Line data Source code
1 : /*
2 : Minetest
3 : Copyright (C) 2010-2014 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
4 :
5 : This program is free software; you can redistribute it and/or modify
6 : it under the terms of the GNU Lesser General Public License as published by
7 : the Free Software Foundation; either version 2.1 of the License, or
8 : (at your option) any later version.
9 :
10 : This program is distributed in the hope that it will be useful,
11 : but WITHOUT ANY WARRANTY; without even the implied warranty of
12 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 : GNU Lesser General Public License for more details.
14 :
15 : You should have received a copy of the GNU Lesser General Public License along
16 : with this program; if not, write to the Free Software Foundation, Inc.,
17 : 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 : */
19 :
20 : #include "test.h"
21 :
22 : #include "util/numeric.h"
23 : #include "exceptions.h"
24 : #include "noise.h"
25 :
26 1 : class TestRandom : public TestBase {
27 : public:
28 1 : TestRandom() { TestManager::registerTestModule(this); }
29 0 : const char *getName() { return "TestRandom"; }
30 :
31 : void runTests(IGameDef *gamedef);
32 :
33 : void testPseudoRandom();
34 : void testPseudoRandomRange();
35 : void testPcgRandom();
36 : void testPcgRandomRange();
37 : void testPcgRandomBytes();
38 : void testPcgRandomNormalDist();
39 :
40 : static const int expected_pseudorandom_results[256];
41 : static const u32 expected_pcgrandom_results[256];
42 : static const u8 expected_pcgrandom_bytes_result[24];
43 : static const u8 expected_pcgrandom_bytes_result2[24];
44 : };
45 :
46 1 : static TestRandom g_test_instance;
47 :
48 0 : void TestRandom::runTests(IGameDef *gamedef)
49 : {
50 0 : TEST(testPseudoRandom);
51 0 : TEST(testPseudoRandomRange);
52 0 : TEST(testPcgRandom);
53 0 : TEST(testPcgRandomRange);
54 0 : TEST(testPcgRandomBytes);
55 0 : TEST(testPcgRandomNormalDist);
56 0 : }
57 :
58 : ////////////////////////////////////////////////////////////////////////////////
59 :
60 0 : void TestRandom::testPseudoRandom()
61 : {
62 0 : PseudoRandom pr(814538);
63 :
64 0 : for (u32 i = 0; i != 256; i++)
65 0 : UASSERTEQ(int, pr.next(), expected_pseudorandom_results[i]);
66 0 : }
67 :
68 :
69 0 : void TestRandom::testPseudoRandomRange()
70 : {
71 0 : PseudoRandom pr((int)time(NULL));
72 :
73 0 : EXCEPTION_CHECK(PrngException, pr.range(2000, 6000));
74 0 : EXCEPTION_CHECK(PrngException, pr.range(5, 1));
75 :
76 0 : for (u32 i = 0; i != 32768; i++) {
77 0 : int min = (pr.next() % 3000) - 500;
78 0 : int max = (pr.next() % 3000) - 500;
79 0 : if (min > max)
80 0 : SWAP(int, min, max);
81 :
82 0 : int randval = pr.range(min, max);
83 0 : UASSERT(randval >= min);
84 0 : UASSERT(randval <= max);
85 : }
86 0 : }
87 :
88 :
89 0 : void TestRandom::testPcgRandom()
90 : {
91 0 : PcgRandom pr(814538, 998877);
92 :
93 0 : for (u32 i = 0; i != 256; i++)
94 0 : UASSERTEQ(u32, pr.next(), expected_pcgrandom_results[i]);
95 0 : }
96 :
97 :
98 0 : void TestRandom::testPcgRandomRange()
99 : {
100 0 : PcgRandom pr((int)time(NULL));
101 :
102 0 : EXCEPTION_CHECK(PrngException, pr.range(5, 1));
103 :
104 0 : for (u32 i = 0; i != 32768; i++) {
105 0 : int min = (pr.next() % 3000) - 500;
106 0 : int max = (pr.next() % 3000) - 500;
107 0 : if (min > max)
108 0 : SWAP(int, min, max);
109 :
110 0 : int randval = pr.range(min, max);
111 0 : UASSERT(randval >= min);
112 0 : UASSERT(randval <= max);
113 : }
114 0 : }
115 :
116 :
117 0 : void TestRandom::testPcgRandomBytes()
118 : {
119 : char buf[32];
120 0 : PcgRandom r(1538, 877);
121 :
122 0 : memset(buf, 0, sizeof(buf));
123 0 : r.bytes(buf + 5, 23);
124 0 : UASSERT(memcmp(buf + 5, expected_pcgrandom_bytes_result,
125 0 : sizeof(expected_pcgrandom_bytes_result)) == 0);
126 :
127 0 : memset(buf, 0, sizeof(buf));
128 0 : r.bytes(buf, 17);
129 0 : UASSERT(memcmp(buf, expected_pcgrandom_bytes_result2,
130 0 : sizeof(expected_pcgrandom_bytes_result2)) == 0);
131 0 : }
132 :
133 :
134 0 : void TestRandom::testPcgRandomNormalDist()
135 : {
136 : static const int max = 120;
137 : static const int min = -120;
138 : static const int num_trials = 20;
139 : static const u32 num_samples = 61000;
140 : s32 bins[max - min + 1];
141 0 : memset(bins, 0, sizeof(bins));
142 :
143 0 : PcgRandom r(486179 + (int)time(NULL));
144 :
145 0 : for (u32 i = 0; i != num_samples; i++) {
146 0 : s32 randval = r.randNormalDist(min, max, num_trials);
147 0 : UASSERT(randval <= max);
148 0 : UASSERT(randval >= min);
149 0 : bins[randval - min]++;
150 : }
151 :
152 : // Note that here we divide variance by the number of trials;
153 : // this is because variance is a biased estimator.
