--- deliantra/server/include/util.h 2010/05/02 14:46:56 1.107 +++ deliantra/server/include/util.h 2011/12/31 06:18:01 1.116 @@ -1,7 +1,7 @@ /* * This file is part of Deliantra, the Roguelike Realtime MMORPG. * - * Copyright (©) 2005,2006,2007,2008,2009,2010 Marc Alexander Lehmann / Robin Redeker / the Deliantra team + * Copyright (©) 2005,2006,2007,2008,2009,2010,2011 Marc Alexander Lehmann / Robin Redeker / the Deliantra team * * Deliantra is free software: you can redistribute it and/or modify it under * the terms of the Affero GNU General Public License as published by the @@ -88,8 +88,8 @@ // 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 static inline T min (T a, U b) { return (U)a < b ? (U)a : b; } -template static inline T max (T a, U b) { return (U)a > b ? (U)a : b; } +template static inline T min (T a, U b) { return a < (T)b ? a : (T)b; } +template static inline T max (T a, U b) { return a > (T)b ? a : (T)b; } template static inline T clamp (T v, U a, V b) { return v < (T)a ? (T)a : v >(T)b ? (T)b : v; } template static inline void min_it (T &v, U m) { v = min (v, (T)m); } @@ -116,6 +116,7 @@ template static inline T sign0 (T v) { return v ? sign (v) : 0; } +//clashes with C++0x template static inline T copysign (T a, U b) { return a > 0 ? b : -b; } @@ -253,6 +254,26 @@ #endif } +// can be substantially faster than floor, if your value range allows for it +template +inline T +fastfloor (T x) +{ + return std::floor (x); +} + +inline float +fastfloor (float x) +{ + return sint32(x) - (x < 0); +} + +inline double +fastfloor (double x) +{ + return sint64(x) - (x < 0); +} + /* * absdir(int): Returns a number between 1 and 8, which represent * the "absolute" direction of a number (it actually takes care of @@ -431,89 +452,6 @@ } }; -// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213. -// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps -// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps -struct tausworthe_random_generator -{ - uint32_t state [4]; - - 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 (); -}; - -// Xorshift RNGs, George Marsaglia -// 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; - - void operator =(const xorshift_random_generator &src) - { - x = src.x; - y = src.y; - } - - void seed (uint32_t seed) - { - x = seed; - y = seed * 69069U; - } - - uint32_t next () - { - uint32_t t = x ^ (x << 10); - x = y; - y = y ^ (y >> 13) ^ t ^ (t >> 10); - return y; - } -}; - -template -struct random_number_generator : generator -{ - // uniform distribution, [0 .. num - 1] - uint32_t operator ()(uint32_t num) - { - return !is_constant (num) ? get_range (num) // non-constant - : num & (num - 1) ? (this->next () * (uint64_t)num) >> 32U // constant, non-power-of-two - : this->next () & (num - 1); // constant, power-of-two - } - - // return a number within the closed interval [min .. max] - int operator () (int r_min, int r_max) - { - return is_constant (r_min <= r_max) && r_min <= r_max - ? r_min + operator ()(r_max - r_min + 1) - : get_range (r_min, r_max); - } - - // return a number within the half-open interval [0..1[ - double operator ()() - { - return this->next () / (double)0x100000000; - } - -protected: - uint32_t get_range (uint32_t r_max); - int get_range (int r_min, int r_max); -}; - -typedef random_number_generator rand_gen; - -extern rand_gen rndm, rmg_rndm; - INTERFACE_CLASS (attachable) struct refcnt_base { @@ -596,12 +534,13 @@ // with good distribution. // FNV-1a is faster on many cpus because the multiplication // runs concurrently with the looping logic. + // we modify the hash a bit to improve its distribution uint32_t hash = STRHSH_NULL; while (*s) hash = (hash ^ *s++) * 16777619U; - return hash; + return hash ^ (hash >> 16); } static inline uint32_t @@ -726,6 +665,74 @@ } }; +///////////////////////////////////////////////////////////////////////////// + +// something like a vector or stack, but without +// out of bounds checking +template +struct fixed_stack +{ + T *data; + int size; + int max; + + fixed_stack () + : size (0), data (0) + { + } + + fixed_stack (int max) + : size (0), max (max) + { + data = salloc (max); + } + + void reset (int new_max) + { + sfree (data, max); + size = 0; + max = new_max; + data = salloc (max); + } + + void free () + { + sfree (data, max); + data = 0; + } + + ~fixed_stack () + { + sfree (data, max); + } + + T &operator[](int idx) + { + return data [idx]; + } + + void push (T v) + { + data [size++] = v; + } + + T &pop () + { + return data [--size]; + } + + T remove (int idx) + { + T v = data [idx]; + + data [idx] = data [--size]; + + return v; + } +}; + +///////////////////////////////////////////////////////////////////////////// + // basically does what strncpy should do, but appends "..." to strings exceeding length // returns the number of bytes actually used (including \0) int assign (char *dst, const char *src, int maxsize);