src/libjin/Math/je_random.cpp


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#include <math.h>
#include "je_random.h"

namespace JinEngine
{
    namespace Math
    {

        RandomGenerator::RandomGenerator(uint32 seed)
            : mSeed(seed)
        {
        }

        uint32 RandomGenerator::rand()
        {
            unsigned int next = mSeed;
            uint32 result;

            next *= 1103515245;
            next += 12345;
            result = (unsigned int)(next / 65536) % 2048;

            next *= 1103515245;
            next += 12345;
            result <<= 10;
            result ^= (unsigned int)(next / 65536) % 1024;

            next *= 1103515245;
            next += 12345;
            result <<= 10;
            result ^= (unsigned int)(next / 65536) % 1024;

            mSeed = next;

            return result;
        }

        uint32 RandomGenerator::rand(uint32 min, uint32 max)
        {
            uint32 n = rand();
            return n % (max - min + 1) + min;
        }

        float RandomGenerator::randf(float min, float max, int ac)
        {
            uint32 a = pow(10.f, ac);
            uint32 n = rand(min*a, max*a);
            return (float)n / a;
        }

    }
}