From 9e425136f1aee51d9c1f3baf48989346bb7d7e16 Mon Sep 17 00:00:00 2001
From: lotodore <pokerth@lotharmay.de>
Date: Sun, 27 Feb 2011 21:54:43 +0000
Subject: [PATCH] Adding new types of random number generators: 1. shuffle a
 list non-deterministic (not the default shuffle) 2. get random numbers of a
 range 3. get random numbers of a range, without duplicates (the latest based
 on floty's idea). Note that the existing random number works quite well, the
 new approach uses boost::random and is more flexible if other distributions
 are needed for the AI. The code is currently disabled due to link problems on
 debian/ubuntu (boost::random seems to be missing there).

---
 src/engine/local_engine/tools.cpp | 67 +++++++++++++++++++++++++++++++
 src/engine/local_engine/tools.h   |  5 +++
 2 files changed, 72 insertions(+)

diff --git a/src/engine/local_engine/tools.cpp b/src/engine/local_engine/tools.cpp
index b03e04c6..3df7d05f 100755
--- a/src/engine/local_engine/tools.cpp
+++ b/src/engine/local_engine/tools.cpp
@@ -23,10 +23,77 @@
 #include <core/loghelper.h>
 #include <core/openssl_wrapper.h>
 
+#include <boost/thread.hpp>
+#include <boost/nondet_random.hpp>
+#include <boost/random/uniform_int.hpp>
+#include <boost/random/variate_generator.hpp>
+#include <set>
 #include <limits>
 
+
 using namespace std;
 
+#if 0 // TODO temporarily disabled until build problems are solved
+boost::thread_specific_ptr<boost::random_device> g_rand_state;
+
+struct nondet_rng : std::unary_function<unsigned, unsigned> {
+	boost::random_device &_state;
+	unsigned operator()(unsigned i) {
+		boost::uniform_int<> rng(0, i - 1);
+		return rng(_state);
+	}
+	nondet_rng(boost::random_device &state) : _state(state) {}
+};
+
+static inline void InitRandState() {
+	if (!g_rand_state.get()) {
+		g_rand_state.reset(new boost::random_device);
+	}
+}
+
+void Tools::ShuffleArrayNonDeterministic(int *inout, unsigned count)
+{
+	InitRandState();
+	nondet_rng rand(*g_rand_state);
+	std::random_shuffle(&inout[0], &inout[count], rand);
+}
+
+void Tools::GetRand(int minValue, int maxValue, unsigned count, int *out)
+{
+	InitRandState();
+	boost::uniform_int<> dist(minValue, maxValue);
+	boost::variate_generator<boost::random_device&, boost::uniform_int<> > gen(*g_rand_state, dist);
+	int *startPtr = out;
+	for (unsigned i = 0; i < count; i++) {
+			*startPtr++ = gen();
+	}
+}
+
+void Tools::GetRandUnique(int minValue, int maxValue, unsigned count, int *out)
+{
+	InitRandState();
+	unsigned numCreated = 0;
+	int *startPtr = out;
+	std::set<int> tmpSet;
+	for (unsigned i = 0; i < count; i++) {
+			boost::uniform_int<> dist(minValue, maxValue - numCreated);
+			boost::variate_generator<boost::random_device&, boost::uniform_int<> > gen(*g_rand_state, dist);
+			*startPtr = gen();
+			std::set<int>::const_iterator v = tmpSet.begin();
+			std::set<int>::const_iterator end = tmpSet.end();
+			while (v != end) {
+					if (*v <= *startPtr) {
+							(*startPtr)++;
+					}
+					++v;
+			}
+			tmpSet.insert(*startPtr);
+			startPtr++;
+			numCreated++;
+	}
+}
+#endif
+
 void Tools::getRandNumber(int start, int end, int howMany, int* randArray, bool different, int* bad, int countBad)
 {
 
diff --git a/src/engine/local_engine/tools.h b/src/engine/local_engine/tools.h
index 29515a29..a8e27bd6 100755
--- a/src/engine/local_engine/tools.h
+++ b/src/engine/local_engine/tools.h
@@ -23,6 +23,11 @@
 class Tools
 {
 public:
+
+	static void ShuffleArrayNonDeterministic(int *inout, unsigned count);
+	static void GetRand(int minValue, int maxValue, unsigned count, int *out);
+	static void GetRandUnique(int minValue, int maxValue, unsigned count, int *out);
+
 	static void getRandNumber(int, int, int, int*, bool, int* = 0, int = 0);
 
 };