/*** $Id: lmathlib.c,v 1.114 2014/12/27 20:32:26 roberto Exp $** Standard mathematical library** See Copyright Notice in lua.h*/ #define lmathlib_c#define LUA_LIB #include "lprefix.h"  #include <stdlib.h>#include <math.h> #include "lua.h" #include "lauxlib.h"#include "lualib.h"  #undef PI#define PI	(l_mathop(3.141592653589793238462643383279502884))  #if !defined(l_rand)		/* { */#if defined(LUA_USE_POSIX)#define l_rand()	random()#define l_srand(x)	srandom(x)#define L_RANDMAX	2147483647	/* (2^31 - 1), following POSIX */#else#define l_rand()	rand()#define l_srand(x)	srand(x)#define L_RANDMAX	RAND_MAX#endif#endif				/* } */  static int math_abs (lua_State *L) {  if (lua_isinteger(L, 1)) {    lua_Integer n = lua_tointeger(L, 1);    if (n < 0) n = (lua_Integer)(0u - n);    lua_pushinteger(L, n);  }  else    lua_pushnumber(L, l_mathop(fabs)(luaL_checknumber(L, 1)));  return 1;} static int math_sin (lua_State *L) {  lua_pushnumber(L, l_mathop(sin)(luaL_checknumber(L, 1)));  return 1;} static int math_cos (lua_State *L) {  lua_pushnumber(L, l_mathop(cos)(luaL_checknumber(L, 1)));  return 1;} static int math_tan (lua_State *L) {  lua_pushnumber(L, l_mathop(tan)(luaL_checknumber(L, 1)));  return 1;} static int math_asin (lua_State *L) {  lua_pushnumber(L, l_mathop(asin)(luaL_checknumber(L, 1)));  return 1;} static int math_acos (lua_State *L) {  lua_pushnumber(L, l_mathop(acos)(luaL_checknumber(L, 1)));  return 1;} static int math_atan (lua_State *L) {  lua_Number y = luaL_checknumber(L, 1);  lua_Number x = luaL_optnumber(L, 2, 1);  lua_pushnumber(L, l_mathop(atan2)(y, x));  return 1;}  static int math_toint (lua_State *L) {  int valid;  lua_Integer n = lua_tointegerx(L, 1, &valid);  if (valid)    lua_pushinteger(L, n);  else {    luaL_checkany(L, 1);    lua_pushnil(L);  /* value is not convertible to integer */  }  return 1;}  static void pushnumint (lua_State *L, lua_Number d) {  lua_Integer n;  if (lua_numbertointeger(d, &n))  /* does 'd' fit in an integer? */    lua_pushinteger(L, n);  /* result is integer */  else    lua_pushnumber(L, d);  /* result is float */}  static int math_floor (lua_State *L) {  if (lua_isinteger(L, 1))    lua_settop(L, 1);  /* integer is its own floor */  else {    lua_Number d = l_mathop(floor)(luaL_checknumber(L, 1));    pushnumint(L, d);  }  return 1;}  static int math_ceil (lua_State *L) {  if (lua_isinteger(L, 1))    lua_settop(L, 1);  /* integer is its own ceil */  else {    lua_Number d = l_mathop(ceil)(luaL_checknumber(L, 1));    pushnumint(L, d);  }  return 1;}  static int math_fmod (lua_State *L) {  if (lua_isinteger(L, 1) && lua_isinteger(L, 2)) {    lua_Integer d = lua_tointeger(L, 2);    if ((lua_Unsigned)d + 1u <= 1u) {  /* special cases: -1 or 0 */      luaL_argcheck(L, d != 0, 2, "zero");      lua_pushinteger(L, 0);  /* avoid overflow with 0x80000... / -1 */    }    else      lua_pushinteger(L, lua_tointeger(L, 1) % d);  }  else    lua_pushnumber(L, l_mathop(fmod)(luaL_checknumber(L, 1),                                     luaL_checknumber(L, 2)));  return 1;}  /*** next function does not use 'modf', avoiding problems with 'double*'** (which is not compatible with 'float*') when lua_Number is not** 'double'.