xref: /netbsd-src/external/mit/lua/dist/src/lmathlib.c (revision 627f7eb200a4419d89b531d55fccd2ee3ffdcde0)
1 /*	$NetBSD: lmathlib.c,v 1.9 2018/08/04 17:30:01 alnsn Exp $	*/
2 
3 /*
4 ** Id: lmathlib.c,v 1.119.1.1 2017/04/19 17:20:42 roberto Exp
5 ** Standard mathematical library
6 ** See Copyright Notice in lua.h
7 */
8 
9 #define lmathlib_c
10 #define LUA_LIB
11 
12 #include "lprefix.h"
13 
14 
15 #include <stdlib.h>
16 #include <math.h>
17 
18 #include "lua.h"
19 
20 #include "lauxlib.h"
21 #include "lualib.h"
22 
23 
24 #undef PI
25 #define PI	(l_mathop(3.141592653589793238462643383279502884))
26 
27 
28 #if !defined(l_rand)		/* { */
29 #if defined(LUA_USE_POSIX)
30 #define l_rand()	random()
31 #define l_srand(x)	srandom(x)
32 #define L_RANDMAX	2147483647	/* (2^31 - 1), following POSIX */
33 #else
34 #define l_rand()	rand()
35 #define l_srand(x)	srand(x)
36 #define L_RANDMAX	RAND_MAX
37 #endif
38 #endif				/* } */
39 
40 
41 static int math_abs (lua_State *L) {
42   if (lua_isinteger(L, 1)) {
43     lua_Integer n = lua_tointeger(L, 1);
44     if (n < 0) n = (lua_Integer)(0u - (lua_Unsigned)n);
45     lua_pushinteger(L, n);
46   }
47   else
48     lua_pushnumber(L, l_mathop(fabs)(luaL_checknumber(L, 1)));
49   return 1;
50 }
51 
52 static int math_sin (lua_State *L) {
53   lua_pushnumber(L, l_mathop(sin)(luaL_checknumber(L, 1)));
54   return 1;
55 }
56 
57 static int math_cos (lua_State *L) {
58   lua_pushnumber(L, l_mathop(cos)(luaL_checknumber(L, 1)));
59   return 1;
60 }
61 
62 static int math_tan (lua_State *L) {
63   lua_pushnumber(L, l_mathop(tan)(luaL_checknumber(L, 1)));
64   return 1;
65 }
66 
67 static int math_asin (lua_State *L) {
68   lua_pushnumber(L, l_mathop(asin)(luaL_checknumber(L, 1)));
69   return 1;
70 }
71 
72 static int math_acos (lua_State *L) {
73   lua_pushnumber(L, l_mathop(acos)(luaL_checknumber(L, 1)));
74   return 1;
75 }
76 
77 static int math_atan (lua_State *L) {
78   lua_Number y = luaL_checknumber(L, 1);
79   lua_Number x = luaL_optnumber(L, 2, 1);
80   lua_pushnumber(L, l_mathop(atan2)(y, x));
81   return 1;
82 }
83 
84 
85 static int math_toint (lua_State *L) {
86   int valid;
87   lua_Integer n = lua_tointegerx(L, 1, &valid);
88   if (valid)
89     lua_pushinteger(L, n);
90   else {
91     luaL_checkany(L, 1);
92     lua_pushnil(L);  /* value is not convertible to integer */
93   }
94   return 1;
95 }
96 
97 
98 static void pushnumint (lua_State *L, lua_Number d) {
99   lua_Integer n;
100   if (lua_numbertointeger(d, &n))  /* does 'd' fit in an integer? */
101     lua_pushinteger(L, n);  /* result is integer */
102   else
103     lua_pushnumber(L, d);  /* result is float */
104 }
105 
106 
107 static int math_floor (lua_State *L) {
108   if (lua_isinteger(L, 1))
109     lua_settop(L, 1);  /* integer is its own floor */
110   else {
111     lua_Number d = l_mathop(floor)(luaL_checknumber(L, 1));
112     pushnumint(L, d);
113   }
114   return 1;
115 }
116 
117 
118 static int math_ceil (lua_State *L) {
119   if (lua_isinteger(L, 1))
120     lua_settop(L, 1);  /* integer is its own ceil */
121   else {
122     lua_Number d = l_mathop(ceil)(luaL_checknumber(L, 1));
123     pushnumint(L, d);
124   }
125   return 1;
126 }
127 
128 
129 static int math_fmod (lua_State *L) {
130   if (lua_isinteger(L, 1) && lua_isinteger(L, 2)) {
131     lua_Integer d = lua_tointeger(L, 2);
132     if ((lua_Unsigned)d + 1u <= 1u) {  /* special cases: -1 or 0 */
133       luaL_argcheck(L, d != 0, 2, "zero");
134       lua_pushinteger(L, 0);  /* avoid overflow with 0x80000... / -1 */
135     }
136     else
137       lua_pushinteger(L, lua_tointeger(L, 1) % d);
138   }
139   else
140     lua_pushnumber(L, l_mathop(fmod)(luaL_checknumber(L, 1),
141                                      luaL_checknumber(L, 2)));
142   return 1;
143 }
144 
145 
146 /*
147 ** next function does not use 'modf', avoiding problems with 'double*'
148 ** (which is not compatible with 'float*') when lua_Number is not
149 ** 'double'.
