/*

** $Id: lmathlib.c,v 1.67.1.1 2007/12/27 13:02:25 roberto Exp $

** Standard mathematical library

** See Copyright Notice in lua.h

*/

#include <stdlib.h>

#include <math.h>

#define lmathlib_c

#define LUA_LIB

#include "lua.h"

#include "lauxlib.h"

#include "lualib.h"

#undef PI

#define PI (3.14159265358979323846)

#define RADIANS_PER_DEGREE (PI/180.0)

static int math_abs (lua_State *L) {

  lua_pushnumber(L, fabs(luaL_checknumber(L, 1)));

  return 1;

}

static int math_sin (lua_State *L) {

  lua_pushnumber(L, sin(luaL_checknumber(L, 1)));

  return 1;

}

static int math_sinh (lua_State *L) {

  lua_pushnumber(L, sinh(luaL_checknumber(L, 1)));

  return 1;

}

static int math_cos (lua_State *L) {

  lua_pushnumber(L, cos(luaL_checknumber(L, 1)));

  return 1;

}

static int math_cosh (lua_State *L) {

  lua_pushnumber(L, cosh(luaL_checknumber(L, 1)));

  return 1;

}

static int math_tan (lua_State *L) {

  lua_pushnumber(L, tan(luaL_checknumber(L, 1)));

  return 1;

}

static int math_tanh (lua_State *L) {

  lua_pushnumber(L, tanh(luaL_checknumber(L, 1)));

  return 1;

}

static int math_asin (lua_State *L) {

  lua_pushnumber(L, asin(luaL_checknumber(L, 1)));

  return 1;

}

static int math_acos (lua_State *L) {

  lua_pushnumber(L, acos(luaL_checknumber(L, 1)));

  return 1;

}

static int math_atan (lua_State *L) {

  lua_pushnumber(L, atan(luaL_checknumber(L, 1)));

  return 1;

}

static int math_atan2 (lua_State *L) {

  lua_pushnumber(L, atan2(luaL_checknumber(L, 1), luaL_checknumber(L, 2)));

  return 1;

}

static int math_ceil (lua_State *L) {

  lua_pushnumber(L, ceil(luaL_checknumber(L, 1)));

  return 1;

}

static int math_floor (lua_State *L) {

  lua_pushnumber(L, floor(luaL_checknumber(L, 1)));

  return 1;

}

static int math_fmod (lua_State *L) {

  lua_pushnumber(L, fmod(luaL_checknumber(L, 1), luaL_checknumber(L, 2)));

  return 1;

}

static int math_modf (lua_State *L) {

  double ip;

  double fp = modf(luaL_checknumber(L, 1), &ip);

  lua_pushnumber(L, ip);

  lua_pushnumber(L, fp);

  return 2;

}

static int math_sqrt (lua_State *L) {

  lua_pushnumber(L, sqrt(luaL_checknumber(L, 1)));

  return 1;

}

static int math_pow (lua_State *L) {

  lua_pushnumber(L, pow(luaL_checknumber(L, 1), luaL_checknumber(L, 2)));

  return 1;

}

static int math_log (lua_State *L) {

  lua_pushnumber(L, log(luaL_checknumber(L, 1)));

  return 1;

}

static int math_log10 (lua_State *L) {

  lua_pushnumber(L, log10(luaL_checknumber(L, 1)));

  return 1;

}

static int math_exp (lua_State *L) {

  lua_pushnumber(L, exp(luaL_checknumber(L, 1)));

  return 1;

}

static int math_deg (lua_State *L) {

  lua_pushnumber(L, luaL_checknumber(L, 1)/RADIANS_PER_DEGREE);

  return 1;

}

static int math_rad (lua_State *L) {

  lua_pushnumber(L, luaL_checknumber(L, 1)*RADIANS_PER_DEGREE);

  return 1;

