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Comparing deliantra/server/include/util.h (file contents):
Revision 1.102 by root, Thu Apr 29 12:24:04 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.
… …
55#endif 55#endif
56 56
57// use C0X decltype for auto declarations until ISO C++ sanctifies them (if ever) 57// use C0X decltype for auto declarations until ISO C++ sanctifies them (if ever)
58#define auto(var,expr) decltype(expr) var = (expr) 58#define auto(var,expr) decltype(expr) var = (expr)
59 59
60// could use the sizeof (arr) /( sizeof (arr [0]) here, but C++ is 60#if cplusplus_does_not_suck
61// much more obfuscated... :) 61// does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
62
63template<typename T, int N> 62template<typename T, int N>
64inline int array_length (const T (&arr)[N]) 63static inline int array_length (const T (&arr)[N])
65{ 64{
66 return N; 65 return N;
67} 66}
67#else
68#define array_length(name) (sizeof (name) / sizeof (name [0]))
69#endif
68 70
69// very ugly macro that basically declares and initialises a variable 71// very ugly macro that basically declares and initialises a variable
70// that is in scope for the next statement only 72// that is in scope for the next statement only
71// works only for stuff that can be assigned 0 and converts to false 73// works only for stuff that can be assigned 0 and converts to false
72// (note: works great for pointers) 74// (note: works great for pointers)
… …
84void cleanup (const char *cause, bool make_core = false); 86void cleanup (const char *cause, bool make_core = false);
85void fork_abort (const char *msg); 87void fork_abort (const char *msg);
86 88
87// 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,
88// 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.
89template<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; }
90template<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; }
91template<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; }
92 94
93template<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); }
94template<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); }
95template<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); }
… …
102// sign returns -1 or +1 104// sign returns -1 or +1
103template<typename T> 105template<typename T>
104static inline T sign (T v) { return v < 0 ? -1 : +1; } 106static inline T sign (T v) { return v < 0 ? -1 : +1; }
105// relies on 2c representation 107// relies on 2c representation
106template<> 108template<>
107inline sint8 sign (sint8 v) { return 1 - (sint8 (uint8 (v) >> 7) * 2); } 109inline sint8 sign (sint8 v) { return 1 - (sint8 (uint8 (v) >> 7) * 2); }
110template<>
111inline sint16 sign (sint16 v) { return 1 - (sint16 (uint16 (v) >> 15) * 2); }
112template<>
113inline sint32 sign (sint32 v) { return 1 - (sint32 (uint32 (v) >> 31) * 2); }
108 114
109// sign0 returns -1, 0 or +1 115// sign0 returns -1, 0 or +1
110template<typename T> 116template<typename T>
111static inline T sign0 (T v) { return v ? sign (v) : 0; } 117static inline T sign0 (T v) { return v ? sign (v) : 0; }
112 118
119//clashes with C++0x
113template<typename T, typename U> 120template<typename T, typename U>
114static 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; }
115 122
116// div* only work correctly for div > 0 123// div* only work correctly for div > 0
117// div, with correct rounding (< 0.5 downwards, >=0.5 upwards) 124// div, with correct rounding (< 0.5 downwards, >=0.5 upwards)
118template<typename T> static inline T div (T val, T div) 125template<typename T> static inline T div (T val, T div)
119{ 126{
120 return expect_false (val < 0) ? - ((-val + (div - 1) / 2) / div) : (val + div / 2) / div; 127 return expect_false (val < 0) ? - ((-val + (div - 1) / 2) / div) : (val + div / 2) / div;
121} 128}
129
130template<> inline float div (float val, float div) { return val / div; }
131template<> inline double div (double val, double div) { return val / div; }
132
122// div, round-up 133// div, round-up
123template<typename T> static inline T div_ru (T val, T div) 134template<typename T> static inline T div_ru (T val, T div)
124{ 135{
125 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div; 136 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div;
126} 137}
… …
241#else 252#else
242 return dx_ + dy_ - min (dx_, dy_) * 5 / 8; 253 return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
243#endif 254#endif
244} 255}
245 256
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
246/* 277/*
247 * absdir(int): Returns a number between 1 and 8, which represent 278 * absdir(int): Returns a number between 1 and 8, which represent
248 * the "absolute" direction of a number (it actually takes care of 279 * the "absolute" direction of a number (it actually takes care of
249 * "overflow" in previous calculations of a direction). 280 * "overflow" in previous calculations of a direction).
