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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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; either version 2
* of the License, or (at your option) any later version.
*
* This program 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. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "common/random.h"
#include "common/system.h"
namespace Common {
RandomSource::RandomSource() {
// Use system time as RNG seed. Normally not a good idea, if you are using
// a RNG for security purposes, but good enough for our purposes.
assert(g_system);
uint32 seed = g_system->getMillis();
setSeed(seed);
}
void RandomSource::setSeed(uint32 seed) {
_randSeed = seed;
}
uint RandomSource::getRandomNumber(uint max) {
_randSeed = 0xDEADBF03 * (_randSeed + 1);
_randSeed = (_randSeed >> 13) | (_randSeed << 19);
return _randSeed % (max + 1);
}
uint RandomSource::getRandomBit() {
_randSeed = 0xDEADBF03 * (_randSeed + 1);
_randSeed = (_randSeed >> 13) | (_randSeed << 19);
return _randSeed & 1;
}
uint RandomSource::getRandomNumberRng(uint min, uint max) {
return getRandomNumber(max - min) + min;
}
} // End of namespace Common
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