1 files changed, 146 insertions, 0 deletions
diff --git a/Examples/lua/embed3/embed3.cpp b/Examples/lua/embed3/embed3.cpp
new file mode 100644
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+++ b/Examples/lua/embed3/embed3.cpp
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+/* embed3.cpp A C++ embeded interpreter
+ 
+This will register a C++ class with Lua, and then call a Lua function
+passing C++ objects to this function.
+ 
+*/
+
+/* Deal with Microsoft's attempt at deprecating C standard runtime functions */
+#if !defined(SWIG_NO_CRT_SECURE_NO_DEPRECATE) && defined(_MSC_VER) && !defined(_CRT_SECURE_NO_DEPRECATE)
+# define _CRT_SECURE_NO_DEPRECATE
+#endif
+
+/* Deal with Microsoft's attempt at deprecating methods in the standard C++ library */
+#if !defined(SWIG_NO_SCL_SECURE_NO_DEPRECATE) && defined(_MSC_VER) && !defined(_SCL_SECURE_NO_DEPRECATE)
+# define _SCL_SECURE_NO_DEPRECATE
+#endif
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdarg.h>
+
+extern "C" {
+#include <lua.h>
+#include <lauxlib.h>
+#include <lualib.h>
+}
+
+/* The SWIG external runtime is generated by using.
+swig -lua -externalruntime swigluarun.h
+It contains useful function used by SWIG in its wrappering
+SWIG_TypeQuery() SWIG_NewPointerObj()
+*/
+#include "swigluarun.h"   // the SWIG external runtime
+
+/* the SWIG wrappered library */
+extern "C" int luaopen_example(lua_State*L);
+
+// the code itself
+#include "example.h"
+
+// this code pushes a C++ pointer as well as the SWIG type onto the Lua stack
+bool push_pointer(lua_State*L, void* ptr, const char* type_name, int owned = 0) {
+  // task 1: get the object 'type' which is registered with SWIG
+  // you need to call SWIG_TypeQuery() with the class name
+  // (normally, just look in the wrapper file to get this)
+  swig_type_info * pTypeInfo = SWIG_TypeQuery(L, type_name);
+  if (pTypeInfo == 0)
+    return false;   // error
+  // task 2: push the pointer to the Lua stack
+  // this requires a pointer & the type
+  // the last param specifies if Lua is responsible for deleting the object
+  SWIG_NewPointerObj(L, ptr, pTypeInfo, owned);
+  return true;
+}
+
+/* This is an example of how to call the Lua function
+    void onEvent(Event e) 
+  its very tedious, but gives you an idea of the issues involed.
+*/
+int call_onEvent(lua_State *L, Event e) {
+  int top;
+  /* ok, here we go:
+  push a, push b, call 'add' check & return res
+  */
+  top = lua_gettop(L);  /* for later */
+  lua_pushstring(L, "onEvent");                                  /* function name */
+  lua_gettable(L, LUA_GLOBALSINDEX);               /* function to be called */
+  if (!lua_isfunction(L, -1)) {
+    printf("[C++] error: cannot find function 'OnEvent'\n");
+    lua_settop(L, top);  // reset
+    return 0;
+  }
+  // push the event object
+  push_pointer(L, &e, "Event *", 0);
+  if (lua_pcall(L, 1, 0, 0) != 0)  /* call function with 1 arguments and no result */
+  {
+    printf("[C++] error running function `OnEvent': %s\n", lua_tostring(L, -1));
+    lua_settop(L, top);  // reset
+    return 0;
+  }
+  lua_settop(L, top);  /* reset stack */
+  return 1;   // ok
+}
+
+
+int main(int argc, char* argv[]) {
+  printf("[C++] Welcome to the simple embedded Lua example v3\n");
+  printf("[C++] We are in C++\n");
+  printf("[C++] opening a Lua state & loading the libraries\n");
+  lua_State *L = lua_open();
+  luaopen_base(L);
+  luaopen_string(L);
+  luaopen_math(L);
+  printf("[C++] now loading the SWIG wrappered library\n");
+  luaopen_example(L);
+  printf("[C++] all looks ok\n");
+  printf("\n");
+  printf("[C++] lets create an Engine and pass a pointer to Lua\n");
+  Engine engine;
+  /* this code will pass a pointer into lua, but C++ still owns the object
+  this is a little tedious, to do, but lets do it
+  we need to pass the pointer (obviously), the type name 
+  and a flag which states if Lua should delete the pointer once its finished with it
+  The type name is a class name string which is registered with SWIG
+  (normally, just look in the wrapper file to get this)
+  in this case we don't want Lua to delete the pointer so the ownership flag is 0
+  */
+  push_pointer(L,&engine,"Engine *",0);
+  lua_setglobal(L, "pEngine");  // set as global variable
+
+  printf("[C++] now lets load the file 'runme.lua'\n");
+  printf("[C++] any lua code in this file will be executed\n");
+  if (luaL_loadfile(L, "runme.lua") || lua_pcall(L, 0, 0, 0)) {
+    printf("[C++] ERROR: cannot run lua file: %s", lua_tostring(L, -1));
+    exit(3);
+  }
+  printf("[C++] We are now back in C++, all looks ok\n");
+  printf("\n");
+
+  printf("[C++] Lets call the Lua function onEvent(e)\n");
+  printf("[C++] We will give it different events, as we wish\n");
+  printf("[C++] Starting with STARTUP\n");
+  Event ev;
+  ev.mType = Event::STARTUP;
+  call_onEvent(L, ev);
+  printf("[C++] ok\n");
+  printf("[C++] now we will try MOUSEPRESS,KEYPRESS,MOUSEPRESS\n");
+  ev.mType = Event::MOUSEPRESS;
+  call_onEvent(L, ev);
+  ev.mType = Event::KEYPRESS;
+  call_onEvent(L, ev);
+  ev.mType = Event::MOUSEPRESS;
+  call_onEvent(L, ev);
+  printf("[C++] ok\n");
+  printf("[C++] Finally we will SHUTDOWN\n");
+  ev.mType = Event::SHUTDOWN;
+  call_onEvent(L, ev);
+  printf("[C++] ok\n");
+
+  printf("\n");
+  printf("[C++] all finished, closing the lua state\n");
+  lua_close(L);
+  return 0;
+}