On Fri, 10 Jan 2003 Jim.Gettys at hp.com wrote:

> > From: Bert Freudenberg <bert at isg.cs.uni-magdeburg.de>
> >
> > Squeak is intentionally agnostic of specific windowing system features. It
> > basically just needs a fast path for pushing pixels to the screen and some
> > way of getting input. Everything else we do ourselves, which serves the
> > goal of running bit-identical across platforms well.
> 
> Recent X servers have the X Render extension: this adds the ability to
> cache glyphs in the X server and paint them (alpha composited, with
> Porter-Duff sematics), rather than dealing with
> the old, broken, core X fonts (in the new model, fonts are entirely
> client side objects); we have a library to uses Freetype to do the rendering,
> and which also does *very* nice subpixel decimation for flat panels (Xft2);
> the results of this are cached at the X server and then painted.
> 
> So the painting and compositing work can go on with hardware assist
> (or with much lower bandwidth usage).
> 
> But any other font rendering technology can be used, and the results
> cached at the X server for fast painting.  Recent network tests show roughly
> comparable bandwidth usage to the old core font mechanism, even though the
> glyphs have to go over the wire.  Certainly much faster than pushing pixels
> all the time (though Xft2 will do that as well, so that this all can be used
> against old X servers).  The intent has been to get identical results
> to the frame buffer whether or not X Render is present.
> 
> This, btw, represents the first fundamental design change in X since
> 1987.  Sometimes you discover you just did it wrong the first time, and
> have to stop putting one's head in the sand.
> 
> Whether is solves anything for Squeak given the portability goals,
> is a different question.

Yep. I think Squeak could benefit from factoring out the compositing
(bitblt to display) operations so they can be hardware-accelerated.  
However, there would have to be a platform-specific plugin to encapsulate
the specifics.  In contrast, OpenGL allows the same kind of compositing
operations and works across multiple platforms so a single implementation
can be shared. Apple's Aqua shows that OpenGL indeed is a viable
foundation for a windowing system. Can you imagine a scenario where
X Render support would be benefitial over OpenGL?

-- Bert