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65 lines
1.6 KiB
C++
65 lines
1.6 KiB
C++
/*******************************************************************************
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Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.
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This file is part of the Sortix C Library.
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The Sortix C Library is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation, either version 3 of the License, or (at your
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option) any later version.
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The Sortix C Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
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rand.cpp
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Returns a random value.
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*******************************************************************************/
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#include <stdlib.h>
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#if 1
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static unsigned int m_w = 1337;
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static unsigned int m_z = 37;
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static unsigned int RandomUnsignedInt()
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{
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m_z = 36969 * (m_z & 65535) + (m_z >> 16);
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m_w = 18000 * (m_w & 65535) + (m_w >> 16);
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return (m_z << 16) + m_w; /* 32-bit result */
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}
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extern "C" int rand()
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{
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return RandomUnsignedInt() % 32768;
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}
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extern "C" void srand(unsigned int seed)
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{
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m_w = seed >> 16 & 0xFFFF;
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m_z = seed >> 0 & 0xFFFF;
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}
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#else
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static unsigned random_seed = 1337;
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extern "C" int rand()
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{
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random_seed = random_seed + 37 * 1103515245 + 12345;
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return random_seed >> 16;
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}
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extern "C" void srand(unsigned int seed)
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{
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random_seed = seed;
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}
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#endif
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