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Comparing deliantra/server/include/util.h (file contents):
Revision 1.109 by root, Tue Jun 29 16:52:53 2010 UTC vs.
Revision 1.116 by root, Sat Dec 31 06:18:01 2011 UTC

1/* 1/*
2 * This file is part of Deliantra, the Roguelike Realtime MMORPG. 2 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
3 * 3 *
4 * Copyright (©) 2005,2006,2007,2008,2009,2010 Marc Alexander Lehmann / Robin Redeker / the Deliantra team 4 * Copyright (©) 2005,2006,2007,2008,2009,2010,2011 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5 * 5 *
6 * Deliantra is free software: you can redistribute it and/or modify it under 6 * Deliantra is free software: you can redistribute it and/or modify it under
7 * the terms of the Affero GNU General Public License as published by the 7 * the terms of the Affero GNU General Public License as published by the
8 * Free Software Foundation, either version 3 of the License, or (at your 8 * Free Software Foundation, either version 3 of the License, or (at your
9 * option) any later version. 9 * option) any later version.
… …
86void cleanup (const char *cause, bool make_core = false); 86void cleanup (const char *cause, bool make_core = false);
87void fork_abort (const char *msg); 87void fork_abort (const char *msg);
88 88
89// rationale for using (U) not (T) is to reduce signed/unsigned issues, 89// rationale for using (U) not (T) is to reduce signed/unsigned issues,
90// as a is often a constant while b is the variable. it is still a bug, though. 90// as a is often a constant while b is the variable. it is still a bug, though.
91template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; } 91template<typename T, typename U> static inline T min (T a, U b) { return a < (T)b ? a : (T)b; }
92template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; } 92template<typename T, typename U> static inline T max (T a, U b) { return a > (T)b ? a : (T)b; }
93template<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; } 93template<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; }
94 94
95template<typename T, typename U> static inline void min_it (T &v, U m) { v = min (v, (T)m); } 95template<typename T, typename U> static inline void min_it (T &v, U m) { v = min (v, (T)m); }
96template<typename T, typename U> static inline void max_it (T &v, U m) { v = max (v, (T)m); } 96template<typename T, typename U> static inline void max_it (T &v, U m) { v = max (v, (T)m); }
97template<typename T, typename U, typename V> static inline void clamp_it (T &v, U a, V b) { v = clamp (v, (T)a, (T)b); } 97template<typename T, typename U, typename V> static inline void clamp_it (T &v, U a, V b) { v = clamp (v, (T)a, (T)b); }
… …
114 114
115// sign0 returns -1, 0 or +1 115// sign0 returns -1, 0 or +1
116template<typename T> 116template<typename T>
117static inline T sign0 (T v) { return v ? sign (v) : 0; } 117static inline T sign0 (T v) { return v ? sign (v) : 0; }
118 118
119//clashes with C++0x
119template<typename T, typename U> 120template<typename T, typename U>
120static inline T copysign (T a, U b) { return a > 0 ? b : -b; } 121static inline T copysign (T a, U b) { return a > 0 ? b : -b; }
121 122
122// div* only work correctly for div > 0 123// div* only work correctly for div > 0
123// div, with correct rounding (< 0.5 downwards, >=0.5 upwards) 124// div, with correct rounding (< 0.5 downwards, >=0.5 upwards)
… …
251#else 252#else
252 return dx_ + dy_ - min (dx_, dy_) * 5 / 8; 253 return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
253#endif 254#endif
254} 255}
255 256
257// can be substantially faster than floor, if your value range allows for it
258template<typename T>
259inline T
260fastfloor (T x)
261{
262 return std::floor (x);
263}
264
265inline float
266fastfloor (float x)
267{
268 return sint32(x) - (x < 0);
269}
270
271inline double
272fastfloor (double x)
273{
274 return sint64(x) - (x < 0);
275}
276
256/* 277/*
257 * absdir(int): Returns a number between 1 and 8, which represent 278 * absdir(int): Returns a number between 1 and 8, which represent
258 * the "absolute" direction of a number (it actually takes care of 279 * the "absolute" direction of a number (it actually takes care of
259 * "overflow" in previous calculations of a direction). 280 * "overflow" in previous calculations of a direction).
260 */ 281 */
… …
429 { 450 {
430 p->~Tp (); 451 p->~Tp ();
431 } 452 }
432}; 453};
433 454
434// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
435// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
436// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
437struct tausworthe_random_generator
438{
439 uint32_t state [4];
440
441 void operator =(const tausworthe_random_generator &src)
442 {
443 state [0] = src.state [0];
444 state [1] = src.state [1];
445 state [2] = src.state [2];
446 state [3] = src.state [3];
447 }
448
449 void seed (uint32_t seed);
450 uint32_t next ();
451};
452
453// Xorshift RNGs, George Marsaglia
454// http://www.jstatsoft.org/v08/i14/paper
455// this one is about 40% faster than the tausworthe one above (i.e. not much),
456// despite the inlining, and has the issue of only creating 2**32-1 numbers.
