765 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			765 lines
		
	
	
		
			18 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
 | 
						|
** $Id: lmathlib.c $
 | 
						|
** Standard mathematical library
 | 
						|
** See Copyright Notice in lua.h
 | 
						|
*/
 | 
						|
 | 
						|
#define lmathlib_c
 | 
						|
#define LUA_LIB
 | 
						|
 | 
						|
#include "lprefix.h"
 | 
						|
 | 
						|
 | 
						|
#include <float.h>
 | 
						|
#include <limits.h>
 | 
						|
#include <math.h>
 | 
						|
#include <stdlib.h>
 | 
						|
#include <time.h>
 | 
						|
 | 
						|
#include "lua.h"
 | 
						|
 | 
						|
#include "lauxlib.h"
 | 
						|
#include "lualib.h"
 | 
						|
 | 
						|
 | 
						|
#undef PI
 | 
						|
#define PI	(l_mathop(3.141592653589793238462643383279502884))
 | 
						|
 | 
						|
 | 
						|
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 - (lua_Unsigned)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 (l_likely(valid))
 | 
						|
    lua_pushinteger(L, n);
 | 
						|
  else {
 | 
						|
    luaL_checkany(L, 1);
 | 
						|
    luaL_pushfail(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 !defined(LUA_USE_C89)
 | 
						|
    if (base == l_mathop(2.0))
 | 
						|
      res = l_mathop(log2)(x);
 | 
						|
    else
 | 
						|
#endif
 | 
						|
    if (base == l_mathop(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;
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
static int math_type (lua_State *L) {
 | 
						|
  if (lua_type(L, 1) == LUA_TNUMBER)
 | 
						|
    lua_pushstring(L, (lua_isinteger(L, 1)) ? "integer" : "float");
 | 
						|
  else {
 | 
						|
    luaL_checkany(L, 1);
 | 
						|
    luaL_pushfail(L);
 | 
						|
  }
 | 
						|
  return 1;
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** {==================================================================
 | 
						|
** Pseudo-Random Number Generator based on 'xoshiro256**'.
 | 
						|
** ===================================================================
 | 
						|
*/
 | 
						|
 | 
						|
/* number of binary digits in the mantissa of a float */
 | 
						|
#define FIGS	l_floatatt(MANT_DIG)
 | 
						|
 | 
						|
#if FIGS > 64
 | 
						|
/* there are only 64 random bits; use them all */
 | 
						|
#undef FIGS
 | 
						|
#define FIGS	64
 | 
						|
#endif
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** LUA_RAND32 forces the use of 32-bit integers in the implementation
 | 
						|
** of the PRN generator (mainly for testing).
 | 
						|
*/
 | 
						|
#if !defined(LUA_RAND32) && !defined(Rand64)
 | 
						|
 | 
						|
/* try to find an integer type with at least 64 bits */
 | 
						|
 | 
						|
#if (ULONG_MAX >> 31 >> 31) >= 3
 | 
						|
 | 
						|
/* 'long' has at least 64 bits */
 | 
						|
#define Rand64		unsigned long
 | 
						|
 | 
						|
#elif !defined(LUA_USE_C89) && defined(LLONG_MAX)
