Add Lua dependencies.

Lua is going to be used for both scene description (it will also provide a YAML importer) and some future expansion in the code. Expect some fun surprises!

(just playing with lua on the main app for now)

source/main.cpp

@@ -8,10 +8,44 @@
  *
  */
 #include <stdio.h>
+#include <string.h>
+#include <math.h>
 
+extern "C" {
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+}
+
+static int l_sin (lua_State *L) {
+    double d = luaL_checknumber(L, 1);  /* get argument */
+    lua_pushnumber(L, sin(d));  /* push result */
+    return 1;  /* number of results */
+}
 
 int main(int argc, char *argv[])
 {
-    printf("Hello !\n");
+    char buff[256];
+    int error;
+    lua_State *L = luaL_newstate();   /* opens Lua */
+    luaL_openlibs(L);             /* opens the basic library */
+
+    lua_pushcfunction(L, l_sin);
+    lua_setglobal(L, "mysin");
+    printf("[0]>");
+
+    while (fgets(buff, sizeof(buff), stdin) != NULL)
+    {
+        error = luaL_loadstring(L, buff) || lua_pcall(L, 0, LUA_MULTRET, 0);
+
+        if (error)
+        {
+            fprintf(stderr, "%s\n", lua_tostring(L, -1));
+            lua_pop(L, 1);  /* pop error message from the stack */
+        }
+        printf("[%d]>", lua_gettop(L));
+    }
+
+    lua_close(L);
     return 0;
 }