*/static int math_modf (lua_State *L) {  if (lua_isinteger(L ,1)) {    lua_settop(L, 1);  /* number is its own integer part */    lua_pushnumber(L, 0);  /* no fractional part */  }  else {    lua_Number n = luaL_checknumber(L, 1);    /* integer part (rounds toward zero) */    lua_Number ip = (n < 0) ? l_mathop(ceil)(n) : l_mathop(floor)(n);    pushnumint(L, ip);    /* fractional part (test needed for inf/-inf) */    lua_pushnumber(L, (n == ip) ? l_mathop(0.0) : (n - ip));  }  return 2;}  static int math_sqrt (lua_State *L) {  lua_pushnumber(L, l_mathop(sqrt)(luaL_checknumber(L, 1)));  return 1;}  static int math_ult (lua_State *L) {  lua_Integer a = luaL_checkinteger(L, 1);  lua_Integer b = luaL_checkinteger(L, 2);  lua_pushboolean(L, (lua_Unsigned)a < (lua_Unsigned)b);  return 1;} static int math_log (lua_State *L) {  lua_Number x = luaL_checknumber(L, 1);  lua_Number res;  if (lua_isnoneornil(L, 2))    res = l_mathop(log)(x);  else {    lua_Number base = luaL_checknumber(L, 2);    if (base == 10.0) res = l_mathop(log10)(x);    else res = l_mathop(log)(x)/l_mathop(log)(base);  }  lua_pushnumber(L, res);  return 1;} static int math_exp (lua_State *L) {  lua_pushnumber(L, l_mathop(exp)(luaL_checknumber(L, 1)));  return 1;} static int math_deg (lua_State *L) {  lua_pushnumber(L, luaL_checknumber(L, 1) * (l_mathop(180.0) / PI));  return 1;} static int math_rad (lua_State *L) {  lua_pushnumber(L, luaL_checknumber(L, 1) * (PI / l_mathop(180.0)));  return 1;}  static int math_min (lua_State *L) {  int n = lua_gettop(L);  /* number of arguments */  int imin = 1;  /* index of current minimum value */  int i;  luaL_argcheck(L, n >= 1, 1, "value expected");  for (i = 2; i <= n; i++) {    if (lua_compare(L, i, imin, LUA_OPLT))      imin = i;  }  lua_pushvalue(L, imin);  return 1;}  static int math_max (lua_State *L) {  int n = lua_gettop(L);  /* number of arguments */  int imax = 1;  /* index of current maximum value */  int i;  luaL_argcheck(L, n >= 1, 1, "value expected");  for (i = 2; i <= n; i++) {    if (lua_compare(L, imax, i, LUA_OPLT))      imax = i;  }  lua_pushvalue(L, imax);  return 1;} /*** This function uses 'double' (instead of 'lua_Number') to ensure that** all bits from 'l_rand' can be represented, and that 'RANDMAX + 1.0'** will keep full precision (ensuring that 'r' is always less than 1.0.)*/static int math_random (lua_State *L) {  lua_Integer low, up;  double r = (double)l_rand() * (1.0 / ((double)L_RANDMAX + 1.0));  switch (lua_gettop(L)) {  /* check number of arguments */    case 0: {  /* no arguments */      lua_pushnumber(L, (lua_Number)r);  /* Number between 0 and 1 */      return 1;    }    case 1: {  /* only upper limit */      low = 1;      up = luaL_checkinteger(L, 1);      break;    }    case 2: {  /* lower and upper limits */      low = luaL_checkinteger(L, 1);      up = luaL_checkinteger(L, 2);      break;    }    default: return luaL_error(L, "wrong number of arguments");  }  /* random integer in the interval [low, up] */  luaL_argcheck(L, low <= up, 1, "interval is empty");   luaL_argcheck(L, low >= 0 || up <= LUA_MAXINTEGER + low, 1,                   "interval too large");  r *= (double)(up - low) + 1.0;  lua_pushinteger(L, (lua_Integer)r + low);  return 1;}  static int math_randomseed (lua_State *L) {  l_srand((unsigned int)(lua_Integer)luaL_checknumber(L, 1));  (void)rand(); /* discard first value to avoid undesirable correlations */  return 0;}  static int math_type (lua_State *L) {  if (lua_type(L, 1) == LUA_TNUMBER) {      if (lua_isinteger(L, 1))        lua_pushliteral(L, "integer");       else        lua_pushliteral(L, "float");   }  else {    luaL_checkany(L, 1);    lua_pushnil(L);  }  return 1;}  /*** {==================================================================** Deprecated functions (for compatibility only)** ===================================================================*/#if defined(LUA_COMPAT_MATHLIB) static int math_cosh (lua_State *L) {  lua_pushnumber(L, l_mathop(cosh)(luaL_checknumber(L, 1)));  return 1;} static int math_sinh (lua_State *L) {  lua_pushnumber(L, l_mathop(sinh)(luaL_checknumber(L, 1)));  return 1;} static int math_tanh (lua_State *L) {  lua_pushnumber(L, l_mathop(tanh)(luaL_checknumber(L, 1)));  return 1;} static int math_pow (lua_State *L) {  lua_Number x = luaL_checknumber(L, 1);  lua_Number y = luaL_checknumber(L, 2);  lua_pushnumber(L, l_mathop(pow)(x, y));  return 1;} static int math_frexp (lua_State *L) {  int e;  lua_pushnumber(L, l_mathop(frexp)(luaL_checknumber(L, 1), &e));  lua_pushinteger(L, e);  return 2;} static int math_ldexp (lua_State *L) {  lua_Number x = luaL_checknumber(L, 1);  int ep = (int)luaL_checkinteger(L, 2);  lua_pushnumber(L, l_mathop(ldexp)(x, ep));  return 1;} static int math_log10 (lua_State *L) {  lua_pushnumber(L, l_mathop(log10)(luaL_checknumber(L, 1)));  return 1;} #endif/* }================================================================== */   static const luaL_Reg mathlib[] = {  {"abs",   math_abs},  {"acos",  math_acos},  {"asin",  math_asin},  {"atan",  math_atan},  {"ceil",  math_ceil},  {"cos",   math_cos},  {"deg",   math_deg},  {"exp",   math_exp},  {"tointeger", math_toint},  {"floor", math_floor},  {"fmod",   math_fmod},  {"ult",   math_ult},  {"log",   math_log},  {"max",   math_max},  {"min",   math_min},  {"modf",   math_modf},  {"rad",   math_rad},  {"random",     math_random},  {"randomseed", math_randomseed},  {"sin",   math_sin},  {"sqrt",  math_sqrt},  {"tan",   math_tan},  {"type", math_type},#if defined(LUA_COMPAT_MATHLIB)  {"atan2", math_atan},  {"cosh",   math_cosh},  {"sinh",   math_sinh},  {"tanh",   math_tanh},  {"pow",   math_pow},  {"frexp", math_frexp},  {"ldexp", math_ldexp},  {"log10", math_log10},#endif  /* placeholders */  {"pi", NULL},  {"huge", NULL},  {"maxinteger", NULL},  {"mininteger", NULL},  {NULL, NULL}};  /*** Open math library*/LUAMOD_API int luaopen_math (lua_State *L) {  luaL_newlib(L, mathlib);  lua_pushnumber(L, PI);  lua_setfield(L, -2, "pi");  lua_pushnumber(L, (lua_Number)HUGE_VAL);  lua_setfield(L, -2, "huge");  lua_pushinteger(L, LUA_MAXINTEGER);  lua_setfield(L, -2, "maxinteger");  lua_pushinteger(L, LUA_MININTEGER);  lua_setfield(L, -2, "mininteger");  return 1;}