150 */
151 static int math_modf (lua_State *L) {
152   if (lua_isinteger(L ,1)) {
153     lua_settop(L, 1);  /* number is its own integer part */
154     lua_pushnumber(L, 0);  /* no fractional part */
155   }
156   else {
157     lua_Number n = luaL_checknumber(L, 1);
158     /* integer part (rounds toward zero) */
159     lua_Number ip = (n < 0) ? l_mathop(ceil)(n) : l_mathop(floor)(n);
160     pushnumint(L, ip);
161     /* fractional part (test needed for inf/-inf) */
162     lua_pushnumber(L, (n == ip) ? l_mathop(0.0) : (n - ip));
163   }
164   return 2;
165 }
166 
167 
168 static int math_sqrt (lua_State *L) {
169   lua_pushnumber(L, l_mathop(sqrt)(luaL_checknumber(L, 1)));
170   return 1;
171 }
172 
173 
174 static int math_ult (lua_State *L) {
175   lua_Integer a = luaL_checkinteger(L, 1);
176   lua_Integer b = luaL_checkinteger(L, 2);
177   lua_pushboolean(L, (lua_Unsigned)a < (lua_Unsigned)b);
178   return 1;
179 }
180 
181 static int math_log (lua_State *L) {
182   lua_Number x = luaL_checknumber(L, 1);
183   lua_Number res;
184   if (lua_isnoneornil(L, 2))
185     res = l_mathop(log)(x);
186   else {
187     lua_Number base = luaL_checknumber(L, 2);
188 #if !defined(LUA_USE_C89)
189     if (base == l_mathop(2.0))
190       res = l_mathop(log2)(x); else
191 #endif
192     if (base == l_mathop(10.0))
193       res = l_mathop(log10)(x);
194     else
195       res = l_mathop(log)(x)/l_mathop(log)(base);
196   }
197   lua_pushnumber(L, res);
198   return 1;
199 }
200 
201 static int math_exp (lua_State *L) {
202   lua_pushnumber(L, l_mathop(exp)(luaL_checknumber(L, 1)));
203   return 1;
204 }
205 
206 static int math_deg (lua_State *L) {
207   lua_pushnumber(L, luaL_checknumber(L, 1) * (l_mathop(180.0) / PI));
208   return 1;
209 }
210 
211 static int math_rad (lua_State *L) {
212   lua_pushnumber(L, luaL_checknumber(L, 1) * (PI / l_mathop(180.0)));
213   return 1;
214 }
215 
216 
217 static int math_min (lua_State *L) {
218   int n = lua_gettop(L);  /* number of arguments */
219   int imin = 1;  /* index of current minimum value */
220   int i;
221   luaL_argcheck(L, n >= 1, 1, "value expected");
222   for (i = 2; i <= n; i++) {
223     if (lua_compare(L, i, imin, LUA_OPLT))
224       imin = i;
225   }
226   lua_pushvalue(L, imin);
227   return 1;
228 }
229 
230 
231 static int math_max (lua_State *L) {
232   int n = lua_gettop(L);  /* number of arguments */
233   int imax = 1;  /* index of current maximum value */
234   int i;
235   luaL_argcheck(L, n >= 1, 1, "value expected");
236   for (i = 2; i <= n; i++) {
237     if (lua_compare(L, imax, i, LUA_OPLT))
238       imax = i;
239   }
240   lua_pushvalue(L, imax);
241   return 1;
242 }
243 
244 /*
245 ** This function uses 'double' (instead of 'lua_Number') to ensure that
246 ** all bits from 'l_rand' can be represented, and that 'RANDMAX + 1.0'
247 ** will keep full precision (ensuring that 'r' is always less than 1.0.)
