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authorskidd13 <skidd13@openttd.org>2008-03-31 16:07:50 +0000
committerskidd13 <skidd13@openttd.org>2008-03-31 16:07:50 +0000
commit9d914a803c0e9d39b8d86427902b0aac4c6d88ce (patch)
tree4a2b8a329970d0d60e89b4b666d0830ac4715a33 /src
parent4cc6140619a9988c1e16ff82bf7edb601ce0ed0c (diff)
downloadopenttd-9d914a803c0e9d39b8d86427902b0aac4c6d88ce.tar.xz
(svn r12516) -Revert r2583: Removed mersenne PRNG cause it is not used and won't be used in the future
Diffstat (limited to 'src')
-rw-r--r--src/core/random_func.cpp100
-rw-r--r--src/core/random_func.hpp4
2 files changed, 1 insertions, 103 deletions
diff --git a/src/core/random_func.cpp b/src/core/random_func.cpp
index 56792ca63..d51e59eeb 100644
--- a/src/core/random_func.cpp
+++ b/src/core/random_func.cpp
@@ -28,101 +28,6 @@ void Randomizer::SetSeed(uint32 seed)
this->state[1] = seed;
}
-#ifdef MERSENNE_TWISTER
-// Source code for Mersenne Twister.
-// A Random number generator with much higher quality random numbers.
-
-#define N (624) // length of _mt_state vector
-#define M (397) // a period parameter
-#define K (0x9908B0DFU) // a magic constant
-#define hiBit(u) ((u) & 0x80000000U) // mask all but highest bit of u
-#define loBit(u) ((u) & 0x00000001U) // mask all but lowest bit of u
-#define loBits(u) ((u) & 0x7FFFFFFFU) // mask the highest bit of u
-#define mixBits(u, v) (hiBit(u)|loBits(v)) // move hi bit of u to hi bit of v
-
-static uint32 _mt_state[N+1]; // _mt_state vector + 1 extra to not violate ANSI C
-static uint32 *_mt_next; // _mt_next random value is computed from here
-static int _mt_left = -1; // can *_mt_next++ this many times before reloading
-
-void SetRandomSeed(register uint32 seed)
-{
- register uint32 *s = _mt_state;
- _mt_left = 0;
-
- seed |= 1U;
- seed &= 0xFFFFFFFFU;
-
- *s = seed;
-
- for (register uint i = N; i != 0; i--) {
- seed *= 69069U;
- *s++;
- *s = seed & 0xFFFFFFFFU;
- }
-}
-
-static uint32 ReloadRandom()
-{
- if (_mt_left < -1) SetRandomSeed(4357U);
-
- _mt_left = N - 1;
- _mt_next = _mt_state + 1;
-
- register uint32 *p0 = _mt_state;
- register uint32 *p2 = _mt_state + 2;
- register uint32 *pM = _mt_state + M;
-
- register uint32 s0 = _mt_state[0];
- register uint32 s1 = _mt_state[1];
-
- register uint i = 0;
-
- for (i = (N - M + 1); i != 0; i--) {
- s0 = s1;
- s1 = *p2;
- *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
- *p0++;
- *p2++;
- *pM++;
- }
-
- pM = _mt_state;
-
- for (i = M; i != 0; i--) {
- s0 = s1;
- s1 = *p2;
- *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
- *p0++;
- *p2++;
- *pM++;
- }
-
- s1 = _mt_state[0];
- *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
-
- s1 ^= (s1 >> 11);
- s1 ^= (s1 << 7) & 0x9D2C5680U;
- s1 ^= (s1 << 15) & 0xEFC60000U;
- s1 ^= (s1 >> 18);
- return s1;
-}
-
-uint32 Random()
-{
- _mt_left--;
- if (_mt_left < 0) return ReloadRandom();
-
- uint32 y = *_mt_next;
- *_mt_next++;
-
- y ^= (y >> 11);
- y ^= (y << 7) & 0x9D2C5680U;
- y ^= (y << 15) & 0xEFC60000U;
- y ^= (y >> 18);
- return y;
-}
-
-#else /* MERSENNE_TWISTER */
void SetRandomSeed(uint32 seed)
{
_random.SetSeed(seed);
@@ -142,12 +47,9 @@ uint32 DoRandom(int line, const char *file)
return _random.Next();
}
-#endif /* RANDOM_DEBUG */
-#endif /* MERSENNE_TWISTER */
-#if defined(RANDOM_DEBUG) && !defined(MERSENNE_TWISTER)
uint DoRandomRange(uint max, int line, const char *file)
{
return GB(DoRandom(line, file), 0, 16) * max >> 16;
}
-#endif /* RANDOM_DEBUG & !MERSENNE_TWISTER */
+#endif /* RANDOM_DEBUG */
diff --git a/src/core/random_func.hpp b/src/core/random_func.hpp
index 8469af661..a301b5b3b 100644
--- a/src/core/random_func.hpp
+++ b/src/core/random_func.hpp
@@ -23,10 +23,6 @@
//#define RANDOM_DEBUG
-// Enable this to produce higher quality random numbers.
-// Doesn't work with network yet.
-// #define MERSENNE_TWISTER
-
/**
* Structure to encapsulate the pseudo random number generators.
*/