///////////////////////////////////////////////////////////////////////////
//
// 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:
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// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
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// in the documentation and/or other materials provided with the
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///////////////////////////////////////////////////////////////////////////
#include <testRandom.h>
#include "ImathRandom.h"
#include "ImathVec.h"
#include "ImathFun.h"
#include <iostream>
#include <iomanip>
#include <assert.h>
using namespace std;
using IMATH_INTERNAL_NAMESPACE::abs;
namespace {
void
testErand48 ()
{
//
// Our implementation of erand48(), nrand48(), etc.
// assumes that sizeof (unsigned short) == 2.
//
assert (sizeof (unsigned short) == 2);
//
// starting with a given seed, erand48() and nrand48()
// must generate the same sequence as the standard
// Unix/Linux functions.
//
unsigned short state[3];
state[0] = 0;
state[1] = 1;
state[2] = 2;
assert (abs (IMATH_INTERNAL_NAMESPACE::erand48 (state) - 0.671004) < 0.00001);
assert (abs (IMATH_INTERNAL_NAMESPACE::erand48 (state) - 0.786905) < 0.00001);
assert (abs (IMATH_INTERNAL_NAMESPACE::erand48 (state) - 0.316850) < 0.00001);
assert (abs (IMATH_INTERNAL_NAMESPACE::erand48 (state) - 0.384870) < 0.00001);
assert (abs (IMATH_INTERNAL_NAMESPACE::erand48 (state) - 0.854650) < 0.00001);
assert (IMATH_INTERNAL_NAMESPACE::nrand48 (state) == 0x4f4e8cb0);
assert (IMATH_INTERNAL_NAMESPACE::nrand48 (state) == 0x063e864b);
assert (IMATH_INTERNAL_NAMESPACE::nrand48 (state) == 0x2d10f1dd);
assert (IMATH_INTERNAL_NAMESPACE::nrand48 (state) == 0x1aadc122);
assert (IMATH_INTERNAL_NAMESPACE::nrand48 (state) == 0x1836a71f);
assert (state[0] == 0x2a42);
assert (state[1] == 0x4e3e);
assert (state[2] == 0x306d);
}
template <class Rand>
void
testGenerator ()
{
//
// Test if the values, and the differences between
// successive values, are evenly distributed.
//
const int N = 10;
const int M = 100000;
int values[N + 1];
int diffs[2 * N + 3];
int *v = &values[0];
int *d = &diffs[N + 2];
for (int i = 0; i <= N; ++i)
v[i] = 0;
for (int i = -N; i <= N; ++i)
d[i] = 0;
Rand rand (0);
float previous = 0;
for (int i = 0; i < M * N; ++i)
{
float r = rand.nextf (0.0, 1.0);
float diff = r - previous;
previous = r;
v[int (r * N)] += 1;
d[IMATH_INTERNAL_NAMESPACE::floor (diff * N + 0.5)] += 1;
}
cout << " values" << endl;
for (int i = 0; i < N; ++i)
{
// cout << setw (4) << i << ' ' << setw(6) << v[i] << ' ';
assert (abs (v[i] - M) < 0.01 * M);
// for (int j = 0; j < v[i] * 60 / M; ++j)
// cout << '*';
// cout << endl;
}
assert (v[N] == 0);
cout << " differences between successive values" << endl;
for (int i = -N; i <= N; ++i)
{
// cout << setw (4) << i << ' ' << setw (6) << d[i] << ' ';
assert (abs ((N - abs (i)) * M / N - d[i]) < 0.05 * M);
// for (int j = 0; j < d[i] * 60 / M; ++j)
// cout << '*';
// cout << endl;
}
cout << " range" << endl;
double rMin = 1.0;
double rMax = 0.0;
for (int i = 0; i <= 10000000; ++i)
{
double r = rand.nextf (0.0, 1.0);
if (rMin > r)
rMin = r;
if (rMax < r)
rMax = r;
}
assert (rMin < 0.0001 && rMax > 0.9999);
const double pow_2_60 = double (1073741824) * double (1073741824);
for (int i = 0; i <= 10000000; ++i)
{
double r0 = rand.nextf (-2.0, 3.0);
assert (r0 >= -2.0 && r0 <= 3.0);
double r1 = rand.nextf (-pow_2_60, 1);
assert (r1 >= -pow_2_60 && r1 <= 1);
double r2 = rand.nextf (-1, pow_2_60);
assert (r2 >= -1 && r2 <= pow_2_60);
}
}
template <class Rand>
void
testSolidSphere ()
{
const int N = 10;
const int M = 10000;
int v[N + 1];
for (int i = 0; i <= N; ++i)
v[i] = 0;
Rand rand (0);
for (int i = 0; i < M * N; ++i)
{
IMATH_INTERNAL_NAMESPACE::V3f p = IMATH_INTERNAL_NAMESPACE::solidSphereRand<IMATH_INTERNAL_NAMESPACE::V3f> (rand);
float l = p.length();
v[IMATH_INTERNAL_NAMESPACE::floor (l * N)] += 1;
assert (l < 1.00001);
}
for (int i = 0; i < N; ++i)
assert (v[i] > 0);
}
template <class Rand>
void
testHollowSphere ()
{
const int M = 100000;
Rand rand (0);
for (int i = 0; i < M; ++i)
{
IMATH_INTERNAL_NAMESPACE::V3f p = IMATH_INTERNAL_NAMESPACE::hollowSphereRand<IMATH_INTERNAL_NAMESPACE::V3f> (rand);
float l = p.length();
assert (abs (l - 1) < 0.00001);
}
}
} // namespace
void
testRandom ()
{
cout << "Testing random number generators" << endl;
cout << "erand48(), nrand48()" << endl;
testErand48();
cout << "Rand32" << endl;
testGenerator<IMATH_INTERNAL_NAMESPACE::Rand32>();
cout << "Rand48" << endl;
testGenerator<IMATH_INTERNAL_NAMESPACE::Rand48>();
cout << "solidSphereRand()" << endl;
testSolidSphere<IMATH_INTERNAL_NAMESPACE::Rand32>();
cout << "hollowSphereRand()" << endl;
testHollowSphere<IMATH_INTERNAL_NAMESPACE::Rand32>();
cout << "ok\n" << endl;
}