250 */ 281 */
… …
419 { 450 {
420 p->~Tp (); 451 p->~Tp ();
421 } 452 }
422}; 453};
423 454
424// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
425// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
426// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
427struct tausworthe_random_generator
428{
429 uint32_t state [4];
430
431 void operator =(const tausworthe_random_generator &src)
432 {
433 state [0] = src.state [0];
434 state [1] = src.state [1];
435 state [2] = src.state [2];
436 state [3] = src.state [3];
437 }
438
439 void seed (uint32_t seed);
440 uint32_t next ();
441};
442
443// Xorshift RNGs, George Marsaglia
444// http://www.jstatsoft.org/v08/i14/paper
445// this one is about 40% faster than the tausworthe one above (i.e. not much),
446// despite the inlining, and has the issue of only creating 2**32-1 numbers.
447// see also http://www.iro.umontreal.ca/~lecuyer/myftp/papers/xorshift.pdf
448struct xorshift_random_generator
449{
450 uint32_t x, y;
451
452 void operator =(const xorshift_random_generator &src)
453 {
454 x = src.x;
455 y = src.y;
456 }
457
458 void seed (uint32_t seed)
459 {
460 x = seed;
461 y = seed * 69069U;
462 }
463
464 uint32_t next ()
465 {
466 uint32_t t = x ^ (x << 10);
467 x = y;
468 y = y ^ (y >> 13) ^ t ^ (t >> 10);
469 return y;
470 }
471};
472
473template<class generator>
474struct random_number_generator : generator
475{
476 // uniform distribution, 0 .. max (0, num - 1)
477 uint32_t operator ()(uint32_t num)
478 {
479 return !is_constant (num) ? get_range (num) // non-constant
480 : num & (num - 1) ? (this->next () * (uint64_t)num) >> 32U // constant, non-power-of-two
481 : this->next () & (num - 1); // constant, power-of-two
482 }
483
484 // return a number within the closed interval [min .. max]
485 int operator () (int r_min, int r_max)
486 {
487 return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
488 ? r_min + operator ()(r_max - r_min + 1)
489 : get_range (r_min, r_max);
490 }
491
492 // return a number within the closed interval [0..1]
493 double operator ()()
494 {
495 return this->next () / (double)0xFFFFFFFFU;
496 }
497
498protected:
499 uint32_t get_range (uint32_t r_max);
500 int get_range (int r_min, int r_max);
501};
502
503typedef random_number_generator<tausworthe_random_generator> rand_gen;
504
505extern rand_gen rndm, rmg_rndm;
506
507INTERFACE_CLASS (attachable) 455INTERFACE_CLASS (attachable)
508struct refcnt_base 456struct refcnt_base
509{ 457{
510 typedef int refcnt_t; 458 typedef int refcnt_t;
511 mutable refcnt_t ACC (RW, refcnt); 459 mutable refcnt_t ACC (RW, refcnt);
… …
584 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/) 532 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
585 // 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,
586 // with good distribution. 534 // with good distribution.
587 // FNV-1a is faster on many cpus because the multiplication 535 // FNV-1a is faster on many cpus because the multiplication
588 // runs concurrently with the looping logic. 536 // runs concurrently with the looping logic.
537 // we modify the hash a bit to improve its distribution
589 uint32_t hash = STRHSH_NULL; 538 uint32_t hash = STRHSH_NULL;
590 539
591 while (*s) 540 while (*s)
592 hash = (hash ^ *s++) * 16777619U; 541 hash = (hash ^ *s++) * 16777619U;
593 542
594 return hash; 543 return hash ^ (hash >> 16);
595} 544}
596 545
597static inline uint32_t 546static inline uint32_t
598memhsh (const char *s, size_t len) 547memhsh (const char *s, size_t len)
599{ 548{
… …
714 { 663 {
715 erase (&obj); 664 erase (&obj);
716 } 665 }
717}; 666};
718 667
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
719// 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
720// returns the number of bytes actually used (including \0) 737// returns the number of bytes actually used (including \0)
721int assign (char *dst, const char *src, int maxsize); 738int assign (char *dst, const char *src, int maxsize);
722 739
723// type-safe version of assign 740// type-safe version of assign

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