ccore/test/modules/RandomTests.c

#include "../Tests.h"
#include "core/Random.h"

static void testAverage(bool light) {
    int limit = light ? 100000 : 1000000;
    Random r;
    initRandom(&r, 553);
    float sum = 0;
    for(int i = 0; i < limit; i++) {
        u32 u = randomU32(&r, 2, 11);
        sum += (float)u;
    }
    sum /= (float)limit;
    TEST_FLOAT(6.0f, sum, 0.01f);
}

static void testCoin(bool light) {
    int limit = light ? 100000 : 1000000;
    Random r;
    initRandom(&r, 5533);
    int c[2] = {0, 0};
    for(int i = 0; i < limit; i++) {
        c[randomBool(&r)]++;
    }
    TEST_FLOAT(0.0f, (float)(c[0] - c[1]) / (float)limit, 0.003f);
}

static void testDistribution(bool light) {
    size_t limit = light ? 100000 : 1000000;
    Random r;
    initRandom(&r, 553);
    int c[102] = {0};
    for(size_t i = 0; i < limit; i++) {
        c[randomSize(&r, 1, 101)]++;
    }
    TEST_INT(0, c[0]);
    TEST_INT(0, c[101]);
    for(size_t i = 1; i < 101; i++) {
        TEST_FLOAT(0.01f, (float)c[i] / (float)limit, 0.001f);
    }
}

static void testFloatAverage(bool light) {
    int limit = light ? 100000 : 1000000;
    Random r;
    initRandom(&r, 553);
    float sum = 0;
    for(int i = 0; i < limit; i++) {
        sum += randomFloat(&r);
    }
    sum /= (float)limit;
    TEST_FLOAT(0.5f, sum, 0.001f);
}

static void testFloatCoin(bool light) {
    int limit = light ? 100000 : 1000000;
    Random r;
    initRandom(&r, 5534);
    int c[2] = {0, 0};
    for(int i = 0; i < limit; i++) {
        c[randomFloat(&r) < 0.5f]++;
    }
    TEST_FLOAT(0.0f, (float)(c[0] - c[1]) / (float)limit, 0.003f);
}

static void testFloatDistribution(bool light) {
    int limit = light ? 100000 : 1000000;
    Random r;
    initRandom(&r, 553);
    int c[102] = {0};
    for(int i = 0; i < limit; i++) {
        c[(size_t)(1.0f + randomFloat(&r) * 100.0f)]++;
    }
    TEST_INT(0, c[0]);
    TEST_INT(0, c[101]);
    for(size_t i = 1; i < 101; i++) {
        TEST_FLOAT(0.01f, (float)c[i] / (float)limit, 0.003f);
    }
}

static void testRandomI32() {
    Random r;
    initRandom(&r, 56346);
    int c[7] = {0};
    for(int i = 0; i < 10000; i++) {
        i32 index = randomI32(&r, -2, 3) + 3;
        if(TEST_TRUE(index >= 0 && index < 7)) {
            c[index]++;
        }
    }
    for(size_t i = 0; i < 7; i++) {
        TEST_BOOL(i != 0 && i != 6, c[i] > 0);
    }
}

void testRandom(bool light) {
    testAverage(light);
    testCoin(light);
    testDistribution(light);
    testFloatAverage(light);
    testFloatCoin(light);
    testFloatDistribution(light);
    testRandomI32();
}