I've got my internal app currently running with vblank_mode=2 at 60Hz, if I put in vblank_mode=3 I get a drop to about 40Hz which is no good for what I need.... I'm told that triple buffering might be the solution to this, does anyone know how much work this would be to implement in the radeon/r200 drivers? or dri in general?
Initially I'd like to do it for a single full screen app (my case) and not worry about the issues with multiple apps...
I would assume I need to allocate a 3rd buffer (wayback buffer...) in VRAM and have the bufferswap take an extra step to go wayback->back->front..
I'm pretty interested to see how much difference triple buffering makes. I used to be somewhat skeptical, but recently I've had that view challenged...
The obvious way to implement it is to extend the current mechanism to allocate another shared buffer at X server startup and add one more blit destination to the pageflipping code.
As Alan points out, we blit the dirty regions to the back buffer rather than re-rendering everything multiple times. This was the easiest scheme to implement, and has a big speed advantage for fallback and complex rendering. It is however the reason that the current page-flipping code isn't strictly conformant, as the situation where X11 and GL rendering to the same drawable simultaneously isn't handled correctly in all circumstances.
I expect that there will be a bunch of annoying compatiblity, etc problems in the drm and dri interfaces to do with getting the information to the client, etc, where the assumption has been made that there are only 2 buffers.
Keith
------------------------------------------------------- This SF.Net email is sponsored by: InterSystems CACHE FREE OODBMS DOWNLOAD - A multidimensional database that combines robust object and relational technologies, making it a perfect match for Java, C++,COM, XML, ODBC and JDBC. www.intersystems.com/match8 -- _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
