/**************************************************************************/
/* test_random_number_generator.h */
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/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
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#ifndef TEST_RANDOM_NUMBER_GENERATOR_H
#define TEST_RANDOM_NUMBER_GENERATOR_H
#include "core/math/random_number_generator.h"
#include "tests/test_macros.h"
namespace TestRandomNumberGenerator {
TEST_CASE("[RandomNumberGenerator] Float") {
Ref<RandomNumberGenerator> rng = memnew(RandomNumberGenerator);
rng->set_seed(0);
INFO("Should give float between 0.0 and 1.0.");
for (int i = 0; i < 1000; i++) {
real_t n = rng->randf();
CHECK(n >= 0.0);
CHECK(n <= 1.0);
}
}
TEST_CASE("[RandomNumberGenerator] Integer range via modulo") {
Ref<RandomNumberGenerator> rng = memnew(RandomNumberGenerator);
rng->set_seed(0);
INFO("Should give integer between 0 and 100.");
for (int i = 0; i < 1000; i++) {
uint32_t n = rng->randi() % 100;
CHECK(n >= 0);
CHECK(n <= 100);
}
}
TEST_CASE_MAY_FAIL("[RandomNumberGenerator] Integer 32 bit") {
Ref<RandomNumberGenerator> rng = memnew(RandomNumberGenerator);
rng->set_seed(0); // Change the seed if this fails.
bool higher = false;
int i;
for (i = 0; i < 1000; i++) {
uint32_t n = rng->randi();
if (n > 0x0fff'ffff) {
higher = true;
break;
}
}
INFO("Current seed: ", rng->get_seed());
INFO("Current iteration: ", i);
CHECK_MESSAGE(higher, "Given current seed, this should give an integer higher than 0x0fff'ffff at least once.");
}
TEST_CASE("[RandomNumberGenerator] Float and integer range") {
Ref<RandomNumberGenerator> rng = memnew(RandomNumberGenerator);
rng->set_seed(0);
uint64_t initial_state = rng->get_state();
uint32_t initial_seed = rng->get_seed();
INFO("Should give float between -100.0 and 100.0, base test.");
for (int i = 0; i < 1000; i++) {
real_t n0 = rng->randf_range(-100.0, 100.0);
CHECK(n0 >= -100);
CHECK(n0 <= 100);
}
rng->randomize();
INFO("Should give float between -75.0 and 75.0.");
INFO("Shouldn't be affected by randomize.");
for (int i = 0; i < 1000; i++) {
real_t n1 = rng->randf_range(-75.0, 75.0);
CHECK(n1 >= -75);
CHECK(n1 <= 75);
}
rng->set_state(initial_state);
INFO("Should give integer between -50 and 50.");
INFO("Shouldn't be affected by set_state.");
for (int i = 0; i < 1000; i++) {
real_t n2 = rng->randi_range(-50, 50);
CHECK(n2 >= -50);
CHECK(n2 <= 50);
}
rng->set_seed(initial_seed);
INFO("Should give integer between -25 and 25.");
INFO("Shouldn't be affected by set_seed.");
for (int i = 0; i < 1000; i++) {
int32_t n3 = rng->randi_range(-25, 25);
CHECK(n3 >= -25);
CHECK(n3 <= 25);
}
rng->randf();
rng->randf();
INFO("Should give float between -10.0 and 10.0.");
INFO("Shouldn't be affected after generating new numbers.");
for (int i = 0; i < 1000; i++) {
real_t n4 = rng->randf_range(-10.0, 10.0);
CHECK(n4 >= -10);
CHECK(n4 <= 10);
}
rng->randi();
rng->randi();
INFO("Should give integer between -5 and 5.");
INFO("Shouldn't be affected after generating new numbers.");
for (int i = 0; i < 1000; i++) {
real_t n5 = rng->randf_range(-5, 5);
CHECK(n5 >= -5);
CHECK(n5 <= 5);
}
}
TEST_CASE_MAY_FAIL("[RandomNumberGenerator] Normal distribution") {
Ref<RandomNumberGenerator> rng = memnew(RandomNumberGenerator);
rng->set_seed(1); // Change the seed if this fails.
