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Comparing deliantra/server/include/util.h (file contents):
Revision 1.72 by root, Wed Apr 30 16:26:28 2008 UTC vs.
Revision 1.84 by root, Wed Dec 31 17:35:37 2008 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 Marc Alexander Lehmann / Robin Redeker / the Deliantra team 4 * Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5 * 5 *
6 * Deliantra is free software: you can redistribute it and/or modify 6 * Deliantra is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by 7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or 8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version. 9 * (at your option) any later version.
… …
41#endif 41#endif
42 42
43// put into ifs if you are very sure that the expression 43// put into ifs if you are very sure that the expression
44// is mostly true or mosty false. note that these return 44// is mostly true or mosty false. note that these return
45// booleans, not the expression. 45// booleans, not the expression.
46#define expect_false(expr) expect ((expr) != 0, 0) 46#define expect_false(expr) expect ((expr) ? 1 : 0, 0)
47#define expect_true(expr) expect ((expr) != 0, 1) 47#define expect_true(expr) expect ((expr) ? 1 : 0, 1)
48 48
49#include <pthread.h> 49#include <pthread.h>
50 50
51#include <cstddef> 51#include <cstddef>
52#include <cmath> 52#include <cmath>
… …
72#endif 72#endif
73 73
74// use C0X decltype for auto declarations until ISO C++ sanctifies them (if ever) 74// use C0X decltype for auto declarations until ISO C++ sanctifies them (if ever)
75#define auto(var,expr) decltype(expr) var = (expr) 75#define auto(var,expr) decltype(expr) var = (expr)
76 76
77// very ugly macro that basicaly declares and initialises a variable 77// very ugly macro that basically declares and initialises a variable
78// that is in scope for the next statement only 78// that is in scope for the next statement only
79// works only for stuff that can be assigned 0 and converts to false 79// works only for stuff that can be assigned 0 and converts to false
80// (note: works great for pointers) 80// (note: works great for pointers)
81// most ugly macro I ever wrote 81// most ugly macro I ever wrote
82#define statementvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1) 82#define statementvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)
… …
96// as a is often a constant while b is the variable. it is still a bug, though. 96// as a is often a constant while b is the variable. it is still a bug, though.
97template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; } 97template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
98template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; } 98template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
99template<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; } 99template<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; }
100 100
101template<typename T, typename U> static inline void min_it (T &v, U m) { v = min (v, (T)m); }
102template<typename T, typename U> static inline void max_it (T &v, U m) { v = max (v, (T)m); }
103template<typename T, typename U, typename V> static inline void clamp_it (T &v, U a, V b) { v = clamp (v, (T)a, (T)b); }
104
101template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; } 105template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
102 106
103template<typename T, typename U, typename V> static inline T min (T a, U b, V c) { return min (a, min (b, c)); } 107template<typename T, typename U, typename V> static inline T min (T a, U b, V c) { return min (a, min (b, c)); }
104template<typename T, typename U, typename V> static inline T max (T a, U b, V c) { return max (a, max (b, c)); } 108template<typename T, typename U, typename V> static inline T max (T a, U b, V c) { return max (a, max (b, c)); }
105 109
110// sign returns -1 or +1
111template<typename T>
112static inline T sign (T v) { return v < 0 ? -1 : +1; }
113// relies on 2c representation
114template<>
115inline sint8 sign (sint8 v) { return 1 - (sint8 (uint8 (v) >> 7) * 2); }
116
117// sign0 returns -1, 0 or +1
118template<typename T>
119static inline T sign0 (T v) { return v ? sign (v) : 0; }
120
121// div, with correct rounding (< 0.5 downwards, >=0.5 upwards)
122template<typename T> static inline T div (T val, T div) { return (val + div / 2) / div; }
123// div, round-up
124template<typename T> static inline T div_ru (T val, T div) { return (val + div - 1) / div; }
125// div, round-down
126template<typename T> static inline T div_rd (T val, T div) { return (val ) / div; }
127
106template<typename T> 128template<typename T>
107static inline T 129static inline T
108lerp (T val, T min_in, T max_in, T min_out, T max_out) 130lerp (T val, T min_in, T max_in, T min_out, T max_out)
109{ 131{
110 return (val - min_in) * (max_out - min_out) / (max_in - min_in) + min_out; 132 return min_out + div <T> ((val - min_in) * (max_out - min_out), max_in - min_in);
133}
134
135// lerp, round-down
136template<typename T>
137static inline T
138lerp_rd (T val, T min_in, T max_in, T min_out, T max_out)
139{
140 return min_out + div_rd<T> ((val - min_in) * (max_out - min_out), max_in - min_in);
141}
142
143// lerp, round-up
144template<typename T>
145static inline T
146lerp_ru (T val, T min_in, T max_in, T min_out, T max_out)
147{
148 return min_out + div_ru<T> ((val - min_in) * (max_out - min_out), max_in - min_in);
