RandomGenerator Class Reference

#include <random_generator.hpp>

List of all members.

Public Member Functions
	RandomGenerator ()
	~RandomGenerator ()
int	srand (int x=0)
int	rand ()
int	rand (int v)
int	rand (int u, int v)
double	randf (double v)
double	randf (double u, double v)
int	rand1i (int v)
int	rand2i (int u, int v)
float	rand1f (float v)
float	rand2f (float u, float v)
void	initialize ()
void	srandom (unsigned long x)
long	random ()
Private Member Functions
	RandomGenerator (const RandomGenerator &)
RandomGenerator &	operator= (const RandomGenerator &)
Private Attributes
bool	initialized
long	degrees [MAX_TYPES]
long	seps [MAX_TYPES]
long	randtbl [DEG_3+1]
long *	fptr
long *	rptr
long *	state
long	rand_type
long	rand_deg
long	rand_sep
long *	end_ptr
int	debug
Static Private Attributes
static const int	TYPE_0 = 0
static const int	BREAK_0 = 8
static const int	DEG_0 = 0
static const int	SEP_0 = 0
static const int	TYPE_1 = 1
static const int	BREAK_1 = 32
static const int	DEG_1 = 7
static const int	SEP_1 = 3
static const int	TYPE_2 = 2
static const int	BREAK_2 = 64
static const int	DEG_2 = 15
static const int	SEP_2 = 1
static const int	TYPE_3 = 3
static const int	BREAK_3 = 128
static const int	DEG_3 = 31
static const int	SEP_3 = 3
static const int	TYPE_4 = 4
static const int	BREAK_4 = 256
static const int	DEG_4 = 63
static const int	SEP_4 = 1
static const int	MAX_TYPES = 5
static const int	rand_max = 0x7fffffff

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Detailed Description

Definition at line 37 of file random_generator.hpp.

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Constructor & Destructor Documentation

RandomGenerator::RandomGenerator

(

)

Definition at line 47 of file random_generator.cpp.

References debug, initialize(), and initialized.

                                 :
  initialized(),
  fptr(),
  rptr(),
  state(),
  rand_type(),
  rand_deg(),
  rand_sep(),
  end_ptr(),
  debug()
{
  assert(sizeof(int) >= 4);
  initialized = 0;
  debug = 0;                              // change this by hand for debug
  initialize();
}

RandomGenerator::~RandomGenerator

(

)

Definition at line 64 of file random_generator.cpp.

                                  {
}

RandomGenerator::RandomGenerator

(

const RandomGenerator &

)

[private]

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Member Function Documentation

int RandomGenerator::srand

(

int

x = 0

)

Definition at line 67 of file random_generator.cpp.

References debug, rand_max, and srandom().

Referenced by Main::init_rand(), scripting::play_demo(), and GameSession::restart_level().

                                   {
  int x0 = x;
  while (x <= 0)                          // random seed of zero means
    x = time(0) % RandomGenerator::rand_max; // randomize with time

  if (debug > 0)
    printf("==== srand(%10d) (%10d) rand_max=%x =====\n",
           x, x0, RandomGenerator::rand_max);

  RandomGenerator::srandom(x);
  return x;                               // let caller know seed used
}

int RandomGenerator::rand

(

)

Definition at line 80 of file random_generator.cpp.

References debug, and random().

Referenced by Stalactite::active_update(), Kugelblitz::active_update(), CloudParticleSystem::CloudParticleSystem(), CometParticleSystem::CometParticleSystem(), SkullTile::draw(), Candle::draw(), BrokenBrick::draw(), get_random_color(), GhostParticleSystem::GhostParticleSystem(), Kugelblitz::hit(), Dispenser::launch_badguy(), Particles::Particles(), RainParticleSystem::RainParticleSystem(), scripting::rand(), rand(), rand1i(), rand2i(), GameSession::restart_level(), SnowParticleSystem::SnowParticleSystem(), Mole::throw_rock(), Wind::update(), RainParticleSystem::update(), Player::update(), GhostParticleSystem::update(), CometParticleSystem::update(), and Zeekling::Zeekling().

                          {
  int rv;                                  // a positive int
  while ((rv = RandomGenerator::random()) <= 0) // neg or zero causes probs
    ;
  if (debug > 0)
    printf("==== rand(): %10d =====\n", rv);
  return rv;
}

int RandomGenerator::rand

(

int

v

)

Definition at line 89 of file random_generator.cpp.

References rand_max, and random().

