Re: [PyOpenGL-Users] Extensions, etc

[Mike C. F. <mcf...@ro...>]

Brian Hammond wrote:

>* Mike C. Fletcher <mcf...@ro...> [2003-08-11 23:09]:
>  
>
>>Writing the .i file is not a particularly difficult task (there's a lot 
>>of samples in the interface directories), but it requires effort by a 
>>developer for every extension so supported.  
>>    
>>
>
>Ok - Why though? Maybe I am too naive with this but can't this be
>automated as well? AFAIK you have to expose the enumerations and the
>functions, both of which you have access to from the specs, no?
>
For simple modules, this works.  The wrapping of an extension module is 
as "automated" as the rest of the PyOpenGL system (which is fairly 
automated for the bulk of OpenGL).  The thing is that there are certain 
types of things that just don't have any automated machinery.  For 
instance, we don't currently have anything to automate generating 
wrappers around Python callbacks.  We also manually encode information 
regarding parameters that should not be passed in for the Python 
versions (i.e. array-length variables or the like).

If an extension doesn't require any of that special handling it's 
basically just the .h file for the extension with some boilerplate 
wrappers to make it get recognised by the system.  Creating *those* 
extensions with an automated script should be quite easy.

>>Even more restrictively, it 
>>requires that the developer *have* that extension on their machine so 
>>that they can *test* it.  My old Radeon 7500 has very few of the 
>>    
>>
>
>Whoa - I wasn't expecting that... Testing that the extension is callable
>is part of the build process?  I would think that having the function
>ptr exposed would be all you'd need to do.
>
It's not part of the build process, it's part of the *development* 
process.  Sending out code that's never been run tends to cause a lot of 
headaches.  There's actually quite a bit of it in PyOpenGL's extensions 
(for exactly this reason), but I'm *not* a fan of doing it for any 
non-trivial extension (i.e. one where we have to write *code* in the 
wrapper).

I'm serious when I say feel free to contribute a script to do the 
downloading and wrapping automatically (that goes for anyone).  It would 
probably allow access to quite a few extensions not currently 
supported.  I just don't have time to do it, as there are lots of things 
on my todo list that are already languishing for all 8 or 9 projects I'm 
running.
...

>>likely be a few years before they do (unless Microsoft decides to write 
>>one)).
>>    
>>
>
>I don't think they're doing any new OGL drivers other than 1.1 AFAIK
>
My impression too.  The ARB still seems to be hoping they will, but it 
just doesn't seem likely that they'll do all that work just to help 
people remain cross-platform.  After all, they *want* developers to lock 
into Direct3D (and therefor Windows).

Enjoy,
Mike

_______________________________________
  Mike C. Fletcher
  Designer, VR Plumber, Coder
  http://members.rogers.com/mcfletch/