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/*==LICENSE==*
CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011 Cyan Worlds, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
You can contact Cyan Worlds, Inc. by email legal@cyan.com
or by snail mail at:
Cyan Worlds, Inc.
14617 N Newport Hwy
Mead, WA 99021
*==LICENSE==*/
#include "hsNoiseFunc.h"
#include "hsTypes.h"
#include "hsScalar.h"
#include "hsGeometry3.h"
hsNoiseFunc::hsNoiseFunc()
{
}
hsNoiseFunc::~hsNoiseFunc()
{
}
void hsNoiseFunc::Seed(UInt32 s)
{
srand(s);
}
hsTableNoise::hsTableNoise()
: fTable(nil), fTableLen(0)
{
}
hsTableNoise::~hsTableNoise()
{
delete [] fTable;
}
void hsTableNoise::SetTable(int len, hsScalar* arr)
{
fTableLen = len;
delete [] fTable;
if( !len )
{
fTable = nil;
return;
}
fTable = TRACKED_NEW hsScalar[len+2];
int i;
for( i = 0; i < len; i++ )
fTable[i] = arr[i];
fTable[i++] = fTable[i-1];
fTable[i++] = fTable[i-1];
}
hsScalar hsTableNoise::Noise(hsScalar lo, hsScalar hi, hsScalar t)
{
hsAssert(fTableLen, "Badly initialized table noise function");
hsScalar r = hsScalar(rand()) / hsScalar(RAND_MAX);
r = lo + (hi - lo) * r;
if( t < 0 )
t = 0;
else if( t > hsScalar1 )
t = hsScalar1;
hsScalar tIdx = t * fTableLen;
UInt32 idx = UInt32(tIdx);
hsScalar frac = tIdx - hsScalar(idx);
hsAssert((idx >= 0)&&(idx <= fTableLen), "Noise parm t out of range [0..1]");
hsScalar scale = fTable[idx] + (fTable[idx+1] - fTable[idx]) * frac;
r *= scale;
return r;
}
hsScalar hsTableNoise::NoisePoint(const hsPoint3& p, hsScalar lo, hsScalar hi, hsScalar t)
{
hsAssert(fTableLen, "Badly initialized table noise function");
UInt32 sX = *((UInt32*)&p.fX);
UInt32 sY = *((UInt32*)&p.fY);
UInt32 sZ = *((UInt32*)&p.fZ);
UInt32 sAll = ((((sX & 0x07800000) >> 16) | ((sX & 0x007fffff) >> 17)) << 20)
| ((((sY & 0x07800000) >> 16) | ((sY & 0x007fffff) >> 17)) << 10)
| ((((sZ & 0x07800000) >> 16) | ((sZ & 0x007fffff) >> 17)) );
const UInt32 kExp = 0x3f800000;
const UInt32 kMsk = 0x007fffff;
const UInt32 kA = 1665636L;
const UInt32 kC = 1013904223L;
UInt32 iR = kA * sAll + kC;
iR &= kMsk;
iR |= kExp;
hsScalar r = (*(float*)&iR) - 1.f;
r = lo + (hi - lo) * r;
if( t < 0 )
t = 0;
else if( t > hsScalar1 )
t = hsScalar1;
hsScalar tIdx = t * fTableLen;
UInt32 idx = UInt32(tIdx);
hsScalar frac = tIdx - hsScalar(idx);
hsAssert((idx >= 0)&&(idx <= fTableLen), "Noise parm t out of range [0..1]");
hsScalar scale = fTable[idx] + (fTable[idx+1] - fTable[idx]) * frac;
r *= scale;
return r;
}