xdpyinfo should list the virtual root window ID, as well as the actual root window ID. This would allow you to parse xdpyinfo's output and find the virtual root window ID. Then you can feed this to $SDL_WINDOWID and run an SDL application as a screensaver (its video targeted at the virtual root window, as required). For more info on using SDL applications as screensavers, see this: http://wiki.openttd.org/index.php?title=Openttd_%28x11%29_screensaver_howto I've created a patch to xdpyinfo (1.0.1) that includes 'vroot.h' from xscreensaver 5.00. The license seems acceptable, but this should be verified. The patched xdpyinfo (1.0.2?) prints the virtual root window ID after the root window ID. I also added a -version option, and a version string in xdpyinfo.c. The build environment needs to support this too (such as the Makefile), but I can't do this. The man page also needs updating. Thanks!
Created attachment 6661 [details] [review] patch to xdpyinfo 1.0.1 to add virtual root window support and *improperly* add -version support; please extend/correct please correct/extend this patch to be cleaner!
The 'vroot.h' added by my patch (from xscreensaver 5.00), and in particular its function 'VirtualRootWindowOfScreen()', might be a candidate for inclusion with Xorg, so that it can be reliably found in /usr/include/X11/ where Xlib.h is expected to be found. The 'Window * VirtualRootWindowOfScreen(Screen *)' fuction is very similar to 'Window * RootWindowOfScreen(Screen *)' in Xlib.h, and depends on it. By including 'VirtualRootWindowOfScreen()' other Xorg utilities, such as xwininfo, could use it, without duplication of files (vroot.h).
Sorry about the phenomenal bug spam, guys. Adding xorg-team@ to the QA contact so bugs don't get lost in future.
Mass closure: This bug has been untouched for more than six years, and is not obviously still valid. Please reopen this bug or file a new report if you continue to experience issues with current releases.
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