 | 
						|
 | 
						|
/* there is a 'long long' type (which must have at least 64 bits) */
 | 
						|
#define Rand64		unsigned long long
 | 
						|
 | 
						|
#elif (LUA_MAXUNSIGNED >> 31 >> 31) >= 3
 | 
						|
 | 
						|
/* 'lua_Integer' has at least 64 bits */
 | 
						|
#define Rand64		lua_Unsigned
 | 
						|
 | 
						|
#endif
 | 
						|
 | 
						|
#endif
 | 
						|
 | 
						|
 | 
						|
#if defined(Rand64)  /* { */
 | 
						|
 | 
						|
/*
 | 
						|
** Standard implementation, using 64-bit integers.
 | 
						|
** If 'Rand64' has more than 64 bits, the extra bits do not interfere
 | 
						|
** with the 64 initial bits, except in a right shift. Moreover, the
 | 
						|
** final result has to discard the extra bits.
 | 
						|
*/
 | 
						|
 | 
						|
/* avoid using extra bits when needed */
 | 
						|
#define trim64(x)	((x) & 0xffffffffffffffffu)
 | 
						|
 | 
						|
 | 
						|
/* rotate left 'x' by 'n' bits */
 | 
						|
static Rand64 rotl (Rand64 x, int n) {
 | 
						|
  return (x << n) | (trim64(x) >> (64 - n));
 | 
						|
}
 | 
						|
 | 
						|
static Rand64 nextrand (Rand64 *state) {
 | 
						|
  Rand64 state0 = state[0];
 | 
						|
  Rand64 state1 = state[1];
 | 
						|
  Rand64 state2 = state[2] ^ state0;
 | 
						|
  Rand64 state3 = state[3] ^ state1;
 | 
						|
  Rand64 res = rotl(state1 * 5, 7) * 9;
 | 
						|
  state[0] = state0 ^ state3;
 | 
						|
  state[1] = state1 ^ state2;
 | 
						|
  state[2] = state2 ^ (state1 << 17);
 | 
						|
  state[3] = rotl(state3, 45);
 | 
						|
  return res;
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
/* must take care to not shift stuff by more than 63 slots */
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** Convert bits from a random integer into a float in the
 | 
						|
** interval [0,1), getting the higher FIG bits from the
 | 
						|
** random unsigned integer and converting that to a float.
 | 
						|
*/
 | 
						|
 | 
						|
/* must throw out the extra (64 - FIGS) bits */
 | 
						|
#define shift64_FIG	(64 - FIGS)
 | 
						|
 | 
						|
/* to scale to [0, 1), multiply by scaleFIG = 2^(-FIGS) */
 | 
						|
#define scaleFIG	(l_mathop(0.5) / ((Rand64)1 << (FIGS - 1)))
 | 
						|
 | 
						|
static lua_Number I2d (Rand64 x) {
 | 
						|
  return (lua_Number)(trim64(x) >> shift64_FIG) * scaleFIG;
 | 
						|
}
 | 
						|
 | 
						|
/* convert a 'Rand64' to a 'lua_Unsigned' */
 | 
						|
#define I2UInt(x)	((lua_Unsigned)trim64(x))
 | 
						|
 | 
						|
/* convert a 'lua_Unsigned' to a 'Rand64' */
 | 
						|
#define Int2I(x)	((Rand64)(x))
 | 
						|
 | 
						|
 | 
						|
#else	/* no 'Rand64'   }{ */
 | 
						|
 | 
						|
/* get an integer with at least 32 bits */
 | 
						|
#if LUAI_IS32INT
 | 
						|
typedef unsigned int lu_int32;
 | 
						|
#else
 | 
						|
typedef unsigned long lu_int32;
 | 
						|
#endif
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** Use two 32-bit integers to represent a 64-bit quantity.
 | 
						|
*/
 | 
						|
typedef struct Rand64 {
 | 
						|
  lu_int32 h;  /* higher half */
 | 
						|
  lu_int32 l;  /* lower half */
 | 
						|
} Rand64;
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** If 'lu_int32' has more than 32 bits, the extra bits do not interfere