                               {
  assert(v >= 0 && v <= RandomGenerator::rand_max); // illegal arg

  // remove biases, esp. when v is large (e.g. v == (rand_max/4)*3;)
  int rv, maxV =(RandomGenerator::rand_max / v) * v;
  assert(maxV <= RandomGenerator::rand_max);
  while ((rv = RandomGenerator::random()) >= maxV)
    ;
  return rv % v;                          // mod it down to 0..(maxV-1)
}

int RandomGenerator::rand	(	int	u,
		int	v
	)

Definition at line 100 of file random_generator.cpp.

References rand().

                                      {
  assert(v > u);
  return u + RandomGenerator::rand(v-u);
}

double RandomGenerator::randf

(

double

v

)

Definition at line 105 of file random_generator.cpp.

References debug, rand_max, and random().

Referenced by FlyingSnowBall::activate(), GhostTree::active_update(), FlyingSnowBall::active_update(), CloudParticleSystem::CloudParticleSystem(), Firefly::collision(), Stumpy::collision_squished(), PoisonIvy::collision_squished(), MrTree::collision_squished(), CometParticleSystem::CometParticleSystem(), Explosion::explode(), GhostParticleSystem::GhostParticleSystem(), LevelIntro::LevelIntro(), PulsingLight::PulsingLight(), RainParticleSystem::RainParticleSystem(), rand1f(), rand2f(), randf(), SkullyHop::set_state(), SnowParticleSystem::SnowParticleSystem(), LevelIntro::update(), Wind::update(), SnowParticleSystem::update(), Player::update(), and Fireworks::update().

                                      {
  float rv;
  do {
    rv = ((double)RandomGenerator::random())/RandomGenerator::rand_max * v;
  } while (rv >= v);                      // rounding might cause rv==v

  if (debug > 0)
    printf("==== rand(): %f =====\n", rv);
  return rv;
}

double RandomGenerator::randf	(	double	u,
		double	v
	)

Definition at line 116 of file random_generator.cpp.

References randf().

                                                {
  return u + RandomGenerator::randf(v-u);
}

int RandomGenerator::rand1i

(

int

v

)

[inline]

Definition at line 108 of file random_generator.hpp.

References rand().

{ return rand(v); }

int RandomGenerator::rand2i	(	int	u,
		int	v
	)			[inline]

Definition at line 109 of file random_generator.hpp.

References rand().

{ return rand(u, v); }

float RandomGenerator::rand1f

(

float

v

)

[inline]

Definition at line 110 of file random_generator.hpp.

References randf().

  { return static_cast<float>(randf(static_cast<double>(v))); }

float RandomGenerator::rand2f	(	float	u,
		float	v
	)			[inline]

Definition at line 112 of file random_generator.hpp.

References randf().

  { return static_cast<float>(randf(static_cast<double>(u),
                                    static_cast<double>(v))); }

void RandomGenerator::initialize

(

)

Definition at line 200 of file random_generator.cpp.

References DEG_0, DEG_1, DEG_2, DEG_3, DEG_4, degrees, end_ptr, fptr, rand_deg, rand_sep, rand_type, randtbl, rptr, SEP_0, SEP_1, SEP_2, SEP_3, SEP_4, seps, state, and TYPE_3.

Referenced by RandomGenerator().

                                 {

#define NSHUFF 100      // To drop part of seed -> 1st value correlation

  //static long degrees[MAX_TYPES] = { DEG_0, DEG_1, DEG_2, DEG_3, DEG_4 };
  //static long seps [MAX_TYPES] = { SEP_0, SEP_1, SEP_2, SEP_3, SEP_4 };

  degrees[0] = DEG_0;
  degrees[1] = DEG_1;
  degrees[2] = DEG_2;
  degrees[3] = DEG_3;
  degrees[4] = DEG_4;

  seps [0] = SEP_0;
  seps [1] = SEP_1;
  seps [2] = SEP_2;
  seps [3] = SEP_3;
  seps [4] = SEP_4;

  //
  // Initially, everything is set up as if from:
  //
  //  initstate(1, randtbl, 128);
  //
  // Note that this initialization takes advantage of the fact that srandom()
  // advances the front and rear pointers 10*rand_deg times, and hence the
  // rear pointer which starts at 0 will also end up at zero; thus the zeroeth
  // element of the state information, which contains info about the current
  // position of the rear pointer is just
  //
  //  MAX_TYPES * (rptr - state) + TYPE_3 == TYPE_3.

