[cells-gtk-devel] Re: GUI programming in CL ..

[Peter Hildebrandt]

Dimitri,

Thanks for your response.  I've been travelling for the last week as 
well, hence the delay.

Dmitri Hrapof wrote:
> Sorry for a late reply, just returned from Zagreb.
> 
> Peter Hildebrandt пишет:
>> I have never tried this.  What is the reason you cannot mix the two?  
>> Does it not work, or is it some issue with the bindings?
> I didn't delve too deep into Cairo/glitz/GtkGlExt, but I guess the 
> problem is that Cairo and OpenGL use different offscreen buffers which 
> are not readily reachable through existing APIs. So I could either use 
> single-buffered mode (and get flickering) or mix OpenGL and Cairo calls 
> (and get flickering, too).
> They promise to add OpenGL support to future version of GTK, though.

I see.  Makes perfect sense.  For now the way I will go with cells-gtk 
is to create a general drawing-area widget based on the gtk drawing 
area, and then subclass it for (a) cairo and (b) opengl drawing.

For my current application this seems to be well sufficient.  After all, 
the two address quite distinct use cases, so this approach appears 
sensible to me.  If someone really needs to mix the two, they can follow 
your approach with cairo rendering into a bitmap.

>> Again, thanks for sharing this.  This will save me from reinventing 
>> the wheel here.  Would it be ok for you if I use your bindings to 
>> integrate a GLDrawingArea widget in cells-gtk?
> Of course.

Thanks, I'm working on it right now.  I'm factoring out the 
commonalities of the gl-drawing-area and the cairo-drawing-area (causing 
some more delays, cf. Slobodan's thread on c.l.l) but I will release a 
patch soon.

Peter

> Good luck,
> Dmitri