代码语言：javascript复制
using UnityEngine;
using Random = UnityEngine.Random;
using System;
using System.Collections.Generic;
namespace SK.Framework
{
/// <summary>
/// 算术相关拓展
/// </summary>
public static class MathExtension
{
/// <summary>
/// 保留小数指定位数
/// </summary>
/// <param name="self">float值</param>
/// <param name="point">保留位置</param>
/// <returns>保留指定小数位数后的float值</returns>
public static float Round(this float self, int point)
{
int scale = 1;
for (int i = 0; i < point; i )
{
scale *= 10;
}
self *= scale;
return Mathf.Round(self) / scale;
}
/// <summary>
/// 判断是否约等于目标值
/// </summary>
/// <param name="self">float值</param>
/// <param name="targetValue">目标值</param>
/// <returns>若约等于则返回true,否则返回false</returns>
public static bool IsApproximately(this float self, float targetValue)
{
return Mathf.Approximately(self, targetValue);
}
/// <summary>
/// 阶乘
/// </summary>
/// <param name="self">int值</param>
/// <returns>阶乘结果</returns>
public static int Fact(this int self)
{
if (self == 0)
{
return 1;
}
else
{
return self * Fact(self - 1);
}
}
/// <summary>
/// 平方和根
/// </summary>
/// <param name="x">int值</param>
/// <param name="y">int值</param>
/// <returns>x与y的平方和根</returns>
public static float Sqrt(this int x, int y)
{
int n2 = x ^ 2 y ^ 2;
return Mathf.Sqrt(n2);
}
/// <summary>
/// 获取随机元素
/// </summary>
/// <typeparam name="T">元素类型</typeparam>
/// <param name="self">数组</param>
/// <returns>随机值</returns>
public static T GetRandomValue<T>(this T[] self)
{
return self[Random.Range(0, self.Length)];
}
/// <summary>
/// 获取随机元素
/// </summary>
/// <typeparam name="T">元素类型</typeparam>
/// <param name="self">列表</param>
/// <returns>随机值</returns>
public static T GetRandomValue<T>(this List<T> self)
{
return self[Random.Range(0, self.Count)];
}
/// <summary>
/// 获取指定个数随机元素
/// </summary>
/// <typeparam name="T">元素类型</typeparam>
/// <param name="self">数组</param>
/// <param name="count">个数</param>
/// <returns>元素数组</returns>
public static T[] GetRandomValue<T>(this T[] self, int count)
{
if (count > self.Length)
{
throw new ArgumentOutOfRangeException();
}
List<T> tempList = new List<T>(self.Length);
for (int i = 0; i < self.Length; i )
{
tempList.Add(self[i]);
}
T[] retArray = new T[count];
for (int i = 0; i < retArray.Length; i )
{
int index = Random.Range(0, tempList.Count);
retArray[i] = tempList[index];
tempList.RemoveAt(index);
}
return retArray;
}
/// <summary>
/// 获取指定个数随机元素
/// </summary>
/// <typeparam name="T">元素类型</typeparam>
/// <param name="self">列表</param>
/// <param name="count">个数</param>
/// <returns>元素数组</returns>
public static T[] GetRandomValue<T>(this List<T> self, int count)
{
if (count > self.Count)
{
throw new ArgumentOutOfRangeException();
}
List<T> tempList = new List<T>(self.Count);
for (int i = 0; i < self.Count; i )
{
tempList.Add(self[i]);
}
T[] retArray = new T[count];
for (int i = 0; i < retArray.Length; i )
{
int index = Random.Range(0, tempList.Count);
retArray[i] = tempList[index];
tempList.RemoveAt(index);
}
return retArray;
}
/// <summary>
/// 计算多边形周长
/// </summary>
/// <param name="self">多边形顶点数组</param>
/// <returns>周长</returns>
public static float GetPolygonPerimeter(this Vector3[] self)
{
if (self.Length < 3) return 0.0f;
float retV = 0f;
for (int i = 0; i < self.Length; i )
{
retV = Vector3.Distance(self[i], self[(i 1 < self.Length ? i 1 : 0)]);
}
return retV;
}
/// <summary>
/// 计算多边形周长
/// </summary>
/// <param name="self">多边形顶点列表</param>
/// <returns>周长</returns>
public static float GetPolygonPerimeter(this List<Vector3> self)
{
if (self.Count < 3) return 0.0f;
float retV = 0f;
for (int i = 0; i < self.Count; i )
{
retV = Vector3.Distance(self[i], self[(i 1 < self.Count ? i 1 : 0)]);
