Unity开发中常用的随机方法扩展

里面就两种功能

一种是排除掉一定范围内的数

另一种是在一个数组中，基于权重随机生成一个索引

csharp 复制代码

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// 随机工具
/// </summary>
public class RandomTool
{
    /// <summary>
    /// 在一个范围中随机，但是排除掉一小个范围
    /// </summary>
    /// <param name="includeMin"></param>
    /// <param name="excludeMax"></param>
    /// <param name="blackMin">排除范围的最小值</param>
    /// <param name="blackMax">排除范围的最大值，会包括这个值</param>
    /// <returns></returns>
    public static int Range(int includeMin, int excludeMax, int blackMin, int blackMax)
    {
        if(blackMin < includeMin || blackMin > excludeMax)
        {
            Debug.LogError("随机数范围异常！");
            return includeMin;
        }

        if(blackMax < blackMin || blackMax > excludeMax)
        {
            Debug.LogError("随机数范围异常！");
            return includeMin;
        }

        int random1 = Random.Range(includeMin, blackMin);
        int random2 = Random.Range(blackMax + 1, excludeMax);
        if(Random.Range(0, 2) == 0)
        {
            return random1;
        }
        else
        {
            return random2;
        }
    }

    /// <summary>
    /// 在一个范围中随机，但是排除掉一小个范围
    /// </summary>
    /// <param name="includeMin"></param>
    /// <param name="excludeMax"></param>
    /// <param name="blackMin">排除范围的最小值</param>
    /// <param name="blackMax">排除范围的最大值，会包括这个值</param>
    /// <returns></returns>
    public static float Range(float includeMin, float excludeMax, float blackMin, float blackMax)
    {
        if (blackMin < includeMin || blackMin > excludeMax)
        {
            Debug.LogError("随机数范围异常！");
            return includeMin;
        }

        if (blackMax < blackMin || blackMax > excludeMax)
        {
            Debug.LogError("随机数范围异常！");
            return includeMin;
        }

        float random1 = Random.Range(includeMin, blackMin);
        float random2 = Random.Range(blackMax + Mathf.Epsilon, excludeMax);
        if (Random.Range(0, 2) == 0)
        {
            return random1;
        }
        else
        {
            return random2;
        }
    }


    /// <summary>
    /// 在一组权重中随机找一个索引
    /// </summary>
    /// <param name="weightArray">权重数组，需要递增</param>
    /// <returns></returns>
    public static int RandomIndex(int[] weightArray)
    {
        int allWeight = 0;
        for(int i = 0; i < weightArray.Length; i++)
        {
            allWeight += weightArray[i];
        }

        int randomWeight = Random.Range(0, allWeight);
        int index = 0;
        int tempWeight = 0;
        for(int i = 0; i < weightArray.Length; i++)
        {
            tempWeight += weightArray[i];
            if(tempWeight > randomWeight)
            {
                index = i;
                break;
            }
        }

        return index;
    }

    /// <summary>
    /// 在一组权重中随机找一个索引
    /// </summary>
    /// <param name="weightArray">权重数组，需要递增</param>
    /// <returns></returns>
    public static int RandomIndex(float[] weightArray)
    {
        float allWeight = 0;
        for (int i = 0; i < weightArray.Length; i++)
        {
            allWeight += weightArray[i];
        }

        float randomWeight = Random.Range(0, allWeight);
        int index = 0;
        float tempWeight = 0;
        for (int i = 0; i < weightArray.Length; i++)
        {
            tempWeight += weightArray[i];
            if (tempWeight > randomWeight)
            {
                index = i;
                break;
            }
        }

        return index;
    }
}

一般的权重用法：

csharp 复制代码

int[] randomNum = new int[] { -11, 999, 10, 66 };
int[] weight = new int[] { 5, 5, 10, 80 };

int[] test = new int[randomNum.Length];
for (int i = 0; i < 1000000; i++)
{
    int index = RandomTool.RandomIndex(weight);
    test[index]++;
}

for (int i = 0; i < test.Length; i++)
{
    Debug.Log($"{randomNum[i]}一共出现了{test[i]}次");
}