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738fbc66d0
Before, this lua code led to a crash: local pcg = PcgRandom(42) local value = pcg:next() This was because if you called s32 PcgRandom::range(min, max) with the minimum and maximum possible values for s32 integers (which the lua binding code did), u32 PcgRandom::range(bound) got called with 0 as the bound. The bound however is one above the maximum value, so 0 is a "special" value to pass to this function. This commit fixes the lua crash by assigning the RNG's full range to the bound 0, which is also fits to the "maximum is bound - 1" principle, as (u32)-1 is the maximum value in the u32 range.
275 lines
10 KiB
C++
275 lines
10 KiB
C++
/*
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Minetest
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Copyright (C) 2010-2014 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License along
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with this program; if not, write to the Free Software Foundation, Inc.,
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51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "test.h"
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#include "util/numeric.h"
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#include "exceptions.h"
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#include "noise.h"
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class TestRandom : public TestBase {
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public:
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TestRandom() { TestManager::registerTestModule(this); }
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const char *getName() { return "TestRandom"; }
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void runTests(IGameDef *gamedef);
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void testPseudoRandom();
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void testPseudoRandomRange();
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void testPcgRandom();
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void testPcgRandomRange();
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void testPcgRandomBytes();
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void testPcgRandomNormalDist();
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static const int expected_pseudorandom_results[256];
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static const u32 expected_pcgrandom_results[256];
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static const u8 expected_pcgrandom_bytes_result[24];
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static const u8 expected_pcgrandom_bytes_result2[24];
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};
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static TestRandom g_test_instance;
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void TestRandom::runTests(IGameDef *gamedef)
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{
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TEST(testPseudoRandom);
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TEST(testPseudoRandomRange);
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TEST(testPcgRandom);
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TEST(testPcgRandomRange);
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TEST(testPcgRandomBytes);
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TEST(testPcgRandomNormalDist);
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}
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////////////////////////////////////////////////////////////////////////////////
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void TestRandom::testPseudoRandom()
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{
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PseudoRandom pr(814538);
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for (u32 i = 0; i != 256; i++)
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UASSERTEQ(int, pr.next(), expected_pseudorandom_results[i]);
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}
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void TestRandom::testPseudoRandomRange()
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{
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PseudoRandom pr((int)time(NULL));
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EXCEPTION_CHECK(PrngException, pr.range(2000, 6000));
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EXCEPTION_CHECK(PrngException, pr.range(5, 1));
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for (u32 i = 0; i != 32768; i++) {
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int min = (pr.next() % 3000) - 500;
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int max = (pr.next() % 3000) - 500;
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if (min > max)
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SWAP(int, min, max);
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int randval = pr.range(min, max);
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UASSERT(randval >= min);
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UASSERT(randval <= max);
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}
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}
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void TestRandom::testPcgRandom()
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{
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PcgRandom pr(814538, 998877);
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for (u32 i = 0; i != 256; i++)
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UASSERTEQ(u32, pr.next(), expected_pcgrandom_results[i]);
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}
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void TestRandom::testPcgRandomRange()
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{
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PcgRandom pr((int)time(NULL));
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EXCEPTION_CHECK(PrngException, pr.range(5, 1));
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// Regression test for bug 3027
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pr.range(pr.RANDOM_MIN, pr.RANDOM_MAX);
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for (u32 i = 0; i != 32768; i++) {
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int min = (pr.next() % 3000) - 500;
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int max = (pr.next() % 3000) - 500;
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if (min > max)
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SWAP(int, min, max);
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int randval = pr.range(min, max);
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UASSERT(randval >= min);
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UASSERT(randval <= max);
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}
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}
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void TestRandom::testPcgRandomBytes()
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{
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char buf[32];
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PcgRandom r(1538, 877);
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memset(buf, 0, sizeof(buf));
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r.bytes(buf + 5, 23);
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UASSERT(memcmp(buf + 5, expected_pcgrandom_bytes_result,
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sizeof(expected_pcgrandom_bytes_result)) == 0);
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memset(buf, 0, sizeof(buf));
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r.bytes(buf, 17);
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UASSERT(memcmp(buf, expected_pcgrandom_bytes_result2,
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sizeof(expected_pcgrandom_bytes_result2)) == 0);
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}
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void TestRandom::testPcgRandomNormalDist()
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{
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static const int max = 120;
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static const int min = -120;
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static const int num_trials = 20;
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static const u32 num_samples = 61000;
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s32 bins[max - min + 1];
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memset(bins, 0, sizeof(bins));
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PcgRandom r(486179 + (int)time(NULL));
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for (u32 i = 0; i != num_samples; i++) {
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s32 randval = r.randNormalDist(min, max, num_trials);
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UASSERT(randval <= max);
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UASSERT(randval >= min);
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bins[randval - min]++;
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}
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// Note that here we divide variance by the number of trials;
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// this is because variance is a biased estimator.
