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Diffstat (limited to 'source/FastRandom.cpp')
| -rw-r--r-- | source/FastRandom.cpp | 174 |
1 files changed, 0 insertions, 174 deletions
diff --git a/source/FastRandom.cpp b/source/FastRandom.cpp deleted file mode 100644 index 887e4426d..000000000 --- a/source/FastRandom.cpp +++ /dev/null @@ -1,174 +0,0 @@ - -// FastRandom.cpp - -// Implements the cFastRandom class representing a fast random number generator - -#include "Globals.h" -#include <time.h> -#include "FastRandom.h" - - - - - -#if 0 && defined(_DEBUG) -// Self-test -// Both ints and floats are quick-tested to see if the random is calculated correctly, checking the range in ASSERTs, -// and if it performs well in terms of distribution (checked by avg, expected to be in the range midpoint -class cFastRandomTest -{ -public: - cFastRandomTest(void) - { - TestInts(); - TestFloats(); - } - - - void TestInts(void) - { - printf("Testing ints...\n"); - cFastRandom rnd; - int sum = 0; - const int BUCKETS = 8; - int Counts[BUCKETS]; - memset(Counts, 0, sizeof(Counts)); - const int ITER = 10000; - for (int i = 0; i < ITER; i++) - { - int v = rnd.NextInt(1000); - ASSERT(v >= 0); - ASSERT(v < 1000); - Counts[v % BUCKETS]++; - sum += v; - } - double avg = (double)sum / ITER; - printf("avg: %f\n", avg); - for (int i = 0; i < BUCKETS; i++) - { - printf(" bucket %d: %d\n", i, Counts[i]); - } - } - - - void TestFloats(void) - { - printf("Testing floats...\n"); - cFastRandom rnd; - float sum = 0; - const int BUCKETS = 8; - int Counts[BUCKETS]; - memset(Counts, 0, sizeof(Counts)); - const int ITER = 10000; - for (int i = 0; i < ITER; i++) - { - float v = rnd.NextFloat(1000); - ASSERT(v >= 0); - ASSERT(v <= 1000); - Counts[((int)v) % BUCKETS]++; - sum += v; - } - sum = sum / ITER; - printf("avg: %f\n", sum); - for (int i = 0; i < BUCKETS; i++) - { - printf(" bucket %d: %d\n", i, Counts[i]); - } - } -} g_Test; - -#endif - - - - - - -int cFastRandom::m_SeedCounter = 0; - - - - - -cFastRandom::cFastRandom(void) : - m_Seed(m_SeedCounter++) -{ -} - - - - - -int cFastRandom::NextInt(int a_Range) -{ - ASSERT(a_Range <= 1000000); // The random is not sufficiently linearly distributed with bigger ranges - ASSERT(a_Range > 0); - - // Make the m_Counter operations as minimal as possible, to emulate atomicity - int Counter = m_Counter++; - - // Use a_Range, m_Counter and m_Seed as inputs to the pseudorandom function: - int n = a_Range + m_Counter * 57 + m_Seed * 57 * 57; - n = (n << 13) ^ n; - n = ((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff); - return ((n / 11) % a_Range); -} - - - - - -int cFastRandom::NextInt(int a_Range, int a_Salt) -{ - ASSERT(a_Range <= 1000000); // The random is not sufficiently linearly distributed with bigger ranges - ASSERT(a_Range > 0); - - // Make the m_Counter operations as minimal as possible, to emulate atomicity - int Counter = m_Counter++; - - // Use a_Range, a_Salt, m_Counter and m_Seed as inputs to the pseudorandom function: - int n = a_Range + m_Counter * 57 + m_Seed * 57 * 57 + a_Salt * 57 * 57 * 57; - n = (n << 13) ^ n; - n = ((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff); - return ((n / 11) % a_Range); -} - - - - - -float cFastRandom::NextFloat(float a_Range) -{ - // Make the m_Counter operations as minimal as possible, to emulate atomicity - int Counter = m_Counter++; - - // Use a_Range, a_Salt, m_Counter and m_Seed as inputs to the pseudorandom function: - int n = (int)a_Range + m_Counter * 57 + m_Seed * 57 * 57; - n = (n << 13) ^ n; - n = ((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff); - - // Convert the integer into float with the specified range: - return (((float)n / (float)0x7fffffff) * a_Range); -} - - - - - -float cFastRandom::NextFloat(float a_Range, int a_Salt) -{ - // Make the m_Counter operations as minimal as possible, to emulate atomicity - int Counter = m_Counter++; - - // Use a_Range, a_Salt, m_Counter and m_Seed as inputs to the pseudorandom function: - int n = (int)a_Range + m_Counter * 57 + m_Seed * 57 * 57 + a_Salt * 57 * 57 * 57; - n = (n << 13) ^ n; - n = ((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff); - - // Convert the integer into float with the specified range: - return (((float)n / (float)0x7fffffff) * a_Range); -} - - - - |