1 /*
2 ** $Id: lmathlib.c,v 1.117 2015/10/02 15:39:23 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
39 static 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
50 static int math_sin (lua_State *L) {
51 lua_pushnumber(L, l_mathop(sin)(luaL_checknumber(L, 1)));
52 return 1;
53 }
54
55 static int math_cos (lua_State *L) {
56 lua_pushnumber(L, l_mathop(cos)(luaL_checknumber(L, 1)));
57 return 1;
58 }
59
60 static int math_tan (lua_State *L) {
61 lua_pushnumber(L, l_mathop(tan)(luaL_checknumber(L, 1)));
62 return 1;
63 }
64
65 static int math_asin (lua_State *L) {
66 lua_pushnumber(L, l_mathop(asin)(luaL_checknumber(L, 1)));
67 return 1;
68 }
69
70 static int math_acos (lua_State *L) {
71 lua_pushnumber(L, l_mathop(acos)(luaL_checknumber(L, 1)));
72 return 1;
73 }
74
75 static 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
83 static 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
96 static 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
105 static 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
116 static 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
127 static 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 */
149 static 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
166 static int math_sqrt (lua_State *L) {
167 lua_pushnumber(L, l_mathop(sqrt)(luaL_checknumber(L, 1)));
168 return 1;
169 }
170
171
172 static 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
179 static 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 == 2.0) res = l_mathop(log2)(x); else
188 #endif
189 if (base == 10.0) res = l_mathop(log10)(x);
190 else res = l_mathop(log)(x)/l_mathop(log)(base);
191 }
192 lua_pushnumber(L, res);
193 return 1;
194 }
195
196 static int math_exp (lua_State *L) {
197 lua_pushnumber(L, l_mathop(exp)(luaL_checknumber(L, 1)));
198 return 1;
199 }
200
201 static int math_deg (lua_State *L) {
202 lua_pushnumber(L, luaL_checknumber(L, 1) * (l_mathop(180.0) / PI));
203 return 1;
204 }
205
206 static int math_rad (lua_State *L) {
207 lua_pushnumber(L, luaL_checknumber(L, 1) * (PI / l_mathop(180.0)));
208 return 1;
209 }
210
211
212 static int math_min (lua_State *L) {
213 int n = lua_gettop(L); /* number of arguments */
214 int imin = 1; /* index of current minimum value */
215 int i;
216 luaL_argcheck(L, n >= 1, 1, "value expected");
217 for (i = 2; i <= n; i++) {
218 if (lua_compare(L, i, imin, LUA_OPLT))
219 imin = i;
220 }
221 lua_pushvalue(L, imin);
222 return 1;
223 }
224
225
226 static int math_max (lua_State *L) {
227 int n = lua_gettop(L); /* number of arguments */
228 int imax = 1; /* index of current maximum value */
229 int i;
230 luaL_argcheck(L, n >= 1, 1, "value expected");
231 for (i = 2; i <= n; i++) {
232 if (lua_compare(L, imax, i, LUA_OPLT))
233 imax = i;
234 }
235 lua_pushvalue(L, imax);
236 return 1;
237 }
238
239 /*
240 ** This function uses 'double' (instead of 'lua_Number') to ensure that
241 ** all bits from 'l_rand' can be represented, and that 'RANDMAX + 1.0'
242 ** will keep full precision (ensuring that 'r' is always less than 1.0.)
