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Integrating Lua into C++

, 2 Sep 2005 CPOL
An article about embedding the Lua scripting language with C++ objects.
 ```/* ** \$Id: lmathlib.c,v 1.56 2003/03/11 12:30:37 roberto Exp \$ ** Standard mathematical library ** See Copyright Notice in lua.h */ #include #include #define lmathlib_c #include "lua.h" #include "lauxlib.h" #include "lualib.h" #undef PI #define PI (3.14159265358979323846) #define RADIANS_PER_DEGREE (PI/180.0) /* ** If you want Lua to operate in degrees (instead of radians), ** define USE_DEGREES */ #ifdef USE_DEGREES #define FROMRAD(a) ((a)/RADIANS_PER_DEGREE) #define TORAD(a) ((a)*RADIANS_PER_DEGREE) #else #define FROMRAD(a) (a) #define TORAD(a) (a) #endif 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(TORAD(luaL_checknumber(L, 1)))); return 1; } static int math_cos (lua_State *L) { lua_pushnumber(L, cos(TORAD(luaL_checknumber(L, 1)))); return 1; } static int math_tan (lua_State *L) { lua_pushnumber(L, tan(TORAD(luaL_checknumber(L, 1)))); return 1; } static int math_asin (lua_State *L) { lua_pushnumber(L, FROMRAD(asin(luaL_checknumber(L, 1)))); return 1; } static int math_acos (lua_State *L) { lua_pushnumber(L, FROMRAD(acos(luaL_checknumber(L, 1)))); return 1; } static int math_atan (lua_State *L) { lua_pushnumber(L, FROMRAD(atan(luaL_checknumber(L, 1)))); return 1; } static int math_atan2 (lua_State *L) { lua_pushnumber(L, FROMRAD(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_mod (lua_State *L) { lua_pushnumber(L, fmod(luaL_checknumber(L, 1), luaL_checknumber(L, 2))); return 1; } 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_pushnumber(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, (int)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, (int)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}, {"sin", math_sin}, {"cos", math_cos}, {"tan", math_tan}, {"asin", math_asin}, {"acos", math_acos}, {"atan", math_atan}, {"atan2", math_atan2}, {"ceil", math_ceil}, {"floor", math_floor}, {"mod", math_mod}, {"frexp", math_frexp}, {"ldexp", math_ldexp}, {"sqrt", math_sqrt}, {"min", math_min}, {"max", math_max}, {"log", math_log}, {"log10", math_log10}, {"exp", math_exp}, {"deg", math_deg}, {"pow", math_pow}, {"rad", math_rad}, {"random", math_random}, {"randomseed", math_randomseed}, {NULL, NULL} }; /* ** Open math library */ LUALIB_API int luaopen_math (lua_State *L) { luaL_openlib(L, LUA_MATHLIBNAME, mathlib, 0); lua_pushliteral(L, "pi"); lua_pushnumber(L, PI); lua_settable(L, -3); lua_pushliteral(L, "__pow"); lua_pushcfunction(L, math_pow); lua_settable(L, LUA_GLOBALSINDEX); return 1; } ```

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