As the QGraphicsScene overlay does not work for all cards/drivers we disable the possible buffer swap of the qpainter, as this could be a potential source of the flickering. If the painter swaps buffers and we do it again the user will see first the correct picture (first swap) and then something uninitalized (second swap)
Be aware that stereo rendering based on SoRenderManager does not allow background colors as the opengl buffers are cleared before rendering. As FreeCAD draws the background before the standart coin rendering the background gets erased again.
As quarter is not wrapped by SWIG we need to expose our own python interface class.
This is a start with the most important functions to access the render and event
manager. Furthermore all extra functions available next to the swig wrapper functions
are exposed. Everything else can be added when needed.
Quarter Widget soes not allow to switch of multisampling on the fly, therefore we need to use glgraphicsitem instead of direct opengl xor rendering for mouse selection
-removes all soqtviewer references
-create a quarter adaptor class which implements missing functionality
-adopts freecad code to make use of SoRenderManager and changed View3DInventorViewer interface
inherit Base.FreeCADError form RuntimeError
inherit Part.OCCError from Base.FreeCADError
inherit OCCDomainError from Part.OCCError
inherit OCCRangeError from Part.OCCError
inherit OCCConstructionError from OCCDomainError
inherit OCCDimensionError from OCCDomainError
Added PY_CATCH_OCC macro
replace PyExc_Exception
use FreeCADError in makeWireString
catch exception in BSplineCurve.increasedegree
