tornavis/source/blender/blenlib/BLI_rand.h

137 lines
5.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright 2001-2002 NaN Holding BV. All rights reserved. */
#pragma once
#include "BLI_compiler_attrs.h"
#include "BLI_sys_types.h"
/** \file
* \ingroup bli
* \brief Random number functions.
*/
#ifdef __cplusplus
extern "C" {
#endif
/**
* RNG is an abstract random number generator type that avoids using globals.
* Always use this instead of the global RNG unless you have a good reason,
* the global RNG is not thread safe and will not give repeatable results.
*/
struct RNG;
typedef struct RNG RNG;
struct RNG_THREAD_ARRAY;
typedef struct RNG_THREAD_ARRAY RNG_THREAD_ARRAY;
struct RNG *BLI_rng_new(unsigned int seed);
/**
* A version of #BLI_rng_new that hashes the seed.
*/
struct RNG *BLI_rng_new_srandom(unsigned int seed);
struct RNG *BLI_rng_copy(struct RNG *rng) ATTR_NONNULL(1);
void BLI_rng_free(struct RNG *rng) ATTR_NONNULL(1);
void BLI_rng_seed(struct RNG *rng, unsigned int seed) ATTR_NONNULL(1);
/**
* Use a hash table to create better seed.
*/
void BLI_rng_srandom(struct RNG *rng, unsigned int seed) ATTR_NONNULL(1);
void BLI_rng_get_char_n(RNG *rng, char *bytes, size_t bytes_len) ATTR_NONNULL(1, 2);
int BLI_rng_get_int(struct RNG *rng) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1);
unsigned int BLI_rng_get_uint(struct RNG *rng) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1);
/**
* \return Random value (0..1), but never 1.0.
*/
double BLI_rng_get_double(struct RNG *rng) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1);
/**
* \return Random value (0..1), but never 1.0.
*/
float BLI_rng_get_float(struct RNG *rng) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1);
void BLI_rng_get_float_unit_v2(struct RNG *rng, float v[2]) ATTR_NONNULL(1, 2);
void BLI_rng_get_float_unit_v3(struct RNG *rng, float v[3]) ATTR_NONNULL(1, 2);
/**
* Generate a random point inside given tri.
*/
void BLI_rng_get_tri_sample_float_v2(struct RNG *rng,
const float v1[2],
const float v2[2],
const float v3[2],
float r_pt[2]) ATTR_NONNULL();
void BLI_rng_get_tri_sample_float_v3(RNG *rng,
const float v1[3],
const float v2[3],
const float v3[3],
float r_pt[3]) ATTR_NONNULL();
void BLI_rng_shuffle_array(struct RNG *rng,
void *data,
unsigned int elem_size_i,
unsigned int elem_num) ATTR_NONNULL(1, 2);
void BLI_rng_shuffle_bitmap(struct RNG *rng, unsigned int *bitmap, unsigned int bits_num)
ATTR_NONNULL(1, 2);
/** Note that skipping is as slow as generating n numbers! */
/**
* Simulate getting \a n random values.
*
* \note Useful when threaded code needs consistent values, independent of task division.
*/
void BLI_rng_skip(struct RNG *rng, int n) ATTR_NONNULL(1);
/**
* Fill an array with random numbers.
*/
void BLI_array_frand(float *ar, int count, unsigned int seed);
/** Return a pseudo-random (hash) float from an integer value */
float BLI_hash_frand(unsigned int seed) ATTR_WARN_UNUSED_RESULT;
/**
* Shuffle an array randomly using the given seed contents.
* This routine does not use nor modify the state of the BLI random number generator.
*/
void BLI_array_randomize(void *data,
unsigned int elem_size,
unsigned int elem_num,
unsigned int seed);
void BLI_bitmap_randomize(unsigned int *bitmap, unsigned int bits_num, unsigned int seed)
ATTR_NONNULL(1);
/** Better seed for the random number generator, using noise.c hash[] */
/** Allows up to BLENDER_MAX_THREADS threads to address */
void BLI_thread_srandom(int thread, unsigned int seed);
/** Return a pseudo-random number N where 0<=N<(2^31) */
/** Allows up to BLENDER_MAX_THREADS threads to address */
int BLI_thread_rand(int thread) ATTR_WARN_UNUSED_RESULT;
/** Return a pseudo-random number N where 0.0f<=N<1.0f */
/** Allows up to BLENDER_MAX_THREADS threads to address */
float BLI_thread_frand(int thread) ATTR_WARN_UNUSED_RESULT;
/** array versions for thread safe random generation */
RNG_THREAD_ARRAY *BLI_rng_threaded_new(void);
void BLI_rng_threaded_free(struct RNG_THREAD_ARRAY *rngarr) ATTR_NONNULL(1);
int BLI_rng_thread_rand(RNG_THREAD_ARRAY *rngarr, int thread) ATTR_WARN_UNUSED_RESULT;
/* Low-discrepancy sequences. */
/** Return the _n_th number of the given low-discrepancy sequence. */
void BLI_halton_1d(unsigned int prime, double offset, int n, double *r);
void BLI_halton_2d(const unsigned int prime[2], double offset[2], int n, double *r);
void BLI_halton_3d(const unsigned int prime[3], double offset[3], int n, double *r);
void BLI_hammersley_1d(unsigned int n, double *r);
/** Return the whole low-discrepancy sequence up to _n_. */
void BLI_halton_2d_sequence(const unsigned int prime[2], double offset[2], int n, double *r);
void BLI_hammersley_2d_sequence(unsigned int n, double *r);
#ifdef __cplusplus
}
#endif