1 /*
2 ** $Id: lmathlib.c,v 1.119 2016/12/22 13:08:50 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
math_abs(lua_State * L)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
math_sin(lua_State * L)50 static int math_sin (lua_State *L) {
51 lua_pushnumber(L, l_mathop(sin)(luaL_checknumber(L, 1)));
52 return 1;
53 }
54
math_cos(lua_State * L)55 static int math_cos (lua_State *L) {
56 lua_pushnumber(L, l_mathop(cos)(luaL_checknumber(L, 1)));
57 return 1;
58 }
59
math_tan(lua_State * L)60 static int math_tan (lua_State *L) {
61 lua_pushnumber(L, l_mathop(tan)(luaL_checknumber(L, 1)));
62 return 1;
63 }
64
math_asin(lua_State * L)65 static int math_asin (lua_State *L) {
66 lua_pushnumber(L, l_mathop(asin)(luaL_checknumber(L, 1)));
67 return 1;
68 }
69
math_acos(lua_State * L)70 static int math_acos (lua_State *L) {
71 lua_pushnumber(L, l_mathop(acos)(luaL_checknumber(L, 1)));
72 return 1;
73 }
74
math_atan(lua_State * L)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
math_toint(lua_State * L)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
pushnumint(lua_State * L,lua_Number d)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
math_floor(lua_State * L)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
math_ceil(lua_State * L)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
math_fmod(lua_State * L)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 */
math_modf(lua_State * L)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
math_sqrt(lua_State * L)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
math_ult(lua_State * L)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
math_log(lua_State * L)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 == 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
math_exp(lua_State * L)199 static int math_exp (lua_State *L) {
200 lua_pushnumber(L, l_mathop(exp)(luaL_checknumber(L, 1)));
201 return 1;
202 }
203
math_deg(lua_State * L)204 static int math_deg (lua_State *L) {
205 lua_pushnumber(L, luaL_checknumber(L, 1) * (l_mathop(180.0) / PI));
206 return 1;
207 }
208
math_rad(lua_State * L)209 static 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
math_min(lua_State * L)215 static 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
math_max(lua_State * L)229 static 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 */
math_random(lua_State * L)247 static 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
math_randomseed(lua_State * L)277 static 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
math_type(lua_State * L)284 static 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
math_cosh(lua_State * L)306 static int math_cosh (lua_State *L) {
307 lua_pushnumber(L, l_mathop(cosh)(luaL_checknumber(L, 1)));
308 return 1;
309 }
310
math_sinh(lua_State * L)311 static int math_sinh (lua_State *L) {
312 lua_pushnumber(L, l_mathop(sinh)(luaL_checknumber(L, 1)));
313 return 1;
314 }
315
math_tanh(lua_State * L)316 static int math_tanh (lua_State *L) {
317 lua_pushnumber(L, l_mathop(tanh)(luaL_checknumber(L, 1)));
318 return 1;
319 }
320
math_pow(lua_State * L)321 static 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
math_frexp(lua_State * L)328 static 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
math_ldexp(lua_State * L)335 static 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
math_log10(lua_State * L)342 static 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
352 static 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 */
luaopen_math(lua_State * L)398 LUAMOD_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