暴击的伪随机算法--PRD算法【转载】

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
/*********************************************************
	文件：PRDCalcC
	作者：dell
	邮箱：630276388@qq.com
	日期：2020/9/3 9:19:06
	功能：计算PRD算法的C值
***********************************************************/
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using System.IO;
using System.Text;
using System.Threading;

public class PRDCalcC : EditorWindow
{
    private static readonly string obj = "lock";
    private static Dictionary<int, int> prdDic = new Dictionary<int, int>();
    private string infoStr = "";
    private string dataStr = "数据运算中....";

    [MenuItem("Tools/PRD_C")]
    static void ShowWindow()
    {
        GetWindow<PRDCalcC>();
    }

    private void OnGUI()
    {
        EditorGUILayout.BeginVertical();
        if (GUILayout.Button("运算数据"))
        {
            // 计算 1% - 100% 暴击率范围所有的 PRD C值
            for (int i = 0; i <= 100; ++i)
            {
                int j = i;
                // 创建线程负责具体计算 C 值
                Thread thread = new Thread(() =>
                {
                    double p = i * 1d / 100d; // 显示给玩家的暴击率
                    double c = CFromP(p); // PRD算法 暴击增量
                    int ic = (int)Math.Round(c * 100, 0); // 将百分数小数转换为整数
                    lock (obj)
                    {
                        prdDic[j] = ic; // 计算结果存放在字典中
                    }
                });
                thread.Start();
            }
        }
        GUILayout.Label(dataStr);
        if (prdDic.Count == 101)
        {
            dataStr = "数据运算完毕";
            if (GUILayout.Button("点击生成配置文件"))
            {
                try
                {
                    CreateXml();
                    infoStr = "配置文件生成成功！";
                }
                catch (Exception e)
                {
                    infoStr = "配置文件生成失败！错误为：" + e;
                }
            }
        }

        GUILayout.Label(infoStr);

        EditorGUILayout.EndVertical();
    }

    // 生成 XML 文件
    private void CreateXml()
    {
        string path = EditorUtility.OpenFolderPanel("选择目标文件夹", "", "") + @"/prd.xml";
        StringBuilder sb = new StringBuilder();
        sb.Append(@"<?xml version=""1.0"" encoding=""UTF - 8"" standalone=""yes""?>");
        sb.Append('n');
        sb.Append(@"<root xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"">");
        sb.Append('n');

        string xml = null;
        lock (obj)
        {
            // 在主线程中 从字典中拿出多线程放入的数据，进行解析
            foreach(var pair in prdDic)
            {
                sb.Append("<item>n");
                sb.Append("    <p>" + pair.Key + "</p>n");
                sb.Append("    <c>" + pair.Value + "</c>n");
                sb.Append("</item>n");
            }
            xml = sb.ToString();
            sb.Clear();
            xml.Remove(xml.Length - 1);
        }
        using(FileStream fs = Directory.Exists(path) ? File.OpenWrite(path) : File.Create(path))
        {
            byte[] bytes = Encoding.UTF8.GetBytes(xml);
            fs.Write(bytes, 0, bytes.Length);
            fs.Flush();
            fs.Close();
        }
        lock (obj)
        {
            prdDic.Clear();
        }
    }

    // 根据 传入 C 值，计算该C值下，最小暴击范围的平均暴击率
    private static double PFromC(double c)
    {
        double dCurP = 0d;
        double dPreSuccessP = 0d;
        double dPE = 0;
        int nMaxFail = (int)Math.Ceiling(1d / c);
        for (int i = 1; i <= nMaxFail; ++i)
        {
            dCurP = Math.Min(1d, i * c) * (1 - dPreSuccessP);
            dPreSuccessP += dCurP;
            dPE += i * dCurP;
        }
        return 1d / dPE;
    }

    // 根据传入的暴击率，计算 PRD 算法中的系数 C
    private static double CFromP(double p)
    {
        double dUp = p;
        double dLow = 0d;
        double dMid = p;
        double dPLast = 1d;
        while (true)
        {
            dMid = (dUp + dLow) / 2d;
            double dPtested = PFromC(dMid);

            if (Math.Abs(dPtested - dPLast) <= 0.00005d) break;

            if (dPtested > p) dUp = dMid;
            else dLow = dMid;

            dPLast = dPtested;
        }

        return dMid;
    }
}