154 0 : int range = (max - min + 1);
155 0 : float mean = (max + min) / 2;
156 0 : float variance = ((range * range - 1) / 12) / num_trials;
157 0 : float stddev = sqrt(variance);
158 :
159 : static const float prediction_intervals[] = {
160 : 0.68269f, // 1.0
161 : 0.86639f, // 1.5
162 : 0.95450f, // 2.0
163 : 0.98758f, // 2.5
164 : 0.99730f, // 3.0
165 : };
166 :
167 : //// Simple normality test using the 68-95-99.7% rule
168 0 : for (u32 i = 0; i != ARRLEN(prediction_intervals); i++) {
169 0 : float deviations = i / 2.f + 1.f;
170 0 : int lbound = myround(mean - deviations * stddev);
171 0 : int ubound = myround(mean + deviations * stddev);
172 0 : UASSERT(lbound >= min);
173 0 : UASSERT(ubound <= max);
174 :
175 0 : int accum = 0;
176 0 : for (int j = lbound; j != ubound; j++)
177 0 : accum += bins[j - min];
178 :
179 0 : float actual = (float)accum / num_samples;
180 0 : UASSERT(fabs(actual - prediction_intervals[i]) < 0.02);
181 : }
182 0 : }
183 :
184 :
185 : const int TestRandom::expected_pseudorandom_results[256] = {
186 : 0x02fa, 0x60d5, 0x6c10, 0x606b, 0x098b, 0x5f1e, 0x4f56, 0x3fbd, 0x77af,
187 : 0x4fe9, 0x419a, 0x6fe1, 0x177b, 0x6858, 0x36f8, 0x6d83, 0x14fc, 0x2d62,
188 : 0x1077, 0x23e2, 0x041b, 0x7a7e, 0x5b52, 0x215d, 0x682b, 0x4716, 0x47e3,
189 : 0x08c0, 0x1952, 0x56ae, 0x146d, 0x4b4f, 0x239f, 0x3fd0, 0x6794, 0x7796,
190 : 0x7be2, 0x75b7, 0x5691, 0x28ee, 0x2656, 0x40c0, 0x133c, 0x63cd, 0x2aeb,
191 : 0x518f, 0x7dbc, 0x6ad8, 0x736e, 0x5b05, 0x160b, 0x589f, 0x6f64, 0x5edc,
192 : 0x092c, 0x0a39, 0x199e, 0x1927, 0x562b, 0x2689, 0x3ba3, 0x366f, 0x46da,
193 : 0x4e49, 0x0abb, 0x40a1, 0x3846, 0x40db, 0x7adb, 0x6ec1, 0x6efa, 0x01cc,
194 : 0x6335, 0x4352, 0x72fb, 0x4b2d, 0x509a, 0x257e, 0x2f7d, 0x5891, 0x2195,
195 : 0x6107, 0x5269, 0x56e3, 0x4849, 0x38f7, 0x2791, 0x04f2, 0x4e05, 0x78ff,
196 : 0x6bae, 0x50b3, 0x74ad, 0x31af, 0x531e, 0x7d56, 0x11c9, 0x0b5e, 0x405e,
197 : 0x1e15, 0x7f6a, 0x5bd3, 0x6649, 0x71b4, 0x3ec2, 0x6ab4, 0x520e, 0x6ad6,
198 : 0x287e, 0x10b8, 0x18f2, 0x7107, 0x46ea, 0x1d85, 0x25cc, 0x2689, 0x35c1,
199 : 0x3065, 0x6237, 0x3edd, 0x23d9, 0x6fb5, 0x37a1, 0x3211, 0x526a, 0x4b09,
200 : 0x23f1, 0x58cc, 0x2e42, 0x341f, 0x5e16, 0x3d1a, 0x5e8c, 0x7a82, 0x4635,
201 : 0x2bf8, 0x6577, 0x3603, 0x1daf, 0x539f, 0x2e91, 0x6bd8, 0x42d3, 0x7a93,
202 : 0x26e3, 0x5a91, 0x6c67, 0x1b66, 0x3ac7, 0x18bf, 0x20d8, 0x7153, 0x558d,
