Legacy:WUtils/WMath

<uscript> /////////////////////////////////////////////////////////////////////////////// // filename: wMath.uc // revision: 102 // authors: various UnrealWiki members (http://wiki.beyondunreal.com) // http://wiki.beyondunreal.com/WUtils ///////////////////////////////////////////////////////////////////////////////

class wMath extends Object;

/** Checks if a string is numeric */ static final function bool IsNumeric(coerce string Param, optional bool bPositiveOnly, optional bool bNoFloat) {

 local int p;

 p=0;
 while (Mid(Param, p, 1) == " ") p++;
 if (!bPositiveOnly) if (Mid(Param, p, 1) == "-") p++;
 while (Mid(Param, p, 1) >= "0" && Mid(Param, p, 1) <= "9" || (!bNoFloat && Mid(Param, p, 1) == ".")) p++;
 while (Mid(Param, p, 1) == " ") p++;
 if (Mid(Param, p) != "") return false;
 return true;

}

/** Check if a string is an int */ static final function bool IsInt(coerce string Param, optional bool bPositiveOnly) {

 return IsNumeric(param, bPositiveOnly, true);

}

/** Check if a string is an float (example: '3.14' -> true '3' -> true); */ static final function bool IsFloat(coerce string Param, optional bool bPositiveOnly) {

 return IsNumeric(param, bPositiveOnly, false);

}

/* Michaeel's CRC32 code

  http//wiki.beyondunreal.com/wiki/CRC32 */

/** This function needs to be called the first time you want to use CRC32 */ static final function CRC32Init(out int CrcTable[256]) {

 const CrcPolynomial = 0xedb88320;

 local int CrcValue;
 local int IndexBit;
 local int IndexEntry;
 
 for (IndexEntry = 0; IndexEntry < 256; IndexEntry++) 
 {
   CrcValue = IndexEntry;

   for (IndexBit = 8; IndexBit > 0; IndexBit--)
     if ((CrcValue & 1) != 0)
       CrcValue = (CrcValue >>> 1) ^ CrcPolynomial;
     else
       CrcValue = CrcValue >>> 1;
   
   CrcTable[IndexEntry] = CrcValue;
 }

}

/** Calculate the CRC32 checksum of Text */ static final function int CRC32(coerce string Text, int CrcTable[256]) {

 local int CrcValue;
 local int IndexChar;
 
 CrcValue = 0xffffffff;
 
 for (IndexChar = 0; IndexChar < Len(Text); IndexChar++)
   CrcValue = (CrcValue >>> 8) ^ CrcTable[Asc(Mid(Text, IndexChar, 1)) ^ (CrcValue & 0xff)];

 return CrcValue;

}

/** Calculate: C^D mod N */ static final function int PowerMod(int C, int D, int N) {

 local int f, g, j;
 if ( D % 2 == 0) 
 {
   G = 1;
   for (j = 1; j <= D/2; j++) 
   {
     F = (C*C) % N;
     G = (F*G) % N;
   }  
 } 
 else {
   G = C;
   for (j = 1; j <= D/2; j++) 
   {
     F = (C*C) % N;
     G = (F*G) % N;
   }
 }
 return g;

}

/* RSA Encode\Decode methods

  Written by El Muerte
  http//wiki.beyondunreal.com/wiki/RSA */

/** Calculate Greatest Common Divider */ static final private function int _RSAGCD(int e, int PHI) {

 local int great, a;
 if (e > PHI) 
 {
   while (e%PHI != 0) 
   {
     a = e%PHI;
     e = PHI;
     PHI = a;
   }
   great = PHI;
 }
 else {
   while (PHI%e != 0) 
   {
     a = PHI%e;
     PHI = e;
     e = a;
   }
   great = e;
 }
 return great;

}

/** Used to calculate the public key E

   P and Q are primes, P!=Q                    

   You need N=P*Q and E to encrYpt the message  */

static final function int RSAPublicKeygen(int p, int q) {

 local int PHI, E, great;
 PHI = (p-1)*(q-1);
 great = 0;
 E = 2;
 while (great != 1)
 {
   E = E+1;
   great = _RSAGCD(E, PHI);
 }
 return E;

}

/** PrivateKey is inverse of the Public key E.

   You need this key (and N) to decrypt the message */

static final function int RSAPrivateKeygen(int E, int p, int q) {

 local int PHI, u1, u2, u3, v1, v2, v3, t1, t2, t3, z;
 PHI = (p-1)*(q-1);
 u1 = 1;
 u2 = 0;
 u3 = PHI;
 v1 = 0;
 v2 = 1;
 v3 = E;
 while (v3 != 0) 
 {
    z = u3/v3;
    t1 = u1-z*v1;
    t2 = u2-z*v2;
    t3 = u3-z*v3;
    u1 = v1;
    u2 = v2;
    u3 = v3;
    v1 = t1;
    v2 = t2;
    v3 = t3;
 }
 if (u2 < 0) 
 {
   return u2 + PHI;
 } 
 else {
   return u2;
 }

}

static final function RSAEncode(coerce string data, int E, int N, out array<int> data2) {

 local int i, c;
 data2.length = len(data);
 for (i = 0; i < len(data); i++)
 {
   c = Asc(Mid(data,i,1));
   data2[i] = PowerMod(c,E,N);
 }

}

static final function string RSADecode(array<int> data, int D, int N) {

 local int i, C;
 local string result;
 for (i = 0; i < data.length; i++)
 {
   c = data[i];
   result = result$chr(PowerMod(c,D,N));
 }
 return result;

} </uscript>

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Comments

Tarquin: here's a few I've used that you might want to add:

<uscript> function float Sgn( float theValue ) { if( theValue == 0 ) return 0; return theValue / Abs(theValue); } // function modulo static final operator(18) float mod ( float A, float B ) { if( A % B >= 0 ) return A % B ; else return ( A % B ) + B ; } static final operator(24) bool divides ( float A , float B ) { //local float quotient ; //quotient = B / A ; if( int( B / A ) == B / A ) return true ; }

</uscript>