Rounding Flags
Rounding flags are used to control the rounding mode of the box when drawn.
Current available rounding flags are:
RoundCornersTopLeft
=0
RoundCornersTopRight
=1
RoundCornersBottomLeft
=2
RoundCornersBottomRight
=3
RoundCornersNone
=4
RoundCornersTop
=5
RoundCornersBottom
=6
RoundCornersLeft
=7
RoundCornersRight
=8
RoundCornersAll
=9