--- deliantra/server/include/util.h	2007/01/18 22:20:00	1.33
+++ deliantra/server/include/util.h	2007/02/15 15:43:36	1.37
@@ -1,6 +1,8 @@
 #ifndef UTIL_H__
 #define UTIL_H__
 
+//#define PREFER_MALLOC
+
 #if __GNUC__ >= 3
 # define is_constant(c) __builtin_constant_p (c)
 #else
@@ -37,12 +39,53 @@
 
 void fork_abort (const char *msg);
 
-template<typename T, typename U> static inline T min (T a, U b) { return a < (T)b ? a : (T)b; }
-template<typename T, typename U> static inline T max (T a, U b) { return a > (T)b ? a : (T)b; }
-template<typename T, typename U, typename V> static inline T clamp (T v, U a, V b) { return v < (T)a ? a : v >(T)b ? b : v; }
+// rationale for using (U) not (T) is to reduce signed/unsigned issues,
+// as a is often a constant while b is the variable. it is still a bug, though.
+template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
+template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
+template<typename T, typename U, typename V> static inline T clamp (T v, U a, V b) { return v < (T)a ? (T)a : v >(T)b ? (T)b : v; }
 
 template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
 
+// lots of stuff taken from FXT
+
+/* Rotate right. This is used in various places for checksumming */
+//TODO: this sucks, use a better checksum algo
+static inline uint32_t
+rotate_right (uint32_t c)
+{
+  return (c << 31) | (c >> 1);
+}
+
+// Return abs(a-b)
+// Both a and b must not have the most significant bit set
+static inline uint32_t
+upos_abs_diff (uint32_t a, uint32_t b)
+{
+  long d1 = b - a;
+  long d2 = (d1 & (d1 >> 31)) << 1;
+
+  return d1 - d2;               // == (b - d) - (a + d);
+}
+
+// Both a and b must not have the most significant bit set
+static inline uint32_t
+upos_min (uint32_t a, uint32_t b)
+{
+  int32_t d = b - a;
+  d &= d >> 31;
+  return a + d;
+}
+
+// Both a and b must not have the most significant bit set
+static inline uint32_t
+upos_max (uint32_t a, uint32_t b)
+{
+  int32_t d = b - a;
+  d &= d >> 31;
+  return b - d;
+}
+
 // this is much faster than crossfires original algorithm
 // on modern cpus
 inline int
@@ -133,7 +176,11 @@
 template<typename T>
 inline void sfree (T *ptr, int n = 1) throw ()
 {
+#ifdef PREFER_MALLOC
+  free (ptr);
+#else
   g_slice_free1 (n * sizeof (T), (void *)ptr);
+#endif
 }
 
 // a STL-compatible allocator that uses g_slice
@@ -196,26 +243,44 @@
 // http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
 struct tausworthe_random_generator
 {
+  // generator
   uint32_t state [4];
 
-  tausworthe_random_generator (uint32_t seed);
+  void operator =(const tausworthe_random_generator &src)
+  {
+    state [0] = src.state [0];
+    state [1] = src.state [1];
+    state [2] = src.state [2];
+    state [3] = src.state [3];
+  }
+
+  void seed (uint32_t seed);
   uint32_t next ();
 
+  // uniform distribution
   uint32_t operator ()(uint32_t r_max)
   {
-    return next () % r_max;
+    return is_constant (r_max)
+             ? this->next () % r_max
+             : get_range (r_max);
   }
 
   // return a number within (min .. max)
   int operator () (int r_min, int r_max)
   {
-    return r_min + (*this) (max (r_max - r_min + 1, 1));
+    return is_constant (r_min) && is_constant (r_max)
+              ? r_min + (*this) (max (r_max - r_min + 1, 1))
+              : get_range (r_min, r_max);
   }
 
   double operator ()()
   {
-    return next () / (double)0xFFFFFFFFU;
+    return this->next () / (double)0xFFFFFFFFU;
   }
+
+protected:
+  uint32_t get_range (uint32_t r_max);
+  int get_range (int r_min, int r_max);
 };
 
 typedef tausworthe_random_generator rand_gen;