On Wed, 2006-11-15 at 01:22 +0000, Ioannis Nousias wrote: > You might have hear this before. I just came across it today. > > from http://blog.beryl-project.org/ > > "I am running your svn and have noticed this non-tfp Beryl, what is this? > > It is exactly what it sounds like, an early attempt (with some success I > might add) to make Beryl run without the need for texture_from_pixmap. > No more black window bug from nvidia, no more Xgl, no more AIGLX. Oh > yeah… and its faster than Xgl/AIGLX (nvidia beta performance looks to be > about the same). The code is all thanks to Onestone who is a true bling > hero, and the idea itself originates from the Project Looking Glass > people. Kudos to them and their great work, we hope to incorporate more > of their experience to Beryl’s code base in the form of optimizations > and improvements." > > it seems to be still in it's infancy though. Even if it's not as > good/fast as the GLX extension, it's still nice to have an alternative > path in case the extension is not available.
I'm assuming that they CopyTexSubImage pixmap content into textures. This is nothing new. We knew that this works when writing the GLX_EXT_tfp spec, of course. We actually agreed that CopyTexSubImage is the appropriate way to handle the case where you have a window that is larger than the maximum texture size. However, that very rarely happens so there hasn't been a lot of motivation for adding this fall-back path to compiz yet. Using CopyTexSubImage might give similar performance to GLX_EXT_tfp implementations right now as they are not very optimized yet. However, CopyTexSubImage will always require a copy operation to get the pixmap content into a texture and as both a texture and a pixmap need to exist, the memory consumption is twice the amount that is really necessary. CopyTexSubImage also requires you to do glXMakeCurrent each time you need to update a texture, which can be expensive. GLX_EXT_tfp solves all these issues. -David _______________________________________________ compiz mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/compiz
