this.recursiveCreate(root, parent);
  }

  public serializeLevelSave(name: string): WorldFile {
    const world = this.world.serialize();
    const environment = this.environment.serialize();
    const assets = assetManager.serialize();
    return {
      name,
      world,
      environment,
      assets,
    };
  }

  public async deserializeLevelSave(save: WorldFile) {
    // Reset the world
    this.events.emit('reset');

    // Load all assets
    await assetManager.loadAll(save.assets);

    // Load environment
    this.environment.deserialize(save.environment);
    this.events.emit('setEnvironment', this.environment);

    // Load world
    this.deserializeObject(save.world);
    this.world.deserialize(save.world);
    this.events.emit('loadComplete');
  }

  private recursiveCreate(entry: SerializedObject, setParent?: Object3D) {
    const parent = setParent || this.world;
    const newObject = this.createObject(entry.objectType, parent, true);
    newObject?.deserialize(entry);
    entry.children.forEach((child) => this.recursiveCreate(child, newObject));
    return newObject;
  }

  private bindEvents() {
    const changeEvent = (event: ChangeEvent) => {
      if (event.applied || !event.object) return;
      const prop = (event.object as any)[event.property];
      if (prop?.copy) prop.copy(event.value);
      else (event.object as any)[event.property] = event.value;
    };

    const removeEvent = (event: RemoveEvent) => {
      if (event.applied || !event.object) return;
      if ((event.object as GameObject).virtual) return;
      if (Array.isArray(event.object)) {
        event.object.forEach((object) => object.removeFromParent());
        return;
      }

      event.object.removeFromParent();
      this.events.emit('sceneLeave', event.object);
    };

    const reparentEvent = (event: ReparentEvent) => {
      if (event.applied || !event.object || !event.parent) return;
      if (Array.isArray(event.object)) {
        event.object.forEach((object) => {
          event.parent.attach(object);
          this.events.emit('change', {
            object: object,
            property: 'parent',
            value: event.parent,
            applied: true,
          });
        });
        return;
      }

      event.parent.attach(event.object);
      this.events.emit('change', {
        object: event.object,
        property: 'parent',
        value: event.parent,
        applied: true,
      });
    };

    const instanceEvent = (event: InstanceEvent) => {
      const parent =
        typeof event.parent === 'string'
          ? this.world.getObjectByProperty('uuid', event.parent)
          : event.parent;
      const object = this.createObject(event.type, parent, !!event.data);

      if (event.data && object) {
        object.deserialize(event.data);
        this.events.emit('sceneJoin', object);
      }
    };

    const resetEvent = () => {
      this.world.clear();
      assetManager.freeAll();
      this.events.emit('setEnvironment', environmentDefaults);
      Object.assign(this.environment, environmentDefaults);
    };

    this.events.addListener('change', changeEvent);
    this.events.addListener('remove', removeEvent);
    this.events.addListener('reparent', reparentEvent);
    this.events.addListener('instance', instanceEvent);
    this.events.addListener('reset', resetEvent);

    return () => {
      this.events.removeEventListener('change', changeEvent);
      this.events.removeEventListener('remove', removeEvent);
      this.events.removeEventListener('reparent', reparentEvent);
      this.events.removeEventListener('instance', instanceEvent);
      this.events.removeEventListener('reset', resetEvent);
    };
  }
}