  randtbl[ 0] =  TYPE_3;
  randtbl[ 1] =  0x991539b1;
  randtbl[ 2] =  0x16a5bce3;
  randtbl[ 3] =  0x6774a4cd;
  randtbl[ 4] =  0x3e01511e;
  randtbl[ 5] =  0x4e508aaa;
  randtbl[ 6] =  0x61048c05;
  randtbl[ 7] =  0xf5500617;
  randtbl[ 8] =  0x846b7115;
  randtbl[ 9] =  0x6a19892c;
  randtbl[10] =  0x896a97af;
  randtbl[11] =  0xdb48f936;
  randtbl[12] =  0x14898454;
  randtbl[13] =  0x37ffd106;
  randtbl[14] =  0xb58bff9c;
  randtbl[15] =  0x59e17104;
  randtbl[16] =  0xcf918a49;
  randtbl[17] =  0x09378c83;
  randtbl[18] =  0x52c7a471;
  randtbl[19] =  0x8d293ea9;
  randtbl[20] =  0x1f4fc301;
  randtbl[21] =  0xc3db71be;
  randtbl[22] =  0x39b44e1c;
  randtbl[23] =  0xf8a44ef9;
  randtbl[24] =  0x4c8b80b1;
  randtbl[25] =  0x19edc328;
  randtbl[26] =  0x87bf4bdd;
  randtbl[27] =  0xc9b240e5;
  randtbl[28] =  0xe9ee4b1b;
  randtbl[29] =  0x4382aee7;
  randtbl[30] =  0x535b6b41;
  randtbl[31] =  0xf3bec5da;

  // static long randtbl[DEG_3 + 1] =
  // {
  //   TYPE_3;
  //   0x991539b1, 0x16a5bce3, 0x6774a4cd, 0x3e01511e, 0x4e508aaa, 0x61048c05,
  //   0xf5500617, 0x846b7115, 0x6a19892c, 0x896a97af, 0xdb48f936, 0x14898454,
  //   0x37ffd106, 0xb58bff9c, 0x59e17104, 0xcf918a49, 0x09378c83, 0x52c7a471,
  //   0x8d293ea9, 0x1f4fc301, 0xc3db71be, 0x39b44e1c, 0xf8a44ef9, 0x4c8b80b1,
  //   0x19edc328, 0x87bf4bdd, 0xc9b240e5, 0xe9ee4b1b, 0x4382aee7, 0x535b6b41,
  //   0xf3bec5da
  // };

  //
  // fptr and rptr are two pointers into the state info, a front and a rear
  // pointer.  These two pointers are always rand_sep places aparts, as they
  // cycle cyclically through the state information.  (Yes, this does mean we
  // could get away with just one pointer, but the code for random() is more
  // efficient this way).  The pointers are left positioned as they would be
  // from the call
  //
  //  initstate(1, randtbl, 128);
  //
  // (The position of the rear pointer, rptr, is really 0 (as explained above
  // in the initialization of randtbl) because the state table pointer is set
  // to point to randtbl[1] (as explained below).
  //

  fptr = &randtbl[SEP_3 + 1];
  rptr = &randtbl[1];

  //
  // The following things are the pointer to the state information table, the
  // type of the current generator, the degree of the current polynomial being
  // used, and the separation between the two pointers.  Note that for efficiency
  // of random(), we remember the first location of the state information, not
  // the zeroeth.  Hence it is valid to access state[-1], which is used to
  // store the type of the R.N.G.  Also, we remember the last location, since
  // this is more efficient than indexing every time to find the address of
  // the last element to see if the front and rear pointers have wrapped.
  //

  state = &randtbl[1];
  rand_type = TYPE_3;
  rand_deg = DEG_3;
  rand_sep = SEP_3;
  end_ptr = &randtbl[DEG_3 + 1];

}

void RandomGenerator::srandom

(

unsigned long

x

)

Definition at line 347 of file random_generator.cpp.

References fptr, good_rand(), initialized, NSHUFF, rand_deg, rand_sep, rand_type, random(), rptr, state, and TYPE_0.

Referenced by srand().

{
  long i, lim;

  state[0] = x;
  if (rand_type == TYPE_0)
    lim = NSHUFF;
  else
  {
    for (i = 1; i < rand_deg; i++) state[i] = good_rand(state[i - 1]);
    fptr = &state[rand_sep];
    rptr = &state[0];
    lim = 10 * rand_deg;
  }

  initialized = 1;
  for (i = 0; i < lim; i++) random();
}

long RandomGenerator::random

(

)

Definition at line 564 of file random_generator.cpp.

References end_ptr, fptr, good_rand(), initialized, rand_type, rptr, and TYPE_0.

Referenced by rand(), randf(), and srandom().

