random_func.cpp

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00001 /* $Id: random_func.cpp 19125 2010-02-13 20:13:34Z frosch $ */
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 
00018 uint32 Randomizer::Next()
00019 {
00020   const uint32 s = this->state[0];
00021   const uint32 t = this->state[1];
00022 
00023   this->state[0] = s + ROR(t ^ 0x1234567F, 7) + 1;
00024   return this->state[1] = ROR(s, 3) - 1;
00025 }
00026 
00027 uint32 Randomizer::Next(uint16 max)
00028 {
00029   return GB(this->Next(), 0, 16) * max >> 16;
00030 }
00031 
00032 void Randomizer::SetSeed(uint32 seed)
00033 {
00034   this->state[0] = seed;
00035   this->state[1] = seed;
00036 }
00037 
00038 void SetRandomSeed(uint32 seed)
00039 {
00040   _random.SetSeed(seed);
00041   _interactive_random.SetSeed(seed * 0x1234567);
00042 }
00043 
00044 #ifdef RANDOM_DEBUG
00045 #include "../network/network.h"
00046 #include "../network/network_internal.h"
00047 #include "../company_func.h"
00048 
00049 uint32 DoRandom(int line, const char *file)
00050 {
00051   if (_networking && (!_network_server || (NetworkClientSocket::IsValidID(0) && NetworkClientSocket::Get(0)->status != STATUS_INACTIVE))) {
00052     printf("Random [%d/%d] %s:%d\n", _frame_counter, (byte)_current_company, file, line);
00053   }
00054 
00055   return _random.Next();
00056 }
00057 
00058 uint DoRandomRange(uint max, int line, const char *file)
00059 {
00060   return GB(DoRandom(line, file), 0, 16) * max >> 16;
00061 }
00062 #endif /* RANDOM_DEBUG */

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