Advertisement

How to instantiate classes in script?

Started by July 16, 2013 01:52 PM
4 comments, last by DJLink 11 years, 4 months ago

Hi guys,

I'm sorry if this is a dumb question but I'm kind of new using AS.

So I have a class in C++ called Sprite with a method set_image(string, string)

I've registered them this way


//register class
engine->RegisterObjectType("Sprite", sizeof(Sprite), asOBJ_VALUE | asOBJ_POD);
// Register method
engine->RegisterObjectMethod("Sprite", "void set_image(const string sheet, const string image)", asMETHODPR(Sprite,set_image,(const string&, const string&),void), asCALL_THISCALL);


But now I can I use that in the script side?

I would assume something like


Sprite@ sp = new Sprite(); // Not sure if @ or *, confusion here
sp->set_image("backgrounds","space"); // is it a -> or . for handles?

After reading some docs on Angescript I found out the @ for object handles, but still, how do I allocate a new Sprite to use in script? Do I need to create a static function that returns a handle in C++?

Once again thanks for reading this.

[twitter]DJ_Link[/twitter]
Blog

Hello :), I guess you could benefit from reading http://www.angelcode.com/angelscript/sdk/docs/manual/doc_reg_basicref.html

So if you want to create an instance in script you will need to register a factory function (it could be as easy as new Class()).

You might also missing reference counter, unless you want to handle all this yourself.

As far as language goes, there is no * or -> in there. So its a dot operator for everything.

But you should really read some docs, it will benefit you in a long run.

http://www.angelcode.com/angelscript/sdk/docs/manual/index.html

Advertisement

Ahh cool, it actually worked, I can now allocated and delete objects via script.

From what I'm getting I cannot have the same class registered as asOBJ_VALUE and asOBJ_REF, correct me if I'm wrong.

I was trying to add some flexibility. Right now I can allocate object using that example you gave like this


Sprite@ spr = Sprite();
// Do something

But I would also like to be able to do


Sprite spr; // local var
// do something

But when I try to register as


engine->RegisterObjectType("Sprite", 0, asOBJ_VALUE | asOBJ_REF| asOBJ_NOCOUNT);


I get the following error

Failed in call to function 'RegisterObjectType' with 'Sprite' (Code: -5)

[twitter]DJ_Link[/twitter]
Blog

Not sure about this one.

As far as I see, you could try registering it as a value type and use handles when needed? (But not as a POD, because it's not.)

According to http://www.angelcode.com/angelscript/sdk/docs/manual/doc_script_handle.html

You can take a handle with "@", so:




object obj; 
object@ obj_h = @obj;
Failed in call to function 'RegisterObjectType' with 'Sprite' (Code: -5)

-5 means that it has invalid arguments asINVALID_ARG = -5, it must be that you can't register like that

But I'm no way a guru in this thing, so don't follow my thoughts directly.

SoulSharer is correct.

An object type cannot be both a value type and a reference type. They are mutually exclusive. Value types are allocated on the stack (or inline in objects if members of another type) and cannot outlive the scope in which they are declared. Reference types are allocated on the heap and will be kept alive until the last reference to them are removed.

AngelCode.com - game development and more - Reference DB - game developer references
AngelScript - free scripting library - BMFont - free bitmap font generator - Tower - free puzzle game

SoulSharer is correct.

An object type cannot be both a value type and a reference type. They are mutually exclusive. Value types are allocated on the stack (or inline in objects if members of another type) and cannot outlive the scope in which they are declared. Reference types are allocated on the heap and will be kept alive until the last reference to them are removed.

Thanks for the help. I think I got most of the basis cover now. I've now able to allocate objects and used them via script :)

[twitter]DJ_Link[/twitter]
Blog

This topic is closed to new replies.

Advertisement