好的,这是我针对定点结构提出的,基于我最初问题中的链接,但还包括一些对它如何处理除法和乘法的修正,并为模块,比较,移位等添加了逻辑:
public struct FInt{ public long RawValue; public const int SHIFT_AMOUNT = 12; //12 is 4096 public const long One = 1 << SHIFT_AMOUNT; public const int oneI = 1 << SHIFT_AMOUNT; public static FInt oneF = FInt.Create( 1, true ); #region Constructors public static FInt Create( long StartingRawValue, bool UseMultiple ) { FInt fInt; fInt.RawValue = StartingRawValue; if ( UseMultiple ) fInt.RawValue = fInt.RawValue << SHIFT_AMOUNT; return fInt; } public static FInt Create( double Doublevalue ) { FInt fInt; Doublevalue *= (double)One; fInt.RawValue = (int)Math.Round( Doublevalue ); return fInt; } #endregion public int IntValue { get { return (int)( this.RawValue >> SHIFT_AMOUNT ); } } public int ToInt() { return (int)( this.RawValue >> SHIFT_AMOUNT ); } public double ToDouble() { return (double)this.RawValue / (double)One; } public FInt Inverse { get { return FInt.Create( -this.RawValue, false ); } } #region FromParts /// <summary> /// Create a fixed-int number from parts. For example, to create 1.5 pass in 1 and 500. /// </summary> /// <param name="PreDecimal">The number above the decimal. For 1.5, this would be 1.</param> /// <param name="PostDecimal">The number below the decimal, to three digits. /// For 1.5, this would be 500. For 1.005, this would be 5.</param> /// <returns>A fixed-int representation of the number parts</returns> public static FInt FromParts( int PreDecimal, int PostDecimal ) { FInt f = FInt.Create( PreDecimal, true ); if ( PostDecimal != 0 ) f.RawValue += ( FInt.Create( PostDecimal ) / 1000 ).RawValue; return f; } #endregion #region * public static FInt operator *( FInt one, FInt other ) { FInt fInt; fInt.RawValue = ( one.RawValue * other.RawValue ) >> SHIFT_AMOUNT; return fInt; } public static FInt operator *( FInt one, int multi ) { return one * (FInt)multi; } public static FInt operator *( int multi, FInt one ) { return one * (FInt)multi; } #endregion #region / public static FInt operator /( FInt one, FInt other ) { FInt fInt; fInt.RawValue = ( one.RawValue << SHIFT_AMOUNT ) / ( other.RawValue ); return fInt; } public static FInt operator /( FInt one, int divisor ) { return one / (FInt)divisor; } public static FInt operator /( int divisor, FInt one ) { return (FInt)divisor / one; } #endregion #region % public static FInt operator %( FInt one, FInt other ) { FInt fInt; fInt.RawValue = ( one.RawValue ) % ( other.RawValue ); return fInt; } public static FInt operator %( FInt one, int divisor ) { return one % (FInt)divisor; } public static FInt operator %( int divisor, FInt one ) { return (FInt)divisor % one; } #endregion #region + public static FInt operator +( FInt one, FInt other ) { FInt fInt; fInt.RawValue = one.RawValue + other.RawValue; return fInt; } public static FInt operator +( FInt one, int other ) { return one + (FInt)other; } public static FInt operator +( int other, FInt one ) { return one + (FInt)other; } #endregion #region - public static FInt operator -( FInt one, FInt other ) { FInt fInt; fInt.RawValue = one.RawValue - other.RawValue; return fInt; } public static FInt operator -( FInt one, int other ) { return one - (FInt)other; } public static FInt operator -( int other, FInt one ) { return (FInt)other - one; } #endregion #region == public static bool operator ==( FInt one, FInt other ) { return one.RawValue == other.RawValue; } public static bool operator ==( FInt one, int other ) { return one == (FInt)other; } public static bool operator ==( int other, FInt one ) { return (FInt)other == one; } #endregion #region != public static bool operator !=( FInt one, FInt other ) { return one.RawValue != other.RawValue; } public static bool operator !=( FInt one, int other ) { return one != (FInt)other; } public static bool operator !