111} 149}
112 150
113// lots of stuff taken from FXT 151// lots of stuff taken from FXT
114 152
115/* Rotate right. This is used in various places for checksumming */ 153/* Rotate right. This is used in various places for checksumming */
… …
262 { 300 {
263 sfree ((char *)p, s); 301 sfree ((char *)p, s);
264 } 302 }
265}; 303};
266 304
305// makes dynamically allocated objects zero-initialised
306struct slice_allocated
307{
308 void *operator new (size_t s, void *p)
309 {
310 return p;
311 }
312
313 void *operator new (size_t s)
314 {
315 return salloc<char> (s);
316 }
317
318 void *operator new[] (size_t s)
319 {
320 return salloc<char> (s);
321 }
322
323 void operator delete (void *p, size_t s)
324 {
325 sfree ((char *)p, s);
326 }
327
328 void operator delete[] (void *p, size_t s)
329 {
330 sfree ((char *)p, s);
331 }
332};
333
267// a STL-compatible allocator that uses g_slice 334// a STL-compatible allocator that uses g_slice
268// boy, this is verbose 335// boy, this is verbose
269template<typename Tp> 336template<typename Tp>
270struct slice_allocator 337struct slice_allocator
271{ 338{
… …
322// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213. 389// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
323// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps 390// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
324// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps 391// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
325struct tausworthe_random_generator 392struct tausworthe_random_generator
326{ 393{
327 // generator
328 uint32_t state [4]; 394 uint32_t state [4];
329 395
330 void operator =(const tausworthe_random_generator &src) 396 void operator =(const tausworthe_random_generator &src)
331 { 397 {
332 state [0] = src.state [0]; 398 state [0] = src.state [0];
… …
335 state [3] = src.state [3]; 401 state [3] = src.state [3];
336 } 402 }
337 403
338 void seed (uint32_t seed); 404 void seed (uint32_t seed);
339 uint32_t next (); 405 uint32_t next ();
406};
340 407
341 // uniform distribution 408// Xorshift RNGs, George Marsaglia
409// http://www.jstatsoft.org/v08/i14/paper
410// this one is about 40% faster than the tausworthe one above (i.e. not much),
411// despite the inlining, and has the issue of only creating 2**32-1 numbers.
412struct xorshift_random_generator
413{
414 uint32_t x, y;
415
416 void operator =(const xorshift_random_generator &src)
417 {
418 x = src.x;
419 y = src.y;
420 }
421
422 void seed (uint32_t seed)
423 {
424 x = seed;
425 y = seed * 69069U;
426 }
427
428 uint32_t next ()
429 {
430 uint32_t t = x ^ (x << 10);
431 x = y;
432 y = y ^ (y >> 13) ^ t ^ (t >> 10);
433 return y;
434 }
435};
436
437template<class generator>
438struct random_number_generator : generator
439{
440 // uniform distribution, 0 .. max (0, num - 1)
342 uint32_t operator ()(uint32_t num) 441 uint32_t operator ()(uint32_t num)
343 { 442 {
344 return is_constant (num) 443 return !is_constant (num) ? get_range (num) // non-constant
345 ? (next () * (uint64_t)num) >> 32U 444 : num & (num - 1) ? (this->next () * (uint64_t)num) >> 32U // constant, non-power-of-two
346 : get_range (num); 445 : this->next () & (num - 1); // constant, power-of-two
347 } 446 }
348 447
349 // return a number within (min .. max) 448 // return a number within (min .. max)
350 int operator () (int r_min, int r_max) 449 int operator () (int r_min, int r_max)
351 { 450 {
… …
362protected: 461protected:
363 uint32_t get_range (uint32_t r_max); 462 uint32_t get_range (uint32_t r_max);
364 int get_range (int r_min, int r_max); 463 int get_range (int r_min, int r_max);
365}; 464};
366 465
367typedef tausworthe_random_generator rand_gen; 466typedef random_number_generator<tausworthe_random_generator> rand_gen;
368 467
369extern rand_gen rndm; 468extern rand_gen rndm, rmg_rndm;
370 469
371INTERFACE_CLASS (attachable) 470INTERFACE_CLASS (attachable)
372struct refcnt_base 471struct refcnt_base
373{ 472{
374 typedef int refcnt_t; 473 typedef int refcnt_t;
… …
441 540
442struct str_hash 541struct str_hash
443{ 542{
444 std::size_t operator ()(const char *s) const 543 std::size_t operator ()(const char *s) const
445 { 544 {
446 unsigned long hash = 0; 545#if 0
546 uint32_t hash = 0;
447 547
448 /* use the one-at-a-time hash function, which supposedly is 548 /* use the one-at-a-time hash function, which supposedly is
449 * better than the djb2-like one used by perl5.005, but 549 * better than the djb2-like one used by perl5.005, but
450 * certainly is better then the bug used here before. 550 * certainly is better then the bug used here before.
451 * see http://burtleburtle.net/bob/hash/doobs.html 551 * see http://burtleburtle.net/bob/hash/doobs.html
… …
458 } 558 }
459 559
460 hash += hash << 3; 560 hash += hash << 3;
461 hash ^= hash >> 11; 561 hash ^= hash >> 11;
462 hash += hash << 15; 562 hash += hash << 15;
563#else
564 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
565 // it is about twice as fast as the one-at-a-time one,
566 // with good distribution.
567 // FNV-1a is faster on many cpus because the multiplication
568 // runs concurrent with the looping logic.
569 uint32_t hash = 2166136261;
570
571 while (*s)
572 hash = (hash ^ *s++) * 16777619;
573#endif
463 574
464 return hash; 575 return hash;
465 } 576 }
466}; 577};
467 578

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