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Diffstat (limited to 'src/pcg.h')
-rw-r--r-- | src/pcg.h | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/src/pcg.h b/src/pcg.h new file mode 100644 index 0000000..e2b526a --- /dev/null +++ b/src/pcg.h @@ -0,0 +1,78 @@ +/* + * PCG Random Number Generation for C. + * + * Copyright 2014 Melissa O'Neill <oneill@pcg-random.org> + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * For additional information about the PCG random number generation scheme, + * including its license and other licensing options, visit + * + * http://www.pcg-random.org + */ + +/* + * This code is derived from the full C implementation, which is in turn + * derived from the canonical C++ PCG implementation. The C++ version + * has many additional features and is preferable if you can use C++ in + * your project. + */ + +#ifndef PCG_BASIC_H_INCLUDED +#define PCG_BASIC_H_INCLUDED 1 + +#include <inttypes.h> + +#if __cplusplus +extern "C" { +#endif + +struct pcg_state_setseq_64 { // Internals are *Private*. + uint64_t state; // RNG state. All values are possible. + uint64_t inc; // Controls which RNG sequence (stream) is + // selected. Must *always* be odd. +}; +typedef struct pcg_state_setseq_64 pcg32_random_t; + +// If you *must* statically initialize it, here's one. + +#define PCG32_INITIALIZER { 0x853c49e6748fea9bULL, 0xda3e39cb94b95bdbULL } + +// pcg32_srandom(initstate, initseq) +// pcg32_srandom_r(rng, initstate, initseq): +// Seed the rng. Specified in two parts, state initializer and a +// sequence selection constant (a.k.a. stream id) + +void pcg32_srandom(uint64_t initstate, uint64_t initseq); +void pcg32_srandom_r(pcg32_random_t* rng, uint64_t initstate, + uint64_t initseq); + +// pcg32_random() +// pcg32_random_r(rng) +// Generate a uniformly distributed 32-bit random number + +uint32_t pcg32_random(void); +uint32_t pcg32_random_r(pcg32_random_t* rng); + +// pcg32_boundedrand(bound): +// pcg32_boundedrand_r(rng, bound): +// Generate a uniformly distributed number, r, where 0 <= r < bound + +uint32_t pcg32_boundedrand(uint32_t bound); +uint32_t pcg32_boundedrand_r(pcg32_random_t* rng, uint32_t bound); + +#if __cplusplus +} +#endif + +#endif // PCG_BASIC_H_INCLUDED |