 | 
						|
** with the 32 initial bits, except in a right shift and comparisons.
 | 
						|
** Moreover, the final result has to discard the extra bits.
 | 
						|
*/
 | 
						|
 | 
						|
/* avoid using extra bits when needed */
 | 
						|
#define trim32(x)	((x) & 0xffffffffu)
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** basic operations on 'Rand64' values
 | 
						|
*/
 | 
						|
 | 
						|
/* build a new Rand64 value */
 | 
						|
static Rand64 packI (lu_int32 h, lu_int32 l) {
 | 
						|
  Rand64 result;
 | 
						|
  result.h = h;
 | 
						|
  result.l = l;
 | 
						|
  return result;
 | 
						|
}
 | 
						|
 | 
						|
/* return i << n */
 | 
						|
static Rand64 Ishl (Rand64 i, int n) {
 | 
						|
  lua_assert(n > 0 && n < 32);
 | 
						|
  return packI((i.h << n) | (trim32(i.l) >> (32 - n)), i.l << n);
 | 
						|
}
 | 
						|
 | 
						|
/* i1 ^= i2 */
 | 
						|
static void Ixor (Rand64 *i1, Rand64 i2) {
 | 
						|
  i1->h ^= i2.h;
 | 
						|
  i1->l ^= i2.l;
 | 
						|
}
 | 
						|
 | 
						|
/* return i1 + i2 */
 | 
						|
static Rand64 Iadd (Rand64 i1, Rand64 i2) {
 | 
						|
  Rand64 result = packI(i1.h + i2.h, i1.l + i2.l);
 | 
						|
  if (trim32(result.l) < trim32(i1.l))  /* carry? */
 | 
						|
    result.h++;
 | 
						|
  return result;
 | 
						|
}
 | 
						|
 | 
						|
/* return i * 5 */
 | 
						|
static Rand64 times5 (Rand64 i) {
 | 
						|
  return Iadd(Ishl(i, 2), i);  /* i * 5 == (i << 2) + i */
 | 
						|
}
 | 
						|
 | 
						|
/* return i * 9 */
 | 
						|
static Rand64 times9 (Rand64 i) {
 | 
						|
  return Iadd(Ishl(i, 3), i);  /* i * 9 == (i << 3) + i */
 | 
						|
}
 | 
						|
 | 
						|
/* return 'i' rotated left 'n' bits */
 | 
						|
static Rand64 rotl (Rand64 i, int n) {
 | 
						|
  lua_assert(n > 0 && n < 32);
 | 
						|
  return packI((i.h << n) | (trim32(i.l) >> (32 - n)),
 | 
						|
               (trim32(i.h) >> (32 - n)) | (i.l << n));
 | 
						|
}
 | 
						|
 | 
						|
/* for offsets larger than 32, rotate right by 64 - offset */
 | 
						|
static Rand64 rotl1 (Rand64 i, int n) {
 | 
						|
  lua_assert(n > 32 && n < 64);
 | 
						|
  n = 64 - n;
 | 
						|
  return packI((trim32(i.h) >> n) | (i.l << (32 - n)),
 | 
						|
               (i.h << (32 - n)) | (trim32(i.l) >> n));
 | 
						|
}
 | 
						|
 | 
						|
/*
 | 
						|
** implementation of 'xoshiro256**' algorithm on 'Rand64' values
 | 
						|
*/
 | 
						|
static Rand64 nextrand (Rand64 *state) {
 | 
						|
  Rand64 res = times9(rotl(times5(state[1]), 7));
 | 
						|
  Rand64 t = Ishl(state[1], 17);
 | 
						|
  Ixor(&state[2], state[0]);
 | 
						|
  Ixor(&state[3], state[1]);
 | 
						|
  Ixor(&state[1], state[2]);
 | 
						|
  Ixor(&state[0], state[3]);
 | 
						|
  Ixor(&state[2], t);
 | 
						|
  state[3] = rotl1(state[3], 45);
 | 
						|
  return res;
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** Converts a 'Rand64' into a float.
 | 
						|
*/
 | 
						|
 | 
						|
/* an unsigned 1 with proper type */
 | 
						|
#define UONE		((lu_int32)1)
 | 
						|
 | 
						|
 | 
						|
#if FIGS <= 32
 | 
						|
 | 
						|
/* 2^(-FIGS) */
 | 
						|
#define scaleFIG       (l_mathop(0.5) / (UONE << (FIGS - 1)))
