Hey Vinnie, is there a means to iterate over a LuaRef and access keys and values? Like pairs() or ipairs()? I'd like to pass lua tables to juce to populate css-like data.

e.g. in lua:

cssstyle = {
  background = "ff336688",
  font_size = 11,
  font_name = "Arial"
}

in juce: (something to this effect)

void doMap(LuaRef v) {

    HashMap<String, String>::Iterator it (v);

    while (it.next()) {
            String keyId = it.getKey();
            String val = it.getValue();
            //dostuff
    }

}

Hi Vinnie,

I think it makes sense to continue the discussion here.

Your suggestion to implement policies was the following:

classname can be expanded to include a policy. Given:

struct Policy
{
  virtual void push () = 0;
  virtual void addref () = 0;
  virtual void release () = 0;

  template <class PolicyType>
  static Policy* getPolicy ()
  {
    static PolicyType policy;
    return &policy;
  }
};

We can add this:

template <typename T>
struct classname
{
  static inline Policy& policy()
  {
     return *classname <T>::m_policy;
  }
  template <class PolicyType>
  static inline void set_policy ()
  {
    classname <T>::m_policy = &Policy::getPolicy <PolicyType> ();
  }

private:
  static PolicyType* m_policy;
};

template <typename T>
PolicyType* classname <T>::m_policy = Policy::getPolicy <DefaultPolicy> ();

Then we expand class__ to include an additional PolicyType template parameter, and set the policy in the classname at the same time we associate the name with it:

template <typename T, class PolicyType>
class__<T>::class__ (lua_State *L_, const char *name_): scope(L_, name_)
{
  assert(!classname<T>::is_const());
  classname<T>::set_name(name_);
  classname<T>::set_policy <typename PolicyType> ();

Here are some examples of code using this scheme:

s.class_ <test3> ("test3").method ("f", &test3::f); // default policy
s.class_ <test3, BoostSharedPtrPolicy> ("test3").method ("f", &test3::f); // use boost::shared_ptr
s.class_ <test3, CustomPolicy> ("test3").method ("f", &test3::f); // use domain specific policy
s.class_ <test3, ImmortalPolicy> ("test3").method ("f", &test3::f); // straight pointer with no ref count policy

Comments, criticisms?

Hello,

I'm currently binding my GameEntity Class like this

.beginClass<GameEntity> ("GameEntity")
    .addConstructor<void (*) (void)> ()
    .addFunction("setGEC", &GameEntity::setGEC)
    .addProperty("id", &GameEntity::getId)
    .addProperty("active", &GameEntity::getIsActive, &GameEntity::setIsActive)
    .addProperty("x", &GameEntity::getPositionX, &GameEntity::setPositionX)
    .addProperty("y", &GameEntity::getPositionY, &GameEntity::setPositionY)
.endClass();

I'm trying to do something like this on the Lua side:

entity = GameEntity()
entity.components = {}

But I get an error:

SampleFile.lua:23: no member named 'components'

Is there a way to circumvent this issue ?

I have this function

    Vector WorldToScreen(const Vector origin) {
        Vector screen(0,0,0);
        /*SOMETHING IN HERE CRASHES*/
        if (!ScreenTransform(origin, screen)) {
                       //Do stuff here
        }
        /*END*/
        return screen;
    }

That call crashes. Why? Because of this.

    bool ScreenTransform(const Vector& point, Vector& screen) {
         matrix3x4_t w2sMatrix = g_pEngine->WorldToScreenMatrix();

that's literally the only thing in there (and a return true). The error is in lua_pcall (static libs, so im not 100% sure where). My last error message: Exception thrown at 0x33D9C121 (the dll.dll) in csgo.exe: 0xC0000005: Access violation reading location 0x8D050014.

