From 18a6b27cfed82e8b131d8709ddb68e9168a62171 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20M=C3=B6bius?= <moebius@cs.rwth-aachen.de>
Date: Fri, 28 Sep 2012 15:28:38 +0000
Subject: [PATCH] Unittest for random number generator

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@719 fdac6126-5c0c-442c-9429-916003d36597
---
 src/Unittests/unittests.cc                    |  1 +
 .../unittests_randomNumberGenerator.hh        | 92 +++++++++++++++++++
 2 files changed, 93 insertions(+)
 create mode 100644 src/Unittests/unittests_randomNumberGenerator.hh

diff --git a/src/Unittests/unittests.cc b/src/Unittests/unittests.cc
index 44ec6240..b849f4fc 100644
--- a/src/Unittests/unittests.cc
+++ b/src/Unittests/unittests.cc
@@ -15,6 +15,7 @@
 #include "unittests_add_face.hh"
 #include "unittests_faceless_mesh.hh"
 #include "unittests_trimesh_garbage_collection.hh"
+#include "unittests_randomNumberGenerator.hh"
 
 int main(int _argc, char** _argv) {
 
diff --git a/src/Unittests/unittests_randomNumberGenerator.hh b/src/Unittests/unittests_randomNumberGenerator.hh
new file mode 100644
index 00000000..91b57b7e
--- /dev/null
+++ b/src/Unittests/unittests_randomNumberGenerator.hh
@@ -0,0 +1,92 @@
+#ifndef INCLUDE_UNITTESTS_RANDOMNUMBER_HH
+#define INCLUDE_UNITTESTS_RANDOMNUMBER_HH
+
+#include <gtest/gtest.h>
+#include <OpenMesh/Core/Utils/RandomNumberGenerator.hh>
+
+class RandomNumberGenerator : public testing::Test {
+
+    protected:
+
+        // This function is called before each test is run
+        virtual void SetUp() {
+            
+            // Do some initial stuff with the member data here...
+        }
+
+        // This function is called after all tests are through
+        virtual void TearDown() {
+
+            // Do some final stuff with the member data here...
+        }
+
+    // Member already defined in OpenMeshBase
+    //Mesh mesh_;  
+};
+
+/*
+ * ====================================================================
+ * Define tests below
+ * ====================================================================
+ */
+
+TEST_F(RandomNumberGenerator, RandomNumberGeneratorMaxTestHighres) {
+
+
+  OpenMesh::RandomNumberGenerator rng(100000000);
+
+  unsigned int lowerZero = 0;
+  unsigned int above1    = 0;
+
+  double average = 0.0;
+
+  for ( unsigned int i = 0 ; i < 100000000 ; ++i) {
+    double randomNumber = rng.getRand();
+    if ( randomNumber < 0.0  )
+      lowerZero++;
+
+    if ( randomNumber > 1.0  )
+      above1++;
+
+    average += randomNumber;
+  }
+
+  average /= 100000000.0;
+
+  EXPECT_EQ(0u, lowerZero ) << "Below zero!";
+  EXPECT_EQ(0u, above1 ) << "Above zero!";
+
+  EXPECT_TRUE( (average - 0.5) < 0.01 ) << "Expected value not 0.5";
+}
+
+TEST_F(RandomNumberGenerator, RandomNumberGeneratorMaxTestLowres) {
+
+  OpenMesh::RandomNumberGenerator rng(1000);
+
+  unsigned int lowerZero = 0;
+  unsigned int above1    = 0;
+
+  double average = 0.0;
+
+  for ( unsigned int i = 0 ; i < 10000000 ; ++i) {
+
+    double randomNumber = rng.getRand();
+     if ( randomNumber < 0.0  )
+       lowerZero++;
+
+     if ( randomNumber > 1.0  )
+       above1++;
+
+     average += randomNumber;
+  }
+
+  average /= 10000000.0;
+
+  EXPECT_EQ(0u, lowerZero ) << "Below zero!";
+  EXPECT_EQ(0u, above1 ) << "Above zero!";
+
+  EXPECT_TRUE( (average - 0.5) < 0.01 ) << "Expected value not 0.5";
+}
+
+
+#endif // INCLUDE GUARD