--- rxvt-unicode/src/rxvtutil.h	2006/01/22 00:36:59	1.19
+++ rxvt-unicode/src/rxvtutil.h	2006/01/29 22:30:21	1.23
@@ -9,6 +9,9 @@
 #define PP_STRINGIFY_(a) #a
 #define PP_STRINGIFY(a) PP_STRINGIFY_(a)
 
+// actually, some gcc-3.x versions work, too
+#define HAVE_GCC_BUILTINS (__GNUC__ >= 4)
+
 extern class byteorder {
   static unsigned int e; // at least 32 bits
 public:
@@ -31,6 +34,24 @@
 
 template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
 
+// linear interpolation
+template<typename T, typename U, typename P>
+static inline
+T lerp (T a, U b, P p)
+{
+  return (int(a) * int(p) + int(b) * int(100 - p)) / 100;
+}
+
+// some bit functions, xft fuck me plenty
+#if HAVE_GCC_BUILTINS
+static inline int ctz      (unsigned int x) { return __builtin_ctz      (x); }
+static inline int popcount (unsigned int x) { return __builtin_popcount (x); }
+#else
+// count trailing zero bits and count # of one bits
+int ctz      (unsigned int x);
+int popcount (unsigned int x);
+#endif
+
 // in range including end
 #define IN_RANGE_INC(val,beg,end) \
   ((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))
@@ -398,5 +419,15 @@
   }
 };
 
+// return a very temporary (and never deallocated) buffer. keep small.
+void *rxvt_temp_buf (int len);
+
+template<typename T>
+inline T *
+rxvt_temp_buf (int len)
+{
+  return (T *)rxvt_temp_buf (len * sizeof (T));
+}
+
 #endif