[Bf-blender-cvs] [cbfedf2139e] master: BLI: add C++ random number generator
Jacques Lucke
noreply at git.blender.org
Fri Jul 10 15:54:55 CEST 2020
Commit: cbfedf2139eb50df03217c9a6f036260a7b9f0b0
Author: Jacques Lucke
Date: Fri Jul 10 15:53:36 2020 +0200
Branches: master
https://developer.blender.org/rBcbfedf2139eb50df03217c9a6f036260a7b9f0b0
BLI: add C++ random number generator
This adds `blender::RandomNumberGenerator` in `BLI_rand.hh`.
Furthermore, `RNG` is now implemented in terms of this new generator.
No functional changes are expected, the generated random numbers
are not changed by this commit.
Reviewers: campbellbarton, brecht
Differential Revision: https://developer.blender.org/D8259
===================================================================
A source/blender/blenlib/BLI_rand.hh
M source/blender/blenlib/intern/rand.cc
===================================================================
diff --git a/source/blender/blenlib/BLI_rand.hh b/source/blender/blenlib/BLI_rand.hh
new file mode 100644
index 00000000000..bfc4d276165
--- /dev/null
+++ b/source/blender/blenlib/BLI_rand.hh
@@ -0,0 +1,109 @@
+/*
+ * 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.
+ */
+
+/** \file
+ * \ingroup bli
+ */
+
+#ifndef __BLI_RAND_HH__
+#define __BLI_RAND_HH__
+
+#include "BLI_float2.hh"
+#include "BLI_float3.hh"
+#include "BLI_math.h"
+#include "BLI_span.hh"
+#include "BLI_utildefines.h"
+
+namespace blender {
+
+class RandomNumberGenerator {
+ private:
+ uint64_t x_;
+
+ public:
+ RandomNumberGenerator(uint32_t seed = 0)
+ {
+ this->seed(seed);
+ }
+
+ /**
+ * Set the seed for future random numbers.
+ */
+ void seed(uint32_t seed)
+ {
+ constexpr uint64_t lowseed = 0x330E;
+ x_ = (((uint64_t)seed) << 16) | lowseed;
+ }
+
+ void seed_random(uint32_t seed);
+
+ uint32_t get_uint32()
+ {
+ this->step();
+ return (uint32_t)(x_ >> 17);
+ }
+
+ int32_t get_int32()
+ {
+ this->step();
+ return (int32_t)(x_ >> 17);
+ }
+
+ /**
+ * \return Random value (0..1), but never 1.0.
+ */
+ double get_double()
+ {
+ return (double)this->get_int32() / 0x80000000;
+ }
+
+ /**
+ * \return Random value (0..1), but never 1.0.
+ */
+ float get_float()
+ {
+ return (float)this->get_int32() / 0x80000000;
+ }
+
+ float2 get_unit_float2();
+ float3 get_unit_float3();
+ float2 get_triangle_sample(float2 v1, float2 v2, float2 v3);
+ void get_bytes(MutableSpan<char> r_bytes);
+
+ /**
+ * Simulate getting \a n random values.
+ */
+ void skip(uint n)
+ {
+ while (n--) {
+ this->step();
+ }
+ }
+
+ private:
+ void step()
+ {
+ constexpr uint64_t multiplier = 0x5DEECE66Dll;
+ constexpr uint64_t addend = 0xB;
+ constexpr uint64_t mask = 0x0000FFFFFFFFFFFFll;
+
+ x_ = (multiplier * x_ + addend) & mask;
+ }
+};
+
+} // namespace blender
+
+#endif /* __BLI_RAND_HH__ */
diff --git a/source/blender/blenlib/intern/rand.cc b/source/blender/blenlib/intern/rand.cc
index 79e98181958..3dbe33764a9 100644
--- a/source/blender/blenlib/intern/rand.cc
+++ b/source/blender/blenlib/intern/rand.cc
@@ -30,6 +30,7 @@
#include "BLI_math.h"
#include "BLI_rand.h"
+#include "BLI_rand.hh"
#include "BLI_threads.h"
/* defines BLI_INLINE */
@@ -38,13 +39,6 @@
#include "BLI_strict_flags.h"
#include "BLI_sys_types.h"
-#define MULTIPLIER 0x5DEECE66Dll
-#define MASK 0x0000FFFFFFFFFFFFll
-#define MASK_BYTES 2
-
-#define ADDEND 0xB
-#define LOWSEED 0x330E
-
extern "C" unsigned char BLI_noise_hash_uchar_512[512]; /* noise.c */
#define hash BLI_noise_hash_uchar_512
@@ -52,15 +46,15 @@ extern "C" unsigned char BLI_noise_hash_uchar_512[512]; /* noise.c */
* Random Number Generator.
