Current implementation of composite operations (alpha blending) on linux is just a general unacceleratred code, these operations are performed on per-pixel basis and, definitely, they are rather slow. But the main reason is that pixel data should be retrieved from the screen to perform the blending. This screen->client memory data transfer is painfully slow on X. Probably, it is the most significant performance gap of the current linux implementation. Maybe, it is possible to improve it in the most general cases by implementing a codepath which uses xrender extension, which will allow to eliminate screen->memory copying, since xrender supports transparency.
Probably, it is also possible to accelerate blit operations by adding the code which uses mitshm extension. Basic rendering w/o transparency theoretically should be much faster then the transparent case. These problems are related to linux implementation only. On 9/22/06, Geir Magnusson Jr. <[EMAIL PROTECTED]> wrote:
Definitely. I will do it today and add a page to our "how are we doing?" page so we can track over time. (That and any other benchmark we're allowed to use and publish). I think that what we have is mighty impressive. (It's just the graphics numbers that are bad...) geir On Sep 22, 2006, at 4:47 AM, Paulex Yang wrote: > Geir Magnusson Jr. wrote: >> I've been playing a bit with caffinemark, and our numbers for >> everything except graphics are amazing. > Convenient to post some results vs RI? I believe many ones(includes > myself of course) would be very interest to see the numbers:) >> >> However, our graphics numbers are *terrible*. I was testing on >> Ubuntu. We need to fix this. Does anyone with familiarity with >> our swing/awt impl that could point us in the right direction? >> >> geir >> >> >> --------------------------------------------------------------------- >> Terms of use : http://incubator.apache.org/harmony/mailing.html >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> For additional commands, e-mail: harmony-dev- >> [EMAIL PROTECTED] >> >> > > > -- > Paulex Yang > China Software Development Lab > IBM > > > > --------------------------------------------------------------------- > Terms of use : http://incubator.apache.org/harmony/mailing.html > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > --------------------------------------------------------------------- Terms of use : http://incubator.apache.org/harmony/mailing.html To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
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