BCGSuite for MFC
virtual void CBCGPGraphicsManager::SetClipEllipse ( const CBCGPEllipse ellipseClip,
int  nFlags = RGN_COPY 

Selects the specified ellipse as clipping region for a device content.

ellipseClipThe ellipse.
nFlagsThis parameter can be one of the following values: RGN_COPY (by default), RGN_AND, RGN_DIFF, RGN_OR or RGN_XOR

See Windows SDK SelectClipPath function documentation for information about RGN_ flags.

Call ReleaseClipArea() method to remove the clipping region.