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int range = (max - min + 1);
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float mean = (max + min) / 2;
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float variance = ((range * range - 1) / 12) / num_trials;
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float stddev = sqrt(variance);
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static const float prediction_intervals[] = {
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0.68269f, // 1.0
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0.86639f, // 1.5
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0.95450f, // 2.0
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0.98758f, // 2.5
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0.99730f, // 3.0
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};
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//// Simple normality test using the 68-95-99.7% rule
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for (u32 i = 0; i != ARRLEN(prediction_intervals); i++) {
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float deviations = i / 2.f + 1.f;
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int lbound = myround(mean - deviations * stddev);
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int ubound = myround(mean + deviations * stddev);
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UASSERT(lbound >= min);
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UASSERT(ubound <= max);
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int accum = 0;
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for (int j = lbound; j != ubound; j++)
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accum += bins[j - min];
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float actual = (float)accum / num_samples;
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UASSERT(fabs(actual - prediction_intervals[i]) < 0.02);
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}
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}
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const int TestRandom::expected_pseudorandom_results[256] = {
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0x02fa, 0x60d5, 0x6c10, 0x606b, 0x098b, 0x5f1e, 0x4f56, 0x3fbd, 0x77af,
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0x4fe9, 0x419a, 0x6fe1, 0x177b, 0x6858, 0x36f8, 0x6d83, 0x14fc, 0x2d62,
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0x1077, 0x23e2, 0x041b, 0x7a7e, 0x5b52, 0x215d, 0x682b, 0x4716, 0x47e3,
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0x08c0, 0x1952, 0x56ae, 0x146d, 0x4b4f, 0x239f, 0x3fd0, 0x6794, 0x7796,
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0x7be2, 0x75b7, 0x5691, 0x28ee, 0x2656, 0x40c0, 0x133c, 0x63cd, 0x2aeb,
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0x518f, 0x7dbc, 0x6ad8, 0x736e, 0x5b05, 0x160b, 0x589f, 0x6f64, 0x5edc,
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0x092c, 0x0a39, 0x199e, 0x1927, 0x562b, 0x2689, 0x3ba3, 0x366f, 0x46da,
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0x4e49, 0x0abb, 0x40a1, 0x3846, 0x40db, 0x7adb, 0x6ec1, 0x6efa, 0x01cc,
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0x6335, 0x4352, 0x72fb, 0x4b2d, 0x509a, 0x257e, 0x2f7d, 0x5891, 0x2195,
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0x6107, 0x5269, 0x56e3, 0x4849, 0x38f7, 0x2791, 0x04f2, 0x4e05, 0x78ff,
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0x6bae, 0x50b3, 0x74ad, 0x31af, 0x531e, 0x7d56, 0x11c9, 0x0b5e, 0x405e,
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0x1e15, 0x7f6a, 0x5bd3, 0x6649, 0x71b4, 0x3ec2, 0x6ab4, 0x520e, 0x6ad6,
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0x287e, 0x10b8, 0x18f2, 0x7107, 0x46ea, 0x1d85, 0x25cc, 0x2689, 0x35c1,
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0x3065, 0x6237, 0x3edd, 0x23d9, 0x6fb5, 0x37a1, 0x3211, 0x526a, 0x4b09,
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0x23f1, 0x58cc, 0x2e42, 0x341f, 0x5e16, 0x3d1a, 0x5e8c, 0x7a82, 0x4635,
