[GLLUG] X Window Managers

[Jo Dillon]

On Fri, Dec 13, 2002 at 01:45:21PM -0500, Sean wrote:
> > server. And there's nothing /that/ special about Display PS/PDF, it's
> > just a graphics language...most GUIs are flinging bitmaps around anyway.
> > If X11 had a decent StretchBlt built in it could do most of the same things.
> 
> IIRC AfterStep uses ghostcript for the rasterization engine so it 
> rasterizes on the fly. Thus the moving graphics are just rasterizations of 
> PS vector objects into bitmaps. The difference is in the clarity of images 
> when you stretch them or magnify them, because you are dealing with 
> vectorized images as your source instead of bitmaps. 

  True. Of course, if it is using GhostScript to render into a bitmap,
then sending that bitmap to X (which it certainly didn't use to a couple
of years ago when I last used it; it was just a normal X11/Xlib-based
window manager) then you just lost all hardware acceleration :/
 
> Any Stretchblt whatever libraries don't have enough information available
> to them to make good images because you are trying to reconstruct data
> that is not there, so it is all guesswork.

  Only if your source data is actually vector data. Most of OS X's
icons, for example, are actually really big bitmaps (256x256, say).
Stretchblt will do just as good a job as PostScript at rendering that
at any given size, and do it slightly faster too since there's less
overhead.