Method onAdded

packages/core/src/ECS/Systems/HierarchySystem.ts:532–537

* 当实体被添加到系统时，将其加入脏集合 * When entity is added to system, add it to dirty set

(entity: Entity)

     * When entity is added to system, add it to dirty set
     */
    protected override onAdded(entity: Entity): void {
        const hierarchy = entity.getComponent(HierarchyComponent);
        if (hierarchy && hierarchy.bCacheDirty) {
            this.dirtyEntities.add(entity);
        }
    }

    /**
     * 当实体被移除时清理层级关系