156 lines
3.3 KiB
C++
Executable File
156 lines
3.3 KiB
C++
Executable File
//-----------------------------------------------------------------------------
|
|
// Torque Game Engine
|
|
// Copyright (C) GarageGames.com, Inc.
|
|
//-----------------------------------------------------------------------------
|
|
|
|
#include "platform/platform.h"
|
|
#include "platform/event.h"
|
|
#include "platform/gameInterface.h"
|
|
#include "math/mRandom.h"
|
|
|
|
MRandomLCG gRandGen;
|
|
U32 gRandGenSeed = 1376312589;
|
|
|
|
void MRandomLCG::setGlobalRandSeed(U32 seed)
|
|
{
|
|
if (Game->isJournalReading())
|
|
Game->journalRead(&gRandGenSeed);
|
|
else
|
|
{
|
|
gRandGenSeed = seed;
|
|
if (Game->isJournalWriting())
|
|
Game->journalWrite(gRandGenSeed);
|
|
}
|
|
|
|
//now actually set the seed
|
|
gRandGen.setSeed(gRandGenSeed);
|
|
}
|
|
|
|
static U32 msSeed = 1376312589;
|
|
|
|
inline U32 generateSeed()
|
|
{
|
|
// A very, VERY crude LCG but good enough to generate
|
|
// a nice range of seed values
|
|
msSeed = (msSeed * 0x015a4e35L) + 1;
|
|
msSeed = (msSeed>>16)&0x7fff;
|
|
return (msSeed);
|
|
}
|
|
|
|
//--------------------------------------
|
|
void MRandomGenerator::setSeed()
|
|
{
|
|
setSeed(generateSeed());
|
|
}
|
|
|
|
|
|
//--------------------------------------
|
|
const S32 MRandomLCG::msQuotient = S32_MAX / 16807L;
|
|
const S32 MRandomLCG::msRemainder = S32_MAX % 16807L;
|
|
|
|
|
|
//--------------------------------------
|
|
MRandomLCG::MRandomLCG()
|
|
{
|
|
setSeed(generateSeed());
|
|
}
|
|
|
|
MRandomLCG::MRandomLCG(S32 s)
|
|
{
|
|
setSeed(s);
|
|
}
|
|
|
|
|
|
//--------------------------------------
|
|
void MRandomLCG::setSeed(S32 s)
|
|
{
|
|
mSeed = s;
|
|
}
|
|
|
|
|
|
//--------------------------------------
|
|
U32 MRandomLCG::randI()
|
|
{
|
|
if ( mSeed <= msQuotient )
|
|
mSeed = (mSeed * 16807L) % S32_MAX;
|
|
else
|
|
{
|
|
S32 high_part = mSeed / msQuotient;
|
|
S32 low_part = mSeed % msQuotient;
|
|
|
|
S32 test = (16807L * low_part) - (msRemainder * high_part);
|
|
|
|
if ( test > 0 )
|
|
mSeed = test;
|
|
else
|
|
mSeed = test + S32_MAX;
|
|
|
|
}
|
|
return mSeed;
|
|
}
|
|
|
|
|
|
|
|
//--------------------------------------
|
|
MRandomR250::MRandomR250()
|
|
{
|
|
setSeed(generateSeed());
|
|
}
|
|
|
|
MRandomR250::MRandomR250(S32 s)
|
|
{
|
|
setSeed(s);
|
|
}
|
|
|
|
|
|
//--------------------------------------
|
|
void MRandomR250::setSeed(S32 s)
|
|
{
|
|
mSeed = s;
|
|
MRandomLCG lcg( s );
|
|
mIndex = 0;
|
|
|
|
S32 j;
|
|
for (j = 0; j < 250; j++) // fill r250 buffer with bit values
|
|
mBuffer[j] = lcg.randI();
|
|
|
|
for (j = 0; j < 250; j++) // set some MSBs to 1
|
|
if ( lcg.randI() > 0x40000000L )
|
|
mBuffer[j] |= 0x80000000L;
|
|
|
|
|
|
U32 msb = 0x80000000; // turn on diagonal bit
|
|
U32 mask = 0xffffffff; // turn off the leftmost bits
|
|
|
|
for (j = 0; j < 32; j++)
|
|
{
|
|
S32 k = 7 * j + 3; // select a word to operate on
|
|
mBuffer[k] &= mask; // turn off bits left of the diagonal
|
|
mBuffer[k] |= msb; // turn on the diagonal bit
|
|
mask >>= 1;
|
|
msb >>= 1;
|
|
}
|
|
}
|
|
|
|
|
|
//--------------------------------------
|
|
U32 MRandomR250::randI()
|
|
{
|
|
S32 j;
|
|
|
|
// wrap pointer around
|
|
if ( mIndex >= 147 ) j = mIndex - 147;
|
|
else j = mIndex + 103;
|
|
|
|
U32 new_rand = mBuffer[ mIndex ] ^ mBuffer[ j ];
|
|
mBuffer[ mIndex ] = new_rand;
|
|
|
|
// increment pointer for next time
|
|
if ( mIndex >= 249 ) mIndex = 0;
|
|
else mIndex++;
|
|
|
|
return new_rand >> 1;
|
|
}
|
|
|
|
|