Moving random

xelatihy · Jan 30, 2024 · caea8ac · caea8ac
1 parent 93093fb
commit caea8ac
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diff --git a/libs/yocto/yocto_math.h b/libs/yocto/yocto_math.h
@@ -2,8 +2,10 @@
 // # Yocto/Math: Math types
 //
 // Yocto/Math defines the basic math primitives used in graphics, including
-// small-sized vectors, matrices, frames, quaternions, rays, bounding boxes
-// and their transforms. Yocto/Math is implemented in `yocto_math.h`.
+// small-sized vectors, matrices, frames and their transforms.
+// Yocto/Math is implemented in `yocto_math.h`.
+// This library includes a stand-alone implementation of the PCG32 random number
+// generator by M.E. O'Neill.
 //
 
 //
@@ -29,6 +31,15 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 //
+//
+// LICENSE FOR RANDOM NUMBER GENERATION
+//
+// This code also includes a small exerpt from http://www.pcg-random.org/
+// licensed as follows
+// *Really* minimal PCG32 code / (c) 2014 M.E. O'Neill / pcg-random.org
+// Licensed under Apache License 2.0 (NO WARRANTY, etc. see website)
+//
+//
 
 #ifndef _YOCTO_MATH_H_
 #define _YOCTO_MATH_H_
@@ -43,6 +54,7 @@
 #include <limits>
 #include <tuple>
 #include <utility>
+#include <vector>
 
 // -----------------------------------------------------------------------------
 // USING DIRECTIVES
@@ -53,6 +65,7 @@ namespace yocto {
 using std::array;
 using std::pair;
 using std::tuple;
+using std::vector;
 
 }  // namespace yocto
 
@@ -1087,6 +1100,36 @@ inline frame3f camera_fpscam(const frame3f& frame, vec3f transl, vec2f rotate);
 
 }  // namespace yocto
 
+// -----------------------------------------------------------------------------
+// RANDOM NUMBER GENERATION
+// -----------------------------------------------------------------------------
+namespace yocto {
+
+// PCG random numbers from http://www.pcg-random.org/
+struct rng_state {
+  uint64_t state = 0x853c49e6748fea9bULL;
+  uint64_t inc   = 0xda3e39cb94b95bdbULL;
+};
+
+// Init a random number generator with a state state from the sequence seq.
+inline rng_state make_rng(uint64_t seed, uint64_t seq = 1);
+
+// Init a sequence of random number generators.
+inline vector<rng_state> make_rngs(
+    int num, uint64_t seed1 = 961748941ull, uint64_t seed2 = 1301081ull);
+
+// Next random numbers: floats in [0,1), ints in [0,n).
+inline int   rand1i(rng_state& rng, int n);
+inline float rand1f(rng_state& rng);
+inline vec2f rand2f(rng_state& rng);
+inline vec3f rand3f(rng_state& rng);
+
+// Shuffles a sequence of elements
+template <typename T>
+inline void shuffle(vector<T>& vals, rng_state& rng);
+
+}  // namespace yocto
+
 // -----------------------------------------------------------------------------
 // PYTHON-LIKE ITERATORS
 // -----------------------------------------------------------------------------
@@ -2708,6 +2751,83 @@ inline void update_fpscam(frame3f& frame, vec3f transl, vec2f rotate) {
 
