On Thu, 15 Jun 2006, Sabuj Pattanayek wrote:

Hi,

With the release of xorg-7.1.1 and mesa-6.5 I finally have direct rendering for my i855gm/i810 intel video device under linux. However I get lots of flickering of an object inside of the chimera display window when I rotate or move the object.

I don't have this issue with pymol (compiled against the system python) and vmd (compiled against C/C++ opengl bindings?) or even glxgears.

Perhaps I can workaround this problem by telling Chimera to use the local python installation? How is this done?

The current version of chimera uses a modified Python, so it is not possible to substitute in a different one. And even if you could, it shouldn't make any difference. The difference is hidden somewhere in the graphics code. The flickering is caused by not updating the contents of the graphics window during the display's vertical retrace. This used to be on by default, but I guess that is no longer the case. Maybe Mesa has environment variable like NVidia's __GL_SYNC_TO_VBLANK, which sets the synchronization? There are also OpenGL extensions, MESA_swap_control and GLX_SGI_swap_control, that control the effect you're seeing. If one of those extensions is supported by your setup, you should see it listed in the output of the glxinfo command. Unfortunately, chimera doesn't use them yet. Please use the "Report a Bug" dialog available via the Help menu and send me the output of the glxinfo command, so I have a bug to log the fix against. Greg Couch UCSF Computer Graphics Lab