203 : 0x7262, 0x653d, 0x417d, 0x3ed3, 0x3117, 0x600d, 0x6d04, 0x719c, 0x3afd,
204 : 0x6ba5, 0x17c5, 0x4935, 0x346c, 0x5479, 0x6ff6, 0x1fcc, 0x1054, 0x3f14,
205 : 0x6266, 0x3acc, 0x3b77, 0x71d8, 0x478b, 0x20fa, 0x4e46, 0x7e77, 0x5554,
206 : 0x3652, 0x719c, 0x072b, 0x61ad, 0x399f, 0x621d, 0x1bba, 0x41d0, 0x7fdc,
207 : 0x3e6c, 0x6a2a, 0x5253, 0x094e, 0x0c10, 0x3f43, 0x73eb, 0x4c5f, 0x1f23,
208 : 0x12c9, 0x0902, 0x5238, 0x50c0, 0x1b77, 0x3ffd, 0x0124, 0x302a, 0x26b9,
209 : 0x3648, 0x30a6, 0x1abc, 0x3031, 0x4029, 0x6358, 0x6696, 0x74e8, 0x6142,
210 : 0x4284, 0x0c00, 0x7e50, 0x41e3, 0x3782, 0x79a5, 0x60fe, 0x2d15, 0x3ed2,
211 : 0x7f70, 0x2b27, 0x6366, 0x5100, 0x7c44, 0x3ee0, 0x4e76, 0x7d34, 0x3a60,
212 : 0x140e, 0x613d, 0x1193, 0x268d, 0x1e2f, 0x3123, 0x6d61, 0x4e0b, 0x51ce,
213 : 0x13bf, 0x58d4, 0x4f43, 0x05c6, 0x4d6a, 0x7eb5, 0x2921, 0x2c36, 0x1c89,
214 : 0x63b9, 0x1555, 0x1f41, 0x2d9f,
215 : };
216 :
217 : const u32 TestRandom::expected_pcgrandom_results[256] = {
218 : 0x48c593f8, 0x054f59f5, 0x0d062dc1, 0x23852a23, 0x7fbbc97b, 0x1f9f141e,
219 : 0x364e6ed8, 0x995bba58, 0xc9307dc0, 0x73fb34c4, 0xcd8de88d, 0x52e8ce08,
220 : 0x1c4a78e4, 0x25c0882e, 0x8a82e2e0, 0xe3bc3311, 0xb8068d42, 0x73186110,
221 : 0x19988df4, 0x69bd970b, 0x7214728c, 0x0aee320c, 0x2a5a536c, 0xaf48d715,
222 : 0x00bce504, 0xd2b8f548, 0x520df366, 0x96d8fff5, 0xa1bb510b, 0x63477049,
223 : 0xb85990b7, 0x7e090689, 0x275fb468, 0x50206257, 0x8bab4f8a, 0x0d6823db,
224 : 0x63faeaac, 0x2d92deeb, 0x2ba78024, 0x0d30f631, 0x338923a0, 0xd07248d8,
225 : 0xa5db62d3, 0xddba8af6, 0x0ad454e9, 0x6f0fd13a, 0xbbfde2bf, 0x91188009,
226 : 0x966b394d, 0xbb9d2012, 0x7e6926cb, 0x95183860, 0x5ff4c59b, 0x035f628a,
227 : 0xb67085ef, 0x33867e23, 0x68d1b887, 0x2e3298d7, 0x84fd0650, 0x8bc91141,
228 : 0x6fcb0452, 0x2836fee9, 0x2e83c0a3, 0xf1bafdc5, 0x9ff77777, 0xfdfbba87,
229 : 0x527aebeb, 0x423e5248, 0xd1756490, 0xe41148fa, 0x3361f7b4, 0xa2824f23,
230 : 0xf4e08072, 0xc50442be, 0x35adcc21, 0x36be153c, 0xc7709012, 0xf0eeb9f2,
231 : 0x3d73114e, 0x1c1574ee, 0x92095b9c, 0x1503d01c, 0xd6ce0677, 0x026a8ec1,
232 : 0x76d0084d, 0x86c23633, 0x36f75ce6, 0x08fa7bbe, 0x35f6ff2a, 0x31cc9525,
233 : 0x2c1a35e6, 0x8effcd62, 0xc782fa07, 0x8a86e248, 0x8fdb7a9b, 0x77246626,
234 : 0x5767723f, 0x3a78b699, 0xe548ce1c, 0x5820f37d, 0x148ed9b8, 0xf6796254,
235 : 0x32232c20, 0x392bf3a2, 0xe9af6625, 0xd40b0d88, 0x636cfa23, 0x6a5de514,
236 : 0xc4a69183, 0xc785c853, 0xab0de901, 0x16ae7e44, 0x376f13b5, 0x070f7f31,