 | 
						|
 | 
						|
/*
 | 
						|
** get up to 32 bits from higher half, shifting right to
 | 
						|
** throw out the extra bits.
 | 
						|
*/
 | 
						|
static lua_Number I2d (Rand64 x) {
 | 
						|
  lua_Number h = (lua_Number)(trim32(x.h) >> (32 - FIGS));
 | 
						|
  return h * scaleFIG;
 | 
						|
}
 | 
						|
 | 
						|
#else	/* 32 < FIGS <= 64 */
 | 
						|
 | 
						|
/* must take care to not shift stuff by more than 31 slots */
 | 
						|
 | 
						|
/* 2^(-FIGS) = 1.0 / 2^30 / 2^3 / 2^(FIGS-33) */
 | 
						|
#define scaleFIG  \
 | 
						|
    (l_mathop(1.0) / (UONE << 30) / l_mathop(8.0) / (UONE << (FIGS - 33)))
 | 
						|
 | 
						|
/*
 | 
						|
** use FIGS - 32 bits from lower half, throwing out the other
 | 
						|
** (32 - (FIGS - 32)) = (64 - FIGS) bits
 | 
						|
*/
 | 
						|
#define shiftLOW	(64 - FIGS)
 | 
						|
 | 
						|
/*
 | 
						|
** higher 32 bits go after those (FIGS - 32) bits: shiftHI = 2^(FIGS - 32)
 | 
						|
*/
 | 
						|
#define shiftHI		((lua_Number)(UONE << (FIGS - 33)) * l_mathop(2.0))
 | 
						|
 | 
						|
 | 
						|
static lua_Number I2d (Rand64 x) {
 | 
						|
  lua_Number h = (lua_Number)trim32(x.h) * shiftHI;
 | 
						|
  lua_Number l = (lua_Number)(trim32(x.l) >> shiftLOW);
 | 
						|
  return (h + l) * scaleFIG;
 | 
						|
}
 | 
						|
 | 
						|
#endif
 | 
						|
 | 
						|
 | 
						|
/* convert a 'Rand64' to a 'lua_Unsigned' */
 | 
						|
static lua_Unsigned I2UInt (Rand64 x) {
 | 
						|
  return ((lua_Unsigned)trim32(x.h) << 31 << 1) | (lua_Unsigned)trim32(x.l);
 | 
						|
}
 | 
						|
 | 
						|
/* convert a 'lua_Unsigned' to a 'Rand64' */
 | 
						|
static Rand64 Int2I (lua_Unsigned n) {
 | 
						|
  return packI((lu_int32)(n >> 31 >> 1), (lu_int32)n);
 | 
						|
}
 | 
						|
 | 
						|
#endif  /* } */
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** A state uses four 'Rand64' values.
 | 
						|
*/
 | 
						|
typedef struct {
 | 
						|
  Rand64 s[4];
 | 
						|
} RanState;
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** Project the random integer 'ran' into the interval [0, n].
 | 
						|
** Because 'ran' has 2^B possible values, the projection can only be
 | 
						|
** uniform when the size of the interval is a power of 2 (exact
 | 
						|
** division). Otherwise, to get a uniform projection into [0, n], we
 | 
						|
** first compute 'lim', the smallest Mersenne number not smaller than
 | 
						|
** 'n'. We then project 'ran' into the interval [0, lim].  If the result
 | 
						|
** is inside [0, n], we are done. Otherwise, we try with another 'ran',
 | 
						|
** until we have a result inside the interval.
 | 
						|
*/
 | 
						|
static lua_Unsigned project (lua_Unsigned ran, lua_Unsigned n,
 | 
						|
                             RanState *state) {
 | 
						|
  if ((n & (n + 1)) == 0)  /* is 'n + 1' a power of 2? */
 | 
						|
    return ran & n;  /* no bias */
 | 
						|
  else {
 | 
						|
    lua_Unsigned lim = n;
 | 
						|
    /* compute the smallest (2^b - 1) not smaller than 'n' */
 | 
						|
    lim |= (lim >> 1);
 | 
						|
    lim |= (lim >> 2);
 | 
						|
    lim |= (lim >> 4);
 | 
						|
    lim |= (lim >> 8);
 | 
						|
    lim |= (lim >> 16);
 | 
						|
#if (LUA_MAXUNSIGNED >> 31) >= 3
 | 
						|
    lim |= (lim >> 32);  /* integer type has more than 32 bits */
 | 
						|
#endif
 | 
						|
    lua_assert((lim & (lim + 1)) == 0  /* 'lim + 1' is a power of 2, */
 | 
						|
      && lim >= n  /* not smaller than 'n', */
 | 
						|
      && (lim >> 1) < n);  /* and it is the smallest one */
 | 
						|
    while ((ran &= lim) > n)  /* project 'ran' into [0..lim] */
 | 
						|
      ran = I2UInt(nextrand(state->s));  /* not inside [0..n]? try again */
