Core/Utils: Moved rng functions to separate header and added utility functions to select a random element from a container where each element can have different chance of being selected

(cherry picked from commit ae20b2ab561bc07d85f443ae914bc597c9d6ac6e)
(cherry picked from commit 921d893c2a82eb6ac0762bf7001df87911b44611)
(cherry picked from commit 9ab10d6e680ca835d1dfdfbceb9f18f330f994fc)
(cherry picked from commit 00c878e73a8c6b8ce3339d224ab5611df3bbd07c)
(cherry picked from commit ff9c999334d87acc3fcea9737753c30b7f1abe25)
(cherry picked from commit bc94bacce404401a480b6871eaa7bc38d766014c)
(cherry picked from commit d5b0ffbe9b0c07beb8d0dfc52a6532c2da805285)

1 files changed, 83 insertions, 0 deletions

diff --git a/src/common/Utilities/Random.cpp b/src/common/Utilities/Random.cpp
new file mode 100644
index 00000000000..cc013110b01
--- /dev/null
+++ b/src/common/Utilities/Random.cpp
@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2008-2015 TrinityCore <http://www.trinitycore.org/>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Random.h"
+#include "Common.h"
+#include "Errors.h"
+#include "SFMT.h"
+#include <boost/thread/tss.hpp>
+
+static boost::thread_specific_ptr<SFMTRand> sfmtRand;
+
+static SFMTRand* GetRng()
+{
+    SFMTRand* rand = sfmtRand.get();
+
+    if (!rand)
+    {
+        rand = new SFMTRand();
+        sfmtRand.reset(rand);
+    }
+
+    return rand;
+}
+
+int32 irand(int32 min, int32 max)
+{
+    ASSERT(max >= min);
+    return int32(GetRng()->IRandom(min, max));
+}
+
+uint32 urand(uint32 min, uint32 max)
+{
+    ASSERT(max >= min);
+    return GetRng()->URandom(min, max);
+}
+
+uint32 urandms(uint32 min, uint32 max)
+{
+    ASSERT(max >= min);
+    ASSERT(INT_MAX / IN_MILLISECONDS >= max);
+    return GetRng()->URandom(min * IN_MILLISECONDS, max * IN_MILLISECONDS);
+}
+
+float frand(float min, float max)
+{
+    ASSERT(max >= min);
+    return float(GetRng()->Random() * (max - min) + min);
+}
+
+uint32 rand32()
+{
+    return GetRng()->BRandom();
+}
+
+double rand_norm()
+{
+    return GetRng()->Random();
+}
+
+double rand_chance()
+{
+    return GetRng()->Random() * 100.0;
+}
+
+SFMTEngine& SFMTEngine::Instance()
+{
+    static SFMTEngine engine;
+    return engine;
+}