src/lib/lmathlib.c

   1 /*
   2 ** $Id: lmathlib.c,v 1.17 1999/07/07 17:54:08 roberto Exp $
   3 ** Lua standard mathematical library
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #include <stdlib.h>
   9 #include <math.h>
  10
  11 #include "lauxlib.h"
  12 #include "lua.h"
  13 #include "lualib.h"
  14
  15
  16 #undef PI
  17 #define PI      (3.14159265358979323846)
  18 #define RADIANS_PER_DEGREE      (PI/180.0)
  19
  20
  21
  22 /*
  23 ** If you want Lua to operate in radians (instead of degrees),
  24 ** define RADIANS
  25 */
  26 #ifdef RADIANS
  27 #define FROMRAD(a)      (a)
  28 #define TORAD(a)        (a)
  29 #else
  30 #define FROMRAD(a)      ((a)/RADIANS_PER_DEGREE)
  31 #define TORAD(a)        ((a)*RADIANS_PER_DEGREE)
  32 #endif
  33
  34
  35 static void math_abs (void) {
  36   lua_pushnumber(fabs(luaL_check_number(1)));
  37 }
  38
  39 static void math_sin (void) {
  40   lua_pushnumber(sin(TORAD(luaL_check_number(1))));
  41 }
  42
  43 static void math_cos (void) {
  44   lua_pushnumber(cos(TORAD(luaL_check_number(1))));
  45 }
  46
  47 static void math_tan (void) {
  48   lua_pushnumber(tan(TORAD(luaL_check_number(1))));
  49 }
  50
  51 static void math_asin (void) {
  52   lua_pushnumber(FROMRAD(asin(luaL_check_number(1))));
  53 }
  54
  55 static void math_acos (void) {
  56   lua_pushnumber(FROMRAD(acos(luaL_check_number(1))));
  57 }
  58
  59 static void math_atan (void) {
  60   lua_pushnumber(FROMRAD(atan(luaL_check_number(1))));
  61 }
  62
  63 static void math_atan2 (void) {
  64   lua_pushnumber(FROMRAD(atan2(luaL_check_number(1), luaL_check_number(2))));
  65 }
  66
  67 static void math_ceil (void) {
  68   lua_pushnumber(ceil(luaL_check_number(1)));
  69 }
  70
  71 static void math_floor (void) {
  72   lua_pushnumber(floor(luaL_check_number(1)));
  73 }
  74
  75 static void math_mod (void) {
  76   lua_pushnumber(fmod(luaL_check_number(1), luaL_check_number(2)));
  77 }
  78
  79 static void math_sqrt (void) {
  80   lua_pushnumber(sqrt(luaL_check_number(1)));
  81 }
  82
  83 static void math_pow (void) {
  84   lua_pushnumber(pow(luaL_check_number(1), luaL_check_number(2)));
  85 }
  86
  87 static void math_log (void) {
  88   lua_pushnumber(log(luaL_check_number(1)));
  89 }
  90
  91 static void math_log10 (void) {
  92   lua_pushnumber(log10(luaL_check_number(1)));
  93 }
  94
  95 static void math_exp (void) {
  96   lua_pushnumber(exp(luaL_check_number(1)));
  97 }
  98
  99 static void math_deg (void) {
 100   lua_pushnumber(luaL_check_number(1)/RADIANS_PER_DEGREE);
 101 }
 102
 103 static void math_rad (void) {
 104   lua_pushnumber(luaL_check_number(1)*RADIANS_PER_DEGREE);
 105 }
 106
 107 static void math_frexp (void) {
 108   int e;
 109   lua_pushnumber(frexp(luaL_check_number(1), &e));
 110   lua_pushnumber(e);
 111 }
 112
 113 static void math_ldexp (void) {
 114   lua_pushnumber(ldexp(luaL_check_number(1), luaL_check_int(2)));
 115 }
 116
 117
 118
 119 static void math_min (void) {
 120   int i = 1;
 121   double dmin = luaL_check_number(i);
 122   while (lua_getparam(++i) != LUA_NOOBJECT) {
 123     double d = luaL_check_number(i);
 124     if (d < dmin)
 125       dmin = d;
 126   }
 127   lua_pushnumber(dmin);
 128 }
 129
 130
 131 static void math_max (void) {
 132   int i = 1;
 133   double dmax = luaL_check_number(i);
 134   while (lua_getparam(++i) != LUA_NOOBJECT) {
 135     double d = luaL_check_number(i);
 136     if (d > dmax)
 137       dmax = d;
 138   }
 139   lua_pushnumber(dmax);
 140 }
 141
 142
 143 static void math_random (void) {
 144   /* the '%' avoids the (rare) case of r==1, and is needed also because on
 145      some systems (SunOS!) "rand()" may return a value bigger than RAND_MAX */
 146   double r = (double)(rand()%RAND_MAX) / (double)RAND_MAX;
 147   int l = luaL_opt_int(1, 0);
 148   if (l == 0)
 149     lua_pushnumber(r);
 150   else {
 151     int u = luaL_opt_int(2, 0);
 152     if (u == 0) {
 153       u = l;
 154       l = 1;
 155     }
 156     luaL_arg_check(l<=u, 1, "interval is empty");
 157     lua_pushnumber((int)(r*(u-l+1))+l);
 158   }
 159 }
 160
 161
 162 static void math_randomseed (void) {
 163   srand(luaL_check_int(1));
 164 }
 165
 166
 167 static struct luaL_reg mathlib[] = {
 168 {"abs",   math_abs},
 169 {"sin",   math_sin},
 170 {"cos",   math_cos},
 171 {"tan",   math_tan},
 172 {"asin",  math_asin},
 173 {"acos",  math_acos},
 174 {"atan",  math_atan},
 175 {"atan2", math_atan2},
 176 {"ceil",  math_ceil},
 177 {"floor", math_floor},
 178 {"mod",   math_mod},
 179 {"frexp", math_frexp},
 180 {"ldexp", math_ldexp},
 181 {"sqrt",  math_sqrt},
 182 {"min",   math_min},
 183 {"max",   math_max},
 184 {"log",   math_log},
 185 {"log10", math_log10},
 186 {"exp",   math_exp},
 187 {"deg",   math_deg},
 188 {"rad",   math_rad},
 189 {"random",     math_random},
 190 {"randomseed", math_randomseed}
 191 };
 192
 193 /*
 194 ** Open math library
 195 */
 196 void lua_mathlibopen (void) {
 197   luaL_openlib(mathlib, (sizeof(mathlib)/sizeof(mathlib[0])));
 198   lua_pushcfunction(math_pow);
 199   lua_pushnumber(0);  /* to get its tag */
 200   lua_settagmethod(lua_tag(lua_pop()), "pow");
 201   lua_pushnumber(PI); lua_setglobal("PI");
 202 }
 203