yup, I was thinking of something like "gemwinOFF" when I said gembuffer.
pix_snap does do what tom needs to do for screen buffers. however it is hideously slow, at least on my hardware.
same here (gforce4) this seems to be what is going on with gem2pdp too..
we need to ensure that wherever possible, fast paths are allowed or provided. ie once you've rendered to an offscreen context which is a pbuffer, you can use that as a texture straight away without extracting the pixels and reloading it as a texture. (that reminds me: i have a pix_snap2tex object that does this in a pix_snap kind of way and runs 100 times faster on my box)
i did some experiments and pbuf<->texture conversion too and it is very fast indeed. i am looking into the possibility to add ogl texture and pbuf support to pdp. if this works out and if gem could export/import textures or pbufs we could have a very fast connection between both.