I got a small vector class and I have some calculation functions in there like Add. It just adds two vectors and returns the one who called the function. But Lua says

-- main.lua:5: bad argument #2 to 'Add' (TexVector expected, got table)

the main.lua is:

Cheap.Moo( ) -- for generall printing test

a = Cheap.TexVector( 1, 2 )
b = Cheap.TexVector( 3, 4 )
a.Add( b )
print( a.X, a.Y, b.X, b.Y )

So what's the problem there ?

platform:win7 lua:5.3

lua file

test = {}

test.Init = function(kernel, self, arg)
    io.write("Hello Lua Init!\n");
end

test.AfterInit = function(kernel, self, arg)
    io.write("Hello Lua AfterInit!\n");
end

C++ file

luabridge::LuaRef compent = luabridge::getGlobal(luaState, "test");
luabridge::LuaRef func = compent.getGlobal(luaState, "Init");
func(NFScriptIdent(kernel, self, arg);

I got an assert,

I tried to use

luabridge::LuaRef func = luabridge::getGlobal(luaState, "test.Init");
func(NFScriptIdent(kernel, self, arg);

it's still assert.

so I'm confused, plz help me, thanks

A simple example: class TestClass { public: TestClass(int id) :_Id(id) {} virtual ~TestClass() {}

void run()
{}
int _Id;

};

... luabridge::scope s(lua_state); s .beginClass ("TestClass") .addConstructor<void (*) (int)> () .addMethod("run", &TestClass::run);

will not compile on Visual Studio 2010 (and 2005 I guess) with the following error: error C2783: 'luabridge::Namespace::Class &luabridge::Namespace::Class::addConstructor(void)' : could not deduce template argument for 'C'

Is there a workaround to explicetly tell the compiler the Type of C?

function isConnected() return 1, "srvname","ip:10.0.0.1" end

LuaRef f_isConnected = getGlobal(L, "isConnected"); LuaRef v = f_isConnected(); /// not supported LUA_MULTRET why?!

please help me to determine the index of the class is on the stack? The function takes an object class, you need what is the object of the class?

int checkerror(lua_State* L, const char* file) {
	int status = luaL_loadfile(L, file);// проверка есть ли ошибки.
	try {
		if (luaL_dostring(L, file) == LUA_OK) {
			return 0;
		}
		else {
			string x = lua_tostring(L, -1);
			throw x;
			return 0;
		}
	}
	catch (string x) {
		cout << x << endl;
		//luaL_error(L,"error"); 
		return 0;
	}
};
struct a {
	int x = 302;
	a(int x) { this->x = x;  }
	void get() const /* время жизни lua.*/ { cout << x << " " << endl; }
};

struct b{
	void show() const /* время жизни lua.*/ { cout << "show " << endl; }
	
};

void pri(lua_State* L) {
	try
	{
		a* b1 = (a*)Userdata::getExact<a>(L, 1);
		b1->get();
		try	{
			b* c = (b*)Userdata::getExact<b>(L, 1);
			c->show();
		}
		catch (std::exception& e)	{	}
	}
	catch (std::exception& e)
	{
	}
};

const char* LUA = R"(
a=st(21)
b1 = st1()
pri(b1)

)";
int main(int argc, char* argv[]) {
	lua_State* L = luaL_newstate();
	luaL_openlibs(L); getGlobalNamespace(L)// получить глоб место.
		.beginClass<a>("st")// имя класса в lua.
		.addConstructor<void(*)(int)>()// конструктор класса.
		.addFunction("get", &a::get)// метод класса
		.endClass()// закрыть регистрацию класса. 
		.beginClass<b>("st1")// имя класса в lua.
		.addConstructor<void(*)()>()// конструктор класса.
		.addFunction("show", &b::show)// метод класса
		.endClass()// закрыть регистрацию класса. 
		.addFunction("pri", &pri);// Регистрация функции.

	checkerror(L, LUA);

	return 0;
};

Hey, so I was wanting to hook up this

getGlobalNamespace(L)
            .beginNamespace("CSGO")
                .beginClass<CEngine>("Engine")
                    .addFunction("Cmd", &CEngine::ClientCmd)
                .endClass()
            .endNamespace();