 }  // namespace yocto
 
+// -----------------------------------------------------------------------------
+// IMPLEMENTATION FOR RANDOM NUMBER GENERATION
+// -----------------------------------------------------------------------------
+namespace yocto {
+
+// PCG random numbers from http://www.pcg-random.org/
+
+// Next random number, used internally only.
+inline uint32_t _advance_rng(rng_state& rng) {
+  uint64_t oldstate = rng.state;
+  rng.state         = oldstate * 6364136223846793005ULL + rng.inc;
+  auto xorshifted   = (uint32_t)(((oldstate >> 18u) ^ oldstate) >> 27u);
+  auto rot          = (uint32_t)(oldstate >> 59u);
+  // return (xorshifted >> rot) | (xorshifted << ((-rot) & 31));
+  return (xorshifted >> rot) | (xorshifted << ((~rot + 1u) & 31));
+}
+
+// Init a random number generator with a state state from the sequence seq.
+inline rng_state make_rng(uint64_t seed, uint64_t seq) {
+  auto rng  = rng_state();
+  rng.state = 0U;
+  rng.inc   = (seq << 1u) | 1u;
+  _advance_rng(rng);
+  rng.state += seed;
+  _advance_rng(rng);
+  return rng;
+}
+
+// Init a sequence of random number generators.
+inline vector<rng_state> make_rngs(int num, uint64_t seed1, uint64_t seed2) {
+  auto rng_ = make_rng(seed2);
+  auto rngs = vector<rng_state>(num);
+  for (auto& rng : rngs) {
+    rng = make_rng(seed1, rand1i(rng_, 1 << 31) / 2 + 1);
+  }
+  return rngs;
+}
+
+// Next random numbers: floats in [0,1), ints in [0,n).
+inline int   rand1i(rng_state& rng, int n) { return _advance_rng(rng) % n; }
+inline float rand1f(rng_state& rng) {
+  union {
+    uint32_t u;
+    float    f;
+  } x;
+  x.u = (_advance_rng(rng) >> 9) | 0x3f800000u;
+  return x.f - 1.0f;
+  // alternate implementation
+  // const static auto scale = (float)(1.0 / numeric_limits<uint32_t>::max());
+  // return advance_rng(rng) * scale;
+}
+inline vec2f rand2f(rng_state& rng) {
+  // force order of evaluation by using separate assignments.
+  auto x = rand1f(rng);
+  auto y = rand1f(rng);
+  return {x, y};
+}
+inline vec3f rand3f(rng_state& rng) {
+  // force order of evaluation by using separate assignments.
+  auto x = rand1f(rng);
+  auto y = rand1f(rng);
+  auto z = rand1f(rng);
+  return {x, y, z};
+}
+
+// Shuffles a sequence of elements
+template <typename T>
+inline void shuffle(vector<T>& vals, rng_state& rng) {
+  // https://en.wikipedia.org/wiki/Fisher–Yates_shuffle
+  for (auto i = (int)vals.size() - 1; i > 0; i--) {
+    auto j = rand1i(rng, i + 1);
+    std::swap(vals[j], vals[i]);
+  }
+}
+
+}  // namespace yocto
+
 // -----------------------------------------------------------------------------
 // PYTHON-LIKE ITERATORS
 // -----------------------------------------------------------------------------

diff --git a/libs/yocto/yocto_sampling.h b/libs/yocto/yocto_sampling.h
@@ -4,8 +4,6 @@
 // Yocto/Sampling provides many functions to generate points and directions
 // useful in path tracing and procedural generation. We also include a random
 // number generator suitable for ray tracing.
-// This library includes a stand-alone implementaton of the PCG32 random number
-// generator by M.E. O'Neill.
 //
 
 //
@@ -73,36 +71,6 @@ using std::vector;
 #define inline inline __device__ __forceinline__
 #endif
 
-// -----------------------------------------------------------------------------
-// RANDOM NUMBER GENERATION
-// -----------------------------------------------------------------------------
-namespace yocto {
-
-// PCG random numbers from http://www.pcg-random.org/
-struct rng_state {
-  uint64_t state = 0x853c49e6748fea9bULL;
-  uint64_t inc   = 0xda3e39cb94b95bdbULL;
-};
-
-// Init a random number generator with a state state from the sequence seq.
-inline rng_state make_rng(uint64_t seed, uint64_t seq = 1);
-
-// Init a sequence of random number generators.
-inline vector<rng_state> make_rngs(
-    int num, uint64_t seed1 = 961748941ull, uint64_t seed2 = 1301081ull);
-
-// Next random numbers: floats in [0,1), ints in [0,n).
-inline int   rand1i(rng_state& rng, int n);
-inline float rand1f(rng_state& rng);
-inline vec2f rand2f(rng_state& rng);
-inline vec3f rand3f(rng_state& rng);
-
-// Shuffles a sequence of elements
-template <typename T>
-inline void shuffle(vector<T>& vals, rng_state& rng);
-
-}  // namespace yocto
-
 // -----------------------------------------------------------------------------
 // MONETACARLO SAMPLING FUNCTIONS
 // -----------------------------------------------------------------------------
@@ -214,83 +182,6 @@ vector<pair<int, vec2f>> sample_shape(
 //
 // -----------------------------------------------------------------------------
 