=( int other, FInt one ) { return (FInt)other != one; } #endregion #region >= public static bool operator >=( FInt one, FInt other ) { return one.RawValue >= other.RawValue; } public static bool operator >=( FInt one, int other ) { return one >= (FInt)other; } public static bool operator >=( int other, FInt one ) { return (FInt)other >= one; } #endregion #region <= public static bool operator <=( FInt one, FInt other ) { return one.RawValue <= other.RawValue; } public static bool operator <=( FInt one, int other ) { return one <= (FInt)other; } public static bool operator <=( int other, FInt one ) { return (FInt)other <= one; } #endregion #region > public static bool operator >( FInt one, FInt other ) { return one.RawValue > other.RawValue; } public static bool operator >( FInt one, int other ) { return one > (FInt)other; } public static bool operator >( int other, FInt one ) { return (FInt)other > one; } #endregion #region < public static bool operator <( FInt one, FInt other ) { return one.RawValue < other.RawValue; } public static bool operator <( FInt one, int other ) { return one < (FInt)other; } public static bool operator <( int other, FInt one ) { return (FInt)other < one; } #endregion public static explicit operator int( FInt src ) { return (int)( src.RawValue >> SHIFT_AMOUNT ); } public static explicit operator FInt( int src ) { return FInt.Create( src, true ); } public static explicit operator FInt( long src ) { return FInt.Create( src, true ); } public static explicit operator FInt( ulong src ) { return FInt.Create( (long)src, true ); } public static FInt operator <<( FInt one, int Amount ) { return FInt.Create( one.RawValue << Amount, false ); } public static FInt operator >>( FInt one, int Amount ) { return FInt.Create( one.RawValue >> Amount, false ); } public override bool Equals( object obj ) { if ( obj is FInt ) return ( (FInt)obj ).RawValue == this.RawValue; else return false; } public override int GetHashCode() { return RawValue.GetHashCode(); } public override string ToString() { return this.RawValue.ToString(); }}public struct FPoint{ public FInt X; public FInt Y; public static FPoint Create( FInt X, FInt Y ) { FPoint fp; fp.X = X; fp.Y = Y; return fp; } public static FPoint FromPoint( Point p ) { FPoint f; f.X = (FInt)p.X; f.Y = (FInt)p.Y; return f; } public static Point ToPoint( FPoint f ) { return new Point( f.X.IntValue, f.Y.IntValue ); } #region Vector Operations public static FPoint VectorAdd( FPoint F1, FPoint F2 ) { FPoint result; result.X = F1.X + F2.X; result.Y = F1.Y + F2.Y; return result; } public static FPoint VectorSubtract( FPoint F1, FPoint F2 ) { FPoint result; result.X = F1.X - F2.X; result.Y = F1.Y - F2.Y; return result; } public static FPoint VectorDivide( FPoint F1, int Divisor ) { FPoint result; result.X = F1.X / Divisor; result.Y = F1.Y / Divisor; return result; } #endregion}根据ShuggyCoUk的评论,我看到它是Q12格式的。就我的目的而言,这相当准确。当然,除了错误修复之外,在提出问题之前,我已经具有此基本格式。我正在寻找的是使用这样的结构在C#中计算Sqrt,Atan2,Sin和Cos的方法。我在C#中没有其他可以解决此问题的方法,但是在Java中,我设法通过Onno
Hommes
找到了MathFP库。这是一个自由源代码软件许可证,因此我已经将他的某些功能转换为我在C#中的用途(我认为已修复了atan2)。请享用:
#region PI, DoublePI public static FInt PI = FInt.Create( 12868, false ); //PI x 2^12 public static FInt TwoPIF = PI * 2; //radian equivalent of 260 degrees public static FInt PIOver180F = PI / (FInt)180; //PI / 180 #endregion #region Sqrt public static FInt Sqrt( FInt f, int NumberOfIterations ) { if ( f.RawValue < 0 ) //NaN in Math.Sqrt throw new ArithmeticException( "Input Error" ); if ( f.RawValue == 0 ) return (FInt)0; FInt k = f + FInt.oneF >> 1; for ( int i = 0; i < NumberOfIterations; i++ ) k = ( k + ( f / k ) ) >> 1; if ( k.RawValue < 0 ) throw new ArithmeticException( "Overflow" ); else return k; } public static FInt Sqrt( FInt f ) { byte numberOfIterations = 8; if ( f.RawValue > 0x64000 ) numberOfIterations = 12; if ( f.RawValue > 0x3e8000 ) numberOfIterations = 16; return Sqrt( f, numberOfIterations ); } #endregion #region Sin public static FInt Sin( FInt i ) { FInt j = (FInt)0; for ( ; i < 0; i += FInt.Create( 25736, false ) ) ; if ( i > FInt.Create( 25736, false ) ) i %= FInt.Create( 25736, false ); FInt k = ( i * FInt.Create( 10, false ) ) / FInt.Create( 714, false ); if ( i != 0 && i != FInt.Create( 6434, false ) && i != FInt.Create( 12868, false ) && i != FInt.Create( 19302, false ) && i != FInt.Create( 25736, false ) ) j = ( i * FInt.Create( 100, false ) ) / FInt.Create( 714, false ) - k * FInt.Create( 10, false ); if ( k <= FInt.Create( 90, false ) ) return sin_lookup( k, j ); if ( k <= FInt.Create( 180, false ) ) return sin_lookup( FInt.Create( 180, false ) - k, j ); if ( k <= FInt.Create( 270, false ) ) return sin_lookup( k - FInt.Create( 180, false ), j ).Inverse; else return sin_lookup( FInt.Create( 360, false ) - k, j ).Inverse; } private static FInt sin_lookup( FInt i, FInt j ) { if ( j > 0 && j < FInt.Create( 10, false ) && i < FInt.Create( 90, false ) ) return FInt.Create( SIN_TABLE[i.RawValue], false ) + ( ( FInt.Create( SIN_TABLE[i.RawValue + 1], false ) - FInt.Create( SIN_TABLE[i.RawValue], false ) ) / FInt.Create( 10, false ) ) * j; else return FInt.Create( SIN_TABLE[i.RawValue], false ); } private static int[] SIN_TABLE = { 0, 71, 142, 214, 285, 357, 428, 499, 570, 641, 711, 781, 851, 921, 990, 1060, 1128, 1197, 1265, 1333, 1400, 1468, 1534, 1600, 1665, 1730, 1795, 1859, 1922, 1985, 2048, 2109, 2170, 2230, 2290, 2349, 2407, 2464, 2521, 2577, 2632, 2686, 2740, 2793, 2845, 2896, 2946, 2995, 3043, 3091, 3137, 3183, 3227, 3271, 3313, 3355, 3395, 3434, 3473, 3510, 3547, 3582, 3616, 3649, 3681, 3712, 3741, 3770, 3797, 3823, 3849, 3872, 3895, 3917, 3937, 3956, 3974, 3991, 4006, 4020, 4033, 4045, 4056, 4065, 4073, 4080, 4086, 4090, 4093, 4095, 4096 }; #endregion private static FInt mul( FInt F1, FInt F2 ) { return F1 * F2; } #region Cos, Tan, Asin public static FInt Cos( FInt i ) { return Sin( i + FInt.Create( 6435, false ) ); } public static FInt Tan( FInt i ) { return Sin( i ) / Cos( i ); } public static FInt Asin( FInt F ) { bool isNegative = F < 0; F = Abs( F ); if ( F > FInt.oneF ) throw new ArithmeticException( "Bad Asin Input:" + F.ToDouble() ); FInt f1 = mul( mul( mul( mul( FInt.Create( 145103 >> FInt.SHIFT_AMOUNT, false ), F ) - FInt.Create( 599880 >> FInt.SHIFT_AMOUNT, false ), F ) + FInt.Create( 1420468 >> FInt.SHIFT_AMOUNT, false ), F ) - FInt.Create( 3592413 >> FInt.SHIFT_AMOUNT, false ), F ) + FInt.Create( 26353447 >> FInt.SHIFT_AMOUNT, false ); FInt f2 = PI / FInt.Create( 2, true ) - ( Sqrt( FInt.oneF - F ) * f1 ); return isNegative ? f2.Inverse : f2; } #endregion #region ATan, ATan2 public static FInt Atan( FInt F ) { return Asin( F / Sqrt( FInt.oneF + ( F * F ) ) ); } public static FInt Atan2( FInt F1, FInt F2 ) { if ( F2.RawValue == 0 && F1.RawValue == 0 ) return (FInt)0; FInt result = (FInt)0; if ( F2 > 0 ) result = Atan( F1 / F2 ); else if ( F2 < 0 ) { if ( F1 >= 0 ) result = ( PI - Atan( Abs( F1 / F2 ) ) ); else result = ( PI - Atan( Abs( F1 / F2 ) ) ).Inverse; } else result = ( F1 >= 0 ? PI : PI.Inverse ) / FInt.Create( 2, true ); return result; } #endregion #region Abs public static FInt Abs( FInt F ) { if ( F < 0 ) return F.Inverse; else return F; } #endregionHommes博士的MathFP库中还有许多其他函数,但是它们超出了我的需要,因此我没有花时间将它们转换为C#(由于他正在使用,这一过程变得更加困难。很长一段时间,而且我使用的是FInt结构,这使得转换规则很难立即看到)。
这些功能在此处进行编码的准确性对于我来说已经足够了,但是如果您需要更多功能,可以增加FInt上的SHIFT
AMOUNT。请注意,如果这样做,则需要将Hommes博士函数的常数除以4096,然后乘以新的SHIFT
AMOUNT所需的值。如果这样做并且不小心,很可能会遇到一些错误,因此请确保对内置的Math函数进行检查,以确保不会因错误地调整常数而推迟结果。
到目前为止,这种FInt逻辑似乎比内置的.net函数要快甚至快一点。这显然会因机器而异,因为fp协处理器会确定这一点,所以我没有运行特定的基准测试。但是它们现在已集成到我的游戏中,与以前相比,我发现处理器利用率略有下降(这是在Q6600四核上-
平均使用率下降了1%)。
再次感谢所有评论您的帮助的人。没有人直接向我指出我要寻找的东西,但是您给了我一些线索,帮助我自己在Google上找到了它。我希望这段代码对其他人有用,因为公开发布的C#中似乎没有可比的东西。