}

static int math_frexp (lua_State *L) {

  int e;

  lua_pushnumber(L, frexp(luaL_checknumber(L, 1), &e));

  lua_pushinteger(L, e);

  return 2;

}

static int math_ldexp (lua_State *L) {

  lua_pushnumber(L, ldexp(luaL_checknumber(L, 1), luaL_checkint(L, 2)));

  return 1;

}

static int math_min (lua_State *L) {

  int n = lua_gettop(L);  /* number of arguments */

  lua_Number dmin = luaL_checknumber(L, 1);

  int i;

  for (i=2; i<=n; i++) {

    lua_Number d = luaL_checknumber(L, i);

    if (d < dmin)

      dmin = d;

  }

  lua_pushnumber(L, dmin);

  return 1;

}

static int math_max (lua_State *L) {

  int n = lua_gettop(L);  /* number of arguments */

  lua_Number dmax = luaL_checknumber(L, 1);

  int i;

  for (i=2; i<=n; i++) {

    lua_Number d = luaL_checknumber(L, i);

    if (d > dmax)

      dmax = d;

  }

  lua_pushnumber(L, dmax);

  return 1;

}

static int math_random (lua_State *L) {

  /* the `%' avoids the (rare) case of r==1, and is needed also because on

     some systems (SunOS!) `rand()' may return a value larger than RAND_MAX */

  lua_Number r = (lua_Number)(rand()%RAND_MAX) / (lua_Number)RAND_MAX;

  switch (lua_gettop(L)) {  /* check number of arguments */

    case 0: {  /* no arguments */

      lua_pushnumber(L, r);  /* Number between 0 and 1 */

      break;

    }

    case 1: {  /* only upper limit */

      int u = luaL_checkint(L, 1);

      luaL_argcheck(L, 1<=u, 1, "interval is empty");

      lua_pushnumber(L, floor(r*u)+1);  /* int between 1 and `u' */

      break;

    }

    case 2: {  /* lower and upper limits */

      int l = luaL_checkint(L, 1);

      int u = luaL_checkint(L, 2);

      luaL_argcheck(L, l<=u, 2, "interval is empty");

      lua_pushnumber(L, floor(r*(u-l+1))+l);  /* int between `l' and `u' */

      break;

    }

    default: return luaL_error(L, "wrong number of arguments");

  }

  return 1;

}

static int math_randomseed (lua_State *L) {

  srand(luaL_checkint(L, 1));

  return 0;

}

static const luaL_Reg mathlib[] = {

  {"abs",   math_abs},

  {"acos",  math_acos},

  {"asin",  math_asin},

  {"atan2", math_atan2},

  {"atan",  math_atan},

  {"ceil",  math_ceil},

  {"cosh",   math_cosh},

  {"cos",   math_cos},

  {"deg",   math_deg},

  {"exp",   math_exp},

  {"floor", math_floor},

  {"fmod",   math_fmod},

  {"frexp", math_frexp},

  {"ldexp", math_ldexp},

  {"log10", math_log10},

  {"log",   math_log},

  {"max",   math_max},

  {"min",   math_min},

  {"modf",   math_modf},

  {"pow",   math_pow},

  {"rad",   math_rad},

  {"random",     math_random},

  {"randomseed", math_randomseed},

  {"sinh",   math_sinh},

  {"sin",   math_sin},

  {"sqrt",  math_sqrt},

  {"tanh",   math_tanh},

  {"tan",   math_tan},

  {NULL, NULL}

};

/*

** Open math library

*/

LUALIB_API int luaopen_math (lua_State *L) {

  luaL_register(L, LUA_MATHLIBNAME, mathlib);

  lua_pushnumber(L, PI);

  lua_setfield(L, -2, "pi");

  lua_pushnumber(L, HUGE_VAL);

  lua_setfield(L, -2, "huge");

#if defined(LUA_COMPAT_MOD)

  lua_getfield(L, -1, "fmod");

  lua_setfield(L, -2, "mod");

#endif

  return 1;

}