Li Ming wrote: > Hi, all, > > Could someone explain a bit in details the > implementation of the TexSubImage function? > > I'm especially interested in the hardware path.
That varies a bit from one DRI driver to the next. Are you interested in a particular DRI driver, or drivers in general? > How is the hardware path hooked in this function? In Mesa, the driver will plug into ctx->Driver.TexSubImage1/2/3D functions if it needs to do something special. > What's done inside this function if there is no PBO? Typically the driver just copies the new texel data into the texture image stored on the graphics card. > What if there is a bound PBO? Ideally, the driver will copy the texel data from the on-card PBO into the texture memory with a blit-like command. I'm not sure any of the DRI drivers do that directly yet. > Why does the use of PBO eliminate a copy according to > the gl extension spec? I'm not sure it does. It seems to me that glTexSubImage from a PBO will still involve a copy since a PBO and a texture image are different memory blocks. Perhaps if the PBO size exactly matches the texture size the driver will effectively texture from the PBO memory. -Brian ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Mesa3d-dev mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