 | 
						|
    return ran;
 | 
						|
  }
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
static int math_random (lua_State *L) {
 | 
						|
  lua_Integer low, up;
 | 
						|
  lua_Unsigned p;
 | 
						|
  RanState *state = (RanState *)lua_touserdata(L, lua_upvalueindex(1));
 | 
						|
  Rand64 rv = nextrand(state->s);  /* next pseudo-random value */
 | 
						|
  switch (lua_gettop(L)) {  /* check number of arguments */
 | 
						|
    case 0: {  /* no arguments */
 | 
						|
      lua_pushnumber(L, I2d(rv));  /* float between 0 and 1 */
 | 
						|
      return 1;
 | 
						|
    }
 | 
						|
    case 1: {  /* only upper limit */
 | 
						|
      low = 1;
 | 
						|
      up = luaL_checkinteger(L, 1);
 | 
						|
      if (up == 0) {  /* single 0 as argument? */
 | 
						|
        lua_pushinteger(L, I2UInt(rv));  /* full random integer */
 | 
						|
        return 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");
 | 
						|
  /* project random integer into the interval [0, up - low] */
 | 
						|
  p = project(I2UInt(rv), (lua_Unsigned)up - (lua_Unsigned)low, state);
 | 
						|
  lua_pushinteger(L, p + (lua_Unsigned)low);
 | 
						|
  return 1;
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
static void setseed (lua_State *L, Rand64 *state,
 | 
						|
                     lua_Unsigned n1, lua_Unsigned n2) {
 | 
						|
  int i;
 | 
						|
  state[0] = Int2I(n1);
 | 
						|
  state[1] = Int2I(0xff);  /* avoid a zero state */
 | 
						|
  state[2] = Int2I(n2);
 | 
						|
  state[3] = Int2I(0);
 | 
						|
  for (i = 0; i < 16; i++)
 | 
						|
    nextrand(state);  /* discard initial values to "spread" seed */
 | 
						|
  lua_pushinteger(L, n1);
 | 
						|
  lua_pushinteger(L, n2);
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** Set a "random" seed. To get some randomness, use the current time
 | 
						|
** and the address of 'L' (in case the machine does address space layout
 | 
						|
** randomization).
 | 
						|
*/
 | 
						|
static void randseed (lua_State *L, RanState *state) {
 | 
						|
  lua_Unsigned seed1 = (lua_Unsigned)time(NULL);
 | 
						|
  lua_Unsigned seed2 = (lua_Unsigned)(size_t)L;
 | 
						|
  setseed(L, state->s, seed1, seed2);
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
static int math_randomseed (lua_State *L) {
 | 
						|
  RanState *state = (RanState *)lua_touserdata(L, lua_upvalueindex(1));
 | 
						|
  if (lua_isnone(L, 1)) {
 | 
						|
    randseed(L, state);
 | 
						|
  }
 | 
						|
  else {
 | 
						|
    lua_Integer n1 = luaL_checkinteger(L, 1);
 | 
						|
    lua_Integer n2 = luaL_optinteger(L, 2, 0);
 | 
						|
    setseed(L, state->s, n1, n2);
 | 
						|
  }
 | 
						|
  return 2;  /* return seeds */
 | 
						|
}
 | 
						|
 | 
						|
 | 
						|
static const luaL_Reg randfuncs[] = {
 | 
						|
  {"random", math_random},
 | 
						|
  {"randomseed", math_randomseed},
 | 
						|
  {NULL, NULL}
 | 
						|
};
 | 
						|
 | 
						|
 | 
						|
/*
 | 
						|
** Register the random functions and initialize their state.
 | 
						|
*/
 | 
						|
static void setrandfunc (lua_State *L) {
 | 
						|
  RanState *state = (RanState *)lua_newuserdatauv(L, sizeof(RanState), 0);
 | 
						|
  randseed(L, state);  /* initialize with a "random" seed */
 | 
						|
  lua_pop(L, 2);  /* remove pushed seeds */
 | 
						|
  luaL_setfuncs(L, randfuncs, 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},
 | 
						|
  {"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 */
 | 
						|
  {"random", NULL},
 | 
						|
  {"randomseed", NULL},
 | 
						|
  {"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");
 | 
						|
  setrandfunc(L);
 | 
						|
  return 1;
 | 
						|
}
 | 
						|
 |