Hello Robert, Sorry to respond this late, I have some more info on this issue:
if you google to "GL_VERSION returns 1.1.0", you'll find similar reports: such as: http://www.gamedev.net/community/forums/topic.asp?topic_id=373109 http://www.codeguru.com/forum/archive/index.php/t-283819.html http://www.opengl.org/resources/faq/technical/mswindows.htm Apparently, in a windows environment, the creation of an opengl context is done in two steps: One needs to create an initial display context to be able to query the exact capabilities of the display and select the correct pixelformat. See the opengl superbible, fourth edition, p 680. This is done in the osgViewer::Win32WindowingSystem class, and seems correct to me - as far as I can tell. However, when the first display context is created, a 24 bits color dept is requested, while my graphics card doesn't support this. This could be one reason why the returned display context is - sometimes - backed up by the generic GDI driver, supporting only opengl version 1.1.0. So, I changed the code in Win32WindowingSystem to request a 32 bit color depth instead: Line 700: PIXELFORMATDESCRIPTOR pixelFormat = { sizeof(PIXELFORMATDESCRIPTOR), 1, PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL, PFD_TYPE_RGBA, 32, // color dept, used to be 24 0, 0, 0, 0, 0, 0, 8, 0, // 8 alpha bits, was 0 0, 0, 0, 0, 0, 16, // 16 bits depth buffer, used to be 24 8, // 8 stencil bits, used to be 0 0, PFD_MAIN_PLANE, 0, 0, 0, 0 }; This works perfectly! ...and almost every time :-( It seems that when I end and restart the application quickly enough, I sometimes still get the generic GDI version but not nearly as often as before. I can reproduce this with the osgViewer application. I can imagine that if the driver lags a bit behind, the system still falls back to the SW version. (BTW, the scene contains 12 x 1Mp bitmaps) I hope this makes sense to you experts out there. Thanks for the help and best regards, Christophe OSG 2.8.1, Visual C++ 2005-SP1, Windows XP-SP3 HP EliteBook 8730w, Nvidia Quadro 2700 FX The OSG examples all work correctly. ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=14437#14437 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