248 */
249 static int math_random (lua_State *L) {
250   lua_Integer low, up;
251   double r = (double)l_rand() * (1.0 / ((double)L_RANDMAX + 1.0));
252   switch (lua_gettop(L)) {  /* check number of arguments */
253     case 0: {  /* no arguments */
254       lua_pushnumber(L, (lua_Number)r);  /* Number between 0 and 1 */
255       return 1;
256     }
257     case 1: {  /* only upper limit */
258       low = 1;
259       up = luaL_checkinteger(L, 1);
260       break;
261     }
262     case 2: {  /* lower and upper limits */
263       low = luaL_checkinteger(L, 1);
264       up = luaL_checkinteger(L, 2);
265       break;
266     }
267     default: return luaL_error(L, "wrong number of arguments");
268   }
269   /* random integer in the interval [low, up] */
270   luaL_argcheck(L, low <= up, 1, "interval is empty");
271   luaL_argcheck(L, low >= 0 || up <= LUA_MAXINTEGER + low, 1,
272                    "interval too large");
273   r *= (double)(up - low) + 1.0;
274   lua_pushinteger(L, (lua_Integer)r + low);
275   return 1;
276 }
277 
278 
279 static int math_randomseed (lua_State *L) {
280   l_srand((unsigned int)(lua_Integer)luaL_checknumber(L, 1));
281   (void)l_rand(); /* discard first value to avoid undesirable correlations */
282   return 0;
283 }
284 
285 
286 static int math_type (lua_State *L) {
287   if (lua_type(L, 1) == LUA_TNUMBER) {
288       if (lua_isinteger(L, 1))
289         lua_pushliteral(L, "integer");
290       else
291         lua_pushliteral(L, "float");
292   }
293   else {
294     luaL_checkany(L, 1);
295     lua_pushnil(L);
296   }
297   return 1;
298 }
299 
300 
301 /*
302 ** {==================================================================
303 ** Deprecated functions (for compatibility only)
304 ** ===================================================================
305 */
306 #if defined(LUA_COMPAT_MATHLIB)
307 
308 static int math_cosh (lua_State *L) {
309   lua_pushnumber(L, l_mathop(cosh)(luaL_checknumber(L, 1)));
310   return 1;
311 }
312 
313 static int math_sinh (lua_State *L) {
314   lua_pushnumber(L, l_mathop(sinh)(luaL_checknumber(L, 1)));
315   return 1;
316 }
317 
318 static int math_tanh (lua_State *L) {
319   lua_pushnumber(L, l_mathop(tanh)(luaL_checknumber(L, 1)));
320   return 1;
321 }
322 
323 static int math_pow (lua_State *L) {
324   lua_Number x = luaL_checknumber(L, 1);
325   lua_Number y = luaL_checknumber(L, 2);
326   lua_pushnumber(L, l_mathop(pow)(x, y));
327   return 1;
328 }
329 
330 static int math_frexp (lua_State *L) {
331   int e;
332   lua_pushnumber(L, l_mathop(frexp)(luaL_checknumber(L, 1), &e));
333   lua_pushinteger(L, e);
334   return 2;
335 }
336 
337 static int math_ldexp (lua_State *L) {
338   lua_Number x = luaL_checknumber(L, 1);
339   int ep = (int)luaL_checkinteger(L, 2);
340   lua_pushnumber(L, l_mathop(ldexp)(x, ep));
341   return 1;
342 }
343 
344 static int math_log10 (lua_State *L) {
345   lua_pushnumber(L, l_mathop(log10)(luaL_checknumber(L, 1)));
346   return 1;
347 }
348 
349 #endif
350 /* }================================================================== */
351 
352 
353 
354 static const luaL_Reg mathlib[] = {
355   {"abs",   math_abs},
356   {"acos",  math_acos},
357   {"asin",  math_asin},
358   {"atan",  math_atan},
359   {"ceil",  math_ceil},
360   {"cos",   math_cos},
361   {"deg",   math_deg},
362   {"exp",   math_exp},
363   {"tointeger", math_toint},
364   {"floor", math_floor},
365   {"fmod",   math_fmod},
366   {"ult",   math_ult},
367   {"log",   math_log},
368   {"max",   math_max},
369   {"min",   math_min},
370   {"modf",   math_modf},
371   {"rad",   math_rad},
372   {"random",     math_random},
373   {"randomseed", math_randomseed},
374   {"sin",   math_sin},
375   {"sqrt",  math_sqrt},
376   {"tan",   math_tan},
377   {"type", math_type},
378 #if defined(LUA_COMPAT_MATHLIB)
379   {"atan2", math_atan},
380   {"cosh",   math_cosh},
381   {"sinh",   math_sinh},
382   {"tanh",   math_tanh},
383   {"pow",   math_pow},
384   {"frexp", math_frexp},
385   {"ldexp", math_ldexp},
386   {"log10", math_log10},
387 #endif
388   /* placeholders */
389   {"pi", NULL},
390   {"huge", NULL},
391   {"maxinteger", NULL},
392   {"mininteger", NULL},
393   {NULL, NULL}
394 };
395 
396 
397 /*
398 ** Open math library
399 */
400 LUAMOD_API int luaopen_math (lua_State *L) {
401   luaL_newlib(L, mathlib);
402   lua_pushnumber(L, PI);
403   lua_setfield(L, -2, "pi");
404   lua_pushnumber(L, (lua_Number)HUGE_VAL);
405   lua_setfield(L, -2, "huge");
406   lua_pushinteger(L, LUA_MAXINTEGER);
407   lua_setfield(L, -2, "maxinteger");
408   lua_pushinteger(L, LUA_MININTEGER);
409   lua_setfield(L, -2, "mininteger");
410   return 1;
411 }
412 
413