OTClient Call C++ functions from Lua side

[oen432]

Hi,

What's the proper and best way to call C++ functions and mostly class methods from Lua side?

Example

void LocalPlayer::doStuff(Position& _position, uint16 _number, bool _alive)
{
    // Code here
}

function localPlayerStuff()
  pos = { x = 123, y = 123, z = 7 }
  number = 123
  alive = true
  g_game.getLocalPlayer().doStuff(pos, number, alive)
end

What I'm struggling with right now are parameters. InGame Terminal is overflown with errors about casting. What am I missing? How to get this done?

 

[Steve Albert]

Hi,

What's the proper and best way to call C++ functions and mostly class methods from Lua side?

Example

void LocalPlayer::doStuff(Position& _position, uint16 _number, bool _alive)
{
    // Code here
}

function localPlayerStuff()
  pos = { x = 123, y = 123, z = 7 }
  number = 123
  alive = true
  g_game.getLocalPlayer().doStuff(pos, number, alive)
end

What I'm struggling with right now are parameters. InGame Terminal is overflown with errors about casting. What am I missing? How to get this done?

1st thing you'll need to do if it is not done already is load the lua libraries then you need to create an instance of lua and finally after you have defined a method it needs to be pushed onto the lua stack.

 

[oen432]

1st thing you'll need to do if it is not done already is load the lua libraries then you need to create an instance of lua and finally after you have defined a method it needs to be pushed onto the lua stack.

So like what is done from the beginning.

g_lua.bindClassMemberFunction<LocalPlayer>("doStuff", &LocalPlayer::doStuff);

It's not about calling function as is. It's more about parameters and type casting.
How to make { x = 123, y = 123, z = 7 } into Position& _position when using g_game.getLocalPlayer().doStuff()

 

[Sarah Wesker]

easy, look at this little function:

void LuaScriptInterface::pushPosition(lua_State* L, const Position& position, int32_t stackpos/* = 0*/)
{
    lua_createtable(L, 0, 4);

    setField(L, "x", position.x);
    setField(L, "y", position.y);
    setField(L, "z", position.z);
    setField(L, "stackpos", stackpos);

    setMetatable(L, -1, "Position");
}

and

void LuaInterface::pushPosition(lua_State* L, const Position& position, uint32_t stackpos)
{
    lua_newtable(L);
    setField(L, "x", position.x);
    setField(L, "y", position.y);
    setField(L, "z", position.z);
    setField(L, "stackpos", stackpos);
}

 

[oen432]

easy, look at this little function:

void LuaScriptInterface::pushPosition(lua_State* L, const Position& position, int32_t stackpos/* = 0*/)
{
    lua_createtable(L, 0, 4);

    setField(L, "x", position.x);
    setField(L, "y", position.y);
    setField(L, "z", position.z);
    setField(L, "stackpos", stackpos);

    setMetatable(L, -1, "Position");
}

and

void LuaInterface::pushPosition(lua_State* L, const Position& position, uint32_t stackpos)
{
    lua_newtable(L);
    setField(L, "x", position.x);
    setField(L, "y", position.y);
    setField(L, "z", position.z);
    setField(L, "stackpos", stackpos);
}

But that's for FTS, I'm talking about OTClient here.

 

[Sarah Wesker]

in this case, it costs nothing to use Visual Studio and look for similar examples throughout the project. with (cntrl+alt+f)

 

[oen432]

in this case, it costs nothing to use Visual Studio and look for similar examples throughout the project. with (cntrl+alt+f)

And how should I use that? It's C++ side. I can't even use numbers, it's not casting to int.

int push_luavalue(const Position& pos)
{
    if(pos.isValid()) {
        g_lua.createTable(0, 3);
        g_lua.pushInteger(pos.x);
        g_lua.setField("x");
        g_lua.pushInteger(pos.y);
        g_lua.setField("y");
        g_lua.pushInteger(pos.z);
        g_lua.setField("z");
    } else
        g_lua.pushNil();
    return 1;
}

bool luavalue_cast(int index, Position& pos)
{
    if(g_lua.isTable(index)) {
        g_lua.getField("x", index);
        pos.x = g_lua.popInteger();
        g_lua.getField("y", index);
        pos.y = g_lua.popInteger();
        g_lua.getField("z", index);
        pos.z = g_lua.popInteger();
        return true;
    }
    return false;
}

 

[lexus21]

you did it?

 

[oen432]

you did it?

Ofc. It was very simple. Just register these methods in luascripts