From aec8880e851a7eedc2669eb3254e52f471264d26 Mon Sep 17 00:00:00 2001
From: alemuntoni <muntoni.alessandro@gmail.com>
Date: Mon, 23 Aug 2021 16:24:23 +0200
Subject: [PATCH] restore deterministic poisson sampling

---
 vcg/complex/algorithms/point_sampling.h | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/vcg/complex/algorithms/point_sampling.h b/vcg/complex/algorithms/point_sampling.h
index d5e711f8..1647e782 100644
--- a/vcg/complex/algorithms/point_sampling.h
+++ b/vcg/complex/algorithms/point_sampling.h
@@ -502,6 +502,18 @@ static unsigned int RandomInt(unsigned int i)
     return (SamplingRandomGenerator().generate(i));
 }
 
+class MarsenneTwisterURBG
+{
+public:
+	typedef unsigned int result_type;
+	MarsenneTwisterURBG(result_type max) : _max(max) {}
+	result_type min() const {return 0;}
+	result_type max() const {return _max;}
+	result_type operator()() {return SamplingRandomGenerator().generate(_max);}
+private:
+	result_type _max;
+};
+
 // Returns a random number in the [0,1) real interval using the improved Marsenne-Twister method.
 static double RandomDouble01()
 {
@@ -714,8 +726,9 @@ static void	FillAndShuffleFacePointerVector(MeshType & m, std::vector<FacePointe
     assert((int)faceVec.size()==m.fn);
 
     //unsigned int (*p_myrandom)(unsigned int) = RandomInt;
-    std::random_device rd;
-    std::mt19937 g(rd());
+    //std::random_device rd;
+    //std::mt19937 g(rd());
+    MarsenneTwisterURBG g(faceVec.size());
     std::shuffle(faceVec.begin(),faceVec.end(), g);
 }
 static void	FillAndShuffleVertexPointerVector(MeshType & m, std::vector<VertexPointer> &vertVec)
@@ -726,8 +739,9 @@ static void	FillAndShuffleVertexPointerVector(MeshType & m, std::vector<VertexPo
     assert((int)vertVec.size()==m.vn);
 
     //unsigned int (*p_myrandom)(unsigned int) = RandomInt;
-    std::random_device rd;
-    std::mt19937 g(rd());
+    //std::random_device rd;
+    //std::mt19937 g(rd());
+    MarsenneTwisterURBG g(vertVec.size());
     std::shuffle(vertVec.begin(),vertVec.end(), g);
 }