RE: glCopyTexSubImage blocks the CPU?
"Pat Brown \(OpenGL\)" <[email protected]> Tue, 14 Mar 2006 19:54:26 -0800
| Newsgroups | gmane.games.devel.opengl |
|---|---|
| Organization | Fat City Network Services, San Diego, California |
| Message-ID | <[email protected]> |
| I'm copying from an FBO straight into a compressed texture. That's not just a "copy". The driver has to compress everything in the FBO, since there's no mechanism to actually render to a compressed surface. For S3TC textures, the driver basically has to try and figure out what encoding for each 4x4 block gives the "best" approximation of what's in the corresponding block of the FBO. It's certainly possible that the code path used to perform this operation is not the fastest possible -- I don't know precisely what our driver does. But the performing the compression (presently done on the CPU) will be a substantial spike. Pat -----Original Message----- Andras Balogh Sent: Tuesday, March 14, 2006 10:39 PM To: Multiple recipients of list OPENGL-GAMEDEV-L Running the profiler on my app, it shows a big spike at the glCopyTexSubImage call. I admit that my usage scenario is a bit odd: I'm copying from an FBO straight into a compressed texture. Still, I can't see why it would have to block the CPU.. Is this a driver problem? I'm running a GF6600 with 81.98 drivers. Thanks, Andras ----- FAQ and OpenGL Resources at: http://www.geocities.com/SiliconValley/Hills/9956/OpenGL -- Author: Andras Balogh INET: [email protected] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [email protected] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB OPENGL-GAMEDEV-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). ----- FAQ and OpenGL Resources at: http://www.geocities.com/SiliconValley/Hills/9956/OpenGL -- Author: Pat Brown \(OpenGL\) INET: [email protected] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [email protected] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB OPENGL-GAMEDEV-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).