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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*/
/** \file
* \ingroup bli
*/
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#include "MEM_guardedalloc.h"
#include "BLI_threads.h"
#include "BLI_rand.h"
#include "BLI_math.h"
/* defines BLI_INLINE */
#include "BLI_compiler_compat.h"
#include "BLI_sys_types.h"
#include "BLI_strict_flags.h"
#define MULTIPLIER 0x5DEECE66Dll
#define MASK 0x0000FFFFFFFFFFFFll
#define MASK_BYTES 2
#define ADDEND 0xB
#define LOWSEED 0x330E
extern unsigned char hash[]; // noise.c
/**
* Random Number Generator.
*/
struct RNG {
uint64_t X;
};
RNG *BLI_rng_new(unsigned int seed)
{
RNG *rng = MEM_mallocN(sizeof(*rng), "rng");
BLI_rng_seed(rng, seed);
return rng;
}
/**
* A version of #BLI_rng_new that hashes the seed.
*/
RNG *BLI_rng_new_srandom(unsigned int seed)
{
RNG *rng = MEM_mallocN(sizeof(*rng), "rng");
BLI_rng_srandom(rng, seed);
return rng;
}
RNG *BLI_rng_copy(RNG *rng)
{
return MEM_dupallocN(rng);
}
void BLI_rng_free(RNG *rng)
{
MEM_freeN(rng);
}
void BLI_rng_seed(RNG *rng, unsigned int seed)
{
rng->X = (((uint64_t) seed) << 16) | LOWSEED;
}
/**
* Use a hash table to create better seed.
*/
void BLI_rng_srandom(RNG *rng, unsigned int seed)
{
BLI_rng_seed(rng, seed + hash[seed & 255]);
seed = BLI_rng_get_uint(rng);
BLI_rng_seed(rng, seed + hash[seed & 255]);
seed = BLI_rng_get_uint(rng);
BLI_rng_seed(rng, seed + hash[seed & 255]);
}
BLI_INLINE void rng_step(RNG *rng)
{
rng->X = (MULTIPLIER * rng->X + ADDEND) & MASK;
}
void BLI_rng_get_char_n(RNG *rng, char *bytes, size_t bytes_len)
{
size_t last_len = 0;
size_t trim_len = bytes_len;
#define RAND_STRIDE (sizeof(rng->X) - MASK_BYTES)
if (trim_len > RAND_STRIDE) {
last_len = trim_len % RAND_STRIDE;
trim_len = trim_len - last_len;
}
else {
trim_len = 0;
last_len = bytes_len;
}
const char *data_src = (void *)&(rng->X);
size_t i = 0;
while (i != trim_len) {
BLI_assert(i < trim_len);
#ifdef __BIG_ENDIAN__
for (size_t j = (RAND_STRIDE + MASK_BYTES) - 1; j != MASK_BYTES - 1; j--)
#else
for (size_t j = 0; j != RAND_STRIDE; j++)
#endif
{
bytes[i++] = data_src[j];
}
rng_step(rng);
}
if (last_len) {
for (size_t j = 0; j != last_len; j++) {
bytes[i++] = data_src[j];
}
}
#undef RAND_STRIDE
}
int BLI_rng_get_int(RNG *rng)
{
rng_step(rng);
return (int) (rng->X >> 17);
}
unsigned int BLI_rng_get_uint(RNG *rng)
{
rng_step(rng);
return (unsigned int) (rng->X >> 17);
}
/**
* \return Random value (0..1), but never 1.0.
*/
double BLI_rng_get_double(RNG *rng)
{
return (double) BLI_rng_get_int(rng) / 0x80000000;
}
/**
* \return Random value (0..1), but never 1.0.
*/
float BLI_rng_get_float(RNG *rng)
{
return (float) BLI_rng_get_int(rng) / 0x80000000;
}
void BLI_rng_get_float_unit_v2(RNG *rng, float v[2])
{
float a = (float)(M_PI * 2.0) * BLI_rng_get_float(rng);
v[0] = cosf(a);
v[1] = sinf(a);
}
void BLI_rng_get_float_unit_v3(RNG *rng, float v[3])
{
float r;
v[2] = (2.0f * BLI_rng_get_float(rng)) - 1.0f;
if ((r = 1.0f - (v[2] * v[2])) > 0.0f) {
float a = (float)(M_PI * 2.0) * BLI_rng_get_float(rng);
r = sqrtf(r);
v[0] = r * cosf(a);
v[1] = r * sinf(a);
}
else {
v[2] = 1.0f;
}
}
/**
* Generate a random point inside given tri.
*/
void BLI_rng_get_tri_sample_float_v2(
RNG *rng, const float v1[2], const float v2[2], const float v3[2],
float r_pt[2])
{
float u = BLI_rng_get_float(rng);
float v = BLI_rng_get_float(rng);
float side_u[2], side_v[2];
if ((u + v) > 1.0f) {
u = 1.0f - u;
v = 1.0f - v;
}
sub_v2_v2v2(side_u, v2, v1);
sub_v2_v2v2(side_v, v3, v1);
copy_v2_v2(r_pt, v1);
madd_v2_v2fl(r_pt, side_u, u);
madd_v2_v2fl(r_pt, side_v, v);
}
void BLI_rng_shuffle_array(RNG *rng, void *data, unsigned int elem_size_i, unsigned int elem_tot)
{
const size_t elem_size = (size_t)elem_size_i;
unsigned int i = elem_tot;
void *temp;
if (elem_tot <= 1) {
return;
}
temp = malloc(elem_size);
while (i--) {
unsigned int j = BLI_rng_get_uint(rng) % elem_tot;
if (i != j) {
void *iElem = (unsigned char *)data + i * elem_size_i;
void *jElem = (unsigned char *)data + j * elem_size_i;
memcpy(temp, iElem, elem_size);
memcpy(iElem, jElem, elem_size);
memcpy(jElem, temp, elem_size);
}
}
free(temp);
}
/**
* Simulate getting \a n random values.
