--- deliantra/server/include/util.h 2009/01/01 20:49:48 1.85 +++ deliantra/server/include/util.h 2009/05/05 04:51:56 1.88 @@ -120,13 +120,25 @@ template static inline T sign0 (T v) { return v ? sign (v) : 0; } +// div* only work correctly for div > 0 // div, with correct rounding (< 0.5 downwards, >=0.5 upwards) -template static inline T div (T val, T div) { return (val + div / 2) / div; } +template static inline T div (T val, T div) +{ + return expect_false (val < 0) ? - ((-val + (div - 1) / 2) / div) : (val + div / 2) / div; +} // div, round-up -template static inline T div_ru (T val, T div) { return (val + div - 1) / div; } +template static inline T div_ru (T val, T div) +{ + return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div; +} // div, round-down -template static inline T div_rd (T val, T div) { return (val ) / div; } +template static inline T div_rd (T val, T div) +{ + return expect_false (val < 0) ? - ((-val + (div - 1) ) / div) : (val ) / div; +} +// lerp* only work correctly for min_in < max_in +// Linear intERPolate, scales val from min_in..max_in to min_out..max_out template static inline T lerp (T val, T min_in, T max_in, T min_out, T max_out) @@ -411,6 +423,7 @@ // http://www.jstatsoft.org/v08/i14/paper // this one is about 40% faster than the tausworthe one above (i.e. not much), // despite the inlining, and has the issue of only creating 2**32-1 numbers. +// see also http://www.iro.umontreal.ca/~lecuyer/myftp/papers/xorshift.pdf struct xorshift_random_generator { uint32_t x, y; @@ -677,13 +690,14 @@ }; // basically does what strncpy should do, but appends "..." to strings exceeding length -void assign (char *dst, const char *src, int maxlen); +// returns the number of bytes actually used (including \0) +int assign (char *dst, const char *src, int maxsize); // type-safe version of assign template -inline void assign (char (&dst)[N], const char *src) +inline int assign (char (&dst)[N], const char *src) { - assign ((char *)&dst, src, N); + return assign ((char *)&dst, src, N); } typedef double tstamp;