lmathlib.c revision 344220 
1/*
2** $Id: lmathlib.c,v 1.119.1.1 2017/04/19 17:20:42 roberto Exp $
3** Standard mathematical library
4** See Copyright Notice in lua.h
5*/
6
7#define lmathlib_c
8#define LUA_LIB
9
10#include "lprefix.h"
11
12
13#include <stdlib.h>
14#include <math.h>
15
16#include "lua.h"
17
18#include "lauxlib.h"
19#include "lualib.h"
20
21
22#undef PI
23#define PI	(l_mathop(3.141592653589793238462643383279502884))
24
25
26#if !defined(l_rand)		/* { */
27#if defined(LUA_USE_POSIX)
28#define l_rand()	random()
29#define l_srand(x)	srandom(x)
30#define L_RANDMAX	2147483647	/* (2^31 - 1), following POSIX */
31#else
32#define l_rand()	rand()
33#define l_srand(x)	srand(x)
34#define L_RANDMAX	RAND_MAX
35#endif
36#endif				/* } */
37
38
39static int math_abs (lua_State *L) {
40  if (lua_isinteger(L, 1)) {
41    lua_Integer n = lua_tointeger(L, 1);
42    if (n < 0) n = (lua_Integer)(0u - (lua_Unsigned)n);
43    lua_pushinteger(L, n);
44  }
45  else
46    lua_pushnumber(L, l_mathop(fabs)(luaL_checknumber(L, 1)));
47  return 1;
48}
49
50static int math_sin (lua_State *L) {
51  lua_pushnumber(L, l_mathop(sin)(luaL_checknumber(L, 1)));
52  return 1;
53}
54
55static int math_cos (lua_State *L) {
56  lua_pushnumber(L, l_mathop(cos)(luaL_checknumber(L, 1)));
57  return 1;
58}
59
60static int math_tan (lua_State *L) {
61  lua_pushnumber(L, l_mathop(tan)(luaL_checknumber(L, 1)));
62  return 1;
63}
64
65static int math_asin (lua_State *L) {
66  lua_pushnumber(L, l_mathop(asin)(luaL_checknumber(L, 1)));
67  return 1;
68}
69
70static int math_acos (lua_State *L) {
71  lua_pushnumber(L, l_mathop(acos)(luaL_checknumber(L, 1)));
72  return 1;
73}
74
75static int math_atan (lua_State *L) {
76  lua_Number y = luaL_checknumber(L, 1);
77  lua_Number x = luaL_optnumber(L, 2, 1);
78  lua_pushnumber(L, l_mathop(atan2)(y, x));
79  return 1;
80}
81
82
83static int math_toint (lua_State *L) {
84  int valid;
85  lua_Integer n = lua_tointegerx(L, 1, &valid);
86  if (valid)
87    lua_pushinteger(L, n);
88  else {
89    luaL_checkany(L, 1);
90    lua_pushnil(L);  /* value is not convertible to integer */
91  }
92  return 1;
93}
94
95
96static void pushnumint (lua_State *L, lua_Number d) {
97  lua_Integer n;
98  if (lua_numbertointeger(d, &n))  /* does 'd' fit in an integer? */
99    lua_pushinteger(L, n);  /* result is integer */
100  else
101    lua_pushnumber(L, d);  /* result is float */
102}
103
104
105static int math_floor (lua_State *L) {
106  if (lua_isinteger(L, 1))
107    lua_settop(L, 1);  /* integer is its own floor */
108  else {
109    lua_Number d = l_mathop(floor)(luaL_checknumber(L, 1));
110    pushnumint(L, d);
111  }
112  return 1;
113}
114
115
116static int math_ceil (lua_State *L) {
117  if (lua_isinteger(L, 1))
118    lua_settop(L, 1);  /* integer is its own ceil */
119  else {
120    lua_Number d = l_mathop(ceil)(luaL_checknumber(L, 1));
121    pushnumint(L, d);
122  }
123  return 1;
124}
125
126
127static int math_fmod (lua_State *L) {
128  if (lua_isinteger(L, 1) && lua_isinteger(L, 2)) {
129    lua_Integer d = lua_tointeger(L, 2);
130    if ((lua_Unsigned)d + 1u <= 1u) {  /* special cases: -1 or 0 */
131      luaL_argcheck(L, d != 0, 2, "zero");
132      lua_pushinteger(L, 0);  /* avoid overflow with 0x80000... / -1 */
133    }
134    else
135      lua_pushinteger(L, lua_tointeger(L, 1) % d);
136  }
137  else
138    lua_pushnumber(L, l_mathop(fmod)(luaL_checknumber(L, 1),
139                                     luaL_checknumber(L, 2)));
140  return 1;
141}
142
143
144/*
145** next function does not use 'modf', avoiding problems with 'double*'
146** (which is not compatible with 'float*') when lua_Number is not
147** 'double'.