{
  long i;
  long *f, *r;
  if (!initialized) {
    throw std::runtime_error("uninitialized RandomGenerator object");
  }

  if (rand_type == TYPE_0)
  {
    i = state[0];
    state[0] = i = (good_rand(i)) & 0x7fffffff;
  }
  else
  {
    f = fptr; r = rptr;
    *f += *r;
    i = (*f >> 1) & 0x7fffffff; // Chucking least random bit
    if (++f >= end_ptr)
    {
      f = state;
      ++r;
    }
    else if (++r >= end_ptr)
      r = state;

    fptr = f; rptr = r;
  }

  return i;
}

RandomGenerator& RandomGenerator::operator=

(

const RandomGenerator &

)

[private]

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Member Data Documentation

const int RandomGenerator::TYPE_0 = 0 [static, private]

Definition at line 42 of file random_generator.hpp.

Referenced by random(), and srandom().

const int RandomGenerator::BREAK_0 = 8 [static, private]

Definition at line 43 of file random_generator.hpp.

const int RandomGenerator::DEG_0 = 0 [static, private]

Definition at line 44 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::SEP_0 = 0 [static, private]

Definition at line 45 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::TYPE_1 = 1 [static, private]

Definition at line 47 of file random_generator.hpp.

const int RandomGenerator::BREAK_1 = 32 [static, private]

Definition at line 48 of file random_generator.hpp.

const int RandomGenerator::DEG_1 = 7 [static, private]

Definition at line 49 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::SEP_1 = 3 [static, private]

Definition at line 50 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::TYPE_2 = 2 [static, private]

Definition at line 52 of file random_generator.hpp.

const int RandomGenerator::BREAK_2 = 64 [static, private]

Definition at line 53 of file random_generator.hpp.

const int RandomGenerator::DEG_2 = 15 [static, private]

Definition at line 54 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::SEP_2 = 1 [static, private]

Definition at line 55 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::TYPE_3 = 3 [static, private]

Definition at line 57 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::BREAK_3 = 128 [static, private]

Definition at line 58 of file random_generator.hpp.

const int RandomGenerator::DEG_3 = 31 [static, private]

Definition at line 59 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::SEP_3 = 3 [static, private]

Definition at line 60 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::TYPE_4 = 4 [static, private]

Definition at line 62 of file random_generator.hpp.

const int RandomGenerator::BREAK_4 = 256 [static, private]

Definition at line 63 of file random_generator.hpp.

const int RandomGenerator::DEG_4 = 63 [static, private]

Definition at line 64 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::SEP_4 = 1 [static, private]

Definition at line 65 of file random_generator.hpp.

Referenced by initialize().

const int RandomGenerator::MAX_TYPES = 5 [static, private]

Definition at line 67 of file random_generator.hpp.

bool RandomGenerator::initialized [private]

Definition at line 69 of file random_generator.hpp.

Referenced by random(), RandomGenerator(), and srandom().

long RandomGenerator::degrees[MAX_TYPES] [private]

Definition at line 70 of file random_generator.hpp.

Referenced by initialize().

long RandomGenerator::seps[MAX_TYPES] [private]

Definition at line 71 of file random_generator.hpp.

Referenced by initialize().

long RandomGenerator::randtbl[DEG_3+1] [private]

Definition at line 72 of file random_generator.hpp.

Referenced by initialize().

long* RandomGenerator::fptr [private]

Definition at line 74 of file random_generator.hpp.

Referenced by initialize(), random(), and srandom().

long* RandomGenerator::rptr [private]

Definition at line 75 of file random_generator.hpp.

Referenced by initialize(), random(), and srandom().

long* RandomGenerator::state [private]

Definition at line 77 of file random_generator.hpp.

Referenced by initialize(), and srandom().

long RandomGenerator::rand_type [private]

Definition at line 78 of file random_generator.hpp.

Referenced by initialize(), random(), and srandom().

long RandomGenerator::rand_deg [private]

Definition at line 79 of file random_generator.hpp.

Referenced by initialize(), and srandom().

long RandomGenerator::rand_sep [private]

Definition at line 80 of file random_generator.hpp.

Referenced by initialize(), and srandom().

long* RandomGenerator::end_ptr [private]

Definition at line 81 of file random_generator.hpp.

Referenced by initialize(), and random().

int RandomGenerator::debug [private]

Definition at line 82 of file random_generator.hpp.

Referenced by rand(), randf(), RandomGenerator(), and srand().

const int RandomGenerator::rand_max = 0x7fffffff [static, private]

Definition at line 83 of file random_generator.hpp.

Referenced by rand(), randf(), and srand().

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The documentation for this class was generated from the following files:

• src/math/random_generator.hpp
• src/math/random_generator.cpp

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