mirror of
https://github.com/opencv/opencv.git
synced 2024-12-30 04:58:54 +08:00
399 lines
9.7 KiB
C++
399 lines
9.7 KiB
C++
///////////////////////////////////////////////////////////////////////////
|
|
//
|
|
// Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
|
|
// Digital Ltd. LLC
|
|
//
|
|
// All rights reserved.
|
|
//
|
|
// 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 Industrial Light & Magic 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 AND CONTRIBUTORS
|
|
// "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.
|
|
//
|
|
///////////////////////////////////////////////////////////////////////////
|
|
|
|
|
|
#ifndef INCLUDED_IMATHRANDOM_H
|
|
#define INCLUDED_IMATHRANDOM_H
|
|
|
|
//-----------------------------------------------------------------------------
|
|
//
|
|
// Generators for uniformly distributed pseudo-random numbers and
|
|
// functions that use those generators to generate numbers with
|
|
// non-uniform distributions:
|
|
//
|
|
// class Rand32
|
|
// class Rand48
|
|
// solidSphereRand()
|
|
// hollowSphereRand()
|
|
// gaussRand()
|
|
// gaussSphereRand()
|
|
//
|
|
// Note: class Rand48() calls erand48() and nrand48(), which are not
|
|
// available on all operating systems. For compatibility we include
|
|
// our own versions of erand48() and nrand48(). Our functions have
|
|
// been reverse-engineered from the corresponding Unix/Linux man page.
|
|
//
|
|
//-----------------------------------------------------------------------------
|
|
|
|
#include <stdlib.h>
|
|
#include <math.h>
|
|
|
|
namespace Imath {
|
|
|
|
//-----------------------------------------------
|
|
// Fast random-number generator that generates
|
|
// a uniformly distributed sequence with a period
|
|
// length of 2^32.
|
|
//-----------------------------------------------
|
|
|
|
class Rand32
|
|
{
|
|
public:
|
|
|
|
//------------
|
|
// Constructor
|
|
//------------
|
|
|
|
Rand32 (unsigned long int seed = 0);
|
|
|
|
|
|
//--------------------------------
|
|
// Re-initialize with a given seed
|
|
//--------------------------------
|
|
|
|
void init (unsigned long int seed);
|
|
|
|
|
|
//----------------------------------------------------------
|
|
// Get the next value in the sequence (range: [false, true])
|
|
//----------------------------------------------------------
|
|
|
|
bool nextb ();
|
|
|
|
|
|
//---------------------------------------------------------------
|
|
// Get the next value in the sequence (range: [0 ... 0xffffffff])
|
|
//---------------------------------------------------------------
|
|
|
|
unsigned long int nexti ();
|
|
|
|
|
|
//------------------------------------------------------
|
|
// Get the next value in the sequence (range: [0 ... 1[)
|
|
//------------------------------------------------------
|
|
|
|
float nextf ();
|
|
|
|
|
|
//-------------------------------------------------------------------
|
|
// Get the next value in the sequence (range [rangeMin ... rangeMax[)
|
|
//-------------------------------------------------------------------
|
|
|
|
float nextf (float rangeMin, float rangeMax);
|
|
|
|
|
|
private:
|
|
|
|
void next ();
|
|
|
|
unsigned long int _state;
|
|
};
|
|
|
|
|
|
//--------------------------------------------------------
|
|
// Random-number generator based on the C Standard Library
|
|
// functions erand48(), nrand48() & company; generates a
|
|
// uniformly distributed sequence.
|
|
//--------------------------------------------------------
|
|
|
|
class Rand48
|
|
{
|
|
public:
|
|
|
|
//------------
|
|
// Constructor
|
|
//------------
|
|
|
|
Rand48 (unsigned long int seed = 0);
|
|
|
|
|
|
//--------------------------------
|
|
// Re-initialize with a given seed
|
|
//--------------------------------
|
|
|
|
void init (unsigned long int seed);
|
|
|
|
|
|
//----------------------------------------------------------
|
|
// Get the next value in the sequence (range: [false, true])
|
|
//----------------------------------------------------------
|
|
|
|
bool nextb ();
|
|
|
|
|
|
//---------------------------------------------------------------
|
|
// Get the next value in the sequence (range: [0 ... 0x7fffffff])
|
|
//---------------------------------------------------------------
|
|
|
|
long int nexti ();
|
|
|
|
|
|
//------------------------------------------------------
|
|
// Get the next value in the sequence (range: [0 ... 1[)
|
|
//------------------------------------------------------
|
|
|
|
double nextf ();
|
|
|
|
|
|
//-------------------------------------------------------------------
|
|
// Get the next value in the sequence (range [rangeMin ... rangeMax[)
|
|
//-------------------------------------------------------------------
|
|
|
|
double nextf (double rangeMin, double rangeMax);
|
|
|
|
|
|
private:
|
|
|
|
unsigned short int _state[3];
|
|
};
|
|
|
|
|
|
//------------------------------------------------------------
|
|
// Return random points uniformly distributed in a sphere with
|
|
// radius 1 around the origin (distance from origin <= 1).
|
|
//------------------------------------------------------------
|
|
|
|
template <class Vec, class Rand>
|
|
Vec
|
|
solidSphereRand (Rand &rand);
|
|
|
|
|
|
//-------------------------------------------------------------
|
|
// Return random points uniformly distributed on the surface of
|
|
// a sphere with radius 1 around the origin.
|
|
//-------------------------------------------------------------
|
|
|
|
template <class Vec, class Rand>
|
|
Vec
|
|
hollowSphereRand (Rand &rand);
|
|
|
|
|
|
//-----------------------------------------------
|
|
// Return random numbers with a normal (Gaussian)
|
|
// distribution with zero mean and unit variance.
