087b7e7abf
This code was not tested and breaks in Release builds, reverting to restore
functionality of the nightly. All in-game menus do not work and generating
a world crashes.
This reverts commit a9be52c41a.
106 lines
2.1 KiB
C++
106 lines
2.1 KiB
C++
#include "stdafx.h"
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#include "Random.h"
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#include "System.h"
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Random::Random()
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{
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// 4J - jave now uses the system nanosecond counter added to a "seedUniquifier" to get an initial seed. Our nanosecond timer is actually only millisecond accuate, so
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// use QueryPerformanceCounter here instead
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int64_t seed;
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QueryPerformanceCounter((LARGE_INTEGER *)&seed);
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seed += 8682522807148012LL;
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setSeed(seed);
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}
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Random::Random(int64_t seed)
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{
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setSeed(seed);
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}
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void Random::setSeed(int64_t s)
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{
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this->seed = (s ^ 0x5DEECE66DLL) & ((1LL << 48) - 1);
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haveNextNextGaussian = false;
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}
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int Random::next(int bits)
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{
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seed = (seed * 0x5DEECE66DLL + 0xBLL) & ((1LL << 48) - 1);
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return (int)(seed >> (48 - bits));
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}
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void Random::nextBytes(byte *bytes, unsigned int count)
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{
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for(unsigned int i = 0; i < count; i++ )
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{
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bytes[i] = (byte)next(8);
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}
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}
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double Random::nextDouble()
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{
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return (((int64_t)next(26) << 27) + next(27))
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/ (double)(1LL << 53);
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}
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double Random::nextGaussian()
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{
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if (haveNextNextGaussian)
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{
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haveNextNextGaussian = false;
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return nextNextGaussian;
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}
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else
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{
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double v1, v2, s;
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do
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{
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v1 = 2 * nextDouble() - 1; // between -1.0 and 1.0
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v2 = 2 * nextDouble() - 1; // between -1.0 and 1.0
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s = v1 * v1 + v2 * v2;
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} while (s >= 1 || s == 0);
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double multiplier = sqrt(-2 * log(s)/s);
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nextNextGaussian = v2 * multiplier;
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haveNextNextGaussian = true;
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return v1 * multiplier;
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}
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}
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int Random::nextInt()
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{
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return next(32);
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}
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int Random::nextInt(int n)
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{
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assert (n>0);
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if ((n & -n) == n) // i.e., n is a power of 2
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return (int)(((int64_t)next(31) * n) >> 31); // 4J Stu - Made int64_t instead of long
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int bits, val;
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do
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{
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bits = next(31);
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val = bits % n;
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} while(bits - val + (n-1) < 0);
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return val;
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}
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float Random::nextFloat()
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{
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return next(24) / ((float)(1 << 24));
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}
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int64_t Random::nextLong()
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{
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return ((int64_t)next(32) << 32) + next(32);
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}
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bool Random::nextBoolean()
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{
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return next(1) != 0;
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} |