Re: [Vala] Using OpenGL 3.0 from Vala

[Tristin Celestin <tristin_celestin yahoo com>]

> If you just need a couple functions, you can just declare
> them as
> "extern" in your vala files. otherwise it's better to write
> a vapi.

Could I see an example of using extern this way?

...

I tried starting to write a .vapi that would cover glext.
I changed my mind about GL3 and instead decided to write to GL2, believing
there would be a better chance it'd be on the target machine.

After some time, I got somewhere in terms of covering what is in glext.h,
but then I had all these other questions...

1. I didn't know how to translate the preprocessing guards for particular
versions of the api, like #ifndef GL_VERSION_2_0.

2. Because I couldn't do the former, I wasn't sure how I would be able to
do compile time checks to see if an extension was supported

3. Can I perform dlopen and dlsym from Vala? If not, how else would I
dynamically load libraries and check to see if a particular extension
exists during runtime

4. If I wanted to avoid figuring out how to do 2 or 3 myself, I could
always use GLew or GLee, except...I end up at my original problem of there not being bindings for what I 
want...


Attached is the glext.vapi file I started writing. I may not use Vala for my project afterall, but perhaps 
this will help someone else out.


--- On Mon, 2/22/10, Abderrahim Kitouni <a kitouni gmail com> wrote:

> From: Abderrahim Kitouni <a kitouni gmail com>
> Subject: Re: [Vala] Using OpenGL 3.0 from Vala
> To: "Tristin Celestin" <tristin_celestin yahoo com>
> Cc: Vala-list gnome org
> Date: Monday, February 22, 2010, 9:00 AM
> Hi,
>
> 2010/2/22 Tristin Celestin <tristin_celestin yahoo com>:
> > I am trying to use OpenGL 3.0 from Vala, but I notice
> that only up to OpenGL 1.3 is defined in the .vapi
> > file. The methods relevant to me are defined in
> GL/glext.h. How would I access the functions
> > declared there?
>
> If you just need a couple functions, you can just declare
> them as
> "extern" in your vala files. otherwise it's better to write
> a vapi.
>
> > Is it enough to just write a .vapi file for myself
> referencing the necessary functions, or should I
> > modify gl.vapi? glext.h had a lot of methods, and I am
> not going to be able to cover all of them
> > myself.
>
> You don't need to bind all the methods, you can just bind
> the methods
> you need. I think it's fine to add to gl.vapi directly
> (maybe in an
> #if GL_3.0 or something), but GL bindings aren't included
> with vala,
> so it may be a good idea to contact the maintainer.
>
> HTH,
> Abderrahim

Attachment: glext.vapi
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