BCGControlBar Pro for MFC
Enumerator
BCGP_GAUGE_LEVEL_OBJECT_RECT 

The level bar is displayed with corners.

BCGP_GAUGE_LEVEL_OBJECT_ROUNDED_RECT 

The level bar is displayed with rounded corners.

BCGP_GAUGE_LEVEL_OBJECT_THERMOMETER 

The level bar is displayed as thermometer (linear gauge only)