Accept hexadecimal and string values for seeds

[minetest.git] / src / util / numeric.cpp

diff --git a/src/util/numeric.cpp b/src/util/numeric.cpp
index 67df4ffbafe0bf8cfdb201ae3084057cc5e5af3e..0426656a5a93393f765f6584abfea8f5e60491eb 100644 (file)
--- a/src/util/numeric.cpp
+++ b/src/util/numeric.cpp
@@ -22,6 +22,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #include "../log.h"
 #include "../constants.h" // BS, MAP_BLOCKSIZE
+#include <string.h>
 #include <iostream>
 
 // Calculate the borders of a "d-radius" cube
@@ -139,6 +140,49 @@ int myrand_range(int min, int max)
        return (myrand()%(max-min+1))+min;
 }
 
+// 64-bit unaligned version of MurmurHash
+u64 murmur_hash_64_ua(const void *key, int len, unsigned int seed)
+{
+       const u64 m = 0xc6a4a7935bd1e995;
+       const int r = 47;
+       u64 h = seed ^ (len * m);
+
+       const u64 *data = (const u64 *)key;
+       const u64 *end = data + (len / 8);
+
+       while (data != end) {
+               u64 k;
+               memcpy(&k, data, sizeof(u64));
+               data++;
+
+               k *= m; 
+               k ^= k >> r; 
+               k *= m; 
+               
+               h ^= k;
+               h *= m; 
+       }
+
+       const unsigned char *data2 = (const unsigned char *)data;
+       switch (len & 7) {
+               case 7: h ^= (u64)data2[6] << 48;
+               case 6: h ^= (u64)data2[5] << 40;
+               case 5: h ^= (u64)data2[4] << 32;
+               case 4: h ^= (u64)data2[3] << 24;
+               case 3: h ^= (u64)data2[2] << 16;
+               case 2: h ^= (u64)data2[1] << 8;
+               case 1: h ^= (u64)data2[0];
+                               h *= m;
+       }
+ 
+       h ^= h >> r;
+       h *= m;
+       h ^= h >> r;
+       
+       return h;
+} 
+
+
 /*
        blockpos: position of block in block coordinates
        camera_pos: position of camera in nodes