random_func.cpp

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00001 /* $Id: random_func.cpp 21886 2011-01-22 09:53:15Z rubidium $ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #include "../stdafx.h"
00013 #include "random_func.hpp"
00014 #include "bitmath_func.hpp"
00015 
00016 Randomizer _random, _interactive_random;
00017 
00022 uint32 Randomizer::Next()
00023 {
00024   const uint32 s = this->state[0];
00025   const uint32 t = this->state[1];
00026 
00027   this->state[0] = s + ROR(t ^ 0x1234567F, 7) + 1;
00028   return this->state[1] = ROR(s, 3) - 1;
00029 }
00030 
00036 uint32 Randomizer::Next(uint32 max)
00037 {
00038   return ((uint64)this->Next() * (uint64)max) >> 32;
00039 }
00040 
00045 void Randomizer::SetSeed(uint32 seed)
00046 {
00047   this->state[0] = seed;
00048   this->state[1] = seed;
00049 }
00050 
00055 void SetRandomSeed(uint32 seed)
00056 {
00057   _random.SetSeed(seed);
00058   _interactive_random.SetSeed(seed * 0x1234567);
00059 }
00060 
00061 #ifdef RANDOM_DEBUG
00062 #include "../network/network.h"
00063 #include "../network/network_server.h"
00064 #include "../network/network_internal.h"
00065 #include "../company_func.h"
00066 
00067 uint32 DoRandom(int line, const char *file)
00068 {
00069   if (_networking && (!_network_server || (NetworkClientSocket::IsValidID(0) && NetworkClientSocket::Get(0)->status != NetworkClientSocket::STATUS_INACTIVE))) {
00070     printf("Random [%d/%d] %s:%d\n", _frame_counter, (byte)_current_company, file, line);
00071   }
00072 
00073   return _random.Next();
00074 }
00075 
00076 uint32 DoRandomRange(uint32 max, int line, const char *file)
00077 {
00078   return ((uint64)DoRandom(line, file) * (uint64)max) >> 32;
00079 }
00080 #endif /* RANDOM_DEBUG */