BizHawk/BizHawk.Common/Extensions/NumberExtensions.cs

141 lines
3.4 KiB
C#

#nullable disable
using System;
using System.Linq;
namespace BizHawk.Common.NumberExtensions
{
public static class NumberExtensions
{
public static string ToHexString(this int n, int numDigits)
{
return string.Format($"{{0:X{numDigits}}}", n);
}
public static string ToHexString(this uint n, int numDigits)
{
return string.Format($"{{0:X{numDigits}}}", n);
}
public static string ToHexString(this long n, int numDigits)
{
return string.Format($"{{0:X{numDigits}}}", n);
}
public static string ToHexString(this ulong n, int numDigits)
{
return string.Format($"{{0:X{numDigits}}}", n);
}
public static bool Bit(this byte b, int index)
{
return (b & (1 << index)) != 0;
}
public static bool Bit(this int b, int index)
{
return (b & (1 << index)) != 0;
}
public static bool Bit(this ushort b, int index)
{
return (b & (1 << index)) != 0;
}
public static bool In(this int i, params int[] options)
{
return options.Any(j => i == j);
}
public static byte BinToBCD(this byte v)
{
return (byte)(((v / 10) * 16) + (v % 10));
}
public static byte BCDtoBin(this byte v)
{
return (byte)(((v / 16) * 10) + (v % 16));
}
/// <summary>
/// Receives a number and returns the number of hexadecimal digits it is
/// Note: currently only returns 2, 4, 6, or 8
/// </summary>
public static int NumHexDigits(this long i)
{
// now this is a bit of a trick. if it was less than 0, it must have been >= 0x80000000 and so takes all 8 digits
if (i < 0)
{
return 8;
}
if (i < 0x100)
{
return 2;
}
if (i < 0x10000)
{
return 4;
}
if (i < 0x1000000)
{
return 6;
}
if (i < 0x100000000)
{
return 8;
}
return 16;
}
/// <summary>
/// The % operator is a remainder operator. (e.g. -1 mod 4 returns -1, not 3.)
/// </summary>
public static int Mod(this int a, int b)
{
return a - (b * (int)Math.Floor((float)a / b));
}
/// <summary>
/// Force the value to be strictly between min and max (both excluded)
/// </summary>
/// <typeparam name="T">Anything that implements <see cref="IComparable{T}"/></typeparam>
/// <param name="val">Value that will be clamped</param>
/// <param name="min">Minimum allowed</param>
/// <param name="max">Maximum allowed</param>
/// <returns>The value if strictly between min and max; otherwise min (or max depending of what is passed)</returns>
public static T Clamp<T>(this T val, T min, T max) where T : IComparable<T>
{
if (val.CompareTo(min) < 0)
{
return min;
}
if (val.CompareTo(max) > 0)
{
return max;
}
return val;
}
public static int RoundToInt(this float f) => (int) Math.Round(f);
/// <summary>2^-53</summary>
private const double ExtremelySmallNumber = 1.1102230246251565E-16;
/// <inheritdoc cref="HawkFloatEquality(float,float,float)"/>
public static bool HawkFloatEquality(this double d, double other, double ε = ExtremelySmallNumber) => Math.Abs(other - d) < ε;
/// <summary>2^-24</summary>
private const float ReallySmallNumber = 5.96046448E-08f;
/// <remarks>don't use this in cores without picking a suitable ε</remarks>
public static bool HawkFloatEquality(this float f, float other, float ε = ReallySmallNumber) => Math.Abs(other - f) < ε;
}
}