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      1 /*
      2 ** $Id: lmathlib.c,v 1.83.1.1 2013/04/12 18:48:47 roberto Exp $
      3 ** Standard mathematical library
      4 ** See Copyright Notice in lua.h
      5 */
      6 
      7 
      8 #include <stdlib.h>
      9 #include <math.h>
     10 
     11 #define lmathlib_c
     12 #define LUA_LIB
     13 
     14 #include "lua.h"
     15 
     16 #include "lauxlib.h"
     17 #include "lualib.h"
     18 
     19 
     20 #undef PI
     21 #define PI  ((lua_Number)(3.1415926535897932384626433832795))
     22 #define RADIANS_PER_DEGREE  ((lua_Number)(PI/180.0))
     23 
     24 
     25 
     26 static int math_abs (lua_State *L) {
     27   lua_pushnumber(L, l_mathop(fabs)(luaL_checknumber(L, 1)));
     28   return 1;
     29 }
     30 
     31 static int math_sin (lua_State *L) {
     32   lua_pushnumber(L, l_mathop(sin)(luaL_checknumber(L, 1)));
     33   return 1;
     34 }
     35 
     36 static int math_sinh (lua_State *L) {
     37   lua_pushnumber(L, l_mathop(sinh)(luaL_checknumber(L, 1)));
     38   return 1;
     39 }
     40 
     41 static int math_cos (lua_State *L) {
     42   lua_pushnumber(L, l_mathop(cos)(luaL_checknumber(L, 1)));
     43   return 1;
     44 }
     45 
     46 static int math_cosh (lua_State *L) {
     47   lua_pushnumber(L, l_mathop(cosh)(luaL_checknumber(L, 1)));
     48   return 1;
     49 }
     50 
     51 static int math_tan (lua_State *L) {
     52   lua_pushnumber(L, l_mathop(tan)(luaL_checknumber(L, 1)));
     53   return 1;
     54 }
     55 
     56 static int math_tanh (lua_State *L) {
     57   lua_pushnumber(L, l_mathop(tanh)(luaL_checknumber(L, 1)));
     58   return 1;
     59 }
     60 
     61 static int math_asin (lua_State *L) {
     62   lua_pushnumber(L, l_mathop(asin)(luaL_checknumber(L, 1)));
     63   return 1;
     64 }
     65 
     66 static int math_acos (lua_State *L) {
     67   lua_pushnumber(L, l_mathop(acos)(luaL_checknumber(L, 1)));
     68   return 1;
     69 }
     70 
     71 static int math_atan (lua_State *L) {
     72   lua_pushnumber(L, l_mathop(atan)(luaL_checknumber(L, 1)));
     73   return 1;
     74 }
     75 
     76 static int math_atan2 (lua_State *L) {
     77   lua_pushnumber(L, l_mathop(atan2)(luaL_checknumber(L, 1),
     78                                 luaL_checknumber(L, 2)));
     79   return 1;
     80 }
     81 
     82 static int math_ceil (lua_State *L) {
     83   lua_pushnumber(L, l_mathop(ceil)(luaL_checknumber(L, 1)));
     84   return 1;
     85 }
     86 
     87 static int math_floor (lua_State *L) {
     88   lua_pushnumber(L, l_mathop(floor)(luaL_checknumber(L, 1)));
     89   return 1;
     90 }
     91 
     92 static int math_fmod (lua_State *L) {
     93   lua_pushnumber(L, l_mathop(fmod)(luaL_checknumber(L, 1),
     94                                luaL_checknumber(L, 2)));
     95   return 1;
     96 }
     97 
     98 static int math_modf (lua_State *L) {
     99   lua_Number ip;
    100   lua_Number fp = l_mathop(modf)(luaL_checknumber(L, 1), &ip);
    101   lua_pushnumber(L, ip);
    102   lua_pushnumber(L, fp);
    103   return 2;
    104 }
    105 
    106 static int math_sqrt (lua_State *L) {
    107   lua_pushnumber(L, l_mathop(sqrt)(luaL_checknumber(L, 1)));
    108   return 1;
    109 }
    110 
    111 static int math_pow (lua_State *L) {
    112   lua_Number x = luaL_checknumber(L, 1);
    113   lua_Number y = luaL_checknumber(L, 2);
    114   lua_pushnumber(L, l_mathop(pow)(x, y));
    115   return 1;
    116 }
    117 
    118 static int math_log (lua_State *L) {
    119   lua_Number x = luaL_checknumber(L, 1);
    120   lua_Number res;
    121   if (lua_isnoneornil(L, 2))
    122     res = l_mathop(log)(x);
    123   else {
    124     lua_Number base = luaL_checknumber(L, 2);
    125     if (base == (lua_Number)10.0) res = l_mathop(log10)(x);
    126     else res = l_mathop(log)(x)/l_mathop(log)(base);
    127   }
    128   lua_pushnumber(L, res);
    129   return 1;
    130 }
    131 
    132 #if defined(LUA_COMPAT_LOG10)
    133 static int math_log10 (lua_State *L) {
    134   lua_pushnumber(L, l_mathop(log10)(luaL_checknumber(L, 1)));
    135   return 1;
    136 }
    137 #endif
    138 
    139 static int math_exp (lua_State *L) {
    140   lua_pushnumber(L, l_mathop(exp)(luaL_checknumber(L, 1)));
    141   return 1;
    142 }
    143 
    144 static int math_deg (lua_State *L) {
