Added option for doing triple buffering, and set the default read format to GL_RGBA
Added option for doing triple buffering, and set the default read format
to GL_RGBA


koshman86/osg,XiaoCC/osg,ntoand/osg,artoolkit/osg,XiaoCC/osg,omega-hub/osg,ghub/osg,ghub/osg,ntoand/osg,koshman86/osg,koshman86/osg,XiaoCC/osg,omega-hub/osg,artoolkit/osg,ghub/osg,stmh/osg,omega-hub/osg,artoolkit/osg,stmh/osg,ntoand/osg,ntoand/osg,omega-hub/osg,stmh/osg,koshman86/osg,artoolkit/osg,stmh/osg,XiaoCC/osg,XiaoCC/osg,stmh/osg,ghub/osg