Hi Marco, Thanks for the link. I've run through it quickly but other than a listing of extensions there isn't an actual coding example showing how they are used. I can make educated guess for most of them, but not enough to know exactly how they should be used in the context of osgViewer - it looks like most calls would be done after viewer.realize() (i.e. once windows are created) and before the frame loop starts. W.r.t swap ready barrier it's not clear to me whether one needs to add an extra barrier call or whether the normal swap buffers will be sync once one joins a swap group.
In the NVidia docs the extensions are all Windows ones, but looking at glxext.h I can see various SwapGroup/Barrier methods that look like they correspond. From searching fpr docs on these on the web it looks like these don't require an extra sync call, rather swap buffer itself will have the sync inbuilt into it. If this is correct then one could do it all without mods to osgViewer itself. Once could however add support for these wgl/glx extension directly into osgViewer, even if it its technical possible to do it without mods, as adding such support might make it a bit more straight forward to OSG users, perhaps only needing to enable the swap groups and to specify a single group id across the cluster might be enough. This changes I'm thinking of right now at quite as extensive as this though. The tweaks to the osgViewer API I was thinking of this time around was in terms of non driver based support for syncing swap buffers, such as software based ones. It might be that we'd want to try and encapsulate some of the API for this type of syncing with the above driver/glx/glw based sync support. Feedback from users who've tackled this would be very useful. Robert. On Mon, Apr 14, 2008 at 1:08 PM, Marco Jez <[EMAIL PROTECTED]> wrote: > Hi Robert, > > > I'm looking for feedback from users who have worked on clusters that > > implement some forms of swap ready synchronization. In particular I'm > > looking at any hooks into osgViewer to allow users to implement their > own > > swap ready implementation, also a software based swap ready could > possibly > > be implemented as part of the core OSG as well. > > I have limited experience with clusters, but this feature will probably be > required in one of our new projects. You may find useful to read the > "Frame > Synchronization User's Guide" by nVIDIA > ( > ftp://download.nvidia.com/Windows/Quadro_Certified/91.36/91.36_Quadro_G-Sync_User_Guide.pdf > ), > especially the section named "Frame Synchronization Using the OpenGL > Extensions". The nVIDIA OpenGL API for hardware-based swap barriers is a > good example of what an user would expect to be able to do in a custom > swap > ready operation. > > Cheers, > Marco > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >
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