62 lines
2.5 KiB
C
62 lines
2.5 KiB
C
/* BSD 3-Clause License
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*
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* Copyright © 2008-2022, Jice and the libtcod contributors.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* 3. Neither the name of the copyright holder nor the names of its
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* contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef LIBTCOD_RANDOM_H_
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#define LIBTCOD_RANDOM_H_
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#include <stdint.h>
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#include "config.h"
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#ifdef __cplusplus
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extern "C" {
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#endif // __cplusplus
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/**
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Return the next random uint64_t from a SplitMix64 generator.
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`state[1]` is a non-NULL pointer to the internal state of the generator.
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There is no initializer function because the first value of `state[1]` is
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itself the seed which can start at any value.
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`state[1]` will be updated by this call.
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This function is provisional and may change.
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*/
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static inline uint64_t TCOD_rng_splitmix64_next(uint64_t* state) {
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// Based on http://xoshiro.di.unimi.it/splitmix64.c
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uint64_t z = (*state += 0x9e3779b97f4a7c15);
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z = (z ^ (z >> 30)) * 0xbf58476d1ce4e5b9;
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z = (z ^ (z >> 27)) * 0x94d049bb133111eb;
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return z ^ (z >> 31);
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}
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#ifdef __cplusplus
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} // extern "C"
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#endif // __cplusplus
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#endif // LIBTCOD_RANDOM_H_
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