Xrender cursor performance / double buffering?

Bert Freudenberg bert at freudenbergs.de
Tue Apr 17 14:29:03 EDT 2007

On Apr 17, 2007, at 18:55 , Adam Jackson wrote:

> On Tue, 2007-04-17 at 13:07 -0400, Jim Gettys wrote:
>> Jordan,
>> One can compute the cursor image once to match the depth of the root
>> window once and store it in devprivates.  Then the server can  
>> composite
>> the image using the fast path image compositing hardware, no  
>> matter what
>> the depth is (it won't matter if computing the cursor to match the
>> screen takes a bit of time; it's the compositing while the cursor  
>> moves
>> that really hurts).
> That won't work if the root window depth is 16.  You won't have any
> place to store your alpha channel.  You can do a transparency blit,  
> but
> then your smooth edges go away.
> Also, the software alpha cursor code in X sucks out loud.  It'll  
> use the
> normal Render path, yes, but it still blinks violently.

... which prompted my original mail. Anything that can be done about  

- Bert -

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