Function queryEntities

packages/core/src/ECS/Systems/EntitySystem.ts:520–549

* 查询匹配的实体

()

     * 查询匹配的实体
     */
    private queryEntities(): readonly Entity[] {
        if (!this.scene?.querySystem || !this._matcher) {
            return [];
        }

        const condition = this._matcher.getCondition();
        const querySystem = this.scene.querySystem;
        let currentEntities: readonly Entity[] = [];

        // matchNothing 条件返回空数组（用于只需要生命周期方法的系统）
        if (this._matcher.isNothing()) {
            return [];
        }

        // 空条件返回所有实体
        if (this._matcher.isEmpty()) {
            currentEntities = querySystem.getAllEntities();
        } else if (this.isSingleCondition(condition)) {
            // 单一条件优化查询
            currentEntities = this.executeSingleConditionQuery(condition, querySystem);
        } else {
            // 复合查询
            currentEntities = this.executeComplexQuery(condition, querySystem);
        }

        // 检查实体变化并触发回调
        this.updateEntityTracking(currentEntities);

        return currentEntities;
    }

    /**
     * 检查是否为单一条件查询