I can only have one instance of the class (It points to a game class)

I have initialized the variable fine and I can call its functions fine in C++.

luabridge::getGlobalNamespace(L)
        .beginNamespace("CSGO")
            .addVariable("Engine", &g_pEngine, false)
        .endNamespace();

I'm trying to add an instance of it to the global namespace. I want to be able to call the function from CEngine in lua. (At this moment, I think it's best i mention g_pEngine is a CEngine*)

But when i try and do this

CSGO.Engine:Cmd("clear;echo testing123")

it throws me this error exec.lua:1: attempt to call a nil value (method 'Cmd')

How can I fix this?

EDIT: Using lua 5.3

Hello,

Thank you for the amazing work you have done on getting LuaBridge 1.0 polished up and improved :)

A lot of folks are on Lua 5.1 and if you're using LuaJIT the 5.2 API isn't available.

Fortunately, this is simple to remedy in LuaBridge right now (and likely in the future) as only some cosmetic 5.2 functions are used. Here are some back ports of these 3 methods to 5.1

// 5.1 backport of 5.2 stuff

/*
** convert an acceptable stack index into an absolute index
*/
LUA_API int lua_absindex (lua_State *L, int idx) {
  return (idx > 0 || idx <= LUA_REGISTRYINDEX)
         ? idx
         : cast_int(L->top - L->ci->func + idx);
}

LUA_API void lua_rawgetp (lua_State *L, int idx, const void *p) {

    idx = lua_absindex(L, idx);
    lua_pushlightuserdata(L, (void *) p);
    lua_rawget(L,idx);

}

LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) {

    idx = lua_absindex(L, idx);
    lua_pushlightuserdata(L, (void*) p);
    // put key behind value
    lua_insert(L, -2);
    lua_rawset(L,idx);
}

This fix prevents a segmentation fault in case a C++ function is called from Lua and nil instead of an object of a registered class is passed as parameter.

• The get function correctly tests if nil is on the stack and returns a null pointer.
• The bug is located in the StackHelper where the returned pointer is always dereferenced. This is the source of the undefined behavior/segmentation fault.

This fix only adds the /MP parameter to Visual Studio compilers instead of adding it to all compilers under Windows. Without this change the build in a MSYS2 environment with a g++ compiler doesn't work.

on i386 32-bit openbsd with luabridge https://github.com/vinniefalco/LuaBridge/commit/9092ace9615d14e3f5926f2e8a3b612ddc6c8efa I get a compilation error when trying to addFunction with a function that uses attribute fastcall. Removing fastcall allows the program to compile.

relevant section of Namespace.h:

   1280     //----------------------------------------------------------------------------
   1281     /**
   1282         Add or replace a free function.
   1283     */
   1284     template<class ReturnType, class... Params>
   1285     Namespace& addFunction(char const* name, ReturnType (*fp)(Params...))
   1286     {

reproducible example:

// c++ -I/usr/local/include -I/usr/local/include/lua-5.3 /usr/local/lib/liblua5.3.so.5.3 luabridge.cpp

#include <vector>
#include <cmath>
#include <iostream>
#include <lua.hpp>
#include <LuaBridge/LuaBridge.h>

using std::vector;
using std::cout;
using std::endl;

//basic types
typedef int8_t  s8;
typedef int16_t s16;
typedef int32_t s32;
typedef int64_t s64;

typedef uint8_t  u8;
typedef uint16_t u16;
typedef uint32_t u32;
typedef uint64_t u64;

typedef float f32;
typedef double f64;

#define DYNACALL __attribute__((fastcall))

u8 DYNACALL _vmem_readt_8(u32 addr)
{
        return 23;
}

using namespace luabridge;

int main()
{
        static lua_State *L;

        getGlobalNamespace(L)
                .beginNamespace("memory")
                        .addFunction("read8", _vmem_readt_8)
                .endNamespace();
        return 0;
}