457// see also http://www.iro.umontreal.ca/~lecuyer/myftp/papers/xorshift.pdf
458struct xorshift_random_generator
459{
460 uint32_t x, y;
461
462 void operator =(const xorshift_random_generator &src)
463 {
464 x = src.x;
465 y = src.y;
466 }
467
468 void seed (uint32_t seed)
469 {
470 x = seed;
471 y = seed * 69069U;
472 }
473
474 uint32_t next ()
475 {
476 uint32_t t = x ^ (x << 10);
477 x = y;
478 y = y ^ (y >> 13) ^ t ^ (t >> 10);
479 return y;
480 }
481};
482
483template<class generator>
484struct random_number_generator : generator
485{
486 // uniform distribution, [0 .. num - 1]
487 uint32_t operator ()(uint32_t num)
488 {
489 return !is_constant (num) ? get_range (num) // non-constant
490 : num & (num - 1) ? (this->next () * (uint64_t)num) >> 32U // constant, non-power-of-two
491 : this->next () & (num - 1); // constant, power-of-two
492 }
493
494 // return a number within the closed interval [min .. max], max can be >, < or == min.
495 int operator () (int r_min, int r_max)
496 {
497 return is_constant (r_min <= r_max) && r_min <= r_max
498 ? r_min + operator ()(r_max - r_min + 1)
499 : get_range (r_min, r_max);
500 }
501
502 // return a number within the half-open interval [0..1[
503 double operator ()()
504 {
505 return this->next () / (double)0x100000000ULL;
506 }
507
508protected:
509 uint32_t get_range (uint32_t r_max);
510 int get_range (int r_min, int r_max);
511};
512
513typedef random_number_generator<tausworthe_random_generator> rand_gen;
514
515extern rand_gen rndm, rmg_rndm;
516
517INTERFACE_CLASS (attachable) 455INTERFACE_CLASS (attachable)
518struct refcnt_base 456struct refcnt_base
519{ 457{
520 typedef int refcnt_t; 458 typedef int refcnt_t;
521 mutable refcnt_t ACC (RW, refcnt); 459 mutable refcnt_t ACC (RW, refcnt);
… …
594 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/) 532 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
595 // it is about twice as fast as the one-at-a-time one, 533 // it is about twice as fast as the one-at-a-time one,
596 // with good distribution. 534 // with good distribution.
597 // FNV-1a is faster on many cpus because the multiplication 535 // FNV-1a is faster on many cpus because the multiplication
598 // runs concurrently with the looping logic. 536 // runs concurrently with the looping logic.
537 // we modify the hash a bit to improve its distribution
599 uint32_t hash = STRHSH_NULL; 538 uint32_t hash = STRHSH_NULL;
600 539
601 while (*s) 540 while (*s)
602 hash = (hash ^ *s++) * 16777619U; 541 hash = (hash ^ *s++) * 16777619U;
603 542
604 return hash; 543 return hash ^ (hash >> 16);
605} 544}
606 545
607static inline uint32_t 546static inline uint32_t
608memhsh (const char *s, size_t len) 547memhsh (const char *s, size_t len)
609{ 548{
… …
724 { 663 {
725 erase (&obj); 664 erase (&obj);
726 } 665 }
727}; 666};
728 667
668/////////////////////////////////////////////////////////////////////////////
669
670// something like a vector or stack, but without
671// out of bounds checking
672template<typename T>
673struct fixed_stack
674{
675 T *data;
676 int size;
677 int max;
678
679 fixed_stack ()
680 : size (0), data (0)
681 {
682 }
683
684 fixed_stack (int max)
685 : size (0), max (max)
686 {
687 data = salloc<T> (max);
688 }
689
690 void reset (int new_max)
691 {
692 sfree (data, max);
693 size = 0;
694 max = new_max;
695 data = salloc<T> (max);
696 }
697
698 void free ()
699 {
700 sfree (data, max);
701 data = 0;
702 }
703
704 ~fixed_stack ()
705 {
706 sfree (data, max);
707 }
708
709 T &operator[](int idx)
710 {
711 return data [idx];
712 }
713
714 void push (T v)
715 {
716 data [size++] = v;
717 }
718
719 T &pop ()
720 {
721 return data [--size];
722 }
723
724 T remove (int idx)
725 {
726 T v = data [idx];
727
728 data [idx] = data [--size];
729
730 return v;
731 }
732};
733
734/////////////////////////////////////////////////////////////////////////////
735
729// basically does what strncpy should do, but appends "..." to strings exceeding length 736// basically does what strncpy should do, but appends "..." to strings exceeding length
730// returns the number of bytes actually used (including \0) 737// returns the number of bytes actually used (including \0)
731int assign (char *dst, const char *src, int maxsize); 738int assign (char *dst, const char *src, int maxsize);
732 739
733// type-safe version of assign 740// type-safe version of assign

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