mirror of
https://github.com/mpv-player/mpv
synced 2025-04-17 20:58:20 +00:00
22f4ff44c5
removes awkward back-and-forth int -> double -> int conversion. the last step also broke uniformity, though it likely doesn't matter much in mpv's playlist shuffle context.
55 lines
1.6 KiB
C
55 lines
1.6 KiB
C
/*
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* Implementation of non-cryptographic pseudo-random number
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* generator algorithm known as xoshiro.
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*
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* This file is part of mpv.
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*
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* mpv is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* mpv 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 Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with mpv. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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#include <stdint.h>
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/*
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* Internal state for the PRNG, should be initialized via mp_rand_seed().
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*/
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typedef struct mp_rand_state {
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uint64_t v[4];
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} mp_rand_state;
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/*
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* Initialize the pseudo-random number generator's state with
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* the given 64-bit seed. If the seed is 0, it is randomized.
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*/
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mp_rand_state mp_rand_seed(uint64_t seed);
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/*
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* Return the next 64-bit pseudo-random integer, and update the state
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* accordingly.
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*/
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uint64_t mp_rand_next(mp_rand_state *s);
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/*
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* Return a double value in the range of [0.0, 1.0) with uniform
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* distribution, and update the state accordingly.
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*/
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double mp_rand_next_double(mp_rand_state *s);
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/*
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* Return a 32 bit integer in the range [min, max) with uniform distribution.
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* Caller should ensure `min < max`.
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*/
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uint32_t mp_rand_in_range32(mp_rand_state *s, uint32_t min, uint32_t max);
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