Calling C++ functions in luawith objects as arguments

Hello folks,

i'm new to Lua/Luabind, i'm trying to call some C++ functions from a library with lua and i hope you can give me some help.

The C++ functions are in a namespace:

namespace ImageProcessor
{
void Invert(const CByteImage *pInputImage, CByteImage *pOutputImage)
{
//Function declaration here!
}

void Canny(const CByteImage *pInputImage, CByteImage *pOutputImage, int nLowThreshold, int nHighThreshold)
{
//Function declaration here!.
}

void Canny(const CByteImage *pInputImage, CVec2dArray &resultPoints, CVec2dArray &resultDirections, int nLowThreshold, int nHighThreshold)
{
//Function declaration here!.
}
...
... More functions here
...
}

As you can see, the functions take several arguments, for example objects of the class CByteImage.

In my C++ Code, I create these objects of the class CByteImage:

CByteImage *m_pInImage;
CByteImage *m_pOutImage;
m_pInImage = new CByteImage(int width, int height, CByteImage::eGrayScale);
m_pOutImage = new CByteImage(int width, int height, CByteImage::ImageType);

Later, i call for example the first two functions in my C++ code like this:

ImageProcessor::Invert(m_pInImage, m_pOutImage);
ImageProcessor::Canny(m_pInImage, m_pOutImage, 50, 50);

Now i want to call these two C++ functions in lua, and that's the point where my problems begin:
Nicolas told me, that i need to bind the functions in the namespace where they are defined.

Now the thing with the objects. I don’t really know how to handle these things. Do I have to bind the whole class CByteImage with the objects that I use as arguments of my function? Do I have to use the “user definded types” thing to tell lua how to handle these data types? Do I use pointers and make them available for lua?

What I’ve done so far:

lua_State* LuaState = lua_open();
// open the new state with luabind
luabind::open(LuaState);
// export the functions we want
luabind::module(LuaState)
[
// First Arg: Name of the function in Lua, Second Arg: Function in C++
luabind::def("Invert", &ImageProcessor::Invert)
//I don't know exactly how to bind the arguments of the Canny function
luabind::def("Canny", &ImageProcessor::Canny, (void), (const CByteImage *), (CByteImage *), (int), (int)),

//Binding of the CByteClass
luabind::class_<CByteImage>("CByteImage")
.def(luabind::constructor<>())
//Not sure how to binb objects
luabind::object global_vars = luabind::globals();
global_vars["a"] = a;

];

Now I have thought that I could call these two C++ functions in lua like this:

--Lua

test = Invert(m_pInImage, m_pOutImage)

test2 = Canny(m_pInImage, m_pOutImage, 50, 50)

Again, is this correct or how do I have to do this?

Thank you very much for your help

Greetz Janik

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