drawArc abstract method
Draw an arc scaled to fit inside the given rectangle.
It starts from
startAngle radians around the oval up to
sweepAngle radians around the oval, with zero radians
being the point on the right hand side of the oval that crosses the
horizontal line that intersects the center of the rectangle and with positive
angles going clockwise around the oval. If
useCenter is true, the arc is
closed back to the center, forming a circle sector. Otherwise, the arc is
not closed, forming a circle segment.
This method is optimized for drawing arcs and should be faster than Path.arcTo.
void drawArc(Rect rect, double startAngle, double sweepAngle, bool useCenter, Paint paint);