}
return retV;
}
/// <summary>
/// 计算多边形面积
/// </summary>
/// <param name="self">多边形顶点数组</param>
/// <returns>面积</returns>
public static float GetPolygonArea(this Vector3[] self)
{
if (self.Length < 3) return 0.0f;
float retV = self[0].z * (self[self.Length - 1].x - self[1].x);
for (int i = 1; i < self.Length; i )
{
retV = self[i].z * (self[i - 1].x - self[(i 1) % self.Length].x);
}
return Mathf.Abs(retV / 2.0f);
}
/// <summary>
/// 计算多边形面积
/// </summary>
/// <param name="self">多边形顶点列表</param>
/// <returns>面积</returns>
public static float GetPolygonArea(this List<Vector3> self)
{
if (self.Count < 3) return 0.0f;
float retV = self[0].z * (self[self.Count - 1].x - self[1].x);
for (int i = 1; i < self.Count; i )
{
retV = self[i].z * (self[i - 1].x - self[(i 1) % self.Count].x);
}
return Mathf.Abs(retV / 2.0f);
}
/// <summary>
/// 计算圆的周长
/// </summary>
/// <param name="self">半径</param>
/// <returns>周长</returns>
public static float GetCirclePerimeter(this float self)
{
return Mathf.PI * 2f * self;
}
/// <summary>
/// 计算圆的面积
/// </summary>
/// <param name="self">半径</param>
/// <returns>面积</returns>
public static float GetCircleArea(this float self)
{
return Mathf.PI * Mathf.Pow(self, 2);
}
/// <summary>
/// 三角函数计算对边的长度
/// </summary>
/// <param name="self">角度</param>
/// <param name="neighbouringSideLength">邻边的长度</param>
/// <returns>对边的长度</returns>
public static float GetFaceSideLength(this float self, float neighbouringSideLength)
{
return neighbouringSideLength * Mathf.Tan(self * Mathf.Deg2Rad);
}
/// <summary>
/// 三角函数计算邻边的长度
/// </summary>
/// <param name="self">角度</param>
/// <param name="faceSideLength">对边的长度</param>
/// <returns>邻边的长度</returns>
public static float GetNeighbouringSideLength(this float self, float faceSideLength)
{
return faceSideLength / Mathf.Tan(self * Mathf.Deg2Rad);
}
/// <summary>
/// 勾股定理计算斜边的长度
/// </summary>
/// <param name="self">直角边的长度</param>
/// <param name="anotherRightangleSideLength">另一条直角边的长度</param>
/// <returns>斜边的长度</returns>
public static float GetHypotenuseLength(this float self, float anotherRightangleSideLength)
{
return Mathf.Sqrt(Mathf.Pow(self, 2f) Mathf.Pow(anotherRightangleSideLength, 2f));
}
/// <summary>
/// 正弦
/// </summary>
/// <param name="self">角度</param>
/// <returns>正弦值</returns>
public static float Sin(this float self)
{
return Mathf.Sin(self * Mathf.Deg2Rad);
}
/// <summary>
/// 余弦
/// </summary>
/// <param name="self">角度</param>
/// <returns></returns>
public static float Cos(this float self)
{
return Mathf.Cos(self * Mathf.Deg2Rad);
}
/// <summary>
/// 正切
/// </summary>
/// <param name="self">角度</param>
/// <returns>正切值</returns>
public static float Tan(this float self)
{
return Mathf.Tan(self * Mathf.Deg2Rad);
}
/// <summary>
/// 反正弦
/// </summary>
/// <param name="self">正弦值</param>
/// <returns>角度</returns>
public static float ArcSin(this float self)
{
return Mathf.Asin(self) * Mathf.Rad2Deg;
}
/// <summary>
/// 反余弦
/// </summary>
/// <param name="self">余弦值</param>
/// <returns>角度</returns>
public static float ArcCos(this float self)
{
return Mathf.Acos(self) * Mathf.Rad2Deg;
}
/// <summary>
/// 反正切
/// </summary>
/// <param name="self">正切值</param>
/// <returns>角度</returns>
public static float ArcTan(this float self)
{
return Mathf.Atan(self) * Mathf.Rad2Deg;
}
/// <summary>
/// 度转弧度
/// </summary>
/// <param name="self">度</param>
/// <returns>弧度</returns>
public static float Deg2Rad(this float self)
{
return self * Mathf.Deg2Rad;
}
/// <summary>
/// 弧度转度
/// </summary>
/// <param name="self">弧度</param>
/// <returns>度</returns>
public static float Rad2Deg(this float self)
{
return self * Mathf.Rad2Deg;
}
}
}
