draw method
Implementation
@override
void draw(Canvas canvas, Paint paint, Offset offset, Size size) {
List<Offset> ol=[];
double r=min(size.width, size.height)*0.5;
double singleAngle = 360 / count;
for (int j = 0; j < count; j++) {
num angle = offsetAngle - 90 + j * singleAngle;
ol.add(circlePoint(r,angle,offset));
}
style.drawPolygonArea(canvas, paint, ol);
}