# random_func.cpp

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    00001 /* $Id$ */
    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 #include "../fileio_func.h"
    00067 #include "../date_func.h"
    00068
    00069 uint32 DoRandom(int line, const char *file)
    00070 {
    00071   if (_networking && (!_network_server || (NetworkClientSocket::IsValidID(0) && NetworkClientSocket::Get(0)->status != NetworkClientSocket::STATUS_INACTIVE))) {
    00072     DEBUG(random, 0, "%08x; %02x; %04x; %02x; %s:%d", _date, _date_fract, _frame_counter, (byte)_current_company, file, line);
    00073   }
    00074
    00075   return _random.Next();
    00076 }
    00077
    00078 uint32 DoRandomRange(uint32 max, int line, const char *file)
    00079 {
    00080   return ((uint64)DoRandom(line, file) * (uint64)max) >> 32;
    00081 }
    00082 #endif /* RANDOM_DEBUG */