If you are writing a minidriver that does not provide accelerators for lines, curves, or filled shapes, you should use the DIB_Output function to draw these objects. To draw lines and curves, the OS_POLYLINE style should be specified for the wStyle parameter. To draw filled shapes the OS_BEGINNSCAN should be specified first, followed by multiple OS_SCANLINES. Once the appropriate number of scan lines have been drawn, the OS_ENDSCAN is specified, followed by OS_POLYLINE to draw the outline of the shape.
See also DIB_Output