Setting Lua properties from C++

[JMLX42]

Hello,

I need to be able to set values from my C++ code. Considering 'rotate' is my "script" class:

function rotate:start(node)
 self.lookAt = Vector3.create()

  -- do some stuff...
end

I would like to be able to do the same thing as self.lookAt = ... but from my C++ code. My goal is to be able to init. my object with values set by other scripts/my C++ code:

function rotate:start(node)
  -- self.lookAt might have been init. from C++ already...
  self.lookAt = self.lookAt or Vector3.create()

  -- do some stuff...
end

How can we do this?

[Tomasu]

Assuming you're using LuaGlue as it was intended, lookAt should just be a C++ class member (or getter/setter). then you can set that in C++ when ever you want, and lua will see the value you set.

[JMLX42]

The thing is as you can see in the sample code the self.lookAt is created/set from Lua and is dynamic. My LuaScript C++ class is a generic class, it just provides methods a "script" will require but has no script-specific bindings. The goal is to be able to create Lua scripts without any specific C++ code.

To explain a bit more the process:

• my C++ main will initialize C++ <-> Lua bindings
• then load a "main.lua" script
• this script can then use the bindings to load new scripts and attach them to scene nodes
• each script might load new scripts and so on...

So declaring explicit bindings in my C++ is not an option. I think I'll create a LuaScript::getInstance() method that returns the C++-side stub object used for binding. In other words the actual Lua "self" of my script object. This way my Lua code can get a script instance and set some values on it.

Still, it would be useful to have C++ LuaGlueClass::set()/get() methods just like the LuaGlueClass::invoke ones... What do you think?

[Tomasu]

I suppose. But really, this funky wrapper class you have is just weird :P

[Tomasu]

Ok, this should be implemented now (in ad75202)

Some api additions:

You can fetch globals now via: glue.getGlobal<TYPE>("name") Get LuaGlueClass<CLASS>* via: glue.getClass<CLASS>("name") get properties via: glue_class->getProperty<TYPE>("name", obj) set properties via: glue_class->setProperty("name", obj, value)

other changes in ad75202 include some std::string handling improvements, and const fixes.