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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 
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