Switch the (P)RNG from a standard Mersenne Twister to PCG.

Author: JoshuaSenouf

CMakeLists.txt

@@ -21,7 +21,6 @@ include(Options)
 include(CXX)
 
 # Setup external dependencies
-# include(SetupBoost)
 include(SetupTBB)
 include(SetupEmbree)
 include(SetupGLFW)

cmake/dependencies/internal/SetupPCG.cmake

@@ -0,0 +1,8 @@
+add_library(
+    pcg INTERFACE
+)
+
+target_include_directories(
+    pcg INTERFACE
+    "pcg"
+)

cpp/include/sampling/sampler.h

@@ -4,6 +4,8 @@
 #include <algorithm>
 #include <random>
 
+#include "pcg_random.hpp"
+
 #include <embree3/common/math/vec2.h>
 #include <embree3/common/math/vec3.h>
 
@@ -13,7 +15,7 @@ class Sampler
     public:
         Sampler();
 
-        unsigned NewSeed();
+        pcg_extras::seed_seq_from<std::random_device> NewSeed();
         float Uniform1D();
         embree::Vec2f Uniform2D();
         std::vector<embree::Vec2f> Stratified2D(
@@ -30,7 +32,7 @@ class Sampler
 
     private:
         std::uniform_real_distribution<float> float_uniform_distribution;
-        std::mt19937 prng;
+        pcg32 prng;
 };
 
 #endif // SAMPLER_H

cpp/src/CMakeLists.txt

@@ -27,6 +27,7 @@ target_link_libraries(
     embree_common
     glad
     imgui
+    pcg
     spdlog
     tinyexr
     # External dependencies.

cpp/src/sampling/sampler.cpp

@@ -9,12 +9,9 @@ Sampler::Sampler():
 {
 }
 
-unsigned Sampler::NewSeed()
+pcg_extras::seed_seq_from<std::random_device> Sampler::NewSeed()
 {
-    std::uniform_int_distribution<unsigned> seed;
-    std::random_device rng;
-
-    return seed(rng);
+    return pcg_extras::seed_seq_from<std::random_device>();
 }
 
 float Sampler::Uniform1D()

thirdparty/CMakeLists.txt

@@ -3,5 +3,6 @@ include(SetupCLI11)
 include(SetupEmbreeCommon)
 include(SetupGLAD)
 include(SetupImGui)
+include(SetupPCG)
 include(SetupSPDLog)
 include(SetupTinyEXR)