Re: New Ada binding to OpenGL

[David Holm <david@realityrift.com>]

Joachim Schr�er wrote:

> Hello,
> 
> to pass null simply write something like
> Gl.Glclipplane(Plane => 1, Equation => null);
> 
> But why do you want to pass null access values.
> 
> I expect some kind of error in the C code then.
> 
> I will have a look for books were Ada/C coding is documented.
> 
> I thing, the Ada95 rationale is a good reference. I will give you links
> later.
> 
>     J. Schr�er
> 

Yeah, you were correct. I got errors in the C code.
The thing is that for instance, glXCreateContext takes a C NULL pointer when 
you want to create a new context that is not a subcontext to an existing 
one.
I have not yet managed to find a solution to how to handle this in Ada as I 
get a segfault in libGL when I do it (which is odd since I have a C 
application that passes a C-NULL here without any problems). In this case I 
had an overloaded function which took System.Address, so I never passed a 
null through an access variable.

I found the rationale on www.adahome.org, so no need to send a link.

//David Holm