mirror of
https://github.com/tribes2/engine.git
synced 2026-01-19 19:24:45 +00:00
122 lines
2.7 KiB
C++
122 lines
2.7 KiB
C++
//-----------------------------------------------------------------------------
|
|
// V12 Engine
|
|
//
|
|
// Copyright (c) 2001 GarageGames.Com
|
|
// Portions Copyright (c) 2001 by Sierra Online, Inc.
|
|
//-----------------------------------------------------------------------------
|
|
|
|
#ifndef _MRANDOM_H_
|
|
#define _MRANDOM_H_
|
|
|
|
|
|
#ifndef _PLATFORM_H_
|
|
#include "Platform/platform.h"
|
|
#endif
|
|
|
|
|
|
//--------------------------------------
|
|
// Base class for random number generators
|
|
class MRandomGenerator
|
|
{
|
|
protected:
|
|
MRandomGenerator() {}
|
|
S32 mSeed;
|
|
|
|
public:
|
|
void setSeed();
|
|
S32 getSeed() { return mSeed; }
|
|
virtual void setSeed(S32 s) = 0;
|
|
|
|
virtual U32 randI( void ) = 0; // 0..2^31
|
|
virtual F32 randF( void ); // 0.0 .. 1.0 F32 generator
|
|
S32 randI(S32 i, S32 n); // i..n integer generator
|
|
F32 randF(F32 i, F32 n); // i..n F32 generator
|
|
};
|
|
|
|
|
|
//--------------------------------------
|
|
inline F32 MRandomGenerator::randF()
|
|
{
|
|
// default: multiply by 1/(2^31)
|
|
return F32(randI()) * F32(1.0/2147483647.0);
|
|
}
|
|
|
|
inline S32 MRandomGenerator::randI(S32 i, S32 n)
|
|
{
|
|
AssertFatal(i<=n, "MRandomGenerator::randi: inverted range.");
|
|
return (S32)(i + (randI() % (n - i + 1)) );
|
|
}
|
|
|
|
inline F32 MRandomGenerator::randF(F32 i, F32 n)
|
|
{
|
|
AssertFatal(i<=n, "MRandomGenerator::randf: inverted range.");
|
|
return (i + (n - i) * randF());
|
|
}
|
|
|
|
|
|
//--------------------------------------
|
|
// Linear Congruential Method, the "minimal standard generator"
|
|
// Fast, farly good random numbers (better than using rand)
|
|
// Park & Miller, 1988, Comm of the ACM, 31(10), pp. 1192-1201
|
|
class MRandomLCG : public MRandomGenerator
|
|
{
|
|
protected:
|
|
static const S32 msQuotient;
|
|
static const S32 msRemainder;
|
|
|
|
public:
|
|
MRandomLCG();
|
|
MRandomLCG(S32 s);
|
|
|
|
static void setGlobalRandSeed(U32 seed);
|
|
|
|
void setSeed(S32 s);
|
|
// using MRandomGenerator::randI;
|
|
S32 randI(S32 i, S32 n); // i..n integer generator
|
|
|
|
U32 randI( void );
|
|
|
|
};
|
|
|
|
// Solution to "using" problem.
|
|
inline S32 MRandomLCG::randI(S32 i, S32 n)
|
|
{
|
|
return( MRandomGenerator::randI(i,n) );
|
|
}
|
|
|
|
|
|
//--------------------------------------
|
|
// Fast, very good random numbers
|
|
//
|
|
// Period = 2^249
|
|
//
|
|
// Kirkpatrick, S., and E. Stoll, 1981; A Very Fast Shift-Register
|
|
// Sequence Random Number Generator, Journal of Computational Physics,
|
|
// V. 40.
|
|
//
|
|
// Maier, W.L., 1991; A Fast Pseudo Random Number Generator,
|
|
// Dr. Dobb's Journal, May, pp. 152 - 157
|
|
|
|
class MRandomR250: public MRandomGenerator
|
|
{
|
|
private:
|
|
U32 mBuffer[250];
|
|
S32 mIndex;
|
|
|
|
public:
|
|
MRandomR250();
|
|
MRandomR250(S32 s);
|
|
|
|
void setSeed(S32 s);
|
|
// using MRandomGenerator::randI;
|
|
U32 randI();
|
|
};
|
|
|
|
|
|
typedef MRandomLCG MRandom;
|
|
|
|
extern MRandomLCG gRandGen;
|
|
|
|
|
|
#endif //_MRANDOM_H_
|