From Galen Faidley," Please find attached the modifications to get the new checkerboard

stereo format to work.  It's a good thing I tested these on a TV
before submitting them since I did indeed have a bug.  One thing I
did not test was to see how this would work in windowed mode.  Does
the interlaced stereo code have support for 'absolute' positions?
For example a given pixel on the screen is always shown in a given
eye no matter where the graphics context is placed?
"

include/osg/DisplaySettings

@@ -94,7 +94,8 @@ class OSG_EXPORT DisplaySettings : public osg::Referenced
             LEFT_EYE,
             RIGHT_EYE,
             HORIZONTAL_INTERLACE,
-            VERTICAL_INTERLACE
+            VERTICAL_INTERLACE,
+            CHECKERBOARD
         };
         
         void setStereoMode(StereoMode mode) { _stereoMode = mode; }