5 files changed, 83 insertions, 0 deletions
diff --git a/Swiften/Base/BoostRandomGenerator.cpp b/Swiften/Base/BoostRandomGenerator.cpp
new file mode 100644
index 0000000..b8c50d0
--- /dev/null
+++ b/Swiften/Base/BoostRandomGenerator.cpp
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2012 Remko Tronçon
+ * Licensed under the GNU General Public License v3.
+ * See Documentation/Licenses/GPLv3.txt for more information.
+ */
+
+#include <Swiften/Base/BoostRandomGenerator.h>
+
+#include <numeric>
+#include <boost/random/uniform_real.hpp>
+#include <boost/random/variate_generator.hpp>
+
+namespace Swift {
+
+int BoostRandomGenerator::generateWeighedRandomNumber(std::vector<double>::const_iterator probabilities_begin, std::vector<double>::const_iterator probabilities_end) {
+	// Only works starting boost 1.47
+	//boost::random::discrete_distribution<> distribution(weights.begin(), weights.end());
+	//return distribution(generator);
+
+	std::vector<double> cumulative;
+	std::partial_sum(probabilities_begin, probabilities_end, std::back_inserter(cumulative));
+	boost::uniform_real<> dist(0, cumulative.back());
+	boost::variate_generator<boost::mt19937&, boost::uniform_real<> > die(generator, dist);
+	return std::lower_bound(cumulative.begin(), cumulative.end(), die()) - cumulative.begin();
+}
+
+}
diff --git a/Swiften/Base/BoostRandomGenerator.h b/Swiften/Base/BoostRandomGenerator.h
new file mode 100644
index 0000000..ffc7a72
--- /dev/null
+++ b/Swiften/Base/BoostRandomGenerator.h
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2012 Remko Tronçon
+ * Licensed under the GNU General Public License v3.
+ * See Documentation/Licenses/GPLv3.txt for more information.
+ */
+
+#pragma once
+
+#include <Swiften/Base/RandomGenerator.h>
+
+#include <boost/random/mersenne_twister.hpp>
+
+namespace Swift {
+	class BoostRandomGenerator : public RandomGenerator{
+		public:
+			int generateWeighedRandomNumber(std::vector<double>::const_iterator probabilities_begin, std::vector<double>::const_iterator probabilities_end);
+
+		private:
+			boost::mt19937 generator;
+	};
+}
diff --git a/Swiften/Base/RandomGenerator.cpp b/Swiften/Base/RandomGenerator.cpp
new file mode 100644
index 0000000..f2dcca3
--- /dev/null
+++ b/Swiften/Base/RandomGenerator.cpp
@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2012 Remko Tronçon
+ * Licensed under the GNU General Public License v3.
+ * See Documentation/Licenses/GPLv3.txt for more information.
+ */
+
+#include <Swiften/Base/RandomGenerator.h>
+
+namespace Swift {
+
+RandomGenerator::~RandomGenerator() {
+
+}
+
+}
diff --git a/Swiften/Base/RandomGenerator.h b/Swiften/Base/RandomGenerator.h
new file mode 100644
index 0000000..a998e0d
--- /dev/null
+++ b/Swiften/Base/RandomGenerator.h
@@ -0,0 +1,18 @@
+/*
+ * Copyright (c) 2012 Remko Tronçon
+ * Licensed under the GNU General Public License v3.
+ * See Documentation/Licenses/GPLv3.txt for more information.
+ */
+
+#pragma once
+
+#include <vector>
+
+namespace Swift {
+	class RandomGenerator {
+		public:
+			virtual ~RandomGenerator();
+
+			virtual int generateWeighedRandomNumber(std::vector<double>::const_iterator probabilities_begin, std::vector<double>::const_iterator probabilities_end) = 0;
+	};
+}
diff --git a/Swiften/Base/SConscript b/Swiften/Base/SConscript
index 1f07483..a5f3592 100644
--- a/Swiften/Base/SConscript
+++ b/Swiften/Base/SConscript
@@ -10,6 +10,8 @@ objects = swiften_env.SwiftenObject([
 			"String.cpp",
 			"IDGenerator.cpp",
 			"SimpleIDGenerator.cpp",
+			"RandomGenerator.cpp",
+			"BoostRandomGenerator.cpp",
 			"sleep.cpp",
 		])
 swiften_env.Append(SWIFTEN_OBJECTS = [objects])