random_func.cpp
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00002
00005 #include "../stdafx.h"
00006 #include "random_func.hpp"
00007 #include "bitmath_func.hpp"
00008
00009 Randomizer _random, _interactive_random;
00010
00011 uint32 Randomizer::Next()
00012 {
00013 const uint32 s = this->state[0];
00014 const uint32 t = this->state[1];
00015
00016 this->state[0] = s + ROR(t ^ 0x1234567F, 7) + 1;
00017 return this->state[1] = ROR(s, 3) - 1;
00018 }
00019
00020 uint32 Randomizer::Next(uint16 max)
00021 {
00022 return GB(this->Next(), 0, 16) * max >> 16;
00023 }
00024
00025 void Randomizer::SetSeed(uint32 seed)
00026 {
00027 this->state[0] = seed;
00028 this->state[1] = seed;
00029 }
00030
00031 #ifdef MERSENNE_TWISTER
00032
00033
00034
00035 #define N (624) // length of _mt_state vector
00036 #define M (397) // a period parameter
00037 #define K (0x9908B0DFU) // a magic constant
00038 #define hiBit(u) ((u) & 0x80000000U) // mask all but highest bit of u
00039 #define loBit(u) ((u) & 0x00000001U) // mask all but lowest bit of u
00040 #define loBits(u) ((u) & 0x7FFFFFFFU) // mask the highest bit of u
00041 #define mixBits(u, v) (hiBit(u)|loBits(v)) // move hi bit of u to hi bit of v
00042
00043 static uint32 _mt_state[N+1];
00044 static uint32 *_mt_next;
00045 static int _mt_left = -1;
00046
00047 void SetRandomSeed(register uint32 seed)
00048 {
00049 register uint32 *s = _mt_state;
00050 _mt_left = 0;
00051
00052 seed |= 1U;
00053 seed &= 0xFFFFFFFFU;
00054
00055 *s = seed;
00056
00057 for (register uint i = N; i != 0; i--) {
00058 seed *= 69069U;
00059 *s++;
00060 *s = seed & 0xFFFFFFFFU;
00061 }
00062 }
00063
00064 static uint32 ReloadRandom()
00065 {
00066 if (_mt_left < -1) SetRandomSeed(4357U);
00067
00068 _mt_left = N - 1;
00069 _mt_next = _mt_state + 1;
00070
00071 register uint32 *p0 = _mt_state;
00072 register uint32 *p2 = _mt_state + 2;
00073 register uint32 *pM = _mt_state + M;
00074
00075 register uint32 s0 = _mt_state[0];
00076 register uint32 s1 = _mt_state[1];
00077
00078 register uint i = 0;
00079
00080 for (i = (N - M + 1); i != 0; i--) {
00081 s0 = s1;
00082 s1 = *p2;
00083 *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
00084 *p0++;
00085 *p2++;
00086 *pM++;
00087 }
00088
00089 pM = _mt_state;
00090
00091 for (i = M; i != 0; i--) {
00092 s0 = s1;
00093 s1 = *p2;
00094 *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
00095 *p0++;
00096 *p2++;
00097 *pM++;
00098 }
00099
00100 s1 = _mt_state[0];
00101 *p0 = *pM ^ (mixBits(s0, s1) >> 1) ^ (loBit(s1) ? K : 0U);
00102
00103 s1 ^= (s1 >> 11);
00104 s1 ^= (s1 << 7) & 0x9D2C5680U;
00105 s1 ^= (s1 << 15) & 0xEFC60000U;
00106 s1 ^= (s1 >> 18);
00107 return s1;
00108 }
00109
00110 uint32 Random()
00111 {
00112 _mt_left--;
00113 if (_mt_left < 0) return ReloadRandom();
00114
00115 uint32 y = *_mt_next;
00116 *_mt_next++;
00117
00118 y ^= (y >> 11);
00119 y ^= (y << 7) & 0x9D2C5680U;
00120 y ^= (y << 15) & 0xEFC60000U;
00121 y ^= (y >> 18);
00122 return y;
00123 }
00124
00125 #else
00126 void SetRandomSeed(uint32 seed)
00127 {
00128 _random.SetSeed(seed);
00129 _interactive_random.SetSeed(seed * 0x1234567);
00130 }
00131
00132 #ifdef RANDOM_DEBUG
00133 #include "../network/network_data.h"
00134 #include "../variables.h"
00135 #include "../player_func.h"
00136
00137 uint32 DoRandom(int line, const char *file)
00138 {
00139 if (_networking && (DEREF_CLIENT(0)->status != STATUS_INACTIVE || !_network_server)) {
00140 printf("Random [%d/%d] %s:%d\n",_frame_counter, (byte)_current_player, file, line);
00141 }
00142
00143 return _random.Next();
00144 }
00145 #endif
00146 #endif
00147
00148 #if defined(RANDOM_DEBUG) && !defined(MERSENNE_TWISTER)
00149 uint DoRandomRange(uint max, int line, const char *file)
00150 {
00151 return GB(DoRandom(line, file), 0, 16) * max >> 16;
00152 }
00153 #endif