// create a native bitmap representation
virtual wxGraphicsBitmap CreateBitmap( const wxBitmap &bitmap ) = 0;
// create a subimage from a native image representation
virtual wxGraphicsBitmap CreateSubBitmap( const wxGraphicsBitmap &bitmap, wxDouble x, wxDouble y, wxDouble w, wxDouble h ) = 0;
// create a native bitmap representation
virtual wxGraphicsBitmap CreateBitmap( const wxBitmap &bitmap ) = 0;
// create a subimage from a native image representation
virtual wxGraphicsBitmap CreateSubBitmap( const wxGraphicsBitmap &bitmap, wxDouble x, wxDouble y, wxDouble w, wxDouble h ) = 0;