The offscreen_render_required flag should only be set into the 2 state if it is currently 0, as the 1 state is a full refresh which should maintain precedence. Intel drivers incorrectly clip new graphics buffers  https://tracker.physiomeproject.org/show_bug.cgi?id=2377 Merge from cmgui_2_7_0_plus_fixes revision 8093
The offscreen_render_required flag should only be set into the 2 state if it is currently 0, as the 1 state is a full refresh which should maintain precedence.
Intel drivers incorrectly clip new graphics buffers 
https://tracker.physiomeproject.org/show_bug.cgi?id=2377
Merge from cmgui_2_7_0_plus_fixes revision 8093

git-svn-id: 4705079bc6b8aadf675e3696f5c015a6aa4916e3@8099 3c1deb5b-d424-0410-962d-aba41a686d42

OpenCMISS/zinc,hsorby/zinc,OpenCMISS/zinc,hsorby/zinc,OpenCMISS/zinc,hsorby/zinc,OpenCMISS/zinc,hsorby/zinc