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0x2bf8, 0x6577, 0x3603, 0x1daf, 0x539f, 0x2e91, 0x6bd8, 0x42d3, 0x7a93,
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0x26e3, 0x5a91, 0x6c67, 0x1b66, 0x3ac7, 0x18bf, 0x20d8, 0x7153, 0x558d,
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0x7262, 0x653d, 0x417d, 0x3ed3, 0x3117, 0x600d, 0x6d04, 0x719c, 0x3afd,
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0x6ba5, 0x17c5, 0x4935, 0x346c, 0x5479, 0x6ff6, 0x1fcc, 0x1054, 0x3f14,
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0x6266, 0x3acc, 0x3b77, 0x71d8, 0x478b, 0x20fa, 0x4e46, 0x7e77, 0x5554,
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0x3652, 0x719c, 0x072b, 0x61ad, 0x399f, 0x621d, 0x1bba, 0x41d0, 0x7fdc,
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0x3e6c, 0x6a2a, 0x5253, 0x094e, 0x0c10, 0x3f43, 0x73eb, 0x4c5f, 0x1f23,
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0x12c9, 0x0902, 0x5238, 0x50c0, 0x1b77, 0x3ffd, 0x0124, 0x302a, 0x26b9,
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0x3648, 0x30a6, 0x1abc, 0x3031, 0x4029, 0x6358, 0x6696, 0x74e8, 0x6142,
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0x4284, 0x0c00, 0x7e50, 0x41e3, 0x3782, 0x79a5, 0x60fe, 0x2d15, 0x3ed2,
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0x7f70, 0x2b27, 0x6366, 0x5100, 0x7c44, 0x3ee0, 0x4e76, 0x7d34, 0x3a60,
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0x140e, 0x613d, 0x1193, 0x268d, 0x1e2f, 0x3123, 0x6d61, 0x4e0b, 0x51ce,
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0x13bf, 0x58d4, 0x4f43, 0x05c6, 0x4d6a, 0x7eb5, 0x2921, 0x2c36, 0x1c89,
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0x63b9, 0x1555, 0x1f41, 0x2d9f,
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};
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const u32 TestRandom::expected_pcgrandom_results[256] = {
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0x48c593f8, 0x054f59f5, 0x0d062dc1, 0x23852a23, 0x7fbbc97b, 0x1f9f141e,
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0x364e6ed8, 0x995bba58, 0xc9307dc0, 0x73fb34c4, 0xcd8de88d, 0x52e8ce08,
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0x1c4a78e4, 0x25c0882e, 0x8a82e2e0, 0xe3bc3311, 0xb8068d42, 0x73186110,
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0x19988df4, 0x69bd970b, 0x7214728c, 0x0aee320c, 0x2a5a536c, 0xaf48d715,
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0x00bce504, 0xd2b8f548, 0x520df366, 0x96d8fff5, 0xa1bb510b, 0x63477049,
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0xb85990b7, 0x7e090689, 0x275fb468, 0x50206257, 0x8bab4f8a, 0x0d6823db,
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0x63faeaac, 0x2d92deeb, 0x2ba78024, 0x0d30f631, 0x338923a0, 0xd07248d8,
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0xa5db62d3, 0xddba8af6, 0x0ad454e9, 0x6f0fd13a, 0xbbfde2bf, 0x91188009,
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0x966b394d, 0xbb9d2012, 0x7e6926cb, 0x95183860, 0x5ff4c59b, 0x035f628a,
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0xb67085ef, 0x33867e23, 0x68d1b887, 0x2e3298d7, 0x84fd0650, 0x8bc91141,
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0x6fcb0452, 0x2836fee9, 0x2e83c0a3, 0xf1bafdc5, 0x9ff77777, 0xfdfbba87,
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0x527aebeb, 0x423e5248, 0xd1756490, 0xe41148fa, 0x3361f7b4, 0xa2824f23,
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0xf4e08072, 0xc50442be, 0x35adcc21, 0x36be153c, 0xc7709012, 0xf0eeb9f2,
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0x3d73114e, 0x1c1574ee, 0x92095b9c, 0x1503d01c, 0xd6ce0677, 0x026a8ec1,
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0x76d0084d, 0x86c23633, 0x36f75ce6, 0x08fa7bbe, 0x35f6ff2a, 0x31cc9525,
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0x2c1a35e6, 0x8effcd62, 0xc782fa07, 0x8a86e248, 0x8fdb7a9b, 0x77246626,
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0x5767723f, 0x3a78b699, 0xe548ce1c, 0x5820f37d, 0x148ed9b8, 0xf6796254,
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0x32232c20, 0x392bf3a2, 0xe9af6625, 0xd40b0d88, 0x636cfa23, 0x6a5de514,