|
|
//-----------------------------------------------
|
|
|
|
template <class Rand>
|
|
float
|
|
gaussRand (Rand &rand);
|
|
|
|
|
|
//----------------------------------------------------
|
|
// Return random points whose distance from the origin
|
|
// has a normal (Gaussian) distribution with zero mean
|
|
// and unit variance.
|
|
//----------------------------------------------------
|
|
|
|
template <class Vec, class Rand>
|
|
Vec
|
|
gaussSphereRand (Rand &rand);
|
|
|
|
|
|
//---------------------------------
|
|
// erand48(), nrand48() and friends
|
|
//---------------------------------
|
|
|
|
double erand48 (unsigned short state[3]);
|
|
double drand48 ();
|
|
long int nrand48 (unsigned short state[3]);
|
|
long int lrand48 ();
|
|
void srand48 (long int seed);
|
|
|
|
|
|
//---------------
|
|
// Implementation
|
|
//---------------
|
|
|
|
|
|
inline void
|
|
Rand32::init (unsigned long int seed)
|
|
{
|
|
_state = (seed * 0xa5a573a5L) ^ 0x5a5a5a5aL;
|
|
}
|
|
|
|
|
|
inline
|
|
Rand32::Rand32 (unsigned long int seed)
|
|
{
|
|
init (seed);
|
|
}
|
|
|
|
|
|
inline void
|
|
Rand32::next ()
|
|
{
|
|
_state = 1664525L * _state + 1013904223L;
|
|
}
|
|
|
|
|
|
inline bool
|
|
Rand32::nextb ()
|
|
{
|
|
next ();
|
|
// Return the 31st (most significant) bit, by and-ing with 2 ^ 31.
|
|
return !!(_state & 2147483648UL);
|
|
}
|
|
|
|
|
|
inline unsigned long int
|
|
Rand32::nexti ()
|
|
{
|
|
next ();
|
|
return _state & 0xffffffff;
|
|
}
|
|
|
|
|
|
inline float
|
|
Rand32::nextf (float rangeMin, float rangeMax)
|
|
{
|
|
float f = nextf();
|
|
return rangeMin * (1 - f) + rangeMax * f;
|
|
}
|
|
|
|
|
|
inline void
|
|
Rand48::init (unsigned long int seed)
|
|
{
|
|
seed = (seed * 0xa5a573a5L) ^ 0x5a5a5a5aL;
|
|
|
|
_state[0] = (unsigned short int) (seed & 0xFFFF);
|
|
_state[1] = (unsigned short int) ((seed >> 16) & 0xFFFF);
|
|
_state[2] = (unsigned short int) (seed & 0xFFFF);
|
|
}
|
|
|
|
|
|
inline
|
|
Rand48::Rand48 (unsigned long int seed)
|
|
{
|
|
init (seed);
|
|
}
|
|
|
|
|
|
inline bool
|
|
Rand48::nextb ()
|
|
{
|
|
return Imath::nrand48 (_state) & 1;
|
|
}
|
|
|
|
|
|
inline long int
|
|
Rand48::nexti ()
|
|
{
|
|
return Imath::nrand48 (_state);
|
|
}
|
|
|
|
|
|
inline double
|
|
Rand48::nextf ()
|
|
{
|
|
return Imath::erand48 (_state);
|
|
}
|
|
|
|
|
|
inline double
|
|
Rand48::nextf (double rangeMin, double rangeMax)
|
|
{
|
|
double f = nextf();
|
|
return rangeMin * (1 - f) + rangeMax * f;
|
|
}
|
|
|
|
|
|
template <class Vec, class Rand>
|
|
Vec
|
|
solidSphereRand (Rand &rand)
|
|
{
|
|
Vec v;
|
|
|
|
do
|
|
{
|
|
for (unsigned int i = 0; i < Vec::dimensions(); i++)
|
|
v[i] = (typename Vec::BaseType) rand.nextf (-1, 1);
|
|
}
|
|
while (v.length2() > 1);
|
|
|
|
return v;
|
|
}
|
|
|
|
|
|
template <class Vec, class Rand>
|
|
Vec
|
|
hollowSphereRand (Rand &rand)
|
|
{
|
|
Vec v;
|
|
typename Vec::BaseType length;
|
|
|
|
do
|
|
{
|
|
for (unsigned int i = 0; i < Vec::dimensions(); i++)
|
|
v[i] = (typename Vec::BaseType) rand.nextf (-1, 1);
|
|
|
|
length = v.length();
|
|
}
|
|
while (length > 1 || length == 0);
|
|
|
|
return v / length;
|
|
}
|
|
|
|
|
|
template <class Rand>
|
|
float
|
|
gaussRand (Rand &rand)
|
|
{
|
|
float x; // Note: to avoid numerical problems with very small
|
|
float y; // numbers, we make these variables singe-precision
|
|
float length2; // floats, but later we call the double-precision log()
|
|
// and sqrt() functions instead of logf() and sqrtf().
|
|
do
|
|
{
|
|
x = float (rand.nextf (-1, 1));
|
|
y = float (rand.nextf (-1, 1));
|
|
length2 = x * x + y * y;
|
|
}
|
|
while (length2 >= 1 || length2 == 0);
|
|
|
|
return x * sqrt (-2 * log (double (length2)) / length2);
|
|
}
|
|
|
|
|
|
template <class Vec, class Rand>
|
|
Vec
|
|
gaussSphereRand (Rand &rand)
|
|
{
|
|
return hollowSphereRand <Vec> (rand) * gaussRand (rand);
|
|
}
|
|
|
|
} // namespace Imath
|
|
|
|
#endif
|