243 */
244 static int math_random (lua_State *L) {
245 lua_Integer low, up;
246 double r = (double)l_rand() * (1.0 / ((double)L_RANDMAX + 1.0));
247 switch (lua_gettop(L)) { /* check number of arguments */
248 case 0: { /* no arguments */
249 lua_pushnumber(L, (lua_Number)r); /* Number between 0 and 1 */
250 return 1;
251 }
252 case 1: { /* only upper limit */
253 low = 1;
254 up = luaL_checkinteger(L, 1);
255 break;
256 }
257 case 2: { /* lower and upper limits */
258 low = luaL_checkinteger(L, 1);
259 up = luaL_checkinteger(L, 2);
260 break;
261 }
262 default: return luaL_error(L, "wrong number of arguments");
263 }
264 /* random integer in the interval [low, up] */
265 luaL_argcheck(L, low <= up, 1, "interval is empty");
266 luaL_argcheck(L, low >= 0 || up <= LUA_MAXINTEGER + low, 1,
267 "interval too large");
268 r *= (double)(up - low) + 1.0;
269 lua_pushinteger(L, (lua_Integer)r + low);
270 return 1;
271 }
272
273
274 static int math_randomseed (lua_State *L) {
275 l_srand((unsigned int)(lua_Integer)luaL_checknumber(L, 1));
|
(1) Event dont_call: |
"random" should not be used for security-related applications, because linear congruential algorithms are too easy to break. |
|
(2) Event remediation: |
Use a compliant random number generator, such as "/dev/random" or "/dev/urandom" on Unix-like systems, and CNG (Cryptography API: Next Generation) on Windows. |
276 (void)l_rand(); /* discard first value to avoid undesirable correlations */
277 return 0;
278 }
279
280
281 static int math_type (lua_State *L) {
282 if (lua_type(L, 1) == LUA_TNUMBER) {
283 if (lua_isinteger(L, 1))
284 lua_pushliteral(L, "integer");
285 else
286 lua_pushliteral(L, "float");
287 }
288 else {
289 luaL_checkany(L, 1);
290 lua_pushnil(L);
291 }
292 return 1;
293 }
294
295
296 /*
297 ** {==================================================================
298 ** Deprecated functions (for compatibility only)
299 ** ===================================================================
300 */
301 #if defined(LUA_COMPAT_MATHLIB)
302
303 static int math_cosh (lua_State *L) {
304 lua_pushnumber(L, l_mathop(cosh)(luaL_checknumber(L, 1)));
305 return 1;
306 }
307
308 static int math_sinh (lua_State *L) {
309 lua_pushnumber(L, l_mathop(sinh)(luaL_checknumber(L, 1)));
310 return 1;
311 }
312
313 static int math_tanh (lua_State *L) {
314 lua_pushnumber(L, l_mathop(tanh)(luaL_checknumber(L, 1)));
315 return 1;
316 }
317
318 static int math_pow (lua_State *L) {
319 lua_Number x = luaL_checknumber(L, 1);
320 lua_Number y = luaL_checknumber(L, 2);
321 lua_pushnumber(L, l_mathop(pow)(x, y));
322 return 1;
323 }
324
325 static int math_frexp (lua_State *L) {
326 int e;
327 lua_pushnumber(L, l_mathop(frexp)(luaL_checknumber(L, 1), &e));
328 lua_pushinteger(L, e);
329 return 2;
330 }
331
332 static int math_ldexp (lua_State *L) {
333 lua_Number x = luaL_checknumber(L, 1);
334 int ep = (int)luaL_checkinteger(L, 2);
335 lua_pushnumber(L, l_mathop(ldexp)(x, ep));
336 return 1;
337 }
338
339 static int math_log10 (lua_State *L) {
340 lua_pushnumber(L, l_mathop(log10)(luaL_checknumber(L, 1)));
341 return 1;
342 }
343
344 #endif
345 /* }================================================================== */
346
347
348
349 static const luaL_Reg mathlib[] = {
350 {"abs", math_abs},
351 {"acos", math_acos},
352 {"asin", math_asin},
353 {"atan", math_atan},
354 {"ceil", math_ceil},
355 {"cos", math_cos},
356 {"deg", math_deg},
357 {"exp", math_exp},
358 {"tointeger", math_toint},
359 {"floor", math_floor},
360 {"fmod", math_fmod},
361 {"ult", math_ult},
362 {"log", math_log},
363 {"max", math_max},
364 {"min", math_min},
365 {"modf", math_modf},
366 {"rad", math_rad},
367 {"random", math_random},
368 {"randomseed", math_randomseed},
369 {"sin", math_sin},
370 {"sqrt", math_sqrt},
371 {"tan", math_tan},
372 {"type", math_type},
373 #if defined(LUA_COMPAT_MATHLIB)
374 {"atan2", math_atan},
375 {"cosh", math_cosh},
376 {"sinh", math_sinh},
377 {"tanh", math_tanh},
378 {"pow", math_pow},
379 {"frexp", math_frexp},
380 {"ldexp", math_ldexp},
381 {"log10", math_log10},
382 #endif
383 /* placeholders */
384 {"pi", NULL},
385 {"huge", NULL},
386 {"maxinteger", NULL},
387 {"mininteger", NULL},
388 {NULL, NULL}
389 };
390
391
392 /*
393 ** Open math library
394 */
395 LUAMOD_API int luaopen_math (lua_State *L) {
396 luaL_newlib(L, mathlib);
397 lua_pushnumber(L, PI);
398 lua_setfield(L, -2, "pi");
399 lua_pushnumber(L, (lua_Number)HUGE_VAL);
400 lua_setfield(L, -2, "huge");
401 lua_pushinteger(L, LUA_MAXINTEGER);
402 lua_setfield(L, -2, "maxinteger");
403 lua_pushinteger(L, LUA_MININTEGER);
404 lua_setfield(L, -2, "mininteger");
405 return 1;
406 }
407
408