148*/
149static int math_modf (lua_State *L) {
150  if (lua_isinteger(L ,1)) {
151    lua_settop(L, 1);  /* number is its own integer part */
152    lua_pushnumber(L, 0);  /* no fractional part */
153  }
154  else {
155    lua_Number n = luaL_checknumber(L, 1);
156    /* integer part (rounds toward zero) */
157    lua_Number ip = (n < 0) ? l_mathop(ceil)(n) : l_mathop(floor)(n);
158    pushnumint(L, ip);
159    /* fractional part (test needed for inf/-inf) */
160    lua_pushnumber(L, (n == ip) ? l_mathop(0.0) : (n - ip));
161  }
162  return 2;
163}
164
165
166static int math_sqrt (lua_State *L) {
167  lua_pushnumber(L, l_mathop(sqrt)(luaL_checknumber(L, 1)));
168  return 1;
169}
170
171
172static int math_ult (lua_State *L) {
173  lua_Integer a = luaL_checkinteger(L, 1);
174  lua_Integer b = luaL_checkinteger(L, 2);
175  lua_pushboolean(L, (lua_Unsigned)a < (lua_Unsigned)b);
176  return 1;
177}
178
179static int math_log (lua_State *L) {
180  lua_Number x = luaL_checknumber(L, 1);
181  lua_Number res;
182  if (lua_isnoneornil(L, 2))
183    res = l_mathop(log)(x);
184  else {
185    lua_Number base = luaL_checknumber(L, 2);
186#if !defined(LUA_USE_C89)
187    if (base == l_mathop(2.0))
188      res = l_mathop(log2)(x); else
189#endif
190    if (base == l_mathop(10.0))
191      res = l_mathop(log10)(x);
192    else
193      res = l_mathop(log)(x)/l_mathop(log)(base);
194  }
195  lua_pushnumber(L, res);
196  return 1;
197}
198
199static int math_exp (lua_State *L) {
200  lua_pushnumber(L, l_mathop(exp)(luaL_checknumber(L, 1)));
201  return 1;
202}
203
204static int math_deg (lua_State *L) {
205  lua_pushnumber(L, luaL_checknumber(L, 1) * (l_mathop(180.0) / PI));
206  return 1;
207}
208
209static int math_rad (lua_State *L) {
210  lua_pushnumber(L, luaL_checknumber(L, 1) * (PI / l_mathop(180.0)));
211  return 1;
212}
213
214
215static int math_min (lua_State *L) {
216  int n = lua_gettop(L);  /* number of arguments */
217  int imin = 1;  /* index of current minimum value */
218  int i;
219  luaL_argcheck(L, n >= 1, 1, "value expected");
220  for (i = 2; i <= n; i++) {
221    if (lua_compare(L, i, imin, LUA_OPLT))
222      imin = i;
223  }
224  lua_pushvalue(L, imin);
225  return 1;
226}
227
228
229static int math_max (lua_State *L) {
230  int n = lua_gettop(L);  /* number of arguments */
231  int imax = 1;  /* index of current maximum value */
232  int i;
233  luaL_argcheck(L, n >= 1, 1, "value expected");
234  for (i = 2; i <= n; i++) {
235    if (lua_compare(L, imax, i, LUA_OPLT))
236      imax = i;
237  }
238  lua_pushvalue(L, imax);
239  return 1;
240}
241
242/*
243** This function uses 'double' (instead of 'lua_Number') to ensure that
244** all bits from 'l_rand' can be represented, and that 'RANDMAX + 1.0'
245** will keep full precision (ensuring that 'r' is always less than 1.0.)
