using System;
using System.Collections.Generic;

using System.Text;
using UnityEngine;

namespace Thousandto.Core.Base
{
    /// <summary>
    /// 一帧之内不作多次变化的数据缓存 -- 根据帧决定更新缓存
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class CacheDataByFrame<T> where T : UnityEngine.Object
    {
        public delegate T GetDataMethod();

        private GetDataMethod _getMethod = null;
        private int _frameCounter = -1;                                        // 缓存数据更新控制
        private T _cacheData;


        public CacheDataByFrame(GetDataMethod getFunc)
        {
            _getMethod = getFunc;
            if (_getMethod != null)
            {
                _cacheData = _getMethod();
            }

        }

        public T GetCacheData()
        {
            if (_frameCounter != Time.frameCount)
            {
                // not the same frame -- get from method
                _frameCounter = Time.frameCount;
                if (_getMethod != null)
                {
                    _cacheData = _getMethod();
                }
            }

            // same frame get cache
            return _cacheData;
        }

        public void Release()
        {
            if (_cacheData != null)
            {
                _cacheData = null;
            }
        }

    }
}