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Thirdparty/DBoW2/DUtils/Random.cpp

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+/*	
+ * File: Random.cpp
+ * Project: DUtils library
+ * Author: Dorian Galvez-Lopez
+ * Date: April 2010
+ * Description: manages pseudo-random numbers
+ * License: see the LICENSE.txt file
+ *
+ */
+
+#include "Random.h"
+#include "Timestamp.h"
+#include <cstdlib>
+using namespace std;
+
+bool DUtils::Random::m_already_seeded = false;
+
+void DUtils::Random::SeedRand(){
+	Timestamp time;
+	time.setToCurrentTime();
+	srand((unsigned)time.getFloatTime()); 
+}
+
+void DUtils::Random::SeedRandOnce()
+{
+  if(!m_already_seeded)
+  {
+    DUtils::Random::SeedRand();
+    m_already_seeded = true;
+  }
+}
+
+void DUtils::Random::SeedRand(int seed)
+{
+	srand(seed); 
+}
+
+void DUtils::Random::SeedRandOnce(int seed)
+{
+  if(!m_already_seeded)
+  {
+    DUtils::Random::SeedRand(seed);
+    m_already_seeded = true;
+  }
+}
+
+int DUtils::Random::RandomInt(int min, int max){
+	int d = max - min + 1;
+	return int(((double)rand()/((double)RAND_MAX + 1.0)) * d) + min;
+}
+
+// ---------------------------------------------------------------------------
+// ---------------------------------------------------------------------------
+
+DUtils::Random::UnrepeatedRandomizer::UnrepeatedRandomizer(int min, int max)
+{
+  if(min <= max)
+  {
+    m_min = min;
+    m_max = max;
+  }
+  else
+  {
+    m_min = max;
+    m_max = min;
+  }
+
+  createValues();
+}
+
+// ---------------------------------------------------------------------------
+
+DUtils::Random::UnrepeatedRandomizer::UnrepeatedRandomizer
+  (const DUtils::Random::UnrepeatedRandomizer& rnd)
+{
+  *this = rnd;
+}
+
+// ---------------------------------------------------------------------------
+
+int DUtils::Random::UnrepeatedRandomizer::get()
+{
+  if(empty()) createValues();
+  
+  DUtils::Random::SeedRandOnce();
+  
+  int k = DUtils::Random::RandomInt(0, m_values.size()-1);
+  int ret = m_values[k];
+  m_values[k] = m_values.back();
+  m_values.pop_back();
+  
+  return ret;
+}
+
+// ---------------------------------------------------------------------------
+
+void DUtils::Random::UnrepeatedRandomizer::createValues()
+{
+  int n = m_max - m_min + 1;
+  
+  m_values.resize(n);
+  for(int i = 0; i < n; ++i) m_values[i] = m_min + i;
+}
+
+// ---------------------------------------------------------------------------
+
+void DUtils::Random::UnrepeatedRandomizer::reset()
+{
+  if((int)m_values.size() != m_max - m_min + 1) createValues();
+}
+
+// ---------------------------------------------------------------------------
+
+DUtils::Random::UnrepeatedRandomizer& 
+DUtils::Random::UnrepeatedRandomizer::operator=
+  (const DUtils::Random::UnrepeatedRandomizer& rnd)
+{
+  if(this != &rnd)
+  {
+    this->m_min = rnd.m_min;
+    this->m_max = rnd.m_max;
+    this->m_values = rnd.m_values;
+  }
+  return *this;
+}
+
+// ---------------------------------------------------------------------------
+
+