-// -----------------------------------------------------------------------------
-// IMPLEMENTATION FOR RANDOM NUMBER GENERATION
-// -----------------------------------------------------------------------------
-namespace yocto {
-
-// PCG random numbers from http://www.pcg-random.org/
-
-// Next random number, used internally only.
-inline uint32_t _advance_rng(rng_state& rng) {
-  uint64_t oldstate = rng.state;
-  rng.state         = oldstate * 6364136223846793005ULL + rng.inc;
-  auto xorshifted   = (uint32_t)(((oldstate >> 18u) ^ oldstate) >> 27u);
-  auto rot          = (uint32_t)(oldstate >> 59u);
-  // return (xorshifted >> rot) | (xorshifted << ((-rot) & 31));
-  return (xorshifted >> rot) | (xorshifted << ((~rot + 1u) & 31));
-}
-
-// Init a random number generator with a state state from the sequence seq.
-inline rng_state make_rng(uint64_t seed, uint64_t seq) {
-  auto rng  = rng_state();
-  rng.state = 0U;
-  rng.inc   = (seq << 1u) | 1u;
-  _advance_rng(rng);
-  rng.state += seed;
-  _advance_rng(rng);
-  return rng;
-}
-
-// Init a sequence of random number generators.
-inline vector<rng_state> make_rngs(int num, uint64_t seed1, uint64_t seed2) {
-  auto rng_ = make_rng(seed2);
-  auto rngs = vector<rng_state>(num);
-  for (auto& rng : rngs) {
-    rng = make_rng(seed1, rand1i(rng_, 1 << 31) / 2 + 1);
-  }
-  return rngs;
-}
-
-// Next random numbers: floats in [0,1), ints in [0,n).
-inline int   rand1i(rng_state& rng, int n) { return _advance_rng(rng) % n; }
-inline float rand1f(rng_state& rng) {
-  union {
-    uint32_t u;
-    float    f;
-  } x;
-  x.u = (_advance_rng(rng) >> 9) | 0x3f800000u;
-  return x.f - 1.0f;
-  // alternate implementation
-  // const static auto scale = (float)(1.0 / numeric_limits<uint32_t>::max());
-  // return advance_rng(rng) * scale;
-}
-inline vec2f rand2f(rng_state& rng) {
-  // force order of evaluation by using separate assignments.
-  auto x = rand1f(rng);
-  auto y = rand1f(rng);
-  return {x, y};
-}
-inline vec3f rand3f(rng_state& rng) {
-  // force order of evaluation by using separate assignments.
-  auto x = rand1f(rng);
-  auto y = rand1f(rng);
-  auto z = rand1f(rng);
-  return {x, y, z};
-}
-
-// Shuffles a sequence of elements
-template <typename T>
-inline void shuffle(vector<T>& vals, rng_state& rng) {
-  // https://en.wikipedia.org/wiki/Fisher–Yates_shuffle
-  for (auto i = (int)vals.size() - 1; i > 0; i--) {
-    auto j = rand1i(rng, i + 1);
-    std::swap(vals[j], vals[i]);
-  }
-}
-
-}  // namespace yocto
-
 // -----------------------------------------------------------------------------
 // IMPLEMENTATION OF MONTECARLO SAMPLING FUNCTIONS
 // -----------------------------------------------------------------------------