65 lines
1.5 KiB
C++
65 lines
1.5 KiB
C++
/*
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* Copyright (C) 2021 Robin Gareus <robin@gareus.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef _pbd_pcg_rand_
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#define _pbd_pcg_rand_
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#include <stdint.h>
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#include "pbd/libpbd_visibility.h"
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namespace PBD
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{
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/**
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* *Really* minimal PCG32 code / (c) 2014 M.E. O'Neill / pcg-random.org
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*
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* To be used in cases where an efficient and realtime-safe random
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* generator is needed.
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*/
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class LIBPBD_API PCGRand
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{
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public:
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PCGRand ();
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/* 32bit (0 .. 4294967295) */
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uint32_t rand_u32 ();
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/* uniform integer min <= rand < max */
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int rand (int max, int min = 0);
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/* unsigned float [0..1] */
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float rand_uf ()
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{
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return rand_u32 () / 4294967295.f;
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}
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/* signed float [-1..+1] */
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float rand_sf ()
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{
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return (rand_u32 () / 2147483647.5f) - 1.f;
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}
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private:
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uint64_t _state;
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uint64_t _inc;
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int _foo;
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};
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} // namespace PBD
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#endif
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