246*/
247static int math_random (lua_State *L) {
248  lua_Integer low, up;
249  double r = (double)l_rand() * (1.0 / ((double)L_RANDMAX + 1.0));
250  switch (lua_gettop(L)) {  /* check number of arguments */
251    case 0: {  /* no arguments */
252      lua_pushnumber(L, (lua_Number)r);  /* Number between 0 and 1 */
253      return 1;
254    }
255    case 1: {  /* only upper limit */
256      low = 1;
257      up = luaL_checkinteger(L, 1);
258      break;
259    }
260    case 2: {  /* lower and upper limits */
261      low = luaL_checkinteger(L, 1);
262      up = luaL_checkinteger(L, 2);
263      break;
264    }
265    default: return luaL_error(L, "wrong number of arguments");
266  }
267  /* random integer in the interval [low, up] */
268  luaL_argcheck(L, low <= up, 1, "interval is empty");
269  luaL_argcheck(L, low >= 0 || up <= LUA_MAXINTEGER + low, 1,
270                   "interval too large");
271  r *= (double)(up - low) + 1.0;
272  lua_pushinteger(L, (lua_Integer)r + low);
273  return 1;
274}
275
276
277static int math_randomseed (lua_State *L) {
278  l_srand((unsigned int)(lua_Integer)luaL_checknumber(L, 1));
279  (void)l_rand(); /* discard first value to avoid undesirable correlations */
280  return 0;
281}
282
283
284static int math_type (lua_State *L) {
285  if (lua_type(L, 1) == LUA_TNUMBER) {
286      if (lua_isinteger(L, 1))
287        lua_pushliteral(L, "integer");
288      else
289        lua_pushliteral(L, "float");
290  }
291  else {
292    luaL_checkany(L, 1);
293    lua_pushnil(L);
294  }
295  return 1;
296}
297
298
299/*
300** {==================================================================
301** Deprecated functions (for compatibility only)
302** ===================================================================
303*/
304#if defined(LUA_COMPAT_MATHLIB)
305
306static int math_cosh (lua_State *L) {
307  lua_pushnumber(L, l_mathop(cosh)(luaL_checknumber(L, 1)));
308  return 1;
309}
310
311static int math_sinh (lua_State *L) {
312  lua_pushnumber(L, l_mathop(sinh)(luaL_checknumber(L, 1)));
313  return 1;
314}
315
316static int math_tanh (lua_State *L) {
317  lua_pushnumber(L, l_mathop(tanh)(luaL_checknumber(L, 1)));
318  return 1;
319}
320
321static int math_pow (lua_State *L) {
322  lua_Number x = luaL_checknumber(L, 1);
323  lua_Number y = luaL_checknumber(L, 2);
324  lua_pushnumber(L, l_mathop(pow)(x, y));
325  return 1;
326}
327
328static int math_frexp (lua_State *L) {
329  int e;
330  lua_pushnumber(L, l_mathop(frexp)(luaL_checknumber(L, 1), &e));
331  lua_pushinteger(L, e);
332  return 2;
333}
334
335static int math_ldexp (lua_State *L) {
336  lua_Number x = luaL_checknumber(L, 1);
337  int ep = (int)luaL_checkinteger(L, 2);
338  lua_pushnumber(L, l_mathop(ldexp)(x, ep));
339  return 1;
340}
341
342static int math_log10 (lua_State *L) {
343  lua_pushnumber(L, l_mathop(log10)(luaL_checknumber(L, 1)));
344  return 1;
345}
346
347#endif
348/* }================================================================== */
349
350
351
352static const luaL_Reg mathlib[] = {
353  {"abs",   math_abs},
354  {"acos",  math_acos},
355  {"asin",  math_asin},
356  {"atan",  math_atan},
357  {"ceil",  math_ceil},
358  {"cos",   math_cos},
359  {"deg",   math_deg},
360  {"exp",   math_exp},
361  {"tointeger", math_toint},
362  {"floor", math_floor},
363  {"fmod",   math_fmod},
364  {"ult",   math_ult},
365  {"log",   math_log},
366  {"max",   math_max},
367  {"min",   math_min},
368  {"modf",   math_modf},
369  {"rad",   math_rad},
370  {"random",     math_random},
371  {"randomseed", math_randomseed},
372  {"sin",   math_sin},
373  {"sqrt",  math_sqrt},
374  {"tan",   math_tan},
375  {"type", math_type},
376#if defined(LUA_COMPAT_MATHLIB)
377  {"atan2", math_atan},
378  {"cosh",   math_cosh},
379  {"sinh",   math_sinh},
380  {"tanh",   math_tanh},
381  {"pow",   math_pow},
382  {"frexp", math_frexp},
383  {"ldexp", math_ldexp},
384  {"log10", math_log10},
385#endif
386  /* placeholders */
387  {"pi", NULL},
388  {"huge", NULL},
389  {"maxinteger", NULL},
390  {"mininteger", NULL},
391  {NULL, NULL}
392};
393
394
395/*
396** Open math library
397*/
398LUAMOD_API int luaopen_math (lua_State *L) {
399  luaL_newlib(L, mathlib);
400  lua_pushnumber(L, PI);
401  lua_setfield(L, -2, "pi");
402  lua_pushnumber(L, (lua_Number)HUGE_VAL);
403  lua_setfield(L, -2, "huge");
404  lua_pushinteger(L, LUA_MAXINTEGER);
405  lua_setfield(L, -2, "maxinteger");
406  lua_pushinteger(L, LUA_MININTEGER);
407  lua_setfield(L, -2, "mininteger");
408  return 1;
409}
410
411