*
* \note Useful when threaded code needs consistent values, independent of task division.
*/
void BLI_rng_skip(RNG *rng, int n)
{
while (n--) {
rng_step(rng);
}
}
/***/
/* fill an array with random numbers */
void BLI_array_frand(float *ar, int count, unsigned int seed)
{
RNG rng;
BLI_rng_srandom(&rng, seed);
for (int i = 0; i < count; i++) {
ar[i] = BLI_rng_get_float(&rng);
}
}
float BLI_hash_frand(unsigned int seed)
{
RNG rng;
BLI_rng_srandom(&rng, seed);
return BLI_rng_get_float(&rng);
}
void BLI_array_randomize(void *data, unsigned int elem_size, unsigned int elem_tot, unsigned int seed)
{
RNG rng;
BLI_rng_seed(&rng, seed);
BLI_rng_shuffle_array(&rng, data, elem_size, elem_tot);
}
/* ********* for threaded random ************** */
static RNG rng_tab[BLENDER_MAX_THREADS];
void BLI_thread_srandom(int thread, unsigned int seed)
{
if (thread >= BLENDER_MAX_THREADS)
thread = 0;
BLI_rng_seed(&rng_tab[thread], seed + hash[seed & 255]);
seed = BLI_rng_get_uint(&rng_tab[thread]);
BLI_rng_seed(&rng_tab[thread], seed + hash[seed & 255]);
seed = BLI_rng_get_uint(&rng_tab[thread]);
BLI_rng_seed(&rng_tab[thread], seed + hash[seed & 255]);
}
int BLI_thread_rand(int thread)
{
return BLI_rng_get_int(&rng_tab[thread]);
}
float BLI_thread_frand(int thread)
{
return BLI_rng_get_float(&rng_tab[thread]);
}
struct RNG_THREAD_ARRAY {
RNG rng_tab[BLENDER_MAX_THREADS];
};
RNG_THREAD_ARRAY *BLI_rng_threaded_new(void)
{
unsigned int i;
RNG_THREAD_ARRAY *rngarr = MEM_mallocN(sizeof(RNG_THREAD_ARRAY), "random_array");
for (i = 0; i < BLENDER_MAX_THREADS; i++) {
BLI_rng_srandom(&rngarr->rng_tab[i], (unsigned int)clock());
}
return rngarr;
}
void BLI_rng_threaded_free(struct RNG_THREAD_ARRAY *rngarr)
{
MEM_freeN(rngarr);
}
int BLI_rng_thread_rand(RNG_THREAD_ARRAY *rngarr, int thread)
{
return BLI_rng_get_int(&rngarr->rng_tab[thread]);
}
/* ********* Low-discrepancy sequences ************** */
/* incremental halton sequence generator, from:
* "Instant Radiosity", Keller A. */
BLI_INLINE double halton_ex(double invprimes, double *offset)
{
double e = fabs((1.0 - *offset) - 1e-10);
if (invprimes >= e) {
double lasth;
double h = invprimes;
do {
lasth = h;
h *= invprimes;
} while (h >= e);
*offset += ((lasth + h) - 1.0);
}
else {
*offset += invprimes;
}
return *offset;
}
void BLI_halton_1D(unsigned int prime, double offset, int n, double *r)
{
const double invprime = 1.0 / (double)prime;
*r = 0.0;
for (int s = 0; s < n; s++) {
*r = halton_ex(invprime, &offset);
}
}
void BLI_halton_2D(unsigned int prime[2], double offset[2], int n, double *r)
{
const double invprimes[2] = {1.0 / (double)prime[0], 1.0 / (double)prime[1]};
r[0] = r[1] = 0.0;
for (int s = 0; s < n; s++) {
for (int i = 0; i < 2; i++) {
r[i] = halton_ex(invprimes[i], &offset[i]);
}
}
}
void BLI_halton_3D(unsigned int prime[3], double offset[3], int n, double *r)
{
const double invprimes[3] = {1.0 / (double)prime[0], 1.0 / (double)prime[1], 1.0 / (double)prime[2]};
r[0] = r[1] = r[2] = 0.0;
for (int s = 0; s < n; s++) {
for (int i = 0; i < 3; i++) {
r[i] = halton_ex(invprimes[i], &offset[i]);
}
}
}
void BLI_halton_2D_sequence(unsigned int prime[2], double offset[2], int n, double *r)
{
const double invprimes[2] = {1.0 / (double)prime[0], 1.0 / (double)prime[1]};
for (int s = 0; s < n; s++) {
for (int i = 0; i < 2; i++) {
r[s * 2 + i] = halton_ex(invprimes[i], &offset[i]);
}
}
}
/* From "Sampling with Hammersley and Halton Points" TT Wong
* Appendix: Source Code 1 */
BLI_INLINE double radical_inverse(unsigned int n)
{
double u = 0;
/* This reverse the bitwise representation
* around the decimal point. */
for (double p = 0.5; n; p *= 0.5, n >>= 1) {
if (n & 1) {
u += p;
}
}
return u;
}
void BLI_hammersley_1D(unsigned int n, double *r)
{
*r = radical_inverse(n);
}
void BLI_hammersley_2D_sequence(unsigned int n, double *r)
{
for (unsigned int s = 0; s < n; s++) {
r[s * 2 + 0] = (double)(s + 0.5) / (double)n;
r[s * 2 + 1] = radical_inverse(s);
}
}
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