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0xc4a69183, 0xc785c853, 0xab0de901, 0x16ae7e44, 0x376f13b5, 0x070f7f31,
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0x34cbc93b, 0xe6184345, 0x1b7f911f, 0x631fbe4b, 0x86d6e023, 0xc689b518,
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0x88ef4f7c, 0xddf06b45, 0xc97f18d4, 0x2aaee94b, 0x45694723, 0x6db111d2,
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0x91974fce, 0xe33e29e2, 0xc5e99494, 0x8017e02b, 0x3ebd8143, 0x471ffb80,
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0xc0d7ca1b, 0x4954c860, 0x48935d6a, 0xf2d27999, 0xb93d608d, 0x40696e90,
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0x60b18162, 0x1a156998, 0x09b8bbab, 0xc80a79b6, 0x8adbcfbc, 0xc375248c,
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0xa584e2ea, 0x5b46fe11, 0x58e84680, 0x8a8bc456, 0xd668b94f, 0x8b9035be,
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0x278509d4, 0x6663a140, 0x81a9817a, 0xd4f9d3cf, 0x6dc5f607, 0x6ae04450,
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0x694f22a4, 0x1d061788, 0x2e39ad8b, 0x748f4db2, 0xee569b52, 0xd157166d,
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0xdabc161e, 0xc8d50176, 0x7e3110e5, 0x9f7d033b, 0x128df67f, 0xb0078583,
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0xa3a75d26, 0xc1ad8011, 0x07dd89ec, 0xef04f456, 0x91bf866c, 0x6aac5306,
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0xdd5a1573, 0xf73ff97a, 0x4e1186ad, 0xb9680680, 0xc8894515, 0xdc95a08e,
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0xc894fd8e, 0xf84ade15, 0xd787f8c1, 0x40dcecca, 0x1b24743e, 0x1ce6ab23,
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0x72321653, 0xb80fbaf7, 0x1bcf099b, 0x1ff26805, 0x78f66c8e, 0xf93bf51a,
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0xfb0c06fe, 0xe50d48cf, 0x310947e0, 0x1b78804a, 0xe73e2c14, 0x8deb8381,
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0xe576122a, 0xe5a8df39, 0x42397c5e, 0xf5503f3c, 0xbe3dbf8d, 0x1b360e5c,
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0x9254caaf, 0x7a9f6744, 0x6d4144fa, 0xd77c65fe, 0x44ca7b12, 0xf58a4c00,
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0x159500d0, 0x92769857, 0x7134fdd4, 0xa3fea693, 0xbd044831, 0xeded39a1,
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0xe4570204, 0xaea37f2f, 0x9a302971, 0x620f8402, 0x1d2f3e5e, 0xf9c2f49c,
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0x738e813a, 0xb3c92251, 0x7ecba63b, 0xbe7eebc7, 0xf800267c, 0x3fdeb760,
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0xf12d5e7d, 0x5a18dce1, 0xb35a539c, 0xe565f057, 0x2babf38c, 0xae5800ad,
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0x421004dd, 0x6715acb6, 0xff529b64, 0xd520d207, 0x7cb193e7, 0xe9b18e4c,
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0xfd2a8a59, 0x47826ae3, 0x56ba43f8, 0x453b3d99, 0x8ae1675f, 0xf66f5c34,
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0x057a6ac1, 0x010769e4, 0xa8324158, 0x410379a5, 0x5dfc8c97, 0x72848afe,
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0x59f169e5, 0xe32acb78, 0x5dfaa9c4, 0x51bb956a,
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};
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const u8 TestRandom::expected_pcgrandom_bytes_result[24] = {
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0xf3, 0x79, 0x8f, 0x31, 0xac, 0xd9, 0x34, 0xf8, 0x3c, 0x6e, 0x82, 0x37,
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0x6b, 0x4b, 0x77, 0xe3, 0xbd, 0x0a, 0xee, 0x22, 0x79, 0x6e, 0x40, 0x00,
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};
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const u8 TestRandom::expected_pcgrandom_bytes_result2[24] = {
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0x47, 0x9e, 0x08, 0x3e, 0xd4, 0x21, 0x2d, 0xf6, 0xb4, 0xb1, 0x9d, 0x7a,
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0x60, 0x02, 0x5a, 0xb2, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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};
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