237 : 0x34cbc93b, 0xe6184345, 0x1b7f911f, 0x631fbe4b, 0x86d6e023, 0xc689b518,
238 : 0x88ef4f7c, 0xddf06b45, 0xc97f18d4, 0x2aaee94b, 0x45694723, 0x6db111d2,
239 : 0x91974fce, 0xe33e29e2, 0xc5e99494, 0x8017e02b, 0x3ebd8143, 0x471ffb80,
240 : 0xc0d7ca1b, 0x4954c860, 0x48935d6a, 0xf2d27999, 0xb93d608d, 0x40696e90,
241 : 0x60b18162, 0x1a156998, 0x09b8bbab, 0xc80a79b6, 0x8adbcfbc, 0xc375248c,
242 : 0xa584e2ea, 0x5b46fe11, 0x58e84680, 0x8a8bc456, 0xd668b94f, 0x8b9035be,
243 : 0x278509d4, 0x6663a140, 0x81a9817a, 0xd4f9d3cf, 0x6dc5f607, 0x6ae04450,
244 : 0x694f22a4, 0x1d061788, 0x2e39ad8b, 0x748f4db2, 0xee569b52, 0xd157166d,
245 : 0xdabc161e, 0xc8d50176, 0x7e3110e5, 0x9f7d033b, 0x128df67f, 0xb0078583,
246 : 0xa3a75d26, 0xc1ad8011, 0x07dd89ec, 0xef04f456, 0x91bf866c, 0x6aac5306,
247 : 0xdd5a1573, 0xf73ff97a, 0x4e1186ad, 0xb9680680, 0xc8894515, 0xdc95a08e,
248 : 0xc894fd8e, 0xf84ade15, 0xd787f8c1, 0x40dcecca, 0x1b24743e, 0x1ce6ab23,
249 : 0x72321653, 0xb80fbaf7, 0x1bcf099b, 0x1ff26805, 0x78f66c8e, 0xf93bf51a,
250 : 0xfb0c06fe, 0xe50d48cf, 0x310947e0, 0x1b78804a, 0xe73e2c14, 0x8deb8381,
251 : 0xe576122a, 0xe5a8df39, 0x42397c5e, 0xf5503f3c, 0xbe3dbf8d, 0x1b360e5c,
252 : 0x9254caaf, 0x7a9f6744, 0x6d4144fa, 0xd77c65fe, 0x44ca7b12, 0xf58a4c00,
253 : 0x159500d0, 0x92769857, 0x7134fdd4, 0xa3fea693, 0xbd044831, 0xeded39a1,
254 : 0xe4570204, 0xaea37f2f, 0x9a302971, 0x620f8402, 0x1d2f3e5e, 0xf9c2f49c,
255 : 0x738e813a, 0xb3c92251, 0x7ecba63b, 0xbe7eebc7, 0xf800267c, 0x3fdeb760,
256 : 0xf12d5e7d, 0x5a18dce1, 0xb35a539c, 0xe565f057, 0x2babf38c, 0xae5800ad,
257 : 0x421004dd, 0x6715acb6, 0xff529b64, 0xd520d207, 0x7cb193e7, 0xe9b18e4c,
258 : 0xfd2a8a59, 0x47826ae3, 0x56ba43f8, 0x453b3d99, 0x8ae1675f, 0xf66f5c34,
259 : 0x057a6ac1, 0x010769e4, 0xa8324158, 0x410379a5, 0x5dfc8c97, 0x72848afe,
260 : 0x59f169e5, 0xe32acb78, 0x5dfaa9c4, 0x51bb956a,
261 : };
262 :
263 : const u8 TestRandom::expected_pcgrandom_bytes_result[24] = {
264 : 0xf3, 0x79, 0x8f, 0x31, 0xac, 0xd9, 0x34, 0xf8, 0x3c, 0x6e, 0x82, 0x37,
265 : 0x6b, 0x4b, 0x77, 0xe3, 0xbd, 0x0a, 0xee, 0x22, 0x79, 0x6e, 0x40, 0x00,
266 : };
267 :
268 : const u8 TestRandom::expected_pcgrandom_bytes_result2[24] = {
269 : 0x47, 0x9e, 0x08, 0x3e, 0xd4, 0x21, 0x2d, 0xf6, 0xb4, 0xb1, 0x9d, 0x7a,
270 : 0x60, 0x02, 0x5a, 0xb2, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
271 3 : };
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