[Xorg] PEX and XIE

[Roland Mainz]

Egbert Eich wrote:
>  > Mozilla's Xlib toolkit has support for XIE... and maybe the (default)
>  > GTK+ toolkit for Mozilla get it's XIE support back since this gives a
>  > huge speedup for image scaling/blending on platforms who still have XIE
>  > support available by default (I am looking here at Solaris/Xsun :) ...
>  > PEX can (IMO) be removed... but if you remove XIE it would be nice to
>  > provide an alternative which supports things like image scaling,
>  > rotation and blending (RENDER doesn't count - it's broken by design...
>  > ;-/).
> 
> If it really gives a signifficant speedup this issue
> should be reinvestigated. I once was told it was slow.
 
XIE makes image scaling faster in Mozilla's case since FAR LESS data are
transferred over the wire. Think about a small 400x300 image scaled up
to 800x600. In the case of client-side scaling four times more image
bytes are transferred over the wire than pushing the image as-is to the
server and let the server scale it.
In the case of alpha blending a whole round-trip is saved - and again
all the image bytes transferred from server to client (XGetImage()) and
back (XPutIMage()) ...

> That it is faster on Solaris may be as SUN has enhanced it.

I am not sure whether Sun touched the XIE sources for their
implementation... I simply guess the issue explained above is enougth to
explain the performace enhancement.

----

Bye,
Roland

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