Re: QuartzCore and Opal

[David Chisnall]

On 25 Jan 2012, at 22:45, Ivan Vučica wrote:

> That is, is it supposed to be written in a way that does not depend 
> explicitly on AppKit?

Absolutely.  Opal is intended to sit in the same place CoreGraphics does in 
Cocoa: below AppKit (or UIKit).

The short-term aim (which has been a short-term aim for about two years) is for 
-back to be modified to just handle event handling and window management and 
delegate the handling of drawing to Opal.

With regard to CoreAnimation, Banlu has some demos of rendering GNUstep AppKit 
views to OpenGL textures and then compositing and animating them.  While it 
should be possible to get basic CoreAnimation stuff working without OpenGL 
(Opal already has CGLayer), I'm not convinced that it's sensible: Apple's 
CoreAnimation also uses CoreImage a lot, and CoreImage allows you to run OpenCL 
programs on the images - this is pretty trivial to implement for an OpenGL 
texture, but requires a bit effort for a Cairo pattern (you need to copy it - 
probably back from the display server - copy it to the GPU, run the program, 
and then do the whole thing in reverse).

David


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