Comment 6 for bug 555641

Actually this is a "fix" for this in the compiz C++ version (which might even be released someday). When it detects a window is larger than max texture size it falls back to (iirc) copySubBuffer and splits the texture in to two or more pieces. This is much slower than using the texture_from_pixmap system but is usually only needed for the desktop window which does not change much.

Ideally Xorg would sort this out though which I believe is the point of the 'shatter' work.