$ c++ -I/usr/local/include -I/usr/local/include/lua-5.3 /usr/local/lib/liblua5.3.so.5.3 luabridge.cpp         
luabridge.cpp:42:5: error: no matching member function for call to 'addFunction'
                        .addFunction("read8", _vmem_readt_8)
                        ~^~~~~~~~~~~
/usr/local/include/LuaBridge/detail/Namespace.h:1326:16: note: candidate function not viable: no known conversion from 'DYNACALL u8 (u32) __attribute__((fastcall))' (aka 'unsigned char (unsigned int) __attribute__((fastcall))') to 'int (*const)(lua_State *)' for 2nd argument
    Namespace& addFunction(char const* name, int (*const fp)(lua_State*))
               ^
/usr/local/include/LuaBridge/detail/Namespace.h:1263:16: note: candidate template ignored: could not match 'function<type-parameter-0-0 (type-parameter-0-1...)>' against 'unsigned char (*)(unsigned int) __attribute__((fastcall))'
    Namespace& addFunction(char const* name, std::function<ReturnType(Params...)> function)
               ^
/usr/local/include/LuaBridge/detail/Namespace.h:1285:16: note: candidate template ignored: deduced type 'unsigned char (*)(unsigned int)' of 2nd parameter does not match adjusted type 'DYNACALL u8 (*)(u32) __attribute__((fastcall))' (aka 'unsigned char (*)(unsigned int) __attribute__((fastcall))') of argument [with ReturnType = unsigned char, Params = <unsigned int>]
    Namespace& addFunction(char const* name, ReturnType (*fp)(Params...))
               ^
1 error generated.

Ok so I'm a student and trying to make a basic game that can be custom coded using lua and I'm using luabridge and i have a custom class that allows the user to render his custom objects

std::vector<luabridge::LuaRef> RenderHooks = std::vector<luabridge::LuaRef>();

class RenderManager {
public:
	void OnRender(luabridge::LuaRef Func) {
		printf("Added a hook\n");
		RenderHooks.push_back(Func);
		printf("Hooks Count: %i\n", RenderHooks.size());
	}
	bool ClearHooks() {
		RenderHooks.clear();
		return true;
	}
	
	void CallHooks() {
		printf("Hooks Count: %i\n", RenderHooks.size());
		for (luabridge::LuaRef hook : RenderHooks) {
			try {
				// call hook
				printf("Calling a hook\n");
				hook();
			}
			catch (luabridge::LuaException const& e) {
				std::cout << e.what() << std::endl;
			}

		}
	}
};

and i use

		.beginClass<RenderManager>("RenderManagerClass")
		.addFunction("OnRender", &RenderManager::OnRender)
		.addFunction("ClearHooks", &RenderManager::ClearHooks)
                .endClass()
		.addVariable("RenderManager", &renderMng, false)
		.endNamespace();

to register it

so i can use

render = function()
    print("a message from lua")
end

Game.RenderManager:OnRender(render)

while true do 
   -- Some game calculations happen here and it can run forever
end

but the issue is when i try to run renderMng.CallHooks() which is supposed to trigger the lua function defined earlier i get the following issue

LuaException: missing error

and access violation some times and the lua function never gets triggered and after a few more calls the app exits when debugging i get

Exception thrown at 0x00007FFDC54EFFA6 (msvcrt.dll) in gamebase.exe: 0xC0000005: Access violation reading location 0x0000000065BCF000. another run Exception thrown at 0x00007FFDC552D2D0 (msvcrt.dll) in gamebase.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF. My console before it exits

0.157??

which seems to be triggered here

I tried calling the function using luabridge::getGlobal(L, "funcname"); and same issue

it seems to be working as expected if i remove my while true loop that I have, but there are some important calculations that are being ran on it so I cannot remove it

Its my first time using luabridge and i don't know what am i wrong at

I'm using luabridge2 from vcpkg and Lua 5.4.4