INFO("Should give a number between -5 to 5 (5 std deviations away; above 99.7% chance it will be in this range).");
INFO("Standard randfn function call.");
for (int i = 0; i < 100; i++) {
real_t n = rng->randfn();
CHECK(n >= -5);
CHECK(n <= 5);
}
INFO("Should give number between -5 to 5 after multiple randi/randf calls.");
INFO("5 std deviations away; above 99.7% chance it will be in this range.");
rng->randf();
rng->randi();
for (int i = 0; i < 100; i++) {
real_t n = rng->randfn();
CHECK(n >= -5);
CHECK(n <= 5);
}
INFO("Checks if user defined mean and deviation work properly.");
INFO("5 std deviations away; above 99.7% chance it will be in this range.");
for (int i = 0; i < 100; i++) {
real_t n = rng->randfn(5, 10);
CHECK(n >= -45);
CHECK(n <= 55);
}
INFO("Checks if randfn works with changed seeds.");
INFO("5 std deviations away; above 99.7% chance it will be in this range.");
rng->randomize();
for (int i = 0; i < 100; i++) {
real_t n = rng->randfn(3, 3);
CHECK(n >= -12);
CHECK(n <= 18);
}
}
TEST_CASE("[RandomNumberGenerator] Zero for first number immediately after seeding") {
Ref<RandomNumberGenerator> rng = memnew(RandomNumberGenerator);
rng->set_seed(0);
uint32_t n1 = rng->randi();
uint32_t n2 = rng->randi();
INFO("Initial random values: ", n1, " ", n2);
CHECK(n1 != 0);
rng->set_seed(1);
uint32_t n3 = rng->randi();
uint32_t n4 = rng->randi();
INFO("Values after changing the seed: ", n3, " ", n4);
CHECK(n3 != 0);
}
TEST_CASE("[RandomNumberGenerator] Restore state") {
Ref<RandomNumberGenerator> rng = memnew(RandomNumberGenerator);
rng->randomize();
uint64_t last_seed = rng->get_seed();
INFO("Current seed: ", last_seed);
rng->randi();
rng->randi();
CHECK_MESSAGE(rng->get_seed() == last_seed,
"The seed should remain the same after generating some numbers");
uint64_t saved_state = rng->get_state();
INFO("Current state: ", saved_state);
real_t f1_before = rng->randf();
real_t f2_before = rng->randf();
INFO("This seed produces: ", f1_before, " ", f2_before);
// Restore now.
rng->set_state(saved_state);
real_t f1_after = rng->randf();
real_t f2_after = rng->randf();
INFO("Resetting the state produces: ", f1_after, " ", f2_after);
String msg = "Should restore the sequence of numbers after resetting the state";
CHECK_MESSAGE(f1_before == f1_after, msg);
CHECK_MESSAGE(f2_before == f2_after, msg);
}
TEST_CASE("[RandomNumberGenerator] Restore from seed") {
Ref<RandomNumberGenerator> rng = memnew(RandomNumberGenerator);
rng->set_seed(0);
INFO("Current seed: ", rng->get_seed());
uint32_t s0_1_before = rng->randi();
uint32_t s0_2_before = rng->randi();
INFO("This seed produces: ", s0_1_before, " ", s0_2_before);
rng->set_seed(9000);
INFO("Current seed: ", rng->get_seed());
uint32_t s9000_1 = rng->randi();
uint32_t s9000_2 = rng->randi();
INFO("This seed produces: ", s9000_1, " ", s9000_2);
rng->set_seed(0);
INFO("Current seed: ", rng->get_seed());
uint32_t s0_1_after = rng->randi();
uint32_t s0_2_after = rng->randi();
INFO("This seed produces: ", s0_1_after, " ", s0_2_after);
String msg = "Should restore the sequence of numbers after resetting the seed";
CHECK_MESSAGE(s0_1_before == s0_1_after, msg);
CHECK_MESSAGE(s0_2_before == s0_2_after, msg);
}
TEST_CASE_MAY_FAIL("[RandomNumberGenerator] randi_range bias check") {
int zeros = 0;
int ones = 0;
Ref<RandomNumberGenerator> rng = memnew(RandomNumberGenerator);
for (int i = 0; i < 10000; i++) {
int val = rng->randi_range(0, 1);
val == 0 ? zeros++ : ones++;
}
CHECK_MESSAGE(abs(zeros * 1.0 / ones - 1.0) < 0.1, "The ratio of zeros to ones should be nearly 1");
int vals[10] = { 0 };
for (int i = 0; i < 1000000; i++) {
vals[rng->randi_range(0, 9)]++;
}
for (int i = 0; i < 10; i++) {
CHECK_MESSAGE(abs(vals[i] / 1000000.0 - 0.1) < 0.01, "Each element should appear roughly 10% of the time");
}
}
} // namespace TestRandomNumberGenerator
#endif // TEST_RANDOM_NUMBER_GENERATOR_H
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