Method forEach

packages/core/src/ECS/Core/Query/CompiledQuery.ts:147–171

* 遍历所有匹配的实体及其组件 * * Iterate all matching entities with their components. * * @param callback 回调函数，接收实体和组件实例 | Callback receiving entity and component instances * * @example * ```typescript * query.forEach((entity, position, velocity) => { * position.x

(
        callback: (entity: Entity, ...components: InstanceTypes<T>) => void
    )

     * ```
     */
    public forEach(
        callback: (entity: Entity, ...components: InstanceTypes<T>) => void
    ): void {
        const entities = this.entities;
        const componentTypes = this._componentTypes;
        const typeCount = componentTypes.length;

        for (let i = 0, len = entities.length; i < len; i++) {
            const entity = entities[i]!;
            const components: Component[] = new Array(typeCount);

            // 获取所有组件
            for (let j = 0; j < typeCount; j++) {
                const component = entity.getComponent(componentTypes[j]!);
                if (!component) {
                    // 组件不存在，跳过这个实体
                    continue;
                }
                components[j] = component;
            }

            // 调用回调
            callback(entity, ...(components as InstanceTypes<T>));
        }
    }

    /**
     * 遍历自指定 epoch 以来发生变更的实体