From: Lorien Dunn <loriend@...>
Date: 2002-04-18T02:04:01+09:00
Subject: Re: visual c, ruby, and fastcall hassle

On Wednesday 17 April 2002 10:28 pm, nobu.nokada@softhome.net wrote:
> Hi,
>
> At Wed, 17 Apr 2002 19:58:27 +0900,
>
> Lorien Dunn wrote:
> > 	today I tried to embed ruby in a computer game I'm working on. It uses
> > Auran's Jet 3d engine (www.auranjet.com), which is closed source, and
> > requires projects using it to be compiled with fastcall enabled. Fastcall
> > is a calling convention that does not permit variable numbers of
> > arguments for the sake of speed. However, by prefixing every function
> > prototype in "ruby.h" and "intern.h" with __cdecl I succeeded in building
> > the app.
>
> Since __cdecl is default, that Jet 3d engine's header should
> have __fastcall?

	No, because you have to set __fastcall as default in the project settings. 
If all the Jet headers used __fastcall it would not be a problem.

>
> > 	Then I tried writing a linked in extension in c, and got a type error
> > from the function ptr argument of "rb_define_method": it wanted a VALUE
> > _cdcel (*) (VALUE, VALUE), and was getting a VALUE __fastcall (*)
> > (VALUE,VALUE), so I declared my function as _cdecl and recieved the same
> > error!
>
> You can write wrapper functions.

	All I was doing was something like this in a project with __fastcall as 
default:

static VALUE cTest;

static VALUE __cdecl cTestBang(VALUE self,VALUE arg)
{
	rb_iv_set(self,"@arg",arg);
	puts("Bang!");
}

void Init_Test()
{
	rb_iv_set
	cTest = rb_define_class("Test");
	rb_define_method(cTest,"Bang",cTestBang,0);
}

	and linking this in with the application that embeds ruby and links to jet, 
and calling Init_Test() after ruby_init().  So I'm afraid I don't understant 
what you mean I should wrap. I'm not wanting to wrap Jet- just make the 
needful parts of the game scriptable.


Thanks,
Lorien