    145   lua_pushnumber(L, luaL_checknumber(L, 1)/RADIANS_PER_DEGREE);
    146   return 1;
    147 }
    148 
    149 static int math_rad (lua_State *L) {
    150   lua_pushnumber(L, luaL_checknumber(L, 1)*RADIANS_PER_DEGREE);
    151   return 1;
    152 }
    153 
    154 static int math_frexp (lua_State *L) {
    155   int e;
    156   lua_pushnumber(L, l_mathop(frexp)(luaL_checknumber(L, 1), &e));
    157   lua_pushinteger(L, e);
    158   return 2;
    159 }
    160 
    161 static int math_ldexp (lua_State *L) {
    162   lua_Number x = luaL_checknumber(L, 1);
    163   int ep = luaL_checkint(L, 2);
    164   lua_pushnumber(L, l_mathop(ldexp)(x, ep));
    165   return 1;
    166 }
    167 
    168 
    169 
    170 static int math_min (lua_State *L) {
    171   int n = lua_gettop(L);  /* number of arguments */
    172   lua_Number dmin = luaL_checknumber(L, 1);
    173   int i;
    174   for (i=2; i<=n; i++) {
    175     lua_Number d = luaL_checknumber(L, i);
    176     if (d < dmin)
    177       dmin = d;
    178   }
    179   lua_pushnumber(L, dmin);
    180   return 1;
    181 }
    182 
    183 
    184 static int math_max (lua_State *L) {
    185   int n = lua_gettop(L);  /* number of arguments */
    186   lua_Number dmax = luaL_checknumber(L, 1);
    187   int i;
    188   for (i=2; i<=n; i++) {
    189     lua_Number d = luaL_checknumber(L, i);
    190     if (d > dmax)
    191       dmax = d;
    192   }
    193   lua_pushnumber(L, dmax);
    194   return 1;
    195 }
    196 
    197 
    198 static int math_random (lua_State *L) {
    199   /* the `%' avoids the (rare) case of r==1, and is needed also because on
    200      some systems (SunOS!) `rand()' may return a value larger than RAND_MAX */
    201   lua_Number r = (lua_Number)(rand()%RAND_MAX) / (lua_Number)RAND_MAX;
    202   switch (lua_gettop(L)) {  /* check number of arguments */
    203     case 0: {  /* no arguments */
    204       lua_pushnumber(L, r);  /* Number between 0 and 1 */
    205       break;
    206     }
    207     case 1: {  /* only upper limit */
    208       lua_Number u = luaL_checknumber(L, 1);
    209       luaL_argcheck(L, (lua_Number)1.0 <= u, 1, "interval is empty");
    210       lua_pushnumber(L, l_mathop(floor)(r*u) + (lua_Number)(1.0));  /* [1, u] */
    211       break;
    212     }
    213     case 2: {  /* lower and upper limits */
    214       lua_Number l = luaL_checknumber(L, 1);
    215       lua_Number u = luaL_checknumber(L, 2);
    216       luaL_argcheck(L, l <= u, 2, "interval is empty");
    217       lua_pushnumber(L, l_mathop(floor)(r*(u-l+1)) + l);  /* [l, u] */
    218       break;
    219     }
    220     default: return luaL_error(L, "wrong number of arguments");
    221   }
    222   return 1;
    223 }
    224 
    225 
    226 static int math_randomseed (lua_State *L) {
    227   srand(luaL_checkunsigned(L, 1));
    228   (void)rand(); /* discard first value to avoid undesirable correlations */
    229   return 0;
    230 }
    231 
    232 
    233 static const luaL_Reg mathlib[] = {
    234   {"abs",   math_abs},
    235   {"acos",  math_acos},
    236   {"asin",  math_asin},
    237   {"atan2", math_atan2},
    238   {"atan",  math_atan},
    239   {"ceil",  math_ceil},
    240   {"cosh",   math_cosh},
    241   {"cos",   math_cos},
    242   {"deg",   math_deg},
    243   {"exp",   math_exp},
    244   {"floor", math_floor},
    245   {"fmod",   math_fmod},
    246   {"frexp", math_frexp},
    247   {"ldexp", math_ldexp},
    248 #if defined(LUA_COMPAT_LOG10)
    249   {"log10", math_log10},
    250 #endif
    251   {"log",   math_log},
    252   {"max",   math_max},
    253   {"min",   math_min},
    254   {"modf",   math_modf},
    255   {"pow",   math_pow},
    256   {"rad",   math_rad},
    257   {"random",     math_random},
    258   {"randomseed", math_randomseed},
    259   {"sinh",   math_sinh},
    260   {"sin",   math_sin},
    261   {"sqrt",  math_sqrt},
    262   {"tanh",   math_tanh},
    263   {"tan",   math_tan},
    264   {NULL, NULL}
    265 };
    266 
    267 
    268 /*
    269 ** Open math library
    270 */
    271 LUAMOD_API int luaopen_math (lua_State *L) {
    272   luaL_newlib(L, mathlib);
    273   lua_pushnumber(L, PI);
    274   lua_setfield(L, -2, "pi");
    275   lua_pushnumber(L, HUGE_VAL);
    276   lua_setfield(L, -2, "huge");
    277   return 1;
    278 }
    279 
    280