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//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of NVIDIA CORPORATION nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Copyright (c) 2008-2018 NVIDIA Corporation. All rights reserved.
// Copyright (c) 2004-2008 AGEIA Technologies, Inc. All rights reserved.
// Copyright (c) 2001-2004 NovodeX AG. All rights reserved.
#include "PxTkRandom.h"
#include "foundation/PxQuat.h"
using namespace physx;
using namespace PxToolkit;
static RandomR250 gRandomR250(0x95d6739b);
PxVec3 BasicRandom::unitRandomPt()
{
PxVec3 v;
do
{
v.x = randomFloat();
v.y = randomFloat();
v.z = randomFloat();
}
while(v.normalize()<1e-6f);
return v;
}
PxQuat BasicRandom::unitRandomQuat()
{
PxQuat v;
do
{
v.x = randomFloat();
v.y = randomFloat();
v.z = randomFloat();
v.w = randomFloat();
}
while(v.normalize()<1e-6f);
return v;
}
void BasicRandom::unitRandomPt(PxVec3& v)
{
v = unitRandomPt();
}
void BasicRandom::unitRandomQuat(PxQuat& v)
{
v = unitRandomQuat();
}
void PxToolkit::SetSeed(PxU32 seed)
{
gRandomR250.setSeed(seed);
}
PxU32 PxToolkit::Rand()
{
return gRandomR250.randI() & TEST_MAX_RAND;
}
RandomR250::RandomR250(PxI32 s)
{
setSeed(s);
}
void RandomR250::setSeed(PxI32 s)
{
BasicRandom lcg(s);
mIndex = 0;
PxI32 j;
for (j = 0; j < 250; j++) // fill r250 buffer with bit values
mBuffer[j] = lcg.randomize();
for (j = 0; j < 250; j++) // set some MSBs to 1
if ( lcg.randomize() > 0x40000000L )
mBuffer[j] |= 0x80000000L;
PxU32 msb = 0x80000000; // turn on diagonal bit
PxU32 mask = 0xffffffff; // turn off the leftmost bits
for (j = 0; j < 32; j++)
{
const PxI32 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;
}
}
PxU32 RandomR250::randI()
{
PxI32 j;
// wrap pointer around
if ( mIndex >= 147 ) j = mIndex - 147;
else j = mIndex + 103;
const PxU32 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;
}
PxReal RandomR250::randUnit()
{
PxU32 mask = (1<<23)-1;
return PxF32(randI()&(mask))/PxF32(mask);
}
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