Merge pull request kennyledet#3 from stolendata/patch-1

kennyledet · kennyledet · commit 4d2cc941f028 · 2013-12-23T21:07:35.000-08:00
Create ranrotb_prng.h
diff --git a/ranrot-b_prng/robinleffmann_ranrotb_prng.h b/ranrot-b_prng/robinleffmann_ranrotb_prng.h
@@ -0,0 +1,28 @@
+/*
+    RANROT-B/32 PRNG
+
+    Call with 1 or higher to set seed; call with 0 to fetch values.
+
+    Robin Leffmann 2005 / <robin at stolendata dot net>
+*/
+
+#include <stdint.h>
+
+static uint32_t rrbRand( uint32_t rrbSeed )
+{
+    static uint32_t rrbLo, rrbHi;
+
+    if( rrbSeed != 0 )
+    {
+        rrbLo = rrbSeed;
+        rrbHi = ~rrbSeed;
+    }
+    else
+    {
+        rrbHi = ( rrbHi << 16 ) + ( rrbHi >> 16 );
+        rrbHi += rrbLo;
+        rrbLo += rrbHi;
+    }
+
+    return rrbHi;
+}