*/
struct RNG {
- uint64_t X;
+ blender::RandomNumberGenerator rng;
+
+ MEM_CXX_CLASS_ALLOC_FUNCS("RNG")
};
RNG *BLI_rng_new(unsigned int seed)
{
- RNG *rng = (RNG *)MEM_mallocN(sizeof(*rng), "rng");
-
- BLI_rng_seed(rng, seed);
-
+ RNG *rng = new RNG();
+ rng->rng.seed(seed);
return rng;
}
@@ -69,26 +63,24 @@ RNG *BLI_rng_new(unsigned int seed)
*/
RNG *BLI_rng_new_srandom(unsigned int seed)
{
- RNG *rng = (RNG *)MEM_mallocN(sizeof(*rng), "rng");
-
- BLI_rng_srandom(rng, seed);
-
+ RNG *rng = new RNG();
+ rng->rng.seed_random(seed);
return rng;
}
RNG *BLI_rng_copy(RNG *rng)
{
- return (RNG *)MEM_dupallocN(rng);
+ return new RNG(*rng);
}
void BLI_rng_free(RNG *rng)
{
- MEM_freeN(rng);
+ delete rng;
}
void BLI_rng_seed(RNG *rng, unsigned int seed)
{
- rng->X = (((uint64_t)seed) << 16) | LOWSEED;
+ rng->rng.seed(seed);
}
/**
@@ -96,67 +88,23 @@ void BLI_rng_seed(RNG *rng, unsigned int 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;
+ rng->rng.seed_random(seed);
}
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 = (const char *)&(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
+ BLI_assert(bytes_len > UINT32_MAX);
+ rng->rng.get_bytes(blender::MutableSpan(bytes, (uint32_t)bytes_len));
}
int BLI_rng_get_int(RNG *rng)
{
- rng_step(rng);
- return (int)(rng->X >> 17);
+ return rng->rng.get_int32();
}
unsigned int BLI_rng_get_uint(RNG *rng)
{
- rng_step(rng);
- return (unsigned int)(rng->X >> 17);
+ return rng->rng.get_uint32();
}
/**
@@ -164,7 +112,7 @@ unsigned int BLI_rng_get_uint(RNG *rng)
*/
double BLI_rng_get_double(RNG *rng)
{
- return (double)BLI_rng_get_int(rng) / 0x80000000;
+ return rng->rng.get_double();
}
/**
@@ -172,29 +120,17 @@ double BLI_rng_get_double(RNG *rng)
*/
float BLI_rng_get_float(RNG *rng)
{
- return (float)BLI_rng_get_int(rng) / 0x80000000;
+ return rng->rng.get_float();
}
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);
+ copy_v2_v2(v, rng->rng.get_unit_float2());
}
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;
- }
+ copy_v3_v3(v, rng->rng.get_unit_float3());
}
/**
@@ -203,27 +139,12 @@ void BLI_rng_get_float_unit_v3(RNG *rng, float v[3])
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);
+ copy_v2_v2(r_pt, rng->rng.get_triangle_sample(v1, v2, v3));
}
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;
+ const uint elem_size = elem_size_i;
unsigned int i = elem_tot;
void *temp;
@@ -254,9 +175,7 @@ void BLI_rng_shuffle_array(RNG *rng, void *data, unsigned int elem_size_i, unsig
*/
void BLI_rng_skip(RNG *rng, int n)
{
- while (n--) {
- rng_step(rng);
- }
+ rng->rng.skip((uint)n);
}
/***/
@@ -450,3 +369,99 @@ void BLI_hammersley_2d_sequence(unsigned int n, double *r)
r[s * 2 + 1] = radical_inverse(s);
}
}
+
+namespace blender {
+
+/**
+ * Set a randomized hash of the value as seed.
+ */
+void RandomNumberGenerator::seed_random(uint32_t seed)
+{
+ this->seed(seed + hash[seed & 255]);
+ seed = this->get_uint32();
+ this->seed(seed + hash[seed & 255]);
+ seed = this->get_uint32();
+ this->seed(seed + hash[seed & 255]);
+}
+
+float2 RandomNumberGenerator::get_unit_float2()
+{
+ float a = (float)(M_PI * 2.0) * this->get_float();
+ return {cosf(a), sinf(a)};
+}
+
+float3 RandomNumberGenerator::get_unit_float3()
+{
+ float z = (2.0f * this->get_float()) - 1.0f;
+ float r = 1.0f - z * z;
+ if (r > 0.0f) {
+ float a = (float)(M_PI * 2.0) * this->get_float();
+ r = sqrtf(r);
+ float x = r * cosf(a);
+ float y = r * sinf(a);
+ return {x, y, z};
+ }
+ return {0.0f, 0.0f, 1.0f};
+}
+
+/**
+ * Generate a random point inside the given triangle.
+ */
+float2 RandomNumberGenerator::get_triangle_sample(float2 v1, float2 v2, float2 v3)
+{
+ float u = this->get_float();
+ float v = this->get_float();
+
+ if (u + v > 1.0f) {
+ u = 1.0f - u;
+ v = 1.0f - v;
+ }
+
+ float2 side_u = v2 - v1;
+ float2 side_v = v3 - v1;
+
+ float2 sample = v1;
+ sample += side_u * u;
+ sample += side_v * v;
+ return sample;
+}
+
+void RandomNumberGenerator::get_bytes(MutableSpan<char> r_bytes)
+{
+ constexpr uint mask_bytes = 2;
+ constexpr uint rand_stride = (uint)sizeof(x_) - mask_bytes;
+
+ uint last_len = 0;
+ uint trim_len = r_bytes.size();
+
+ if (trim_len > rand_stride) {
+ last_len = trim_len % rand_stride;
+ trim_len = trim_len - last_len;
+ }
+ else {
+ trim_len = 0;
+ last_len = r_bytes.size();
+ }
+
+ const char *data_src = (const char *)&x_;
+ uint i = 0;
+ while (i != trim_len) {
+ BLI_assert(i < trim_len);
+#ifdef __BIG_ENDIAN__
+ for (uint j = (rand_stride + mask_bytes) - 1; j != mask_bytes - 1; j--)
+#else
+ for (uint j = 0; j != rand_stride; j++)
+#endif
+ {
+ r_bytes[i++] = data_src[j];
+ }
+ this->step();
+ }
+ if (
@@ Diff output truncated at 10240 characters. @@
More information about the Bf-blender-cvs
mailing list