Hi Chris, The present version of PixelBufferObject only supports copying from main memory to GPU, not back. For the recent osgscreencapture example use PBO's but I had to implement the PBO setup myself since the core osg::PixelBufferObject didn't support it. I haven't had a chance to refactor osg::PixelBufferObject to include unpack/pack functionality, but I do plan this for the longer term.
Right now you're best route is to just implement the PBO support yourself, see the osgscreencapture example, in 2.5.1/SVN, for a guide, note that for performance you'll need to double buffer and use RGBA frame buffer formats. Robert. On Thu, Jun 5, 2008 at 4:39 PM, Chris Best <[EMAIL PROTECTED]> wrote: > Quick question... Based on digging through the source, it seems all > PixelBufferObjects are currently automatically set to > GL_PIXEL_UNPACK_BUFFER_ARB by default and there's no way to change this to > GL_PIXEL_PACK_BUFFER_ARB, correct? Meaning they can only be used for writing > to the framebuffer, not reading from it? The application I'm writing is > going to do a lot of reading colors back from a FBO as part of a > pre-processing step, and based on my limited understanding reading pixels to > a PBO is supposed to be significantly faster... > > Since it's a pre-processing step, speed isn't of utmost importance, but > later on this step may end up being run relatively often (~1-5Hz or so), so > should I try and take the time to extend osg::Image and > osg::PixelBufferObject to support PACK operations or am I worried over > nothing? :) > > -Chris B > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
